1 /* Convenience declarations when working with <signal.h>.
3 Copyright (C) 2008-2013 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 #ifndef _GL_SIG_HANDLER_H
19 #define _GL_SIG_HANDLER_H
23 _GL_INLINE_HEADER_BEGIN
24 #ifndef SIG_HANDLER_INLINE
25 # define SIG_HANDLER_INLINE _GL_INLINE
28 /* Convenience type when working with signal handlers. */
29 typedef void (*sa_handler_t) (int);
31 /* Return the handler of a signal, as a sa_handler_t value regardless
32 of its true type. The resulting function can be compared to
33 special values like SIG_IGN but it is not portable to call it. */
34 SIG_HANDLER_INLINE sa_handler_t
35 get_handler (struct sigaction const *a)
38 /* POSIX says that special values like SIG_IGN can only occur when
39 action.sa_flags does not contain SA_SIGINFO. But in Linux 2.4,
40 for example, sa_sigaction and sa_handler are aliases and a signal
41 is ignored if sa_sigaction (after casting) equals SIG_IGN. So
42 use (and cast) sa_sigaction in that case. */
43 if (a->sa_flags & SA_SIGINFO)
44 return (sa_handler_t) a->sa_sigaction;
51 #endif /* _GL_SIG_HANDLER_H */