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 * All rights reserved.
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 #ifndef lint
24 #ifndef NOID
25 static const char elsieid[] = "@(#)strftime.3 8.3";
26 /*
27 * Based on the UCB version with the ID appearing below.
28 * This is ANSIish only when "multibyte character == plain character".
29 */
30 #endif /* !defined NOID */
31 #endif /* !defined lint */
32
33 #include "namespace.h"
34 #include "private.h"
35
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static const char sccsid[] = "@(#)strftime.c 5.4 (Berkeley) 3/14/89";
38 #endif /* LIBC_SCCS and not lint */
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41
42 #include "tzfile.h"
43 #include <fcntl.h>
44 #include <sys/stat.h>
45 #include "un-namespace.h"
46 #include "timelocal.h"
47
48 static char * _add(const char *, char *, const char *);
49 static char * _conv(int, const char *, char *, const char *, locale_t);
50 static char * _fmt(const char *, const struct tm *, char *, const char *,
51 int *, locale_t);
52 static char * _yconv(int, int, int, int, char *, const char *, locale_t);
53
54 extern char * tzname[];
55
56 #ifndef YEAR_2000_NAME
57 #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
58 #endif /* !defined YEAR_2000_NAME */
59
60 #define IN_NONE 0
61 #define IN_SOME 1
62 #define IN_THIS 2
63 #define IN_ALL 3
64
65 #define PAD_DEFAULT 0
66 #define PAD_LESS 1
67 #define PAD_SPACE 2
68 #define PAD_ZERO 3
69
70 static const char fmt_padding[][4][5] = {
71 /* DEFAULT, LESS, SPACE, ZERO */
72 #define PAD_FMT_MONTHDAY 0
73 #define PAD_FMT_HMS 0
74 #define PAD_FMT_CENTURY 0
75 #define PAD_FMT_SHORTYEAR 0
76 #define PAD_FMT_MONTH 0
77 #define PAD_FMT_WEEKOFYEAR 0
78 #define PAD_FMT_DAYOFMONTH 0
79 { "%02d", "%d", "%2d", "%02d" },
80 #define PAD_FMT_SDAYOFMONTH 1
81 #define PAD_FMT_SHMS 1
82 { "%2d", "%d", "%2d", "%02d" },
83 #define PAD_FMT_DAYOFYEAR 2
84 { "%03d", "%d", "%3d", "%03d" },
85 #define PAD_FMT_YEAR 3
86 { "%04d", "%d", "%4d", "%04d" }
87 };
88
89 size_t
strftime_l(char * __restrict s,size_t maxsize,const char * __restrict format,const struct tm * __restrict t,locale_t loc)90 strftime_l(char * __restrict s, size_t maxsize, const char * __restrict format,
91 const struct tm * __restrict t, locale_t loc)
92 {
93 char * p;
94 int warn;
95 FIX_LOCALE(loc);
96
97 tzset();
98 warn = IN_NONE;
99 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn, loc);
100 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
101 if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
102 (void) fprintf_l(stderr, loc, "\n");
103 if (format == NULL)
104 (void) fputs("NULL strftime format ", stderr);
105 else (void) fprintf_l(stderr, loc, "strftime format \"%s\" ",
106 format);
107 (void) fputs("yields only two digits of years in ", stderr);
108 if (warn == IN_SOME)
109 (void) fputs("some locales", stderr);
110 else if (warn == IN_THIS)
111 (void) fputs("the current locale", stderr);
112 else (void) fputs("all locales", stderr);
113 (void) fputs("\n", stderr);
114 }
115 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
116 if (p == s + maxsize)
117 return (0);
118 *p = '\0';
119 return p - s;
120 }
121
122 size_t
strftime(char * __restrict s,size_t maxsize,const char * __restrict format,const struct tm * __restrict t)123 strftime(char * __restrict s, size_t maxsize, const char * __restrict format,
124 const struct tm * __restrict t)
125 {
126 return strftime_l(s, maxsize, format, t, __get_locale());
127 }
128
129 static char *
_fmt(const char * format,const struct tm * const t,char * pt,const char * const ptlim,int * warnp,locale_t loc)130 _fmt(const char *format, const struct tm * const t, char *pt,
131 const char * const ptlim, int *warnp, locale_t loc)
132 {
133 int Ealternative, Oalternative, PadIndex;
134 struct lc_time_T *tptr = __get_current_time_locale(loc);
135
136 for ( ; *format; ++format) {
137 if (*format == '%') {
138 Ealternative = 0;
139 Oalternative = 0;
140 PadIndex = PAD_DEFAULT;
141 label:
142 switch (*++format) {
143 case '\0':
144 --format;
145 break;
146 case 'A':
147 pt = _add((t->tm_wday < 0 ||
148 t->tm_wday >= DAYSPERWEEK) ?
149 "?" : tptr->weekday[t->tm_wday],
150 pt, ptlim);
151 continue;
152 case 'a':
153 pt = _add((t->tm_wday < 0 ||
154 t->tm_wday >= DAYSPERWEEK) ?
155 "?" : tptr->wday[t->tm_wday],
156 pt, ptlim);
157 continue;
158 case 'B':
159 pt = _add((t->tm_mon < 0 ||
160 t->tm_mon >= MONSPERYEAR) ?
161 "?" : (Oalternative ? tptr->alt_month :
162 tptr->month)[t->tm_mon],
163 pt, ptlim);
164 continue;
165 case 'b':
166 case 'h':
167 pt = _add((t->tm_mon < 0 ||
168 t->tm_mon >= MONSPERYEAR) ?
169 "?" : tptr->mon[t->tm_mon],
170 pt, ptlim);
171 continue;
172 case 'C':
173 /*
174 * %C used to do a...
175 * _fmt("%a %b %e %X %Y", t);
176 * ...whereas now POSIX 1003.2 calls for
177 * something completely different.
178 * (ado, 1993-05-24)
179 */
180 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
181 pt, ptlim, loc);
182 continue;
183 case 'c':
184 {
185 int warn2 = IN_SOME;
186
187 pt = _fmt(tptr->c_fmt, t, pt, ptlim, &warn2, loc);
188 if (warn2 == IN_ALL)
189 warn2 = IN_THIS;
190 if (warn2 > *warnp)
191 *warnp = warn2;
192 }
193 continue;
194 case 'D':
195 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp, loc);
196 continue;
197 case 'd':
198 pt = _conv(t->tm_mday,
199 fmt_padding[PAD_FMT_DAYOFMONTH][PadIndex],
200 pt, ptlim, loc);
201 continue;
202 case 'E':
203 if (Ealternative || Oalternative)
204 break;
205 Ealternative++;
206 goto label;
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 * FreeBSD extension
218 * %OB
219 */
220 if (Ealternative || Oalternative)
221 break;
222 Oalternative++;
223 goto label;
224 case 'e':
225 pt = _conv(t->tm_mday,
226 fmt_padding[PAD_FMT_SDAYOFMONTH][PadIndex],
227 pt, ptlim, loc);
228 continue;
229 case 'F':
230 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, loc);
231 continue;
232 case 'H':
233 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_HMS][PadIndex],
234 pt, ptlim, loc);
235 continue;
236 case 'I':
237 pt = _conv((t->tm_hour % 12) ?
238 (t->tm_hour % 12) : 12,
239 fmt_padding[PAD_FMT_HMS][PadIndex],
240 pt, ptlim, loc);
241 continue;
242 case 'j':
243 pt = _conv(t->tm_yday + 1,
244 fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex],
245 pt, ptlim, loc);
246 continue;
247 case 'k':
248 /*
249 * This used to be...
250 * _conv(t->tm_hour % 12 ?
251 * t->tm_hour % 12 : 12, 2, ' ');
252 * ...and has been changed to the below to
253 * match SunOS 4.1.1 and Arnold Robbins'
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, fmt_padding[PAD_FMT_SHMS][PadIndex],
259 pt, ptlim, loc);
260 continue;
261 #ifdef KITCHEN_SINK
262 case 'K':
263 /*
264 ** After all this time, still unclaimed!
265 */
266 pt = _add("kitchen sink", pt, ptlim);
267 continue;
268 #endif /* defined KITCHEN_SINK */
269 case 'l':
270 /*
271 * This used to be...
272 * _conv(t->tm_hour, 2, ' ');
273 * ...and has been changed to the below to
274 * match SunOS 4.1.1 and Arnold Robbin's
275 * strftime version 3.0. That is, "%k" and
276 * "%l" have been swapped.
277 * (ado, 1993-05-24)
278 */
279 pt = _conv((t->tm_hour % 12) ?
280 (t->tm_hour % 12) : 12,
281 fmt_padding[PAD_FMT_SHMS][PadIndex],
282 pt, ptlim, loc);
283 continue;
284 case 'M':
285 pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex],
286 pt, ptlim, loc);
287 continue;
288 case 'm':
289 pt = _conv(t->tm_mon + 1,
290 fmt_padding[PAD_FMT_MONTH][PadIndex],
291 pt, ptlim, loc);
292 continue;
293 case 'n':
294 pt = _add("\n", pt, ptlim);
295 continue;
296 case 'p':
297 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
298 tptr->pm : tptr->am,
299 pt, ptlim);
300 continue;
301 case 'R':
302 pt = _fmt("%H:%M", t, pt, ptlim, warnp, loc);
303 continue;
304 case 'r':
305 pt = _fmt(tptr->ampm_fmt, t, pt, ptlim,
306 warnp, loc);
307 continue;
308 case 'S':
309 pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex],
310 pt, ptlim, loc);
311 continue;
312 case 's':
313 {
314 struct tm tm;
315 char buf[INT_STRLEN_MAXIMUM(
316 time_t) + 1];
317 time_t mkt;
318
319 tm = *t;
320 mkt = mktime(&tm);
321 if (TYPE_SIGNED(time_t))
322 (void) sprintf_l(buf, loc, "%ld",
323 (long) mkt);
324 else (void) sprintf_l(buf, loc, "%lu",
325 (unsigned long) mkt);
326 pt = _add(buf, pt, ptlim);
327 }
328 continue;
329 case 'T':
330 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, loc);
331 continue;
332 case 't':
333 pt = _add("\t", pt, ptlim);
334 continue;
335 case 'U':
336 pt = _conv((t->tm_yday + DAYSPERWEEK -
337 t->tm_wday) / DAYSPERWEEK,
338 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
339 pt, ptlim, loc);
340 continue;
341 case 'u':
342 /*
343 * From Arnold Robbins' strftime version 3.0:
344 * "ISO 8601: Weekday as a decimal number
345 * [1 (Monday) - 7]"
346 * (ado, 1993-05-24)
347 */
348 pt = _conv((t->tm_wday == 0) ?
349 DAYSPERWEEK : t->tm_wday,
350 "%d", pt, ptlim, loc);
351 continue;
352 case 'V': /* ISO 8601 week number */
353 case 'G': /* ISO 8601 year (four digits) */
354 case 'g': /* ISO 8601 year (two digits) */
355 /*
356 * From Arnold Robbins' strftime version 3.0: "the week number of the
357 * year (the first Monday as the first day of week 1) as a decimal number
358 * (01-53)."
359 * (ado, 1993-05-24)
360 *
361 * From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
362 * "Week 01 of a year is per definition the first week which has the
363 * Thursday in this year, which is equivalent to the week which contains
364 * the fourth day of January. In other words, the first week of a new year
365 * is the week which has the majority of its days in the new year. Week 01
366 * might also contain days from the previous year and the week before week
367 * 01 of a year is the last week (52 or 53) of the previous year even if
368 * it contains days from the new year. A week starts with Monday (day 1)
369 * and ends with Sunday (day 7). For example, the first week of the year
370 * 1997 lasts from 1996-12-30 to 1997-01-05..."
371 * (ado, 1996-01-02)
372 */
373 {
374 int year;
375 int base;
376 int yday;
377 int wday;
378 int w;
379
380 year = t->tm_year;
381 base = TM_YEAR_BASE;
382 yday = t->tm_yday;
383 wday = t->tm_wday;
384 for ( ; ; ) {
385 int len;
386 int bot;
387 int top;
388
389 len = isleap_sum(year, base) ?
390 DAYSPERLYEAR :
391 DAYSPERNYEAR;
392 /*
393 * What yday (-3 ... 3) does
394 * the ISO year begin on?
395 */
396 bot = ((yday + 11 - wday) %
397 DAYSPERWEEK) - 3;
398 /*
399 * What yday does the NEXT
400 * ISO year begin on?
401 */
402 top = bot -
403 (len % DAYSPERWEEK);
404 if (top < -3)
405 top += DAYSPERWEEK;
406 top += len;
407 if (yday >= top) {
408 ++base;
409 w = 1;
410 break;
411 }
412 if (yday >= bot) {
413 w = 1 + ((yday - bot) /
414 DAYSPERWEEK);
415 break;
416 }
417 --base;
418 yday += isleap_sum(year, base) ?
419 DAYSPERLYEAR :
420 DAYSPERNYEAR;
421 }
422 #ifdef XPG4_1994_04_09
423 if ((w == 52 &&
424 t->tm_mon == TM_JANUARY) ||
425 (w == 1 &&
426 t->tm_mon == TM_DECEMBER))
427 w = 53;
428 #endif /* defined XPG4_1994_04_09 */
429 if (*format == 'V')
430 pt = _conv(w, fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
431 pt, ptlim, loc);
432 else if (*format == 'g') {
433 *warnp = IN_ALL;
434 pt = _yconv(year, base, 0, 1,
435 pt, ptlim, loc);
436 } else pt = _yconv(year, base, 1, 1,
437 pt, ptlim, loc);
438 }
439 continue;
440 case 'v':
441 /*
442 * From Arnold Robbins' strftime version 3.0:
443 * "date as dd-bbb-YYYY"
444 * (ado, 1993-05-24)
445 */
446 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, loc);
447 continue;
448 case 'W':
449 pt = _conv((t->tm_yday + DAYSPERWEEK -
450 (t->tm_wday ?
451 (t->tm_wday - 1) :
452 (DAYSPERWEEK - 1))) / DAYSPERWEEK,
453 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
454 pt, ptlim, loc);
455 continue;
456 case 'w':
457 pt = _conv(t->tm_wday, "%d", pt, ptlim, loc);
458 continue;
459 case 'X':
460 pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp, loc);
461 continue;
462 case 'x':
463 {
464 int warn2 = IN_SOME;
465
466 pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2, loc);
467 if (warn2 == IN_ALL)
468 warn2 = IN_THIS;
469 if (warn2 > *warnp)
470 *warnp = warn2;
471 }
472 continue;
473 case 'y':
474 *warnp = IN_ALL;
475 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
476 pt, ptlim, loc);
477 continue;
478 case 'Y':
479 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
480 pt, ptlim, loc);
481 continue;
482 case 'Z':
483 #ifdef TM_ZONE
484 if (t->TM_ZONE != NULL)
485 pt = _add(t->TM_ZONE, pt, ptlim);
486 else
487 #endif /* defined TM_ZONE */
488 if (t->tm_isdst >= 0)
489 pt = _add(tzname[t->tm_isdst != 0],
490 pt, ptlim);
491 /*
492 * C99 says that %Z must be replaced by the
493 * empty string if the time zone is not
494 * determinable.
495 */
496 continue;
497 case 'z':
498 {
499 int diff;
500 char const * sign;
501
502 if (t->tm_isdst < 0)
503 continue;
504 #ifdef TM_GMTOFF
505 diff = t->TM_GMTOFF;
506 #else /* !defined TM_GMTOFF */
507 /*
508 * C99 says that the UTC offset must
509 * be computed by looking only at
510 * tm_isdst. This requirement is
511 * incorrect, since it means the code
512 * must rely on magic (in this case
513 * altzone and timezone), and the
514 * magic might not have the correct
515 * offset. Doing things correctly is
516 * tricky and requires disobeying C99;
517 * see GNU C strftime for details.
518 * For now, punt and conform to the
519 * standard, even though it's incorrect.
520 *
521 * C99 says that %z must be replaced by the
522 * empty string if the time zone is not
523 * determinable, so output nothing if the
524 * appropriate variables are not available.
525 */
526 if (t->tm_isdst == 0)
527 #ifdef USG_COMPAT
528 diff = -timezone;
529 #else /* !defined USG_COMPAT */
530 continue;
531 #endif /* !defined USG_COMPAT */
532 else
533 #ifdef ALTZONE
534 diff = -altzone;
535 #else /* !defined ALTZONE */
536 continue;
537 #endif /* !defined ALTZONE */
538 #endif /* !defined TM_GMTOFF */
539 if (diff < 0) {
540 sign = "-";
541 diff = -diff;
542 } else
543 sign = "+";
544 pt = _add(sign, pt, ptlim);
545 diff /= SECSPERMIN;
546 diff = (diff / MINSPERHOUR) * 100 +
547 (diff % MINSPERHOUR);
548 pt = _conv(diff,
549 fmt_padding[PAD_FMT_YEAR][PadIndex],
550 pt, ptlim, loc);
551 }
552 continue;
553 case '+':
554 pt = _fmt(tptr->date_fmt, t, pt, ptlim,
555 warnp, loc);
556 continue;
557 case '-':
558 if (PadIndex != PAD_DEFAULT)
559 break;
560 PadIndex = PAD_LESS;
561 goto label;
562 case '_':
563 if (PadIndex != PAD_DEFAULT)
564 break;
565 PadIndex = PAD_SPACE;
566 goto label;
567 case '0':
568 if (PadIndex != PAD_DEFAULT)
569 break;
570 PadIndex = PAD_ZERO;
571 goto label;
572 case '%':
573 /*
574 * X311J/88-090 (4.12.3.5): if conversion char is
575 * undefined, behavior is undefined. Print out the
576 * character itself as printf(3) also does.
577 */
578 default:
579 break;
580 }
581 }
582 if (pt == ptlim)
583 break;
584 *pt++ = *format;
585 }
586 return (pt);
587 }
588
589 static char *
_conv(const int n,const char * const format,char * const pt,const char * const ptlim,locale_t loc)590 _conv(const int n, const char * const format, char * const pt,
591 const char * const ptlim, locale_t loc)
592 {
593 char buf[INT_STRLEN_MAXIMUM(int) + 1];
594
595 (void) sprintf_l(buf, loc, format, n);
596 return _add(buf, pt, ptlim);
597 }
598
599 static char *
_add(const char * str,char * pt,const char * const ptlim)600 _add(const char *str, char *pt, const char * const ptlim)
601 {
602 while (pt < ptlim && (*pt = *str++) != '\0')
603 ++pt;
604 return (pt);
605 }
606
607 /*
608 * POSIX and the C Standard are unclear or inconsistent about
609 * what %C and %y do if the year is negative or exceeds 9999.
610 * Use the convention that %C concatenated with %y yields the
611 * same output as %Y, and that %Y contains at least 4 bytes,
612 * with more only if necessary.
613 */
614
615 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)616 _yconv(const int a, const int b, const int convert_top, const int convert_yy,
617 char *pt, const char * const ptlim, locale_t loc)
618 {
619 register int lead;
620 register int trail;
621
622 #define DIVISOR 100
623 trail = a % DIVISOR + b % DIVISOR;
624 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
625 trail %= DIVISOR;
626 if (trail < 0 && lead > 0) {
627 trail += DIVISOR;
628 --lead;
629 } else if (lead < 0 && trail > 0) {
630 trail -= DIVISOR;
631 ++lead;
632 }
633 if (convert_top) {
634 if (lead == 0 && trail < 0)
635 pt = _add("-0", pt, ptlim);
636 else pt = _conv(lead, "%02d", pt, ptlim, loc);
637 }
638 if (convert_yy)
639 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt,
640 ptlim, loc);
641 return (pt);
642 }
643