cosmopolitan/libc/calls/sigismember.c

37 lines
2.2 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;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/sigbits.h"
#include "libc/sysv/errfuns.h"
/**
* Returns true if signal is member of set.
*
* @return true, false, or -1 w/ errno
* @asyncsignalsafe
*/
int sigismember(const sigset_t *set, int sig) {
unsigned i = sig - 1;
if (i < sizeof(set->__bits) * 8) {
return (set->__bits[i >> 6] >> (i & 63)) & 1;
} else {
return einval();
}
}