1 /*
2 * Copyright (c) 1989 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Copyright (c) 2011 The FreeBSD Foundation
6 *
7 * Portions of this software were developed by David Chisnall
8 * under sponsorship from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms are permitted
11 * provided that the above copyright notice and this paragraph are
12 * duplicated in all such forms and that any documentation,
13 * advertising materials, and other materials related to such
14 * distribution and use acknowledge that the software was developed
15 * by the University of California, Berkeley. The name of the
16 * University may not be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
21 */
22
23 #include "namespace.h"
24 #include "private.h"
25
26 #include "tzfile.h"
27 #include <fcntl.h>
28 #include <sys/stat.h>
29 #include <stdio.h>
30 #include "un-namespace.h"
31 #include "timelocal.h"
32
33 static char * _add(const char *, char *, const char *);
34 static char * _conv(int, const char *, char *, const char *, locale_t);
35 static char * _fmt(const char *, const struct tm *, char *, const char *,
36 int *, locale_t);
37 static char * _yconv(int, int, int, int, char *, const char *, locale_t);
38
39 extern char * tzname[];
40
41 #ifndef YEAR_2000_NAME
42 #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
43 #endif /* !defined YEAR_2000_NAME */
44
45 #define IN_NONE 0
46 #define IN_SOME 1
47 #define IN_THIS 2
48 #define IN_ALL 3
49
50 #define PAD_DEFAULT 0
51 #define PAD_LESS 1
52 #define PAD_SPACE 2
53 #define PAD_ZERO 3
54
55 static const char fmt_padding[][4][5] = {
56 /* DEFAULT, LESS, SPACE, ZERO */
57 #define PAD_FMT_MONTHDAY 0
58 #define PAD_FMT_HMS 0
59 #define PAD_FMT_CENTURY 0
60 #define PAD_FMT_SHORTYEAR 0
61 #define PAD_FMT_MONTH 0
62 #define PAD_FMT_WEEKOFYEAR 0
63 #define PAD_FMT_DAYOFMONTH 0
64 { "%02d", "%d", "%2d", "%02d" },
65 #define PAD_FMT_SDAYOFMONTH 1
66 #define PAD_FMT_SHMS 1
67 { "%2d", "%d", "%2d", "%02d" },
68 #define PAD_FMT_DAYOFYEAR 2
69 { "%03d", "%d", "%3d", "%03d" },
70 #define PAD_FMT_YEAR 3
71 { "%04d", "%d", "%4d", "%04d" }
72 };
73
74 size_t
strftime_l(char * __restrict s,size_t maxsize,const char * __restrict format,const struct tm * __restrict t,locale_t loc)75 strftime_l(char * __restrict s, size_t maxsize, const char * __restrict format,
76 const struct tm * __restrict t, locale_t loc)
77 {
78 char * p;
79 int warn;
80 FIX_LOCALE(loc);
81
82 tzset();
83 warn = IN_NONE;
84 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn, loc);
85 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
86 if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
87 (void) fprintf_l(stderr, loc, "\n");
88 if (format == NULL)
89 (void) fputs("NULL strftime format ", stderr);
90 else (void) fprintf_l(stderr, loc, "strftime format \"%s\" ",
91 format);
92 (void) fputs("yields only two digits of years in ", stderr);
93 if (warn == IN_SOME)
94 (void) fputs("some locales", stderr);
95 else if (warn == IN_THIS)
96 (void) fputs("the current locale", stderr);
97 else (void) fputs("all locales", stderr);
98 (void) fputs("\n", stderr);
99 }
100 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
101 if (p == s + maxsize)
102 return (0);
103 *p = '\0';
104 return p - s;
105 }
106
107 size_t
strftime(char * __restrict s,size_t maxsize,const char * __restrict format,const struct tm * __restrict t)108 strftime(char * __restrict s, size_t maxsize, const char * __restrict format,
109 const struct tm * __restrict t)
110 {
111 return strftime_l(s, maxsize, format, t, __get_locale());
112 }
113
114 static char *
_fmt(const char * format,const struct tm * const t,char * pt,const char * const ptlim,int * warnp,locale_t loc)115 _fmt(const char *format, const struct tm * const t, char *pt,
116 const char * const ptlim, int *warnp, locale_t loc)
117 {
118 int Ealternative, Oalternative, PadIndex;
119 struct lc_time_T *tptr = __get_current_time_locale(loc);
120
121 for ( ; *format; ++format) {
122 if (*format == '%') {
123 Ealternative = 0;
124 Oalternative = 0;
125 PadIndex = PAD_DEFAULT;
126 label:
127 switch (*++format) {
128 case '\0':
129 --format;
130 break;
131 case 'A':
132 pt = _add((t->tm_wday < 0 ||
133 t->tm_wday >= DAYSPERWEEK) ?
134 "?" : tptr->weekday[t->tm_wday],
135 pt, ptlim);
136 continue;
137 case 'a':
138 pt = _add((t->tm_wday < 0 ||
139 t->tm_wday >= DAYSPERWEEK) ?
140 "?" : tptr->wday[t->tm_wday],
141 pt, ptlim);
142 continue;
143 case 'B':
144 pt = _add((t->tm_mon < 0 ||
145 t->tm_mon >= MONSPERYEAR) ?
146 "?" : (Oalternative ? tptr->alt_month :
147 tptr->month)[t->tm_mon],
148 pt, ptlim);
149 continue;
150 case 'b':
151 case 'h':
152 pt = _add((t->tm_mon < 0 ||
153 t->tm_mon >= MONSPERYEAR) ?
154 "?" : tptr->mon[t->tm_mon],
155 pt, ptlim);
156 continue;
157 case 'C':
158 /*
159 * %C used to do a...
160 * _fmt("%a %b %e %X %Y", t);
161 * ...whereas now POSIX 1003.2 calls for
162 * something completely different.
163 * (ado, 1993-05-24)
164 */
165 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
166 pt, ptlim, loc);
167 continue;
168 case 'c':
169 {
170 int warn2 = IN_SOME;
171
172 pt = _fmt(tptr->c_fmt, t, pt, ptlim, &warn2, loc);
173 if (warn2 == IN_ALL)
174 warn2 = IN_THIS;
175 if (warn2 > *warnp)
176 *warnp = warn2;
177 }
178 continue;
179 case 'D':
180 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp, loc);
181 continue;
182 case 'd':
183 pt = _conv(t->tm_mday,
184 fmt_padding[PAD_FMT_DAYOFMONTH][PadIndex],
185 pt, ptlim, loc);
186 continue;
187 case 'E':
188 if (Ealternative || Oalternative)
189 break;
190 Ealternative++;
191 goto label;
192 case 'O':
193 /*
194 * C99 locale modifiers.
195 * The sequences
196 * %Ec %EC %Ex %EX %Ey %EY
197 * %Od %oe %OH %OI %Om %OM
198 * %OS %Ou %OU %OV %Ow %OW %Oy
199 * are supposed to provide alternate
200 * representations.
201 *
202 * FreeBSD extension
203 * %OB
204 */
205 if (Ealternative || Oalternative)
206 break;
207 Oalternative++;
208 goto label;
209 case 'e':
210 pt = _conv(t->tm_mday,
211 fmt_padding[PAD_FMT_SDAYOFMONTH][PadIndex],
212 pt, ptlim, loc);
213 continue;
214 case 'F':
215 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, loc);
216 continue;
217 case 'H':
218 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_HMS][PadIndex],
219 pt, ptlim, loc);
220 continue;
221 case 'I':
222 pt = _conv((t->tm_hour % 12) ?
223 (t->tm_hour % 12) : 12,
224 fmt_padding[PAD_FMT_HMS][PadIndex],
225 pt, ptlim, loc);
226 continue;
227 case 'j':
228 pt = _conv(t->tm_yday + 1,
229 fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex],
230 pt, ptlim, loc);
231 continue;
232 case 'k':
233 /*
234 * This used to be...
235 * _conv(t->tm_hour % 12 ?
236 * t->tm_hour % 12 : 12, 2, ' ');
237 * ...and has been changed to the below to
238 * match SunOS 4.1.1 and Arnold Robbins'
239 * strftime version 3.0. That is, "%k" and
240 * "%l" have been swapped.
241 * (ado, 1993-05-24)
242 */
243 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_SHMS][PadIndex],
244 pt, ptlim, loc);
245 continue;
246 #ifdef KITCHEN_SINK
247 case 'K':
248 /*
249 ** After all this time, still unclaimed!
250 */
251 pt = _add("kitchen sink", pt, ptlim);
252 continue;
253 #endif /* defined KITCHEN_SINK */
254 case 'l':
255 /*
256 * This used to be...
257 * _conv(t->tm_hour, 2, ' ');
258 * ...and has been changed to the below to
259 * match SunOS 4.1.1 and Arnold Robbin's
260 * strftime version 3.0. That is, "%k" and
261 * "%l" have been swapped.
262 * (ado, 1993-05-24)
263 */
264 pt = _conv((t->tm_hour % 12) ?
265 (t->tm_hour % 12) : 12,
266 fmt_padding[PAD_FMT_SHMS][PadIndex],
267 pt, ptlim, loc);
268 continue;
269 case 'M':
270 pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex],
271 pt, ptlim, loc);
272 continue;
273 case 'm':
274 pt = _conv(t->tm_mon + 1,
275 fmt_padding[PAD_FMT_MONTH][PadIndex],
276 pt, ptlim, loc);
277 continue;
278 case 'n':
279 pt = _add("\n", pt, ptlim);
280 continue;
281 case 'p':
282 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
283 tptr->pm : tptr->am,
284 pt, ptlim);
285 continue;
286 case 'R':
287 pt = _fmt("%H:%M", t, pt, ptlim, warnp, loc);
288 continue;
289 case 'r':
290 pt = _fmt(tptr->ampm_fmt, t, pt, ptlim,
291 warnp, loc);
292 continue;
293 case 'S':
294 pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex],
295 pt, ptlim, loc);
296 continue;
297 case 's':
298 {
299 struct tm tm;
300 char buf[INT_STRLEN_MAXIMUM(
301 time_t) + 1];
302 time_t mkt;
303
304 tm = *t;
305 mkt = timeoff(&tm, t->tm_gmtoff);
306 if (TYPE_SIGNED(time_t))
307 (void) sprintf_l(buf, loc, "%ld",
308 (long) mkt);
309 else (void) sprintf_l(buf, loc, "%lu",
310 (unsigned long) mkt);
311 pt = _add(buf, pt, ptlim);
312 }
313 continue;
314 case 'T':
315 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, loc);
316 continue;
317 case 't':
318 pt = _add("\t", pt, ptlim);
319 continue;
320 case 'U':
321 pt = _conv((t->tm_yday + DAYSPERWEEK -
322 t->tm_wday) / DAYSPERWEEK,
323 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
324 pt, ptlim, loc);
325 continue;
326 case 'u':
327 /*
328 * From Arnold Robbins' strftime version 3.0:
329 * "ISO 8601: Weekday as a decimal number
330 * [1 (Monday) - 7]"
331 * (ado, 1993-05-24)
332 */
333 pt = _conv((t->tm_wday == 0) ?
334 DAYSPERWEEK : t->tm_wday,
335 "%d", pt, ptlim, loc);
336 continue;
337 case 'V': /* ISO 8601 week number */
338 case 'G': /* ISO 8601 year (four digits) */
339 case 'g': /* ISO 8601 year (two digits) */
340 /*
341 * From Arnold Robbins' strftime version 3.0: "the week number of the
342 * year (the first Monday as the first day of week 1) as a decimal number
343 * (01-53)."
344 * (ado, 1993-05-24)
345 *
346 * From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
347 * "Week 01 of a year is per definition the first week which has the
348 * Thursday in this year, which is equivalent to the week which contains
349 * the fourth day of January. In other words, the first week of a new year
350 * is the week which has the majority of its days in the new year. Week 01
351 * might also contain days from the previous year and the week before week
352 * 01 of a year is the last week (52 or 53) of the previous year even if
353 * it contains days from the new year. A week starts with Monday (day 1)
354 * and ends with Sunday (day 7). For example, the first week of the year
355 * 1997 lasts from 1996-12-30 to 1997-01-05..."
356 * (ado, 1996-01-02)
357 */
358 {
359 int year;
360 int base;
361 int yday;
362 int wday;
363 int w;
364
365 year = t->tm_year;
366 base = TM_YEAR_BASE;
367 yday = t->tm_yday;
368 wday = t->tm_wday;
369 for ( ; ; ) {
370 int len;
371 int bot;
372 int top;
373
374 len = isleap_sum(year, base) ?
375 DAYSPERLYEAR :
376 DAYSPERNYEAR;
377 /*
378 * What yday (-3 ... 3) does
379 * the ISO year begin on?
380 */
381 bot = ((yday + 11 - wday) %
382 DAYSPERWEEK) - 3;
383 /*
384 * What yday does the NEXT
385 * ISO year begin on?
386 */
387 top = bot -
388 (len % DAYSPERWEEK);
389 if (top < -3)
390 top += DAYSPERWEEK;
391 top += len;
392 if (yday >= top) {
393 ++base;
394 w = 1;
395 break;
396 }
397 if (yday >= bot) {
398 w = 1 + ((yday - bot) /
399 DAYSPERWEEK);
400 break;
401 }
402 --base;
403 yday += isleap_sum(year, base) ?
404 DAYSPERLYEAR :
405 DAYSPERNYEAR;
406 }
407 #ifdef XPG4_1994_04_09
408 if ((w == 52 &&
409 t->tm_mon == TM_JANUARY) ||
410 (w == 1 &&
411 t->tm_mon == TM_DECEMBER))
412 w = 53;
413 #endif /* defined XPG4_1994_04_09 */
414 if (*format == 'V')
415 pt = _conv(w, fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
416 pt, ptlim, loc);
417 else if (*format == 'g') {
418 *warnp = IN_ALL;
419 pt = _yconv(year, base, 0, 1,
420 pt, ptlim, loc);
421 } else pt = _yconv(year, base, 1, 1,
422 pt, ptlim, loc);
423 }
424 continue;
425 case 'v':
426 /*
427 * From Arnold Robbins' strftime version 3.0:
428 * "date as dd-bbb-YYYY"
429 * (ado, 1993-05-24)
430 */
431 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, loc);
432 continue;
433 case 'W':
434 pt = _conv((t->tm_yday + DAYSPERWEEK -
435 (t->tm_wday ?
436 (t->tm_wday - 1) :
437 (DAYSPERWEEK - 1))) / DAYSPERWEEK,
438 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
439 pt, ptlim, loc);
440 continue;
441 case 'w':
442 pt = _conv(t->tm_wday, "%d", pt, ptlim, loc);
443 continue;
444 case 'X':
445 pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp, loc);
446 continue;
447 case 'x':
448 {
449 int warn2 = IN_SOME;
450
451 pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2, loc);
452 if (warn2 == IN_ALL)
453 warn2 = IN_THIS;
454 if (warn2 > *warnp)
455 *warnp = warn2;
456 }
457 continue;
458 case 'y':
459 *warnp = IN_ALL;
460 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
461 pt, ptlim, loc);
462 continue;
463 case 'Y':
464 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
465 pt, ptlim, loc);
466 continue;
467 case 'Z':
468 #ifdef TM_ZONE
469 if (t->TM_ZONE != NULL)
470 pt = _add(t->TM_ZONE, pt, ptlim);
471 else
472 #endif /* defined TM_ZONE */
473 if (t->tm_isdst >= 0)
474 pt = _add(tzname[t->tm_isdst != 0],
475 pt, ptlim);
476 /*
477 * C99 says that %Z must be replaced by the
478 * empty string if the time zone is not
479 * determinable.
480 */
481 continue;
482 case 'z':
483 {
484 int diff;
485 char const * sign;
486
487 if (t->tm_isdst < 0)
488 continue;
489 #ifdef TM_GMTOFF
490 diff = t->TM_GMTOFF;
491 #else /* !defined TM_GMTOFF */
492 /*
493 * C99 says that the UTC offset must
494 * be computed by looking only at
495 * tm_isdst. This requirement is
496 * incorrect, since it means the code
497 * must rely on magic (in this case
498 * altzone and timezone), and the
499 * magic might not have the correct
500 * offset. Doing things correctly is
501 * tricky and requires disobeying C99;
502 * see GNU C strftime for details.
503 * For now, punt and conform to the
504 * standard, even though it's incorrect.
505 *
506 * C99 says that %z must be replaced by the
507 * empty string if the time zone is not
508 * determinable, so output nothing if the
509 * appropriate variables are not available.
510 */
511 if (t->tm_isdst == 0)
512 #ifdef USG_COMPAT
513 diff = -timezone;
514 #else /* !defined USG_COMPAT */
515 continue;
516 #endif /* !defined USG_COMPAT */
517 else
518 #ifdef ALTZONE
519 diff = -altzone;
520 #else /* !defined ALTZONE */
521 continue;
522 #endif /* !defined ALTZONE */
523 #endif /* !defined TM_GMTOFF */
524 if (diff < 0) {
525 sign = "-";
526 diff = -diff;
527 } else
528 sign = "+";
529 pt = _add(sign, pt, ptlim);
530 diff /= SECSPERMIN;
531 diff = (diff / MINSPERHOUR) * 100 +
532 (diff % MINSPERHOUR);
533 pt = _conv(diff,
534 fmt_padding[PAD_FMT_YEAR][PadIndex],
535 pt, ptlim, loc);
536 }
537 continue;
538 case '+':
539 pt = _fmt(tptr->date_fmt, t, pt, ptlim,
540 warnp, loc);
541 continue;
542 case '-':
543 if (PadIndex != PAD_DEFAULT)
544 break;
545 PadIndex = PAD_LESS;
546 goto label;
547 case '_':
548 if (PadIndex != PAD_DEFAULT)
549 break;
550 PadIndex = PAD_SPACE;
551 goto label;
552 case '0':
553 if (PadIndex != PAD_DEFAULT)
554 break;
555 PadIndex = PAD_ZERO;
556 goto label;
557 case '%':
558 /*
559 * X311J/88-090 (4.12.3.5): if conversion char is
560 * undefined, behavior is undefined. Print out the
561 * character itself as printf(3) also does.
562 */
563 default:
564 break;
565 }
566 }
567 if (pt == ptlim)
568 break;
569 *pt++ = *format;
570 }
571 return (pt);
572 }
573
574 static char *
_conv(const int n,const char * const format,char * const pt,const char * const ptlim,locale_t loc)575 _conv(const int n, const char * const format, char * const pt,
576 const char * const ptlim, locale_t loc)
577 {
578 char buf[INT_STRLEN_MAXIMUM(int) + 1];
579
580 (void) sprintf_l(buf, loc, format, n);
581 return _add(buf, pt, ptlim);
582 }
583
584 static char *
_add(const char * str,char * pt,const char * const ptlim)585 _add(const char *str, char *pt, const char * const ptlim)
586 {
587 while (pt < ptlim && (*pt = *str++) != '\0')
588 ++pt;
589 return (pt);
590 }
591
592 /*
593 * POSIX and the C Standard are unclear or inconsistent about
594 * what %C and %y do if the year is negative or exceeds 9999.
595 * Use the convention that %C concatenated with %y yields the
596 * same output as %Y, and that %Y contains at least 4 bytes,
597 * with more only if necessary.
598 */
599
600 static char *
_yconv(const int a,const int b,const int convert_top,const int convert_yy,char * pt,const char * const ptlim,locale_t loc)601 _yconv(const int a, const int b, const int convert_top, const int convert_yy,
602 char *pt, const char * const ptlim, locale_t loc)
603 {
604 register int lead;
605 register int trail;
606
607 #define DIVISOR 100
608 trail = a % DIVISOR + b % DIVISOR;
609 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
610 trail %= DIVISOR;
611 if (trail < 0 && lead > 0) {
612 trail += DIVISOR;
613 --lead;
614 } else if (lead < 0 && trail > 0) {
615 trail -= DIVISOR;
616 ++lead;
617 }
618 if (convert_top) {
619 if (lead == 0 && trail < 0)
620 pt = _add("-0", pt, ptlim);
621 else pt = _conv(lead, "%02d", pt, ptlim, loc);
622 }
623 if (convert_yy)
624 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt,
625 ptlim, loc);
626 return (pt);
627 }
628