1 /* Convenience declarations when working with <signal.h>. 2 3 Copyright (C) 2008-2012 Free Software Foundation, Inc. 4 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. 9 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. 14 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/>. */ 17 18 #ifndef _GL_SIG_HANDLER_H 19 #define _GL_SIG_HANDLER_H 20 21 #include <signal.h> 22 23 _GL_INLINE_HEADER_BEGIN 24 #ifndef SIG_HANDLER_INLINE 25 # define SIG_HANDLER_INLINE _GL_INLINE 26 #endif 27 28 /* Convenience type when working with signal handlers. */ 29 typedef void (*sa_handler_t) (int); 30 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 get_handler(struct sigaction const * a)35get_handler (struct sigaction const *a) 36 { 37 #ifdef SA_SIGINFO 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; 45 #endif 46 return a->sa_handler; 47 } 48 49 _GL_INLINE_HEADER_END 50 51 #endif /* _GL_SIG_HANDLER_H */ 52