1 /*
2 * Copyright 2010 Nexenta Systems, Inc. All rights reserved.
3 * Copyright (c) 1989 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * Copyright (c) 2011 The FreeBSD Foundation
7 * All rights reserved.
8 * Portions of this software were developed by David Chisnall
9 * under sponsorship from the FreeBSD Foundation.
10 *
11 * Redistribution and use in source and binary forms are permitted
12 * provided that the above copyright notice and this paragraph are
13 * duplicated in all such forms and that any documentation,
14 * advertising materials, and other materials related to such
15 * distribution and use acknowledge that the software was developed
16 * by the University of California, Berkeley. The name of the
17 * University may not be used to endorse or promote products derived
18 * from this software without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22 */
23
24 #include "lint.h"
25 #include "tzfile.h"
26 #include <fcntl.h>
27 #include <sys/stat.h>
28 #include <string.h>
29 #include <stdio.h>
30 #include "timelocal.h"
31
32 static char *_add(const char *, char *, const char *);
33 static char *_conv(int, const char *, char *, const char *);
34 static char *_fmt(const char *, const struct tm *, char *, const char * const,
35 int *, locale_t);
36 static char *_yconv(int, int, int, int, char *, const char *);
37
38 extern char *tzname[];
39
40 #define IN_NONE 0
41 #define IN_SOME 1
42 #define IN_THIS 2
43 #define IN_ALL 3
44
45 #define PAD_DEFAULT 0
46 #define PAD_LESS 1
47 #define PAD_SPACE 2
48 #define PAD_ZERO 3
49
50 static const char *fmt_padding[][4] = {
51 /* DEFAULT, LESS, SPACE, ZERO */
52 #define PAD_FMT_MONTHDAY 0
53 #define PAD_FMT_HMS 0
54 #define PAD_FMT_CENTURY 0
55 #define PAD_FMT_SHORTYEAR 0
56 #define PAD_FMT_MONTH 0
57 #define PAD_FMT_WEEKOFYEAR 0
58 #define PAD_FMT_DAYOFMONTH 0
59 { "%02d", "%d", "%2d", "%02d" },
60 #define PAD_FMT_SDAYOFMONTH 1
61 #define PAD_FMT_SHMS 1
62 { "%2d", "%d", "%2d", "%02d" },
63 #define PAD_FMT_DAYOFYEAR 2
64 { "%03d", "%d", "%3d", "%03d" },
65 #define PAD_FMT_YEAR 3
66 { "%04d", "%d", "%4d", "%04d" }
67 };
68
69
70 size_t
71 strftime_l(char *_RESTRICT_KYWD s, size_t maxsize,
72 const char *_RESTRICT_KYWD format, const struct tm *_RESTRICT_KYWD t,
73 locale_t loc)
74 {
75 char *p;
76 int warn;
77 FIX_LOCALE(loc);
78
79 tzset();
80 warn = IN_NONE;
81 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize,
82 &warn, loc);
83 /* XXX YEAR_2000 */
84 if (p == s + maxsize)
85 return (0);
86 *p = '\0';
87 return (p - s);
88 }
89
90 size_t
91 strftime(char *_RESTRICT_KYWD s, size_t maxsize,
92 const char *_RESTRICT_KYWD format, const struct tm *_RESTRICT_KYWD t)
93 {
94 return (strftime_l(s, maxsize, format, t, __get_locale()));
95 }
96
97 static char *
98 _fmt(const char *format, const struct tm *t, char *pt, const char * const ptlim,
99 int *warnp, locale_t loc)
100 {
101 int Ealternative, Oalternative, PadIndex;
102 struct lc_time_T *tptr = __get_current_time_locale(loc);
103
104 #define PADDING(x) fmt_padding[x][PadIndex]
105
106 for (; *format; ++format) {
107 if (*format == '%') {
108 Ealternative = 0;
109 Oalternative = 0;
110 PadIndex = PAD_DEFAULT;
111 label:
112 switch (*++format) {
113 case '\0':
114 --format;
115 break;
116 case 'A':
117 pt = _add((t->tm_wday < 0 ||
118 t->tm_wday >= DAYSPERWEEK) ?
119 "?" : tptr->weekday[t->tm_wday],
120 pt, ptlim);
121 continue;
122 case 'a':
123 pt = _add((t->tm_wday < 0 ||
124 t->tm_wday >= DAYSPERWEEK) ?
125 "?" : tptr->wday[t->tm_wday],
126 pt, ptlim);
127 continue;
128 case 'B':
129 pt = _add((t->tm_mon < 0 ||
130 t->tm_mon >= MONSPERYEAR) ?
131 "?" : (tptr->month)[t->tm_mon],
132 pt, ptlim);
133 continue;
134 case 'b':
135 case 'h':
136 pt = _add((t->tm_mon < 0 ||
137 t->tm_mon >= MONSPERYEAR) ?
138 "?" : tptr->mon[t->tm_mon],
139 pt, ptlim);
140 continue;
141 case 'C':
142 /*
143 * %C used to do a...
144 * _fmt("%a %b %e %X %Y", t);
145 * ...whereas now POSIX 1003.2 calls for
146 * something completely different.
147 * (ado, 1993-05-24)
148 */
149 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
150 pt, ptlim);
151 continue;
152 case 'c':
153 {
154 int warn2 = IN_SOME;
155
156 pt = _fmt(tptr->c_fmt, t, pt, ptlim, &warn2,
157 loc);
158 /* XXX */
159 }
160 continue;
161 case 'D':
162 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp,
163 loc);
164 continue;
165 case 'd':
166 pt = _conv(t->tm_mday,
167 PADDING(PAD_FMT_DAYOFMONTH), pt, ptlim);
168 continue;
169 case 'E':
170 if (Ealternative || Oalternative)
171 break;
172 Ealternative++;
173 goto label;
174 case 'O':
175 /*
176 * C99 locale modifiers.
177 * The sequences
178 * %Ec %EC %Ex %EX %Ey %EY
179 * %Od %oe %OH %OI %Om %OM
180 * %OS %Ou %OU %OV %Ow %OW %Oy
181 * are supposed to provide alternate
182 * representations.
183 */
184 if (Ealternative || Oalternative)
185 break;
186 Oalternative++;
187 goto label;
188 case 'e':
189 pt = _conv(t->tm_mday,
190 PADDING(PAD_FMT_SDAYOFMONTH), pt, ptlim);
191 continue;
192 case 'F':
193 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp,
194 loc);
195 continue;
196 case 'H':
197 pt = _conv(t->tm_hour, PADDING(PAD_FMT_HMS),
198 pt, ptlim);
199 continue;
200 case 'I':
201 pt = _conv((t->tm_hour % 12) ?
202 (t->tm_hour % 12) : 12,
203 PADDING(PAD_FMT_HMS), pt, ptlim);
204 continue;
205 case 'j':
206 pt = _conv(t->tm_yday + 1,
207 PADDING(PAD_FMT_DAYOFYEAR), pt, ptlim);
208 continue;
209 case 'k':
210 /*
211 * This used to be...
212 * _conv(t->tm_hour % 12 ?
213 * t->tm_hour % 12 : 12, 2, ' ');
214 * ...and has been changed to the below to
215 * match SunOS 4.1.1 and Arnold Robbins'
216 * strftime version 3.0. That is, "%k" and
217 * "%l" have been swapped.
218 * (ado, 1993-05-24)
219 */
220 pt = _conv(t->tm_hour,
221 PADDING(PAD_FMT_SHMS), pt, ptlim);
222 continue;
223 case 'l':
224 /*
225 * This used to be...
226 * _conv(t->tm_hour, 2, ' ');
227 * ...and has been changed to the below to
228 * match SunOS 4.1.1 and Arnold Robbin's
229 * strftime version 3.0. That is, "%k" and
230 * "%l" have been swapped.
231 * (ado, 1993-05-24)
232 */
233 pt = _conv((t->tm_hour % 12) ?
234 (t->tm_hour % 12) : 12,
235 PADDING(PAD_FMT_SHMS), pt, ptlim);
236 continue;
237 case 'M':
238 pt = _conv(t->tm_min, PADDING(PAD_FMT_HMS),
239 pt, ptlim);
240 continue;
241 case 'm':
242 pt = _conv(t->tm_mon + 1,
243 PADDING(PAD_FMT_MONTH),
244 pt, ptlim);
245 continue;
246 case 'n':
247 pt = _add("\n", pt, ptlim);
248 continue;
249 case 'p':
250 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
251 tptr->pm : tptr->am, pt, ptlim);
252 continue;
253 case 'R':
254 pt = _fmt("%H:%M", t, pt, ptlim, warnp, loc);
255 continue;
256 case 'r':
257 pt = _fmt(tptr->ampm_fmt, t, pt, ptlim,
258 warnp, loc);
259 continue;
260 case 'S':
261 pt = _conv(t->tm_sec, PADDING(PAD_FMT_HMS),
262 pt, ptlim);
263 continue;
264
265 case 's':
266 {
267 struct tm tm;
268 char *buf;
269 /* XXX */
270 tm = *t;
271 (void) asprintf(&buf, "%ld", mktime(&tm));
272 pt = _add(buf, pt, ptlim);
273 }
274 continue;
275 case 'T':
276 pt = _fmt("%H:%M:%S", t, pt, ptlim,
277 warnp, loc);
278 continue;
279 case 't':
280 pt = _add("\t", pt, ptlim);
281 continue;
282 case 'U':
283 pt = _conv((t->tm_yday + DAYSPERWEEK -
284 t->tm_wday) / DAYSPERWEEK,
285 PADDING(PAD_FMT_WEEKOFYEAR),
286 pt, ptlim);
287 continue;
288 case 'u':
289 /*
290 * From Arnold Robbins' strftime version 3.0:
291 * "ISO 8601: Weekday as a decimal number
292 * [1 (Monday) - 7]"
293 * (ado, 1993-05-24)
294 */
295 pt = _conv((t->tm_wday == 0) ?
296 DAYSPERWEEK : t->tm_wday,
297 "%d", pt, ptlim);
298 continue;
299 case 'V': /* ISO 8601 week number */
300 case 'G': /* ISO 8601 year (four digits) */
301 case 'g': /* ISO 8601 year (two digits) */
302 /*
303 * From Arnold Robbins' strftime version 3.0: "the week number of the
304 * year (the first Monday as the first day of week 1) as a decimal number
305 * (01-53)."
306 * (ado, 1993-05-24)
307 *
308 * From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
309 * "Week 01 of a year is per definition the first week which has the
310 * Thursday in this year, which is equivalent to the week which contains
311 * the fourth day of January. In other words, the first week of a new year
312 * is the week which has the majority of its days in the new year. Week 01
313 * might also contain days from the previous year and the week before week
314 * 01 of a year is the last week (52 or 53) of the previous year even if
315 * it contains days from the new year. A week starts with Monday (day 1)
316 * and ends with Sunday (day 7). For example, the first week of the year
317 * 1997 lasts from 1996-12-30 to 1997-01-05..."
318 * (ado, 1996-01-02)
319 */
320 {
321 int year;
322 int base;
323 int yday;
324 int wday;
325 int w;
326
327 year = t->tm_year;
328 base = TM_YEAR_BASE;
329 yday = t->tm_yday;
330 wday = t->tm_wday;
331 for (;;) {
332 int len;
333 int bot;
334 int top;
335
336 len = isleap_sum(year, base) ?
337 DAYSPERLYEAR : DAYSPERNYEAR;
338 /*
339 * What yday (-3 ... 3) does
340 * the ISO year begin on?
341 */
342 bot = ((yday + 11 - wday) %
343 DAYSPERWEEK) - 3;
344 /*
345 * What yday does the NEXT
346 * ISO year begin on?
347 */
348 top = bot - (len % DAYSPERWEEK);
349 if (top < -3)
350 top += DAYSPERWEEK;
351 top += len;
352 if (yday >= top) {
353 ++base;
354 w = 1;
355 break;
356 }
357 if (yday >= bot) {
358 w = 1 + ((yday - bot) /
359 DAYSPERWEEK);
360 break;
361 }
362 --base;
363 yday += isleap_sum(year, base) ?
364 DAYSPERLYEAR : DAYSPERNYEAR;
365 }
366 #ifdef XPG4_1994_04_09
367 if ((w == 52 && t->tm_mon == TM_JANUARY) ||
368 (w == 1 && t->tm_mon == TM_DECEMBER))
369 w = 53;
370 #endif /* defined XPG4_1994_04_09 */
371 if (*format == 'V')
372 pt = _conv(w,
373 PADDING(PAD_FMT_WEEKOFYEAR),
374 pt, ptlim);
375 else if (*format == 'g') {
376 pt = _yconv(year, base, 0, 1,
377 pt, ptlim);
378 } else
379 pt = _yconv(year, base, 1, 1,
380 pt, ptlim);
381 }
382 continue;
383 case 'v':
384 /*
385 * From Arnold Robbins' strftime version 3.0:
386 * "date as dd-bbb-YYYY"
387 * (ado, 1993-05-24)
388 */
389 pt = _fmt("%e-%b-%Y", t, pt, ptlim,
390 warnp, loc);
391 continue;
392 case 'W':
393 pt = _conv((t->tm_yday + DAYSPERWEEK -
394 (t->tm_wday ?
395 (t->tm_wday - 1) :
396 (DAYSPERWEEK - 1))) / DAYSPERWEEK,
397 PADDING(PAD_FMT_WEEKOFYEAR),
398 pt, ptlim);
399 continue;
400 case 'w':
401 pt = _conv(t->tm_wday, "%d", pt, ptlim);
402 continue;
403 case 'X':
404 pt = _fmt(tptr->X_fmt, t, pt, ptlim,
405 warnp, loc);
406 continue;
407 case 'x':
408 {
409 int warn2 = IN_SOME;
410
411 pt = _fmt(tptr->x_fmt, t, pt, ptlim,
412 &warn2, loc);
413 }
414 continue;
415 case 'y':
416 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
417 pt, ptlim);
418 continue;
419 case 'Y':
420 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
421 pt, ptlim);
422 continue;
423 case 'Z':
424 if (t->tm_isdst >= 0)
425 pt = _add(tzname[t->tm_isdst != 0],
426 pt, ptlim);
427 /*
428 * C99 says that %Z must be replaced by the
429 * empty string if the time zone is not
430 * determinable.
431 */
432 continue;
433 case 'z':
434 {
435 int diff;
436 char const * sign;
437
438 if (t->tm_isdst < 0)
439 continue;
440 /*
441 * C99 says that the UTC offset must
442 * be computed by looking only at
443 * tm_isdst. This requirement is
444 * incorrect, since it means the code
445 * must rely on magic (in this case
446 * altzone and timezone), and the
447 * magic might not have the correct
448 * offset. Doing things correctly is
449 * tricky and requires disobeying C99;
450 * see GNU C strftime for details.
451 * For now, punt and conform to the
452 * standard, even though it's incorrect.
453 *
454 * C99 says that %z must be replaced by the
455 * empty string if the time zone is not
456 * determinable, so output nothing if the
457 * appropriate variables are not available.
458 */
459 if (t->tm_isdst == 0)
460 diff = -timezone;
461 else
462 diff = -altzone;
463 if (diff < 0) {
464 sign = "-";
465 diff = -diff;
466 } else
467 sign = "+";
468 pt = _add(sign, pt, ptlim);
469 diff /= SECSPERMIN;
470 diff = (diff / MINSPERHOUR) * 100 +
471 (diff % MINSPERHOUR);
472 pt = _conv(diff, PADDING(PAD_FMT_YEAR),
473 pt, ptlim);
474 }
475 continue;
476 case '+':
477 pt = _fmt(tptr->date_fmt, t, pt, ptlim,
478 warnp, loc);
479 continue;
480 case '-':
481 if (PadIndex != PAD_DEFAULT)
482 break;
483 PadIndex = PAD_LESS;
484 goto label;
485 case '_':
486 if (PadIndex != PAD_DEFAULT)
487 break;
488 PadIndex = PAD_SPACE;
489 goto label;
490 case '0':
491 if (PadIndex != PAD_DEFAULT)
492 break;
493 PadIndex = PAD_ZERO;
494 goto label;
495 case '%':
496 /*
497 * X311J/88-090 (4.12.3.5): if conversion char is
498 * undefined, behavior is undefined. Print out the
499 * character itself as printf(3) also does.
500 */
501 default:
502 break;
503 }
504 }
505 if (pt == ptlim)
506 break;
507 *pt++ = *format;
508 }
509 return (pt);
510 }
511
512 static char *
513 _conv(const int n, const char *format, char *const pt,
514 const char *const ptlim)
515 {
516 char buf[12];
517
518 (void) sprintf(buf, format, n);
519 return (_add(buf, pt, ptlim));
520 }
521
522 static char *
523 _add(const char *str, char *pt, const char *const ptlim)
524 {
525 while (pt < ptlim && (*pt = *str++) != '\0')
526 ++pt;
527 return (pt);
528 }
529
530 /*
531 * POSIX and the C Standard are unclear or inconsistent about
532 * what %C and %y do if the year is negative or exceeds 9999.
533 * Use the convention that %C concatenated with %y yields the
534 * same output as %Y, and that %Y contains at least 4 bytes,
535 * with more only if necessary.
536 */
537
538 static char *
539 _yconv(const int a, const int b, const int convert_top, const int convert_yy,
540 char *pt, const char * const ptlim)
541 {
542 register int lead;
543 register int trail;
544
545 #define DIVISOR 100
546 trail = a % DIVISOR + b % DIVISOR;
547 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
548 trail %= DIVISOR;
549 if (trail < 0 && lead > 0) {
550 trail += DIVISOR;
551 --lead;
552 } else if (lead < 0 && trail > 0) {
553 trail -= DIVISOR;
554 ++lead;
555 }
556 if (convert_top) {
557 if (lead == 0 && trail < 0)
558 pt = _add("-0", pt, ptlim);
559 else pt = _conv(lead, "%02d", pt, ptlim);
560 }
561 if (convert_yy)
562 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim);
563 return (pt);
564 }