7  *      int sigaction(int sig, struct sigaction *act,
9  *      int sigaddset(sigset_t *mask, int sig);
10  *      int sigdelset(sigset_t *mask, int sig);
13  *      int sigismember(sigset_t *mask, int sig);
18  *      SIG_HDLR (*Signal(int sig, SIG_HDLR (*disp)(int)))(int);
68  *      sigaddset() adds "sig" to the sigset_t pointed to by "mask".
70  *      sigdelset() removes "sig" from the sigset_t pointed to
78  *      sigismember() returns true if "sig" is found in "*mask".
189 sigaction(int sig,  in sigaction()  argument
197 		oldh = sigset(sig, act->sa_handler);  in sigaction()
199 		oldh = signal(sig, act->sa_handler);  in sigaction()
204 			oldh = sigset(sig, SIG_IGN);  in sigaction()
206 			oldh = signal(sig, SIG_IGN);  in sigaction()
210 				(void) sigset(sig, oldh);  in sigaction()
212 				(void) signal(sig, oldh);  in sigaction()
225 sigaddset(sigset_t *mask, int sig)  in sigaddset()  argument
227 	*mask |= sigmask(sig);  in sigaddset()
233 sigdelset(sigset_t *mask, int sig)  in sigdelset()  argument
235 	*mask &= ~(sigmask(sig));  in sigdelset()
257 sigismember(const sigset_t *mask, int sig)  in sigismember()  argument
259 	return ((*mask) & sigmask(sig));  in sigismember()
382 extern void (*Signal (int sig, void (*handler) (int)))(int);
384 SIG_HDLR(*signal(int sig, SIG_HDLR(*handler)(int))
386 	return (Signal(sig, handler));