xref: /netbsd/lib/libc/gen/signal.c (revision 6550d01e)
1 /*	$NetBSD: signal.c,v 1.12 2003/08/07 16:42:56 agc Exp $	*/
2 
3 /*
4  * Copyright (c) 1985, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)signal.c	8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: signal.c,v 1.12 2003/08/07 16:42:56 agc Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 /*
42  * Almost backwards compatible signal.
43  */
44 #include "namespace.h"
45 #include <signal.h>
46 
47 #ifdef __weak_alias
48 __weak_alias(signal,_signal)
49 #endif
50 
51 sigset_t __sigintr;		/* shared with siginterrupt */
52 
53 sig_t
54 signal(s, a)
55 	int s;
56 	sig_t a;
57 {
58 	struct sigaction sa, osa;
59 
60 	sa.sa_handler = a;
61 	sigemptyset(&sa.sa_mask);
62 	sa.sa_flags = 0;
63 	if (!sigismember(&__sigintr, s))
64 		sa.sa_flags |= SA_RESTART;
65 	if (sigaction(s, &sa, &osa) < 0)
66 		return (SIG_ERR);
67 	return (osa.sa_handler);
68 }
69