lib/libc/stdtime/strptime.c

   1 /*
   2  * Powerdog Industries kindly requests feedback from anyone modifying
   3  * this function:
   4  *
   5  * Date: Thu, 05 Jun 1997 23:17:17 -0400
   6  * From: Kevin Ruddy <kevin.ruddy@powerdog.com>
   7  * To: James FitzGibbon <james@nexis.net>
   8  * Subject: Re: Use of your strptime(3) code (fwd)
   9  *
  10  * The reason for the "no mod" clause was so that modifications would
  11  * come back and we could integrate them and reissue so that a wider
  12  * audience could use it (thereby spreading the wealth).  This has
  13  * made it possible to get strptime to work on many operating systems.
  14  * I'm not sure why that's "plain unacceptable" to the FreeBSD team.
  15  *
  16  * Anyway, you can change it to "with or without modification" as
  17  * you see fit.  Enjoy.
  18  *
  19  * Kevin Ruddy
  20  * Powerdog Industries, Inc.
  21  */
  22 /*
  23  * Copyright (c) 1994 Powerdog Industries.  All rights reserved.
  24  *
  25  * Redistribution and use in source and binary forms, with or without
  26  * modification, are permitted provided that the following conditions
  27  * are met:
  28  * 1. Redistributions of source code must retain the above copyright
  29  *    notice, this list of conditions and the following disclaimer.
  30  * 2. Redistributions in binary form must reproduce the above copyright
  31  *    notice, this list of conditions and the following disclaimer
  32  *    in the documentation and/or other materials provided with the
  33  *    distribution.
  34  * 3. All advertising materials mentioning features or use of this
  35  *    software must display the following acknowledgement:
  36  *      This product includes software developed by Powerdog Industries.
  37  * 4. The name of Powerdog Industries may not be used to endorse or
  38  *    promote products derived from this software without specific prior
  39  *    written permission.
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY POWERDOG INDUSTRIES ``AS IS'' AND ANY
  42  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  44  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE POWERDOG INDUSTRIES BE
  45  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  46  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  47  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  48  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  49  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  50  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  51  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  52  */
  53
  54 #include <sys/cdefs.h>
  55 #ifndef lint
  56 #ifndef NOID
  57 static char copyright[] __unused =
  58 "@(#) Copyright (c) 1994 Powerdog Industries.  All rights reserved.";
  59 static char sccsid[] __unused = "@(#)strptime.c 0.1 (Powerdog) 94/03/27";
  60 #endif /* !defined NOID */
  61 #endif /* not lint */
  62 __FBSDID("$FreeBSD$");
  63
  64 #include "namespace.h"
  65 #include <time.h>
  66 #include <ctype.h>
  67 #include <errno.h>
  68 #include <stdlib.h>
  69 #include <string.h>
  70 #include <pthread.h>
  71 #include "un-namespace.h"
  72 #include "libc_private.h"
  73 #include "timelocal.h"
  74
  75 static char * _strptime(const char *, const char *, struct tm *, int *);
  76
  77 #define asizeof(a)      (sizeof (a) / sizeof ((a)[0]))
  78
  79 static char *
  80 _strptime(const char *buf, const char *fmt, struct tm *tm, int *GMTp)
  81 {
  82         char    c;
  83         const char *ptr;
  84         int     i,
  85                 len;
  86         int Ealternative, Oalternative;
  87         struct lc_time_T *tptr = __get_current_time_locale();
  88
  89         ptr = fmt;
  90         while (*ptr != 0) {
  91                 if (*buf == 0)
  92                         break;
  93
  94                 c = *ptr++;
  95
  96                 if (c != '%') {
  97                         if (isspace((unsigned char)c))
  98                                 while (*buf != 0 && isspace((unsigned char)*buf))
  99                                         buf++;
 100                         else if (c != *buf++)
 101                                 return 0;
 102                         continue;
 103                 }
 104
 105                 Ealternative = 0;
 106                 Oalternative = 0;
 107 label:
 108                 c = *ptr++;
 109                 switch (c) {
 110                 case 0:
 111                 case '%':
 112                         if (*buf++ != '%')
 113                                 return 0;
 114                         break;
 115
 116                 case '+':
 117                         buf = _strptime(buf, tptr->date_fmt, tm, GMTp);
 118                         if (buf == 0)
 119                                 return 0;
 120                         break;
 121
 122                 case 'C':
 123                         if (!isdigit((unsigned char)*buf))
 124                                 return 0;
 125
 126                         /* XXX This will break for 3-digit centuries. */
 127                         len = 2;
 128                         for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
 129                                 i *= 10;
 130                                 i += *buf - '0';
 131                                 len--;
 132                         }
 133                         if (i < 19)
 134                                 return 0;
 135
 136                         tm->tm_year = i * 100 - 1900;
 137                         break;
 138
 139                 case 'c':
 140                         buf = _strptime(buf, tptr->c_fmt, tm, GMTp);
 141                         if (buf == 0)
 142                                 return 0;
 143                         break;
 144
 145                 case 'D':
 146                         buf = _strptime(buf, "%m/%d/%y", tm, GMTp);
 147                         if (buf == 0)
 148                                 return 0;
 149                         break;
 150
 151                 case 'E':
 152                         if (Ealternative || Oalternative)
 153                                 break;
 154                         Ealternative++;
 155                         goto label;
 156
 157                 case 'O':
 158                         if (Ealternative || Oalternative)
 159                                 break;
 160                         Oalternative++;
 161                         goto label;
 162
 163                 case 'F':
 164                         buf = _strptime(buf, "%Y-%m-%d", tm, GMTp);
 165                         if (buf == 0)
 166                                 return 0;
 167                         break;
 168
 169                 case 'R':
 170                         buf = _strptime(buf, "%H:%M", tm, GMTp);
 171                         if (buf == 0)
 172                                 return 0;
 173                         break;
 174
 175                 case 'r':
 176                         buf = _strptime(buf, tptr->ampm_fmt, tm, GMTp);
 177                         if (buf == 0)
 178                                 return 0;
 179                         break;
 180
 181                 case 'T':
 182                         buf = _strptime(buf, "%H:%M:%S", tm, GMTp);
 183                         if (buf == 0)
 184                                 return 0;
 185                         break;
 186
 187                 case 'X':
 188                         buf = _strptime(buf, tptr->X_fmt, tm, GMTp);
 189                         if (buf == 0)
 190                                 return 0;
 191                         break;
 192
 193                 case 'x':
 194                         buf = _strptime(buf, tptr->x_fmt, tm, GMTp);
 195                         if (buf == 0)
 196                                 return 0;
 197                         break;
 198
 199                 case 'j':
 200                         if (!isdigit((unsigned char)*buf))
 201                                 return 0;
 202
 203                         len = 3;
 204                         for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
 205                                 i *= 10;
 206                                 i += *buf - '0';
 207                                 len--;
 208                         }
 209                         if (i < 1 || i > 366)
 210                                 return 0;
 211
 212                         tm->tm_yday = i - 1;
 213                         break;
 214
 215                 case 'M':
 216                 case 'S':
 217                         if (*buf == 0 || isspace((unsigned char)*buf))
 218                                 break;
 219
 220                         if (!isdigit((unsigned char)*buf))
 221                                 return 0;
 222
 223                         len = 2;
 224                         for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
 225                                 i *= 10;
 226                                 i += *buf - '0';
 227                                 len--;
 228                         }
 229
 230                         if (c == 'M') {
 231                                 if (i > 59)
 232                                         return 0;
 233                                 tm->tm_min = i;
 234                         } else {
 235                                 if (i > 60)
 236                                         return 0;
 237                                 tm->tm_sec = i;
 238                         }
 239
 240                         if (*buf != 0 && isspace((unsigned char)*buf))
 241                                 while (*ptr != 0 && !isspace((unsigned char)*ptr))
 242                                         ptr++;
 243                         break;
 244
 245                 case 'H':
 246                 case 'I':
 247                 case 'k':
 248                 case 'l':
 249                         /*
 250                          * Of these, %l is the only specifier explicitly
 251                          * documented as not being zero-padded.  However,
 252                          * there is no harm in allowing zero-padding.
 253                          *
 254                          * XXX The %l specifier may gobble one too many
 255                          * digits if used incorrectly.
 256                          */
 257                         if (!isdigit((unsigned char)*buf))
 258                                 return 0;
 259
 260                         len = 2;
 261                         for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
 262                                 i *= 10;
 263                                 i += *buf - '0';
 264                                 len--;
 265                         }
 266                         if (c == 'H' || c == 'k') {
 267                                 if (i > 23)
 268                                         return 0;
 269                         } else if (i > 12)
 270                                 return 0;
 271
 272                         tm->tm_hour = i;
 273
 274                         if (*buf != 0 && isspace((unsigned char)*buf))
 275                                 while (*ptr != 0 && !isspace((unsigned char)*ptr))
 276                                         ptr++;
 277                         break;
 278
 279                 case 'p':
 280                         /*
 281                          * XXX This is bogus if parsed before hour-related
 282                          * specifiers.
 283                          */
 284                         len = strlen(tptr->am);
 285                         if (strncasecmp(buf, tptr->am, len) == 0) {
 286                                 if (tm->tm_hour > 12)
 287                                         return 0;
 288                                 if (tm->tm_hour == 12)
 289                                         tm->tm_hour = 0;
 290                                 buf += len;
 291                                 break;
 292                         }
 293
 294                         len = strlen(tptr->pm);
 295                         if (strncasecmp(buf, tptr->pm, len) == 0) {
 296                                 if (tm->tm_hour > 12)
 297                                         return 0;
 298                                 if (tm->tm_hour != 12)
 299                                         tm->tm_hour += 12;
 300                                 buf += len;
 301                                 break;
 302                         }
 303
 304                         return 0;
 305
 306                 case 'A':
 307                 case 'a':
 308                         for (i = 0; i < asizeof(tptr->weekday); i++) {
 309                                 len = strlen(tptr->weekday[i]);
 310                                 if (strncasecmp(buf, tptr->weekday[i],
 311                                                 len) == 0)
 312                                         break;
 313                                 len = strlen(tptr->wday[i]);
 314                                 if (strncasecmp(buf, tptr->wday[i],
 315                                                 len) == 0)
 316                                         break;
 317                         }
 318                         if (i == asizeof(tptr->weekday))
 319                                 return 0;
 320
 321                         tm->tm_wday = i;
 322                         buf += len;
 323                         break;
 324
 325                 case 'U':
 326                 case 'W':
 327                         /*
 328                          * XXX This is bogus, as we can not assume any valid
 329                          * information present in the tm structure at this
 330                          * point to calculate a real value, so just check the
 331                          * range for now.
 332                          */
 333                         if (!isdigit((unsigned char)*buf))
 334                                 return 0;
 335
 336                         len = 2;
 337                         for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
 338                                 i *= 10;
 339                                 i += *buf - '0';
 340                                 len--;
 341                         }
 342                         if (i > 53)
 343                                 return 0;
 344
 345                         if (*buf != 0 && isspace((unsigned char)*buf))
 346                                 while (*ptr != 0 && !isspace((unsigned char)*ptr))
 347                                         ptr++;
 348                         break;
 349
 350                 case 'w':
 351                         if (!isdigit((unsigned char)*buf))
 352                                 return 0;
 353
 354                         i = *buf - '0';
 355                         if (i > 6)
 356                                 return 0;
 357
 358                         tm->tm_wday = i;
 359
 360                         if (*buf != 0 && isspace((unsigned char)*buf))
 361                                 while (*ptr != 0 && !isspace((unsigned char)*ptr))
 362                                         ptr++;
 363                         break;
 364
 365                 case 'd':
 366                 case 'e':
 367                         /*
 368                          * The %e specifier is explicitly documented as not
 369                          * being zero-padded but there is no harm in allowing
 370                          * such padding.
 371                          *
 372                          * XXX The %e specifier may gobble one too many
 373                          * digits if used incorrectly.
 374                          */
 375                         if (!isdigit((unsigned char)*buf))
 376                                 return 0;
 377
 378                         len = 2;
 379                         for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
 380                                 i *= 10;
 381                                 i += *buf - '0';
 382                                 len--;
 383                         }
 384                         if (i > 31)
 385                                 return 0;
 386
 387                         tm->tm_mday = i;
 388
 389                         if (*buf != 0 && isspace((unsigned char)*buf))
 390                                 while (*ptr != 0 && !isspace((unsigned char)*ptr))
 391                                         ptr++;
 392                         break;
 393
 394                 case 'B':
 395                 case 'b':
 396                 case 'h':
 397                         for (i = 0; i < asizeof(tptr->month); i++) {
 398                                 if (Oalternative) {
 399                                         if (c == 'B') {
 400                                                 len = strlen(tptr->alt_month[i]);
 401                                                 if (strncasecmp(buf,
 402                                                                 tptr->alt_month[i],
 403                                                                 len) == 0)
 404                                                         break;
 405                                         }
 406                                 } else {
 407                                         len = strlen(tptr->month[i]);
 408                                         if (strncasecmp(buf, tptr->month[i],
 409                                                         len) == 0)
 410                                                 break;
 411                                         len = strlen(tptr->mon[i]);
 412                                         if (strncasecmp(buf, tptr->mon[i],
 413                                                         len) == 0)
 414                                                 break;
 415                                 }
 416                         }
 417                         if (i == asizeof(tptr->month))
 418                                 return 0;
 419
 420                         tm->tm_mon = i;
 421                         buf += len;
 422                         break;
 423
 424                 case 'm':
 425                         if (!isdigit((unsigned char)*buf))
 426                                 return 0;
 427
 428                         len = 2;
 429                         for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
 430                                 i *= 10;
 431                                 i += *buf - '0';
 432                                 len--;
 433                         }
 434                         if (i < 1 || i > 12)
 435                                 return 0;
 436
 437                         tm->tm_mon = i - 1;
 438
 439                         if (*buf != 0 && isspace((unsigned char)*buf))
 440                                 while (*ptr != 0 && !isspace((unsigned char)*ptr))
 441                                         ptr++;
 442                         break;
 443
 444                 case 's':
 445                         {
 446                         char *cp;
 447                         int sverrno;
 448                         long n;
 449                         time_t t;
 450
 451                         sverrno = errno;
 452                         errno = 0;
 453                         n = strtol(buf, &cp, 10);
 454                         if (errno == ERANGE || (long)(t = n) != n) {
 455                                 errno = sverrno;
 456                                 return 0;
 457                         }
 458                         errno = sverrno;
 459                         buf = cp;
 460                         gmtime_r(&t, tm);
 461                         *GMTp = 1;
 462                         }
 463                         break;
 464
 465                 case 'Y':
 466                 case 'y':
 467                         if (*buf == 0 || isspace((unsigned char)*buf))
 468                                 break;
 469
 470                         if (!isdigit((unsigned char)*buf))
 471                                 return 0;
 472
 473                         len = (c == 'Y') ? 4 : 2;
 474                         for (i = 0; len && *buf != 0 && isdigit((unsigned char)*buf); buf++) {
 475                                 i *= 10;
 476                                 i += *buf - '0';
 477                                 len--;
 478                         }
 479                         if (c == 'Y')
 480                                 i -= 1900;
 481                         if (c == 'y' && i < 69)
 482                                 i += 100;
 483                         if (i < 0)
 484                                 return 0;
 485
 486                         tm->tm_year = i;
 487
 488                         if (*buf != 0 && isspace((unsigned char)*buf))
 489                                 while (*ptr != 0 && !isspace((unsigned char)*ptr))
 490                                         ptr++;
 491                         break;
 492
 493                 case 'Z':
 494                         {
 495                         const char *cp;
 496                         char *zonestr;
 497
 498                         for (cp = buf; *cp && isupper((unsigned char)*cp); ++cp) {/*empty*/}
 499                         if (cp - buf) {
 500                                 zonestr = alloca(cp - buf + 1);
 501                                 strncpy(zonestr, buf, cp - buf);
 502                                 zonestr[cp - buf] = '\0';
 503                                 tzset();
 504                                 if (0 == strcmp(zonestr, "GMT")) {
 505                                     *GMTp = 1;
 506                                 } else if (0 == strcmp(zonestr, tzname[0])) {
 507                                     tm->tm_isdst = 0;
 508                                 } else if (0 == strcmp(zonestr, tzname[1])) {
 509                                     tm->tm_isdst = 1;
 510                                 } else {
 511                                     return 0;
 512                                 }
 513                                 buf += cp - buf;
 514                         }
 515                         }
 516                         break;
 517
 518                 case 'z':
 519                         {
 520                         int sign = 1;
 521
 522                         if (*buf != '+') {
 523                                 if (*buf == '-')
 524                                         sign = -1;
 525                                 else
 526                                         return 0;
 527                         }
 528
 529                         buf++;
 530                         i = 0;
 531                         for (len = 4; len > 0; len--) {
 532                                 if (isdigit((int)*buf)) {
 533                                         i *= 10;
 534                                         i += *buf - '0';
 535                                         buf++;
 536                                 } else
 537                                         return 0;
 538                         }
 539
 540                         tm->tm_hour -= sign * (i / 100);
 541                         tm->tm_min  -= sign * (i % 100);
 542                         *GMTp = 1;
 543                         }
 544                         break;
 545                 }
 546         }
 547         return (char *)buf;
 548 }
 549
 550
 551 char *
 552 strptime(const char * __restrict buf, const char * __restrict fmt,
 553     struct tm * __restrict tm)
 554 {
 555         char *ret;
 556         int gmt;
 557
 558         gmt = 0;
 559         ret = _strptime(buf, fmt, tm, &gmt);
 560         if (ret && gmt) {
 561                 time_t t = timegm(tm);
 562                 localtime_r(&t, tm);
 563         }
 564
 565         return (ret);
 566 }