TD2/exercise3/exercise.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5
   6 #include <sys/types.h>
   7 #include <sys/wait.h>
   8
   9 int main() {
  10     int pipefd[2];
  11     char tmpbuf;
  12
  13     if (pipe(pipefd) == -1) {
  14         perror("Pipe creation failure\n");
  15         exit(EXIT_FAILURE);
  16     };
  17
  18     pid_t cpid = fork();
  19
  20     if (cpid == -1) {
  21         perror("fork failure\n");
  22         exit(EXIT_FAILURE);
  23     } else if (cpid == 0) {
  24         close(pipefd[0]);
  25         dup2(pipefd[1], STDOUT_FILENO);
  26         execl("/bin/ls", "ls", (char*)NULL);
  27         close(pipefd[1]);
  28         exit(EXIT_SUCCESS);
  29     } else {
  30         close(pipefd[1]);
  31         printf("[%d] REDIRECTION: \n", getpid());
  32         //determine the pipe size to avoid this kind of code
  33         while (read(pipefd[0], &tmpbuf, 1) > 0) {
  34             write(STDOUT_FILENO, &tmpbuf, 1);
  35         }
  36         close(pipefd[0]);
  37         wait(NULL);
  38     }
  39
  40     return EXIT_SUCCESS;
  41 }