89 lines
2.0 KiB
C
89 lines
2.0 KiB
C
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <string.h>
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#include <errno.h>
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int main() {
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int pipefd[2];
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if (pipe(pipefd) == -1) {
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perror("pipe");
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exit(EXIT_FAILURE);
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}
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pid_t pf1 = fork();
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if (pf1 < 0) {
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perror("fork Pf1");
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exit(EXIT_FAILURE);
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}
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if (pf1 == 0) {
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pid_t pf1f1 = fork();
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if (pf1f1 < 0) {
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perror("fork Pf1f1");
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exit(EXIT_FAILURE);
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}
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if (pf1f1 == 0) {
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close(pipefd[1]);
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pid_t received_pid;
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while (1) {
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ssize_t bytesRead = read(pipefd[0], &received_pid, sizeof(pid_t));
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if (bytesRead == sizeof(pid_t)) {
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printf("\t%d received %d\n", getpid(), received_pid);
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fflush(stdout);
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} else if (bytesRead == 0) {
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break;
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} else {
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perror("read");
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break;
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}
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sleep(1);
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}
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close(pipefd[0]);
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exit(EXIT_SUCCESS);
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} else {
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wait(NULL);
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exit(EXIT_SUCCESS);
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}
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} else {
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pid_t pf2 = fork();
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if (pf2 < 0) {
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perror("fork Pf2");
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exit(EXIT_FAILURE);
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}
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if (pf2 == 0) {
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close(pipefd[0]);
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pid_t my_pid = getpid();
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while (1) {
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ssize_t bytesWritten = write(pipefd[1], &my_pid, sizeof(pid_t));
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if (bytesWritten == sizeof(pid_t)) {
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printf("%d sent %d\n", my_pid, my_pid);
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fflush(stdout);
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} else {
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perror("write");
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break;
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}
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sleep(3);
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}
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close(pipefd[1]);
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exit(EXIT_SUCCESS);
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} else {
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wait(NULL);
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wait(NULL);
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}
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}
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return 0;
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}
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