sysdeps/unix/bsd/sigaction.c

   1 /* Copyright (C) 1991, 1995 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <sysdep.h>
  21 #include <errno.h>
  22 #include <stddef.h>
  23 #include <signal.h>
  24
  25
  26 /* If ACT is not NULL, change the action for SIG to *ACT.
  27    If OACT is not NULL, put the old action for SIG in *OACT.  */
  28 int
  29 DEFUN(__sigaction, (sig, act, oact),
  30       int sig AND CONST struct sigaction *act AND struct sigaction *oact)
  31 {
  32   struct sigvec vec, ovec;
  33
  34   if (sig <= 0 || sig >= NSIG)
  35     {
  36       errno = EINVAL;
  37       return -1;
  38     }
  39
  40   if (act != NULL)
  41     {
  42       vec.sv_mask = act->sa_mask;
  43       vec.sv_handler = act->sa_handler;
  44       vec.sv_flags = (((act->sa_flags & SA_ONSTACK) ? SV_ONSTACK : 0) |
  45                       (!(act->sa_flags & SA_RESTART) ? SV_INTERRUPT : 0));
  46     }
  47
  48   if (__sigvec(sig, act != NULL ? &vec : (struct sigvec *) NULL, &ovec) < 0)
  49     return -1;
  50
  51   if (oact != NULL)
  52     {
  53       oact->sa_handler = (void EXFUN((*), (int))) ovec.sv_handler;
  54       oact->sa_mask = ovec.sv_mask;
  55       oact->sa_flags = (((ovec.sv_flags & SV_ONSTACK) ? SA_ONSTACK : 0) |
  56                         (!(ovec.sv_flags & SV_INTERRUPT) ? SA_RESTART : 0));
  57     }
  58
  59   return 0;
  60 }
  61
  62 weak_alias (__sigaction, sigaction)