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asctime.c revision 1.1.1.3 
      1 /*
      2 ** This file is in the public domain, so clarified as of
      3 ** 1996-06-05 by Arthur David Olson (arthur_david_olson (at) nih.gov).
      4 */
      5 
      6 #ifndef lint
      7 #ifndef NOID
      8 static char	elsieid[] = "@(#)asctime.c	7.8";
      9 #endif /* !defined NOID */
     10 #endif /* !defined lint */
     11 
     12 /*LINTLIBRARY*/
     13 
     14 #include "private.h"
     15 #include "tzfile.h"
     16 
     17 /*
     18 ** A la X3J11, with core dump avoidance.
     19 */
     20 
     21 char *
     22 asctime(timeptr)
     23 register const struct tm *	timeptr;
     24 {
     25 	static const char	wday_name[][3] = {
     26 		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
     27 	};
     28 	static const char	mon_name[][3] = {
     29 		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
     30 		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
     31 	};
     32 	/*
     33 	** Big enough for something such as
     34 	** ??? ???-2147483648 -2147483648:-2147483648:-2147483648 -2147483648\n
     35 	** (two three-character abbreviations, five strings denoting integers,
     36 	** three explicit spaces, two explicit colons, a newline,
     37 	** and a trailing ASCII nul).
     38 	*/
     39 	static char		result[3 * 2 + 5 * INT_STRLEN_MAXIMUM(int) +
     40 					3 + 2 + 1 + 1];
     41 	register const char *	wn;
     42 	register const char *	mn;
     43 
     44 	if (timeptr->tm_wday < 0 || timeptr->tm_wday >= DAYSPERWEEK)
     45 		wn = "???";
     46 	else	wn = wday_name[timeptr->tm_wday];
     47 	if (timeptr->tm_mon < 0 || timeptr->tm_mon >= MONSPERYEAR)
     48 		mn = "???";
     49 	else	mn = mon_name[timeptr->tm_mon];
     50 	/*
     51 	** The X3J11-suggested format is
     52 	**	"%.3s %.3s%3d %02.2d:%02.2d:%02.2d %d\n"
     53 	** Since the .2 in 02.2d is ignored, we drop it.
     54 	*/
     55 	(void) sprintf(result, "%.3s %.3s%3d %02d:%02d:%02d %d\n",
     56 		wn, mn,
     57 		timeptr->tm_mday, timeptr->tm_hour,
     58 		timeptr->tm_min, timeptr->tm_sec,
     59 		TM_YEAR_BASE + timeptr->tm_year);
     60 	return result;
     61 }
     62