cosmopolitan/libc/calls/signal.c

34 lines
2.3 KiB
C

/*-*- mode:c; indent-tabs-mode:nil; tab-width:2; coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/struct/sigaction.h"
#include "libc/sysv/consts/sa.h"
/**
* Installs kernel interrupt handler.
*
* @see sigaction() which has more features
*/
sighandler_t(signal)(int sig, sighandler_t func) {
struct sigaction sa_old, sa = {.sa_handler = func, .sa_flags = SA_RESTART};
if ((sigaction)(sig, &sa, &sa_old) == -1) return SIG_ERR;
return sa_old.sa_handler;
}