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