test reaping caps

fork_reaper.c

#include <stdio.h>
#include <unistd.h>
#include <sys/prctl.h>

int main() {
  printf("origin: pid=%d, ppid=%d, pgid=%d\n", getpid(), getppid(), getpgid(getpid()));

  printf("prctl %d\n", prctl(PR_SET_CHILD_SUBREAPER, 1, 0, 0, 0));

  pid_t pid = fork();

  if (pid == 0) {
    printf("pid=%d, ppid=%d, pgid=%d: child=%d\n", getpid(), getppid(), getpgid(getpid()), pid);

    pid_t pid = fork();

    if (pid == 0) {
        printf("pid=%d, ppid=%d, pgid=%d: child=%d\n", getpid(), getppid(), getpgid(getpid()), pid);

        pid_t pid = fork();
        printf("pid=%d, ppid=%d, pgid=%d\n", getpid(), getppid(), getpgid(getpid()));
        sleep(10);
        printf("pid=%d, ppid=%d, pgid=%d\n", getpid(), getppid(), getpgid(getpid()));
        sleep(10);
    } else {
        printf("pid=%d, ppid=%d, pgid=%d: child=%d\n", getpid(), getppid(), getpgid(getpid()), pid);

        sleep(5);
    }
  } else {
      while (1) {
        printf("pid=%d, ppid=%d, pgid=%d: child=%d\n", getpid(), getppid(), getpgid(getpid()), pid);
        sleep(20);
      }
  }

  return 0;
}