[apple/libc.git] / stdtime / FreeBSD / asctime.c

/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson.
*/

/*
** Avoid the temptation to punt entirely to strftime;
** the output of strftime is supposed to be locale specific
** whereas the output of asctime is supposed to be constant.
*/

#include <sys/cdefs.h>
#ifndef lint
#ifndef NOID
static char	elsieid[] __unused = "@(#)asctime.c	8.2";
#endif /* !defined NOID */
#endif /* !defined lint */
__FBSDID("$FreeBSD: src/lib/libc/stdtime/asctime.c,v 1.13 2009/05/23 06:31:50 edwin Exp $");

/*LINTLIBRARY*/

#include "namespace.h"
#include "private.h"
#include "un-namespace.h"
#include "tzfile.h"

/*
** Some systems only handle "%.2d"; others only handle "%02d";
** "%02.2d" makes (most) everybody happy.
** At least some versions of gcc warn about the %02.2d;
** we conditionalize below to avoid the warning.
*/
/*
** All years associated with 32-bit time_t values are exactly four digits long;
** some years associated with 64-bit time_t values are not.
** Vintage programs are coded for years that are always four digits long
** and may assume that the newline always lands in the same place.
** For years that are less than four digits, we pad the output with
** leading zeroes to get the newline in the traditional place.
** The -4 ensures that we get four characters of output even if
** we call a strftime variant that produces fewer characters for some years.
** The ISO C 1999 and POSIX 1003.1-2004 standards prohibit padding the year,
** but many implementations pad anyway; most likely the standards are buggy.
*/
#ifdef __GNUC__
#define ASCTIME_FMT	"%.3s %.3s%3d %2.2d:%2.2d:%2.2d %-4s\n"
#else /* !defined __GNUC__ */
#define ASCTIME_FMT	"%.3s %.3s%3d %02.2d:%02.2d:%02.2d %-4s\n"
#endif /* !defined __GNUC__ */
/*
** For years that are more than four digits we put extra spaces before the year
** so that code trying to overwrite the newline won't end up overwriting
** a digit within a year and truncating the year (operating on the assumption
** that no output is better than wrong output).
*/
#ifdef __GNUC__
#define ASCTIME_FMT_B	"%.3s %.3s%3d %2.2d:%2.2d:%2.2d     %s\n"
#else /* !defined __GNUC__ */
#define ASCTIME_FMT_B	"%.3s %.3s%3d %02.2d:%02.2d:%02.2d     %s\n"
#endif /* !defined __GNUC__ */

#define STD_ASCTIME_BUF_SIZE	26
/*
** Big enough for something such as
** ??? ???-2147483648 -2147483648:-2147483648:-2147483648     -2147483648\n
** (two three-character abbreviations, five strings denoting integers,
** seven explicit spaces, two explicit colons, a newline,
** and a trailing ASCII nul).
** The values above are for systems where an int is 32 bits and are provided
** as an example; the define below calculates the maximum for the system at
** hand.
*/
#define MAX_ASCTIME_BUF_SIZE	(2*3+5*INT_STRLEN_MAXIMUM(int)+7+2+1+1)

static char	buf_asctime[MAX_ASCTIME_BUF_SIZE];

/*
** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, 2004 Edition.
*/

char *
asctime_r(const struct tm * __restrict timeptr, char * __restrict buf)
{
	static const char	wday_name[][3] = {
		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
	};
	static const char	mon_name[][3] = {
		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
	};
	const char *	wn;
	const char *	mn;
	char			year[INT_STRLEN_MAXIMUM(int) + 2];
	char			result[MAX_ASCTIME_BUF_SIZE];

	if (timeptr->tm_wday < 0 || timeptr->tm_wday >= DAYSPERWEEK)
		wn = "???";
	else	wn = wday_name[timeptr->tm_wday];
	if (timeptr->tm_mon < 0 || timeptr->tm_mon >= MONSPERYEAR)
		mn = "???";
	else	mn = mon_name[timeptr->tm_mon];
	/*
	** Use strftime's %Y to generate the year, to avoid overflow problems
	** when computing timeptr->tm_year + TM_YEAR_BASE.
	** Assume that strftime is unaffected by other out-of-range members
	** (e.g., timeptr->tm_mday) when processing "%Y".
	*/
	(void) strftime(year, sizeof year, "%Y", timeptr);
	/*
	** We avoid using snprintf since it's not available on all systems.
	*/
	(void) sprintf(result,
		((strlen(year) <= 4) ? ASCTIME_FMT : ASCTIME_FMT_B),
		wn, mn,
		timeptr->tm_mday, timeptr->tm_hour,
		timeptr->tm_min, timeptr->tm_sec,
		year);
	if (strlen(result) < STD_ASCTIME_BUF_SIZE || buf == buf_asctime) {
		(void) strcpy(buf, result);
		return buf;
	} else {
#ifdef EOVERFLOW
		errno = EOVERFLOW;
#else /* !defined EOVERFLOW */
		errno = EINVAL;
#endif /* !defined EOVERFLOW */
		return NULL;
	}
}

/*
** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, 2004 Edition.
*/

char *
asctime(timeptr)
const struct tm *	timeptr;
{
	return asctime_r(timeptr, buf_asctime);
}
Commit	Line	Data
5b2abdfb A	1	/*
5b2abdfb A	2	** This file is in the public domain, so clarified as of
1f2f436a A	3	** 1996-06-05 by Arthur David Olson.
	4	*/
	5
	6	/*
	7	** Avoid the temptation to punt entirely to strftime;
	8	** the output of strftime is supposed to be locale specific
	9	** whereas the output of asctime is supposed to be constant.
5b2abdfb A	10	*/
5b2abdfb A	11
9385eb3d	12	#include <sys/cdefs.h>
5b2abdfb A	13	#ifndef lint
5b2abdfb A	14	#ifndef NOID
1f2f436a	15	static char elsieid[] __unused = "@(#)asctime.c 8.2";
5b2abdfb A	16	#endif /* !defined NOID */
5b2abdfb A	17	#endif /* !defined lint */
1f2f436a	18	__FBSDID("$FreeBSD: src/lib/libc/stdtime/asctime.c,v 1.13 2009/05/23 06:31:50 edwin Exp $");
5b2abdfb A	19
	20	/LINTLIBRARY/
	21
9385eb3d	22	#include "namespace.h"
5b2abdfb	23	#include "private.h"
9385eb3d	24	#include "un-namespace.h"
5b2abdfb A	25	#include "tzfile.h"
	26
	27	/*
1f2f436a A	28	** Some systems only handle "%.2d"; others only handle "%02d";
	29	** "%02.2d" makes (most) everybody happy.
	30	** At least some versions of gcc warn about the %02.2d;
	31	** we conditionalize below to avoid the warning.
	32	*/
	33	/*
	34	** All years associated with 32-bit time_t values are exactly four digits long;
	35	** some years associated with 64-bit time_t values are not.
	36	** Vintage programs are coded for years that are always four digits long
	37	** and may assume that the newline always lands in the same place.
	38	** For years that are less than four digits, we pad the output with
	39	** leading zeroes to get the newline in the traditional place.
	40	** The -4 ensures that we get four characters of output even if
	41	** we call a strftime variant that produces fewer characters for some years.
	42	** The ISO C 1999 and POSIX 1003.1-2004 standards prohibit padding the year,
	43	** but many implementations pad anyway; most likely the standards are buggy.
	44	*/
	45	#ifdef __GNUC__
	46	#define ASCTIME_FMT "%.3s %.3s%3d %2.2d:%2.2d:%2.2d %-4s\n"
	47	#else /* !defined __GNUC__ */
	48	#define ASCTIME_FMT "%.3s %.3s%3d %02.2d:%02.2d:%02.2d %-4s\n"
	49	#endif /* !defined __GNUC__ */
	50	/*
	51	** For years that are more than four digits we put extra spaces before the year
	52	** so that code trying to overwrite the newline won't end up overwriting
	53	** a digit within a year and truncating the year (operating on the assumption
	54	** that no output is better than wrong output).
	55	*/
	56	#ifdef __GNUC__
	57	#define ASCTIME_FMT_B "%.3s %.3s%3d %2.2d:%2.2d:%2.2d %s\n"
	58	#else /* !defined __GNUC__ */
	59	#define ASCTIME_FMT_B "%.3s %.3s%3d %02.2d:%02.2d:%02.2d %s\n"
	60	#endif /* !defined __GNUC__ */
	61
	62	#define STD_ASCTIME_BUF_SIZE 26
	63	/*
	64	** Big enough for something such as
	65	** ??? ???-2147483648 -2147483648:-2147483648:-2147483648 -2147483648\n
	66	** (two three-character abbreviations, five strings denoting integers,
	67	** seven explicit spaces, two explicit colons, a newline,
	68	** and a trailing ASCII nul).
	69	** The values above are for systems where an int is 32 bits and are provided
	70	** as an example; the define below calculates the maximum for the system at
	71	** hand.
	72	*/
	73	#define MAX_ASCTIME_BUF_SIZE (23+5INT_STRLEN_MAXIMUM(int)+7+2+1+1)
	74
	75	static char buf_asctime[MAX_ASCTIME_BUF_SIZE];
	76
	77	/*
	78	** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, 2004 Edition.
5b2abdfb A	79	*/
5b2abdfb A	80
5b2abdfb	81	char *
ad3c9f2a	82	asctime_r(const struct tm * __restrict timeptr, char * __restrict buf)
5b2abdfb A	83	{
	84	static const char wday_name[][3] = {
	85	"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
	86	};
	87	static const char mon_name[][3] = {
	88	"Jan", "Feb", "Mar", "Apr", "May", "Jun",
	89	"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
	90	};
9385eb3d A	91	const char * wn;
9385eb3d A	92	const char * mn;
1f2f436a A	93	char year[INT_STRLEN_MAXIMUM(int) + 2];
1f2f436a A	94	char result[MAX_ASCTIME_BUF_SIZE];
5b2abdfb A	95
	96	if (timeptr->tm_wday < 0 \|\| timeptr->tm_wday >= DAYSPERWEEK)
	97	wn = "???";
	98	else wn = wday_name[timeptr->tm_wday];
	99	if (timeptr->tm_mon < 0 \|\| timeptr->tm_mon >= MONSPERYEAR)
	100	mn = "???";
	101	else mn = mon_name[timeptr->tm_mon];
	102	/*
1f2f436a A	103	** Use strftime's %Y to generate the year, to avoid overflow problems
	104	** when computing timeptr->tm_year + TM_YEAR_BASE.
	105	** Assume that strftime is unaffected by other out-of-range members
	106	** (e.g., timeptr->tm_mday) when processing "%Y".
5b2abdfb	107	*/
1f2f436a A	108	(void) strftime(year, sizeof year, "%Y", timeptr);
	109	/*
	110	** We avoid using snprintf since it's not available on all systems.
	111	*/
	112	(void) sprintf(result,
	113	((strlen(year) <= 4) ? ASCTIME_FMT : ASCTIME_FMT_B),
5b2abdfb A	114	wn, mn,
	115	timeptr->tm_mday, timeptr->tm_hour,
	116	timeptr->tm_min, timeptr->tm_sec,
1f2f436a A	117	year);
	118	if (strlen(result) < STD_ASCTIME_BUF_SIZE \|\| buf == buf_asctime) {
	119	(void) strcpy(buf, result);
	120	return buf;
	121	} else {
	122	#ifdef EOVERFLOW
	123	errno = EOVERFLOW;
	124	#else /* !defined EOVERFLOW */
	125	errno = EINVAL;
	126	#endif /* !defined EOVERFLOW */
	127	return NULL;
	128	}
3d9156a7 A	129	}
	130
	131	/*
1f2f436a	132	** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, 2004 Edition.
3d9156a7 A	133	*/
	134
	135	char *
	136	asctime(timeptr)
	137	const struct tm * timeptr;
	138	{
1f2f436a	139	return asctime_r(timeptr, buf_asctime);
5b2abdfb	140	}