strptime.c revision 1.40
1 /* $NetBSD: strptime.c,v 1.40 2015/07/03 13:06:54 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1997, 1998, 2005, 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code was contributed to The NetBSD Foundation by Klaus Klein. 8 * Heavily optimised by David Laight 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 __RCSID("$NetBSD: strptime.c,v 1.40 2015/07/03 13:06:54 christos Exp $"); 35 #endif 36 37 #include "namespace.h" 38 #include <sys/localedef.h> 39 #include <sys/types.h> 40 #include <sys/clock.h> 41 #include <ctype.h> 42 #include <locale.h> 43 #include <string.h> 44 #include <time.h> 45 #include <tzfile.h> 46 #include "private.h" 47 #include "setlocale_local.h" 48 49 #ifdef __weak_alias 50 __weak_alias(strptime,_strptime) 51 __weak_alias(strptime_l, _strptime_l) 52 #endif 53 54 #define _TIME_LOCALE(loc) \ 55 ((_TimeLocale *)((loc)->part_impl[(size_t)LC_TIME])) 56 57 /* 58 * We do not implement alternate representations. However, we always 59 * check whether a given modifier is allowed for a certain conversion. 60 */ 61 #define ALT_E 0x01 62 #define ALT_O 0x02 63 #define LEGAL_ALT(x) { if (alt_format & ~(x)) return NULL; } 64 65 #define FLAG_YEAR (1 << 0) 66 #define FLAG_MONTH (1 << 1) 67 #define FLAG_YDAY (1 << 2) 68 #define FLAG_MDAY (1 << 3) 69 #define FLAG_WDAY (1 << 4) 70 71 static char gmt[] = { "GMT" }; 72 static char utc[] = { "UTC" }; 73 /* RFC-822/RFC-2822 */ 74 static const char * const nast[5] = { 75 "EST", "CST", "MST", "PST", "\0\0\0" 76 }; 77 static const char * const nadt[5] = { 78 "EDT", "CDT", "MDT", "PDT", "\0\0\0" 79 }; 80 81 static const u_char *conv_num(const unsigned char *, int *, uint, uint); 82 static const u_char *find_string(const u_char *, int *, const char * const *, 83 const char * const *, int); 84 85 static const int start_of_month[2][13] = { 86 { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }, 87 { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 } 88 }; 89 90 /* 91 * Calculate the week day of the first day of a year. Valid for 92 * the Gregorian calendar, which began Sept 14, 1752 in the UK 93 * and its colonies. Ref: 94 * http://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week 95 */ 96 97 static int 98 first_wday_of(int yr) 99 { 100 return ((2 * (3 - (yr / 100) % 4)) + (yr % 100) + ((yr % 100) / 4) + 101 (is_leap_year(yr) ? 6 : 0) + 1) % 7; 102 } 103 104 char * 105 strptime(const char *buf, const char *fmt, struct tm *tm) 106 { 107 return strptime_l(buf, fmt, tm, _current_locale()); 108 } 109 110 char * 111 strptime_l(const char *buf, const char *fmt, struct tm *tm, locale_t loc) 112 { 113 unsigned char c; 114 const unsigned char *bp, *ep; 115 int alt_format, i, split_year = 0, neg = 0, flags = 0, 116 day_offset = -1, week_offset = 0, offs; 117 const char *new_fmt; 118 119 bp = (const u_char *)buf; 120 121 while (bp != NULL && (c = *fmt++) != '\0') { 122 /* Clear `alternate' modifier prior to new conversion. */ 123 alt_format = 0; 124 i = 0; 125 126 /* Eat up white-space. */ 127 if (isspace(c)) { 128 while (isspace(*bp)) 129 bp++; 130 continue; 131 } 132 133 if (c != '%') 134 goto literal; 135 136 137 again: switch (c = *fmt++) { 138 case '%': /* "%%" is converted to "%". */ 139 literal: 140 if (c != *bp++) 141 return NULL; 142 LEGAL_ALT(0); 143 continue; 144 145 /* 146 * "Alternative" modifiers. Just set the appropriate flag 147 * and start over again. 148 */ 149 case 'E': /* "%E?" alternative conversion modifier. */ 150 LEGAL_ALT(0); 151 alt_format |= ALT_E; 152 goto again; 153 154 case 'O': /* "%O?" alternative conversion modifier. */ 155 LEGAL_ALT(0); 156 alt_format |= ALT_O; 157 goto again; 158 159 /* 160 * "Complex" conversion rules, implemented through recursion. 161 */ 162 case 'c': /* Date and time, using the locale's format. */ 163 new_fmt = _TIME_LOCALE(loc)->d_t_fmt; 164 flags |= FLAG_WDAY | FLAG_MONTH | FLAG_MDAY | 165 FLAG_YEAR; 166 goto recurse; 167 168 case 'D': /* The date as "%m/%d/%y". */ 169 new_fmt = "%m/%d/%y"; 170 LEGAL_ALT(0); 171 flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR; 172 goto recurse; 173 174 case 'F': /* The date as "%Y-%m-%d". */ 175 new_fmt = "%Y-%m-%d"; 176 LEGAL_ALT(0); 177 flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR; 178 goto recurse; 179 180 case 'R': /* The time as "%H:%M". */ 181 new_fmt = "%H:%M"; 182 LEGAL_ALT(0); 183 goto recurse; 184 185 case 'r': /* The time in 12-hour clock representation. */ 186 new_fmt = _TIME_LOCALE(loc)->t_fmt_ampm; 187 LEGAL_ALT(0); 188 goto recurse; 189 190 case 'T': /* The time as "%H:%M:%S". */ 191 new_fmt = "%H:%M:%S"; 192 LEGAL_ALT(0); 193 goto recurse; 194 195 case 'X': /* The time, using the locale's format. */ 196 new_fmt = _TIME_LOCALE(loc)->t_fmt; 197 goto recurse; 198 199 case 'x': /* The date, using the locale's format. */ 200 new_fmt = _TIME_LOCALE(loc)->d_fmt; 201 flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR; 202 recurse: 203 bp = (const u_char *)strptime((const char *)bp, 204 new_fmt, tm); 205 LEGAL_ALT(ALT_E); 206 continue; 207 208 /* 209 * "Elementary" conversion rules. 210 */ 211 case 'A': /* The day of week, using the locale's form. */ 212 case 'a': 213 bp = find_string(bp, &tm->tm_wday, 214 _TIME_LOCALE(loc)->day, _TIME_LOCALE(loc)->abday, 7); 215 LEGAL_ALT(0); 216 flags |= FLAG_WDAY; 217 continue; 218 219 case 'B': /* The month, using the locale's form. */ 220 case 'b': 221 case 'h': 222 bp = find_string(bp, &tm->tm_mon, 223 _TIME_LOCALE(loc)->mon, _TIME_LOCALE(loc)->abmon, 224 12); 225 LEGAL_ALT(0); 226 flags |= FLAG_MONTH; 227 continue; 228 229 case 'C': /* The century number. */ 230 i = 20; 231 bp = conv_num(bp, &i, 0, 99); 232 233 i = i * 100 - TM_YEAR_BASE; 234 if (split_year) 235 i += tm->tm_year % 100; 236 split_year = 1; 237 tm->tm_year = i; 238 LEGAL_ALT(ALT_E); 239 flags |= FLAG_YEAR; 240 continue; 241 242 case 'd': /* The day of month. */ 243 case 'e': 244 bp = conv_num(bp, &tm->tm_mday, 1, 31); 245 LEGAL_ALT(ALT_O); 246 flags |= FLAG_MDAY; 247 continue; 248 249 case 'k': /* The hour (24-hour clock representation). */ 250 LEGAL_ALT(0); 251 /* FALLTHROUGH */ 252 case 'H': 253 bp = conv_num(bp, &tm->tm_hour, 0, 23); 254 LEGAL_ALT(ALT_O); 255 continue; 256 257 case 'l': /* The hour (12-hour clock representation). */ 258 LEGAL_ALT(0); 259 /* FALLTHROUGH */ 260 case 'I': 261 bp = conv_num(bp, &tm->tm_hour, 1, 12); 262 if (tm->tm_hour == 12) 263 tm->tm_hour = 0; 264 LEGAL_ALT(ALT_O); 265 continue; 266 267 case 'j': /* The day of year. */ 268 i = 1; 269 bp = conv_num(bp, &i, 1, 366); 270 tm->tm_yday = i - 1; 271 LEGAL_ALT(0); 272 flags |= FLAG_YDAY; 273 continue; 274 275 case 'M': /* The minute. */ 276 bp = conv_num(bp, &tm->tm_min, 0, 59); 277 LEGAL_ALT(ALT_O); 278 continue; 279 280 case 'm': /* The month. */ 281 i = 1; 282 bp = conv_num(bp, &i, 1, 12); 283 tm->tm_mon = i - 1; 284 LEGAL_ALT(ALT_O); 285 flags |= FLAG_MONTH; 286 continue; 287 288 case 'p': /* The locale's equivalent of AM/PM. */ 289 bp = find_string(bp, &i, _TIME_LOCALE(loc)->am_pm, 290 NULL, 2); 291 if (tm->tm_hour > 11) 292 return NULL; 293 tm->tm_hour += i * 12; 294 LEGAL_ALT(0); 295 continue; 296 297 case 'S': /* The seconds. */ 298 bp = conv_num(bp, &tm->tm_sec, 0, 61); 299 LEGAL_ALT(ALT_O); 300 continue; 301 302 #ifndef TIME_MAX 303 #define TIME_MAX INT64_MAX 304 #endif 305 case 's': /* seconds since the epoch */ 306 { 307 time_t sse = 0; 308 uint64_t rulim = TIME_MAX; 309 310 if (*bp < '0' || *bp > '9') { 311 bp = NULL; 312 continue; 313 } 314 315 do { 316 sse *= 10; 317 sse += *bp++ - '0'; 318 rulim /= 10; 319 } while ((sse * 10 <= TIME_MAX) && 320 rulim && *bp >= '0' && *bp <= '9'); 321 322 if (sse < 0 || (uint64_t)sse > TIME_MAX) { 323 bp = NULL; 324 continue; 325 } 326 327 if (localtime_r(&sse, tm) == NULL) 328 bp = NULL; 329 else 330 flags |= FLAG_YDAY | FLAG_WDAY | 331 FLAG_MONTH | FLAG_MDAY | FLAG_YEAR; 332 } 333 continue; 334 335 case 'U': /* The week of year, beginning on sunday. */ 336 case 'W': /* The week of year, beginning on monday. */ 337 /* 338 * XXX This is bogus, as we can not assume any valid 339 * information present in the tm structure at this 340 * point to calculate a real value, so just check the 341 * range for now. 342 */ 343 bp = conv_num(bp, &i, 0, 53); 344 LEGAL_ALT(ALT_O); 345 if (c == 'U') 346 day_offset = TM_SUNDAY; 347 else 348 day_offset = TM_MONDAY; 349 week_offset = i; 350 continue; 351 352 case 'w': /* The day of week, beginning on sunday. */ 353 bp = conv_num(bp, &tm->tm_wday, 0, 6); 354 LEGAL_ALT(ALT_O); 355 flags |= FLAG_WDAY; 356 continue; 357 358 case 'u': /* The day of week, monday = 1. */ 359 bp = conv_num(bp, &i, 1, 7); 360 tm->tm_wday = i % 7; 361 LEGAL_ALT(ALT_O); 362 continue; 363 364 case 'g': /* The year corresponding to the ISO week 365 * number but without the century. 366 */ 367 bp = conv_num(bp, &i, 0, 99); 368 continue; 369 370 case 'G': /* The year corresponding to the ISO week 371 * number with century. 372 */ 373 do 374 bp++; 375 while (isdigit(*bp)); 376 continue; 377 378 case 'V': /* The ISO 8601:1988 week number as decimal */ 379 bp = conv_num(bp, &i, 0, 53); 380 continue; 381 382 case 'Y': /* The year. */ 383 i = TM_YEAR_BASE; /* just for data sanity... */ 384 bp = conv_num(bp, &i, 0, 9999); 385 tm->tm_year = i - TM_YEAR_BASE; 386 LEGAL_ALT(ALT_E); 387 flags |= FLAG_YEAR; 388 continue; 389 390 case 'y': /* The year within 100 years of the epoch. */ 391 /* LEGAL_ALT(ALT_E | ALT_O); */ 392 bp = conv_num(bp, &i, 0, 99); 393 394 if (split_year) 395 /* preserve century */ 396 i += (tm->tm_year / 100) * 100; 397 else { 398 split_year = 1; 399 if (i <= 68) 400 i = i + 2000 - TM_YEAR_BASE; 401 else 402 i = i + 1900 - TM_YEAR_BASE; 403 } 404 tm->tm_year = i; 405 flags |= FLAG_YEAR; 406 continue; 407 408 case 'Z': 409 tzset(); 410 if (strncmp((const char *)bp, gmt, 3) == 0 || 411 strncmp((const char *)bp, utc, 3) == 0) { 412 tm->tm_isdst = 0; 413 #ifdef TM_GMTOFF 414 tm->TM_GMTOFF = 0; 415 #endif 416 #ifdef TM_ZONE 417 tm->TM_ZONE = gmt; 418 #endif 419 bp += 3; 420 } else { 421 ep = find_string(bp, &i, 422 (const char * const *)tzname, 423 NULL, 2); 424 if (ep != NULL) { 425 tm->tm_isdst = i; 426 #ifdef TM_GMTOFF 427 tm->TM_GMTOFF = -(timezone); 428 #endif 429 #ifdef TM_ZONE 430 tm->TM_ZONE = tzname[i]; 431 #endif 432 } 433 bp = ep; 434 } 435 continue; 436 437 case 'z': 438 /* 439 * We recognize all ISO 8601 formats: 440 * Z = Zulu time/UTC 441 * [+-]hhmm 442 * [+-]hh:mm 443 * [+-]hh 444 * We recognize all RFC-822/RFC-2822 formats: 445 * UT|GMT 446 * North American : UTC offsets 447 * E[DS]T = Eastern : -4 | -5 448 * C[DS]T = Central : -5 | -6 449 * M[DS]T = Mountain: -6 | -7 450 * P[DS]T = Pacific : -7 | -8 451 * Military 452 * [A-IL-M] = -1 ... -9 (J not used) 453 * [N-Y] = +1 ... +12 454 */ 455 while (isspace(*bp)) 456 bp++; 457 458 switch (*bp++) { 459 case 'G': 460 if (*bp++ != 'M') 461 return NULL; 462 /*FALLTHROUGH*/ 463 case 'U': 464 if (*bp++ != 'T') 465 return NULL; 466 /*FALLTHROUGH*/ 467 case 'Z': 468 tm->tm_isdst = 0; 469 #ifdef TM_GMTOFF 470 tm->TM_GMTOFF = 0; 471 #endif 472 #ifdef TM_ZONE 473 tm->TM_ZONE = utc; 474 #endif 475 continue; 476 case '+': 477 neg = 0; 478 flags |= FLAG_WDAY | FLAG_MONTH | FLAG_MDAY | 479 FLAG_YEAR; 480 break; 481 case '-': 482 neg = 1; 483 break; 484 default: 485 --bp; 486 ep = find_string(bp, &i, nast, NULL, 4); 487 if (ep != NULL) { 488 #ifdef TM_GMTOFF 489 tm->TM_GMTOFF = -5 - i; 490 #endif 491 #ifdef TM_ZONE 492 tm->TM_ZONE = __UNCONST(nast[i]); 493 #endif 494 bp = ep; 495 continue; 496 } 497 ep = find_string(bp, &i, nadt, NULL, 4); 498 if (ep != NULL) { 499 tm->tm_isdst = 1; 500 #ifdef TM_GMTOFF 501 tm->TM_GMTOFF = -4 - i; 502 #endif 503 #ifdef TM_ZONE 504 tm->TM_ZONE = __UNCONST(nadt[i]); 505 #endif 506 bp = ep; 507 continue; 508 } 509 510 if ((*bp >= 'A' && *bp <= 'I') || 511 (*bp >= 'L' && *bp <= 'Y')) { 512 #ifdef TM_GMTOFF 513 /* Argh! No 'J'! */ 514 if (*bp >= 'A' && *bp <= 'I') 515 tm->TM_GMTOFF = 516 ('A' - 1) - (int)*bp; 517 else if (*bp >= 'L' && *bp <= 'M') 518 tm->TM_GMTOFF = 'A' - (int)*bp; 519 else if (*bp >= 'N' && *bp <= 'Y') 520 tm->TM_GMTOFF = (int)*bp - 'M'; 521 #endif 522 #ifdef TM_ZONE 523 tm->TM_ZONE = NULL; /* XXX */ 524 #endif 525 bp++; 526 continue; 527 } 528 return NULL; 529 } 530 offs = 0; 531 for (i = 0; i < 4; ) { 532 if (isdigit(*bp)) { 533 offs = offs * 10 + (*bp++ - '0'); 534 i++; 535 continue; 536 } 537 if (i == 2 && *bp == ':') { 538 bp++; 539 continue; 540 } 541 break; 542 } 543 switch (i) { 544 case 2: 545 offs *= 100; 546 break; 547 case 4: 548 i = offs % 100; 549 if (i >= 60) 550 return NULL; 551 /* Convert minutes into decimal */ 552 offs = (offs / 100) * 100 + (i * 50) / 30; 553 break; 554 default: 555 return NULL; 556 } 557 if (neg) 558 offs = -offs; 559 tm->tm_isdst = 0; /* XXX */ 560 #ifdef TM_GMTOFF 561 tm->TM_GMTOFF = offs; 562 #endif 563 #ifdef TM_ZONE 564 tm->TM_ZONE = NULL; /* XXX */ 565 #endif 566 continue; 567 568 /* 569 * Miscellaneous conversions. 570 */ 571 case 'n': /* Any kind of white-space. */ 572 case 't': 573 while (isspace(*bp)) 574 bp++; 575 LEGAL_ALT(0); 576 continue; 577 578 579 default: /* Unknown/unsupported conversion. */ 580 return NULL; 581 } 582 } 583 584 if (!(flags & FLAG_YDAY) && (flags & FLAG_YEAR)) { 585 if ((flags & (FLAG_MONTH | FLAG_MDAY)) == 586 (FLAG_MONTH | FLAG_MDAY)) { 587 tm->tm_yday = start_of_month[is_leap_year(tm->tm_year + 588 TM_YEAR_BASE)][tm->tm_mon] + (tm->tm_mday - 1); 589 flags |= FLAG_YDAY; 590 } else if (day_offset != -1) { 591 /* Set the date to the first Sunday (or Monday) 592 * of the specified week of the year. 593 */ 594 if (!(flags & FLAG_WDAY)) { 595 tm->tm_wday = day_offset; 596 flags |= FLAG_WDAY; 597 } 598 tm->tm_yday = (7 - 599 first_wday_of(tm->tm_year + TM_YEAR_BASE) + 600 day_offset) % 7 + (week_offset - 1) * 7 + 601 tm->tm_wday - day_offset; 602 flags |= FLAG_YDAY; 603 } 604 } 605 606 if ((flags & (FLAG_YEAR | FLAG_YDAY)) == (FLAG_YEAR | FLAG_YDAY)) { 607 int isleap; 608 if (!(flags & FLAG_MONTH)) { 609 i = 0; 610 isleap = is_leap_year(tm->tm_year + TM_YEAR_BASE); 611 while (tm->tm_yday >= start_of_month[isleap][i]) 612 i++; 613 if (i > 12) { 614 i = 1; 615 tm->tm_yday -= start_of_month[isleap][12]; 616 tm->tm_year++; 617 } 618 tm->tm_mon = i - 1; 619 flags |= FLAG_MONTH; 620 } 621 if (!(flags & FLAG_MDAY)) { 622 isleap = is_leap_year(tm->tm_year + TM_YEAR_BASE); 623 tm->tm_mday = tm->tm_yday - 624 start_of_month[isleap][tm->tm_mon] + 1; 625 flags |= FLAG_MDAY; 626 } 627 if (!(flags & FLAG_WDAY)) { 628 i = 0; 629 week_offset = first_wday_of(tm->tm_year); 630 while (i++ <= tm->tm_yday) { 631 if (week_offset++ >= 6) 632 week_offset = 0; 633 } 634 tm->tm_wday = week_offset; 635 flags |= FLAG_WDAY; 636 } 637 } 638 639 return __UNCONST(bp); 640 } 641 642 643 static const u_char * 644 conv_num(const unsigned char *buf, int *dest, uint llim, uint ulim) 645 { 646 uint result = 0; 647 unsigned char ch; 648 649 /* The limit also determines the number of valid digits. */ 650 uint rulim = ulim; 651 652 ch = *buf; 653 if (ch < '0' || ch > '9') 654 return NULL; 655 656 do { 657 result *= 10; 658 result += ch - '0'; 659 rulim /= 10; 660 ch = *++buf; 661 } while ((result * 10 <= ulim) && rulim && ch >= '0' && ch <= '9'); 662 663 if (result < llim || result > ulim) 664 return NULL; 665 666 *dest = result; 667 return buf; 668 } 669 670 static const u_char * 671 find_string(const u_char *bp, int *tgt, const char * const *n1, 672 const char * const *n2, int c) 673 { 674 int i; 675 size_t len; 676 677 /* check full name - then abbreviated ones */ 678 for (; n1 != NULL; n1 = n2, n2 = NULL) { 679 for (i = 0; i < c; i++, n1++) { 680 len = strlen(*n1); 681 if (strncasecmp(*n1, (const char *)bp, len) == 0) { 682 *tgt = i; 683 return bp + len; 684 } 685 } 686 } 687 688 /* Nothing matched */ 689 return NULL; 690 } 691
Indexes created Mon Sep 29 21:09:56 GMT 2025