1/*	$OpenBSD: wcsftime.c,v 1.3 2014/05/06 15:49:45 tedu Exp $ */
2#include "private.h"
3
4/*
5** Based on the UCB version with the ID appearing below.
6** This is ANSIish only when "multibyte character == plain character".
7**
8** Copyright (c) 1989, 1993
9**	The Regents of the University of California.  All rights reserved.
10**
11** Redistribution and use in source and binary forms, with or without
12** modification, are permitted provided that the following conditions
13** are met:
14** 1. Redistributions of source code must retain the above copyright
15**    notice, this list of conditions and the following disclaimer.
16** 2. Redistributions in binary form must reproduce the above copyright
17**    notice, this list of conditions and the following disclaimer in the
18**    documentation and/or other materials provided with the distribution.
19** 3. Neither the name of the University nor the names of its contributors
20**    may be used to endorse or promote products derived from this software
21**    without specific prior written permission.
22**
23** THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26** ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33** SUCH DAMAGE.
34*/
35
36#include "tzfile.h"
37#include "fcntl.h"
38#include <locale.h>
39#include <wchar.h>
40
41struct lc_time_T {
42	const wchar_t *	mon[MONSPERYEAR];
43	const wchar_t *	month[MONSPERYEAR];
44	const wchar_t *	wday[DAYSPERWEEK];
45	const wchar_t *	weekday[DAYSPERWEEK];
46	const wchar_t *	X_fmt;
47	const wchar_t *	x_fmt;
48	const wchar_t *	c_fmt;
49	const wchar_t *	am;
50	const wchar_t *	pm;
51	const wchar_t *	date_fmt;
52};
53
54#define Locale	(&C_time_locale)
55
56static const struct lc_time_T	C_time_locale = {
57	{
58		L"Jan", L"Feb", L"Mar", L"Apr", L"May", L"Jun",
59		L"Jul", L"Aug", L"Sep", L"Oct", L"Nov", L"Dec"
60	}, {
61		L"January", L"February", L"March", L"April", L"May", L"June",
62		L"July", L"August", L"September", L"October", L"November",
63		L"December"
64	}, {
65		L"Sun", L"Mon", L"Tue", L"Wed",
66		L"Thu", L"Fri", L"Sat"
67	}, {
68		L"Sunday", L"Monday", L"Tuesday", L"Wednesday",
69		L"Thursday", L"Friday", L"Saturday"
70	},
71
72	/* X_fmt */
73	L"%H:%M:%S",
74
75	/*
76	** x_fmt
77	** C99 requires this format.
78	** Using just numbers (as here) makes Quakers happier;
79	** it's also compatible with SVR4.
80	*/
81	L"%m/%d/%y",
82
83	/*
84	** c_fmt
85	** C99 requires this format.
86	** Previously this code used "%D %X", but we now conform to C99.
87	** Note that
88	**	"%a %b %d %H:%M:%S %Y"
89	** is used by Solaris 2.3.
90	*/
91	L"%a %b %e %T %Y",
92
93	/* am */
94	L"AM",
95
96	/* pm */
97	L"PM",
98
99	/* date_fmt */
100	L"%a %b %e %H:%M:%S %Z %Y"
101};
102
103#define UNKNOWN L"?"
104static wchar_t *	_add(const wchar_t *, wchar_t *, const wchar_t *);
105static wchar_t *	_sadd(const char *, wchar_t *, const wchar_t *);
106static wchar_t *	_conv(int, const wchar_t *, wchar_t *, const wchar_t *);
107static wchar_t *	_fmt(const wchar_t *, const struct tm *, wchar_t *, const wchar_t *,
108			int *);
109static wchar_t *	_yconv(int, int, int, int, wchar_t *, const wchar_t *);
110
111extern char *	tzname[];
112
113#define IN_NONE	0
114#define IN_SOME	1
115#define IN_THIS	2
116#define IN_ALL	3
117
118size_t
119wcsftime(wchar_t *__restrict s, size_t maxsize,
120    const wchar_t *__restrict format, const struct tm *__restrict t)
121{
122	wchar_t *p;
123	int	warn;
124
125	tzset();
126	warn = IN_NONE;
127	p = _fmt(((format == NULL) ? L"%c" : format), t, s, s + maxsize, &warn);
128	if (p == s + maxsize) {
129		if (maxsize > 0)
130			s[maxsize - 1] = '\0';
131		return 0;
132	}
133	*p = L'\0';
134	return p - s;
135}
136
137static wchar_t *
138_fmt(const wchar_t *format, const struct tm *t, wchar_t *pt,
139    const wchar_t *ptlim, int *warnp)
140{
141	for ( ; *format; ++format) {
142		if (*format != L'%') {
143			if (pt == ptlim)
144				break;
145			*pt++ = *format;
146			continue;
147		}
148label:
149		switch (*++format) {
150		case '\0':
151			--format;
152			break;
153		case 'A':
154			pt = _add((t->tm_wday < 0 ||
155				t->tm_wday >= DAYSPERWEEK) ?
156				UNKNOWN : Locale->weekday[t->tm_wday],
157				pt, ptlim);
158			continue;
159		case 'a':
160			pt = _add((t->tm_wday < 0 ||
161				t->tm_wday >= DAYSPERWEEK) ?
162				UNKNOWN : Locale->wday[t->tm_wday],
163				pt, ptlim);
164			continue;
165		case 'B':
166			pt = _add((t->tm_mon < 0 ||
167				t->tm_mon >= MONSPERYEAR) ?
168				UNKNOWN : Locale->month[t->tm_mon],
169				pt, ptlim);
170			continue;
171		case 'b':
172		case 'h':
173			pt = _add((t->tm_mon < 0 ||
174				t->tm_mon >= MONSPERYEAR) ?
175				UNKNOWN : Locale->mon[t->tm_mon],
176				pt, ptlim);
177			continue;
178		case 'C':
179			/*
180			** %C used to do a...
181			**	_fmt("%a %b %e %X %Y", t);
182			** ...whereas now POSIX 1003.2 calls for
183			** something completely different.
184			** (ado, 1993-05-24)
185			*/
186			pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
187				pt, ptlim);
188			continue;
189		case 'c':
190			{
191			int warn2 = IN_SOME;
192
193			pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2);
194			if (warn2 == IN_ALL)
195				warn2 = IN_THIS;
196			if (warn2 > *warnp)
197				*warnp = warn2;
198			}
199			continue;
200		case 'D':
201			pt = _fmt(L"%m/%d/%y", t, pt, ptlim, warnp);
202			continue;
203		case 'd':
204			pt = _conv(t->tm_mday, L"%02d", pt, ptlim);
205			continue;
206		case 'E':
207		case 'O':
208			/*
209			** C99 locale modifiers.
210			** The sequences
211			**	%Ec %EC %Ex %EX %Ey %EY
212			**	%Od %oe %OH %OI %Om %OM
213			**	%OS %Ou %OU %OV %Ow %OW %Oy
214			** are supposed to provide alternate
215			** representations.
216			*/
217			goto label;
218		case 'e':
219			pt = _conv(t->tm_mday, L"%2d", pt, ptlim);
220			continue;
221		case 'F':
222			pt = _fmt(L"%Y-%m-%d", t, pt, ptlim, warnp);
223			continue;
224		case 'H':
225			pt = _conv(t->tm_hour, L"%02d", pt, ptlim);
226			continue;
227		case 'I':
228			pt = _conv((t->tm_hour % 12) ?
229				(t->tm_hour % 12) : 12,
230				L"%02d", pt, ptlim);
231			continue;
232		case 'j':
233			pt = _conv(t->tm_yday + 1, L"%03d", pt, ptlim);
234			continue;
235		case 'k':
236			/*
237			** This used to be...
238			**	_conv(t->tm_hour % 12 ?
239			**		t->tm_hour % 12 : 12, 2, ' ');
240			** ...and has been changed to the below to
241			** match SunOS 4.1.1 and Arnold Robbins'
242			** strftime version 3.0. That is, "%k" and
243			** "%l" have been swapped.
244			** (ado, 1993-05-24)
245			*/
246			pt = _conv(t->tm_hour, L"%2d", pt, ptlim);
247			continue;
248		case 'l':
249			/*
250			** This used to be...
251			**	_conv(t->tm_hour, 2, ' ');
252			** ...and has been changed to the below to
253			** match SunOS 4.1.1 and Arnold Robbin's
254			** strftime version 3.0. That is, "%k" and
255			** "%l" have been swapped.
256			** (ado, 1993-05-24)
257			*/
258			pt = _conv((t->tm_hour % 12) ?
259				(t->tm_hour % 12) : 12,
260				L"%2d", pt, ptlim);
261			continue;
262		case 'M':
263			pt = _conv(t->tm_min, L"%02d", pt, ptlim);
264			continue;
265		case 'm':
266			pt = _conv(t->tm_mon + 1, L"%02d", pt, ptlim);
267			continue;
268		case 'n':
269			pt = _add(L"\n", pt, ptlim);
270			continue;
271		case 'p':
272			pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
273				Locale->pm :
274				Locale->am,
275				pt, ptlim);
276			continue;
277		case 'R':
278			pt = _fmt(L"%H:%M", t, pt, ptlim, warnp);
279			continue;
280		case 'r':
281			pt = _fmt(L"%I:%M:%S %p", t, pt, ptlim, warnp);
282			continue;
283		case 'S':
284			pt = _conv(t->tm_sec, L"%02d", pt, ptlim);
285			continue;
286		case 's':
287			{
288				struct tm	tm;
289				wchar_t		buf[INT_STRLEN_MAXIMUM(
290							time_t) + 1];
291				time_t		mkt;
292
293				tm = *t;
294				mkt = mktime(&tm);
295				if (TYPE_SIGNED(time_t))
296					(void) swprintf(buf,
297					    sizeof buf/sizeof buf[0],
298					    L"%ld", (long) mkt);
299				else
300					(void) swprintf(buf,
301					    sizeof buf/sizeof buf[0],
302					    L"%lu", (unsigned long) mkt);
303				pt = _add(buf, pt, ptlim);
304			}
305			continue;
306		case 'T':
307			pt = _fmt(L"%H:%M:%S", t, pt, ptlim, warnp);
308			continue;
309		case 't':
310			pt = _add(L"\t", pt, ptlim);
311			continue;
312		case 'U':
313			pt = _conv((t->tm_yday + DAYSPERWEEK -
314				t->tm_wday) / DAYSPERWEEK,
315				L"%02d", pt, ptlim);
316			continue;
317		case 'u':
318			/*
319			** From Arnold Robbins' strftime version 3.0:
320			** "ISO 8601: Weekday as a decimal number
321			** [1 (Monday) - 7]"
322			** (ado, 1993-05-24)
323			*/
324			pt = _conv((t->tm_wday == 0) ?
325				DAYSPERWEEK : t->tm_wday,
326				L"%d", pt, ptlim);
327			continue;
328		case 'V':	/* ISO 8601 week number */
329		case 'G':	/* ISO 8601 year (four digits) */
330		case 'g':	/* ISO 8601 year (two digits) */
331/*
332** From Arnold Robbins' strftime version 3.0: "the week number of the
333** year (the first Monday as the first day of week 1) as a decimal number
334** (01-53)."
335** (ado, 1993-05-24)
336**
337** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
338** "Week 01 of a year is per definition the first week which has the
339** Thursday in this year, which is equivalent to the week which contains
340** the fourth day of January. In other words, the first week of a new year
341** is the week which has the majority of its days in the new year. Week 01
342** might also contain days from the previous year and the week before week
343** 01 of a year is the last week (52 or 53) of the previous year even if
344** it contains days from the new year. A week starts with Monday (day 1)
345** and ends with Sunday (day 7). For example, the first week of the year
346** 1997 lasts from 1996-12-30 to 1997-01-05..."
347** (ado, 1996-01-02)
348*/
349			{
350			int	year;
351			int	base;
352			int	yday;
353			int	wday;
354			int	w;
355
356			year = t->tm_year;
357			base = TM_YEAR_BASE;
358			yday = t->tm_yday;
359			wday = t->tm_wday;
360			for ( ; ; ) {
361				int	len;
362				int	bot;
363				int	top;
364
365				len = isleap_sum(year, base) ?
366					DAYSPERLYEAR :
367					DAYSPERNYEAR;
368				/*
369				** What yday (-3 ... 3) does the ISO year
370				** begin on?
371				*/
372				bot = ((yday + 11 - wday) % DAYSPERWEEK) - 3;
373				/*
374				** What yday does the NEXT ISO year begin on?
375				*/
376				top = bot - (len % DAYSPERWEEK);
377				if (top < -3)
378					top += DAYSPERWEEK;
379				top += len;
380				if (yday >= top) {
381					++base;
382					w = 1;
383					break;
384				}
385				if (yday >= bot) {
386					w = 1 + ((yday - bot) / DAYSPERWEEK);
387					break;
388				}
389				--base;
390				yday += isleap_sum(year, base) ?
391					DAYSPERLYEAR :
392					DAYSPERNYEAR;
393			}
394			if ((w == 52 && t->tm_mon == TM_JANUARY) ||
395				(w == 1 && t->tm_mon == TM_DECEMBER))
396					w = 53;
397			if (*format == 'V')
398				pt = _conv(w, L"%02d", pt, ptlim);
399			else if (*format == 'g') {
400				*warnp = IN_ALL;
401				pt = _yconv(year, base, 0, 1, pt, ptlim);
402			} else
403				pt = _yconv(year, base, 1, 1, pt, ptlim);
404			}
405			continue;
406		case 'v':
407			/*
408			** From Arnold Robbins' strftime version 3.0:
409			** "date as dd-bbb-YYYY"
410			** (ado, 1993-05-24)
411			*/
412			pt = _fmt(L"%e-%b-%Y", t, pt, ptlim, warnp);
413			continue;
414		case 'W':
415			pt = _conv((t->tm_yday + DAYSPERWEEK -
416				(t->tm_wday ?
417				(t->tm_wday - 1) :
418				(DAYSPERWEEK - 1))) / DAYSPERWEEK,
419				L"%02d", pt, ptlim);
420			continue;
421		case 'w':
422			pt = _conv(t->tm_wday, L"%d", pt, ptlim);
423			continue;
424		case 'X':
425			pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp);
426			continue;
427		case 'x':
428			{
429			int	warn2 = IN_SOME;
430
431			pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
432			if (warn2 == IN_ALL)
433				warn2 = IN_THIS;
434			if (warn2 > *warnp)
435				*warnp = warn2;
436			}
437			continue;
438		case 'y':
439			*warnp = IN_ALL;
440			pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1, pt, ptlim);
441			continue;
442		case 'Y':
443			pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1, pt, ptlim);
444			continue;
445		case 'Z':
446			if (t->tm_zone != NULL)
447				pt = _sadd(t->TM_ZONE, pt, ptlim);
448			else
449				if (t->tm_isdst >= 0)
450					pt = _sadd(tzname[t->tm_isdst != 0],
451					    pt, ptlim);
452			/*
453			** C99 says that %Z must be replaced by the
454			** empty string if the time zone is not
455			** determinable.
456			*/
457			continue;
458		case 'z':
459			{
460			int		diff;
461			wchar_t const *	sign;
462
463			if (t->tm_isdst < 0)
464				continue;
465			diff = t->tm_gmtoff;
466			if (diff < 0) {
467				sign = L"-";
468				diff = -diff;
469			} else
470				sign = L"+";
471			pt = _add(sign, pt, ptlim);
472			diff /= SECSPERMIN;
473			diff = (diff / MINSPERHOUR) * 100 +
474				(diff % MINSPERHOUR);
475			pt = _conv(diff, L"%04d", pt, ptlim);
476			}
477			continue;
478		case '+':
479			pt = _fmt(Locale->date_fmt, t, pt, ptlim, warnp);
480			continue;
481		case '%':
482		/*
483		** X311J/88-090 (4.12.3.5): if conversion wchar_t is
484		** undefined, behavior is undefined. Print out the
485		** character itself as printf(3) also does.
486		*/
487		default:
488			if (pt != ptlim)
489				*pt++ = *format;
490			break;
491		}
492	}
493	return pt;
494}
495
496static wchar_t *
497_conv(int n, const wchar_t *format, wchar_t *pt, const wchar_t *ptlim)
498{
499	wchar_t	buf[INT_STRLEN_MAXIMUM(int) + 1];
500
501	(void) swprintf(buf, sizeof buf/sizeof buf[0], format, n);
502	return _add(buf, pt, ptlim);
503}
504
505static wchar_t *
506_add(const wchar_t *str, wchar_t *pt, const wchar_t *ptlim)
507{
508	while (pt < ptlim && (*pt = *str++) != L'\0')
509		++pt;
510	return pt;
511}
512
513static wchar_t *
514_sadd(const char *str, wchar_t *pt, const wchar_t *ptlim)
515{
516	while (pt < ptlim && (*pt = btowc(*str++)) != L'\0')
517		++pt;
518	return pt;
519}
520/*
521** POSIX and the C Standard are unclear or inconsistent about
522** what %C and %y do if the year is negative or exceeds 9999.
523** Use the convention that %C concatenated with %y yields the
524** same output as %Y, and that %Y contains at least 4 bytes,
525** with more only if necessary.
526*/
527
528static wchar_t *
529_yconv(int a, int b, int convert_top, int convert_yy, wchar_t *pt,
530    const wchar_t *ptlim)
531{
532	register int	lead;
533	register int	trail;
534
535#define DIVISOR	100
536	trail = a % DIVISOR + b % DIVISOR;
537	lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
538	trail %= DIVISOR;
539	if (trail < 0 && lead > 0) {
540		trail += DIVISOR;
541		--lead;
542	} else if (lead < 0 && trail > 0) {
543		trail -= DIVISOR;
544		++lead;
545	}
546	if (convert_top) {
547		if (lead == 0 && trail < 0)
548			pt = _add(L"-0", pt, ptlim);
549		else	pt = _conv(lead, L"%02d", pt, ptlim);
550	}
551	if (convert_yy)
552		pt = _conv(((trail < 0) ? -trail : trail), L"%02d", pt, ptlim);
553	return pt;
554}
555
556