/* set the Ctrl-C signal handlers */
    if(signal(SIGINT, SignalInterrupt)==SIG_ERR)
    {
        perror("Can not set handler for SIGINT\n");
        exit(1);
    }        /* set the Ctrl-Z signal handlers */
    if(signal(SIGTSTP, SignalSuspend)==SIG_ERR)
    {
        perror("Can not set handler for SIGSTP\n");
        exit(1);
    }