sigset.c (1907B)
1 /* 2 * Copyright (c) 2004 Gunnar Ritter 3 * 4 * This software is provided 'as-is', without any express or implied 5 * warranty. In no event will the authors be held liable for any damages 6 * arising from the use of this software. 7 * 8 * Permission is granted to anyone to use this software for any purpose, 9 * including commercial applications, and to alter it and redistribute 10 * it freely, subject to the following restrictions: 11 * 12 * 1. The origin of this software must not be misrepresented; you must not 13 * claim that you wrote the original software. If you use this software 14 * in a product, an acknowledgment in the product documentation would be 15 * appreciated but is not required. 16 * 17 * 2. Altered source versions must be plainly marked as such, and must not be 18 * misrepresented as being the original software. 19 * 20 * 3. This notice may not be removed or altered from any source distribution. 21 */ 22 /* Sccsid @(#)sigset.c 1.7 (gritter) 1/22/06 */ 23 24 #if defined (__FreeBSD__) || defined (__dietlibc__) || defined (__NetBSD__) || \ 25 defined (__OpenBSD__) || defined (__DragonFly__) || defined (__APPLE__) 26 #include <signal.h> 27 #include "sigset.h" 28 29 void (*sigset(int sig, void (*func)(int)))(int) 30 { 31 struct sigaction nact, oact; 32 sigset_t nset, oset; 33 34 if (sig <= 0) 35 return SIG_ERR; 36 sigemptyset(&nset); 37 sigaddset(&nset, sig); 38 if (sigprocmask(func==SIG_HOLD?SIG_BLOCK:SIG_UNBLOCK, &nset, &oset) < 0) 39 return SIG_ERR; 40 nact.sa_handler = func; 41 nact.sa_flags = 0; 42 if (sig == SIGCHLD && func == SIG_IGN) 43 nact.sa_flags |= SA_NOCLDSTOP|SA_NOCLDWAIT; 44 sigemptyset(&nact.sa_mask); 45 sigaddset(&nact.sa_mask, sig); 46 if (sigaction(sig, func==SIG_HOLD?(struct sigaction *)0:&nact, &oact) 47 == -1) 48 return SIG_ERR; 49 if (sigismember(&oset, sig)) 50 return SIG_HOLD; 51 else 52 return (oact.sa_handler); 53 } 54 #endif /* __FreeBSD__ || __dietlibc__ || __NetBSD__ || __OpenBSD__ || 55 __DragonFly__ || __APPLE__ */