libs/rfc822/rfc822_mkdate.c

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