stdtime/asctime-fbsd.c

   1 /*
   2 ** This file is in the public domain, so clarified as of
   3 ** 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
   4 */
   5
   6 #include <sys/cdefs.h>
   7 #ifndef lint
   8 #ifndef NOID
   9 static char     elsieid[] __unused = "@(#)asctime.c     7.9";
  10 #endif /* !defined NOID */
  11 #endif /* !defined lint */
  12 __FBSDID("$FreeBSD: src/lib/libc/stdtime/asctime.c,v 1.12 2004/06/14 10:31:52 stefanf Exp $");
  13
  14 /*LINTLIBRARY*/
  15
  16 #include "namespace.h"
  17 #include "private.h"
  18 #include "un-namespace.h"
  19 #include "tzfile.h"
  20
  21 /*
  22 ** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, Second Edition, 1996-07-12.
  23 */
  24
  25 #define EXPECTEDLEN     26
  26
  27 char *
  28 asctime_r(const struct tm * __restrict timeptr, char * __restrict buf)
  29 {
  30         static const char       wday_name[][3] = {
  31                 "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
  32         };
  33         static const char       mon_name[][3] = {
  34                 "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  35                 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
  36         };
  37         const char *    wn;
  38         const char *    mn;
  39         int             len;
  40         char            tmp[EXPECTEDLEN];
  41
  42         if (timeptr->tm_wday < 0 || timeptr->tm_wday >= DAYSPERWEEK)
  43                 wn = "???";
  44         else    wn = wday_name[timeptr->tm_wday];
  45         if (timeptr->tm_mon < 0 || timeptr->tm_mon >= MONSPERYEAR)
  46                 mn = "???";
  47         else    mn = mon_name[timeptr->tm_mon];
  48         /*
  49         ** The X3J11-suggested format is
  50         **      "%.3s %.3s%3d %02.2d:%02.2d:%02.2d %d\n"
  51         ** Since the .2 in 02.2d is ignored, we drop it.
  52         */
  53         /*
  54         ** Because various values in the tm structure may cause the
  55         ** resulting string to be longer than the 26-bytes that is
  56         ** specified in the spec, we should return NULL rather than
  57         ** possibly overwrite beyond the string.
  58         */
  59         len = snprintf(tmp, EXPECTEDLEN, "%.3s %.3s%3d %02d:%02d:%02d %d\n",
  60                 wn, mn,
  61                 timeptr->tm_mday, timeptr->tm_hour,
  62                 timeptr->tm_min, timeptr->tm_sec,
  63                 TM_YEAR_BASE + timeptr->tm_year);
  64         if (len >= EXPECTEDLEN)
  65                 return NULL;
  66         strcpy(buf, tmp);
  67         return buf;
  68 }
  69
  70 char *
  71 asctime(timeptr)
  72 const struct tm *       timeptr;
  73 {
  74         static char             result[EXPECTEDLEN];
  75
  76         return asctime_r(timeptr, result);
  77 }