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

main()
{ int pid;
  union wait status;   /* explain this */

  pid = fork();
  if (pid == -1)
  { perror("fork failed");
    exit(-1);
  }
  else if (pid == 0)   /* Child */
  { sleep(1);
    printf("Hello");
  }
  else                 /* Parent */
  { wait(&status);     /* Comment out the wait and see what happens */
    printf(" World\n");
  }
}