gl/timegm.c

   1 /* Convert UTC calendar time to simple time.  Like mktime but assumes UTC.
   2
   3    Copyright (C) 1994, 1997, 2003 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #ifdef _LIBC
  25 # include <time.h>
  26 #else
  27 # include "timegm.h"
  28 # include <time_r.h>
  29 # undef __gmtime_r
  30 # define __gmtime_r gmtime_r
  31 time_t __mktime_internal (struct tm *,
  32                           struct tm * (*) (time_t const *, struct tm *),
  33                           time_t *);
  34 #endif
  35
  36 time_t
  37 timegm (struct tm *tmp)
  38 {
  39   static time_t gmtime_offset;
  40   tmp->tm_isdst = 0;
  41   return __mktime_internal (tmp, __gmtime_r, &gmtime_offset);
  42 }