sig-handler.h 1.7 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344
  1. /* Convenience declarations when working with <signal.h>.
  2. Copyright (C) 2008-2011 Free Software Foundation, Inc.
  3. This program is free software: you can redistribute it and/or modify
  4. it under the terms of the GNU General Public License as published by
  5. the Free Software Foundation; either version 3 of the License, or
  6. (at your option) any later version.
  7. This program is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  10. GNU General Public License for more details.
  11. You should have received a copy of the GNU General Public License
  12. along with this program. If not, see <http://www.gnu.org/licenses/>. */
  13. #ifndef _GL_SIG_HANDLER_H
  14. #define _GL_SIG_HANDLER_H
  15. #include <signal.h>
  16. /* Convenience type when working with signal handlers. */
  17. typedef void (*sa_handler_t) (int);
  18. /* Return the handler of a signal, as a sa_handler_t value regardless
  19. of its true type. The resulting function can be compared to
  20. special values like SIG_IGN but it is not portable to call it. */
  21. static inline sa_handler_t
  22. get_handler (struct sigaction const *a)
  23. {
  24. #ifdef SA_SIGINFO
  25. /* POSIX says that special values like SIG_IGN can only occur when
  26. action.sa_flags does not contain SA_SIGINFO. But in Linux 2.4,
  27. for example, sa_sigaction and sa_handler are aliases and a signal
  28. is ignored if sa_sigaction (after casting) equals SIG_IGN. So
  29. use (and cast) sa_sigaction in that case. */
  30. if (a->sa_flags & SA_SIGINFO)
  31. return (sa_handler_t) a->sa_sigaction;
  32. #endif
  33. return a->sa_handler;
  34. }
  35. #endif /* _GL_SIG_HANDLER_H */