inc/3rdparty/simplepie/SimplePie/Parse/Date.php

   1 <?php
   2 /**
   3  * SimplePie
   4  *
   5  * A PHP-Based RSS and Atom Feed Framework.
   6  * Takes the hard work out of managing a complete RSS/Atom solution.
   7  *
   8  * Copyright (c) 2004-2009, Ryan Parman, Geoffrey Sneddon, Ryan McCue, and contributors
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without modification, are
  12  * permitted provided that the following conditions are met:
  13  *
  14  *      * Redistributions of source code must retain the above copyright notice, this list of
  15  *        conditions and the following disclaimer.
  16  *
  17  *      * Redistributions in binary form must reproduce the above copyright notice, this list
  18  *        of conditions and the following disclaimer in the documentation and/or other materials
  19  *        provided with the distribution.
  20  *
  21  *      * Neither the name of the SimplePie Team nor the names of its contributors may be used
  22  *        to endorse or promote products derived from this software without specific prior
  23  *        written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
  26  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  27  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS
  28  * AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  30  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  32  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  33  * POSSIBILITY OF SUCH DAMAGE.
  34  *
  35  * @package SimplePie
  36  * @version 1.3-dev
  37  * @copyright 2004-2010 Ryan Parman, Geoffrey Sneddon, Ryan McCue
  38  * @author Ryan Parman
  39  * @author Geoffrey Sneddon
  40  * @author Ryan McCue
  41  * @link http://simplepie.org/ SimplePie
  42  * @license http://www.opensource.org/licenses/bsd-license.php BSD License
  43  * @todo phpDoc comments
  44  */
  45
  46
  47 /**
  48  * Date Parser
  49  *
  50  * @package SimplePie
  51  */
  52 class SimplePie_Parse_Date
  53 {
  54         /**
  55          * Input data
  56          *
  57          * @access protected
  58          * @var string
  59          */
  60         var $date;
  61
  62         /**
  63          * List of days, calendar day name => ordinal day number in the week
  64          *
  65          * @access protected
  66          * @var array
  67          */
  68         var $day = array(
  69                 // English
  70                 'mon' => 1,
  71                 'monday' => 1,
  72                 'tue' => 2,
  73                 'tuesday' => 2,
  74                 'wed' => 3,
  75                 'wednesday' => 3,
  76                 'thu' => 4,
  77                 'thursday' => 4,
  78                 'fri' => 5,
  79                 'friday' => 5,
  80                 'sat' => 6,
  81                 'saturday' => 6,
  82                 'sun' => 7,
  83                 'sunday' => 7,
  84                 // Dutch
  85                 'maandag' => 1,
  86                 'dinsdag' => 2,
  87                 'woensdag' => 3,
  88                 'donderdag' => 4,
  89                 'vrijdag' => 5,
  90                 'zaterdag' => 6,
  91                 'zondag' => 7,
  92                 // French
  93                 'lundi' => 1,
  94                 'mardi' => 2,
  95                 'mercredi' => 3,
  96                 'jeudi' => 4,
  97                 'vendredi' => 5,
  98                 'samedi' => 6,
  99                 'dimanche' => 7,
 100                 // German
 101                 'montag' => 1,
 102                 'dienstag' => 2,
 103                 'mittwoch' => 3,
 104                 'donnerstag' => 4,
 105                 'freitag' => 5,
 106                 'samstag' => 6,
 107                 'sonnabend' => 6,
 108                 'sonntag' => 7,
 109                 // Italian
 110                 'lunedì' => 1,
 111                 'martedì' => 2,
 112                 'mercoledì' => 3,
 113                 'giovedì' => 4,
 114                 'venerdì' => 5,
 115                 'sabato' => 6,
 116                 'domenica' => 7,
 117                 // Spanish
 118                 'lunes' => 1,
 119                 'martes' => 2,
 120                 'miércoles' => 3,
 121                 'jueves' => 4,
 122                 'viernes' => 5,
 123                 'sábado' => 6,
 124                 'domingo' => 7,
 125                 // Finnish
 126                 'maanantai' => 1,
 127                 'tiistai' => 2,
 128                 'keskiviikko' => 3,
 129                 'torstai' => 4,
 130                 'perjantai' => 5,
 131                 'lauantai' => 6,
 132                 'sunnuntai' => 7,
 133                 // Hungarian
 134                 'hétfő' => 1,
 135                 'kedd' => 2,
 136                 'szerda' => 3,
 137                 'csütörtok' => 4,
 138                 'péntek' => 5,
 139                 'szombat' => 6,
 140                 'vasárnap' => 7,
 141                 // Greek
 142                 'Δευ' => 1,
 143                 'Τρι' => 2,
 144                 'Τετ' => 3,
 145                 'Πεμ' => 4,
 146                 'Παρ' => 5,
 147                 'Σαβ' => 6,
 148                 'Κυρ' => 7,
 149         );
 150
 151         /**
 152          * List of months, calendar month name => calendar month number
 153          *
 154          * @access protected
 155          * @var array
 156          */
 157         var $month = array(
 158                 // English
 159                 'jan' => 1,
 160                 'january' => 1,
 161                 'feb' => 2,
 162                 'february' => 2,
 163                 'mar' => 3,
 164                 'march' => 3,
 165                 'apr' => 4,
 166                 'april' => 4,
 167                 'may' => 5,
 168                 // No long form of May
 169                 'jun' => 6,
 170                 'june' => 6,
 171                 'jul' => 7,
 172                 'july' => 7,
 173                 'aug' => 8,
 174                 'august' => 8,
 175                 'sep' => 9,
 176                 'september' => 8,
 177                 'oct' => 10,
 178                 'october' => 10,
 179                 'nov' => 11,
 180                 'november' => 11,
 181                 'dec' => 12,
 182                 'december' => 12,
 183                 // Dutch
 184                 'januari' => 1,
 185                 'februari' => 2,
 186                 'maart' => 3,
 187                 'april' => 4,
 188                 'mei' => 5,
 189                 'juni' => 6,
 190                 'juli' => 7,
 191                 'augustus' => 8,
 192                 'september' => 9,
 193                 'oktober' => 10,
 194                 'november' => 11,
 195                 'december' => 12,
 196                 // French
 197                 'janvier' => 1,
 198                 'février' => 2,
 199                 'mars' => 3,
 200                 'avril' => 4,
 201                 'mai' => 5,
 202                 'juin' => 6,
 203                 'juillet' => 7,
 204                 'août' => 8,
 205                 'septembre' => 9,
 206                 'octobre' => 10,
 207                 'novembre' => 11,
 208                 'décembre' => 12,
 209                 // German
 210                 'januar' => 1,
 211                 'februar' => 2,
 212                 'märz' => 3,
 213                 'april' => 4,
 214                 'mai' => 5,
 215                 'juni' => 6,
 216                 'juli' => 7,
 217                 'august' => 8,
 218                 'september' => 9,
 219                 'oktober' => 10,
 220                 'november' => 11,
 221                 'dezember' => 12,
 222                 // Italian
 223                 'gennaio' => 1,
 224                 'febbraio' => 2,
 225                 'marzo' => 3,
 226                 'aprile' => 4,
 227                 'maggio' => 5,
 228                 'giugno' => 6,
 229                 'luglio' => 7,
 230                 'agosto' => 8,
 231                 'settembre' => 9,
 232                 'ottobre' => 10,
 233                 'novembre' => 11,
 234                 'dicembre' => 12,
 235                 // Spanish
 236                 'enero' => 1,
 237                 'febrero' => 2,
 238                 'marzo' => 3,
 239                 'abril' => 4,
 240                 'mayo' => 5,
 241                 'junio' => 6,
 242                 'julio' => 7,
 243                 'agosto' => 8,
 244                 'septiembre' => 9,
 245                 'setiembre' => 9,
 246                 'octubre' => 10,
 247                 'noviembre' => 11,
 248                 'diciembre' => 12,
 249                 // Finnish
 250                 'tammikuu' => 1,
 251                 'helmikuu' => 2,
 252                 'maaliskuu' => 3,
 253                 'huhtikuu' => 4,
 254                 'toukokuu' => 5,
 255                 'kesäkuu' => 6,
 256                 'heinäkuu' => 7,
 257                 'elokuu' => 8,
 258                 'suuskuu' => 9,
 259                 'lokakuu' => 10,
 260                 'marras' => 11,
 261                 'joulukuu' => 12,
 262                 // Hungarian
 263                 'január' => 1,
 264                 'február' => 2,
 265                 'március' => 3,
 266                 'április' => 4,
 267                 'május' => 5,
 268                 'június' => 6,
 269                 'július' => 7,
 270                 'augusztus' => 8,
 271                 'szeptember' => 9,
 272                 'október' => 10,
 273                 'november' => 11,
 274                 'december' => 12,
 275                 // Greek
 276                 'Ιαν' => 1,
 277                 'Φεβ' => 2,
 278                 'Μάώ' => 3,
 279                 'Μαώ' => 3,
 280                 'Απρ' => 4,
 281                 'Μάι' => 5,
 282                 'Μαϊ' => 5,
 283                 'Μαι' => 5,
 284                 'Ιούν' => 6,
 285                 'Ιον' => 6,
 286                 'Ιούλ' => 7,
 287                 'Ιολ' => 7,
 288                 'Αύγ' => 8,
 289                 'Αυγ' => 8,
 290                 'Σεπ' => 9,
 291                 'Οκτ' => 10,
 292                 'Νοέ' => 11,
 293                 'Δεκ' => 12,
 294         );
 295
 296         /**
 297          * List of timezones, abbreviation => offset from UTC
 298          *
 299          * @access protected
 300          * @var array
 301          */
 302         var $timezone = array(
 303                 'ACDT' => 37800,
 304                 'ACIT' => 28800,
 305                 'ACST' => 34200,
 306                 'ACT' => -18000,
 307                 'ACWDT' => 35100,
 308                 'ACWST' => 31500,
 309                 'AEDT' => 39600,
 310                 'AEST' => 36000,
 311                 'AFT' => 16200,
 312                 'AKDT' => -28800,
 313                 'AKST' => -32400,
 314                 'AMDT' => 18000,
 315                 'AMT' => -14400,
 316                 'ANAST' => 46800,
 317                 'ANAT' => 43200,
 318                 'ART' => -10800,
 319                 'AZOST' => -3600,
 320                 'AZST' => 18000,
 321                 'AZT' => 14400,
 322                 'BIOT' => 21600,
 323                 'BIT' => -43200,
 324                 'BOT' => -14400,
 325                 'BRST' => -7200,
 326                 'BRT' => -10800,
 327                 'BST' => 3600,
 328                 'BTT' => 21600,
 329                 'CAST' => 18000,
 330                 'CAT' => 7200,
 331                 'CCT' => 23400,
 332                 'CDT' => -18000,
 333                 'CEDT' => 7200,
 334                 'CET' => 3600,
 335                 'CGST' => -7200,
 336                 'CGT' => -10800,
 337                 'CHADT' => 49500,
 338                 'CHAST' => 45900,
 339                 'CIST' => -28800,
 340                 'CKT' => -36000,
 341                 'CLDT' => -10800,
 342                 'CLST' => -14400,
 343                 'COT' => -18000,
 344                 'CST' => -21600,
 345                 'CVT' => -3600,
 346                 'CXT' => 25200,
 347                 'DAVT' => 25200,
 348                 'DTAT' => 36000,
 349                 'EADT' => -18000,
 350                 'EAST' => -21600,
 351                 'EAT' => 10800,
 352                 'ECT' => -18000,
 353                 'EDT' => -14400,
 354                 'EEST' => 10800,
 355                 'EET' => 7200,
 356                 'EGT' => -3600,
 357                 'EKST' => 21600,
 358                 'EST' => -18000,
 359                 'FJT' => 43200,
 360                 'FKDT' => -10800,
 361                 'FKST' => -14400,
 362                 'FNT' => -7200,
 363                 'GALT' => -21600,
 364                 'GEDT' => 14400,
 365                 'GEST' => 10800,
 366                 'GFT' => -10800,
 367                 'GILT' => 43200,
 368                 'GIT' => -32400,
 369                 'GST' => 14400,
 370                 'GST' => -7200,
 371                 'GYT' => -14400,
 372                 'HAA' => -10800,
 373                 'HAC' => -18000,
 374                 'HADT' => -32400,
 375                 'HAE' => -14400,
 376                 'HAP' => -25200,
 377                 'HAR' => -21600,
 378                 'HAST' => -36000,
 379                 'HAT' => -9000,
 380                 'HAY' => -28800,
 381                 'HKST' => 28800,
 382                 'HMT' => 18000,
 383                 'HNA' => -14400,
 384                 'HNC' => -21600,
 385                 'HNE' => -18000,
 386                 'HNP' => -28800,
 387                 'HNR' => -25200,
 388                 'HNT' => -12600,
 389                 'HNY' => -32400,
 390                 'IRDT' => 16200,
 391                 'IRKST' => 32400,
 392                 'IRKT' => 28800,
 393                 'IRST' => 12600,
 394                 'JFDT' => -10800,
 395                 'JFST' => -14400,
 396                 'JST' => 32400,
 397                 'KGST' => 21600,
 398                 'KGT' => 18000,
 399                 'KOST' => 39600,
 400                 'KOVST' => 28800,
 401                 'KOVT' => 25200,
 402                 'KRAST' => 28800,
 403                 'KRAT' => 25200,
 404                 'KST' => 32400,
 405                 'LHDT' => 39600,
 406                 'LHST' => 37800,
 407                 'LINT' => 50400,
 408                 'LKT' => 21600,
 409                 'MAGST' => 43200,
 410                 'MAGT' => 39600,
 411                 'MAWT' => 21600,
 412                 'MDT' => -21600,
 413                 'MESZ' => 7200,
 414                 'MEZ' => 3600,
 415                 'MHT' => 43200,
 416                 'MIT' => -34200,
 417                 'MNST' => 32400,
 418                 'MSDT' => 14400,
 419                 'MSST' => 10800,
 420                 'MST' => -25200,
 421                 'MUT' => 14400,
 422                 'MVT' => 18000,
 423                 'MYT' => 28800,
 424                 'NCT' => 39600,
 425                 'NDT' => -9000,
 426                 'NFT' => 41400,
 427                 'NMIT' => 36000,
 428                 'NOVST' => 25200,
 429                 'NOVT' => 21600,
 430                 'NPT' => 20700,
 431                 'NRT' => 43200,
 432                 'NST' => -12600,
 433                 'NUT' => -39600,
 434                 'NZDT' => 46800,
 435                 'NZST' => 43200,
 436                 'OMSST' => 25200,
 437                 'OMST' => 21600,
 438                 'PDT' => -25200,
 439                 'PET' => -18000,
 440                 'PETST' => 46800,
 441                 'PETT' => 43200,
 442                 'PGT' => 36000,
 443                 'PHOT' => 46800,
 444                 'PHT' => 28800,
 445                 'PKT' => 18000,
 446                 'PMDT' => -7200,
 447                 'PMST' => -10800,
 448                 'PONT' => 39600,
 449                 'PST' => -28800,
 450                 'PWT' => 32400,
 451                 'PYST' => -10800,
 452                 'PYT' => -14400,
 453                 'RET' => 14400,
 454                 'ROTT' => -10800,
 455                 'SAMST' => 18000,
 456                 'SAMT' => 14400,
 457                 'SAST' => 7200,
 458                 'SBT' => 39600,
 459                 'SCDT' => 46800,
 460                 'SCST' => 43200,
 461                 'SCT' => 14400,
 462                 'SEST' => 3600,
 463                 'SGT' => 28800,
 464                 'SIT' => 28800,
 465                 'SRT' => -10800,
 466                 'SST' => -39600,
 467                 'SYST' => 10800,
 468                 'SYT' => 7200,
 469                 'TFT' => 18000,
 470                 'THAT' => -36000,
 471                 'TJT' => 18000,
 472                 'TKT' => -36000,
 473                 'TMT' => 18000,
 474                 'TOT' => 46800,
 475                 'TPT' => 32400,
 476                 'TRUT' => 36000,
 477                 'TVT' => 43200,
 478                 'TWT' => 28800,
 479                 'UYST' => -7200,
 480                 'UYT' => -10800,
 481                 'UZT' => 18000,
 482                 'VET' => -14400,
 483                 'VLAST' => 39600,
 484                 'VLAT' => 36000,
 485                 'VOST' => 21600,
 486                 'VUT' => 39600,
 487                 'WAST' => 7200,
 488                 'WAT' => 3600,
 489                 'WDT' => 32400,
 490                 'WEST' => 3600,
 491                 'WFT' => 43200,
 492                 'WIB' => 25200,
 493                 'WIT' => 32400,
 494                 'WITA' => 28800,
 495                 'WKST' => 18000,
 496                 'WST' => 28800,
 497                 'YAKST' => 36000,
 498                 'YAKT' => 32400,
 499                 'YAPT' => 36000,
 500                 'YEKST' => 21600,
 501                 'YEKT' => 18000,
 502         );
 503
 504         /**
 505          * Cached PCRE for SimplePie_Parse_Date::$day
 506          *
 507          * @access protected
 508          * @var string
 509          */
 510         var $day_pcre;
 511
 512         /**
 513          * Cached PCRE for SimplePie_Parse_Date::$month
 514          *
 515          * @access protected
 516          * @var string
 517          */
 518         var $month_pcre;
 519
 520         /**
 521          * Array of user-added callback methods
 522          *
 523          * @access private
 524          * @var array
 525          */
 526         var $built_in = array();
 527
 528         /**
 529          * Array of user-added callback methods
 530          *
 531          * @access private
 532          * @var array
 533          */
 534         var $user = array();
 535
 536         /**
 537          * Create new SimplePie_Parse_Date object, and set self::day_pcre,
 538          * self::month_pcre, and self::built_in
 539          *
 540          * @access private
 541          */
 542         public function __construct()
 543         {
 544                 $this->day_pcre = '(' . implode(array_keys($this->day), '|') . ')';
 545                 $this->month_pcre = '(' . implode(array_keys($this->month), '|') . ')';
 546
 547                 static $cache;
 548                 if (!isset($cache[get_class($this)]))
 549                 {
 550                         $all_methods = get_class_methods($this);
 551
 552                         foreach ($all_methods as $method)
 553                         {
 554                                 if (strtolower(substr($method, 0, 5)) === 'date_')
 555                                 {
 556                                         $cache[get_class($this)][] = $method;
 557                                 }
 558                         }
 559                 }
 560
 561                 foreach ($cache[get_class($this)] as $method)
 562                 {
 563                         $this->built_in[] = $method;
 564                 }
 565         }
 566
 567         /**
 568          * Get the object
 569          *
 570          * @access public
 571          */
 572         public static function get()
 573         {
 574                 static $object;
 575                 if (!$object)
 576                 {
 577                         $object = new SimplePie_Parse_Date;
 578                 }
 579                 return $object;
 580         }
 581
 582         /**
 583          * Parse a date
 584          *
 585          * @final
 586          * @access public
 587          * @param string $date Date to parse
 588          * @return int Timestamp corresponding to date string, or false on failure
 589          */
 590         public function parse($date)
 591         {
 592                 foreach ($this->user as $method)
 593                 {
 594                         if (($returned = call_user_func($method, $date)) !== false)
 595                         {
 596                                 return $returned;
 597                         }
 598                 }
 599
 600                 foreach ($this->built_in as $method)
 601                 {
 602                         if (($returned = call_user_func(array(&$this, $method), $date)) !== false)
 603                         {
 604                                 return $returned;
 605                         }
 606                 }
 607
 608                 return false;
 609         }
 610
 611         /**
 612          * Add a callback method to parse a date
 613          *
 614          * @final
 615          * @access public
 616          * @param callback $callback
 617          */
 618         public function add_callback($callback)
 619         {
 620                 if (is_callable($callback))
 621                 {
 622                         $this->user[] = $callback;
 623                 }
 624                 else
 625                 {
 626                         trigger_error('User-supplied function must be a valid callback', E_USER_WARNING);
 627                 }
 628         }
 629
 630         /**
 631          * Parse a superset of W3C-DTF (allows hyphens and colons to be omitted, as
 632          * well as allowing any of upper or lower case "T", horizontal tabs, or
 633          * spaces to be used as the time seperator (including more than one))
 634          *
 635          * @access protected
 636          * @return int Timestamp
 637          */
 638         public function date_w3cdtf($date)
 639         {
 640                 static $pcre;
 641                 if (!$pcre)
 642                 {
 643                         $year = '([0-9]{4})';
 644                         $month = $day = $hour = $minute = $second = '([0-9]{2})';
 645                         $decimal = '([0-9]*)';
 646                         $zone = '(?:(Z)|([+\-])([0-9]{1,2}):?([0-9]{1,2}))';
 647                         $pcre = '/^' . $year . '(?:-?' . $month . '(?:-?' . $day . '(?:[Tt\x09\x20]+' . $hour . '(?::?' . $minute . '(?::?' . $second . '(?:.' . $decimal . ')?)?)?' . $zone . ')?)?)?$/';
 648                 }
 649                 if (preg_match($pcre, $date, $match))
 650                 {
 651                         /*
 652                         Capturing subpatterns:
 653                         1: Year
 654                         2: Month
 655                         3: Day
 656                         4: Hour
 657                         5: Minute
 658                         6: Second
 659                         7: Decimal fraction of a second
 660                         8: Zulu
 661                         9: Timezone ±
 662                         10: Timezone hours
 663                         11: Timezone minutes
 664                         */
 665
 666                         // Fill in empty matches
 667                         for ($i = count($match); $i <= 3; $i++)
 668                         {
 669                                 $match[$i] = '1';
 670                         }
 671
 672                         for ($i = count($match); $i <= 7; $i++)
 673                         {
 674                                 $match[$i] = '0';
 675                         }
 676
 677                         // Numeric timezone
 678                         if (isset($match[9]) && $match[9] !== '')
 679                         {
 680                                 $timezone = $match[10] * 3600;
 681                                 $timezone += $match[11] * 60;
 682                                 if ($match[9] === '-')
 683                                 {
 684                                         $timezone = 0 - $timezone;
 685                                 }
 686                         }
 687                         else
 688                         {
 689                                 $timezone = 0;
 690                         }
 691
 692                         // Convert the number of seconds to an integer, taking decimals into account
 693                         $second = round($match[6] + $match[7] / pow(10, strlen($match[7])));
 694
 695                         return gmmktime($match[4], $match[5], $second, $match[2], $match[3], $match[1]) - $timezone;
 696                 }
 697                 else
 698                 {
 699                         return false;
 700                 }
 701         }
 702
 703         /**
 704          * Remove RFC822 comments
 705          *
 706          * @access protected
 707          * @param string $data Data to strip comments from
 708          * @return string Comment stripped string
 709          */
 710         public function remove_rfc2822_comments($string)
 711         {
 712                 $string = (string) $string;
 713                 $position = 0;
 714                 $length = strlen($string);
 715                 $depth = 0;
 716
 717                 $output = '';
 718
 719                 while ($position < $length && ($pos = strpos($string, '(', $position)) !== false)
 720                 {
 721                         $output .= substr($string, $position, $pos - $position);
 722                         $position = $pos + 1;
 723                         if ($string[$pos - 1] !== '\\')
 724                         {
 725                                 $depth++;
 726                                 while ($depth && $position < $length)
 727                                 {
 728                                         $position += strcspn($string, '()', $position);
 729                                         if ($string[$position - 1] === '\\')
 730                                         {
 731                                                 $position++;
 732                                                 continue;
 733                                         }
 734                                         elseif (isset($string[$position]))
 735                                         {
 736                                                 switch ($string[$position])
 737                                                 {
 738                                                         case '(':
 739                                                                 $depth++;
 740                                                                 break;
 741
 742                                                         case ')':
 743                                                                 $depth--;
 744                                                                 break;
 745                                                 }
 746                                                 $position++;
 747                                         }
 748                                         else
 749                                         {
 750                                                 break;
 751                                         }
 752                                 }
 753                         }
 754                         else
 755                         {
 756                                 $output .= '(';
 757                         }
 758                 }
 759                 $output .= substr($string, $position);
 760
 761                 return $output;
 762         }
 763
 764         /**
 765          * Parse RFC2822's date format
 766          *
 767          * @access protected
 768          * @return int Timestamp
 769          */
 770         public function date_rfc2822($date)
 771         {
 772                 static $pcre;
 773                 if (!$pcre)
 774                 {
 775                         $wsp = '[\x09\x20]';
 776                         $fws = '(?:' . $wsp . '+|' . $wsp . '*(?:\x0D\x0A' . $wsp . '+)+)';
 777                         $optional_fws = $fws . '?';
 778                         $day_name = $this->day_pcre;
 779                         $month = $this->month_pcre;
 780                         $day = '([0-9]{1,2})';
 781                         $hour = $minute = $second = '([0-9]{2})';
 782                         $year = '([0-9]{2,4})';
 783                         $num_zone = '([+\-])([0-9]{2})([0-9]{2})';
 784                         $character_zone = '([A-Z]{1,5})';
 785                         $zone = '(?:' . $num_zone . '|' . $character_zone . ')';
 786                         $pcre = '/(?:' . $optional_fws . $day_name . $optional_fws . ',)?' . $optional_fws . $day . $fws . $month . $fws . $year . $fws . $hour . $optional_fws . ':' . $optional_fws . $minute . '(?:' . $optional_fws . ':' . $optional_fws . $second . ')?' . $fws . $zone . '/i';
 787                 }
 788                 if (preg_match($pcre, $this->remove_rfc2822_comments($date), $match))
 789                 {
 790                         /*
 791                         Capturing subpatterns:
 792                         1: Day name
 793                         2: Day
 794                         3: Month
 795                         4: Year
 796                         5: Hour
 797                         6: Minute
 798                         7: Second
 799                         8: Timezone ±
 800                         9: Timezone hours
 801                         10: Timezone minutes
 802                         11: Alphabetic timezone
 803                         */
 804
 805                         // Find the month number
 806                         $month = $this->month[strtolower($match[3])];
 807
 808                         // Numeric timezone
 809                         if ($match[8] !== '')
 810                         {
 811                                 $timezone = $match[9] * 3600;
 812                                 $timezone += $match[10] * 60;
 813                                 if ($match[8] === '-')
 814                                 {
 815                                         $timezone = 0 - $timezone;
 816                                 }
 817                         }
 818                         // Character timezone
 819                         elseif (isset($this->timezone[strtoupper($match[11])]))
 820                         {
 821                                 $timezone = $this->timezone[strtoupper($match[11])];
 822                         }
 823                         // Assume everything else to be -0000
 824                         else
 825                         {
 826                                 $timezone = 0;
 827                         }
 828
 829                         // Deal with 2/3 digit years
 830                         if ($match[4] < 50)
 831                         {
 832                                 $match[4] += 2000;
 833                         }
 834                         elseif ($match[4] < 1000)
 835                         {
 836                                 $match[4] += 1900;
 837                         }
 838
 839                         // Second is optional, if it is empty set it to zero
 840                         if ($match[7] !== '')
 841                         {
 842                                 $second = $match[7];
 843                         }
 844                         else
 845                         {
 846                                 $second = 0;
 847                         }
 848
 849                         return gmmktime($match[5], $match[6], $second, $month, $match[2], $match[4]) - $timezone;
 850                 }
 851                 else
 852                 {
 853                         return false;
 854                 }
 855         }
 856
 857         /**
 858          * Parse RFC850's date format
 859          *
 860          * @access protected
 861          * @return int Timestamp
 862          */
 863         public function date_rfc850($date)
 864         {
 865                 static $pcre;
 866                 if (!$pcre)
 867                 {
 868                         $space = '[\x09\x20]+';
 869                         $day_name = $this->day_pcre;
 870                         $month = $this->month_pcre;
 871                         $day = '([0-9]{1,2})';
 872                         $year = $hour = $minute = $second = '([0-9]{2})';
 873                         $zone = '([A-Z]{1,5})';
 874                         $pcre = '/^' . $day_name . ',' . $space . $day . '-' . $month . '-' . $year . $space . $hour . ':' . $minute . ':' . $second . $space . $zone . '$/i';
 875                 }
 876                 if (preg_match($pcre, $date, $match))
 877                 {
 878                         /*
 879                         Capturing subpatterns:
 880                         1: Day name
 881                         2: Day
 882                         3: Month
 883                         4: Year
 884                         5: Hour
 885                         6: Minute
 886                         7: Second
 887                         8: Timezone
 888                         */
 889
 890                         // Month
 891                         $month = $this->month[strtolower($match[3])];
 892
 893                         // Character timezone
 894                         if (isset($this->timezone[strtoupper($match[8])]))
 895                         {
 896                                 $timezone = $this->timezone[strtoupper($match[8])];
 897                         }
 898                         // Assume everything else to be -0000
 899                         else
 900                         {
 901                                 $timezone = 0;
 902                         }
 903
 904                         // Deal with 2 digit year
 905                         if ($match[4] < 50)
 906                         {
 907                                 $match[4] += 2000;
 908                         }
 909                         else
 910                         {
 911                                 $match[4] += 1900;
 912                         }
 913
 914                         return gmmktime($match[5], $match[6], $match[7], $month, $match[2], $match[4]) - $timezone;
 915                 }
 916                 else
 917                 {
 918                         return false;
 919                 }
 920         }
 921
 922         /**
 923          * Parse C99's asctime()'s date format
 924          *
 925          * @access protected
 926          * @return int Timestamp
 927          */
 928         public function date_asctime($date)
 929         {
 930                 static $pcre;
 931                 if (!$pcre)
 932                 {
 933                         $space = '[\x09\x20]+';
 934                         $wday_name = $this->day_pcre;
 935                         $mon_name = $this->month_pcre;
 936                         $day = '([0-9]{1,2})';
 937                         $hour = $sec = $min = '([0-9]{2})';
 938                         $year = '([0-9]{4})';
 939                         $terminator = '\x0A?\x00?';
 940                         $pcre = '/^' . $wday_name . $space . $mon_name . $space . $day . $space . $hour . ':' . $min . ':' . $sec . $space . $year . $terminator . '$/i';
 941                 }
 942                 if (preg_match($pcre, $date, $match))
 943                 {
 944                         /*
 945                         Capturing subpatterns:
 946                         1: Day name
 947                         2: Month
 948                         3: Day
 949                         4: Hour
 950                         5: Minute
 951                         6: Second
 952                         7: Year
 953                         */
 954
 955                         $month = $this->month[strtolower($match[2])];
 956                         return gmmktime($match[4], $match[5], $match[6], $month, $match[3], $match[7]);
 957                 }
 958                 else
 959                 {
 960                         return false;
 961                 }
 962         }
 963
 964         /**
 965          * Parse dates using strtotime()
 966          *
 967          * @access protected
 968          * @return int Timestamp
 969          */
 970         public function date_strtotime($date)
 971         {
 972                 $strtotime = strtotime($date);
 973                 if ($strtotime === -1 || $strtotime === false)
 974                 {
 975                         return false;
 976                 }
 977                 else
 978                 {
 979                         return $strtotime;
 980                 }
 981         }
 982 }
 983