]> git.saurik.com Git - apple/libc.git/blob - stdtime/strftime.c
projects / apple / libc.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Libc-262.2.12.tar.gz
[apple/libc.git] / stdtime / strftime.c
1 /*
2 * Copyright (c) 1989 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms are permitted
6 * provided that the above copyright notice and this paragraph are
7 * duplicated in all such forms and that any documentation,
8 * advertising materials, and other materials related to such
9 * distribution and use acknowledge that the software was developed
10 * by the University of California, Berkeley. The name of the
11 * University may not be used to endorse or promote products derived
12 * from this software without specific prior written permission.
13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16 */
17
18 #ifdef LIBC_RCS
19 static const char rcsid[] =
20 "$FreeBSD: src/lib/libc/stdtime/strftime.c,v 1.25.2.3 2001/02/18 04:06:49 kris Exp $";
21 #endif
22
23 #ifndef lint
24 #ifndef NOID
25 static const char elsieid[] = "@(#)strftime.c 7.38";
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 "private.h"
34
35 #ifndef LIBC_SCCS
36 #ifndef lint
37 static const char sccsid[] = "@(#)strftime.c 5.4 (Berkeley) 3/14/89";
38 #endif /* !defined lint */
39 #endif /* !defined LIBC_SCCS */
40
41 #include "tzfile.h"
42 #include <fcntl.h>
43 #include <sys/stat.h>
44 #include "timelocal.h"
45
46 static char * _add P((const char *, char *, const char *));
47 static char * _conv P((int, const char *, char *, const char *));
48 static char * _fmt P((const char *, const struct tm *, char *, const char *));
49
50 size_t strftime P((char *, size_t, const char *, const struct tm *));
51
52 extern char * tzname[];
53
54 size_t
55 strftime(s, maxsize, format, t)
56 char *const s;
57 const size_t maxsize;
58 const char *const format;
59 const struct tm *const t;
60 {
61 char *p;
62
63 tzset();
64 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize);
65 if (p == s + maxsize)
66 return 0;
67 *p = '\0';
68 return p - s;
69 }
70
71 static char *
72 _fmt(format, t, pt, ptlim)
73 const char *format;
74 const struct tm *const t;
75 char *pt;
76 const char *const ptlim;
77 {
78 int Ealternative, Oalternative;
79
80 for ( ; *format; ++format) {
81 if (*format == '%') {
82 Ealternative = 0;
83 Oalternative = 0;
84 label:
85 switch (*++format) {
86 case '\0':
87 --format;
88 break;
89 case 'A':
90 pt = _add((t->tm_wday < 0 || t->tm_wday > 6) ?
91 "?" : Locale->weekday[t->tm_wday],
92 pt, ptlim);
93 continue;
94 case 'a':
95 pt = _add((t->tm_wday < 0 || t->tm_wday > 6) ?
96 "?" : Locale->wday[t->tm_wday],
97 pt, ptlim);
98 continue;
99 case 'B':
100 pt = _add((t->tm_mon < 0 || t->tm_mon > 11) ?
101 "?" : (Oalternative ? Locale->alt_month :
102 Locale->month)[t->tm_mon],
103 pt, ptlim);
104 continue;
105 case 'b':
106 case 'h':
107 pt = _add((t->tm_mon < 0 || t->tm_mon > 11) ?
108 "?" : Locale->mon[t->tm_mon],
109 pt, ptlim);
110 continue;
111 case 'C':
112 /*
113 ** %C used to do a...
114 ** _fmt("%a %b %e %X %Y", t);
115 ** ...whereas now POSIX 1003.2 calls for
116 ** something completely different.
117 ** (ado, 5/24/93)
118 */
119 pt = _conv((t->tm_year + TM_YEAR_BASE) / 100,
120 "%02d", pt, ptlim);
121 continue;
122 case 'c':
123 /* NOTE: c_fmt is intentionally ignored */
124 pt = _fmt("%a %Ef %T %Y", t, pt, ptlim);
125 continue;
126 case 'D':
127 pt = _fmt("%m/%d/%y", t, pt, ptlim);
128 continue;
129 case 'd':
130 pt = _conv(t->tm_mday, "%02d", pt, ptlim);
131 continue;
132 case 'E':
133 if (Ealternative || Oalternative)
134 break;
135 Ealternative++;
136 goto label;
137 case 'O':
138 /*
139 ** POSIX locale extensions, a la
140 ** Arnold Robbins' strftime version 3.0.
141 ** The sequences
142 ** %Ec %EC %Ex %EX %Ey %EY
143 ** %Od %oe %OH %OI %Om %OM
144 ** %OS %Ou %OU %OV %Ow %OW %Oy
145 ** are supposed to provide alternate
146 ** representations.
147 ** (ado, 5/24/93)
148 **
149 ** FreeBSD extensions
150 ** %OB %Ef %EF
151 */
152 if (Ealternative || Oalternative)
153 break;
154 Oalternative++;
155 goto label;
156 case 'e':
157 pt = _conv(t->tm_mday, "%2d", pt, ptlim);
158 continue;
159 case 'f':
160 if (!Ealternative)
161 break;
162 pt = _fmt(Locale->Ef_fmt, t, pt, ptlim);
163 continue;
164 case 'F':
165 if (!Ealternative)
166 break;
167 pt = _fmt(Locale->EF_fmt, t, pt, ptlim);
168 continue;
169 case 'H':
170 pt = _conv(t->tm_hour, "%02d", pt, ptlim);
171 continue;
172 case 'I':
173 pt = _conv((t->tm_hour % 12) ?
174 (t->tm_hour % 12) : 12,
175 "%02d", pt, ptlim);
176 continue;
177 case 'j':
178 pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim);
179 continue;
180 case 'k':
181 /*
182 ** This used to be...
183 ** _conv(t->tm_hour % 12 ?
184 ** t->tm_hour % 12 : 12, 2, ' ');
185 ** ...and has been changed to the below to
186 ** match SunOS 4.1.1 and Arnold Robbins'
187 ** strftime version 3.0. That is, "%k" and
188 ** "%l" have been swapped.
189 ** (ado, 5/24/93)
190 */
191 pt = _conv(t->tm_hour, "%2d", pt, ptlim);
192 continue;
193 #ifdef KITCHEN_SINK
194 case 'K':
195 /*
196 ** After all this time, still unclaimed!
197 */
198 pt = _add("kitchen sink", pt, ptlim);
199 continue;
200 #endif /* defined KITCHEN_SINK */
201 case 'l':
202 /*
203 ** This used to be...
204 ** _conv(t->tm_hour, 2, ' ');
205 ** ...and has been changed to the below to
206 ** match SunOS 4.1.1 and Arnold Robbin's
207 ** strftime version 3.0. That is, "%k" and
208 ** "%l" have been swapped.
209 ** (ado, 5/24/93)
210 */
211 pt = _conv((t->tm_hour % 12) ?
212 (t->tm_hour % 12) : 12,
213 "%2d", pt, ptlim);
214 continue;
215 case 'M':
216 pt = _conv(t->tm_min, "%02d", pt, ptlim);
217 continue;
218 case 'm':
219 pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim);
220 continue;
221 case 'n':
222 pt = _add("\n", pt, ptlim);
223 continue;
224 case 'p':
225 pt = _add((t->tm_hour >= 12) ?
226 Locale->pm :
227 Locale->am,
228 pt, ptlim);
229 continue;
230 case 'R':
231 pt = _fmt("%H:%M", t, pt, ptlim);
232 continue;
233 case 'r':
234 pt = _fmt("%I:%M:%S %p", t, pt, ptlim);
235 continue;
236 case 'S':
237 pt = _conv(t->tm_sec, "%02d", pt, ptlim);
238 continue;
239 case 's':
240 {
241 struct tm tm;
242 char buf[INT_STRLEN_MAXIMUM(
243 time_t) + 1];
244 time_t mkt;
245
246 tm = *t;
247 mkt = mktime(&tm);
248 if (TYPE_SIGNED(time_t))
249 (void) sprintf(buf, "%ld",
250 (long) mkt);
251 else (void) sprintf(buf, "%lu",
252 (unsigned long) mkt);
253 pt = _add(buf, pt, ptlim);
254 }
255 continue;
256 case 'T':
257 pt = _fmt("%H:%M:%S", t, pt, ptlim);
258 continue;
259 case 't':
260 pt = _add("\t", pt, ptlim);
261 continue;
262 case 'U':
263 pt = _conv((t->tm_yday + 7 - t->tm_wday) / 7,
264 "%02d", pt, ptlim);
265 continue;
266 case 'u':
267 /*
268 ** From Arnold Robbins' strftime version 3.0:
269 ** "ISO 8601: Weekday as a decimal number
270 ** [1 (Monday) - 7]"
271 ** (ado, 5/24/93)
272 */
273 pt = _conv((t->tm_wday == 0) ? 7 : t->tm_wday,
274 "%d", pt, ptlim);
275 continue;
276 case 'V': /* ISO 8601 week number */
277 case 'G': /* ISO 8601 year (four digits) */
278 case 'g': /* ISO 8601 year (two digits) */
279 /*
280 ** From Arnold Robbins' strftime version 3.0: "the week number of the
281 ** year (the first Monday as the first day of week 1) as a decimal number
282 ** (01-53)."
283 ** (ado, 1993-05-24)
284 **
285 ** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
286 ** "Week 01 of a year is per definition the first week which has the
287 ** Thursday in this year, which is equivalent to the week which contains
288 ** the fourth day of January. In other words, the first week of a new year
289 ** is the week which has the majority of its days in the new year. Week 01
290 ** might also contain days from the previous year and the week before week
291 ** 01 of a year is the last week (52 or 53) of the previous year even if
292 ** it contains days from the new year. A week starts with Monday (day 1)
293 ** and ends with Sunday (day 7). For example, the first week of the year
294 ** 1997 lasts from 1996-12-30 to 1997-01-05..."
295 ** (ado, 1996-01-02)
296 */
297 {
298 int year;
299 int yday;
300 int wday;
301 int w;
302
303 year = t->tm_year + TM_YEAR_BASE;
304 yday = t->tm_yday;
305 wday = t->tm_wday;
306 for ( ; ; ) {
307 int len;
308 int bot;
309 int top;
310
311 len = isleap(year) ?
312 DAYSPERLYEAR :
313 DAYSPERNYEAR;
314 /*
315 ** What yday (-3 ... 3) does
316 ** the ISO year begin on?
317 */
318 bot = ((yday + 11 - wday) %
319 DAYSPERWEEK) - 3;
320 /*
321 ** What yday does the NEXT
322 ** ISO year begin on?
323 */
324 top = bot -
325 (len % DAYSPERWEEK);
326 if (top < -3)
327 top += DAYSPERWEEK;
328 top += len;
329 if (yday >= top) {
330 ++year;
331 w = 1;
332 break;
333 }
334 if (yday >= bot) {
335 w = 1 + ((yday - bot) /
336 DAYSPERWEEK);
337 break;
338 }
339 --year;
340 yday += isleap(year) ?
341 DAYSPERLYEAR :
342 DAYSPERNYEAR;
343 }
344 #ifdef XPG4_1994_04_09
345 if ((w == 52
346 && t->tm_mon == TM_JANUARY)
347 || (w == 1
348 && t->tm_mon == TM_DECEMBER))
349 w = 53;
350 #endif /* defined XPG4_1994_04_09 */
351 if (*format == 'V')
352 pt = _conv(w, "%02d",
353 pt, ptlim);
354 else if (*format == 'g') {
355 pt = _conv(year % 100, "%02d",
356 pt, ptlim);
357 } else pt = _conv(year, "%04d",
358 pt, ptlim);
359 }
360 continue;
361 case 'v':
362 /*
363 ** From Arnold Robbins' strftime version 3.0:
364 ** "date as dd-bbb-YYYY"
365 ** (ado, 5/24/93)
366 */
367 pt = _fmt("%e-%b-%Y", t, pt, ptlim);
368 continue;
369 case 'W':
370 pt = _conv((t->tm_yday + 7 -
371 (t->tm_wday ?
372 (t->tm_wday - 1) : 6)) / 7,
373 "%02d", pt, ptlim);
374 continue;
375 case 'w':
376 pt = _conv(t->tm_wday, "%d", pt, ptlim);
377 continue;
378 case 'X':
379 pt = _fmt(Locale->X_fmt, t, pt, ptlim);
380 continue;
381 case 'x':
382 pt = _fmt(Locale->x_fmt, t, pt, ptlim);
383 continue;
384 case 'y':
385 pt = _conv((t->tm_year + TM_YEAR_BASE) % 100,
386 "%02d", pt, ptlim);
387 continue;
388 case 'Y':
389 pt = _conv(t->tm_year + TM_YEAR_BASE, "%04d",
390 pt, ptlim);
391 continue;
392 case 'Z':
393 if (t->tm_zone != NULL)
394 pt = _add(t->tm_zone, pt, ptlim);
395 else
396 if (t->tm_isdst == 0 || t->tm_isdst == 1) {
397 pt = _add(tzname[t->tm_isdst],
398 pt, ptlim);
399 } else pt = _add("?", pt, ptlim);
400 continue;
401 case 'z':
402 {
403 long absoff;
404 if (t->tm_gmtoff >= 0) {
405 absoff = t->tm_gmtoff;
406 pt = _add("+", pt, ptlim);
407 } else {
408 absoff = -t->tm_gmtoff;
409 pt = _add("-", pt, ptlim);
410 }
411 pt = _conv(absoff / 3600, "%02d",
412 pt, ptlim);
413 pt = _conv((absoff % 3600) / 60, "%02d",
414 pt, ptlim);
415 };
416 continue;
417 case '+':
418 pt = _fmt(Locale->date_fmt, t, pt, ptlim);
419 continue;
420 case '%':
421 /*
422 * X311J/88-090 (4.12.3.5): if conversion char is
423 * undefined, behavior is undefined. Print out the
424 * character itself as printf(3) also does.
425 */
426 default:
427 break;
428 }
429 }
430 if (pt == ptlim)
431 break;
432 *pt++ = *format;
433 }
434 return pt;
435 }
436
437 static char *
438 _conv(n, format, pt, ptlim)
439 const int n;
440 const char *const format;
441 char *const pt;
442 const char *const ptlim;
443 {
444 char buf[INT_STRLEN_MAXIMUM(int) + 1];
445
446 (void) sprintf(buf, format, n);
447 return _add(buf, pt, ptlim);
448 }
449
450 static char *
451 _add(str, pt, ptlim)
452 const char *str;
453 char *pt;
454 const char *const ptlim;
455 {
456 while (pt < ptlim && (*pt = *str++) != '\0')
457 ++pt;
458 return pt;
459 }
mirror of libc