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glibc  2.9
sigaction.c
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00001 /* Copyright (C) 1991,1995,1996,1997,2002,2004 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #include <sysdep.h>
00020 #include <errno.h>
00021 #include <stddef.h>
00022 #include <signal.h>
00023 
00024 
00025 /* If ACT is not NULL, change the action for SIG to *ACT.
00026    If OACT is not NULL, put the old action for SIG in *OACT.  */
00027 int
00028 __sigaction (sig, act, oact)
00029      int sig;
00030      const struct sigaction *act;
00031      struct sigaction *oact;
00032 {
00033   struct sigvec vec, ovec;
00034 
00035   if (sig <= 0 || sig >= NSIG)
00036     {
00037       __set_errno (EINVAL);
00038       return -1;
00039     }
00040 
00041   if (act != NULL)
00042     {
00043       vec.sv_mask = act->sa_mask;
00044       vec.sv_handler = act->sa_handler;
00045       vec.sv_flags = (((act->sa_flags & SA_ONSTACK) ? SV_ONSTACK : 0) |
00046                     (!(act->sa_flags & SA_RESTART) ? SV_INTERRUPT : 0));
00047     }
00048 
00049   if (__sigvec(sig, act != NULL ? &vec : (struct sigvec *) NULL, &ovec) < 0)
00050     return -1;
00051 
00052   if (oact != NULL)
00053     {
00054       oact->sa_handler = (void (*) (int)) ovec.sv_handler;
00055       oact->sa_mask = ovec.sv_mask;
00056       oact->sa_flags = (((ovec.sv_flags & SV_ONSTACK) ? SA_ONSTACK : 0) |
00057                      (!(ovec.sv_flags & SV_INTERRUPT) ? SA_RESTART : 0));
00058     }
00059 
00060   return 0;
00061 }
00062 libc_hidden_def (__sigaction)
00063 weak_alias (__sigaction, sigaction)