fig10.18

unix环境高级编程第二版配套源代码 unix环境高级编程第二版配套源代码

#include "apue.h"

/* Reliable version of signal(), using POSIX sigaction().  */
Sigfunc *
signal(int signo, Sigfunc *func)
{
	struct sigaction	act, oact;

	act.sa_handler = func;
	sigemptyset(&act.sa_mask);
	act.sa_flags = 0;
	if (signo == SIGALRM) {
#ifdef	SA_INTERRUPT
		act.sa_flags |= SA_INTERRUPT;
#endif
	} else {
#ifdef	SA_RESTART
		act.sa_flags |= SA_RESTART;
#endif
	}
	if (sigaction(signo, &act, &oact) < 0)
		return(SIG_ERR);
	return(oact.sa_handler);
}