TD1/part_two/exo.c

   1 #include <sys/types.h>
   2 #include <sys/wait.h>
   3
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <unistd.h>
   8
   9 void show_proc_pids() {
  10     pid_t current_pid = getpid();
  11     pid_t parent_pid = getppid();
  12
  13     printf("[%d] Mon PID: %d\n", current_pid, current_pid);
  14     printf("[%d] PID du parent: %d\n", current_pid, parent_pid);
  15 }
  16
  17 int main() {
  18     int pipefd[2];
  19     char buf;
  20     printf("Courant:\n");
  21     show_proc_pids();
  22
  23     if (pipe(pipefd) == -1) {
  24         printf("Pipe creation erreur\n");
  25         exit(EXIT_FAILURE);
  26     };
  27
  28     pid_t cpid = fork();
  29
  30     if (cpid == -1) {
  31         printf("Erreur de clonage\n");
  32         exit(EXIT_FAILURE);
  33     } else if (cpid == 0) {
  34         printf("Fils:\n");
  35         show_proc_pids();
  36         const char* str_fmt = "[%d] Coucou papa !\n";
  37         close(pipefd[0]);
  38         write(pipefd[1], str_fmt, strlen(str_fmt));
  39         close(pipefd[1]);
  40         exit(EXIT_SUCCESS);
  41     } else {
  42         printf("Parent:\n");
  43         show_proc_pids();
  44         close(pipefd[1]);
  45         read(pipefd[0], &buf, 20*sizeof(buf));
  46         printf(&buf, getpid());
  47         close(pipefd[0]);
  48         wait(NULL);
  49         exit(EXIT_SUCCESS);
  50     }
  51
  52     /* unreachable code */
  53     return EXIT_SUCCESS;
  54 }