asctime.c revision 17209 
1/*
2** This file is in the public domain, so clarified as of
3** June 5, 1996 by Arthur David Olson (arthur_david_olson@nih.gov).
4*/
5
6#ifndef lint
7#ifndef NOID
8static char	elsieid[] = "@(#)asctime.c	7.7";
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
21char *
22asctime(timeptr)
23register 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