rfc822/rfc822_mkdate.c

   1 /*
   2 ** Copyright 1998 - 1999 Double Precision, Inc.
   3 ** See COPYING for distribution information.
   4 */
   5
   6 /*
   7 ** $Id: rfc822_mkdate.c,v 1.4 2002/04/09 02:49:55 mrsam Exp $
   8 */
   9
  10 #include        "rfc822.h"
  11
  12 #include        <sys/types.h>
  13 #include        <time.h>
  14 #include        <stdio.h>
  15 #include        <string.h>
  16 #if     HAVE_UNISTD_H
  17 #include        <unistd.h>
  18 #endif
  19
  20 static const char * const months[]={
  21         "Jan",
  22         "Feb",
  23         "Mar",
  24         "Apr",
  25         "May",
  26         "Jun",
  27         "Jul",
  28         "Aug",
  29         "Sep",
  30         "Oct",
  31         "Nov",
  32         "Dec"};
  33
  34 static const char * const wdays[]={
  35         "Sun",
  36         "Mon",
  37         "Tue",
  38         "Wed",
  39         "Thu",
  40         "Fri",
  41         "Sat"};
  42
  43 void rfc822_mkdate_buf(time_t t, char *buf)
  44 {
  45 struct  tm *p;
  46 int     offset;
  47
  48 #if     USE_TIME_ALTZONE
  49
  50         p=localtime(&t);
  51         offset= -(int)timezone;
  52
  53         if (p->tm_isdst > 0)
  54                 offset= -(int)altzone;
  55
  56         if (offset % 60)
  57         {
  58                 offset=0;
  59                 p=gmtime(&t);
  60         }
  61         offset /= 60;
  62 #else
  63 #if     USE_TIME_DAYLIGHT
  64
  65         p=localtime(&t);
  66         offset= -(int)timezone;
  67
  68         if (p->tm_isdst > 0)
  69                 offset += 60*60;
  70         if (offset % 60)
  71         {
  72                 offset=0;
  73                 p=gmtime(&t);
  74         }
  75         offset /= 60;
  76 #else
  77 #if     USE_TIME_GMTOFF
  78         p=localtime(&t);
  79         offset= p->tm_gmtoff;
  80
  81         if (offset % 60)
  82         {
  83                 offset=0;
  84                 p=gmtime(&t);
  85         }
  86         offset /= 60;
  87 #else
  88         p=gmtime(&t);
  89         offset=0;
  90 #endif
  91 #endif
  92 #endif
  93
  94         offset = (offset % 60) + offset / 60 * 100;
  95
  96         sprintf(buf, "%s, %02d %s %04d %02d:%02d:%02d %+05d",
  97                 wdays[p->tm_wday],
  98                 p->tm_mday,
  99                 months[p->tm_mon],
 100                 p->tm_year+1900,
 101                 p->tm_hour,
 102                 p->tm_min,
 103                 p->tm_sec,
 104                 offset);
 105 }
 106
 107 const char *rfc822_mkdate(time_t t)
 108 {
 109 static char buf[50];
 110
 111         rfc822_mkdate_buf(t, buf);
 112         return (buf);
 113 }