93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
#include <stdio.h> /* entrées sorties */
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#include <unistd.h> /* pimitives de base : fork, ...*/
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#include <stdlib.h> /* exit */
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#include <sys/wait.h> /* wait */
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#include <string.h> /* opérations sur les chaines */
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#include <fcntl.h> /* opérations sur les fichiers */
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#include <errno.h>
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int main(int argc, char *argv[])
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{
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extern int errno;
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int retour;
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int pipes[2][2];
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if (pipe(pipes[0]) < 0)
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{ // pipe failed
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fprintf(stderr, "ERROR: pipe error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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}
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if (pipe(pipes[1]) < 0)
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{ // pipe failed
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fprintf(stderr, "ERROR: pipe error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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}
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if ((retour = fork()) < 0)
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{ // fork failed
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fprintf(stderr, "ERROR: fork error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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}
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else if (retour == 0)
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{ ////////// pipes[0][0] --> grep --> pipes[1][1] //////////
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if (dup2(pipes[0][0], 0) == -1)
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{ // dup2 fail
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fprintf(stderr, "ERROR: dup2 error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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}
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if (dup2(pipes[1][1], 1) == -1)
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{ // dup2 fail
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fprintf(stderr, "ERROR: dup2 error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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}
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close(pipes[0][1]);
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close(pipes[1][0]);
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execlp("grep", "grep", argv[1], NULL);
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fprintf(stderr, "ERROR: execlp error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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}
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if ((retour = fork()) < 0)
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{ // fork failed
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fprintf(stderr, "ERROR: fork error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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}
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else if (retour == 0)
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{ ////////// pipes[1][0] --> wc --> stdout //////////
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if (dup2(pipes[1][0], 0) == -1)
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{ // dup2 fail
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fprintf(stderr, "ERROR: dup2 error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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}
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close(pipes[0][0]);
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close(pipes[0][1]);
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close(pipes[1][1]);
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execlp("wc", "wc", "-l", NULL);
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fprintf(stderr, "ERROR: execlp error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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}
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////////// stdin --> who --> pipes[0][0] //////////
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if (dup2(pipes[0][1], 1) == -1)
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{ // dup2 fail
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fprintf(stderr, "ERROR: dup2 error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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}
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close(pipes[0][0]);
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close(pipes[1][0]);
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close(pipes[1][1]);
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execlp("who", "who", NULL);
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fprintf(stderr, "ERROR: execlp error, (%d) %s\n", errno, strerror(errno));
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exit(errno);
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// on atteint jamais cet endroit
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return EXIT_FAILURE;
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}
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