xref: /netbsd-src/lib/libc/time/strftime.c (revision 62a8debe1dc62962e18a1c918def78666141273b)
1 /*	$NetBSD: strftime.c,v 1.20 2009/12/31 22:49:16 mlelstv Exp $	*/
2 
3 #include <sys/cdefs.h>
4 #if defined(LIBC_SCCS) && !defined(lint)
5 #if 0
6 static char	elsieid[] = "@(#)strftime.c	7.64";
7 static char	elsieid[] = "@(#)strftime.c	8.3";
8 #else
9 __RCSID("$NetBSD: strftime.c,v 1.20 2009/12/31 22:49:16 mlelstv Exp $");
10 #endif
11 #endif /* LIBC_SCCS and not lint */
12 
13 #include "namespace.h"
14 
15 /*
16 ** Based on the UCB version with the ID appearing below.
17 ** This is ANSIish only when "multibyte character == plain character".
18 */
19 
20 #include "private.h"
21 
22 /*
23 ** We don't use these extensions in strftime operation even when
24 ** supported by the local tzcode configuration.  A strictly
25 ** conforming C application may leave them in undefined state.
26 */
27 
28 #ifdef _LIBC
29 #undef TM_ZONE
30 #undef TM_GMTOFF
31 #endif
32 
33 /*
34 ** Copyright (c) 1989, 1993
35 **	The Regents of the University of California.  All rights reserved.
36 **
37 ** Redistribution and use in source and binary forms, with or without
38 ** modification, are permitted provided that the following conditions
39 ** are met:
40 ** 1. Redistributions of source code must retain the above copyright
41 **    notice, this list of conditions and the following disclaimer.
42 ** 2. Redistributions in binary form must reproduce the above copyright
43 **    notice, this list of conditions and the following disclaimer in the
44 **    documentation and/or other materials provided with the distribution.
45 ** 3. All advertising materials mentioning features or use of this software
46 **    must display the following acknowledgement:
47 **	This product includes software developed by the University of
48 **	California, Berkeley and its contributors.
49 ** 4. Neither the name of the University nor the names of its contributors
50 **    may be used to endorse or promote products derived from this software
51 **    without specific prior written permission.
52 **
53 ** THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 ** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 ** ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 ** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 ** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 ** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 ** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 ** SUCH DAMAGE.
64 */
65 
66 #ifndef LIBC_SCCS
67 #ifndef lint
68 static const char	sccsid[] = "@(#)strftime.c	5.4 (Berkeley) 3/14/89";
69 #endif /* !defined lint */
70 #endif /* !defined LIBC_SCCS */
71 
72 #include "tzfile.h"
73 #include "fcntl.h"
74 #include "locale.h"
75 
76 #include "sys/localedef.h"
77 #define Locale	_CurrentTimeLocale
78 #define c_fmt   d_t_fmt
79 
80 static char *	_add(const char *, char *, const char *);
81 static char *	_conv(int, const char *, char *, const char *);
82 static char *	_fmt(const char *, const struct tm *, char *, const char *,
83 			int *);
84 static char *	_yconv(int, int, int, int, char *, const char *);
85 
86 extern char *	tzname[];
87 
88 #ifndef YEAR_2000_NAME
89 #define YEAR_2000_NAME	"CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
90 #endif /* !defined YEAR_2000_NAME */
91 
92 #define IN_NONE	0
93 #define IN_SOME	1
94 #define IN_THIS	2
95 #define IN_ALL	3
96 
97 size_t
98 strftime(s, maxsize, format, t)
99 char * const		s;
100 const size_t		maxsize;
101 const char * const	format;
102 const struct tm * const	t;
103 {
104 	char *	p;
105 	int	warn;
106 
107 	tzset();
108 	warn = IN_NONE;
109 	p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn);
110 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
111 	if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
112 		(void) fprintf(stderr, "\n");
113 		if (format == NULL)
114 			(void) fprintf(stderr, "NULL strftime format ");
115 		else	(void) fprintf(stderr, "strftime format \"%s\" ",
116 				format);
117 		(void) fprintf(stderr, "yields only two digits of years in ");
118 		if (warn == IN_SOME)
119 			(void) fprintf(stderr, "some locales");
120 		else if (warn == IN_THIS)
121 			(void) fprintf(stderr, "the current locale");
122 		else	(void) fprintf(stderr, "all locales");
123 		(void) fprintf(stderr, "\n");
124 	}
125 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
126 	if (p == s + maxsize)
127 		return 0;
128 	*p = '\0';
129 	return p - s;
130 }
131 
132 static char *
133 _fmt(format, t, pt, ptlim, warnp)
134 const char *		format;
135 const struct tm * const	t;
136 char *			pt;
137 const char * const	ptlim;
138 int *			warnp;
139 {
140 	for ( ; *format; ++format) {
141 		if (*format == '%') {
142 label:
143 			switch (*++format) {
144 			case '\0':
145 				--format;
146 				break;
147 			case 'A':
148 				pt = _add((t->tm_wday < 0 ||
149 					t->tm_wday >= DAYSPERWEEK) ?
150 					"?" : Locale->day[t->tm_wday],
151 					pt, ptlim);
152 				continue;
153 			case 'a':
154 				pt = _add((t->tm_wday < 0 ||
155 					t->tm_wday >= DAYSPERWEEK) ?
156 					"?" : Locale->abday[t->tm_wday],
157 					pt, ptlim);
158 				continue;
159 			case 'B':
160 				pt = _add((t->tm_mon < 0 ||
161 					t->tm_mon >= MONSPERYEAR) ?
162 					"?" : Locale->mon[t->tm_mon],
163 					pt, ptlim);
164 				continue;
165 			case 'b':
166 			case 'h':
167 				pt = _add((t->tm_mon < 0 ||
168 					t->tm_mon >= MONSPERYEAR) ?
169 					"?" : Locale->abmon[t->tm_mon],
170 					pt, ptlim);
171 				continue;
172 			case 'C':
173 				/*
174 				** %C used to do a...
175 				**	_fmt("%a %b %e %X %Y", t);
176 				** ...whereas now POSIX 1003.2 calls for
177 				** something completely different.
178 				** (ado, 1993-05-24)
179 				*/
180 				pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
181 					pt, ptlim);
182 				continue;
183 			case 'c':
184 				{
185 				int warn2 = IN_SOME;
186 
187 				pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2);
188 				if (warn2 == IN_ALL)
189 					warn2 = IN_THIS;
190 				if (warn2 > *warnp)
191 					*warnp = warn2;
192 				}
193 				continue;
194 			case 'D':
195 				pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp);
196 				continue;
197 			case 'd':
198 				pt = _conv(t->tm_mday, "%02d", pt, ptlim);
199 				continue;
200 			case 'E':
201 			case 'O':
202 				/*
203 				** C99 locale modifiers.
204 				** The sequences
205 				**	%Ec %EC %Ex %EX %Ey %EY
206 				**	%Od %oe %OH %OI %Om %OM
207 				**	%OS %Ou %OU %OV %Ow %OW %Oy
208 				** are supposed to provide alternate
209 				** representations.
210 				*/
211 				goto label;
212 			case 'e':
213 				pt = _conv(t->tm_mday, "%2d", pt, ptlim);
214 				continue;
215 			case 'F':
216 				pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp);
217 				continue;
218 			case 'H':
219 				pt = _conv(t->tm_hour, "%02d", pt, ptlim);
220 				continue;
221 			case 'I':
222 				pt = _conv((t->tm_hour % 12) ?
223 					(t->tm_hour % 12) : 12,
224 					"%02d", pt, ptlim);
225 				continue;
226 			case 'j':
227 				pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim);
228 				continue;
229 			case 'k':
230 				/*
231 				** This used to be...
232 				**	_conv(t->tm_hour % 12 ?
233 				**		t->tm_hour % 12 : 12, 2, ' ');
234 				** ...and has been changed to the below to
235 				** match SunOS 4.1.1 and Arnold Robbins'
236 				** strftime version 3.0. That is, "%k" and
237 				** "%l" have been swapped.
238 				** (ado, 1993-05-24)
239 				*/
240 				pt = _conv(t->tm_hour, "%2d", pt, ptlim);
241 				continue;
242 #ifdef KITCHEN_SINK
243 			case 'K':
244 				/*
245 				** After all this time, still unclaimed!
246 				*/
247 				pt = _add("kitchen sink", pt, ptlim);
248 				continue;
249 #endif /* defined KITCHEN_SINK */
250 			case 'l':
251 				/*
252 				** This used to be...
253 				**	_conv(t->tm_hour, 2, ' ');
254 				** ...and has been changed to the below to
255 				** match SunOS 4.1.1 and Arnold Robbin's
256 				** strftime version 3.0. That is, "%k" and
257 				** "%l" have been swapped.
258 				** (ado, 1993-05-24)
259 				*/
260 				pt = _conv((t->tm_hour % 12) ?
261 					(t->tm_hour % 12) : 12,
262 					"%2d", pt, ptlim);
263 				continue;
264 			case 'M':
265 				pt = _conv(t->tm_min, "%02d", pt, ptlim);
266 				continue;
267 			case 'm':
268 				pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim);
269 				continue;
270 			case 'n':
271 				pt = _add("\n", pt, ptlim);
272 				continue;
273 			case 'p':
274 				pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
275 					Locale->am_pm[1] :
276 					Locale->am_pm[0],
277 					pt, ptlim);
278 				continue;
279 			case 'R':
280 				pt = _fmt("%H:%M", t, pt, ptlim, warnp);
281 				continue;
282 			case 'r':
283 				pt = _fmt(Locale->t_fmt_ampm, t, pt, ptlim,
284 				       	warnp);
285 				continue;
286 			case 'S':
287 				pt = _conv(t->tm_sec, "%02d", pt, ptlim);
288 				continue;
289 			case 's':
290 				{
291 					struct tm	tm;
292 					char		buf[INT_STRLEN_MAXIMUM(
293 								time_t) + 1];
294 					time_t		mkt;
295 
296 					tm = *t;
297 					mkt = mktime(&tm);
298 					/* CONSTCOND */
299 					if (TYPE_SIGNED(time_t))
300 						(void) snprintf(buf, sizeof(buf),
301 						    "%lld", (long long) mkt);
302 					else	(void) snprintf(buf, sizeof(buf),
303 						    "%llu", (unsigned long long)
304 						    mkt);
305 					pt = _add(buf, pt, ptlim);
306 				}
307 				continue;
308 			case 'T':
309 				pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp);
310 				continue;
311 			case 't':
312 				pt = _add("\t", pt, ptlim);
313 				continue;
314 			case 'U':
315 				pt = _conv((t->tm_yday + DAYSPERWEEK -
316 					t->tm_wday) / DAYSPERWEEK,
317 					"%02d", pt, ptlim);
318 				continue;
319 			case 'u':
320 				/*
321 				** From Arnold Robbins' strftime version 3.0:
322 				** "ISO 8601: Weekday as a decimal number
323 				** [1 (Monday) - 7]"
324 				** (ado, 1993-05-24)
325 				*/
326 				pt = _conv((t->tm_wday == 0) ?
327 					DAYSPERWEEK : t->tm_wday,
328 					"%d", pt, ptlim);
329 				continue;
330 			case 'V':	/* ISO 8601 week number */
331 			case 'G':	/* ISO 8601 year (four digits) */
332 			case 'g':	/* ISO 8601 year (two digits) */
333 /*
334 ** From Arnold Robbins' strftime version 3.0: "the week number of the
335 ** year (the first Monday as the first day of week 1) as a decimal number
336 ** (01-53)."
337 ** (ado, 1993-05-24)
338 **
339 ** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
340 ** "Week 01 of a year is per definition the first week which has the
341 ** Thursday in this year, which is equivalent to the week which contains
342 ** the fourth day of January. In other words, the first week of a new year
343 ** is the week which has the majority of its days in the new year. Week 01
344 ** might also contain days from the previous year and the week before week
345 ** 01 of a year is the last week (52 or 53) of the previous year even if
346 ** it contains days from the new year. A week starts with Monday (day 1)
347 ** and ends with Sunday (day 7). For example, the first week of the year
348 ** 1997 lasts from 1996-12-30 to 1997-01-05..."
349 ** (ado, 1996-01-02)
350 */
351 				{
352 					int	year;
353 					int	base;
354 					int	yday;
355 					int	wday;
356 					int	w;
357 
358 					year = t->tm_year;
359 					base = TM_YEAR_BASE;
360 					yday = t->tm_yday;
361 					wday = t->tm_wday;
362 					for ( ; ; ) {
363 						int	len;
364 						int	bot;
365 						int	top;
366 
367 						len = isleap_sum(year, base) ?
368 							DAYSPERLYEAR :
369 							DAYSPERNYEAR;
370 						/*
371 						** What yday (-3 ... 3) does
372 						** the ISO year begin on?
373 						*/
374 						bot = ((yday + 11 - wday) %
375 							DAYSPERWEEK) - 3;
376 						/*
377 						** What yday does the NEXT
378 						** ISO year begin on?
379 						*/
380 						top = bot -
381 							(len % DAYSPERWEEK);
382 						if (top < -3)
383 							top += DAYSPERWEEK;
384 						top += len;
385 						if (yday >= top) {
386 							++base;
387 							w = 1;
388 							break;
389 						}
390 						if (yday >= bot) {
391 							w = 1 + ((yday - bot) /
392 								DAYSPERWEEK);
393 							break;
394 						}
395 						--base;
396 						yday += isleap_sum(year, base) ?
397 							DAYSPERLYEAR :
398 							DAYSPERNYEAR;
399 					}
400 #ifdef XPG4_1994_04_09
401 					if ((w == 52 &&
402 						t->tm_mon == TM_JANUARY) ||
403 						(w == 1 &&
404 						t->tm_mon == TM_DECEMBER))
405 							w = 53;
406 #endif /* defined XPG4_1994_04_09 */
407 					if (*format == 'V')
408 						pt = _conv(w, "%02d",
409 							pt, ptlim);
410 					else if (*format == 'g') {
411 						*warnp = IN_ALL;
412 						pt = _yconv(year, base, 0, 1,
413 							pt, ptlim);
414 					} else	pt = _yconv(year, base, 1, 1,
415 							pt, ptlim);
416 				}
417 				continue;
418 			case 'v':
419 				/*
420 				** From Arnold Robbins' strftime version 3.0:
421 				** "date as dd-bbb-YYYY"
422 				** (ado, 1993-05-24)
423 				*/
424 				pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp);
425 				continue;
426 			case 'W':
427 				pt = _conv((t->tm_yday + DAYSPERWEEK -
428 					(t->tm_wday ?
429 					(t->tm_wday - 1) :
430 					(DAYSPERWEEK - 1))) / DAYSPERWEEK,
431 					"%02d", pt, ptlim);
432 				continue;
433 			case 'w':
434 				pt = _conv(t->tm_wday, "%d", pt, ptlim);
435 				continue;
436 			case 'X':
437 				pt = _fmt(Locale->t_fmt, t, pt, ptlim, warnp);
438 				continue;
439 			case 'x':
440 				{
441 				int	warn2 = IN_SOME;
442 
443 				pt = _fmt(Locale->d_fmt, t, pt, ptlim, &warn2);
444 				if (warn2 == IN_ALL)
445 					warn2 = IN_THIS;
446 				if (warn2 > *warnp)
447 					*warnp = warn2;
448 				}
449 				continue;
450 			case 'y':
451 				*warnp = IN_ALL;
452 				pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
453 					pt, ptlim);
454 				continue;
455 			case 'Y':
456 				pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
457 					pt, ptlim);
458 				continue;
459 			case 'Z':
460 #ifdef TM_ZONE
461 				if (t->TM_ZONE != NULL)
462 					pt = _add(t->TM_ZONE, pt, ptlim);
463 				else
464 #endif /* defined TM_ZONE */
465 				if (t->tm_isdst >= 0)
466 					pt = _add(tzname[t->tm_isdst != 0],
467 						pt, ptlim);
468 				/*
469 				** C99 says that %Z must be replaced by the
470 				** empty string if the time zone is not
471 				** determinable.
472 				*/
473 				continue;
474 			case 'z':
475 				{
476 				int		diff;
477 				char const *	sign;
478 
479 				if (t->tm_isdst < 0)
480 					continue;
481 #ifdef TM_GMTOFF
482 				diff = (int)t->TM_GMTOFF;
483 #else /* !defined TM_GMTOFF */
484 				/*
485 				** C99 says that the UTC offset must
486 				** be computed by looking only at
487 				** tm_isdst. This requirement is
488 				** incorrect, since it means the code
489 				** must rely on magic (in this case
490 				** altzone and timezone), and the
491 				** magic might not have the correct
492 				** offset. Doing things correctly is
493 				** tricky and requires disobeying C99;
494 				** see GNU C strftime for details.
495 				** For now, punt and conform to the
496 				** standard, even though it's incorrect.
497 				**
498 				** C99 says that %z must be replaced by the
499 				** empty string if the time zone is not
500 				** determinable, so output nothing if the
501 				** appropriate variables are not available.
502 				*/
503 #ifndef STD_INSPIRED
504 				if (t->tm_isdst == 0)
505 #ifdef USG_COMPAT
506 					diff = -timezone;
507 #else /* !defined USG_COMPAT */
508 					continue;
509 #endif /* !defined USG_COMPAT */
510 				else
511 #ifdef ALTZONE
512 					diff = -altzone;
513 #else /* !defined ALTZONE */
514 					continue;
515 #endif /* !defined ALTZONE */
516 #else /* defined STD_INSPIRED */
517 				{
518 					struct tm tmp;
519 					time_t lct, gct;
520 
521 					/*
522 					** Get calendar time from t
523 					** being treated as local.
524 					*/
525 					tmp = *t; /* mktime discards const */
526 					lct = mktime(&tmp);
527 
528 					if (lct == (time_t)-1)
529 						continue;
530 
531 					/*
532 					** Get calendar time from t
533 					** being treated as GMT.
534 					**/
535 					tmp = *t; /* mktime discards const */
536 					gct = timegm(&tmp);
537 
538 					if (gct == (time_t)-1)
539 						continue;
540 
541 					/* LINTED difference will fit int */
542 					diff = (intmax_t)gct - (intmax_t)lct;
543 				}
544 #endif /* defined STD_INSPIRED */
545 #endif /* !defined TM_GMTOFF */
546 				if (diff < 0) {
547 					sign = "-";
548 					diff = -diff;
549 				} else	sign = "+";
550 				pt = _add(sign, pt, ptlim);
551 				diff /= SECSPERMIN;
552 				diff = (diff / MINSPERHOUR) * 100 +
553 					(diff % MINSPERHOUR);
554 				pt = _conv(diff, "%04d", pt, ptlim);
555 				}
556 				continue;
557 #if 0
558 			case '+':
559 				pt = _fmt(Locale->date_fmt, t, pt, ptlim,
560 					warnp);
561 				continue;
562 #endif
563 			case '%':
564 			/*
565 			** X311J/88-090 (4.12.3.5): if conversion char is
566 			** undefined, behavior is undefined. Print out the
567 			** character itself as printf(3) also does.
568 			*/
569 			default:
570 				break;
571 			}
572 		}
573 		if (pt == ptlim)
574 			break;
575 		*pt++ = *format;
576 	}
577 	return pt;
578 }
579 
580 static char *
581 _conv(n, format, pt, ptlim)
582 const int		n;
583 const char * const	format;
584 char * const		pt;
585 const char * const	ptlim;
586 {
587 	char	buf[INT_STRLEN_MAXIMUM(int) + 1];
588 
589 	(void) snprintf(buf, sizeof(buf), format, n);
590 	return _add(buf, pt, ptlim);
591 }
592 
593 static char *
594 _add(str, pt, ptlim)
595 const char *		str;
596 char *			pt;
597 const char * const	ptlim;
598 {
599 	while (pt < ptlim && (*pt = *str++) != '\0')
600 		++pt;
601 	return pt;
602 }
603 
604 /*
605 ** POSIX and the C Standard are unclear or inconsistent about
606 ** what %C and %y do if the year is negative or exceeds 9999.
607 ** Use the convention that %C concatenated with %y yields the
608 ** same output as %Y, and that %Y contains at least 4 bytes,
609 ** with more only if necessary.
610 */
611 
612 static char *
613 _yconv(a, b, convert_top, convert_yy, pt, ptlim)
614 const int		a;
615 const int		b;
616 const int		convert_top;
617 const int		convert_yy;
618 char *			pt;
619 const char * const	ptlim;
620 {
621 	register int	lead;
622 	register int	trail;
623 
624 #define DIVISOR	100
625 	trail = a % DIVISOR + b % DIVISOR;
626 	lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
627 	trail %= DIVISOR;
628 	if (trail < 0 && lead > 0) {
629 		trail += DIVISOR;
630 		--lead;
631 	} else if (lead < 0 && trail > 0) {
632 		trail -= DIVISOR;
633 		++lead;
634 	}
635 	if (convert_top) {
636 		if (lead == 0 && trail < 0)
637 			pt = _add("-0", pt, ptlim);
638 		else	pt = _conv(lead, "%02d", pt, ptlim);
639 	}
640 	if (convert_yy)
641 		pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim);
642 	return pt;
643 }
644 
645 #ifdef LOCALE_HOME
646 static struct lc_time_T *
647 _loc(void)
648 {
649 	static const char	locale_home[] = LOCALE_HOME;
650 	static const char	lc_time[] = "LC_TIME";
651 	static char *		locale_buf;
652 
653 	int			fd;
654 	int			oldsun;	/* "...ain't got nothin' to do..." */
655 	char *			lbuf;
656 	char *			name;
657 	char *			p;
658 	const char **		ap;
659 	const char *		plim;
660 	char			filename[FILENAME_MAX];
661 	struct stat		st;
662 	size_t			namesize;
663 	size_t			bufsize;
664 
665 	/*
666 	** Use localebuf.mon[0] to signal whether locale is already set up.
667 	*/
668 	if (localebuf.mon[0])
669 		return &localebuf;
670 	name = setlocale(LC_TIME, (char *) NULL);
671 	if (name == NULL || *name == '\0')
672 		goto no_locale;
673 	/*
674 	** If the locale name is the same as our cache, use the cache.
675 	*/
676 	lbuf = locale_buf;
677 	if (lbuf != NULL && strcmp(name, lbuf) == 0) {
678 		p = lbuf;
679 		for (ap = (const char **) &localebuf;
680 			ap < (const char **) (&localebuf + 1);
681 				++ap)
682 					*ap = p += strlen(p) + 1;
683 		return &localebuf;
684 	}
685 	/*
686 	** Slurp the locale file into the cache.
687 	*/
688 	namesize = strlen(name) + 1;
689 	if (sizeof filename <
690 		((sizeof locale_home) + namesize + (sizeof lc_time)))
691 			goto no_locale;
692 	oldsun = 0;
693 	(void) sprintf(filename, "%s/%s/%s", locale_home, name, lc_time);
694 	fd = open(filename, O_RDONLY);
695 	if (fd < 0) {
696 		/*
697 		** Old Sun systems have a different naming and data convention.
698 		*/
699 		oldsun = 1;
700 		(void) sprintf(filename, "%s/%s/%s", locale_home,
701 			lc_time, name);
702 		fd = open(filename, O_RDONLY);
703 		if (fd < 0)
704 			goto no_locale;
705 	}
706 	if (fstat(fd, &st) != 0)
707 		goto bad_locale;
708 	if (st.st_size <= 0)
709 		goto bad_locale;
710 	bufsize = namesize + st.st_size;
711 	locale_buf = NULL;
712 	lbuf = (lbuf == NULL) ? malloc(bufsize) : realloc(lbuf, bufsize);
713 	if (lbuf == NULL)
714 		goto bad_locale;
715 	(void) strcpy(lbuf, name);
716 	p = lbuf + namesize;
717 	plim = p + st.st_size;
718 	if (read(fd, p, (size_t) st.st_size) != st.st_size)
719 		goto bad_lbuf;
720 	if (close(fd) != 0)
721 		goto bad_lbuf;
722 	/*
723 	** Parse the locale file into localebuf.
724 	*/
725 	if (plim[-1] != '\n')
726 		goto bad_lbuf;
727 	for (ap = (const char **) &localebuf;
728 		ap < (const char **) (&localebuf + 1);
729 			++ap) {
730 				if (p == plim)
731 					goto bad_lbuf;
732 				*ap = p;
733 				while (*p != '\n')
734 					++p;
735 				*p++ = '\0';
736 	}
737 	if (oldsun) {
738 		/*
739 		** SunOS 4 used an obsolescent format; see localdtconv(3).
740 		** c_fmt had the ``short format for dates and times together''
741 		** (SunOS 4 date, "%a %b %e %T %Z %Y" in the C locale);
742 		** date_fmt had the ``long format for dates''
743 		** (SunOS 4 strftime %C, "%A, %B %e, %Y" in the C locale).
744 		** Discard the latter in favor of the former.
745 		*/
746 		localebuf.date_fmt = localebuf.c_fmt;
747 	}
748 	/*
749 	** Record the successful parse in the cache.
750 	*/
751 	locale_buf = lbuf;
752 
753 	return &localebuf;
754 
755 bad_lbuf:
756 	free(lbuf);
757 bad_locale:
758 	(void) close(fd);
759 no_locale:
760 	localebuf = C_time_locale;
761 	locale_buf = NULL;
762 	return &localebuf;
763 }
764 #endif /* defined LOCALE_HOME */
765