stdtime/FreeBSD/strptime.c

   1 /*-
   2  * Copyright (c) 2014 Gary Mills
   3  * Copyright 2011, Nexenta Systems, Inc.  All rights reserved.
   4  * Copyright (c) 1994 Powerdog Industries.  All rights reserved.
   5  *
   6  * Copyright (c) 2011 The FreeBSD Foundation
   7  * All rights reserved.
   8  * Portions of this software were developed by David Chisnall
   9  * under sponsorship from the FreeBSD Foundation.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer
  18  *    in the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY POWERDOG INDUSTRIES ``AS IS'' AND ANY
  22  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE POWERDOG INDUSTRIES BE
  25  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  28  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  30  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  31  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  *
  33  * The views and conclusions contained in the software and documentation
  34  * are those of the authors and should not be interpreted as representing
  35  * official policies, either expressed or implied, of Powerdog Industries.
  36  */
  37
  38 #include <sys/cdefs.h>
  39 #ifndef lint
  40 #ifndef NOID
  41 static char copyright[] __unused =
  42 "@(#) Copyright (c) 1994 Powerdog Industries.  All rights reserved.";
  43 static char sccsid[] __unused = "@(#)strptime.c 0.1 (Powerdog) 94/03/27";
  44 #endif /* !defined NOID */
  45 #endif /* not lint */
  46 __FBSDID("$FreeBSD$");
  47
  48 #include "xlocale_private.h"
  49
  50 #include "namespace.h"
  51 #include <time.h>
  52 #include <ctype.h>
  53 #include <errno.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <pthread.h>
  58 #include "un-namespace.h"
  59 #include "libc_private.h"
  60 #include "timelocal.h"
  61 #include "tzfile.h"
  62
  63 time_t _mktime(struct tm *, const char *);
  64
  65 #define asizeof(a)      (sizeof(a) / sizeof((a)[0]))
  66
  67 enum {CONVERT_NONE, CONVERT_GMT, CONVERT_ZONE};
  68 enum week_kind { WEEK_U = 'U', WEEK_V = 'V', WEEK_W = 'W'};
  69
  70 #define _strptime(b,f,t,c,l)    _strptime0(b,f,t,c,l,FLAG_NONE,0,WEEK_U)
  71
  72 #define FLAG_NONE       0x01
  73 #define FLAG_YEAR       0x02
  74 #define FLAG_MONTH      0x04
  75 #define FLAG_YDAY       0x08
  76 #define FLAG_MDAY       0x10
  77 #define FLAG_WDAY       0x20
  78 #define FLAG_WEEK       0x40
  79 #define FLAG_CENTURY 0x100
  80 #define FLAG_YEAR_IN_CENTURY 0x200
  81
  82 /*
  83  * Calculate the week day of the first day of a year. Valid for
  84  * the Gregorian calendar, which began Sept 14, 1752 in the UK
  85  * and its colonies. Ref:
  86  * http://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week
  87  */
  88
  89 static int
  90 first_wday_of(int year)
  91 {
  92         return (((2 * (3 - (year / 100) % 4)) + (year % 100) +
  93                 ((year % 100) / 4) + (isleap(year) ? 6 : 0) + 1) % 7);
  94 }
  95
  96 static char *
  97 _strptime0(const char *buf, const char *fmt, struct tm *tm, int *convp, locale_t locale, int flags, int week_number, enum week_kind week_kind)
  98 {
  99         char    c;
 100         const char *ptr;
 101         int wday_offset;
 102         int     i, len;
 103         int Ealternative, Oalternative;
 104         const struct lc_time_T *tptr = __get_current_time_locale(locale);
 105         static int start_of_month[2][13] = {
 106                 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
 107                 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
 108         };
 109
 110         ptr = fmt;
 111         while (*ptr != 0) {
 112                 c = *ptr++;
 113
 114                 if (c != '%') {
 115                         if (isspace_l((unsigned char)c, locale))
 116                                 while (*buf != 0 &&
 117                                        isspace_l((unsigned char)*buf, locale))
 118                                         buf++;
 119                         else if (c != *buf++)
 120                                 return (NULL);
 121                         continue;
 122                 }
 123
 124                 Ealternative = 0;
 125                 Oalternative = 0;
 126 label:
 127                 c = *ptr++;
 128                 switch (c) {
 129                 case '%':
 130                         if (*buf++ != '%')
 131                                 return (NULL);
 132                         break;
 133
 134                 case '+':
 135                         buf = _strptime(buf, tptr->date_fmt, tm, convp, locale);
 136                         if (buf == NULL)
 137                                 return (NULL);
 138                         flags |= FLAG_WDAY | FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 139                         break;
 140
 141                 case 'C':
 142                         if (!isdigit_l((unsigned char)*buf, locale))
 143                                 return (NULL);
 144
 145                         /* XXX This will break for 3-digit centuries. */
 146                         len = 2;
 147                         for (i = 0; len && *buf != 0 &&
 148                              isdigit_l((unsigned char)*buf, locale); buf++) {
 149                                 i *= 10;
 150                                 i += *buf - '0';
 151                                 len--;
 152                         }
 153                         if (i < 19)
 154                                 return (NULL);
 155
 156                         if (flags & FLAG_YEAR_IN_CENTURY) {
 157                                 tm->tm_year = i * 100 + (tm->tm_year % 100) - TM_YEAR_BASE;
 158                                 flags &= ~FLAG_YEAR_IN_CENTURY;
 159                         } else {
 160                                 tm->tm_year = i * 100 - TM_YEAR_BASE;
 161                                 flags |= FLAG_YEAR;
 162                                 flags |= FLAG_CENTURY;
 163                         }
 164
 165                         break;
 166
 167                 case 'c':
 168                         buf = _strptime(buf, tptr->c_fmt, tm, convp, locale);
 169                         if (buf == NULL)
 170                                 return (NULL);
 171                         flags |= FLAG_WDAY | FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 172                         flags &= ~(FLAG_CENTURY | FLAG_YEAR_IN_CENTURY);
 173                         break;
 174
 175                 case 'D':
 176                         buf = _strptime(buf, "%m/%d/%y", tm, convp, locale);
 177                         if (buf == NULL)
 178                                 return (NULL);
 179                         flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 180                         flags &= ~(FLAG_CENTURY | FLAG_YEAR_IN_CENTURY);
 181                         break;
 182
 183                 case 'E':
 184                         if (Ealternative || Oalternative)
 185                                 break;
 186                         Ealternative++;
 187                         if (*ptr == '%') return (NULL);
 188                         goto label;
 189
 190                 case 'O':
 191                         if (Ealternative || Oalternative)
 192                                 break;
 193                         Oalternative++;
 194                         if (*ptr == '%') return (NULL);
 195                         goto label;
 196
 197                 case 'F':
 198                         buf = _strptime(buf, "%Y-%m-%d", tm, convp, locale);
 199                         if (buf == NULL)
 200                                 return (NULL);
 201                         flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 202                         flags &= ~(FLAG_CENTURY | FLAG_YEAR_IN_CENTURY);
 203                         break;
 204
 205                 case 'R':
 206                         buf = _strptime(buf, "%H:%M", tm, convp, locale);
 207                         if (buf == NULL)
 208                                 return (NULL);
 209                         break;
 210
 211                 case 'r':
 212                         buf = _strptime(buf, tptr->ampm_fmt, tm, convp, locale);
 213                         if (buf == NULL)
 214                                 return (NULL);
 215                         break;
 216
 217                 case 'T':
 218                         buf = _strptime(buf, "%H:%M:%S", tm, convp, locale);
 219                         if (buf == NULL)
 220                                 return (NULL);
 221                         break;
 222
 223                 case 'X':
 224                         buf = _strptime(buf, tptr->X_fmt, tm, convp, locale);
 225                         if (buf == NULL)
 226                                 return (NULL);
 227                         break;
 228
 229                 case 'x':
 230                         buf = _strptime(buf, tptr->x_fmt, tm, convp, locale);
 231                         if (buf == NULL)
 232                                 return (NULL);
 233                         flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
 234                         flags &= ~(FLAG_CENTURY | FLAG_YEAR_IN_CENTURY);
 235                         break;
 236
 237                 case 'j':
 238                         if (!isdigit_l((unsigned char)*buf, locale))
 239                                 return (NULL);
 240
 241                         len = 3;
 242                         for (i = 0; len && *buf != 0 &&
 243                              isdigit_l((unsigned char)*buf, locale); buf++){
 244                                 i *= 10;
 245                                 i += *buf - '0';
 246                                 len--;
 247                         }
 248                         if (i < 1 || i > 366)
 249                                 return (NULL);
 250
 251                         tm->tm_yday = i - 1;
 252                         flags |= FLAG_YDAY;
 253
 254                         break;
 255
 256                 case 'M':
 257                 case 'S':
 258                         if (*buf == 0 ||
 259                                 isspace_l((unsigned char)*buf, locale))
 260                                 break;
 261
 262                         if (!isdigit_l((unsigned char)*buf, locale))
 263                                 return (NULL);
 264
 265                         len = 2;
 266                         for (i = 0; len && *buf != 0 &&
 267                                 isdigit_l((unsigned char)*buf, locale); buf++){
 268                                 i *= 10;
 269                                 i += *buf - '0';
 270                                 len--;
 271                         }
 272
 273                         if (c == 'M') {
 274                                 if (i > 59)
 275                                         return (NULL);
 276                                 tm->tm_min = i;
 277                         } else {
 278                                 if (i > 60)
 279                                         return (NULL);
 280                                 tm->tm_sec = i;
 281                         }
 282
 283                         break;
 284
 285                 case 'H':
 286                 case 'I':
 287                 case 'k':
 288                 case 'l':
 289                         /*
 290                          * Of these, %l is the only specifier explicitly
 291                          * documented as not being zero-padded.  However,
 292                          * there is no harm in allowing zero-padding.
 293                          *
 294                          * XXX The %l specifier may gobble one too many
 295                          * digits if used incorrectly.
 296                          */
 297                         if (!isdigit_l((unsigned char)*buf, locale))
 298                                 return (NULL);
 299
 300                         len = 2;
 301                         for (i = 0; len && *buf != 0 &&
 302                              isdigit_l((unsigned char)*buf, locale); buf++) {
 303                                 i *= 10;
 304                                 i += *buf - '0';
 305                                 len--;
 306                         }
 307                         if (c == 'H' || c == 'k') {
 308                                 if (i > 23)
 309                                         return (NULL);
 310                         } else if (i > 12)
 311                                 return (NULL);
 312
 313                         tm->tm_hour = i;
 314
 315                         break;
 316
 317                 case 'p':
 318                         /*
 319                          * XXX This is bogus if parsed before hour-related
 320                          * specifiers.
 321                          */
 322                         len = strlen(tptr->am);
 323                         if (strncasecmp_l(buf, tptr->am, len, locale) == 0) {
 324                                 if (tm->tm_hour > 12)
 325                                         return (NULL);
 326                                 if (tm->tm_hour == 12)
 327                                         tm->tm_hour = 0;
 328                                 buf += len;
 329                                 break;
 330                         }
 331
 332                         len = strlen(tptr->pm);
 333                         if (strncasecmp_l(buf, tptr->pm, len, locale) == 0) {
 334                                 if (tm->tm_hour > 12)
 335                                         return (NULL);
 336                                 if (tm->tm_hour != 12)
 337                                         tm->tm_hour += 12;
 338                                 buf += len;
 339                                 break;
 340                         }
 341
 342                         return (NULL);
 343
 344                 case 'A':
 345                 case 'a':
 346                         for (i = 0; i < asizeof(tptr->weekday); i++) {
 347                                 len = strlen(tptr->weekday[i]);
 348                                 if (strncasecmp_l(buf, tptr->weekday[i],
 349                                                 len, locale) == 0)
 350                                         break;
 351                                 len = strlen(tptr->wday[i]);
 352                                 if (strncasecmp_l(buf, tptr->wday[i],
 353                                                 len, locale) == 0)
 354                                         break;
 355                         }
 356                         if (i == asizeof(tptr->weekday))
 357                                 return (NULL);
 358
 359                         buf += len;
 360                         tm->tm_wday = i;
 361                         flags |= FLAG_WDAY;
 362                         break;
 363
 364                 case 'U':       /* Sunday week */
 365                 case 'V':       /* ISO 8601 week */
 366                 case 'W':       /* Monday week */
 367                         if (!isdigit_l((unsigned char)*buf, locale))
 368                                 return (NULL);
 369
 370                         len = 2;
 371                         for (i = 0; len && *buf != 0 &&
 372                              isdigit_l((unsigned char)*buf, locale); buf++) {
 373                                 i *= 10;
 374                                 i += *buf - '0';
 375                                 len--;
 376                         }
 377                         if (i > 53)
 378                                 return (NULL);
 379                         if (c == WEEK_V && i < 1)
 380                                 return (NULL);
 381
 382                         week_number = i;
 383                         week_kind = c;
 384                         flags |= FLAG_WEEK;
 385
 386                         break;
 387
 388                 case 'u':       /* [1,7] */
 389                 case 'w':       /* [0,6] */
 390                         if (!isdigit_l((unsigned char)*buf, locale))
 391                                 return (NULL);
 392
 393                         i = *buf - '0';
 394                         if (i > 6 + (c == 'u'))
 395                                 return (NULL);
 396                         if (i == 7)
 397                                 i = 0;
 398
 399                         tm->tm_wday = i;
 400                         flags |= FLAG_WDAY;
 401                         buf++;
 402
 403                         break;
 404
 405                 case 'e':
 406                         /*
 407                          * With %e format, our strftime(3) adds a blank space
 408                          * before single digits.
 409                          */
 410                         if (*buf != 0 &&
 411                             isspace_l((unsigned char)*buf, locale))
 412                                buf++;
 413                         /* FALLTHROUGH */
 414                 case 'd':
 415                         /*
 416                          * The %e specifier was once explicitly documented as
 417                          * not being zero-padded but was later changed to
 418                          * equivalent to %d.  There is no harm in allowing
 419                          * such padding.
 420                          *
 421                          * XXX The %e specifier may gobble one too many
 422                          * digits if used incorrectly.
 423                          */
 424                         /* Leading space is ok if date is single digit */
 425                         len = 2;
 426                         if (isspace_l((unsigned char)buf[0], locale) &&
 427                                 isdigit_l((unsigned char)buf[1], locale) &&
 428                                 !isdigit_l((unsigned char)buf[2], locale)) {
 429                                 len = 1;
 430                                 buf++;
 431                         }
 432                         if (!isdigit_l((unsigned char)*buf, locale))
 433                                 return (NULL);
 434
 435                         for (i = 0; len && *buf != 0 &&
 436                              isdigit_l((unsigned char)*buf, locale); buf++) {
 437                                 i *= 10;
 438                                 i += *buf - '0';
 439                                 len--;
 440                         }
 441                         if (i > 31)
 442                                 return (NULL);
 443
 444                         tm->tm_mday = i;
 445                         flags |= FLAG_MDAY;
 446
 447                         break;
 448
 449                 case 'B':
 450                 case 'b':
 451                 case 'h':
 452                         for (i = 0; i < asizeof(tptr->month); i++) {
 453                                 if (Oalternative) {
 454                                         if (c == 'B') {
 455                                                 len = strlen(tptr->alt_month[i]);
 456                                                 if (strncasecmp_l(buf,
 457                                                                 tptr->alt_month[i],
 458                                                                 len, locale) == 0)
 459                                                         break;
 460                                         }
 461                                 } else {
 462                                         len = strlen(tptr->month[i]);
 463                                         if (strncasecmp_l(buf, tptr->month[i],
 464                                                         len, locale) == 0)
 465                                                 break;
 466                                 }
 467                         }
 468                         /*
 469                          * Try the abbreviated month name if the full name
 470                          * wasn't found and Oalternative was not requested.
 471                          */
 472                         if (i == asizeof(tptr->month) && !Oalternative) {
 473                                 for (i = 0; i < asizeof(tptr->month); i++) {
 474                                         len = strlen(tptr->mon[i]);
 475                                         if (strncasecmp_l(buf, tptr->mon[i],
 476                                                         len, locale) == 0)
 477                                                 break;
 478                                 }
 479                         }
 480                         if (i == asizeof(tptr->month))
 481                                 return (NULL);
 482
 483                         tm->tm_mon = i;
 484                         buf += len;
 485                         flags |= FLAG_MONTH;
 486
 487                         break;
 488
 489                 case 'm':
 490                         if (!isdigit_l((unsigned char)*buf, locale))
 491                                 return (NULL);
 492
 493                         len = 2;
 494                         for (i = 0; len && *buf != 0 &&
 495                              isdigit_l((unsigned char)*buf, locale); buf++) {
 496                                 i *= 10;
 497                                 i += *buf - '0';
 498                                 len--;
 499                         }
 500                         if (i < 1 || i > 12)
 501                                 return (NULL);
 502
 503                         tm->tm_mon = i - 1;
 504                         flags |= FLAG_MONTH;
 505
 506                         break;
 507
 508                 case 's':
 509                         {
 510                         char *cp;
 511                         int sverrno;
 512                         long n;
 513                         time_t t;
 514
 515                         sverrno = errno;
 516                         errno = 0;
 517                         n = strtol_l(buf, &cp, 10, locale);
 518                         if (errno == ERANGE || (long)(t = n) != n) {
 519                                 errno = sverrno;
 520                                 return (NULL);
 521                         }
 522                         errno = sverrno;
 523                         buf = cp;
 524                         if (gmtime_r(&t, tm) == NULL)
 525                                 return (NULL);
 526                         *convp = CONVERT_GMT;
 527                         flags |= FLAG_YDAY | FLAG_WDAY | FLAG_MONTH |
 528                             FLAG_MDAY | FLAG_YEAR;
 529                         flags &= ~(FLAG_CENTURY | FLAG_YEAR_IN_CENTURY);
 530                         }
 531                         break;
 532
 533                 case 'Y':
 534                 case 'y':
 535                         if (*buf == 0 ||
 536                             isspace_l((unsigned char)*buf, locale))
 537                                 break;
 538
 539                         if (!isdigit_l((unsigned char)*buf, locale))
 540                                 return (NULL);
 541
 542 #if __DARWIN_UNIX03
 543                         if (c == 'Y') {
 544                                 int savei = 0;
 545                                 const char *savebuf = buf;
 546                                 int64_t i64 = 0;
 547                                 int overflow = 0;
 548
 549                                 for (len = 0; *buf != 0 && isdigit_l((unsigned char)*buf, locale); buf++) {
 550                                         i64 *= 10;
 551                                         i64 += *buf - '0';
 552                                         if (++len <= 4) {
 553                                                 savei = i64;
 554                                                 savebuf = buf + 1;
 555                                         }
 556                                         if (i64 > INT_MAX) {
 557                                                 overflow++;
 558                                                 break;
 559                                         }
 560                                 }
 561                                 /*
 562                                  * Conformance requires %Y to be more then 4
 563                                  * digits.  However, there are several cases
 564                                  * where %Y is immediately followed by other
 565                                  * digits values.  So we do the conformance
 566                                  * case first (as many digits as possible),
 567                                  * and if we fail, we backup and try just 4
 568                                  * digits for %Y.
 569                                  */
 570                                 if (len > 4 && !overflow) {
 571                                         struct tm savetm = *tm;
 572                                         int saveconv = *convp;
 573                                         const char *saveptr = ptr;
 574                                         char *ret;
 575
 576                                         if (i64 < 1900)
 577                                                 return 0;
 578
 579                                         tm->tm_year = i64 - 1900;
 580
 581                                         if (*buf != 0 && isspace_l((unsigned char)*buf, locale))
 582                                                 while (*ptr != 0 && !isspace_l((unsigned char)*ptr, locale) && *ptr != '%')
 583                                                         ptr++;
 584                                         ret = _strptime0(buf, ptr, tm, convp, locale, flags, week_number, week_kind);
 585                                         if (ret) return ret;
 586                                         /* Failed, so try 4-digit year */
 587                                         *tm = savetm;
 588                                         *convp = saveconv;
 589                                         ptr = saveptr;
 590                                 }
 591                                 buf = savebuf;
 592                                 i = savei;
 593                         } else {
 594                                 len = 2;
 595 #else /* !__DARWIN_UNIX03 */
 596                                 len = (c == 'Y') ? 4 : 2;
 597 #endif /* __DARWIN_UNIX03 */
 598
 599                                 for (i = 0; len && *buf != 0 &&
 600                                          isdigit_l((unsigned char)*buf, locale); buf++) {
 601                                         i *= 10;
 602                                         i += *buf - '0';
 603                                         len--;
 604                                 }
 605 #if __DARWIN_UNIX03
 606                         }
 607 #endif /* __DARWIN_UNIX03 */
 608
 609                         if (i < 0)
 610                                 return (NULL);
 611
 612                         if (c == 'Y'){
 613                                 i -= TM_YEAR_BASE;
 614                         } else if (c == 'y' && flags & FLAG_CENTURY) {
 615                                 i = tm->tm_year + (i % 100);
 616                                 flags &= ~FLAG_CENTURY;
 617                         } else if (c == 'y'){
 618                                 if (i < 69) i += 100;
 619                                 flags |= FLAG_YEAR_IN_CENTURY;
 620                         }
 621
 622                         tm->tm_year = i;
 623                         flags |= FLAG_YEAR;
 624                         if (c == 'Y'){
 625                                 flags &= ~(FLAG_CENTURY | FLAG_YEAR_IN_CENTURY);
 626                         }
 627
 628                         break;
 629
 630                 case 'Z':
 631                         {
 632                                 const char *cp;
 633                                 size_t tzlen, len;
 634
 635                                 for (cp = buf; *cp &&
 636                                          isupper_l((unsigned char)*cp, locale); ++cp) {
 637                                         /*empty*/
 638                                 }
 639                                 len = cp - buf;
 640                                 if (len == 3 && strncmp(buf, "GMT", 3) == 0) {
 641                                         *convp = CONVERT_GMT;
 642                                         buf += len;
 643                                         break;
 644                                 }
 645
 646                                 tzset();
 647                                 tzlen = strlen(tzname[0]);
 648                                 if (len == tzlen && strncmp(buf, tzname[0], tzlen) == 0) {
 649                                         tm->tm_isdst = 0;
 650                                         buf += len;
 651                                         break;
 652                                 }
 653                                 tzlen = strlen(tzname[1]);
 654                                 if (len == tzlen && strncmp(buf, tzname[1], tzlen) == 0) {
 655                                         tm->tm_isdst = 1;
 656                                         buf += len;
 657                                         break;
 658                                 }
 659                                 return (NULL);
 660                         }
 661
 662                 case 'z':
 663                         {
 664                                 char sign;
 665                                 int hr, min;
 666                                 if ((buf[0] != '+' && buf[0] != '-')
 667                                         || !isdigit_l((unsigned char)buf[1], locale)
 668                                         || !isdigit_l((unsigned char)buf[2], locale)
 669                                         || !isdigit_l((unsigned char)buf[3], locale)
 670                                         || !isdigit_l((unsigned char)buf[4], locale))
 671                                         return 0;
 672                                 sscanf(buf, "%c%2d%2d", &sign, &hr, &min);
 673                                 *convp = CONVERT_ZONE;
 674                                 tm->tm_gmtoff = 60 * (60 * hr + min);
 675                                 if (sign == '-')
 676                                         tm->tm_gmtoff = -tm->tm_gmtoff;
 677                                 buf += 5;
 678                         }
 679                         break;
 680
 681                 case 'n':
 682                 case 't':
 683                         if (!isspace((unsigned char)*buf))
 684                                 return 0;
 685                         while (isspace_l((unsigned char)*buf, locale))
 686                                 buf++;
 687                         break;
 688
 689                 default:
 690                         return (NULL);
 691                 }
 692         }
 693
 694         if (!(flags & FLAG_YDAY) && (flags & FLAG_YEAR)) {
 695                 if ((flags & (FLAG_MONTH | FLAG_MDAY)) ==
 696                     (FLAG_MONTH | FLAG_MDAY)) {
 697                         tm->tm_yday = start_of_month[isleap(tm->tm_year +
 698                             TM_YEAR_BASE)][tm->tm_mon] + (tm->tm_mday - 1);
 699                         flags |= FLAG_YDAY;
 700                 } else if (flags & FLAG_WEEK){
 701                         if (!(flags & FLAG_WDAY)) {
 702                                 tm->tm_wday = week_kind == WEEK_U ? TM_SUNDAY : TM_MONDAY;
 703                                 flags |= FLAG_WDAY;
 704                         }
 705
 706                         struct tm t = {0};
 707                         t.tm_mday = week_kind == WEEK_V ? 4 : 1;
 708                         t.tm_hour = 12; /* avoid any DST effects */
 709                         t.tm_year = tm->tm_year;
 710                         if (timegm(&t) == (time_t)-1) return 0;
 711
 712                         int off = t.tm_wday;
 713                         int wday = tm->tm_wday;
 714
 715                         if (week_kind != WEEK_U) {
 716                                 off = (off + 6) % 7;
 717                                 wday = (wday + 6) % 7;
 718                         }
 719
 720                         if (week_kind == WEEK_V) {
 721                                 t.tm_mday = 7 * week_number + wday - off - 3;
 722                         } else {
 723                                 if(off == 0) off = 7;
 724                                 t.tm_mday = 7 * week_number + wday - off + 1;
 725                         }
 726                         if (timegm(&t) == (time_t)-1) return 0;
 727
 728                         tm->tm_yday = t.tm_yday;
 729
 730                         flags |= FLAG_YDAY;
 731                 }
 732         }
 733
 734         if ((flags & (FLAG_YEAR | FLAG_YDAY)) == (FLAG_YEAR | FLAG_YDAY)) {
 735                 if (!(flags & FLAG_MONTH)) {
 736                         i = 0;
 737                         while (tm->tm_yday >=
 738                             start_of_month[isleap(tm->tm_year +
 739                             TM_YEAR_BASE)][i])
 740                                 i++;
 741                         if (i > 12) {
 742                                 i = 1;
 743                                 tm->tm_yday -=
 744                                     start_of_month[isleap(tm->tm_year +
 745                                     TM_YEAR_BASE)][12];
 746                                 tm->tm_year++;
 747                         }
 748                         tm->tm_mon = i - 1;
 749                         flags |= FLAG_MONTH;
 750                 }
 751                 if (!(flags & FLAG_MDAY)) {
 752                         tm->tm_mday = tm->tm_yday -
 753                             start_of_month[isleap(tm->tm_year + TM_YEAR_BASE)]
 754                             [tm->tm_mon] + 1;
 755                         flags |= FLAG_MDAY;
 756                 }
 757                 if (!(flags & FLAG_WDAY)) {
 758                         i = 0;
 759                         wday_offset = first_wday_of(tm->tm_year);
 760                         while (i++ <= tm->tm_yday) {
 761                                 if (wday_offset++ >= 6)
 762                                         wday_offset = 0;
 763                         }
 764                         tm->tm_wday = wday_offset;
 765                         flags |= FLAG_WDAY;
 766                 }
 767         }
 768
 769         return ((char *)buf);
 770 }
 771
 772
 773 char *
 774 strptime(const char * __restrict buf, const char * __restrict fmt,
 775                  struct tm * __restrict tm)
 776 {
 777         return strptime_l(buf, fmt, tm, __current_locale());
 778 }
 779
 780 extern time_t timeoff(struct tm *, long);
 781
 782 char *
 783 strptime_l(const char * __restrict buf, const char * __restrict fmt,
 784     struct tm * __restrict tm, locale_t loc)
 785 {
 786         char *ret;
 787         int conv;
 788
 789         NORMALIZE_LOCALE(loc);
 790         conv = CONVERT_NONE;
 791         tm->tm_zone = NULL;
 792         ret = _strptime(buf, fmt, tm, &conv, loc);
 793         if (ret) {
 794                 time_t t;
 795
 796                 switch(conv) {
 797                 case CONVERT_GMT:
 798                         t = timegm(tm);
 799                         localtime_r(&t, tm);
 800                         break;
 801                 case CONVERT_ZONE:
 802                     {
 803                         long offset = tm->tm_gmtoff;
 804                         tm->tm_gmtoff = 0;
 805                         t = timeoff(tm, offset);
 806                         localtime_r(&t, tm);
 807                         break;
 808                     }
 809                 }
 810         }
 811
 812         return (ret);
 813 }