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