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