lib/localtime-buffer.c

   1 /* Provide access to the last buffer returned by localtime() or gmtime().
   2
   3    Copyright (C) 2001-2003, 2005-2007, 2009-2019 Free Software
   4    Foundation, Inc.
   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 3, 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, see <https://www.gnu.org/licenses/>.  */
  18
  19 /* written by Jim Meyering */
  20
  21 #include <config.h>
  22
  23 /* Specification.  */
  24 #include "localtime-buffer.h"
  25
  26 #if GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME
  27
  28 static struct tm tm_zero_buffer;
  29 struct tm *localtime_buffer_addr = &tm_zero_buffer;
  30
  31 /* This is a wrapper for localtime.
  32
  33    On the first call, record the address of the static buffer that
  34    localtime uses for its result.  */
  35
  36 struct tm *
  37 rpl_localtime (time_t const *timep)
  38 {
  39   struct tm *tm = localtime (timep);
  40
  41   if (localtime_buffer_addr == &tm_zero_buffer)
  42     localtime_buffer_addr = tm;
  43
  44   return tm;
  45 }
  46
  47 /* Same as above, since gmtime and localtime use the same buffer.  */
  48 struct tm *
  49 rpl_gmtime (time_t const *timep)
  50 {
  51   struct tm *tm = gmtime (timep);
  52
  53   if (localtime_buffer_addr == &tm_zero_buffer)
  54     localtime_buffer_addr = tm;
  55
  56   return tm;
  57 }
  58
  59 #endif