xref: /netbsd-src/external/gpl2/gettext/dist/gettext-tools/src/po-time.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /* PO/POT file timestamps.
2    Copyright (C) 1995-1998, 2000-2003, 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
18 
19 #ifdef HAVE_CONFIG_H
20 # include <config.h>
21 #endif
22 
23 /* Specification.  */
24 #include "po-time.h"
25 
26 #include "xvasprintf.h"
27 
28 
29 #define TM_YEAR_ORIGIN 1900
30 
31 /* Yield A - B, measured in seconds.  */
32 static long
difftm(const struct tm * a,const struct tm * b)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 *
po_strftime(const time_t * tp)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 }
77