/*
COMP201/2401 - Winter 2013

fork: create a clone of the current process

*/

#include <stdio.h> 
#include <unistd.h>

int main() {
  int pid;
  int i;
  printf("Forking...\n");
  sleep(1);

  // create a clone process
  pid = fork();

  if (pid == 0) {
    // in the child process, the return value of fork
    // is zero
    printf("child process: fork returned %d \n", pid);
    printf("child process: process id is %d \n", getpid());
    printf("child process: parent pid is %d \n", getppid());
   
    for (i=1; i<=10; ++i) {
      printf("  child iteration %2d \n", i);
      sleep(2);
    }
  }
  else {
    // in the original process, the return value of fork
    // is the PID of the child process 
    printf("parent process: fork returned %d \n", pid);
    printf("parent process: process is is %d \n", getpid());
    printf("parent process: parent pid is %d \n", getppid());
    for (i=1; i<=10; ++i) {
      printf(" parent iteration %2d \n", i);
      sleep(1);
    }
  }
}