includes/GlobalFunctions.php

   1 <?php
   2
   3 if ( !defined( 'MEDIAWIKI' ) ) {
   4         die( "This file is part of MediaWiki, it is not a valid entry point" );
   5 }
   6
   7 /**
   8  * Global functions used everywhere
   9  */
  10
  11 /**
  12  * Some globals and requires needed
  13  */
  14
  15 /** Total number of articles */
  16 $wgNumberOfArticles = -1; # Unset
  17
  18 /** Total number of views */
  19 $wgTotalViews = -1;
  20
  21 /** Total number of edits */
  22 $wgTotalEdits = -1;
  23
  24
  25 global $IP;
  26 require_once dirname(__FILE__) . '/LogPage.php';
  27 require_once dirname(__FILE__) . '/normal/UtfNormalUtil.php';
  28 require_once dirname(__FILE__) . '/XmlFunctions.php';
  29
  30 /**
  31  * Compatibility functions
  32  *
  33  * We more or less support PHP 5.0.x and up.
  34  * Re-implementations of newer functions or functions in non-standard
  35  * PHP extensions may be included here.
  36  */
  37 if( !function_exists('iconv') ) {
  38         # iconv support is not in the default configuration and so may not be present.
  39         # Assume will only ever use utf-8 and iso-8859-1.
  40         # This will *not* work in all circumstances.
  41         function iconv( $from, $to, $string ) {
  42                 if(strcasecmp( $from, $to ) == 0) return $string;
  43                 if(strcasecmp( $from, 'utf-8' ) == 0) return utf8_decode( $string );
  44                 if(strcasecmp( $to, 'utf-8' ) == 0) return utf8_encode( $string );
  45                 return $string;
  46         }
  47 }
  48
  49 # UTF-8 substr function based on a PHP manual comment
  50 if ( !function_exists( 'mb_substr' ) ) {
  51         function mb_substr( $str, $start ) {
  52                 $ar = array();
  53                 preg_match_all( '/./us', $str, $ar );
  54
  55                 if( func_num_args() >= 3 ) {
  56                         $end = func_get_arg( 2 );
  57                         return join( '', array_slice( $ar[0], $start, $end ) );
  58                 } else {
  59                         return join( '', array_slice( $ar[0], $start ) );
  60                 }
  61         }
  62 }
  63
  64 if ( !function_exists( 'array_diff_key' ) ) {
  65         /**
  66          * Exists in PHP 5.1.0+
  67          * Not quite compatible, two-argument version only
  68          * Null values will cause problems due to this use of isset()
  69          */
  70         function array_diff_key( $left, $right ) {
  71                 $result = $left;
  72                 foreach ( $left as $key => $unused ) {
  73                         if ( isset( $right[$key] ) ) {
  74                                 unset( $result[$key] );
  75                         }
  76                 }
  77                 return $result;
  78         }
  79 }
  80
  81
  82 /**
  83  * Wrapper for clone(), for compatibility with PHP4-friendly extensions.
  84  * PHP 5 won't let you declare a 'clone' function, even conditionally,
  85  * so it has to be a wrapper with a different name.
  86  */
  87 function wfClone( $object ) {
  88         return clone( $object );
  89 }
  90
  91 /**
  92  * Where as we got a random seed
  93  */
  94 $wgRandomSeeded = false;
  95
  96 /**
  97  * Seed Mersenne Twister
  98  * No-op for compatibility; only necessary in PHP < 4.2.0
  99  */
 100 function wfSeedRandom() {
 101         /* No-op */
 102 }
 103
 104 /**
 105  * Get a random decimal value between 0 and 1, in a way
 106  * not likely to give duplicate values for any realistic
 107  * number of articles.
 108  *
 109  * @return string
 110  */
 111 function wfRandom() {
 112         # The maximum random value is "only" 2^31-1, so get two random
 113         # values to reduce the chance of dupes
 114         $max = mt_getrandmax() + 1;
 115         $rand = number_format( (mt_rand() * $max + mt_rand())
 116                 / $max / $max, 12, '.', '' );
 117         return $rand;
 118 }
 119
 120 /**
 121  * We want / and : to be included as literal characters in our title URLs.
 122  * %2F in the page titles seems to fatally break for some reason.
 123  *
 124  * @param $s String:
 125  * @return string
 126 */
 127 function wfUrlencode ( $s ) {
 128         $s = urlencode( $s );
 129         $s = preg_replace( '/%3[Aa]/', ':', $s );
 130         $s = preg_replace( '/%2[Ff]/', '/', $s );
 131
 132         return $s;
 133 }
 134
 135 /**
 136  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 137  * In normal operation this is a NOP.
 138  *
 139  * Controlling globals:
 140  * $wgDebugLogFile - points to the log file
 141  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 142  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 143  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 144  *
 145  * @param $text String
 146  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 147  */
 148 function wfDebug( $text, $logonly = false ) {
 149         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 150         static $recursion = 0;
 151
 152         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 153         if ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' && !$wgDebugRawPage ) {
 154                 return;
 155         }
 156
 157         if ( $wgDebugComments && !$logonly ) {
 158                 if ( !isset( $wgOut ) ) {
 159                         return;
 160                 }
 161                 if ( !StubObject::isRealObject( $wgOut ) ) {
 162                         if ( $recursion ) {
 163                                 return;
 164                         }
 165                         $recursion++;
 166                         $wgOut->_unstub();
 167                         $recursion--;
 168                 }
 169                 $wgOut->debug( $text );
 170         }
 171         if ( '' != $wgDebugLogFile && !$wgProfileOnly ) {
 172                 # Strip unprintables; they can switch terminal modes when binary data
 173                 # gets dumped, which is pretty annoying.
 174                 $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 175                 wfErrorLog( $text, $wgDebugLogFile );
 176         }
 177 }
 178
 179 /**
 180  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 181  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 182  *
 183  * @param $logGroup String
 184  * @param $text String
 185  * @param $public Bool: whether to log the event in the public log if no private
 186  *                     log file is specified, (default true)
 187  */
 188 function wfDebugLog( $logGroup, $text, $public = true ) {
 189         global $wgDebugLogGroups;
 190         if( $text{strlen( $text ) - 1} != "\n" ) $text .= "\n";
 191         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 192                 $time = wfTimestamp( TS_DB );
 193                 $wiki = wfWikiID();
 194                 wfErrorLog( "$time $wiki: $text", $wgDebugLogGroups[$logGroup] );
 195         } else if ( $public === true ) {
 196                 wfDebug( $text, true );
 197         }
 198 }
 199
 200 /**
 201  * Log for database errors
 202  * @param $text String: database error message.
 203  */
 204 function wfLogDBError( $text ) {
 205         global $wgDBerrorLog, $wgDBname;
 206         if ( $wgDBerrorLog ) {
 207                 $host = trim(`hostname`);
 208                 $text = date('D M j G:i:s T Y') . "\t$host\t$wgDBname\t$text";
 209                 wfErrorLog( $text, $wgDBerrorLog );
 210         }
 211 }
 212
 213 /**
 214  * Log to a file without getting "file size exceeded" signals
 215  */
 216 function wfErrorLog( $text, $file ) {
 217         wfSuppressWarnings();
 218         $exists = file_exists( $file );
 219         $size = filesize( $file );
 220         if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 221                 error_log( $text, 3, $file );
 222         }
 223         wfRestoreWarnings();
 224 }
 225
 226 /**
 227  * @todo document
 228  */
 229 function wfLogProfilingData() {
 230         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 231         global $wgProfiling, $wgUser;
 232         if ( $wgProfiling ) {
 233                 $now = wfTime();
 234                 $elapsed = $now - $wgRequestTime;
 235                 $prof = wfGetProfilingOutput( $wgRequestTime, $elapsed );
 236                 $forward = '';
 237                 if( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) )
 238                         $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 239                 if( !empty( $_SERVER['HTTP_CLIENT_IP'] ) )
 240                         $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 241                 if( !empty( $_SERVER['HTTP_FROM'] ) )
 242                         $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 243                 if( $forward )
 244                         $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 245                 // Don't unstub $wgUser at this late stage just for statistics purposes
 246                 if( StubObject::isRealObject($wgUser) && $wgUser->isAnon() )
 247                         $forward .= ' anon';
 248                 $log = sprintf( "%s\t%04.3f\t%s\n",
 249                   gmdate( 'YmdHis' ), $elapsed,
 250                   urldecode( $wgRequest->getRequestURL() . $forward ) );
 251                 if ( '' != $wgDebugLogFile && ( $wgRequest->getVal('action') != 'raw' || $wgDebugRawPage ) ) {
 252                         wfErrorLog( $log . $prof, $wgDebugLogFile );
 253                 }
 254         }
 255 }
 256
 257 /**
 258  * Check if the wiki read-only lock file is present. This can be used to lock
 259  * off editing functions, but doesn't guarantee that the database will not be
 260  * modified.
 261  * @return bool
 262  */
 263 function wfReadOnly() {
 264         global $wgReadOnlyFile, $wgReadOnly;
 265
 266         if ( !is_null( $wgReadOnly ) ) {
 267                 return (bool)$wgReadOnly;
 268         }
 269         if ( '' == $wgReadOnlyFile ) {
 270                 return false;
 271         }
 272         // Set $wgReadOnly for faster access next time
 273         if ( is_file( $wgReadOnlyFile ) ) {
 274                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
 275         } else {
 276                 $wgReadOnly = false;
 277         }
 278         return (bool)$wgReadOnly;
 279 }
 280
 281
 282 /**
 283  * Get a message from anywhere, for the current user language.
 284  *
 285  * Use wfMsgForContent() instead if the message should NOT
 286  * change depending on the user preferences.
 287  *
 288  * Note that the message may contain HTML, and is therefore
 289  * not safe for insertion anywhere. Some functions such as
 290  * addWikiText will do the escaping for you. Use wfMsgHtml()
 291  * if you need an escaped message.
 292  *
 293  * @param $key String: lookup key for the message, usually
 294  *    defined in languages/Language.php
 295  *
 296  * This function also takes extra optional parameters (not
 297  * shown in the function definition), which can by used to
 298  * insert variable text into the predefined message.
 299  */
 300 function wfMsg( $key ) {
 301         $args = func_get_args();
 302         array_shift( $args );
 303         return wfMsgReal( $key, $args, true );
 304 }
 305
 306 /**
 307  * Same as above except doesn't transform the message
 308  */
 309 function wfMsgNoTrans( $key ) {
 310         $args = func_get_args();
 311         array_shift( $args );
 312         return wfMsgReal( $key, $args, true, false, false );
 313 }
 314
 315 /**
 316  * Get a message from anywhere, for the current global language
 317  * set with $wgLanguageCode.
 318  *
 319  * Use this if the message should NOT change  dependent on the
 320  * language set in the user's preferences. This is the case for
 321  * most text written into logs, as well as link targets (such as
 322  * the name of the copyright policy page). Link titles, on the
 323  * other hand, should be shown in the UI language.
 324  *
 325  * Note that MediaWiki allows users to change the user interface
 326  * language in their preferences, but a single installation
 327  * typically only contains content in one language.
 328  *
 329  * Be wary of this distinction: If you use wfMsg() where you should
 330  * use wfMsgForContent(), a user of the software may have to
 331  * customize over 70 messages in order to, e.g., fix a link in every
 332  * possible language.
 333  *
 334  * @param $key String: lookup key for the message, usually
 335  *    defined in languages/Language.php
 336  */
 337 function wfMsgForContent( $key ) {
 338         global $wgForceUIMsgAsContentMsg;
 339         $args = func_get_args();
 340         array_shift( $args );
 341         $forcontent = true;
 342         if( is_array( $wgForceUIMsgAsContentMsg ) &&
 343                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
 344                 $forcontent = false;
 345         return wfMsgReal( $key, $args, true, $forcontent );
 346 }
 347
 348 /**
 349  * Same as above except doesn't transform the message
 350  */
 351 function wfMsgForContentNoTrans( $key ) {
 352         global $wgForceUIMsgAsContentMsg;
 353         $args = func_get_args();
 354         array_shift( $args );
 355         $forcontent = true;
 356         if( is_array( $wgForceUIMsgAsContentMsg ) &&
 357                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
 358                 $forcontent = false;
 359         return wfMsgReal( $key, $args, true, $forcontent, false );
 360 }
 361
 362 /**
 363  * Get a message from the language file, for the UI elements
 364  */
 365 function wfMsgNoDB( $key ) {
 366         $args = func_get_args();
 367         array_shift( $args );
 368         return wfMsgReal( $key, $args, false );
 369 }
 370
 371 /**
 372  * Get a message from the language file, for the content
 373  */
 374 function wfMsgNoDBForContent( $key ) {
 375         global $wgForceUIMsgAsContentMsg;
 376         $args = func_get_args();
 377         array_shift( $args );
 378         $forcontent = true;
 379         if( is_array( $wgForceUIMsgAsContentMsg ) &&
 380                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
 381                 $forcontent = false;
 382         return wfMsgReal( $key, $args, false, $forcontent );
 383 }
 384
 385
 386 /**
 387  * Really get a message
 388  * @param $key String: key to get.
 389  * @param $args
 390  * @param $useDB Boolean
 391  * @param $transform Boolean: Whether or not to transform the message.
 392  * @param $forContent Boolean
 393  * @return String: the requested message.
 394  */
 395 function wfMsgReal( $key, $args, $useDB = true, $forContent=false, $transform = true ) {
 396         $fname = 'wfMsgReal';
 397         wfProfileIn( $fname );
 398         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
 399         $message = wfMsgReplaceArgs( $message, $args );
 400         wfProfileOut( $fname );
 401         return $message;
 402 }
 403
 404 /**
 405  * This function provides the message source for messages to be edited which are *not* stored in the database.
 406  * @param $key String:
 407  */
 408 function wfMsgWeirdKey ( $key ) {
 409         $subsource = str_replace ( ' ' , '_' , $key ) ;
 410         $source = wfMsgForContentNoTrans( $subsource ) ;
 411         if ( wfEmptyMsg( $subsource, $source) ) {
 412                 # Try again with first char lower case
 413                 $subsource = strtolower ( substr ( $subsource , 0 , 1 ) ) . substr ( $subsource , 1 ) ;
 414                 $source = wfMsgForContentNoTrans( $subsource ) ;
 415         }
 416         if ( wfEmptyMsg( $subsource, $source ) ) {
 417                 # Didn't work either, return blank text
 418                 $source = "" ;
 419         }
 420         return $source ;
 421 }
 422
 423 /**
 424  * Fetch a message string value, but don't replace any keys yet.
 425  * @param string $key
 426  * @param bool $useDB
 427  * @param bool $forContent
 428  * @return string
 429  * @private
 430  */
 431 function wfMsgGetKey( $key, $useDB, $forContent = false, $transform = true ) {
 432         global $wgParser, $wgContLang, $wgMessageCache, $wgLang;
 433
 434         if ( is_object( $wgMessageCache ) )
 435                 $transstat = $wgMessageCache->getTransform();
 436
 437         if( is_object( $wgMessageCache ) ) {
 438                 if ( ! $transform )
 439                         $wgMessageCache->disableTransform();
 440                 $message = $wgMessageCache->get( $key, $useDB, $forContent );
 441         } else {
 442                 if( $forContent ) {
 443                         $lang = &$wgContLang;
 444                 } else {
 445                         $lang = &$wgLang;
 446                 }
 447
 448                 wfSuppressWarnings();
 449
 450                 if( is_object( $lang ) ) {
 451                         $message = $lang->getMessage( $key );
 452                 } else {
 453                         $message = false;
 454                 }
 455                 wfRestoreWarnings();
 456                 if($message === false)
 457                         $message = Language::getMessage($key);
 458                 if ( $transform && strstr( $message, '{{' ) !== false ) {
 459                         $message = $wgParser->transformMsg($message, $wgMessageCache->getParserOptions() );
 460                 }
 461         }
 462
 463         if ( is_object( $wgMessageCache ) && ! $transform )
 464                 $wgMessageCache->setTransform( $transstat );
 465
 466         return $message;
 467 }
 468
 469 /**
 470  * Replace message parameter keys on the given formatted output.
 471  *
 472  * @param string $message
 473  * @param array $args
 474  * @return string
 475  * @private
 476  */
 477 function wfMsgReplaceArgs( $message, $args ) {
 478         # Fix windows line-endings
 479         # Some messages are split with explode("\n", $msg)
 480         $message = str_replace( "\r", '', $message );
 481
 482         // Replace arguments
 483         if ( count( $args ) ) {
 484                 if ( is_array( $args[0] ) ) {
 485                         foreach ( $args[0] as $key => $val ) {
 486                                 $message = str_replace( '$' . $key, $val, $message );
 487                         }
 488                 } else {
 489                         foreach( $args as $n => $param ) {
 490                                 $replacementKeys['$' . ($n + 1)] = $param;
 491                         }
 492                         $message = strtr( $message, $replacementKeys );
 493                 }
 494         }
 495
 496         return $message;
 497 }
 498
 499 /**
 500  * Return an HTML-escaped version of a message.
 501  * Parameter replacements, if any, are done *after* the HTML-escaping,
 502  * so parameters may contain HTML (eg links or form controls). Be sure
 503  * to pre-escape them if you really do want plaintext, or just wrap
 504  * the whole thing in htmlspecialchars().
 505  *
 506  * @param string $key
 507  * @param string ... parameters
 508  * @return string
 509  */
 510 function wfMsgHtml( $key ) {
 511         $args = func_get_args();
 512         array_shift( $args );
 513         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key, true ) ), $args );
 514 }
 515
 516 /**
 517  * Return an HTML version of message
 518  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
 519  * so parameters may contain HTML (eg links or form controls). Be sure
 520  * to pre-escape them if you really do want plaintext, or just wrap
 521  * the whole thing in htmlspecialchars().
 522  *
 523  * @param string $key
 524  * @param string ... parameters
 525  * @return string
 526  */
 527 function wfMsgWikiHtml( $key ) {
 528         global $wgOut;
 529         $args = func_get_args();
 530         array_shift( $args );
 531         return wfMsgReplaceArgs( $wgOut->parse( wfMsgGetKey( $key, true ), /* can't be set to false */ true ), $args );
 532 }
 533
 534 /**
 535  * Returns message in the requested format
 536  * @param string $key Key of the message
 537  * @param array $options Processing rules:
 538  *  <i>parse<i>: parses wikitext to html
 539  *  <i>parseinline<i>: parses wikitext to html and removes the surrounding p's added by parser or tidy
 540  *  <i>escape<i>: filters message trough htmlspecialchars
 541  *  <i>replaceafter<i>: parameters are substituted after parsing or escaping
 542  *  <i>parsemag<i>: transform the message using magic phrases
 543  */
 544 function wfMsgExt( $key, $options ) {
 545         global $wgOut, $wgParser;
 546
 547         $args = func_get_args();
 548         array_shift( $args );
 549         array_shift( $args );
 550
 551         if( !is_array($options) ) {
 552                 $options = array($options);
 553         }
 554
 555         $string = wfMsgGetKey( $key, true, false, false );
 556
 557         if( !in_array('replaceafter', $options) ) {
 558                 $string = wfMsgReplaceArgs( $string, $args );
 559         }
 560
 561         if( in_array('parse', $options) ) {
 562                 $string = $wgOut->parse( $string, true, true );
 563         } elseif ( in_array('parseinline', $options) ) {
 564                 $string = $wgOut->parse( $string, true, true );
 565                 $m = array();
 566                 if( preg_match( "~^<p>(.*)\n?</p>$~", $string, $m ) ) {
 567                         $string = $m[1];
 568                 }
 569         } elseif ( in_array('parsemag', $options) ) {
 570                 global $wgMessageCache;
 571                 if ( isset( $wgMessageCache ) ) {
 572                         $string = $wgMessageCache->transform( $string );
 573                 }
 574         }
 575
 576         if ( in_array('escape', $options) ) {
 577                 $string = htmlspecialchars ( $string );
 578         }
 579
 580         if( in_array('replaceafter', $options) ) {
 581                 $string = wfMsgReplaceArgs( $string, $args );
 582         }
 583
 584         return $string;
 585 }
 586
 587
 588 /**
 589  * Just like exit() but makes a note of it.
 590  * Commits open transactions except if the error parameter is set
 591  *
 592  * @obsolete Please return control to the caller or throw an exception
 593  */
 594 function wfAbruptExit( $error = false ){
 595         global $wgLoadBalancer;
 596         static $called = false;
 597         if ( $called ){
 598                 exit( -1 );
 599         }
 600         $called = true;
 601
 602         $bt = wfDebugBacktrace();
 603         if( $bt ) {
 604                 for($i = 0; $i < count($bt) ; $i++){
 605                         $file = isset($bt[$i]['file']) ? $bt[$i]['file'] : "unknown";
 606                         $line = isset($bt[$i]['line']) ? $bt[$i]['line'] : "unknown";
 607                         wfDebug("WARNING: Abrupt exit in $file at line $line\n");
 608                 }
 609         } else {
 610                 wfDebug('WARNING: Abrupt exit\n');
 611         }
 612
 613         wfLogProfilingData();
 614
 615         if ( !$error ) {
 616                 $wgLoadBalancer->closeAll();
 617         }
 618         exit( -1 );
 619 }
 620
 621 /**
 622  * @obsolete Please return control the caller or throw an exception
 623  */
 624 function wfErrorExit() {
 625         wfAbruptExit( true );
 626 }
 627
 628 /**
 629  * Print a simple message and die, returning nonzero to the shell if any.
 630  * Plain die() fails to return nonzero to the shell if you pass a string.
 631  * @param string $msg
 632  */
 633 function wfDie( $msg='' ) {
 634         echo $msg;
 635         die( 1 );
 636 }
 637
 638 /**
 639  * Throw a debugging exception. This function previously once exited the process,
 640  * but now throws an exception instead, with similar results.
 641  *
 642  * @param string $msg Message shown when dieing.
 643  */
 644 function wfDebugDieBacktrace( $msg = '' ) {
 645         throw new MWException( $msg );
 646 }
 647
 648 /**
 649  * Fetch server name for use in error reporting etc.
 650  * Use real server name if available, so we know which machine
 651  * in a server farm generated the current page.
 652  * @return string
 653  */
 654 function wfHostname() {
 655         if ( function_exists( 'posix_uname' ) ) {
 656                 // This function not present on Windows
 657                 $uname = @posix_uname();
 658         } else {
 659                 $uname = false;
 660         }
 661         if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
 662                 return $uname['nodename'];
 663         } else {
 664                 # This may be a virtual server.
 665                 return $_SERVER['SERVER_NAME'];
 666         }
 667 }
 668
 669         /**
 670          * Returns a HTML comment with the elapsed time since request.
 671          * This method has no side effects.
 672          * @return string
 673          */
 674         function wfReportTime() {
 675                 global $wgRequestTime;
 676
 677                 $now = wfTime();
 678                 $elapsed = $now - $wgRequestTime;
 679
 680                 $com = sprintf( "<!-- Served by %s in %01.3f secs. -->",
 681                   wfHostname(), $elapsed );
 682                 return $com;
 683         }
 684
 685 /**
 686  * Safety wrapper for debug_backtrace().
 687  *
 688  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
 689  * murky circumstances, which may be triggered in part by stub objects
 690  * or other fancy talkin'.
 691  *
 692  * Will return an empty array if Zend Optimizer is detected, otherwise
 693  * the output from debug_backtrace() (trimmed).
 694  *
 695  * @return array of backtrace information
 696  */
 697 function wfDebugBacktrace() {
 698         if( extension_loaded( 'Zend Optimizer' ) ) {
 699                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
 700                 return array();
 701         } else {
 702                 return array_slice( debug_backtrace(), 1 );
 703         }
 704 }
 705
 706 function wfBacktrace() {
 707         global $wgCommandLineMode;
 708
 709         if ( $wgCommandLineMode ) {
 710                 $msg = '';
 711         } else {
 712                 $msg = "<ul>\n";
 713         }
 714         $backtrace = wfDebugBacktrace();
 715         foreach( $backtrace as $call ) {
 716                 if( isset( $call['file'] ) ) {
 717                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
 718                         $file = $f[count($f)-1];
 719                 } else {
 720                         $file = '-';
 721                 }
 722                 if( isset( $call['line'] ) ) {
 723                         $line = $call['line'];
 724                 } else {
 725                         $line = '-';
 726                 }
 727                 if ( $wgCommandLineMode ) {
 728                         $msg .= "$file line $line calls ";
 729                 } else {
 730                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
 731                 }
 732                 if( !empty( $call['class'] ) ) $msg .= $call['class'] . '::';
 733                 $msg .= $call['function'] . '()';
 734
 735                 if ( $wgCommandLineMode ) {
 736                         $msg .= "\n";
 737                 } else {
 738                         $msg .= "</li>\n";
 739                 }
 740         }
 741         if ( $wgCommandLineMode ) {
 742                 $msg .= "\n";
 743         } else {
 744                 $msg .= "</ul>\n";
 745         }
 746
 747         return $msg;
 748 }
 749
 750
 751 /* Some generic result counters, pulled out of SearchEngine */
 752
 753
 754 /**
 755  * @todo document
 756  */
 757 function wfShowingResults( $offset, $limit ) {
 758         global $wgLang;
 759         return wfMsgExt( 'showingresults', array( 'parseinline' ), $wgLang->formatNum( $limit ), $wgLang->formatNum( $offset+1 ) );
 760 }
 761
 762 /**
 763  * @todo document
 764  */
 765 function wfShowingResultsNum( $offset, $limit, $num ) {
 766         global $wgLang;
 767         return wfMsgExt( 'showingresultsnum', array( 'parseinline' ), $wgLang->formatNum( $limit ), $wgLang->formatNum( $offset+1 ), $wgLang->formatNum( $num ) );
 768 }
 769
 770 /**
 771  * @todo document
 772  */
 773 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
 774         global $wgLang;
 775         $fmtLimit = $wgLang->formatNum( $limit );
 776         $prev = wfMsg( 'prevn', $fmtLimit );
 777         $next = wfMsg( 'nextn', $fmtLimit );
 778
 779         if( is_object( $link ) ) {
 780                 $title =& $link;
 781         } else {
 782                 $title = Title::newFromText( $link );
 783                 if( is_null( $title ) ) {
 784                         return false;
 785                 }
 786         }
 787
 788         if ( 0 != $offset ) {
 789                 $po = $offset - $limit;
 790                 if ( $po < 0 ) { $po = 0; }
 791                 $q = "limit={$limit}&offset={$po}";
 792                 if ( '' != $query ) { $q .= '&'.$query; }
 793                 $plink = '<a href="' . $title->escapeLocalUrl( $q ) . "\">{$prev}</a>";
 794         } else { $plink = $prev; }
 795
 796         $no = $offset + $limit;
 797         $q = 'limit='.$limit.'&offset='.$no;
 798         if ( '' != $query ) { $q .= '&'.$query; }
 799
 800         if ( $atend ) {
 801                 $nlink = $next;
 802         } else {
 803                 $nlink = '<a href="' . $title->escapeLocalUrl( $q ) . "\">{$next}</a>";
 804         }
 805         $nums = wfNumLink( $offset, 20, $title, $query ) . ' | ' .
 806           wfNumLink( $offset, 50, $title, $query ) . ' | ' .
 807           wfNumLink( $offset, 100, $title, $query ) . ' | ' .
 808           wfNumLink( $offset, 250, $title, $query ) . ' | ' .
 809           wfNumLink( $offset, 500, $title, $query );
 810
 811         return wfMsg( 'viewprevnext', $plink, $nlink, $nums );
 812 }
 813
 814 /**
 815  * @todo document
 816  */
 817 function wfNumLink( $offset, $limit, &$title, $query = '' ) {
 818         global $wgLang;
 819         if ( '' == $query ) { $q = ''; }
 820         else { $q = $query.'&'; }
 821         $q .= 'limit='.$limit.'&offset='.$offset;
 822
 823         $fmtLimit = $wgLang->formatNum( $limit );
 824         $s = '<a href="' . $title->escapeLocalUrl( $q ) . "\">{$fmtLimit}</a>";
 825         return $s;
 826 }
 827
 828 /**
 829  * @todo document
 830  * @todo FIXME: we may want to blacklist some broken browsers
 831  *
 832  * @return bool Whereas client accept gzip compression
 833  */
 834 function wfClientAcceptsGzip() {
 835         global $wgUseGzip;
 836         if( $wgUseGzip ) {
 837                 # FIXME: we may want to blacklist some broken browsers
 838                 $m = array();
 839                 if( preg_match(
 840                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
 841                         $_SERVER['HTTP_ACCEPT_ENCODING'],
 842                         $m ) ) {
 843                         if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) return false;
 844                         wfDebug( " accepts gzip\n" );
 845                         return true;
 846                 }
 847         }
 848         return false;
 849 }
 850
 851 /**
 852  * Obtain the offset and limit values from the request string;
 853  * used in special pages
 854  *
 855  * @param $deflimit Default limit if none supplied
 856  * @param $optionname Name of a user preference to check against
 857  * @return array
 858  *
 859  */
 860 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
 861         global $wgRequest;
 862         return $wgRequest->getLimitOffset( $deflimit, $optionname );
 863 }
 864
 865 /**
 866  * Escapes the given text so that it may be output using addWikiText()
 867  * without any linking, formatting, etc. making its way through. This
 868  * is achieved by substituting certain characters with HTML entities.
 869  * As required by the callers, <nowiki> is not used. It currently does
 870  * not filter out characters which have special meaning only at the
 871  * start of a line, such as "*".
 872  *
 873  * @param string $text Text to be escaped
 874  */
 875 function wfEscapeWikiText( $text ) {
 876         $text = str_replace(
 877                 array( '[',     '|',      '\'',    'ISBN ',     'RFC ',     '://',     "\n=",     '{{' ),
 878                 array( '&#91;', '&#124;', '&#39;', 'ISBN&#32;', 'RFC&#32;', '&#58;//', "\n&#61;", '&#123;&#123;' ),
 879                 htmlspecialchars($text) );
 880         return $text;
 881 }
 882
 883 /**
 884  * @todo document
 885  */
 886 function wfQuotedPrintable( $string, $charset = '' ) {
 887         # Probably incomplete; see RFC 2045
 888         if( empty( $charset ) ) {
 889                 global $wgInputEncoding;
 890                 $charset = $wgInputEncoding;
 891         }
 892         $charset = strtoupper( $charset );
 893         $charset = str_replace( 'ISO-8859', 'ISO8859', $charset ); // ?
 894
 895         $illegal = '\x00-\x08\x0b\x0c\x0e-\x1f\x7f-\xff=';
 896         $replace = $illegal . '\t ?_';
 897         if( !preg_match( "/[$illegal]/", $string ) ) return $string;
 898         $out = "=?$charset?Q?";
 899         $out .= preg_replace( "/([$replace])/e", 'sprintf("=%02X",ord("$1"))', $string );
 900         $out .= '?=';
 901         return $out;
 902 }
 903
 904
 905 /**
 906  * @todo document
 907  * @return float
 908  */
 909 function wfTime() {
 910         return microtime(true);
 911 }
 912
 913 /**
 914  * Sets dest to source and returns the original value of dest
 915  * If source is NULL, it just returns the value, it doesn't set the variable
 916  */
 917 function wfSetVar( &$dest, $source ) {
 918         $temp = $dest;
 919         if ( !is_null( $source ) ) {
 920                 $dest = $source;
 921         }
 922         return $temp;
 923 }
 924
 925 /**
 926  * As for wfSetVar except setting a bit
 927  */
 928 function wfSetBit( &$dest, $bit, $state = true ) {
 929         $temp = (bool)($dest & $bit );
 930         if ( !is_null( $state ) ) {
 931                 if ( $state ) {
 932                         $dest |= $bit;
 933                 } else {
 934                         $dest &= ~$bit;
 935                 }
 936         }
 937         return $temp;
 938 }
 939
 940 /**
 941  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 942  * "days=7&limit=100". Options in the first array override options in the second.
 943  * Options set to "" will not be output.
 944  */
 945 function wfArrayToCGI( $array1, $array2 = NULL )
 946 {
 947         if ( !is_null( $array2 ) ) {
 948                 $array1 = $array1 + $array2;
 949         }
 950
 951         $cgi = '';
 952         foreach ( $array1 as $key => $value ) {
 953                 if ( '' !== $value ) {
 954                         if ( '' != $cgi ) {
 955                                 $cgi .= '&';
 956                         }
 957                         $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 958                 }
 959         }
 960         return $cgi;
 961 }
 962
 963 /**
 964  * This is obsolete, use SquidUpdate::purge()
 965  * @deprecated
 966  */
 967 function wfPurgeSquidServers ($urlArr) {
 968         SquidUpdate::purge( $urlArr );
 969 }
 970
 971 /**
 972  * Windows-compatible version of escapeshellarg()
 973  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
 974  * function puts single quotes in regardless of OS
 975  */
 976 function wfEscapeShellArg( ) {
 977         $args = func_get_args();
 978         $first = true;
 979         $retVal = '';
 980         foreach ( $args as $arg ) {
 981                 if ( !$first ) {
 982                         $retVal .= ' ';
 983                 } else {
 984                         $first = false;
 985                 }
 986
 987                 if ( wfIsWindows() ) {
 988                         // Escaping for an MSVC-style command line parser
 989                         // Ref: http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
 990                         // Double the backslashes before any double quotes. Escape the double quotes.
 991                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
 992                         $arg = '';
 993                         $delim = false;
 994                         foreach ( $tokens as $token ) {
 995                                 if ( $delim ) {
 996                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
 997                                 } else {
 998                                         $arg .= $token;
 999                                 }
1000                                 $delim = !$delim;
1001                         }
1002                         // Double the backslashes before the end of the string, because
1003                         // we will soon add a quote
1004                         $m = array();
1005                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1006                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1007                         }
1008
1009                         // Add surrounding quotes
1010                         $retVal .= '"' . $arg . '"';
1011                 } else {
1012                         $retVal .= escapeshellarg( $arg );
1013                 }
1014         }
1015         return $retVal;
1016 }
1017
1018 /**
1019  * wfMerge attempts to merge differences between three texts.
1020  * Returns true for a clean merge and false for failure or a conflict.
1021  */
1022 function wfMerge( $old, $mine, $yours, &$result ){
1023         global $wgDiff3;
1024
1025         # This check may also protect against code injection in
1026         # case of broken installations.
1027         if(! file_exists( $wgDiff3 ) ){
1028                 wfDebug( "diff3 not found\n" );
1029                 return false;
1030         }
1031
1032         # Make temporary files
1033         $td = wfTempDir();
1034         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1035         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1036         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1037
1038         fwrite( $oldtextFile, $old ); fclose( $oldtextFile );
1039         fwrite( $mytextFile, $mine ); fclose( $mytextFile );
1040         fwrite( $yourtextFile, $yours ); fclose( $yourtextFile );
1041
1042         # Check for a conflict
1043         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1044           wfEscapeShellArg( $mytextName ) . ' ' .
1045           wfEscapeShellArg( $oldtextName ) . ' ' .
1046           wfEscapeShellArg( $yourtextName );
1047         $handle = popen( $cmd, 'r' );
1048
1049         if( fgets( $handle, 1024 ) ){
1050                 $conflict = true;
1051         } else {
1052                 $conflict = false;
1053         }
1054         pclose( $handle );
1055
1056         # Merge differences
1057         $cmd = $wgDiff3 . ' -a -e --merge ' .
1058           wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1059         $handle = popen( $cmd, 'r' );
1060         $result = '';
1061         do {
1062                 $data = fread( $handle, 8192 );
1063                 if ( strlen( $data ) == 0 ) {
1064                         break;
1065                 }
1066                 $result .= $data;
1067         } while ( true );
1068         pclose( $handle );
1069         unlink( $mytextName ); unlink( $oldtextName ); unlink( $yourtextName );
1070
1071         if ( $result === '' && $old !== '' && $conflict == false ) {
1072                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1073                 $conflict = true;
1074         }
1075         return ! $conflict;
1076 }
1077
1078 /**
1079  * @todo document
1080  */
1081 function wfVarDump( $var ) {
1082         global $wgOut;
1083         $s = str_replace("\n","<br />\n", var_export( $var, true ) . "\n");
1084         if ( headers_sent() || !@is_object( $wgOut ) ) {
1085                 print $s;
1086         } else {
1087                 $wgOut->addHTML( $s );
1088         }
1089 }
1090
1091 /**
1092  * Provide a simple HTTP error.
1093  */
1094 function wfHttpError( $code, $label, $desc ) {
1095         global $wgOut;
1096         $wgOut->disable();
1097         header( "HTTP/1.0 $code $label" );
1098         header( "Status: $code $label" );
1099         $wgOut->sendCacheControl();
1100
1101         header( 'Content-type: text/html; charset=utf-8' );
1102         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1103                 "<html><head><title>" .
1104                 htmlspecialchars( $label ) .
1105                 "</title></head><body><h1>" .
1106                 htmlspecialchars( $label ) .
1107                 "</h1><p>" .
1108                 nl2br( htmlspecialchars( $desc ) ) .
1109                 "</p></body></html>\n";
1110 }
1111
1112 /**
1113  * Clear away any user-level output buffers, discarding contents.
1114  *
1115  * Suitable for 'starting afresh', for instance when streaming
1116  * relatively large amounts of data without buffering, or wanting to
1117  * output image files without ob_gzhandler's compression.
1118  *
1119  * The optional $resetGzipEncoding parameter controls suppression of
1120  * the Content-Encoding header sent by ob_gzhandler; by default it
1121  * is left. See comments for wfClearOutputBuffers() for why it would
1122  * be used.
1123  *
1124  * Note that some PHP configuration options may add output buffer
1125  * layers which cannot be removed; these are left in place.
1126  *
1127  * @parameter bool $resetGzipEncoding
1128  */
1129 function wfResetOutputBuffers( $resetGzipEncoding=true ) {
1130         if( $resetGzipEncoding ) {
1131                 // Suppress Content-Encoding and Content-Length
1132                 // headers from 1.10+s wfOutputHandler
1133                 global $wgDisableOutputCompression;
1134                 $wgDisableOutputCompression = true;
1135         }
1136         while( $status = ob_get_status() ) {
1137                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1138                         // Probably from zlib.output_compression or other
1139                         // PHP-internal setting which can't be removed.
1140                         //
1141                         // Give up, and hope the result doesn't break
1142                         // output behavior.
1143                         break;
1144                 }
1145                 if( !ob_end_clean() ) {
1146                         // Could not remove output buffer handler; abort now
1147                         // to avoid getting in some kind of infinite loop.
1148                         break;
1149                 }
1150                 if( $resetGzipEncoding ) {
1151                         if( $status['name'] == 'ob_gzhandler' ) {
1152                                 // Reset the 'Content-Encoding' field set by this handler
1153                                 // so we can start fresh.
1154                                 header( 'Content-Encoding:' );
1155                         }
1156                 }
1157         }
1158 }
1159
1160 /**
1161  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1162  *
1163  * Clear away output buffers, but keep the Content-Encoding header
1164  * produced by ob_gzhandler, if any.
1165  *
1166  * This should be used for HTTP 304 responses, where you need to
1167  * preserve the Content-Encoding header of the real result, but
1168  * also need to suppress the output of ob_gzhandler to keep to spec
1169  * and avoid breaking Firefox in rare cases where the headers and
1170  * body are broken over two packets.
1171  */
1172 function wfClearOutputBuffers() {
1173         wfResetOutputBuffers( false );
1174 }
1175
1176 /**
1177  * Converts an Accept-* header into an array mapping string values to quality
1178  * factors
1179  */
1180 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1181         # No arg means accept anything (per HTTP spec)
1182         if( !$accept ) {
1183                 return array( $def => 1 );
1184         }
1185
1186         $prefs = array();
1187
1188         $parts = explode( ',', $accept );
1189
1190         foreach( $parts as $part ) {
1191                 # FIXME: doesn't deal with params like 'text/html; level=1'
1192                 @list( $value, $qpart ) = explode( ';', $part );
1193                 $match = array();
1194                 if( !isset( $qpart ) ) {
1195                         $prefs[$value] = 1;
1196                 } elseif( preg_match( '/q\s*=\s*(\d*\.\d+)/', $qpart, $match ) ) {
1197                         $prefs[$value] = $match[1];
1198                 }
1199         }
1200
1201         return $prefs;
1202 }
1203
1204 /**
1205  * Checks if a given MIME type matches any of the keys in the given
1206  * array. Basic wildcards are accepted in the array keys.
1207  *
1208  * Returns the matching MIME type (or wildcard) if a match, otherwise
1209  * NULL if no match.
1210  *
1211  * @param string $type
1212  * @param array $avail
1213  * @return string
1214  * @private
1215  */
1216 function mimeTypeMatch( $type, $avail ) {
1217         if( array_key_exists($type, $avail) ) {
1218                 return $type;
1219         } else {
1220                 $parts = explode( '/', $type );
1221                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
1222                         return $parts[0] . '/*';
1223                 } elseif( array_key_exists( '*/*', $avail ) ) {
1224                         return '*/*';
1225                 } else {
1226                         return NULL;
1227                 }
1228         }
1229 }
1230
1231 /**
1232  * Returns the 'best' match between a client's requested internet media types
1233  * and the server's list of available types. Each list should be an associative
1234  * array of type to preference (preference is a float between 0.0 and 1.0).
1235  * Wildcards in the types are acceptable.
1236  *
1237  * @param array $cprefs Client's acceptable type list
1238  * @param array $sprefs Server's offered types
1239  * @return string
1240  *
1241  * @todo FIXME: doesn't handle params like 'text/plain; charset=UTF-8'
1242  * XXX: generalize to negotiate other stuff
1243  */
1244 function wfNegotiateType( $cprefs, $sprefs ) {
1245         $combine = array();
1246
1247         foreach( array_keys($sprefs) as $type ) {
1248                 $parts = explode( '/', $type );
1249                 if( $parts[1] != '*' ) {
1250                         $ckey = mimeTypeMatch( $type, $cprefs );
1251                         if( $ckey ) {
1252                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1253                         }
1254                 }
1255         }
1256
1257         foreach( array_keys( $cprefs ) as $type ) {
1258                 $parts = explode( '/', $type );
1259                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
1260                         $skey = mimeTypeMatch( $type, $sprefs );
1261                         if( $skey ) {
1262                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1263                         }
1264                 }
1265         }
1266
1267         $bestq = 0;
1268         $besttype = NULL;
1269
1270         foreach( array_keys( $combine ) as $type ) {
1271                 if( $combine[$type] > $bestq ) {
1272                         $besttype = $type;
1273                         $bestq = $combine[$type];
1274                 }
1275         }
1276
1277         return $besttype;
1278 }
1279
1280 /**
1281  * Array lookup
1282  * Returns an array where the values in the first array are replaced by the
1283  * values in the second array with the corresponding keys
1284  *
1285  * @return array
1286  */
1287 function wfArrayLookup( $a, $b ) {
1288         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
1289 }
1290
1291 /**
1292  * Convenience function; returns MediaWiki timestamp for the present time.
1293  * @return string
1294  */
1295 function wfTimestampNow() {
1296         # return NOW
1297         return wfTimestamp( TS_MW, time() );
1298 }
1299
1300 /**
1301  * Reference-counted warning suppression
1302  */
1303 function wfSuppressWarnings( $end = false ) {
1304         static $suppressCount = 0;
1305         static $originalLevel = false;
1306
1307         if ( $end ) {
1308                 if ( $suppressCount ) {
1309                         --$suppressCount;
1310                         if ( !$suppressCount ) {
1311                                 error_reporting( $originalLevel );
1312                         }
1313                 }
1314         } else {
1315                 if ( !$suppressCount ) {
1316                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE ) );
1317                 }
1318                 ++$suppressCount;
1319         }
1320 }
1321
1322 /**
1323  * Restore error level to previous value
1324  */
1325 function wfRestoreWarnings() {
1326         wfSuppressWarnings( true );
1327 }
1328
1329 # Autodetect, convert and provide timestamps of various types
1330
1331 /**
1332  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
1333  */
1334 define('TS_UNIX', 0);
1335
1336 /**
1337  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
1338  */
1339 define('TS_MW', 1);
1340
1341 /**
1342  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
1343  */
1344 define('TS_DB', 2);
1345
1346 /**
1347  * RFC 2822 format, for E-mail and HTTP headers
1348  */
1349 define('TS_RFC2822', 3);
1350
1351 /**
1352  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
1353  *
1354  * This is used by Special:Export
1355  */
1356 define('TS_ISO_8601', 4);
1357
1358 /**
1359  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
1360  *
1361  * @url http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
1362  *       DateTime tag and page 36 for the DateTimeOriginal and
1363  *       DateTimeDigitized tags.
1364  */
1365 define('TS_EXIF', 5);
1366
1367 /**
1368  * Oracle format time.
1369  */
1370 define('TS_ORACLE', 6);
1371
1372 /**
1373  * Postgres format time.
1374  */
1375 define('TS_POSTGRES', 7);
1376
1377 /**
1378  * @param mixed $outputtype A timestamp in one of the supported formats, the
1379  *                          function will autodetect which format is supplied
1380  *                          and act accordingly.
1381  * @return string Time in the format specified in $outputtype
1382  */
1383 function wfTimestamp($outputtype=TS_UNIX,$ts=0) {
1384         $uts = 0;
1385         $da = array();
1386         if ($ts==0) {
1387                 $uts=time();
1388         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D',$ts,$da)) {
1389                 # TS_DB
1390                 $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
1391                             (int)$da[2],(int)$da[3],(int)$da[1]);
1392         } elseif (preg_match('/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D',$ts,$da)) {
1393                 # TS_EXIF
1394                 $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
1395                         (int)$da[2],(int)$da[3],(int)$da[1]);
1396         } elseif (preg_match('/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D',$ts,$da)) {
1397                 # TS_MW
1398                 $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
1399                             (int)$da[2],(int)$da[3],(int)$da[1]);
1400         } elseif (preg_match('/^(\d{1,13})$/D',$ts,$da)) {
1401                 # TS_UNIX
1402                 $uts = $ts;
1403         } elseif (preg_match('/^(\d{1,2})-(...)-(\d\d(\d\d)?) (\d\d)\.(\d\d)\.(\d\d)/', $ts, $da)) {
1404                 # TS_ORACLE
1405                 $uts = strtotime(preg_replace('/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
1406                                 str_replace("+00:00", "UTC", $ts)));
1407         } elseif (preg_match('/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})Z$/', $ts, $da)) {
1408                 # TS_ISO_8601
1409                 $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
1410                         (int)$da[2],(int)$da[3],(int)$da[1]);
1411         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)[\+\- ](\d\d)$/',$ts,$da)) {
1412                 # TS_POSTGRES
1413                 $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
1414                 (int)$da[2],(int)$da[3],(int)$da[1]);
1415         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d) GMT$/',$ts,$da)) {
1416                 # TS_POSTGRES
1417                 $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
1418                 (int)$da[2],(int)$da[3],(int)$da[1]);
1419         } else {
1420                 # Bogus value; fall back to the epoch...
1421                 wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
1422                 $uts = 0;
1423         }
1424
1425
1426         switch($outputtype) {
1427                 case TS_UNIX:
1428                         return $uts;
1429                 case TS_MW:
1430                         return gmdate( 'YmdHis', $uts );
1431                 case TS_DB:
1432                         return gmdate( 'Y-m-d H:i:s', $uts );
1433                 case TS_ISO_8601:
1434                         return gmdate( 'Y-m-d\TH:i:s\Z', $uts );
1435                 // This shouldn't ever be used, but is included for completeness
1436                 case TS_EXIF:
1437                         return gmdate(  'Y:m:d H:i:s', $uts );
1438                 case TS_RFC2822:
1439                         return gmdate( 'D, d M Y H:i:s', $uts ) . ' GMT';
1440                 case TS_ORACLE:
1441                         return gmdate( 'd-M-y h.i.s A', $uts) . ' +00:00';
1442                 case TS_POSTGRES:
1443                         return gmdate( 'Y-m-d H:i:s', $uts) . ' GMT';
1444                 default:
1445                         throw new MWException( 'wfTimestamp() called with illegal output type.');
1446         }
1447 }
1448
1449 /**
1450  * Return a formatted timestamp, or null if input is null.
1451  * For dealing with nullable timestamp columns in the database.
1452  * @param int $outputtype
1453  * @param string $ts
1454  * @return string
1455  */
1456 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
1457         if( is_null( $ts ) ) {
1458                 return null;
1459         } else {
1460                 return wfTimestamp( $outputtype, $ts );
1461         }
1462 }
1463
1464 /**
1465  * Check if the operating system is Windows
1466  *
1467  * @return bool True if it's Windows, False otherwise.
1468  */
1469 function wfIsWindows() {
1470         if (substr(php_uname(), 0, 7) == 'Windows') {
1471                 return true;
1472         } else {
1473                 return false;
1474         }
1475 }
1476
1477 /**
1478  * Swap two variables
1479  */
1480 function swap( &$x, &$y ) {
1481         $z = $x;
1482         $x = $y;
1483         $y = $z;
1484 }
1485
1486 function wfGetCachedNotice( $name ) {
1487         global $wgOut, $parserMemc;
1488         $fname = 'wfGetCachedNotice';
1489         wfProfileIn( $fname );
1490
1491         $needParse = false;
1492
1493         if( $name === 'default' ) {
1494                 // special case
1495                 global $wgSiteNotice;
1496                 $notice = $wgSiteNotice;
1497                 if( empty( $notice ) ) {
1498                         wfProfileOut( $fname );
1499                         return false;
1500                 }
1501         } else {
1502                 $notice = wfMsgForContentNoTrans( $name );
1503                 if( wfEmptyMsg( $name, $notice ) || $notice == '-' ) {
1504                         wfProfileOut( $fname );
1505                         return( false );
1506                 }
1507         }
1508
1509         $cachedNotice = $parserMemc->get( wfMemcKey( $name ) );
1510         if( is_array( $cachedNotice ) ) {
1511                 if( md5( $notice ) == $cachedNotice['hash'] ) {
1512                         $notice = $cachedNotice['html'];
1513                 } else {
1514                         $needParse = true;
1515                 }
1516         } else {
1517                 $needParse = true;
1518         }
1519
1520         if( $needParse ) {
1521                 if( is_object( $wgOut ) ) {
1522                         $parsed = $wgOut->parse( $notice );
1523                         $parserMemc->set( wfMemcKey( $name ), array( 'html' => $parsed, 'hash' => md5( $notice ) ), 600 );
1524                         $notice = $parsed;
1525                 } else {
1526                         wfDebug( 'wfGetCachedNotice called for ' . $name . ' with no $wgOut available' );
1527                         $notice = '';
1528                 }
1529         }
1530
1531         wfProfileOut( $fname );
1532         return $notice;
1533 }
1534
1535 function wfGetNamespaceNotice() {
1536         global $wgTitle;
1537
1538         # Paranoia
1539         if ( !isset( $wgTitle ) || !is_object( $wgTitle ) )
1540                 return "";
1541
1542         $fname = 'wfGetNamespaceNotice';
1543         wfProfileIn( $fname );
1544
1545         $key = "namespacenotice-" . $wgTitle->getNsText();
1546         $namespaceNotice = wfGetCachedNotice( $key );
1547         if ( $namespaceNotice && substr ( $namespaceNotice , 0 ,7 ) != "<p>&lt;" ) {
1548                  $namespaceNotice = '<div id="namespacebanner">' . $namespaceNotice . "</div>";
1549         } else {
1550                 $namespaceNotice = "";
1551         }
1552
1553         wfProfileOut( $fname );
1554         return $namespaceNotice;
1555 }
1556
1557 function wfGetSiteNotice() {
1558         global $wgUser, $wgSiteNotice;
1559         $fname = 'wfGetSiteNotice';
1560         wfProfileIn( $fname );
1561         $siteNotice = '';
1562
1563         if( wfRunHooks( 'SiteNoticeBefore', array( &$siteNotice ) ) ) {
1564                 if( is_object( $wgUser ) && $wgUser->isLoggedIn() ) {
1565                         $siteNotice = wfGetCachedNotice( 'sitenotice' );
1566                 } else {
1567                         $anonNotice = wfGetCachedNotice( 'anonnotice' );
1568                         if( !$anonNotice ) {
1569                                 $siteNotice = wfGetCachedNotice( 'sitenotice' );
1570                         } else {
1571                                 $siteNotice = $anonNotice;
1572                         }
1573                 }
1574                 if( !$siteNotice ) {
1575                         $siteNotice = wfGetCachedNotice( 'default' );
1576                 }
1577         }
1578
1579         wfRunHooks( 'SiteNoticeAfter', array( &$siteNotice ) );
1580         wfProfileOut( $fname );
1581         return $siteNotice;
1582 }
1583
1584 /**
1585  * BC wrapper for MimeMagic::singleton()
1586  * @deprecated
1587  */
1588 function &wfGetMimeMagic() {
1589         return MimeMagic::singleton();
1590 }
1591
1592 /**
1593  * Tries to get the system directory for temporary files.
1594  * The TMPDIR, TMP, and TEMP environment variables are checked in sequence,
1595  * and if none are set /tmp is returned as the generic Unix default.
1596  *
1597  * NOTE: When possible, use the tempfile() function to create temporary
1598  * files to avoid race conditions on file creation, etc.
1599  *
1600  * @return string
1601  */
1602 function wfTempDir() {
1603         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
1604                 $tmp = getenv( $var );
1605                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
1606                         return $tmp;
1607                 }
1608         }
1609         # Hope this is Unix of some kind!
1610         return '/tmp';
1611 }
1612
1613 /**
1614  * Make directory, and make all parent directories if they don't exist
1615  */
1616 function wfMkdirParents( $fullDir, $mode = 0777 ) {
1617         if ( strval( $fullDir ) === '' ) {
1618                 return true;
1619         }
1620
1621         # Go back through the paths to find the first directory that exists
1622         $currentDir = $fullDir;
1623         $createList = array();
1624         while ( strval( $currentDir ) !== '' && !file_exists( $currentDir ) ) {
1625                 # Strip trailing slashes
1626                 $currentDir = rtrim( $currentDir, '/\\' );
1627
1628                 # Add to create list
1629                 $createList[] = $currentDir;
1630
1631                 # Find next delimiter searching from the end
1632                 $p = max( strrpos( $currentDir, '/' ), strrpos( $currentDir, '\\' ) );
1633                 if ( $p === false ) {
1634                         $currentDir = false;
1635                 } else {
1636                         $currentDir = substr( $currentDir, 0, $p );
1637                 }
1638         }
1639
1640         if ( count( $createList ) == 0 ) {
1641                 # Directory specified already exists
1642                 return true;
1643         } elseif ( $currentDir === false ) {
1644                 # Went all the way back to root and it apparently doesn't exist
1645                 return false;
1646         }
1647
1648         # Now go forward creating directories
1649         $createList = array_reverse( $createList );
1650         foreach ( $createList as $dir ) {
1651                 # use chmod to override the umask, as suggested by the PHP manual
1652                 if ( !mkdir( $dir, $mode ) || !chmod( $dir, $mode ) ) {
1653                         wfDebugLog( 'mkdir', "Unable to create directory $dir\n" );
1654                         return false;
1655                 }
1656         }
1657         return true;
1658 }
1659
1660 /**
1661  * Increment a statistics counter
1662  */
1663  function wfIncrStats( $key ) {
1664          global $wgMemc;
1665          $key = wfMemcKey( 'stats', $key );
1666          if ( is_null( $wgMemc->incr( $key ) ) ) {
1667                  $wgMemc->add( $key, 1 );
1668          }
1669  }
1670
1671 /**
1672  * @param mixed $nr The number to format
1673  * @param int $acc The number of digits after the decimal point, default 2
1674  * @param bool $round Whether or not to round the value, default true
1675  * @return float
1676  */
1677 function wfPercent( $nr, $acc = 2, $round = true ) {
1678         $ret = sprintf( "%.${acc}f", $nr );
1679         return $round ? round( $ret, $acc ) . '%' : "$ret%";
1680 }
1681
1682 /**
1683  * Encrypt a username/password.
1684  *
1685  * @param string $userid ID of the user
1686  * @param string $password Password of the user
1687  * @return string Hashed password
1688  */
1689 function wfEncryptPassword( $userid, $password ) {
1690         global $wgPasswordSalt;
1691         $p = md5( $password);
1692
1693         if($wgPasswordSalt)
1694                 return md5( "{$userid}-{$p}" );
1695         else
1696                 return $p;
1697 }
1698
1699 /**
1700  * Appends to second array if $value differs from that in $default
1701  */
1702 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
1703         if ( is_null( $changed ) ) {
1704                 throw new MWException('GlobalFunctions::wfAppendToArrayIfNotDefault got null');
1705         }
1706         if ( $default[$key] !== $value ) {
1707                 $changed[$key] = $value;
1708         }
1709 }
1710
1711 /**
1712  * Since wfMsg() and co suck, they don't return false if the message key they
1713  * looked up didn't exist but a XHTML string, this function checks for the
1714  * nonexistance of messages by looking at wfMsg() output
1715  *
1716  * @param $msg      The message key looked up
1717  * @param $wfMsgOut The output of wfMsg*()
1718  * @return bool
1719  */
1720 function wfEmptyMsg( $msg, $wfMsgOut ) {
1721         return $wfMsgOut === "&lt;$msg&gt;";
1722 }
1723
1724 /**
1725  * Find out whether or not a mixed variable exists in a string
1726  *
1727  * @param mixed  needle
1728  * @param string haystack
1729  * @return bool
1730  */
1731 function in_string( $needle, $str ) {
1732         return strpos( $str, $needle ) !== false;
1733 }
1734
1735 function wfSpecialList( $page, $details ) {
1736         global $wgContLang;
1737         $details = $details ? ' ' . $wgContLang->getDirMark() . "($details)" : "";
1738         return $page . $details;
1739 }
1740
1741 /**
1742  * Returns a regular expression of url protocols
1743  *
1744  * @return string
1745  */
1746 function wfUrlProtocols() {
1747         global $wgUrlProtocols;
1748
1749         // Support old-style $wgUrlProtocols strings, for backwards compatibility
1750         // with LocalSettings files from 1.5
1751         if ( is_array( $wgUrlProtocols ) ) {
1752                 $protocols = array();
1753                 foreach ($wgUrlProtocols as $protocol)
1754                         $protocols[] = preg_quote( $protocol, '/' );
1755
1756                 return implode( '|', $protocols );
1757         } else {
1758                 return $wgUrlProtocols;
1759         }
1760 }
1761
1762 /**
1763  * Execute a shell command, with time and memory limits mirrored from the PHP
1764  * configuration if supported.
1765  * @param $cmd Command line, properly escaped for shell.
1766  * @param &$retval optional, will receive the program's exit code.
1767  *                 (non-zero is usually failure)
1768  * @return collected stdout as a string (trailing newlines stripped)
1769  */
1770 function wfShellExec( $cmd, &$retval=null ) {
1771         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize;
1772
1773         if( ini_get( 'safe_mode' ) ) {
1774                 wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
1775                 $retval = 1;
1776                 return "Unable to run external programs in safe mode.";
1777         }
1778
1779         if ( php_uname( 's' ) == 'Linux' ) {
1780                 $time = ini_get( 'max_execution_time' );
1781                 $mem = intval( $wgMaxShellMemory );
1782                 $filesize = intval( $wgMaxShellFileSize );
1783
1784                 if ( $time > 0 && $mem > 0 ) {
1785                         $script = "$IP/bin/ulimit-tvf.sh";
1786                         if ( is_executable( $script ) ) {
1787                                 $cmd = escapeshellarg( $script ) . " $time $mem $filesize $cmd";
1788                         }
1789                 }
1790         } elseif ( php_uname( 's' ) == 'Windows NT' ) {
1791                 # This is a hack to work around PHP's flawed invocation of cmd.exe
1792                 # http://news.php.net/php.internals/21796
1793                 $cmd = '"' . $cmd . '"';
1794         }
1795         wfDebug( "wfShellExec: $cmd\n" );
1796
1797         $output = array();
1798         $retval = 1; // error by default?
1799         exec( $cmd, $output, $retval ); // returns the last line of output.
1800         return implode( "\n", $output );
1801
1802 }
1803
1804 /**
1805  * This function works like "use VERSION" in Perl, the program will die with a
1806  * backtrace if the current version of PHP is less than the version provided
1807  *
1808  * This is useful for extensions which due to their nature are not kept in sync
1809  * with releases, and might depend on other versions of PHP than the main code
1810  *
1811  * Note: PHP might die due to parsing errors in some cases before it ever
1812  *       manages to call this function, such is life
1813  *
1814  * @see perldoc -f use
1815  *
1816  * @param mixed $version The version to check, can be a string, an integer, or
1817  *                       a float
1818  */
1819 function wfUsePHP( $req_ver ) {
1820         $php_ver = PHP_VERSION;
1821
1822         if ( version_compare( $php_ver, (string)$req_ver, '<' ) )
1823                  throw new MWException( "PHP $req_ver required--this is only $php_ver" );
1824 }
1825
1826 /**
1827  * This function works like "use VERSION" in Perl except it checks the version
1828  * of MediaWiki, the program will die with a backtrace if the current version
1829  * of MediaWiki is less than the version provided.
1830  *
1831  * This is useful for extensions which due to their nature are not kept in sync
1832  * with releases
1833  *
1834  * @see perldoc -f use
1835  *
1836  * @param mixed $version The version to check, can be a string, an integer, or
1837  *                       a float
1838  */
1839 function wfUseMW( $req_ver ) {
1840         global $wgVersion;
1841
1842         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) )
1843                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
1844 }
1845
1846 /**
1847  * @deprecated use StringUtils::escapeRegexReplacement
1848  */
1849 function wfRegexReplacement( $string ) {
1850         return StringUtils::escapeRegexReplacement( $string );
1851 }
1852
1853 /**
1854  * Return the final portion of a pathname.
1855  * Reimplemented because PHP5's basename() is buggy with multibyte text.
1856  * http://bugs.php.net/bug.php?id=33898
1857  *
1858  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
1859  * We'll consider it so always, as we don't want \s in our Unix paths either.
1860  *
1861  * @param string $path
1862  * @return string
1863  */
1864 function wfBaseName( $path ) {
1865         $matches = array();
1866         if( preg_match( '#([^/\\\\]*)[/\\\\]*$#', $path, $matches ) ) {
1867                 return $matches[1];
1868         } else {
1869                 return '';
1870         }
1871 }
1872
1873 /**
1874  * Generate a relative path name to the given file.
1875  * May explode on non-matching case-insensitive paths,
1876  * funky symlinks, etc.
1877  *
1878  * @param string $path Absolute destination path including target filename
1879  * @param string $from Absolute source path, directory only
1880  * @return string
1881  */
1882 function wfRelativePath( $path, $from ) {
1883         // Normalize mixed input on Windows...
1884         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
1885         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
1886
1887         $pieces  = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
1888         $against = explode( DIRECTORY_SEPARATOR, $from );
1889
1890         // Trim off common prefix
1891         while( count( $pieces ) && count( $against )
1892                 && $pieces[0] == $against[0] ) {
1893                 array_shift( $pieces );
1894                 array_shift( $against );
1895         }
1896
1897         // relative dots to bump us to the parent
1898         while( count( $against ) ) {
1899                 array_unshift( $pieces, '..' );
1900                 array_shift( $against );
1901         }
1902
1903         array_push( $pieces, wfBaseName( $path ) );
1904
1905         return implode( DIRECTORY_SEPARATOR, $pieces );
1906 }
1907
1908 /**
1909  * Make a URL index, appropriate for the el_index field of externallinks.
1910  */
1911 function wfMakeUrlIndex( $url ) {
1912         wfSuppressWarnings();
1913         $bits = parse_url( $url );
1914         wfRestoreWarnings();
1915         if ( !$bits || $bits['scheme'] !== 'http' ) {
1916                 return false;
1917         }
1918         // Reverse the labels in the hostname, convert to lower case
1919         $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
1920         // Add an extra dot to the end
1921         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
1922                 $reversedHost .= '.';
1923         }
1924         // Reconstruct the pseudo-URL
1925         $index = "http://$reversedHost";
1926         // Leave out user and password. Add the port, path, query and fragment
1927         if ( isset( $bits['port'] ) )      $index .= ':' . $bits['port'];
1928         if ( isset( $bits['path'] ) ) {
1929                 $index .= $bits['path'];
1930         } else {
1931                 $index .= '/';
1932         }
1933         if ( isset( $bits['query'] ) )     $index .= '?' . $bits['query'];
1934         if ( isset( $bits['fragment'] ) )  $index .= '#' . $bits['fragment'];
1935         return $index;
1936 }
1937
1938 /**
1939  * Do any deferred updates and clear the list
1940  * TODO: This could be in Wiki.php if that class made any sense at all
1941  */
1942 function wfDoUpdates()
1943 {
1944         global $wgPostCommitUpdateList, $wgDeferredUpdateList;
1945         foreach ( $wgDeferredUpdateList as $update ) {
1946                 $update->doUpdate();
1947         }
1948         foreach ( $wgPostCommitUpdateList as $update ) {
1949                 $update->doUpdate();
1950         }
1951         $wgDeferredUpdateList = array();
1952         $wgPostCommitUpdateList = array();
1953 }
1954
1955 /**
1956  * @deprecated use StringUtils::explodeMarkup
1957  */
1958 function wfExplodeMarkup( $separator, $text ) {
1959         return StringUtils::explodeMarkup( $separator, $text );
1960 }
1961
1962 /**
1963  * Convert an arbitrarily-long digit string from one numeric base
1964  * to another, optionally zero-padding to a minimum column width.
1965  *
1966  * Supports base 2 through 36; digit values 10-36 are represented
1967  * as lowercase letters a-z. Input is case-insensitive.
1968  *
1969  * @param $input string of digits
1970  * @param $sourceBase int 2-36
1971  * @param $destBase int 2-36
1972  * @param $pad int 1 or greater
1973  * @return string or false on invalid input
1974  */
1975 function wfBaseConvert( $input, $sourceBase, $destBase, $pad=1 ) {
1976         if( $sourceBase < 2 ||
1977                 $sourceBase > 36 ||
1978                 $destBase < 2 ||
1979                 $destBase > 36 ||
1980                 $pad < 1 ||
1981                 $sourceBase != intval( $sourceBase ) ||
1982                 $destBase != intval( $destBase ) ||
1983                 $pad != intval( $pad ) ||
1984                 !is_string( $input ) ||
1985                 $input == '' ) {
1986                 return false;
1987         }
1988
1989         $digitChars = '0123456789abcdefghijklmnopqrstuvwxyz';
1990         $inDigits = array();
1991         $outChars = '';
1992
1993         // Decode and validate input string
1994         $input = strtolower( $input );
1995         for( $i = 0; $i < strlen( $input ); $i++ ) {
1996                 $n = strpos( $digitChars, $input{$i} );
1997                 if( $n === false || $n > $sourceBase ) {
1998                         return false;
1999                 }
2000                 $inDigits[] = $n;
2001         }
2002
2003         // Iterate over the input, modulo-ing out an output digit
2004         // at a time until input is gone.
2005         while( count( $inDigits ) ) {
2006                 $work = 0;
2007                 $workDigits = array();
2008
2009                 // Long division...
2010                 foreach( $inDigits as $digit ) {
2011                         $work *= $sourceBase;
2012                         $work += $digit;
2013
2014                         if( $work < $destBase ) {
2015                                 // Gonna need to pull another digit.
2016                                 if( count( $workDigits ) ) {
2017                                         // Avoid zero-padding; this lets us find
2018                                         // the end of the input very easily when
2019                                         // length drops to zero.
2020                                         $workDigits[] = 0;
2021                                 }
2022                         } else {
2023                                 // Finally! Actual division!
2024                                 $workDigits[] = intval( $work / $destBase );
2025
2026                                 // Isn't it annoying that most programming languages
2027                                 // don't have a single divide-and-remainder operator,
2028                                 // even though the CPU implements it that way?
2029                                 $work = $work % $destBase;
2030                         }
2031                 }
2032
2033                 // All that division leaves us with a remainder,
2034                 // which is conveniently our next output digit.
2035                 $outChars .= $digitChars[$work];
2036
2037                 // And we continue!
2038                 $inDigits = $workDigits;
2039         }
2040
2041         while( strlen( $outChars ) < $pad ) {
2042                 $outChars .= '0';
2043         }
2044
2045         return strrev( $outChars );
2046 }
2047
2048 /**
2049  * Create an object with a given name and an array of construct parameters
2050  * @param string $name
2051  * @param array $p parameters
2052  */
2053 function wfCreateObject( $name, $p ){
2054         $p = array_values( $p );
2055         switch ( count( $p ) ) {
2056                 case 0:
2057                         return new $name;
2058                 case 1:
2059                         return new $name( $p[0] );
2060                 case 2:
2061                         return new $name( $p[0], $p[1] );
2062                 case 3:
2063                         return new $name( $p[0], $p[1], $p[2] );
2064                 case 4:
2065                         return new $name( $p[0], $p[1], $p[2], $p[3] );
2066                 case 5:
2067                         return new $name( $p[0], $p[1], $p[2], $p[3], $p[4] );
2068                 case 6:
2069                         return new $name( $p[0], $p[1], $p[2], $p[3], $p[4], $p[5] );
2070                 default:
2071                         throw new MWException( "Too many arguments to construtor in wfCreateObject" );
2072         }
2073 }
2074
2075 /**
2076  * Aliases for modularized functions
2077  */
2078 function wfGetHTTP( $url, $timeout = 'default' ) {
2079         return Http::get( $url, $timeout );
2080 }
2081 function wfIsLocalURL( $url ) {
2082         return Http::isLocalURL( $url );
2083 }
2084
2085 /**
2086  * Initialise php session
2087  */
2088 function wfSetupSession() {
2089         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain, $wgCookieSecure;
2090         if( $wgSessionsInMemcached ) {
2091                 require_once( 'MemcachedSessions.php' );
2092         } elseif( 'files' != ini_get( 'session.save_handler' ) ) {
2093                 # If it's left on 'user' or another setting from another
2094                 # application, it will end up failing. Try to recover.
2095                 ini_set ( 'session.save_handler', 'files' );
2096         }
2097         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure);
2098         session_cache_limiter( 'private, must-revalidate' );
2099         @session_start();
2100 }
2101
2102 /**
2103  * Get an object from the precompiled serialized directory
2104  *
2105  * @return mixed The variable on success, false on failure
2106  */
2107 function wfGetPrecompiledData( $name ) {
2108         global $IP;
2109
2110         $file = "$IP/serialized/$name";
2111         if ( file_exists( $file ) ) {
2112                 $blob = file_get_contents( $file );
2113                 if ( $blob ) {
2114                         return unserialize( $blob );
2115                 }
2116         }
2117         return false;
2118 }
2119
2120 function wfGetCaller( $level = 2 ) {
2121         $backtrace = wfDebugBacktrace();
2122         if ( isset( $backtrace[$level] ) ) {
2123                 if ( isset( $backtrace[$level]['class'] ) ) {
2124                         $caller = $backtrace[$level]['class'] . '::' . $backtrace[$level]['function'];
2125                 } else {
2126                         $caller = $backtrace[$level]['function'];
2127                 }
2128         } else {
2129                 $caller = 'unknown';
2130         }
2131         return $caller;
2132 }
2133
2134 /** Return a string consisting all callers in stack, somewhat useful sometimes for profiling specific points */
2135 function wfGetAllCallers() {
2136         return implode('/', array_map(
2137                 create_function('$frame','
2138                         return isset( $frame["class"] )?
2139                                 $frame["class"]."::".$frame["function"]:
2140                                 $frame["function"];
2141                         '),
2142                 array_reverse(wfDebugBacktrace())));
2143 }
2144
2145 /**
2146  * Get a cache key
2147  */
2148 function wfMemcKey( /*... */ ) {
2149         global $wgDBprefix, $wgDBname;
2150         $args = func_get_args();
2151         if ( $wgDBprefix ) {
2152                 $key = "$wgDBname-$wgDBprefix:" . implode( ':', $args );
2153         } else {
2154                 $key = $wgDBname . ':' . implode( ':', $args );
2155         }
2156         return $key;
2157 }
2158
2159 /**
2160  * Get a cache key for a foreign DB
2161  */
2162 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
2163         $args = array_slice( func_get_args(), 2 );
2164         if ( $prefix ) {
2165                 $key = "$db-$prefix:" . implode( ':', $args );
2166         } else {
2167                 $key = $db . ':' . implode( ':', $args );
2168         }
2169         return $key;
2170 }
2171
2172 /**
2173  * Get an ASCII string identifying this wiki
2174  * This is used as a prefix in memcached keys
2175  */
2176 function wfWikiID() {
2177         global $wgDBprefix, $wgDBname;
2178         if ( $wgDBprefix ) {
2179                 return "$wgDBname-$wgDBprefix";
2180         } else {
2181                 return $wgDBname;
2182         }
2183 }
2184
2185 /*
2186  * Get a Database object
2187  * @param integer $db Index of the connection to get. May be DB_MASTER for the
2188  *                master (for write queries), DB_SLAVE for potentially lagged
2189  *                read queries, or an integer >= 0 for a particular server.
2190  *
2191  * @param mixed $groups Query groups. An array of group names that this query
2192  *              belongs to. May contain a single string if the query is only
2193  *              in one group.
2194  */
2195 function &wfGetDB( $db = DB_LAST, $groups = array() ) {
2196         global $wgLoadBalancer;
2197         $ret = $wgLoadBalancer->getConnection( $db, true, $groups );
2198         return $ret;
2199 }
2200 ?>