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 #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 "tzfile.h"
40 #include <fcntl.h>
41 #include <sys/stat.h>
42 #include <stdio.h>
43 #include "un-namespace.h"
44 #include "timelocal.h"
45
46 static char * _add(const char *, char *, const char *);
47 static char * _conv(int, const char *, char *, const char *, locale_t);
48 static char * _fmt(const char *, const struct tm *, char *, const char *,
49 int *, locale_t);
50 static char * _yconv(int, int, int, int, char *, const char *, locale_t);
51
52 extern char * tzname[];
53
54 #ifndef YEAR_2000_NAME
55 #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
56 #endif /* !defined YEAR_2000_NAME */
57
58 #define IN_NONE 0
59 #define IN_SOME 1
60 #define IN_THIS 2
61 #define IN_ALL 3
62
63 #define PAD_DEFAULT 0
64 #define PAD_LESS 1
65 #define PAD_SPACE 2
66 #define PAD_ZERO 3
67
68 static const char fmt_padding[][4][5] = {
69 /* DEFAULT, LESS, SPACE, ZERO */
70 #define PAD_FMT_MONTHDAY 0
71 #define PAD_FMT_HMS 0
72 #define PAD_FMT_CENTURY 0
73 #define PAD_FMT_SHORTYEAR 0
74 #define PAD_FMT_MONTH 0
75 #define PAD_FMT_WEEKOFYEAR 0
76 #define PAD_FMT_DAYOFMONTH 0
77 { "%02d", "%d", "%2d", "%02d" },
78 #define PAD_FMT_SDAYOFMONTH 1
79 #define PAD_FMT_SHMS 1
80 { "%2d", "%d", "%2d", "%02d" },
81 #define PAD_FMT_DAYOFYEAR 2
82 { "%03d", "%d", "%3d", "%03d" },
83 #define PAD_FMT_YEAR 3
84 { "%04d", "%d", "%4d", "%04d" }
85 };
86
87 size_t
strftime_l(char * __restrict s,size_t maxsize,const char * __restrict format,const struct tm * __restrict t,locale_t loc)88 strftime_l(char * __restrict s, size_t maxsize, const char * __restrict format,
89 const struct tm * __restrict t, locale_t loc)
90 {
91 char * p;
92 int warn;
93 FIX_LOCALE(loc);
94
95 tzset();
96 warn = IN_NONE;
97 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn, loc);
98 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
99 if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
100 (void) fprintf_l(stderr, loc, "\n");
101 if (format == NULL)
102 (void) fputs("NULL strftime format ", stderr);
103 else (void) fprintf_l(stderr, loc, "strftime format \"%s\" ",
104 format);
105 (void) fputs("yields only two digits of years in ", stderr);
106 if (warn == IN_SOME)
107 (void) fputs("some locales", stderr);
108 else if (warn == IN_THIS)
109 (void) fputs("the current locale", stderr);
110 else (void) fputs("all locales", stderr);
111 (void) fputs("\n", stderr);
112 }
113 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
114 if (p == s + maxsize)
115 return (0);
116 *p = '\0';
117 return p - s;
118 }
119
120 size_t
strftime(char * __restrict s,size_t maxsize,const char * __restrict format,const struct tm * __restrict t)121 strftime(char * __restrict s, size_t maxsize, const char * __restrict format,
122 const struct tm * __restrict t)
123 {
124 return strftime_l(s, maxsize, format, t, __get_locale());
125 }
126
127 static char *
_fmt(const char * format,const struct tm * const t,char * pt,const char * const ptlim,int * warnp,locale_t loc)128 _fmt(const char *format, const struct tm * const t, char *pt,
129 const char * const ptlim, int *warnp, locale_t loc)
130 {
131 int Ealternative, Oalternative, PadIndex;
132 struct lc_time_T *tptr = __get_current_time_locale(loc);
133
134 for ( ; *format; ++format) {
135 if (*format == '%') {
136 Ealternative = 0;
137 Oalternative = 0;
138 PadIndex = PAD_DEFAULT;
139 label:
140 switch (*++format) {
141 case '\0':
142 --format;
143 break;
144 case 'A':
145 pt = _add((t->tm_wday < 0 ||
146 t->tm_wday >= DAYSPERWEEK) ?
147 "?" : tptr->weekday[t->tm_wday],
148 pt, ptlim);
149 continue;
150 case 'a':
151 pt = _add((t->tm_wday < 0 ||
152 t->tm_wday >= DAYSPERWEEK) ?
153 "?" : tptr->wday[t->tm_wday],
154 pt, ptlim);
155 continue;
156 case 'B':
157 pt = _add((t->tm_mon < 0 ||
158 t->tm_mon >= MONSPERYEAR) ?
159 "?" : (Oalternative ? tptr->alt_month :
160 tptr->month)[t->tm_mon],
161 pt, ptlim);
162 continue;
163 case 'b':
164 case 'h':
165 pt = _add((t->tm_mon < 0 ||
166 t->tm_mon >= MONSPERYEAR) ?
167 "?" : tptr->mon[t->tm_mon],
168 pt, ptlim);
169 continue;
170 case 'C':
171 /*
172 * %C used to do a...
173 * _fmt("%a %b %e %X %Y", t);
174 * ...whereas now POSIX 1003.2 calls for
175 * something completely different.
176 * (ado, 1993-05-24)
177 */
178 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
179 pt, ptlim, loc);
180 continue;
181 case 'c':
182 {
183 int warn2 = IN_SOME;
184
185 pt = _fmt(tptr->c_fmt, t, pt, ptlim, &warn2, loc);
186 if (warn2 == IN_ALL)
187 warn2 = IN_THIS;
188 if (warn2 > *warnp)
189 *warnp = warn2;
190 }
191 continue;
192 case 'D':
193 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp, loc);
194 continue;
195 case 'd':
196 pt = _conv(t->tm_mday,
197 fmt_padding[PAD_FMT_DAYOFMONTH][PadIndex],
198 pt, ptlim, loc);
199 continue;
200 case 'E':
201 if (Ealternative || Oalternative)
202 break;
203 Ealternative++;
204 goto label;
205 case 'O':
206 /*
207 * C99 locale modifiers.
208 * The sequences
209 * %Ec %EC %Ex %EX %Ey %EY
210 * %Od %oe %OH %OI %Om %OM
211 * %OS %Ou %OU %OV %Ow %OW %Oy
212 * are supposed to provide alternate
213 * representations.
214 *
215 * FreeBSD extension
216 * %OB
217 */
218 if (Ealternative || Oalternative)
219 break;
220 Oalternative++;
221 goto label;
222 case 'e':
223 pt = _conv(t->tm_mday,
224 fmt_padding[PAD_FMT_SDAYOFMONTH][PadIndex],
225 pt, ptlim, loc);
226 continue;
227 case 'F':
228 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, loc);
229 continue;
230 case 'H':
231 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_HMS][PadIndex],
232 pt, ptlim, loc);
233 continue;
234 case 'I':
235 pt = _conv((t->tm_hour % 12) ?
236 (t->tm_hour % 12) : 12,
237 fmt_padding[PAD_FMT_HMS][PadIndex],
238 pt, ptlim, loc);
239 continue;
240 case 'j':
241 pt = _conv(t->tm_yday + 1,
242 fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex],
243 pt, ptlim, loc);
244 continue;
245 case 'k':
246 /*
247 * This used to be...
248 * _conv(t->tm_hour % 12 ?
249 * t->tm_hour % 12 : 12, 2, ' ');
250 * ...and has been changed to the below to
251 * match SunOS 4.1.1 and Arnold Robbins'
252 * strftime version 3.0. That is, "%k" and
253 * "%l" have been swapped.
254 * (ado, 1993-05-24)
255 */
256 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_SHMS][PadIndex],
257 pt, ptlim, loc);
258 continue;
259 #ifdef KITCHEN_SINK
260 case 'K':
261 /*
262 ** After all this time, still unclaimed!
263 */
264 pt = _add("kitchen sink", pt, ptlim);
265 continue;
266 #endif /* defined KITCHEN_SINK */
267 case 'l':
268 /*
269 * This used to be...
270 * _conv(t->tm_hour, 2, ' ');
271 * ...and has been changed to the below to
272 * match SunOS 4.1.1 and Arnold Robbin's
273 * strftime version 3.0. That is, "%k" and
274 * "%l" have been swapped.
275 * (ado, 1993-05-24)
276 */
277 pt = _conv((t->tm_hour % 12) ?
278 (t->tm_hour % 12) : 12,
279 fmt_padding[PAD_FMT_SHMS][PadIndex],
280 pt, ptlim, loc);
281 continue;
282 case 'M':
283 pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex],
284 pt, ptlim, loc);
285 continue;
286 case 'm':
287 pt = _conv(t->tm_mon + 1,
288 fmt_padding[PAD_FMT_MONTH][PadIndex],
289 pt, ptlim, loc);
290 continue;
291 case 'n':
292 pt = _add("\n", pt, ptlim);
293 continue;
294 case 'p':
295 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
296 tptr->pm : tptr->am,
297 pt, ptlim);
298 continue;
299 case 'R':
300 pt = _fmt("%H:%M", t, pt, ptlim, warnp, loc);
301 continue;
302 case 'r':
303 pt = _fmt(tptr->ampm_fmt, t, pt, ptlim,
304 warnp, loc);
305 continue;
306 case 'S':
307 pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex],
308 pt, ptlim, loc);
309 continue;
310 case 's':
311 {
312 struct tm tm;
313 char buf[INT_STRLEN_MAXIMUM(
314 time_t) + 1];
315 time_t mkt;
316
317 tm = *t;
318 mkt = timeoff(&tm, t->tm_gmtoff);
319 if (TYPE_SIGNED(time_t))
320 (void) sprintf_l(buf, loc, "%ld",
321 (long) mkt);
322 else (void) sprintf_l(buf, loc, "%lu",
323 (unsigned long) mkt);
324 pt = _add(buf, pt, ptlim);
325 }
326 continue;
327 case 'T':
328 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, loc);
329 continue;
330 case 't':
331 pt = _add("\t", pt, ptlim);
332 continue;
333 case 'U':
334 pt = _conv((t->tm_yday + DAYSPERWEEK -
335 t->tm_wday) / DAYSPERWEEK,
336 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
337 pt, ptlim, loc);
338 continue;
339 case 'u':
340 /*
341 * From Arnold Robbins' strftime version 3.0:
342 * "ISO 8601: Weekday as a decimal number
343 * [1 (Monday) - 7]"
344 * (ado, 1993-05-24)
345 */
346 pt = _conv((t->tm_wday == 0) ?
347 DAYSPERWEEK : t->tm_wday,
348 "%d", pt, ptlim, loc);
349 continue;
350 case 'V': /* ISO 8601 week number */
351 case 'G': /* ISO 8601 year (four digits) */
352 case 'g': /* ISO 8601 year (two digits) */
353 /*
354 * From Arnold Robbins' strftime version 3.0: "the week number of the
355 * year (the first Monday as the first day of week 1) as a decimal number
356 * (01-53)."
357 * (ado, 1993-05-24)
358 *
359 * From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
360 * "Week 01 of a year is per definition the first week which has the
361 * Thursday in this year, which is equivalent to the week which contains
362 * the fourth day of January. In other words, the first week of a new year
363 * is the week which has the majority of its days in the new year. Week 01
364 * might also contain days from the previous year and the week before week
365 * 01 of a year is the last week (52 or 53) of the previous year even if
366 * it contains days from the new year. A week starts with Monday (day 1)
367 * and ends with Sunday (day 7). For example, the first week of the year
368 * 1997 lasts from 1996-12-30 to 1997-01-05..."
369 * (ado, 1996-01-02)
370 */
371 {
372 int year;
373 int base;
374 int yday;
375 int wday;
376 int w;
377
378 year = t->tm_year;
379 base = TM_YEAR_BASE;
380 yday = t->tm_yday;
381 wday = t->tm_wday;
382 for ( ; ; ) {
383 int len;
384 int bot;
385 int top;
386
387 len = isleap_sum(year, base) ?
388 DAYSPERLYEAR :
389 DAYSPERNYEAR;
390 /*
391 * What yday (-3 ... 3) does
392 * the ISO year begin on?
393 */
394 bot = ((yday + 11 - wday) %
395 DAYSPERWEEK) - 3;
396 /*
397 * What yday does the NEXT
398 * ISO year begin on?
399 */
400 top = bot -
401 (len % DAYSPERWEEK);
402 if (top < -3)
403 top += DAYSPERWEEK;
404 top += len;
405 if (yday >= top) {
406 ++base;
407 w = 1;
408 break;
409 }
410 if (yday >= bot) {
411 w = 1 + ((yday - bot) /
412 DAYSPERWEEK);
413 break;
414 }
415 --base;
416 yday += isleap_sum(year, base) ?
417 DAYSPERLYEAR :
418 DAYSPERNYEAR;
419 }
420 #ifdef XPG4_1994_04_09
421 if ((w == 52 &&
422 t->tm_mon == TM_JANUARY) ||
423 (w == 1 &&
424 t->tm_mon == TM_DECEMBER))
425 w = 53;
426 #endif /* defined XPG4_1994_04_09 */
427 if (*format == 'V')
428 pt = _conv(w, fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
429 pt, ptlim, loc);
430 else if (*format == 'g') {
431 *warnp = IN_ALL;
432 pt = _yconv(year, base, 0, 1,
433 pt, ptlim, loc);
434 } else pt = _yconv(year, base, 1, 1,
435 pt, ptlim, loc);
436 }
437 continue;
438 case 'v':
439 /*
440 * From Arnold Robbins' strftime version 3.0:
441 * "date as dd-bbb-YYYY"
442 * (ado, 1993-05-24)
443 */
444 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, loc);
445 continue;
446 case 'W':
447 pt = _conv((t->tm_yday + DAYSPERWEEK -
448 (t->tm_wday ?
449 (t->tm_wday - 1) :
450 (DAYSPERWEEK - 1))) / DAYSPERWEEK,
451 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
452 pt, ptlim, loc);
453 continue;
454 case 'w':
455 pt = _conv(t->tm_wday, "%d", pt, ptlim, loc);
456 continue;
457 case 'X':
458 pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp, loc);
459 continue;
460 case 'x':
461 {
462 int warn2 = IN_SOME;
463
464 pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2, loc);
465 if (warn2 == IN_ALL)
466 warn2 = IN_THIS;
467 if (warn2 > *warnp)
468 *warnp = warn2;
469 }
470 continue;
471 case 'y':
472 *warnp = IN_ALL;
473 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
474 pt, ptlim, loc);
475 continue;
476 case 'Y':
477 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
478 pt, ptlim, loc);
479 continue;
480 case 'Z':
481 #ifdef TM_ZONE
482 if (t->TM_ZONE != NULL)
483 pt = _add(t->TM_ZONE, pt, ptlim);
484 else
485 #endif /* defined TM_ZONE */
486 if (t->tm_isdst >= 0)
487 pt = _add(tzname[t->tm_isdst != 0],
488 pt, ptlim);
489 /*
490 * C99 says that %Z must be replaced by the
491 * empty string if the time zone is not
492 * determinable.
493 */
494 continue;
495 case 'z':
496 {
497 int diff;
498 char const * sign;
499
500 if (t->tm_isdst < 0)
501 continue;
502 #ifdef TM_GMTOFF
503 diff = t->TM_GMTOFF;
504 #else /* !defined TM_GMTOFF */
505 /*
506 * C99 says that the UTC offset must
507 * be computed by looking only at
508 * tm_isdst. This requirement is
509 * incorrect, since it means the code
510 * must rely on magic (in this case
511 * altzone and timezone), and the
512 * magic might not have the correct
513 * offset. Doing things correctly is
514 * tricky and requires disobeying C99;
515 * see GNU C strftime for details.
516 * For now, punt and conform to the
517 * standard, even though it's incorrect.
518 *
519 * C99 says that %z must be replaced by the
520 * empty string if the time zone is not
521 * determinable, so output nothing if the
522 * appropriate variables are not available.
523 */
524 if (t->tm_isdst == 0)
525 #ifdef USG_COMPAT
526 diff = -timezone;
527 #else /* !defined USG_COMPAT */
528 continue;
529 #endif /* !defined USG_COMPAT */
530 else
531 #ifdef ALTZONE
532 diff = -altzone;
533 #else /* !defined ALTZONE */
534 continue;
535 #endif /* !defined ALTZONE */
536 #endif /* !defined TM_GMTOFF */
537 if (diff < 0) {
538 sign = "-";
539 diff = -diff;
540 } else
541 sign = "+";
542 pt = _add(sign, pt, ptlim);
543 diff /= SECSPERMIN;
544 diff = (diff / MINSPERHOUR) * 100 +
545 (diff % MINSPERHOUR);
546 pt = _conv(diff,
547 fmt_padding[PAD_FMT_YEAR][PadIndex],
548 pt, ptlim, loc);
549 }
550 continue;
551 case '+':
552 pt = _fmt(tptr->date_fmt, t, pt, ptlim,
553 warnp, loc);
554 continue;
555 case '-':
556 if (PadIndex != PAD_DEFAULT)
557 break;
558 PadIndex = PAD_LESS;
559 goto label;
560 case '_':
561 if (PadIndex != PAD_DEFAULT)
562 break;
563 PadIndex = PAD_SPACE;
564 goto label;
565 case '0':
566 if (PadIndex != PAD_DEFAULT)
567 break;
568 PadIndex = PAD_ZERO;
569 goto label;
570 case '%':
571 /*
572 * X311J/88-090 (4.12.3.5): if conversion char is
573 * undefined, behavior is undefined. Print out the
574 * character itself as printf(3) also does.
575 */
576 default:
577 break;
578 }
579 }
580 if (pt == ptlim)
581 break;
582 *pt++ = *format;
583 }
584 return (pt);
585 }
586
587 static char *
_conv(const int n,const char * const format,char * const pt,const char * const ptlim,locale_t loc)588 _conv(const int n, const char * const format, char * const pt,
589 const char * const ptlim, locale_t loc)
590 {
591 char buf[INT_STRLEN_MAXIMUM(int) + 1];
592
593 (void) sprintf_l(buf, loc, format, n);
594 return _add(buf, pt, ptlim);
595 }
596
597 static char *
_add(const char * str,char * pt,const char * const ptlim)598 _add(const char *str, char *pt, const char * const ptlim)
599 {
600 while (pt < ptlim && (*pt = *str++) != '\0')
601 ++pt;
602 return (pt);
603 }
604
605 /*
606 * POSIX and the C Standard are unclear or inconsistent about
607 * what %C and %y do if the year is negative or exceeds 9999.
608 * Use the convention that %C concatenated with %y yields the
609 * same output as %Y, and that %Y contains at least 4 bytes,
610 * with more only if necessary.
611 */
612
613 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)614 _yconv(const int a, const int b, const int convert_top, const int convert_yy,
615 char *pt, const char * const ptlim, locale_t loc)
616 {
617 register int lead;
618 register int trail;
619
620 #define DIVISOR 100
621 trail = a % DIVISOR + b % DIVISOR;
622 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
623 trail %= DIVISOR;
624 if (trail < 0 && lead > 0) {
625 trail += DIVISOR;
626 --lead;
627 } else if (lead < 0 && trail > 0) {
628 trail -= DIVISOR;
629 ++lead;
630 }
631 if (convert_top) {
632 if (lead == 0 && trail < 0)
633 pt = _add("-0", pt, ptlim);
634 else pt = _conv(lead, "%02d", pt, ptlim, loc);
635 }
636 if (convert_yy)
637 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt,
638 ptlim, loc);
639 return (pt);
640 }
641