diff --git a/TP3/Exo4/exo4.c b/TP3/Exo4/exo4.c
new file mode 100644
index 0000000..1bd2bce
--- /dev/null
+++ b/TP3/Exo4/exo4.c
@@ -0,0 +1,39 @@
+#include <sys/types.h>
+#include <unistd.h>
+#include<stdio.h>
+#include <stdlib.h>
+#include<assert.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/wait.h>
+
+int main(int argc,char * argv[])
+{
+    int status;
+    pid_t p, n;
+
+
+    p = fork();
+    assert(p != -1);
+
+    if (p==0) {
+        printf("Le retour du fork est %d\n", p);
+        printf("Mon PID est %d\n", getpid());
+        printf("Le PID de mon pere est %d\n", getppid());
+        sleep(4);
+        exit(2);
+    }
+
+    if (p>0) {
+        sleep(1);
+        printf("\nLe retour du fork est %d\n", p);
+        printf("Mon PID est %d\n", getpid());
+        printf("Le PID de mon pere est %d\n", getppid());
+        n = wait(&status);
+        printf("Le fils %d a termine avec le code %d\n", n, WEXITSTATUS(status));
+        execl("/usr/bin/ps", "ps", "-ef", NULL);
+        exit(0);
+    }
+}
\ No newline at end of file