sysdeps/unix/bsd/sigaction.c

   1 /* Copyright (C) 1991,1995,1996,1997,2002,2004 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <sysdep.h>
  19 #include <errno.h>
  20 #include <stddef.h>
  21 #include <signal.h>
  22
  23
  24 /* If ACT is not NULL, change the action for SIG to *ACT.
  25    If OACT is not NULL, put the old action for SIG in *OACT.  */
  26 int
  27 __sigaction (sig, act, oact)
  28      int sig;
  29      const struct sigaction *act;
  30      struct sigaction *oact;
  31 {
  32   struct sigvec vec, ovec;
  33
  34   if (sig <= 0 || sig >= NSIG)
  35     {
  36       __set_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 (*) (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 libc_hidden_def (__sigaction)
  62 weak_alias (__sigaction, sigaction)