[unix-history] / lib / libc / string / strftime.c

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strftime.c	5.11 (Berkeley) 2/24/91";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <sys/time.h>
#include <tzfile.h>
#include <string.h>

static char *abday[] = {
	"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
};
static char *day[] = {
	"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday",
	"Saturday",
};
static char *abmon[] = {
	"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
	"Oct", "Nov", "Dec",
};
static char *mon[] = {
	"January", "February", "March", "April", "May", "June", "July",
	"August", "September", "October", "November", "December",
};
static char *ampm[] = {
	"AM", "PM",
};

static const char *d_t_fmt = "%a %b %e %H:%M:%S %Y";
static const char *d_fmt = "%m/%d/%y";
static const char *t_fmt = "%H:%M:%S";
static const char *t_fmt_ampm = "%I:%M:%S %p";

static size_t gsize;
static char *pt;
static int _add(), _conv(), _secs();
static size_t _fmt();

size_t
strftime(s, maxsize, format, t)
	char *s;
	size_t maxsize;
	const char *format;
	const struct tm *t;
{
	pt = s;
	if ((gsize = maxsize) < 1)
		return(0);
	if (_fmt(format, t)) {
		*pt = '\0';
		return(maxsize - gsize);
	}
	return(0);
}

#define SUN_WEEK(t)	(((t)->tm_yday + 7 - \
				((t)->tm_wday)) / 7)
#define MON_WEEK(t)	(((t)->tm_yday + 7 - \
				((t)->tm_wday ? (t)->tm_wday - 1 : 6)) / 7)
static size_t
_fmt(format, t)
	register char *format;
	struct tm *t;
{
	for (; *format; ++format) {
		if (*format == '%') {
			++format;
			if (*format == 'E') {
				/* Alternate Era */
				++format;
			} else if (*format == 'O') {
				/* Alternate numeric symbols */
				++format;
			}
			switch(*format) {
			case '\0':
				--format;
				break;
			case 'A':
				if (t->tm_wday < 0 || t->tm_wday > 6)
					return(0);
				if (!_add(day[t->tm_wday]))
					return(0);
				continue;
			case 'a':
				if (t->tm_wday < 0 || t->tm_wday > 6)
					return(0);
				if (!_add(abday[t->tm_wday]))
					return(0);
				continue;
			case 'B':
				if (t->tm_mon < 0 || t->tm_mon > 11)
					return(0);
				if (!_add(mon[t->tm_mon]))
					return(0);
				continue;
			case 'b':
			case 'h':
				if (t->tm_mon < 0 || t->tm_mon > 11)
					return(0);
				if (!_add(abmon[t->tm_mon]))
					return(0);
				continue;
			case 'C':
				if (!_conv((t->tm_year + TM_YEAR_BASE) / 100,
				    2, '0'))
					return(0);
				continue;
			case 'c':
				if (!_fmt(d_t_fmt, t))
					return(0);
				continue;
			case 'D':
				if (!_fmt("%m/%d/%y", t))
					return(0);
				continue;
			case 'd':
				if (!_conv(t->tm_mday, 2, '0'))
					return(0);
				continue;
			case 'e':
				if (!_conv(t->tm_mday, 2, ' '))
					return(0);
				continue;
			case 'H':
				if (!_conv(t->tm_hour, 2, '0'))
					return(0);
				continue;
			case 'I':
				if (!_conv(t->tm_hour % 12 ?
				    t->tm_hour % 12 : 12, 2, '0'))
					return(0);
				continue;
			case 'j':
				if (!_conv(t->tm_yday + 1, 3, '0'))
					return(0);
				continue;
			case 'k':
				if (!_conv(t->tm_hour, 2, ' '))
					return(0);
				continue;
			case 'l':
				if (!_conv(t->tm_hour % 12 ?
				    t->tm_hour % 12: 12, 2, ' '))
					return(0);
				continue;
			case 'M':
				if (!_conv(t->tm_min, 2, '0'))
					return(0);
				continue;
			case 'm':
				if (!_conv(t->tm_mon + 1, 2, '0'))
					return(0);
				continue;
			case 'n':
				if (!_add("\n"))
					return(0);
				continue;
			case 'p':
				if (!_add(ampm[t->tm_hour >= 12]))
					return(0);
				continue;
			case 'R':
				if (!_fmt("%H:%M", t))
					return(0);
			case 'r':
				if (!_fmt(t_fmt_ampm, t))
					return(0);
				continue;
			case 'S':
				if (!_conv(t->tm_sec, 2, '0'))
					return(0);
				continue;
			case 's':
				if (!_secs(t))
					return(0);
				continue;
			case 'T':
				if (!_fmt("%H:%M:%S", t))
					return(0);
				continue;
			case 't':
				if (!_add("\t"))
					return(0);
				continue;
			case 'U':
				if (!_conv(SUN_WEEK(t), 2, '0'))
					return(0);
				continue;
			case 'u':
				if (!_conv(t->tm_wday ? t->tm_wday : 7, 2, '0'))
					return(0);
				continue;
			case 'V':
				{
				/* ISO 8601 Week Of Year:
				   If the week (Monday - Sunday) containing
				   January 1 has four or more days in the new 
				   year, then it is week 1; otherwise it is 
				   week 53 of the previous year and the next
				   week is week one. */
				 
				int week = MON_WEEK(t);

				if (((t->tm_yday + 7 - (t->tm_wday + 1)) % 7) >= 4) {
					week++;
				} else if (week == 0) {
					week = 53;
				}

				if (!_conv(week, 2, '0'))
					return(0);
				continue;
				}
			case 'W':
				if (!_conv(MON_WEEK(t), 2, '0'))
					return(0);
				continue;
			case 'w':
				if (!_conv(t->tm_wday, 1, '0'))
					return(0);
				continue;
			case 'x':
				if (!_fmt(d_fmt, t))
					return(0);
				continue;
			case 'X':
				if (!_fmt(t_fmt, t))
					return(0);
				continue;
			case 'y':
				if (!_conv((t->tm_year + TM_YEAR_BASE) % 100,
				    2, '0'))
					return(0);
				continue;
			case 'Y':
				if (!_conv((t->tm_year + TM_YEAR_BASE), 4, '0'))
					return(0);
				continue;
			case 'Z':
				if (t->tm_zone && !_add(t->tm_zone))
					return(0);
				continue;
			case '%':
			/*
			 * X311J/88-090 (4.12.3.5): if conversion char is
			 * undefined, behavior is undefined.  Print out the
			 * character itself as printf(3) does.
			 */
			default:
				break;
			}
		}
		if (!gsize--)
			return(0);
		*pt++ = *format;
	}
	return(gsize);
}

static
_secs(t)
	struct tm *t;
{
	static char buf[15];
	register time_t s;
	register char *p;
	struct tm tmp;

	/* Make a copy, mktime(3) modifies the tm struct. */
	tmp = *t;
	s = mktime(&tmp);
	for (p = buf + sizeof(buf) - 2; s > 0 && p > buf; s /= 10)
		*p-- = s % 10 + '0';
	return(_add(++p));
}

static
_conv(n, digits, pad)
	int n, digits;
	char pad;
{
	static char buf[10];
	register char *p;

	for (p = buf + sizeof(buf) - 2; n > 0 && p > buf; n /= 10, --digits)
		*p-- = n % 10 + '0';
	while (p > buf && digits-- > 0)
		*p-- = pad;
	return(_add(++p));
}

static
_add(str)
	register char *str;
{
	for (;; ++pt, --gsize) {
		if (!gsize)
			return(0);
		if (!(*pt = *str++))
			return(1);
	}
}
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Copyright (c) 1989 The Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
	34	#if defined(LIBC_SCCS) && !defined(lint)
	35	static char sccsid[] = "@(#)strftime.c 5.11 (Berkeley) 2/24/91";
	36	#endif /* LIBC_SCCS and not lint */
	37
	38	#include <sys/types.h>
	39	#include <sys/time.h>
	40	#include <tzfile.h>
	41	#include <string.h>
	42
78ed81a3	43	static char *abday[] = {
15637ed4 RG	44	"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
15637ed4 RG	45	};
78ed81a3	46	static char *day[] = {
15637ed4 RG	47	"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday",
	48	"Saturday",
	49	};
78ed81a3	50	static char *abmon[] = {
15637ed4 RG	51	"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
	52	"Oct", "Nov", "Dec",
	53	};
78ed81a3	54	static char *mon[] = {
15637ed4 RG	55	"January", "February", "March", "April", "May", "June", "July",
	56	"August", "September", "October", "November", "December",
	57	};
78ed81a3	58	static char *ampm[] = {
	59	"AM", "PM",
	60	};
	61
	62	static const char *d_t_fmt = "%a %b %e %H:%M:%S %Y";
	63	static const char *d_fmt = "%m/%d/%y";
	64	static const char *t_fmt = "%H:%M:%S";
	65	static const char *t_fmt_ampm = "%I:%M:%S %p";
15637ed4 RG	66
	67	static size_t gsize;
	68	static char *pt;
	69	static int _add(), _conv(), _secs();
78ed81a3	70	static size_t _fmt();
15637ed4 RG	71
	72	size_t
	73	strftime(s, maxsize, format, t)
	74	char *s;
	75	size_t maxsize;
	76	const char *format;
	77	const struct tm *t;
	78	{
15637ed4 RG	79	pt = s;
	80	if ((gsize = maxsize) < 1)
	81	return(0);
	82	if (_fmt(format, t)) {
	83	*pt = '\0';
	84	return(maxsize - gsize);
	85	}
	86	return(0);
	87	}
	88
78ed81a3	89	#define SUN_WEEK(t) (((t)->tm_yday + 7 - \
	90	((t)->tm_wday)) / 7)
	91	#define MON_WEEK(t) (((t)->tm_yday + 7 - \
	92	((t)->tm_wday ? (t)->tm_wday - 1 : 6)) / 7)
15637ed4 RG	93	static size_t
	94	_fmt(format, t)
	95	register char *format;
	96	struct tm *t;
	97	{
	98	for (; *format; ++format) {
78ed81a3	99	if (*format == '%') {
	100	++format;
	101	if (*format == 'E') {
	102	/* Alternate Era */
	103	++format;
	104	} else if (*format == 'O') {
	105	/* Alternate numeric symbols */
	106	++format;
	107	}
	108	switch(*format) {
15637ed4 RG	109	case '\0':
	110	--format;
	111	break;
	112	case 'A':
	113	if (t->tm_wday < 0 \|\| t->tm_wday > 6)
	114	return(0);
78ed81a3	115	if (!_add(day[t->tm_wday]))
15637ed4 RG	116	return(0);
	117	continue;
	118	case 'a':
	119	if (t->tm_wday < 0 \|\| t->tm_wday > 6)
	120	return(0);
78ed81a3	121	if (!_add(abday[t->tm_wday]))
15637ed4 RG	122	return(0);
	123	continue;
	124	case 'B':
	125	if (t->tm_mon < 0 \|\| t->tm_mon > 11)
	126	return(0);
78ed81a3	127	if (!_add(mon[t->tm_mon]))
15637ed4 RG	128	return(0);
	129	continue;
	130	case 'b':
	131	case 'h':
	132	if (t->tm_mon < 0 \|\| t->tm_mon > 11)
	133	return(0);
78ed81a3	134	if (!_add(abmon[t->tm_mon]))
15637ed4 RG	135	return(0);
	136	continue;
	137	case 'C':
78ed81a3	138	if (!_conv((t->tm_year + TM_YEAR_BASE) / 100,
78ed81a3	139	2, '0'))
15637ed4 RG	140	return(0);
	141	continue;
	142	case 'c':
78ed81a3	143	if (!_fmt(d_t_fmt, t))
15637ed4 RG	144	return(0);
	145	continue;
	146	case 'D':
	147	if (!_fmt("%m/%d/%y", t))
	148	return(0);
	149	continue;
	150	case 'd':
	151	if (!_conv(t->tm_mday, 2, '0'))
	152	return(0);
	153	continue;
	154	case 'e':
	155	if (!_conv(t->tm_mday, 2, ' '))
	156	return(0);
	157	continue;
	158	case 'H':
	159	if (!_conv(t->tm_hour, 2, '0'))
	160	return(0);
	161	continue;
	162	case 'I':
	163	if (!_conv(t->tm_hour % 12 ?
	164	t->tm_hour % 12 : 12, 2, '0'))
	165	return(0);
	166	continue;
	167	case 'j':
	168	if (!_conv(t->tm_yday + 1, 3, '0'))
	169	return(0);
	170	continue;
	171	case 'k':
	172	if (!_conv(t->tm_hour, 2, ' '))
	173	return(0);
	174	continue;
	175	case 'l':
	176	if (!_conv(t->tm_hour % 12 ?
78ed81a3	177	t->tm_hour % 12: 12, 2, ' '))
15637ed4 RG	178	return(0);
	179	continue;
	180	case 'M':
	181	if (!_conv(t->tm_min, 2, '0'))
	182	return(0);
	183	continue;
	184	case 'm':
	185	if (!_conv(t->tm_mon + 1, 2, '0'))
	186	return(0);
	187	continue;
	188	case 'n':
	189	if (!_add("\n"))
	190	return(0);
	191	continue;
	192	case 'p':
78ed81a3	193	if (!_add(ampm[t->tm_hour >= 12]))
15637ed4 RG	194	return(0);
	195	continue;
	196	case 'R':
	197	if (!_fmt("%H:%M", t))
	198	return(0);
15637ed4	199	case 'r':
78ed81a3	200	if (!_fmt(t_fmt_ampm, t))
15637ed4 RG	201	return(0);
	202	continue;
	203	case 'S':
	204	if (!_conv(t->tm_sec, 2, '0'))
	205	return(0);
	206	continue;
	207	case 's':
	208	if (!_secs(t))
	209	return(0);
	210	continue;
	211	case 'T':
15637ed4 RG	212	if (!_fmt("%H:%M:%S", t))
	213	return(0);
	214	continue;
	215	case 't':
	216	if (!_add("\t"))
	217	return(0);
	218	continue;
	219	case 'U':
78ed81a3	220	if (!_conv(SUN_WEEK(t), 2, '0'))
	221	return(0);
	222	continue;
	223	case 'u':
	224	if (!_conv(t->tm_wday ? t->tm_wday : 7, 2, '0'))
15637ed4 RG	225	return(0);
15637ed4 RG	226	continue;
78ed81a3	227	case 'V':
	228	{
	229	/* ISO 8601 Week Of Year:
	230	If the week (Monday - Sunday) containing
	231	January 1 has four or more days in the new
	232	year, then it is week 1; otherwise it is
	233	week 53 of the previous year and the next
	234	week is week one. */
	235
	236	int week = MON_WEEK(t);
	237
	238	if (((t->tm_yday + 7 - (t->tm_wday + 1)) % 7) >= 4) {
	239	week++;
	240	} else if (week == 0) {
	241	week = 53;
	242	}
	243
	244	if (!_conv(week, 2, '0'))
	245	return(0);
	246	continue;
	247	}
15637ed4	248	case 'W':
78ed81a3	249	if (!_conv(MON_WEEK(t), 2, '0'))
15637ed4 RG	250	return(0);
	251	continue;
	252	case 'w':
	253	if (!_conv(t->tm_wday, 1, '0'))
	254	return(0);
	255	continue;
	256	case 'x':
78ed81a3	257	if (!_fmt(d_fmt, t))
	258	return(0);
	259	continue;
	260	case 'X':
	261	if (!_fmt(t_fmt, t))
15637ed4 RG	262	return(0);
	263	continue;
	264	case 'y':
78ed81a3	265	if (!_conv((t->tm_year + TM_YEAR_BASE) % 100,
78ed81a3	266	2, '0'))
15637ed4 RG	267	return(0);
	268	continue;
	269	case 'Y':
78ed81a3	270	if (!_conv((t->tm_year + TM_YEAR_BASE), 4, '0'))
15637ed4 RG	271	return(0);
	272	continue;
	273	case 'Z':
78ed81a3	274	if (t->tm_zone && !_add(t->tm_zone))
15637ed4 RG	275	return(0);
	276	continue;
	277	case '%':
	278	/*
	279	* X311J/88-090 (4.12.3.5): if conversion char is
	280	* undefined, behavior is undefined. Print out the
	281	* character itself as printf(3) does.
	282	*/
	283	default:
	284	break;
78ed81a3	285	}
15637ed4 RG	286	}
	287	if (!gsize--)
	288	return(0);
	289	pt++ = format;
	290	}
	291	return(gsize);
	292	}
	293
	294	static
	295	_secs(t)
	296	struct tm *t;
	297	{
	298	static char buf[15];
	299	register time_t s;
	300	register char *p;
	301	struct tm tmp;
	302
	303	/* Make a copy, mktime(3) modifies the tm struct. */
	304	tmp = *t;
	305	s = mktime(&tmp);
	306	for (p = buf + sizeof(buf) - 2; s > 0 && p > buf; s /= 10)
	307	*p-- = s % 10 + '0';
	308	return(_add(++p));
	309	}
	310
	311	static
	312	_conv(n, digits, pad)
	313	int n, digits;
	314	char pad;
	315	{
	316	static char buf[10];
	317	register char *p;
	318
	319	for (p = buf + sizeof(buf) - 2; n > 0 && p > buf; n /= 10, --digits)
	320	*p-- = n % 10 + '0';
	321	while (p > buf && digits-- > 0)
	322	*p-- = pad;
	323	return(_add(++p));
	324	}
	325
	326	static
	327	_add(str)
	328	register char *str;
	329	{
	330	for (;; ++pt, --gsize) {
	331	if (!gsize)
	332	return(0);
	333	if (!(pt = str++))
	334	return(1);
	335	}
	336	}