1 /*
2 * Copyright 2013 Garrett D'Amore <garrett@damore.org>
3 * Copyright 2010 Nexenta Systems, Inc. All rights reserved.
4 * Copyright (c) 1989 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms are permitted
8 * provided that the above copyright notice and this paragraph are
9 * duplicated in all such forms and that any documentation,
10 * advertising materials, and other materials related to such
11 * distribution and use acknowledge that the software was developed
12 * by the University of California, Berkeley. The name of the
13 * University may not be used to endorse or promote products derived
14 * from this software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
18 */
19
20 #include "lint.h"
21 #include "tzfile.h"
22 #include <fcntl.h>
23 #include <sys/stat.h>
24 #include <string.h>
25 #include <stdio.h>
26 #include <locale.h>
27 #include "timelocal.h"
28 #include "localeimpl.h"
29
30 static char *_add(const char *, char *, const char *);
31 static char *_conv(int, const char *, char *, const char *);
32 static char *_fmt(locale_t, const char *, const struct tm *, char *,
33 const char * const);
34 static char *_yconv(int, int, int, int, char *, const char *);
35
36 extern char *tzname[];
37
38 #define IN_NONE 0
39 #define IN_SOME 1
40 #define IN_THIS 2
41 #define IN_ALL 3
42
43 #define PAD_DEFAULT 0
44 #define PAD_LESS 1
45 #define PAD_SPACE 2
46 #define PAD_ZERO 3
47
48 static const char *fmt_padding[][4] = {
49 /* DEFAULT, LESS, SPACE, ZERO */
50 #define PAD_FMT_MONTHDAY 0
51 #define PAD_FMT_HMS 0
52 #define PAD_FMT_CENTURY 0
53 #define PAD_FMT_SHORTYEAR 0
54 #define PAD_FMT_MONTH 0
55 #define PAD_FMT_WEEKOFYEAR 0
56 #define PAD_FMT_DAYOFMONTH 0
57 { "%02d", "%d", "%2d", "%02d" },
58 #define PAD_FMT_SDAYOFMONTH 1
59 #define PAD_FMT_SHMS 1
60 { "%2d", "%d", "%2d", "%02d" },
61 #define PAD_FMT_DAYOFYEAR 2
62 { "%03d", "%d", "%3d", "%03d" },
63 #define PAD_FMT_YEAR 3
64 { "%04d", "%d", "%4d", "%04d" }
65 };
66
67
68 size_t
69 strftime_l(char *_RESTRICT_KYWD s, size_t maxsize,
70 const char *_RESTRICT_KYWD format, const struct tm *_RESTRICT_KYWD t,
71 locale_t loc)
72 {
73 char *p;
74
75 tzset();
76 p = _fmt(loc, ((format == NULL) ? "%c" : format), t, s, s + maxsize);
77 if (p == s + maxsize)
78 return (0);
79 *p = '\0';
80 return (p - s);
81 }
82
83 size_t
84 strftime(char *_RESTRICT_KYWD s, size_t maxsize,
85 const char *_RESTRICT_KYWD format, const struct tm *_RESTRICT_KYWD t)
86 {
87 return (strftime_l(s, maxsize, format, t, uselocale(NULL)));
88 }
89
90 static char *
91 _fmt(locale_t loc, const char *format, const struct tm *t, char *pt,
92 const char * const ptlim)
93 {
94 int Ealternative, Oalternative, PadIndex;
95 const struct lc_time *tptr = loc->time;
96
97 #define PADDING(x) fmt_padding[x][PadIndex]
98
99 for (; *format; ++format) {
100 if (*format == '%') {
101 Ealternative = 0;
102 Oalternative = 0;
103 PadIndex = PAD_DEFAULT;
104 label:
105 switch (*++format) {
106 case '\0':
107 --format;
108 break;
109 case 'A':
110 pt = _add((t->tm_wday < 0 ||
111 t->tm_wday >= DAYSPERWEEK) ?
112 "?" : tptr->weekday[t->tm_wday],
113 pt, ptlim);
114 continue;
115 case 'a':
116 pt = _add((t->tm_wday < 0 ||
117 t->tm_wday >= DAYSPERWEEK) ?
118 "?" : tptr->wday[t->tm_wday],
119 pt, ptlim);
120 continue;
121 case 'B':
122 pt = _add((t->tm_mon < 0 ||
123 t->tm_mon >= MONSPERYEAR) ?
124 "?" : (tptr->month)[t->tm_mon],
125 pt, ptlim);
126 continue;
127 case 'b':
128 case 'h':
129 pt = _add((t->tm_mon < 0 ||
130 t->tm_mon >= MONSPERYEAR) ?
131 "?" : tptr->mon[t->tm_mon],
132 pt, ptlim);
133 continue;
134 case 'C':
135 /*
136 * %C used to do a...
137 * _fmt("%a %b %e %X %Y", t);
138 * ...whereas now POSIX 1003.2 calls for
139 * something completely different.
140 * (ado, 1993-05-24)
141 */
142 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
143 pt, ptlim);
144 continue;
145 case 'c':
146 pt = _fmt(loc, tptr->c_fmt, t, pt, ptlim);
147 continue;
148 case 'D':
149 pt = _fmt(loc, "%m/%d/%y", t, pt, ptlim);
150 continue;
151 case 'd':
152 pt = _conv(t->tm_mday,
153 PADDING(PAD_FMT_DAYOFMONTH), pt, ptlim);
154 continue;
155 case 'E':
156 if (Ealternative || Oalternative)
157 break;
158 Ealternative++;
159 goto label;
160 case 'O':
161 /*
162 * C99 locale modifiers.
163 * The sequences
164 * %Ec %EC %Ex %EX %Ey %EY
165 * %Od %oe %OH %OI %Om %OM
166 * %OS %Ou %OU %OV %Ow %OW %Oy
167 * are supposed to provide alternate
168 * representations.
169 */
170 if (Ealternative || Oalternative)
171 break;
172 Oalternative++;
173 goto label;
174 case 'e':
175 pt = _conv(t->tm_mday,
176 PADDING(PAD_FMT_SDAYOFMONTH), pt, ptlim);
177 continue;
178 case 'F':
179 pt = _fmt(loc, "%Y-%m-%d", t, pt, ptlim);
180 continue;
181 case 'H':
182 pt = _conv(t->tm_hour, PADDING(PAD_FMT_HMS),
183 pt, ptlim);
184 continue;
185 case 'I':
186 pt = _conv((t->tm_hour % 12) ?
187 (t->tm_hour % 12) : 12,
188 PADDING(PAD_FMT_HMS), pt, ptlim);
189 continue;
190 case 'j':
191 pt = _conv(t->tm_yday + 1,
192 PADDING(PAD_FMT_DAYOFYEAR), pt, ptlim);
193 continue;
194 case 'k':
195 /*
196 * This used to be...
197 * _conv(t->tm_hour % 12 ?
198 * t->tm_hour % 12 : 12, 2, ' ');
199 * ...and has been changed to the below to
200 * match SunOS 4.1.1 and Arnold Robbins'
201 * strftime version 3.0. That is, "%k" and
202 * "%l" have been swapped.
203 * (ado, 1993-05-24)
204 */
205 pt = _conv(t->tm_hour,
206 PADDING(PAD_FMT_SHMS), pt, ptlim);
207 continue;
208 case 'l':
209 /*
210 * This used to be...
211 * _conv(t->tm_hour, 2, ' ');
212 * ...and has been changed to the below to
213 * match SunOS 4.1.1 and Arnold Robbin's
214 * strftime version 3.0. That is, "%k" and
215 * "%l" have been swapped.
216 * (ado, 1993-05-24)
217 */
218 pt = _conv((t->tm_hour % 12) ?
219 (t->tm_hour % 12) : 12,
220 PADDING(PAD_FMT_SHMS), pt, ptlim);
221 continue;
222 case 'M':
223 pt = _conv(t->tm_min, PADDING(PAD_FMT_HMS),
224 pt, ptlim);
225 continue;
226 case 'm':
227 pt = _conv(t->tm_mon + 1,
228 PADDING(PAD_FMT_MONTH),
229 pt, ptlim);
230 continue;
231 case 'n':
232 pt = _add("\n", pt, ptlim);
233 continue;
234 case 'p':
235 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
236 tptr->pm : tptr->am, pt, ptlim);
237 continue;
238 case 'R':
239 pt = _fmt(loc, "%H:%M", t, pt, ptlim);
240 continue;
241 case 'r':
242 pt = _fmt(loc, tptr->ampm_fmt, t, pt, ptlim);
243 continue;
244 case 'S':
245 pt = _conv(t->tm_sec, PADDING(PAD_FMT_HMS),
246 pt, ptlim);
247 continue;
248
249 case 's':
250 {
251 struct tm tm;
252 char *buf;
253
254 tm = *t;
255 (void) asprintf(&buf, "%ld", mktime(&tm));
256 pt = _add(buf, pt, ptlim);
257 continue;
258 }
259
260 case 'T':
261 pt = _fmt(loc, "%H:%M:%S", t, pt, ptlim);
262 continue;
263 case 't':
264 pt = _add("\t", pt, ptlim);
265 continue;
266 case 'U':
267 pt = _conv((t->tm_yday + DAYSPERWEEK -
268 t->tm_wday) / DAYSPERWEEK,
269 PADDING(PAD_FMT_WEEKOFYEAR),
270 pt, ptlim);
271 continue;
272 case 'u':
273 /*
274 * From Arnold Robbins' strftime version 3.0:
275 * "ISO 8601: Weekday as a decimal number
276 * [1 (Monday) - 7]"
277 * (ado, 1993-05-24)
278 */
279 pt = _conv((t->tm_wday == 0) ?
280 DAYSPERWEEK : t->tm_wday,
281 "%d", pt, ptlim);
282 continue;
283 case 'V': /* ISO 8601 week number */
284 case 'G': /* ISO 8601 year (four digits) */
285 case 'g': /* ISO 8601 year (two digits) */
286 /*
287 * From Arnold Robbins' strftime version 3.0: "the week number of the
288 * year (the first Monday as the first day of week 1) as a decimal number
289 * (01-53)."
290 * (ado, 1993-05-24)
291 *
292 * From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
293 * "Week 01 of a year is per definition the first week which has the
294 * Thursday in this year, which is equivalent to the week which contains
295 * the fourth day of January. In other words, the first week of a new year
296 * is the week which has the majority of its days in the new year. Week 01
297 * might also contain days from the previous year and the week before week
298 * 01 of a year is the last week (52 or 53) of the previous year even if
299 * it contains days from the new year. A week starts with Monday (day 1)
300 * and ends with Sunday (day 7). For example, the first week of the year
301 * 1997 lasts from 1996-12-30 to 1997-01-05..."
302 * (ado, 1996-01-02)
303 */
304 {
305 int year;
306 int base;
307 int yday;
308 int wday;
309 int w;
310
311 year = t->tm_year;
312 base = TM_YEAR_BASE;
313 yday = t->tm_yday;
314 wday = t->tm_wday;
315 for (;;) {
316 int len;
317 int bot;
318 int top;
319
320 len = isleap_sum(year, base) ?
321 DAYSPERLYEAR : DAYSPERNYEAR;
322 /*
323 * What yday (-3 ... 3) does
324 * the ISO year begin on?
325 */
326 bot = ((yday + 11 - wday) %
327 DAYSPERWEEK) - 3;
328 /*
329 * What yday does the NEXT
330 * ISO year begin on?
331 */
332 top = bot - (len % DAYSPERWEEK);
333 if (top < -3)
334 top += DAYSPERWEEK;
335 top += len;
336 if (yday >= top) {
337 ++base;
338 w = 1;
339 break;
340 }
341 if (yday >= bot) {
342 w = 1 + ((yday - bot) /
343 DAYSPERWEEK);
344 break;
345 }
346 --base;
347 yday += isleap_sum(year, base) ?
348 DAYSPERLYEAR : DAYSPERNYEAR;
349 }
350 #ifdef XPG4_1994_04_09
351 if ((w == 52 && t->tm_mon == TM_JANUARY) ||
352 (w == 1 && t->tm_mon == TM_DECEMBER))
353 w = 53;
354 #endif /* defined XPG4_1994_04_09 */
355 if (*format == 'V')
356 pt = _conv(w,
357 PADDING(PAD_FMT_WEEKOFYEAR),
358 pt, ptlim);
359 else if (*format == 'g') {
360 pt = _yconv(year, base, 0, 1,
361 pt, ptlim);
362 } else
363 pt = _yconv(year, base, 1, 1,
364 pt, ptlim);
365 }
366 continue;
367 case 'v':
368 /*
369 * From Arnold Robbins' strftime version 3.0:
370 * "date as dd-bbb-YYYY"
371 * (ado, 1993-05-24)
372 */
373 pt = _fmt(loc, "%e-%b-%Y", t, pt, ptlim);
374 continue;
375 case 'W':
376 pt = _conv((t->tm_yday + DAYSPERWEEK -
377 (t->tm_wday ?
378 (t->tm_wday - 1) :
379 (DAYSPERWEEK - 1))) / DAYSPERWEEK,
380 PADDING(PAD_FMT_WEEKOFYEAR),
381 pt, ptlim);
382 continue;
383 case 'w':
384 pt = _conv(t->tm_wday, "%d", pt, ptlim);
385 continue;
386 case 'X':
387 pt = _fmt(loc, tptr->X_fmt, t, pt, ptlim);
388 continue;
389 case 'x':
390 pt = _fmt(loc, tptr->x_fmt, t, pt, ptlim);
391 continue;
392 case 'y':
393 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
394 pt, ptlim);
395 continue;
396 case 'Y':
397 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
398 pt, ptlim);
399 continue;
400 case 'Z':
401 if (t->tm_isdst >= 0)
402 pt = _add(tzname[t->tm_isdst != 0],
403 pt, ptlim);
404 /*
405 * C99 says that %Z must be replaced by the
406 * empty string if the time zone is not
407 * determinable.
408 */
409 continue;
410 case 'z':
411 {
412 int diff;
413 char const * sign;
414
415 if (t->tm_isdst < 0)
416 continue;
417 /*
418 * C99 says that the UTC offset must
419 * be computed by looking only at
420 * tm_isdst. This requirement is
421 * incorrect, since it means the code
422 * must rely on magic (in this case
423 * altzone and timezone), and the
424 * magic might not have the correct
425 * offset. Doing things correctly is
426 * tricky and requires disobeying C99;
427 * see GNU C strftime for details.
428 * For now, punt and conform to the
429 * standard, even though it's incorrect.
430 *
431 * C99 says that %z must be replaced by the
432 * empty string if the time zone is not
433 * determinable, so output nothing if the
434 * appropriate variables are not available.
435 */
436 if (t->tm_isdst == 0)
437 diff = -timezone;
438 else
439 diff = -altzone;
440 if (diff < 0) {
441 sign = "-";
442 diff = -diff;
443 } else
444 sign = "+";
445 pt = _add(sign, pt, ptlim);
446 diff /= SECSPERMIN;
447 diff = (diff / MINSPERHOUR) * 100 +
448 (diff % MINSPERHOUR);
449 pt = _conv(diff, PADDING(PAD_FMT_YEAR),
450 pt, ptlim);
451 }
452 continue;
453 case '+':
454 pt = _fmt(loc, tptr->date_fmt, t, pt, ptlim);
455 continue;
456 case '-':
457 if (PadIndex != PAD_DEFAULT)
458 break;
459 PadIndex = PAD_LESS;
460 goto label;
461 case '_':
462 if (PadIndex != PAD_DEFAULT)
463 break;
464 PadIndex = PAD_SPACE;
465 goto label;
466 case '0':
467 if (PadIndex != PAD_DEFAULT)
468 break;
469 PadIndex = PAD_ZERO;
470 goto label;
471 case '%':
472 /*
473 * X311J/88-090 (4.12.3.5): if conversion char is
474 * undefined, behavior is undefined. Print out the
475 * character itself as printf(3) also does.
476 */
477 default:
478 break;
479 }
480 }
481 if (pt == ptlim)
482 break;
483 *pt++ = *format;
484 }
485 return (pt);
486 }
487
488 static char *
489 _conv(const int n, const char *format, char *const pt,
490 const char *const ptlim)
491 {
492 char buf[12];
493
494 (void) sprintf(buf, format, n);
495 return (_add(buf, pt, ptlim));
496 }
497
498 static char *
499 _add(const char *str, char *pt, const char *const ptlim)
500 {
501 while (pt < ptlim && (*pt = *str++) != '\0')
502 ++pt;
503 return (pt);
504 }
505
506 /*
507 * POSIX and the C Standard are unclear or inconsistent about
508 * what %C and %y do if the year is negative or exceeds 9999.
509 * Use the convention that %C concatenated with %y yields the
510 * same output as %Y, and that %Y contains at least 4 bytes,
511 * with more only if necessary.
512 */
513
514 static char *
515 _yconv(const int a, const int b, const int convert_top, const int convert_yy,
516 char *pt, const char * const ptlim)
517 {
518 register int lead;
519 register int trail;
520
521 #define DIVISOR 100
522 trail = a % DIVISOR + b % DIVISOR;
523 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
524 trail %= DIVISOR;
525 if (trail < 0 && lead > 0) {
526 trail += DIVISOR;
527 --lead;
528 } else if (lead < 0 && trail > 0) {
529 trail -= DIVISOR;
530 ++lead;
531 }
532 if (convert_top) {
533 if (lead == 0 && trail < 0)
534 pt = _add("-0", pt, ptlim);
535 else pt = _conv(lead, "%02d", pt, ptlim);
536 }
537 if (convert_yy)
538 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim);
539 return (pt);
540 }