diff --git a/SCR.1.1/##tp01-reponses.txt##~ b/SCR.1.1/##tp01-reponses.txt##~ new file mode 100644 index 0000000..5862446 --- /dev/null +++ b/SCR.1.1/##tp01-reponses.txt##~ @@ -0,0 +1,22 @@ +TP01 + +I.1) - Cette commande m'informe que je suis sur l'utilisateur YOLOU (moi) +- Et l'autre m'informe sur les informations id de l'utilisateur: son groupe et +lui. + +2) - Cette commande m'informe sur quel système d'exploitation dans ce contexte là c'est Linux les informations suplémentaire sa version. + +3) Cette commande m'informe sur quel home je suis actuellement dans ce cas je suis dans l'emplacement yolou, mon home. + +4) La commande ls permet de lister les répertoires sur un emplacement. L'option -l montre les détails de chaque entrées et l'option -a permet d'afficher les entrées cachées. -man ls est menu + +5) Ce répertoire montre les fichiers de configurations pour que le système foncctionne. + +II - 1) La commande pwd sert à connaitre l'emplacement actuel, où tu te situes dans les répertoires. + +2) La commande la plus simple pour revenir dans son home est la commande cd. (man donne le mannuelrâce l'option -p permet de réaliser quand même la créaction de plusieurs répertoires dans un répertoire. + +III- 1) Grâce l'option -p permet de réaliser quand même la créaction de plusieurs répertoires dans un répertoire. +ls SCR/TP01/AA/DIR3 + +Explication : Je \ No newline at end of file diff --git a/SCR.1.1/.##tp01-reponses.txt# b/SCR.1.1/.##tp01-reponses.txt# new file mode 120000 index 0000000..37837f8 --- /dev/null +++ b/SCR.1.1/.##tp01-reponses.txt# @@ -0,0 +1 @@ +yolou@archlinux.1322:1726649723 \ No newline at end of file diff --git a/SCR.1.1/TP01/##tp01-reponses.txt## b/SCR.1.1/TP01/##tp01-reponses.txt## new file mode 100644 index 0000000..8e19d09 --- /dev/null +++ b/SCR.1.1/TP01/##tp01-reponses.txt## @@ -0,0 +1,31 @@ +TP01 + +I.1) - Cette commande m'informe que je suis sur l'utilisateur YOLOU (moi) +- Et l'autre m'informe sur les informations id de l'utilisateur: son groupe et +lui. + +2) - Cette commande m'informe sur quel système d'exploitation dans ce contexte là c'est Linux les informations suplémentaire sa version. + +3) Cette commande m'informe sur quel home je suis actuellement dans ce cas je suis dans l'emplacement yolou, mon home. + +4) La commande ls permet de lister les répertoires sur un emplacement. L'option -l montre les détails de chaque entrées et l'option -a permet d'afficher les entrées cachées. -man ls est menu + +5) Ce répertoire montre les fichiers de configurations pour que le système foncctionne. + +II - 1) La commande pwd sert à connaitre l'emplacement actuel, où tu te situes dans les répertoires. + +2) La commande la plus simple pour revenir dans son home est la commande cd. (man donne le mannuel) + +III- 1) Grâce l'option -p permet de réaliser quand même la créaction de plusieurs répertoires dans un répertoire. +ls SCR/TP01/AA/DIR3 + +Explication : Je suis sur mon domicile est grâce à cette commande je peux depuis mon home j'ai consulté le répertoire DIR3/ (RÉPONSE DE LA MACHINE : [yolou@archlinux ~]$ ls SCR/TP01/AA/DIR3 +fi31) +et pour DIR11/ (REPONSE DE LA MACHINE : [yolou@archlinux ~]$ ls SCR/TP01/AA/DIR1/DIR11 +fi111 fi113 fi31) + +2) cp SCR/TP01/AA/DIR3/fi31 SCR/TP01/AA/DIR1/fi11 + +Explication : Ça a crée un fichierr + + \ No newline at end of file diff --git a/SCR.1.1/TP01/#tp01-reponses.txt# b/SCR.1.1/TP01/#tp01-reponses.txt# new file mode 100644 index 0000000..3ec3032 --- /dev/null +++ b/SCR.1.1/TP01/#tp01-reponses.txt# @@ -0,0 +1,19 @@ +TP01 + +I.1) - Cette commande m'informe que je suis sur l'utilisateur YOLOU (moi) +- Et l'autre m'informe sur les informations id de l'utilisateur: son groupe et +lui. + +2) - Cette commande m'informe sur quel système d'exploitation dans ce contexte là c'est Linux les informations suplémentaire sa version. + +3) Cette commande m'informe sur quel home je suis actuellement dans ce cas je suis dans l'emplacement yolou, mon home. + +4) La commande ls permet de lister les répertoires sur un emplacement. L'option -l montre les détails de chaque entrées et l'option -a permet d'afficher les entrées cachées. -man ls est menu + +5) Ce répertoire montre les fichiers de configurations pour que le système foncctionne. + +II - 1) La commande pwd sert à connaitre l'emplacement actuel, où tu te situes dans les répertoires. + +2) La commande la plus simple pour revenir dans son home est la commande cd. (man donne le mannuel) + +III- 1) Grâce l'option -p permet de réaliser quand même la créaction de plusieurs répertoires dans un répertoire. diff --git a/SCR.1.1/TP01/.~lock.tp01-reponses.txt# b/SCR.1.1/TP01/.~lock.tp01-reponses.txt# new file mode 100644 index 0000000..4e3f8c5 --- /dev/null +++ b/SCR.1.1/TP01/.~lock.tp01-reponses.txt# @@ -0,0 +1 @@ +,yolou,archlinux,23.10.2024 10:31,file:///export/home/senart24/yolou/.config/libreoffice/4; \ No newline at end of file diff --git a/SCR.1.1/TP01/AA/DIR1/DIR11/.fi112 b/SCR.1.1/TP01/AA/DIR1/DIR11/.fi112 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/AA/DIR1/DIR11/fi111 b/SCR.1.1/TP01/AA/DIR1/DIR11/fi111 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/AA/DIR1/DIR11/fi113 b/SCR.1.1/TP01/AA/DIR1/DIR11/fi113 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/AA/DIR1/DIR11/fi31 b/SCR.1.1/TP01/AA/DIR1/DIR11/fi31 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/AA/DIR1/fi11 b/SCR.1.1/TP01/AA/DIR1/fi11 new file mode 100644 index 0000000..3e1cd0a --- /dev/null +++ b/SCR.1.1/TP01/AA/DIR1/fi11 @@ -0,0 +1,7 @@ +# 1 "AA/DIR3/fi31" +# 1 "" +# 1 "" +# 31 "" +# 1 "/usr/include/stdc-predef.h" 1 3 4 +# 32 "" 2 +# 1 "AA/DIR3/fi31" diff --git a/SCR.1.1/TP01/AA/DIR1/fi31 b/SCR.1.1/TP01/AA/DIR1/fi31 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/AA/DIR2/fi21 b/SCR.1.1/TP01/AA/DIR2/fi21 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/AA/DIR3/fi31 b/SCR.1.1/TP01/AA/DIR3/fi31 new file mode 100644 index 0000000..3e1cd0a --- /dev/null +++ b/SCR.1.1/TP01/AA/DIR3/fi31 @@ -0,0 +1,7 @@ +# 1 "AA/DIR3/fi31" +# 1 "" +# 1 "" +# 31 "" +# 1 "/usr/include/stdc-predef.h" 1 3 4 +# 32 "" 2 +# 1 "AA/DIR3/fi31" diff --git a/SCR.1.1/TP01/BB/DIR1/DIR11/.fi112 b/SCR.1.1/TP01/BB/DIR1/DIR11/.fi112 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/BB/DIR1/DIR11/fi111 b/SCR.1.1/TP01/BB/DIR1/DIR11/fi111 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/BB/DIR1/DIR11/fi31 b/SCR.1.1/TP01/BB/DIR1/DIR11/fi31 new file mode 100644 index 0000000..3e1cd0a --- /dev/null +++ b/SCR.1.1/TP01/BB/DIR1/DIR11/fi31 @@ -0,0 +1,7 @@ +# 1 "AA/DIR3/fi31" +# 1 "" +# 1 "" +# 31 "" +# 1 "/usr/include/stdc-predef.h" 1 3 4 +# 32 "" 2 +# 1 "AA/DIR3/fi31" diff --git a/SCR.1.1/TP01/BB/DIR1/DIR11/fi31cp b/SCR.1.1/TP01/BB/DIR1/DIR11/fi31cp new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/BB/DIR1/fi11 b/SCR.1.1/TP01/BB/DIR1/fi11 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/BB/DIR2/fi21 b/SCR.1.1/TP01/BB/DIR2/fi21 new file mode 100755 index 0000000..013c184 --- /dev/null +++ b/SCR.1.1/TP01/BB/DIR2/fi21 @@ -0,0 +1 @@ +pwd \ No newline at end of file diff --git a/SCR.1.1/TP01/BB/DIR3/fi32 b/SCR.1.1/TP01/BB/DIR3/fi32 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/BB/hh b/SCR.1.1/TP01/BB/hh new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP01/tp01-reponses.txt b/SCR.1.1/TP01/tp01-reponses.txt new file mode 100644 index 0000000..d622c8d --- /dev/null +++ b/SCR.1.1/TP01/tp01-reponses.txt @@ -0,0 +1,117 @@ +TP01 + +I.1) - Cette commande m'informe que je suis sur l'utilisateur YOLOU (moi) +- Et l'autre m'informe sur les informations id de l'utilisateur: son groupe et +lui. + +2) - Cette commande m'informe sur quel système d'exploitation dans ce contexte là c'est Linux les informations suplémentaire sa version. + +3) Cette commande m'informe sur quel home je suis actuellement dans ce cas je suis dans l'emplacement yolou, mon home. + +4) La commande ls permet de lister les répertoires sur un emplacement. L'option -l montre les détails de chaque entrées et l'option -a permet d'afficher les entrées cachées. -man ls est menu + +5) Ce répertoire montre les fichiers de configurations pour que le système foncctionne. + +II - 1) La commande pwd sert à connaitre l'emplacement actuel, où tu te situes dans les répertoires. + +2) La commande la plus simple pour revenir dans son home est la commande cd. (man donne le mannuel) + +III- 1) [yolou@archlinux]$ ls SCR/TP01/AA/DIR1/DIR11/ SCR/TP01/AA/DIR3/ + +Explication : La machine a consulté le répertoire DIR11 depuis son domicile et de même pour DIR3 en parcourant l'arborescence de celle ci + +2)[yolou@archlinux]$ cp SCR/TP01/AA/DIR3/fi31 SCR/TP01/AA/DIR2 ls SCR/TP01/AA/DIR1/DIR11/ SCR/TP01/AA/DIR3/ +SCR/TP01/AA/DIR1/DIR11/: +fi111 fi113 fi31 + +Explication : Depuis le domicile j'ai copié le fichier fi31 de DIR3 vers le DIR2 du répertoire AA j'ai consulté grâce à la commande ls il m'a affiché les fichier qu'il contient dans ce contexte fi31 est disponible. + +3)[yolou@archlinux]$ cp SCR/TP01/AA/DIR3/fi31 SCR/TP01/AA/DIR1/fi11 +[yolou@archlinux]$ ls SCR/TP01/AA/DIR1/fi11 +SCR/TP01/AA/DIR1/fi11 + +Explication : Depuis mon home j'ai cp le fichier fi31 de DIR3 vers le DIR11 en faisant une copie nommait fi11 dans le répertoire AA et il me l'a affiché ensuite + +IV) + +[yolou@archlinux ~]$ ls +bash: syntax error near unexpected token `newline' + +Explication : Après la commande ls la machine réagit mal parce que elle considère que j'ai mal + +1) [yolou@archlinux ~]$ fi21 +bash: fi21: command not found +[yolou@archlinux TP01]$ ls fi21 +ls: cannot access 'fi21': No such file or directory + +Explication : Après la commande fi21 l'intepretateur de commande me repond que je n'ai accès au fichier depuis ce repertoire car je suis pas dans le Path + +[yolou@archlinux ~]$ printenv PATH +/bin:/usr/bin:/usr/local/bin:/usr/local/sbin:/opt/android-sdk/platform-tools:/opt/android-sdk/tools:/opt/android-sdk/tools/bin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl + +Explication : Après avoir executé la commande printenv, l'interpréteur de commande m'informe des répertoires aux quels j'ai accès. + +Non, il n'est pas dedans effectivement le printenv ne l'a poijt affiché. + +2) [yolou@archlinux ~]$ ./fi21 +bash: ./fi21: No such file or directory + + +3)[yolou@archlinux TPO1]$ cd +[yolou@archlinux TPO1]$ echo $PATH +/bin:/usr/bin:/usr/local/bin:/usr/local/sbin:/opt/android-sdk/platform-tools:/opt/android-sdk/tools:/opt/android-sdk/tools/bin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl + + + +Explication : maintenant qu'on à donné le chemin complet vers fi21, l'interpréteur de commandes ne va plus le chercher dans la variable PATH. Par contre il se plaint d'une certaine permissiosn non accordée + +4) [yolou@archlinux SCR]$ ./fi21 +bash: ./fi21: No such file or directory + +Explication : On lance fi21 commande; Alors l'interpréteur de commande va chercher le nom fi21 dans la liste des repertoires cités dans le PATH. Or DIR2 qui contient fi21 n'est pas cité dans PATH(CE QUE ME MONTRE LE printenv PATH) + +5) [yolou@archlinux ~]$ cd SCR/TP01/BB/DIR2 +[yolou@archlinux DIR2]$ ./fi21 +bash: ./fi21: Permission denied + + +Explication : Le . est remplacé par le chemain complet vers le repertoire courant . La ligne de commande ~/SCR/TP01/BB/DIR2/fi21 et l'interpréteur de commande ne va plus cher cher dans PATH. Par contre il se plaint d'une permission non accordée +On consulte alors les permssions sur fi21. + +6)[yolou@archlinux DIR2]$ ls -la +total 8 +drwxr-xr-x 2 yolou senart24 4096 Sep 11 16:24 . +drwxr-xr-x 5 yolou senart24 4096 Sep 11 16:24 .. +-rwxr--r-- 1 yolou senart24 0 Sep 11 16:24 fi21 +[yolou@archlinux DIR2]$ ./fi21 + +Explication : Comme pour la question (DIR2). Si fi21 est bien là et à la permission d'exécutation, donc l'interpréteur de commande me repond sans dire quelque chose je verifie et j'observe que j'ai bien les permissiosn pour ouvrir le fichier fi21. + +7) Explication : Lorsque je lance editeur de texte sur fi21 et que je place un pwd à l'interieur, et que je l'enregistre. Quand je vais exécuté le fichier l'interpréteur de commande va lancé le pwd donc après avoir utiliser un editeur de texte sur ficher quelque conque et qu'on place une commande le cmd peut exécuter la commande à l'intérieur. + +V) + +1) + +"-i" permet de demander avant de supprimer, ou de faire un commande quelconque une confirmation de la part de l'utilisateur pour ne pas faire un erreur irréversible. + +2) Après avoir tapé man alias : +j'ai plusieurs exemples conn upar le shell comme : alias lf +alias r +alias du +alias nohup + +3) [yolou@archlinux DIR2]$ alias rm="rm -i" +[yolou@archlinux DIR2]$ alias cp="cp -i" +[yolou@archlinux DIR2]$ alias mv="mv -i" + +Explication : Cela permet de assigner aux commandes rm, cp ou mv de ajouter une confirmations avant de lancer la commande pour une question de prudence. + +4) Cela ne marche car il était seulement dans le registre de la sessionn du cmd ouvert; + +5) [yolou@archlinux DIR2]$ emacs ~/.bashrc & +[1] 1678 + +Explication : J'ai permi pour chaque cmd lancer un alias pour chaque des commande que j'ai prescit le rm, cp ou mv donc a chque que fois je vais taper alias il me repond les alias que j'ai inscrit dans le bash. + +6) Cela marche car il est inscrit dans le bash donc chaque cmd que j'ai fait serra possible \ No newline at end of file diff --git a/SCR.1.1/TP01/tp01-reponses.txt~ b/SCR.1.1/TP01/tp01-reponses.txt~ new file mode 100644 index 0000000..de3a22f --- /dev/null +++ b/SCR.1.1/TP01/tp01-reponses.txt~ @@ -0,0 +1,19 @@ +TP01 + +I.1) - Cette commande m'informe que je suis sur l'utilisateur YOLOU (moi) +- Et l'autre m'informe sur les informations id de l'utilisateur: son groupe et +lui. + +2) - Cette commande m'informe sur quel système d'exploitation dans ce contexte là c'est Linux les informations suplémentaire sa version. + +3) Cette commande m'informe sur quel home je suis actuellement dans ce cas je suis dans l'emplacement yolou, mon home. + +4) La commande ls permet de lister les répertoires sur un emplacement. L'option -l montre les détails de chaque entrées et l'option -a permet d'afficher les entrées cachées. -man ls est menu + +5) Ce répertoire montre les fichiers de configurations pour que le système foncctionne. + +II - 1) La commande pwd sert à connaitre l'emplacement actuel, où tu te situes dans les répertoires. + +2) La commande la plus simple pour revenir dans son home est la commande cd. (man donne le mannuel) + +III- 1) cp AA/DIR1/DIR11/ AA/DIR3/ diff --git a/SCR.1.1/TP02/.~lock.tp02-reponses.txt# b/SCR.1.1/TP02/.~lock.tp02-reponses.txt# new file mode 100644 index 0000000..9444af3 --- /dev/null +++ b/SCR.1.1/TP02/.~lock.tp02-reponses.txt# @@ -0,0 +1 @@ +,yolou,archlinux,23.10.2024 10:47,file:///export/home/senart24/yolou/.config/libreoffice/4; \ No newline at end of file diff --git a/SCR.1.1/TP02/fi b/SCR.1.1/TP02/fi new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP02/fifi b/SCR.1.1/TP02/fifi new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP02/output_file b/SCR.1.1/TP02/output_file new file mode 100644 index 0000000..b45cab4 --- /dev/null +++ b/SCR.1.1/TP02/output_file @@ -0,0 +1 @@ +ls: cannot access 'ofifi': No such file or directory diff --git a/SCR.1.1/TP02/tp02-reponses.txt b/SCR.1.1/TP02/tp02-reponses.txt new file mode 100644 index 0000000..929dffc --- /dev/null +++ b/SCR.1.1/TP02/tp02-reponses.txt @@ -0,0 +1,136 @@ +TP 02 + +I) +1) La commande echo permet d'écrire sur le terminal pour que l'interpréteur de commande reçoit ce qu'on a écrit après le echo. + +2) [yolou@archlinux TP02]$ echo "Hello word" +Hello word + +Explication : Il m'affiche Hello World. + +3) [yolou@archlinux TP02]$ echo "$?" +0 + +Explication : l'interpréteur de commande me renvoie 0 car tout c'est bien passé + +4) [yolou@archlinux TP02]$ ls fi +fi + +Explication : L'interpréteur de commande me répete fi car il se trouve correctement dans le repertoire TP02. + +5) [yolou@archlinux TP02]$ echo "$?" +0 + +Explication : l'interpréteur de commande me renvoie 0 car tout c'est bien passé + + +6) [yolou@archlinux TP02]$ ls -l fi +-rw-r--r-- 1 yolou senart24 0 Sep 25 15:30 fi + +Explication : a l'aide de ls -ls fi j'accede au permissions du fichiers fi je remarque que l'utilisateur a les permissiosn r et w donc le droit d'ecrire et lire, pour les groupes utilisateur r donc lire et pour finir le groupe a comme permission r pour lire aussi. + +7) [yolou@archlinux TP02]$ echo "$?" +0 + +Explication : l'interpréteur de commande me renvoie 0 car tout c'est bien passé + +8) [yolou@archlinux TP02]$ ls nofi +ls: cannot access 'nofi': No such file or directory +[yolou@archlinux TP02]$ man nofi +No manual entry for nofi + +Explication : L'interpréteur de commande m'informe apresz la commande pour regarder le répertoire ou/fichier qu'il ne connait pas lun fichier ou repertoire comportant ce nom la. Par précaution je regarde si c'est une comamnde en regardant son manuel est cela m'indique qu'il ny'a pas de commande de ce nom. + +9)[yolou@archlinux TP02]$ echo "$?" +0 + +Explication : l'interpréteur de commande me renvoie 0 car tout c'est bien passé + +Pipeline: +1-2) La natotation | ne considère plus la commande avant celle ci donc elle priorise la commande tapait après la notation | même si la commande aprs est fausse. + +Liste : + +1) En faisant suivre chacune des ligne de commandes par ; echo"$?", cela nous permet savoir si la commande est vrai ou correcte. + +2)Quand je tape par exemple ls fi; echo "$", cela m'affiche le fichier fi il me le repeté et il exécute la commande en m'affichant 0 après cela signifie que la commande est correct. + +3) [yolou@archlinux TP02]$ ls nofi ; echo "$?" +ls: cannot access 'nofi': No such file or directory +2 + +Explication : Comme le ls n'a pas trouvé le fichier ou dossier nofi le echo "$" ne repond pas par 0 mais 2 car la comamnde n'a pas abouti / incorrect. + +4) [yolou@archlinux TP02]$ ls fi && echo "Hello world!" ; echo "$?" +fi +Hello world! + + +Explication : Après avoir tapé la commande pour voir fi et ajouté la notation && pour qu'il exécute les deux commande en meme temps , le echo "$?" m'apprend que cela c'est bien passé la commande est correct avec le 0. + +5) [yolou@archlinux TP02]$ ls nofi && echo "Hello world!" ; echo "$?" +ls: cannot access 'nofi': No such file or directory +2 + +Explication : Comme le ls n'a pas trouvé le fichier ou dossier nofi et que la commande allait aboutir comme seulement si les deux commande etait correcte elle n'affiche pas le resultat de la commande suivant donc lele echo "$" ne repond pas par 0 mais 2 car la comamnde n'a pas abouti / incorrect. + +6) [yolou@archlinux TP02]$ ls fi || echo "Hello world!" ; echo "$?" +fi +0 + +Explication : Après avoir tapé la commande pour voir fi et ajouté la notation || l'interpréteur de commande exécute effectivement la commande apres la notation donc le echo "$?" m'apprend que cela c'est bien passé la commande est correct avec le 0. + +7)[yolou@archlinux TP02]$ ls nofi || echo "Hello world!" ; echo "$?" +ls: cannot access 'nofi': No such file or directory +Hello world! +0 + Explication : Comme l'une des commandes est correct le echo "$?" m'informe que ce j'ai ecrit est correct (0) grace a la notation qui dit que soit l'une des commande est vrai. || + + 8) [yolou@archlinux TP02]$ ls nofi || ls fi ; echo "$?" +ls: cannot access 'nofi': No such file or directory +fi +0 + + Explication : Comme l'une des commandes est correct le echo "$?" m'informe que ce j'ai ecrit est correct (0) grace a la notation qui dit que soit l'une des commande est vrai. || MAIS on remarque bien que la commande ls nofi pour voir le fichier ou le repertoire qui n'a pas marché avec le message recu d'erreur. + + 9) + [yolou@archlinux TP02]$ ls fi || ls nofi ; echo "$?" +fi +0 +Explication : Après avoir tapé la commande pour voir fi et ajouté la notation || l'interpréteur de commande exécute effectivement la commande apres la notation donc le echo "$?" m'apprend que cela c'est bien passé la commande est correct avec le 0. On remarque qu'elle n'a pas exécuté la commande suivante car du moment ou la 1er commande est vrai le message est bien attendu et bien sorti alors pas besoin d'effecuter l'autre. + +10)[yolou@archlinux TP02]$ ls nofi && ls fi ; echo "$?" +ls: cannot access 'nofi': No such file or directory +2 + +Explication : Le message est recu est une erreur car le ficheir ou dossier nofi n'existe pas donc le il ne cherche pas a regarde exécuter la commande suivant car pour ce que j'ai considéré comme vrai quand seulemtn les deux commandes ont vrai pas l'une, il me l'informe avec le message 2. + +II) + +1) [yolou@archlinux TP02]$ ls nofi fi +ls: cannot access 'nofi': No such file or directory +fi + +Explication : L'interpréteur de commande m'affiche que ficher ou repertoire nofi n'existe pas et on remarque qu'il fait a la suite la commande pour voir le fichier dossier fi est il excute. + +2) [yolou@archlinux TP02]$ ls nofi fi > output_file +ls: cannot access 'nofi': No such file or directory + +Explication : A premier vu il ne comprend pas la commande la commande est incorrect car il n'exite pas et pour le ficher fi injecte les message attendu dans le fichier output-file grace au >. + +3) [yolou@archlinux TP02]$ cat output_file +fi + +Explication : Lors de l'exécution du fichier output_file on remarque qu'il contient le fichier fi donc le message attendu après la commande fi d'après la question précedente le supérier > +2> il va stocker l'erreur du nofi dans un autre file +4) +[yolou@archlinux TP02]$ ls nofi > output_file +ls: cannot access 'nofi': No such file or directory + +Explication : Il m'affiche un message d'erruer car le chier nofi n'existe pas. + +5) [yolou@archlinux TP02]$ cat output_file +[yolou@archlinux TP02]$ + +Explication : Il va stocker l'information du message d'erreur dans un autre fichier avec 2> mais le > n'insert pas les message erreur mais seulement fichier attendu. +6) \ No newline at end of file diff --git a/SCR.1.1/TP03/reponses-tp03.tt b/SCR.1.1/TP03/reponses-tp03.tt new file mode 100644 index 0000000..bcaf7df --- /dev/null +++ b/SCR.1.1/TP03/reponses-tp03.tt @@ -0,0 +1,98 @@ +TP03 + +I- + +0 --> 1 octet ASCII +110.. --> 3 octets +1110.. --> 3 octets et après 10... à l'octet suivant +11110.. --> 4 octets + +c2 = (110)0 0010, a5= (10)10 0101 == u+a5 symbole yen +2c = (0)010 1100 == u+2c "," +20 = (0)010 0000 == u+20 "" +e2 = (111)0 0010, 99 = (10)01 1000, a0 = (10)10 0000 == u+2660 +2c = (0)010 1100 == u+2c "," +20 = (0)010 0000 == u+20 "" +e2 = (111)0 0010, 84 = (10)00 0100, 97 = (10)01 0111 == u+2117 +2c = (0)010 1100 == u+2c "," +20 = (0)010 0000 == u+20 "" +24 = (0)010 0100 == u+24 $ +2c = (0)010 1100 == u+2c "," +20 = (0)010 0000 == u+20 "" +c2 = (110)0 0010, a3= (10)10 0011 == u+a3 pound sign +2c = (0)010 1100 == u+2c "," +20 = (0)010 0000 == u+20 "" +e2 = (111)0 0010, 82 = (10)00 0010, ac = (10)10 1100 == u+20ac +2c = (0)010 1100 == u+2c "," +e2 = (111)0 0010, 98 = (10)01 1000, bb = (10)11 1011 == u+263b +2c = (0)010 1100 == u+2c "," +20 = (0)010 0000 == u+20 "" +61 = (0)110 0001 == u+61 +72 = (0)111 0010 == u+71 +20 = (0)010 0000 == u+20 "" +6e = (0)110 1110 == u+6e +6f = u+6f +74 = u+74 +20 = " " +61 = u+61 +6c = u +| +| +| +| +| +| +| +| +| +| +0a = u+0a + +II- + +1) ma bash +--> paragraphe "SHELL BUILTIN COMMANDS" + +2) +-->$x: VALEUR DE LA VARIABLE x + +3) read x +--> echo $x + +4) read -p "Prompt:"x +Prompt: ______ +echo$x on demande à l'utilisateur le x la valeur de x + +5) l'option -n +echo -n "blabla" + +6) Séquence, il fait les choses dans l'ordre quand tu demandes au cmd de faire exemple cd; rm quelque chose + +7) echo -n "Type var value " + +III - + +1) echo -e "\U45" -e + +2) echo -n "Type en HEX UNICODE"; read x; echo -e "Corresponding CHAR \U$x" + +==> Type on HEX UNICODE: ___ +Corresponding CHAR : le symbole + +3) print-unicode-char +chmod u+r print-unicode-char +./print-unicode-char +c'est pour ajouter le code à l'intérieur et il rajoute des perm pour l'executé avec X +___________ +printen PATH +which ls + +IV - + +1) echo -en "\U2660" | hexdumb -C +permet d'afficher le code utf-8 (hexé) du unicode donné +2) en créant un ficher nommé print-hex avec la commande "echo -en "\U$1"de prendre l'argument cad après avoir mit le ficher la commande ou ce que t'a écrit après le fichier il va prendre en compte +chmod u+x print-hex +./print-hex ... +00000000000 .... .... .... ("caractère") +0000000000. \ No newline at end of file diff --git a/SCR.1.1/TP04/tp-reponses-04 Seri Khane Yolou.pdf b/SCR.1.1/TP04/tp-reponses-04 Seri Khane Yolou.pdf new file mode 100644 index 0000000..345554c Binary files /dev/null and b/SCR.1.1/TP04/tp-reponses-04 Seri Khane Yolou.pdf differ diff --git a/SCR.1.1/TP04/tp-reponses-04.odt b/SCR.1.1/TP04/tp-reponses-04.odt new file mode 100644 index 0000000..3f60473 Binary files /dev/null and b/SCR.1.1/TP04/tp-reponses-04.odt differ diff --git a/SCR.1.1/TP04/tp-reponses-04.pdf b/SCR.1.1/TP04/tp-reponses-04.pdf new file mode 100644 index 0000000..a9237d0 Binary files /dev/null and b/SCR.1.1/TP04/tp-reponses-04.pdf differ diff --git a/SCR.1.1/TP05/tp05-reponses.odt b/SCR.1.1/TP05/tp05-reponses.odt new file mode 100644 index 0000000..18f4277 Binary files /dev/null and b/SCR.1.1/TP05/tp05-reponses.odt differ diff --git a/SCR.1.1/TP06/.~lock.yolou-reponses.odt# b/SCR.1.1/TP06/.~lock.yolou-reponses.odt# new file mode 100644 index 0000000..850595a --- /dev/null +++ b/SCR.1.1/TP06/.~lock.yolou-reponses.odt# @@ -0,0 +1 @@ +,yolou,archlinux,23.10.2024 12:17,file:///export/home/senart24/yolou/.config/libreoffice/4; \ No newline at end of file diff --git a/SCR.1.1/TP06/3 b/SCR.1.1/TP06/3 new file mode 100644 index 0000000..867e5eb --- /dev/null +++ b/SCR.1.1/TP06/3 @@ -0,0 +1 @@ +les consignes toto \ No newline at end of file diff --git a/SCR.1.1/TP06/toto b/SCR.1.1/TP06/toto new file mode 100644 index 0000000..7f76f72 --- /dev/null +++ b/SCR.1.1/TP06/toto @@ -0,0 +1,3 @@ +Bonjour! +Il faut bien respecter +les consignes diff --git a/SCR.1.1/TP06/yolou-reponses.odt b/SCR.1.1/TP06/yolou-reponses.odt new file mode 100644 index 0000000..4addf4b Binary files /dev/null and b/SCR.1.1/TP06/yolou-reponses.odt differ diff --git a/SCR.1.1/TP07/TP06/GLOB/11glob22blog3 b/SCR.1.1/TP07/TP06/GLOB/11glob22blog3 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP07/TP06/GLOB/1glob b/SCR.1.1/TP07/TP06/GLOB/1glob new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP07/TP06/GLOB/1glob22 b/SCR.1.1/TP07/TP06/GLOB/1glob22 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP07/TP06/GLOB/1glob22gloB333 b/SCR.1.1/TP07/TP06/GLOB/1glob22gloB333 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP07/TP06/GLOB/gLob/44patterN b/SCR.1.1/TP07/TP06/GLOB/gLob/44patterN new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP07/TP06/GLOB/gLob/Pattern4 b/SCR.1.1/TP07/TP06/GLOB/gLob/Pattern4 new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP07/TP06/GLOB/gLob/pAtterN b/SCR.1.1/TP07/TP06/GLOB/gLob/pAtterN new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP07/TP06/GLOB/gLob/paTTerN/theglobpattern b/SCR.1.1/TP07/TP06/GLOB/gLob/paTTerN/theglobpattern new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP07/TP06/GLOB/gLob/patterN b/SCR.1.1/TP07/TP06/GLOB/gLob/patterN new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP07/TP06/GLOB/gloB1bloG b/SCR.1.1/TP07/TP06/GLOB/gloB1bloG new file mode 100644 index 0000000..e69de29 diff --git a/SCR.1.1/TP07/TP06/SHELL BUILTIN COMMANDS b/SCR.1.1/TP07/TP06/SHELL BUILTIN COMMANDS new file mode 100644 index 0000000..4cd78a8 --- /dev/null +++ b/SCR.1.1/TP07/TP06/SHELL BUILTIN COMMANDS @@ -0,0 +1,5932 @@ +BASH(1) General Commands Manual BASH(1) + +NNAAMMEE + bash - GNU Bourne-Again SHell + +SSYYNNOOPPSSIISS + bbaasshh [options] [command_string | file] + +CCOOPPYYRRIIGGHHTT + Bash is Copyright (C) 1989-2016 by the Free Software Foundation, Inc. + +DDEESSCCRRIIPPTTIIOONN + BBaasshh is an sshh-compatible command language interpreter that executes + commands read from the standard input or from a file. BBaasshh also incor- + porates useful features from the _K_o_r_n and _C shells (kksshh and ccsshh). + + BBaasshh is intended to be a conformant implementation of the Shell and + Utilities portion of the IEEE POSIX specification (IEEE Standard + 1003.1). BBaasshh can be configured to be POSIX-conformant by default. + +OOPPTTIIOONNSS + All of the single-character shell options documented in the description + of the sseett builtin command can be used as options when the shell is + invoked. In addition, bbaasshh interprets the following options when it is + invoked: + + --cc If the --cc option is present, then commands are read from the + first non-option argument _c_o_m_m_a_n_d___s_t_r_i_n_g. If there are argu- + ments after the _c_o_m_m_a_n_d___s_t_r_i_n_g, the first argument is + assigned to $$00 and any remaining arguments are assigned to + the positional parameters. The assignment to $$00 sets the + name of the shell, which is used in warning and error mes- + sages. + --ii If the --ii option is present, the shell is _i_n_t_e_r_a_c_t_i_v_e. + --ll Make bbaasshh act as if it had been invoked as a login shell (see + IINNVVOOCCAATTIIOONN below). + --rr If the --rr option is present, the shell becomes _r_e_s_t_r_i_c_t_e_d + (see RREESSTTRRIICCTTEEDD SSHHEELLLL below). + --ss If the --ss option is present, or if no arguments remain after + option processing, then commands are read from the standard + input. This option allows the positional parameters to be + set when invoking an interactive shell. + --DD A list of all double-quoted strings preceded by $$ is printed + on the standard output. These are the strings that are sub- + ject to language translation when the current locale is not CC + or PPOOSSIIXX. This implies the --nn option; no commands will be + executed. + [[--++]]OO [[_s_h_o_p_t___o_p_t_i_o_n]] + _s_h_o_p_t___o_p_t_i_o_n is one of the shell options accepted by the + sshhoopptt builtin (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). If + _s_h_o_p_t___o_p_t_i_o_n is present, --OO sets the value of that option; ++OO + unsets it. If _s_h_o_p_t___o_p_t_i_o_n is not supplied, the names and + values of the shell options accepted by sshhoopptt are printed on + the standard output. If the invocation option is ++OO, the + output is displayed in a format that may be reused as input. + ---- A ---- signals the end of options and disables further option + processing. Any arguments after the ---- are treated as file- + names and arguments. An argument of -- is equivalent to ----. + + BBaasshh also interprets a number of multi-character options. These + options must appear on the command line before the single-character + options to be recognized. + + ----ddeebbuuggggeerr + Arrange for the debugger profile to be executed before the shell + starts. Turns on extended debugging mode (see the description + of the eexxttddeebbuugg option to the sshhoopptt builtin below). + ----dduummpp--ppoo--ssttrriinnggss + Equivalent to --DD, but the output is in the GNU _g_e_t_t_e_x_t ppoo (por- + table object) file format. + ----dduummpp--ssttrriinnggss + Equivalent to --DD. + ----hheellpp Display a usage message on standard output and exit success- + fully. + ----iinniitt--ffiillee _f_i_l_e + ----rrccffiillee _f_i_l_e + Execute commands from _f_i_l_e instead of the standard personal ini- + tialization file _~_/_._b_a_s_h_r_c if the shell is interactive (see + IINNVVOOCCAATTIIOONN below). + + ----llooggiinn + Equivalent to --ll. + + ----nnooeeddiittiinngg + Do not use the GNU rreeaaddlliinnee library to read command lines when + the shell is interactive. + + ----nnoopprrooffiillee + Do not read either the system-wide startup file _/_e_t_c_/_p_r_o_f_i_l_e or + any of the personal initialization files _~_/_._b_a_s_h___p_r_o_f_i_l_e, + _~_/_._b_a_s_h___l_o_g_i_n, or _~_/_._p_r_o_f_i_l_e. By default, bbaasshh reads these + files when it is invoked as a login shell (see IINNVVOOCCAATTIIOONN + below). + + ----nnoorrcc Do not read and execute the personal initialization file + _~_/_._b_a_s_h_r_c if the shell is interactive. This option is on by + default if the shell is invoked as sshh. + + ----ppoossiixx + Change the behavior of bbaasshh where the default operation differs + from the POSIX standard to match the standard (_p_o_s_i_x _m_o_d_e). See + SSEEEE AALLSSOO below for a reference to a document that details how + posix mode affects bash's behavior. + + ----rreessttrriicctteedd + The shell becomes restricted (see RREESSTTRRIICCTTEEDD SSHHEELLLL below). + + ----vveerrbboossee + Equivalent to --vv. + + ----vveerrssiioonn + Show version information for this instance of bbaasshh on the stan- + dard output and exit successfully. + +AARRGGUUMMEENNTTSS + If arguments remain after option processing, and neither the --cc nor the + --ss option has been supplied, the first argument is assumed to be the + name of a file containing shell commands. If bbaasshh is invoked in this + fashion, $$00 is set to the name of the file, and the positional parame- + ters are set to the remaining arguments. BBaasshh reads and executes com- + mands from this file, then exits. BBaasshh's exit status is the exit sta- + tus of the last command executed in the script. If no commands are + executed, the exit status is 0. An attempt is first made to open the + file in the current directory, and, if no file is found, then the shell + searches the directories in PPAATTHH for the script. + +IINNVVOOCCAATTIIOONN + A _l_o_g_i_n _s_h_e_l_l is one whose first character of argument zero is a --, or + one started with the ----llooggiinn option. + + An _i_n_t_e_r_a_c_t_i_v_e shell is one started without non-option arguments + (unless --ss is specified) and without the --cc option whose standard input + and error are both connected to terminals (as determined by _i_s_a_t_t_y(3)), + or one started with the --ii option. PPSS11 is set and $$-- includes ii if + bbaasshh is interactive, allowing a shell script or a startup file to test + this state. + + The following paragraphs describe how bbaasshh executes its startup files. + If any of the files exist but cannot be read, bbaasshh reports an error. + Tildes are expanded in filenames as described below under TTiillddee EExxppaann-- + ssiioonn in the EEXXPPAANNSSIIOONN section. + + When bbaasshh is invoked as an interactive login shell, or as a non-inter- + active shell with the ----llooggiinn option, it first reads and executes com- + mands from the file _/_e_t_c_/_p_r_o_f_i_l_e, if that file exists. After reading + that file, it looks for _~_/_._b_a_s_h___p_r_o_f_i_l_e, _~_/_._b_a_s_h___l_o_g_i_n, and _~_/_._p_r_o_f_i_l_e, + in that order, and reads and executes commands from the first one that + exists and is readable. The ----nnoopprrooffiillee option may be used when the + shell is started to inhibit this behavior. + + When an interactive login shell exits, or a non-interactive login shell + executes the eexxiitt builtin command, bbaasshh reads and executes commands + from the file _~_/_._b_a_s_h___l_o_g_o_u_t, if it exists. + + When an interactive shell that is not a login shell is started, bbaasshh + reads and executes commands from _~_/_._b_a_s_h_r_c, if that file exists. This + may be inhibited by using the ----nnoorrcc option. The ----rrccffiillee _f_i_l_e option + will force bbaasshh to read and execute commands from _f_i_l_e instead of + _~_/_._b_a_s_h_r_c. + + When bbaasshh is started non-interactively, to run a shell script, for + example, it looks for the variable BBAASSHH__EENNVV in the environment, expands + its value if it appears there, and uses the expanded value as the name + of a file to read and execute. BBaasshh behaves as if the following com- + mand were executed: + if [ -n "$BASH_ENV" ]; then . "$BASH_ENV"; fi + but the value of the PPAATTHH variable is not used to search for the file- + name. + + If bbaasshh is invoked with the name sshh, it tries to mimic the startup + behavior of historical versions of sshh as closely as possible, while + conforming to the POSIX standard as well. When invoked as an interac- + tive login shell, or a non-interactive shell with the ----llooggiinn option, + it first attempts to read and execute commands from _/_e_t_c_/_p_r_o_f_i_l_e and + _~_/_._p_r_o_f_i_l_e, in that order. The ----nnoopprrooffiillee option may be used to + inhibit this behavior. When invoked as an interactive shell with the + name sshh, bbaasshh looks for the variable EENNVV, expands its value if it is + defined, and uses the expanded value as the name of a file to read and + execute. Since a shell invoked as sshh does not attempt to read and exe- + cute commands from any other startup files, the ----rrccffiillee option has no + effect. A non-interactive shell invoked with the name sshh does not + attempt to read any other startup files. When invoked as sshh, bbaasshh + enters _p_o_s_i_x mode after the startup files are read. + + When bbaasshh is started in _p_o_s_i_x mode, as with the ----ppoossiixx command line + option, it follows the POSIX standard for startup files. In this mode, + interactive shells expand the EENNVV variable and commands are read and + executed from the file whose name is the expanded value. No other + startup files are read. + + BBaasshh attempts to determine when it is being run with its standard input + connected to a network connection, as when executed by the remote shell + daemon, usually _r_s_h_d, or the secure shell daemon _s_s_h_d. If bbaasshh deter- + mines it is being run in this fashion, it reads and executes commands + from _~_/_._b_a_s_h_r_c, if that file exists and is readable. It will not do + this if invoked as sshh. The ----nnoorrcc option may be used to inhibit this + behavior, and the ----rrccffiillee option may be used to force another file to + be read, but neither _r_s_h_d nor _s_s_h_d generally invoke the shell with + those options or allow them to be specified. + + If the shell is started with the effective user (group) id not equal to + the real user (group) id, and the --pp option is not supplied, no startup + files are read, shell functions are not inherited from the environment, + the SSHHEELLLLOOPPTTSS, BBAASSHHOOPPTTSS, CCDDPPAATTHH, and GGLLOOBBIIGGNNOORREE variables, if they + appear in the environment, are ignored, and the effective user id is + set to the real user id. If the --pp option is supplied at invocation, + the startup behavior is the same, but the effective user id is not + reset. + +DDEEFFIINNIITTIIOONNSS + The following definitions are used throughout the rest of this docu- + ment. + bbllaannkk A space or tab. + wwoorrdd A sequence of characters considered as a single unit by the + shell. Also known as a ttookkeenn. + nnaammee A _w_o_r_d consisting only of alphanumeric characters and under- + scores, and beginning with an alphabetic character or an under- + score. Also referred to as an iiddeennttiiffiieerr. + mmeettaacchhaarraacctteerr + A character that, when unquoted, separates words. One of the + following: + || && ;; (( )) << >> ssppaaccee ttaabb nneewwlliinnee + ccoonnttrrooll ooppeerraattoorr + A _t_o_k_e_n that performs a control function. It is one of the fol- + lowing symbols: + |||| && &&&& ;; ;;;; ;;&& ;;;;&& (( )) || ||&& <> + +RREESSEERRVVEEDD WWOORRDDSS + _R_e_s_e_r_v_e_d _w_o_r_d_s are words that have a special meaning to the shell. The + following words are recognized as reserved when unquoted and either the + first word of a simple command (see SSHHEELLLL GGRRAAMMMMAARR below) or the third + word of a ccaassee or ffoorr command: + + !! ccaassee ccoopprroocc ddoo ddoonnee eelliiff eellssee eessaacc ffii ffoorr ffuunnccttiioonn iiff iinn sseelleecctt + tthheenn uunnttiill wwhhiillee {{ }} ttiimmee [[[[ ]]]] + +SSHHEELLLL GGRRAAMMMMAARR + SSiimmppllee CCoommmmaannddss + A _s_i_m_p_l_e _c_o_m_m_a_n_d is a sequence of optional variable assignments fol- + lowed by bbllaannkk-separated words and redirections, and terminated by a + _c_o_n_t_r_o_l _o_p_e_r_a_t_o_r. The first word specifies the command to be executed, + and is passed as argument zero. The remaining words are passed as + arguments to the invoked command. + + The return value of a _s_i_m_p_l_e _c_o_m_m_a_n_d is its exit status, or 128+_n if + the command is terminated by signal _n. + + PPiippeelliinneess + A _p_i_p_e_l_i_n_e is a sequence of one or more commands separated by one of + the control operators || or ||&&. The format for a pipeline is: + + [ttiimmee [--pp]] [ ! ] _c_o_m_m_a_n_d [ [|||||&&] _c_o_m_m_a_n_d_2 ... ] + + The standard output of _c_o_m_m_a_n_d is connected via a pipe to the standard + input of _c_o_m_m_a_n_d_2. This connection is performed before any redirec- + tions specified by the command (see RREEDDIIRREECCTTIIOONN below). If ||&& is used, + _c_o_m_m_a_n_d's standard error, in addition to its standard output, is con- + nected to _c_o_m_m_a_n_d_2's standard input through the pipe; it is shorthand + for 22>>&&11 ||. This implicit redirection of the standard error to the + standard output is performed after any redirections specified by the + command. + + The return status of a pipeline is the exit status of the last command, + unless the ppiippeeffaaiill option is enabled. If ppiippeeffaaiill is enabled, the + pipeline's return status is the value of the last (rightmost) command + to exit with a non-zero status, or zero if all commands exit success- + fully. If the reserved word !! precedes a pipeline, the exit status of + that pipeline is the logical negation of the exit status as described + above. The shell waits for all commands in the pipeline to terminate + before returning a value. + + If the ttiimmee reserved word precedes a pipeline, the elapsed as well as + user and system time consumed by its execution are reported when the + pipeline terminates. The --pp option changes the output format to that + specified by POSIX. When the shell is in _p_o_s_i_x _m_o_d_e, it does not rec- + ognize ttiimmee as a reserved word if the next token begins with a `-'. + The TTIIMMEEFFOORRMMAATT variable may be set to a format string that specifies + how the timing information should be displayed; see the description of + TTIIMMEEFFOORRMMAATT under SShheellll VVaarriiaabblleess below. + + When the shell is in _p_o_s_i_x _m_o_d_e, ttiimmee may be followed by a newline. In + this case, the shell displays the total user and system time consumed + by the shell and its children. The TTIIMMEEFFOORRMMAATT variable may be used to + specify the format of the time information. + + Each command in a pipeline is executed as a separate process (i.e., in + a subshell). + + LLiissttss + A _l_i_s_t is a sequence of one or more pipelines separated by one of the + operators ;;, &&, &&&&, or ||||, and optionally terminated by one of ;;, &&, or + <>. + + Of these list operators, &&&& and |||| have equal precedence, followed by ;; + and &&, which have equal precedence. + + A sequence of one or more newlines may appear in a _l_i_s_t instead of a + semicolon to delimit commands. + + If a command is terminated by the control operator &&, the shell exe- + cutes the command in the _b_a_c_k_g_r_o_u_n_d in a subshell. The shell does not + wait for the command to finish, and the return status is 0. Commands + separated by a ;; are executed sequentially; the shell waits for each + command to terminate in turn. The return status is the exit status of + the last command executed. + + AND and OR lists are sequences of one or more pipelines separated by + the &&&& and |||| control operators, respectively. AND and OR lists are + executed with left associativity. An AND list has the form + + _c_o_m_m_a_n_d_1 &&&& _c_o_m_m_a_n_d_2 + + _c_o_m_m_a_n_d_2 is executed if, and only if, _c_o_m_m_a_n_d_1 returns an exit status + of zero. + + An OR list has the form + + _c_o_m_m_a_n_d_1 |||| _c_o_m_m_a_n_d_2 + + _c_o_m_m_a_n_d_2 is executed if and only if _c_o_m_m_a_n_d_1 returns a non-zero exit + status. The return status of AND and OR lists is the exit status of + the last command executed in the list. + + CCoommppoouunndd CCoommmmaannddss + A _c_o_m_p_o_u_n_d _c_o_m_m_a_n_d is one of the following. In most cases a _l_i_s_t in a + command's description may be separated from the rest of the command by + one or more newlines, and may be followed by a newline in place of a + semicolon. + + (_l_i_s_t) _l_i_s_t is executed in a subshell environment (see CCOOMMMMAANNDD EEXXEECCUU-- + TTIIOONN EENNVVIIRROONNMMEENNTT below). Variable assignments and builtin com- + mands that affect the shell's environment do not remain in + effect after the command completes. The return status is the + exit status of _l_i_s_t. + + { _l_i_s_t; } + _l_i_s_t is simply executed in the current shell environment. _l_i_s_t + must be terminated with a newline or semicolon. This is known + as a _g_r_o_u_p _c_o_m_m_a_n_d. The return status is the exit status of + _l_i_s_t. Note that unlike the metacharacters (( and )), {{ and }} are + _r_e_s_e_r_v_e_d _w_o_r_d_s and must occur where a reserved word is permitted + to be recognized. Since they do not cause a word break, they + must be separated from _l_i_s_t by whitespace or another shell + metacharacter. + + ((_e_x_p_r_e_s_s_i_o_n)) + The _e_x_p_r_e_s_s_i_o_n is evaluated according to the rules described + below under AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN. If the value of the expres- + sion is non-zero, the return status is 0; otherwise the return + status is 1. This is exactly equivalent to lleett ""_e_x_p_r_e_s_s_i_o_n"". + + [[[[ _e_x_p_r_e_s_s_i_o_n ]]]] + Return a status of 0 or 1 depending on the evaluation of the + conditional expression _e_x_p_r_e_s_s_i_o_n. Expressions are composed of + the primaries described below under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS. + Word splitting and pathname expansion are not performed on the + words between the [[[[ and ]]]]; tilde expansion, parameter and + variable expansion, arithmetic expansion, command substitution, + process substitution, and quote removal are performed. Condi- + tional operators such as --ff must be unquoted to be recognized as + primaries. + + When used with [[[[, the << and >> operators sort lexicographically + using the current locale. + + When the ==== and !!== operators are used, the string to the right + of the operator is considered a pattern and matched according to + the rules described below under PPaatttteerrnn MMaattcchhiinngg, as if the eexxtt-- + gglloobb shell option were enabled. The == operator is equivalent to + ====. If the nnooccaasseemmaattcchh shell option is enabled, the match is + performed without regard to the case of alphabetic characters. + The return value is 0 if the string matches (====) or does not + match (!!==) the pattern, and 1 otherwise. Any part of the pat- + tern may be quoted to force the quoted portion to be matched as + a string. + + An additional binary operator, ==~~, is available, with the same + precedence as ==== and !!==. When it is used, the string to the + right of the operator is considered an extended regular expres- + sion and matched accordingly (as in _r_e_g_e_x(3)). The return value + is 0 if the string matches the pattern, and 1 otherwise. If the + regular expression is syntactically incorrect, the conditional + expression's return value is 2. If the nnooccaasseemmaattcchh shell option + is enabled, the match is performed without regard to the case of + alphabetic characters. Any part of the pattern may be quoted to + force the quoted portion to be matched as a string. Bracket + expressions in regular expressions must be treated carefully, + since normal quoting characters lose their meanings between + brackets. If the pattern is stored in a shell variable, quoting + the variable expansion forces the entire pattern to be matched + as a string. Substrings matched by parenthesized subexpressions + within the regular expression are saved in the array variable + BBAASSHH__RREEMMAATTCCHH. The element of BBAASSHH__RREEMMAATTCCHH with index 0 is the + portion of the string matching the entire regular expression. + The element of BBAASSHH__RREEMMAATTCCHH with index _n is the portion of the + string matching the _nth parenthesized subexpression. + + Expressions may be combined using the following operators, + listed in decreasing order of precedence: + + (( _e_x_p_r_e_s_s_i_o_n )) + Returns the value of _e_x_p_r_e_s_s_i_o_n. This may be used to + override the normal precedence of operators. + !! _e_x_p_r_e_s_s_i_o_n + True if _e_x_p_r_e_s_s_i_o_n is false. + _e_x_p_r_e_s_s_i_o_n_1 &&&& _e_x_p_r_e_s_s_i_o_n_2 + True if both _e_x_p_r_e_s_s_i_o_n_1 and _e_x_p_r_e_s_s_i_o_n_2 are true. + _e_x_p_r_e_s_s_i_o_n_1 |||| _e_x_p_r_e_s_s_i_o_n_2 + True if either _e_x_p_r_e_s_s_i_o_n_1 or _e_x_p_r_e_s_s_i_o_n_2 is true. + + The &&&& and |||| operators do not evaluate _e_x_p_r_e_s_s_i_o_n_2 if the value + of _e_x_p_r_e_s_s_i_o_n_1 is sufficient to determine the return value of + the entire conditional expression. + + ffoorr _n_a_m_e [ [ iinn [ _w_o_r_d _._._. ] ] ; ] ddoo _l_i_s_t ; ddoonnee + The list of words following iinn is expanded, generating a list of + items. The variable _n_a_m_e is set to each element of this list in + turn, and _l_i_s_t is executed each time. If the iinn _w_o_r_d is omit- + ted, the ffoorr command executes _l_i_s_t once for each positional + parameter that is set (see PPAARRAAMMEETTEERRSS below). The return status + is the exit status of the last command that executes. If the + expansion of the items following iinn results in an empty list, no + commands are executed, and the return status is 0. + + ffoorr (( _e_x_p_r_1 ; _e_x_p_r_2 ; _e_x_p_r_3 )) ; ddoo _l_i_s_t ; ddoonnee + First, the arithmetic expression _e_x_p_r_1 is evaluated according to + the rules described below under AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN. The + arithmetic expression _e_x_p_r_2 is then evaluated repeatedly until + it evaluates to zero. Each time _e_x_p_r_2 evaluates to a non-zero + value, _l_i_s_t is executed and the arithmetic expression _e_x_p_r_3 is + evaluated. If any expression is omitted, it behaves as if it + evaluates to 1. The return value is the exit status of the last + command in _l_i_s_t that is executed, or false if any of the expres- + sions is invalid. + + sseelleecctt _n_a_m_e [ iinn _w_o_r_d ] ; ddoo _l_i_s_t ; ddoonnee + The list of words following iinn is expanded, generating a list of + items. The set of expanded words is printed on the standard + error, each preceded by a number. If the iinn _w_o_r_d is omitted, + the positional parameters are printed (see PPAARRAAMMEETTEERRSS below). + The PPSS33 prompt is then displayed and a line read from the stan- + dard input. If the line consists of a number corresponding to + one of the displayed words, then the value of _n_a_m_e is set to + that word. If the line is empty, the words and prompt are dis- + played again. If EOF is read, the command completes. Any other + value read causes _n_a_m_e to be set to null. The line read is + saved in the variable RREEPPLLYY. The _l_i_s_t is executed after each + selection until a bbrreeaakk command is executed. The exit status of + sseelleecctt is the exit status of the last command executed in _l_i_s_t, + or zero if no commands were executed. + + ccaassee _w_o_r_d iinn [ [(] _p_a_t_t_e_r_n [ || _p_a_t_t_e_r_n ] ... ) _l_i_s_t ;; ] ... eessaacc + A ccaassee command first expands _w_o_r_d, and tries to match it against + each _p_a_t_t_e_r_n in turn, using the same matching rules as for path- + name expansion (see PPaatthhnnaammee EExxppaannssiioonn below). The _w_o_r_d is + expanded using tilde expansion, parameter and variable expan- + sion, arithmetic expansion, command substitution, process sub- + stitution and quote removal. Each _p_a_t_t_e_r_n examined is expanded + using tilde expansion, parameter and variable expansion, arith- + metic expansion, command substitution, and process substitution. + If the nnooccaasseemmaattcchh shell option is enabled, the match is per- + formed without regard to the case of alphabetic characters. + When a match is found, the corresponding _l_i_s_t is executed. If + the ;;;; operator is used, no subsequent matches are attempted + after the first pattern match. Using ;;&& in place of ;;;; causes + execution to continue with the _l_i_s_t associated with the next set + of patterns. Using ;;;;&& in place of ;;;; causes the shell to test + the next pattern list in the statement, if any, and execute any + associated _l_i_s_t on a successful match. The exit status is zero + if no pattern matches. Otherwise, it is the exit status of the + last command executed in _l_i_s_t. + + iiff _l_i_s_t; tthheenn _l_i_s_t; [ eelliiff _l_i_s_t; tthheenn _l_i_s_t; ] ... [ eellssee _l_i_s_t; ] ffii + The iiff _l_i_s_t is executed. If its exit status is zero, the tthheenn + _l_i_s_t is executed. Otherwise, each eelliiff _l_i_s_t is executed in + turn, and if its exit status is zero, the corresponding tthheenn + _l_i_s_t is executed and the command completes. Otherwise, the eellssee + _l_i_s_t is executed, if present. The exit status is the exit sta- + tus of the last command executed, or zero if no condition tested + true. + + wwhhiillee _l_i_s_t_-_1; ddoo _l_i_s_t_-_2; ddoonnee + uunnttiill _l_i_s_t_-_1; ddoo _l_i_s_t_-_2; ddoonnee + The wwhhiillee command continuously executes the list _l_i_s_t_-_2 as long + as the last command in the list _l_i_s_t_-_1 returns an exit status of + zero. The uunnttiill command is identical to the wwhhiillee command, + except that the test is negated: _l_i_s_t_-_2 is executed as long as + the last command in _l_i_s_t_-_1 returns a non-zero exit status. The + exit status of the wwhhiillee and uunnttiill commands is the exit status + of the last command executed in _l_i_s_t_-_2, or zero if none was exe- + cuted. + + CCoopprroocceesssseess + A _c_o_p_r_o_c_e_s_s is a shell command preceded by the ccoopprroocc reserved word. A + coprocess is executed asynchronously in a subshell, as if the command + had been terminated with the && control operator, with a two-way pipe + established between the executing shell and the coprocess. + + The format for a coprocess is: + + ccoopprroocc [_N_A_M_E] _c_o_m_m_a_n_d [_r_e_d_i_r_e_c_t_i_o_n_s] + + This creates a coprocess named _N_A_M_E. If _N_A_M_E is not supplied, the + default name is CCOOPPRROOCC. _N_A_M_E must not be supplied if _c_o_m_m_a_n_d is a _s_i_m_- + _p_l_e _c_o_m_m_a_n_d (see above); otherwise, it is interpreted as the first word + of the simple command. When the coprocess is executed, the shell cre- + ates an array variable (see AArrrraayyss below) named _N_A_M_E in the context of + the executing shell. The standard output of _c_o_m_m_a_n_d is connected via a + pipe to a file descriptor in the executing shell, and that file + descriptor is assigned to _N_A_M_E[0]. The standard input of _c_o_m_m_a_n_d is + connected via a pipe to a file descriptor in the executing shell, and + that file descriptor is assigned to _N_A_M_E[1]. This pipe is established + before any redirections specified by the command (see RREEDDIIRREECCTTIIOONN + below). The file descriptors can be utilized as arguments to shell + commands and redirections using standard word expansions. The file + descriptors are not available in subshells. The process ID of the + shell spawned to execute the coprocess is available as the value of the + variable _N_A_M_E_PID. The wwaaiitt builtin command may be used to wait for + the coprocess to terminate. + + Since the coprocess is created as an asynchronous command, the ccoopprroocc + command always returns success. The return status of a coprocess is + the exit status of _c_o_m_m_a_n_d. + + SShheellll FFuunnccttiioonn DDeeffiinniittiioonnss + A shell function is an object that is called like a simple command and + executes a compound command with a new set of positional parameters. + Shell functions are declared as follows: + + _n_a_m_e () _c_o_m_p_o_u_n_d_-_c_o_m_m_a_n_d [_r_e_d_i_r_e_c_t_i_o_n] + ffuunnccttiioonn _n_a_m_e [()] _c_o_m_p_o_u_n_d_-_c_o_m_m_a_n_d [_r_e_d_i_r_e_c_t_i_o_n] + This defines a function named _n_a_m_e. The reserved word ffuunnccttiioonn + is optional. If the ffuunnccttiioonn reserved word is supplied, the + parentheses are optional. The _b_o_d_y of the function is the com- + pound command _c_o_m_p_o_u_n_d_-_c_o_m_m_a_n_d (see CCoommppoouunndd CCoommmmaannddss above). + That command is usually a _l_i_s_t of commands between { and }, but + may be any command listed under CCoommppoouunndd CCoommmmaannddss above, with + one exception: If the ffuunnccttiioonn reserved word is used, but the + parentheses are not supplied, the braces are required. _c_o_m_- + _p_o_u_n_d_-_c_o_m_m_a_n_d is executed whenever _n_a_m_e is specified as the name + of a simple command. When in _p_o_s_i_x _m_o_d_e, _n_a_m_e may not be the + name of one of the POSIX _s_p_e_c_i_a_l _b_u_i_l_t_i_n_s. Any redirections + (see RREEDDIIRREECCTTIIOONN below) specified when a function is defined are + performed when the function is executed. The exit status of a + function definition is zero unless a syntax error occurs or a + readonly function with the same name already exists. When exe- + cuted, the exit status of a function is the exit status of the + last command executed in the body. (See FFUUNNCCTTIIOONNSS below.) + +CCOOMMMMEENNTTSS + In a non-interactive shell, or an interactive shell in which the iinntteerr-- + aaccttiivvee__ccoommmmeennttss option to the sshhoopptt builtin is enabled (see SSHHEELLLL + BBUUIILLTTIINN CCOOMMMMAANNDDSS below), a word beginning with ## causes that word and + all remaining characters on that line to be ignored. An interactive + shell without the iinntteerraaccttiivvee__ccoommmmeennttss option enabled does not allow + comments. The iinntteerraaccttiivvee__ccoommmmeennttss option is on by default in interac- + tive shells. + +QQUUOOTTIINNGG + _Q_u_o_t_i_n_g is used to remove the special meaning of certain characters or + words to the shell. Quoting can be used to disable special treatment + for special characters, to prevent reserved words from being recognized + as such, and to prevent parameter expansion. + + Each of the _m_e_t_a_c_h_a_r_a_c_t_e_r_s listed above under DDEEFFIINNIITTIIOONNSS has special + meaning to the shell and must be quoted if it is to represent itself. + + When the command history expansion facilities are being used (see HHIISS-- + TTOORRYY EEXXPPAANNSSIIOONN below), the _h_i_s_t_o_r_y _e_x_p_a_n_s_i_o_n character, usually !!, must + be quoted to prevent history expansion. + + There are three quoting mechanisms: the _e_s_c_a_p_e _c_h_a_r_a_c_t_e_r, single + quotes, and double quotes. + + A non-quoted backslash (\\) is the _e_s_c_a_p_e _c_h_a_r_a_c_t_e_r. It preserves the + literal value of the next character that follows, with the exception of + . If a \\ pair appears, and the backslash is not + itself quoted, the \\ is treated as a line continuation (that + is, it is removed from the input stream and effectively ignored). + + Enclosing characters in single quotes preserves the literal value of + each character within the quotes. A single quote may not occur between + single quotes, even when preceded by a backslash. + + Enclosing characters in double quotes preserves the literal value of + all characters within the quotes, with the exception of $$, ``, \\, and, + when history expansion is enabled, !!. When the shell is in _p_o_s_i_x _m_o_d_e, + the !! has no special meaning within double quotes, even when history + expansion is enabled. The characters $$ and `` retain their special + meaning within double quotes. The backslash retains its special mean- + ing only when followed by one of the following characters: $$, ``, "", \\, + or <>. A double quote may be quoted within double quotes by + preceding it with a backslash. If enabled, history expansion will be + performed unless an !! appearing in double quotes is escaped using a + backslash. The backslash preceding the !! is not removed. + + The special parameters ** and @@ have special meaning when in double + quotes (see PPAARRAAMMEETTEERRSS below). + + Words of the form $$'_s_t_r_i_n_g' are treated specially. The word expands to + _s_t_r_i_n_g, with backslash-escaped characters replaced as specified by the + ANSI C standard. Backslash escape sequences, if present, are decoded + as follows: + \\aa alert (bell) + \\bb backspace + \\ee + \\EE an escape character + \\ff form feed + \\nn new line + \\rr carriage return + \\tt horizontal tab + \\vv vertical tab + \\\\ backslash + \\'' single quote + \\"" double quote + \\?? question mark + \\_n_n_n the eight-bit character whose value is the octal value + _n_n_n (one to three digits) + \\xx_H_H the eight-bit character whose value is the hexadecimal + value _H_H (one or two hex digits) + \\uu_H_H_H_H the Unicode (ISO/IEC 10646) character whose value is the + hexadecimal value _H_H_H_H (one to four hex digits) + \\UU_H_H_H_H_H_H_H_H + the Unicode (ISO/IEC 10646) character whose value is the + hexadecimal value _H_H_H_H_H_H_H_H (one to eight hex digits) + \\cc_x a control-_x character + + The expanded result is single-quoted, as if the dollar sign had not + been present. + + A double-quoted string preceded by a dollar sign ($$"_s_t_r_i_n_g") will cause + the string to be translated according to the current locale. If the + current locale is CC or PPOOSSIIXX, the dollar sign is ignored. If the + string is translated and replaced, the replacement is double-quoted. + +PPAARRAAMMEETTEERRSS + A _p_a_r_a_m_e_t_e_r is an entity that stores values. It can be a _n_a_m_e, a num- + ber, or one of the special characters listed below under SSppeecciiaall PPaarraamm-- + eetteerrss. A _v_a_r_i_a_b_l_e is a parameter denoted by a _n_a_m_e. A variable has a + _v_a_l_u_e and zero or more _a_t_t_r_i_b_u_t_e_s. Attributes are assigned using the + ddeeccllaarree builtin command (see ddeeccllaarree below in SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS). + + A parameter is set if it has been assigned a value. The null string is + a valid value. Once a variable is set, it may be unset only by using + the uunnsseett builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). + + A _v_a_r_i_a_b_l_e may be assigned to by a statement of the form + + _n_a_m_e=[_v_a_l_u_e] + + If _v_a_l_u_e is not given, the variable is assigned the null string. All + _v_a_l_u_e_s undergo tilde expansion, parameter and variable expansion, com- + mand substitution, arithmetic expansion, and quote removal (see EEXXPPAANN-- + SSIIOONN below). If the variable has its iinntteeggeerr attribute set, then _v_a_l_u_e + is evaluated as an arithmetic expression even if the $((...)) expansion + is not used (see AArriitthhmmeettiicc EExxppaannssiioonn below). Word splitting is not + performed, with the exception of ""$$@@"" as explained below under SSppeecciiaall + PPaarraammeetteerrss. Pathname expansion is not performed. Assignment state- + ments may also appear as arguments to the aalliiaass, ddeeccllaarree, ttyyppeesseett, + eexxppoorrtt, rreeaaddoonnllyy, and llooccaall builtin commands (_d_e_c_l_a_r_a_t_i_o_n commands). + When in _p_o_s_i_x _m_o_d_e, these builtins may appear in a command after one or + more instances of the ccoommmmaanndd builtin and retain these assignment + statement properties. + + In the context where an assignment statement is assigning a value to a + shell variable or array index, the += operator can be used to append to + or add to the variable's previous value. This includes arguments to + builtin commands such as ddeeccllaarree that accept assignment statements + (_d_e_c_l_a_r_a_t_i_o_n commands). When += is applied to a variable for which the + _i_n_t_e_g_e_r attribute has been set, _v_a_l_u_e is evaluated as an arithmetic + expression and added to the variable's current value, which is also + evaluated. When += is applied to an array variable using compound + assignment (see AArrrraayyss below), the variable's value is not unset (as it + is when using =), and new values are appended to the array beginning at + one greater than the array's maximum index (for indexed arrays) or + added as additional key-value pairs in an associative array. When + applied to a string-valued variable, _v_a_l_u_e is expanded and appended to + the variable's value. + + A variable can be assigned the _n_a_m_e_r_e_f attribute using the --nn option to + the ddeeccllaarree or llooccaall builtin commands (see the descriptions of ddeeccllaarree + and llooccaall below) to create a _n_a_m_e_r_e_f, or a reference to another vari- + able. This allows variables to be manipulated indirectly. Whenever + the nameref variable is referenced, assigned to, unset, or has its + attributes modified (other than using or changing the _n_a_m_e_r_e_f attribute + itself), the operation is actually performed on the variable specified + by the nameref variable's value. A nameref is commonly used within + shell functions to refer to a variable whose name is passed as an argu- + ment to the function. For instance, if a variable name is passed to a + shell function as its first argument, running + declare -n ref=$1 + inside the function creates a nameref variable rreeff whose value is the + variable name passed as the first argument. References and assignments + to rreeff, and changes to its attributes, are treated as references, + assignments, and attribute modifications to the variable whose name was + passed as $$11. If the control variable in a ffoorr loop has the nameref + attribute, the list of words can be a list of shell variables, and a + name reference will be established for each word in the list, in turn, + when the loop is executed. Array variables cannot be given the nnaammeerreeff + attribute. However, nameref variables can reference array variables + and subscripted array variables. Namerefs can be unset using the --nn + option to the uunnsseett builtin. Otherwise, if uunnsseett is executed with the + name of a nameref variable as an argument, the variable referenced by + the nameref variable will be unset. + + PPoossiittiioonnaall PPaarraammeetteerrss + A _p_o_s_i_t_i_o_n_a_l _p_a_r_a_m_e_t_e_r is a parameter denoted by one or more digits, + other than the single digit 0. Positional parameters are assigned from + the shell's arguments when it is invoked, and may be reassigned using + the sseett builtin command. Positional parameters may not be assigned to + with assignment statements. The positional parameters are temporarily + replaced when a shell function is executed (see FFUUNNCCTTIIOONNSS below). + + When a positional parameter consisting of more than a single digit is + expanded, it must be enclosed in braces (see EEXXPPAANNSSIIOONN below). + + SSppeecciiaall PPaarraammeetteerrss + The shell treats several parameters specially. These parameters may + only be referenced; assignment to them is not allowed. + ** Expands to the positional parameters, starting from one. When + the expansion is not within double quotes, each positional + parameter expands to a separate word. In contexts where it is + performed, those words are subject to further word splitting and + pathname expansion. When the expansion occurs within double + quotes, it expands to a single word with the value of each + parameter separated by the first character of the IIFFSS special + variable. That is, "$$**" is equivalent to "$$11_c$$22_c......", where _c + is the first character of the value of the IIFFSS variable. If IIFFSS + is unset, the parameters are separated by spaces. If IIFFSS is + null, the parameters are joined without intervening separators. + @@ Expands to the positional parameters, starting from one. When + the expansion occurs within double quotes, each parameter + expands to a separate word. That is, "$$@@" is equivalent to "$$11" + "$$22" ... If the double-quoted expansion occurs within a word, + the expansion of the first parameter is joined with the begin- + ning part of the original word, and the expansion of the last + parameter is joined with the last part of the original word. + When there are no positional parameters, "$$@@" and $$@@ expand to + nothing (i.e., they are removed). + ## Expands to the number of positional parameters in decimal. + ?? Expands to the exit status of the most recently executed fore- + ground pipeline. + -- Expands to the current option flags as specified upon invoca- + tion, by the sseett builtin command, or those set by the shell + itself (such as the --ii option). + $$ Expands to the process ID of the shell. In a () subshell, it + expands to the process ID of the current shell, not the sub- + shell. + !! Expands to the process ID of the job most recently placed into + the background, whether executed as an asynchronous command or + using the bbgg builtin (see JJOOBB CCOONNTTRROOLL below). + 00 Expands to the name of the shell or shell script. This is set + at shell initialization. If bbaasshh is invoked with a file of com- + mands, $$00 is set to the name of that file. If bbaasshh is started + with the --cc option, then $$00 is set to the first argument after + the string to be executed, if one is present. Otherwise, it is + set to the filename used to invoke bbaasshh, as given by argument + zero. + __ At shell startup, set to the absolute pathname used to invoke + the shell or shell script being executed as passed in the envi- + ronment or argument list. Subsequently, expands to the last + argument to the previous command, after expansion. Also set to + the full pathname used to invoke each command executed and + placed in the environment exported to that command. When check- + ing mail, this parameter holds the name of the mail file cur- + rently being checked. + + SShheellll VVaarriiaabblleess + The following variables are set by the shell: + + BBAASSHH Expands to the full filename used to invoke this instance of + bbaasshh. + BBAASSHHOOPPTTSS + A colon-separated list of enabled shell options. Each word in + the list is a valid argument for the --ss option to the sshhoopptt + builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). The options + appearing in BBAASSHHOOPPTTSS are those reported as _o_n by sshhoopptt. If + this variable is in the environment when bbaasshh starts up, each + shell option in the list will be enabled before reading any + startup files. This variable is read-only. + BBAASSHHPPIIDD + Expands to the process ID of the current bbaasshh process. This + differs from $$$$ under certain circumstances, such as subshells + that do not require bbaasshh to be re-initialized. + BBAASSHH__AALLIIAASSEESS + An associative array variable whose members correspond to the + internal list of aliases as maintained by the aalliiaass builtin. + Elements added to this array appear in the alias list; however, + unsetting array elements currently does not cause aliases to be + removed from the alias list. If BBAASSHH__AALLIIAASSEESS is unset, it loses + its special properties, even if it is subsequently reset. + BBAASSHH__AARRGGCC + An array variable whose values are the number of parameters in + each frame of the current bbaasshh execution call stack. The number + of parameters to the current subroutine (shell function or + script executed with .. or ssoouurrccee) is at the top of the stack. + When a subroutine is executed, the number of parameters passed + is pushed onto BBAASSHH__AARRGGCC. The shell sets BBAASSHH__AARRGGCC only when in + extended debugging mode (see the description of the eexxttddeebbuugg + option to the sshhoopptt builtin below) + BBAASSHH__AARRGGVV + An array variable containing all of the parameters in the cur- + rent bbaasshh execution call stack. The final parameter of the last + subroutine call is at the top of the stack; the first parameter + of the initial call is at the bottom. When a subroutine is exe- + cuted, the parameters supplied are pushed onto BBAASSHH__AARRGGVV. The + shell sets BBAASSHH__AARRGGVV only when in extended debugging mode (see + the description of the eexxttddeebbuugg option to the sshhoopptt builtin + below) + BBAASSHH__CCMMDDSS + An associative array variable whose members correspond to the + internal hash table of commands as maintained by the hhaasshh + builtin. Elements added to this array appear in the hash table; + however, unsetting array elements currently does not cause com- + mand names to be removed from the hash table. If BBAASSHH__CCMMDDSS is + unset, it loses its special properties, even if it is subse- + quently reset. + BBAASSHH__CCOOMMMMAANNDD + The command currently being executed or about to be executed, + unless the shell is executing a command as the result of a trap, + in which case it is the command executing at the time of the + trap. + BBAASSHH__EEXXEECCUUTTIIOONN__SSTTRRIINNGG + The command argument to the --cc invocation option. + BBAASSHH__LLIINNEENNOO + An array variable whose members are the line numbers in source + files where each corresponding member of FFUUNNCCNNAAMMEE was invoked. + $${{BBAASSHH__LLIINNEENNOO[[_$_i]]}} is the line number in the source file + ($${{BBAASSHH__SSOOUURRCCEE[[_$_i_+_1]]}}) where $${{FFUUNNCCNNAAMMEE[[_$_i]]}} was called (or + $${{BBAASSHH__LLIINNEENNOO[[_$_i_-_1]]}} if referenced within another shell func- + tion). Use LLIINNEENNOO to obtain the current line number. + BBAASSHH__LLOOAADDAABBLLEESS__PPAATTHH + A colon-separated list of directories in which the shell looks + for dynamically loadable builtins specified by the eennaabbllee com- + mand. + BBAASSHH__RREEMMAATTCCHH + An array variable whose members are assigned by the ==~~ binary + operator to the [[[[ conditional command. The element with index + 0 is the portion of the string matching the entire regular + expression. The element with index _n is the portion of the + string matching the _nth parenthesized subexpression. This vari- + able is read-only. + BBAASSHH__SSOOUURRCCEE + An array variable whose members are the source filenames where + the corresponding shell function names in the FFUUNNCCNNAAMMEE array + variable are defined. The shell function $${{FFUUNNCCNNAAMMEE[[_$_i]]}} is + defined in the file $${{BBAASSHH__SSOOUURRCCEE[[_$_i]]}} and called from + $${{BBAASSHH__SSOOUURRCCEE[[_$_i_+_1]]}}. + BBAASSHH__SSUUBBSSHHEELLLL + Incremented by one within each subshell or subshell environment + when the shell begins executing in that environment. The ini- + tial value is 0. + BBAASSHH__VVEERRSSIINNFFOO + A readonly array variable whose members hold version information + for this instance of bbaasshh. The values assigned to the array + members are as follows: + BBAASSHH__VVEERRSSIINNFFOO[[0]] The major version number (the _r_e_l_e_a_s_e). + BBAASSHH__VVEERRSSIINNFFOO[[1]] The minor version number (the _v_e_r_s_i_o_n). + BBAASSHH__VVEERRSSIINNFFOO[[2]] The patch level. + BBAASSHH__VVEERRSSIINNFFOO[[3]] The build version. + BBAASSHH__VVEERRSSIINNFFOO[[4]] The release status (e.g., _b_e_t_a_1). + BBAASSHH__VVEERRSSIINNFFOO[[5]] The value of MMAACCHHTTYYPPEE. + BBAASSHH__VVEERRSSIIOONN + Expands to a string describing the version of this instance of + bbaasshh. + CCOOMMPP__CCWWOORRDD + An index into $${{CCOOMMPP__WWOORRDDSS}} of the word containing the current + cursor position. This variable is available only in shell func- + tions invoked by the programmable completion facilities (see + PPrrooggrraammmmaabbllee CCoommpplleettiioonn below). + CCOOMMPP__KKEEYY + The key (or final key of a key sequence) used to invoke the cur- + rent completion function. + CCOOMMPP__LLIINNEE + The current command line. This variable is available only in + shell functions and external commands invoked by the program- + mable completion facilities (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn below). + CCOOMMPP__PPOOIINNTT + The index of the current cursor position relative to the begin- + ning of the current command. If the current cursor position is + at the end of the current command, the value of this variable is + equal to $${{##CCOOMMPP__LLIINNEE}}. This variable is available only in + shell functions and external commands invoked by the program- + mable completion facilities (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn below). + CCOOMMPP__TTYYPPEE + Set to an integer value corresponding to the type of completion + attempted that caused a completion function to be called: _T_A_B, + for normal completion, _?, for listing completions after succes- + sive tabs, _!, for listing alternatives on partial word comple- + tion, _@, to list completions if the word is not unmodified, or + _%, for menu completion. This variable is available only in + shell functions and external commands invoked by the program- + mable completion facilities (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn below). + CCOOMMPP__WWOORRDDBBRREEAAKKSS + The set of characters that the rreeaaddlliinnee library treats as word + separators when performing word completion. If CCOOMMPP__WWOORRDDBBRREEAAKKSS + is unset, it loses its special properties, even if it is subse- + quently reset. + CCOOMMPP__WWOORRDDSS + An array variable (see AArrrraayyss below) consisting of the individ- + ual words in the current command line. The line is split into + words as rreeaaddlliinnee would split it, using CCOOMMPP__WWOORRDDBBRREEAAKKSS as + described above. This variable is available only in shell func- + tions invoked by the programmable completion facilities (see + PPrrooggrraammmmaabbllee CCoommpplleettiioonn below). + CCOOPPRROOCC An array variable (see AArrrraayyss below) created to hold the file + descriptors for output from and input to an unnamed coprocess + (see CCoopprroocceesssseess above). + DDIIRRSSTTAACCKK + An array variable (see AArrrraayyss below) containing the current con- + tents of the directory stack. Directories appear in the stack + in the order they are displayed by the ddiirrss builtin. Assigning + to members of this array variable may be used to modify directo- + ries already in the stack, but the ppuusshhdd and ppooppdd builtins must + be used to add and remove directories. Assignment to this vari- + able will not change the current directory. If DDIIRRSSTTAACCKK is + unset, it loses its special properties, even if it is subse- + quently reset. + EEUUIIDD Expands to the effective user ID of the current user, initial- + ized at shell startup. This variable is readonly. + FFUUNNCCNNAAMMEE + An array variable containing the names of all shell functions + currently in the execution call stack. The element with index 0 + is the name of any currently-executing shell function. The bot- + tom-most element (the one with the highest index) is "main". + This variable exists only when a shell function is executing. + Assignments to FFUUNNCCNNAAMMEE have no effect. If FFUUNNCCNNAAMMEE is unset, + it loses its special properties, even if it is subsequently + reset. + + This variable can be used with BBAASSHH__LLIINNEENNOO and BBAASSHH__SSOOUURRCCEE. + Each element of FFUUNNCCNNAAMMEE has corresponding elements in + BBAASSHH__LLIINNEENNOO and BBAASSHH__SSOOUURRCCEE to describe the call stack. For + instance, $${{FFUUNNCCNNAAMMEE[[_$_i]]}} was called from the file + $${{BBAASSHH__SSOOUURRCCEE[[_$_i_+_1]]}} at line number $${{BBAASSHH__LLIINNEENNOO[[_$_i]]}}. The + ccaalllleerr builtin displays the current call stack using this infor- + mation. + GGRROOUUPPSS An array variable containing the list of groups of which the + current user is a member. Assignments to GGRROOUUPPSS have no effect. + If GGRROOUUPPSS is unset, it loses its special properties, even if it + is subsequently reset. + HHIISSTTCCMMDD + The history number, or index in the history list, of the current + command. If HHIISSTTCCMMDD is unset, it loses its special properties, + even if it is subsequently reset. + HHOOSSTTNNAAMMEE + Automatically set to the name of the current host. + HHOOSSTTTTYYPPEE + Automatically set to a string that uniquely describes the type + of machine on which bbaasshh is executing. The default is system- + dependent. + LLIINNEENNOO Each time this parameter is referenced, the shell substitutes a + decimal number representing the current sequential line number + (starting with 1) within a script or function. When not in a + script or function, the value substituted is not guaranteed to + be meaningful. If LLIINNEENNOO is unset, it loses its special proper- + ties, even if it is subsequently reset. + MMAACCHHTTYYPPEE + Automatically set to a string that fully describes the system + type on which bbaasshh is executing, in the standard GNU _c_p_u_-_c_o_m_- + _p_a_n_y_-_s_y_s_t_e_m format. The default is system-dependent. + MMAAPPFFIILLEE + An array variable (see AArrrraayyss below) created to hold the text + read by the mmaappffiillee builtin when no variable name is supplied. + OOLLDDPPWWDD The previous working directory as set by the ccdd command. + OOPPTTAARRGG The value of the last option argument processed by the ggeettooppttss + builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). + OOPPTTIINNDD The index of the next argument to be processed by the ggeettooppttss + builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). + OOSSTTYYPPEE Automatically set to a string that describes the operating sys- + tem on which bbaasshh is executing. The default is system-depen- + dent. + PPIIPPEESSTTAATTUUSS + An array variable (see AArrrraayyss below) containing a list of exit + status values from the processes in the most-recently-executed + foreground pipeline (which may contain only a single command). + PPPPIIDD The process ID of the shell's parent. This variable is read- + only. + PPWWDD The current working directory as set by the ccdd command. + RRAANNDDOOMM Each time this parameter is referenced, a random integer between + 0 and 32767 is generated. The sequence of random numbers may be + initialized by assigning a value to RRAANNDDOOMM. If RRAANNDDOOMM is unset, + it loses its special properties, even if it is subsequently + reset. + RREEAADDLLIINNEE__LLIINNEE + The contents of the rreeaaddlliinnee line buffer, for use with "bind -x" + (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). + RREEAADDLLIINNEE__PPOOIINNTT + The position of the insertion point in the rreeaaddlliinnee line buffer, + for use with "bind -x" (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). + RREEPPLLYY Set to the line of input read by the rreeaadd builtin command when + no arguments are supplied. + SSEECCOONNDDSS + Each time this parameter is referenced, the number of seconds + since shell invocation is returned. If a value is assigned to + SSEECCOONNDDSS, the value returned upon subsequent references is the + number of seconds since the assignment plus the value assigned. + If SSEECCOONNDDSS is unset, it loses its special properties, even if it + is subsequently reset. + SSHHEELLLLOOPPTTSS + A colon-separated list of enabled shell options. Each word in + the list is a valid argument for the --oo option to the sseett + builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). The options + appearing in SSHHEELLLLOOPPTTSS are those reported as _o_n by sseett --oo. If + this variable is in the environment when bbaasshh starts up, each + shell option in the list will be enabled before reading any + startup files. This variable is read-only. + SSHHLLVVLL Incremented by one each time an instance of bbaasshh is started. + UUIIDD Expands to the user ID of the current user, initialized at shell + startup. This variable is readonly. + + The following variables are used by the shell. In some cases, bbaasshh + assigns a default value to a variable; these cases are noted below. + + BBAASSHH__CCOOMMPPAATT + The value is used to set the shell's compatibility level. See + the description of the sshhoopptt builtin below under SSHHEELLLL BBUUIILLTTIINN + CCOOMMMMAANNDDSS for a description of the various compatibility levels + and their effects. The value may be a decimal number (e.g., + 4.2) or an integer (e.g., 42) corresponding to the desired com- + patibility level. If BBAASSHH__CCOOMMPPAATT is unset or set to the empty + string, the compatibility level is set to the default for the + current version. If BBAASSHH__CCOOMMPPAATT is set to a value that is not + one of the valid compatibility levels, the shell prints an error + message and sets the compatibility level to the default for the + current version. The valid compatibility levels correspond to + the compatibility options accepted by the sshhoopptt builtin + described below (for example, ccoommppaatt4422 means that 4.2 and 42 are + valid values). The current version is also a valid value. + BBAASSHH__EENNVV + If this parameter is set when bbaasshh is executing a shell script, + its value is interpreted as a filename containing commands to + initialize the shell, as in _~_/_._b_a_s_h_r_c. The value of BBAASSHH__EENNVV is + subjected to parameter expansion, command substitution, and + arithmetic expansion before being interpreted as a filename. + PPAATTHH is not used to search for the resultant filename. + BBAASSHH__XXTTRRAACCEEFFDD + If set to an integer corresponding to a valid file descriptor, + bbaasshh will write the trace output generated when _s_e_t _-_x is + enabled to that file descriptor. The file descriptor is closed + when BBAASSHH__XXTTRRAACCEEFFDD is unset or assigned a new value. Unsetting + BBAASSHH__XXTTRRAACCEEFFDD or assigning it the empty string causes the trace + output to be sent to the standard error. Note that setting + BBAASSHH__XXTTRRAACCEEFFDD to 2 (the standard error file descriptor) and then + unsetting it will result in the standard error being closed. + CCDDPPAATTHH The search path for the ccdd command. This is a colon-separated + list of directories in which the shell looks for destination + directories specified by the ccdd command. A sample value is + ".:~:/usr". + CCHHIILLDD__MMAAXX + Set the number of exited child status values for the shell to + remember. Bash will not allow this value to be decreased below + a POSIX-mandated minimum, and there is a maximum value (cur- + rently 8192) that this may not exceed. The minimum value is + system-dependent. + CCOOLLUUMMNNSS + Used by the sseelleecctt compound command to determine the terminal + width when printing selection lists. Automatically set if the + cchheecckkwwiinnssiizzee option is enabled or in an interactive shell upon + receipt of a SSIIGGWWIINNCCHH. + CCOOMMPPRREEPPLLYY + An array variable from which bbaasshh reads the possible completions + generated by a shell function invoked by the programmable com- + pletion facility (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn below). Each + array element contains one possible completion. + EEMMAACCSS If bbaasshh finds this variable in the environment when the shell + starts with value "t", it assumes that the shell is running in + an Emacs shell buffer and disables line editing. + EENNVV Similar to BBAASSHH__EENNVV; used when the shell is invoked in POSIX + mode. + EEXXEECCIIGGNNOORREE + A colon-separated list of shell patterns (see PPaatttteerrnn MMaattcchhiinngg) + defining the list of filenames to be ignored by command search + using PPAATTHH. Files whose full pathnames match one of these pat- + terns are not considered executable files for the purposes of + completion and command execution via PPAATTHH lookup. This does not + affect the behavior of the [[, tteesstt, and [[[[ commands. Full path- + names in the command hash table are not subject to EEXXEECCIIGGNNOORREE. + Use this variable to ignore shared library files that have the + executable bit set, but are not executable files. The pattern + matching honors the setting of the eexxttgglloobb shell option. + FFCCEEDDIITT The default editor for the ffcc builtin command. + FFIIGGNNOORREE + A colon-separated list of suffixes to ignore when performing + filename completion (see RREEAADDLLIINNEE below). A filename whose suf- + fix matches one of the entries in FFIIGGNNOORREE is excluded from the + list of matched filenames. A sample value is ".o:~". + FFUUNNCCNNEESSTT + If set to a numeric value greater than 0, defines a maximum + function nesting level. Function invocations that exceed this + nesting level will cause the current command to abort. + GGLLOOBBIIGGNNOORREE + A colon-separated list of patterns defining the set of filenames + to be ignored by pathname expansion. If a filename matched by a + pathname expansion pattern also matches one of the patterns in + GGLLOOBBIIGGNNOORREE, it is removed from the list of matches. + HHIISSTTCCOONNTTRROOLL + A colon-separated list of values controlling how commands are + saved on the history list. If the list of values includes + _i_g_n_o_r_e_s_p_a_c_e, lines which begin with a ssppaaccee character are not + saved in the history list. A value of _i_g_n_o_r_e_d_u_p_s causes lines + matching the previous history entry to not be saved. A value of + _i_g_n_o_r_e_b_o_t_h is shorthand for _i_g_n_o_r_e_s_p_a_c_e and _i_g_n_o_r_e_d_u_p_s. A value + of _e_r_a_s_e_d_u_p_s causes all previous lines matching the current line + to be removed from the history list before that line is saved. + Any value not in the above list is ignored. If HHIISSTTCCOONNTTRROOLL is + unset, or does not include a valid value, all lines read by the + shell parser are saved on the history list, subject to the value + of HHIISSTTIIGGNNOORREE. The second and subsequent lines of a multi-line + compound command are not tested, and are added to the history + regardless of the value of HHIISSTTCCOONNTTRROOLL. + HHIISSTTFFIILLEE + The name of the file in which command history is saved (see HHIISS-- + TTOORRYY below). The default value is _~_/_._b_a_s_h___h_i_s_t_o_r_y. If unset, + the command history is not saved when a shell exits. + HHIISSTTFFIILLEESSIIZZEE + The maximum number of lines contained in the history file. When + this variable is assigned a value, the history file is trun- + cated, if necessary, to contain no more than that number of + lines by removing the oldest entries. The history file is also + truncated to this size after writing it when a shell exits. If + the value is 0, the history file is truncated to zero size. + Non-numeric values and numeric values less than zero inhibit + truncation. The shell sets the default value to the value of + HHIISSTTSSIIZZEE after reading any startup files. + HHIISSTTIIGGNNOORREE + A colon-separated list of patterns used to decide which command + lines should be saved on the history list. Each pattern is + anchored at the beginning of the line and must match the com- + plete line (no implicit `**' is appended). Each pattern is + tested against the line after the checks specified by HHIISSTTCCOONN-- + TTRROOLL are applied. In addition to the normal shell pattern + matching characters, `&&' matches the previous history line. `&&' + may be escaped using a backslash; the backslash is removed + before attempting a match. The second and subsequent lines of a + multi-line compound command are not tested, and are added to the + history regardless of the value of HHIISSTTIIGGNNOORREE. The pattern + matching honors the setting of the eexxttgglloobb shell option. + HHIISSTTSSIIZZEE + The number of commands to remember in the command history (see + HHIISSTTOORRYY below). If the value is 0, commands are not saved in + the history list. Numeric values less than zero result in every + command being saved on the history list (there is no limit). + The shell sets the default value to 500 after reading any + startup files. + HHIISSTTTTIIMMEEFFOORRMMAATT + If this variable is set and not null, its value is used as a + format string for _s_t_r_f_t_i_m_e(3) to print the time stamp associated + with each history entry displayed by the hhiissttoorryy builtin. If + this variable is set, time stamps are written to the history + file so they may be preserved across shell sessions. This uses + the history comment character to distinguish timestamps from + other history lines. + HHOOMMEE The home directory of the current user; the default argument for + the ccdd builtin command. The value of this variable is also used + when performing tilde expansion. + HHOOSSTTFFIILLEE + Contains the name of a file in the same format as _/_e_t_c_/_h_o_s_t_s + that should be read when the shell needs to complete a hostname. + The list of possible hostname completions may be changed while + the shell is running; the next time hostname completion is + attempted after the value is changed, bbaasshh adds the contents of + the new file to the existing list. If HHOOSSTTFFIILLEE is set, but has + no value, or does not name a readable file, bbaasshh attempts to + read _/_e_t_c_/_h_o_s_t_s to obtain the list of possible hostname comple- + tions. When HHOOSSTTFFIILLEE is unset, the hostname list is cleared. + IIFFSS The _I_n_t_e_r_n_a_l _F_i_e_l_d _S_e_p_a_r_a_t_o_r that is used for word splitting + after expansion and to split lines into words with the rreeaadd + builtin command. The default value is ``''. + IIGGNNOORREEEEOOFF + Controls the action of an interactive shell on receipt of an EEOOFF + character as the sole input. If set, the value is the number of + consecutive EEOOFF characters which must be typed as the first + characters on an input line before bbaasshh exits. If the variable + exists but does not have a numeric value, or has no value, the + default value is 10. If it does not exist, EEOOFF signifies the + end of input to the shell. + IINNPPUUTTRRCC + The filename for the rreeaaddlliinnee startup file, overriding the + default of _~_/_._i_n_p_u_t_r_c (see RREEAADDLLIINNEE below). + LLAANNGG Used to determine the locale category for any category not + specifically selected with a variable starting with LLCC__. + LLCC__AALLLL This variable overrides the value of LLAANNGG and any other LLCC__ + variable specifying a locale category. + LLCC__CCOOLLLLAATTEE + This variable determines the collation order used when sorting + the results of pathname expansion, and determines the behavior + of range expressions, equivalence classes, and collating + sequences within pathname expansion and pattern matching. + LLCC__CCTTYYPPEE + This variable determines the interpretation of characters and + the behavior of character classes within pathname expansion and + pattern matching. + LLCC__MMEESSSSAAGGEESS + This variable determines the locale used to translate double- + quoted strings preceded by a $$. + LLCC__NNUUMMEERRIICC + This variable determines the locale category used for number + formatting. + LLCC__TTIIMMEE + This variable determines the locale category used for data and + time formatting. + LLIINNEESS Used by the sseelleecctt compound command to determine the column + length for printing selection lists. Automatically set if the + cchheecckkwwiinnssiizzee option is enabled or in an interactive shell upon + receipt of a SSIIGGWWIINNCCHH. + MMAAIILL If this parameter is set to a file or directory name and the + MMAAIILLPPAATTHH variable is not set, bbaasshh informs the user of the + arrival of mail in the specified file or Maildir-format direc- + tory. + MMAAIILLCCHHEECCKK + Specifies how often (in seconds) bbaasshh checks for mail. The + default is 60 seconds. When it is time to check for mail, the + shell does so before displaying the primary prompt. If this + variable is unset, or set to a value that is not a number + greater than or equal to zero, the shell disables mail checking. + MMAAIILLPPAATTHH + A colon-separated list of filenames to be checked for mail. The + message to be printed when mail arrives in a particular file may + be specified by separating the filename from the message with a + `?'. When used in the text of the message, $$__ expands to the + name of the current mailfile. Example: + MMAAIILLPPAATTHH='/var/mail/bfox?"You have mail":~/shell-mail?"$_ has + mail!"' + BBaasshh can be configured to supply a default value for this vari- + able (there is no value by default), but the location of the + user mail files that it uses is system dependent (e.g., + /var/mail/$$UUSSEERR). + OOPPTTEERRRR If set to the value 1, bbaasshh displays error messages generated by + the ggeettooppttss builtin command (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). + OOPPTTEERRRR is initialized to 1 each time the shell is invoked or a + shell script is executed. + PPAATTHH The search path for commands. It is a colon-separated list of + directories in which the shell looks for commands (see CCOOMMMMAANNDD + EEXXEECCUUTTIIOONN below). A zero-length (null) directory name in the + value of PPAATTHH indicates the current directory. A null directory + name may appear as two adjacent colons, or as an initial or + trailing colon. The default path is system-dependent, and is + set by the administrator who installs bbaasshh. A common value is + ``/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin''. + PPOOSSIIXXLLYY__CCOORRRREECCTT + If this variable is in the environment when bbaasshh starts, the + shell enters _p_o_s_i_x _m_o_d_e before reading the startup files, as if + the ----ppoossiixx invocation option had been supplied. If it is set + while the shell is running, bbaasshh enables _p_o_s_i_x _m_o_d_e, as if the + command _s_e_t _-_o _p_o_s_i_x had been executed. + PPRROOMMPPTT__CCOOMMMMAANNDD + If set, the value is executed as a command prior to issuing each + primary prompt. + PPRROOMMPPTT__DDIIRRTTRRIIMM + If set to a number greater than zero, the value is used as the + number of trailing directory components to retain when expanding + the \\ww and \\WW prompt string escapes (see PPRROOMMPPTTIINNGG below). + Characters removed are replaced with an ellipsis. + PPSS00 The value of this parameter is expanded (see PPRROOMMPPTTIINNGG below) + and displayed by interactive shells after reading a command and + before the command is executed. + PPSS11 The value of this parameter is expanded (see PPRROOMMPPTTIINNGG below) + and used as the primary prompt string. The default value is + ``\\ss--\\vv\\$$ ''. + PPSS22 The value of this parameter is expanded as with PPSS11 and used as + the secondary prompt string. The default is ``>> ''. + PPSS33 The value of this parameter is used as the prompt for the sseelleecctt + command (see SSHHEELLLL GGRRAAMMMMAARR above). + PPSS44 The value of this parameter is expanded as with PPSS11 and the + value is printed before each command bbaasshh displays during an + execution trace. The first character of PPSS44 is replicated mul- + tiple times, as necessary, to indicate multiple levels of indi- + rection. The default is ``++ ''. + SSHHEELLLL The full pathname to the shell is kept in this environment vari- + able. If it is not set when the shell starts, bbaasshh assigns to + it the full pathname of the current user's login shell. + TTIIMMEEFFOORRMMAATT + The value of this parameter is used as a format string specify- + ing how the timing information for pipelines prefixed with the + ttiimmee reserved word should be displayed. The %% character intro- + duces an escape sequence that is expanded to a time value or + other information. The escape sequences and their meanings are + as follows; the braces denote optional portions. + %%%% A literal %%. + %%[[_p]][[ll]]RR The elapsed time in seconds. + %%[[_p]][[ll]]UU The number of CPU seconds spent in user mode. + %%[[_p]][[ll]]SS The number of CPU seconds spent in system mode. + %%PP The CPU percentage, computed as (%U + %S) / %R. + + The optional _p is a digit specifying the _p_r_e_c_i_s_i_o_n, the number + of fractional digits after a decimal point. A value of 0 causes + no decimal point or fraction to be output. At most three places + after the decimal point may be specified; values of _p greater + than 3 are changed to 3. If _p is not specified, the value 3 is + used. + + The optional ll specifies a longer format, including minutes, of + the form _M_Mm_S_S._F_Fs. The value of _p determines whether or not + the fraction is included. + + If this variable is not set, bbaasshh acts as if it had the value + $$''\\nnrreeaall\\tt%%33llRR\\nnuusseerr\\tt%%33llUU\\nnssyyss\\tt%%33llSS''. If the value is null, + no timing information is displayed. A trailing newline is added + when the format string is displayed. + TTMMOOUUTT If set to a value greater than zero, TTMMOOUUTT is treated as the + default timeout for the rreeaadd builtin. The sseelleecctt command termi- + nates if input does not arrive after TTMMOOUUTT seconds when input is + coming from a terminal. In an interactive shell, the value is + interpreted as the number of seconds to wait for a line of input + after issuing the primary prompt. BBaasshh terminates after waiting + for that number of seconds if a complete line of input does not + arrive. + TTMMPPDDIIRR If set, bbaasshh uses its value as the name of a directory in which + bbaasshh creates temporary files for the shell's use. + aauuttoo__rreessuummee + This variable controls how the shell interacts with the user and + job control. If this variable is set, single word simple com- + mands without redirections are treated as candidates for resump- + tion of an existing stopped job. There is no ambiguity allowed; + if there is more than one job beginning with the string typed, + the job most recently accessed is selected. The _n_a_m_e of a + stopped job, in this context, is the command line used to start + it. If set to the value _e_x_a_c_t, the string supplied must match + the name of a stopped job exactly; if set to _s_u_b_s_t_r_i_n_g, the + string supplied needs to match a substring of the name of a + stopped job. The _s_u_b_s_t_r_i_n_g value provides functionality analo- + gous to the %%?? job identifier (see JJOOBB CCOONNTTRROOLL below). If set + to any other value, the supplied string must be a prefix of a + stopped job's name; this provides functionality analogous to the + %%_s_t_r_i_n_g job identifier. + hhiissttcchhaarrss + The two or three characters which control history expansion and + tokenization (see HHIISSTTOORRYY EEXXPPAANNSSIIOONN below). The first character + is the _h_i_s_t_o_r_y _e_x_p_a_n_s_i_o_n character, the character which signals + the start of a history expansion, normally `!!'. The second + character is the _q_u_i_c_k _s_u_b_s_t_i_t_u_t_i_o_n character, which is used as + shorthand for re-running the previous command entered, substi- + tuting one string for another in the command. The default is + `^^'. The optional third character is the character which indi- + cates that the remainder of the line is a comment when found as + the first character of a word, normally `##'. The history com- + ment character causes history substitution to be skipped for the + remaining words on the line. It does not necessarily cause the + shell parser to treat the rest of the line as a comment. + + AArrrraayyss + BBaasshh provides one-dimensional indexed and associative array variables. + Any variable may be used as an indexed array; the ddeeccllaarree builtin will + explicitly declare an array. There is no maximum limit on the size of + an array, nor any requirement that members be indexed or assigned con- + tiguously. Indexed arrays are referenced using integers (including + arithmetic expressions) and are zero-based; associative arrays are ref- + erenced using arbitrary strings. Unless otherwise noted, indexed array + indices must be non-negative integers. + + An indexed array is created automatically if any variable is assigned + to using the syntax _n_a_m_e[_s_u_b_s_c_r_i_p_t]=_v_a_l_u_e. The _s_u_b_s_c_r_i_p_t is treated as + an arithmetic expression that must evaluate to a number. To explicitly + declare an indexed array, use ddeeccllaarree --aa _n_a_m_e (see SSHHEELLLL BBUUIILLTTIINN CCOOMM-- + MMAANNDDSS below). ddeeccllaarree --aa _n_a_m_e[[_s_u_b_s_c_r_i_p_t]] is also accepted; the _s_u_b_- + _s_c_r_i_p_t is ignored. + + Associative arrays are created using ddeeccllaarree --AA _n_a_m_e. + + Attributes may be specified for an array variable using the ddeeccllaarree and + rreeaaddoonnllyy builtins. Each attribute applies to all members of an array. + + Arrays are assigned to using compound assignments of the form + _n_a_m_e=((value_1 ... value_n)), where each _v_a_l_u_e is of the form [_s_u_b_- + _s_c_r_i_p_t]=_s_t_r_i_n_g. Indexed array assignments do not require anything but + _s_t_r_i_n_g. When assigning to indexed arrays, if the optional brackets and + subscript are supplied, that index is assigned to; otherwise the index + of the element assigned is the last index assigned to by the statement + plus one. Indexing starts at zero. + + When assigning to an associative array, the subscript is required. + + This syntax is also accepted by the ddeeccllaarree builtin. Individual array + elements may be assigned to using the _n_a_m_e[_s_u_b_s_c_r_i_p_t]=_v_a_l_u_e syntax + introduced above. When assigning to an indexed array, if _n_a_m_e is sub- + scripted by a negative number, that number is interpreted as relative + to one greater than the maximum index of _n_a_m_e, so negative indices + count back from the end of the array, and an index of -1 references the + last element. + + Any element of an array may be referenced using ${_n_a_m_e[_s_u_b_s_c_r_i_p_t]}. + The braces are required to avoid conflicts with pathname expansion. If + _s_u_b_s_c_r_i_p_t is @@ or **, the word expands to all members of _n_a_m_e. These + subscripts differ only when the word appears within double quotes. If + the word is double-quoted, ${_n_a_m_e[*]} expands to a single word with the + value of each array member separated by the first character of the IIFFSS + special variable, and ${_n_a_m_e[@]} expands each element of _n_a_m_e to a sep- + arate word. When there are no array members, ${_n_a_m_e[@]} expands to + nothing. If the double-quoted expansion occurs within a word, the + expansion of the first parameter is joined with the beginning part of + the original word, and the expansion of the last parameter is joined + with the last part of the original word. This is analogous to the + expansion of the special parameters ** and @@ (see SSppeecciiaall PPaarraammeetteerrss + above). ${#_n_a_m_e[_s_u_b_s_c_r_i_p_t]} expands to the length of ${_n_a_m_e[_s_u_b_- + _s_c_r_i_p_t]}. If _s_u_b_s_c_r_i_p_t is ** or @@, the expansion is the number of ele- + ments in the array. If the _s_u_b_s_c_r_i_p_t used to reference an element of + an indexed array evaluates to a number less than zero, it is inter- + preted as relative to one greater than the maximum index of the array, + so negative indices count back from the end of the array, and an index + of -1 references the last element. + + Referencing an array variable without a subscript is equivalent to ref- + erencing the array with a subscript of 0. Any reference to a variable + using a valid subscript is legal, and bbaasshh will create an array if nec- + essary. + + An array variable is considered set if a subscript has been assigned a + value. The null string is a valid value. + + It is possible to obtain the keys (indices) of an array as well as the + values. ${!!_n_a_m_e[_@]} and ${!!_n_a_m_e[_*]} expand to the indices assigned in + array variable _n_a_m_e. The treatment when in double quotes is similar to + the expansion of the special parameters _@ and _* within double quotes. + + The uunnsseett builtin is used to destroy arrays. uunnsseett _n_a_m_e[_s_u_b_s_c_r_i_p_t] + destroys the array element at index _s_u_b_s_c_r_i_p_t. Negative subscripts to + indexed arrays are interpreted as described above. Care must be taken + to avoid unwanted side effects caused by pathname expansion. uunnsseett + _n_a_m_e, where _n_a_m_e is an array, or uunnsseett _n_a_m_e[_s_u_b_s_c_r_i_p_t], where _s_u_b_s_c_r_i_p_t + is ** or @@, removes the entire array. + + The ddeeccllaarree, llooccaall, and rreeaaddoonnllyy builtins each accept a --aa option to + specify an indexed array and a --AA option to specify an associative + array. If both options are supplied, --AA takes precedence. The rreeaadd + builtin accepts a --aa option to assign a list of words read from the + standard input to an array. The sseett and ddeeccllaarree builtins display array + values in a way that allows them to be reused as assignments. + +EEXXPPAANNSSIIOONN + Expansion is performed on the command line after it has been split into + words. There are seven kinds of expansion performed: _b_r_a_c_e _e_x_p_a_n_s_i_o_n, + _t_i_l_d_e _e_x_p_a_n_s_i_o_n, _p_a_r_a_m_e_t_e_r _a_n_d _v_a_r_i_a_b_l_e _e_x_p_a_n_s_i_o_n, _c_o_m_m_a_n_d _s_u_b_s_t_i_t_u_- + _t_i_o_n, _a_r_i_t_h_m_e_t_i_c _e_x_p_a_n_s_i_o_n, _w_o_r_d _s_p_l_i_t_t_i_n_g, and _p_a_t_h_n_a_m_e _e_x_p_a_n_s_i_o_n. + + The order of expansions is: brace expansion; tilde expansion, parameter + and variable expansion, arithmetic expansion, and command substitution + (done in a left-to-right fashion); word splitting; and pathname expan- + sion. + + On systems that can support it, there is an additional expansion avail- + able: _p_r_o_c_e_s_s _s_u_b_s_t_i_t_u_t_i_o_n. This is performed at the same time as + tilde, parameter, variable, and arithmetic expansion and command sub- + stitution. + + After these expansions are performed, quote characters present in the + original word are removed unless they have been quoted themselves + (_q_u_o_t_e _r_e_m_o_v_a_l). + + Only brace expansion, word splitting, and pathname expansion can change + the number of words of the expansion; other expansions expand a single + word to a single word. The only exceptions to this are the expansions + of "$$@@" and "$${{_n_a_m_e[[@@]]}}" as explained above (see PPAARRAAMMEETTEERRSS). + + BBrraaccee EExxppaannssiioonn + _B_r_a_c_e _e_x_p_a_n_s_i_o_n is a mechanism by which arbitrary strings may be gener- + ated. This mechanism is similar to _p_a_t_h_n_a_m_e _e_x_p_a_n_s_i_o_n, but the file- + names generated need not exist. Patterns to be brace expanded take the + form of an optional _p_r_e_a_m_b_l_e, followed by either a series of comma-sep- + arated strings or a sequence expression between a pair of braces, fol- + lowed by an optional _p_o_s_t_s_c_r_i_p_t. The preamble is prefixed to each + string contained within the braces, and the postscript is then appended + to each resulting string, expanding left to right. + + Brace expansions may be nested. The results of each expanded string + are not sorted; left to right order is preserved. For example, + a{{d,c,b}}e expands into `ade ace abe'. + + A sequence expression takes the form {{_x...._y[[...._i_n_c_r]]}}, where _x and _y are + either integers or single characters, and _i_n_c_r, an optional increment, + is an integer. When integers are supplied, the expression expands to + each number between _x and _y, inclusive. Supplied integers may be pre- + fixed with _0 to force each term to have the same width. When either _x + or _y begins with a zero, the shell attempts to force all generated + terms to contain the same number of digits, zero-padding where neces- + sary. When characters are supplied, the expression expands to each + character lexicographically between _x and _y, inclusive, using the + default C locale. Note that both _x and _y must be of the same type. + When the increment is supplied, it is used as the difference between + each term. The default increment is 1 or -1 as appropriate. + + Brace expansion is performed before any other expansions, and any char- + acters special to other expansions are preserved in the result. It is + strictly textual. BBaasshh does not apply any syntactic interpretation to + the context of the expansion or the text between the braces. + + A correctly-formed brace expansion must contain unquoted opening and + closing braces, and at least one unquoted comma or a valid sequence + expression. Any incorrectly formed brace expansion is left unchanged. + A {{ or ,, may be quoted with a backslash to prevent its being considered + part of a brace expression. To avoid conflicts with parameter expan- + sion, the string $${{ is not considered eligible for brace expansion. + + This construct is typically used as shorthand when the common prefix of + the strings to be generated is longer than in the above example: + + mkdir /usr/local/src/bash/{old,new,dist,bugs} + or + chown root /usr/{ucb/{ex,edit},lib/{ex?.?*,how_ex}} + + Brace expansion introduces a slight incompatibility with historical + versions of sshh. sshh does not treat opening or closing braces specially + when they appear as part of a word, and preserves them in the output. + BBaasshh removes braces from words as a consequence of brace expansion. + For example, a word entered to sshh as _f_i_l_e_{_1_,_2_} appears identically in + the output. The same word is output as _f_i_l_e_1 _f_i_l_e_2 after expansion by + bbaasshh. If strict compatibility with sshh is desired, start bbaasshh with the + ++BB option or disable brace expansion with the ++BB option to the sseett com- + mand (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). + + TTiillddee EExxppaannssiioonn + If a word begins with an unquoted tilde character (`~~'), all of the + characters preceding the first unquoted slash (or all characters, if + there is no unquoted slash) are considered a _t_i_l_d_e_-_p_r_e_f_i_x. If none of + the characters in the tilde-prefix are quoted, the characters in the + tilde-prefix following the tilde are treated as a possible _l_o_g_i_n _n_a_m_e. + If this login name is the null string, the tilde is replaced with the + value of the shell parameter HHOOMMEE. If HHOOMMEE is unset, the home direc- + tory of the user executing the shell is substituted instead. Other- + wise, the tilde-prefix is replaced with the home directory associated + with the specified login name. + + If the tilde-prefix is a `~+', the value of the shell variable PPWWDD + replaces the tilde-prefix. If the tilde-prefix is a `~-', the value of + the shell variable OOLLDDPPWWDD, if it is set, is substituted. If the char- + acters following the tilde in the tilde-prefix consist of a number _N, + optionally prefixed by a `+' or a `-', the tilde-prefix is replaced + with the corresponding element from the directory stack, as it would be + displayed by the ddiirrss builtin invoked with the tilde-prefix as an argu- + ment. If the characters following the tilde in the tilde-prefix con- + sist of a number without a leading `+' or `-', `+' is assumed. + + If the login name is invalid, or the tilde expansion fails, the word is + unchanged. + + Each variable assignment is checked for unquoted tilde-prefixes immedi- + ately following a :: or the first ==. In these cases, tilde expansion is + also performed. Consequently, one may use filenames with tildes in + assignments to PPAATTHH, MMAAIILLPPAATTHH, and CCDDPPAATTHH, and the shell assigns the + expanded value. + + PPaarraammeetteerr EExxppaannssiioonn + The `$$' character introduces parameter expansion, command substitution, + or arithmetic expansion. The parameter name or symbol to be expanded + may be enclosed in braces, which are optional but serve to protect the + variable to be expanded from characters immediately following it which + could be interpreted as part of the name. + + When braces are used, the matching ending brace is the first `}}' not + escaped by a backslash or within a quoted string, and not within an + embedded arithmetic expansion, command substitution, or parameter + expansion. + + ${_p_a_r_a_m_e_t_e_r} + The value of _p_a_r_a_m_e_t_e_r is substituted. The braces are required + when _p_a_r_a_m_e_t_e_r is a positional parameter with more than one + digit, or when _p_a_r_a_m_e_t_e_r is followed by a character which is not + to be interpreted as part of its name. The _p_a_r_a_m_e_t_e_r is a shell + parameter as described above PPAARRAAMMEETTEERRSS) or an array reference + (AArrrraayyss). + + If the first character of _p_a_r_a_m_e_t_e_r is an exclamation point (!!), and + _p_a_r_a_m_e_t_e_r is not a _n_a_m_e_r_e_f, it introduces a level of variable indirec- + tion. BBaasshh uses the value of the variable formed from the rest of + _p_a_r_a_m_e_t_e_r as the name of the variable; this variable is then expanded + and that value is used in the rest of the substitution, rather than the + value of _p_a_r_a_m_e_t_e_r itself. This is known as _i_n_d_i_r_e_c_t _e_x_p_a_n_s_i_o_n. If + _p_a_r_a_m_e_t_e_r is a nameref, this expands to the name of the variable refer- + enced by _p_a_r_a_m_e_t_e_r instead of performing the complete indirect expan- + sion. The exceptions to this are the expansions of ${!!_p_r_e_f_i_x**} and + ${!!_n_a_m_e[_@]} described below. The exclamation point must immediately + follow the left brace in order to introduce indirection. + + In each of the cases below, _w_o_r_d is subject to tilde expansion, parame- + ter expansion, command substitution, and arithmetic expansion. + + When not performing substring expansion, using the forms documented + below (e.g., ::--), bbaasshh tests for a parameter that is unset or null. + Omitting the colon results in a test only for a parameter that is + unset. + + ${_p_a_r_a_m_e_t_e_r::--_w_o_r_d} + UUssee DDeeffaauulltt VVaalluueess. If _p_a_r_a_m_e_t_e_r is unset or null, the expan- + sion of _w_o_r_d is substituted. Otherwise, the value of _p_a_r_a_m_e_t_e_r + is substituted. + ${_p_a_r_a_m_e_t_e_r::==_w_o_r_d} + AAssssiiggnn DDeeffaauulltt VVaalluueess. If _p_a_r_a_m_e_t_e_r is unset or null, the + expansion of _w_o_r_d is assigned to _p_a_r_a_m_e_t_e_r. The value of _p_a_r_a_m_- + _e_t_e_r is then substituted. Positional parameters and special + parameters may not be assigned to in this way. + ${_p_a_r_a_m_e_t_e_r::??_w_o_r_d} + DDiissppllaayy EErrrroorr iiff NNuullll oorr UUnnsseett. If _p_a_r_a_m_e_t_e_r is null or unset, + the expansion of _w_o_r_d (or a message to that effect if _w_o_r_d is + not present) is written to the standard error and the shell, if + it is not interactive, exits. Otherwise, the value of _p_a_r_a_m_e_t_e_r + is substituted. + ${_p_a_r_a_m_e_t_e_r::++_w_o_r_d} + UUssee AAlltteerrnnaattee VVaalluuee. If _p_a_r_a_m_e_t_e_r is null or unset, nothing is + substituted, otherwise the expansion of _w_o_r_d is substituted. + ${_p_a_r_a_m_e_t_e_r::_o_f_f_s_e_t} + ${_p_a_r_a_m_e_t_e_r::_o_f_f_s_e_t::_l_e_n_g_t_h} + SSuubbssttrriinngg EExxppaannssiioonn. Expands to up to _l_e_n_g_t_h characters of the + value of _p_a_r_a_m_e_t_e_r starting at the character specified by _o_f_f_- + _s_e_t. If _p_a_r_a_m_e_t_e_r is @@, an indexed array subscripted by @@ or **, + or an associative array name, the results differ as described + below. If _l_e_n_g_t_h is omitted, expands to the substring of the + value of _p_a_r_a_m_e_t_e_r starting at the character specified by _o_f_f_s_e_t + and extending to the end of the value. _l_e_n_g_t_h and _o_f_f_s_e_t are + arithmetic expressions (see AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN below). + + If _o_f_f_s_e_t evaluates to a number less than zero, the value is + used as an offset in characters from the end of the value of + _p_a_r_a_m_e_t_e_r. If _l_e_n_g_t_h evaluates to a number less than zero, it + is interpreted as an offset in characters from the end of the + value of _p_a_r_a_m_e_t_e_r rather than a number of characters, and the + expansion is the characters between _o_f_f_s_e_t and that result. + Note that a negative offset must be separated from the colon by + at least one space to avoid being confused with the ::-- expan- + sion. + + If _p_a_r_a_m_e_t_e_r is @@, the result is _l_e_n_g_t_h positional parameters + beginning at _o_f_f_s_e_t. A negative _o_f_f_s_e_t is taken relative to one + greater than the greatest positional parameter, so an offset of + -1 evaluates to the last positional parameter. It is an expan- + sion error if _l_e_n_g_t_h evaluates to a number less than zero. + + If _p_a_r_a_m_e_t_e_r is an indexed array name subscripted by @ or *, the + result is the _l_e_n_g_t_h members of the array beginning with + ${_p_a_r_a_m_e_t_e_r[_o_f_f_s_e_t]}. A negative _o_f_f_s_e_t is taken relative to + one greater than the maximum index of the specified array. It + is an expansion error if _l_e_n_g_t_h evaluates to a number less than + zero. + + Substring expansion applied to an associative array produces + undefined results. + + Substring indexing is zero-based unless the positional parame- + ters are used, in which case the indexing starts at 1 by + default. If _o_f_f_s_e_t is 0, and the positional parameters are + used, $$00 is prefixed to the list. + + ${!!_p_r_e_f_i_x**} + ${!!_p_r_e_f_i_x@@} + NNaammeess mmaattcchhiinngg pprreeffiixx. Expands to the names of variables whose + names begin with _p_r_e_f_i_x, separated by the first character of the + IIFFSS special variable. When _@ is used and the expansion appears + within double quotes, each variable name expands to a separate + word. + + ${!!_n_a_m_e[_@]} + ${!!_n_a_m_e[_*]} + LLiisstt ooff aarrrraayy kkeeyyss. If _n_a_m_e is an array variable, expands to + the list of array indices (keys) assigned in _n_a_m_e. If _n_a_m_e is + not an array, expands to 0 if _n_a_m_e is set and null otherwise. + When _@ is used and the expansion appears within double quotes, + each key expands to a separate word. + + ${##_p_a_r_a_m_e_t_e_r} + PPaarraammeetteerr lleennggtthh. The length in characters of the value of + _p_a_r_a_m_e_t_e_r is substituted. If _p_a_r_a_m_e_t_e_r is ** or @@, the value + substituted is the number of positional parameters. If _p_a_r_a_m_e_- + _t_e_r is an array name subscripted by ** or @@, the value substi- + tuted is the number of elements in the array. If _p_a_r_a_m_e_t_e_r is + an indexed array name subscripted by a negative number, that + number is interpreted as relative to one greater than the maxi- + mum index of _p_a_r_a_m_e_t_e_r, so negative indices count back from the + end of the array, and an index of -1 references the last ele- + ment. + + ${_p_a_r_a_m_e_t_e_r##_w_o_r_d} + ${_p_a_r_a_m_e_t_e_r####_w_o_r_d} + RReemmoovvee mmaattcchhiinngg pprreeffiixx ppaatttteerrnn. The _w_o_r_d is expanded to produce + a pattern just as in pathname expansion. If the pattern matches + the beginning of the value of _p_a_r_a_m_e_t_e_r, then the result of the + expansion is the expanded value of _p_a_r_a_m_e_t_e_r with the shortest + matching pattern (the ``##'' case) or the longest matching pat- + tern (the ``####'' case) deleted. If _p_a_r_a_m_e_t_e_r is @@ or **, the + pattern removal operation is applied to each positional parame- + ter in turn, and the expansion is the resultant list. If _p_a_r_a_m_- + _e_t_e_r is an array variable subscripted with @@ or **, the pattern + removal operation is applied to each member of the array in + turn, and the expansion is the resultant list. + + ${_p_a_r_a_m_e_t_e_r%%_w_o_r_d} + ${_p_a_r_a_m_e_t_e_r%%%%_w_o_r_d} + RReemmoovvee mmaattcchhiinngg ssuuffffiixx ppaatttteerrnn. The _w_o_r_d is expanded to produce + a pattern just as in pathname expansion. If the pattern matches + a trailing portion of the expanded value of _p_a_r_a_m_e_t_e_r, then the + result of the expansion is the expanded value of _p_a_r_a_m_e_t_e_r with + the shortest matching pattern (the ``%%'' case) or the longest + matching pattern (the ``%%%%'' case) deleted. If _p_a_r_a_m_e_t_e_r is @@ + or **, the pattern removal operation is applied to each posi- + tional parameter in turn, and the expansion is the resultant + list. If _p_a_r_a_m_e_t_e_r is an array variable subscripted with @@ or + **, the pattern removal operation is applied to each member of + the array in turn, and the expansion is the resultant list. + + ${_p_a_r_a_m_e_t_e_r//_p_a_t_t_e_r_n//_s_t_r_i_n_g} + PPaatttteerrnn ssuubbssttiittuuttiioonn. The _p_a_t_t_e_r_n is expanded to produce a pat- + tern just as in pathname expansion. _P_a_r_a_m_e_t_e_r is expanded and + the longest match of _p_a_t_t_e_r_n against its value is replaced with + _s_t_r_i_n_g. If _p_a_t_t_e_r_n begins with //, all matches of _p_a_t_t_e_r_n are + replaced with _s_t_r_i_n_g. Normally only the first match is + replaced. If _p_a_t_t_e_r_n begins with ##, it must match at the begin- + ning of the expanded value of _p_a_r_a_m_e_t_e_r. If _p_a_t_t_e_r_n begins with + %%, it must match at the end of the expanded value of _p_a_r_a_m_e_t_e_r. + If _s_t_r_i_n_g is null, matches of _p_a_t_t_e_r_n are deleted and the // fol- + lowing _p_a_t_t_e_r_n may be omitted. If the nnooccaasseemmaattcchh shell option + is enabled, the match is performed without regard to the case of + alphabetic characters. If _p_a_r_a_m_e_t_e_r is @@ or **, the substitution + operation is applied to each positional parameter in turn, and + the expansion is the resultant list. If _p_a_r_a_m_e_t_e_r is an array + variable subscripted with @@ or **, the substitution operation is + applied to each member of the array in turn, and the expansion + is the resultant list. + + ${_p_a_r_a_m_e_t_e_r^^_p_a_t_t_e_r_n} + ${_p_a_r_a_m_e_t_e_r^^^^_p_a_t_t_e_r_n} + ${_p_a_r_a_m_e_t_e_r,,_p_a_t_t_e_r_n} + ${_p_a_r_a_m_e_t_e_r,,,,_p_a_t_t_e_r_n} + CCaassee mmooddiiffiiccaattiioonn. This expansion modifies the case of alpha- + betic characters in _p_a_r_a_m_e_t_e_r. The _p_a_t_t_e_r_n is expanded to pro- + duce a pattern just as in pathname expansion. Each character in + the expanded value of _p_a_r_a_m_e_t_e_r is tested against _p_a_t_t_e_r_n, and, + if it matches the pattern, its case is converted. The pattern + should not attempt to match more than one character. The ^^ + operator converts lowercase letters matching _p_a_t_t_e_r_n to upper- + case; the ,, operator converts matching uppercase letters to low- + ercase. The ^^^^ and ,,,, expansions convert each matched character + in the expanded value; the ^^ and ,, expansions match and convert + only the first character in the expanded value. If _p_a_t_t_e_r_n is + omitted, it is treated like a ??, which matches every character. + If _p_a_r_a_m_e_t_e_r is @@ or **, the case modification operation is + applied to each positional parameter in turn, and the expansion + is the resultant list. If _p_a_r_a_m_e_t_e_r is an array variable sub- + scripted with @@ or **, the case modification operation is applied + to each member of the array in turn, and the expansion is the + resultant list. + + ${_p_a_r_a_m_e_t_e_r@@_o_p_e_r_a_t_o_r} + PPaarraammeetteerr ttrraannssffoorrmmaattiioonn. The expansion is either a transforma- + tion of the value of _p_a_r_a_m_e_t_e_r or information about _p_a_r_a_m_e_t_e_r + itself, depending on the value of _o_p_e_r_a_t_o_r. Each _o_p_e_r_a_t_o_r is a + single letter: + + QQ The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r + quoted in a format that can be reused as input. + EE The expansion is a string that is the value of _p_a_r_a_m_e_t_e_r + with backslash escape sequences expanded as with the + $$''......'' quoting mechansim. + PP The expansion is a string that is the result of expanding + the value of _p_a_r_a_m_e_t_e_r as if it were a prompt string (see + PPRROOMMPPTTIINNGG below). + AA The expansion is a string in the form of an assignment + statement or ddeeccllaarree command that, if evaluated, will + recreate _p_a_r_a_m_e_t_e_r with its attributes and value. + aa The expansion is a string consisting of flag values rep- + resenting _p_a_r_a_m_e_t_e_r's attributes. + + If _p_a_r_a_m_e_t_e_r is @@ or **, the operation is applied to each posi- + tional parameter in turn, and the expansion is the resultant + list. If _p_a_r_a_m_e_t_e_r is an array variable subscripted with @@ or + **, the case modification operation is applied to each member of + the array in turn, and the expansion is the resultant list. + + The result of the expansion is subject to word splitting and + pathname expansion as described below. + + CCoommmmaanndd SSuubbssttiittuuttiioonn + _C_o_m_m_a_n_d _s_u_b_s_t_i_t_u_t_i_o_n allows the output of a command to replace the com- + mand name. There are two forms: + + $$((_c_o_m_m_a_n_d)) + or + ``_c_o_m_m_a_n_d`` + + BBaasshh performs the expansion by executing _c_o_m_m_a_n_d in a subshell environ- + ment and replacing the command substitution with the standard output of + the command, with any trailing newlines deleted. Embedded newlines are + not deleted, but they may be removed during word splitting. The com- + mand substitution $$((ccaatt _f_i_l_e)) can be replaced by the equivalent but + faster $$((<< _f_i_l_e)). + + When the old-style backquote form of substitution is used, backslash + retains its literal meaning except when followed by $$, ``, or \\. The + first backquote not preceded by a backslash terminates the command sub- + stitution. When using the $(_c_o_m_m_a_n_d) form, all characters between the + parentheses make up the command; none are treated specially. + + Command substitutions may be nested. To nest when using the backquoted + form, escape the inner backquotes with backslashes. + + If the substitution appears within double quotes, word splitting and + pathname expansion are not performed on the results. + + AArriitthhmmeettiicc EExxppaannssiioonn + Arithmetic expansion allows the evaluation of an arithmetic expression + and the substitution of the result. The format for arithmetic expan- + sion is: + + $$((((_e_x_p_r_e_s_s_i_o_n)))) + + The _e_x_p_r_e_s_s_i_o_n is treated as if it were within double quotes, but a + double quote inside the parentheses is not treated specially. All + tokens in the expression undergo parameter and variable expansion, com- + mand substitution, and quote removal. The result is treated as the + arithmetic expression to be evaluated. Arithmetic expansions may be + nested. + + The evaluation is performed according to the rules listed below under + AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN. If _e_x_p_r_e_s_s_i_o_n is invalid, bbaasshh prints a message + indicating failure and no substitution occurs. + + PPrroocceessss SSuubbssttiittuuttiioonn + _P_r_o_c_e_s_s _s_u_b_s_t_i_t_u_t_i_o_n allows a process's input or output to be referred + to using a filename. It takes the form of <<((_l_i_s_t)) or >>((_l_i_s_t)). The + process _l_i_s_t is run asynchronously, and its input or output appears as + a filename. This filename is passed as an argument to the current com- + mand as the result of the expansion. If the >>((_l_i_s_t)) form is used, + writing to the file will provide input for _l_i_s_t. If the <<((_l_i_s_t)) form + is used, the file passed as an argument should be read to obtain the + output of _l_i_s_t. Process substitution is supported on systems that sup- + port named pipes (_F_I_F_O_s) or the //ddeevv//ffdd method of naming open files. + + When available, process substitution is performed simultaneously with + parameter and variable expansion, command substitution, and arithmetic + expansion. + + WWoorrdd SSpplliittttiinngg + The shell scans the results of parameter expansion, command substitu- + tion, and arithmetic expansion that did not occur within double quotes + for _w_o_r_d _s_p_l_i_t_t_i_n_g. + + The shell treats each character of IIFFSS as a delimiter, and splits the + results of the other expansions into words using these characters as + field terminators. If IIFFSS is unset, or its value is exactly + <><><>, the default, then sequences of <>, <>, + and <> at the beginning and end of the results of the previous + expansions are ignored, and any sequence of IIFFSS characters not at the + beginning or end serves to delimit words. If IIFFSS has a value other + than the default, then sequences of the whitespace characters ssppaaccee, + ttaabb, and nneewwlliinnee are ignored at the beginning and end of the word, as + long as the whitespace character is in the value of IIFFSS (an IIFFSS white- + space character). Any character in IIFFSS that is not IIFFSS whitespace, + along with any adjacent IIFFSS whitespace characters, delimits a field. A + sequence of IIFFSS whitespace characters is also treated as a delimiter. + If the value of IIFFSS is null, no word splitting occurs. + + Explicit null arguments ("""" or '''') are retained and passed to commands + as empty strings. Unquoted implicit null arguments, resulting from the + expansion of parameters that have no values, are removed. If a parame- + ter with no value is expanded within double quotes, a null argument + results and is retained and passed to a command as an empty string. + When a quoted null argument appears as part of a word whose expansion + is non-null, the null argument is removed. That is, the word -d'' + becomes -d after word splitting and null argument removal. + + Note that if no expansion occurs, no splitting is performed. + + PPaatthhnnaammee EExxppaannssiioonn + After word splitting, unless the --ff option has been set, bbaasshh scans + each word for the characters **, ??, and [[. If one of these characters + appears, then the word is regarded as a _p_a_t_t_e_r_n, and replaced with an + alphabetically sorted list of filenames matching the pattern (see PPaatt-- + tteerrnn MMaattcchhiinngg below). If no matching filenames are found, and the + shell option nnuullllgglloobb is not enabled, the word is left unchanged. If + the nnuullllgglloobb option is set, and no matches are found, the word is + removed. If the ffaaiillgglloobb shell option is set, and no matches are + found, an error message is printed and the command is not executed. If + the shell option nnooccaasseegglloobb is enabled, the match is performed without + regard to the case of alphabetic characters. When a pattern is used + for pathname expansion, the character ````..'''' at the start of a name or + immediately following a slash must be matched explicitly, unless the + shell option ddoottgglloobb is set. When matching a pathname, the slash char- + acter must always be matched explicitly. In other cases, the ````..'''' + character is not treated specially. See the description of sshhoopptt below + under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS for a description of the nnooccaasseegglloobb, nnuullll-- + gglloobb, ffaaiillgglloobb, and ddoottgglloobb shell options. + + The GGLLOOBBIIGGNNOORREE shell variable may be used to restrict the set of file- + names matching a _p_a_t_t_e_r_n. If GGLLOOBBIIGGNNOORREE is set, each matching filename + that also matches one of the patterns in GGLLOOBBIIGGNNOORREE is removed from the + list of matches. If the nnooccaasseegglloobb option is set, the matching against + the patterns in GGLLOOBBIIGGNNOORREE is performed without regard to case. The + filenames ````..'''' and ````....'''' are always ignored when GGLLOOBBIIGGNNOORREE is set + and not null. However, setting GGLLOOBBIIGGNNOORREE to a non-null value has the + effect of enabling the ddoottgglloobb shell option, so all other filenames + beginning with a ````..'''' will match. To get the old behavior of ignor- + ing filenames beginning with a ````..'''', make ````..**'''' one of the patterns + in GGLLOOBBIIGGNNOORREE. The ddoottgglloobb option is disabled when GGLLOOBBIIGGNNOORREE is + unset. The pattern matching honors the setting of the eexxttgglloobb shell + option. + + PPaatttteerrnn MMaattcchhiinngg + + Any character that appears in a pattern, other than the special pattern + characters described below, matches itself. The NUL character may not + occur in a pattern. A backslash escapes the following character; the + escaping backslash is discarded when matching. The special pattern + characters must be quoted if they are to be matched literally. + + The special pattern characters have the following meanings: + + ** Matches any string, including the null string. When the + gglloobbssttaarr shell option is enabled, and ** is used in a + pathname expansion context, two adjacent **s used as a + single pattern will match all files and zero or more + directories and subdirectories. If followed by a //, two + adjacent **s will match only directories and subdirecto- + ries. + ?? Matches any single character. + [[......]] Matches any one of the enclosed characters. A pair of + characters separated by a hyphen denotes a _r_a_n_g_e _e_x_p_r_e_s_- + _s_i_o_n; any character that falls between those two charac- + ters, inclusive, using the current locale's collating + sequence and character set, is matched. If the first + character following the [[ is a !! or a ^^ then any charac- + ter not enclosed is matched. The sorting order of char- + acters in range expressions is determined by the current + locale and the values of the LLCC__CCOOLLLLAATTEE or LLCC__AALLLL shell + variables, if set. To obtain the traditional interpreta- + tion of range expressions, where [[aa--dd]] is equivalent to + [[aabbccdd]], set value of the LLCC__AALLLL shell variable to CC, or + enable the gglloobbaasscciiiirraannggeess shell option. A -- may be + matched by including it as the first or last character in + the set. A ]] may be matched by including it as the first + character in the set. + + Within [[ and ]], _c_h_a_r_a_c_t_e_r _c_l_a_s_s_e_s can be specified using + the syntax [[::_c_l_a_s_s::]], where _c_l_a_s_s is one of the following + classes defined in the POSIX standard: + aallnnuumm aallpphhaa aasscciiii bbllaannkk ccnnttrrll ddiiggiitt ggrraapphh lloowweerr pprriinntt + ppuunncctt ssppaaccee uuppppeerr wwoorrdd xxddiiggiitt + A character class matches any character belonging to that + class. The wwoorrdd character class matches letters, digits, + and the character _. + + Within [[ and ]], an _e_q_u_i_v_a_l_e_n_c_e _c_l_a_s_s can be specified + using the syntax [[==_c==]], which matches all characters with + the same collation weight (as defined by the current + locale) as the character _c. + + Within [[ and ]], the syntax [[.._s_y_m_b_o_l..]] matches the collat- + ing symbol _s_y_m_b_o_l. + + If the eexxttgglloobb shell option is enabled using the sshhoopptt builtin, several + extended pattern matching operators are recognized. In the following + description, a _p_a_t_t_e_r_n_-_l_i_s_t is a list of one or more patterns separated + by a ||. Composite patterns may be formed using one or more of the fol- + lowing sub-patterns: + + ??((_p_a_t_t_e_r_n_-_l_i_s_t)) + Matches zero or one occurrence of the given patterns + **((_p_a_t_t_e_r_n_-_l_i_s_t)) + Matches zero or more occurrences of the given patterns + ++((_p_a_t_t_e_r_n_-_l_i_s_t)) + Matches one or more occurrences of the given patterns + @@((_p_a_t_t_e_r_n_-_l_i_s_t)) + Matches one of the given patterns + !!((_p_a_t_t_e_r_n_-_l_i_s_t)) + Matches anything except one of the given patterns + + QQuuoottee RReemmoovvaall + After the preceding expansions, all unquoted occurrences of the charac- + ters \\, '', and "" that did not result from one of the above expansions + are removed. + +RREEDDIIRREECCTTIIOONN + Before a command is executed, its input and output may be _r_e_d_i_r_e_c_t_e_d + using a special notation interpreted by the shell. Redirection allows + commands' file handles to be duplicated, opened, closed, made to refer + to different files, and can change the files the command reads from and + writes to. Redirection may also be used to modify file handles in the + current shell execution environment. The following redirection opera- + tors may precede or appear anywhere within a _s_i_m_p_l_e _c_o_m_m_a_n_d or may fol- + low a _c_o_m_m_a_n_d. Redirections are processed in the order they appear, + from left to right. + + Each redirection that may be preceded by a file descriptor number may + instead be preceded by a word of the form {_v_a_r_n_a_m_e}. In this case, for + each redirection operator except >&- and <&-, the shell will allocate a + file descriptor greater than or equal to 10 and assign it to _v_a_r_n_a_m_e. + If >&- or <&- is preceded by {_v_a_r_n_a_m_e}, the value of _v_a_r_n_a_m_e defines + the file descriptor to close. + + In the following descriptions, if the file descriptor number is omit- + ted, and the first character of the redirection operator is <<, the re- + direction refers to the standard input (file descriptor 0). If the + first character of the redirection operator is >>, the redirection + refers to the standard output (file descriptor 1). + + The word following the redirection operator in the following descrip- + tions, unless otherwise noted, is subjected to brace expansion, tilde + expansion, parameter and variable expansion, command substitution, + arithmetic expansion, quote removal, pathname expansion, and word + splitting. If it expands to more than one word, bbaasshh reports an error. + + Note that the order of redirections is significant. For example, the + command + + ls >> dirlist 2>>&&1 + + directs both standard output and standard error to the file _d_i_r_l_i_s_t, + while the command + + ls 2>>&&1 >> dirlist + + directs only the standard output to file _d_i_r_l_i_s_t, because the standard + error was duplicated from the standard output before the standard out- + put was redirected to _d_i_r_l_i_s_t. + + BBaasshh handles several filenames specially when they are used in redirec- + tions, as described in the following table. If the operating system on + which bbaasshh is running provides these special files, bash will use them; + otherwise it will emulate them internally with the behavior described + below. + + //ddeevv//ffdd//_f_d + If _f_d is a valid integer, file descriptor _f_d is dupli- + cated. + //ddeevv//ssttddiinn + File descriptor 0 is duplicated. + //ddeevv//ssttddoouutt + File descriptor 1 is duplicated. + //ddeevv//ssttddeerrrr + File descriptor 2 is duplicated. + //ddeevv//ttccpp//_h_o_s_t//_p_o_r_t + If _h_o_s_t is a valid hostname or Internet address, and _p_o_r_t + is an integer port number or service name, bbaasshh attempts + to open the corresponding TCP socket. + //ddeevv//uuddpp//_h_o_s_t//_p_o_r_t + If _h_o_s_t is a valid hostname or Internet address, and _p_o_r_t + is an integer port number or service name, bbaasshh attempts + to open the corresponding UDP socket. + + A failure to open or create a file causes the redirection to fail. + + Redirections using file descriptors greater than 9 should be used with + care, as they may conflict with file descriptors the shell uses inter- + nally. + + RReeddiirreeccttiinngg IInnppuutt + Redirection of input causes the file whose name results from the expan- + sion of _w_o_r_d to be opened for reading on file descriptor _n, or the + standard input (file descriptor 0) if _n is not specified. + + The general format for redirecting input is: + + [_n]<<_w_o_r_d + + RReeddiirreeccttiinngg OOuuttppuutt + Redirection of output causes the file whose name results from the + expansion of _w_o_r_d to be opened for writing on file descriptor _n, or the + standard output (file descriptor 1) if _n is not specified. If the file + does not exist it is created; if it does exist it is truncated to zero + size. + + The general format for redirecting output is: + + [_n]>>_w_o_r_d + + If the redirection operator is >>, and the nnoocclloobbbbeerr option to the sseett + builtin has been enabled, the redirection will fail if the file whose + name results from the expansion of _w_o_r_d exists and is a regular file. + If the redirection operator is >>||, or the redirection operator is >> and + the nnoocclloobbbbeerr option to the sseett builtin command is not enabled, the re- + direction is attempted even if the file named by _w_o_r_d exists. + + AAppppeennddiinngg RReeddiirreecctteedd OOuuttppuutt + Redirection of output in this fashion causes the file whose name + results from the expansion of _w_o_r_d to be opened for appending on file + descriptor _n, or the standard output (file descriptor 1) if _n is not + specified. If the file does not exist it is created. + + The general format for appending output is: + + [_n]>>>>_w_o_r_d + + RReeddiirreeccttiinngg SSttaannddaarrdd OOuuttppuutt aanndd SSttaannddaarrdd EErrrroorr + This construct allows both the standard output (file descriptor 1) and + the standard error output (file descriptor 2) to be redirected to the + file whose name is the expansion of _w_o_r_d. + + There are two formats for redirecting standard output and standard + error: + + &&>>_w_o_r_d + and + >>&&_w_o_r_d + + Of the two forms, the first is preferred. This is semantically equiva- + lent to + + >>_w_o_r_d 2>>&&1 + + When using the second form, _w_o_r_d may not expand to a number or --. If + it does, other redirection operators apply (see DDuupplliiccaattiinngg FFiillee + DDeessccrriippttoorrss below) for compatibility reasons. + + AAppppeennddiinngg SSttaannddaarrdd OOuuttppuutt aanndd SSttaannddaarrdd EErrrroorr + This construct allows both the standard output (file descriptor 1) and + the standard error output (file descriptor 2) to be appended to the + file whose name is the expansion of _w_o_r_d. + + The format for appending standard output and standard error is: + + &&>>>>_w_o_r_d + + This is semantically equivalent to + + >>>>_w_o_r_d 2>>&&1 + + (see DDuupplliiccaattiinngg FFiillee DDeessccrriippttoorrss below). + + HHeerree DDooccuummeennttss + This type of redirection instructs the shell to read input from the + current source until a line containing only _d_e_l_i_m_i_t_e_r (with no trailing + blanks) is seen. All of the lines read up to that point are then used + as the standard input (or file descriptor _n if _n is specified) for a + command. + + The format of here-documents is: + + [_n]<<<<[--]_w_o_r_d + _h_e_r_e_-_d_o_c_u_m_e_n_t + _d_e_l_i_m_i_t_e_r + + No parameter and variable expansion, command substitution, arithmetic + expansion, or pathname expansion is performed on _w_o_r_d. If any part of + _w_o_r_d is quoted, the _d_e_l_i_m_i_t_e_r is the result of quote removal on _w_o_r_d, + and the lines in the here-document are not expanded. If _w_o_r_d is + unquoted, all lines of the here-document are subjected to parameter + expansion, command substitution, and arithmetic expansion, the charac- + ter sequence \\<> is ignored, and \\ must be used to quote the + characters \\, $$, and ``. + + If the redirection operator is <<<<--, then all leading tab characters are + stripped from input lines and the line containing _d_e_l_i_m_i_t_e_r. This + allows here-documents within shell scripts to be indented in a natural + fashion. + + HHeerree SSttrriinnggss + A variant of here documents, the format is: + + [_n]<<<<<<_w_o_r_d + + The _w_o_r_d undergoes brace expansion, tilde expansion, parameter and + variable expansion, command substitution, arithmetic expansion, and + quote removal. Pathname expansion and word splitting are not per- + formed. The result is supplied as a single string, with a newline + appended, to the command on its standard input (or file descriptor _n if + _n is specified). + + DDuupplliiccaattiinngg FFiillee DDeessccrriippttoorrss + The redirection operator + + [_n]<<&&_w_o_r_d + + is used to duplicate input file descriptors. If _w_o_r_d expands to one or + more digits, the file descriptor denoted by _n is made to be a copy of + that file descriptor. If the digits in _w_o_r_d do not specify a file + descriptor open for input, a redirection error occurs. If _w_o_r_d evalu- + ates to --, file descriptor _n is closed. If _n is not specified, the + standard input (file descriptor 0) is used. + + The operator + + [_n]>>&&_w_o_r_d + + is used similarly to duplicate output file descriptors. If _n is not + specified, the standard output (file descriptor 1) is used. If the + digits in _w_o_r_d do not specify a file descriptor open for output, a re- + direction error occurs. If _w_o_r_d evaluates to --, file descriptor _n is + closed. As a special case, if _n is omitted, and _w_o_r_d does not expand + to one or more digits or --, the standard output and standard error are + redirected as described previously. + + MMoovviinngg FFiillee DDeessccrriippttoorrss + The redirection operator + + [_n]<<&&_d_i_g_i_t-- + + moves the file descriptor _d_i_g_i_t to file descriptor _n, or the standard + input (file descriptor 0) if _n is not specified. _d_i_g_i_t is closed after + being duplicated to _n. + + Similarly, the redirection operator + + [_n]>>&&_d_i_g_i_t-- + + moves the file descriptor _d_i_g_i_t to file descriptor _n, or the standard + output (file descriptor 1) if _n is not specified. + + OOppeenniinngg FFiillee DDeessccrriippttoorrss ffoorr RReeaaddiinngg aanndd WWrriittiinngg + The redirection operator + + [_n]<<>>_w_o_r_d + + causes the file whose name is the expansion of _w_o_r_d to be opened for + both reading and writing on file descriptor _n, or on file descriptor 0 + if _n is not specified. If the file does not exist, it is created. + +AALLIIAASSEESS + _A_l_i_a_s_e_s allow a string to be substituted for a word when it is used as + the first word of a simple command. The shell maintains a list of + aliases that may be set and unset with the aalliiaass and uunnaalliiaass builtin + commands (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). The first word of each + simple command, if unquoted, is checked to see if it has an alias. If + so, that word is replaced by the text of the alias. The characters //, + $$, ``, and == and any of the shell _m_e_t_a_c_h_a_r_a_c_t_e_r_s or quoting characters + listed above may not appear in an alias name. The replacement text may + contain any valid shell input, including shell metacharacters. The + first word of the replacement text is tested for aliases, but a word + that is identical to an alias being expanded is not expanded a second + time. This means that one may alias llss to llss --FF, for instance, and + bbaasshh does not try to recursively expand the replacement text. If the + last character of the alias value is a _b_l_a_n_k, then the next command + word following the alias is also checked for alias expansion. + + Aliases are created and listed with the aalliiaass command, and removed with + the uunnaalliiaass command. + + There is no mechanism for using arguments in the replacement text. If + arguments are needed, a shell function should be used (see FFUUNNCCTTIIOONNSS + below). + + Aliases are not expanded when the shell is not interactive, unless the + eexxppaanndd__aalliiaasseess shell option is set using sshhoopptt (see the description of + sshhoopptt under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). + + The rules concerning the definition and use of aliases are somewhat + confusing. BBaasshh always reads at least one complete line of input + before executing any of the commands on that line. Aliases are + expanded when a command is read, not when it is executed. Therefore, + an alias definition appearing on the same line as another command does + not take effect until the next line of input is read. The commands + following the alias definition on that line are not affected by the new + alias. This behavior is also an issue when functions are executed. + Aliases are expanded when a function definition is read, not when the + function is executed, because a function definition is itself a com- + mand. As a consequence, aliases defined in a function are not avail- + able until after that function is executed. To be safe, always put + alias definitions on a separate line, and do not use aalliiaass in compound + commands. + + For almost every purpose, aliases are superseded by shell functions. + +FFUUNNCCTTIIOONNSS + A shell function, defined as described above under SSHHEELLLL GGRRAAMMMMAARR, + stores a series of commands for later execution. When the name of a + shell function is used as a simple command name, the list of commands + associated with that function name is executed. Functions are executed + in the context of the current shell; no new process is created to + interpret them (contrast this with the execution of a shell script). + When a function is executed, the arguments to the function become the + positional parameters during its execution. The special parameter ## is + updated to reflect the change. Special parameter 00 is unchanged. The + first element of the FFUUNNCCNNAAMMEE variable is set to the name of the func- + tion while the function is executing. + + All other aspects of the shell execution environment are identical + between a function and its caller with these exceptions: the DDEEBBUUGG and + RREETTUURRNN traps (see the description of the ttrraapp builtin under SSHHEELLLL + BBUUIILLTTIINN CCOOMMMMAANNDDSS below) are not inherited unless the function has been + given the ttrraaccee attribute (see the description of the ddeeccllaarree builtin + below) or the --oo ffuunnccttrraaccee shell option has been enabled with the sseett + builtin (in which case all functions inherit the DDEEBBUUGG and RREETTUURRNN + traps), and the EERRRR trap is not inherited unless the --oo eerrrrttrraaccee shell + option has been enabled. + + Variables local to the function may be declared with the llooccaall builtin + command. Ordinarily, variables and their values are shared between the + function and its caller. + + The FFUUNNCCNNEESSTT variable, if set to a numeric value greater than 0, + defines a maximum function nesting level. Function invocations that + exceed the limit cause the entire command to abort. + + If the builtin command rreettuurrnn is executed in a function, the function + completes and execution resumes with the next command after the func- + tion call. Any command associated with the RREETTUURRNN trap is executed + before execution resumes. When a function completes, the values of the + positional parameters and the special parameter ## are restored to the + values they had prior to the function's execution. + + Function names and definitions may be listed with the --ff option to the + ddeeccllaarree or ttyyppeesseett builtin commands. The --FF option to ddeeccllaarree or ttyyppee-- + sseett will list the function names only (and optionally the source file + and line number, if the eexxttddeebbuugg shell option is enabled). Functions + may be exported so that subshells automatically have them defined with + the --ff option to the eexxppoorrtt builtin. A function definition may be + deleted using the --ff option to the uunnsseett builtin. Note that shell + functions and variables with the same name may result in multiple iden- + tically-named entries in the environment passed to the shell's chil- + dren. Care should be taken in cases where this may cause a problem. + + Functions may be recursive. The FFUUNNCCNNEESSTT variable may be used to limit + the depth of the function call stack and restrict the number of func- + tion invocations. By default, no limit is imposed on the number of + recursive calls. + +AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN + The shell allows arithmetic expressions to be evaluated, under certain + circumstances (see the lleett and ddeeccllaarree builtin commands, the (((( com- + pound command, and AArriitthhmmeettiicc EExxppaannssiioonn). Evaluation is done in fixed- + width integers with no check for overflow, though division by 0 is + trapped and flagged as an error. The operators and their precedence, + associativity, and values are the same as in the C language. The fol- + lowing list of operators is grouped into levels of equal-precedence + operators. The levels are listed in order of decreasing precedence. + + _i_d++++ _i_d---- + variable post-increment and post-decrement + ++++_i_d ----_i_d + variable pre-increment and pre-decrement + -- ++ unary minus and plus + !! ~~ logical and bitwise negation + **** exponentiation + ** // %% multiplication, division, remainder + ++ -- addition, subtraction + <<<< >>>> left and right bitwise shifts + <<== >>== << >> + comparison + ==== !!== equality and inequality + && bitwise AND + ^^ bitwise exclusive OR + || bitwise OR + &&&& logical AND + |||| logical OR + _e_x_p_r??_e_x_p_r::_e_x_p_r + conditional operator + == **== //== %%== ++== --== <<<<== >>>>== &&== ^^== ||== + assignment + _e_x_p_r_1 ,, _e_x_p_r_2 + comma + + Shell variables are allowed as operands; parameter expansion is per- + formed before the expression is evaluated. Within an expression, shell + variables may also be referenced by name without using the parameter + expansion syntax. A shell variable that is null or unset evaluates to + 0 when referenced by name without using the parameter expansion syntax. + The value of a variable is evaluated as an arithmetic expression when + it is referenced, or when a variable which has been given the _i_n_t_e_g_e_r + attribute using ddeeccllaarree --ii is assigned a value. A null value evaluates + to 0. A shell variable need not have its _i_n_t_e_g_e_r attribute turned on + to be used in an expression. + + Constants with a leading 0 are interpreted as octal numbers. A leading + 0x or 0X denotes hexadecimal. Otherwise, numbers take the form + [_b_a_s_e_#]n, where the optional _b_a_s_e is a decimal number between 2 and 64 + representing the arithmetic base, and _n is a number in that base. If + _b_a_s_e_# is omitted, then base 10 is used. When specifying _n, the digits + greater than 9 are represented by the lowercase letters, the uppercase + letters, @, and _, in that order. If _b_a_s_e is less than or equal to 36, + lowercase and uppercase letters may be used interchangeably to repre- + sent numbers between 10 and 35. + + Operators are evaluated in order of precedence. Sub-expressions in + parentheses are evaluated first and may override the precedence rules + above. + +CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS + Conditional expressions are used by the [[[[ compound command and the + tteesstt and [[ builtin commands to test file attributes and perform string + and arithmetic comparisons. Expressions are formed from the following + unary or binary primaries. BBaasshh handles several filenames specially + when they are used in expressions. If the operating system on which + bbaasshh is running provides these special files, bash will use them; oth- + erwise it will emulate them internally with this behavior: If any _f_i_l_e + argument to one of the primaries is of the form _/_d_e_v_/_f_d_/_n, then file + descriptor _n is checked. If the _f_i_l_e argument to one of the primaries + is one of _/_d_e_v_/_s_t_d_i_n, _/_d_e_v_/_s_t_d_o_u_t, or _/_d_e_v_/_s_t_d_e_r_r, file descriptor 0, + 1, or 2, respectively, is checked. + + Unless otherwise specified, primaries that operate on files follow sym- + bolic links and operate on the target of the link, rather than the link + itself. + + When used with [[[[, the << and >> operators sort lexicographically using + the current locale. The tteesstt command sorts using ASCII ordering. + + --aa _f_i_l_e + True if _f_i_l_e exists. + --bb _f_i_l_e + True if _f_i_l_e exists and is a block special file. + --cc _f_i_l_e + True if _f_i_l_e exists and is a character special file. + --dd _f_i_l_e + True if _f_i_l_e exists and is a directory. + --ee _f_i_l_e + True if _f_i_l_e exists. + --ff _f_i_l_e + True if _f_i_l_e exists and is a regular file. + --gg _f_i_l_e + True if _f_i_l_e exists and is set-group-id. + --hh _f_i_l_e + True if _f_i_l_e exists and is a symbolic link. + --kk _f_i_l_e + True if _f_i_l_e exists and its ``sticky'' bit is set. + --pp _f_i_l_e + True if _f_i_l_e exists and is a named pipe (FIFO). + --rr _f_i_l_e + True if _f_i_l_e exists and is readable. + --ss _f_i_l_e + True if _f_i_l_e exists and has a size greater than zero. + --tt _f_d True if file descriptor _f_d is open and refers to a terminal. + --uu _f_i_l_e + True if _f_i_l_e exists and its set-user-id bit is set. + --ww _f_i_l_e + True if _f_i_l_e exists and is writable. + --xx _f_i_l_e + True if _f_i_l_e exists and is executable. + --GG _f_i_l_e + True if _f_i_l_e exists and is owned by the effective group id. + --LL _f_i_l_e + True if _f_i_l_e exists and is a symbolic link. + --NN _f_i_l_e + True if _f_i_l_e exists and has been modified since it was last + read. + --OO _f_i_l_e + True if _f_i_l_e exists and is owned by the effective user id. + --SS _f_i_l_e + True if _f_i_l_e exists and is a socket. + _f_i_l_e_1 --eeff _f_i_l_e_2 + True if _f_i_l_e_1 and _f_i_l_e_2 refer to the same device and inode num- + bers. + _f_i_l_e_1 -nntt _f_i_l_e_2 + True if _f_i_l_e_1 is newer (according to modification date) than + _f_i_l_e_2, or if _f_i_l_e_1 exists and _f_i_l_e_2 does not. + _f_i_l_e_1 -oott _f_i_l_e_2 + True if _f_i_l_e_1 is older than _f_i_l_e_2, or if _f_i_l_e_2 exists and _f_i_l_e_1 + does not. + --oo _o_p_t_n_a_m_e + True if the shell option _o_p_t_n_a_m_e is enabled. See the list of + options under the description of the --oo option to the sseett + builtin below. + --vv _v_a_r_n_a_m_e + True if the shell variable _v_a_r_n_a_m_e is set (has been assigned a + value). + --RR _v_a_r_n_a_m_e + True if the shell variable _v_a_r_n_a_m_e is set and is a name refer- + ence. + --zz _s_t_r_i_n_g + True if the length of _s_t_r_i_n_g is zero. + _s_t_r_i_n_g + --nn _s_t_r_i_n_g + True if the length of _s_t_r_i_n_g is non-zero. + + _s_t_r_i_n_g_1 ==== _s_t_r_i_n_g_2 + _s_t_r_i_n_g_1 == _s_t_r_i_n_g_2 + True if the strings are equal. == should be used with the tteesstt + command for POSIX conformance. When used with the [[[[ command, + this performs pattern matching as described above (CCoommppoouunndd CCoomm-- + mmaannddss). + + _s_t_r_i_n_g_1 !!== _s_t_r_i_n_g_2 + True if the strings are not equal. + + _s_t_r_i_n_g_1 << _s_t_r_i_n_g_2 + True if _s_t_r_i_n_g_1 sorts before _s_t_r_i_n_g_2 lexicographically. + + _s_t_r_i_n_g_1 >> _s_t_r_i_n_g_2 + True if _s_t_r_i_n_g_1 sorts after _s_t_r_i_n_g_2 lexicographically. + + _a_r_g_1 OOPP _a_r_g_2 + OOPP is one of --eeqq, --nnee, --lltt, --llee, --ggtt, or --ggee. These arithmetic + binary operators return true if _a_r_g_1 is equal to, not equal to, + less than, less than or equal to, greater than, or greater than + or equal to _a_r_g_2, respectively. _A_r_g_1 and _a_r_g_2 may be positive + or negative integers. + +SSIIMMPPLLEE CCOOMMMMAANNDD EEXXPPAANNSSIIOONN + When a simple command is executed, the shell performs the following + expansions, assignments, and redirections, from left to right. + + 1. The words that the parser has marked as variable assignments + (those preceding the command name) and redirections are saved + for later processing. + + 2. The words that are not variable assignments or redirections are + expanded. If any words remain after expansion, the first word + is taken to be the name of the command and the remaining words + are the arguments. + + 3. Redirections are performed as described above under RREEDDIIRREECCTTIIOONN. + + 4. The text after the == in each variable assignment undergoes tilde + expansion, parameter expansion, command substitution, arithmetic + expansion, and quote removal before being assigned to the vari- + able. + + If no command name results, the variable assignments affect the current + shell environment. Otherwise, the variables are added to the environ- + ment of the executed command and do not affect the current shell envi- + ronment. If any of the assignments attempts to assign a value to a + readonly variable, an error occurs, and the command exits with a non- + zero status. + + If no command name results, redirections are performed, but do not + affect the current shell environment. A redirection error causes the + command to exit with a non-zero status. + + If there is a command name left after expansion, execution proceeds as + described below. Otherwise, the command exits. If one of the expan- + sions contained a command substitution, the exit status of the command + is the exit status of the last command substitution performed. If + there were no command substitutions, the command exits with a status of + zero. + +CCOOMMMMAANNDD EEXXEECCUUTTIIOONN + After a command has been split into words, if it results in a simple + command and an optional list of arguments, the following actions are + taken. + + If the command name contains no slashes, the shell attempts to locate + it. If there exists a shell function by that name, that function is + invoked as described above in FFUUNNCCTTIIOONNSS. If the name does not match a + function, the shell searches for it in the list of shell builtins. If + a match is found, that builtin is invoked. + + If the name is neither a shell function nor a builtin, and contains no + slashes, bbaasshh searches each element of the PPAATTHH for a directory con- + taining an executable file by that name. BBaasshh uses a hash table to + remember the full pathnames of executable files (see hhaasshh under SSHHEELLLL + BBUUIILLTTIINN CCOOMMMMAANNDDSS below). A full search of the directories in PPAATTHH is + performed only if the command is not found in the hash table. If the + search is unsuccessful, the shell searches for a defined shell function + named ccoommmmaanndd__nnoott__ffoouunndd__hhaannddllee. If that function exists, it is invoked + with the original command and the original command's arguments as its + arguments, and the function's exit status becomes the exit status of + the shell. If that function is not defined, the shell prints an error + message and returns an exit status of 127. + + If the search is successful, or if the command name contains one or + more slashes, the shell executes the named program in a separate execu- + tion environment. Argument 0 is set to the name given, and the remain- + ing arguments to the command are set to the arguments given, if any. + + If this execution fails because the file is not in executable format, + and the file is not a directory, it is assumed to be a _s_h_e_l_l _s_c_r_i_p_t, a + file containing shell commands. A subshell is spawned to execute it. + This subshell reinitializes itself, so that the effect is as if a new + shell had been invoked to handle the script, with the exception that + the locations of commands remembered by the parent (see hhaasshh below + under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS) are retained by the child. + + If the program is a file beginning with ##!!, the remainder of the first + line specifies an interpreter for the program. The shell executes the + specified interpreter on operating systems that do not handle this exe- + cutable format themselves. The arguments to the interpreter consist of + a single optional argument following the interpreter name on the first + line of the program, followed by the name of the program, followed by + the command arguments, if any. + +CCOOMMMMAANNDD EEXXEECCUUTTIIOONN EENNVVIIRROONNMMEENNTT + The shell has an _e_x_e_c_u_t_i_o_n _e_n_v_i_r_o_n_m_e_n_t, which consists of the follow- + ing: + + +o open files inherited by the shell at invocation, as modified by + redirections supplied to the eexxeecc builtin + + +o the current working directory as set by ccdd, ppuusshhdd, or ppooppdd, or + inherited by the shell at invocation + + +o the file creation mode mask as set by uummaasskk or inherited from + the shell's parent + + +o current traps set by ttrraapp + + +o shell parameters that are set by variable assignment or with sseett + or inherited from the shell's parent in the environment + + +o shell functions defined during execution or inherited from the + shell's parent in the environment + + +o options enabled at invocation (either by default or with com- + mand-line arguments) or by sseett + + +o options enabled by sshhoopptt + + +o shell aliases defined with aalliiaass + + +o various process IDs, including those of background jobs, the + value of $$$$, and the value of PPPPIIDD + + When a simple command other than a builtin or shell function is to be + executed, it is invoked in a separate execution environment that con- + sists of the following. Unless otherwise noted, the values are inher- + ited from the shell. + + +o the shell's open files, plus any modifications and additions + specified by redirections to the command + + +o the current working directory + + +o the file creation mode mask + + +o shell variables and functions marked for export, along with + variables exported for the command, passed in the environment + + +o traps caught by the shell are reset to the values inherited from + the shell's parent, and traps ignored by the shell are ignored + + A command invoked in this separate environment cannot affect the + shell's execution environment. + + Command substitution, commands grouped with parentheses, and asynchro- + nous commands are invoked in a subshell environment that is a duplicate + of the shell environment, except that traps caught by the shell are + reset to the values that the shell inherited from its parent at invoca- + tion. Builtin commands that are invoked as part of a pipeline are also + executed in a subshell environment. Changes made to the subshell envi- + ronment cannot affect the shell's execution environment. + + Subshells spawned to execute command substitutions inherit the value of + the --ee option from the parent shell. When not in _p_o_s_i_x mode, bbaasshh + clears the --ee option in such subshells. + + If a command is followed by a && and job control is not active, the + default standard input for the command is the empty file _/_d_e_v_/_n_u_l_l. + Otherwise, the invoked command inherits the file descriptors of the + calling shell as modified by redirections. + +EENNVVIIRROONNMMEENNTT + When a program is invoked it is given an array of strings called the + _e_n_v_i_r_o_n_m_e_n_t. This is a list of _n_a_m_e-_v_a_l_u_e pairs, of the form + _n_a_m_e=_v_a_l_u_e. + + The shell provides several ways to manipulate the environment. On + invocation, the shell scans its own environment and creates a parameter + for each name found, automatically marking it for _e_x_p_o_r_t to child pro- + cesses. Executed commands inherit the environment. The eexxppoorrtt and + ddeeccllaarree --xx commands allow parameters and functions to be added to and + deleted from the environment. If the value of a parameter in the envi- + ronment is modified, the new value becomes part of the environment, + replacing the old. The environment inherited by any executed command + consists of the shell's initial environment, whose values may be modi- + fied in the shell, less any pairs removed by the uunnsseett command, plus + any additions via the eexxppoorrtt and ddeeccllaarree --xx commands. + + The environment for any _s_i_m_p_l_e _c_o_m_m_a_n_d or function may be augmented + temporarily by prefixing it with parameter assignments, as described + above in PPAARRAAMMEETTEERRSS. These assignment statements affect only the envi- + ronment seen by that command. + + If the --kk option is set (see the sseett builtin command below), then _a_l_l + parameter assignments are placed in the environment for a command, not + just those that precede the command name. + + When bbaasshh invokes an external command, the variable __ is set to the + full filename of the command and passed to that command in its environ- + ment. + +EEXXIITT SSTTAATTUUSS + The exit status of an executed command is the value returned by the + _w_a_i_t_p_i_d system call or equivalent function. Exit statuses fall between + 0 and 255, though, as explained below, the shell may use values above + 125 specially. Exit statuses from shell builtins and compound commands + are also limited to this range. Under certain circumstances, the shell + will use special values to indicate specific failure modes. + + For the shell's purposes, a command which exits with a zero exit status + has succeeded. An exit status of zero indicates success. A non-zero + exit status indicates failure. When a command terminates on a fatal + signal _N, bbaasshh uses the value of 128+_N as the exit status. + + If a command is not found, the child process created to execute it + returns a status of 127. If a command is found but is not executable, + the return status is 126. + + If a command fails because of an error during expansion or redirection, + the exit status is greater than zero. + + Shell builtin commands return a status of 0 (_t_r_u_e) if successful, and + non-zero (_f_a_l_s_e) if an error occurs while they execute. All builtins + return an exit status of 2 to indicate incorrect usage, generally + invalid options or missing arguments. + + BBaasshh itself returns the exit status of the last command executed, + unless a syntax error occurs, in which case it exits with a non-zero + value. See also the eexxiitt builtin command below. + +SSIIGGNNAALLSS + When bbaasshh is interactive, in the absence of any traps, it ignores + SSIIGGTTEERRMM (so that kkiillll 00 does not kill an interactive shell), and SSIIGGIINNTT + is caught and handled (so that the wwaaiitt builtin is interruptible). In + all cases, bbaasshh ignores SSIIGGQQUUIITT. If job control is in effect, bbaasshh + ignores SSIIGGTTTTIINN, SSIIGGTTTTOOUU, and SSIIGGTTSSTTPP. + + Non-builtin commands run by bbaasshh have signal handlers set to the values + inherited by the shell from its parent. When job control is not in + effect, asynchronous commands ignore SSIIGGIINNTT and SSIIGGQQUUIITT in addition to + these inherited handlers. Commands run as a result of command substi- + tution ignore the keyboard-generated job control signals SSIIGGTTTTIINN, SSIIGGTT-- + TTOOUU, and SSIIGGTTSSTTPP. + + The shell exits by default upon receipt of a SSIIGGHHUUPP. Before exiting, + an interactive shell resends the SSIIGGHHUUPP to all jobs, running or + stopped. Stopped jobs are sent SSIIGGCCOONNTT to ensure that they receive the + SSIIGGHHUUPP. To prevent the shell from sending the signal to a particular + job, it should be removed from the jobs table with the ddiissoowwnn builtin + (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below) or marked to not receive SSIIGGHHUUPP + using ddiissoowwnn --hh. + + If the hhuuppoonneexxiitt shell option has been set with sshhoopptt, bbaasshh sends a + SSIIGGHHUUPP to all jobs when an interactive login shell exits. + + If bbaasshh is waiting for a command to complete and receives a signal for + which a trap has been set, the trap will not be executed until the com- + mand completes. When bbaasshh is waiting for an asynchronous command via + the wwaaiitt builtin, the reception of a signal for which a trap has been + set will cause the wwaaiitt builtin to return immediately with an exit sta- + tus greater than 128, immediately after which the trap is executed. + +JJOOBB CCOONNTTRROOLL + _J_o_b _c_o_n_t_r_o_l refers to the ability to selectively stop (_s_u_s_p_e_n_d) the + execution of processes and continue (_r_e_s_u_m_e) their execution at a later + point. A user typically employs this facility via an interactive + interface supplied jointly by the operating system kernel's terminal + driver and bbaasshh. + + The shell associates a _j_o_b with each pipeline. It keeps a table of + currently executing jobs, which may be listed with the jjoobbss command. + When bbaasshh starts a job asynchronously (in the _b_a_c_k_g_r_o_u_n_d), it prints a + line that looks like: + + [1] 25647 + + indicating that this job is job number 1 and that the process ID of the + last process in the pipeline associated with this job is 25647. All of + the processes in a single pipeline are members of the same job. BBaasshh + uses the _j_o_b abstraction as the basis for job control. + + To facilitate the implementation of the user interface to job control, + the operating system maintains the notion of a _c_u_r_r_e_n_t _t_e_r_m_i_n_a_l _p_r_o_c_e_s_s + _g_r_o_u_p _I_D. Members of this process group (processes whose process group + ID is equal to the current terminal process group ID) receive keyboard- + generated signals such as SSIIGGIINNTT. These processes are said to be in + the _f_o_r_e_g_r_o_u_n_d. _B_a_c_k_g_r_o_u_n_d processes are those whose process group ID + differs from the terminal's; such processes are immune to keyboard-gen- + erated signals. Only foreground processes are allowed to read from or, + if the user so specifies with stty tostop, write to the terminal. + Background processes which attempt to read from (write to when stty + tostop is in effect) the terminal are sent a SSIIGGTTTTIINN ((SSIIGGTTTTOOUU)) signal + by the kernel's terminal driver, which, unless caught, suspends the + process. + + If the operating system on which bbaasshh is running supports job control, + bbaasshh contains facilities to use it. Typing the _s_u_s_p_e_n_d character (typ- + ically ^^ZZ, Control-Z) while a process is running causes that process to + be stopped and returns control to bbaasshh. Typing the _d_e_l_a_y_e_d _s_u_s_p_e_n_d + character (typically ^^YY, Control-Y) causes the process to be stopped + when it attempts to read input from the terminal, and control to be + returned to bbaasshh. The user may then manipulate the state of this job, + using the bbgg command to continue it in the background, the ffgg command + to continue it in the foreground, or the kkiillll command to kill it. A ^^ZZ + takes effect immediately, and has the additional side effect of causing + pending output and typeahead to be discarded. + + There are a number of ways to refer to a job in the shell. The charac- + ter %% introduces a job specification (_j_o_b_s_p_e_c). Job number _n may be + referred to as %%nn. A job may also be referred to using a prefix of the + name used to start it, or using a substring that appears in its command + line. For example, %%ccee refers to a stopped ccee job. If a prefix + matches more than one job, bbaasshh reports an error. Using %%??ccee, on the + other hand, refers to any job containing the string ccee in its command + line. If the substring matches more than one job, bbaasshh reports an + error. The symbols %%%% and %%++ refer to the shell's notion of the _c_u_r_- + _r_e_n_t _j_o_b, which is the last job stopped while it was in the foreground + or started in the background. The _p_r_e_v_i_o_u_s _j_o_b may be referenced using + %%--. If there is only a single job, %%++ and %%-- can both be used to refer + to that job. In output pertaining to jobs (e.g., the output of the + jjoobbss command), the current job is always flagged with a ++, and the pre- + vious job with a --. A single % (with no accompanying job specifica- + tion) also refers to the current job. + + Simply naming a job can be used to bring it into the foreground: %%11 is + a synonym for ````ffgg %%11'''', bringing job 1 from the background into the + foreground. Similarly, ````%%11 &&'''' resumes job 1 in the background, + equivalent to ````bbgg %%11''''. + + The shell learns immediately whenever a job changes state. Normally, + bbaasshh waits until it is about to print a prompt before reporting changes + in a job's status so as to not interrupt any other output. If the --bb + option to the sseett builtin command is enabled, bbaasshh reports such changes + immediately. Any trap on SSIIGGCCHHLLDD is executed for each child that + exits. + + If an attempt to exit bbaasshh is made while jobs are stopped (or, if the + cchheecckkjjoobbss shell option has been enabled using the sshhoopptt builtin, run- + ning), the shell prints a warning message, and, if the cchheecckkjjoobbss option + is enabled, lists the jobs and their statuses. The jjoobbss command may + then be used to inspect their status. If a second attempt to exit is + made without an intervening command, the shell does not print another + warning, and any stopped jobs are terminated. + +PPRROOMMPPTTIINNGG + When executing interactively, bbaasshh displays the primary prompt PPSS11 when + it is ready to read a command, and the secondary prompt PPSS22 when it + needs more input to complete a command. BBaasshh displays PPSS00 after it + reads a command but before executing it. BBaasshh allows these prompt + strings to be customized by inserting a number of backslash-escaped + special characters that are decoded as follows: + \\aa an ASCII bell character (07) + \\dd the date in "Weekday Month Date" format (e.g., "Tue May + 26") + \\DD{{_f_o_r_m_a_t}} + the _f_o_r_m_a_t is passed to _s_t_r_f_t_i_m_e(3) and the result is + inserted into the prompt string; an empty _f_o_r_m_a_t results + in a locale-specific time representation. The braces are + required + \\ee an ASCII escape character (033) + \\hh the hostname up to the first `.' + \\HH the hostname + \\jj the number of jobs currently managed by the shell + \\ll the basename of the shell's terminal device name + \\nn newline + \\rr carriage return + \\ss the name of the shell, the basename of $$00 (the portion + following the final slash) + \\tt the current time in 24-hour HH:MM:SS format + \\TT the current time in 12-hour HH:MM:SS format + \\@@ the current time in 12-hour am/pm format + \\AA the current time in 24-hour HH:MM format + \\uu the username of the current user + \\vv the version of bbaasshh (e.g., 2.00) + \\VV the release of bbaasshh, version + patch level (e.g., 2.00.0) + \\ww the current working directory, with $$HHOOMMEE abbreviated + with a tilde (uses the value of the PPRROOMMPPTT__DDIIRRTTRRIIMM vari- + able) + \\WW the basename of the current working directory, with $$HHOOMMEE + abbreviated with a tilde + \\!! the history number of this command + \\## the command number of this command + \\$$ if the effective UID is 0, a ##, otherwise a $$ + \\_n_n_n the character corresponding to the octal number _n_n_n + \\\\ a backslash + \\[[ begin a sequence of non-printing characters, which could + be used to embed a terminal control sequence into the + prompt + \\]] end a sequence of non-printing characters + + The command number and the history number are usually different: the + history number of a command is its position in the history list, which + may include commands restored from the history file (see HHIISSTTOORRYY + below), while the command number is the position in the sequence of + commands executed during the current shell session. After the string + is decoded, it is expanded via parameter expansion, command substitu- + tion, arithmetic expansion, and quote removal, subject to the value of + the pprroommppttvvaarrss shell option (see the description of the sshhoopptt command + under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). + +RREEAADDLLIINNEE + This is the library that handles reading input when using an interac- + tive shell, unless the ----nnooeeddiittiinngg option is given at shell invocation. + Line editing is also used when using the --ee option to the rreeaadd builtin. + By default, the line editing commands are similar to those of Emacs. A + vi-style line editing interface is also available. Line editing can be + enabled at any time using the --oo eemmaaccss or --oo vvii options to the sseett + builtin (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). To turn off line editing + after the shell is running, use the ++oo eemmaaccss or ++oo vvii options to the + sseett builtin. + + RReeaaddlliinnee NNoottaattiioonn + In this section, the Emacs-style notation is used to denote keystrokes. + Control keys are denoted by C-_k_e_y, e.g., C-n means Control-N. Simi- + larly, _m_e_t_a keys are denoted by M-_k_e_y, so M-x means Meta-X. (On key- + boards without a _m_e_t_a key, M-_x means ESC _x, i.e., press the Escape key + then the _x key. This makes ESC the _m_e_t_a _p_r_e_f_i_x. The combination M-C-_x + means ESC-Control-_x, or press the Escape key then hold the Control key + while pressing the _x key.) + + Readline commands may be given numeric _a_r_g_u_m_e_n_t_s, which normally act as + a repeat count. Sometimes, however, it is the sign of the argument + that is significant. Passing a negative argument to a command that + acts in the forward direction (e.g., kkiillll--lliinnee) causes that command to + act in a backward direction. Commands whose behavior with arguments + deviates from this are noted below. + + When a command is described as _k_i_l_l_i_n_g text, the text deleted is saved + for possible future retrieval (_y_a_n_k_i_n_g). The killed text is saved in a + _k_i_l_l _r_i_n_g. Consecutive kills cause the text to be accumulated into one + unit, which can be yanked all at once. Commands which do not kill text + separate the chunks of text on the kill ring. + + RReeaaddlliinnee IInniittiiaalliizzaattiioonn + Readline is customized by putting commands in an initialization file + (the _i_n_p_u_t_r_c file). The name of this file is taken from the value of + the IINNPPUUTTRRCC variable. If that variable is unset, the default is + _~_/_._i_n_p_u_t_r_c. When a program which uses the readline library starts up, + the initialization file is read, and the key bindings and variables are + set. There are only a few basic constructs allowed in the readline + initialization file. Blank lines are ignored. Lines beginning with a + ## are comments. Lines beginning with a $$ indicate conditional con- + structs. Other lines denote key bindings and variable settings. + + The default key-bindings may be changed with an _i_n_p_u_t_r_c file. Other + programs that use this library may add their own commands and bindings. + + For example, placing + + M-Control-u: universal-argument + or + C-Meta-u: universal-argument + into the _i_n_p_u_t_r_c would make M-C-u execute the readline command _u_n_i_v_e_r_- + _s_a_l_-_a_r_g_u_m_e_n_t. + + The following symbolic character names are recognized: _R_U_B_O_U_T, _D_E_L, + _E_S_C, _L_F_D, _N_E_W_L_I_N_E, _R_E_T, _R_E_T_U_R_N, _S_P_C, _S_P_A_C_E, and _T_A_B. + + In addition to command names, readline allows keys to be bound to a + string that is inserted when the key is pressed (a _m_a_c_r_o). + + RReeaaddlliinnee KKeeyy BBiinnddiinnggss + The syntax for controlling key bindings in the _i_n_p_u_t_r_c file is simple. + All that is required is the name of the command or the text of a macro + and a key sequence to which it should be bound. The name may be speci- + fied in one of two ways: as a symbolic key name, possibly with _M_e_t_a_- or + _C_o_n_t_r_o_l_- prefixes, or as a key sequence. + + When using the form kkeeyynnaammee:_f_u_n_c_t_i_o_n_-_n_a_m_e or _m_a_c_r_o, _k_e_y_n_a_m_e is the name + of a key spelled out in English. For example: + + Control-u: universal-argument + Meta-Rubout: backward-kill-word + Control-o: "> output" + + In the above example, _C_-_u is bound to the function uunniivveerrssaall--aarrgguummeenntt, + _M_-_D_E_L is bound to the function bbaacckkwwaarrdd--kkiillll--wwoorrdd, and _C_-_o is bound to + run the macro expressed on the right hand side (that is, to insert the + text ``> output'' into the line). + + In the second form, ""kkeeyysseeqq"":_f_u_n_c_t_i_o_n_-_n_a_m_e or _m_a_c_r_o, kkeeyysseeqq differs + from kkeeyynnaammee above in that strings denoting an entire key sequence may + be specified by placing the sequence within double quotes. Some GNU + Emacs style key escapes can be used, as in the following example, but + the symbolic character names are not recognized. + + "\C-u": universal-argument + "\C-x\C-r": re-read-init-file + "\e[11~": "Function Key 1" + + In this example, _C_-_u is again bound to the function uunniivveerrssaall--aarrgguummeenntt. + _C_-_x _C_-_r is bound to the function rree--rreeaadd--iinniitt--ffiillee, and _E_S_C _[ _1 _1 _~ is + bound to insert the text ``Function Key 1''. + + The full set of GNU Emacs style escape sequences is + \\CC-- control prefix + \\MM-- meta prefix + \\ee an escape character + \\\\ backslash + \\"" literal " + \\'' literal ' + + In addition to the GNU Emacs style escape sequences, a second set of + backslash escapes is available: + \\aa alert (bell) + \\bb backspace + \\dd delete + \\ff form feed + \\nn newline + \\rr carriage return + \\tt horizontal tab + \\vv vertical tab + \\_n_n_n the eight-bit character whose value is the octal value + _n_n_n (one to three digits) + \\xx_H_H the eight-bit character whose value is the hexadecimal + value _H_H (one or two hex digits) + + When entering the text of a macro, single or double quotes must be used + to indicate a macro definition. Unquoted text is assumed to be a func- + tion name. In the macro body, the backslash escapes described above + are expanded. Backslash will quote any other character in the macro + text, including " and '. + + BBaasshh allows the current readline key bindings to be displayed or modi- + fied with the bbiinndd builtin command. The editing mode may be switched + during interactive use by using the --oo option to the sseett builtin com- + mand (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). + + RReeaaddlliinnee VVaarriiaabblleess + Readline has variables that can be used to further customize its behav- + ior. A variable may be set in the _i_n_p_u_t_r_c file with a statement of the + form + + sseett _v_a_r_i_a_b_l_e_-_n_a_m_e _v_a_l_u_e + + Except where noted, readline variables can take the values OOnn or OOffff + (without regard to case). Unrecognized variable names are ignored. + When a variable value is read, empty or null values, "on" (case-insen- + sitive), and "1" are equivalent to OOnn. All other values are equivalent + to OOffff. The variables and their default values are: + + bbeellll--ssttyyllee ((aauuddiibbllee)) + Controls what happens when readline wants to ring the terminal + bell. If set to nnoonnee, readline never rings the bell. If set to + vviissiibbllee, readline uses a visible bell if one is available. If + set to aauuddiibbllee, readline attempts to ring the terminal's bell. + bbiinndd--ttttyy--ssppeecciiaall--cchhaarrss ((OOnn)) + If set to OOnn, readline attempts to bind the control characters + treated specially by the kernel's terminal driver to their read- + line equivalents. + bblliinnkk--mmaattcchhiinngg--ppaarreenn ((OOffff)) + If set to OOnn, readline attempts to briefly move the cursor to an + opening parenthesis when a closing parenthesis is inserted. + ccoolloorreedd--ccoommpplleettiioonn--pprreeffiixx ((OOffff)) + If set to OOnn, when listing completions, readline displays the + common prefix of the set of possible completions using a differ- + ent color. The color definitions are taken from the value of + the LLSS__CCOOLLOORRSS environment variable. + ccoolloorreedd--ssttaattss ((OOffff)) + If set to OOnn, readline displays possible completions using dif- + ferent colors to indicate their file type. The color defini- + tions are taken from the value of the LLSS__CCOOLLOORRSS environment + variable. + ccoommmmeenntt--bbeeggiinn ((````##'''')) + The string that is inserted when the readline iinnsseerrtt--ccoommmmeenntt + command is executed. This command is bound to MM--## in emacs mode + and to ## in vi command mode. + ccoommpplleettiioonn--ddiissppllaayy--wwiiddtthh ((--11)) + The number of screen columns used to display possible matches + when performing completion. The value is ignored if it is less + than 0 or greater than the terminal screen width. A value of 0 + will cause matches to be displayed one per line. The default + value is -1. + ccoommpplleettiioonn--iiggnnoorree--ccaassee ((OOffff)) + If set to OOnn, readline performs filename matching and completion + in a case-insensitive fashion. + ccoommpplleettiioonn--mmaapp--ccaassee ((OOffff)) + If set to OOnn, and ccoommpplleettiioonn--iiggnnoorree--ccaassee is enabled, readline + treats hyphens (_-) and underscores (__) as equivalent when per- + forming case-insensitive filename matching and completion. + ccoommpplleettiioonn--pprreeffiixx--ddiissppllaayy--lleennggtthh ((00)) + The length in characters of the common prefix of a list of pos- + sible completions that is displayed without modification. When + set to a value greater than zero, common prefixes longer than + this value are replaced with an ellipsis when displaying possi- + ble completions. + ccoommpplleettiioonn--qquueerryy--iitteemmss ((110000)) + This determines when the user is queried about viewing the num- + ber of possible completions generated by the ppoossssiibbllee--ccoommppllee-- + ttiioonnss command. It may be set to any integer value greater than + or equal to zero. If the number of possible completions is + greater than or equal to the value of this variable, the user is + asked whether or not he wishes to view them; otherwise they are + simply listed on the terminal. + ccoonnvveerrtt--mmeettaa ((OOnn)) + If set to OOnn, readline will convert characters with the eighth + bit set to an ASCII key sequence by stripping the eighth bit and + prefixing an escape character (in effect, using escape as the + _m_e_t_a _p_r_e_f_i_x). The default is _O_n, but readline will set it to + _O_f_f if the locale contains eight-bit characters. + ddiissaabbllee--ccoommpplleettiioonn ((OOffff)) + If set to OOnn, readline will inhibit word completion. Completion + characters will be inserted into the line as if they had been + mapped to sseellff--iinnsseerrtt. + eecchhoo--ccoonnttrrooll--cchhaarraacctteerrss ((OOnn)) + When set to OOnn, on operating systems that indicate they support + it, readline echoes a character corresponding to a signal gener- + ated from the keyboard. + eeddiittiinngg--mmooddee ((eemmaaccss)) + Controls whether readline begins with a set of key bindings sim- + ilar to _E_m_a_c_s or _v_i. eeddiittiinngg--mmooddee can be set to either eemmaaccss or + vvii. + eennaabbllee--bbrraacckkeetteedd--ppaassttee ((OOffff)) + When set to OOnn, readline will configure the terminal in a way + that will enable it to insert each paste into the editing buffer + as a single string of characters, instead of treating each char- + acter as if it had been read from the keyboard. This can pre- + vent pasted characters from being interpreted as editing com- + mands. + eennaabbllee--kkeeyyppaadd ((OOffff)) + When set to OOnn, readline will try to enable the application key- + pad when it is called. Some systems need this to enable the + arrow keys. + eennaabbllee--mmeettaa--kkeeyy ((OOnn)) + When set to OOnn, readline will try to enable any meta modifier + key the terminal claims to support when it is called. On many + terminals, the meta key is used to send eight-bit characters. + eexxppaanndd--ttiillddee ((OOffff)) + If set to OOnn, tilde expansion is performed when readline + attempts word completion. + hhiissttoorryy--pprreesseerrvvee--ppooiinntt ((OOffff)) + If set to OOnn, the history code attempts to place point at the + same location on each history line retrieved with pprreevviioouuss--hhiiss-- + ttoorryy or nneexxtt--hhiissttoorryy. + hhiissttoorryy--ssiizzee ((uunnsseett)) + Set the maximum number of history entries saved in the history + list. If set to zero, any existing history entries are deleted + and no new entries are saved. If set to a value less than zero, + the number of history entries is not limited. By default, the + number of history entries is set to the value of the HHIISSTTSSIIZZEE + shell variable. If an attempt is made to set _h_i_s_t_o_r_y_-_s_i_z_e to a + non-numeric value, the maximum number of history entries will be + set to 500. + hhoorriizzoonnttaall--ssccrroollll--mmooddee ((OOffff)) + When set to OOnn, makes readline use a single line for display, + scrolling the input horizontally on a single screen line when it + becomes longer than the screen width rather than wrapping to a + new line. + iinnppuutt--mmeettaa ((OOffff)) + If set to OOnn, readline will enable eight-bit input (that is, it + will not strip the eighth bit from the characters it reads), + regardless of what the terminal claims it can support. The name + mmeettaa--ffllaagg is a synonym for this variable. The default is _O_f_f, + but readline will set it to _O_n if the locale contains eight-bit + characters. + iisseeaarrcchh--tteerrmmiinnaattoorrss ((````CC--[[CC--JJ'''')) + The string of characters that should terminate an incremental + search without subsequently executing the character as a com- + mand. If this variable has not been given a value, the charac- + ters _E_S_C and _C_-_J will terminate an incremental search. + kkeeyymmaapp ((eemmaaccss)) + Set the current readline keymap. The set of valid keymap names + is _e_m_a_c_s_, _e_m_a_c_s_-_s_t_a_n_d_a_r_d_, _e_m_a_c_s_-_m_e_t_a_, _e_m_a_c_s_-_c_t_l_x_, _v_i_, _v_i_-_c_o_m_- + _m_a_n_d, and _v_i_-_i_n_s_e_r_t. _v_i is equivalent to _v_i_-_c_o_m_m_a_n_d; _e_m_a_c_s is + equivalent to _e_m_a_c_s_-_s_t_a_n_d_a_r_d. The default value is _e_m_a_c_s; the + value of eeddiittiinngg--mmooddee also affects the default keymap. + eemmaaccss--mmooddee--ssttrriinngg ((@@)) + This string is displayed immediately before the last line of the + primary prompt when emacs editing mode is active. The value is + expanded like a key binding, so the standard set of meta- and + control prefixes and backslash escape sequences is available. + Use the \1 and \2 escapes to begin and end sequences of non- + printing characters, which can be used to embed a terminal con- + trol sequence into the mode string. + kkeeyysseeqq--ttiimmeeoouutt ((550000)) + Specifies the duration _r_e_a_d_l_i_n_e will wait for a character when + reading an ambiguous key sequence (one that can form a complete + key sequence using the input read so far, or can take additional + input to complete a longer key sequence). If no input is + received within the timeout, _r_e_a_d_l_i_n_e will use the shorter but + complete key sequence. The value is specified in milliseconds, + so a value of 1000 means that _r_e_a_d_l_i_n_e will wait one second for + additional input. If this variable is set to a value less than + or equal to zero, or to a non-numeric value, _r_e_a_d_l_i_n_e will wait + until another key is pressed to decide which key sequence to + complete. + mmaarrkk--ddiirreeccttoorriieess ((OOnn)) + If set to OOnn, completed directory names have a slash appended. + mmaarrkk--mmooddiiffiieedd--lliinneess ((OOffff)) + If set to OOnn, history lines that have been modified are dis- + played with a preceding asterisk (**). + mmaarrkk--ssyymmlliinnkkeedd--ddiirreeccttoorriieess ((OOffff)) + If set to OOnn, completed names which are symbolic links to direc- + tories have a slash appended (subject to the value of + mmaarrkk--ddiirreeccttoorriieess). + mmaattcchh--hhiiddddeenn--ffiilleess ((OOnn)) + This variable, when set to OOnn, causes readline to match files + whose names begin with a `.' (hidden files) when performing + filename completion. If set to OOffff, the leading `.' must be + supplied by the user in the filename to be completed. + mmeennuu--ccoommpplleettee--ddiissppllaayy--pprreeffiixx ((OOffff)) + If set to OOnn, menu completion displays the common prefix of the + list of possible completions (which may be empty) before cycling + through the list. + oouuttppuutt--mmeettaa ((OOffff)) + If set to OOnn, readline will display characters with the eighth + bit set directly rather than as a meta-prefixed escape sequence. + The default is _O_f_f, but readline will set it to _O_n if the locale + contains eight-bit characters. + ppaaggee--ccoommpplleettiioonnss ((OOnn)) + If set to OOnn, readline uses an internal _m_o_r_e-like pager to dis- + play a screenful of possible completions at a time. + pprriinntt--ccoommpplleettiioonnss--hhoorriizzoonnttaallllyy ((OOffff)) + If set to OOnn, readline will display completions with matches + sorted horizontally in alphabetical order, rather than down the + screen. + rreevveerrtt--aallll--aatt--nneewwlliinnee ((OOffff)) + If set to OOnn, readline will undo all changes to history lines + before returning when aacccceepptt--lliinnee is executed. By default, his- + tory lines may be modified and retain individual undo lists + across calls to rreeaaddlliinnee. + sshhooww--aallll--iiff--aammbbiigguuoouuss ((OOffff)) + This alters the default behavior of the completion functions. + If set to OOnn, words which have more than one possible completion + cause the matches to be listed immediately instead of ringing + the bell. + sshhooww--aallll--iiff--uunnmmooddiiffiieedd ((OOffff)) + This alters the default behavior of the completion functions in + a fashion similar to sshhooww--aallll--iiff--aammbbiigguuoouuss. If set to OOnn, words + which have more than one possible completion without any possi- + ble partial completion (the possible completions don't share a + common prefix) cause the matches to be listed immediately + instead of ringing the bell. + sshhooww--mmooddee--iinn--pprroommpptt ((OOffff)) + If set to OOnn, add a character to the beginning of the prompt + indicating the editing mode: emacs (@), vi command (:) or vi + insertion (+). + sskkiipp--ccoommpplleetteedd--tteexxtt ((OOffff)) + If set to OOnn, this alters the default completion behavior when + inserting a single match into the line. It's only active when + performing completion in the middle of a word. If enabled, + readline does not insert characters from the completion that + match characters after point in the word being completed, so + portions of the word following the cursor are not duplicated. + vvii--ccmmdd--mmooddee--ssttrriinngg ((((ccmmdd)))) + This string is displayed immediately before the last line of the + primary prompt when vi editing mode is active and in command + mode. The value is expanded like a key binding, so the standard + set of meta- and control prefixes and backslash escape sequences + is available. Use the \1 and \2 escapes to begin and end + sequences of non-printing characters, which can be used to embed + a terminal control sequence into the mode string. + vvii--iinnss--mmooddee--ssttrriinngg ((((iinnss)))) + This string is displayed immediately before the last line of the + primary prompt when vi editing mode is active and in insertion + mode. The value is expanded like a key binding, so the standard + set of meta- and control prefixes and backslash escape sequences + is available. Use the \1 and \2 escapes to begin and end + sequences of non-printing characters, which can be used to embed + a terminal control sequence into the mode string. + vviissiibbllee--ssttaattss ((OOffff)) + If set to OOnn, a character denoting a file's type as reported by + _s_t_a_t(2) is appended to the filename when listing possible com- + pletions. + + RReeaaddlliinnee CCoonnddiittiioonnaall CCoonnssttrruuccttss + Readline implements a facility similar in spirit to the conditional + compilation features of the C preprocessor which allows key bindings + and variable settings to be performed as the result of tests. There + are four parser directives used. + + $$iiff The $$iiff construct allows bindings to be made based on the edit- + ing mode, the terminal being used, or the application using + readline. The text of the test extends to the end of the line; + no characters are required to isolate it. + + mmooddee The mmooddee== form of the $$iiff directive is used to test + whether readline is in emacs or vi mode. This may be + used in conjunction with the sseett kkeeyymmaapp command, for + instance, to set bindings in the _e_m_a_c_s_-_s_t_a_n_d_a_r_d and + _e_m_a_c_s_-_c_t_l_x keymaps only if readline is starting out in + emacs mode. + + tteerrmm The tteerrmm== form may be used to include terminal-specific + key bindings, perhaps to bind the key sequences output by + the terminal's function keys. The word on the right side + of the == is tested against both the full name of the ter- + minal and the portion of the terminal name before the + first --. This allows _s_u_n to match both _s_u_n and _s_u_n_-_c_m_d, + for instance. + + aapppplliiccaattiioonn + The aapppplliiccaattiioonn construct is used to include application- + specific settings. Each program using the readline + library sets the _a_p_p_l_i_c_a_t_i_o_n _n_a_m_e, and an initialization + file can test for a particular value. This could be used + to bind key sequences to functions useful for a specific + program. For instance, the following command adds a key + sequence that quotes the current or previous word in + bbaasshh: + + $$iiff Bash + # Quote the current or previous word + "\C-xq": "\eb\"\ef\"" + $$eennddiiff + + $$eennddiiff This command, as seen in the previous example, terminates an $$iiff + command. + + $$eellssee Commands in this branch of the $$iiff directive are executed if the + test fails. + + $$iinncclluuddee + This directive takes a single filename as an argument and reads + commands and bindings from that file. For example, the follow- + ing directive would read _/_e_t_c_/_i_n_p_u_t_r_c: + + $$iinncclluuddee _/_e_t_c_/_i_n_p_u_t_r_c + + SSeeaarrcchhiinngg + Readline provides commands for searching through the command history + (see HHIISSTTOORRYY below) for lines containing a specified string. There are + two search modes: _i_n_c_r_e_m_e_n_t_a_l and _n_o_n_-_i_n_c_r_e_m_e_n_t_a_l. + + Incremental searches begin before the user has finished typing the + search string. As each character of the search string is typed, read- + line displays the next entry from the history matching the string typed + so far. An incremental search requires only as many characters as + needed to find the desired history entry. The characters present in + the value of the iisseeaarrcchh--tteerrmmiinnaattoorrss variable are used to terminate an + incremental search. If that variable has not been assigned a value the + Escape and Control-J characters will terminate an incremental search. + Control-G will abort an incremental search and restore the original + line. When the search is terminated, the history entry containing the + search string becomes the current line. + + To find other matching entries in the history list, type Control-S or + Control-R as appropriate. This will search backward or forward in the + history for the next entry matching the search string typed so far. + Any other key sequence bound to a readline command will terminate the + search and execute that command. For instance, a _n_e_w_l_i_n_e will termi- + nate the search and accept the line, thereby executing the command from + the history list. + + Readline remembers the last incremental search string. If two Control- + Rs are typed without any intervening characters defining a new search + string, any remembered search string is used. + + Non-incremental searches read the entire search string before starting + to search for matching history lines. The search string may be typed + by the user or be part of the contents of the current line. + + RReeaaddlliinnee CCoommmmaanndd NNaammeess + The following is a list of the names of the commands and the default + key sequences to which they are bound. Command names without an accom- + panying key sequence are unbound by default. In the following descrip- + tions, _p_o_i_n_t refers to the current cursor position, and _m_a_r_k refers to + a cursor position saved by the sseett--mmaarrkk command. The text between the + point and mark is referred to as the _r_e_g_i_o_n. + + CCoommmmaannddss ffoorr MMoovviinngg + bbeeggiinnnniinngg--ooff--lliinnee ((CC--aa)) + Move to the start of the current line. + eenndd--ooff--lliinnee ((CC--ee)) + Move to the end of the line. + ffoorrwwaarrdd--cchhaarr ((CC--ff)) + Move forward a character. + bbaacckkwwaarrdd--cchhaarr ((CC--bb)) + Move back a character. + ffoorrwwaarrdd--wwoorrdd ((MM--ff)) + Move forward to the end of the next word. Words are composed of + alphanumeric characters (letters and digits). + bbaacckkwwaarrdd--wwoorrdd ((MM--bb)) + Move back to the start of the current or previous word. Words + are composed of alphanumeric characters (letters and digits). + sshheellll--ffoorrwwaarrdd--wwoorrdd + Move forward to the end of the next word. Words are delimited + by non-quoted shell metacharacters. + sshheellll--bbaacckkwwaarrdd--wwoorrdd + Move back to the start of the current or previous word. Words + are delimited by non-quoted shell metacharacters. + cclleeaarr--ssccrreeeenn ((CC--ll)) + Clear the screen leaving the current line at the top of the + screen. With an argument, refresh the current line without + clearing the screen. + rreeddrraaww--ccuurrrreenntt--lliinnee + Refresh the current line. + + CCoommmmaannddss ffoorr MMaanniippuullaattiinngg tthhee HHiissttoorryy + aacccceepptt--lliinnee ((NNeewwlliinnee,, RReettuurrnn)) + Accept the line regardless of where the cursor is. If this line + is non-empty, add it to the history list according to the state + of the HHIISSTTCCOONNTTRROOLL variable. If the line is a modified history + line, then restore the history line to its original state. + pprreevviioouuss--hhiissttoorryy ((CC--pp)) + Fetch the previous command from the history list, moving back in + the list. + nneexxtt--hhiissttoorryy ((CC--nn)) + Fetch the next command from the history list, moving forward in + the list. + bbeeggiinnnniinngg--ooff--hhiissttoorryy ((MM--<<)) + Move to the first line in the history. + eenndd--ooff--hhiissttoorryy ((MM-->>)) + Move to the end of the input history, i.e., the line currently + being entered. + rreevveerrssee--sseeaarrcchh--hhiissttoorryy ((CC--rr)) + Search backward starting at the current line and moving `up' + through the history as necessary. This is an incremental + search. + ffoorrwwaarrdd--sseeaarrcchh--hhiissttoorryy ((CC--ss)) + Search forward starting at the current line and moving `down' + through the history as necessary. This is an incremental + search. + nnoonn--iinnccrreemmeennttaall--rreevveerrssee--sseeaarrcchh--hhiissttoorryy ((MM--pp)) + Search backward through the history starting at the current line + using a non-incremental search for a string supplied by the + user. + nnoonn--iinnccrreemmeennttaall--ffoorrwwaarrdd--sseeaarrcchh--hhiissttoorryy ((MM--nn)) + Search forward through the history using a non-incremental + search for a string supplied by the user. + hhiissttoorryy--sseeaarrcchh--ffoorrwwaarrdd + Search forward through the history for the string of characters + between the start of the current line and the point. This is a + non-incremental search. + hhiissttoorryy--sseeaarrcchh--bbaacckkwwaarrdd + Search backward through the history for the string of characters + between the start of the current line and the point. This is a + non-incremental search. + yyaannkk--nntthh--aarrgg ((MM--CC--yy)) + Insert the first argument to the previous command (usually the + second word on the previous line) at point. With an argument _n, + insert the _nth word from the previous command (the words in the + previous command begin with word 0). A negative argument + inserts the _nth word from the end of the previous command. Once + the argument _n is computed, the argument is extracted as if the + "!_n" history expansion had been specified. + yyaannkk--llaasstt--aarrgg ((MM--..,, MM--__)) + Insert the last argument to the previous command (the last word + of the previous history entry). With a numeric argument, behave + exactly like yyaannkk--nntthh--aarrgg. Successive calls to yyaannkk--llaasstt--aarrgg + move back through the history list, inserting the last word (or + the word specified by the argument to the first call) of each + line in turn. Any numeric argument supplied to these successive + calls determines the direction to move through the history. A + negative argument switches the direction through the history + (back or forward). The history expansion facilities are used to + extract the last word, as if the "!$" history expansion had been + specified. + sshheellll--eexxppaanndd--lliinnee ((MM--CC--ee)) + Expand the line as the shell does. This performs alias and his- + tory expansion as well as all of the shell word expansions. See + HHIISSTTOORRYY EEXXPPAANNSSIIOONN below for a description of history expansion. + hhiissttoorryy--eexxppaanndd--lliinnee ((MM--^^)) + Perform history expansion on the current line. See HHIISSTTOORRYY + EEXXPPAANNSSIIOONN below for a description of history expansion. + mmaaggiicc--ssppaaccee + Perform history expansion on the current line and insert a + space. See HHIISSTTOORRYY EEXXPPAANNSSIIOONN below for a description of history + expansion. + aalliiaass--eexxppaanndd--lliinnee + Perform alias expansion on the current line. See AALLIIAASSEESS above + for a description of alias expansion. + hhiissttoorryy--aanndd--aalliiaass--eexxppaanndd--lliinnee + Perform history and alias expansion on the current line. + iinnsseerrtt--llaasstt--aarrgguummeenntt ((MM--..,, MM--__)) + A synonym for yyaannkk--llaasstt--aarrgg. + ooppeerraattee--aanndd--ggeett--nneexxtt ((CC--oo)) + Accept the current line for execution and fetch the next line + relative to the current line from the history for editing. Any + argument is ignored. + eeddiitt--aanndd--eexxeeccuuttee--ccoommmmaanndd ((CC--xxCC--ee)) + Invoke an editor on the current command line, and execute the + result as shell commands. BBaasshh attempts to invoke $$VVIISSUUAALL, + $$EEDDIITTOORR, and _e_m_a_c_s as the editor, in that order. + + CCoommmmaannddss ffoorr CChhaannggiinngg TTeexxtt + _e_n_d_-_o_f_-_f_i_l_e ((uussuuaallllyy CC--dd)) + The character indicating end-of-file as set, for example, by + ``stty''. If this character is read when there are no charac- + ters on the line, and point is at the beginning of the line, + Readline interprets it as the end of input and returns EEOOFF. + ddeelleettee--cchhaarr ((CC--dd)) + Delete the character at point. If this function is bound to the + same character as the tty EEOOFF character, as CC--dd commonly is, see + above for the effects. + bbaacckkwwaarrdd--ddeelleettee--cchhaarr ((RRuubboouutt)) + Delete the character behind the cursor. When given a numeric + argument, save the deleted text on the kill ring. + ffoorrwwaarrdd--bbaacckkwwaarrdd--ddeelleettee--cchhaarr + Delete the character under the cursor, unless the cursor is at + the end of the line, in which case the character behind the cur- + sor is deleted. + qquuootteedd--iinnsseerrtt ((CC--qq,, CC--vv)) + Add the next character typed to the line verbatim. This is how + to insert characters like CC--qq, for example. + ttaabb--iinnsseerrtt ((CC--vv TTAABB)) + Insert a tab character. + sseellff--iinnsseerrtt ((aa,, bb,, AA,, 11,, !!,, ......)) + Insert the character typed. + ttrraannssppoossee--cchhaarrss ((CC--tt)) + Drag the character before point forward over the character at + point, moving point forward as well. If point is at the end of + the line, then this transposes the two characters before point. + Negative arguments have no effect. + ttrraannssppoossee--wwoorrddss ((MM--tt)) + Drag the word before point past the word after point, moving + point over that word as well. If point is at the end of the + line, this transposes the last two words on the line. + uuppccaassee--wwoorrdd ((MM--uu)) + Uppercase the current (or following) word. With a negative + argument, uppercase the previous word, but do not move point. + ddoowwnnccaassee--wwoorrdd ((MM--ll)) + Lowercase the current (or following) word. With a negative + argument, lowercase the previous word, but do not move point. + ccaappiittaalliizzee--wwoorrdd ((MM--cc)) + Capitalize the current (or following) word. With a negative + argument, capitalize the previous word, but do not move point. + oovveerrwwrriittee--mmooddee + Toggle overwrite mode. With an explicit positive numeric argu- + ment, switches to overwrite mode. With an explicit non-positive + numeric argument, switches to insert mode. This command affects + only eemmaaccss mode; vvii mode does overwrite differently. Each call + to _r_e_a_d_l_i_n_e_(_) starts in insert mode. In overwrite mode, charac- + ters bound to sseellff--iinnsseerrtt replace the text at point rather than + pushing the text to the right. Characters bound to bbaacckk-- + wwaarrdd--ddeelleettee--cchhaarr replace the character before point with a + space. By default, this command is unbound. + + KKiilllliinngg aanndd YYaannkkiinngg + kkiillll--lliinnee ((CC--kk)) + Kill the text from point to the end of the line. + bbaacckkwwaarrdd--kkiillll--lliinnee ((CC--xx RRuubboouutt)) + Kill backward to the beginning of the line. + uunniixx--lliinnee--ddiissccaarrdd ((CC--uu)) + Kill backward from point to the beginning of the line. The + killed text is saved on the kill-ring. + kkiillll--wwhhoollee--lliinnee + Kill all characters on the current line, no matter where point + is. + kkiillll--wwoorrdd ((MM--dd)) + Kill from point to the end of the current word, or if between + words, to the end of the next word. Word boundaries are the + same as those used by ffoorrwwaarrdd--wwoorrdd. + bbaacckkwwaarrdd--kkiillll--wwoorrdd ((MM--RRuubboouutt)) + Kill the word behind point. Word boundaries are the same as + those used by bbaacckkwwaarrdd--wwoorrdd. + sshheellll--kkiillll--wwoorrdd + Kill from point to the end of the current word, or if between + words, to the end of the next word. Word boundaries are the + same as those used by sshheellll--ffoorrwwaarrdd--wwoorrdd. + sshheellll--bbaacckkwwaarrdd--kkiillll--wwoorrdd + Kill the word behind point. Word boundaries are the same as + those used by sshheellll--bbaacckkwwaarrdd--wwoorrdd. + uunniixx--wwoorrdd--rruubboouutt ((CC--ww)) + Kill the word behind point, using white space as a word bound- + ary. The killed text is saved on the kill-ring. + uunniixx--ffiilleennaammee--rruubboouutt + Kill the word behind point, using white space and the slash + character as the word boundaries. The killed text is saved on + the kill-ring. + ddeelleettee--hhoorriizzoonnttaall--ssppaaccee ((MM--\\)) + Delete all spaces and tabs around point. + kkiillll--rreeggiioonn + Kill the text in the current region. + ccooppyy--rreeggiioonn--aass--kkiillll + Copy the text in the region to the kill buffer. + ccooppyy--bbaacckkwwaarrdd--wwoorrdd + Copy the word before point to the kill buffer. The word bound- + aries are the same as bbaacckkwwaarrdd--wwoorrdd. + ccooppyy--ffoorrwwaarrdd--wwoorrdd + Copy the word following point to the kill buffer. The word + boundaries are the same as ffoorrwwaarrdd--wwoorrdd. + yyaannkk ((CC--yy)) + Yank the top of the kill ring into the buffer at point. + yyaannkk--ppoopp ((MM--yy)) + Rotate the kill ring, and yank the new top. Only works follow- + ing yyaannkk or yyaannkk--ppoopp. + + NNuummeerriicc AArrgguummeennttss + ddiiggiitt--aarrgguummeenntt ((MM--00,, MM--11,, ......,, MM----)) + Add this digit to the argument already accumulating, or start a + new argument. M-- starts a negative argument. + uunniivveerrssaall--aarrgguummeenntt + This is another way to specify an argument. If this command is + followed by one or more digits, optionally with a leading minus + sign, those digits define the argument. If the command is fol- + lowed by digits, executing uunniivveerrssaall--aarrgguummeenntt again ends the + numeric argument, but is otherwise ignored. As a special case, + if this command is immediately followed by a character that is + neither a digit nor minus sign, the argument count for the next + command is multiplied by four. The argument count is initially + one, so executing this function the first time makes the argu- + ment count four, a second time makes the argument count sixteen, + and so on. + + CCoommpplleettiinngg + ccoommpplleettee ((TTAABB)) + Attempt to perform completion on the text before point. BBaasshh + attempts completion treating the text as a variable (if the text + begins with $$), username (if the text begins with ~~), hostname + (if the text begins with @@), or command (including aliases and + functions) in turn. If none of these produces a match, filename + completion is attempted. + ppoossssiibbllee--ccoommpplleettiioonnss ((MM--??)) + List the possible completions of the text before point. + iinnsseerrtt--ccoommpplleettiioonnss ((MM--**)) + Insert all completions of the text before point that would have + been generated by ppoossssiibbllee--ccoommpplleettiioonnss. + mmeennuu--ccoommpplleettee + Similar to ccoommpplleettee, but replaces the word to be completed with + a single match from the list of possible completions. Repeated + execution of mmeennuu--ccoommpplleettee steps through the list of possible + completions, inserting each match in turn. At the end of the + list of completions, the bell is rung (subject to the setting of + bbeellll--ssttyyllee) and the original text is restored. An argument of _n + moves _n positions forward in the list of matches; a negative + argument may be used to move backward through the list. This + command is intended to be bound to TTAABB, but is unbound by + default. + mmeennuu--ccoommpplleettee--bbaacckkwwaarrdd + Identical to mmeennuu--ccoommpplleettee, but moves backward through the list + of possible completions, as if mmeennuu--ccoommpplleettee had been given a + negative argument. This command is unbound by default. + ddeelleettee--cchhaarr--oorr--lliisstt + Deletes the character under the cursor if not at the beginning + or end of the line (like ddeelleettee--cchhaarr). If at the end of the + line, behaves identically to ppoossssiibbllee--ccoommpplleettiioonnss. This command + is unbound by default. + ccoommpplleettee--ffiilleennaammee ((MM--//)) + Attempt filename completion on the text before point. + ppoossssiibbllee--ffiilleennaammee--ccoommpplleettiioonnss ((CC--xx //)) + List the possible completions of the text before point, treating + it as a filename. + ccoommpplleettee--uusseerrnnaammee ((MM--~~)) + Attempt completion on the text before point, treating it as a + username. + ppoossssiibbllee--uusseerrnnaammee--ccoommpplleettiioonnss ((CC--xx ~~)) + List the possible completions of the text before point, treating + it as a username. + ccoommpplleettee--vvaarriiaabbllee ((MM--$$)) + Attempt completion on the text before point, treating it as a + shell variable. + ppoossssiibbllee--vvaarriiaabbllee--ccoommpplleettiioonnss ((CC--xx $$)) + List the possible completions of the text before point, treating + it as a shell variable. + ccoommpplleettee--hhoossttnnaammee ((MM--@@)) + Attempt completion on the text before point, treating it as a + hostname. + ppoossssiibbllee--hhoossttnnaammee--ccoommpplleettiioonnss ((CC--xx @@)) + List the possible completions of the text before point, treating + it as a hostname. + ccoommpplleettee--ccoommmmaanndd ((MM--!!)) + Attempt completion on the text before point, treating it as a + command name. Command completion attempts to match the text + against aliases, reserved words, shell functions, shell + builtins, and finally executable filenames, in that order. + ppoossssiibbllee--ccoommmmaanndd--ccoommpplleettiioonnss ((CC--xx !!)) + List the possible completions of the text before point, treating + it as a command name. + ddyynnaammiicc--ccoommpplleettee--hhiissttoorryy ((MM--TTAABB)) + Attempt completion on the text before point, comparing the text + against lines from the history list for possible completion + matches. + ddaabbbbrreevv--eexxppaanndd + Attempt menu completion on the text before point, comparing the + text against lines from the history list for possible completion + matches. + ccoommpplleettee--iinnttoo--bbrraacceess ((MM--{{)) + Perform filename completion and insert the list of possible com- + pletions enclosed within braces so the list is available to the + shell (see BBrraaccee EExxppaannssiioonn above). + + KKeeyybbooaarrdd MMaaccrrooss + ssttaarrtt--kkbbdd--mmaaccrroo ((CC--xx (()) + Begin saving the characters typed into the current keyboard + macro. + eenndd--kkbbdd--mmaaccrroo ((CC--xx )))) + Stop saving the characters typed into the current keyboard macro + and store the definition. + ccaallll--llaasstt--kkbbdd--mmaaccrroo ((CC--xx ee)) + Re-execute the last keyboard macro defined, by making the char- + acters in the macro appear as if typed at the keyboard. + pprriinntt--llaasstt--kkbbdd--mmaaccrroo (()) + Print the last keyboard macro defined in a format suitable for + the _i_n_p_u_t_r_c file. + + MMiisscceellllaanneeoouuss + rree--rreeaadd--iinniitt--ffiillee ((CC--xx CC--rr)) + Read in the contents of the _i_n_p_u_t_r_c file, and incorporate any + bindings or variable assignments found there. + aabboorrtt ((CC--gg)) + Abort the current editing command and ring the terminal's bell + (subject to the setting of bbeellll--ssttyyllee). + ddoo--uuppppeerrccaassee--vveerrssiioonn ((MM--aa,, MM--bb,, MM--_x,, ......)) + If the metafied character _x is lowercase, run the command that + is bound to the corresponding uppercase character. + pprreeffiixx--mmeettaa ((EESSCC)) + Metafy the next character typed. EESSCC ff is equivalent to MMeettaa--ff. + uunnddoo ((CC--__,, CC--xx CC--uu)) + Incremental undo, separately remembered for each line. + rreevveerrtt--lliinnee ((MM--rr)) + Undo all changes made to this line. This is like executing the + uunnddoo command enough times to return the line to its initial + state. + ttiillddee--eexxppaanndd ((MM--&&)) + Perform tilde expansion on the current word. + sseett--mmaarrkk ((CC--@@,, MM--<>)) + Set the mark to the point. If a numeric argument is supplied, + the mark is set to that position. + eexxcchhaannggee--ppooiinntt--aanndd--mmaarrkk ((CC--xx CC--xx)) + Swap the point with the mark. The current cursor position is + set to the saved position, and the old cursor position is saved + as the mark. + cchhaarraacctteerr--sseeaarrcchh ((CC--]])) + A character is read and point is moved to the next occurrence of + that character. A negative count searches for previous occur- + rences. + cchhaarraacctteerr--sseeaarrcchh--bbaacckkwwaarrdd ((MM--CC--]])) + A character is read and point is moved to the previous occur- + rence of that character. A negative count searches for subse- + quent occurrences. + sskkiipp--ccssii--sseeqquueennccee + Read enough characters to consume a multi-key sequence such as + those defined for keys like Home and End. Such sequences begin + with a Control Sequence Indicator (CSI), usually ESC-[. If this + sequence is bound to "\[", keys producing such sequences will + have no effect unless explicitly bound to a readline command, + instead of inserting stray characters into the editing buffer. + This is unbound by default, but usually bound to ESC-[. + iinnsseerrtt--ccoommmmeenntt ((MM--##)) + Without a numeric argument, the value of the readline ccoomm-- + mmeenntt--bbeeggiinn variable is inserted at the beginning of the current + line. If a numeric argument is supplied, this command acts as a + toggle: if the characters at the beginning of the line do not + match the value of ccoommmmeenntt--bbeeggiinn, the value is inserted, other- + wise the characters in ccoommmmeenntt--bbeeggiinn are deleted from the begin- + ning of the line. In either case, the line is accepted as if a + newline had been typed. The default value of ccoommmmeenntt--bbeeggiinn + causes this command to make the current line a shell comment. + If a numeric argument causes the comment character to be + removed, the line will be executed by the shell. + gglloobb--ccoommpplleettee--wwoorrdd ((MM--gg)) + The word before point is treated as a pattern for pathname + expansion, with an asterisk implicitly appended. This pattern + is used to generate a list of matching filenames for possible + completions. + gglloobb--eexxppaanndd--wwoorrdd ((CC--xx **)) + The word before point is treated as a pattern for pathname + expansion, and the list of matching filenames is inserted, + replacing the word. If a numeric argument is supplied, an + asterisk is appended before pathname expansion. + gglloobb--lliisstt--eexxppaannssiioonnss ((CC--xx gg)) + The list of expansions that would have been generated by + gglloobb--eexxppaanndd--wwoorrdd is displayed, and the line is redrawn. If a + numeric argument is supplied, an asterisk is appended before + pathname expansion. + dduummpp--ffuunnccttiioonnss + Print all of the functions and their key bindings to the read- + line output stream. If a numeric argument is supplied, the out- + put is formatted in such a way that it can be made part of an + _i_n_p_u_t_r_c file. + dduummpp--vvaarriiaabblleess + Print all of the settable readline variables and their values to + the readline output stream. If a numeric argument is supplied, + the output is formatted in such a way that it can be made part + of an _i_n_p_u_t_r_c file. + dduummpp--mmaaccrrooss + Print all of the readline key sequences bound to macros and the + strings they output. If a numeric argument is supplied, the + output is formatted in such a way that it can be made part of an + _i_n_p_u_t_r_c file. + ddiissppllaayy--sshheellll--vveerrssiioonn ((CC--xx CC--vv)) + Display version information about the current instance of bbaasshh. + + PPrrooggrraammmmaabbllee CCoommpplleettiioonn + When word completion is attempted for an argument to a command for + which a completion specification (a _c_o_m_p_s_p_e_c) has been defined using + the ccoommpplleettee builtin (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below), the program- + mable completion facilities are invoked. + + First, the command name is identified. If the command word is the + empty string (completion attempted at the beginning of an empty line), + any compspec defined with the --EE option to ccoommpplleettee is used. If a + compspec has been defined for that command, the compspec is used to + generate the list of possible completions for the word. If the command + word is a full pathname, a compspec for the full pathname is searched + for first. If no compspec is found for the full pathname, an attempt + is made to find a compspec for the portion following the final slash. + If those searches do not result in a compspec, any compspec defined + with the --DD option to ccoommpplleettee is used as the default. + + Once a compspec has been found, it is used to generate the list of + matching words. If a compspec is not found, the default bbaasshh comple- + tion as described above under CCoommpplleettiinngg is performed. + + First, the actions specified by the compspec are used. Only matches + which are prefixed by the word being completed are returned. When the + --ff or --dd option is used for filename or directory name completion, the + shell variable FFIIGGNNOORREE is used to filter the matches. + + Any completions specified by a pathname expansion pattern to the --GG + option are generated next. The words generated by the pattern need not + match the word being completed. The GGLLOOBBIIGGNNOORREE shell variable is not + used to filter the matches, but the FFIIGGNNOORREE variable is used. + + Next, the string specified as the argument to the --WW option is consid- + ered. The string is first split using the characters in the IIFFSS spe- + cial variable as delimiters. Shell quoting is honored. Each word is + then expanded using brace expansion, tilde expansion, parameter and + variable expansion, command substitution, and arithmetic expansion, as + described above under EEXXPPAANNSSIIOONN. The results are split using the rules + described above under WWoorrdd SSpplliittttiinngg. The results of the expansion are + prefix-matched against the word being completed, and the matching words + become the possible completions. + + After these matches have been generated, any shell function or command + specified with the --FF and --CC options is invoked. When the command or + function is invoked, the CCOOMMPP__LLIINNEE, CCOOMMPP__PPOOIINNTT, CCOOMMPP__KKEEYY, and CCOOMMPP__TTYYPPEE + variables are assigned values as described above under SShheellll VVaarriiaabblleess. + If a shell function is being invoked, the CCOOMMPP__WWOORRDDSS and CCOOMMPP__CCWWOORRDD + variables are also set. When the function or command is invoked, the + first argument ($$11) is the name of the command whose arguments are + being completed, the second argument ($$22) is the word being completed, + and the third argument ($$33) is the word preceding the word being com- + pleted on the current command line. No filtering of the generated com- + pletions against the word being completed is performed; the function or + command has complete freedom in generating the matches. + + Any function specified with --FF is invoked first. The function may use + any of the shell facilities, including the ccoommppggeenn builtin described + below, to generate the matches. It must put the possible completions + in the CCOOMMPPRREEPPLLYY array variable, one per array element. + + Next, any command specified with the --CC option is invoked in an envi- + ronment equivalent to command substitution. It should print a list of + completions, one per line, to the standard output. Backslash may be + used to escape a newline, if necessary. + + After all of the possible completions are generated, any filter speci- + fied with the --XX option is applied to the list. The filter is a pat- + tern as used for pathname expansion; a && in the pattern is replaced + with the text of the word being completed. A literal && may be escaped + with a backslash; the backslash is removed before attempting a match. + Any completion that matches the pattern will be removed from the list. + A leading !! negates the pattern; in this case any completion not match- + ing the pattern will be removed. If the nnooccaasseemmaattcchh shell option is + enabled, the match is performed without regard to the case of alpha- + betic characters. + + Finally, any prefix and suffix specified with the --PP and --SS options are + added to each member of the completion list, and the result is returned + to the readline completion code as the list of possible completions. + + If the previously-applied actions do not generate any matches, and the + --oo ddiirrnnaammeess option was supplied to ccoommpplleettee when the compspec was + defined, directory name completion is attempted. + + If the --oo pplluussddiirrss option was supplied to ccoommpplleettee when the compspec + was defined, directory name completion is attempted and any matches are + added to the results of the other actions. + + By default, if a compspec is found, whatever it generates is returned + to the completion code as the full set of possible completions. The + default bbaasshh completions are not attempted, and the readline default of + filename completion is disabled. If the --oo bbaasshhddeeffaauulltt option was sup- + plied to ccoommpplleettee when the compspec was defined, the bbaasshh default com- + pletions are attempted if the compspec generates no matches. If the --oo + ddeeffaauulltt option was supplied to ccoommpplleettee when the compspec was defined, + readline's default completion will be performed if the compspec (and, + if attempted, the default bbaasshh completions) generate no matches. + + When a compspec indicates that directory name completion is desired, + the programmable completion functions force readline to append a slash + to completed names which are symbolic links to directories, subject to + the value of the mmaarrkk--ddiirreeccttoorriieess readline variable, regardless of the + setting of the mmaarrkk--ssyymmlliinnkkeedd--ddiirreeccttoorriieess readline variable. + + There is some support for dynamically modifying completions. This is + most useful when used in combination with a default completion speci- + fied with ccoommpplleettee --DD. It's possible for shell functions executed as + completion handlers to indicate that completion should be retried by + returning an exit status of 124. If a shell function returns 124, and + changes the compspec associated with the command on which completion is + being attempted (supplied as the first argument when the function is + executed), programmable completion restarts from the beginning, with an + attempt to find a new compspec for that command. This allows a set of + completions to be built dynamically as completion is attempted, rather + than being loaded all at once. + + For instance, assuming that there is a library of compspecs, each kept + in a file corresponding to the name of the command, the following + default completion function would load completions dynamically: + + _completion_loader() + { + . "/etc/bash_completion.d/$1.sh" >/dev/null 2>&1 && return 124 + } + complete -D -F _completion_loader -o bashdefault -o default + +HHIISSTTOORRYY + When the --oo hhiissttoorryy option to the sseett builtin is enabled, the shell + provides access to the _c_o_m_m_a_n_d _h_i_s_t_o_r_y, the list of commands previously + typed. The value of the HHIISSTTSSIIZZEE variable is used as the number of + commands to save in a history list. The text of the last HHIISSTTSSIIZZEE com- + mands (default 500) is saved. The shell stores each command in the + history list prior to parameter and variable expansion (see EEXXPPAANNSSIIOONN + above) but after history expansion is performed, subject to the values + of the shell variables HHIISSTTIIGGNNOORREE and HHIISSTTCCOONNTTRROOLL. + + On startup, the history is initialized from the file named by the vari- + able HHIISSTTFFIILLEE (default _~_/_._b_a_s_h___h_i_s_t_o_r_y). The file named by the value + of HHIISSTTFFIILLEE is truncated, if necessary, to contain no more than the + number of lines specified by the value of HHIISSTTFFIILLEESSIIZZEE. If HHIISSTTFFIILLEE-- + SSIIZZEE is unset, or set to null, a non-numeric value, or a numeric value + less than zero, the history file is not truncated. When the history + file is read, lines beginning with the history comment character fol- + lowed immediately by a digit are interpreted as timestamps for the pre- + ceding history line. These timestamps are optionally displayed depend- + ing on the value of the HHIISSTTTTIIMMEEFFOORRMMAATT variable. When a shell with + history enabled exits, the last $$HHIISSTTSSIIZZEE lines are copied from the + history list to $$HHIISSTTFFIILLEE. If the hhiissttaappppeenndd shell option is enabled + (see the description of sshhoopptt under SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below), the + lines are appended to the history file, otherwise the history file is + overwritten. If HHIISSTTFFIILLEE is unset, or if the history file is + unwritable, the history is not saved. If the HHIISSTTTTIIMMEEFFOORRMMAATT variable + is set, time stamps are written to the history file, marked with the + history comment character, so they may be preserved across shell ses- + sions. This uses the history comment character to distinguish time- + stamps from other history lines. After saving the history, the history + file is truncated to contain no more than HHIISSTTFFIILLEESSIIZZEE lines. If HHIISSTT-- + FFIILLEESSIIZZEE is unset, or set to null, a non-numeric value, or a numeric + value less than zero, the history file is not truncated. + + The builtin command ffcc (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below) may be used + to list or edit and re-execute a portion of the history list. The hhiiss-- + ttoorryy builtin may be used to display or modify the history list and + manipulate the history file. When using command-line editing, search + commands are available in each editing mode that provide access to the + history list. + + The shell allows control over which commands are saved on the history + list. The HHIISSTTCCOONNTTRROOLL and HHIISSTTIIGGNNOORREE variables may be set to cause the + shell to save only a subset of the commands entered. The ccmmddhhiisstt shell + option, if enabled, causes the shell to attempt to save each line of a + multi-line command in the same history entry, adding semicolons where + necessary to preserve syntactic correctness. The lliitthhiisstt shell option + causes the shell to save the command with embedded newlines instead of + semicolons. See the description of the sshhoopptt builtin below under SSHHEELLLL + BBUUIILLTTIINN CCOOMMMMAANNDDSS for information on setting and unsetting shell + options. + +HHIISSTTOORRYY EEXXPPAANNSSIIOONN + The shell supports a history expansion feature that is similar to the + history expansion in ccsshh.. This section describes what syntax features + are available. This feature is enabled by default for interactive + shells, and can be disabled using the ++HH option to the sseett builtin com- + mand (see SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS below). Non-interactive shells do not + perform history expansion by default. + + History expansions introduce words from the history list into the input + stream, making it easy to repeat commands, insert the arguments to a + previous command into the current input line, or fix errors in previous + commands quickly. + + History expansion is performed immediately after a complete line is + read, before the shell breaks it into words. It takes place in two + parts. The first is to determine which line from the history list to + use during substitution. The second is to select portions of that line + for inclusion into the current one. The line selected from the history + is the _e_v_e_n_t, and the portions of that line that are acted upon are + _w_o_r_d_s. Various _m_o_d_i_f_i_e_r_s are available to manipulate the selected + words. The line is broken into words in the same fashion as when read- + ing input, so that several _m_e_t_a_c_h_a_r_a_c_t_e_r-separated words surrounded by + quotes are considered one word. History expansions are introduced by + the appearance of the history expansion character, which is !! by + default. Only backslash (\\) and single quotes can quote the history + expansion character, but the history expansion character is also + treated as quoted if it immediately precedes the closing double quote + in a double-quoted string. + + Several characters inhibit history expansion if found immediately fol- + lowing the history expansion character, even if it is unquoted: space, + tab, newline, carriage return, and ==. If the eexxttgglloobb shell option is + enabled, (( will also inhibit expansion. + + Several shell options settable with the sshhoopptt builtin may be used to + tailor the behavior of history expansion. If the hhiissttvveerriiffyy shell + option is enabled (see the description of the sshhoopptt builtin below), and + rreeaaddlliinnee is being used, history substitutions are not immediately + passed to the shell parser. Instead, the expanded line is reloaded + into the rreeaaddlliinnee editing buffer for further modification. If rreeaaddlliinnee + is being used, and the hhiissttrreeeeddiitt shell option is enabled, a failed + history substitution will be reloaded into the rreeaaddlliinnee editing buffer + for correction. The --pp option to the hhiissttoorryy builtin command may be + used to see what a history expansion will do before using it. The --ss + option to the hhiissttoorryy builtin may be used to add commands to the end of + the history list without actually executing them, so that they are + available for subsequent recall. + + The shell allows control of the various characters used by the history + expansion mechanism (see the description of hhiissttcchhaarrss above under SShheellll + VVaarriiaabblleess). The shell uses the history comment character to mark his- + tory timestamps when writing the history file. + + EEvveenntt DDeessiiggnnaattoorrss + An event designator is a reference to a command line entry in the his- + tory list. Unless the reference is absolute, events are relative to + the current position in the history list. + + !! Start a history substitution, except when followed by a bbllaannkk, + newline, carriage return, = or ( (when the eexxttgglloobb shell option + is enabled using the sshhoopptt builtin). + !!_n Refer to command line _n. + !!--_n Refer to the current command minus _n. + !!!! Refer to the previous command. This is a synonym for `!-1'. + !!_s_t_r_i_n_g + Refer to the most recent command preceding the current position + in the history list starting with _s_t_r_i_n_g. + !!??_s_t_r_i_n_g[[??]] + Refer to the most recent command preceding the current position + in the history list containing _s_t_r_i_n_g. The trailing ?? may be + omitted if _s_t_r_i_n_g is followed immediately by a newline. + ^^_s_t_r_i_n_g_1^^_s_t_r_i_n_g_2^^ + Quick substitution. Repeat the previous command, replacing + _s_t_r_i_n_g_1 with _s_t_r_i_n_g_2. Equivalent to ``!!:s/_s_t_r_i_n_g_1/_s_t_r_i_n_g_2/'' + (see MMooddiiffiieerrss below). + !!## The entire command line typed so far. + + WWoorrdd DDeessiiggnnaattoorrss + Word designators are used to select desired words from the event. A :: + separates the event specification from the word designator. It may be + omitted if the word designator begins with a ^^, $$, **, --, or %%. Words + are numbered from the beginning of the line, with the first word being + denoted by 0 (zero). Words are inserted into the current line sepa- + rated by single spaces. + + 00 ((zzeerroo)) + The zeroth word. For the shell, this is the command word. + _n The _nth word. + ^^ The first argument. That is, word 1. + $$ The last word. This is usually the last argument, but will + expand to the zeroth word if there is only one word in the line. + %% The word matched by the most recent `?_s_t_r_i_n_g?' search. + _x--_y A range of words; `-_y' abbreviates `0-_y'. + ** All of the words but the zeroth. This is a synonym for `_1_-_$'. + It is not an error to use ** if there is just one word in the + event; the empty string is returned in that case. + xx** Abbreviates _x_-_$. + xx-- Abbreviates _x_-_$ like xx**, but omits the last word. + + If a word designator is supplied without an event specification, the + previous command is used as the event. + + MMooddiiffiieerrss + After the optional word designator, there may appear a sequence of one + or more of the following modifiers, each preceded by a `:'. + + hh Remove a trailing filename component, leaving only the head. + tt Remove all leading filename components, leaving the tail. + rr Remove a trailing suffix of the form _._x_x_x, leaving the basename. + ee Remove all but the trailing suffix. + pp Print the new command but do not execute it. + qq Quote the substituted words, escaping further substitutions. + xx Quote the substituted words as with qq, but break into words at + bbllaannkkss and newlines. + ss//_o_l_d//_n_e_w// + Substitute _n_e_w for the first occurrence of _o_l_d in the event + line. Any delimiter can be used in place of /. The final + delimiter is optional if it is the last character of the event + line. The delimiter may be quoted in _o_l_d and _n_e_w with a single + backslash. If & appears in _n_e_w, it is replaced by _o_l_d. A sin- + gle backslash will quote the &. If _o_l_d is null, it is set to + the last _o_l_d substituted, or, if no previous history substitu- + tions took place, the last _s_t_r_i_n_g in a !!??_s_t_r_i_n_g[[??]] search. + && Repeat the previous substitution. + gg Cause changes to be applied over the entire event line. This is + used in conjunction with `::ss' (e.g., `::ggss//_o_l_d//_n_e_w//') or `::&&'. + If used with `::ss', any delimiter can be used in place of /, and + the final delimiter is optional if it is the last character of + the event line. An aa may be used as a synonym for gg. + GG Apply the following `ss' modifier once to each word in the event + line. + +SSHHEELLLL BBUUIILLTTIINN CCOOMMMMAANNDDSS + Unless otherwise noted, each builtin command documented in this section + as accepting options preceded by -- accepts ---- to signify the end of the + options. The ::, ttrruuee, ffaallssee, and tteesstt builtins do not accept options + and do not treat ---- specially. The eexxiitt, llooggoouutt, rreettuurrnn, bbrreeaakk, ccoonn-- + ttiinnuuee, lleett, and sshhiifftt builtins accept and process arguments beginning + with -- without requiring ----. Other builtins that accept arguments but + are not specified as accepting options interpret arguments beginning + with -- as invalid options and require ---- to prevent this interpreta- + tion. + :: [_a_r_g_u_m_e_n_t_s] + No effect; the command does nothing beyond expanding _a_r_g_u_m_e_n_t_s + and performing any specified redirections. The return status is + zero. + + .. _f_i_l_e_n_a_m_e [_a_r_g_u_m_e_n_t_s] + ssoouurrccee _f_i_l_e_n_a_m_e [_a_r_g_u_m_e_n_t_s] + Read and execute commands from _f_i_l_e_n_a_m_e in the current shell + environment and return the exit status of the last command exe- + cuted from _f_i_l_e_n_a_m_e. If _f_i_l_e_n_a_m_e does not contain a slash, + filenames in PPAATTHH are used to find the directory containing + _f_i_l_e_n_a_m_e. The file searched for in PPAATTHH need not be executable. + When bbaasshh is not in _p_o_s_i_x _m_o_d_e, the current directory is + searched if no file is found in PPAATTHH. If the ssoouurrcceeppaatthh option + to the sshhoopptt builtin command is turned off, the PPAATTHH is not + searched. If any _a_r_g_u_m_e_n_t_s are supplied, they become the posi- + tional parameters when _f_i_l_e_n_a_m_e is executed. Otherwise the + positional parameters are unchanged. If the --TT option is + enabled, ssoouurrccee inherits any trap on DDEEBBUUGG; if it is not, any + DDEEBBUUGG trap string is saved and restored around the call to + ssoouurrccee, and ssoouurrccee unsets the DDEEBBUUGG trap while it executes. If + --TT is not set, and the sourced file changes the DDEEBBUUGG trap, the + new value is retained when ssoouurrccee completes. The return status + is the status of the last command exited within the script (0 if + no commands are executed), and false if _f_i_l_e_n_a_m_e is not found or + cannot be read. + + aalliiaass [--pp] [_n_a_m_e[=_v_a_l_u_e] ...] + AAlliiaass with no arguments or with the --pp option prints the list of + aliases in the form aalliiaass _n_a_m_e=_v_a_l_u_e on standard output. When + arguments are supplied, an alias is defined for each _n_a_m_e whose + _v_a_l_u_e is given. A trailing space in _v_a_l_u_e causes the next word + to be checked for alias substitution when the alias is expanded. + For each _n_a_m_e in the argument list for which no _v_a_l_u_e is sup- + plied, the name and value of the alias is printed. AAlliiaass + returns true unless a _n_a_m_e is given for which no alias has been + defined. + + bbgg [_j_o_b_s_p_e_c ...] + Resume each suspended job _j_o_b_s_p_e_c in the background, as if it + had been started with &&. If _j_o_b_s_p_e_c is not present, the shell's + notion of the _c_u_r_r_e_n_t _j_o_b is used. bbgg _j_o_b_s_p_e_c returns 0 unless + run when job control is disabled or, when run with job control + enabled, any specified _j_o_b_s_p_e_c was not found or was started + without job control. + + bbiinndd [--mm _k_e_y_m_a_p] [--llppssvvPPSSVVXX] + bbiinndd [--mm _k_e_y_m_a_p] [--qq _f_u_n_c_t_i_o_n] [--uu _f_u_n_c_t_i_o_n] [--rr _k_e_y_s_e_q] + bbiinndd [--mm _k_e_y_m_a_p] --ff _f_i_l_e_n_a_m_e + bbiinndd [--mm _k_e_y_m_a_p] --xx _k_e_y_s_e_q:_s_h_e_l_l_-_c_o_m_m_a_n_d + bbiinndd [--mm _k_e_y_m_a_p] _k_e_y_s_e_q:_f_u_n_c_t_i_o_n_-_n_a_m_e + bbiinndd [--mm _k_e_y_m_a_p] _k_e_y_s_e_q:_r_e_a_d_l_i_n_e_-_c_o_m_m_a_n_d + Display current rreeaaddlliinnee key and function bindings, bind a key + sequence to a rreeaaddlliinnee function or macro, or set a rreeaaddlliinnee + variable. Each non-option argument is a command as it would + appear in _._i_n_p_u_t_r_c, but each binding or command must be passed + as a separate argument; e.g., '"\C-x\C-r": re-read-init-file'. + Options, if supplied, have the following meanings: + --mm _k_e_y_m_a_p + Use _k_e_y_m_a_p as the keymap to be affected by the subsequent + bindings. Acceptable _k_e_y_m_a_p names are _e_m_a_c_s_, _e_m_a_c_s_-_s_t_a_n_- + _d_a_r_d_, _e_m_a_c_s_-_m_e_t_a_, _e_m_a_c_s_-_c_t_l_x_, _v_i_, _v_i_-_m_o_v_e_, _v_i_-_c_o_m_m_a_n_d, + and _v_i_-_i_n_s_e_r_t. _v_i is equivalent to _v_i_-_c_o_m_m_a_n_d (_v_i_-_m_o_v_e + is also a synonym); _e_m_a_c_s is equivalent to _e_m_a_c_s_-_s_t_a_n_- + _d_a_r_d. + --ll List the names of all rreeaaddlliinnee functions. + --pp Display rreeaaddlliinnee function names and bindings in such a + way that they can be re-read. + --PP List current rreeaaddlliinnee function names and bindings. + --ss Display rreeaaddlliinnee key sequences bound to macros and the + strings they output in such a way that they can be re- + read. + --SS Display rreeaaddlliinnee key sequences bound to macros and the + strings they output. + --vv Display rreeaaddlliinnee variable names and values in such a way + that they can be re-read. + --VV List current rreeaaddlliinnee variable names and values. + --ff _f_i_l_e_n_a_m_e + Read key bindings from _f_i_l_e_n_a_m_e. + --qq _f_u_n_c_t_i_o_n + Query about which keys invoke the named _f_u_n_c_t_i_o_n. + --uu _f_u_n_c_t_i_o_n + Unbind all keys bound to the named _f_u_n_c_t_i_o_n. + --rr _k_e_y_s_e_q + Remove any current binding for _k_e_y_s_e_q. + --xx _k_e_y_s_e_q::_s_h_e_l_l_-_c_o_m_m_a_n_d + Cause _s_h_e_l_l_-_c_o_m_m_a_n_d to be executed whenever _k_e_y_s_e_q is + entered. When _s_h_e_l_l_-_c_o_m_m_a_n_d is executed, the shell sets + the RREEAADDLLIINNEE__LLIINNEE variable to the contents of the rreeaadd-- + lliinnee line buffer and the RREEAADDLLIINNEE__PPOOIINNTT variable to the + current location of the insertion point. If the executed + command changes the value of RREEAADDLLIINNEE__LLIINNEE or RREEAADD-- + LLIINNEE__PPOOIINNTT, those new values will be reflected in the + editing state. + --XX List all key sequences bound to shell commands and the + associated commands in a format that can be reused as + input. + + The return value is 0 unless an unrecognized option is given or + an error occurred. + + bbrreeaakk [_n] + Exit from within a ffoorr, wwhhiillee, uunnttiill, or sseelleecctt loop. If _n is + specified, break _n levels. _n must be >= 1. If _n is greater + than the number of enclosing loops, all enclosing loops are + exited. The return value is 0 unless _n is not greater than or + equal to 1. + + bbuuiillttiinn _s_h_e_l_l_-_b_u_i_l_t_i_n [_a_r_g_u_m_e_n_t_s] + Execute the specified shell builtin, passing it _a_r_g_u_m_e_n_t_s, and + return its exit status. This is useful when defining a function + whose name is the same as a shell builtin, retaining the func- + tionality of the builtin within the function. The ccdd builtin is + commonly redefined this way. The return status is false if + _s_h_e_l_l_-_b_u_i_l_t_i_n is not a shell builtin command. + + ccaalllleerr [_e_x_p_r] + Returns the context of any active subroutine call (a shell func- + tion or a script executed with the .. or ssoouurrccee builtins). With- + out _e_x_p_r, ccaalllleerr displays the line number and source filename of + the current subroutine call. If a non-negative integer is sup- + plied as _e_x_p_r, ccaalllleerr displays the line number, subroutine name, + and source file corresponding to that position in the current + execution call stack. This extra information may be used, for + example, to print a stack trace. The current frame is frame 0. + The return value is 0 unless the shell is not executing a sub- + routine call or _e_x_p_r does not correspond to a valid position in + the call stack. + + ccdd [--LL|[--PP [--ee]] [-@]] [_d_i_r] + Change the current directory to _d_i_r. if _d_i_r is not supplied, + the value of the HHOOMMEE shell variable is the default. Any addi- + tional arguments following _d_i_r are ignored. The variable CCDDPPAATTHH + defines the search path for the directory containing _d_i_r: each + directory name in CCDDPPAATTHH is searched for _d_i_r. Alternative + directory names in CCDDPPAATTHH are separated by a colon (:). A null + directory name in CCDDPPAATTHH is the same as the current directory, + i.e., ``..''. If _d_i_r begins with a slash (/), then CCDDPPAATTHH is not + used. The --PP option causes ccdd to use the physical directory + structure by resolving symbolic links while traversing _d_i_r and + before processing instances of _._. in _d_i_r (see also the --PP option + to the sseett builtin command); the --LL option forces symbolic links + to be followed by resolving the link after processing instances + of _._. in _d_i_r. If _._. appears in _d_i_r, it is processed by removing + the immediately previous pathname component from _d_i_r, back to a + slash or the beginning of _d_i_r. If the --ee option is supplied + with --PP, and the current working directory cannot be success- + fully determined after a successful directory change, ccdd will + return an unsuccessful status. On systems that support it, the + --@@ option presents the extended attributes associated with a + file as a directory. An argument of -- is converted to $$OOLLDDPPWWDD + before the directory change is attempted. If a non-empty direc- + tory name from CCDDPPAATTHH is used, or if -- is the first argument, + and the directory change is successful, the absolute pathname of + the new working directory is written to the standard output. + The return value is true if the directory was successfully + changed; false otherwise. + + ccoommmmaanndd [--ppVVvv] _c_o_m_m_a_n_d [_a_r_g ...] + Run _c_o_m_m_a_n_d with _a_r_g_s suppressing the normal shell function + lookup. Only builtin commands or commands found in the PPAATTHH are + executed. If the --pp option is given, the search for _c_o_m_m_a_n_d is + performed using a default value for PPAATTHH that is guaranteed to + find all of the standard utilities. If either the --VV or --vv + option is supplied, a description of _c_o_m_m_a_n_d is printed. The --vv + option causes a single word indicating the command or filename + used to invoke _c_o_m_m_a_n_d to be displayed; the --VV option produces a + more verbose description. If the --VV or --vv option is supplied, + the exit status is 0 if _c_o_m_m_a_n_d was found, and 1 if not. If + neither option is supplied and an error occurred or _c_o_m_m_a_n_d can- + not be found, the exit status is 127. Otherwise, the exit sta- + tus of the ccoommmmaanndd builtin is the exit status of _c_o_m_m_a_n_d. + + ccoommppggeenn [_o_p_t_i_o_n] [_w_o_r_d] + Generate possible completion matches for _w_o_r_d according to the + _o_p_t_i_o_ns, which may be any option accepted by the ccoommpplleettee + builtin with the exception of --pp and --rr, and write the matches + to the standard output. When using the --FF or --CC options, the + various shell variables set by the programmable completion + facilities, while available, will not have useful values. + + The matches will be generated in the same way as if the program- + mable completion code had generated them directly from a comple- + tion specification with the same flags. If _w_o_r_d is specified, + only those completions matching _w_o_r_d will be displayed. + + The return value is true unless an invalid option is supplied, + or no matches were generated. + + ccoommpplleettee [--aabbccddeeffggjjkkssuuvv] [--oo _c_o_m_p_-_o_p_t_i_o_n] [--DDEE] [--AA _a_c_t_i_o_n] [--GG _g_l_o_b_- + _p_a_t] [--WW _w_o_r_d_l_i_s_t] [--FF _f_u_n_c_t_i_o_n] [--CC _c_o_m_m_a_n_d] + [--XX _f_i_l_t_e_r_p_a_t] [--PP _p_r_e_f_i_x] [--SS _s_u_f_f_i_x] _n_a_m_e [_n_a_m_e _._._.] + ccoommpplleettee --pprr [--DDEE] [_n_a_m_e ...] + Specify how arguments to each _n_a_m_e should be completed. If the + --pp option is supplied, or if no options are supplied, existing + completion specifications are printed in a way that allows them + to be reused as input. The --rr option removes a completion spec- + ification for each _n_a_m_e, or, if no _n_a_m_es are supplied, all com- + pletion specifications. The --DD option indicates that the + remaining options and actions should apply to the ``default'' + command completion; that is, completion attempted on a command + for which no completion has previously been defined. The --EE + option indicates that the remaining options and actions should + apply to ``empty'' command completion; that is, completion + attempted on a blank line. + + The process of applying these completion specifications when + word completion is attempted is described above under PPrrooggrraamm-- + mmaabbllee CCoommpplleettiioonn. + + Other options, if specified, have the following meanings. The + arguments to the --GG, --WW, and --XX options (and, if necessary, the + --PP and --SS options) should be quoted to protect them from expan- + sion before the ccoommpplleettee builtin is invoked. + --oo _c_o_m_p_-_o_p_t_i_o_n + The _c_o_m_p_-_o_p_t_i_o_n controls several aspects of the comp- + spec's behavior beyond the simple generation of comple- + tions. _c_o_m_p_-_o_p_t_i_o_n may be one of: + bbaasshhddeeffaauulltt + Perform the rest of the default bbaasshh completions + if the compspec generates no matches. + ddeeffaauulltt Use readline's default filename completion if + the compspec generates no matches. + ddiirrnnaammeess + Perform directory name completion if the comp- + spec generates no matches. + ffiilleennaammeess + Tell readline that the compspec generates file- + names, so it can perform any filename-specific + processing (like adding a slash to directory + names, quoting special characters, or suppress- + ing trailing spaces). Intended to be used with + shell functions. + nnooqquuoottee Tell readline not to quote the completed words + if they are filenames (quoting filenames is the + default). + nnoossoorrtt Tell readline not to sort the list of possible + completions alphabetically. + nnoossppaaccee Tell readline not to append a space (the + default) to words completed at the end of the + line. + pplluussddiirrss + After any matches defined by the compspec are + generated, directory name completion is + attempted and any matches are added to the + results of the other actions. + --AA _a_c_t_i_o_n + The _a_c_t_i_o_n may be one of the following to generate a + list of possible completions: + aalliiaass Alias names. May also be specified as --aa. + aarrrraayyvvaarr + Array variable names. + bbiinnddiinngg RReeaaddlliinnee key binding names. + bbuuiillttiinn Names of shell builtin commands. May also be + specified as --bb. + ccoommmmaanndd Command names. May also be specified as --cc. + ddiirreeccttoorryy + Directory names. May also be specified as --dd. + ddiissaabblleedd + Names of disabled shell builtins. + eennaabblleedd Names of enabled shell builtins. + eexxppoorrtt Names of exported shell variables. May also be + specified as --ee. + ffiillee File names. May also be specified as --ff. + ffuunnccttiioonn + Names of shell functions. + ggrroouupp Group names. May also be specified as --gg. + hheellppttooppiicc + Help topics as accepted by the hheellpp builtin. + hhoossttnnaammee + Hostnames, as taken from the file specified by + the HHOOSSTTFFIILLEE shell variable. + jjoobb Job names, if job control is active. May also + be specified as --jj. + kkeeyywwoorrdd Shell reserved words. May also be specified as + --kk. + rruunnnniinngg Names of running jobs, if job control is active. + sseerrvviiccee Service names. May also be specified as --ss. + sseettoopptt Valid arguments for the --oo option to the sseett + builtin. + sshhoopptt Shell option names as accepted by the sshhoopptt + builtin. + ssiiggnnaall Signal names. + ssttooppppeedd Names of stopped jobs, if job control is active. + uusseerr User names. May also be specified as --uu. + vvaarriiaabbllee + Names of all shell variables. May also be spec- + ified as --vv. + --CC _c_o_m_m_a_n_d + _c_o_m_m_a_n_d is executed in a subshell environment, and its + output is used as the possible completions. + --FF _f_u_n_c_t_i_o_n + The shell function _f_u_n_c_t_i_o_n is executed in the current + shell environment. When the function is executed, the + first argument ($$11) is the name of the command whose + arguments are being completed, the second argument ($$22) + is the word being completed, and the third argument ($$33) + is the word preceding the word being completed on the + current command line. When it finishes, the possible + completions are retrieved from the value of the CCOOMMPPRREE-- + PPLLYY array variable. + --GG _g_l_o_b_p_a_t + The pathname expansion pattern _g_l_o_b_p_a_t is expanded to + generate the possible completions. + --PP _p_r_e_f_i_x + _p_r_e_f_i_x is added at the beginning of each possible com- + pletion after all other options have been applied. + --SS _s_u_f_f_i_x + _s_u_f_f_i_x is appended to each possible completion after all + other options have been applied. + --WW _w_o_r_d_l_i_s_t + The _w_o_r_d_l_i_s_t is split using the characters in the IIFFSS + special variable as delimiters, and each resultant word + is expanded. The possible completions are the members + of the resultant list which match the word being com- + pleted. + --XX _f_i_l_t_e_r_p_a_t + _f_i_l_t_e_r_p_a_t is a pattern as used for pathname expansion. + It is applied to the list of possible completions gener- + ated by the preceding options and arguments, and each + completion matching _f_i_l_t_e_r_p_a_t is removed from the list. + A leading !! in _f_i_l_t_e_r_p_a_t negates the pattern; in this + case, any completion not matching _f_i_l_t_e_r_p_a_t is removed. + + The return value is true unless an invalid option is supplied, + an option other than --pp or --rr is supplied without a _n_a_m_e argu- + ment, an attempt is made to remove a completion specification + for a _n_a_m_e for which no specification exists, or an error occurs + adding a completion specification. + + ccoommppoopptt [--oo _o_p_t_i_o_n] [--DDEE] [++oo _o_p_t_i_o_n] [_n_a_m_e] + Modify completion options for each _n_a_m_e according to the + _o_p_t_i_o_ns, or for the currently-executing completion if no _n_a_m_es + are supplied. If no _o_p_t_i_o_ns are given, display the completion + options for each _n_a_m_e or the current completion. The possible + values of _o_p_t_i_o_n are those valid for the ccoommpplleettee builtin + described above. The --DD option indicates that the remaining + options should apply to the ``default'' command completion; that + is, completion attempted on a command for which no completion + has previously been defined. The --EE option indicates that the + remaining options should apply to ``empty'' command completion; + that is, completion attempted on a blank line. + + The return value is true unless an invalid option is supplied, + an attempt is made to modify the options for a _n_a_m_e for which no + completion specification exists, or an output error occurs. + + ccoonnttiinnuuee [_n] + Resume the next iteration of the enclosing ffoorr, wwhhiillee, uunnttiill, or + sseelleecctt loop. If _n is specified, resume at the _nth enclosing + loop. _n must be >= 1. If _n is greater than the number of + enclosing loops, the last enclosing loop (the ``top-level'' + loop) is resumed. The return value is 0 unless _n is not greater + than or equal to 1. + + ddeeccllaarree [--aaAAffFFggiillnnrrttuuxx] [--pp] [_n_a_m_e[=_v_a_l_u_e] ...] + ttyyppeesseett [--aaAAffFFggiillnnrrttuuxx] [--pp] [_n_a_m_e[=_v_a_l_u_e] ...] + Declare variables and/or give them attributes. If no _n_a_m_es are + given then display the values of variables. The --pp option will + display the attributes and values of each _n_a_m_e. When --pp is used + with _n_a_m_e arguments, additional options, other than --ff and --FF, + are ignored. When --pp is supplied without _n_a_m_e arguments, it + will display the attributes and values of all variables having + the attributes specified by the additional options. If no other + options are supplied with --pp, ddeeccllaarree will display the + attributes and values of all shell variables. The --ff option + will restrict the display to shell functions. The --FF option + inhibits the display of function definitions; only the function + name and attributes are printed. If the eexxttddeebbuugg shell option + is enabled using sshhoopptt, the source file name and line number + where each _n_a_m_e is defined are displayed as well. The --FF option + implies --ff. The --gg option forces variables to be created or + modified at the global scope, even when ddeeccllaarree is executed in a + shell function. It is ignored in all other cases. The follow- + ing options can be used to restrict output to variables with the + specified attribute or to give variables attributes: + --aa Each _n_a_m_e is an indexed array variable (see AArrrraayyss + above). + --AA Each _n_a_m_e is an associative array variable (see AArrrraayyss + above). + --ff Use function names only. + --ii The variable is treated as an integer; arithmetic evalua- + tion (see AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN above) is performed when + the variable is assigned a value. + --ll When the variable is assigned a value, all upper-case + characters are converted to lower-case. The upper-case + attribute is disabled. + --nn Give each _n_a_m_e the _n_a_m_e_r_e_f attribute, making it a name + reference to another variable. That other variable is + defined by the value of _n_a_m_e. All references, assign- + ments, and attribute modifications to _n_a_m_e, except those + using or changing the --nn attribute itself, are performed + on the variable referenced by _n_a_m_e's value. The nameref + attribute cannot be applied to array variables. + --rr Make _n_a_m_es readonly. These names cannot then be assigned + values by subsequent assignment statements or unset. + --tt Give each _n_a_m_e the _t_r_a_c_e attribute. Traced functions + inherit the DDEEBBUUGG and RREETTUURRNN traps from the calling + shell. The trace attribute has no special meaning for + variables. + --uu When the variable is assigned a value, all lower-case + characters are converted to upper-case. The lower-case + attribute is disabled. + --xx Mark _n_a_m_es for export to subsequent commands via the + environment. + + Using `+' instead of `-' turns off the attribute instead, with + the exceptions that ++aa may not be used to destroy an array vari- + able and ++rr will not remove the readonly attribute. When used + in a function, ddeeccllaarree and ttyyppeesseett make each _n_a_m_e local, as with + the llooccaall command, unless the --gg option is supplied. If a vari- + able name is followed by =_v_a_l_u_e, the value of the variable is + set to _v_a_l_u_e. When using --aa or --AA and the compound assignment + syntax to create array variables, additional attributes do not + take effect until subsequent assignments. The return value is 0 + unless an invalid option is encountered, an attempt is made to + define a function using ``-f foo=bar'', an attempt is made to + assign a value to a readonly variable, an attempt is made to + assign a value to an array variable without using the compound + assignment syntax (see AArrrraayyss above), one of the _n_a_m_e_s is not a + valid shell variable name, an attempt is made to turn off read- + only status for a readonly variable, an attempt is made to turn + off array status for an array variable, or an attempt is made to + display a non-existent function with --ff. + + ddiirrss [[--ccllppvv]] [[++_n]] [[--_n]] + Without options, displays the list of currently remembered + directories. The default display is on a single line with + directory names separated by spaces. Directories are added to + the list with the ppuusshhdd command; the ppooppdd command removes + entries from the list. The current directory is always the + first directory in the stack. + --cc Clears the directory stack by deleting all of the + entries. + --ll Produces a listing using full pathnames; the default + listing format uses a tilde to denote the home directory. + --pp Print the directory stack with one entry per line. + --vv Print the directory stack with one entry per line, pre- + fixing each entry with its index in the stack. + ++_n Displays the _nth entry counting from the left of the list + shown by ddiirrss when invoked without options, starting with + zero. + --_n Displays the _nth entry counting from the right of the + list shown by ddiirrss when invoked without options, starting + with zero. + + The return value is 0 unless an invalid option is supplied or _n + indexes beyond the end of the directory stack. + + ddiissoowwnn [--aarr] [--hh] [_j_o_b_s_p_e_c ... | _p_i_d ... ] + Without options, remove each _j_o_b_s_p_e_c from the table of active + jobs. If _j_o_b_s_p_e_c is not present, and neither the --aa nor the --rr + option is supplied, the _c_u_r_r_e_n_t _j_o_b is used. If the --hh option + is given, each _j_o_b_s_p_e_c is not removed from the table, but is + marked so that SSIIGGHHUUPP is not sent to the job if the shell + receives a SSIIGGHHUUPP. If no _j_o_b_s_p_e_c is supplied, the --aa option + means to remove or mark all jobs; the --rr option without a _j_o_b_- + _s_p_e_c argument restricts operation to running jobs. The return + value is 0 unless a _j_o_b_s_p_e_c does not specify a valid job. + + eecchhoo [--nneeEE] [_a_r_g ...] + Output the _a_r_gs, separated by spaces, followed by a newline. + The return status is 0 unless a write error occurs. If --nn is + specified, the trailing newline is suppressed. If the --ee option + is given, interpretation of the following backslash-escaped + characters is enabled. The --EE option disables the interpreta- + tion of these escape characters, even on systems where they are + interpreted by default. The xxppgg__eecchhoo shell option may be used + to dynamically determine whether or not eecchhoo expands these + escape characters by default. eecchhoo does not interpret ---- to + mean the end of options. eecchhoo interprets the following escape + sequences: + \\aa alert (bell) + \\bb backspace + \\cc suppress further output + \\ee + \\EE an escape character + \\ff form feed + \\nn new line + \\rr carriage return + \\tt horizontal tab + \\vv vertical tab + \\\\ backslash + \\00_n_n_n the eight-bit character whose value is the octal value + _n_n_n (zero to three octal digits) + \\xx_H_H the eight-bit character whose value is the hexadecimal + value _H_H (one or two hex digits) + \\uu_H_H_H_H the Unicode (ISO/IEC 10646) character whose value is the + hexadecimal value _H_H_H_H (one to four hex digits) + \\UU_H_H_H_H_H_H_H_H + the Unicode (ISO/IEC 10646) character whose value is the + hexadecimal value _H_H_H_H_H_H_H_H (one to eight hex digits) + + eennaabbllee [--aa] [--ddnnppss] [--ff _f_i_l_e_n_a_m_e] [_n_a_m_e ...] + Enable and disable builtin shell commands. Disabling a builtin + allows a disk command which has the same name as a shell builtin + to be executed without specifying a full pathname, even though + the shell normally searches for builtins before disk commands. + If --nn is used, each _n_a_m_e is disabled; otherwise, _n_a_m_e_s are + enabled. For example, to use the tteesstt binary found via the PPAATTHH + instead of the shell builtin version, run ``enable -n test''. + The --ff option means to load the new builtin command _n_a_m_e from + shared object _f_i_l_e_n_a_m_e, on systems that support dynamic loading. + The --dd option will delete a builtin previously loaded with --ff. + If no _n_a_m_e arguments are given, or if the --pp option is supplied, + a list of shell builtins is printed. With no other option argu- + ments, the list consists of all enabled shell builtins. If --nn + is supplied, only disabled builtins are printed. If --aa is sup- + plied, the list printed includes all builtins, with an indica- + tion of whether or not each is enabled. If --ss is supplied, the + output is restricted to the POSIX _s_p_e_c_i_a_l builtins. The return + value is 0 unless a _n_a_m_e is not a shell builtin or there is an + error loading a new builtin from a shared object. + + eevvaall [_a_r_g ...] + The _a_r_gs are read and concatenated together into a single com- + mand. This command is then read and executed by the shell, and + its exit status is returned as the value of eevvaall. If there are + no _a_r_g_s, or only null arguments, eevvaall returns 0. + + eexxeecc [--ccll] [--aa _n_a_m_e] [_c_o_m_m_a_n_d [_a_r_g_u_m_e_n_t_s]] + If _c_o_m_m_a_n_d is specified, it replaces the shell. No new process + is created. The _a_r_g_u_m_e_n_t_s become the arguments to _c_o_m_m_a_n_d. If + the --ll option is supplied, the shell places a dash at the begin- + ning of the zeroth argument passed to _c_o_m_m_a_n_d. This is what + _l_o_g_i_n(1) does. The --cc option causes _c_o_m_m_a_n_d to be executed with + an empty environment. If --aa is supplied, the shell passes _n_a_m_e + as the zeroth argument to the executed command. If _c_o_m_m_a_n_d can- + not be executed for some reason, a non-interactive shell exits, + unless the eexxeeccffaaiill shell option is enabled. In that case, it + returns failure. An interactive shell returns failure if the + file cannot be executed. If _c_o_m_m_a_n_d is not specified, any redi- + rections take effect in the current shell, and the return status + is 0. If there is a redirection error, the return status is 1. + + eexxiitt [_n] + Cause the shell to exit with a status of _n. If _n is omitted, + the exit status is that of the last command executed. A trap on + EEXXIITT is executed before the shell terminates. + + eexxppoorrtt [--ffnn] [_n_a_m_e[=_w_o_r_d]] ... + eexxppoorrtt --pp + The supplied _n_a_m_e_s are marked for automatic export to the envi- + ronment of subsequently executed commands. If the --ff option is + given, the _n_a_m_e_s refer to functions. If no _n_a_m_e_s are given, or + if the --pp option is supplied, a list of names of all exported + variables is printed. The --nn option causes the export property + to be removed from each _n_a_m_e. If a variable name is followed by + =_w_o_r_d, the value of the variable is set to _w_o_r_d. eexxppoorrtt returns + an exit status of 0 unless an invalid option is encountered, one + of the _n_a_m_e_s is not a valid shell variable name, or --ff is sup- + plied with a _n_a_m_e that is not a function. + + ffcc [--ee _e_n_a_m_e] [--llnnrr] [_f_i_r_s_t] [_l_a_s_t] + ffcc --ss [_p_a_t=_r_e_p] [_c_m_d] + The first form selects a range of commands from _f_i_r_s_t to _l_a_s_t + from the history list and displays or edits and re-executes + them. _F_i_r_s_t and _l_a_s_t may be specified as a string (to locate + the last command beginning with that string) or as a number (an + index into the history list, where a negative number is used as + an offset from the current command number). If _l_a_s_t is not + specified it is set to the current command for listing (so that + ``fc -l -10'' prints the last 10 commands) and to _f_i_r_s_t other- + wise. If _f_i_r_s_t is not specified it is set to the previous com- + mand for editing and -16 for listing. + + The --nn option suppresses the command numbers when listing. The + --rr option reverses the order of the commands. If the --ll option + is given, the commands are listed on standard output. Other- + wise, the editor given by _e_n_a_m_e is invoked on a file containing + those commands. If _e_n_a_m_e is not given, the value of the FFCCEEDDIITT + variable is used, and the value of EEDDIITTOORR if FFCCEEDDIITT is not set. + If neither variable is set, _v_i is used. When editing is com- + plete, the edited commands are echoed and executed. + + In the second form, _c_o_m_m_a_n_d is re-executed after each instance + of _p_a_t is replaced by _r_e_p. _C_o_m_m_a_n_d is intepreted the same as + _f_i_r_s_t above. A useful alias to use with this is ``r="fc -s"'', + so that typing ``r cc'' runs the last command beginning with + ``cc'' and typing ``r'' re-executes the last command. + + If the first form is used, the return value is 0 unless an + invalid option is encountered or _f_i_r_s_t or _l_a_s_t specify history + lines out of range. If the --ee option is supplied, the return + value is the value of the last command executed or failure if an + error occurs with the temporary file of commands. If the second + form is used, the return status is that of the command re-exe- + cuted, unless _c_m_d does not specify a valid history line, in + which case ffcc returns failure. + + ffgg [_j_o_b_s_p_e_c] + Resume _j_o_b_s_p_e_c in the foreground, and make it the current job. + If _j_o_b_s_p_e_c is not present, the shell's notion of the _c_u_r_r_e_n_t _j_o_b + is used. The return value is that of the command placed into + the foreground, or failure if run when job control is disabled + or, when run with job control enabled, if _j_o_b_s_p_e_c does not spec- + ify a valid job or _j_o_b_s_p_e_c specifies a job that was started + without job control. + + ggeettooppttss _o_p_t_s_t_r_i_n_g _n_a_m_e [_a_r_g_s] + ggeettooppttss is used by shell procedures to parse positional parame- + ters. _o_p_t_s_t_r_i_n_g contains the option characters to be recog- + nized; if a character is followed by a colon, the option is + expected to have an argument, which should be separated from it + by white space. The colon and question mark characters may not + be used as option characters. Each time it is invoked, ggeettooppttss + places the next option in the shell variable _n_a_m_e, initializing + _n_a_m_e if it does not exist, and the index of the next argument to + be processed into the variable OOPPTTIINNDD. OOPPTTIINNDD is initialized to + 1 each time the shell or a shell script is invoked. When an + option requires an argument, ggeettooppttss places that argument into + the variable OOPPTTAARRGG. The shell does not reset OOPPTTIINNDD automati- + cally; it must be manually reset between multiple calls to + ggeettooppttss within the same shell invocation if a new set of parame- + ters is to be used. + + When the end of options is encountered, ggeettooppttss exits with a + return value greater than zero. OOPPTTIINNDD is set to the index of + the first non-option argument, and _n_a_m_e is set to ?. + + ggeettooppttss normally parses the positional parameters, but if more + arguments are given in _a_r_g_s, ggeettooppttss parses those instead. + + ggeettooppttss can report errors in two ways. If the first character + of _o_p_t_s_t_r_i_n_g is a colon, _s_i_l_e_n_t error reporting is used. In + normal operation, diagnostic messages are printed when invalid + options or missing option arguments are encountered. If the + variable OOPPTTEERRRR is set to 0, no error messages will be dis- + played, even if the first character of _o_p_t_s_t_r_i_n_g is not a colon. + + If an invalid option is seen, ggeettooppttss places ? into _n_a_m_e and, if + not silent, prints an error message and unsets OOPPTTAARRGG. If + ggeettooppttss is silent, the option character found is placed in + OOPPTTAARRGG and no diagnostic message is printed. + + If a required argument is not found, and ggeettooppttss is not silent, + a question mark (??) is placed in _n_a_m_e, OOPPTTAARRGG is unset, and a + diagnostic message is printed. If ggeettooppttss is silent, then a + colon (::) is placed in _n_a_m_e and OOPPTTAARRGG is set to the option + character found. + + ggeettooppttss returns true if an option, specified or unspecified, is + found. It returns false if the end of options is encountered or + an error occurs. + + hhaasshh [--llrr] [--pp _f_i_l_e_n_a_m_e] [--ddtt] [_n_a_m_e] + Each time hhaasshh is invoked, the full pathname of the command _n_a_m_e + is determined by searching the directories in $$PPAATTHH and remem- + bered. Any previously-remembered pathname is discarded. If the + --pp option is supplied, no path search is performed, and _f_i_l_e_n_a_m_e + is used as the full filename of the command. The --rr option + causes the shell to forget all remembered locations. The --dd + option causes the shell to forget the remembered location of + each _n_a_m_e. If the --tt option is supplied, the full pathname to + which each _n_a_m_e corresponds is printed. If multiple _n_a_m_e argu- + ments are supplied with --tt, the _n_a_m_e is printed before the + hashed full pathname. The --ll option causes output to be dis- + played in a format that may be reused as input. If no arguments + are given, or if only --ll is supplied, information about remem- + bered commands is printed. The return status is true unless a + _n_a_m_e is not found or an invalid option is supplied. + + hheellpp [--ddmmss] [_p_a_t_t_e_r_n] + Display helpful information about builtin commands. If _p_a_t_t_e_r_n + is specified, hheellpp gives detailed help on all commands matching + _p_a_t_t_e_r_n; otherwise help for all the builtins and shell control + structures is printed. + --dd Display a short description of each _p_a_t_t_e_r_n + --mm Display the description of each _p_a_t_t_e_r_n in a manpage-like + format + --ss Display only a short usage synopsis for each _p_a_t_t_e_r_n + + The return status is 0 unless no command matches _p_a_t_t_e_r_n. + + hhiissttoorryy [[_n]] + hhiissttoorryy --cc + hhiissttoorryy --dd _o_f_f_s_e_t + hhiissttoorryy --aannrrww [_f_i_l_e_n_a_m_e] + hhiissttoorryy --pp _a_r_g [_a_r_g _._._.] + hhiissttoorryy --ss _a_r_g [_a_r_g _._._.] + With no options, display the command history list with line num- + bers. Lines listed with a ** have been modified. An argument of + _n lists only the last _n lines. If the shell variable HHIISSTTTTIIMMEE-- + FFOORRMMAATT is set and not null, it is used as a format string for + _s_t_r_f_t_i_m_e(3) to display the time stamp associated with each dis- + played history entry. No intervening blank is printed between + the formatted time stamp and the history line. If _f_i_l_e_n_a_m_e is + supplied, it is used as the name of the history file; if not, + the value of HHIISSTTFFIILLEE is used. Options, if supplied, have the + following meanings: + --cc Clear the history list by deleting all the entries. + --dd _o_f_f_s_e_t + Delete the history entry at position _o_f_f_s_e_t. + --aa Append the ``new'' history lines to the history file. + These are history lines entered since the beginning of + the current bbaasshh session, but not already appended to the + history file. + --nn Read the history lines not already read from the history + file into the current history list. These are lines + appended to the history file since the beginning of the + current bbaasshh session. + --rr Read the contents of the history file and append them to + the current history list. + --ww Write the current history list to the history file, over- + writing the history file's contents. + --pp Perform history substitution on the following _a_r_g_s and + display the result on the standard output. Does not + store the results in the history list. Each _a_r_g must be + quoted to disable normal history expansion. + --ss Store the _a_r_g_s in the history list as a single entry. + The last command in the history list is removed before + the _a_r_g_s are added. + + If the HHIISSTTTTIIMMEEFFOORRMMAATT variable is set, the time stamp informa- + tion associated with each history entry is written to the his- + tory file, marked with the history comment character. When the + history file is read, lines beginning with the history comment + character followed immediately by a digit are interpreted as + timestamps for the following history entry. The return value is + 0 unless an invalid option is encountered, an error occurs while + reading or writing the history file, an invalid _o_f_f_s_e_t is sup- + plied as an argument to --dd, or the history expansion supplied as + an argument to --pp fails. + + jjoobbss [--llnnpprrss] [ _j_o_b_s_p_e_c ... ] + jjoobbss --xx _c_o_m_m_a_n_d [ _a_r_g_s ... ] + The first form lists the active jobs. The options have the fol- + lowing meanings: + --ll List process IDs in addition to the normal information. + --nn Display information only about jobs that have changed + status since the user was last notified of their status. + --pp List only the process ID of the job's process group + leader. + --rr Display only running jobs. + --ss Display only stopped jobs. + + If _j_o_b_s_p_e_c is given, output is restricted to information about + that job. The return status is 0 unless an invalid option is + encountered or an invalid _j_o_b_s_p_e_c is supplied. + + If the --xx option is supplied, jjoobbss replaces any _j_o_b_s_p_e_c found in + _c_o_m_m_a_n_d or _a_r_g_s with the corresponding process group ID, and + executes _c_o_m_m_a_n_d passing it _a_r_g_s, returning its exit status. + + kkiillll [--ss _s_i_g_s_p_e_c | --nn _s_i_g_n_u_m | --_s_i_g_s_p_e_c] [_p_i_d | _j_o_b_s_p_e_c] ... + kkiillll --ll|--LL [_s_i_g_s_p_e_c | _e_x_i_t___s_t_a_t_u_s] + Send the signal named by _s_i_g_s_p_e_c or _s_i_g_n_u_m to the processes + named by _p_i_d or _j_o_b_s_p_e_c. _s_i_g_s_p_e_c is either a case-insensitive + signal name such as SSIIGGKKIILLLL (with or without the SSIIGG prefix) or + a signal number; _s_i_g_n_u_m is a signal number. If _s_i_g_s_p_e_c is not + present, then SSIIGGTTEERRMM is assumed. An argument of --ll lists the + signal names. If any arguments are supplied when --ll is given, + the names of the signals corresponding to the arguments are + listed, and the return status is 0. The _e_x_i_t___s_t_a_t_u_s argument to + --ll is a number specifying either a signal number or the exit + status of a process terminated by a signal. The --LL option is + equivalent to --ll. kkiillll returns true if at least one signal was + successfully sent, or false if an error occurs or an invalid + option is encountered. + + lleett _a_r_g [_a_r_g ...] + Each _a_r_g is an arithmetic expression to be evaluated (see AARRIITTHH-- + MMEETTIICC EEVVAALLUUAATTIIOONN above). If the last _a_r_g evaluates to 0, lleett + returns 1; 0 is returned otherwise. + + llooccaall [_o_p_t_i_o_n] [_n_a_m_e[=_v_a_l_u_e] ... | - ] + For each argument, a local variable named _n_a_m_e is created, and + assigned _v_a_l_u_e. The _o_p_t_i_o_n can be any of the options accepted + by ddeeccllaarree. When llooccaall is used within a function, it causes the + variable _n_a_m_e to have a visible scope restricted to that func- + tion and its children. If _n_a_m_e is -, the set of shell options + is made local to the function in which llooccaall is invoked: shell + options changed using the sseett builtin inside the function are + restored to their original values when the function returns. + With no operands, llooccaall writes a list of local variables to the + standard output. It is an error to use llooccaall when not within a + function. The return status is 0 unless llooccaall is used outside a + function, an invalid _n_a_m_e is supplied, or _n_a_m_e is a readonly + variable. + + llooggoouutt Exit a login shell. + + mmaappffiillee [--dd _d_e_l_i_m] [--nn _c_o_u_n_t] [--OO _o_r_i_g_i_n] [--ss _c_o_u_n_t] [--tt] [--uu _f_d] [--CC + _c_a_l_l_b_a_c_k] [--cc _q_u_a_n_t_u_m] [_a_r_r_a_y] + rreeaaddaarrrraayy [--dd _d_e_l_i_m] [--nn _c_o_u_n_t] [--OO _o_r_i_g_i_n] [--ss _c_o_u_n_t] [--tt] [--uu _f_d] [--CC + _c_a_l_l_b_a_c_k] [--cc _q_u_a_n_t_u_m] [_a_r_r_a_y] + Read lines from the standard input into the indexed array vari- + able _a_r_r_a_y, or from file descriptor _f_d if the --uu option is sup- + plied. The variable MMAAPPFFIILLEE is the default _a_r_r_a_y. Options, if + supplied, have the following meanings: + --dd The first character of _d_e_l_i_m is used to terminate each + input line, rather than newline. + --nn Copy at most _c_o_u_n_t lines. If _c_o_u_n_t is 0, all lines are + copied. + --OO Begin assigning to _a_r_r_a_y at index _o_r_i_g_i_n. The default + index is 0. + --ss Discard the first _c_o_u_n_t lines read. + --tt Remove a trailing _d_e_l_i_m (default newline) from each line + read. + --uu Read lines from file descriptor _f_d instead of the stan- + dard input. + --CC Evaluate _c_a_l_l_b_a_c_k each time _q_u_a_n_t_u_m lines are read. The + --cc option specifies _q_u_a_n_t_u_m. + --cc Specify the number of lines read between each call to + _c_a_l_l_b_a_c_k. + + If --CC is specified without --cc, the default quantum is 5000. + When _c_a_l_l_b_a_c_k is evaluated, it is supplied the index of the next + array element to be assigned and the line to be assigned to that + element as additional arguments. _c_a_l_l_b_a_c_k is evaluated after + the line is read but before the array element is assigned. + + If not supplied with an explicit origin, mmaappffiillee will clear + _a_r_r_a_y before assigning to it. + + mmaappffiillee returns successfully unless an invalid option or option + argument is supplied, _a_r_r_a_y is invalid or unassignable, or if + _a_r_r_a_y is not an indexed array. + + ppooppdd [-nn] [+_n] [-_n] + Removes entries from the directory stack. With no arguments, + removes the top directory from the stack, and performs a ccdd to + the new top directory. Arguments, if supplied, have the follow- + ing meanings: + --nn Suppresses the normal change of directory when removing + directories from the stack, so that only the stack is + manipulated. + ++_n Removes the _nth entry counting from the left of the list + shown by ddiirrss, starting with zero. For example: ``popd + +0'' removes the first directory, ``popd +1'' the second. + --_n Removes the _nth entry counting from the right of the list + shown by ddiirrss, starting with zero. For example: ``popd + -0'' removes the last directory, ``popd -1'' the next to + last. + + If the ppooppdd command is successful, a ddiirrss is performed as well, + and the return status is 0. ppooppdd returns false if an invalid + option is encountered, the directory stack is empty, a non-exis- + tent directory stack entry is specified, or the directory change + fails. + + pprriinnttff [--vv _v_a_r] _f_o_r_m_a_t [_a_r_g_u_m_e_n_t_s] + Write the formatted _a_r_g_u_m_e_n_t_s to the standard output under the + control of the _f_o_r_m_a_t. The --vv option causes the output to be + assigned to the variable _v_a_r rather than being printed to the + standard output. + + The _f_o_r_m_a_t is a character string which contains three types of + objects: plain characters, which are simply copied to standard + output, character escape sequences, which are converted and + copied to the standard output, and format specifications, each + of which causes printing of the next successive _a_r_g_u_m_e_n_t. In + addition to the standard _p_r_i_n_t_f(1) format specifications, pprriinnttff + interprets the following extensions: + %%bb causes pprriinnttff to expand backslash escape sequences in the + corresponding _a_r_g_u_m_e_n_t in the same way as eecchhoo --ee. + %%qq causes pprriinnttff to output the corresponding _a_r_g_u_m_e_n_t in a + format that can be reused as shell input. + %%((_d_a_t_e_f_m_t))TT + causes pprriinnttff to output the date-time string resulting + from using _d_a_t_e_f_m_t as a format string for _s_t_r_f_t_i_m_e(3). + The corresponding _a_r_g_u_m_e_n_t is an integer representing the + number of seconds since the epoch. Two special argument + values may be used: -1 represents the current time, and + -2 represents the time the shell was invoked. If no + argument is specified, conversion behaves as if -1 had + been given. This is an exception to the usual pprriinnttff + behavior. + + Arguments to non-string format specifiers are treated as C con- + stants, except that a leading plus or minus sign is allowed, and + if the leading character is a single or double quote, the value + is the ASCII value of the following character. + + The _f_o_r_m_a_t is reused as necessary to consume all of the _a_r_g_u_- + _m_e_n_t_s. If the _f_o_r_m_a_t requires more _a_r_g_u_m_e_n_t_s than are supplied, + the extra format specifications behave as if a zero value or + null string, as appropriate, had been supplied. The return + value is zero on success, non-zero on failure. + + ppuusshhdd [--nn] [+_n] [-_n] + ppuusshhdd [--nn] [_d_i_r] + Adds a directory to the top of the directory stack, or rotates + the stack, making the new top of the stack the current working + directory. With no arguments, ppuusshhdd exchanges the top two + directories and returns 0, unless the directory stack is empty. + Arguments, if supplied, have the following meanings: + --nn Suppresses the normal change of directory when rotating + or adding directories to the stack, so that only the + stack is manipulated. + ++_n Rotates the stack so that the _nth directory (counting + from the left of the list shown by ddiirrss, starting with + zero) is at the top. + --_n Rotates the stack so that the _nth directory (counting + from the right of the list shown by ddiirrss, starting with + zero) is at the top. + _d_i_r Adds _d_i_r to the directory stack at the top, making it the + new current working directory as if it had been supplied + as the argument to the ccdd builtin. + + If the ppuusshhdd command is successful, a ddiirrss is performed as well. + If the first form is used, ppuusshhdd returns 0 unless the cd to _d_i_r + fails. With the second form, ppuusshhdd returns 0 unless the direc- + tory stack is empty, a non-existent directory stack element is + specified, or the directory change to the specified new current + directory fails. + + ppwwdd [--LLPP] + Print the absolute pathname of the current working directory. + The pathname printed contains no symbolic links if the --PP option + is supplied or the --oo pphhyyssiiccaall option to the sseett builtin command + is enabled. If the --LL option is used, the pathname printed may + contain symbolic links. The return status is 0 unless an error + occurs while reading the name of the current directory or an + invalid option is supplied. + + rreeaadd [--eerrss] [--aa _a_n_a_m_e] [--dd _d_e_l_i_m] [--ii _t_e_x_t] [--nn _n_c_h_a_r_s] [--NN _n_c_h_a_r_s] [--pp + _p_r_o_m_p_t] [--tt _t_i_m_e_o_u_t] [--uu _f_d] [_n_a_m_e ...] + One line is read from the standard input, or from the file + descriptor _f_d supplied as an argument to the --uu option, split + into words as described above under WWoorrdd SSpplliittttiinngg, and the + first word is assigned to the first _n_a_m_e, the second word to the + second _n_a_m_e, and so on. If there are more words than names, the + remaining words and their intervening delimiters are assigned to + the last _n_a_m_e. If there are fewer words read from the input + stream than names, the remaining names are assigned empty val- + ues. The characters in IIFFSS are used to split the line into + words using the same rules the shell uses for expansion + (described above under WWoorrdd SSpplliittttiinngg). The backslash character + (\\) may be used to remove any special meaning for the next char- + acter read and for line continuation. Options, if supplied, + have the following meanings: + --aa _a_n_a_m_e + The words are assigned to sequential indices of the array + variable _a_n_a_m_e, starting at 0. _a_n_a_m_e is unset before any + new values are assigned. Other _n_a_m_e arguments are + ignored. + --dd _d_e_l_i_m + The first character of _d_e_l_i_m is used to terminate the + input line, rather than newline. + --ee If the standard input is coming from a terminal, rreeaaddlliinnee + (see RREEAADDLLIINNEE above) is used to obtain the line. Read- + line uses the current (or default, if line editing was + not previously active) editing settings. + --ii _t_e_x_t + If rreeaaddlliinnee is being used to read the line, _t_e_x_t is + placed into the editing buffer before editing begins. + --nn _n_c_h_a_r_s + rreeaadd returns after reading _n_c_h_a_r_s characters rather than + waiting for a complete line of input, but honors a delim- + iter if fewer than _n_c_h_a_r_s characters are read before the + delimiter. + --NN _n_c_h_a_r_s + rreeaadd returns after reading exactly _n_c_h_a_r_s characters + rather than waiting for a complete line of input, unless + EOF is encountered or rreeaadd times out. Delimiter charac- + ters encountered in the input are not treated specially + and do not cause rreeaadd to return until _n_c_h_a_r_s characters + are read. The result is not split on the characters in + IIFFSS; the intent is that the variable is assigned exactly + the characters read (with the exception of backslash; see + the --rr option below). + --pp _p_r_o_m_p_t + Display _p_r_o_m_p_t on standard error, without a trailing new- + line, before attempting to read any input. The prompt is + displayed only if input is coming from a terminal. + --rr Backslash does not act as an escape character. The back- + slash is considered to be part of the line. In particu- + lar, a backslash-newline pair may not be used as a line + continuation. + --ss Silent mode. If input is coming from a terminal, charac- + ters are not echoed. + --tt _t_i_m_e_o_u_t + Cause rreeaadd to time out and return failure if a complete + line of input (or a specified number of characters) is + not read within _t_i_m_e_o_u_t seconds. _t_i_m_e_o_u_t may be a deci- + mal number with a fractional portion following the deci- + mal point. This option is only effective if rreeaadd is + reading input from a terminal, pipe, or other special + file; it has no effect when reading from regular files. + If rreeaadd times out, rreeaadd saves any partial input read into + the specified variable _n_a_m_e. If _t_i_m_e_o_u_t is 0, rreeaadd + returns immediately, without trying to read any data. + The exit status is 0 if input is available on the speci- + fied file descriptor, non-zero otherwise. The exit sta- + tus is greater than 128 if the timeout is exceeded. + --uu _f_d Read input from file descriptor _f_d. + + If no _n_a_m_e_s are supplied, the line read is assigned to the vari- + able RREEPPLLYY. The exit status is zero, unless end-of-file is + encountered, rreeaadd times out (in which case the status is greater + than 128), a variable assignment error (such as assigning to a + readonly variable) occurs, or an invalid file descriptor is sup- + plied as the argument to --uu. + + rreeaaddoonnllyy [--aaAAff] [--pp] [_n_a_m_e[=_w_o_r_d] ...] + The given _n_a_m_e_s are marked readonly; the values of these _n_a_m_e_s + may not be changed by subsequent assignment. If the --ff option + is supplied, the functions corresponding to the _n_a_m_e_s are so + marked. The --aa option restricts the variables to indexed + arrays; the --AA option restricts the variables to associative + arrays. If both options are supplied, --AA takes precedence. If + no _n_a_m_e arguments are given, or if the --pp option is supplied, a + list of all readonly names is printed. The other options may be + used to restrict the output to a subset of the set of readonly + names. The --pp option causes output to be displayed in a format + that may be reused as input. If a variable name is followed by + =_w_o_r_d, the value of the variable is set to _w_o_r_d. The return + status is 0 unless an invalid option is encountered, one of the + _n_a_m_e_s is not a valid shell variable name, or --ff is supplied with + a _n_a_m_e that is not a function. + + rreettuurrnn [_n] + Causes a function to stop executing and return the value speci- + fied by _n to its caller. If _n is omitted, the return status is + that of the last command executed in the function body. If + rreettuurrnn is executed by a trap handler, the last command used to + determine the status is the last command executed before the + trap handler. if rreettuurrnn is executed during a DDEEBBUUGG trap, the + last command used to determine the status is the last command + executed by the trap handler before rreettuurrnn was invoked. If + rreettuurrnn is used outside a function, but during execution of a + script by the .. (ssoouurrccee) command, it causes the shell to stop + executing that script and return either _n or the exit status of + the last command executed within the script as the exit status + of the script. If _n is supplied, the return value is its least + significant 8 bits. The return status is non-zero if rreettuurrnn is + supplied a non-numeric argument, or is used outside a function + and not during execution of a script by .. or ssoouurrccee. Any com- + mand associated with the RREETTUURRNN trap is executed before execu- + tion resumes after the function or script. + + sseett [----aabbeeffhhkkmmnnppttuuvvxxBBCCEEHHPPTT] [--oo _o_p_t_i_o_n_-_n_a_m_e] [_a_r_g ...] + sseett [++aabbeeffhhkkmmnnppttuuvvxxBBCCEEHHPPTT] [++oo _o_p_t_i_o_n_-_n_a_m_e] [_a_r_g ...] + Without options, the name and value of each shell variable are + displayed in a format that can be reused as input for setting or + resetting the currently-set variables. Read-only variables can- + not be reset. In _p_o_s_i_x mode, only shell variables are listed. + The output is sorted according to the current locale. When + options are specified, they set or unset shell attributes. Any + arguments remaining after option processing are treated as val- + ues for the positional parameters and are assigned, in order, to + $$11, $$22, ...... $$_n. Options, if specified, have the following + meanings: + --aa Each variable or function that is created or modified is + given the export attribute and marked for export to the + environment of subsequent commands. + --bb Report the status of terminated background jobs immedi- + ately, rather than before the next primary prompt. This + is effective only when job control is enabled. + --ee Exit immediately if a _p_i_p_e_l_i_n_e (which may consist of a + single _s_i_m_p_l_e _c_o_m_m_a_n_d), a _l_i_s_t, or a _c_o_m_p_o_u_n_d _c_o_m_m_a_n_d + (see SSHHEELLLL GGRRAAMMMMAARR above), exits with a non-zero status. + The shell does not exit if the command that fails is + part of the command list immediately following a wwhhiillee + or uunnttiill keyword, part of the test following the iiff or + eelliiff reserved words, part of any command executed in a + &&&& or |||| list except the command following the final &&&& + or ||||, any command in a pipeline but the last, or if the + command's return value is being inverted with !!. If a + compound command other than a subshell returns a non- + zero status because a command failed while --ee was being + ignored, the shell does not exit. A trap on EERRRR, if + set, is executed before the shell exits. This option + applies to the shell environment and each subshell envi- + ronment separately (see CCOOMMMMAANNDD EEXXEECCUUTTIIOONN EENNVVIIRROONNMMEENNTT + above), and may cause subshells to exit before executing + all the commands in the subshell. + + If a compound command or shell function executes in a + context where --ee is being ignored, none of the commands + executed within the compound command or function body + will be affected by the --ee setting, even if --ee is set + and a command returns a failure status. If a compound + command or shell function sets --ee while executing in a + context where --ee is ignored, that setting will not have + any effect until the compound command or the command + containing the function call completes. + --ff Disable pathname expansion. + --hh Remember the location of commands as they are looked up + for execution. This is enabled by default. + --kk All arguments in the form of assignment statements are + placed in the environment for a command, not just those + that precede the command name. + --mm Monitor mode. Job control is enabled. This option is + on by default for interactive shells on systems that + support it (see JJOOBB CCOONNTTRROOLL above). All processes run + in a separate process group. When a background job com- + pletes, the shell prints a line containing its exit sta- + tus. + --nn Read commands but do not execute them. This may be used + to check a shell script for syntax errors. This is + ignored by interactive shells. + --oo _o_p_t_i_o_n_-_n_a_m_e + The _o_p_t_i_o_n_-_n_a_m_e can be one of the following: + aalllleexxppoorrtt + Same as --aa. + bbrraacceeeexxppaanndd + Same as --BB. + eemmaaccss Use an emacs-style command line editing inter- + face. This is enabled by default when the shell + is interactive, unless the shell is started with + the ----nnooeeddiittiinngg option. This also affects the + editing interface used for rreeaadd --ee. + eerrrreexxiitt Same as --ee. + eerrrrttrraaccee + Same as --EE. + ffuunnccttrraaccee + Same as --TT. + hhaasshhaallll Same as --hh. + hhiisstteexxppaanndd + Same as --HH. + hhiissttoorryy Enable command history, as described above under + HHIISSTTOORRYY. This option is on by default in inter- + active shells. + iiggnnoorreeeeooff + The effect is as if the shell command + ``IGNOREEOF=10'' had been executed (see SShheellll + VVaarriiaabblleess above). + kkeeyywwoorrdd Same as --kk. + mmoonniittoorr Same as --mm. + nnoocclloobbbbeerr + Same as --CC. + nnooeexxeecc Same as --nn. + nnoogglloobb Same as --ff. + nnoolloogg Currently ignored. + nnoottiiffyy Same as --bb. + nnoouunnsseett Same as --uu. + oonneeccmmdd Same as --tt. + pphhyyssiiccaall + Same as --PP. + ppiippeeffaaiill + If set, the return value of a pipeline is the + value of the last (rightmost) command to exit + with a non-zero status, or zero if all commands + in the pipeline exit successfully. This option + is disabled by default. + ppoossiixx Change the behavior of bbaasshh where the default + operation differs from the POSIX standard to + match the standard (_p_o_s_i_x _m_o_d_e). See SSEEEE AALLSSOO + below for a reference to a document that details + how posix mode affects bash's behavior. + pprriivviilleeggeedd + Same as --pp. + vveerrbboossee Same as --vv. + vvii Use a vi-style command line editing interface. + This also affects the editing interface used for + rreeaadd --ee. + xxttrraaccee Same as --xx. + If --oo is supplied with no _o_p_t_i_o_n_-_n_a_m_e, the values of the + current options are printed. If ++oo is supplied with no + _o_p_t_i_o_n_-_n_a_m_e, a series of sseett commands to recreate the + current option settings is displayed on the standard + output. + --pp Turn on _p_r_i_v_i_l_e_g_e_d mode. In this mode, the $$EENNVV and + $$BBAASSHH__EENNVV files are not processed, shell functions are + not inherited from the environment, and the SSHHEELLLLOOPPTTSS, + BBAASSHHOOPPTTSS, CCDDPPAATTHH, and GGLLOOBBIIGGNNOORREE variables, if they + appear in the environment, are ignored. If the shell is + started with the effective user (group) id not equal to + the real user (group) id, and the --pp option is not sup- + plied, these actions are taken and the effective user id + is set to the real user id. If the --pp option is sup- + plied at startup, the effective user id is not reset. + Turning this option off causes the effective user and + group ids to be set to the real user and group ids. + --tt Exit after reading and executing one command. + --uu Treat unset variables and parameters other than the spe- + cial parameters "@" and "*" as an error when performing + parameter expansion. If expansion is attempted on an + unset variable or parameter, the shell prints an error + message, and, if not interactive, exits with a non-zero + status. + --vv Print shell input lines as they are read. + --xx After expanding each _s_i_m_p_l_e _c_o_m_m_a_n_d, ffoorr command, ccaassee + command, sseelleecctt command, or arithmetic ffoorr command, dis- + play the expanded value of PPSS44, followed by the command + and its expanded arguments or associated word list. + --BB The shell performs brace expansion (see BBrraaccee EExxppaannssiioonn + above). This is on by default. + --CC If set, bbaasshh does not overwrite an existing file with + the >>, >>&&, and <<>> redirection operators. This may be + overridden when creating output files by using the redi- + rection operator >>|| instead of >>. + --EE If set, any trap on EERRRR is inherited by shell functions, + command substitutions, and commands executed in a sub- + shell environment. The EERRRR trap is normally not inher- + ited in such cases. + --HH Enable !! style history substitution. This option is on + by default when the shell is interactive. + --PP If set, the shell does not resolve symbolic links when + executing commands such as ccdd that change the current + working directory. It uses the physical directory + structure instead. By default, bbaasshh follows the logical + chain of directories when performing commands which + change the current directory. + --TT If set, any traps on DDEEBBUUGG and RREETTUURRNN are inherited by + shell functions, command substitutions, and commands + executed in a subshell environment. The DDEEBBUUGG and + RREETTUURRNN traps are normally not inherited in such cases. + ---- If no arguments follow this option, then the positional + parameters are unset. Otherwise, the positional parame- + ters are set to the _a_r_gs, even if some of them begin + with a --. + -- Signal the end of options, cause all remaining _a_r_gs to + be assigned to the positional parameters. The --xx and --vv + options are turned off. If there are no _a_r_gs, the posi- + tional parameters remain unchanged. + + The options are off by default unless otherwise noted. Using + + rather than - causes these options to be turned off. The + options can also be specified as arguments to an invocation of + the shell. The current set of options may be found in $$--. The + return status is always true unless an invalid option is encoun- + tered. + + sshhiifftt [_n] + The positional parameters from _n+1 ... are renamed to $$11 ........ + Parameters represented by the numbers $$## down to $$##-_n+1 are + unset. _n must be a non-negative number less than or equal to + $$##. If _n is 0, no parameters are changed. If _n is not given, + it is assumed to be 1. If _n is greater than $$##, the positional + parameters are not changed. The return status is greater than + zero if _n is greater than $$## or less than zero; otherwise 0. + + sshhoopptt [--ppqqssuu] [--oo] [_o_p_t_n_a_m_e ...] + Toggle the values of settings controlling optional shell behav- + ior. The settings can be either those listed below, or, if the + --oo option is used, those available with the --oo option to the sseett + builtin command. With no options, or with the --pp option, a list + of all settable options is displayed, with an indication of + whether or not each is set. The --pp option causes output to be + displayed in a form that may be reused as input. Other options + have the following meanings: + --ss Enable (set) each _o_p_t_n_a_m_e. + --uu Disable (unset) each _o_p_t_n_a_m_e. + --qq Suppresses normal output (quiet mode); the return status + indicates whether the _o_p_t_n_a_m_e is set or unset. If multi- + ple _o_p_t_n_a_m_e arguments are given with --qq, the return sta- + tus is zero if all _o_p_t_n_a_m_e_s are enabled; non-zero other- + wise. + --oo Restricts the values of _o_p_t_n_a_m_e to be those defined for + the --oo option to the sseett builtin. + + If either --ss or --uu is used with no _o_p_t_n_a_m_e arguments, sshhoopptt + shows only those options which are set or unset, respectively. + Unless otherwise noted, the sshhoopptt options are disabled (unset) + by default. + + The return status when listing options is zero if all _o_p_t_n_a_m_e_s + are enabled, non-zero otherwise. When setting or unsetting + options, the return status is zero unless an _o_p_t_n_a_m_e is not a + valid shell option. + + The list of sshhoopptt options is: + + aauuttooccdd If set, a command name that is the name of a directory + is executed as if it were the argument to the ccdd com- + mand. This option is only used by interactive shells. + ccddaabbllee__vvaarrss + If set, an argument to the ccdd builtin command that is + not a directory is assumed to be the name of a variable + whose value is the directory to change to. + ccddssppeellll If set, minor errors in the spelling of a directory com- + ponent in a ccdd command will be corrected. The errors + checked for are transposed characters, a missing charac- + ter, and one character too many. If a correction is + found, the corrected filename is printed, and the com- + mand proceeds. This option is only used by interactive + shells. + cchheecckkhhaasshh + If set, bbaasshh checks that a command found in the hash ta- + ble exists before trying to execute it. If a hashed + command no longer exists, a normal path search is per- + formed. + cchheecckkjjoobbss + If set, bbaasshh lists the status of any stopped and running + jobs before exiting an interactive shell. If any jobs + are running, this causes the exit to be deferred until a + second exit is attempted without an intervening command + (see JJOOBB CCOONNTTRROOLL above). The shell always postpones + exiting if any jobs are stopped. + cchheecckkwwiinnssiizzee + If set, bbaasshh checks the window size after each command + and, if necessary, updates the values of LLIINNEESS and CCOOLL-- + UUMMNNSS. + ccmmddhhiisstt If set, bbaasshh attempts to save all lines of a multiple- + line command in the same history entry. This allows + easy re-editing of multi-line commands. + ccoommppaatt3311 + If set, bbaasshh changes its behavior to that of version 3.1 + with respect to quoted arguments to the [[[[ conditional + command's ==~~ operator and locale-specific string compar- + ison when using the [[[[ conditional command's << and >> + operators. Bash versions prior to bash-4.1 use ASCII + collation and _s_t_r_c_m_p(3); bash-4.1 and later use the cur- + rent locale's collation sequence and _s_t_r_c_o_l_l(3). + ccoommppaatt3322 + If set, bbaasshh changes its behavior to that of version 3.2 + with respect to locale-specific string comparison when + using the [[[[ conditional command's << and >> operators + (see previous item) and the effect of interrupting a + command list. Bash versions 3.2 and earlier continue + with the next command in the list after one terminates + due to an interrupt. + ccoommppaatt4400 + If set, bbaasshh changes its behavior to that of version 4.0 + with respect to locale-specific string comparison when + using the [[[[ conditional command's << and >> operators + (see description of ccoommppaatt3311) and the effect of inter- + rupting a command list. Bash versions 4.0 and later + interrupt the list as if the shell received the inter- + rupt; previous versions continue with the next command + in the list. + ccoommppaatt4411 + If set, bbaasshh, when in _p_o_s_i_x mode, treats a single quote + in a double-quoted parameter expansion as a special + character. The single quotes must match (an even num- + ber) and the characters between the single quotes are + considered quoted. This is the behavior of posix mode + through version 4.1. The default bash behavior remains + as in previous versions. + ccoommppaatt4422 + If set, bbaasshh does not process the replacement string in + the pattern substitution word expansion using quote + removal. + ccoommppaatt4433 + If set, bbaasshh does not print a warning message if an + attempt is made to use a quoted compound array assign- + ment as an argument to ddeeccllaarree, makes word expansion + errors non-fatal errors that cause the current command + to fail (the default behavior is to make them fatal + errors that cause the shell to exit), and does not reset + the loop state when a shell function is executed (this + allows bbrreeaakk or ccoonnttiinnuuee in a shell function to affect + loops in the caller's context). + ccoommpplleettee__ffuullllqquuoottee + If set, bbaasshh quotes all shell metacharacters in file- + names and directory names when performing completion. + If not set, bbaasshh removes metacharacters such as the dol- + lar sign from the set of characters that will be quoted + in completed filenames when these metacharacters appear + in shell variable references in words to be completed. + This means that dollar signs in variable names that + expand to directories will not be quoted; however, any + dollar signs appearing in filenames will not be quoted, + either. This is active only when bash is using back- + slashes to quote completed filenames. This variable is + set by default, which is the default bash behavior in + versions through 4.2. + ddiirreexxppaanndd + If set, bbaasshh replaces directory names with the results + of word expansion when performing filename completion. + This changes the contents of the readline editing buf- + fer. If not set, bbaasshh attempts to preserve what the + user typed. + ddiirrssppeellll + If set, bbaasshh attempts spelling correction on directory + names during word completion if the directory name ini- + tially supplied does not exist. + ddoottgglloobb If set, bbaasshh includes filenames beginning with a `.' in + the results of pathname expansion. + eexxeeccffaaiill + If set, a non-interactive shell will not exit if it can- + not execute the file specified as an argument to the + eexxeecc builtin command. An interactive shell does not + exit if eexxeecc fails. + eexxppaanndd__aalliiaasseess + If set, aliases are expanded as described above under + AALLIIAASSEESS. This option is enabled by default for interac- + tive shells. + eexxttddeebbuugg + If set at shell invocation, arrange to execute the + debugger profile before the shell starts, identical to + the ----ddeebbuuggggeerr option. If set after invocation, behav- + ior intended for use by debuggers is enabled: + 11.. The --FF option to the ddeeccllaarree builtin displays the + source file name and line number corresponding to + each function name supplied as an argument. + 22.. If the command run by the DDEEBBUUGG trap returns a + non-zero value, the next command is skipped and + not executed. + 33.. If the command run by the DDEEBBUUGG trap returns a + value of 2, and the shell is executing in a sub- + routine (a shell function or a shell script exe- + cuted by the .. or ssoouurrccee builtins), the shell + simulates a call to rreettuurrnn. + 44.. BBAASSHH__AARRGGCC and BBAASSHH__AARRGGVV are updated as described + in their descriptions above. + 55.. Function tracing is enabled: command substitu- + tion, shell functions, and subshells invoked with + (( _c_o_m_m_a_n_d )) inherit the DDEEBBUUGG and RREETTUURRNN traps. + 66.. Error tracing is enabled: command substitution, + shell functions, and subshells invoked with (( + _c_o_m_m_a_n_d )) inherit the EERRRR trap. + eexxttgglloobb If set, the extended pattern matching features described + above under PPaatthhnnaammee EExxppaannssiioonn are enabled. + eexxttqquuoottee + If set, $$'_s_t_r_i_n_g' and $$"_s_t_r_i_n_g" quoting is performed + within $${{_p_a_r_a_m_e_t_e_r}} expansions enclosed in double + quotes. This option is enabled by default. + ffaaiillgglloobb + If set, patterns which fail to match filenames during + pathname expansion result in an expansion error. + ffoorrccee__ffiiggnnoorree + If set, the suffixes specified by the FFIIGGNNOORREE shell + variable cause words to be ignored when performing word + completion even if the ignored words are the only possi- + ble completions. See SSHHEELLLL VVAARRIIAABBLLEESS above for a + description of FFIIGGNNOORREE. This option is enabled by + default. + gglloobbaasscciiiirraannggeess + If set, range expressions used in pattern matching + bracket expressions (see PPaatttteerrnn MMaattcchhiinngg above) behave + as if in the traditional C locale when performing com- + parisons. That is, the current locale's collating + sequence is not taken into account, so bb will not col- + late between AA and BB, and upper-case and lower-case + ASCII characters will collate together. + gglloobbssttaarr + If set, the pattern **** used in a pathname expansion con- + text will match all files and zero or more directories + and subdirectories. If the pattern is followed by a //, + only directories and subdirectories match. + ggnnuu__eerrrrffmmtt + If set, shell error messages are written in the standard + GNU error message format. + hhiissttaappppeenndd + If set, the history list is appended to the file named + by the value of the HHIISSTTFFIILLEE variable when the shell + exits, rather than overwriting the file. + hhiissttrreeeeddiitt + If set, and rreeaaddlliinnee is being used, a user is given the + opportunity to re-edit a failed history substitution. + hhiissttvveerriiffyy + If set, and rreeaaddlliinnee is being used, the results of his- + tory substitution are not immediately passed to the + shell parser. Instead, the resulting line is loaded + into the rreeaaddlliinnee editing buffer, allowing further modi- + fication. + hhoossttccoommpplleettee + If set, and rreeaaddlliinnee is being used, bbaasshh will attempt to + perform hostname completion when a word containing a @@ + is being completed (see CCoommpplleettiinngg under RREEAADDLLIINNEE + above). This is enabled by default. + hhuuppoonneexxiitt + If set, bbaasshh will send SSIIGGHHUUPP to all jobs when an inter- + active login shell exits. + iinnhheerriitt__eerrrreexxiitt + If set, command substitution inherits the value of the + eerrrreexxiitt option, instead of unsetting it in the subshell + environment. This option is enabled when _p_o_s_i_x _m_o_d_e is + enabled. + iinntteerraaccttiivvee__ccoommmmeennttss + If set, allow a word beginning with ## to cause that word + and all remaining characters on that line to be ignored + in an interactive shell (see CCOOMMMMEENNTTSS above). This + option is enabled by default. + llaassttppiippee + If set, and job control is not active, the shell runs + the last command of a pipeline not executed in the back- + ground in the current shell environment. + lliitthhiisstt If set, and the ccmmddhhiisstt option is enabled, multi-line + commands are saved to the history with embedded newlines + rather than using semicolon separators where possible. + llooggiinn__sshheellll + The shell sets this option if it is started as a login + shell (see IINNVVOOCCAATTIIOONN above). The value may not be + changed. + mmaaiillwwaarrnn + If set, and a file that bbaasshh is checking for mail has + been accessed since the last time it was checked, the + message ``The mail in _m_a_i_l_f_i_l_e has been read'' is dis- + played. + nnoo__eemmppttyy__ccmmdd__ccoommpplleettiioonn + If set, and rreeaaddlliinnee is being used, bbaasshh will not + attempt to search the PPAATTHH for possible completions when + completion is attempted on an empty line. + nnooccaasseegglloobb + If set, bbaasshh matches filenames in a case-insensitive + fashion when performing pathname expansion (see PPaatthhnnaammee + EExxppaannssiioonn above). + nnooccaasseemmaattcchh + If set, bbaasshh matches patterns in a case-insensitive + fashion when performing matching while executing ccaassee or + [[[[ conditional commands, when performing pattern substi- + tution word expansions, or when filtering possible com- + pletions as part of programmable completion. + nnuullllgglloobb + If set, bbaasshh allows patterns which match no files (see + PPaatthhnnaammee EExxppaannssiioonn above) to expand to a null string, + rather than themselves. + pprrooggccoommpp + If set, the programmable completion facilities (see PPrroo-- + ggrraammmmaabbllee CCoommpplleettiioonn above) are enabled. This option is + enabled by default. + pprroommppttvvaarrss + If set, prompt strings undergo parameter expansion, com- + mand substitution, arithmetic expansion, and quote + removal after being expanded as described in PPRROOMMPPTTIINNGG + above. This option is enabled by default. + rreessttrriicctteedd__sshheellll + The shell sets this option if it is started in + restricted mode (see RREESSTTRRIICCTTEEDD SSHHEELLLL below). The value + may not be changed. This is not reset when the startup + files are executed, allowing the startup files to dis- + cover whether or not a shell is restricted. + sshhiifftt__vveerrbboossee + If set, the sshhiifftt builtin prints an error message when + the shift count exceeds the number of positional parame- + ters. + ssoouurrcceeppaatthh + If set, the ssoouurrccee (..) builtin uses the value of PPAATTHH to + find the directory containing the file supplied as an + argument. This option is enabled by default. + xxppgg__eecchhoo + If set, the eecchhoo builtin expands backslash-escape + sequences by default. + + ssuussppeenndd [--ff] + Suspend the execution of this shell until it receives a SSIIGGCCOONNTT + signal. A login shell cannot be suspended; the --ff option can be + used to override this and force the suspension. The return sta- + tus is 0 unless the shell is a login shell and --ff is not sup- + plied, or if job control is not enabled. + + tteesstt _e_x_p_r + [[ _e_x_p_r ]] + Return a status of 0 (true) or 1 (false) depending on the evalu- + ation of the conditional expression _e_x_p_r. Each operator and op- + erand must be a separate argument. Expressions are composed of + the primaries described above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS. + tteesstt does not accept any options, nor does it accept and ignore + an argument of ---- as signifying the end of options. + + Expressions may be combined using the following operators, + listed in decreasing order of precedence. The evaluation + depends on the number of arguments; see below. Operator prece- + dence is used when there are five or more arguments. + !! _e_x_p_r True if _e_x_p_r is false. + (( _e_x_p_r )) + Returns the value of _e_x_p_r. This may be used to override + the normal precedence of operators. + _e_x_p_r_1 -aa _e_x_p_r_2 + True if both _e_x_p_r_1 and _e_x_p_r_2 are true. + _e_x_p_r_1 -oo _e_x_p_r_2 + True if either _e_x_p_r_1 or _e_x_p_r_2 is true. + + tteesstt and [[ evaluate conditional expressions using a set of rules + based on the number of arguments. + + 0 arguments + The expression is false. + 1 argument + The expression is true if and only if the argument is not + null. + 2 arguments + If the first argument is !!, the expression is true if and + only if the second argument is null. If the first argu- + ment is one of the unary conditional operators listed + above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS, the expression is + true if the unary test is true. If the first argument is + not a valid unary conditional operator, the expression is + false. + 3 arguments + The following conditions are applied in the order listed. + If the second argument is one of the binary conditional + operators listed above under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS, the + result of the expression is the result of the binary test + using the first and third arguments as operands. The --aa + and --oo operators are considered binary operators when + there are three arguments. If the first argument is !!, + the value is the negation of the two-argument test using + the second and third arguments. If the first argument is + exactly (( and the third argument is exactly )), the result + is the one-argument test of the second argument. Other- + wise, the expression is false. + 4 arguments + If the first argument is !!, the result is the negation of + the three-argument expression composed of the remaining + arguments. Otherwise, the expression is parsed and eval- + uated according to precedence using the rules listed + above. + 5 or more arguments + The expression is parsed and evaluated according to + precedence using the rules listed above. + + When used with tteesstt or [[, the << and >> operators sort lexico- + graphically using ASCII ordering. + + ttiimmeess Print the accumulated user and system times for the shell and + for processes run from the shell. The return status is 0. + + ttrraapp [--llpp] [[_a_r_g] _s_i_g_s_p_e_c ...] + The command _a_r_g is to be read and executed when the shell + receives signal(s) _s_i_g_s_p_e_c. If _a_r_g is absent (and there is a + single _s_i_g_s_p_e_c) or --, each specified signal is reset to its + original disposition (the value it had upon entrance to the + shell). If _a_r_g is the null string the signal specified by each + _s_i_g_s_p_e_c is ignored by the shell and by the commands it invokes. + If _a_r_g is not present and --pp has been supplied, then the trap + commands associated with each _s_i_g_s_p_e_c are displayed. If no + arguments are supplied or if only --pp is given, ttrraapp prints the + list of commands associated with each signal. The --ll option + causes the shell to print a list of signal names and their cor- + responding numbers. Each _s_i_g_s_p_e_c is either a signal name + defined in <_s_i_g_n_a_l_._h>, or a signal number. Signal names are + case insensitive and the SSIIGG prefix is optional. + + If a _s_i_g_s_p_e_c is EEXXIITT (0) the command _a_r_g is executed on exit + from the shell. If a _s_i_g_s_p_e_c is DDEEBBUUGG, the command _a_r_g is exe- + cuted before every _s_i_m_p_l_e _c_o_m_m_a_n_d, _f_o_r command, _c_a_s_e command, + _s_e_l_e_c_t command, every arithmetic _f_o_r command, and before the + first command executes in a shell function (see SSHHEELLLL GGRRAAMMMMAARR + above). Refer to the description of the eexxttddeebbuugg option to the + sshhoopptt builtin for details of its effect on the DDEEBBUUGG trap. If a + _s_i_g_s_p_e_c is RREETTUURRNN, the command _a_r_g is executed each time a shell + function or a script executed with the .. or ssoouurrccee builtins fin- + ishes executing. + + If a _s_i_g_s_p_e_c is EERRRR, the command _a_r_g is executed whenever a + pipeline (which may consist of a single simple command), a list, + or a compound command returns a non-zero exit status, subject to + the following conditions. The EERRRR trap is not executed if the + failed command is part of the command list immediately following + a wwhhiillee or uunnttiill keyword, part of the test in an _i_f statement, + part of a command executed in a &&&& or |||| list except the command + following the final &&&& or ||||, any command in a pipeline but the + last, or if the command's return value is being inverted using + !!. These are the same conditions obeyed by the eerrrreexxiitt (--ee) + option. + + Signals ignored upon entry to the shell cannot be trapped or + reset. Trapped signals that are not being ignored are reset to + their original values in a subshell or subshell environment when + one is created. The return status is false if any _s_i_g_s_p_e_c is + invalid; otherwise ttrraapp returns true. + + ttyyppee [--aaffttppPP] _n_a_m_e [_n_a_m_e ...] + With no options, indicate how each _n_a_m_e would be interpreted if + used as a command name. If the --tt option is used, ttyyppee prints a + string which is one of _a_l_i_a_s, _k_e_y_w_o_r_d, _f_u_n_c_t_i_o_n, _b_u_i_l_t_i_n, or + _f_i_l_e if _n_a_m_e is an alias, shell reserved word, function, + builtin, or disk file, respectively. If the _n_a_m_e is not found, + then nothing is printed, and an exit status of false is + returned. If the --pp option is used, ttyyppee either returns the + name of the disk file that would be executed if _n_a_m_e were speci- + fied as a command name, or nothing if ``type -t name'' would not + return _f_i_l_e. The --PP option forces a PPAATTHH search for each _n_a_m_e, + even if ``type -t name'' would not return _f_i_l_e. If a command is + hashed, --pp and --PP print the hashed value, which is not necessar- + ily the file that appears first in PPAATTHH. If the --aa option is + used, ttyyppee prints all of the places that contain an executable + named _n_a_m_e. This includes aliases and functions, if and only if + the --pp option is not also used. The table of hashed commands is + not consulted when using --aa. The --ff option suppresses shell + function lookup, as with the ccoommmmaanndd builtin. ttyyppee returns true + if all of the arguments are found, false if any are not found. + + uulliimmiitt [--HHSSaabbccddeeffiikkllmmnnppqqrrssttuuvvxxPPTT [_l_i_m_i_t]] + Provides control over the resources available to the shell and + to processes started by it, on systems that allow such control. + The --HH and --SS options specify that the hard or soft limit is set + for the given resource. A hard limit cannot be increased by a + non-root user once it is set; a soft limit may be increased up + to the value of the hard limit. If neither --HH nor --SS is speci- + fied, both the soft and hard limits are set. The value of _l_i_m_i_t + can be a number in the unit specified for the resource or one of + the special values hhaarrdd, ssoofftt, or uunnlliimmiitteedd, which stand for the + current hard limit, the current soft limit, and no limit, + respectively. If _l_i_m_i_t is omitted, the current value of the + soft limit of the resource is printed, unless the --HH option is + given. When more than one resource is specified, the limit name + and unit are printed before the value. Other options are inter- + preted as follows: + --aa All current limits are reported + --bb The maximum socket buffer size + --cc The maximum size of core files created + --dd The maximum size of a process's data segment + --ee The maximum scheduling priority ("nice") + --ff The maximum size of files written by the shell and its + children + --ii The maximum number of pending signals + --kk The maximum number of kqueues that may be allocated + --ll The maximum size that may be locked into memory + --mm The maximum resident set size (many systems do not honor + this limit) + --nn The maximum number of open file descriptors (most systems + do not allow this value to be set) + --pp The pipe size in 512-byte blocks (this may not be set) + --qq The maximum number of bytes in POSIX message queues + --rr The maximum real-time scheduling priority + --ss The maximum stack size + --tt The maximum amount of cpu time in seconds + --uu The maximum number of processes available to a single + user + --vv The maximum amount of virtual memory available to the + shell and, on some systems, to its children + --xx The maximum number of file locks + --PP The maximum number of pseudoterminals + --TT The maximum number of threads + + If _l_i_m_i_t is given, and the --aa option is not used, _l_i_m_i_t is the + new value of the specified resource. If no option is given, + then --ff is assumed. Values are in 1024-byte increments, except + for --tt, which is in seconds; --pp, which is in units of 512-byte + blocks; --PP, --TT, --bb, --kk, --nn, and --uu, which are unscaled values; + and, when in Posix mode, --cc and --ff, which are in 512-byte incre- + ments. The return status is 0 unless an invalid option or argu- + ment is supplied, or an error occurs while setting a new limit. + + uummaasskk [--pp] [--SS] [_m_o_d_e] + The user file-creation mask is set to _m_o_d_e. If _m_o_d_e begins with + a digit, it is interpreted as an octal number; otherwise it is + interpreted as a symbolic mode mask similar to that accepted by + _c_h_m_o_d(1). If _m_o_d_e is omitted, the current value of the mask is + printed. The --SS option causes the mask to be printed in sym- + bolic form; the default output is an octal number. If the --pp + option is supplied, and _m_o_d_e is omitted, the output is in a form + that may be reused as input. The return status is 0 if the mode + was successfully changed or if no _m_o_d_e argument was supplied, + and false otherwise. + + uunnaalliiaass [-aa] [_n_a_m_e ...] + Remove each _n_a_m_e from the list of defined aliases. If --aa is + supplied, all alias definitions are removed. The return value + is true unless a supplied _n_a_m_e is not a defined alias. + + uunnsseett [-ffvv] [-nn] [_n_a_m_e ...] + For each _n_a_m_e, remove the corresponding variable or function. + If the --vv option is given, each _n_a_m_e refers to a shell variable, + and that variable is removed. Read-only variables may not be + unset. If --ff is specified, each _n_a_m_e refers to a shell func- + tion, and the function definition is removed. If the --nn option + is supplied, and _n_a_m_e is a variable with the _n_a_m_e_r_e_f attribute, + _n_a_m_e will be unset rather than the variable it references. --nn + has no effect if the --ff option is supplied. If no options are + supplied, each _n_a_m_e refers to a variable; if there is no vari- + able by that name, any function with that name is unset. Each + unset variable or function is removed from the environment + passed to subsequent commands. If any of CCOOMMPP__WWOORRDDBBRREEAAKKSS, RRAANN-- + DDOOMM, SSEECCOONNDDSS, LLIINNEENNOO, HHIISSTTCCMMDD, FFUUNNCCNNAAMMEE, GGRROOUUPPSS, or DDIIRRSSTTAACCKK are + unset, they lose their special properties, even if they are sub- + sequently reset. The exit status is true unless a _n_a_m_e is read- + only. + + wwaaiitt [--nn] [_n _._._.] + Wait for each specified child process and return its termination + status. Each _n may be a process ID or a job specification; if a + job spec is given, all processes in that job's pipeline are + waited for. If _n is not given, all currently active child pro- + cesses are waited for, and the return status is zero. If the --nn + option is supplied, wwaaiitt waits for any job to terminate and + returns its exit status. If _n specifies a non-existent process + or job, the return status is 127. Otherwise, the return status + is the exit status of the last process or job waited for. + +RREESSTTRRIICCTTEEDD SSHHEELLLL + If bbaasshh is started with the name rrbbaasshh, or the --rr option is supplied at + invocation, the shell becomes restricted. A restricted shell is used + to set up an environment more controlled than the standard shell. It + behaves identically to bbaasshh with the exception that the following are + disallowed or not performed: + + +o changing directories with ccdd + + +o setting or unsetting the values of SSHHEELLLL, PPAATTHH, EENNVV, or BBAASSHH__EENNVV + + +o specifying command names containing // + + +o specifying a filename containing a // as an argument to the .. + builtin command + + +o specifying a filename containing a slash as an argument to the + --pp option to the hhaasshh builtin command + + +o importing function definitions from the shell environment at + startup + + +o parsing the value of SSHHEELLLLOOPPTTSS from the shell environment at + startup + + +o redirecting output using the >, >|, <>, >&, &>, and >> redirect- + ion operators + + +o using the eexxeecc builtin command to replace the shell with another + command + + +o adding or deleting builtin commands with the --ff and --dd options + to the eennaabbllee builtin command + + +o using the eennaabbllee builtin command to enable disabled shell + builtins + + +o specifying the --pp option to the ccoommmmaanndd builtin command + + +o turning off restricted mode with sseett ++rr or sseett ++oo rreessttrriicctteedd. + + These restrictions are enforced after any startup files are read. + + When a command that is found to be a shell script is executed (see CCOOMM-- + MMAANNDD EEXXEECCUUTTIIOONN above), rrbbaasshh turns off any restrictions in the shell + spawned to execute the script. + +SSEEEE AALLSSOO + _B_a_s_h _R_e_f_e_r_e_n_c_e _M_a_n_u_a_l, Brian Fox and Chet Ramey + _T_h_e _G_n_u _R_e_a_d_l_i_n_e _L_i_b_r_a_r_y, Brian Fox and Chet Ramey + _T_h_e _G_n_u _H_i_s_t_o_r_y _L_i_b_r_a_r_y, Brian Fox and Chet Ramey + _P_o_r_t_a_b_l_e _O_p_e_r_a_t_i_n_g _S_y_s_t_e_m _I_n_t_e_r_f_a_c_e _(_P_O_S_I_X_) _P_a_r_t _2_: _S_h_e_l_l _a_n_d _U_t_i_l_i_- + _t_i_e_s, IEEE -- + http://pubs.opengroup.org/onlinepubs/9699919799/ + http://tiswww.case.edu/~chet/bash/POSIX -- a description of posix mode + _s_h(1), _k_s_h(1), _c_s_h(1) + _e_m_a_c_s(1), _v_i(1) + _r_e_a_d_l_i_n_e(3) + +FFIILLEESS + _/_b_i_n_/_b_a_s_h + The bbaasshh executable + _/_e_t_c_/_p_r_o_f_i_l_e + The systemwide initialization file, executed for login shells + _~_/_._b_a_s_h___p_r_o_f_i_l_e + The personal initialization file, executed for login shells + _~_/_._b_a_s_h_r_c + The individual per-interactive-shell startup file + _~_/_._b_a_s_h___l_o_g_o_u_t + The individual login shell cleanup file, executed when a login + shell exits + _~_/_._i_n_p_u_t_r_c + Individual _r_e_a_d_l_i_n_e initialization file + +AAUUTTHHOORRSS + Brian Fox, Free Software Foundation + bfox@gnu.org + + Chet Ramey, Case Western Reserve University + chet.ramey@case.edu + +BBUUGG RREEPPOORRTTSS + If you find a bug in bbaasshh,, you should report it. But first, you should + make sure that it really is a bug, and that it appears in the latest + version of bbaasshh. The latest version is always available from + _f_t_p_:_/_/_f_t_p_._g_n_u_._o_r_g_/_p_u_b_/_g_n_u_/_b_a_s_h_/. + + Once you have determined that a bug actually exists, use the _b_a_s_h_b_u_g + command to submit a bug report. If you have a fix, you are encouraged + to mail that as well! Suggestions and `philosophical' bug reports may + be mailed to _b_u_g_-_b_a_s_h_@_g_n_u_._o_r_g or posted to the Usenet newsgroup + ggnnuu..bbaasshh..bbuugg. + + ALL bug reports should include: + + The version number of bbaasshh + The hardware and operating system + The compiler used to compile + A description of the bug behaviour + A short script or `recipe' which exercises the bug + + _b_a_s_h_b_u_g inserts the first three items automatically into the template + it provides for filing a bug report. + + Comments and bug reports concerning this manual page should be directed + to _c_h_e_t_._r_a_m_e_y_@_c_a_s_e_._e_d_u. + +BBUUGGSS + It's too big and too slow. + + There are some subtle differences between bbaasshh and traditional versions + of sshh, mostly because of the PPOOSSIIXX specification. + + Aliases are confusing in some uses. + + Shell builtin commands and functions are not stoppable/restartable. + + Compound commands and command sequences of the form `a ; b ; c' are not + handled gracefully when process suspension is attempted. When a + process is stopped, the shell immediately executes the next command in + the sequence. It suffices to place the sequence of commands between + parentheses to force it into a subshell, which may be stopped as a + unit. + + Array variables may not (yet) be exported. + + There may be only one active coprocess at a time. + +GNU Bash 4.4 2016 August 26 BASH(1) diff --git a/SCR.1.1/TP07/TP06/globpattern.tar b/SCR.1.1/TP07/TP06/globpattern.tar new file mode 100644 index 0000000..0b8e547 Binary files /dev/null and b/SCR.1.1/TP07/TP06/globpattern.tar differ diff --git a/SCR.1.1/TP07/TP06/tp06-fichereponsesSCR1.2.odt b/SCR.1.1/TP07/TP06/tp06-fichereponsesSCR1.2.odt new file mode 100644 index 0000000..3dda48a Binary files /dev/null and b/SCR.1.1/TP07/TP06/tp06-fichereponsesSCR1.2.odt differ diff --git a/SCR.1.1/TP07/TP07/.~lock.TP07-fichiereponses-SCR1.2.odt# b/SCR.1.1/TP07/TP07/.~lock.TP07-fichiereponses-SCR1.2.odt# new file mode 100644 index 0000000..99ee1a0 --- /dev/null +++ b/SCR.1.1/TP07/TP07/.~lock.TP07-fichiereponses-SCR1.2.odt# @@ -0,0 +1 @@ +,yolou,archlinux,13.11.2024 11:03,file:///export/home/senart24/yolou/.config/libreoffice/4; \ No newline at end of file diff --git a/SCR.1.1/TP07/TP07/TP07-fichiereponses-SCR1.2.odt b/SCR.1.1/TP07/TP07/TP07-fichiereponses-SCR1.2.odt new file mode 100644 index 0000000..416b38c Binary files /dev/null and b/SCR.1.1/TP07/TP07/TP07-fichiereponses-SCR1.2.odt differ diff --git a/SCR.1.1/TP07/TP07/q b/SCR.1.1/TP07/TP07/q new file mode 100644 index 0000000..c11ccb8 --- /dev/null +++ b/SCR.1.1/TP07/TP07/q @@ -0,0 +1,108 @@ +EXPR(1) User Commands EXPR(1) + +NNAAMMEE + expr - evaluate expressions + +SSYYNNOOPPSSIISS + eexxpprr _E_X_P_R_E_S_S_I_O_N + eexxpprr _O_P_T_I_O_N + +DDEESSCCRRIIPPTTIIOONN + ----hheellpp display this help and exit + + ----vveerrssiioonn + output version information and exit + + Print the value of EXPRESSION to standard output. A blank line below + separates increasing precedence groups. EXPRESSION may be: + + ARG1 | ARG2 + ARG1 if it is neither null nor 0, otherwise ARG2 + + ARG1 & ARG2 + ARG1 if neither argument is null or 0, otherwise 0 + + ARG1 < ARG2 + ARG1 is less than ARG2 + + ARG1 <= ARG2 + ARG1 is less than or equal to ARG2 + + ARG1 = ARG2 + ARG1 is equal to ARG2 + + ARG1 != ARG2 + ARG1 is unequal to ARG2 + + ARG1 >= ARG2 + ARG1 is greater than or equal to ARG2 + + ARG1 > ARG2 + ARG1 is greater than ARG2 + + ARG1 + ARG2 + arithmetic sum of ARG1 and ARG2 + + ARG1 - ARG2 + arithmetic difference of ARG1 and ARG2 + + ARG1 * ARG2 + arithmetic product of ARG1 and ARG2 + + ARG1 / ARG2 + arithmetic quotient of ARG1 divided by ARG2 + + ARG1 % ARG2 + arithmetic remainder of ARG1 divided by ARG2 + + STRING : REGEXP + anchored pattern match of REGEXP in STRING + + match STRING REGEXP + same as STRING : REGEXP + + substr STRING POS LENGTH + substring of STRING, POS counted from 1 + + index STRING CHARS + index in STRING where any CHARS is found, or 0 + + length STRING + length of STRING + + + TOKEN + interpret TOKEN as a string, even if it is a + + keyword like 'match' or an operator like '/' + + ( EXPRESSION ) + value of EXPRESSION + + Beware that many operators need to be escaped or quoted for shells. + Comparisons are arithmetic if both ARGs are numbers, else lexicographi- + cal. Pattern matches return the string matched between \( and \) or + null; if \( and \) are not used, they return the number of characters + matched or 0. + + Exit status is 0 if EXPRESSION is neither null nor 0, 1 if EXPRESSION + is null or 0, 2 if EXPRESSION is syntactically invalid, and 3 if an + error occurred. + +AAUUTTHHOORR + Written by Mike Parker, James Youngman, and Paul Eggert. + +RREEPPOORRTTIINNGG BBUUGGSS + GNU coreutils online help: + Report expr translation bugs to + +CCOOPPYYRRIIGGHHTT + Copyright (C) 2017 Free Software Foundation, Inc. License GPLv3+: GNU + GPL version 3 or later . + This is free software: you are free to change and redistribute it. + There is NO WARRANTY, to the extent permitted by law. + +SSEEEE AALLSSOO + Full documentation at: + or available locally via: info '(coreutils) expr invocation' + +GNU coreutils 8.29 December 2017 EXPR(1) diff --git a/SCR.1.1/tp01-reponses.txt~ b/SCR.1.1/tp01-reponses.txt~ new file mode 100644 index 0000000..469f423 --- /dev/null +++ b/SCR.1.1/tp01-reponses.txt~ @@ -0,0 +1,3 @@ +TP01 + +I. 1) Cette diff --git a/SCR.1.2/TP09/fichier-reponses-tp08.txt b/SCR.1.2/TP09/fichier-reponses-tp08.txt index 4cfa6f9..bc593c7 100644 --- a/SCR.1.2/TP09/fichier-reponses-tp08.txt +++ b/SCR.1.2/TP09/fichier-reponses-tp08.txt @@ -108,5 +108,10 @@ Explication : des fichiers réguliers dont le contenu occupe moins de 3 blocs. +12) [yolou@archlinux TREE]$ find . -mtime -4 (il y'a aucun fichier / repertoire qui a été modifié il y a 4 jours) + + +Explication : des éléments dans toute l’arborescence commençant à partir de lib/krb5/syn/ qui ont +étés modifiés il y a moins de 4 jours.