citadel/genstamp.c

   1 /*
   2  * Function to generate RFC822-compliant textual time/date stamp
   3  */
   4
   5 #include "sysdep.h"
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <ctype.h>
   9 #include <string.h>
  10
  11 #if TIME_WITH_SYS_TIME
  12 # include <sys/time.h>
  13 # include <time.h>
  14 #else
  15 # if HAVE_SYS_TIME_H
  16 #  include <sys/time.h>
  17 # else
  18 #  include <time.h>
  19 # endif
  20 #endif
  21
  22 #include "genstamp.h"
  23
  24
  25 static char *months[] = {
  26         "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  27         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
  28 };
  29
  30 static char *weekdays[] = {
  31         "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
  32 };
  33
  34
  35 /*
  36  * Supplied with a unix timestamp, generate an RFC822-compliant textual
  37  * time and date stamp.
  38  */
  39 long datestring(char *buf, size_t n, time_t xtime, int which_format) {
  40         struct tm t;
  41
  42         long offset;
  43         char offsign;
  44
  45         localtime_r(&xtime, &t);
  46
  47         /* Convert "seconds west of GMT" to "hours/minutes offset" */
  48 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
  49         offset = t.tm_gmtoff;
  50 #else
  51         offset = timezone;
  52 #endif
  53         if (offset > 0) {
  54                 offsign = '+';
  55         }
  56         else {
  57                 offset = 0L - offset;
  58                 offsign = '-';
  59         }
  60         offset = ( (offset / 3600) * 100 ) + ( offset % 60 );
  61
  62         switch(which_format) {
  63
  64                 case DATESTRING_RFC822:
  65                         return snprintf(
  66                                 buf, n,
  67                                 "%s, %02d %s %04d %02d:%02d:%02d %c%04ld",
  68                                 weekdays[t.tm_wday],
  69                                 t.tm_mday,
  70                                 months[t.tm_mon],
  71                                 t.tm_year + 1900,
  72                                 t.tm_hour,
  73                                 t.tm_min,
  74                                 t.tm_sec,
  75                                 offsign, offset
  76                                 );
  77                 break;
  78
  79                 case DATESTRING_IMAP:
  80                         return snprintf(
  81                                 buf, n,
  82                                 "%02d-%s-%04d %02d:%02d:%02d %c%04ld",
  83                                 t.tm_mday,
  84                                 months[t.tm_mon],
  85                                 t.tm_year + 1900,
  86                                 t.tm_hour,
  87                                 t.tm_min,
  88                                 t.tm_sec,
  89                                 offsign, offset
  90                                 );
  91                 break;
  92
  93         }
  94         return 0;
  95 }