src/src/tod.c

   1 /* $Cambridge: exim/src/src/tod.c,v 1.3 2006/02/07 11:19:00 ph10 Exp $ */
   2
   3 /*************************************************
   4 *     Exim - an Internet mail transport agent    *
   5 *************************************************/
   6
   7 /* Copyright (c) University of Cambridge 1995 - 2006 */
   8 /* See the file NOTICE for conditions of use and distribution. */
   9
  10 /* A function for returning the time of day in various formats */
  11
  12
  13 #include "exim.h"
  14
  15 /* #define TESTING_LOG_DATESTAMP */
  16
  17
  18 static uschar timebuf[sizeof("www, dd-mmm-yyyy hh:mm:ss +zzzz")];
  19
  20
  21 /*************************************************
  22 *                Return timestamp                *
  23 *************************************************/
  24
  25 /* The log timestamp format is dd-mmm-yy so as to be non-confusing on both
  26 sides of the Atlantic. We calculate an explicit numerical offset from GMT for
  27 the full datestamp and BSD inbox datestamp. Note that on some systems
  28 localtime() and gmtime() re-use the same store, so we must save the local time
  29 values before calling gmtime(). If timestamps_utc is set, don't use
  30 localtime(); all times are then in UTC (with offset +0000).
  31
  32 There are also some contortions to get the day of the month without
  33 a leading zero for the full stamp, since Ustrftime() doesn't provide this
  34 option.
  35
  36 Argument:  type of timestamp required:
  37              tod_bsdin          BSD inbox format
  38              tod_epoch          Unix epoch format
  39              tod_full           full date and time
  40              tod_log            log file data line format,
  41                                   with zone if log_timezone is TRUE
  42              tod_log_bare       always without zone
  43              tod_log_datestamp  for log file names when datestamped
  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 = time(NULL);
  56 struct tm *t;
  57
  58 /* Vary log type according to timezone requirement */
  59
  60 if (type == tod_log) type = log_timezone? tod_log_zone : tod_log_bare;
  61
  62 /* Styles that don't need local time */
  63
  64 else if (type == tod_epoch)
  65   {
  66   (void) sprintf(CS timebuf, "%d", (int)now);  /* Unix epoch format */
  67   return timebuf;
  68   }
  69
  70 else if (type == tod_zulu)
  71   {
  72   t = gmtime(&now);
  73   (void) sprintf(CS timebuf, "%04d%02d%02d%02d%02d%02dZ",
  74     1900 + t->tm_year, 1 + t->tm_mon, t->tm_mday, t->tm_hour, t->tm_min,
  75     t->tm_sec);
  76   return timebuf;
  77   }
  78
  79 /* Convert to local time or UTC */
  80
  81 t = timestamps_utc? gmtime(&now) : localtime(&now);
  82
  83 switch(type)
  84   {
  85   case tod_log_bare:          /* Format used in logging without timezone */
  86   (void) sprintf(CS timebuf, "%04d-%02d-%02d %02d:%02d:%02d",
  87     1900 + t->tm_year, 1 + t->tm_mon, t->tm_mday,
  88     t->tm_hour, t->tm_min, t->tm_sec);
  89   break;
  90
  91   /* Format used as suffix of log file name when 'log_datestamp' is active. For
  92   testing purposes, it changes the file every second. */
  93
  94   case tod_log_datestamp:
  95   #ifdef TESTING_LOG_DATESTAMP
  96   (void) sprintf(CS timebuf, "%04d%02d%02d%02d%02d",
  97     1900 + t->tm_year, 1 + t->tm_mon, t->tm_mday, t->tm_hour, t->tm_min);
  98   #else
  99   (void) sprintf(CS timebuf, "%04d%02d%02d",
 100     1900 + t->tm_year, 1 + t->tm_mon, t->tm_mday);
 101   #endif
 102   break;
 103
 104   /* Format used in BSD inbox separator lines. Sort-of documented in RFC 976
 105   ("UUCP Mail Interchange Format Standard") but only by example, not by
 106   explicit definition. The examples show no timezone offsets, and some MUAs
 107   appear to be sensitive to this, so Exim has been changed to remove the
 108   timezone offsets that originally appeared. */
 109
 110   case tod_bsdin:
 111     {
 112     int len = Ustrftime(timebuf, sizeof(timebuf), "%a %b %d %H:%M:%S", t);
 113     Ustrftime(timebuf + len, sizeof(timebuf) - len, " %Y", t);
 114     }
 115   break;
 116
 117   /* Other types require the GMT offset to be calculated, or just set up in the
 118   case of UTC timestamping. We need to take a copy of the local time first. */
 119
 120   default:
 121     {
 122     int diff_hour, diff_min;
 123     struct tm local;
 124     memcpy(&local, t, sizeof(struct tm));
 125
 126     if (timestamps_utc)
 127       {
 128       diff_hour = diff_min = 0;
 129       }
 130     else
 131       {
 132       struct tm *gmt = gmtime(&now);
 133       diff_min = 60*(local.tm_hour - gmt->tm_hour) + local.tm_min - gmt->tm_min;
 134       if (local.tm_year != gmt->tm_year)
 135         diff_min += (local.tm_year > gmt->tm_year)? 1440 : -1440;
 136       else if (local.tm_yday != gmt->tm_yday)
 137         diff_min += (local.tm_yday > gmt->tm_yday)? 1440 : -1440;
 138       diff_hour = diff_min/60;
 139       diff_min  = abs(diff_min - diff_hour*60);
 140       }
 141
 142     switch(type)
 143       {
 144       case tod_log_zone:          /* Format used in logging with timezone */
 145       (void) sprintf(CS timebuf, "%04d-%02d-%02d %02d:%02d:%02d %+03d%02d",
 146         1900 + local.tm_year, 1 + local.tm_mon, local.tm_mday,
 147         local.tm_hour, local.tm_min, local.tm_sec,
 148         diff_hour, diff_min);
 149       break;
 150
 151       case tod_zone:              /* Just the timezone offset */
 152       (void) sprintf(CS timebuf, "%+03d%02d", diff_hour, diff_min);
 153       break;
 154
 155       /* tod_mbx: format used in MBX mailboxes - subtly different to tod_full */
 156
 157       #ifdef SUPPORT_MBX
 158       case tod_mbx:
 159         {
 160         int len;
 161         (void) sprintf(CS timebuf, "%02d-", local.tm_mday);
 162         len = Ustrlen(timebuf);
 163         len += Ustrftime(timebuf + len, sizeof(timebuf) - len, "%b-%Y %H:%M:%S",
 164           &local);
 165         (void) sprintf(CS timebuf + len, " %+03d%02d", diff_hour, diff_min);
 166         }
 167       break;
 168       #endif
 169
 170       /* tod_full: format used in Received: headers (use as default just in case
 171       called with a junk type value) */
 172
 173       default:
 174         {
 175         int len = Ustrftime(timebuf, sizeof(timebuf), "%a, ", &local);
 176         (void) sprintf(CS timebuf + len, "%02d ", local.tm_mday);
 177         len += Ustrlen(timebuf + len);
 178         len += Ustrftime(timebuf + len, sizeof(timebuf) - len, "%b %Y %H:%M:%S",
 179           &local);
 180         (void) sprintf(CS timebuf + len, " %+03d%02d", diff_hour, diff_min);
 181         }
 182       break;
 183       }
 184     }
 185   break;
 186   }
 187
 188 return timebuf;
 189 }
 190
 191 /* End of tod.c */