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