1 void alarm_hand(int sig) {
2 /* check if the signal is the right one */
3 if (sig != SIGALRM) { /* if not exit with error */
4 printf("Something wrong, handler for SIGALRM\n");
6 } else { /* do nothing, just interrupt pause */
10 unsigned int sleep(unsigned int seconds)
12 sighandler_t prev_handler;
13 /* install and check new handler */
14 if ((prev_handler = signal(SIGALRM, alarm_hand)) == SIG_ERR) {
15 printf("Cannot set handler for alarm\n");
18 /* set alarm and go to sleep */
21 /* restore previous signal handler */
22 signal(SIGALRM, prev_handler);
23 /* return remaining time */