--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sigset.c	Mon Sep 05 16:31:35 2011 +0200
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2004 Gunnar Ritter
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute
+ * it freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ *
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ *
+ * 3. This notice may not be removed or altered from any source distribution.
+ */
+/*	Sccsid @(#)sigset.c	1.7 (gritter) 1/22/06	*/
+
+#if defined (__FreeBSD__) || defined (__dietlibc__) || defined (__NetBSD__) || \
+	defined (__OpenBSD__) || defined (__DragonFly__) || defined (__APPLE__)
+#include <signal.h>
+#include "sigset.h"
+
+void (*sigset(int sig, void (*func)(int)))(int)
+{
+	struct sigaction nact, oact;
+	sigset_t	nset, oset;
+
+	if (sig <= 0)
+		return SIG_ERR;
+	sigemptyset(&nset);
+	sigaddset(&nset, sig);
+	if (sigprocmask(func==SIG_HOLD?SIG_BLOCK:SIG_UNBLOCK, &nset, &oset) < 0)
+		return SIG_ERR;
+	nact.sa_handler = func;
+	nact.sa_flags = 0;
+	if (sig == SIGCHLD && func == SIG_IGN)
+		nact.sa_flags |= SA_NOCLDSTOP|SA_NOCLDWAIT;
+	sigemptyset(&nact.sa_mask);
+	sigaddset(&nact.sa_mask, sig);
+	if (sigaction(sig, func==SIG_HOLD?(struct sigaction *)0:&nact, &oact)
+			== -1)
+		return SIG_ERR;
+	if (sigismember(&oset, sig))
+		return SIG_HOLD;
+	else
+		return (oact.sa_handler);
+}
+#endif	/* __FreeBSD__ || __dietlibc__ || __NetBSD__ || __OpenBSD__ ||
+	__DragonFly__ || __APPLE__ */