src/src/tod.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2009 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 /* A function for returning the time of day in various formats */
   9
  10
  11 #include "exim.h"
  12
  13 /* #define TESTING_LOG_DATESTAMP */
  14
  15
  16 static uschar timebuf[sizeof("www, dd-mmm-yyyy hh:mm:ss +zzzz")];
  17
  18
  19 /*************************************************
  20 *                Return timestamp                *
  21 *************************************************/
  22
  23 /* The log timestamp format is dd-mmm-yy so as to be non-confusing on both
  24 sides of the Atlantic. We calculate an explicit numerical offset from GMT for
  25 the full datestamp and BSD inbox datestamp. Note that on some systems
  26 localtime() and gmtime() re-use the same store, so we must save the local time
  27 values before calling gmtime(). If timestamps_utc is set, don't use
  28 localtime(); all times are then in UTC (with offset +0000).
  29
  30 There are also some contortions to get the day of the month without
  31 a leading zero for the full stamp, since Ustrftime() doesn't provide this
  32 option.
  33
  34 Argument:  type of timestamp required:
  35              tod_bsdin                  BSD inbox format
  36              tod_epoch                  Unix epoch format
  37              tod_epochl                 Unix epoch/usec format
  38              tod_full                   full date and time
  39              tod_log                    log file data line format,
  40                                           with zone if log_timezone is TRUE
  41              tod_log_bare               always without zone
  42              tod_log_datestamp_daily    for log file names when datestamped daily
  43              tod_log_datestamp_monthly  for log file names when datestamped monthly
  44              tod_log_zone               always with zone
  45              tod_mbx                    MBX inbox format
  46              tod_zone                   just the timezone offset
  47              tod_zulu                   time in 8601 zulu format
  48
  49 Returns:   pointer to fixed buffer containing the timestamp
  50 */
  51
  52 uschar *
  53 tod_stamp(int type)
  54 {
  55 time_t now;
  56 struct tm *t;
  57
  58 if (type == tod_epoch_l)
  59   {
  60   struct timeval tv;
  61   gettimeofday(&tv, NULL);
  62   (void) sprintf(CS timebuf, "%ld%06ld", tv.tv_sec, tv.tv_usec );  /* Unix epoch/usec format */
  63   return timebuf;
  64   }
  65
  66 now = time(NULL);
  67
  68 /* Vary log type according to timezone requirement */
  69
  70 if (type == tod_log) type = log_timezone? tod_log_zone : tod_log_bare;
  71
  72 /* Styles that don't need local time */
  73
  74 else if (type == tod_epoch)
  75   {
  76   (void) sprintf(CS timebuf, "%d", (int)now);  /* Unix epoch format */
  77   return timebuf;
  78   }
  79
  80 else if (type == tod_zulu)
  81   {
  82   t = gmtime(&now);
  83   (void) sprintf(CS timebuf, "%04d%02d%02d%02d%02d%02dZ",
  84     1900 + t->tm_year, 1 + t->tm_mon, t->tm_mday, t->tm_hour, t->tm_min,
  85     t->tm_sec);
  86   return timebuf;
  87   }
  88
  89 /* Convert to local time or UTC */
  90
  91 t = timestamps_utc? gmtime(&now) : localtime(&now);
  92
  93 switch(type)
  94   {
  95   case tod_log_bare:          /* Format used in logging without timezone */
  96   (void) sprintf(CS timebuf, "%04d-%02d-%02d %02d:%02d:%02d",
  97     1900 + t->tm_year, 1 + t->tm_mon, t->tm_mday,
  98     t->tm_hour, t->tm_min, t->tm_sec);
  99   break;
 100
 101   /* Format used as suffix of log file name when 'log_datestamp' is active. For
 102   testing purposes, it changes the file every second. */
 103
 104   #ifdef TESTING_LOG_DATESTAMP
 105   case tod_log_datestamp_daily:
 106   case tod_log_datestamp_monthly:
 107   (void) sprintf(CS timebuf, "%04d%02d%02d%02d%02d",
 108     1900 + t->tm_year, 1 + t->tm_mon, t->tm_mday, t->tm_hour, t->tm_min);
 109   break;
 110
 111   #else
 112   case tod_log_datestamp_daily:
 113   (void) sprintf(CS timebuf, "%04d%02d%02d",
 114     1900 + t->tm_year, 1 + t->tm_mon, t->tm_mday);
 115   break;
 116
 117   case tod_log_datestamp_monthly:
 118   (void) sprintf(CS timebuf, "%04d%02d",
 119     1900 + t->tm_year, 1 + t->tm_mon);
 120   break;
 121   #endif
 122
 123   /* Format used in BSD inbox separator lines. Sort-of documented in RFC 976
 124   ("UUCP Mail Interchange Format Standard") but only by example, not by
 125   explicit definition. The examples show no timezone offsets, and some MUAs
 126   appear to be sensitive to this, so Exim has been changed to remove the
 127   timezone offsets that originally appeared. */
 128
 129   case tod_bsdin:
 130     {
 131     int len = Ustrftime(timebuf, sizeof(timebuf), "%a %b %d %H:%M:%S", t);
 132     Ustrftime(timebuf + len, sizeof(timebuf) - len, " %Y", t);
 133     }
 134   break;
 135
 136   /* Other types require the GMT offset to be calculated, or just set up in the
 137   case of UTC timestamping. We need to take a copy of the local time first. */
 138
 139   default:
 140     {
 141     int diff_hour, diff_min;
 142     struct tm local;
 143     memcpy(&local, t, sizeof(struct tm));
 144
 145     if (timestamps_utc)
 146       {
 147       diff_hour = diff_min = 0;
 148       }
 149     else
 150       {
 151       struct tm *gmt = gmtime(&now);
 152       diff_min = 60*(local.tm_hour - gmt->tm_hour) + local.tm_min - gmt->tm_min;
 153       if (local.tm_year != gmt->tm_year)
 154         diff_min += (local.tm_year > gmt->tm_year)? 1440 : -1440;
 155       else if (local.tm_yday != gmt->tm_yday)
 156         diff_min += (local.tm_yday > gmt->tm_yday)? 1440 : -1440;
 157       diff_hour = diff_min/60;
 158       diff_min  = abs(diff_min - diff_hour*60);
 159       }
 160
 161     switch(type)
 162       {
 163       case tod_log_zone:          /* Format used in logging with timezone */
 164       (void) sprintf(CS timebuf, "%04d-%02d-%02d %02d:%02d:%02d %+03d%02d",
 165         1900 + local.tm_year, 1 + local.tm_mon, local.tm_mday,
 166         local.tm_hour, local.tm_min, local.tm_sec,
 167         diff_hour, diff_min);
 168       break;
 169
 170       case tod_zone:              /* Just the timezone offset */
 171       (void) sprintf(CS timebuf, "%+03d%02d", diff_hour, diff_min);
 172       break;
 173
 174       /* tod_mbx: format used in MBX mailboxes - subtly different to tod_full */
 175
 176       #ifdef SUPPORT_MBX
 177       case tod_mbx:
 178         {
 179         int len;
 180         (void) sprintf(CS timebuf, "%02d-", local.tm_mday);
 181         len = Ustrlen(timebuf);
 182         len += Ustrftime(timebuf + len, sizeof(timebuf) - len, "%b-%Y %H:%M:%S",
 183           &local);
 184         (void) sprintf(CS timebuf + len, " %+03d%02d", diff_hour, diff_min);
 185         }
 186       break;
 187       #endif
 188
 189       /* tod_full: format used in Received: headers (use as default just in case
 190       called with a junk type value) */
 191
 192       default:
 193         {
 194         int len = Ustrftime(timebuf, sizeof(timebuf), "%a, ", &local);
 195         (void) sprintf(CS timebuf + len, "%02d ", local.tm_mday);
 196         len += Ustrlen(timebuf + len);
 197         len += Ustrftime(timebuf + len, sizeof(timebuf) - len, "%b %Y %H:%M:%S",
 198           &local);
 199         (void) sprintf(CS timebuf + len, " %+03d%02d", diff_hour, diff_min);
 200         }
 201       break;
 202       }
 203     }
 204   break;
 205   }
 206
 207 return timebuf;
 208 }
 209
 210 /* End of tod.c */