1   
    2   void sigint_handler(int sig)
    3   {
    4     printf("pid %d got SIGINT, terminating\n", getpid());
    5     exit(0);
    6   }
    7   
    8   
    9   int main()
   10   {
   11     pid_t pid;
   12   
   13     Signal(SIGINT, sigint_handler);
   14     if ( (pid = fork()) == 0 ) {
   15       printf("child pid = %d, gid = %d\n", getpid(), getpgrp());
   16       pause();
   17     }
   18     printf("parent pid = %d, gid = %d\n", getpid(), getpgrp());
   19     pause();
   20   
   21     return 0;
   22   }