TP-systeme-exploitation-cen.../TP_tubes/verif_tubes/etu/wgw.c
2023-06-20 20:57:09 +02:00

94 lines
2.6 KiB
C

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