includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere
   4  * @file
   5  */
   6
   7 if ( !defined( 'MEDIAWIKI' ) ) {
   8         die( "This file is part of MediaWiki, it is not a valid entry point" );
   9 }
  10
  11 // Hide compatibility functions from Doxygen
  12 /// @cond
  13
  14 /**
  15  * Compatibility functions
  16  *
  17  * We support PHP 5.2.3 and up.
  18  * Re-implementations of newer functions or functions in non-standard
  19  * PHP extensions may be included here.
  20  */
  21
  22 if( !function_exists( 'iconv' ) ) {
  23         /** @codeCoverageIgnore */
  24         function iconv( $from, $to, $string ) {
  25                 return Fallback::iconv( $from, $to, $string );
  26         }
  27 }
  28
  29 if ( !function_exists( 'mb_substr' ) ) {
  30         /** @codeCoverageIgnore */
  31         function mb_substr( $str, $start, $count='end' ) {
  32                 return Fallback::mb_substr( $str, $start, $count );
  33         }
  34
  35         /** @codeCoverageIgnore */
  36         function mb_substr_split_unicode( $str, $splitPos ) {
  37                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  38         }
  39 }
  40
  41 if ( !function_exists( 'mb_strlen' ) ) {
  42         /** @codeCoverageIgnore */
  43         function mb_strlen( $str, $enc = '' ) {
  44                 return Fallback::mb_strlen( $str, $enc );
  45         }
  46 }
  47
  48 if( !function_exists( 'mb_strpos' ) ) {
  49         /** @codeCoverageIgnore */
  50         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  51                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  52         }
  53
  54 }
  55
  56 if( !function_exists( 'mb_strrpos' ) ) {
  57         /** @codeCoverageIgnore */
  58         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  59                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  60         }
  61 }
  62
  63
  64 // Support for Wietse Venema's taint feature
  65 if ( !function_exists( 'istainted' ) ) {
  66         /** @codeCoverageIgnore */
  67         function istainted( $var ) {
  68                 return 0;
  69         }
  70         /** @codeCoverageIgnore */
  71         function taint( $var, $level = 0 ) {}
  72         /** @codeCoverageIgnore */
  73         function untaint( $var, $level = 0 ) {}
  74         define( 'TC_HTML', 1 );
  75         define( 'TC_SHELL', 1 );
  76         define( 'TC_MYSQL', 1 );
  77         define( 'TC_PCRE', 1 );
  78         define( 'TC_SELF', 1 );
  79 }
  80 /// @endcond
  81
  82 /**
  83  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
  84  */
  85 function wfArrayDiff2( $a, $b ) {
  86         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
  87 }
  88
  89 function wfArrayDiff2_cmp( $a, $b ) {
  90         if ( !is_array( $a ) ) {
  91                 return strcmp( $a, $b );
  92         } elseif ( count( $a ) !== count( $b ) ) {
  93                 return count( $a ) < count( $b ) ? -1 : 1;
  94         } else {
  95                 reset( $a );
  96                 reset( $b );
  97                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
  98                         $cmp = strcmp( $valueA, $valueB );
  99                         if ( $cmp !== 0 ) {
 100                                 return $cmp;
 101                         }
 102                 }
 103                 return 0;
 104         }
 105 }
 106
 107 /**
 108  * Array lookup
 109  * Returns an array where the values in the first array are replaced by the
 110  * values in the second array with the corresponding keys
 111  *
 112  * @param $a Array
 113  * @param $b Array
 114  * @return array
 115  */
 116 function wfArrayLookup( $a, $b ) {
 117         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 118 }
 119
 120 /**
 121  * Appends to second array if $value differs from that in $default
 122  *
 123  * @param $key String|Int
 124  * @param $value Mixed
 125  * @param $default Mixed
 126  * @param $changed Array to alter
 127  */
 128 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 129         if ( is_null( $changed ) ) {
 130                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 131         }
 132         if ( $default[$key] !== $value ) {
 133                 $changed[$key] = $value;
 134         }
 135 }
 136
 137 /**
 138  * Backwards array plus for people who haven't bothered to read the PHP manual
 139  * XXX: will not darn your socks for you.
 140  *
 141  * @param $array1 Array
 142  * @param [$array2, [...]] Arrays
 143  * @return Array
 144  */
 145 function wfArrayMerge( $array1/* ... */ ) {
 146         $args = func_get_args();
 147         $args = array_reverse( $args, true );
 148         $out = array();
 149         foreach ( $args as $arg ) {
 150                 $out += $arg;
 151         }
 152         return $out;
 153 }
 154
 155 /**
 156  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 157  * e.g.
 158  *      wfMergeErrorArrays(
 159  *              array( array( 'x' ) ),
 160  *              array( array( 'x', '2' ) ),
 161  *              array( array( 'x' ) ),
 162  *              array( array( 'y') )
 163  *      );
 164  * returns:
 165  *              array(
 166  *              array( 'x', '2' ),
 167  *              array( 'x' ),
 168  *              array( 'y' )
 169  *      )
 170  * @param varargs
 171  * @return Array
 172  */
 173 function wfMergeErrorArrays( /*...*/ ) {
 174         $args = func_get_args();
 175         $out = array();
 176         foreach ( $args as $errors ) {
 177                 foreach ( $errors as $params ) {
 178                         # @todo FIXME: Sometimes get nested arrays for $params,
 179                         # which leads to E_NOTICEs
 180                         $spec = implode( "\t", $params );
 181                         $out[$spec] = $params;
 182                 }
 183         }
 184         return array_values( $out );
 185 }
 186
 187 /**
 188  * Insert array into another array after the specified *KEY*
 189  *
 190  * @param $array Array: The array.
 191  * @param $insert Array: The array to insert.
 192  * @param $after Mixed: The key to insert after
 193  * @return Array
 194  */
 195 function wfArrayInsertAfter( $array, $insert, $after ) {
 196         // Find the offset of the element to insert after.
 197         $keys = array_keys( $array );
 198         $offsetByKey = array_flip( $keys );
 199
 200         $offset = $offsetByKey[$after];
 201
 202         // Insert at the specified offset
 203         $before = array_slice( $array, 0, $offset + 1, true );
 204         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 205
 206         $output = $before + $insert + $after;
 207
 208         return $output;
 209 }
 210
 211 /**
 212  * Recursively converts the parameter (an object) to an array with the same data
 213  *
 214  * @param $objOrArray Object|Array
 215  * @param $recursive Bool
 216  * @return Array
 217  */
 218 function wfObjectToArray( $objOrArray, $recursive = true ) {
 219         $array = array();
 220         if( is_object( $objOrArray ) ) {
 221                 $objOrArray = get_object_vars( $objOrArray );
 222         }
 223         foreach ( $objOrArray as $key => $value ) {
 224                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 225                         $value = wfObjectToArray( $value );
 226                 }
 227
 228                 $array[$key] = $value;
 229         }
 230
 231         return $array;
 232 }
 233
 234 /**
 235  * Wrapper around array_map() which also taints variables
 236  *
 237  * @param  $function Callback
 238  * @param  $input Array
 239  * @return Array
 240  */
 241 function wfArrayMap( $function, $input ) {
 242         $ret = array_map( $function, $input );
 243         foreach ( $ret as $key => $value ) {
 244                 $taint = istainted( $input[$key] );
 245                 if ( $taint ) {
 246                         taint( $ret[$key], $taint );
 247                 }
 248         }
 249         return $ret;
 250 }
 251
 252 /**
 253  * Get a random decimal value between 0 and 1, in a way
 254  * not likely to give duplicate values for any realistic
 255  * number of articles.
 256  *
 257  * @return string
 258  */
 259 function wfRandom() {
 260         # The maximum random value is "only" 2^31-1, so get two random
 261         # values to reduce the chance of dupes
 262         $max = mt_getrandmax() + 1;
 263         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 264                 / $max / $max, 12, '.', '' );
 265         return $rand;
 266 }
 267
 268 /**
 269  * We want some things to be included as literal characters in our title URLs
 270  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 271  * all of the following should be safe:
 272  *
 273  * ;:@&=$-_.+!*'(),
 274  *
 275  * But + is not safe because it's used to indicate a space; &= are only safe in
 276  * paths and not in queries (and we don't distinguish here); ' seems kind of
 277  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 278  * is reserved, we don't care.  So the list we unescape is:
 279  *
 280  * ;:@$!*(),/
 281  *
 282  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 283  * so no fancy : for IIS7.
 284  *
 285  * %2F in the page titles seems to fatally break for some reason.
 286  *
 287  * @param $s String:
 288  * @return string
 289 */
 290 function wfUrlencode( $s ) {
 291         static $needle;
 292         if ( is_null( $needle ) ) {
 293                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 294                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 295                         $needle[] = '%3A';
 296                 }
 297         }
 298
 299         $s = urlencode( $s );
 300         $s = str_ireplace(
 301                 $needle,
 302                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 303                 $s
 304         );
 305
 306         return $s;
 307 }
 308
 309 /**
 310  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 311  * In normal operation this is a NOP.
 312  *
 313  * Controlling globals:
 314  * $wgDebugLogFile - points to the log file
 315  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 316  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 317  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 318  *
 319  * @param $text String
 320  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 321  */
 322 function wfDebug( $text, $logonly = false ) {
 323         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 324         global $wgDebugLogPrefix, $wgShowDebug;
 325
 326         static $cache = array(); // Cache of unoutputted messages
 327         $text = wfDebugTimer() . $text;
 328
 329         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 330         if ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' && !$wgDebugRawPage ) {
 331                 return;
 332         }
 333
 334         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 335                 $cache[] = $text;
 336
 337                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 338                         // add the message and any cached messages to the output
 339                         array_map( array( $wgOut, 'debug' ), $cache );
 340                         $cache = array();
 341                 }
 342         }
 343         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 344                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 345                         # Strip unprintables; they can switch terminal modes when binary data
 346                         # gets dumped, which is pretty annoying.
 347                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 348                         $text = $wgDebugLogPrefix . $text;
 349                         wfErrorLog( $text, $wgDebugLogFile );
 350                 }
 351         }
 352 }
 353
 354 /**
 355  * Get microsecond timestamps for debug logs
 356  *
 357  * @return string
 358  */
 359 function wfDebugTimer() {
 360         global $wgDebugTimestamps;
 361         if ( !$wgDebugTimestamps ) {
 362                 return '';
 363         }
 364         static $start = null;
 365
 366         if ( $start === null ) {
 367                 $start = microtime( true );
 368                 $prefix = "\n$start";
 369         } else {
 370                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 371         }
 372
 373         return $prefix . '  ';
 374 }
 375
 376 /**
 377  * Send a line giving PHP memory usage.
 378  *
 379  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 380  */
 381 function wfDebugMem( $exact = false ) {
 382         $mem = memory_get_usage();
 383         if( !$exact ) {
 384                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 385         } else {
 386                 $mem .= ' bytes';
 387         }
 388         wfDebug( "Memory usage: $mem\n" );
 389 }
 390
 391 /**
 392  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 393  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 394  *
 395  * @param $logGroup String
 396  * @param $text String
 397  * @param $public Bool: whether to log the event in the public log if no private
 398  *                     log file is specified, (default true)
 399  */
 400 function wfDebugLog( $logGroup, $text, $public = true ) {
 401         global $wgDebugLogGroups, $wgShowHostnames;
 402         $text = trim( $text ) . "\n";
 403         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 404                 $time = wfTimestamp( TS_DB );
 405                 $wiki = wfWikiID();
 406                 if ( $wgShowHostnames ) {
 407                         $host = wfHostname();
 408                 } else {
 409                         $host = '';
 410                 }
 411                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 412                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 413                 }
 414         } elseif ( $public === true ) {
 415                 wfDebug( $text, true );
 416         }
 417 }
 418
 419 /**
 420  * Log for database errors
 421  *
 422  * @param $text String: database error message.
 423  */
 424 function wfLogDBError( $text ) {
 425         global $wgDBerrorLog, $wgDBname;
 426         if ( $wgDBerrorLog ) {
 427                 $host = trim(`hostname`);
 428                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 429                 wfErrorLog( $text, $wgDBerrorLog );
 430         }
 431 }
 432
 433 /**
 434  * Log to a file without getting "file size exceeded" signals.
 435  *
 436  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 437  * send lines to the specified port, prefixed by the specified prefix and a space.
 438  *
 439  * @param $text String
 440  * @param $file String filename
 441  */
 442 function wfErrorLog( $text, $file ) {
 443         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 444                 # Needs the sockets extension
 445                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 446                         // IPv6 bracketed host
 447                         $host = $m[2];
 448                         $port = intval( $m[3] );
 449                         $prefix = isset( $m[4] ) ? $m[4] : false;
 450                         $domain = AF_INET6;
 451                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 452                         $host = $m[2];
 453                         if ( !IP::isIPv4( $host ) ) {
 454                                 $host = gethostbyname( $host );
 455                         }
 456                         $port = intval( $m[3] );
 457                         $prefix = isset( $m[4] ) ? $m[4] : false;
 458                         $domain = AF_INET;
 459                 } else {
 460                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 461                 }
 462
 463                 // Clean it up for the multiplexer
 464                 if ( strval( $prefix ) !== '' ) {
 465                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 466
 467                         // Limit to 64KB
 468                         if ( strlen( $text ) > 65534 ) {
 469                                 $text = substr( $text, 0, 65534 );
 470                         }
 471
 472                         if ( substr( $text, -1 ) != "\n" ) {
 473                                 $text .= "\n";
 474                         }
 475                 } elseif ( strlen( $text ) > 65535 ) {
 476                         $text = substr( $text, 0, 65535 );
 477                 }
 478
 479                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 480                 if ( !$sock ) {
 481                         return;
 482                 }
 483                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 484                 socket_close( $sock );
 485         } else {
 486                 wfSuppressWarnings();
 487                 $exists = file_exists( $file );
 488                 $size = $exists ? filesize( $file ) : false;
 489                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 490                         file_put_contents( $file, $text, FILE_APPEND );
 491                 }
 492                 wfRestoreWarnings();
 493         }
 494 }
 495
 496 /**
 497  * @todo document
 498  */
 499 function wfLogProfilingData() {
 500         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 501         global $wgProfileLimit, $wgUser;
 502
 503         $profiler = Profiler::instance();
 504
 505         # Profiling must actually be enabled...
 506         if ( $profiler->isStub() ) {
 507                 return;
 508         }
 509
 510         // Get total page request time and only show pages that longer than
 511         // $wgProfileLimit time (default is 0)
 512         $now = wfTime();
 513         $elapsed = $now - $wgRequestTime;
 514         if ( $elapsed <= $wgProfileLimit ) {
 515                 return;
 516         }
 517
 518         $profiler->logData();
 519
 520         // Check whether this should be logged in the debug file.
 521         if ( $wgDebugLogFile == '' || ( $wgRequest->getVal( 'action' ) == 'raw' && !$wgDebugRawPage ) ) {
 522                 return;
 523         }
 524
 525         $forward = '';
 526         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
 527                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 528         }
 529         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
 530                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 531         }
 532         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
 533                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 534         }
 535         if ( $forward ) {
 536                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 537         }
 538         // Don't load $wgUser at this late stage just for statistics purposes
 539         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
 540         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
 541                 $forward .= ' anon';
 542         }
 543         $log = sprintf( "%s\t%04.3f\t%s\n",
 544                 gmdate( 'YmdHis' ), $elapsed,
 545                 urldecode( $wgRequest->getRequestURL() . $forward ) );
 546
 547         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
 548 }
 549
 550 /**
 551  * Check if the wiki read-only lock file is present. This can be used to lock
 552  * off editing functions, but doesn't guarantee that the database will not be
 553  * modified.
 554  *
 555  * @return bool
 556  */
 557 function wfReadOnly() {
 558         global $wgReadOnlyFile, $wgReadOnly;
 559
 560         if ( !is_null( $wgReadOnly ) ) {
 561                 return (bool)$wgReadOnly;
 562         }
 563         if ( $wgReadOnlyFile == '' ) {
 564                 return false;
 565         }
 566         // Set $wgReadOnly for faster access next time
 567         if ( is_file( $wgReadOnlyFile ) ) {
 568                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
 569         } else {
 570                 $wgReadOnly = false;
 571         }
 572         return (bool)$wgReadOnly;
 573 }
 574
 575 function wfReadOnlyReason() {
 576         global $wgReadOnly;
 577         wfReadOnly();
 578         return $wgReadOnly;
 579 }
 580
 581 /**
 582  * Return a Language object from $langcode
 583  *
 584  * @param $langcode Mixed: either:
 585  *                  - a Language object
 586  *                  - code of the language to get the message for, if it is
 587  *                    a valid code create a language for that language, if
 588  *                    it is a string but not a valid code then make a basic
 589  *                    language object
 590  *                  - a boolean: if it's false then use the current users
 591  *                    language (as a fallback for the old parameter
 592  *                    functionality), or if it is true then use the wikis
 593  * @return Language object
 594  */
 595 function wfGetLangObj( $langcode = false ) {
 596         # Identify which language to get or create a language object for.
 597         # Using is_object here due to Stub objects.
 598         if( is_object( $langcode ) ) {
 599                 # Great, we already have the object (hopefully)!
 600                 return $langcode;
 601         }
 602
 603         global $wgContLang, $wgLanguageCode;
 604         if( $langcode === true || $langcode === $wgLanguageCode ) {
 605                 # $langcode is the language code of the wikis content language object.
 606                 # or it is a boolean and value is true
 607                 return $wgContLang;
 608         }
 609
 610         global $wgLang;
 611         if( $langcode === false || $langcode === $wgLang->getCode() ) {
 612                 # $langcode is the language code of user language object.
 613                 # or it was a boolean and value is false
 614                 return $wgLang;
 615         }
 616
 617         $validCodes = array_keys( Language::getLanguageNames() );
 618         if( in_array( $langcode, $validCodes ) ) {
 619                 # $langcode corresponds to a valid language.
 620                 return Language::factory( $langcode );
 621         }
 622
 623         # $langcode is a string, but not a valid language code; use content language.
 624         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
 625         return $wgContLang;
 626 }
 627
 628 /**
 629  * Use this instead of $wgContLang, when working with user interface.
 630  * User interface is currently hard coded according to wiki content language
 631  * in many ways, especially regarding to text direction. There is lots stuff
 632  * to fix, hence this function to keep the old behaviour unless the global
 633  * $wgBetterDirectionality is enabled (or removed when everything works).
 634  *
 635  * @return Language
 636  */
 637 function wfUILang() {
 638         global $wgBetterDirectionality;
 639         return wfGetLangObj( !$wgBetterDirectionality );
 640 }
 641
 642 /**
 643  * This is the new function for getting translated interface messages.
 644  * See the Message class for documentation how to use them.
 645  * The intention is that this function replaces all old wfMsg* functions.
 646  * @param $key \string Message key.
 647  * Varargs: normal message parameters.
 648  * @return Message
 649  * @since 1.17
 650  */
 651 function wfMessage( $key /*...*/) {
 652         $params = func_get_args();
 653         array_shift( $params );
 654         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 655                 $params = $params[0];
 656         }
 657         return new Message( $key, $params );
 658 }
 659
 660 /**
 661  * This function accepts multiple message keys and returns a message instance
 662  * for the first message which is non-empty. If all messages are empty then an
 663  * instance of the first message key is returned.
 664  * @param varargs: message keys
 665  * @return Message
 666  * @since 1.18
 667  */
 668 function wfMessageFallback( /*...*/ ) {
 669         $args = func_get_args();
 670         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
 671 }
 672
 673 /**
 674  * Get a message from anywhere, for the current user language.
 675  *
 676  * Use wfMsgForContent() instead if the message should NOT
 677  * change depending on the user preferences.
 678  *
 679  * @param $key String: lookup key for the message, usually
 680  *    defined in languages/Language.php
 681  *
 682  * This function also takes extra optional parameters (not
 683  * shown in the function definition), which can be used to
 684  * insert variable text into the predefined message.
 685  * @return String
 686  */
 687 function wfMsg( $key ) {
 688         $args = func_get_args();
 689         array_shift( $args );
 690         return wfMsgReal( $key, $args, true );
 691 }
 692
 693 /**
 694  * Same as above except doesn't transform the message
 695  *
 696  * @param $key String
 697  * @return String
 698  */
 699 function wfMsgNoTrans( $key ) {
 700         $args = func_get_args();
 701         array_shift( $args );
 702         return wfMsgReal( $key, $args, true, false, false );
 703 }
 704
 705 /**
 706  * Get a message from anywhere, for the current global language
 707  * set with $wgLanguageCode.
 708  *
 709  * Use this if the message should NOT change dependent on the
 710  * language set in the user's preferences. This is the case for
 711  * most text written into logs, as well as link targets (such as
 712  * the name of the copyright policy page). Link titles, on the
 713  * other hand, should be shown in the UI language.
 714  *
 715  * Note that MediaWiki allows users to change the user interface
 716  * language in their preferences, but a single installation
 717  * typically only contains content in one language.
 718  *
 719  * Be wary of this distinction: If you use wfMsg() where you should
 720  * use wfMsgForContent(), a user of the software may have to
 721  * customize potentially hundreds of messages in
 722  * order to, e.g., fix a link in every possible language.
 723  *
 724  * @param $key String: lookup key for the message, usually
 725  *     defined in languages/Language.php
 726  * @return String
 727  */
 728 function wfMsgForContent( $key ) {
 729         global $wgForceUIMsgAsContentMsg;
 730         $args = func_get_args();
 731         array_shift( $args );
 732         $forcontent = true;
 733         if( is_array( $wgForceUIMsgAsContentMsg ) &&
 734                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
 735         {
 736                 $forcontent = false;
 737         }
 738         return wfMsgReal( $key, $args, true, $forcontent );
 739 }
 740
 741 /**
 742  * Same as above except doesn't transform the message
 743  *
 744  * @param $key String
 745  * @return String
 746  */
 747 function wfMsgForContentNoTrans( $key ) {
 748         global $wgForceUIMsgAsContentMsg;
 749         $args = func_get_args();
 750         array_shift( $args );
 751         $forcontent = true;
 752         if( is_array( $wgForceUIMsgAsContentMsg ) &&
 753                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
 754         {
 755                 $forcontent = false;
 756         }
 757         return wfMsgReal( $key, $args, true, $forcontent, false );
 758 }
 759
 760 /**
 761  * Get a message from the language file, for the UI elements
 762  *
 763  * @deprecated since 1.18; use wfMessage()
 764  */
 765 function wfMsgNoDB( $key ) {
 766         wfDeprecated( __FUNCTION__ );
 767         $args = func_get_args();
 768         array_shift( $args );
 769         return wfMsgReal( $key, $args, false );
 770 }
 771
 772 /**
 773  * Get a message from the language file, for the content
 774  *
 775  * @deprecated since 1.18; use wfMessage()
 776  */
 777 function wfMsgNoDBForContent( $key ) {
 778         wfDeprecated( __FUNCTION__ );
 779         global $wgForceUIMsgAsContentMsg;
 780         $args = func_get_args();
 781         array_shift( $args );
 782         $forcontent = true;
 783         if( is_array( $wgForceUIMsgAsContentMsg ) &&
 784                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
 785         {
 786                 $forcontent = false;
 787         }
 788         return wfMsgReal( $key, $args, false, $forcontent );
 789 }
 790
 791
 792 /**
 793  * Really get a message
 794  *
 795  * @param $key String: key to get.
 796  * @param $args
 797  * @param $useDB Boolean
 798  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
 799  * @param $transform Boolean: Whether or not to transform the message.
 800  * @return String: the requested message.
 801  */
 802 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
 803         wfProfileIn( __METHOD__ );
 804         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
 805         $message = wfMsgReplaceArgs( $message, $args );
 806         wfProfileOut( __METHOD__ );
 807         return $message;
 808 }
 809
 810 /**
 811  * This function provides the message source for messages to be edited which are *not* stored in the database.
 812  *
 813  * @deprecated since 1.18; use wfMessage()
 814  * @param $key String
 815  */
 816 function wfMsgWeirdKey( $key ) {
 817         wfDeprecated( __FUNCTION__ );
 818         $source = wfMsgGetKey( $key, false, true, false );
 819         if ( wfEmptyMsg( $key ) ) {
 820                 return '';
 821         } else {
 822                 return $source;
 823         }
 824 }
 825
 826 /**
 827  * Fetch a message string value, but don't replace any keys yet.
 828  *
 829  * @param $key String
 830  * @param $useDB Bool
 831  * @param $langCode String: Code of the language to get the message for, or
 832  *                  behaves as a content language switch if it is a boolean.
 833  * @param $transform Boolean: whether to parse magic words, etc.
 834  * @return string
 835  */
 836 function wfMsgGetKey( $key, $useDB, $langCode = false, $transform = true ) {
 837         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
 838
 839         $cache = MessageCache::singleton();
 840         $message = $cache->get( $key, $useDB, $langCode );
 841         if( $message === false ) {
 842                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
 843         } elseif ( $transform ) {
 844                 $message = $cache->transform( $message );
 845         }
 846         return $message;
 847 }
 848
 849 /**
 850  * Replace message parameter keys on the given formatted output.
 851  *
 852  * @param $message String
 853  * @param $args Array
 854  * @return string
 855  * @private
 856  */
 857 function wfMsgReplaceArgs( $message, $args ) {
 858         # Fix windows line-endings
 859         # Some messages are split with explode("\n", $msg)
 860         $message = str_replace( "\r", '', $message );
 861
 862         // Replace arguments
 863         if ( count( $args ) ) {
 864                 if ( is_array( $args[0] ) ) {
 865                         $args = array_values( $args[0] );
 866                 }
 867                 $replacementKeys = array();
 868                 foreach( $args as $n => $param ) {
 869                         $replacementKeys['$' . ( $n + 1 )] = $param;
 870                 }
 871                 $message = strtr( $message, $replacementKeys );
 872         }
 873
 874         return $message;
 875 }
 876
 877 /**
 878  * Return an HTML-escaped version of a message.
 879  * Parameter replacements, if any, are done *after* the HTML-escaping,
 880  * so parameters may contain HTML (eg links or form controls). Be sure
 881  * to pre-escape them if you really do want plaintext, or just wrap
 882  * the whole thing in htmlspecialchars().
 883  *
 884  * @param $key String
 885  * @param string ... parameters
 886  * @return string
 887  */
 888 function wfMsgHtml( $key ) {
 889         $args = func_get_args();
 890         array_shift( $args );
 891         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key, true ) ), $args );
 892 }
 893
 894 /**
 895  * Return an HTML version of message
 896  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
 897  * so parameters may contain HTML (eg links or form controls). Be sure
 898  * to pre-escape them if you really do want plaintext, or just wrap
 899  * the whole thing in htmlspecialchars().
 900  *
 901  * @param $key String
 902  * @param string ... parameters
 903  * @return string
 904  */
 905 function wfMsgWikiHtml( $key ) {
 906         $args = func_get_args();
 907         array_shift( $args );
 908         return wfMsgReplaceArgs(
 909                 MessageCache::singleton()->parse( wfMsgGetKey( $key, true ), null, /* can't be set to false */ true )->getText(),
 910                 $args );
 911 }
 912
 913 /**
 914  * Returns message in the requested format
 915  * @param $key String: key of the message
 916  * @param $options Array: processing rules. Can take the following options:
 917  *   <i>parse</i>: parses wikitext to HTML
 918  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
 919  *       p's added by parser or tidy
 920  *   <i>escape</i>: filters message through htmlspecialchars
 921  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
 922  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
 923  *   <i>parsemag</i>: transform the message using magic phrases
 924  *   <i>content</i>: fetch message for content language instead of interface
 925  * Also can accept a single associative argument, of the form 'language' => 'xx':
 926  *   <i>language</i>: Language object or language code to fetch message for
 927  *       (overriden by <i>content</i>).
 928  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
 929  *
 930  * @return String
 931  */
 932 function wfMsgExt( $key, $options ) {
 933         $args = func_get_args();
 934         array_shift( $args );
 935         array_shift( $args );
 936         $options = (array)$options;
 937
 938         foreach( $options as $arrayKey => $option ) {
 939                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
 940                         # An unknown index, neither numeric nor "language"
 941                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
 942                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
 943                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
 944                 'replaceafter', 'parsemag', 'content' ) ) ) {
 945                         # A numeric index with unknown value
 946                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
 947                 }
 948         }
 949
 950         if( in_array( 'content', $options, true ) ) {
 951                 $forContent = true;
 952                 $langCode = true;
 953                 $langCodeObj = null;
 954         } elseif( array_key_exists( 'language', $options ) ) {
 955                 $forContent = false;
 956                 $langCode = wfGetLangObj( $options['language'] );
 957                 $langCodeObj = $langCode;
 958         } else {
 959                 $forContent = false;
 960                 $langCode = false;
 961                 $langCodeObj = null;
 962         }
 963
 964         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
 965
 966         if( !in_array( 'replaceafter', $options, true ) ) {
 967                 $string = wfMsgReplaceArgs( $string, $args );
 968         }
 969
 970         $messageCache = MessageCache::singleton();
 971         if( in_array( 'parse', $options, true ) ) {
 972                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
 973         } elseif ( in_array( 'parseinline', $options, true ) ) {
 974                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
 975                 $m = array();
 976                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
 977                         $string = $m[1];
 978                 }
 979         } elseif ( in_array( 'parsemag', $options, true ) ) {
 980                 $string = $messageCache->transform( $string,
 981                                 !$forContent, $langCodeObj );
 982         }
 983
 984         if ( in_array( 'escape', $options, true ) ) {
 985                 $string = htmlspecialchars ( $string );
 986         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
 987                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
 988         }
 989
 990         if( in_array( 'replaceafter', $options, true ) ) {
 991                 $string = wfMsgReplaceArgs( $string, $args );
 992         }
 993
 994         return $string;
 995 }
 996
 997 /**
 998  * Since wfMsg() and co suck, they don't return false if the message key they
 999  * looked up didn't exist but a XHTML string, this function checks for the
1000  * nonexistance of messages by checking the MessageCache::get() result directly.
1001  *
1002  * @param $key      String: the message key looked up
1003  * @return Boolean True if the message *doesn't* exist.
1004  */
1005 function wfEmptyMsg( $key ) {
1006         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1007 }
1008
1009 /**
1010  * Print an error message and die, returning nonzero to the shell if any.  Plain die()
1011  * fails to return nonzero to the shell if you pass a string.  Entry points may customise
1012  * this function to return a prettier error message, but implementations must not assume
1013  * access to any of the usual MediaWiki infrastructure (AutoLoader, localisation, database,
1014  * etc).  This should not be called directly once $wgFullyInitialised is set; instead,
1015  * throw an exception and let Exception.php handle whether or not it's possible to show
1016  * a prettier error.
1017  *
1018  * @param $msg String
1019  */
1020 if( !function_exists( 'wfDie' ) ){
1021         function wfDie( $msg = '' ) {
1022                 echo $msg;
1023                 die( 1 );
1024         }
1025 }
1026
1027 /**
1028  * Throw a debugging exception. This function previously once exited the process,
1029  * but now throws an exception instead, with similar results.
1030  *
1031  * @param $msg String: message shown when dieing.
1032  */
1033 function wfDebugDieBacktrace( $msg = '' ) {
1034         throw new MWException( $msg );
1035 }
1036
1037 /**
1038  * Fetch server name for use in error reporting etc.
1039  * Use real server name if available, so we know which machine
1040  * in a server farm generated the current page.
1041  *
1042  * @return string
1043  */
1044 function wfHostname() {
1045         static $host;
1046         if ( is_null( $host ) ) {
1047                 if ( function_exists( 'posix_uname' ) ) {
1048                         // This function not present on Windows
1049                         $uname = @posix_uname();
1050                 } else {
1051                         $uname = false;
1052                 }
1053                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1054                         $host = $uname['nodename'];
1055                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1056                         # Windows computer name
1057                         $host = getenv( 'COMPUTERNAME' );
1058                 } else {
1059                         # This may be a virtual server.
1060                         $host = $_SERVER['SERVER_NAME'];
1061                 }
1062         }
1063         return $host;
1064 }
1065
1066 /**
1067  * Returns a HTML comment with the elapsed time since request.
1068  * This method has no side effects.
1069  *
1070  * @return string
1071  */
1072 function wfReportTime() {
1073         global $wgRequestTime, $wgShowHostnames;
1074
1075         $now = wfTime();
1076         $elapsed = $now - $wgRequestTime;
1077
1078         return $wgShowHostnames
1079                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1080                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1081 }
1082
1083 /**
1084  * Safety wrapper for debug_backtrace().
1085  *
1086  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1087  * murky circumstances, which may be triggered in part by stub objects
1088  * or other fancy talkin'.
1089  *
1090  * Will return an empty array if Zend Optimizer is detected or if
1091  * debug_backtrace is disabled, otherwise the output from
1092  * debug_backtrace() (trimmed).
1093  *
1094  * @return array of backtrace information
1095  */
1096 function wfDebugBacktrace() {
1097         static $disabled = null;
1098
1099         if( extension_loaded( 'Zend Optimizer' ) ) {
1100                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1101                 return array();
1102         }
1103
1104         if ( is_null( $disabled ) ) {
1105                 $disabled = false;
1106                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1107                 $functions = array_map( 'trim', $functions );
1108                 $functions = array_map( 'strtolower', $functions );
1109                 if ( in_array( 'debug_backtrace', $functions ) ) {
1110                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1111                         $disabled = true;
1112                 }
1113         }
1114         if ( $disabled ) {
1115                 return array();
1116         }
1117
1118         return array_slice( debug_backtrace(), 1 );
1119 }
1120
1121 /**
1122  * Get a debug backtrace as a string
1123  *
1124  * @return string
1125  */
1126 function wfBacktrace() {
1127         global $wgCommandLineMode;
1128
1129         if ( $wgCommandLineMode ) {
1130                 $msg = '';
1131         } else {
1132                 $msg = "<ul>\n";
1133         }
1134         $backtrace = wfDebugBacktrace();
1135         foreach( $backtrace as $call ) {
1136                 if( isset( $call['file'] ) ) {
1137                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1138                         $file = $f[count( $f ) - 1];
1139                 } else {
1140                         $file = '-';
1141                 }
1142                 if( isset( $call['line'] ) ) {
1143                         $line = $call['line'];
1144                 } else {
1145                         $line = '-';
1146                 }
1147                 if ( $wgCommandLineMode ) {
1148                         $msg .= "$file line $line calls ";
1149                 } else {
1150                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1151                 }
1152                 if( !empty( $call['class'] ) ) {
1153                         $msg .= $call['class'] . '::';
1154                 }
1155                 $msg .= $call['function'] . '()';
1156
1157                 if ( $wgCommandLineMode ) {
1158                         $msg .= "\n";
1159                 } else {
1160                         $msg .= "</li>\n";
1161                 }
1162         }
1163         if ( $wgCommandLineMode ) {
1164                 $msg .= "\n";
1165         } else {
1166                 $msg .= "</ul>\n";
1167         }
1168
1169         return $msg;
1170 }
1171
1172 /**
1173  * Get the name of the function which called this function
1174  *
1175  * @param $level Int
1176  * @return Bool|string
1177  */
1178 function wfGetCaller( $level = 2 ) {
1179         $backtrace = wfDebugBacktrace();
1180         if ( isset( $backtrace[$level] ) ) {
1181                 return wfFormatStackFrame( $backtrace[$level] );
1182         } else {
1183                 $caller = 'unknown';
1184         }
1185         return $caller;
1186 }
1187
1188 /**
1189  * Return a string consisting of callers in the stack. Useful sometimes
1190  * for profiling specific points.
1191  *
1192  * @param $limit The maximum depth of the stack frame to return, or false for
1193  *               the entire stack.
1194  * @return String
1195  */
1196 function wfGetAllCallers( $limit = 3 ) {
1197         $trace = array_reverse( wfDebugBacktrace() );
1198         if ( !$limit || $limit > count( $trace ) - 1 ) {
1199                 $limit = count( $trace ) - 1;
1200         }
1201         $trace = array_slice( $trace, -$limit - 1, $limit );
1202         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1203 }
1204
1205 /**
1206  * Return a string representation of frame
1207  *
1208  * @param $frame Array
1209  * @return Bool
1210  */
1211 function wfFormatStackFrame( $frame ) {
1212         return isset( $frame['class'] ) ?
1213                 $frame['class'] . '::' . $frame['function'] :
1214                 $frame['function'];
1215 }
1216
1217
1218 /* Some generic result counters, pulled out of SearchEngine */
1219
1220
1221 /**
1222  * @todo document
1223  *
1224  * @param $offset Int
1225  * @param $limit Int
1226  * @return String
1227  */
1228 function wfShowingResults( $offset, $limit ) {
1229         global $wgLang;
1230         return wfMsgExt(
1231                 'showingresults',
1232                 array( 'parseinline' ),
1233                 $wgLang->formatNum( $limit ),
1234                 $wgLang->formatNum( $offset + 1 )
1235         );
1236 }
1237
1238 /**
1239  * @todo document
1240  *
1241  * @param $offset Int
1242  * @param $limit Int
1243  * @param $num Int
1244  * @return String
1245  */
1246 function wfShowingResultsNum( $offset, $limit, $num ) {
1247         global $wgLang;
1248         return wfMsgExt(
1249                 'showingresultsnum',
1250                 array( 'parseinline' ),
1251                 $wgLang->formatNum( $limit ),
1252                 $wgLang->formatNum( $offset + 1 ),
1253                 $wgLang->formatNum( $num )
1254         );
1255 }
1256
1257 /**
1258  * Generate (prev x| next x) (20|50|100...) type links for paging
1259  *
1260  * @param $offset String
1261  * @param $limit Integer
1262  * @param $link String
1263  * @param $query String: optional URL query parameter string
1264  * @param $atend Bool: optional param for specified if this is the last page
1265  * @return String
1266  */
1267 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1268         global $wgLang;
1269         $fmtLimit = $wgLang->formatNum( $limit );
1270         // @todo FIXME: Why on earth this needs one message for the text and another one for tooltip?
1271         # Get prev/next link display text
1272         $prev = wfMsgExt( 'prevn', array( 'parsemag', 'escape' ), $fmtLimit );
1273         $next = wfMsgExt( 'nextn', array( 'parsemag', 'escape' ), $fmtLimit );
1274         # Get prev/next link title text
1275         $pTitle = wfMsgExt( 'prevn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1276         $nTitle = wfMsgExt( 'nextn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1277         # Fetch the title object
1278         if( is_object( $link ) ) {
1279                 $title =& $link;
1280         } else {
1281                 $title = Title::newFromText( $link );
1282                 if( is_null( $title ) ) {
1283                         return false;
1284                 }
1285         }
1286         # Make 'previous' link
1287         if( 0 != $offset ) {
1288                 $po = $offset - $limit;
1289                 $po = max( $po, 0 );
1290                 $q = "limit={$limit}&offset={$po}";
1291                 if( $query != '' ) {
1292                         $q .= '&' . $query;
1293                 }
1294                 $plink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$pTitle}\" class=\"mw-prevlink\">{$prev}</a>";
1295         } else {
1296                 $plink = $prev;
1297         }
1298         # Make 'next' link
1299         $no = $offset + $limit;
1300         $q = "limit={$limit}&offset={$no}";
1301         if( $query != '' ) {
1302                 $q .= '&' . $query;
1303         }
1304         if( $atend ) {
1305                 $nlink = $next;
1306         } else {
1307                 $nlink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$nTitle}\" class=\"mw-nextlink\">{$next}</a>";
1308         }
1309         # Make links to set number of items per page
1310         $nums = $wgLang->pipeList( array(
1311                 wfNumLink( $offset, 20, $title, $query ),
1312                 wfNumLink( $offset, 50, $title, $query ),
1313                 wfNumLink( $offset, 100, $title, $query ),
1314                 wfNumLink( $offset, 250, $title, $query ),
1315                 wfNumLink( $offset, 500, $title, $query )
1316         ) );
1317         return wfMsgHtml( 'viewprevnext', $plink, $nlink, $nums );
1318 }
1319
1320 /**
1321  * Generate links for (20|50|100...) items-per-page links
1322  *
1323  * @param $offset String
1324  * @param $limit Integer
1325  * @param $title Title
1326  * @param $query String: optional URL query parameter string
1327  */
1328 function wfNumLink( $offset, $limit, $title, $query = '' ) {
1329         global $wgLang;
1330         if( $query == '' ) {
1331                 $q = '';
1332         } else {
1333                 $q = $query.'&';
1334         }
1335         $q .= "limit={$limit}&offset={$offset}";
1336         $fmtLimit = $wgLang->formatNum( $limit );
1337         $lTitle = wfMsgExt( 'shown-title', array( 'parsemag', 'escape' ), $limit );
1338         $s = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$lTitle}\" class=\"mw-numlink\">{$fmtLimit}</a>";
1339         return $s;
1340 }
1341
1342 /**
1343  * @todo document
1344  * @todo FIXME: We may want to blacklist some broken browsers
1345  *
1346  * @param $force Bool
1347  * @return bool Whereas client accept gzip compression
1348  */
1349 function wfClientAcceptsGzip( $force = false ) {
1350         static $result = null;
1351         if ( $result === null || $force ) {
1352                 $result = false;
1353                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1354                         # @todo FIXME: We may want to blacklist some broken browsers
1355                         $m = array();
1356                         if( preg_match(
1357                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1358                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1359                                 $m )
1360                         )
1361                         {
1362                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1363                                         $result = false;
1364                                         return $result;
1365                                 }
1366                                 wfDebug( " accepts gzip\n" );
1367                                 $result = true;
1368                         }
1369                 }
1370         }
1371         return $result;
1372 }
1373
1374 /**
1375  * Obtain the offset and limit values from the request string;
1376  * used in special pages
1377  *
1378  * @param $deflimit Int default limit if none supplied
1379  * @param $optionname String Name of a user preference to check against
1380  * @return array
1381  *
1382  */
1383 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1384         global $wgRequest;
1385         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1386 }
1387
1388 /**
1389  * Escapes the given text so that it may be output using addWikiText()
1390  * without any linking, formatting, etc. making its way through. This
1391  * is achieved by substituting certain characters with HTML entities.
1392  * As required by the callers, <nowiki> is not used.
1393  *
1394  * @param $text String: text to be escaped
1395  * @return String
1396  */
1397 function wfEscapeWikiText( $text ) {
1398         $text = strtr( "\n$text", array(
1399                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1400                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1401                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1402                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1403                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1404                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1405         ) );
1406         return substr( $text, 1 );
1407 }
1408
1409 /**
1410  * Get the current unix timetstamp with microseconds.  Useful for profiling
1411  * @return Float
1412  */
1413 function wfTime() {
1414         return microtime( true );
1415 }
1416
1417 /**
1418  * Sets dest to source and returns the original value of dest
1419  * If source is NULL, it just returns the value, it doesn't set the variable
1420  * If force is true, it will set the value even if source is NULL
1421  *
1422  * @param $dest Mixed
1423  * @param $source Mixed
1424  * @param $force Bool
1425  * @return Mixed
1426  */
1427 function wfSetVar( &$dest, $source, $force = false ) {
1428         $temp = $dest;
1429         if ( !is_null( $source ) || $force ) {
1430                 $dest = $source;
1431         }
1432         return $temp;
1433 }
1434
1435 /**
1436  * As for wfSetVar except setting a bit
1437  *
1438  * @param $dest Int
1439  * @param $bit Int
1440  * @param $state Bool
1441  */
1442 function wfSetBit( &$dest, $bit, $state = true ) {
1443         $temp = (bool)( $dest & $bit );
1444         if ( !is_null( $state ) ) {
1445                 if ( $state ) {
1446                         $dest |= $bit;
1447                 } else {
1448                         $dest &= ~$bit;
1449                 }
1450         }
1451         return $temp;
1452 }
1453
1454 /**
1455  * This function takes two arrays as input, and returns a CGI-style string, e.g.
1456  * "days=7&limit=100". Options in the first array override options in the second.
1457  * Options set to "" will not be output.
1458  *
1459  * @param $array1 Array( String|Array )
1460  * @param $array2 Array( String|Array )
1461  * @return String
1462  */
1463 function wfArrayToCGI( $array1, $array2 = null ) {
1464         if ( !is_null( $array2 ) ) {
1465                 $array1 = $array1 + $array2;
1466         }
1467
1468         $cgi = '';
1469         foreach ( $array1 as $key => $value ) {
1470                 if ( $value !== '' ) {
1471                         if ( $cgi != '' ) {
1472                                 $cgi .= '&';
1473                         }
1474                         if ( is_array( $value ) ) {
1475                                 $firstTime = true;
1476                                 foreach ( $value as $v ) {
1477                                         $cgi .= ( $firstTime ? '' : '&') .
1478                                                 urlencode( $key . '[]' ) . '=' .
1479                                                 urlencode( $v );
1480                                         $firstTime = false;
1481                                 }
1482                         } else {
1483                                 if ( is_object( $value ) ) {
1484                                         $value = $value->__toString();
1485                                 }
1486                                 $cgi .= urlencode( $key ) . '=' .
1487                                         urlencode( $value );
1488                         }
1489                 }
1490         }
1491         return $cgi;
1492 }
1493
1494 /**
1495  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
1496  * its argument and returns the same string in array form.  This allows compa-
1497  * tibility with legacy functions that accept raw query strings instead of nice
1498  * arrays.  Of course, keys and values are urldecode()d.  Don't try passing in-
1499  * valid query strings, or it will explode.
1500  *
1501  * @param $query String: query string
1502  * @return array Array version of input
1503  */
1504 function wfCgiToArray( $query ) {
1505         if( isset( $query[0] ) && $query[0] == '?' ) {
1506                 $query = substr( $query, 1 );
1507         }
1508         $bits = explode( '&', $query );
1509         $ret = array();
1510         foreach( $bits as $bit ) {
1511                 if( $bit === '' ) {
1512                         continue;
1513                 }
1514                 list( $key, $value ) = explode( '=', $bit );
1515                 $key = urldecode( $key );
1516                 $value = urldecode( $value );
1517                 $ret[$key] = $value;
1518         }
1519         return $ret;
1520 }
1521
1522 /**
1523  * Append a query string to an existing URL, which may or may not already
1524  * have query string parameters already. If so, they will be combined.
1525  *
1526  * @param $url String
1527  * @param $query Mixed: string or associative array
1528  * @return string
1529  */
1530 function wfAppendQuery( $url, $query ) {
1531         if ( is_array( $query ) ) {
1532                 $query = wfArrayToCGI( $query );
1533         }
1534         if( $query != '' ) {
1535                 if( false === strpos( $url, '?' ) ) {
1536                         $url .= '?';
1537                 } else {
1538                         $url .= '&';
1539                 }
1540                 $url .= $query;
1541         }
1542         return $url;
1543 }
1544
1545 /**
1546  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
1547  * and $wgProto are correct.
1548  *
1549  * @todo this won't work with current-path-relative URLs
1550  * like "subdir/foo.html", etc.
1551  *
1552  * @param $url String: either fully-qualified or a local path + query
1553  * @return string Fully-qualified URL
1554  */
1555 function wfExpandUrl( $url ) {
1556         if( substr( $url, 0, 2 ) == '//' ) {
1557                 global $wgProto;
1558                 return $wgProto . ':' . $url;
1559         } elseif( substr( $url, 0, 1 ) == '/' ) {
1560                 global $wgServer;
1561                 return $wgServer . $url;
1562         } else {
1563                 return $url;
1564         }
1565 }
1566
1567 /**
1568  * Windows-compatible version of escapeshellarg()
1569  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
1570  * function puts single quotes in regardless of OS.
1571  *
1572  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
1573  * earlier distro releases of PHP)
1574  *
1575  * @param varargs
1576  * @return String
1577  */
1578 function wfEscapeShellArg( ) {
1579         wfInitShellLocale();
1580
1581         $args = func_get_args();
1582         $first = true;
1583         $retVal = '';
1584         foreach ( $args as $arg ) {
1585                 if ( !$first ) {
1586                         $retVal .= ' ';
1587                 } else {
1588                         $first = false;
1589                 }
1590
1591                 if ( wfIsWindows() ) {
1592                         // Escaping for an MSVC-style command line parser and CMD.EXE
1593                         // Refs:
1594                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
1595                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
1596                         //  * Bug #13518
1597                         //  * CR r63214
1598                         // Double the backslashes before any double quotes. Escape the double quotes.
1599                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
1600                         $arg = '';
1601                         $iteration = 0;
1602                         foreach ( $tokens as $token ) {
1603                                 if ( $iteration % 2 == 1 ) {
1604                                         // Delimiter, a double quote preceded by zero or more slashes
1605                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
1606                                 } elseif ( $iteration % 4 == 2 ) {
1607                                         // ^ in $token will be outside quotes, need to be escaped
1608                                         $arg .= str_replace( '^', '^^', $token );
1609                                 } else { // $iteration % 4 == 0
1610                                         // ^ in $token will appear inside double quotes, so leave as is
1611                                         $arg .= $token;
1612                                 }
1613                                 $iteration++;
1614                         }
1615                         // Double the backslashes before the end of the string, because
1616                         // we will soon add a quote
1617                         $m = array();
1618                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1619                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1620                         }
1621
1622                         // Add surrounding quotes
1623                         $retVal .= '"' . $arg . '"';
1624                 } else {
1625                         $retVal .= escapeshellarg( $arg );
1626                 }
1627         }
1628         return $retVal;
1629 }
1630
1631 /**
1632  * wfMerge attempts to merge differences between three texts.
1633  * Returns true for a clean merge and false for failure or a conflict.
1634  *
1635  * @param $old String
1636  * @param $mine String
1637  * @param $yours String
1638  * @param $result String
1639  * @return Bool
1640  */
1641 function wfMerge( $old, $mine, $yours, &$result ) {
1642         global $wgDiff3;
1643
1644         # This check may also protect against code injection in
1645         # case of broken installations.
1646         wfSuppressWarnings();
1647         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
1648         wfRestoreWarnings();
1649
1650         if( !$haveDiff3 ) {
1651                 wfDebug( "diff3 not found\n" );
1652                 return false;
1653         }
1654
1655         # Make temporary files
1656         $td = wfTempDir();
1657         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1658         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1659         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1660
1661         fwrite( $oldtextFile, $old );
1662         fclose( $oldtextFile );
1663         fwrite( $mytextFile, $mine );
1664         fclose( $mytextFile );
1665         fwrite( $yourtextFile, $yours );
1666         fclose( $yourtextFile );
1667
1668         # Check for a conflict
1669         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1670                 wfEscapeShellArg( $mytextName ) . ' ' .
1671                 wfEscapeShellArg( $oldtextName ) . ' ' .
1672                 wfEscapeShellArg( $yourtextName );
1673         $handle = popen( $cmd, 'r' );
1674
1675         if( fgets( $handle, 1024 ) ) {
1676                 $conflict = true;
1677         } else {
1678                 $conflict = false;
1679         }
1680         pclose( $handle );
1681
1682         # Merge differences
1683         $cmd = $wgDiff3 . ' -a -e --merge ' .
1684                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1685         $handle = popen( $cmd, 'r' );
1686         $result = '';
1687         do {
1688                 $data = fread( $handle, 8192 );
1689                 if ( strlen( $data ) == 0 ) {
1690                         break;
1691                 }
1692                 $result .= $data;
1693         } while ( true );
1694         pclose( $handle );
1695         unlink( $mytextName );
1696         unlink( $oldtextName );
1697         unlink( $yourtextName );
1698
1699         if ( $result === '' && $old !== '' && !$conflict ) {
1700                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1701                 $conflict = true;
1702         }
1703         return !$conflict;
1704 }
1705
1706 /**
1707  * Returns unified plain-text diff of two texts.
1708  * Useful for machine processing of diffs.
1709  *
1710  * @param $before String: the text before the changes.
1711  * @param $after String: the text after the changes.
1712  * @param $params String: command-line options for the diff command.
1713  * @return String: unified diff of $before and $after
1714  */
1715 function wfDiff( $before, $after, $params = '-u' ) {
1716         if ( $before == $after ) {
1717                 return '';
1718         }
1719
1720         global $wgDiff;
1721         wfSuppressWarnings();
1722         $haveDiff = $wgDiff && file_exists( $wgDiff );
1723         wfRestoreWarnings();
1724
1725         # This check may also protect against code injection in
1726         # case of broken installations.
1727         if( !$haveDiff ) {
1728                 wfDebug( "diff executable not found\n" );
1729                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
1730                 $format = new UnifiedDiffFormatter();
1731                 return $format->format( $diffs );
1732         }
1733
1734         # Make temporary files
1735         $td = wfTempDir();
1736         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1737         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
1738
1739         fwrite( $oldtextFile, $before );
1740         fclose( $oldtextFile );
1741         fwrite( $newtextFile, $after );
1742         fclose( $newtextFile );
1743
1744         // Get the diff of the two files
1745         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
1746
1747         $h = popen( $cmd, 'r' );
1748
1749         $diff = '';
1750
1751         do {
1752                 $data = fread( $h, 8192 );
1753                 if ( strlen( $data ) == 0 ) {
1754                         break;
1755                 }
1756                 $diff .= $data;
1757         } while ( true );
1758
1759         // Clean up
1760         pclose( $h );
1761         unlink( $oldtextName );
1762         unlink( $newtextName );
1763
1764         // Kill the --- and +++ lines. They're not useful.
1765         $diff_lines = explode( "\n", $diff );
1766         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
1767                 unset( $diff_lines[0] );
1768         }
1769         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
1770                 unset( $diff_lines[1] );
1771         }
1772
1773         $diff = implode( "\n", $diff_lines );
1774
1775         return $diff;
1776 }
1777
1778 /**
1779  * A wrapper around the PHP function var_export().
1780  * Either print it or add it to the regular output ($wgOut).
1781  *
1782  * @param $var A PHP variable to dump.
1783  */
1784 function wfVarDump( $var ) {
1785         global $wgOut;
1786         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1787         if ( headers_sent() || !@is_object( $wgOut ) ) {
1788                 print $s;
1789         } else {
1790                 $wgOut->addHTML( $s );
1791         }
1792 }
1793
1794 /**
1795  * Provide a simple HTTP error.
1796  *
1797  * @param $code Int|String
1798  * @param $label String
1799  * @param $desc String
1800  */
1801 function wfHttpError( $code, $label, $desc ) {
1802         global $wgOut;
1803         $wgOut->disable();
1804         header( "HTTP/1.0 $code $label" );
1805         header( "Status: $code $label" );
1806         $wgOut->sendCacheControl();
1807
1808         header( 'Content-type: text/html; charset=utf-8' );
1809         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1810                 '<html><head><title>' .
1811                 htmlspecialchars( $label ) .
1812                 '</title></head><body><h1>' .
1813                 htmlspecialchars( $label ) .
1814                 '</h1><p>' .
1815                 nl2br( htmlspecialchars( $desc ) ) .
1816                 "</p></body></html>\n";
1817 }
1818
1819 /**
1820  * Clear away any user-level output buffers, discarding contents.
1821  *
1822  * Suitable for 'starting afresh', for instance when streaming
1823  * relatively large amounts of data without buffering, or wanting to
1824  * output image files without ob_gzhandler's compression.
1825  *
1826  * The optional $resetGzipEncoding parameter controls suppression of
1827  * the Content-Encoding header sent by ob_gzhandler; by default it
1828  * is left. See comments for wfClearOutputBuffers() for why it would
1829  * be used.
1830  *
1831  * Note that some PHP configuration options may add output buffer
1832  * layers which cannot be removed; these are left in place.
1833  *
1834  * @param $resetGzipEncoding Bool
1835  */
1836 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1837         if( $resetGzipEncoding ) {
1838                 // Suppress Content-Encoding and Content-Length
1839                 // headers from 1.10+s wfOutputHandler
1840                 global $wgDisableOutputCompression;
1841                 $wgDisableOutputCompression = true;
1842         }
1843         while( $status = ob_get_status() ) {
1844                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1845                         // Probably from zlib.output_compression or other
1846                         // PHP-internal setting which can't be removed.
1847                         //
1848                         // Give up, and hope the result doesn't break
1849                         // output behavior.
1850                         break;
1851                 }
1852                 if( !ob_end_clean() ) {
1853                         // Could not remove output buffer handler; abort now
1854                         // to avoid getting in some kind of infinite loop.
1855                         break;
1856                 }
1857                 if( $resetGzipEncoding ) {
1858                         if( $status['name'] == 'ob_gzhandler' ) {
1859                                 // Reset the 'Content-Encoding' field set by this handler
1860                                 // so we can start fresh.
1861                                 if ( function_exists( 'header_remove' ) ) {
1862                                         // Available since PHP 5.3.0
1863                                         header_remove( 'Content-Encoding' );
1864                                 } else {
1865                                         // We need to provide a valid content-coding. See bug 28069
1866                                         header( 'Content-Encoding: identity' );
1867                                 }
1868                                 break;
1869                         }
1870                 }
1871         }
1872 }
1873
1874 /**
1875  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1876  *
1877  * Clear away output buffers, but keep the Content-Encoding header
1878  * produced by ob_gzhandler, if any.
1879  *
1880  * This should be used for HTTP 304 responses, where you need to
1881  * preserve the Content-Encoding header of the real result, but
1882  * also need to suppress the output of ob_gzhandler to keep to spec
1883  * and avoid breaking Firefox in rare cases where the headers and
1884  * body are broken over two packets.
1885  */
1886 function wfClearOutputBuffers() {
1887         wfResetOutputBuffers( false );
1888 }
1889
1890 /**
1891  * Converts an Accept-* header into an array mapping string values to quality
1892  * factors
1893  *
1894  * @param $accept String
1895  * @param $def String default
1896  * @return Array
1897  */
1898 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1899         # No arg means accept anything (per HTTP spec)
1900         if( !$accept ) {
1901                 return array( $def => 1.0 );
1902         }
1903
1904         $prefs = array();
1905
1906         $parts = explode( ',', $accept );
1907
1908         foreach( $parts as $part ) {
1909                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1910                 @list( $value, $qpart ) = explode( ';', trim( $part ) );
1911                 $match = array();
1912                 if( !isset( $qpart ) ) {
1913                         $prefs[$value] = 1.0;
1914                 } elseif( preg_match( '/q\s*=\s*(\d*\.\d+)/', $qpart, $match ) ) {
1915                         $prefs[$value] = floatval( $match[1] );
1916                 }
1917         }
1918
1919         return $prefs;
1920 }
1921
1922 /**
1923  * Checks if a given MIME type matches any of the keys in the given
1924  * array. Basic wildcards are accepted in the array keys.
1925  *
1926  * Returns the matching MIME type (or wildcard) if a match, otherwise
1927  * NULL if no match.
1928  *
1929  * @param $type String
1930  * @param $avail Array
1931  * @return string
1932  * @private
1933  */
1934 function mimeTypeMatch( $type, $avail ) {
1935         if( array_key_exists( $type, $avail ) ) {
1936                 return $type;
1937         } else {
1938                 $parts = explode( '/', $type );
1939                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
1940                         return $parts[0] . '/*';
1941                 } elseif( array_key_exists( '*/*', $avail ) ) {
1942                         return '*/*';
1943                 } else {
1944                         return null;
1945                 }
1946         }
1947 }
1948
1949 /**
1950  * Returns the 'best' match between a client's requested internet media types
1951  * and the server's list of available types. Each list should be an associative
1952  * array of type to preference (preference is a float between 0.0 and 1.0).
1953  * Wildcards in the types are acceptable.
1954  *
1955  * @param $cprefs Array: client's acceptable type list
1956  * @param $sprefs Array: server's offered types
1957  * @return string
1958  *
1959  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1960  * XXX: generalize to negotiate other stuff
1961  */
1962 function wfNegotiateType( $cprefs, $sprefs ) {
1963         $combine = array();
1964
1965         foreach( array_keys($sprefs) as $type ) {
1966                 $parts = explode( '/', $type );
1967                 if( $parts[1] != '*' ) {
1968                         $ckey = mimeTypeMatch( $type, $cprefs );
1969                         if( $ckey ) {
1970                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1971                         }
1972                 }
1973         }
1974
1975         foreach( array_keys( $cprefs ) as $type ) {
1976                 $parts = explode( '/', $type );
1977                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
1978                         $skey = mimeTypeMatch( $type, $sprefs );
1979                         if( $skey ) {
1980                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1981                         }
1982                 }
1983         }
1984
1985         $bestq = 0;
1986         $besttype = null;
1987
1988         foreach( array_keys( $combine ) as $type ) {
1989                 if( $combine[$type] > $bestq ) {
1990                         $besttype = $type;
1991                         $bestq = $combine[$type];
1992                 }
1993         }
1994
1995         return $besttype;
1996 }
1997
1998 /**
1999  * Reference-counted warning suppression
2000  *
2001  * @param $end Bool
2002  */
2003 function wfSuppressWarnings( $end = false ) {
2004         static $suppressCount = 0;
2005         static $originalLevel = false;
2006
2007         if ( $end ) {
2008                 if ( $suppressCount ) {
2009                         --$suppressCount;
2010                         if ( !$suppressCount ) {
2011                                 error_reporting( $originalLevel );
2012                         }
2013                 }
2014         } else {
2015                 if ( !$suppressCount ) {
2016                         // E_DEPRECATED is undefined in PHP 5.2
2017                         if( !defined( 'E_DEPRECATED' ) ){
2018                                 define( 'E_DEPRECATED', 8192 );
2019                         }
2020                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2021                 }
2022                 ++$suppressCount;
2023         }
2024 }
2025
2026 /**
2027  * Restore error level to previous value
2028  */
2029 function wfRestoreWarnings() {
2030         wfSuppressWarnings( true );
2031 }
2032
2033 # Autodetect, convert and provide timestamps of various types
2034
2035 /**
2036  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2037  */
2038 define( 'TS_UNIX', 0 );
2039
2040 /**
2041  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2042  */
2043 define( 'TS_MW', 1 );
2044
2045 /**
2046  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2047  */
2048 define( 'TS_DB', 2 );
2049
2050 /**
2051  * RFC 2822 format, for E-mail and HTTP headers
2052  */
2053 define( 'TS_RFC2822', 3 );
2054
2055 /**
2056  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2057  *
2058  * This is used by Special:Export
2059  */
2060 define( 'TS_ISO_8601', 4 );
2061
2062 /**
2063  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2064  *
2065  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2066  *       DateTime tag and page 36 for the DateTimeOriginal and
2067  *       DateTimeDigitized tags.
2068  */
2069 define( 'TS_EXIF', 5 );
2070
2071 /**
2072  * Oracle format time.
2073  */
2074 define( 'TS_ORACLE', 6 );
2075
2076 /**
2077  * Postgres format time.
2078  */
2079 define( 'TS_POSTGRES', 7 );
2080
2081 /**
2082  * DB2 format time
2083  */
2084 define( 'TS_DB2', 8 );
2085
2086 /**
2087  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2088  */
2089 define( 'TS_ISO_8601_BASIC', 9 );
2090
2091 /**
2092  * Get a timestamp string in one of various formats
2093  *
2094  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2095  *                    function will autodetect which format is supplied and act
2096  *                    accordingly.
2097  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2098  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2099  */
2100 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2101         $uts = 0;
2102         $da = array();
2103         $strtime = '';
2104
2105         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2106                 $uts = time();
2107                 $strtime = "@$uts";
2108         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2109                 # TS_DB
2110         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2111                 # TS_EXIF
2112         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2113                 # TS_MW
2114         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2115                 # TS_UNIX
2116                 $uts = $ts;
2117                 $strtime = "@$ts"; // Undocumented?
2118         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2119                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2120                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2121                                 str_replace( '+00:00', 'UTC', $ts ) );
2122         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2123                 # TS_ISO_8601
2124         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2125                 #TS_ISO_8601_BASIC
2126         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2127                 # TS_POSTGRES
2128         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2129                 # TS_POSTGRES
2130         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/',$ts,$da)) {
2131                 # TS_DB2
2132         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2133                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2134                                                         '[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d/S', $ts ) ) { # hh:mm:ss
2135                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2136                 # The regex is a superset of rfc2822 for readability
2137                 $strtime = strtok( $ts, ';' );
2138         } elseif ( preg_match( '/^[A-Z][a-z]{5,8}, \d\d-[A-Z][a-z]{2}-\d{2} \d\d:\d\d:\d\d/', $ts ) ) {
2139                 # TS_RFC850
2140                 $strtime = $ts;
2141         } elseif ( preg_match( '/^[A-Z][a-z]{2} [A-Z][a-z]{2} +\d{1,2} \d\d:\d\d:\d\d \d{4}/', $ts ) ) {
2142                 # asctime
2143                 $strtime = $ts;
2144         } else {
2145                 # Bogus value...
2146                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2147
2148                 return false;
2149         }
2150
2151
2152
2153         static $formats = array(
2154                 TS_UNIX => 'U',
2155                 TS_MW => 'YmdHis',
2156                 TS_DB => 'Y-m-d H:i:s',
2157                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2158                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2159                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2160                 TS_RFC2822 => 'D, d M Y H:i:s',
2161                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2162                 TS_POSTGRES => 'Y-m-d H:i:s',
2163                 TS_DB2 => 'Y-m-d H:i:s',
2164         );
2165
2166         if ( !isset( $formats[$outputtype] ) ) {
2167                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2168         }
2169
2170         if ( function_exists( "date_create" ) ) {
2171                 if ( count( $da ) ) {
2172                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2173                                 (int)$da[1], (int)$da[2], (int)$da[3],
2174                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2175
2176                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2177                 } elseif ( $strtime ) {
2178                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2179                 } else {
2180                         return false;
2181                 }
2182
2183                 if ( !$d ) {
2184                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2185                         return false;
2186                 }
2187
2188                 $output = $d->format( $formats[$outputtype] );
2189         } else {
2190                 if ( count( $da ) ) {
2191                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2192                         // We may want to handle that explicitly at some point
2193                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2194                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2195                 } elseif ( $strtime ) {
2196                         $uts = strtotime( $strtime );
2197                 }
2198
2199                 if ( $uts === false ) {
2200                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2201                         return false;
2202                 }
2203
2204                 if ( TS_UNIX == $outputtype ) {
2205                         return $uts;
2206                 }
2207                 $output = gmdate( $formats[$outputtype], $uts );
2208         }
2209
2210         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2211                 $output .= ' GMT';
2212         }
2213
2214         return $output;
2215 }
2216
2217 /**
2218  * Return a formatted timestamp, or null if input is null.
2219  * For dealing with nullable timestamp columns in the database.
2220  *
2221  * @param $outputtype Integer
2222  * @param $ts String
2223  * @return String
2224  */
2225 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2226         if( is_null( $ts ) ) {
2227                 return null;
2228         } else {
2229                 return wfTimestamp( $outputtype, $ts );
2230         }
2231 }
2232
2233 /**
2234  * Convenience function; returns MediaWiki timestamp for the present time.
2235  *
2236  * @return string
2237  */
2238 function wfTimestampNow() {
2239         # return NOW
2240         return wfTimestamp( TS_MW, time() );
2241 }
2242
2243 /**
2244  * Check if the operating system is Windows
2245  *
2246  * @return Bool: true if it's Windows, False otherwise.
2247  */
2248 function wfIsWindows() {
2249         static $isWindows = null;
2250         if ( $isWindows === null ) {
2251                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2252         }
2253         return $isWindows;
2254 }
2255
2256 /**
2257  * Check if we are running under HipHop
2258  *
2259  * @return Bool
2260  */
2261 function wfIsHipHop() {
2262         return function_exists( 'hphp_thread_set_warmup_enabled' );
2263 }
2264
2265 /**
2266  * Swap two variables
2267  *
2268  * @param $x Mixed
2269  * @param $y Mixed
2270  */
2271 function swap( &$x, &$y ) {
2272         $z = $x;
2273         $x = $y;
2274         $y = $z;
2275 }
2276
2277 /**
2278  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2279  * TEMP environment variables are then checked in sequence, and if none are set
2280  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2281  * or C:\Windows\Temp for Windows and hope for the best.
2282  * It is common to call it with tempnam().
2283  *
2284  * NOTE: When possible, use instead the tmpfile() function to create
2285  * temporary files to avoid race conditions on file creation, etc.
2286  *
2287  * @return String
2288  */
2289 function wfTempDir() {
2290         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2291                 $tmp = getenv( $var );
2292                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2293                         return $tmp;
2294                 }
2295         }
2296         if( function_exists( 'sys_get_temp_dir' ) ) {
2297                 return sys_get_temp_dir();
2298         }
2299         # Usual defaults
2300         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2301 }
2302
2303 /**
2304  * Make directory, and make all parent directories if they don't exist
2305  *
2306  * @param $dir String: full path to directory to create
2307  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2308  * @param $caller String: optional caller param for debugging.
2309  * @return bool
2310  */
2311 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2312         global $wgDirectoryMode;
2313
2314         if ( !is_null( $caller ) ) {
2315                 wfDebug( "$caller: called wfMkdirParents($dir)" );
2316         }
2317
2318         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2319                 return true;
2320         }
2321
2322         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2323
2324         if ( is_null( $mode ) ) {
2325                 $mode = $wgDirectoryMode;
2326         }
2327
2328         // Turn off the normal warning, we're doing our own below
2329         wfSuppressWarnings();
2330         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2331         wfRestoreWarnings();
2332
2333         if( !$ok ) {
2334                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2335                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2336         }
2337         return $ok;
2338 }
2339
2340 /**
2341  * Increment a statistics counter
2342  *
2343  * @param $key String
2344  * @param $count Int
2345  */
2346 function wfIncrStats( $key, $count = 1 ) {
2347         global $wgStatsMethod;
2348
2349         $count = intval( $count );
2350
2351         if( $wgStatsMethod == 'udp' ) {
2352                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2353                 static $socket;
2354
2355                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2356
2357                 if ( !$socket ) {
2358                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2359                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2360                         socket_sendto(
2361                                 $socket,
2362                                 $statline,
2363                                 strlen( $statline ),
2364                                 0,
2365                                 $wgUDPProfilerHost,
2366                                 $wgUDPProfilerPort
2367                         );
2368                 }
2369                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2370                 wfSuppressWarnings();
2371                 socket_sendto(
2372                         $socket,
2373                         $statline,
2374                         strlen( $statline ),
2375                         0,
2376                         $wgUDPProfilerHost,
2377                         $wgUDPProfilerPort
2378                 );
2379                 wfRestoreWarnings();
2380         } elseif( $wgStatsMethod == 'cache' ) {
2381                 global $wgMemc;
2382                 $key = wfMemcKey( 'stats', $key );
2383                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2384                         $wgMemc->add( $key, $count );
2385                 }
2386         } else {
2387                 // Disabled
2388         }
2389 }
2390
2391 /**
2392  * @param $nr Mixed: the number to format
2393  * @param $acc Integer: the number of digits after the decimal point, default 2
2394  * @param $round Boolean: whether or not to round the value, default true
2395  * @return float
2396  */
2397 function wfPercent( $nr, $acc = 2, $round = true ) {
2398         $ret = sprintf( "%.${acc}f", $nr );
2399         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2400 }
2401
2402 /**
2403  * Find out whether or not a mixed variable exists in a string
2404  *
2405  * @param $needle String
2406  * @param $str String
2407  * @param $insensitive Boolean
2408  * @return Boolean
2409  */
2410 function in_string( $needle, $str, $insensitive = false ) {
2411         $func = 'strpos';
2412         if( $insensitive ) $func = 'stripos';
2413
2414         return $func( $str, $needle ) !== false;
2415 }
2416
2417 function wfSpecialList( $page, $details ) {
2418         global $wgContLang;
2419         $details = $details ? ' ' . $wgContLang->getDirMark() . "($details)" : '';
2420         return $page . $details;
2421 }
2422
2423 /**
2424  * Returns a regular expression of url protocols
2425  *
2426  * @return String
2427  */
2428 function wfUrlProtocols() {
2429         global $wgUrlProtocols;
2430
2431         static $retval = null;
2432         if ( !is_null( $retval ) ) {
2433                 return $retval;
2434         }
2435
2436         // Support old-style $wgUrlProtocols strings, for backwards compatibility
2437         // with LocalSettings files from 1.5
2438         if ( is_array( $wgUrlProtocols ) ) {
2439                 $protocols = array();
2440                 foreach ( $wgUrlProtocols as $protocol ) {
2441                         $protocols[] = preg_quote( $protocol, '/' );
2442                 }
2443
2444                 $retval = implode( '|', $protocols );
2445         } else {
2446                 $retval = $wgUrlProtocols;
2447         }
2448         return $retval;
2449 }
2450
2451 /**
2452  * Safety wrapper around ini_get() for boolean settings.
2453  * The values returned from ini_get() are pre-normalized for settings
2454  * set via php.ini or php_flag/php_admin_flag... but *not*
2455  * for those set via php_value/php_admin_value.
2456  *
2457  * It's fairly common for people to use php_value instead of php_flag,
2458  * which can leave you with an 'off' setting giving a false positive
2459  * for code that just takes the ini_get() return value as a boolean.
2460  *
2461  * To make things extra interesting, setting via php_value accepts
2462  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2463  * Unrecognized values go false... again opposite PHP's own coercion
2464  * from string to bool.
2465  *
2466  * Luckily, 'properly' set settings will always come back as '0' or '1',
2467  * so we only have to worry about them and the 'improper' settings.
2468  *
2469  * I frickin' hate PHP... :P
2470  *
2471  * @param $setting String
2472  * @return Bool
2473  */
2474 function wfIniGetBool( $setting ) {
2475         $val = ini_get( $setting );
2476         // 'on' and 'true' can't have whitespace around them, but '1' can.
2477         return strtolower( $val ) == 'on'
2478                 || strtolower( $val ) == 'true'
2479                 || strtolower( $val ) == 'yes'
2480                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2481 }
2482
2483 /**
2484  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2485  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2486  *
2487  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2488  *                          should be omitted
2489  * @param $fileName String Name of the library, if not $extension.suffix
2490  * @return Bool - Whether or not the extension is loaded
2491  */
2492 function wfDl( $extension, $fileName = null ) {
2493         if( extension_loaded( $extension ) ) {
2494                 return true;
2495         }
2496
2497         $canDl = false;
2498         $sapi = php_sapi_name();
2499         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2500                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2501         {
2502                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2503                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2504         }
2505
2506         if( $canDl ) {
2507                 $fileName = $fileName ? $fileName : $extension;
2508                 if( wfIsWindows() ) {
2509                         $fileName = 'php_' . $fileName;
2510                 }
2511                 wfSuppressWarnings();
2512                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2513                 wfRestoreWarnings();
2514         }
2515         return extension_loaded( $extension );
2516 }
2517
2518 /**
2519  * Execute a shell command, with time and memory limits mirrored from the PHP
2520  * configuration if supported.
2521  * @param $cmd String Command line, properly escaped for shell.
2522  * @param &$retval optional, will receive the program's exit code.
2523  *                 (non-zero is usually failure)
2524  * @param $environ Array optional environment variables which should be
2525  *                 added to the executed command environment.
2526  * @return collected stdout as a string (trailing newlines stripped)
2527  */
2528 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2529         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2530
2531         static $disabled;
2532         if ( is_null( $disabled ) ) {
2533                 $disabled = false;
2534                 if( wfIniGetBool( 'safe_mode' ) ) {
2535                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2536                         $disabled = 'safemode';
2537                 } else {
2538                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2539                         $functions = array_map( 'trim', $functions );
2540                         $functions = array_map( 'strtolower', $functions );
2541                         if ( in_array( 'passthru', $functions ) ) {
2542                                 wfDebug( "passthru is in disabled_functions\n" );
2543                                 $disabled = 'passthru';
2544                         }
2545                 }
2546         }
2547         if ( $disabled ) {
2548                 $retval = 1;
2549                 return $disabled == 'safemode' ?
2550                         'Unable to run external programs in safe mode.' :
2551                         'Unable to run external programs, passthru() is disabled.';
2552         }
2553
2554         wfInitShellLocale();
2555
2556         $envcmd = '';
2557         foreach( $environ as $k => $v ) {
2558                 if ( wfIsWindows() ) {
2559                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2560                          * appear in the environment variable, so we must use carat escaping as documented in
2561                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2562                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2563                          * are listed there but doesn't appear to need it.
2564                          */
2565                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2566                 } else {
2567                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2568                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2569                          */
2570                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2571                 }
2572         }
2573         $cmd = $envcmd . $cmd;
2574
2575         if ( wfIsWindows() ) {
2576                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2577                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2578                 {
2579                         # Hack to work around PHP's flawed invocation of cmd.exe
2580                         # http://news.php.net/php.internals/21796
2581                         # Windows 9x doesn't accept any kind of quotes
2582                         $cmd = '"' . $cmd . '"';
2583                 }
2584         } elseif ( php_uname( 's' ) == 'Linux' ) {
2585                 $time = intval( $wgMaxShellTime );
2586                 $mem = intval( $wgMaxShellMemory );
2587                 $filesize = intval( $wgMaxShellFileSize );
2588
2589                 if ( $time > 0 && $mem > 0 ) {
2590                         $script = "$IP/bin/ulimit4.sh";
2591                         if ( is_executable( $script ) ) {
2592                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2593                         }
2594                 }
2595         }
2596         wfDebug( "wfShellExec: $cmd\n" );
2597
2598         $retval = 1; // error by default?
2599         ob_start();
2600         passthru( $cmd, $retval );
2601         $output = ob_get_contents();
2602         ob_end_clean();
2603
2604         if ( $retval == 127 ) {
2605                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2606         }
2607         return $output;
2608 }
2609
2610 /**
2611  * Workaround for http://bugs.php.net/bug.php?id=45132
2612  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2613  */
2614 function wfInitShellLocale() {
2615         static $done = false;
2616         if ( $done ) {
2617                 return;
2618         }
2619         $done = true;
2620         global $wgShellLocale;
2621         if ( !wfIniGetBool( 'safe_mode' ) ) {
2622                 putenv( "LC_CTYPE=$wgShellLocale" );
2623                 setlocale( LC_CTYPE, $wgShellLocale );
2624         }
2625 }
2626
2627 /**
2628  * This function works like "use VERSION" in Perl, the program will die with a
2629  * backtrace if the current version of PHP is less than the version provided
2630  *
2631  * This is useful for extensions which due to their nature are not kept in sync
2632  * with releases, and might depend on other versions of PHP than the main code
2633  *
2634  * Note: PHP might die due to parsing errors in some cases before it ever
2635  *       manages to call this function, such is life
2636  *
2637  * @see perldoc -f use
2638  *
2639  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2640  *                 a float
2641  */
2642 function wfUsePHP( $req_ver ) {
2643         $php_ver = PHP_VERSION;
2644
2645         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2646                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2647         }
2648 }
2649
2650 /**
2651  * This function works like "use VERSION" in Perl except it checks the version
2652  * of MediaWiki, the program will die with a backtrace if the current version
2653  * of MediaWiki is less than the version provided.
2654  *
2655  * This is useful for extensions which due to their nature are not kept in sync
2656  * with releases
2657  *
2658  * @see perldoc -f use
2659  *
2660  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2661  *                 a float
2662  */
2663 function wfUseMW( $req_ver ) {
2664         global $wgVersion;
2665
2666         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2667                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2668         }
2669 }
2670
2671 /**
2672  * Return the final portion of a pathname.
2673  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2674  * http://bugs.php.net/bug.php?id=33898
2675  *
2676  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2677  * We'll consider it so always, as we don't want \s in our Unix paths either.
2678  *
2679  * @param $path String
2680  * @param $suffix String: to remove if present
2681  * @return String
2682  */
2683 function wfBaseName( $path, $suffix = '' ) {
2684         $encSuffix = ( $suffix == '' )
2685                 ? ''
2686                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2687         $matches = array();
2688         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2689                 return $matches[1];
2690         } else {
2691                 return '';
2692         }
2693 }
2694
2695 /**
2696  * Generate a relative path name to the given file.
2697  * May explode on non-matching case-insensitive paths,
2698  * funky symlinks, etc.
2699  *
2700  * @param $path String: absolute destination path including target filename
2701  * @param $from String: Absolute source path, directory only
2702  * @return String
2703  */
2704 function wfRelativePath( $path, $from ) {
2705         // Normalize mixed input on Windows...
2706         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2707         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2708
2709         // Trim trailing slashes -- fix for drive root
2710         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2711         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2712
2713         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2714         $against = explode( DIRECTORY_SEPARATOR, $from );
2715
2716         if( $pieces[0] !== $against[0] ) {
2717                 // Non-matching Windows drive letters?
2718                 // Return a full path.
2719                 return $path;
2720         }
2721
2722         // Trim off common prefix
2723         while( count( $pieces ) && count( $against )
2724                 && $pieces[0] == $against[0] ) {
2725                 array_shift( $pieces );
2726                 array_shift( $against );
2727         }
2728
2729         // relative dots to bump us to the parent
2730         while( count( $against ) ) {
2731                 array_unshift( $pieces, '..' );
2732                 array_shift( $against );
2733         }
2734
2735         array_push( $pieces, wfBaseName( $path ) );
2736
2737         return implode( DIRECTORY_SEPARATOR, $pieces );
2738 }
2739
2740 /**
2741  * parse_url() work-alike, but non-broken.  Differences:
2742  *
2743  * 1) Does not raise warnings on bad URLs (just returns false)
2744  * 2) Handles protocols that don't use :// (e.g., mailto: and news:) correctly
2745  * 3) Adds a "delimiter" element to the array, either '://' or ':' (see (2))
2746  *
2747  * @param $url String: a URL to parse
2748  * @return Array: bits of the URL in an associative array, per PHP docs
2749  */
2750 function wfParseUrl( $url ) {
2751         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
2752         wfSuppressWarnings();
2753         $bits = parse_url( $url );
2754         wfRestoreWarnings();
2755         if ( !$bits ) {
2756                 return false;
2757         }
2758
2759         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
2760         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
2761                 $bits['delimiter'] = '://';
2762         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
2763                 $bits['delimiter'] = ':';
2764                 // parse_url detects for news: and mailto: the host part of an url as path
2765                 // We have to correct this wrong detection
2766                 if ( isset( $bits['path'] ) ) {
2767                         $bits['host'] = $bits['path'];
2768                         $bits['path'] = '';
2769                 }
2770         } else {
2771                 return false;
2772         }
2773
2774         return $bits;
2775 }
2776
2777 /**
2778  * Make a URL index, appropriate for the el_index field of externallinks.
2779  *
2780  * @param $url String
2781  * @return String
2782  */
2783 function wfMakeUrlIndex( $url ) {
2784         $bits = wfParseUrl( $url );
2785
2786         // Reverse the labels in the hostname, convert to lower case
2787         // For emails reverse domainpart only
2788         if ( $bits['scheme'] == 'mailto' ) {
2789                 $mailparts = explode( '@', $bits['host'], 2 );
2790                 if ( count( $mailparts ) === 2 ) {
2791                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
2792                 } else {
2793                         // No domain specified, don't mangle it
2794                         $domainpart = '';
2795                 }
2796                 $reversedHost = $domainpart . '@' . $mailparts[0];
2797         } else if ( isset( $bits['host'] ) ) {
2798                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
2799         } else {
2800                 // In file: URIs for instance it's common to have an empty host,
2801                 // which turns up as not getting a 'host' member from parse_url.
2802                 $reversedHost = '.';
2803         }
2804         // Add an extra dot to the end
2805         // Why? Is it in wrong place in mailto links?
2806         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
2807                 $reversedHost .= '.';
2808         }
2809         // Reconstruct the pseudo-URL
2810         $prot = $bits['scheme'];
2811         $index = $prot . $bits['delimiter'] . $reversedHost;
2812         // Leave out user and password. Add the port, path, query and fragment
2813         if ( isset( $bits['port'] ) ) {
2814                 $index .= ':' . $bits['port'];
2815         }
2816         if ( isset( $bits['path'] ) ) {
2817                 // parse_url() removes the initial '/' from the path
2818                 // for file: URLs with Windows-style paths, such as
2819                 // file:///c:/windows/stuff. We need to add it back
2820                 // to keep our division between host and path properly.
2821                 if ( strlen( $bits['path'] ) > 0 && substr( $bits['path'], 0, 1 ) !== '/' ) {
2822                         $index .= '/';
2823                 }
2824                 $index .= $bits['path'];
2825         } else {
2826                 $index .= '/';
2827         }
2828         if ( isset( $bits['query'] ) ) {
2829                 $index .= '?' . $bits['query'];
2830         }
2831         if ( isset( $bits['fragment'] ) ) {
2832                 $index .= '#' . $bits['fragment'];
2833         }
2834         return $index;
2835 }
2836
2837 /**
2838  * Do any deferred updates and clear the list
2839  *
2840  * @param $commit String: set to 'commit' to commit after every update to
2841  *                prevent lock contention
2842  */
2843 function wfDoUpdates( $commit = '' ) {
2844         global $wgDeferredUpdateList;
2845
2846         wfProfileIn( __METHOD__ );
2847
2848         // No need to get master connections in case of empty updates array
2849         if ( !count( $wgDeferredUpdateList ) ) {
2850                 wfProfileOut( __METHOD__ );
2851                 return;
2852         }
2853
2854         $doCommit = $commit == 'commit';
2855         if ( $doCommit ) {
2856                 $dbw = wfGetDB( DB_MASTER );
2857         }
2858
2859         foreach ( $wgDeferredUpdateList as $update ) {
2860                 $update->doUpdate();
2861
2862                 if ( $doCommit && $dbw->trxLevel() ) {
2863                         $dbw->commit();
2864                 }
2865         }
2866
2867         $wgDeferredUpdateList = array();
2868         wfProfileOut( __METHOD__ );
2869 }
2870
2871 /**
2872  * Convert an arbitrarily-long digit string from one numeric base
2873  * to another, optionally zero-padding to a minimum column width.
2874  *
2875  * Supports base 2 through 36; digit values 10-36 are represented
2876  * as lowercase letters a-z. Input is case-insensitive.
2877  *
2878  * @param $input String: of digits
2879  * @param $sourceBase Integer: 2-36
2880  * @param $destBase Integer: 2-36
2881  * @param $pad Integer: 1 or greater
2882  * @param $lowercase Boolean
2883  * @return String or false on invalid input
2884  */
2885 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2886         $input = strval( $input );
2887         if( $sourceBase < 2 ||
2888                 $sourceBase > 36 ||
2889                 $destBase < 2 ||
2890                 $destBase > 36 ||
2891                 $pad < 1 ||
2892                 $sourceBase != intval( $sourceBase ) ||
2893                 $destBase != intval( $destBase ) ||
2894                 $pad != intval( $pad ) ||
2895                 !is_string( $input ) ||
2896                 $input == '' ) {
2897                 return false;
2898         }
2899         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2900         $inDigits = array();
2901         $outChars = '';
2902
2903         // Decode and validate input string
2904         $input = strtolower( $input );
2905         for( $i = 0; $i < strlen( $input ); $i++ ) {
2906                 $n = strpos( $digitChars, $input[$i] );
2907                 if( $n === false || $n > $sourceBase ) {
2908                         return false;
2909                 }
2910                 $inDigits[] = $n;
2911         }
2912
2913         // Iterate over the input, modulo-ing out an output digit
2914         // at a time until input is gone.
2915         while( count( $inDigits ) ) {
2916                 $work = 0;
2917                 $workDigits = array();
2918
2919                 // Long division...
2920                 foreach( $inDigits as $digit ) {
2921                         $work *= $sourceBase;
2922                         $work += $digit;
2923
2924                         if( $work < $destBase ) {
2925                                 // Gonna need to pull another digit.
2926                                 if( count( $workDigits ) ) {
2927                                         // Avoid zero-padding; this lets us find
2928                                         // the end of the input very easily when
2929                                         // length drops to zero.
2930                                         $workDigits[] = 0;
2931                                 }
2932                         } else {
2933                                 // Finally! Actual division!
2934                                 $workDigits[] = intval( $work / $destBase );
2935
2936                                 // Isn't it annoying that most programming languages
2937                                 // don't have a single divide-and-remainder operator,
2938                                 // even though the CPU implements it that way?
2939                                 $work = $work % $destBase;
2940                         }
2941                 }
2942
2943                 // All that division leaves us with a remainder,
2944                 // which is conveniently our next output digit.
2945                 $outChars .= $digitChars[$work];
2946
2947                 // And we continue!
2948                 $inDigits = $workDigits;
2949         }
2950
2951         while( strlen( $outChars ) < $pad ) {
2952                 $outChars .= '0';
2953         }
2954
2955         return strrev( $outChars );
2956 }
2957
2958 /**
2959  * Create an object with a given name and an array of construct parameters
2960  *
2961  * @param $name String
2962  * @param $p Array: parameters
2963  * @deprecated since 1.18, warnings in 1.19, removal in 1.20
2964  */
2965 function wfCreateObject( $name, $p ) {
2966         wfDeprecated( __FUNCTION__ );
2967         return MWFunction::newObj( $name, $p );
2968 }
2969
2970 function wfHttpOnlySafe() {
2971         global $wgHttpOnlyBlacklist;
2972
2973         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
2974                 foreach( $wgHttpOnlyBlacklist as $regex ) {
2975                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
2976                                 return false;
2977                         }
2978                 }
2979         }
2980
2981         return true;
2982 }
2983
2984 /**
2985  * Initialise php session
2986  *
2987  * @param $sessionId Bool
2988  */
2989 function wfSetupSession( $sessionId = false ) {
2990         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
2991                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
2992         if( $wgSessionsInMemcached ) {
2993                 if ( !defined( 'MW_COMPILED' ) ) {
2994                         global $IP;
2995                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
2996                 }
2997                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
2998                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
2999
3000                 // It's necessary to register a shutdown function to call session_write_close(),
3001                 // because by the time the request shutdown function for the session module is
3002                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3003                 // this way are called before object destruction.
3004                 register_shutdown_function( 'memsess_write_close' );
3005         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3006                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3007                 # hasn't already been set to the desired value (that causes errors)
3008                 ini_set( 'session.save_handler', $wgSessionHandler );
3009         }
3010         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3011         wfDebugLog( 'cookie',
3012                 'session_set_cookie_params: "' . implode( '", "',
3013                         array(
3014                                 0,
3015                                 $wgCookiePath,
3016                                 $wgCookieDomain,
3017                                 $wgCookieSecure,
3018                                 $httpOnlySafe ) ) . '"' );
3019         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3020         session_cache_limiter( 'private, must-revalidate' );
3021         if ( $sessionId ) {
3022                 session_id( $sessionId );
3023         }
3024         wfSuppressWarnings();
3025         session_start();
3026         wfRestoreWarnings();
3027 }
3028
3029 /**
3030  * Get an object from the precompiled serialized directory
3031  *
3032  * @param $name String
3033  * @return Mixed: the variable on success, false on failure
3034  */
3035 function wfGetPrecompiledData( $name ) {
3036         global $IP;
3037
3038         $file = "$IP/serialized/$name";
3039         if ( file_exists( $file ) ) {
3040                 $blob = file_get_contents( $file );
3041                 if ( $blob ) {
3042                         return unserialize( $blob );
3043                 }
3044         }
3045         return false;
3046 }
3047
3048 /**
3049  * Get a cache key
3050  *
3051  * @param varargs
3052  * @return String
3053  */
3054 function wfMemcKey( /*... */ ) {
3055         $args = func_get_args();
3056         $key = wfWikiID() . ':' . implode( ':', $args );
3057         $key = str_replace( ' ', '_', $key );
3058         return $key;
3059 }
3060
3061 /**
3062  * Get a cache key for a foreign DB
3063  *
3064  * @param $db String
3065  * @param $prefix String
3066  * @param varargs String
3067  * @return String
3068  */
3069 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3070         $args = array_slice( func_get_args(), 2 );
3071         if ( $prefix ) {
3072                 $key = "$db-$prefix:" . implode( ':', $args );
3073         } else {
3074                 $key = $db . ':' . implode( ':', $args );
3075         }
3076         return $key;
3077 }
3078
3079 /**
3080  * Get an ASCII string identifying this wiki
3081  * This is used as a prefix in memcached keys
3082  *
3083  * @return String
3084  */
3085 function wfWikiID() {
3086         global $wgDBprefix, $wgDBname;
3087         if ( $wgDBprefix ) {
3088                 return "$wgDBname-$wgDBprefix";
3089         } else {
3090                 return $wgDBname;
3091         }
3092 }
3093
3094 /**
3095  * Split a wiki ID into DB name and table prefix
3096  *
3097  * @param $wiki String
3098  * @param $bits String
3099  */
3100 function wfSplitWikiID( $wiki ) {
3101         $bits = explode( '-', $wiki, 2 );
3102         if ( count( $bits ) < 2 ) {
3103                 $bits[] = '';
3104         }
3105         return $bits;
3106 }
3107
3108 /**
3109  * Get a Database object.
3110  *
3111  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3112  *            master (for write queries), DB_SLAVE for potentially lagged read
3113  *            queries, or an integer >= 0 for a particular server.
3114  *
3115  * @param $groups Mixed: query groups. An array of group names that this query
3116  *                belongs to. May contain a single string if the query is only
3117  *                in one group.
3118  *
3119  * @param $wiki String: the wiki ID, or false for the current wiki
3120  *
3121  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3122  * will always return the same object, unless the underlying connection or load
3123  * balancer is manually destroyed.
3124  *
3125  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3126  * updater to ensure that a proper database is being updated.
3127  *
3128  * @return DatabaseBase
3129  */
3130 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3131         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3132 }
3133
3134 /**
3135  * Get a load balancer object.
3136  *
3137  * @param $wiki String: wiki ID, or false for the current wiki
3138  * @return LoadBalancer
3139  */
3140 function wfGetLB( $wiki = false ) {
3141         return wfGetLBFactory()->getMainLB( $wiki );
3142 }
3143
3144 /**
3145  * Get the load balancer factory object
3146  *
3147  * @return LBFactory
3148  */
3149 function &wfGetLBFactory() {
3150         return LBFactory::singleton();
3151 }
3152
3153 /**
3154  * Find a file.
3155  * Shortcut for RepoGroup::singleton()->findFile()
3156  *
3157  * @param $title String or Title object
3158  * @param $options Associative array of options:
3159  *     time:           requested time for an archived image, or false for the
3160  *                     current version. An image object will be returned which was
3161  *                     created at the specified time.
3162  *
3163  *     ignoreRedirect: If true, do not follow file redirects
3164  *
3165  *     private:        If true, return restricted (deleted) files if the current
3166  *                     user is allowed to view them. Otherwise, such files will not
3167  *                     be found.
3168  *
3169  *     bypassCache:    If true, do not use the process-local cache of File objects
3170  *
3171  * @return File, or false if the file does not exist
3172  */
3173 function wfFindFile( $title, $options = array() ) {
3174         return RepoGroup::singleton()->findFile( $title, $options );
3175 }
3176
3177 /**
3178  * Get an object referring to a locally registered file.
3179  * Returns a valid placeholder object if the file does not exist.
3180  *
3181  * @param $title Title or String
3182  * @return File, or null if passed an invalid Title
3183  */
3184 function wfLocalFile( $title ) {
3185         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3186 }
3187
3188 /**
3189  * Should low-performance queries be disabled?
3190  *
3191  * @return Boolean
3192  * @codeCoverageIgnore
3193  */
3194 function wfQueriesMustScale() {
3195         global $wgMiserMode;
3196         return $wgMiserMode
3197                 || ( SiteStats::pages() > 100000
3198                 && SiteStats::edits() > 1000000
3199                 && SiteStats::users() > 10000 );
3200 }
3201
3202 /**
3203  * Get the path to a specified script file, respecting file
3204  * extensions; this is a wrapper around $wgScriptExtension etc.
3205  *
3206  * @param $script String: script filename, sans extension
3207  * @return String
3208  */
3209 function wfScript( $script = 'index' ) {
3210         global $wgScriptPath, $wgScriptExtension;
3211         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3212 }
3213
3214 /**
3215  * Get the script URL.
3216  *
3217  * @return script URL
3218  */
3219 function wfGetScriptUrl() {
3220         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3221                 #
3222                 # as it was called, minus the query string.
3223                 #
3224                 # Some sites use Apache rewrite rules to handle subdomains,
3225                 # and have PHP set up in a weird way that causes PHP_SELF
3226                 # to contain the rewritten URL instead of the one that the
3227                 # outside world sees.
3228                 #
3229                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3230                 # provides containing the "before" URL.
3231                 return $_SERVER['SCRIPT_NAME'];
3232         } else {
3233                 return $_SERVER['URL'];
3234         }
3235 }
3236
3237 /**
3238  * Convenience function converts boolean values into "true"
3239  * or "false" (string) values
3240  *
3241  * @param $value Boolean
3242  * @return String
3243  */
3244 function wfBoolToStr( $value ) {
3245         return $value ? 'true' : 'false';
3246 }
3247
3248 /**
3249  * Load an extension messages file
3250  *
3251  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3252  * @codeCoverageIgnore
3253  */
3254 function wfLoadExtensionMessages() {
3255         wfDeprecated( __FUNCTION__ );
3256 }
3257
3258 /**
3259  * Get a platform-independent path to the null file, e.g. /dev/null
3260  *
3261  * @return string
3262  */
3263 function wfGetNull() {
3264         return wfIsWindows()
3265                 ? 'NUL'
3266                 : '/dev/null';
3267 }
3268
3269 /**
3270  * Throws a warning that $function is deprecated
3271  *
3272  * @param $function String
3273  * @return null
3274  */
3275 function wfDeprecated( $function ) {
3276         static $functionsWarned = array();
3277         if ( !isset( $functionsWarned[$function] ) ) {
3278                 $functionsWarned[$function] = true;
3279                 wfWarn( "Use of $function is deprecated.", 2 );
3280         }
3281 }
3282
3283 /**
3284  * Send a warning either to the debug log or in a PHP error depending on
3285  * $wgDevelopmentWarnings
3286  *
3287  * @param $msg String: message to send
3288  * @param $callerOffset Integer: number of items to go back in the backtrace to
3289  *        find the correct caller (1 = function calling wfWarn, ...)
3290  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3291  *        is true
3292  */
3293 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3294         global $wgDevelopmentWarnings;
3295
3296         $callers = wfDebugBacktrace();
3297         if ( isset( $callers[$callerOffset + 1] ) ) {
3298                 $callerfunc = $callers[$callerOffset + 1];
3299                 $callerfile = $callers[$callerOffset];
3300                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3301                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3302                 } else {
3303                         $file = '(internal function)';
3304                 }
3305                 $func = '';
3306                 if ( isset( $callerfunc['class'] ) ) {
3307                         $func .= $callerfunc['class'] . '::';
3308                 }
3309                 if ( isset( $callerfunc['function'] ) ) {
3310                         $func .= $callerfunc['function'];
3311                 }
3312                 $msg .= " [Called from $func in $file]";
3313         }
3314
3315         if ( $wgDevelopmentWarnings ) {
3316                 trigger_error( $msg, $level );
3317         } else {
3318                 wfDebug( "$msg\n" );
3319         }
3320 }
3321
3322 /**
3323  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3324  * and waiting for it to go down, this waits for the slaves to catch up to the
3325  * master position. Use this when updating very large numbers of rows, as
3326  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3327  * a no-op if there are no slaves.
3328  *
3329  * @param $maxLag Integer (deprecated)
3330  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3331  * @return null
3332  */
3333 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3334         $lb = wfGetLB( $wiki );
3335         // bug 27975 - Don't try to wait for slaves if there are none
3336         // Prevents permission error when getting master position
3337         if ( $lb->getServerCount() > 1 ) {
3338                 $dbw = $lb->getConnection( DB_MASTER );
3339                 $pos = $dbw->getMasterPos();
3340                 $lb->waitForAll( $pos );
3341         }
3342 }
3343
3344 /**
3345  * Used to be used for outputting text in the installer/updater
3346  * @deprecated since 1.18, warnings in 1.19, remove in 1.20
3347  */
3348 function wfOut( $s ) {
3349         wfDeprecated( __METHOD__ );
3350         global $wgCommandLineMode;
3351         if ( $wgCommandLineMode && !defined( 'MEDIAWIKI_INSTALL' ) ) {
3352                 echo $s;
3353         } else {
3354                 echo htmlspecialchars( $s );
3355         }
3356         flush();
3357 }
3358
3359 /**
3360  * Count down from $n to zero on the terminal, with a one-second pause
3361  * between showing each number. For use in command-line scripts.
3362  * @codeCoverageIgnore
3363  */
3364 function wfCountDown( $n ) {
3365         for ( $i = $n; $i >= 0; $i-- ) {
3366                 if ( $i != $n ) {
3367                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3368                 }
3369                 echo $i;
3370                 flush();
3371                 if ( $i ) {
3372                         sleep( 1 );
3373                 }
3374         }
3375         echo "\n";
3376 }
3377
3378 /**
3379  * Generate a random 32-character hexadecimal token.
3380  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3381  *              characters before hashing.
3382  * @return string
3383  * @codeCoverageIgnore
3384  */
3385 function wfGenerateToken( $salt = '' ) {
3386         $salt = serialize( $salt );
3387         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3388 }
3389
3390 /**
3391  * Replace all invalid characters with -
3392  *
3393  * @param $name Mixed: filename to process
3394  * @return String
3395  */
3396 function wfStripIllegalFilenameChars( $name ) {
3397         global $wgIllegalFileChars;
3398         $name = wfBaseName( $name );
3399         $name = preg_replace(
3400                 "/[^" . Title::legalChars() . "]" .
3401                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3402                         "/",
3403                 '-',
3404                 $name
3405         );
3406         return $name;
3407 }
3408
3409 /**
3410  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3411  *
3412  * @return Integer value memory was set to.
3413  */
3414 function wfMemoryLimit() {
3415         global $wgMemoryLimit;
3416         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3417         if( $memlimit != -1 ) {
3418                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3419                 if( $conflimit == -1 ) {
3420                         wfDebug( "Removing PHP's memory limit\n" );
3421                         wfSuppressWarnings();
3422                         ini_set( 'memory_limit', $conflimit );
3423                         wfRestoreWarnings();
3424                         return $conflimit;
3425                 } elseif ( $conflimit > $memlimit ) {
3426                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3427                         wfSuppressWarnings();
3428                         ini_set( 'memory_limit', $conflimit );
3429                         wfRestoreWarnings();
3430                         return $conflimit;
3431                 }
3432         }
3433         return $memlimit;
3434 }
3435
3436 /**
3437  * Converts shorthand byte notation to integer form
3438  *
3439  * @param $string String
3440  * @return Integer
3441  */
3442 function wfShorthandToInteger( $string = '' ) {
3443         $string = trim( $string );
3444         if( $string === '' ) {
3445                 return -1;
3446         }
3447         $last = $string[strlen( $string ) - 1];
3448         $val = intval( $string );
3449         switch( $last ) {
3450                 case 'g':
3451                 case 'G':
3452                         $val *= 1024;
3453                         // break intentionally missing
3454                 case 'm':
3455                 case 'M':
3456                         $val *= 1024;
3457                         // break intentionally missing
3458                 case 'k':
3459                 case 'K':
3460                         $val *= 1024;
3461         }
3462
3463         return $val;
3464 }
3465
3466 /**
3467  * Get the normalised IETF language tag
3468  * See unit test for examples.
3469  *
3470  * @param $code String: The language code.
3471  * @return $langCode String: The language code which complying with BCP 47 standards.
3472  */
3473 function wfBCP47( $code ) {
3474         $codeSegment = explode( '-', $code );
3475         $codeBCP = array();
3476         foreach ( $codeSegment as $segNo => $seg ) {
3477                 if ( count( $codeSegment ) > 0 ) {
3478                         // when previous segment is x, it is a private segment and should be lc
3479                         if( $segNo > 0 && strtolower( $codeSegment[($segNo - 1)] ) == 'x') {
3480                                 $codeBCP[$segNo] = strtolower( $seg );
3481                         // ISO 3166 country code
3482                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3483                                 $codeBCP[$segNo] = strtoupper( $seg );
3484                         // ISO 15924 script code
3485                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3486                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3487                         // Use lowercase for other cases
3488                         } else {
3489                                 $codeBCP[$segNo] = strtolower( $seg );
3490                         }
3491                 } else {
3492                 // Use lowercase for single segment
3493                         $codeBCP[$segNo] = strtolower( $seg );
3494                 }
3495         }
3496         $langCode = implode( '-', $codeBCP );
3497         return $langCode;
3498 }
3499
3500 /**
3501  * Get a cache object.
3502  *
3503  * @param integer $inputType Cache type, one the the CACHE_* constants.
3504  * @return BagOStuff
3505  */
3506 function wfGetCache( $inputType ) {
3507         return ObjectCache::getInstance( $inputType );
3508 }
3509
3510 /**
3511  * Get the main cache object
3512  *
3513  * @return BagOStuff
3514  */
3515 function wfGetMainCache() {
3516         global $wgMainCacheType;
3517         return ObjectCache::getInstance( $wgMainCacheType );
3518 }
3519
3520 /**
3521  * Get the cache object used by the message cache
3522  *
3523  * @return BagOStuff
3524  */
3525 function wfGetMessageCacheStorage() {
3526         global $wgMessageCacheType;
3527         return ObjectCache::getInstance( $wgMessageCacheType );
3528 }
3529
3530 /**
3531  * Get the cache object used by the parser cache
3532  *
3533  * @return BagOStuff
3534  */
3535 function wfGetParserCacheStorage() {
3536         global $wgParserCacheType;
3537         return ObjectCache::getInstance( $wgParserCacheType );
3538 }
3539
3540 /**
3541  * Call hook functions defined in $wgHooks
3542  *
3543  * @param $event String: event name
3544  * @param $args Array: parameters passed to hook functions
3545  * @return Boolean
3546  */
3547 function wfRunHooks( $event, $args = array() ) {
3548         return Hooks::run( $event, $args );
3549 }