time/timegm.c

   1 /* Convert UTC calendar time to simple time.  Like mktime but assumes UTC.
   2
   3    Copyright (C) 1994-2018 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library 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 GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _LIBC
  21 # include <config.h>
  22 #endif
  23
  24 #include <time.h>
  25
  26 #include "mktime-internal.h"
  27
  28 time_t
  29 timegm (struct tm *tmp)
  30 {
  31   static mktime_offset_t gmtime_offset;
  32   tmp->tm_isdst = 0;
  33   return __mktime_internal (tmp, __gmtime_r, &gmtime_offset);
  34 }