process creation using posix in c.

process_creation.c

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>

int main() {
  int x, y;
  x = fork();
  if (x == 0) {
    printf("I'm the child %d of %d\n", getpid(), getppid());
    exit(3);
  } else if (x == -1) {
    printf("error!!\n");
  } else {
    y=wait(NULL);
    printf("hello world it is me the father of %d and the child of %d\n", y, getppid());
    printf("==== the end ====\n");
  }
  return 0;
}