localtime.c revision 2713
1#ifndef lint 2#ifndef NOID 3static char elsieid[] = "@(#)localtime.c 7.19"; 4#endif /* !defined NOID */ 5#endif /* !defined lint */ 6 7/* 8** Leap second handling from Bradley White (bww@k.gp.cs.cmu.edu). 9** POSIX-style TZ environment variable handling from Guy Harris 10** (guy@auspex.com). 11*/ 12 13/*LINTLIBRARY*/ 14 15#include "private.h" 16#include "tzfile.h" 17#include "fcntl.h" 18 19#define ACCESS_MODE O_RDONLY 20 21#ifdef O_BINARY 22#define OPEN_MODE (O_RDONLY | O_BINARY) 23#endif /* defined O_BINARY */ 24#ifndef O_BINARY 25#define OPEN_MODE O_RDONLY 26#endif /* !defined O_BINARY */ 27 28#ifndef WILDABBR 29/* 30** Someone might make incorrect use of a time zone abbreviation: 31** 1. They might reference tzname[0] before calling tzset (explicitly 32** or implicitly). 33** 2. They might reference tzname[1] before calling tzset (explicitly 34** or implicitly). 35** 3. They might reference tzname[1] after setting to a time zone 36** in which Daylight Saving Time is never observed. 37** 4. They might reference tzname[0] after setting to a time zone 38** in which Standard Time is never observed. 39** 5. They might reference tm.TM_ZONE after calling offtime. 40** What's best to do in the above cases is open to debate; 41** for now, we just set things up so that in any of the five cases 42** WILDABBR is used. Another possibility: initialize tzname[0] to the 43** string "tzname[0] used before set", and similarly for the other cases. 44** And another: initialize tzname[0] to "ERA", with an explanation in the 45** manual page of what this "time zone abbreviation" means (doing this so 46** that tzname[0] has the "normal" length of three characters). 47*/ 48#define WILDABBR " " 49#endif /* !defined WILDABBR */ 50 51static const char GMT[] = "GMT"; 52 53struct ttinfo { /* time type information */ 54 long tt_gmtoff; /* GMT offset in seconds */ 55 int tt_isdst; /* used to set tm_isdst */ 56 int tt_abbrind; /* abbreviation list index */ 57 int tt_ttisstd; /* TRUE if transition is std time */ 58}; 59 60struct lsinfo { /* leap second information */ 61 time_t ls_trans; /* transition time */ 62 long ls_corr; /* correction to apply */ 63}; 64 65#define BIGGEST(a, b) (((a) > (b)) ? (a) : (b)) 66 67#ifdef TZNAME_MAX 68#define MY_TZNAME_MAX TZNAME_MAX 69#endif /* defined TZNAME_MAX */ 70#ifndef TZNAME_MAX 71#define MY_TZNAME_MAX 255 72#endif /* !defined TZNAME_MAX */ 73 74struct state { 75 int leapcnt; 76 int timecnt; 77 int typecnt; 78 int charcnt; 79 time_t ats[TZ_MAX_TIMES]; 80 unsigned char types[TZ_MAX_TIMES]; 81 struct ttinfo ttis[TZ_MAX_TYPES]; 82 char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof GMT), 83 (2 * (MY_TZNAME_MAX + 1)))]; 84 struct lsinfo lsis[TZ_MAX_LEAPS]; 85}; 86 87struct rule { 88 int r_type; /* type of rule--see below */ 89 int r_day; /* day number of rule */ 90 int r_week; /* week number of rule */ 91 int r_mon; /* month number of rule */ 92 long r_time; /* transition time of rule */ 93}; 94 95#define JULIAN_DAY 0 /* Jn - Julian day */ 96#define DAY_OF_YEAR 1 /* n - day of year */ 97#define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */ 98 99/* 100** Prototypes for static functions. 101*/ 102 103static long detzcode P((const char * codep)); 104static const char * getzname P((const char * strp)); 105static const char * getnum P((const char * strp, int * nump, int min, 106 int max)); 107static const char * getsecs P((const char * strp, long * secsp)); 108static const char * getoffset P((const char * strp, long * offsetp)); 109static const char * getrule P((const char * strp, struct rule * rulep)); 110static void gmtload P((struct state * sp)); 111static void gmtsub P((const time_t * timep, long offset, 112 struct tm * tmp)); 113static void localsub P((const time_t * timep, long offset, 114 struct tm * tmp)); 115static int increment_overflow P((int * number, int delta)); 116static int normalize_overflow P((int * tensptr, int * unitsptr, 117 int base)); 118static void settzname P((void)); 119static time_t time1 P((struct tm * tmp, void (* funcp)(), 120 long offset)); 121static time_t time2 P((struct tm *tmp, void (* funcp)(), 122 long offset, int * okayp)); 123static void timesub P((const time_t * timep, long offset, 124 const struct state * sp, struct tm * tmp)); 125static int tmcomp P((const struct tm * atmp, 126 const struct tm * btmp)); 127static time_t transtime P((time_t janfirst, int year, 128 const struct rule * rulep, long offset)); 129static int tzload P((const char * name, struct state * sp)); 130static int tzparse P((const char * name, struct state * sp, 131 int lastditch)); 132 133#ifdef ALL_STATE 134static struct state * lclptr; 135static struct state * gmtptr; 136#endif /* defined ALL_STATE */ 137 138#ifndef ALL_STATE 139static struct state lclmem; 140static struct state gmtmem; 141#define lclptr (&lclmem) 142#define gmtptr (&gmtmem) 143#endif /* State Farm */ 144 145static int lcl_is_set; 146static int gmt_is_set; 147 148char * tzname[2] = { 149 WILDABBR, 150 WILDABBR 151}; 152 153#ifdef USG_COMPAT 154time_t timezone = 0; 155int daylight = 0; 156#endif /* defined USG_COMPAT */ 157 158#ifdef ALTZONE 159time_t altzone = 0; 160#endif /* defined ALTZONE */ 161 162static long 163detzcode(codep) 164const char * const codep; 165{ 166 register long result; 167 register int i; 168 169 result = 0; 170 for (i = 0; i < 4; ++i) 171 result = (result << 8) | (codep[i] & 0xff); 172 return result; 173} 174 175static void 176settzname() 177{ 178 register const struct state * const sp = lclptr; 179 register int i; 180 181 tzname[0] = WILDABBR; 182 tzname[1] = WILDABBR; 183#ifdef USG_COMPAT 184 daylight = 0; 185 timezone = 0; 186#endif /* defined USG_COMPAT */ 187#ifdef ALTZONE 188 altzone = 0; 189#endif /* defined ALTZONE */ 190#ifdef ALL_STATE 191 if (sp == NULL) { 192 tzname[0] = tzname[1] = GMT; 193 return; 194 } 195#endif /* defined ALL_STATE */ 196 for (i = 0; i < sp->typecnt; ++i) { 197 register const struct ttinfo * const ttisp = &sp->ttis[i]; 198 199 tzname[ttisp->tt_isdst] = 200 (char *) &sp->chars[ttisp->tt_abbrind]; 201#ifdef USG_COMPAT 202 if (ttisp->tt_isdst) 203 daylight = 1; 204 if (i == 0 || !ttisp->tt_isdst) 205 timezone = -(ttisp->tt_gmtoff); 206#endif /* defined USG_COMPAT */ 207#ifdef ALTZONE 208 if (i == 0 || ttisp->tt_isdst) 209 altzone = -(ttisp->tt_gmtoff); 210#endif /* defined ALTZONE */ 211 } 212 /* 213 ** And to get the latest zone names into tzname. . . 214 */ 215 for (i = 0; i < sp->timecnt; ++i) { 216 register const struct ttinfo * const ttisp = 217 &sp->ttis[ 218 sp->types[i]]; 219 220 tzname[ttisp->tt_isdst] = 221 (char *) &sp->chars[ttisp->tt_abbrind]; 222 } 223} 224 225static int 226tzload(name, sp) 227register const char * name; 228register struct state * const sp; 229{ 230 register const char * p; 231 register int i; 232 register int fid; 233 234 if (name == NULL && (name = TZDEFAULT) == NULL) 235 return -1; 236 { 237 register int doaccess; 238 char fullname[FILENAME_MAX + 1]; 239 240 if (name[0] == ':') 241 ++name; 242 doaccess = name[0] == '/'; 243 if (!doaccess) { 244 if ((p = TZDIR) == NULL) 245 return -1; 246 if ((strlen(p) + strlen(name) + 1) >= sizeof fullname) 247 return -1; 248 (void) strcpy(fullname, p); 249 (void) strcat(fullname, "/"); 250 (void) strcat(fullname, name); 251 /* 252 ** Set doaccess if '.' (as in "../") shows up in name. 253 */ 254 if (strchr(name, '.') != NULL) 255 doaccess = TRUE; 256 name = fullname; 257 } 258 if (doaccess && access(name, ACCESS_MODE) != 0) 259 return -1; 260 if ((fid = open(name, OPEN_MODE)) == -1) 261 return -1; 262 } 263 { 264 register const struct tzhead * tzhp; 265 char buf[sizeof *sp + sizeof *tzhp]; 266 int ttisstdcnt; 267 268 i = read(fid, buf, sizeof buf); 269 if (close(fid) != 0 || i < sizeof *tzhp) 270 return -1; 271 tzhp = (struct tzhead *) buf; 272 ttisstdcnt = (int) detzcode(tzhp->tzh_ttisstdcnt); 273 sp->leapcnt = (int) detzcode(tzhp->tzh_leapcnt); 274 sp->timecnt = (int) detzcode(tzhp->tzh_timecnt); 275 sp->typecnt = (int) detzcode(tzhp->tzh_typecnt); 276 sp->charcnt = (int) detzcode(tzhp->tzh_charcnt); 277 if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS || 278 sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES || 279 sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES || 280 sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS || 281 (ttisstdcnt != sp->typecnt && ttisstdcnt != 0)) 282 return -1; 283 if (i < sizeof *tzhp + 284 sp->timecnt * (4 + sizeof (char)) + 285 sp->typecnt * (4 + 2 * sizeof (char)) + 286 sp->charcnt * sizeof (char) + 287 sp->leapcnt * 2 * 4 + 288 ttisstdcnt * sizeof (char)) 289 return -1; 290 p = buf + sizeof *tzhp; 291 for (i = 0; i < sp->timecnt; ++i) { 292 sp->ats[i] = detzcode(p); 293 p += 4; 294 } 295 for (i = 0; i < sp->timecnt; ++i) { 296 sp->types[i] = (unsigned char) *p++; 297 if (sp->types[i] >= sp->typecnt) 298 return -1; 299 } 300 for (i = 0; i < sp->typecnt; ++i) { 301 register struct ttinfo * ttisp; 302 303 ttisp = &sp->ttis[i]; 304 ttisp->tt_gmtoff = detzcode(p); 305 p += 4; 306 ttisp->tt_isdst = (unsigned char) *p++; 307 if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1) 308 return -1; 309 ttisp->tt_abbrind = (unsigned char) *p++; 310 if (ttisp->tt_abbrind < 0 || 311 ttisp->tt_abbrind > sp->charcnt) 312 return -1; 313 } 314 for (i = 0; i < sp->charcnt; ++i) 315 sp->chars[i] = *p++; 316 sp->chars[i] = '\0'; /* ensure '\0' at end */ 317 for (i = 0; i < sp->leapcnt; ++i) { 318 register struct lsinfo * lsisp; 319 320 lsisp = &sp->lsis[i]; 321 lsisp->ls_trans = detzcode(p); 322 p += 4; 323 lsisp->ls_corr = detzcode(p); 324 p += 4; 325 } 326 for (i = 0; i < sp->typecnt; ++i) { 327 register struct ttinfo * ttisp; 328 329 ttisp = &sp->ttis[i]; 330 if (ttisstdcnt == 0) 331 ttisp->tt_ttisstd = FALSE; 332 else { 333 ttisp->tt_ttisstd = *p++; 334 if (ttisp->tt_ttisstd != TRUE && 335 ttisp->tt_ttisstd != FALSE) 336 return -1; 337 } 338 } 339 } 340 return 0; 341} 342 343static const int mon_lengths[2][MONSPERYEAR] = { 344 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 345 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 346}; 347 348static const int year_lengths[2] = { 349 DAYSPERNYEAR, DAYSPERLYEAR 350}; 351 352/* 353** Given a pointer into a time zone string, scan until a character that is not 354** a valid character in a zone name is found. Return a pointer to that 355** character. 356*/ 357 358static const char * 359getzname(strp) 360register const char * strp; 361{ 362 register char c; 363 364 while ((c = *strp) != '\0' && !isdigit(c) && c != ',' && c != '-' && 365 c != '+') 366 ++strp; 367 return strp; 368} 369 370/* 371** Given a pointer into a time zone string, extract a number from that string. 372** Check that the number is within a specified range; if it is not, return 373** NULL. 374** Otherwise, return a pointer to the first character not part of the number. 375*/ 376 377static const char * 378getnum(strp, nump, min, max) 379register const char * strp; 380int * const nump; 381const int min; 382const int max; 383{ 384 register char c; 385 register int num; 386 387 if (strp == NULL || !isdigit(*strp)) 388 return NULL; 389 num = 0; 390 while ((c = *strp) != '\0' && isdigit(c)) { 391 num = num * 10 + (c - '0'); 392 if (num > max) 393 return NULL; /* illegal value */ 394 ++strp; 395 } 396 if (num < min) 397 return NULL; /* illegal value */ 398 *nump = num; 399 return strp; 400} 401 402/* 403** Given a pointer into a time zone string, extract a number of seconds, 404** in hh[:mm[:ss]] form, from the string. 405** If any error occurs, return NULL. 406** Otherwise, return a pointer to the first character not part of the number 407** of seconds. 408*/ 409 410static const char * 411getsecs(strp, secsp) 412register const char * strp; 413long * const secsp; 414{ 415 int num; 416 417 strp = getnum(strp, &num, 0, HOURSPERDAY); 418 if (strp == NULL) 419 return NULL; 420 *secsp = num * SECSPERHOUR; 421 if (*strp == ':') { 422 ++strp; 423 strp = getnum(strp, &num, 0, MINSPERHOUR - 1); 424 if (strp == NULL) 425 return NULL; 426 *secsp += num * SECSPERMIN; 427 if (*strp == ':') { 428 ++strp; 429 strp = getnum(strp, &num, 0, SECSPERMIN - 1); 430 if (strp == NULL) 431 return NULL; 432 *secsp += num; 433 } 434 } 435 return strp; 436} 437 438/* 439** Given a pointer into a time zone string, extract an offset, in 440** [+-]hh[:mm[:ss]] form, from the string. 441** If any error occurs, return NULL. 442** Otherwise, return a pointer to the first character not part of the time. 443*/ 444 445static const char * 446getoffset(strp, offsetp) 447register const char * strp; 448long * const offsetp; 449{ 450 register int neg; 451 452 if (*strp == '-') { 453 neg = 1; 454 ++strp; 455 } else if (isdigit(*strp) || *strp++ == '+') 456 neg = 0; 457 else return NULL; /* illegal offset */ 458 strp = getsecs(strp, offsetp); 459 if (strp == NULL) 460 return NULL; /* illegal time */ 461 if (neg) 462 *offsetp = -*offsetp; 463 return strp; 464} 465 466/* 467** Given a pointer into a time zone string, extract a rule in the form 468** date[/time]. See POSIX section 8 for the format of "date" and "time". 469** If a valid rule is not found, return NULL. 470** Otherwise, return a pointer to the first character not part of the rule. 471*/ 472 473static const char * 474getrule(strp, rulep) 475const char * strp; 476register struct rule * const rulep; 477{ 478 if (*strp == 'J') { 479 /* 480 ** Julian day. 481 */ 482 rulep->r_type = JULIAN_DAY; 483 ++strp; 484 strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR); 485 } else if (*strp == 'M') { 486 /* 487 ** Month, week, day. 488 */ 489 rulep->r_type = MONTH_NTH_DAY_OF_WEEK; 490 ++strp; 491 strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR); 492 if (strp == NULL) 493 return NULL; 494 if (*strp++ != '.') 495 return NULL; 496 strp = getnum(strp, &rulep->r_week, 1, 5); 497 if (strp == NULL) 498 return NULL; 499 if (*strp++ != '.') 500 return NULL; 501 strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1); 502 } else if (isdigit(*strp)) { 503 /* 504 ** Day of year. 505 */ 506 rulep->r_type = DAY_OF_YEAR; 507 strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1); 508 } else return NULL; /* invalid format */ 509 if (strp == NULL) 510 return NULL; 511 if (*strp == '/') { 512 /* 513 ** Time specified. 514 */ 515 ++strp; 516 strp = getsecs(strp, &rulep->r_time); 517 } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */ 518 return strp; 519} 520 521/* 522** Given the Epoch-relative time of January 1, 00:00:00 GMT, in a year, the 523** year, a rule, and the offset from GMT at the time that rule takes effect, 524** calculate the Epoch-relative time that rule takes effect. 525*/ 526 527static time_t 528transtime(janfirst, year, rulep, offset) 529const time_t janfirst; 530const int year; 531register const struct rule * const rulep; 532const long offset; 533{ 534 register int leapyear; 535 register time_t value; 536 register int i; 537 int d, m1, yy0, yy1, yy2, dow; 538 539 leapyear = isleap(year); 540 switch (rulep->r_type) { 541 542 case JULIAN_DAY: 543 /* 544 ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap 545 ** years. 546 ** In non-leap years, or if the day number is 59 or less, just 547 ** add SECSPERDAY times the day number-1 to the time of 548 ** January 1, midnight, to get the day. 549 */ 550 value = janfirst + (rulep->r_day - 1) * SECSPERDAY; 551 if (leapyear && rulep->r_day >= 60) 552 value += SECSPERDAY; 553 break; 554 555 case DAY_OF_YEAR: 556 /* 557 ** n - day of year. 558 ** Just add SECSPERDAY times the day number to the time of 559 ** January 1, midnight, to get the day. 560 */ 561 value = janfirst + rulep->r_day * SECSPERDAY; 562 break; 563 564 case MONTH_NTH_DAY_OF_WEEK: 565 /* 566 ** Mm.n.d - nth "dth day" of month m. 567 */ 568 value = janfirst; 569 for (i = 0; i < rulep->r_mon - 1; ++i) 570 value += mon_lengths[leapyear][i] * SECSPERDAY; 571 572 /* 573 ** Use Zeller's Congruence to get day-of-week of first day of 574 ** month. 575 */ 576 m1 = (rulep->r_mon + 9) % 12 + 1; 577 yy0 = (rulep->r_mon <= 2) ? (year - 1) : year; 578 yy1 = yy0 / 100; 579 yy2 = yy0 % 100; 580 dow = ((26 * m1 - 2) / 10 + 581 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7; 582 if (dow < 0) 583 dow += DAYSPERWEEK; 584 585 /* 586 ** "dow" is the day-of-week of the first day of the month. Get 587 ** the day-of-month (zero-origin) of the first "dow" day of the 588 ** month. 589 */ 590 d = rulep->r_day - dow; 591 if (d < 0) 592 d += DAYSPERWEEK; 593 for (i = 1; i < rulep->r_week; ++i) { 594 if (d + DAYSPERWEEK >= 595 mon_lengths[leapyear][rulep->r_mon - 1]) 596 break; 597 d += DAYSPERWEEK; 598 } 599 600 /* 601 ** "d" is the day-of-month (zero-origin) of the day we want. 602 */ 603 value += d * SECSPERDAY; 604 break; 605 } 606 607 /* 608 ** "value" is the Epoch-relative time of 00:00:00 GMT on the day in 609 ** question. To get the Epoch-relative time of the specified local 610 ** time on that day, add the transition time and the current offset 611 ** from GMT. 612 */ 613 return value + rulep->r_time + offset; 614} 615 616/* 617** Given a POSIX section 8-style TZ string, fill in the rule tables as 618** appropriate. 619*/ 620 621static int 622tzparse(name, sp, lastditch) 623const char * name; 624register struct state * const sp; 625const int lastditch; 626{ 627 const char * stdname; 628 const char * dstname; 629 int stdlen; 630 int dstlen; 631 long stdoffset; 632 long dstoffset; 633 register time_t * atp; 634 register unsigned char * typep; 635 register char * cp; 636 register int load_result; 637 638 stdname = name; 639 if (lastditch) { 640 stdlen = strlen(name); /* length of standard zone name */ 641 name += stdlen; 642 if (stdlen >= sizeof sp->chars) 643 stdlen = (sizeof sp->chars) - 1; 644 } else { 645 name = getzname(name); 646 stdlen = name - stdname; 647 if (stdlen < 3) 648 return -1; 649 } 650 if (*name == '\0') 651 return -1; /* was "stdoffset = 0;" */ 652 else { 653 name = getoffset(name, &stdoffset); 654 if (name == NULL) 655 return -1; 656 } 657 load_result = tzload(TZDEFRULES, sp); 658 if (load_result != 0) 659 sp->leapcnt = 0; /* so, we're off a little */ 660 if (*name != '\0') { 661 dstname = name; 662 name = getzname(name); 663 dstlen = name - dstname; /* length of DST zone name */ 664 if (dstlen < 3) 665 return -1; 666 if (*name != '\0' && *name != ',' && *name != ';') { 667 name = getoffset(name, &dstoffset); 668 if (name == NULL) 669 return -1; 670 } else dstoffset = stdoffset - SECSPERHOUR; 671 if (*name == ',' || *name == ';') { 672 struct rule start; 673 struct rule end; 674 register int year; 675 register time_t janfirst; 676 time_t starttime; 677 time_t endtime; 678 679 ++name; 680 if ((name = getrule(name, &start)) == NULL) 681 return -1; 682 if (*name++ != ',') 683 return -1; 684 if ((name = getrule(name, &end)) == NULL) 685 return -1; 686 if (*name != '\0') 687 return -1; 688 sp->typecnt = 2; /* standard time and DST */ 689 /* 690 ** Two transitions per year, from EPOCH_YEAR to 2037. 691 */ 692 sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1); 693 if (sp->timecnt > TZ_MAX_TIMES) 694 return -1; 695 sp->ttis[0].tt_gmtoff = -dstoffset; 696 sp->ttis[0].tt_isdst = 1; 697 sp->ttis[0].tt_abbrind = stdlen + 1; 698 sp->ttis[1].tt_gmtoff = -stdoffset; 699 sp->ttis[1].tt_isdst = 0; 700 sp->ttis[1].tt_abbrind = 0; 701 atp = sp->ats; 702 typep = sp->types; 703 janfirst = 0; 704 for (year = EPOCH_YEAR; year <= 2037; ++year) { 705 starttime = transtime(janfirst, year, &start, 706 stdoffset); 707 endtime = transtime(janfirst, year, &end, 708 dstoffset); 709 if (starttime > endtime) { 710 *atp++ = endtime; 711 *typep++ = 1; /* DST ends */ 712 *atp++ = starttime; 713 *typep++ = 0; /* DST begins */ 714 } else { 715 *atp++ = starttime; 716 *typep++ = 0; /* DST begins */ 717 *atp++ = endtime; 718 *typep++ = 1; /* DST ends */ 719 } 720 janfirst += year_lengths[isleap(year)] * 721 SECSPERDAY; 722 } 723 } else { 724 int sawstd; 725 int sawdst; 726 long stdfix; 727 long dstfix; 728 long oldfix; 729 int isdst; 730 register int i; 731 732 if (*name != '\0') 733 return -1; 734 if (load_result != 0) 735 return -1; 736 /* 737 ** Compute the difference between the real and 738 ** prototype standard and summer time offsets 739 ** from GMT, and put the real standard and summer 740 ** time offsets into the rules in place of the 741 ** prototype offsets. 742 */ 743 sawstd = FALSE; 744 sawdst = FALSE; 745 stdfix = 0; 746 dstfix = 0; 747 for (i = 0; i < sp->typecnt; ++i) { 748 if (sp->ttis[i].tt_isdst) { 749 oldfix = dstfix; 750 dstfix = sp->ttis[i].tt_gmtoff + 751 dstoffset; 752 if (sawdst && (oldfix != dstfix)) 753 return -1; 754 sp->ttis[i].tt_gmtoff = -dstoffset; 755 sp->ttis[i].tt_abbrind = stdlen + 1; 756 sawdst = TRUE; 757 } else { 758 oldfix = stdfix; 759 stdfix = sp->ttis[i].tt_gmtoff + 760 stdoffset; 761 if (sawstd && (oldfix != stdfix)) 762 return -1; 763 sp->ttis[i].tt_gmtoff = -stdoffset; 764 sp->ttis[i].tt_abbrind = 0; 765 sawstd = TRUE; 766 } 767 } 768 /* 769 ** Make sure we have both standard and summer time. 770 */ 771 if (!sawdst || !sawstd) 772 return -1; 773 /* 774 ** Now correct the transition times by shifting 775 ** them by the difference between the real and 776 ** prototype offsets. Note that this difference 777 ** can be different in standard and summer time; 778 ** the prototype probably has a 1-hour difference 779 ** between standard and summer time, but a different 780 ** difference can be specified in TZ. 781 */ 782 isdst = FALSE; /* we start in standard time */ 783 for (i = 0; i < sp->timecnt; ++i) { 784 register const struct ttinfo * ttisp; 785 786 /* 787 ** If summer time is in effect, and the 788 ** transition time was not specified as 789 ** standard time, add the summer time 790 ** offset to the transition time; 791 ** otherwise, add the standard time offset 792 ** to the transition time. 793 */ 794 ttisp = &sp->ttis[sp->types[i]]; 795 sp->ats[i] += 796 (isdst && !ttisp->tt_ttisstd) ? 797 dstfix : stdfix; 798 isdst = ttisp->tt_isdst; 799 } 800 } 801 } else { 802 dstlen = 0; 803 sp->typecnt = 1; /* only standard time */ 804 sp->timecnt = 0; 805 sp->ttis[0].tt_gmtoff = -stdoffset; 806 sp->ttis[0].tt_isdst = 0; 807 sp->ttis[0].tt_abbrind = 0; 808 } 809 sp->charcnt = stdlen + 1; 810 if (dstlen != 0) 811 sp->charcnt += dstlen + 1; 812 if (sp->charcnt > sizeof sp->chars) 813 return -1; 814 cp = sp->chars; 815 (void) strncpy(cp, stdname, stdlen); 816 cp += stdlen; 817 *cp++ = '\0'; 818 if (dstlen != 0) { 819 (void) strncpy(cp, dstname, dstlen); 820 *(cp + dstlen) = '\0'; 821 } 822 return 0; 823} 824 825static void 826gmtload(sp) 827struct state * const sp; 828{ 829 if (tzload(GMT, sp) != 0) 830 (void) tzparse(GMT, sp, TRUE); 831} 832 833#ifndef STD_INSPIRED 834static 835#endif /* !defined STD_INSPIRED */ 836void 837tzsetwall() 838{ 839 lcl_is_set = TRUE; 840#ifdef ALL_STATE 841 if (lclptr == NULL) { 842 lclptr = (struct state *) malloc(sizeof *lclptr); 843 if (lclptr == NULL) { 844 settzname(); /* all we can do */ 845 return; 846 } 847 } 848#endif /* defined ALL_STATE */ 849 if (tzload((char *) NULL, lclptr) != 0) 850 gmtload(lclptr); 851 settzname(); 852} 853 854void 855tzset() 856{ 857 register const char * name; 858 859 name = getenv("TZ"); 860 if (name == NULL) { 861 tzsetwall(); 862 return; 863 } 864 lcl_is_set = TRUE; 865#ifdef ALL_STATE 866 if (lclptr == NULL) { 867 lclptr = (struct state *) malloc(sizeof *lclptr); 868 if (lclptr == NULL) { 869 settzname(); /* all we can do */ 870 return; 871 } 872 } 873#endif /* defined ALL_STATE */ 874 if (*name == '\0') { 875 /* 876 ** User wants it fast rather than right. 877 */ 878 lclptr->leapcnt = 0; /* so, we're off a little */ 879 lclptr->timecnt = 0; 880 lclptr->ttis[0].tt_gmtoff = 0; 881 lclptr->ttis[0].tt_abbrind = 0; 882 (void) strcpy(lclptr->chars, GMT); 883 } else if (tzload(name, lclptr) != 0) 884 if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) 885 (void) gmtload(lclptr); 886 settzname(); 887} 888 889/* 890** The easy way to behave "as if no library function calls" localtime 891** is to not call it--so we drop its guts into "localsub", which can be 892** freely called. (And no, the PANS doesn't require the above behavior-- 893** but it *is* desirable.) 894** 895** The unused offset argument is for the benefit of mktime variants. 896*/ 897 898/*ARGSUSED*/ 899static void 900localsub(timep, offset, tmp) 901const time_t * const timep; 902const long offset; 903struct tm * const tmp; 904{ 905 register const struct state * sp; 906 register const struct ttinfo * ttisp; 907 register int i; 908 const time_t t = *timep; 909 910 if (!lcl_is_set) 911 tzset(); 912 sp = lclptr; 913#ifdef ALL_STATE 914 if (sp == NULL) { 915 gmtsub(timep, offset, tmp); 916 return; 917 } 918#endif /* defined ALL_STATE */ 919 if (sp->timecnt == 0 || t < sp->ats[0]) { 920 i = 0; 921 while (sp->ttis[i].tt_isdst) 922 if (++i >= sp->typecnt) { 923 i = 0; 924 break; 925 } 926 } else { 927 for (i = 1; i < sp->timecnt; ++i) 928 if (t < sp->ats[i]) 929 break; 930 i = sp->types[i - 1]; 931 } 932 ttisp = &sp->ttis[i]; 933 /* 934 ** To get (wrong) behavior that's compatible with System V Release 2.0 935 ** you'd replace the statement below with 936 ** t += ttisp->tt_gmtoff; 937 ** timesub(&t, 0L, sp, tmp); 938 */ 939 timesub(&t, ttisp->tt_gmtoff, sp, tmp); 940 tmp->tm_isdst = ttisp->tt_isdst; 941 tzname[tmp->tm_isdst] = (char *) &sp->chars[ttisp->tt_abbrind]; 942#ifdef TM_ZONE 943 tmp->TM_ZONE = (char *)&sp->chars[ttisp->tt_abbrind]; 944#endif /* defined TM_ZONE */ 945} 946 947struct tm * 948localtime(timep) 949const time_t * const timep; 950{ 951 static struct tm tm; 952 953 localsub(timep, 0L, &tm); 954 return &tm; 955} 956 957/* 958** gmtsub is to gmtime as localsub is to localtime. 959*/ 960 961static void 962gmtsub(timep, offset, tmp) 963const time_t * const timep; 964const long offset; 965struct tm * const tmp; 966{ 967 if (!gmt_is_set) { 968 gmt_is_set = TRUE; 969#ifdef ALL_STATE 970 gmtptr = (struct state *) malloc(sizeof *gmtptr); 971 if (gmtptr != NULL) 972#endif /* defined ALL_STATE */ 973 gmtload(gmtptr); 974 } 975 timesub(timep, offset, gmtptr, tmp); 976#ifdef TM_ZONE 977 /* 978 ** Could get fancy here and deliver something such as 979 ** "GMT+xxxx" or "GMT-xxxx" if offset is non-zero, 980 ** but this is no time for a treasure hunt. 981 */ 982 if (offset != 0) 983 tmp->TM_ZONE = WILDABBR; 984 else { 985#ifdef ALL_STATE 986 if (gmtptr == NULL) 987 tmp->TM_ZONE = GMT; 988 else tmp->TM_ZONE = gmtptr->chars; 989#endif /* defined ALL_STATE */ 990#ifndef ALL_STATE 991 tmp->TM_ZONE = gmtptr->chars; 992#endif /* State Farm */ 993 } 994#endif /* defined TM_ZONE */ 995} 996 997struct tm * 998gmtime(timep) 999const time_t * const timep; 1000{ 1001 static struct tm tm; 1002 1003 gmtsub(timep, 0L, &tm); 1004 return &tm; 1005} 1006 1007#ifdef STD_INSPIRED 1008 1009struct tm * 1010offtime(timep, offset) 1011const time_t * const timep; 1012const long offset; 1013{ 1014 static struct tm tm; 1015 1016 gmtsub(timep, offset, &tm); 1017 return &tm; 1018} 1019 1020#endif /* defined STD_INSPIRED */ 1021 1022static void 1023timesub(timep, offset, sp, tmp) 1024const time_t * const timep; 1025const long offset; 1026register const struct state * const sp; 1027register struct tm * const tmp; 1028{ 1029 register const struct lsinfo * lp; 1030 register long days; 1031 register long rem; 1032 register int y; 1033 register int yleap; 1034 register const int * ip; 1035 register long corr; 1036 register int hit; 1037 register int i; 1038 1039 corr = 0; 1040 hit = 0; 1041#ifdef ALL_STATE 1042 i = (sp == NULL) ? 0 : sp->leapcnt; 1043#endif /* defined ALL_STATE */ 1044#ifndef ALL_STATE 1045 i = sp->leapcnt; 1046#endif /* State Farm */ 1047 while (--i >= 0) { 1048 lp = &sp->lsis[i]; 1049 if (*timep >= lp->ls_trans) { 1050 if (*timep == lp->ls_trans) { 1051 hit = ((i == 0 && lp->ls_corr > 0) || 1052 lp->ls_corr > sp->lsis[i - 1].ls_corr); 1053 if (hit) 1054 while (i > 0 && 1055 sp->lsis[i].ls_trans == 1056 sp->lsis[i - 1].ls_trans + 1 && 1057 sp->lsis[i].ls_corr == 1058 sp->lsis[i - 1].ls_corr + 1) { 1059 ++hit; 1060 --i; 1061 } 1062 } 1063 corr = lp->ls_corr; 1064 break; 1065 } 1066 } 1067 days = *timep / SECSPERDAY; 1068 rem = *timep % SECSPERDAY; 1069#ifdef mc68k 1070 if (*timep == 0x80000000) { 1071 /* 1072 ** A 3B1 muffs the division on the most negative number. 1073 */ 1074 days = -24855; 1075 rem = -11648; 1076 } 1077#endif /* mc68k */ 1078 rem += (offset - corr); 1079 while (rem < 0) { 1080 rem += SECSPERDAY; 1081 --days; 1082 } 1083 while (rem >= SECSPERDAY) { 1084 rem -= SECSPERDAY; 1085 ++days; 1086 } 1087 tmp->tm_hour = (int) (rem / SECSPERHOUR); 1088 rem = rem % SECSPERHOUR; 1089 tmp->tm_min = (int) (rem / SECSPERMIN); 1090 tmp->tm_sec = (int) (rem % SECSPERMIN); 1091 if (hit) 1092 /* 1093 ** A positive leap second requires a special 1094 ** representation. This uses "... ??:59:60" et seq. 1095 */ 1096 tmp->tm_sec += hit; 1097 tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK); 1098 if (tmp->tm_wday < 0) 1099 tmp->tm_wday += DAYSPERWEEK; 1100 y = EPOCH_YEAR; 1101 if (days >= 0) 1102 for ( ; ; ) { 1103 yleap = isleap(y); 1104 if (days < (long) year_lengths[yleap]) 1105 break; 1106 ++y; 1107 days = days - (long) year_lengths[yleap]; 1108 } 1109 else do { 1110 --y; 1111 yleap = isleap(y); 1112 days = days + (long) year_lengths[yleap]; 1113 } while (days < 0); 1114 tmp->tm_year = y - TM_YEAR_BASE; 1115 tmp->tm_yday = (int) days; 1116 ip = mon_lengths[yleap]; 1117 for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon)) 1118 days = days - (long) ip[tmp->tm_mon]; 1119 tmp->tm_mday = (int) (days + 1); 1120 tmp->tm_isdst = 0; 1121#ifdef TM_GMTOFF 1122 tmp->TM_GMTOFF = offset; 1123#endif /* defined TM_GMTOFF */ 1124} 1125 1126char * 1127ctime(timep) 1128const time_t * const timep; 1129{ 1130 return asctime(localtime(timep)); 1131} 1132 1133/* 1134** Adapted from code provided by Robert Elz, who writes: 1135** The "best" way to do mktime I think is based on an idea of Bob 1136** Kridle's (so its said...) from a long time ago. (mtxinu!kridle now). 1137** It does a binary search of the time_t space. Since time_t's are 1138** just 32 bits, its a max of 32 iterations (even at 64 bits it 1139** would still be very reasonable). 1140*/ 1141 1142#ifndef WRONG 1143#define WRONG (-1) 1144#endif /* !defined WRONG */ 1145 1146/* 1147** Simplified normalize logic courtesy Paul Eggert (eggert@twinsun.com). 1148*/ 1149 1150static int 1151increment_overflow(number, delta) 1152int * number; 1153int delta; 1154{ 1155 int number0; 1156 1157 number0 = *number; 1158 *number += delta; 1159 return (*number < number0) != (delta < 0); 1160} 1161 1162static int 1163normalize_overflow(tensptr, unitsptr, base) 1164int * const tensptr; 1165int * const unitsptr; 1166const int base; 1167{ 1168 register int tensdelta; 1169 1170 tensdelta = (*unitsptr >= 0) ? 1171 (*unitsptr / base) : 1172 (-1 - (-1 - *unitsptr) / base); 1173 *unitsptr -= tensdelta * base; 1174 return increment_overflow(tensptr, tensdelta); 1175} 1176 1177static int 1178tmcomp(atmp, btmp) 1179register const struct tm * const atmp; 1180register const struct tm * const btmp; 1181{ 1182 register int result; 1183 1184 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 1185 (result = (atmp->tm_mon - btmp->tm_mon)) == 0 && 1186 (result = (atmp->tm_mday - btmp->tm_mday)) == 0 && 1187 (result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 1188 (result = (atmp->tm_min - btmp->tm_min)) == 0) 1189 result = atmp->tm_sec - btmp->tm_sec; 1190 return result; 1191} 1192 1193static time_t 1194time2(tmp, funcp, offset, okayp) 1195struct tm * const tmp; 1196void (* const funcp)(); 1197const long offset; 1198int * const okayp; 1199{ 1200 register const struct state * sp; 1201 register int dir; 1202 register int bits; 1203 register int i, j ; 1204 register int saved_seconds; 1205 time_t newt; 1206 time_t t; 1207 struct tm yourtm, mytm; 1208 1209 *okayp = FALSE; 1210 yourtm = *tmp; 1211 if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR)) 1212 return WRONG; 1213 if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY)) 1214 return WRONG; 1215 if (normalize_overflow(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR)) 1216 return WRONG; 1217 /* 1218 ** Turn yourtm.tm_year into an actual year number for now. 1219 ** It is converted back to an offset from TM_YEAR_BASE later. 1220 */ 1221 if (increment_overflow(&yourtm.tm_year, TM_YEAR_BASE)) 1222 return WRONG; 1223 while (yourtm.tm_mday <= 0) { 1224 if (increment_overflow(&yourtm.tm_year, -1)) 1225 return WRONG; 1226 yourtm.tm_mday += year_lengths[isleap(yourtm.tm_year)]; 1227 } 1228 while (yourtm.tm_mday > DAYSPERLYEAR) { 1229 yourtm.tm_mday -= year_lengths[isleap(yourtm.tm_year)]; 1230 if (increment_overflow(&yourtm.tm_year, 1)) 1231 return WRONG; 1232 } 1233 for ( ; ; ) { 1234 i = mon_lengths[isleap(yourtm.tm_year)][yourtm.tm_mon]; 1235 if (yourtm.tm_mday <= i) 1236 break; 1237 yourtm.tm_mday -= i; 1238 if (++yourtm.tm_mon >= MONSPERYEAR) { 1239 yourtm.tm_mon = 0; 1240 if (increment_overflow(&yourtm.tm_year, 1)) 1241 return WRONG; 1242 } 1243 } 1244 if (increment_overflow(&yourtm.tm_year, -TM_YEAR_BASE)) 1245 return WRONG; 1246 if (yourtm.tm_year + TM_YEAR_BASE < EPOCH_YEAR) { 1247 /* 1248 ** We can't set tm_sec to 0, because that might push the 1249 ** time below the minimum representable time. 1250 ** Set tm_sec to 59 instead. 1251 ** This assumes that the minimum representable time is 1252 ** not in the same minute that a leap second was deleted from, 1253 ** which is a safer assumption than using 58 would be. 1254 */ 1255 if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN)) 1256 return WRONG; 1257 saved_seconds = yourtm.tm_sec; 1258 yourtm.tm_sec = SECSPERMIN - 1; 1259 } else { 1260 saved_seconds = yourtm.tm_sec; 1261 yourtm.tm_sec = 0; 1262 } 1263 /* 1264 ** Calculate the number of magnitude bits in a time_t 1265 ** (this works regardless of whether time_t is 1266 ** signed or unsigned, though lint complains if unsigned). 1267 */ 1268 for (bits = 0, t = 1; t > 0; ++bits, t <<= 1) 1269 continue; 1270 /* 1271 ** If time_t is signed, then 0 is the median value, 1272 ** if time_t is unsigned, then 1 << bits is median. 1273 */ 1274 t = (t < 0) ? 0 : ((time_t) 1 << bits); 1275 for ( ; ; ) { 1276 (*funcp)(&t, offset, &mytm); 1277 dir = tmcomp(&mytm, &yourtm); 1278 if (dir != 0) { 1279 if (bits-- < 0) 1280 return WRONG; 1281 if (bits < 0) 1282 --t; 1283 else if (dir > 0) 1284 t -= (time_t) 1 << bits; 1285 else t += (time_t) 1 << bits; 1286 continue; 1287 } 1288 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 1289 break; 1290 /* 1291 ** Right time, wrong type. 1292 ** Hunt for right time, right type. 1293 ** It's okay to guess wrong since the guess 1294 ** gets checked. 1295 */ 1296 /* 1297 ** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's. 1298 */ 1299 sp = (const struct state *) 1300 (((void *) funcp == (void *) localsub) ? 1301 lclptr : gmtptr); 1302#ifdef ALL_STATE 1303 if (sp == NULL) 1304 return WRONG; 1305#endif /* defined ALL_STATE */ 1306 for (i = 0; i < sp->typecnt; ++i) { 1307 if (sp->ttis[i].tt_isdst != yourtm.tm_isdst) 1308 continue; 1309 for (j = 0; j < sp->typecnt; ++j) { 1310 if (sp->ttis[j].tt_isdst == yourtm.tm_isdst) 1311 continue; 1312 newt = t + sp->ttis[j].tt_gmtoff - 1313 sp->ttis[i].tt_gmtoff; 1314 (*funcp)(&newt, offset, &mytm); 1315 if (tmcomp(&mytm, &yourtm) != 0) 1316 continue; 1317 if (mytm.tm_isdst != yourtm.tm_isdst) 1318 continue; 1319 /* 1320 ** We have a match. 1321 */ 1322 t = newt; 1323 goto label; 1324 } 1325 } 1326 return WRONG; 1327 } 1328label: 1329 newt = t + saved_seconds; 1330 if ((newt < t) != (saved_seconds < 0)) 1331 return WRONG; 1332 t = newt; 1333 (*funcp)(&t, offset, tmp); 1334 *okayp = TRUE; 1335 return t; 1336} 1337 1338static time_t 1339time1(tmp, funcp, offset) 1340struct tm * const tmp; 1341void (* const funcp)(); 1342const long offset; 1343{ 1344 register time_t t; 1345 register const struct state * sp; 1346 register int samei, otheri; 1347 int okay; 1348 1349 if (tmp->tm_isdst > 1) 1350 tmp->tm_isdst = 1; 1351 t = time2(tmp, funcp, offset, &okay); 1352#ifdef PCTS 1353 /* 1354 ** PCTS code courtesy Grant Sullivan (grant@osf.org). 1355 */ 1356 if (okay) 1357 return t; 1358 if (tmp->tm_isdst < 0) 1359 tmp->tm_isdst = 0; /* reset to std and try again */ 1360#endif /* defined PCTS */ 1361#ifndef PCTS 1362 if (okay || tmp->tm_isdst < 0) 1363 return t; 1364#endif /* !defined PCTS */ 1365 /* 1366 ** We're supposed to assume that somebody took a time of one type 1367 ** and did some math on it that yielded a "struct tm" that's bad. 1368 ** We try to divine the type they started from and adjust to the 1369 ** type they need. 1370 */ 1371 /* 1372 ** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's. 1373 */ 1374 sp = (const struct state *) (((void *) funcp == (void *) localsub) ? 1375 lclptr : gmtptr); 1376#ifdef ALL_STATE 1377 if (sp == NULL) 1378 return WRONG; 1379#endif /* defined ALL_STATE */ 1380 for (samei = 0; samei < sp->typecnt; ++samei) { 1381 if (sp->ttis[samei].tt_isdst != tmp->tm_isdst) 1382 continue; 1383 for (otheri = 0; otheri < sp->typecnt; ++otheri) { 1384 if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst) 1385 continue; 1386 tmp->tm_sec += sp->ttis[otheri].tt_gmtoff - 1387 sp->ttis[samei].tt_gmtoff; 1388 tmp->tm_isdst = !tmp->tm_isdst; 1389 t = time2(tmp, funcp, offset, &okay); 1390 if (okay) 1391 return t; 1392 tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff - 1393 sp->ttis[samei].tt_gmtoff; 1394 tmp->tm_isdst = !tmp->tm_isdst; 1395 } 1396 } 1397 return WRONG; 1398} 1399 1400time_t 1401mktime(tmp) 1402struct tm * const tmp; 1403{ 1404 return time1(tmp, localsub, 0L); 1405} 1406 1407#ifdef STD_INSPIRED 1408 1409time_t 1410timelocal(tmp) 1411struct tm * const tmp; 1412{ 1413 tmp->tm_isdst = -1; /* in case it wasn't initialized */ 1414 return mktime(tmp); 1415} 1416 1417time_t 1418timegm(tmp) 1419struct tm * const tmp; 1420{ 1421 tmp->tm_isdst = 0; 1422 return time1(tmp, gmtsub, 0L); 1423} 1424 1425time_t 1426timeoff(tmp, offset) 1427struct tm * const tmp; 1428const long offset; 1429{ 1430 tmp->tm_isdst = 0; 1431 return time1(tmp, gmtsub, offset); 1432} 1433 1434#endif /* defined STD_INSPIRED */ 1435 1436#ifdef CMUCS 1437 1438/* 1439** The following is supplied for compatibility with 1440** previous versions of the CMUCS runtime library. 1441*/ 1442 1443long 1444gtime(tmp) 1445struct tm * const tmp; 1446{ 1447 const time_t t = mktime(tmp); 1448 1449 if (t == WRONG) 1450 return -1; 1451 return t; 1452} 1453 1454#endif /* defined CMUCS */ 1455 1456/* 1457** XXX--is the below the right way to conditionalize?? 1458*/ 1459 1460#ifdef STD_INSPIRED 1461 1462/* 1463** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 1464** shall correspond to "Wed Dec 31 23:59:59 GMT 1986", which 1465** is not the case if we are accounting for leap seconds. 1466** So, we provide the following conversion routines for use 1467** when exchanging timestamps with POSIX conforming systems. 1468*/ 1469 1470static long 1471leapcorr(timep) 1472time_t * timep; 1473{ 1474 register struct state * sp; 1475 register struct lsinfo * lp; 1476 register int i; 1477 1478 if (!lcl_is_set) 1479 (void) tzset(); 1480 sp = lclptr; 1481 i = sp->leapcnt; 1482 while (--i >= 0) { 1483 lp = &sp->lsis[i]; 1484 if (*timep >= lp->ls_trans) 1485 return lp->ls_corr; 1486 } 1487 return 0; 1488} 1489 1490time_t 1491time2posix(t) 1492time_t t; 1493{ 1494 return t - leapcorr(&t); 1495} 1496 1497time_t 1498posix2time(t) 1499time_t t; 1500{ 1501 time_t x; 1502 time_t y; 1503 1504 /* 1505 ** For a positive leap second hit, the result 1506 ** is not unique. For a negative leap second 1507 ** hit, the corresponding time doesn't exist, 1508 ** so we return an adjacent second. 1509 */ 1510 x = t + leapcorr(&t); 1511 y = x - leapcorr(&x); 1512 if (y < t) { 1513 do { 1514 x++; 1515 y = x - leapcorr(&x); 1516 } while (y < t); 1517 if (t != y) 1518 return x - 1; 1519 } else if (y > t) { 1520 do { 1521 --x; 1522 y = x - leapcorr(&x); 1523 } while (y > t); 1524 if (t != y) 1525 return x + 1; 1526 } 1527 return x; 1528} 1529 1530#endif /* defined STD_INSPIRED */ 1531