[unix-history] / usr / src / 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 are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strftime.c	5.3 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

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

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

static size_t gsize;
static char *pt;

size_t
strftime(s, maxsize, format, t)
	char *s;
	char *format;
	size_t maxsize;
	struct tm *t;
{
	size_t _fmt();

	pt = s;
	if ((gsize = maxsize) < 1)
		return(0);
	if (_fmt(format, t)) {
		*pt = '\0';
		return(maxsize - gsize);
	}
	return(0);
}

static size_t
_fmt(format, t)
	register char *format;
	struct tm *t;
{
	for (; *format; ++format) {
		if (*format == '%')
			switch(*++format) {
			case '\0':
				--format;
				break;
			case 'A':
				if (t->tm_wday < 0 || t->tm_wday > 6)
					return(0);
				if (!_add(Afmt[t->tm_wday]))
					return(0);
				continue;
			case 'a':
				if (t->tm_wday < 0 || t->tm_wday > 6)
					return(0);
				if (!_add(afmt[t->tm_wday]))
					return(0);
				continue;
			case 'B':
				if (t->tm_mon < 0 || t->tm_mon > 11)
					return(0);
				if (!_add(Bfmt[t->tm_mon]))
					return(0);
				continue;
			case 'b':
			case 'h':
				if (t->tm_mon < 0 || t->tm_mon > 11)
					return(0);
				if (!_add(bfmt[t->tm_mon]))
					return(0);
				continue;
			case 'c':
				if (!_fmt("%x %X %Z %Y", t))
					return(0);
				continue;
			case 'D':
				if (!_fmt("%m/%d/%y", t))
					return(0);
				continue;
			case 'd':
				if (!_conv(t->tm_mday, 2))
					return(0);
				continue;
			case 'H':
				if (!_conv(t->tm_hour, 2))
					return(0);
				continue;
			case 'I':
				if (!_conv(t->tm_hour % 12 ?
				    t->tm_hour % 12 : 12, 2))
					return(0);
				continue;
			case 'j':
				if (!_conv(t->tm_yday + 1, 3))
					return(0);
				continue;
			case 'M':
				if (!_conv(t->tm_min, 2))
					return(0);
				continue;
			case 'm':
				if (!_conv(t->tm_mon + 1, 2))
					return(0);
				continue;
			case 'n':
				if (!_add("\n"))
					return(0);
				continue;
			case 'p':
				if (!_add(t->tm_hour >= 12 ? "PM" : "AM"))
					return(0);
				continue;
			case 'R':
				if (!_fmt("%H:%M", t))
					return(0);
				continue;
			case 'r':
				if (!_fmt("%I:%M:%S %p", t))
					return(0);
				continue;
			case 'S':
				if (!_conv(t->tm_sec, 2))
					return(0);
				continue;
			case 'T':
			case 'X':
				if (!_fmt("%H:%M:%S", t))
					return(0);
				continue;
			case 't':
				if (!_add("\t"))
					return(0);
				continue;
			case 'U':
				if (!_conv((t->tm_yday + 7 - t->tm_wday) / 7,
				    2))
					return(0);
				continue;
			case 'W':
				if (!_conv((t->tm_yday + 7 -
				    (t->tm_wday ? (t->tm_wday - 1) : 6))
				    / 7, 2))
					return(0);
				continue;
			case 'w':
				if (!_conv(t->tm_wday, 1))
					return(0);
				continue;
			case 'x':
				if (!_fmt("%a %b %d %Y", t))
					return(0);
				continue;
			case 'y':
				if (!_conv((t->tm_year + TM_YEAR_BASE)
				    % 100, 2))
					return(0);
				continue;
			case 'Y':
				if (!_conv(t->tm_year + TM_YEAR_BASE, 4))
					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) also does.
			 */
			default:
				break;
		}
		if (!gsize--)
			return(0);
		*pt++ = *format;
	}
	return(gsize);
}

static
_conv(n, digits)
	int n, digits;
{
	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-- = '0';
	return(_add(++p));
}

static
_add(str)
	register char *str;
{
	for (;; ++pt, --gsize) {
		if (!gsize)
			return(0);
		if (!(*pt = *str++))
			return(1);
	}
}
Commit	Line	Data
e9fe19df KB	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 are permitted
	6	* provided that the above copyright notice and this paragraph are
	7	* duplicated in all such forms and that any documentation,
	8	* advertising materials, and other materials related to such
	9	* distribution and use acknowledge that the software was developed
	10	* by the University of California, Berkeley. The name of the
	11	* University may not be used to endorse or promote products derived
	12	* from this software without specific prior written permission.
	13	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
	14	* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
	15	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	16	*/
	17
	18	#if defined(LIBC_SCCS) && !defined(lint)
e2abfca3	19	static char sccsid[] = "@(#)strftime.c 5.3 (Berkeley) %G%";
e9fe19df KB	20	#endif /* LIBC_SCCS and not lint */
	21
	22	#include <sys/types.h>
	23	#include <sys/time.h>
	24	#include <tzfile.h>
	25
	26	static char *afmt[] = {
	27	"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
	28	};
	29	static char *Afmt[] = {
	30	"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday",
	31	"Saturday",
	32	};
	33	static char *bfmt[] = {
	34	"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
	35	"Oct", "Nov", "Dec",
	36	};
	37	static char *Bfmt[] = {
	38	"January", "February", "March", "April", "May", "June", "July",
	39	"August", "September", "October", "November", "December",
	40	};
	41
	42	static size_t gsize;
	43	static char *pt;
	44
	45	size_t
	46	strftime(s, maxsize, format, t)
	47	char *s;
	48	char *format;
	49	size_t maxsize;
	50	struct tm *t;
	51	{
	52	size_t _fmt();
	53
	54	pt = s;
	55	if ((gsize = maxsize) < 1)
	56	return(0);
	57	if (_fmt(format, t)) {
	58	*pt = '\0';
	59	return(maxsize - gsize);
	60	}
	61	return(0);
	62	}
	63
	64	static size_t
	65	_fmt(format, t)
	66	register char *format;
	67	struct tm *t;
	68	{
e9fe19df KB	69	for (; *format; ++format) {
	70	if (*format == '%')
	71	switch(*++format) {
e2abfca3 KB	72	case '\0':
	73	--format;
	74	break;
e9fe19df	75	case 'A':
e2abfca3 KB	76	if (t->tm_wday < 0 \|\| t->tm_wday > 6)
	77	return(0);
	78	if (!_add(Afmt[t->tm_wday]))
e9fe19df KB	79	return(0);
	80	continue;
	81	case 'a':
e2abfca3 KB	82	if (t->tm_wday < 0 \|\| t->tm_wday > 6)
	83	return(0);
	84	if (!_add(afmt[t->tm_wday]))
e9fe19df KB	85	return(0);
	86	continue;
	87	case 'B':
e2abfca3 KB	88	if (t->tm_mon < 0 \|\| t->tm_mon > 11)
e2abfca3 KB	89	return(0);
e9fe19df KB	90	if (!_add(Bfmt[t->tm_mon]))
	91	return(0);
	92	continue;
	93	case 'b':
e386ba1e	94	case 'h':
e2abfca3 KB	95	if (t->tm_mon < 0 \|\| t->tm_mon > 11)
e2abfca3 KB	96	return(0);
e9fe19df KB	97	if (!_add(bfmt[t->tm_mon]))
	98	return(0);
	99	continue;
	100	case 'c':
	101	if (!_fmt("%x %X %Z %Y", t))
	102	return(0);
	103	continue;
e386ba1e KB	104	case 'D':
	105	if (!_fmt("%m/%d/%y", t))
	106	return(0);
	107	continue;
e9fe19df KB	108	case 'd':
	109	if (!_conv(t->tm_mday, 2))
	110	return(0);
	111	continue;
	112	case 'H':
	113	if (!_conv(t->tm_hour, 2))
	114	return(0);
	115	continue;
	116	case 'I':
e2abfca3 KB	117	if (!_conv(t->tm_hour % 12 ?
e2abfca3 KB	118	t->tm_hour % 12 : 12, 2))
e9fe19df KB	119	return(0);
	120	continue;
	121	case 'j':
	122	if (!_conv(t->tm_yday + 1, 3))
	123	return(0);
	124	continue;
	125	case 'M':
	126	if (!_conv(t->tm_min, 2))
	127	return(0);
	128	continue;
	129	case 'm':
	130	if (!_conv(t->tm_mon + 1, 2))
	131	return(0);
	132	continue;
e386ba1e KB	133	case 'n':
	134	if (!_add("\n"))
	135	return(0);
	136	continue;
e9fe19df	137	case 'p':
e2abfca3	138	if (!_add(t->tm_hour >= 12 ? "PM" : "AM"))
e9fe19df KB	139	return(0);
e9fe19df KB	140	continue;
e386ba1e KB	141	case 'R':
	142	if (!_fmt("%H:%M", t))
	143	return(0);
	144	continue;
	145	case 'r':
	146	if (!_fmt("%I:%M:%S %p", t))
	147	return(0);
	148	continue;
e9fe19df KB	149	case 'S':
	150	if (!_conv(t->tm_sec, 2))
	151	return(0);
	152	continue;
e386ba1e KB	153	case 'T':
	154	case 'X':
	155	if (!_fmt("%H:%M:%S", t))
	156	return(0);
	157	continue;
	158	case 't':
	159	if (!_add("\t"))
	160	return(0);
	161	continue;
e9fe19df KB	162	case 'U':
	163	if (!_conv((t->tm_yday + 7 - t->tm_wday) / 7,
	164	2))
	165	return(0);
	166	continue;
	167	case 'W':
	168	if (!_conv((t->tm_yday + 7 -
e2abfca3 KB	169	(t->tm_wday ? (t->tm_wday - 1) : 6))
e2abfca3 KB	170	/ 7, 2))
e9fe19df KB	171	return(0);
	172	continue;
	173	case 'w':
	174	if (!_conv(t->tm_wday, 1))
	175	return(0);
e9fe19df KB	176	continue;
e9fe19df KB	177	case 'x':
e2abfca3	178	if (!_fmt("%a %b %d %Y", t))
e9fe19df KB	179	return(0);
	180	continue;
	181	case 'y':
	182	if (!_conv((t->tm_year + TM_YEAR_BASE)
	183	% 100, 2))
	184	return(0);
	185	continue;
	186	case 'Y':
	187	if (!_conv(t->tm_year + TM_YEAR_BASE, 4))
	188	return(0);
	189	continue;
	190	case 'Z':
e2abfca3	191	if (!t->tm_zone \|\| !_add(t->tm_zone))
e9fe19df KB	192	return(0);
	193	continue;
	194	case '%':
	195	/*
	196	* X311J/88-090 (4.12.3.5): if conversion char is
	197	* undefined, behavior is undefined. Print out the
	198	* character itself as printf(3) also does.
	199	*/
	200	default:
	201	break;
	202	}
	203	if (!gsize--)
	204	return(0);
	205	pt++ = format;
	206	}
	207	return(gsize);
	208	}
	209
	210	static
	211	_conv(n, digits)
	212	int n, digits;
	213	{
	214	static char buf[10];
	215	register char *p;
	216
	217	for (p = buf + sizeof(buf) - 2; n > 0 && p > buf; n /= 10, --digits)
	218	*p-- = n % 10 + '0';
	219	while (p > buf && digits-- > 0)
	220	*p-- = '0';
	221	return(_add(++p));
	222	}
	223
	224	static
	225	_add(str)
	226	register char *str;
	227	{
	228	for (;; ++pt, --gsize) {
	229	if (!gsize)
	230	return(0);
	231	if (!(pt = str++))
	232	return(1);
	233	}
	234	}