localtime.c revision 1.8 1 /* $NetBSD: localtime.c,v 1.8 1997/01/23 14:02:29 mrg Exp $ */
2
3 /*
4 ** This file is in the public domain, so clarified as of
5 ** June 5, 1996 by Arthur David Olson (arthur_david_olson (at) nih.gov).
6 */
7
8 #ifndef lint
9 #ifndef NOID
10 static char elsieid[] = "@(#)localtime.c 7.58";
11 #endif /* !defined NOID */
12 #endif /* !defined lint */
13
14 /*
15 ** Leap second handling from Bradley White (bww (at) k.gp.cs.cmu.edu).
16 ** POSIX-style TZ environment variable handling from Guy Harris
17 ** (guy (at) auspex.com).
18 */
19
20 /*LINTLIBRARY*/
21
22 #include "private.h"
23 #include "tzfile.h"
24 #include "fcntl.h"
25
26 /*
27 ** SunOS 4.1.1 headers lack O_BINARY.
28 */
29
30 #ifdef O_BINARY
31 #define OPEN_MODE (O_RDONLY | O_BINARY)
32 #endif /* defined O_BINARY */
33 #ifndef O_BINARY
34 #define OPEN_MODE O_RDONLY
35 #endif /* !defined O_BINARY */
36
37 #ifndef WILDABBR
38 /*
39 ** Someone might make incorrect use of a time zone abbreviation:
40 ** 1. They might reference tzname[0] before calling tzset (explicitly
41 ** or implicitly).
42 ** 2. They might reference tzname[1] before calling tzset (explicitly
43 ** or implicitly).
44 ** 3. They might reference tzname[1] after setting to a time zone
45 ** in which Daylight Saving Time is never observed.
46 ** 4. They might reference tzname[0] after setting to a time zone
47 ** in which Standard Time is never observed.
48 ** 5. They might reference tm.TM_ZONE after calling offtime.
49 ** What's best to do in the above cases is open to debate;
50 ** for now, we just set things up so that in any of the five cases
51 ** WILDABBR is used. Another possibility: initialize tzname[0] to the
52 ** string "tzname[0] used before set", and similarly for the other cases.
53 ** And another: initialize tzname[0] to "ERA", with an explanation in the
54 ** manual page of what this "time zone abbreviation" means (doing this so
55 ** that tzname[0] has the "normal" length of three characters).
56 */
57 #define WILDABBR " "
58 #endif /* !defined WILDABBR */
59
60 static char wildabbr[] = "WILDABBR";
61
62 static const char gmt[] = "GMT";
63
64 struct ttinfo { /* time type information */
65 long tt_gmtoff; /* GMT offset in seconds */
66 int tt_isdst; /* used to set tm_isdst */
67 int tt_abbrind; /* abbreviation list index */
68 int tt_ttisstd; /* TRUE if transition is std time */
69 int tt_ttisgmt; /* TRUE if transition is GMT */
70 };
71
72 struct lsinfo { /* leap second information */
73 time_t ls_trans; /* transition time */
74 long ls_corr; /* correction to apply */
75 };
76
77 #define BIGGEST(a, b) (((a) > (b)) ? (a) : (b))
78
79 #ifdef TZNAME_MAX
80 #define MY_TZNAME_MAX TZNAME_MAX
81 #endif /* defined TZNAME_MAX */
82 #ifndef TZNAME_MAX
83 #define MY_TZNAME_MAX 255
84 #endif /* !defined TZNAME_MAX */
85
86 struct state {
87 int leapcnt;
88 int timecnt;
89 int typecnt;
90 int charcnt;
91 time_t ats[TZ_MAX_TIMES];
92 unsigned char types[TZ_MAX_TIMES];
93 struct ttinfo ttis[TZ_MAX_TYPES];
94 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
95 (2 * (MY_TZNAME_MAX + 1)))];
96 struct lsinfo lsis[TZ_MAX_LEAPS];
97 };
98
99 struct rule {
100 int r_type; /* type of rule--see below */
101 int r_day; /* day number of rule */
102 int r_week; /* week number of rule */
103 int r_mon; /* month number of rule */
104 long r_time; /* transition time of rule */
105 };
106
107 #define JULIAN_DAY 0 /* Jn - Julian day */
108 #define DAY_OF_YEAR 1 /* n - day of year */
109 #define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */
110
111 /*
112 ** Prototypes for static functions.
113 */
114
115 static long detzcode P((const char * codep));
116 static const char * getzname P((const char * strp));
117 static const char * getnum P((const char * strp, int * nump, int min,
118 int max));
119 static const char * getsecs P((const char * strp, long * secsp));
120 static const char * getoffset P((const char * strp, long * offsetp));
121 static const char * getrule P((const char * strp, struct rule * rulep));
122 static void gmtload P((struct state * sp));
123 static void gmtsub P((const time_t * timep, long offset,
124 struct tm * tmp));
125 static void localsub P((const time_t * timep, long offset,
126 struct tm * tmp));
127 static int increment_overflow P((int * number, int delta));
128 static int normalize_overflow P((int * tensptr, int * unitsptr,
129 int base));
130 static void settzname P((void));
131 static time_t time1 P((struct tm * tmp,
132 void(*funcp) P((const time_t *,
133 long, struct tm *)),
134 long offset));
135 static time_t time2 P((struct tm *tmp,
136 void(*funcp) P((const time_t *,
137 long, struct tm*)),
138 long offset, int * okayp));
139 static void timesub P((const time_t * timep, long offset,
140 const struct state * sp, struct tm * tmp));
141 static int tmcomp P((const struct tm * atmp,
142 const struct tm * btmp));
143 static time_t transtime P((time_t janfirst, int year,
144 const struct rule * rulep, long offset));
145 static int tzload P((const char * name, struct state * sp));
146 static int tzparse P((const char * name, struct state * sp,
147 int lastditch));
148
149 #ifdef ALL_STATE
150 static struct state * lclptr;
151 static struct state * gmtptr;
152 #endif /* defined ALL_STATE */
153
154 #ifndef ALL_STATE
155 static struct state lclmem;
156 static struct state gmtmem;
157 #define lclptr (&lclmem)
158 #define gmtptr (&gmtmem)
159 #endif /* State Farm */
160
161 #ifndef TZ_STRLEN_MAX
162 #define TZ_STRLEN_MAX 255
163 #endif /* !defined TZ_STRLEN_MAX */
164
165 static char lcl_TZname[TZ_STRLEN_MAX + 1];
166 static int lcl_is_set;
167 static int gmt_is_set;
168
169 char * tzname[2] = {
170 wildabbr,
171 wildabbr
172 };
173
174 /*
175 ** Section 4.12.3 of X3.159-1989 requires that
176 ** Except for the strftime function, these functions [asctime,
177 ** ctime, gmtime, localtime] return values in one of two static
178 ** objects: a broken-down time structure and an array of char.
179 ** Thanks to Paul Eggert (eggert (at) twinsun.com) for noting this.
180 */
181
182 static struct tm tm;
183
184 #ifdef USG_COMPAT
185 time_t timezone = 0;
186 int daylight = 0;
187 #endif /* defined USG_COMPAT */
188
189 #ifdef ALTZONE
190 time_t altzone = 0;
191 #endif /* defined ALTZONE */
192
193 static long
194 detzcode(codep)
195 const char * const codep;
196 {
197 register long result;
198
199 /*
200 ** The first character must be sign extended on systems with >32bit
201 ** longs. This was solved differently in the master tzcode sources
202 ** (the fix first appeared in tzcode95c.tar.gz). But I believe
203 ** that this implementation is superior.
204 */
205
206 #ifdef __STDC__
207 #define SIGN_EXTEND_CHAR(x) ((signed char) x)
208 #else
209 #define SIGN_EXTEND_CHAR(x) ((x & 0x80) ? ((~0 << 8) | x) : x)
210 #endif
211
212 result = (SIGN_EXTEND_CHAR(codep[0]) << 24) \
213 | (codep[1] & 0xff) << 16 \
214 | (codep[2] & 0xff) << 8
215 | (codep[3] & 0xff);
216 return result;
217 }
218
219 static void
220 settzname P((void))
221 {
222 register struct state * const sp = lclptr;
223 register int i;
224
225 tzname[0] = wildabbr;
226 tzname[1] = wildabbr;
227 #ifdef USG_COMPAT
228 daylight = 0;
229 timezone = 0;
230 #endif /* defined USG_COMPAT */
231 #ifdef ALTZONE
232 altzone = 0;
233 #endif /* defined ALTZONE */
234 #ifdef ALL_STATE
235 if (sp == NULL) {
236 tzname[0] = tzname[1] = gmt;
237 return;
238 }
239 #endif /* defined ALL_STATE */
240 for (i = 0; i < sp->typecnt; ++i) {
241 register const struct ttinfo * const ttisp = &sp->ttis[i];
242
243 tzname[ttisp->tt_isdst] =
244 &sp->chars[ttisp->tt_abbrind];
245 #ifdef USG_COMPAT
246 if (ttisp->tt_isdst)
247 daylight = 1;
248 if (i == 0 || !ttisp->tt_isdst)
249 timezone = -(ttisp->tt_gmtoff);
250 #endif /* defined USG_COMPAT */
251 #ifdef ALTZONE
252 if (i == 0 || ttisp->tt_isdst)
253 altzone = -(ttisp->tt_gmtoff);
254 #endif /* defined ALTZONE */
255 }
256 /*
257 ** And to get the latest zone names into tzname. . .
258 */
259 for (i = 0; i < sp->timecnt; ++i) {
260 register const struct ttinfo * const ttisp =
261 &sp->ttis[
262 sp->types[i]];
263
264 tzname[ttisp->tt_isdst] =
265 &sp->chars[ttisp->tt_abbrind];
266 }
267 }
268
269 static int
270 tzload(name, sp)
271 register const char * name;
272 register struct state * const sp;
273 {
274 register const char * p;
275 register int i;
276 register int fid;
277
278 if (name == NULL && (name = TZDEFAULT) == NULL)
279 return -1;
280 {
281 register int doaccess;
282 /*
283 ** Section 4.9.1 of the C standard says that
284 ** "FILENAME_MAX expands to an integral constant expression
285 ** that is the sie needed for an array of char large enough
286 ** to hold the longest file name string that the implementation
287 ** guarantees can be opened."
288 */
289 char fullname[FILENAME_MAX + 1];
290
291 if (name[0] == ':')
292 ++name;
293 doaccess = name[0] == '/';
294 if (!doaccess) {
295 if ((p = TZDIR) == NULL)
296 return -1;
297 if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
298 return -1;
299 (void) strcpy(fullname, p); /* XXX strcpy is safe */
300 (void) strcat(fullname, "/"); /* XXX strcat is safe */
301 (void) strcat(fullname, name); /* XXX strcat is safe */
302 /*
303 ** Set doaccess if '.' (as in "../") shows up in name.
304 */
305 if (strchr(name, '.') != NULL)
306 doaccess = TRUE;
307 name = fullname;
308 }
309 if (doaccess && access(name, R_OK) != 0)
310 return -1;
311 if ((fid = open(name, OPEN_MODE)) == -1)
312 return -1;
313 }
314 {
315 struct tzhead * tzhp;
316 char buf[sizeof *sp + sizeof *tzhp];
317 int ttisstdcnt;
318 int ttisgmtcnt;
319
320 i = read(fid, buf, sizeof buf);
321 if (close(fid) != 0)
322 return -1;
323 p = buf;
324 p += sizeof tzhp->tzh_reserved;
325 ttisstdcnt = (int) detzcode(p);
326 p += 4;
327 ttisgmtcnt = (int) detzcode(p);
328 p += 4;
329 sp->leapcnt = (int) detzcode(p);
330 p += 4;
331 sp->timecnt = (int) detzcode(p);
332 p += 4;
333 sp->typecnt = (int) detzcode(p);
334 p += 4;
335 sp->charcnt = (int) detzcode(p);
336 p += 4;
337 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
338 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
339 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
340 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
341 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
342 (ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
343 return -1;
344 if (i - (p - buf) < sp->timecnt * 4 + /* ats */
345 sp->timecnt + /* types */
346 sp->typecnt * (4 + 2) + /* ttinfos */
347 sp->charcnt + /* chars */
348 sp->leapcnt * (4 + 4) + /* lsinfos */
349 ttisstdcnt + /* ttisstds */
350 ttisgmtcnt) /* ttisgmts */
351 return -1;
352 for (i = 0; i < sp->timecnt; ++i) {
353 sp->ats[i] = detzcode(p);
354 p += 4;
355 }
356 for (i = 0; i < sp->timecnt; ++i) {
357 sp->types[i] = (unsigned char) *p++;
358 if (sp->types[i] >= sp->typecnt)
359 return -1;
360 }
361 for (i = 0; i < sp->typecnt; ++i) {
362 register struct ttinfo * ttisp;
363
364 ttisp = &sp->ttis[i];
365 ttisp->tt_gmtoff = detzcode(p);
366 p += 4;
367 ttisp->tt_isdst = (unsigned char) *p++;
368 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
369 return -1;
370 ttisp->tt_abbrind = (unsigned char) *p++;
371 if (ttisp->tt_abbrind < 0 ||
372 ttisp->tt_abbrind > sp->charcnt)
373 return -1;
374 }
375 for (i = 0; i < sp->charcnt; ++i)
376 sp->chars[i] = *p++;
377 sp->chars[i] = '\0'; /* ensure '\0' at end */
378 for (i = 0; i < sp->leapcnt; ++i) {
379 register struct lsinfo * lsisp;
380
381 lsisp = &sp->lsis[i];
382 lsisp->ls_trans = detzcode(p);
383 p += 4;
384 lsisp->ls_corr = detzcode(p);
385 p += 4;
386 }
387 for (i = 0; i < sp->typecnt; ++i) {
388 register struct ttinfo * ttisp;
389
390 ttisp = &sp->ttis[i];
391 if (ttisstdcnt == 0)
392 ttisp->tt_ttisstd = FALSE;
393 else {
394 ttisp->tt_ttisstd = *p++;
395 if (ttisp->tt_ttisstd != TRUE &&
396 ttisp->tt_ttisstd != FALSE)
397 return -1;
398 }
399 }
400 for (i = 0; i < sp->typecnt; ++i) {
401 register struct ttinfo * ttisp;
402
403 ttisp = &sp->ttis[i];
404 if (ttisgmtcnt == 0)
405 ttisp->tt_ttisgmt = FALSE;
406 else {
407 ttisp->tt_ttisgmt = *p++;
408 if (ttisp->tt_ttisgmt != TRUE &&
409 ttisp->tt_ttisgmt != FALSE)
410 return -1;
411 }
412 }
413 }
414 return 0;
415 }
416
417 static const int mon_lengths[2][MONSPERYEAR] = {
418 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
419 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
420 };
421
422 static const int year_lengths[2] = {
423 DAYSPERNYEAR, DAYSPERLYEAR
424 };
425
426 /*
427 ** Given a pointer into a time zone string, scan until a character that is not
428 ** a valid character in a zone name is found. Return a pointer to that
429 ** character.
430 */
431
432 static const char *
433 getzname(strp)
434 register const char * strp;
435 {
436 register char c;
437
438 while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
439 c != '+')
440 ++strp;
441 return strp;
442 }
443
444 /*
445 ** Given a pointer into a time zone string, extract a number from that string.
446 ** Check that the number is within a specified range; if it is not, return
447 ** NULL.
448 ** Otherwise, return a pointer to the first character not part of the number.
449 */
450
451 static const char *
452 getnum(strp, nump, min, max)
453 register const char * strp;
454 int * const nump;
455 const int min;
456 const int max;
457 {
458 register char c;
459 register int num;
460
461 if (strp == NULL || !is_digit(c = *strp))
462 return NULL;
463 num = 0;
464 do {
465 num = num * 10 + (c - '0');
466 if (num > max)
467 return NULL; /* illegal value */
468 c = *++strp;
469 } while (is_digit(c));
470 if (num < min)
471 return NULL; /* illegal value */
472 *nump = num;
473 return strp;
474 }
475
476 /*
477 ** Given a pointer into a time zone string, extract a number of seconds,
478 ** in hh[:mm[:ss]] form, from the string.
479 ** If any error occurs, return NULL.
480 ** Otherwise, return a pointer to the first character not part of the number
481 ** of seconds.
482 */
483
484 static const char *
485 getsecs(strp, secsp)
486 register const char * strp;
487 long * const secsp;
488 {
489 int num;
490
491 /*
492 ** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
493 ** "M10.4.6/26", which does not conform to Posix,
494 ** but which specifies the equivalent of
495 ** ``02:00 on the first Sunday on or after 23 Oct''.
496 */
497 strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
498 if (strp == NULL)
499 return NULL;
500 *secsp = num * (long) SECSPERHOUR;
501 if (*strp == ':') {
502 ++strp;
503 strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
504 if (strp == NULL)
505 return NULL;
506 *secsp += num * SECSPERMIN;
507 if (*strp == ':') {
508 ++strp;
509 /* `SECSPERMIN' allows for leap seconds. */
510 strp = getnum(strp, &num, 0, SECSPERMIN);
511 if (strp == NULL)
512 return NULL;
513 *secsp += num;
514 }
515 }
516 return strp;
517 }
518
519 /*
520 ** Given a pointer into a time zone string, extract an offset, in
521 ** [+-]hh[:mm[:ss]] form, from the string.
522 ** If any error occurs, return NULL.
523 ** Otherwise, return a pointer to the first character not part of the time.
524 */
525
526 static const char *
527 getoffset(strp, offsetp)
528 register const char * strp;
529 long * const offsetp;
530 {
531 register int neg = 0;
532
533 if (*strp == '-') {
534 neg = 1;
535 ++strp;
536 } else if (*strp == '+')
537 ++strp;
538 strp = getsecs(strp, offsetp);
539 if (strp == NULL)
540 return NULL; /* illegal time */
541 if (neg)
542 *offsetp = -*offsetp;
543 return strp;
544 }
545
546 /*
547 ** Given a pointer into a time zone string, extract a rule in the form
548 ** date[/time]. See POSIX section 8 for the format of "date" and "time".
549 ** If a valid rule is not found, return NULL.
550 ** Otherwise, return a pointer to the first character not part of the rule.
551 */
552
553 static const char *
554 getrule(strp, rulep)
555 const char * strp;
556 register struct rule * const rulep;
557 {
558 if (*strp == 'J') {
559 /*
560 ** Julian day.
561 */
562 rulep->r_type = JULIAN_DAY;
563 ++strp;
564 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
565 } else if (*strp == 'M') {
566 /*
567 ** Month, week, day.
568 */
569 rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
570 ++strp;
571 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
572 if (strp == NULL)
573 return NULL;
574 if (*strp++ != '.')
575 return NULL;
576 strp = getnum(strp, &rulep->r_week, 1, 5);
577 if (strp == NULL)
578 return NULL;
579 if (*strp++ != '.')
580 return NULL;
581 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
582 } else if (is_digit(*strp)) {
583 /*
584 ** Day of year.
585 */
586 rulep->r_type = DAY_OF_YEAR;
587 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
588 } else return NULL; /* invalid format */
589 if (strp == NULL)
590 return NULL;
591 if (*strp == '/') {
592 /*
593 ** Time specified.
594 */
595 ++strp;
596 strp = getsecs(strp, &rulep->r_time);
597 } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */
598 return strp;
599 }
600
601 /*
602 ** Given the Epoch-relative time of January 1, 00:00:00 GMT, in a year, the
603 ** year, a rule, and the offset from GMT at the time that rule takes effect,
604 ** calculate the Epoch-relative time that rule takes effect.
605 */
606
607 static time_t
608 transtime(janfirst, year, rulep, offset)
609 const time_t janfirst;
610 const int year;
611 register const struct rule * const rulep;
612 const long offset;
613 {
614 register int leapyear;
615 register time_t value;
616 register int i;
617 int d, m1, yy0, yy1, yy2, dow;
618
619 INITIALIZE(value);
620 leapyear = isleap(year);
621 switch (rulep->r_type) {
622
623 case JULIAN_DAY:
624 /*
625 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
626 ** years.
627 ** In non-leap years, or if the day number is 59 or less, just
628 ** add SECSPERDAY times the day number-1 to the time of
629 ** January 1, midnight, to get the day.
630 */
631 value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
632 if (leapyear && rulep->r_day >= 60)
633 value += SECSPERDAY;
634 break;
635
636 case DAY_OF_YEAR:
637 /*
638 ** n - day of year.
639 ** Just add SECSPERDAY times the day number to the time of
640 ** January 1, midnight, to get the day.
641 */
642 value = janfirst + rulep->r_day * SECSPERDAY;
643 break;
644
645 case MONTH_NTH_DAY_OF_WEEK:
646 /*
647 ** Mm.n.d - nth "dth day" of month m.
648 */
649 value = janfirst;
650 for (i = 0; i < rulep->r_mon - 1; ++i)
651 value += mon_lengths[leapyear][i] * SECSPERDAY;
652
653 /*
654 ** Use Zeller's Congruence to get day-of-week of first day of
655 ** month.
656 */
657 m1 = (rulep->r_mon + 9) % 12 + 1;
658 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
659 yy1 = yy0 / 100;
660 yy2 = yy0 % 100;
661 dow = ((26 * m1 - 2) / 10 +
662 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
663 if (dow < 0)
664 dow += DAYSPERWEEK;
665
666 /*
667 ** "dow" is the day-of-week of the first day of the month. Get
668 ** the day-of-month (zero-origin) of the first "dow" day of the
669 ** month.
670 */
671 d = rulep->r_day - dow;
672 if (d < 0)
673 d += DAYSPERWEEK;
674 for (i = 1; i < rulep->r_week; ++i) {
675 if (d + DAYSPERWEEK >=
676 mon_lengths[leapyear][rulep->r_mon - 1])
677 break;
678 d += DAYSPERWEEK;
679 }
680
681 /*
682 ** "d" is the day-of-month (zero-origin) of the day we want.
683 */
684 value += d * SECSPERDAY;
685 break;
686 }
687
688 /*
689 ** "value" is the Epoch-relative time of 00:00:00 GMT on the day in
690 ** question. To get the Epoch-relative time of the specified local
691 ** time on that day, add the transition time and the current offset
692 ** from GMT.
693 */
694 return value + rulep->r_time + offset;
695 }
696
697 /*
698 ** Given a POSIX section 8-style TZ string, fill in the rule tables as
699 ** appropriate.
700 */
701
702 static int
703 tzparse(name, sp, lastditch)
704 const char * name;
705 register struct state * const sp;
706 const int lastditch;
707 {
708 const char * stdname;
709 const char * dstname;
710 size_t stdlen;
711 size_t dstlen;
712 long stdoffset;
713 long dstoffset;
714 register time_t * atp;
715 register unsigned char * typep;
716 register char * cp;
717 register int load_result;
718
719 INITIALIZE(dstname);
720 stdname = name;
721 if (lastditch) {
722 stdlen = strlen(name); /* length of standard zone name */
723 name += stdlen;
724 if (stdlen >= sizeof sp->chars)
725 stdlen = (sizeof sp->chars) - 1;
726 } else {
727 name = getzname(name);
728 stdlen = name - stdname;
729 if (stdlen < 3)
730 return -1;
731 }
732 if (*name == '\0')
733 return -1; /* was "stdoffset = 0;" */
734 else {
735 name = getoffset(name, &stdoffset);
736 if (name == NULL)
737 return -1;
738 }
739 load_result = tzload(TZDEFRULES, sp);
740 if (load_result != 0)
741 sp->leapcnt = 0; /* so, we're off a little */
742 if (*name != '\0') {
743 dstname = name;
744 name = getzname(name);
745 dstlen = name - dstname; /* length of DST zone name */
746 if (dstlen < 3)
747 return -1;
748 if (*name != '\0' && *name != ',' && *name != ';') {
749 name = getoffset(name, &dstoffset);
750 if (name == NULL)
751 return -1;
752 } else dstoffset = stdoffset - SECSPERHOUR;
753 if (*name == ',' || *name == ';') {
754 struct rule start;
755 struct rule end;
756 register int year;
757 register time_t janfirst;
758 time_t starttime;
759 time_t endtime;
760
761 ++name;
762 if ((name = getrule(name, &start)) == NULL)
763 return -1;
764 if (*name++ != ',')
765 return -1;
766 if ((name = getrule(name, &end)) == NULL)
767 return -1;
768 if (*name != '\0')
769 return -1;
770 sp->typecnt = 2; /* standard time and DST */
771 /*
772 ** Two transitions per year, from EPOCH_YEAR to 2037.
773 */
774 sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1);
775 if (sp->timecnt > TZ_MAX_TIMES)
776 return -1;
777 sp->ttis[0].tt_gmtoff = -dstoffset;
778 sp->ttis[0].tt_isdst = 1;
779 sp->ttis[0].tt_abbrind = stdlen + 1;
780 sp->ttis[1].tt_gmtoff = -stdoffset;
781 sp->ttis[1].tt_isdst = 0;
782 sp->ttis[1].tt_abbrind = 0;
783 atp = sp->ats;
784 typep = sp->types;
785 janfirst = 0;
786 for (year = EPOCH_YEAR; year <= 2037; ++year) {
787 starttime = transtime(janfirst, year, &start,
788 stdoffset);
789 endtime = transtime(janfirst, year, &end,
790 dstoffset);
791 if (starttime > endtime) {
792 *atp++ = endtime;
793 *typep++ = 1; /* DST ends */
794 *atp++ = starttime;
795 *typep++ = 0; /* DST begins */
796 } else {
797 *atp++ = starttime;
798 *typep++ = 0; /* DST begins */
799 *atp++ = endtime;
800 *typep++ = 1; /* DST ends */
801 }
802 janfirst += year_lengths[isleap(year)] *
803 SECSPERDAY;
804 }
805 } else {
806 register long theirstdoffset;
807 register long theirdstoffset;
808 register long theiroffset;
809 register int isdst;
810 register int i;
811 register int j;
812
813 if (*name != '\0')
814 return -1;
815 if (load_result != 0)
816 return -1;
817 /*
818 ** Initial values of theirstdoffset and theirdstoffset.
819 */
820 theirstdoffset = 0;
821 for (i = 0; i < sp->timecnt; ++i) {
822 j = sp->types[i];
823 if (!sp->ttis[j].tt_isdst) {
824 theirstdoffset =
825 -sp->ttis[j].tt_gmtoff;
826 break;
827 }
828 }
829 theirdstoffset = 0;
830 for (i = 0; i < sp->timecnt; ++i) {
831 j = sp->types[i];
832 if (sp->ttis[j].tt_isdst) {
833 theirdstoffset =
834 -sp->ttis[j].tt_gmtoff;
835 break;
836 }
837 }
838 /*
839 ** Initially we're assumed to be in standard time.
840 */
841 isdst = FALSE;
842 theiroffset = theirstdoffset;
843 /*
844 ** Now juggle transition times and types
845 ** tracking offsets as you do.
846 */
847 for (i = 0; i < sp->timecnt; ++i) {
848 j = sp->types[i];
849 sp->types[i] = sp->ttis[j].tt_isdst;
850 if (sp->ttis[j].tt_ttisgmt) {
851 /* No adjustment to transition time */
852 } else {
853 /*
854 ** If summer time is in effect, and the
855 ** transition time was not specified as
856 ** standard time, add the summer time
857 ** offset to the transition time;
858 ** otherwise, add the standard time
859 ** offset to the transition time.
860 */
861 /*
862 ** Transitions from DST to DDST
863 ** will effectively disappear since
864 ** POSIX provides for only one DST
865 ** offset.
866 */
867 if (isdst && !sp->ttis[j].tt_ttisstd) {
868 sp->ats[i] += dstoffset -
869 theirdstoffset;
870 } else {
871 sp->ats[i] += stdoffset -
872 theirstdoffset;
873 }
874 }
875 theiroffset = -sp->ttis[j].tt_gmtoff;
876 if (sp->ttis[j].tt_isdst)
877 theirdstoffset = theiroffset;
878 else theirstdoffset = theiroffset;
879 }
880 /*
881 ** Finally, fill in ttis.
882 ** ttisstd and ttisgmt need not be handled.
883 */
884 sp->ttis[0].tt_gmtoff = -stdoffset;
885 sp->ttis[0].tt_isdst = FALSE;
886 sp->ttis[0].tt_abbrind = 0;
887 sp->ttis[1].tt_gmtoff = -dstoffset;
888 sp->ttis[1].tt_isdst = TRUE;
889 sp->ttis[1].tt_abbrind = stdlen + 1;
890 sp->typecnt = 2;
891 }
892 } else {
893 dstlen = 0;
894 sp->typecnt = 1; /* only standard time */
895 sp->timecnt = 0;
896 sp->ttis[0].tt_gmtoff = -stdoffset;
897 sp->ttis[0].tt_isdst = 0;
898 sp->ttis[0].tt_abbrind = 0;
899 }
900 sp->charcnt = stdlen + 1;
901 if (dstlen != 0)
902 sp->charcnt += dstlen + 1;
903 if (sp->charcnt > sizeof sp->chars)
904 return -1;
905 cp = sp->chars;
906 (void) strncpy(cp, stdname, stdlen);
907 cp += stdlen;
908 *cp++ = '\0';
909 if (dstlen != 0) {
910 (void) strncpy(cp, dstname, dstlen);
911 *(cp + dstlen) = '\0';
912 }
913 return 0;
914 }
915
916 static void
917 gmtload(sp)
918 struct state * const sp;
919 {
920 if (tzload(gmt, sp) != 0)
921 (void) tzparse(gmt, sp, TRUE);
922 }
923
924 #ifndef STD_INSPIRED
925 /*
926 ** A non-static declaration of tzsetwall in a system header file
927 ** may cause a warning about this upcoming static declaration...
928 */
929 static
930 #endif /* !defined STD_INSPIRED */
931 void
932 tzsetwall P((void))
933 {
934 if (lcl_is_set < 0)
935 return;
936 lcl_is_set = -1;
937
938 #ifdef ALL_STATE
939 if (lclptr == NULL) {
940 lclptr = (struct state *) malloc(sizeof *lclptr);
941 if (lclptr == NULL) {
942 settzname(); /* all we can do */
943 return;
944 }
945 }
946 #endif /* defined ALL_STATE */
947 if (tzload((char *) NULL, lclptr) != 0)
948 gmtload(lclptr);
949 settzname();
950 }
951
952 void
953 tzset P((void))
954 {
955 register const char * name;
956
957 name = getenv("TZ");
958 if (name == NULL) {
959 tzsetwall();
960 return;
961 }
962
963 if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0)
964 return;
965 lcl_is_set = (strlen(name) < sizeof(lcl_TZname));
966 if (lcl_is_set)
967 (void)strncpy(lcl_TZname, name, sizeof(lcl_TZname) - 1);
968
969 #ifdef ALL_STATE
970 if (lclptr == NULL) {
971 lclptr = (struct state *) malloc(sizeof *lclptr);
972 if (lclptr == NULL) {
973 settzname(); /* all we can do */
974 return;
975 }
976 }
977 #endif /* defined ALL_STATE */
978 if (*name == '\0') {
979 /*
980 ** User wants it fast rather than right.
981 */
982 lclptr->leapcnt = 0; /* so, we're off a little */
983 lclptr->timecnt = 0;
984 lclptr->ttis[0].tt_gmtoff = 0;
985 lclptr->ttis[0].tt_abbrind = 0;
986 (void)strncpy(lclptr->chars, gmt, sizeof(lclptr->chars) - 1);
987 } else if (tzload(name, lclptr) != 0)
988 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0)
989 (void) gmtload(lclptr);
990 settzname();
991 }
992
993 /*
994 ** The easy way to behave "as if no library function calls" localtime
995 ** is to not call it--so we drop its guts into "localsub", which can be
996 ** freely called. (And no, the PANS doesn't require the above behavior--
997 ** but it *is* desirable.)
998 **
999 ** The unused offset argument is for the benefit of mktime variants.
1000 */
1001
1002 /*ARGSUSED*/
1003 static void
1004 localsub(timep, offset, tmp)
1005 const time_t * const timep;
1006 const long offset;
1007 struct tm * const tmp;
1008 {
1009 register struct state * sp;
1010 register const struct ttinfo * ttisp;
1011 register int i;
1012 const time_t t = *timep;
1013
1014 sp = lclptr;
1015 #ifdef ALL_STATE
1016 if (sp == NULL) {
1017 gmtsub(timep, offset, tmp);
1018 return;
1019 }
1020 #endif /* defined ALL_STATE */
1021 if (sp->timecnt == 0 || t < sp->ats[0]) {
1022 i = 0;
1023 while (sp->ttis[i].tt_isdst)
1024 if (++i >= sp->typecnt) {
1025 i = 0;
1026 break;
1027 }
1028 } else {
1029 for (i = 1; i < sp->timecnt; ++i)
1030 if (t < sp->ats[i])
1031 break;
1032 i = sp->types[i - 1];
1033 }
1034 ttisp = &sp->ttis[i];
1035 /*
1036 ** To get (wrong) behavior that's compatible with System V Release 2.0
1037 ** you'd replace the statement below with
1038 ** t += ttisp->tt_gmtoff;
1039 ** timesub(&t, 0L, sp, tmp);
1040 */
1041 timesub(&t, ttisp->tt_gmtoff, sp, tmp);
1042 tmp->tm_isdst = ttisp->tt_isdst;
1043 tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
1044 #ifdef TM_ZONE
1045 tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
1046 #endif /* defined TM_ZONE */
1047 }
1048
1049 struct tm *
1050 localtime(timep)
1051 const time_t * const timep;
1052 {
1053 tzset();
1054 localsub(timep, 0L, &tm);
1055 return &tm;
1056 }
1057
1058 /*
1059 ** gmtsub is to gmtime as localsub is to localtime.
1060 */
1061
1062 static void
1063 gmtsub(timep, offset, tmp)
1064 const time_t * const timep;
1065 const long offset;
1066 struct tm * const tmp;
1067 {
1068 if (!gmt_is_set) {
1069 gmt_is_set = TRUE;
1070 #ifdef ALL_STATE
1071 gmtptr = (struct state *) malloc(sizeof *gmtptr);
1072 if (gmtptr != NULL)
1073 #endif /* defined ALL_STATE */
1074 gmtload(gmtptr);
1075 }
1076 timesub(timep, offset, gmtptr, tmp);
1077 #ifdef TM_ZONE
1078 /*
1079 ** Could get fancy here and deliver something such as
1080 ** "GMT+xxxx" or "GMT-xxxx" if offset is non-zero,
1081 ** but this is no time for a treasure hunt.
1082 */
1083 if (offset != 0)
1084 tmp->TM_ZONE = wildabbr;
1085 else {
1086 #ifdef ALL_STATE
1087 if (gmtptr == NULL)
1088 tmp->TM_ZONE = gmt;
1089 else tmp->TM_ZONE = gmtptr->chars;
1090 #endif /* defined ALL_STATE */
1091 #ifndef ALL_STATE
1092 tmp->TM_ZONE = gmtptr->chars;
1093 #endif /* State Farm */
1094 }
1095 #endif /* defined TM_ZONE */
1096 }
1097
1098 struct tm *
1099 gmtime(timep)
1100 const time_t * const timep;
1101 {
1102 gmtsub(timep, 0L, &tm);
1103 return &tm;
1104 }
1105
1106 #ifdef STD_INSPIRED
1107
1108 struct tm *
1109 offtime(timep, offset)
1110 const time_t * const timep;
1111 const long offset;
1112 {
1113 gmtsub(timep, offset, &tm);
1114 return &tm;
1115 }
1116
1117 #endif /* defined STD_INSPIRED */
1118
1119 static void
1120 timesub(timep, offset, sp, tmp)
1121 const time_t * const timep;
1122 const long offset;
1123 register const struct state * const sp;
1124 register struct tm * const tmp;
1125 {
1126 register const struct lsinfo * lp;
1127 register long days;
1128 register long rem;
1129 register int y;
1130 register int yleap;
1131 register const int * ip;
1132 register long corr;
1133 register int hit;
1134 register int i;
1135
1136 corr = 0;
1137 hit = 0;
1138 #ifdef ALL_STATE
1139 i = (sp == NULL) ? 0 : sp->leapcnt;
1140 #endif /* defined ALL_STATE */
1141 #ifndef ALL_STATE
1142 i = sp->leapcnt;
1143 #endif /* State Farm */
1144 while (--i >= 0) {
1145 lp = &sp->lsis[i];
1146 if (*timep >= lp->ls_trans) {
1147 if (*timep == lp->ls_trans) {
1148 hit = ((i == 0 && lp->ls_corr > 0) ||
1149 lp->ls_corr > sp->lsis[i - 1].ls_corr);
1150 if (hit)
1151 while (i > 0 &&
1152 sp->lsis[i].ls_trans ==
1153 sp->lsis[i - 1].ls_trans + 1 &&
1154 sp->lsis[i].ls_corr ==
1155 sp->lsis[i - 1].ls_corr + 1) {
1156 ++hit;
1157 --i;
1158 }
1159 }
1160 corr = lp->ls_corr;
1161 break;
1162 }
1163 }
1164 days = *timep / SECSPERDAY;
1165 rem = *timep % SECSPERDAY;
1166 #ifdef mc68k
1167 if (*timep == 0x80000000) {
1168 /*
1169 ** A 3B1 muffs the division on the most negative number.
1170 */
1171 days = -24855;
1172 rem = -11648;
1173 }
1174 #endif /* defined mc68k */
1175 rem += (offset - corr);
1176 while (rem < 0) {
1177 rem += SECSPERDAY;
1178 --days;
1179 }
1180 while (rem >= SECSPERDAY) {
1181 rem -= SECSPERDAY;
1182 ++days;
1183 }
1184 tmp->tm_hour = (int) (rem / SECSPERHOUR);
1185 rem = rem % SECSPERHOUR;
1186 tmp->tm_min = (int) (rem / SECSPERMIN);
1187 /*
1188 ** A positive leap second requires a special
1189 ** representation. This uses "... ??:59:60" et seq.
1190 */
1191 tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
1192 tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);
1193 if (tmp->tm_wday < 0)
1194 tmp->tm_wday += DAYSPERWEEK;
1195 y = EPOCH_YEAR;
1196 #define LEAPS_THRU_END_OF(y) ((y) / 4 - (y) / 100 + (y) / 400)
1197 while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
1198 register int newy;
1199
1200 newy = y + days / DAYSPERNYEAR;
1201 if (days < 0)
1202 --newy;
1203 days -= (newy - y) * DAYSPERNYEAR +
1204 LEAPS_THRU_END_OF(newy - 1) -
1205 LEAPS_THRU_END_OF(y - 1);
1206 y = newy;
1207 }
1208 tmp->tm_year = y - TM_YEAR_BASE;
1209 tmp->tm_yday = (int) days;
1210 ip = mon_lengths[yleap];
1211 for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
1212 days = days - (long) ip[tmp->tm_mon];
1213 tmp->tm_mday = (int) (days + 1);
1214 tmp->tm_isdst = 0;
1215 #ifdef TM_GMTOFF
1216 tmp->TM_GMTOFF = offset;
1217 #endif /* defined TM_GMTOFF */
1218 }
1219
1220 char *
1221 ctime(timep)
1222 const time_t * const timep;
1223 {
1224 /*
1225 ** Section 4.12.3.2 of X3.159-1989 requires that
1226 ** The ctime funciton converts the calendar time pointed to by timer
1227 ** to local time in the form of a string. It is equivalent to
1228 ** asctime(localtime(timer))
1229 */
1230 return asctime(localtime(timep));
1231 }
1232
1233 /*
1234 ** Adapted from code provided by Robert Elz, who writes:
1235 ** The "best" way to do mktime I think is based on an idea of Bob
1236 ** Kridle's (so its said...) from a long time ago.
1237 ** [kridle (at) xinet.com as of 1996-01-16.]
1238 ** It does a binary search of the time_t space. Since time_t's are
1239 ** just 32 bits, its a max of 32 iterations (even at 64 bits it
1240 ** would still be very reasonable).
1241 */
1242
1243 #ifndef WRONG
1244 #define WRONG (-1)
1245 #endif /* !defined WRONG */
1246
1247 /*
1248 ** Simplified normalize logic courtesy Paul Eggert (eggert (at) twinsun.com).
1249 */
1250
1251 static int
1252 increment_overflow(number, delta)
1253 int * number;
1254 int delta;
1255 {
1256 int number0;
1257
1258 number0 = *number;
1259 *number += delta;
1260 return (*number < number0) != (delta < 0);
1261 }
1262
1263 static int
1264 normalize_overflow(tensptr, unitsptr, base)
1265 int * const tensptr;
1266 int * const unitsptr;
1267 const int base;
1268 {
1269 register int tensdelta;
1270
1271 tensdelta = (*unitsptr >= 0) ?
1272 (*unitsptr / base) :
1273 (-1 - (-1 - *unitsptr) / base);
1274 *unitsptr -= tensdelta * base;
1275 return increment_overflow(tensptr, tensdelta);
1276 }
1277
1278 static int
1279 tmcomp(atmp, btmp)
1280 register const struct tm * const atmp;
1281 register const struct tm * const btmp;
1282 {
1283 register int result;
1284
1285 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
1286 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
1287 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
1288 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
1289 (result = (atmp->tm_min - btmp->tm_min)) == 0)
1290 result = atmp->tm_sec - btmp->tm_sec;
1291 return result;
1292 }
1293
1294 static time_t
1295 time2(tmp, funcp, offset, okayp)
1296 struct tm * const tmp;
1297 void (* const funcp) P((const time_t*, long, struct tm*));
1298 const long offset;
1299 int * const okayp;
1300 {
1301 register const struct state * sp;
1302 register int dir;
1303 register int bits;
1304 register int i, j ;
1305 register int saved_seconds;
1306 time_t newt;
1307 time_t t;
1308 struct tm yourtm, mytm;
1309
1310 *okayp = FALSE;
1311 yourtm = *tmp;
1312 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
1313 return WRONG;
1314 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
1315 return WRONG;
1316 if (normalize_overflow(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR))
1317 return WRONG;
1318 /*
1319 ** Turn yourtm.tm_year into an actual year number for now.
1320 ** It is converted back to an offset from TM_YEAR_BASE later.
1321 */
1322 if (increment_overflow(&yourtm.tm_year, TM_YEAR_BASE))
1323 return WRONG;
1324 while (yourtm.tm_mday <= 0) {
1325 if (increment_overflow(&yourtm.tm_year, -1))
1326 return WRONG;
1327 i = yourtm.tm_year + (1 < yourtm.tm_mon);
1328 yourtm.tm_mday += year_lengths[isleap(i)];
1329 }
1330 while (yourtm.tm_mday > DAYSPERLYEAR) {
1331 i = yourtm.tm_year + (1 < yourtm.tm_mon);
1332 yourtm.tm_mday -= year_lengths[isleap(i)];
1333 if (increment_overflow(&yourtm.tm_year, 1))
1334 return WRONG;
1335 }
1336 for ( ; ; ) {
1337 i = mon_lengths[isleap(yourtm.tm_year)][yourtm.tm_mon];
1338 if (yourtm.tm_mday <= i)
1339 break;
1340 yourtm.tm_mday -= i;
1341 if (++yourtm.tm_mon >= MONSPERYEAR) {
1342 yourtm.tm_mon = 0;
1343 if (increment_overflow(&yourtm.tm_year, 1))
1344 return WRONG;
1345 }
1346 }
1347 if (increment_overflow(&yourtm.tm_year, -TM_YEAR_BASE))
1348 return WRONG;
1349 if (yourtm.tm_year + TM_YEAR_BASE < EPOCH_YEAR) {
1350 /*
1351 ** We can't set tm_sec to 0, because that might push the
1352 ** time below the minimum representable time.
1353 ** Set tm_sec to 59 instead.
1354 ** This assumes that the minimum representable time is
1355 ** not in the same minute that a leap second was deleted from,
1356 ** which is a safer assumption than using 58 would be.
1357 */
1358 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
1359 return WRONG;
1360 saved_seconds = yourtm.tm_sec;
1361 yourtm.tm_sec = SECSPERMIN - 1;
1362 } else {
1363 saved_seconds = yourtm.tm_sec;
1364 yourtm.tm_sec = 0;
1365 }
1366 /*
1367 ** Divide the search space in half
1368 ** (this works whether time_t is signed or unsigned).
1369 */
1370 bits = TYPE_BIT(time_t) - 1;
1371 /*
1372 ** If time_t is signed, then 0 is just above the median,
1373 ** assuming two's complement arithmetic.
1374 ** If time_t is unsigned, then (1 << bits) is just above the median.
1375 */
1376 t = TYPE_SIGNED(time_t) ? 0 : (((time_t) 1) << bits);
1377 for ( ; ; ) {
1378 (*funcp)(&t, offset, &mytm);
1379 dir = tmcomp(&mytm, &yourtm);
1380 if (dir != 0) {
1381 if (bits-- < 0)
1382 return WRONG;
1383 if (bits < 0)
1384 --t; /* may be needed if new t is minimal */
1385 else if (dir > 0)
1386 t -= ((time_t) 1) << bits;
1387 else t += ((time_t) 1) << bits;
1388 continue;
1389 }
1390 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
1391 break;
1392 /*
1393 ** Right time, wrong type.
1394 ** Hunt for right time, right type.
1395 ** It's okay to guess wrong since the guess
1396 ** gets checked.
1397 */
1398 /*
1399 ** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
1400 */
1401 sp = (const struct state *)
1402 (((void *) funcp == (void *) localsub) ?
1403 lclptr : gmtptr);
1404 #ifdef ALL_STATE
1405 if (sp == NULL)
1406 return WRONG;
1407 #endif /* defined ALL_STATE */
1408 for (i = sp->typecnt - 1; i >= 0; --i) {
1409 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
1410 continue;
1411 for (j = sp->typecnt - 1; j >= 0; --j) {
1412 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
1413 continue;
1414 newt = t + sp->ttis[j].tt_gmtoff -
1415 sp->ttis[i].tt_gmtoff;
1416 (*funcp)(&newt, offset, &mytm);
1417 if (tmcomp(&mytm, &yourtm) != 0)
1418 continue;
1419 if (mytm.tm_isdst != yourtm.tm_isdst)
1420 continue;
1421 /*
1422 ** We have a match.
1423 */
1424 t = newt;
1425 goto label;
1426 }
1427 }
1428 return WRONG;
1429 }
1430 label:
1431 newt = t + saved_seconds;
1432 if ((newt < t) != (saved_seconds < 0))
1433 return WRONG;
1434 t = newt;
1435 (*funcp)(&t, offset, tmp);
1436 *okayp = TRUE;
1437 return t;
1438 }
1439
1440 static time_t
1441 time1(tmp, funcp, offset)
1442 struct tm * const tmp;
1443 void (* const funcp) P((const time_t *, long, struct tm *));
1444 const long offset;
1445 {
1446 register time_t t;
1447 register const struct state * sp;
1448 register int samei, otheri;
1449 int okay;
1450
1451 if (tmp->tm_isdst > 1)
1452 tmp->tm_isdst = 1;
1453 t = time2(tmp, funcp, offset, &okay);
1454 #ifdef PCTS
1455 /*
1456 ** PCTS code courtesy Grant Sullivan (grant (at) osf.org).
1457 */
1458 if (okay)
1459 return t;
1460 if (tmp->tm_isdst < 0)
1461 tmp->tm_isdst = 0; /* reset to std and try again */
1462 #endif /* defined PCTS */
1463 #ifndef PCTS
1464 if (okay || tmp->tm_isdst < 0)
1465 return t;
1466 #endif /* !defined PCTS */
1467 /*
1468 ** We're supposed to assume that somebody took a time of one type
1469 ** and did some math on it that yielded a "struct tm" that's bad.
1470 ** We try to divine the type they started from and adjust to the
1471 ** type they need.
1472 */
1473 /*
1474 ** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
1475 */
1476 sp = (const struct state *) (((void *) funcp == (void *) localsub) ?
1477 lclptr : gmtptr);
1478 #ifdef ALL_STATE
1479 if (sp == NULL)
1480 return WRONG;
1481 #endif /* defined ALL_STATE */
1482 for (samei = sp->typecnt - 1; samei >= 0; --samei) {
1483 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
1484 continue;
1485 for (otheri = sp->typecnt - 1; otheri >= 0; --otheri) {
1486 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
1487 continue;
1488 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
1489 sp->ttis[samei].tt_gmtoff;
1490 tmp->tm_isdst = !tmp->tm_isdst;
1491 t = time2(tmp, funcp, offset, &okay);
1492 if (okay)
1493 return t;
1494 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
1495 sp->ttis[samei].tt_gmtoff;
1496 tmp->tm_isdst = !tmp->tm_isdst;
1497 }
1498 }
1499 return WRONG;
1500 }
1501
1502 time_t
1503 mktime(tmp)
1504 struct tm * const tmp;
1505 {
1506 tzset();
1507 return time1(tmp, localsub, 0L);
1508 }
1509
1510 #ifdef STD_INSPIRED
1511
1512 time_t
1513 timelocal(tmp)
1514 struct tm * const tmp;
1515 {
1516 tmp->tm_isdst = -1; /* in case it wasn't initialized */
1517 return mktime(tmp);
1518 }
1519
1520 time_t
1521 timegm(tmp)
1522 struct tm * const tmp;
1523 {
1524 tmp->tm_isdst = 0;
1525 return time1(tmp, gmtsub, 0L);
1526 }
1527
1528 time_t
1529 timeoff(tmp, offset)
1530 struct tm * const tmp;
1531 const long offset;
1532 {
1533 tmp->tm_isdst = 0;
1534 return time1(tmp, gmtsub, offset);
1535 }
1536
1537 #endif /* defined STD_INSPIRED */
1538
1539 #ifdef CMUCS
1540
1541 /*
1542 ** The following is supplied for compatibility with
1543 ** previous versions of the CMUCS runtime library.
1544 */
1545
1546 long
1547 gtime(tmp)
1548 struct tm * const tmp;
1549 {
1550 const time_t t = mktime(tmp);
1551
1552 if (t == WRONG)
1553 return -1;
1554 return t;
1555 }
1556
1557 #endif /* defined CMUCS */
1558
1559 /*
1560 ** XXX--is the below the right way to conditionalize??
1561 */
1562
1563 #ifdef STD_INSPIRED
1564
1565 /*
1566 ** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
1567 ** shall correspond to "Wed Dec 31 23:59:59 GMT 1986", which
1568 ** is not the case if we are accounting for leap seconds.
1569 ** So, we provide the following conversion routines for use
1570 ** when exchanging timestamps with POSIX conforming systems.
1571 */
1572
1573 static long
1574 leapcorr(timep)
1575 time_t * timep;
1576 {
1577 register struct state * sp;
1578 register struct lsinfo * lp;
1579 register int i;
1580
1581 sp = lclptr;
1582 i = sp->leapcnt;
1583 while (--i >= 0) {
1584 lp = &sp->lsis[i];
1585 if (*timep >= lp->ls_trans)
1586 return lp->ls_corr;
1587 }
1588 return 0;
1589 }
1590
1591 time_t
1592 time2posix(t)
1593 time_t t;
1594 {
1595 tzset();
1596 return t - leapcorr(&t);
1597 }
1598
1599 time_t
1600 posix2time(t)
1601 time_t t;
1602 {
1603 time_t x;
1604 time_t y;
1605
1606 tzset();
1607 /*
1608 ** For a positive leap second hit, the result
1609 ** is not unique. For a negative leap second
1610 ** hit, the corresponding time doesn't exist,
1611 ** so we return an adjacent second.
1612 */
1613 x = t + leapcorr(&t);
1614 y = x - leapcorr(&x);
1615 if (y < t) {
1616 do {
1617 x++;
1618 y = x - leapcorr(&x);
1619 } while (y < t);
1620 if (t != y)
1621 return x - 1;
1622 } else if (y > t) {
1623 do {
1624 --x;
1625 y = x - leapcorr(&x);
1626 } while (y > t);
1627 if (t != y)
1628 return x + 1;
1629 }
1630 return x;
1631 }
1632
1633 #endif /* defined STD_INSPIRED */
1634