lib/timefmt.c

   1 /* Time formatting functions
   2    Copyright (C) 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003,
   3    2004, 2005, 2007, 2009, 2010 Free Software Foundation, Inc.
   4    Written 1994, 1995, 1996 by:
   5    Miguel de Icaza, Janne Kukonlehto, Dugan Porter,
   6    Jakub Jelinek, Mauricio Plaza.
   7
   8    The file_date routine is mostly from GNU's fileutils package,
   9    written by Richard Stallman and David MacKenzie.
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 2 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program; if not, write to the Free Software
  23    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  24
  25 /** \file
  26  *  \brief Source: time formatting functions
  27  */
  28
  29 #include <config.h>
  30
  31 #include <stdlib.h>
  32
  33 #include "lib/global.h"
  34 #include "lib/strutil.h"
  35
  36 #include "lib/timefmt.h"
  37
  38 /*** global variables ****************************************************************************/
  39
  40 char *user_recent_timeformat = NULL;    /* time format string for recent dates */
  41 char *user_old_timeformat = NULL;       /* time format string for older dates */
  42
  43 /*** file scope macro definitions ****************************************************************/
  44
  45 /*** file scope type declarations ****************************************************************/
  46
  47 /*** file scope variables ************************************************************************/
  48
  49 /*
  50  * Cache variable for the i18n_checktimelength function,
  51  * initially set to a clearly invalid value to show that
  52  * it hasn't been initialized yet.
  53  */
  54 static size_t i18n_timelength_cache = MAX_I18NTIMELENGTH + 1;
  55
  56 /*** file scope functions ************************************************************************/
  57
  58 /*** public functions ****************************************************************************/
  59
  60 /* --------------------------------------------------------------------------------------------- */
  61 /**
  62  * Check strftime() results. Some systems (i.e. Solaris) have different
  63  *  short-month and month name sizes for different locales
  64  */
  65 size_t
  66 i18n_checktimelength (void)
  67 {
  68     size_t length = 0;
  69     const time_t testtime = time (NULL);
  70     struct tm *lt = localtime (&testtime);
  71
  72     if (i18n_timelength_cache <= MAX_I18NTIMELENGTH)
  73         return i18n_timelength_cache;
  74
  75     if (lt == NULL)
  76     {
  77         /* huh, localtime() doesnt seem to work ... falling back to "(invalid)" */
  78         length = str_term_width1 (_(INVALID_TIME_TEXT));
  79     }
  80     else
  81     {
  82         char buf[MB_LEN_MAX * MAX_I18NTIMELENGTH + 1];
  83
  84         /* We are interested in the longest possible date */
  85         lt->tm_sec = lt->tm_min = lt->tm_hour = lt->tm_mday = 10;
  86
  87         /* Loop through all months to find out the longest one */
  88         for (lt->tm_mon = 0; lt->tm_mon < 12; lt->tm_mon++)
  89         {
  90             strftime (buf, sizeof (buf) - 1, user_recent_timeformat, lt);
  91             length = max ((size_t) str_term_width1 (buf), length);
  92             strftime (buf, sizeof (buf) - 1, user_old_timeformat, lt);
  93             length = max ((size_t) str_term_width1 (buf), length);
  94         }
  95
  96         length = max ((size_t) str_term_width1 (_(INVALID_TIME_TEXT)), length);
  97     }
  98
  99     /* Don't handle big differences. Use standard value (email bug, please) */
 100     if (length > MAX_I18NTIMELENGTH || length < MIN_I18NTIMELENGTH)
 101         length = STD_I18NTIMELENGTH;
 102
 103     /* Save obtained value to the cache */
 104     i18n_timelength_cache = length;
 105
 106     return i18n_timelength_cache;
 107 }
 108
 109 /* --------------------------------------------------------------------------------------------- */
 110
 111 const char *
 112 file_date (time_t when)
 113 {
 114     static char timebuf[MB_LEN_MAX * MAX_I18NTIMELENGTH + 1];
 115     time_t current_time = time ((time_t) 0);
 116     const char *fmt;
 117
 118     if (current_time > when + 6L * 30L * 24L * 60L * 60L        /* Old. */
 119         || current_time < when - 60L * 60L)     /* In the future. */
 120         /* The file is fairly old or in the future.
 121            POSIX says the cutoff is 6 months old;
 122            approximate this by 6*30 days.
 123            Allow a 1 hour slop factor for what is considered "the future",
 124            to allow for NFS server/client clock disagreement.
 125            Show the year instead of the time of day.  */
 126
 127         fmt = user_old_timeformat;
 128     else
 129         fmt = user_recent_timeformat;
 130
 131     FMT_LOCALTIME (timebuf, sizeof (timebuf), fmt, when);
 132
 133     return timebuf;
 134 }
 135
 136 /* --------------------------------------------------------------------------------------------- */