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

/* to compile:
  gcc -Wall clone-pid-test.c -o clone-pid-test
 */

static int run_thread(void *arg)
{
  printf("thread reported pid: %d\n", getpid()); 

  return 0;
}

static char stack[4096];

static int create_thread()
{
  int
    pid;

  /* create thread */
  if ( (pid = clone(run_thread, stack + sizeof(stack) -1,
		    CLONE_FS|CLONE_FILES|CLONE_VM|SIGCHLD, NULL)) == -1 ) {
    perror("clone:");
    exit(-1);
  }/* end if */

  return pid ;
}

int main(int argc, char *argv[])
{
  printf("parent pid: %d\n", getpid());
  printf("clone returned pid: %d\n",  create_thread());
  wait(NULL);
  return 0;
}