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1 /*	$OpenBSD: wcsftime.c,v 1.7 2019/05/12 12:49:52 schwarze Exp $ */
2 /*
3 ** Based on the UCB version with the ID appearing below.
4 ** This is ANSIish only when "multibyte character == plain character".
5 **
6 ** Copyright (c) 1989, 1993
7 **	The Regents of the University of California.  All rights reserved.
8 **
9 ** Redistribution and use in source and binary forms, with or without
10 ** modification, are permitted provided that the following conditions
11 ** are met:
12 ** 1. Redistributions of source code must retain the above copyright
13 **    notice, this list of conditions and the following disclaimer.
14 ** 2. Redistributions in binary form must reproduce the above copyright
15 **    notice, this list of conditions and the following disclaimer in the
16 **    documentation and/or other materials provided with the distribution.
17 ** 3. 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 #include <fcntl.h>
35 #include <locale.h>
36 #include <wchar.h>
37 
38 #include "private.h"
39 #include "tzfile.h"
40 
41 struct 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 
56 static 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"?"
104 static wchar_t *	_add(const wchar_t *, wchar_t *, const wchar_t *);
105 static wchar_t *	_sadd(const char *, wchar_t *, const wchar_t *);
106 static wchar_t *	_conv(int, const wchar_t *, wchar_t *, const wchar_t *);
107 static wchar_t *	_fmt(const wchar_t *, const struct tm *, wchar_t *, const wchar_t *,
108 			int *);
109 static wchar_t *	_yconv(int, int, int, int, wchar_t *, const wchar_t *);
110 
111 extern char *	tzname[];
112 
113 #define IN_NONE	0
114 #define IN_SOME	1
115 #define IN_THIS	2
116 #define IN_ALL	3
117 
118 size_t
wcsftime(wchar_t * __restrict s,size_t maxsize,const wchar_t * __restrict format,const struct tm * __restrict t)119 wcsftime(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 
137 static wchar_t *
_fmt(const wchar_t * format,const struct tm * t,wchar_t * pt,const wchar_t * ptlim,int * warnp)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 		}
148 label:
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 				(void) swprintf(buf,
296 				    sizeof buf/sizeof buf[0],
297 				    L"%ld", (long) mkt);
298 				pt = _add(buf, pt, ptlim);
299 			}
300 			continue;
301 		case 'T':
302 			pt = _fmt(L"%H:%M:%S", t, pt, ptlim, warnp);
303 			continue;
304 		case 't':
305 			pt = _add(L"\t", pt, ptlim);
306 			continue;
307 		case 'U':
308 			pt = _conv((t->tm_yday + DAYSPERWEEK -
309 				t->tm_wday) / DAYSPERWEEK,
310 				L"%02d", pt, ptlim);
311 			continue;
312 		case 'u':
313 			/*
314 			** From Arnold Robbins' strftime version 3.0:
315 			** "ISO 8601: Weekday as a decimal number
316 			** [1 (Monday) - 7]"
317 			** (ado, 1993-05-24)
318 			*/
319 			pt = _conv((t->tm_wday == 0) ?
320 				DAYSPERWEEK : t->tm_wday,
321 				L"%d", pt, ptlim);
322 			continue;
323 		case 'V':	/* ISO 8601 week number */
324 		case 'G':	/* ISO 8601 year (four digits) */
325 		case 'g':	/* ISO 8601 year (two digits) */
326 /*
327 ** From Arnold Robbins' strftime version 3.0: "the week number of the
328 ** year (the first Monday as the first day of week 1) as a decimal number
329 ** (01-53)."
330 ** (ado, 1993-05-24)
331 **
332 ** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
333 ** "Week 01 of a year is per definition the first week which has the
334 ** Thursday in this year, which is equivalent to the week which contains
335 ** the fourth day of January. In other words, the first week of a new year
336 ** is the week which has the majority of its days in the new year. Week 01
337 ** might also contain days from the previous year and the week before week
338 ** 01 of a year is the last week (52 or 53) of the previous year even if
339 ** it contains days from the new year. A week starts with Monday (day 1)
340 ** and ends with Sunday (day 7). For example, the first week of the year
341 ** 1997 lasts from 1996-12-30 to 1997-01-05..."
342 ** (ado, 1996-01-02)
343 */
344 			{
345 			int	year;
346 			int	base;
347 			int	yday;
348 			int	wday;
349 			int	w;
350 
351 			year = t->tm_year;
352 			base = TM_YEAR_BASE;
353 			yday = t->tm_yday;
354 			wday = t->tm_wday;
355 			for ( ; ; ) {
356 				int	len;
357 				int	bot;
358 				int	top;
359 
360 				len = isleap_sum(year, base) ?
361 					DAYSPERLYEAR :
362 					DAYSPERNYEAR;
363 				/*
364 				** What yday (-3 ... 3) does the ISO year
365 				** begin on?
366 				*/
367 				bot = ((yday + 11 - wday) % DAYSPERWEEK) - 3;
368 				/*
369 				** What yday does the NEXT ISO year begin on?
370 				*/
371 				top = bot - (len % DAYSPERWEEK);
372 				if (top < -3)
373 					top += DAYSPERWEEK;
374 				top += len;
375 				if (yday >= top) {
376 					++base;
377 					w = 1;
378 					break;
379 				}
380 				if (yday >= bot) {
381 					w = 1 + ((yday - bot) / DAYSPERWEEK);
382 					break;
383 				}
384 				--base;
385 				yday += isleap_sum(year, base) ?
386 					DAYSPERLYEAR :
387 					DAYSPERNYEAR;
388 			}
389 			if ((w == 52 && t->tm_mon == TM_JANUARY) ||
390 				(w == 1 && t->tm_mon == TM_DECEMBER))
391 					w = 53;
392 			if (*format == 'V')
393 				pt = _conv(w, L"%02d", pt, ptlim);
394 			else if (*format == 'g') {
395 				*warnp = IN_ALL;
396 				pt = _yconv(year, base, 0, 1, pt, ptlim);
397 			} else
398 				pt = _yconv(year, base, 1, 1, pt, ptlim);
399 			}
400 			continue;
401 		case 'v':
402 			/*
403 			** From Arnold Robbins' strftime version 3.0:
404 			** "date as dd-bbb-YYYY"
405 			** (ado, 1993-05-24)
406 			*/
407 			pt = _fmt(L"%e-%b-%Y", t, pt, ptlim, warnp);
408 			continue;
409 		case 'W':
410 			pt = _conv((t->tm_yday + DAYSPERWEEK -
411 				(t->tm_wday ?
412 				(t->tm_wday - 1) :
413 				(DAYSPERWEEK - 1))) / DAYSPERWEEK,
414 				L"%02d", pt, ptlim);
415 			continue;
416 		case 'w':
417 			pt = _conv(t->tm_wday, L"%d", pt, ptlim);
418 			continue;
419 		case 'X':
420 			pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp);
421 			continue;
422 		case 'x':
423 			{
424 			int	warn2 = IN_SOME;
425 
426 			pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
427 			if (warn2 == IN_ALL)
428 				warn2 = IN_THIS;
429 			if (warn2 > *warnp)
430 				*warnp = warn2;
431 			}
432 			continue;
433 		case 'y':
434 			*warnp = IN_ALL;
435 			pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1, pt, ptlim);
436 			continue;
437 		case 'Y':
438 			pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1, pt, ptlim);
439 			continue;
440 		case 'Z':
441 			if (t->tm_zone != NULL)
442 				pt = _sadd(t->tm_zone, pt, ptlim);
443 			else
444 				if (t->tm_isdst >= 0)
445 					pt = _sadd(tzname[t->tm_isdst != 0],
446 					    pt, ptlim);
447 			/*
448 			** C99 says that %Z must be replaced by the
449 			** empty string if the time zone is not
450 			** determinable.
451 			*/
452 			continue;
453 		case 'z':
454 			{
455 			int		diff;
456 			wchar_t const *	sign;
457 
458 			if (t->tm_isdst < 0)
459 				continue;
460 			diff = t->tm_gmtoff;
461 			if (diff < 0) {
462 				sign = L"-";
463 				diff = -diff;
464 			} else
465 				sign = L"+";
466 			pt = _add(sign, pt, ptlim);
467 			diff /= SECSPERMIN;
468 			diff = (diff / MINSPERHOUR) * 100 +
469 				(diff % MINSPERHOUR);
470 			pt = _conv(diff, L"%04d", pt, ptlim);
471 			}
472 			continue;
473 		case '+':
474 			pt = _fmt(Locale->date_fmt, t, pt, ptlim, warnp);
475 			continue;
476 		case '%':
477 		/*
478 		** X311J/88-090 (4.12.3.5): if conversion wchar_t is
479 		** undefined, behavior is undefined. Print out the
480 		** character itself as printf(3) also does.
481 		*/
482 		default:
483 			if (pt != ptlim)
484 				*pt++ = *format;
485 			break;
486 		}
487 	}
488 	return pt;
489 }
490 
491 static wchar_t *
_conv(int n,const wchar_t * format,wchar_t * pt,const wchar_t * ptlim)492 _conv(int n, const wchar_t *format, wchar_t *pt, const wchar_t *ptlim)
493 {
494 	wchar_t	buf[INT_STRLEN_MAXIMUM(int) + 1];
495 
496 	(void) swprintf(buf, sizeof buf/sizeof buf[0], format, n);
497 	return _add(buf, pt, ptlim);
498 }
499 
500 static wchar_t *
_add(const wchar_t * str,wchar_t * pt,const wchar_t * ptlim)501 _add(const wchar_t *str, wchar_t *pt, const wchar_t *ptlim)
502 {
503 	while (pt < ptlim && (*pt = *str++) != L'\0')
504 		++pt;
505 	return pt;
506 }
507 
508 static wchar_t *
_sadd(const char * str,wchar_t * pt,const wchar_t * ptlim)509 _sadd(const char *str, wchar_t *pt, const wchar_t *ptlim)
510 {
511 	while (pt < ptlim && (*pt = btowc(*str++)) != L'\0')
512 		++pt;
513 	return pt;
514 }
515 /*
516 ** POSIX and the C Standard are unclear or inconsistent about
517 ** what %C and %y do if the year is negative or exceeds 9999.
518 ** Use the convention that %C concatenated with %y yields the
519 ** same output as %Y, and that %Y contains at least 4 bytes,
520 ** with more only if necessary.
521 */
522 
523 static wchar_t *
_yconv(int a,int b,int convert_top,int convert_yy,wchar_t * pt,const wchar_t * ptlim)524 _yconv(int a, int b, int convert_top, int convert_yy, wchar_t *pt,
525     const wchar_t *ptlim)
526 {
527 	int	lead;
528 	int	trail;
529 
530 #define DIVISOR	100
531 	trail = a % DIVISOR + b % DIVISOR;
532 	lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
533 	trail %= DIVISOR;
534 	if (trail < 0 && lead > 0) {
535 		trail += DIVISOR;
536 		--lead;
537 	} else if (lead < 0 && trail > 0) {
538 		trail -= DIVISOR;
539 		++lead;
540 	}
541 	if (convert_top) {
542 		if (lead == 0 && trail < 0)
543 			pt = _add(L"-0", pt, ptlim);
544 		else	pt = _conv(lead, L"%02d", pt, ptlim);
545 	}
546 	if (convert_yy)
547 		pt = _conv(((trail < 0) ? -trail : trail), L"%02d", pt, ptlim);
548 	return pt;
549 }
550 
551