strftime.c revision 15927 
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#ifdef LIBC_RCS
19static const char rcsid[] =
20	"$Id: strftime.c,v 1.7 1996/05/27 04:10:27 scrappy Exp $";
21#endif
22
23#ifndef lint
24#ifndef NOID
25static const char	elsieid[] = "@(#)strftime.c	7.38";
26/*
27** Based on the UCB version with the ID appearing below.
28** This is ANSIish only when "multibyte character == plain character".
29*/
30#endif /* !defined NOID */
31#endif /* !defined lint */
32
33#include "private.h"
34
35#ifndef LIBC_SCCS
36#ifndef lint
37static const char	sccsid[] = "@(#)strftime.c	5.4 (Berkeley) 3/14/89";
38#endif /* !defined lint */
39#endif /* !defined LIBC_SCCS */
40
41#include "tzfile.h"
42#include <fcntl.h>
43#include <locale.h>
44#include <rune.h>		/* for _PATH_LOCALE */
45#include <sys/stat.h>
46
47#define LOCALE_HOME _PATH_LOCALE
48
49struct lc_time_T {
50	const char *	mon[12];
51	const char *	month[12];
52	const char *	wday[7];
53	const char *	weekday[7];
54	const char *	X_fmt;
55	const char *	x_fmt;
56	const char *	c_fmt;
57	const char *	am;
58	const char *	pm;
59	const char *	date_fmt;
60};
61
62static struct lc_time_T		localebuf;
63static struct lc_time_T *	_loc P((void));
64static int using_locale;
65
66#define Locale	(using_locale ? &localebuf : &C_time_locale)
67
68static const struct lc_time_T	C_time_locale = {
69	{
70		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
71		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
72	}, {
73		"January", "February", "March", "April", "May", "June",
74		"July", "August", "September", "October", "November", "December"
75	}, {
76		"Sun", "Mon", "Tue", "Wed",
77		"Thu", "Fri", "Sat"
78	}, {
79		"Sunday", "Monday", "Tuesday", "Wednesday",
80		"Thursday", "Friday", "Saturday"
81	},
82
83	/* X_fmt */
84	"%H:%M:%S",
85
86	/*
87	** x_fmt
88	** Since the C language standard calls for
89	** "date, using locale's date format," anything goes.
90	** Using just numbers (as here) makes Quakers happier;
91	** it's also compatible with SVR4.
92	*/
93	"%m/%d/%y",
94
95	/*
96	** c_fmt (ctime-compatible)
97	** Note that
98	**	"%a %b %d %H:%M:%S %Y"
99	** is used by Solaris 2.3.
100	*/
101	"%a %b %e %X %Y",
102
103	/* am */
104	"AM",
105
106	/* pm */
107	"PM",
108
109	/* date_fmt */
110	"%a %b %e %X %Z %Y"
111};
112
113static char *	_add P((const char *, char *, const char *));
114static char *	_conv P((int, const char *, char *, const char *));
115static char *	_fmt P((const char *, const struct tm *, char *, const char *));
116static char *   _secs P((const struct tm *, char *, const char *));
117
118size_t strftime P((char *, size_t, const char *, const struct tm *));
119
120extern char *	tzname[];
121
122size_t
123strftime(s, maxsize, format, t)
124	char *const s;
125	const size_t maxsize;
126	const char *const format;
127	const struct tm *const t;
128{
129	char *p;
130
131	tzset();
132	p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize);
133	if (p == s + maxsize)
134		return 0;
135	*p = '\0';
136	return p - s;
137}
138
139static char *
140_fmt(format, t, pt, ptlim)
141	const char *format;
142	const struct tm *const t;
143	char *pt;
144	const char *const ptlim;
145{
146	for ( ; *format; ++format) {
147		if (*format == '%') {
148label:
149			switch (*++format) {
150			case '\0':
151				--format;
152				break;
153			case 'A':
154				pt = _add((t->tm_wday < 0 || t->tm_wday > 6) ?
155					"?" : Locale->weekday[t->tm_wday],
156					pt, ptlim);
157				continue;
158			case 'a':
159				pt = _add((t->tm_wday < 0 || t->tm_wday > 6) ?
160					"?" : Locale->wday[t->tm_wday],
161					pt, ptlim);
162				continue;
163			case 'B':
164				pt = _add((t->tm_mon < 0 || t->tm_mon > 11) ?
165					"?" : Locale->month[t->tm_mon],
166					pt, ptlim);
167				continue;
168			case 'b':
169			case 'h':
170				pt = _add((t->tm_mon < 0 || t->tm_mon > 11) ?
171					"?" : Locale->mon[t->tm_mon],
172					pt, ptlim);
173				continue;
174			case 'C':
175				/*
176				** %C used to do a...
177				**	_fmt("%a %b %e %X %Y", t);
178				** ...whereas now POSIX 1003.2 calls for
179				** something completely different.
180				** (ado, 5/24/93)
181				*/
182				pt = _conv((t->tm_year + TM_YEAR_BASE) / 100,
183					"%02d", pt, ptlim);
184				continue;
185			case 'c':
186				pt = _fmt(Locale->c_fmt, t, pt, ptlim);
187				continue;
188			case 'D':
189				pt = _fmt("%m/%d/%y", t, pt, ptlim);
190				continue;
191			case 'd':
192				pt = _conv(t->tm_mday, "%02d", pt, ptlim);
193				continue;
194			case 'E':
195			case 'O':
196				/*
197				** POSIX locale extensions, a la
198				** Arnold Robbins' strftime version 3.0.
199				** The sequences
200				**	%Ec %EC %Ex %Ey %EY
201				**	%Od %oe %OH %OI %Om %OM
202				**	%OS %Ou %OU %OV %Ow %OW %Oy
203				** are supposed to provide alternate
204				** representations.
205				** (ado, 5/24/93)
206				*/
207				goto label;
208			case 'e':
209				pt = _conv(t->tm_mday, "%2d", pt, ptlim);
210				continue;
211			case 'H':
212				pt = _conv(t->tm_hour, "%02d", pt, ptlim);
213				continue;
214			case 'I':
215				pt = _conv((t->tm_hour % 12) ?
216					(t->tm_hour % 12) : 12,
217					"%02d", pt, ptlim);
218				continue;
219			case 'j':
220				pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim);
221				continue;
222			case 'k':
223				/*
224				** This used to be...
225				**	_conv(t->tm_hour % 12 ?
226				**		t->tm_hour % 12 : 12, 2, ' ');
227				** ...and has been changed to the below to
228				** match SunOS 4.1.1 and Arnold Robbins'
229				** strftime version 3.0.  That is, "%k" and
230				** "%l" have been swapped.
231				** (ado, 5/24/93)
232				*/
233				pt = _conv(t->tm_hour, "%2d", pt, ptlim);
234				continue;
235#ifdef KITCHEN_SINK
236			case 'K':
237				/*
238				** After all this time, still unclaimed!
239				*/
240				pt = _add("kitchen sink", pt, ptlim);
241				continue;
242#endif /* defined KITCHEN_SINK */
243			case 'l':
244				/*
245				** This used to be...
246				**	_conv(t->tm_hour, 2, ' ');
247				** ...and has been changed to the below to
248				** match SunOS 4.1.1 and Arnold Robbin's
249				** strftime version 3.0.  That is, "%k" and
250				** "%l" have been swapped.
251				** (ado, 5/24/93)
252				*/
253				pt = _conv((t->tm_hour % 12) ?
254					(t->tm_hour % 12) : 12,
255					"%2d", pt, ptlim);
256				continue;
257			case 'M':
258				pt = _conv(t->tm_min, "%02d", pt, ptlim);
259				continue;
260			case 'm':
261				pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim);
262				continue;
263			case 'n':
264				pt = _add("\n", pt, ptlim);
265				continue;
266			case 'p':
267				pt = _add((t->tm_hour >= 12) ?
268					Locale->pm :
269					Locale->am,
270					pt, ptlim);
271				continue;
272			case 'R':
273				pt = _fmt("%H:%M", t, pt, ptlim);
274				continue;
275			case 'r':
276				pt = _fmt("%I:%M:%S %p", t, pt, ptlim);
277				continue;
278			case 'S':
279				pt = _conv(t->tm_sec, "%02d", pt, ptlim);
280				continue;
281			case 's':
282				pt = _secs(t, pt, ptlim);
283				continue;
284			case 'T':
285				pt = _fmt("%H:%M:%S", t, pt, ptlim);
286				continue;
287			case 't':
288				pt = _add("\t", pt, ptlim);
289				continue;
290			case 'U':
291				pt = _conv((t->tm_yday + 7 - t->tm_wday) / 7,
292					"%02d", pt, ptlim);
293				continue;
294			case 'u':
295				/*
296				** From Arnold Robbins' strftime version 3.0:
297				** "ISO 8601: Weekday as a decimal number
298				** [1 (Monday) - 7]"
299				** (ado, 5/24/93)
300				*/
301				pt = _conv((t->tm_wday == 0) ? 7 : t->tm_wday,
302					"%d", pt, ptlim);
303				continue;
304			case 'V':
305				/*
306				** From Arnold Robbins' strftime version 3.0:
307				** "the week number of the year (the first
308				** Monday as the first day of week 1) as a
309				** decimal number (01-53).  The method for
310				** determining the week number is as specified
311				** by ISO 8601 (to wit: if the week containing
312				** January 1 has four or more days in the new
313				** year, then it is week 1, otherwise it is
314				** week 53 of the previous year and the next
315				** week is week 1)."
316				** (ado, 5/24/93)
317				*/
318				/*
319				** XXX--If January 1 falls on a Friday,
320				** January 1-3 are part of week 53 of the
321				** previous year.  By analogy, if January
322				** 1 falls on a Thursday, are December 29-31
323				** of the PREVIOUS year part of week 1???
324				** (ado 5/24/93)
325				*/
326				/*
327				** You are understood not to expect this.
328				*/
329				{
330					int	i;
331
332					i = (t->tm_yday + 10 - (t->tm_wday ?
333						(t->tm_wday - 1) : 6)) / 7;
334					if (i == 0) {
335						/*
336						** What day of the week does
337						** January 1 fall on?
338						*/
339						i = t->tm_wday -
340							(t->tm_yday - 1);
341						/*
342						** Fri Jan 1: 53
343						** Sun Jan 1: 52
344						** Sat Jan 1: 53 if previous
345						**		 year a leap
346						**		 year, else 52
347						*/
348						if (i == TM_FRIDAY)
349							i = 53;
350						else if (i == TM_SUNDAY)
351							i = 52;
352						else	i = isleap(t->tm_year +
353								TM_YEAR_BASE) ?
354								53 : 52;
355#ifdef XPG4_1994_04_09
356						/*
357						** As of 4/9/94, though,
358						** XPG4 calls for 53
359						** unconditionally.
360						*/
361						i = 53;
362#endif /* defined XPG4_1994_04_09 */
363					}
364					pt = _conv(i, "%02d", pt, ptlim);
365				}
366				continue;
367			case 'v':
368				/*
369				** From Arnold Robbins' strftime version 3.0:
370				** "date as dd-bbb-YYYY"
371				** (ado, 5/24/93)
372				*/
373				pt = _fmt("%e-%b-%Y", t, pt, ptlim);
374				continue;
375			case 'W':
376				pt = _conv((t->tm_yday + 7 -
377					(t->tm_wday ?
378					(t->tm_wday - 1) : 6)) / 7,
379					"%02d", pt, ptlim);
380				continue;
381			case 'w':
382				pt = _conv(t->tm_wday, "%d", pt, ptlim);
383				continue;
384			case 'X':
385				pt = _fmt(Locale->X_fmt, t, pt, ptlim);
386				continue;
387			case 'x':
388				pt = _fmt(Locale->x_fmt, t, pt, ptlim);
389				continue;
390			case 'y':
391				pt = _conv((t->tm_year + TM_YEAR_BASE) % 100,
392					"%02d", pt, ptlim);
393				continue;
394			case 'Y':
395				pt = _conv(t->tm_year + TM_YEAR_BASE, "%04d",
396					pt, ptlim);
397				continue;
398			case 'Z':
399				if (t->tm_zone != NULL)
400					pt = _add(t->tm_zone, pt, ptlim);
401				else
402				if (t->tm_isdst == 0 || t->tm_isdst == 1) {
403					pt = _add(tzname[t->tm_isdst],
404						pt, ptlim);
405				} else  pt = _add("?", pt, ptlim);
406				continue;
407			case '+':
408				pt = _fmt(Locale->date_fmt, t, pt, ptlim);
409				continue;
410			case '%':
411			/*
412			 * X311J/88-090 (4.12.3.5): if conversion char is
413			 * undefined, behavior is undefined.  Print out the
414			 * character itself as printf(3) also does.
415			 */
416			default:
417				break;
418			}
419		}
420		if (pt == ptlim)
421			break;
422		*pt++ = *format;
423	}
424	return pt;
425}
426
427static char *
428_conv(n, format, pt, ptlim)
429	const int n;
430	const char *const format;
431	char *const pt;
432	const char *const ptlim;
433{
434	char	buf[INT_STRLEN_MAXIMUM(int) + 1];
435
436	(void) sprintf(buf, format, n);
437	return _add(buf, pt, ptlim);
438}
439
440static char *
441_secs(t, pt, ptlim)
442	const struct tm *t;
443	char *pt;
444	const char *ptlim;
445{
446	char    buf[INT_STRLEN_MAXIMUM(int) + 1];
447	register time_t s;
448	struct tm tmp;
449
450	/* Make a copy, mktime(3) modifies the tm struct. */
451	tmp = *t;
452	s = mktime(&tmp);
453	(void) sprintf(buf, "%ld", s);
454	return _add(buf, pt, ptlim);
455}
456
457static char *
458_add(str, pt, ptlim)
459	const char *str;
460	char *pt;
461	const char *const ptlim;
462{
463	while (pt < ptlim && (*pt = *str++) != '\0')
464		++pt;
465	return pt;
466}
467
468extern char *_PathLocale;
469
470int
471__time_load_locale(const char *name)
472{
473	static const char	lc_time[] = "LC_TIME";
474	static char *		locale_buf;
475	static char		locale_buf_C[] = "C";
476
477	int			fd;
478	char *			lbuf;
479	char *			p;
480	const char **		ap;
481	const char *		plim;
482	char			filename[FILENAME_MAX];
483	struct stat		st;
484	size_t			namesize;
485	size_t			bufsize;
486	int                     save_using_locale;
487
488	save_using_locale = using_locale;
489	using_locale = 0;
490
491	if (name == NULL)
492		goto no_locale;
493
494	if (!*name || !strcmp(name, "C") || !strcmp(name, "POSIX"))
495		return 0;
496
497	/*
498	** If the locale name is the same as our cache, use the cache.
499	*/
500	lbuf = locale_buf;
501	if (lbuf != NULL && strcmp(name, lbuf) == 0) {
502		p = lbuf;
503		for (ap = (const char **) &localebuf;
504			ap < (const char **) (&localebuf + 1);
505				++ap)
506					*ap = p += strlen(p) + 1;
507		using_locale = 1;
508		return 0;
509	}
510	/*
511	** Slurp the locale file into the cache.
512	*/
513	namesize = strlen(name) + 1;
514
515	snprintf(filename, sizeof filename,
516		 "%s/%s/%s",
517		 _PathLocale, name, lc_time);
518	fd = open(filename, O_RDONLY);
519	if (fd < 0)
520		goto no_locale;
521	if (fstat(fd, &st) != 0)
522		goto bad_locale;
523	if (st.st_size <= 0)
524		goto bad_locale;
525	bufsize = namesize + st.st_size;
526	locale_buf = NULL;
527	lbuf = (lbuf == NULL || lbuf == locale_buf_C) ?
528		malloc(bufsize) : realloc(lbuf, bufsize);
529	if (lbuf == NULL)
530		goto bad_locale;
531	(void) strcpy(lbuf, name);
532	p = lbuf + namesize;
533	plim = p + st.st_size;
534	if (read(fd, p, (size_t) st.st_size) != st.st_size)
535		goto bad_lbuf;
536	if (close(fd) != 0)
537		goto bad_lbuf;
538	/*
539	** Parse the locale file into localebuf.
540	*/
541	if (plim[-1] != '\n')
542		goto bad_lbuf;
543	for (ap = (const char **) &localebuf;
544		ap < (const char **) (&localebuf + 1);
545			++ap) {
546				if (p == plim)
547					goto reset_locale;
548				*ap = p;
549				while (*p != '\n')
550					++p;
551				*p++ = '\0';
552	}
553	/*
554	** Record the successful parse in the cache.
555	*/
556	locale_buf = lbuf;
557
558	using_locale = 1;
559	return 0;
560
561reset_locale:
562	/*
563	 * XXX - This may not be the correct thing to do in this case.
564	 * setlocale() assumes that we left the old locale alone.
565	 */
566	locale_buf = locale_buf_C;
567	localebuf = C_time_locale;
568	save_using_locale = 0;
569bad_lbuf:
570	free(lbuf);
571bad_locale:
572	(void) close(fd);
573no_locale:
574	using_locale = save_using_locale;
575	return -1;
576}
577