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#ifndef lint
19#ifndef NOID
20static const char	elsieid[] = "@(#)strftime.3	8.3";
21/*
22** Based on the UCB version with the ID appearing below.
23** This is ANSIish only when "multibyte character == plain character".
24*/
25#endif /* !defined NOID */
26#endif /* !defined lint */
27
28#include "xlocale_private.h"
29
30#include "namespace.h"
31#include "private.h"
32
33#if defined(LIBC_SCCS) && !defined(lint)
34static const char	sccsid[] = "@(#)strftime.c	5.4 (Berkeley) 3/14/89";
35#endif /* LIBC_SCCS and not lint */
36#include <sys/cdefs.h>
37__FBSDID("$FreeBSD: src/lib/libc/stdtime/strftime.c,v 1.44 2009/06/09 09:02:58 delphij Exp $");
38
39#include "tzfile.h"
40#include <time.h>
41#include <fcntl.h>
42#include <sys/stat.h>
43#include "un-namespace.h"
44#include "timelocal.h"
45
46#if !BUILDING_VARIANT
47static char *	_add(const char *, char *, const char *);
48static char *	_conv(int, const char *, char *, const char *, locale_t);
49static char *	_yconv(int, int, int, int, char *, const char *, locale_t);
50#endif
51#define	_fmt	_st_fmt
52__private_extern__ char *	_fmt(const char *, const struct tm *, char *, const char *,
53			int *, struct lc_time_T *, locale_t);
54
55extern char *	tzname[];
56__private_extern__ long __darwin_altzone;		/* DST timezone offset */
57#define altzone __darwin_altzone
58__private_extern__ long _st_get_timezone(void);
59
60#ifndef YEAR_2000_NAME
61#define YEAR_2000_NAME	"CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
62#endif /* !defined YEAR_2000_NAME */
63
64#define IN_NONE	0
65#define IN_SOME	1
66#define IN_THIS	2
67#define IN_ALL	3
68
69#define PAD_DEFAULT	0
70#define PAD_LESS	1
71#define PAD_SPACE	2
72#define PAD_ZERO	3
73
74#ifndef BUILDING_VARIANT
75static const char * const fmt_padding[][4] = {
76	/* DEFAULT,	LESS,	SPACE,	ZERO */
77#define PAD_FMT_MONTHDAY	0
78#define PAD_FMT_HMS		0
79#define PAD_FMT_CENTURY		0
80#define PAD_FMT_SHORTYEAR	0
81#define PAD_FMT_MONTH		0
82#define PAD_FMT_WEEKOFYEAR	0
83#define PAD_FMT_DAYOFMONTH	0
84	{ "%02d",	"%d",	"%2d",	"%02d" },
85#define PAD_FMT_SDAYOFMONTH	1
86#define PAD_FMT_SHMS		1
87	{ "%2d",	"%d",	"%2d",	"%02d" },
88#define	PAD_FMT_DAYOFYEAR	2
89	{ "%03d",	"%d",	"%3d",	"%03d" },
90#define PAD_FMT_YEAR		3
91	{ "%04d",	"%d",	"%4d",	"%04d" }
92};
93#endif
94
95#define USG_COMPAT
96#define ALTZONE
97
98size_t
99strftime_l(char * __restrict s, size_t maxsize, const char * __restrict format,
100    const struct tm * __restrict t, locale_t loc)
101{
102	char *	p;
103	int	warn;
104
105	NORMALIZE_LOCALE(loc);
106	tzset();
107	warn = IN_NONE;
108	p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn, __get_current_time_locale(loc), loc);
109#ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
110	if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
111		(void) fputs("\n", stderr);
112		if (format == NULL)
113			(void) fputs("NULL strftime format ", stderr);
114		else	(void) fprintf_l(stderr, loc, "strftime format \"%s\" ",
115				format);
116		(void) fputs("yields only two digits of years in ", stderr);
117		if (warn == IN_SOME)
118			(void) fputs("some locales", stderr);
119		else if (warn == IN_THIS)
120			(void) fputs("the current locale", stderr);
121		else	(void) fputs("all locales", stderr);
122		(void) fputs("\n", stderr);
123	}
124#endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
125	if (p == s + maxsize)
126		return 0;
127	*p = '\0';
128	return p - s;
129}
130
131size_t
132strftime(char * __restrict s, size_t maxsize, const char * __restrict format,
133    const struct tm * __restrict t)
134{
135	return strftime_l(s, maxsize, format, t, __current_locale());
136}
137
138#ifndef BUILDING_VARIANT
139__private_extern__ char *
140_fmt(format, t, pt, ptlim, warnp, tptr, loc)
141const char *		format;
142const struct tm * const	t;
143char *			pt;
144const char * const	ptlim;
145int *			warnp;
146struct lc_time_T *	tptr;
147locale_t		loc;
148{
149	int Ealternative, Oalternative, PadIndex;
150
151	for ( ; *format; ++format) {
152		if (*format == '%') {
153			Ealternative = 0;
154			Oalternative = 0;
155			PadIndex	 = PAD_DEFAULT;
156label:
157			switch (*++format) {
158			case '\0':
159				--format;
160				break;
161			case 'A':
162				pt = _add((t->tm_wday < 0 ||
163					t->tm_wday >= DAYSPERWEEK) ?
164					"?" : tptr->weekday[t->tm_wday],
165					pt, ptlim);
166				continue;
167			case 'a':
168				pt = _add((t->tm_wday < 0 ||
169					t->tm_wday >= DAYSPERWEEK) ?
170					"?" : tptr->wday[t->tm_wday],
171					pt, ptlim);
172				continue;
173			case 'B':
174				pt = _add((t->tm_mon < 0 ||
175					t->tm_mon >= MONSPERYEAR) ?
176					"?" : (Oalternative ? tptr->alt_month :
177					tptr->month)[t->tm_mon],
178					pt, ptlim);
179				continue;
180			case 'b':
181			case 'h':
182				pt = _add((t->tm_mon < 0 ||
183					t->tm_mon >= MONSPERYEAR) ?
184					"?" : tptr->mon[t->tm_mon],
185					pt, ptlim);
186				continue;
187			case 'C':
188				/*
189				** %C used to do a...
190				**	_fmt("%a %b %e %X %Y", t, tptr, loc);
191				** ...whereas now POSIX 1003.2 calls for
192				** something completely different.
193				** (ado, 1993-05-24)
194				*/
195				pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
196					pt, ptlim, loc);
197				continue;
198			case 'c':
199				{
200				int warn2 = IN_SOME;
201
202				pt = _fmt(tptr->c_fmt, t, pt, ptlim, &warn2, tptr, loc);
203				if (warn2 == IN_ALL)
204					warn2 = IN_THIS;
205				if (warn2 > *warnp)
206					*warnp = warn2;
207				}
208				continue;
209			case 'D':
210				pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp, tptr, loc);
211				continue;
212			case 'd':
213				pt = _conv(t->tm_mday, fmt_padding[PAD_FMT_DAYOFMONTH][PadIndex],
214					pt, ptlim, loc);
215				continue;
216			case 'E':
217				if (Ealternative || Oalternative)
218					break;
219				Ealternative++;
220				goto label;
221			case 'O':
222				/*
223				** C99 locale modifiers.
224				** The sequences
225				**	%Ec %EC %Ex %EX %Ey %EY
226				**	%Od %oe %OH %OI %Om %OM
227				**	%OS %Ou %OU %OV %Ow %OW %Oy
228				** are supposed to provide alternate
229				** representations.
230				**
231				** FreeBSD extension
232				**      %OB
233				*/
234				if (Ealternative || Oalternative)
235					break;
236				Oalternative++;
237				goto label;
238			case 'e':
239				pt = _conv(t->tm_mday,
240					fmt_padding[PAD_FMT_SDAYOFMONTH][PadIndex], pt, ptlim, loc);
241				continue;
242			case 'F':
243				pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, tptr, loc);
244				continue;
245			case 'H':
246				pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_HMS][PadIndex],
247					pt, ptlim, loc);
248				continue;
249			case 'I':
250				pt = _conv((t->tm_hour % 12) ?
251					(t->tm_hour % 12) : 12,
252					fmt_padding[PAD_FMT_HMS][PadIndex], pt, ptlim, loc);
253				continue;
254			case 'j':
255				pt = _conv(t->tm_yday + 1,
256					fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex], pt, ptlim, loc);
257				continue;
258			case 'k':
259				/*
260				** This used to be...
261				**	_conv(t->tm_hour % 12 ?
262				**		t->tm_hour % 12 : 12, 2, ' ', loc);
263				** ...and has been changed to the below to
264				** match SunOS 4.1.1 and Arnold Robbins'
265				** strftime version 3.0. That is, "%k" and
266				** "%l" have been swapped.
267				** (ado, 1993-05-24)
268				*/
269				pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_SHMS][PadIndex],
270					pt, ptlim, loc);
271				continue;
272#ifdef KITCHEN_SINK
273			case 'K':
274				/*
275				** After all this time, still unclaimed!
276				*/
277				pt = _add("kitchen sink", pt, ptlim);
278				continue;
279#endif /* defined KITCHEN_SINK */
280			case 'l':
281				/*
282				** This used to be...
283				**	_conv(t->tm_hour, 2, ' ');
284				** ...and has been changed to the below to
285				** match SunOS 4.1.1 and Arnold Robbin's
286				** strftime version 3.0. That is, "%k" and
287				** "%l" have been swapped.
288				** (ado, 1993-05-24)
289				*/
290				pt = _conv((t->tm_hour % 12) ?
291					(t->tm_hour % 12) : 12,
292					fmt_padding[PAD_FMT_SHMS][PadIndex], pt, ptlim, loc);
293				continue;
294			case 'M':
295				pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex],
296					pt, ptlim, loc);
297				continue;
298			case 'm':
299				pt = _conv(t->tm_mon + 1,
300					fmt_padding[PAD_FMT_MONTH][PadIndex], pt, ptlim, loc);
301				continue;
302			case 'n':
303				pt = _add("\n", pt, ptlim);
304				continue;
305			case 'p':
306				pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
307					tptr->pm :
308					tptr->am,
309					pt, ptlim);
310				continue;
311			case 'R':
312				pt = _fmt("%H:%M", t, pt, ptlim, warnp, tptr, loc);
313				continue;
314			case 'r':
315				pt = _fmt(tptr->ampm_fmt, t, pt, ptlim,
316					warnp, tptr, loc);
317				continue;
318			case 'S':
319				pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex],
320					pt, ptlim, loc);
321				continue;
322			case 's':
323				{
324					struct tm	tm;
325					char		buf[INT_STRLEN_MAXIMUM(
326								time_t) + 1];
327					time_t		mkt;
328
329					tm = *t;
330					mkt = mktime(&tm);
331					if (TYPE_SIGNED(time_t))
332						(void) sprintf_l(buf, loc, "%ld",
333							(long) mkt);
334					else	(void) sprintf_l(buf, loc, "%lu",
335							(unsigned long) mkt);
336					pt = _add(buf, pt, ptlim);
337				}
338				continue;
339			case 'T':
340				pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, tptr, loc);
341				continue;
342			case 't':
343				pt = _add("\t", pt, ptlim);
344				continue;
345			case 'U':
346				pt = _conv((t->tm_yday + DAYSPERWEEK -
347					t->tm_wday) / DAYSPERWEEK,
348					fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], pt, ptlim, loc);
349				continue;
350			case 'u':
351				/*
352				** From Arnold Robbins' strftime version 3.0:
353				** "ISO 8601: Weekday as a decimal number
354				** [1 (Monday) - 7]"
355				** (ado, 1993-05-24)
356				*/
357				pt = _conv((t->tm_wday == 0) ?
358					DAYSPERWEEK : t->tm_wday,
359					"%d", pt, ptlim, loc);
360				continue;
361			case 'V':	/* ISO 8601 week number */
362			case 'G':	/* ISO 8601 year (four digits) */
363			case 'g':	/* ISO 8601 year (two digits) */
364/*
365** From Arnold Robbins' strftime version 3.0: "the week number of the
366** year (the first Monday as the first day of week 1) as a decimal number
367** (01-53)."
368** (ado, 1993-05-24)
369**
370** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
371** "Week 01 of a year is per definition the first week which has the
372** Thursday in this year, which is equivalent to the week which contains
373** the fourth day of January. In other words, the first week of a new year
374** is the week which has the majority of its days in the new year. Week 01
375** might also contain days from the previous year and the week before week
376** 01 of a year is the last week (52 or 53) of the previous year even if
377** it contains days from the new year. A week starts with Monday (day 1)
378** and ends with Sunday (day 7). For example, the first week of the year
379** 1997 lasts from 1996-12-30 to 1997-01-05..."
380** (ado, 1996-01-02)
381*/
382				{
383					int	year;
384					int	base;
385					int	yday;
386					int	wday;
387					int	w;
388
389					year = t->tm_year;
390					base = TM_YEAR_BASE;
391					yday = t->tm_yday;
392					wday = t->tm_wday;
393					for ( ; ; ) {
394						int	len;
395						int	bot;
396						int	top;
397
398						len = isleap_sum(year, base) ?
399							DAYSPERLYEAR :
400							DAYSPERNYEAR;
401						/*
402						** What yday (-3 ... 3) does
403						** the ISO year begin on?
404						*/
405						bot = ((yday + 11 - wday) %
406							DAYSPERWEEK) - 3;
407						/*
408						** What yday does the NEXT
409						** ISO year begin on?
410						*/
411						top = bot -
412							(len % DAYSPERWEEK);
413						if (top < -3)
414							top += DAYSPERWEEK;
415						top += len;
416						if (yday >= top) {
417							++base;
418							w = 1;
419							break;
420						}
421						if (yday >= bot) {
422							w = 1 + ((yday - bot) /
423								DAYSPERWEEK);
424							break;
425						}
426						--base;
427						yday += isleap_sum(year, base) ?
428							DAYSPERLYEAR :
429							DAYSPERNYEAR;
430					}
431#ifdef XPG4_1994_04_09
432					if ((w == 52 &&
433						t->tm_mon == TM_JANUARY) ||
434						(w == 1 &&
435						t->tm_mon == TM_DECEMBER))
436							w = 53;
437#endif /* defined XPG4_1994_04_09 */
438					if (*format == 'V')
439						pt = _conv(w, fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
440							pt, ptlim, loc);
441					else if (*format == 'g') {
442						*warnp = IN_ALL;
443						pt = _yconv(year, base, 0, 1,
444							pt, ptlim, loc);
445					} else	pt = _yconv(year, base, 1, 1,
446							pt, ptlim, loc);
447				}
448				continue;
449			case 'v':
450				/*
451				** From Arnold Robbins' strftime version 3.0:
452				** "date as dd-bbb-YYYY"
453				** (ado, 1993-05-24)
454				*/
455				pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, tptr, loc);
456				continue;
457			case 'W':
458				pt = _conv((t->tm_yday + DAYSPERWEEK -
459					(t->tm_wday ?
460					(t->tm_wday - 1) :
461					(DAYSPERWEEK - 1))) / DAYSPERWEEK,
462					fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], pt, ptlim, loc);
463				continue;
464			case 'w':
465				pt = _conv(t->tm_wday, "%d", pt, ptlim, loc);
466				continue;
467			case 'X':
468				pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp, tptr, loc);
469				continue;
470			case 'x':
471				{
472				int	warn2 = IN_SOME;
473
474				pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2, tptr, loc);
475				if (warn2 == IN_ALL)
476					warn2 = IN_THIS;
477				if (warn2 > *warnp)
478					*warnp = warn2;
479				}
480				continue;
481			case 'y':
482				*warnp = IN_ALL;
483				pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
484					pt, ptlim, loc);
485				continue;
486			case 'Y':
487				pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
488					pt, ptlim, loc);
489				continue;
490			case 'Z':
491#ifdef TM_ZONE
492				if (t->TM_ZONE != NULL)
493					pt = _add(t->TM_ZONE, pt, ptlim);
494				else
495#endif /* defined TM_ZONE */
496				if (t->tm_isdst >= 0)
497					pt = _add(tzname[t->tm_isdst != 0],
498						pt, ptlim);
499				/*
500				** C99 says that %Z must be replaced by the
501				** empty string if the time zone is not
502				** determinable.
503				*/
504				continue;
505			case 'z':
506				{
507				int		diff;
508				char const *	sign;
509
510				if (t->tm_isdst < 0)
511					continue;
512#if defined(TM_GMTOFF) && !__DARWIN_UNIX03
513				diff = t->TM_GMTOFF;
514#else /* !defined TM_GMTOFF || __DARWIN_UNIX03 */
515				/*
516				** C99 says that the UTC offset must
517				** be computed by looking only at
518				** tm_isdst. This requirement is
519				** incorrect, since it means the code
520				** must rely on magic (in this case
521				** altzone and timezone), and the
522				** magic might not have the correct
523				** offset. Doing things correctly is
524				** tricky and requires disobeying C99;
525				** see GNU C strftime for details.
526				** For now, punt and conform to the
527				** standard, even though it's incorrect.
528				**
529				** C99 says that %z must be replaced by the
530				** empty string if the time zone is not
531				** determinable, so output nothing if the
532				** appropriate variables are not available.
533				*/
534				if (t->tm_isdst == 0)
535#ifdef USG_COMPAT
536					diff = -_st_get_timezone();
537#else /* !defined USG_COMPAT */
538					continue;
539#endif /* !defined USG_COMPAT */
540				else
541#ifdef ALTZONE
542					diff = -altzone;
543#else /* !defined ALTZONE */
544					continue;
545#endif /* !defined ALTZONE */
546#endif /* !defined TM_GMTOFF || __DARWIN_UNIX03 */
547				if (diff < 0) {
548					sign = "-";
549					diff = -diff;
550				} else	sign = "+";
551				pt = _add(sign, pt, ptlim);
552				diff /= SECSPERMIN;
553				diff = (diff / MINSPERHOUR) * 100 +
554					(diff % MINSPERHOUR);
555				pt = _conv(diff,
556					fmt_padding[PAD_FMT_YEAR][PadIndex], pt, ptlim, loc);
557				}
558				continue;
559			case '+':
560				pt = _fmt(tptr->date_fmt, t, pt, ptlim,
561					warnp, tptr, loc);
562				continue;
563			case '-':
564				if (PadIndex != PAD_DEFAULT)
565					break;
566				PadIndex = PAD_LESS;
567				goto label;
568			case '_':
569				if (PadIndex != PAD_DEFAULT)
570					break;
571				PadIndex = PAD_SPACE;
572				goto label;
573			case '0':
574				if (PadIndex != PAD_DEFAULT)
575					break;
576				PadIndex = PAD_ZERO;
577				goto label;
578			case '%':
579			/*
580			** X311J/88-090 (4.12.3.5): if conversion char is
581			** undefined, behavior is undefined. Print out the
582			** character itself as printf(3) also does.
583			*/
584			default:
585				break;
586			}
587		}
588		if (pt == ptlim)
589			break;
590		*pt++ = *format;
591	}
592	return pt;
593}
594
595static char *
596_conv(n, format, pt, ptlim, loc)
597const int		n;
598const char * const	format;
599char * const		pt;
600const char * const	ptlim;
601locale_t		loc;
602{
603	char	buf[INT_STRLEN_MAXIMUM(int) + 1];
604
605	(void) sprintf_l(buf, loc, format, n);
606	return _add(buf, pt, ptlim);
607}
608
609static char *
610_add(str, pt, ptlim)
611const char *		str;
612char *			pt;
613const char * const	ptlim;
614{
615	while (pt < ptlim && (*pt = *str++) != '\0')
616		++pt;
617	return pt;
618}
619
620/*
621** POSIX and the C Standard are unclear or inconsistent about
622** what %C and %y do if the year is negative or exceeds 9999.
623** Use the convention that %C concatenated with %y yields the
624** same output as %Y, and that %Y contains at least 4 bytes,
625** with more only if necessary.
626*/
627
628static char *
629_yconv(a, b, convert_top, convert_yy, pt, ptlim, loc)
630const int		a;
631const int		b;
632const int		convert_top;
633const int		convert_yy;
634char *			pt;
635const char * const	ptlim;
636locale_t		loc;
637{
638	register int	lead;
639	register int	trail;
640
641#define DIVISOR	100
642	trail = a % DIVISOR + b % DIVISOR;
643	lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
644	trail %= DIVISOR;
645	if (trail < 0 && lead > 0) {
646		trail += DIVISOR;
647		--lead;
648	} else if (lead < 0 && trail > 0) {
649		trail -= DIVISOR;
650		++lead;
651	}
652	if (convert_top) {
653		if (lead == 0 && trail < 0)
654			pt = _add("-0", pt, ptlim);
655		else	pt = _conv(lead, "%02d", pt, ptlim, loc);
656	}
657	if (convert_yy)
658		pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim, loc);
659	return pt;
660}
661#endif /* !BUILDING_VARIANT */
662