Linux 下設定時間間隔的Signal函數

#include <sys/time.h>#include <signal.h>#include <unistd.h>#include <stdio.h>/* ARGSUSED */static void catch_sigalrm(int sig){printf("%s\n", "SIGALRM received.");return ;}static void (*Signal (int sig, void (*handler)(int)))(int){  struct sigaction act, oact;  act.sa_handler = handler;  act.sa_flags = 0;#ifdef SA_INTERRUPT  act.sa_flags |= SA_INTERRUPT;#endif  if (sigaction(sig, &act, &oact))return SIG_ERR;  return oact.sa_handler;}int main(void){struct itimerval it;Signal(SIGALRM, &catch_sigalrm);it.it_interval.tv_sec = 1;it.it_interval.tv_usec = 0;it.it_value.tv_sec = 1;it.it_value.tv_usec = 0;setitimer(ITIMER_REAL, &it, NULL);/* CONSTCOND */for (;;)pause();/* NOTREACHED */  return 0;}