glibc/time/timegm.c

48 lines
1.5 KiB
C

/* Convert UTC calendar time to simple time. Like mktime but assumes UTC.
Copyright (C) 1994-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#ifdef _LIBC
# include <time.h>
#else
# include "timegm.h"
/* Portable standalone applications should supply a "time_r.h" that
declares a POSIX-compliant gmtime_r, for the benefit of older
implementations that lack gmtime_r or have a nonstandard one.
See the gnulib time_r module for one way to implement this. */
# include <time_r.h>
# undef __gmtime_r
# define __gmtime_r gmtime_r
time_t __mktime_internal (struct tm *,
struct tm * (*) (time_t const *, struct tm *),
time_t *);
#endif
time_t
timegm (struct tm *tmp)
{
static time_t gmtime_offset;
tmp->tm_isdst = 0;
return __mktime_internal (tmp, __gmtime_r, &gmtime_offset);
}