fork-exec-example.c

// System
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <pwd.h>
#include <assert.h>
#include <errno.h>
#include <uuid/uuid.h>

int main()
{
  pid_t child1, child2;

  if ((child1 = fork()) == 0) {
    if ((child2 = fork()) == 0) {
      printf("This is the second child!\n");
      sleep(2);
    } else {
      wait(NULL);
      printf("This should be the first child.\n");
    }
  } else {
    wait(NULL);
    printf("This is the parent\n");
  }

  return 0;
}