gnu/dist/gettext/gettext-tools/src/po-time.c

   1 /* PO/POT file timestamps.
   2    Copyright (C) 1995-1998, 2000-2003 Free Software Foundation, Inc.
   3    Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, April 1995.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 # include <config.h>
  21 #endif
  22
  23 /* Specification.  */
  24 #include "po-time.h"
  25
  26 #include "xerror.h"
  27
  28
  29 #define TM_YEAR_ORIGIN 1900
  30
  31 /* Yield A - B, measured in seconds.  */
  32 static long
  33 difftm (const struct tm *a, const struct tm *b)
  34 {
  35   int ay = a->tm_year + TM_YEAR_ORIGIN - 1;
  36   int by = b->tm_year + TM_YEAR_ORIGIN - 1;
  37   /* Some compilers cannot handle this as a single return statement.  */
  38   long days = (
  39                /* difference in day of year  */
  40                a->tm_yday - b->tm_yday
  41                /* + intervening leap days  */
  42                + ((ay >> 2) - (by >> 2))
  43                - (ay / 100 - by / 100)
  44                + ((ay / 100 >> 2) - (by / 100 >> 2))
  45                /* + difference in years * 365  */
  46                + (long) (ay - by) * 365l);
  47
  48   return 60l * (60l * (24l * days + (a->tm_hour - b->tm_hour))
  49                 + (a->tm_min - b->tm_min))
  50          + (a->tm_sec - b->tm_sec);
  51 }
  52
  53
  54 char *
  55 po_strftime (const time_t *tp)
  56 {
  57   struct tm local_time;
  58   char tz_sign;
  59   long tz_min;
  60
  61   local_time = *localtime (tp);
  62   tz_sign = '+';
  63   tz_min = difftm (&local_time, gmtime (tp)) / 60;
  64   if (tz_min < 0)
  65     {
  66       tz_min = -tz_min;
  67       tz_sign = '-';
  68     }
  69   return xasprintf ("%d-%02d-%02d %02d:%02d%c%02ld%02ld",
  70                     local_time.tm_year + TM_YEAR_ORIGIN,
  71                     local_time.tm_mon + 1,
  72                     local_time.tm_mday,
  73                     local_time.tm_hour,
  74                     local_time.tm_min,
  75                     tz_sign, tz_min / 60, tz_min % 60);
  76 }