includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 // Hide compatibility functions from Doxygen
  28 /// @cond
  29
  30 /**
  31  * Compatibility functions
  32  *
  33  * We support PHP 5.3.2 and up.
  34  * Re-implementations of newer functions or functions in non-standard
  35  * PHP extensions may be included here.
  36  */
  37
  38 if( !function_exists( 'iconv' ) ) {
  39         /**
  40          * @codeCoverageIgnore
  41          * @return string
  42          */
  43         function iconv( $from, $to, $string ) {
  44                 return Fallback::iconv( $from, $to, $string );
  45         }
  46 }
  47
  48 if ( !function_exists( 'mb_substr' ) ) {
  49         /**
  50          * @codeCoverageIgnore
  51          * @return string
  52          */
  53         function mb_substr( $str, $start, $count = 'end' ) {
  54                 return Fallback::mb_substr( $str, $start, $count );
  55         }
  56
  57         /**
  58          * @codeCoverageIgnore
  59          * @return int
  60          */
  61         function mb_substr_split_unicode( $str, $splitPos ) {
  62                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  63         }
  64 }
  65
  66 if ( !function_exists( 'mb_strlen' ) ) {
  67         /**
  68          * @codeCoverageIgnore
  69          * @return int
  70          */
  71         function mb_strlen( $str, $enc = '' ) {
  72                 return Fallback::mb_strlen( $str, $enc );
  73         }
  74 }
  75
  76 if( !function_exists( 'mb_strpos' ) ) {
  77         /**
  78          * @codeCoverageIgnore
  79          * @return int
  80          */
  81         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  82                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  83         }
  84
  85 }
  86
  87 if( !function_exists( 'mb_strrpos' ) ) {
  88         /**
  89          * @codeCoverageIgnore
  90          * @return int
  91          */
  92         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  93                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  94         }
  95 }
  96
  97 // Support for Wietse Venema's taint feature
  98 if ( !function_exists( 'istainted' ) ) {
  99         /**
 100          * @codeCoverageIgnore
 101          * @return int
 102          */
 103         function istainted( $var ) {
 104                 return 0;
 105         }
 106         /** @codeCoverageIgnore */
 107         function taint( $var, $level = 0 ) {}
 108         /** @codeCoverageIgnore */
 109         function untaint( $var, $level = 0 ) {}
 110         define( 'TC_HTML', 1 );
 111         define( 'TC_SHELL', 1 );
 112         define( 'TC_MYSQL', 1 );
 113         define( 'TC_PCRE', 1 );
 114         define( 'TC_SELF', 1 );
 115 }
 116 /// @endcond
 117
 118 /**
 119  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 120  * @param $a array
 121  * @param $b array
 122  * @return array
 123  */
 124 function wfArrayDiff2( $a, $b ) {
 125         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 126 }
 127
 128 /**
 129  * @param $a
 130  * @param $b
 131  * @return int
 132  */
 133 function wfArrayDiff2_cmp( $a, $b ) {
 134         if ( !is_array( $a ) ) {
 135                 return strcmp( $a, $b );
 136         } elseif ( count( $a ) !== count( $b ) ) {
 137                 return count( $a ) < count( $b ) ? -1 : 1;
 138         } else {
 139                 reset( $a );
 140                 reset( $b );
 141                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 142                         $cmp = strcmp( $valueA, $valueB );
 143                         if ( $cmp !== 0 ) {
 144                                 return $cmp;
 145                         }
 146                 }
 147                 return 0;
 148         }
 149 }
 150
 151 /**
 152  * Array lookup
 153  * Returns an array where the values in the first array are replaced by the
 154  * values in the second array with the corresponding keys
 155  *
 156  * @param $a Array
 157  * @param $b Array
 158  * @return array
 159  */
 160 function wfArrayLookup( $a, $b ) {
 161         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 162 }
 163
 164 /**
 165  * Appends to second array if $value differs from that in $default
 166  *
 167  * @param $key String|Int
 168  * @param $value Mixed
 169  * @param $default Mixed
 170  * @param array $changed to alter
 171  * @throws MWException
 172  */
 173 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 174         if ( is_null( $changed ) ) {
 175                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 176         }
 177         if ( $default[$key] !== $value ) {
 178                 $changed[$key] = $value;
 179         }
 180 }
 181
 182 /**
 183  * Backwards array plus for people who haven't bothered to read the PHP manual
 184  * XXX: will not darn your socks for you.
 185  *
 186  * @param $array1 Array
 187  * @param [$array2, [...]] Arrays
 188  * @return Array
 189  */
 190 function wfArrayMerge( $array1/* ... */ ) {
 191         $args = func_get_args();
 192         $args = array_reverse( $args, true );
 193         $out = array();
 194         foreach ( $args as $arg ) {
 195                 $out += $arg;
 196         }
 197         return $out;
 198 }
 199
 200 /**
 201  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 202  * e.g.
 203  *      wfMergeErrorArrays(
 204  *              array( array( 'x' ) ),
 205  *              array( array( 'x', '2' ) ),
 206  *              array( array( 'x' ) ),
 207  *              array( array( 'y' ) )
 208  *      );
 209  * returns:
 210  *              array(
 211  *              array( 'x', '2' ),
 212  *              array( 'x' ),
 213  *              array( 'y' )
 214  *      )
 215  * @param varargs
 216  * @return Array
 217  */
 218 function wfMergeErrorArrays( /*...*/ ) {
 219         $args = func_get_args();
 220         $out = array();
 221         foreach ( $args as $errors ) {
 222                 foreach ( $errors as $params ) {
 223                         # @todo FIXME: Sometimes get nested arrays for $params,
 224                         # which leads to E_NOTICEs
 225                         $spec = implode( "\t", $params );
 226                         $out[$spec] = $params;
 227                 }
 228         }
 229         return array_values( $out );
 230 }
 231
 232 /**
 233  * Insert array into another array after the specified *KEY*
 234  *
 235  * @param array $array The array.
 236  * @param array $insert The array to insert.
 237  * @param $after Mixed: The key to insert after
 238  * @return Array
 239  */
 240 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 241         // Find the offset of the element to insert after.
 242         $keys = array_keys( $array );
 243         $offsetByKey = array_flip( $keys );
 244
 245         $offset = $offsetByKey[$after];
 246
 247         // Insert at the specified offset
 248         $before = array_slice( $array, 0, $offset + 1, true );
 249         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 250
 251         $output = $before + $insert + $after;
 252
 253         return $output;
 254 }
 255
 256 /**
 257  * Recursively converts the parameter (an object) to an array with the same data
 258  *
 259  * @param $objOrArray Object|Array
 260  * @param $recursive Bool
 261  * @return Array
 262  */
 263 function wfObjectToArray( $objOrArray, $recursive = true ) {
 264         $array = array();
 265         if( is_object( $objOrArray ) ) {
 266                 $objOrArray = get_object_vars( $objOrArray );
 267         }
 268         foreach ( $objOrArray as $key => $value ) {
 269                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 270                         $value = wfObjectToArray( $value );
 271                 }
 272
 273                 $array[$key] = $value;
 274         }
 275
 276         return $array;
 277 }
 278
 279 /**
 280  * Wrapper around array_map() which also taints variables
 281  *
 282  * @param  $function Callback
 283  * @param  $input Array
 284  * @return Array
 285  */
 286 function wfArrayMap( $function, $input ) {
 287         $ret = array_map( $function, $input );
 288         foreach ( $ret as $key => $value ) {
 289                 $taint = istainted( $input[$key] );
 290                 if ( $taint ) {
 291                         taint( $ret[$key], $taint );
 292                 }
 293         }
 294         return $ret;
 295 }
 296
 297 /**
 298  * Get a random decimal value between 0 and 1, in a way
 299  * not likely to give duplicate values for any realistic
 300  * number of articles.
 301  *
 302  * @return string
 303  */
 304 function wfRandom() {
 305         # The maximum random value is "only" 2^31-1, so get two random
 306         # values to reduce the chance of dupes
 307         $max = mt_getrandmax() + 1;
 308         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 309                 / $max / $max, 12, '.', '' );
 310         return $rand;
 311 }
 312
 313 /**
 314  * Get a random string containing a number of pseudo-random hex
 315  * characters.
 316  * @note This is not secure, if you are trying to generate some sort
 317  *       of token please use MWCryptRand instead.
 318  *
 319  * @param int $length The length of the string to generate
 320  * @return String
 321  * @since 1.20
 322  */
 323 function wfRandomString( $length = 32 ) {
 324         $str = '';
 325         while ( strlen( $str ) < $length ) {
 326                 $str .= dechex( mt_rand() );
 327         }
 328         return substr( $str, 0, $length );
 329 }
 330
 331 /**
 332  * We want some things to be included as literal characters in our title URLs
 333  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 334  * all of the following should be safe:
 335  *
 336  * ;:@&=$-_.+!*'(),
 337  *
 338  * But + is not safe because it's used to indicate a space; &= are only safe in
 339  * paths and not in queries (and we don't distinguish here); ' seems kind of
 340  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 341  * is reserved, we don't care.  So the list we unescape is:
 342  *
 343  * ;:@$!*(),/
 344  *
 345  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 346  * so no fancy : for IIS7.
 347  *
 348  * %2F in the page titles seems to fatally break for some reason.
 349  *
 350  * @param $s String:
 351  * @return string
 352  */
 353 function wfUrlencode( $s ) {
 354         static $needle;
 355         if ( is_null( $s ) ) {
 356                 $needle = null;
 357                 return '';
 358         }
 359
 360         if ( is_null( $needle ) ) {
 361                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 362                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 363                         $needle[] = '%3A';
 364                 }
 365         }
 366
 367         $s = urlencode( $s );
 368         $s = str_ireplace(
 369                 $needle,
 370                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 371                 $s
 372         );
 373
 374         return $s;
 375 }
 376
 377 /**
 378  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 379  * "days=7&limit=100". Options in the first array override options in the second.
 380  * Options set to null or false will not be output.
 381  *
 382  * @param array $array1 ( String|Array )
 383  * @param array $array2 ( String|Array )
 384  * @param $prefix String
 385  * @return String
 386  */
 387 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 388         if ( !is_null( $array2 ) ) {
 389                 $array1 = $array1 + $array2;
 390         }
 391
 392         $cgi = '';
 393         foreach ( $array1 as $key => $value ) {
 394                 if ( !is_null( $value ) && $value !== false ) {
 395                         if ( $cgi != '' ) {
 396                                 $cgi .= '&';
 397                         }
 398                         if ( $prefix !== '' ) {
 399                                 $key = $prefix . "[$key]";
 400                         }
 401                         if ( is_array( $value ) ) {
 402                                 $firstTime = true;
 403                                 foreach ( $value as $k => $v ) {
 404                                         $cgi .= $firstTime ? '' : '&';
 405                                         if ( is_array( $v ) ) {
 406                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 407                                         } else {
 408                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 409                                         }
 410                                         $firstTime = false;
 411                                 }
 412                         } else {
 413                                 if ( is_object( $value ) ) {
 414                                         $value = $value->__toString();
 415                                 }
 416                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 417                         }
 418                 }
 419         }
 420         return $cgi;
 421 }
 422
 423 /**
 424  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 425  * its argument and returns the same string in array form.  This allows compatibility
 426  * with legacy functions that accept raw query strings instead of nice
 427  * arrays.  Of course, keys and values are urldecode()d.
 428  *
 429  * @param string $query query string
 430  * @return array Array version of input
 431  */
 432 function wfCgiToArray( $query ) {
 433         if ( isset( $query[0] ) && $query[0] == '?' ) {
 434                 $query = substr( $query, 1 );
 435         }
 436         $bits = explode( '&', $query );
 437         $ret = array();
 438         foreach ( $bits as $bit ) {
 439                 if ( $bit === '' ) {
 440                         continue;
 441                 }
 442                 if ( strpos( $bit, '=' ) === false ) {
 443                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 444                         $key = $bit;
 445                         $value = '';
 446                 } else {
 447                         list( $key, $value ) = explode( '=', $bit );
 448                 }
 449                 $key = urldecode( $key );
 450                 $value = urldecode( $value );
 451                 if ( strpos( $key, '[' ) !== false ) {
 452                         $keys = array_reverse( explode( '[', $key ) );
 453                         $key = array_pop( $keys );
 454                         $temp = $value;
 455                         foreach ( $keys as $k ) {
 456                                 $k = substr( $k, 0, -1 );
 457                                 $temp = array( $k => $temp );
 458                         }
 459                         if ( isset( $ret[$key] ) ) {
 460                                 $ret[$key] = array_merge( $ret[$key], $temp );
 461                         } else {
 462                                 $ret[$key] = $temp;
 463                         }
 464                 } else {
 465                         $ret[$key] = $value;
 466                 }
 467         }
 468         return $ret;
 469 }
 470
 471 /**
 472  * Append a query string to an existing URL, which may or may not already
 473  * have query string parameters already. If so, they will be combined.
 474  *
 475  * @param $url String
 476  * @param $query Mixed: string or associative array
 477  * @return string
 478  */
 479 function wfAppendQuery( $url, $query ) {
 480         if ( is_array( $query ) ) {
 481                 $query = wfArrayToCgi( $query );
 482         }
 483         if( $query != '' ) {
 484                 if( false === strpos( $url, '?' ) ) {
 485                         $url .= '?';
 486                 } else {
 487                         $url .= '&';
 488                 }
 489                 $url .= $query;
 490         }
 491         return $url;
 492 }
 493
 494 /**
 495  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 496  * is correct.
 497  *
 498  * The meaning of the PROTO_* constants is as follows:
 499  * PROTO_HTTP: Output a URL starting with http://
 500  * PROTO_HTTPS: Output a URL starting with https://
 501  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 502  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 503  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 504  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 505  *
 506  * @todo this won't work with current-path-relative URLs
 507  * like "subdir/foo.html", etc.
 508  *
 509  * @param string $url either fully-qualified or a local path + query
 510  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 511  *                             protocol to use if $url or $wgServer is
 512  *                             protocol-relative
 513  * @return string Fully-qualified URL, current-path-relative URL or false if
 514  *                no valid URL can be constructed
 515  */
 516 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 517         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 518         $serverUrl = $wgServer;
 519         if ( $defaultProto === PROTO_CANONICAL ) {
 520                 $serverUrl = $wgCanonicalServer;
 521         }
 522         // Make $wgInternalServer fall back to $wgServer if not set
 523         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 524                 $serverUrl = $wgInternalServer;
 525         }
 526         if ( $defaultProto === PROTO_CURRENT ) {
 527                 $defaultProto = WebRequest::detectProtocol() . '://';
 528         }
 529
 530         // Analyze $serverUrl to obtain its protocol
 531         $bits = wfParseUrl( $serverUrl );
 532         $serverHasProto = $bits && $bits['scheme'] != '';
 533
 534         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 535                 if ( $serverHasProto ) {
 536                         $defaultProto = $bits['scheme'] . '://';
 537                 } else {
 538                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 539                         // Fall back to HTTP in this ridiculous case
 540                         $defaultProto = PROTO_HTTP;
 541                 }
 542         }
 543
 544         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 545
 546         if ( substr( $url, 0, 2 ) == '//' ) {
 547                 $url = $defaultProtoWithoutSlashes . $url;
 548         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 549                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 550                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 551         }
 552
 553         $bits = wfParseUrl( $url );
 554         if ( $bits && isset( $bits['path'] ) ) {
 555                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 556                 return wfAssembleUrl( $bits );
 557         } elseif ( $bits ) {
 558                 # No path to expand
 559                 return $url;
 560         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 561                 # URL is a relative path
 562                 return wfRemoveDotSegments( $url );
 563         }
 564
 565         # Expanded URL is not valid.
 566         return false;
 567 }
 568
 569 /**
 570  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 571  * if you need to edit part of a URL and put it back together.
 572  *
 573  * This is the basic structure used (brackets contain keys for $urlParts):
 574  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 575  *
 576  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 577  *
 578  * @since 1.19
 579  * @param array $urlParts URL parts, as output from wfParseUrl
 580  * @return string URL assembled from its component parts
 581  */
 582 function wfAssembleUrl( $urlParts ) {
 583         $result = '';
 584
 585         if ( isset( $urlParts['delimiter'] ) ) {
 586                 if ( isset( $urlParts['scheme'] ) ) {
 587                         $result .= $urlParts['scheme'];
 588                 }
 589
 590                 $result .= $urlParts['delimiter'];
 591         }
 592
 593         if ( isset( $urlParts['host'] ) ) {
 594                 if ( isset( $urlParts['user'] ) ) {
 595                         $result .= $urlParts['user'];
 596                         if ( isset( $urlParts['pass'] ) ) {
 597                                 $result .= ':' . $urlParts['pass'];
 598                         }
 599                         $result .= '@';
 600                 }
 601
 602                 $result .= $urlParts['host'];
 603
 604                 if ( isset( $urlParts['port'] ) ) {
 605                         $result .= ':' . $urlParts['port'];
 606                 }
 607         }
 608
 609         if ( isset( $urlParts['path'] ) ) {
 610                 $result .= $urlParts['path'];
 611         }
 612
 613         if ( isset( $urlParts['query'] ) ) {
 614                 $result .= '?' . $urlParts['query'];
 615         }
 616
 617         if ( isset( $urlParts['fragment'] ) ) {
 618                 $result .= '#' . $urlParts['fragment'];
 619         }
 620
 621         return $result;
 622 }
 623
 624 /**
 625  * Remove all dot-segments in the provided URL path.  For example,
 626  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 627  * RFC3986 section 5.2.4.
 628  *
 629  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 630  *
 631  * @param string $urlPath URL path, potentially containing dot-segments
 632  * @return string URL path with all dot-segments removed
 633  */
 634 function wfRemoveDotSegments( $urlPath ) {
 635         $output = '';
 636         $inputOffset = 0;
 637         $inputLength = strlen( $urlPath );
 638
 639         while ( $inputOffset < $inputLength ) {
 640                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 641                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 642                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 643                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 644                 $trimOutput = false;
 645
 646                 if ( $prefixLengthTwo == './' ) {
 647                         # Step A, remove leading "./"
 648                         $inputOffset += 2;
 649                 } elseif ( $prefixLengthThree == '../' ) {
 650                         # Step A, remove leading "../"
 651                         $inputOffset += 3;
 652                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 653                         # Step B, replace leading "/.$" with "/"
 654                         $inputOffset += 1;
 655                         $urlPath[$inputOffset] = '/';
 656                 } elseif ( $prefixLengthThree == '/./' ) {
 657                         # Step B, replace leading "/./" with "/"
 658                         $inputOffset += 2;
 659                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 660                         # Step C, replace leading "/..$" with "/" and
 661                         # remove last path component in output
 662                         $inputOffset += 2;
 663                         $urlPath[$inputOffset] = '/';
 664                         $trimOutput = true;
 665                 } elseif ( $prefixLengthFour == '/../' ) {
 666                         # Step C, replace leading "/../" with "/" and
 667                         # remove last path component in output
 668                         $inputOffset += 3;
 669                         $trimOutput = true;
 670                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 671                         # Step D, remove "^.$"
 672                         $inputOffset += 1;
 673                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 674                         # Step D, remove "^..$"
 675                         $inputOffset += 2;
 676                 } else {
 677                         # Step E, move leading path segment to output
 678                         if ( $prefixLengthOne == '/' ) {
 679                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 680                         } else {
 681                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 682                         }
 683                         if ( $slashPos === false ) {
 684                                 $output .= substr( $urlPath, $inputOffset );
 685                                 $inputOffset = $inputLength;
 686                         } else {
 687                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 688                                 $inputOffset += $slashPos - $inputOffset;
 689                         }
 690                 }
 691
 692                 if ( $trimOutput ) {
 693                         $slashPos = strrpos( $output, '/' );
 694                         if ( $slashPos === false ) {
 695                                 $output = '';
 696                         } else {
 697                                 $output = substr( $output, 0, $slashPos );
 698                         }
 699                 }
 700         }
 701
 702         return $output;
 703 }
 704
 705 /**
 706  * Returns a regular expression of url protocols
 707  *
 708  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 709  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 710  * @return String
 711  */
 712 function wfUrlProtocols( $includeProtocolRelative = true ) {
 713         global $wgUrlProtocols;
 714
 715         // Cache return values separately based on $includeProtocolRelative
 716         static $withProtRel = null, $withoutProtRel = null;
 717         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 718         if ( !is_null( $cachedValue ) ) {
 719                 return $cachedValue;
 720         }
 721
 722         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 723         // with LocalSettings files from 1.5
 724         if ( is_array( $wgUrlProtocols ) ) {
 725                 $protocols = array();
 726                 foreach ( $wgUrlProtocols as $protocol ) {
 727                         // Filter out '//' if !$includeProtocolRelative
 728                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 729                                 $protocols[] = preg_quote( $protocol, '/' );
 730                         }
 731                 }
 732
 733                 $retval = implode( '|', $protocols );
 734         } else {
 735                 // Ignore $includeProtocolRelative in this case
 736                 // This case exists for pre-1.6 compatibility, and we can safely assume
 737                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 738                 // URLs weren't supported until 1.18
 739                 $retval = $wgUrlProtocols;
 740         }
 741
 742         // Cache return value
 743         if ( $includeProtocolRelative ) {
 744                 $withProtRel = $retval;
 745         } else {
 746                 $withoutProtRel = $retval;
 747         }
 748         return $retval;
 749 }
 750
 751 /**
 752  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 753  * you need a regex that matches all URL protocols but does not match protocol-
 754  * relative URLs
 755  * @return String
 756  */
 757 function wfUrlProtocolsWithoutProtRel() {
 758         return wfUrlProtocols( false );
 759 }
 760
 761 /**
 762  * parse_url() work-alike, but non-broken.  Differences:
 763  *
 764  * 1) Does not raise warnings on bad URLs (just returns false)
 765  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 766  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 767  *
 768  * @param string $url a URL to parse
 769  * @return Array: bits of the URL in an associative array, per PHP docs
 770  */
 771 function wfParseUrl( $url ) {
 772         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 773
 774         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 775         // way to handle them is to just prepend 'http:' and strip the protocol out later
 776         $wasRelative = substr( $url, 0, 2 ) == '//';
 777         if ( $wasRelative ) {
 778                 $url = "http:$url";
 779         }
 780         wfSuppressWarnings();
 781         $bits = parse_url( $url );
 782         wfRestoreWarnings();
 783         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 784         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 785         if ( !$bits || !isset( $bits['scheme'] ) ) {
 786                 return false;
 787         }
 788
 789         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 790         $bits['scheme'] = strtolower( $bits['scheme'] );
 791
 792         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 793         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 794                 $bits['delimiter'] = '://';
 795         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 796                 $bits['delimiter'] = ':';
 797                 // parse_url detects for news: and mailto: the host part of an url as path
 798                 // We have to correct this wrong detection
 799                 if ( isset( $bits['path'] ) ) {
 800                         $bits['host'] = $bits['path'];
 801                         $bits['path'] = '';
 802                 }
 803         } else {
 804                 return false;
 805         }
 806
 807         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 808         if ( !isset( $bits['host'] ) ) {
 809                 $bits['host'] = '';
 810
 811                 // bug 45069
 812                 if ( isset( $bits['path'] ) ) {
 813                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 814                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 815                                 $bits['path'] = '/' . $bits['path'];
 816                         }
 817                 } else {
 818                         $bits['path'] = '';
 819                 }
 820         }
 821
 822         // If the URL was protocol-relative, fix scheme and delimiter
 823         if ( $wasRelative ) {
 824                 $bits['scheme'] = '';
 825                 $bits['delimiter'] = '//';
 826         }
 827         return $bits;
 828 }
 829
 830 /**
 831  * Take a URL, make sure it's expanded to fully qualified, and replace any
 832  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 833  * for more compact display and legibility for local audiences.
 834  *
 835  * @todo handle punycode domains too
 836  *
 837  * @param $url string
 838  * @return string
 839  */
 840 function wfExpandIRI( $url ) {
 841         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 842 }
 843
 844 /**
 845  * Private callback for wfExpandIRI
 846  * @param array $matches
 847  * @return string
 848  */
 849 function wfExpandIRI_callback( $matches ) {
 850         return urldecode( $matches[1] );
 851 }
 852
 853 /**
 854  * Make URL indexes, appropriate for the el_index field of externallinks.
 855  *
 856  * @param $url String
 857  * @return array
 858  */
 859 function wfMakeUrlIndexes( $url ) {
 860         $bits = wfParseUrl( $url );
 861
 862         // Reverse the labels in the hostname, convert to lower case
 863         // For emails reverse domainpart only
 864         if ( $bits['scheme'] == 'mailto' ) {
 865                 $mailparts = explode( '@', $bits['host'], 2 );
 866                 if ( count( $mailparts ) === 2 ) {
 867                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 868                 } else {
 869                         // No domain specified, don't mangle it
 870                         $domainpart = '';
 871                 }
 872                 $reversedHost = $domainpart . '@' . $mailparts[0];
 873         } else {
 874                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 875         }
 876         // Add an extra dot to the end
 877         // Why? Is it in wrong place in mailto links?
 878         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 879                 $reversedHost .= '.';
 880         }
 881         // Reconstruct the pseudo-URL
 882         $prot = $bits['scheme'];
 883         $index = $prot . $bits['delimiter'] . $reversedHost;
 884         // Leave out user and password. Add the port, path, query and fragment
 885         if ( isset( $bits['port'] ) ) {
 886                 $index .= ':' . $bits['port'];
 887         }
 888         if ( isset( $bits['path'] ) ) {
 889                 $index .= $bits['path'];
 890         } else {
 891                 $index .= '/';
 892         }
 893         if ( isset( $bits['query'] ) ) {
 894                 $index .= '?' . $bits['query'];
 895         }
 896         if ( isset( $bits['fragment'] ) ) {
 897                 $index .= '#' . $bits['fragment'];
 898         }
 899
 900         if ( $prot == '' ) {
 901                 return array( "http:$index", "https:$index" );
 902         } else {
 903                 return array( $index );
 904         }
 905 }
 906
 907 /**
 908  * Check whether a given URL has a domain that occurs in a given set of domains
 909  * @param string $url URL
 910  * @param array $domains Array of domains (strings)
 911  * @return bool True if the host part of $url ends in one of the strings in $domains
 912  */
 913 function wfMatchesDomainList( $url, $domains ) {
 914         $bits = wfParseUrl( $url );
 915         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 916                 foreach ( (array)$domains as $domain ) {
 917                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 918                         // We should use something that interprets dots instead
 919                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 920                                 return true;
 921                         }
 922                 }
 923         }
 924         return false;
 925 }
 926
 927 /**
 928  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 929  * In normal operation this is a NOP.
 930  *
 931  * Controlling globals:
 932  * $wgDebugLogFile - points to the log file
 933  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 934  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 935  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 936  *
 937  * @param $text String
 938  * @param bool $logonly set true to avoid appearing in HTML when $wgDebugComments is set
 939  */
 940 function wfDebug( $text, $logonly = false ) {
 941         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 942
 943         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 944                 return;
 945         }
 946
 947         $timer = wfDebugTimer();
 948         if ( $timer !== '' ) {
 949                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 950         }
 951
 952         if ( !$logonly ) {
 953                 MWDebug::debugMsg( $text );
 954         }
 955
 956         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 957                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 958                         # Strip unprintables; they can switch terminal modes when binary data
 959                         # gets dumped, which is pretty annoying.
 960                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 961                         $text = $wgDebugLogPrefix . $text;
 962                         wfErrorLog( $text, $wgDebugLogFile );
 963                 }
 964         }
 965 }
 966
 967 /**
 968  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 969  * @return bool
 970  */
 971 function wfIsDebugRawPage() {
 972         static $cache;
 973         if ( $cache !== null ) {
 974                 return $cache;
 975         }
 976         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 977         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 978                 || (
 979                         isset( $_SERVER['SCRIPT_NAME'] )
 980                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 981                 ) )
 982         {
 983                 $cache = true;
 984         } else {
 985                 $cache = false;
 986         }
 987         return $cache;
 988 }
 989
 990 /**
 991  * Get microsecond timestamps for debug logs
 992  *
 993  * @return string
 994  */
 995 function wfDebugTimer() {
 996         global $wgDebugTimestamps, $wgRequestTime;
 997
 998         if ( !$wgDebugTimestamps ) {
 999                 return '';
1000         }
1001
1002         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1003         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1004         return "$prefix $mem  ";
1005 }
1006
1007 /**
1008  * Send a line giving PHP memory usage.
1009  *
1010  * @param bool $exact print exact values instead of kilobytes (default: false)
1011  */
1012 function wfDebugMem( $exact = false ) {
1013         $mem = memory_get_usage();
1014         if( !$exact ) {
1015                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1016         } else {
1017                 $mem .= ' bytes';
1018         }
1019         wfDebug( "Memory usage: $mem\n" );
1020 }
1021
1022 /**
1023  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1024  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1025  *
1026  * @param $logGroup String
1027  * @param $text String
1028  * @param bool $public whether to log the event in the public log if no private
1029  *                     log file is specified, (default true)
1030  */
1031 function wfDebugLog( $logGroup, $text, $public = true ) {
1032         global $wgDebugLogGroups;
1033         $text = trim( $text ) . "\n";
1034         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
1035                 $time = wfTimestamp( TS_DB );
1036                 $wiki = wfWikiID();
1037                 $host = wfHostname();
1038                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1039                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1040                 }
1041         } elseif ( $public === true ) {
1042                 wfDebug( "[$logGroup] $text", true );
1043         }
1044 }
1045
1046 /**
1047  * Log for database errors
1048  *
1049  * @param string $text database error message.
1050  */
1051 function wfLogDBError( $text ) {
1052         global $wgDBerrorLog, $wgDBerrorLogTZ;
1053         static $logDBErrorTimeZoneObject = null;
1054
1055         if ( $wgDBerrorLog ) {
1056                 $host = wfHostname();
1057                 $wiki = wfWikiID();
1058
1059                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1060                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1061                 }
1062
1063                 // Workaround for https://bugs.php.net/bug.php?id=52063
1064                 // Can be removed when min PHP > 5.3.2
1065                 if ( $logDBErrorTimeZoneObject === null ) {
1066                         $d = date_create( "now" );
1067                 } else {
1068                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1069                 }
1070
1071                 $date = $d->format( 'D M j G:i:s T Y' );
1072
1073                 $text = "$date\t$host\t$wiki\t$text";
1074                 wfErrorLog( $text, $wgDBerrorLog );
1075         }
1076 }
1077
1078 /**
1079  * Throws a warning that $function is deprecated
1080  *
1081  * @param $function String
1082  * @param string|bool $version Version of MediaWiki that the function was deprecated in (Added in 1.19).
1083  * @param string|bool $component Added in 1.19.
1084  * @param $callerOffset integer: How far up the call stack is the original
1085  *    caller. 2 = function that called the function that called
1086  *    wfDeprecated (Added in 1.20)
1087  *
1088  * @return null
1089  */
1090 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1091         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1092 }
1093
1094 /**
1095  * Send a warning either to the debug log or in a PHP error depending on
1096  * $wgDevelopmentWarnings
1097  *
1098  * @param string $msg message to send
1099  * @param $callerOffset Integer: number of items to go back in the backtrace to
1100  *        find the correct caller (1 = function calling wfWarn, ...)
1101  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1102  *        is true
1103  */
1104 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1105         MWDebug::warning( $msg, $callerOffset + 1, $level );
1106 }
1107
1108 /**
1109  * Log to a file without getting "file size exceeded" signals.
1110  *
1111  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1112  * send lines to the specified port, prefixed by the specified prefix and a space.
1113  *
1114  * @param $text String
1115  * @param string $file filename
1116  * @throws MWException
1117  */
1118 function wfErrorLog( $text, $file ) {
1119         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1120                 # Needs the sockets extension
1121                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1122                         // IPv6 bracketed host
1123                         $host = $m[2];
1124                         $port = intval( $m[3] );
1125                         $prefix = isset( $m[4] ) ? $m[4] : false;
1126                         $domain = AF_INET6;
1127                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1128                         $host = $m[2];
1129                         if ( !IP::isIPv4( $host ) ) {
1130                                 $host = gethostbyname( $host );
1131                         }
1132                         $port = intval( $m[3] );
1133                         $prefix = isset( $m[4] ) ? $m[4] : false;
1134                         $domain = AF_INET;
1135                 } else {
1136                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1137                 }
1138
1139                 // Clean it up for the multiplexer
1140                 if ( strval( $prefix ) !== '' ) {
1141                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1142
1143                         // Limit to 64KB
1144                         if ( strlen( $text ) > 65506 ) {
1145                                 $text = substr( $text, 0, 65506 );
1146                         }
1147
1148                         if ( substr( $text, -1 ) != "\n" ) {
1149                                 $text .= "\n";
1150                         }
1151                 } elseif ( strlen( $text ) > 65507 ) {
1152                         $text = substr( $text, 0, 65507 );
1153                 }
1154
1155                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1156                 if ( !$sock ) {
1157                         return;
1158                 }
1159
1160                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1161                 socket_close( $sock );
1162         } else {
1163                 wfSuppressWarnings();
1164                 $exists = file_exists( $file );
1165                 $size = $exists ? filesize( $file ) : false;
1166                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1167                         file_put_contents( $file, $text, FILE_APPEND );
1168                 }
1169                 wfRestoreWarnings();
1170         }
1171 }
1172
1173 /**
1174  * @todo document
1175  */
1176 function wfLogProfilingData() {
1177         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1178         global $wgProfileLimit, $wgUser;
1179
1180         $profiler = Profiler::instance();
1181
1182         # Profiling must actually be enabled...
1183         if ( $profiler->isStub() ) {
1184                 return;
1185         }
1186
1187         // Get total page request time and only show pages that longer than
1188         // $wgProfileLimit time (default is 0)
1189         $elapsed = microtime( true ) - $wgRequestTime;
1190         if ( $elapsed <= $wgProfileLimit ) {
1191                 return;
1192         }
1193
1194         $profiler->logData();
1195
1196         // Check whether this should be logged in the debug file.
1197         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1198                 return;
1199         }
1200
1201         $forward = '';
1202         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1203                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1204         }
1205         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1206                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1207         }
1208         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1209                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1210         }
1211         if ( $forward ) {
1212                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1213         }
1214         // Don't load $wgUser at this late stage just for statistics purposes
1215         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1216         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1217                 $forward .= ' anon';
1218         }
1219
1220         // Command line script uses a FauxRequest object which does not have
1221         // any knowledge about an URL and throw an exception instead.
1222         try {
1223                 $requestUrl = $wgRequest->getRequestURL();
1224         } catch ( MWException $e ) {
1225                 $requestUrl = 'n/a';
1226         }
1227
1228         $log = sprintf( "%s\t%04.3f\t%s\n",
1229                 gmdate( 'YmdHis' ), $elapsed,
1230                 urldecode( $requestUrl . $forward ) );
1231
1232         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1233 }
1234
1235 /**
1236  * Increment a statistics counter
1237  *
1238  * @param $key String
1239  * @param $count Int
1240  * @return void
1241  */
1242 function wfIncrStats( $key, $count = 1 ) {
1243         global $wgStatsMethod;
1244
1245         $count = intval( $count );
1246         if ( $count == 0 ) {
1247                 return;
1248         }
1249
1250         if( $wgStatsMethod == 'udp' ) {
1251                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgAggregateStatsID;
1252                 static $socket;
1253
1254                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : wfWikiID();
1255
1256                 if ( !$socket ) {
1257                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1258                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1259                         socket_sendto(
1260                                 $socket,
1261                                 $statline,
1262                                 strlen( $statline ),
1263                                 0,
1264                                 $wgUDPProfilerHost,
1265                                 $wgUDPProfilerPort
1266                         );
1267                 }
1268                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1269                 wfSuppressWarnings();
1270                 socket_sendto(
1271                         $socket,
1272                         $statline,
1273                         strlen( $statline ),
1274                         0,
1275                         $wgUDPProfilerHost,
1276                         $wgUDPProfilerPort
1277                 );
1278                 wfRestoreWarnings();
1279         } elseif( $wgStatsMethod == 'cache' ) {
1280                 global $wgMemc;
1281                 $key = wfMemcKey( 'stats', $key );
1282                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1283                         $wgMemc->add( $key, $count );
1284                 }
1285         } else {
1286                 // Disabled
1287         }
1288 }
1289
1290 /**
1291  * Check if the wiki read-only lock file is present. This can be used to lock
1292  * off editing functions, but doesn't guarantee that the database will not be
1293  * modified.
1294  *
1295  * @return bool
1296  */
1297 function wfReadOnly() {
1298         global $wgReadOnlyFile, $wgReadOnly;
1299
1300         if ( !is_null( $wgReadOnly ) ) {
1301                 return (bool)$wgReadOnly;
1302         }
1303         if ( $wgReadOnlyFile == '' ) {
1304                 return false;
1305         }
1306         // Set $wgReadOnly for faster access next time
1307         if ( is_file( $wgReadOnlyFile ) ) {
1308                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1309         } else {
1310                 $wgReadOnly = false;
1311         }
1312         return (bool)$wgReadOnly;
1313 }
1314
1315 /**
1316  * @return bool
1317  */
1318 function wfReadOnlyReason() {
1319         global $wgReadOnly;
1320         wfReadOnly();
1321         return $wgReadOnly;
1322 }
1323
1324 /**
1325  * Return a Language object from $langcode
1326  *
1327  * @param $langcode Mixed: either:
1328  *                  - a Language object
1329  *                  - code of the language to get the message for, if it is
1330  *                    a valid code create a language for that language, if
1331  *                    it is a string but not a valid code then make a basic
1332  *                    language object
1333  *                  - a boolean: if it's false then use the global object for
1334  *                    the current user's language (as a fallback for the old parameter
1335  *                    functionality), or if it is true then use global object
1336  *                    for the wiki's content language.
1337  * @return Language object
1338  */
1339 function wfGetLangObj( $langcode = false ) {
1340         # Identify which language to get or create a language object for.
1341         # Using is_object here due to Stub objects.
1342         if( is_object( $langcode ) ) {
1343                 # Great, we already have the object (hopefully)!
1344                 return $langcode;
1345         }
1346
1347         global $wgContLang, $wgLanguageCode;
1348         if( $langcode === true || $langcode === $wgLanguageCode ) {
1349                 # $langcode is the language code of the wikis content language object.
1350                 # or it is a boolean and value is true
1351                 return $wgContLang;
1352         }
1353
1354         global $wgLang;
1355         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1356                 # $langcode is the language code of user language object.
1357                 # or it was a boolean and value is false
1358                 return $wgLang;
1359         }
1360
1361         $validCodes = array_keys( Language::fetchLanguageNames() );
1362         if( in_array( $langcode, $validCodes ) ) {
1363                 # $langcode corresponds to a valid language.
1364                 return Language::factory( $langcode );
1365         }
1366
1367         # $langcode is a string, but not a valid language code; use content language.
1368         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1369         return $wgContLang;
1370 }
1371
1372 /**
1373  * Old function when $wgBetterDirectionality existed
1374  * All usage removed, wfUILang can be removed in near future
1375  *
1376  * @deprecated since 1.18
1377  * @return Language
1378  */
1379 function wfUILang() {
1380         wfDeprecated( __METHOD__, '1.18' );
1381         global $wgLang;
1382         return $wgLang;
1383 }
1384
1385 /**
1386  * This is the function for getting translated interface messages.
1387  *
1388  * @see Message class for documentation how to use them.
1389  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1390  *
1391  * This function replaces all old wfMsg* functions.
1392  *
1393  * @param $key \string Message key.
1394  * Varargs: normal message parameters.
1395  * @return Message
1396  * @since 1.17
1397  */
1398 function wfMessage( $key /*...*/) {
1399         $params = func_get_args();
1400         array_shift( $params );
1401         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1402                 $params = $params[0];
1403         }
1404         return new Message( $key, $params );
1405 }
1406
1407 /**
1408  * This function accepts multiple message keys and returns a message instance
1409  * for the first message which is non-empty. If all messages are empty then an
1410  * instance of the first message key is returned.
1411  * @param varargs: message keys
1412  * @return Message
1413  * @since 1.18
1414  */
1415 function wfMessageFallback( /*...*/ ) {
1416         $args = func_get_args();
1417         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1418 }
1419
1420 /**
1421  * Get a message from anywhere, for the current user language.
1422  *
1423  * Use wfMsgForContent() instead if the message should NOT
1424  * change depending on the user preferences.
1425  *
1426  * @deprecated since 1.18
1427  *
1428  * @param string $key lookup key for the message, usually
1429  *    defined in languages/Language.php
1430  *
1431  * Parameters to the message, which can be used to insert variable text into
1432  * it, can be passed to this function in the following formats:
1433  * - One per argument, starting at the second parameter
1434  * - As an array in the second parameter
1435  * These are not shown in the function definition.
1436  *
1437  * @return String
1438  */
1439 function wfMsg( $key ) {
1440         wfDeprecated( __METHOD__, '1.21' );
1441
1442         $args = func_get_args();
1443         array_shift( $args );
1444         return wfMsgReal( $key, $args );
1445 }
1446
1447 /**
1448  * Same as above except doesn't transform the message
1449  *
1450  * @deprecated since 1.18
1451  *
1452  * @param $key String
1453  * @return String
1454  */
1455 function wfMsgNoTrans( $key ) {
1456         wfDeprecated( __METHOD__, '1.21' );
1457
1458         $args = func_get_args();
1459         array_shift( $args );
1460         return wfMsgReal( $key, $args, true, false, false );
1461 }
1462
1463 /**
1464  * Get a message from anywhere, for the current global language
1465  * set with $wgLanguageCode.
1466  *
1467  * Use this if the message should NOT change dependent on the
1468  * language set in the user's preferences. This is the case for
1469  * most text written into logs, as well as link targets (such as
1470  * the name of the copyright policy page). Link titles, on the
1471  * other hand, should be shown in the UI language.
1472  *
1473  * Note that MediaWiki allows users to change the user interface
1474  * language in their preferences, but a single installation
1475  * typically only contains content in one language.
1476  *
1477  * Be wary of this distinction: If you use wfMsg() where you should
1478  * use wfMsgForContent(), a user of the software may have to
1479  * customize potentially hundreds of messages in
1480  * order to, e.g., fix a link in every possible language.
1481  *
1482  * @deprecated since 1.18
1483  *
1484  * @param string $key lookup key for the message, usually
1485  *     defined in languages/Language.php
1486  * @return String
1487  */
1488 function wfMsgForContent( $key ) {
1489         wfDeprecated( __METHOD__, '1.21' );
1490
1491         global $wgForceUIMsgAsContentMsg;
1492         $args = func_get_args();
1493         array_shift( $args );
1494         $forcontent = true;
1495         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1496                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1497         {
1498                 $forcontent = false;
1499         }
1500         return wfMsgReal( $key, $args, true, $forcontent );
1501 }
1502
1503 /**
1504  * Same as above except doesn't transform the message
1505  *
1506  * @deprecated since 1.18
1507  *
1508  * @param $key String
1509  * @return String
1510  */
1511 function wfMsgForContentNoTrans( $key ) {
1512         wfDeprecated( __METHOD__, '1.21' );
1513
1514         global $wgForceUIMsgAsContentMsg;
1515         $args = func_get_args();
1516         array_shift( $args );
1517         $forcontent = true;
1518         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1519                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1520         {
1521                 $forcontent = false;
1522         }
1523         return wfMsgReal( $key, $args, true, $forcontent, false );
1524 }
1525
1526 /**
1527  * Really get a message
1528  *
1529  * @deprecated since 1.18
1530  *
1531  * @param string $key key to get.
1532  * @param $args
1533  * @param $useDB Boolean
1534  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1535  * @param $transform Boolean: Whether or not to transform the message.
1536  * @return String: the requested message.
1537  */
1538 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1539         wfDeprecated( __METHOD__, '1.21' );
1540
1541         wfProfileIn( __METHOD__ );
1542         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1543         $message = wfMsgReplaceArgs( $message, $args );
1544         wfProfileOut( __METHOD__ );
1545         return $message;
1546 }
1547
1548 /**
1549  * Fetch a message string value, but don't replace any keys yet.
1550  *
1551  * @deprecated since 1.18
1552  *
1553  * @param $key String
1554  * @param $useDB Bool
1555  * @param string $langCode Code of the language to get the message for, or
1556  *                  behaves as a content language switch if it is a boolean.
1557  * @param $transform Boolean: whether to parse magic words, etc.
1558  * @return string
1559  */
1560 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1561         wfDeprecated( __METHOD__, '1.21' );
1562
1563         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1564
1565         $cache = MessageCache::singleton();
1566         $message = $cache->get( $key, $useDB, $langCode );
1567         if( $message === false ) {
1568                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1569         } elseif ( $transform ) {
1570                 $message = $cache->transform( $message );
1571         }
1572         return $message;
1573 }
1574
1575 /**
1576  * Replace message parameter keys on the given formatted output.
1577  *
1578  * @param $message String
1579  * @param $args Array
1580  * @return string
1581  * @private
1582  */
1583 function wfMsgReplaceArgs( $message, $args ) {
1584         # Fix windows line-endings
1585         # Some messages are split with explode("\n", $msg)
1586         $message = str_replace( "\r", '', $message );
1587
1588         // Replace arguments
1589         if ( count( $args ) ) {
1590                 if ( is_array( $args[0] ) ) {
1591                         $args = array_values( $args[0] );
1592                 }
1593                 $replacementKeys = array();
1594                 foreach( $args as $n => $param ) {
1595                         $replacementKeys['$' . ( $n + 1 )] = $param;
1596                 }
1597                 $message = strtr( $message, $replacementKeys );
1598         }
1599
1600         return $message;
1601 }
1602
1603 /**
1604  * Return an HTML-escaped version of a message.
1605  * Parameter replacements, if any, are done *after* the HTML-escaping,
1606  * so parameters may contain HTML (eg links or form controls). Be sure
1607  * to pre-escape them if you really do want plaintext, or just wrap
1608  * the whole thing in htmlspecialchars().
1609  *
1610  * @deprecated since 1.18
1611  *
1612  * @param $key String
1613  * @param string ... parameters
1614  * @return string
1615  */
1616 function wfMsgHtml( $key ) {
1617         wfDeprecated( __METHOD__, '1.21' );
1618
1619         $args = func_get_args();
1620         array_shift( $args );
1621         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1622 }
1623
1624 /**
1625  * Return an HTML version of message
1626  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1627  * so parameters may contain HTML (eg links or form controls). Be sure
1628  * to pre-escape them if you really do want plaintext, or just wrap
1629  * the whole thing in htmlspecialchars().
1630  *
1631  * @deprecated since 1.18
1632  *
1633  * @param $key String
1634  * @param string ... parameters
1635  * @return string
1636  */
1637 function wfMsgWikiHtml( $key ) {
1638         wfDeprecated( __METHOD__, '1.21' );
1639
1640         $args = func_get_args();
1641         array_shift( $args );
1642         return wfMsgReplaceArgs(
1643                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1644                 /* can't be set to false */ true, /* interface */ true )->getText(),
1645                 $args );
1646 }
1647
1648 /**
1649  * Returns message in the requested format
1650  *
1651  * @deprecated since 1.18
1652  *
1653  * @param string $key key of the message
1654  * @param array $options processing rules. Can take the following options:
1655  *   <i>parse</i>: parses wikitext to HTML
1656  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1657  *       p's added by parser or tidy
1658  *   <i>escape</i>: filters message through htmlspecialchars
1659  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1660  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1661  *   <i>parsemag</i>: transform the message using magic phrases
1662  *   <i>content</i>: fetch message for content language instead of interface
1663  * Also can accept a single associative argument, of the form 'language' => 'xx':
1664  *   <i>language</i>: Language object or language code to fetch message for
1665  *       (overridden by <i>content</i>).
1666  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1667  *
1668  * @return String
1669  */
1670 function wfMsgExt( $key, $options ) {
1671         wfDeprecated( __METHOD__, '1.21' );
1672
1673         $args = func_get_args();
1674         array_shift( $args );
1675         array_shift( $args );
1676         $options = (array)$options;
1677
1678         foreach( $options as $arrayKey => $option ) {
1679                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1680                         # An unknown index, neither numeric nor "language"
1681                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1682                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1683                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1684                 'replaceafter', 'parsemag', 'content' ) ) ) {
1685                         # A numeric index with unknown value
1686                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1687                 }
1688         }
1689
1690         if( in_array( 'content', $options, true ) ) {
1691                 $forContent = true;
1692                 $langCode = true;
1693                 $langCodeObj = null;
1694         } elseif( array_key_exists( 'language', $options ) ) {
1695                 $forContent = false;
1696                 $langCode = wfGetLangObj( $options['language'] );
1697                 $langCodeObj = $langCode;
1698         } else {
1699                 $forContent = false;
1700                 $langCode = false;
1701                 $langCodeObj = null;
1702         }
1703
1704         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1705
1706         if( !in_array( 'replaceafter', $options, true ) ) {
1707                 $string = wfMsgReplaceArgs( $string, $args );
1708         }
1709
1710         $messageCache = MessageCache::singleton();
1711         $parseInline = in_array( 'parseinline', $options, true );
1712         if( in_array( 'parse', $options, true ) || $parseInline ) {
1713                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1714                 if ( $string instanceof ParserOutput ) {
1715                         $string = $string->getText();
1716                 }
1717
1718                 if ( $parseInline ) {
1719                         $m = array();
1720                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1721                                 $string = $m[1];
1722                         }
1723                 }
1724         } elseif ( in_array( 'parsemag', $options, true ) ) {
1725                 $string = $messageCache->transform( $string,
1726                                 !$forContent, $langCodeObj );
1727         }
1728
1729         if ( in_array( 'escape', $options, true ) ) {
1730                 $string = htmlspecialchars ( $string );
1731         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1732                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1733         }
1734
1735         if( in_array( 'replaceafter', $options, true ) ) {
1736                 $string = wfMsgReplaceArgs( $string, $args );
1737         }
1738
1739         return $string;
1740 }
1741
1742 /**
1743  * Since wfMsg() and co suck, they don't return false if the message key they
1744  * looked up didn't exist but a XHTML string, this function checks for the
1745  * nonexistence of messages by checking the MessageCache::get() result directly.
1746  *
1747  * @deprecated since 1.18. Use Message::isDisabled().
1748  *
1749  * @param $key      String: the message key looked up
1750  * @return Boolean True if the message *doesn't* exist.
1751  */
1752 function wfEmptyMsg( $key ) {
1753         wfDeprecated( __METHOD__, '1.21' );
1754
1755         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1756 }
1757
1758 /**
1759  * Throw a debugging exception. This function previously once exited the process,
1760  * but now throws an exception instead, with similar results.
1761  *
1762  * @param string $msg message shown when dying.
1763  * @throws MWException
1764  */
1765 function wfDebugDieBacktrace( $msg = '' ) {
1766         throw new MWException( $msg );
1767 }
1768
1769 /**
1770  * Fetch server name for use in error reporting etc.
1771  * Use real server name if available, so we know which machine
1772  * in a server farm generated the current page.
1773  *
1774  * @return string
1775  */
1776 function wfHostname() {
1777         static $host;
1778         if ( is_null( $host ) ) {
1779
1780                 # Hostname overriding
1781                 global $wgOverrideHostname;
1782                 if( $wgOverrideHostname !== false ) {
1783                         # Set static and skip any detection
1784                         $host = $wgOverrideHostname;
1785                         return $host;
1786                 }
1787
1788                 if ( function_exists( 'posix_uname' ) ) {
1789                         // This function not present on Windows
1790                         $uname = posix_uname();
1791                 } else {
1792                         $uname = false;
1793                 }
1794                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1795                         $host = $uname['nodename'];
1796                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1797                         # Windows computer name
1798                         $host = getenv( 'COMPUTERNAME' );
1799                 } else {
1800                         # This may be a virtual server.
1801                         $host = $_SERVER['SERVER_NAME'];
1802                 }
1803         }
1804         return $host;
1805 }
1806
1807 /**
1808  * Returns a HTML comment with the elapsed time since request.
1809  * This method has no side effects.
1810  *
1811  * @return string
1812  */
1813 function wfReportTime() {
1814         global $wgRequestTime, $wgShowHostnames;
1815
1816         $elapsed = microtime( true ) - $wgRequestTime;
1817
1818         return $wgShowHostnames
1819                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1820                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1821 }
1822
1823 /**
1824  * Safety wrapper for debug_backtrace().
1825  *
1826  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1827  * murky circumstances, which may be triggered in part by stub objects
1828  * or other fancy talking'.
1829  *
1830  * Will return an empty array if Zend Optimizer is detected or if
1831  * debug_backtrace is disabled, otherwise the output from
1832  * debug_backtrace() (trimmed).
1833  *
1834  * @param int $limit This parameter can be used to limit the number of stack frames returned
1835  *
1836  * @return array of backtrace information
1837  */
1838 function wfDebugBacktrace( $limit = 0 ) {
1839         static $disabled = null;
1840
1841         if( extension_loaded( 'Zend Optimizer' ) ) {
1842                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1843                 return array();
1844         }
1845
1846         if ( is_null( $disabled ) ) {
1847                 $disabled = false;
1848                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1849                 $functions = array_map( 'trim', $functions );
1850                 $functions = array_map( 'strtolower', $functions );
1851                 if ( in_array( 'debug_backtrace', $functions ) ) {
1852                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1853                         $disabled = true;
1854                 }
1855         }
1856         if ( $disabled ) {
1857                 return array();
1858         }
1859
1860         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1861                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1862         } else {
1863                 return array_slice( debug_backtrace(), 1 );
1864         }
1865 }
1866
1867 /**
1868  * Get a debug backtrace as a string
1869  *
1870  * @return string
1871  */
1872 function wfBacktrace() {
1873         global $wgCommandLineMode;
1874
1875         if ( $wgCommandLineMode ) {
1876                 $msg = '';
1877         } else {
1878                 $msg = "<ul>\n";
1879         }
1880         $backtrace = wfDebugBacktrace();
1881         foreach( $backtrace as $call ) {
1882                 if( isset( $call['file'] ) ) {
1883                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1884                         $file = $f[count( $f ) - 1];
1885                 } else {
1886                         $file = '-';
1887                 }
1888                 if( isset( $call['line'] ) ) {
1889                         $line = $call['line'];
1890                 } else {
1891                         $line = '-';
1892                 }
1893                 if ( $wgCommandLineMode ) {
1894                         $msg .= "$file line $line calls ";
1895                 } else {
1896                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1897                 }
1898                 if( !empty( $call['class'] ) ) {
1899                         $msg .= $call['class'] . $call['type'];
1900                 }
1901                 $msg .= $call['function'] . '()';
1902
1903                 if ( $wgCommandLineMode ) {
1904                         $msg .= "\n";
1905                 } else {
1906                         $msg .= "</li>\n";
1907                 }
1908         }
1909         if ( $wgCommandLineMode ) {
1910                 $msg .= "\n";
1911         } else {
1912                 $msg .= "</ul>\n";
1913         }
1914
1915         return $msg;
1916 }
1917
1918 /**
1919  * Get the name of the function which called this function
1920  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1921  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1922  * wfGetCaller( 3 ) is the parent of that.
1923  *
1924  * @param $level Int
1925  * @return string
1926  */
1927 function wfGetCaller( $level = 2 ) {
1928         $backtrace = wfDebugBacktrace( $level + 1 );
1929         if ( isset( $backtrace[$level] ) ) {
1930                 return wfFormatStackFrame( $backtrace[$level] );
1931         } else {
1932                 return 'unknown';
1933         }
1934 }
1935
1936 /**
1937  * Return a string consisting of callers in the stack. Useful sometimes
1938  * for profiling specific points.
1939  *
1940  * @param int $limit The maximum depth of the stack frame to return, or false for
1941  *               the entire stack.
1942  * @return String
1943  */
1944 function wfGetAllCallers( $limit = 3 ) {
1945         $trace = array_reverse( wfDebugBacktrace() );
1946         if ( !$limit || $limit > count( $trace ) - 1 ) {
1947                 $limit = count( $trace ) - 1;
1948         }
1949         $trace = array_slice( $trace, -$limit - 1, $limit );
1950         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1951 }
1952
1953 /**
1954  * Return a string representation of frame
1955  *
1956  * @param $frame Array
1957  * @return string
1958  */
1959 function wfFormatStackFrame( $frame ) {
1960         return isset( $frame['class'] ) ?
1961                 $frame['class'] . '::' . $frame['function'] :
1962                 $frame['function'];
1963 }
1964
1965 /* Some generic result counters, pulled out of SearchEngine */
1966
1967 /**
1968  * @todo document
1969  *
1970  * @param $offset Int
1971  * @param $limit Int
1972  * @return String
1973  */
1974 function wfShowingResults( $offset, $limit ) {
1975         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1976 }
1977
1978 /**
1979  * Generate (prev x| next x) (20|50|100...) type links for paging
1980  *
1981  * @param $offset String
1982  * @param $limit Integer
1983  * @param $link String
1984  * @param string $query optional URL query parameter string
1985  * @param bool $atend optional param for specified if this is the last page
1986  * @return String
1987  * @deprecated in 1.19; use Language::viewPrevNext() instead
1988  */
1989 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1990         wfDeprecated( __METHOD__, '1.19' );
1991
1992         global $wgLang;
1993
1994         $query = wfCgiToArray( $query );
1995
1996         if( is_object( $link ) ) {
1997                 $title = $link;
1998         } else {
1999                 $title = Title::newFromText( $link );
2000                 if( is_null( $title ) ) {
2001                         return false;
2002                 }
2003         }
2004
2005         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
2006 }
2007
2008 /**
2009  * Make a list item, used by various special pages
2010  *
2011  * @param string $page Page link
2012  * @param string $details Text between brackets
2013  * @param $oppositedm Boolean   Add the direction mark opposite to your
2014  *                                                              language, to display text properly
2015  * @return String
2016  * @deprecated since 1.19; use Language::specialList() instead
2017  */
2018 function wfSpecialList( $page, $details, $oppositedm = true ) {
2019         wfDeprecated( __METHOD__, '1.19' );
2020
2021         global $wgLang;
2022         return $wgLang->specialList( $page, $details, $oppositedm );
2023 }
2024
2025 /**
2026  * @todo document
2027  * @todo FIXME: We may want to blacklist some broken browsers
2028  *
2029  * @param $force Bool
2030  * @return bool Whereas client accept gzip compression
2031  */
2032 function wfClientAcceptsGzip( $force = false ) {
2033         static $result = null;
2034         if ( $result === null || $force ) {
2035                 $result = false;
2036                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2037                         # @todo FIXME: We may want to blacklist some broken browsers
2038                         $m = array();
2039                         if( preg_match(
2040                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2041                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
2042                                 $m )
2043                         )
2044                         {
2045                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2046                                         $result = false;
2047                                         return $result;
2048                                 }
2049                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2050                                 $result = true;
2051                         }
2052                 }
2053         }
2054         return $result;
2055 }
2056
2057 /**
2058  * Obtain the offset and limit values from the request string;
2059  * used in special pages
2060  *
2061  * @param int $deflimit default limit if none supplied
2062  * @param string $optionname Name of a user preference to check against
2063  * @return array
2064  *
2065  */
2066 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2067         global $wgRequest;
2068         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2069 }
2070
2071 /**
2072  * Escapes the given text so that it may be output using addWikiText()
2073  * without any linking, formatting, etc. making its way through. This
2074  * is achieved by substituting certain characters with HTML entities.
2075  * As required by the callers, "<nowiki>" is not used.
2076  *
2077  * @param string $text text to be escaped
2078  * @return String
2079  */
2080 function wfEscapeWikiText( $text ) {
2081         $text = strtr( "\n$text", array(
2082                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2083                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2084                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2085                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2086                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2087                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2088         ) );
2089         return substr( $text, 1 );
2090 }
2091
2092 /**
2093  * Get the current unix timestamp with microseconds.  Useful for profiling
2094  * @return Float
2095  */
2096 function wfTime() {
2097         return microtime( true );
2098 }
2099
2100 /**
2101  * Sets dest to source and returns the original value of dest
2102  * If source is NULL, it just returns the value, it doesn't set the variable
2103  * If force is true, it will set the value even if source is NULL
2104  *
2105  * @param $dest Mixed
2106  * @param $source Mixed
2107  * @param $force Bool
2108  * @return Mixed
2109  */
2110 function wfSetVar( &$dest, $source, $force = false ) {
2111         $temp = $dest;
2112         if ( !is_null( $source ) || $force ) {
2113                 $dest = $source;
2114         }
2115         return $temp;
2116 }
2117
2118 /**
2119  * As for wfSetVar except setting a bit
2120  *
2121  * @param $dest Int
2122  * @param $bit Int
2123  * @param $state Bool
2124  *
2125  * @return bool
2126  */
2127 function wfSetBit( &$dest, $bit, $state = true ) {
2128         $temp = (bool)( $dest & $bit );
2129         if ( !is_null( $state ) ) {
2130                 if ( $state ) {
2131                         $dest |= $bit;
2132                 } else {
2133                         $dest &= ~$bit;
2134                 }
2135         }
2136         return $temp;
2137 }
2138
2139 /**
2140  * A wrapper around the PHP function var_export().
2141  * Either print it or add it to the regular output ($wgOut).
2142  *
2143  * @param $var mixed A PHP variable to dump.
2144  */
2145 function wfVarDump( $var ) {
2146         global $wgOut;
2147         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2148         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2149                 print $s;
2150         } else {
2151                 $wgOut->addHTML( $s );
2152         }
2153 }
2154
2155 /**
2156  * Provide a simple HTTP error.
2157  *
2158  * @param $code Int|String
2159  * @param $label String
2160  * @param $desc String
2161  */
2162 function wfHttpError( $code, $label, $desc ) {
2163         global $wgOut;
2164         $wgOut->disable();
2165         header( "HTTP/1.0 $code $label" );
2166         header( "Status: $code $label" );
2167         $wgOut->sendCacheControl();
2168
2169         header( 'Content-type: text/html; charset=utf-8' );
2170         print "<!doctype html>" .
2171                 '<html><head><title>' .
2172                 htmlspecialchars( $label ) .
2173                 '</title></head><body><h1>' .
2174                 htmlspecialchars( $label ) .
2175                 '</h1><p>' .
2176                 nl2br( htmlspecialchars( $desc ) ) .
2177                 "</p></body></html>\n";
2178 }
2179
2180 /**
2181  * Clear away any user-level output buffers, discarding contents.
2182  *
2183  * Suitable for 'starting afresh', for instance when streaming
2184  * relatively large amounts of data without buffering, or wanting to
2185  * output image files without ob_gzhandler's compression.
2186  *
2187  * The optional $resetGzipEncoding parameter controls suppression of
2188  * the Content-Encoding header sent by ob_gzhandler; by default it
2189  * is left. See comments for wfClearOutputBuffers() for why it would
2190  * be used.
2191  *
2192  * Note that some PHP configuration options may add output buffer
2193  * layers which cannot be removed; these are left in place.
2194  *
2195  * @param $resetGzipEncoding Bool
2196  */
2197 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2198         if( $resetGzipEncoding ) {
2199                 // Suppress Content-Encoding and Content-Length
2200                 // headers from 1.10+s wfOutputHandler
2201                 global $wgDisableOutputCompression;
2202                 $wgDisableOutputCompression = true;
2203         }
2204         while( $status = ob_get_status() ) {
2205                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2206                         // Probably from zlib.output_compression or other
2207                         // PHP-internal setting which can't be removed.
2208                         //
2209                         // Give up, and hope the result doesn't break
2210                         // output behavior.
2211                         break;
2212                 }
2213                 if( !ob_end_clean() ) {
2214                         // Could not remove output buffer handler; abort now
2215                         // to avoid getting in some kind of infinite loop.
2216                         break;
2217                 }
2218                 if( $resetGzipEncoding ) {
2219                         if( $status['name'] == 'ob_gzhandler' ) {
2220                                 // Reset the 'Content-Encoding' field set by this handler
2221                                 // so we can start fresh.
2222                                 header_remove( 'Content-Encoding' );
2223                                 break;
2224                         }
2225                 }
2226         }
2227 }
2228
2229 /**
2230  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2231  *
2232  * Clear away output buffers, but keep the Content-Encoding header
2233  * produced by ob_gzhandler, if any.
2234  *
2235  * This should be used for HTTP 304 responses, where you need to
2236  * preserve the Content-Encoding header of the real result, but
2237  * also need to suppress the output of ob_gzhandler to keep to spec
2238  * and avoid breaking Firefox in rare cases where the headers and
2239  * body are broken over two packets.
2240  */
2241 function wfClearOutputBuffers() {
2242         wfResetOutputBuffers( false );
2243 }
2244
2245 /**
2246  * Converts an Accept-* header into an array mapping string values to quality
2247  * factors
2248  *
2249  * @param $accept String
2250  * @param string $def default
2251  * @return Array
2252  */
2253 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2254         # No arg means accept anything (per HTTP spec)
2255         if( !$accept ) {
2256                 return array( $def => 1.0 );
2257         }
2258
2259         $prefs = array();
2260
2261         $parts = explode( ',', $accept );
2262
2263         foreach( $parts as $part ) {
2264                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2265                 $values = explode( ';', trim( $part ) );
2266                 $match = array();
2267                 if ( count( $values ) == 1 ) {
2268                         $prefs[$values[0]] = 1.0;
2269                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2270                         $prefs[$values[0]] = floatval( $match[1] );
2271                 }
2272         }
2273
2274         return $prefs;
2275 }
2276
2277 /**
2278  * Checks if a given MIME type matches any of the keys in the given
2279  * array. Basic wildcards are accepted in the array keys.
2280  *
2281  * Returns the matching MIME type (or wildcard) if a match, otherwise
2282  * NULL if no match.
2283  *
2284  * @param $type String
2285  * @param $avail Array
2286  * @return string
2287  * @private
2288  */
2289 function mimeTypeMatch( $type, $avail ) {
2290         if( array_key_exists( $type, $avail ) ) {
2291                 return $type;
2292         } else {
2293                 $parts = explode( '/', $type );
2294                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2295                         return $parts[0] . '/*';
2296                 } elseif( array_key_exists( '*/*', $avail ) ) {
2297                         return '*/*';
2298                 } else {
2299                         return null;
2300                 }
2301         }
2302 }
2303
2304 /**
2305  * Returns the 'best' match between a client's requested internet media types
2306  * and the server's list of available types. Each list should be an associative
2307  * array of type to preference (preference is a float between 0.0 and 1.0).
2308  * Wildcards in the types are acceptable.
2309  *
2310  * @param array $cprefs client's acceptable type list
2311  * @param array $sprefs server's offered types
2312  * @return string
2313  *
2314  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2315  * XXX: generalize to negotiate other stuff
2316  */
2317 function wfNegotiateType( $cprefs, $sprefs ) {
2318         $combine = array();
2319
2320         foreach( array_keys( $sprefs ) as $type ) {
2321                 $parts = explode( '/', $type );
2322                 if( $parts[1] != '*' ) {
2323                         $ckey = mimeTypeMatch( $type, $cprefs );
2324                         if( $ckey ) {
2325                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2326                         }
2327                 }
2328         }
2329
2330         foreach( array_keys( $cprefs ) as $type ) {
2331                 $parts = explode( '/', $type );
2332                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2333                         $skey = mimeTypeMatch( $type, $sprefs );
2334                         if( $skey ) {
2335                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2336                         }
2337                 }
2338         }
2339
2340         $bestq = 0;
2341         $besttype = null;
2342
2343         foreach( array_keys( $combine ) as $type ) {
2344                 if( $combine[$type] > $bestq ) {
2345                         $besttype = $type;
2346                         $bestq = $combine[$type];
2347                 }
2348         }
2349
2350         return $besttype;
2351 }
2352
2353 /**
2354  * Reference-counted warning suppression
2355  *
2356  * @param $end Bool
2357  */
2358 function wfSuppressWarnings( $end = false ) {
2359         static $suppressCount = 0;
2360         static $originalLevel = false;
2361
2362         if ( $end ) {
2363                 if ( $suppressCount ) {
2364                         --$suppressCount;
2365                         if ( !$suppressCount ) {
2366                                 error_reporting( $originalLevel );
2367                         }
2368                 }
2369         } else {
2370                 if ( !$suppressCount ) {
2371                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT ) );
2372                 }
2373                 ++$suppressCount;
2374         }
2375 }
2376
2377 /**
2378  * Restore error level to previous value
2379  */
2380 function wfRestoreWarnings() {
2381         wfSuppressWarnings( true );
2382 }
2383
2384 # Autodetect, convert and provide timestamps of various types
2385
2386 /**
2387  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2388  */
2389 define( 'TS_UNIX', 0 );
2390
2391 /**
2392  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2393  */
2394 define( 'TS_MW', 1 );
2395
2396 /**
2397  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2398  */
2399 define( 'TS_DB', 2 );
2400
2401 /**
2402  * RFC 2822 format, for E-mail and HTTP headers
2403  */
2404 define( 'TS_RFC2822', 3 );
2405
2406 /**
2407  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2408  *
2409  * This is used by Special:Export
2410  */
2411 define( 'TS_ISO_8601', 4 );
2412
2413 /**
2414  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2415  *
2416  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2417  *       DateTime tag and page 36 for the DateTimeOriginal and
2418  *       DateTimeDigitized tags.
2419  */
2420 define( 'TS_EXIF', 5 );
2421
2422 /**
2423  * Oracle format time.
2424  */
2425 define( 'TS_ORACLE', 6 );
2426
2427 /**
2428  * Postgres format time.
2429  */
2430 define( 'TS_POSTGRES', 7 );
2431
2432 /**
2433  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2434  */
2435 define( 'TS_ISO_8601_BASIC', 9 );
2436
2437 /**
2438  * Get a timestamp string in one of various formats
2439  *
2440  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2441  *                    function will autodetect which format is supplied and act
2442  *                    accordingly.
2443  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2444  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2445  */
2446 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2447         try {
2448                 $timestamp = new MWTimestamp( $ts );
2449                 return $timestamp->getTimestamp( $outputtype );
2450         } catch( TimestampException $e ) {
2451                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2452                 return false;
2453         }
2454 }
2455
2456 /**
2457  * Return a formatted timestamp, or null if input is null.
2458  * For dealing with nullable timestamp columns in the database.
2459  *
2460  * @param $outputtype Integer
2461  * @param $ts String
2462  * @return String
2463  */
2464 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2465         if( is_null( $ts ) ) {
2466                 return null;
2467         } else {
2468                 return wfTimestamp( $outputtype, $ts );
2469         }
2470 }
2471
2472 /**
2473  * Convenience function; returns MediaWiki timestamp for the present time.
2474  *
2475  * @return string
2476  */
2477 function wfTimestampNow() {
2478         # return NOW
2479         return wfTimestamp( TS_MW, time() );
2480 }
2481
2482 /**
2483  * Check if the operating system is Windows
2484  *
2485  * @return Bool: true if it's Windows, False otherwise.
2486  */
2487 function wfIsWindows() {
2488         static $isWindows = null;
2489         if ( $isWindows === null ) {
2490                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2491         }
2492         return $isWindows;
2493 }
2494
2495 /**
2496  * Check if we are running under HipHop
2497  *
2498  * @return Bool
2499  */
2500 function wfIsHipHop() {
2501         return function_exists( 'hphp_thread_set_warmup_enabled' );
2502 }
2503
2504 /**
2505  * Swap two variables
2506  *
2507  * @param $x Mixed
2508  * @param $y Mixed
2509  */
2510 function swap( &$x, &$y ) {
2511         $z = $x;
2512         $x = $y;
2513         $y = $z;
2514 }
2515
2516 /**
2517  * Tries to get the system directory for temporary files. First
2518  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2519  * environment variables are then checked in sequence, and if none are
2520  * set try sys_get_temp_dir().
2521  *
2522  * NOTE: When possible, use instead the tmpfile() function to create
2523  * temporary files to avoid race conditions on file creation, etc.
2524  *
2525  * @return String
2526  */
2527 function wfTempDir() {
2528         global $wgTmpDirectory;
2529
2530         if ( $wgTmpDirectory !== false ) {
2531                 return $wgTmpDirectory;
2532         }
2533
2534         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2535
2536         foreach( $tmpDir as $tmp ) {
2537                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2538                         return $tmp;
2539                 }
2540         }
2541         return sys_get_temp_dir();
2542 }
2543
2544 /**
2545  * Make directory, and make all parent directories if they don't exist
2546  *
2547  * @param string $dir full path to directory to create
2548  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2549  * @param string $caller optional caller param for debugging.
2550  * @throws MWException
2551  * @return bool
2552  */
2553 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2554         global $wgDirectoryMode;
2555
2556         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2557                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2558         }
2559
2560         if ( !is_null( $caller ) ) {
2561                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2562         }
2563
2564         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2565                 return true;
2566         }
2567
2568         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2569
2570         if ( is_null( $mode ) ) {
2571                 $mode = $wgDirectoryMode;
2572         }
2573
2574         // Turn off the normal warning, we're doing our own below
2575         wfSuppressWarnings();
2576         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2577         wfRestoreWarnings();
2578
2579         if( !$ok ) {
2580                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2581                 trigger_error( sprintf( "%s: failed to mkdir \"%s\" mode 0%o", __FUNCTION__, $dir, $mode ),
2582                         E_USER_WARNING );
2583         }
2584         return $ok;
2585 }
2586
2587 /**
2588  * Remove a directory and all its content.
2589  * Does not hide error.
2590  */
2591 function wfRecursiveRemoveDir( $dir ) {
2592         wfDebug( __FUNCTION__ . "( $dir )\n" );
2593         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2594         if ( is_dir( $dir ) ) {
2595                 $objects = scandir( $dir );
2596                 foreach ( $objects as $object ) {
2597                         if ( $object != "." && $object != ".." ) {
2598                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2599                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2600                                 } else {
2601                                         unlink( $dir . '/' . $object );
2602                                 }
2603                         }
2604                 }
2605                 reset( $objects );
2606                 rmdir( $dir );
2607         }
2608 }
2609
2610 /**
2611  * @param $nr Mixed: the number to format
2612  * @param $acc Integer: the number of digits after the decimal point, default 2
2613  * @param $round Boolean: whether or not to round the value, default true
2614  * @return float
2615  */
2616 function wfPercent( $nr, $acc = 2, $round = true ) {
2617         $ret = sprintf( "%.${acc}f", $nr );
2618         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2619 }
2620
2621 /**
2622  * Find out whether or not a mixed variable exists in a string
2623  *
2624  * @deprecated Just use str(i)pos
2625  * @param $needle String
2626  * @param $str String
2627  * @param $insensitive Boolean
2628  * @return Boolean
2629  */
2630 function in_string( $needle, $str, $insensitive = false ) {
2631         wfDeprecated( __METHOD__, '1.21' );
2632         $func = 'strpos';
2633         if( $insensitive ) $func = 'stripos';
2634
2635         return $func( $str, $needle ) !== false;
2636 }
2637
2638 /**
2639  * Safety wrapper around ini_get() for boolean settings.
2640  * The values returned from ini_get() are pre-normalized for settings
2641  * set via php.ini or php_flag/php_admin_flag... but *not*
2642  * for those set via php_value/php_admin_value.
2643  *
2644  * It's fairly common for people to use php_value instead of php_flag,
2645  * which can leave you with an 'off' setting giving a false positive
2646  * for code that just takes the ini_get() return value as a boolean.
2647  *
2648  * To make things extra interesting, setting via php_value accepts
2649  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2650  * Unrecognized values go false... again opposite PHP's own coercion
2651  * from string to bool.
2652  *
2653  * Luckily, 'properly' set settings will always come back as '0' or '1',
2654  * so we only have to worry about them and the 'improper' settings.
2655  *
2656  * I frickin' hate PHP... :P
2657  *
2658  * @param $setting String
2659  * @return Bool
2660  */
2661 function wfIniGetBool( $setting ) {
2662         $val = ini_get( $setting );
2663         // 'on' and 'true' can't have whitespace around them, but '1' can.
2664         return strtolower( $val ) == 'on'
2665                 || strtolower( $val ) == 'true'
2666                 || strtolower( $val ) == 'yes'
2667                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2668 }
2669
2670 /**
2671  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2672  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2673  *
2674  * @param string $extension A PHP extension. The file suffix (.so or .dll)
2675  *                          should be omitted
2676  * @param string $fileName Name of the library, if not $extension.suffix
2677  * @return Bool - Whether or not the extension is loaded
2678  */
2679 function wfDl( $extension, $fileName = null ) {
2680         if( extension_loaded( $extension ) ) {
2681                 return true;
2682         }
2683
2684         $canDl = false;
2685         if( PHP_SAPI == 'cli' || PHP_SAPI == 'cgi' || PHP_SAPI == 'embed' ) {
2686                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2687                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2688         }
2689
2690         if( $canDl ) {
2691                 $fileName = $fileName ? $fileName : $extension;
2692                 if( wfIsWindows() ) {
2693                         $fileName = 'php_' . $fileName;
2694                 }
2695                 wfSuppressWarnings();
2696                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2697                 wfRestoreWarnings();
2698         }
2699         return extension_loaded( $extension );
2700 }
2701
2702 /**
2703  * Windows-compatible version of escapeshellarg()
2704  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2705  * function puts single quotes in regardless of OS.
2706  *
2707  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2708  * earlier distro releases of PHP)
2709  *
2710  * @param varargs
2711  * @return String
2712  */
2713 function wfEscapeShellArg() {
2714         wfInitShellLocale();
2715
2716         $args = func_get_args();
2717         $first = true;
2718         $retVal = '';
2719         foreach ( $args as $arg ) {
2720                 if ( !$first ) {
2721                         $retVal .= ' ';
2722                 } else {
2723                         $first = false;
2724                 }
2725
2726                 if ( wfIsWindows() ) {
2727                         // Escaping for an MSVC-style command line parser and CMD.EXE
2728                         // Refs:
2729                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2730                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2731                         //  * Bug #13518
2732                         //  * CR r63214
2733                         // Double the backslashes before any double quotes. Escape the double quotes.
2734                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2735                         $arg = '';
2736                         $iteration = 0;
2737                         foreach ( $tokens as $token ) {
2738                                 if ( $iteration % 2 == 1 ) {
2739                                         // Delimiter, a double quote preceded by zero or more slashes
2740                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2741                                 } elseif ( $iteration % 4 == 2 ) {
2742                                         // ^ in $token will be outside quotes, need to be escaped
2743                                         $arg .= str_replace( '^', '^^', $token );
2744                                 } else { // $iteration % 4 == 0
2745                                         // ^ in $token will appear inside double quotes, so leave as is
2746                                         $arg .= $token;
2747                                 }
2748                                 $iteration++;
2749                         }
2750                         // Double the backslashes before the end of the string, because
2751                         // we will soon add a quote
2752                         $m = array();
2753                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2754                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2755                         }
2756
2757                         // Add surrounding quotes
2758                         $retVal .= '"' . $arg . '"';
2759                 } else {
2760                         $retVal .= escapeshellarg( $arg );
2761                 }
2762         }
2763         return $retVal;
2764 }
2765
2766 /**
2767  * Execute a shell command, with time and memory limits mirrored from the PHP
2768  * configuration if supported.
2769  * @param string $cmd Command line, properly escaped for shell.
2770  * @param &$retval null|Mixed optional, will receive the program's exit code.
2771  *                 (non-zero is usually failure)
2772  * @param array $environ optional environment variables which should be
2773  *                 added to the executed command environment.
2774  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2775  *                 this overwrites the global wgShellMax* limits.
2776  * @return string collected stdout as a string (trailing newlines stripped)
2777  */
2778 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2779         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2780                 $wgMaxShellWallClockTime, $wgShellCgroup;
2781
2782         static $disabled;
2783         if ( is_null( $disabled ) ) {
2784                 $disabled = false;
2785                 if( wfIniGetBool( 'safe_mode' ) ) {
2786                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2787                         $disabled = 'safemode';
2788                 } else {
2789                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2790                         $functions = array_map( 'trim', $functions );
2791                         $functions = array_map( 'strtolower', $functions );
2792                         if ( in_array( 'passthru', $functions ) ) {
2793                                 wfDebug( "passthru is in disabled_functions\n" );
2794                                 $disabled = 'passthru';
2795                         }
2796                 }
2797         }
2798         if ( $disabled ) {
2799                 $retval = 1;
2800                 return $disabled == 'safemode' ?
2801                         'Unable to run external programs in safe mode.' :
2802                         'Unable to run external programs, passthru() is disabled.';
2803         }
2804
2805         wfInitShellLocale();
2806
2807         $envcmd = '';
2808         foreach( $environ as $k => $v ) {
2809                 if ( wfIsWindows() ) {
2810                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2811                          * appear in the environment variable, so we must use carat escaping as documented in
2812                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2813                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2814                          * are listed there but doesn't appear to need it.
2815                          */
2816                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2817                 } else {
2818                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2819                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2820                          */
2821                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2822                 }
2823         }
2824         $cmd = $envcmd . $cmd;
2825
2826         if ( php_uname( 's' ) == 'Linux' ) {
2827                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2828                 if ( isset( $limits['walltime'] ) ) {
2829                         $wallTime = intval( $limits['walltime'] );
2830                 } elseif ( isset( $limits['time'] ) ) {
2831                         $wallTime = $time;
2832                 } else {
2833                         $wallTime = intval( $wgMaxShellWallClockTime );
2834                 }
2835                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2836                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2837
2838                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2839                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2840                                 escapeshellarg( $cmd ) . ' ' .
2841                                 escapeshellarg(
2842                                         "MW_CPU_LIMIT=$time; " .
2843                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2844                                         "MW_MEM_LIMIT=$mem; " .
2845                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2846                                         "MW_WALL_CLOCK_LIMIT=$wallTime"
2847                                 );
2848                 }
2849         }
2850         wfDebug( "wfShellExec: $cmd\n" );
2851
2852         $retval = 1; // error by default?
2853         ob_start();
2854         passthru( $cmd, $retval );
2855         $output = ob_get_contents();
2856         ob_end_clean();
2857
2858         if ( $retval == 127 ) {
2859                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2860         }
2861         return $output;
2862 }
2863
2864 /**
2865  * Workaround for http://bugs.php.net/bug.php?id=45132
2866  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2867  */
2868 function wfInitShellLocale() {
2869         static $done = false;
2870         if ( $done ) {
2871                 return;
2872         }
2873         $done = true;
2874         global $wgShellLocale;
2875         if ( !wfIniGetBool( 'safe_mode' ) ) {
2876                 putenv( "LC_CTYPE=$wgShellLocale" );
2877                 setlocale( LC_CTYPE, $wgShellLocale );
2878         }
2879 }
2880
2881 /**
2882  * Alias to wfShellWikiCmd()
2883  * @see wfShellWikiCmd()
2884  */
2885 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2886         return wfShellWikiCmd( $script, $parameters, $options );
2887 }
2888
2889 /**
2890  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2891  * Note that $parameters should be a flat array and an option with an argument
2892  * should consist of two consecutive items in the array (do not use "--option value").
2893  * @param string $script MediaWiki cli script path
2894  * @param array $parameters Arguments and options to the script
2895  * @param array $options Associative array of options:
2896  *              'php': The path to the php executable
2897  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2898  * @return Array
2899  */
2900 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2901         global $wgPhpCli;
2902         // Give site config file a chance to run the script in a wrapper.
2903         // The caller may likely want to call wfBasename() on $script.
2904         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2905         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2906         if ( isset( $options['wrapper'] ) ) {
2907                 $cmd[] = $options['wrapper'];
2908         }
2909         $cmd[] = $script;
2910         // Escape each parameter for shell
2911         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2912 }
2913
2914 /**
2915  * wfMerge attempts to merge differences between three texts.
2916  * Returns true for a clean merge and false for failure or a conflict.
2917  *
2918  * @param $old String
2919  * @param $mine String
2920  * @param $yours String
2921  * @param $result String
2922  * @return Bool
2923  */
2924 function wfMerge( $old, $mine, $yours, &$result ) {
2925         global $wgDiff3;
2926
2927         # This check may also protect against code injection in
2928         # case of broken installations.
2929         wfSuppressWarnings();
2930         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2931         wfRestoreWarnings();
2932
2933         if( !$haveDiff3 ) {
2934                 wfDebug( "diff3 not found\n" );
2935                 return false;
2936         }
2937
2938         # Make temporary files
2939         $td = wfTempDir();
2940         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2941         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2942         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2943
2944         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2945         #       a newline character. To avoid this, we normalize the trailing whitespace before
2946         #       creating the diff.
2947
2948         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2949         fclose( $oldtextFile );
2950         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2951         fclose( $mytextFile );
2952         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2953         fclose( $yourtextFile );
2954
2955         # Check for a conflict
2956         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
2957                 wfEscapeShellArg( $mytextName ) . ' ' .
2958                 wfEscapeShellArg( $oldtextName ) . ' ' .
2959                 wfEscapeShellArg( $yourtextName );
2960         $handle = popen( $cmd, 'r' );
2961
2962         if( fgets( $handle, 1024 ) ) {
2963                 $conflict = true;
2964         } else {
2965                 $conflict = false;
2966         }
2967         pclose( $handle );
2968
2969         # Merge differences
2970         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
2971                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2972         $handle = popen( $cmd, 'r' );
2973         $result = '';
2974         do {
2975                 $data = fread( $handle, 8192 );
2976                 if ( strlen( $data ) == 0 ) {
2977                         break;
2978                 }
2979                 $result .= $data;
2980         } while ( true );
2981         pclose( $handle );
2982         unlink( $mytextName );
2983         unlink( $oldtextName );
2984         unlink( $yourtextName );
2985
2986         if ( $result === '' && $old !== '' && !$conflict ) {
2987                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2988                 $conflict = true;
2989         }
2990         return !$conflict;
2991 }
2992
2993 /**
2994  * Returns unified plain-text diff of two texts.
2995  * Useful for machine processing of diffs.
2996  *
2997  * @param string $before the text before the changes.
2998  * @param string $after the text after the changes.
2999  * @param string $params command-line options for the diff command.
3000  * @return String: unified diff of $before and $after
3001  */
3002 function wfDiff( $before, $after, $params = '-u' ) {
3003         if ( $before == $after ) {
3004                 return '';
3005         }
3006
3007         global $wgDiff;
3008         wfSuppressWarnings();
3009         $haveDiff = $wgDiff && file_exists( $wgDiff );
3010         wfRestoreWarnings();
3011
3012         # This check may also protect against code injection in
3013         # case of broken installations.
3014         if( !$haveDiff ) {
3015                 wfDebug( "diff executable not found\n" );
3016                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3017                 $format = new UnifiedDiffFormatter();
3018                 return $format->format( $diffs );
3019         }
3020
3021         # Make temporary files
3022         $td = wfTempDir();
3023         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3024         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3025
3026         fwrite( $oldtextFile, $before );
3027         fclose( $oldtextFile );
3028         fwrite( $newtextFile, $after );
3029         fclose( $newtextFile );
3030
3031         // Get the diff of the two files
3032         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3033
3034         $h = popen( $cmd, 'r' );
3035
3036         $diff = '';
3037
3038         do {
3039                 $data = fread( $h, 8192 );
3040                 if ( strlen( $data ) == 0 ) {
3041                         break;
3042                 }
3043                 $diff .= $data;
3044         } while ( true );
3045
3046         // Clean up
3047         pclose( $h );
3048         unlink( $oldtextName );
3049         unlink( $newtextName );
3050
3051         // Kill the --- and +++ lines. They're not useful.
3052         $diff_lines = explode( "\n", $diff );
3053         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3054                 unset( $diff_lines[0] );
3055         }
3056         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3057                 unset( $diff_lines[1] );
3058         }
3059
3060         $diff = implode( "\n", $diff_lines );
3061
3062         return $diff;
3063 }
3064
3065 /**
3066  * This function works like "use VERSION" in Perl, the program will die with a
3067  * backtrace if the current version of PHP is less than the version provided
3068  *
3069  * This is useful for extensions which due to their nature are not kept in sync
3070  * with releases, and might depend on other versions of PHP than the main code
3071  *
3072  * Note: PHP might die due to parsing errors in some cases before it ever
3073  *       manages to call this function, such is life
3074  *
3075  * @see perldoc -f use
3076  *
3077  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3078  *                 a float
3079  * @throws MWException
3080  */
3081 function wfUsePHP( $req_ver ) {
3082         $php_ver = PHP_VERSION;
3083
3084         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3085                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3086         }
3087 }
3088
3089 /**
3090  * This function works like "use VERSION" in Perl except it checks the version
3091  * of MediaWiki, the program will die with a backtrace if the current version
3092  * of MediaWiki is less than the version provided.
3093  *
3094  * This is useful for extensions which due to their nature are not kept in sync
3095  * with releases
3096  *
3097  * @see perldoc -f use
3098  *
3099  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3100  *                 a float
3101  * @throws MWException
3102  */
3103 function wfUseMW( $req_ver ) {
3104         global $wgVersion;
3105
3106         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3107                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3108         }
3109 }
3110
3111 /**
3112  * Return the final portion of a pathname.
3113  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3114  * http://bugs.php.net/bug.php?id=33898
3115  *
3116  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3117  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3118  *
3119  * @param $path String
3120  * @param string $suffix to remove if present
3121  * @return String
3122  */
3123 function wfBaseName( $path, $suffix = '' ) {
3124         $encSuffix = ( $suffix == '' )
3125                 ? ''
3126                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3127         $matches = array();
3128         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3129                 return $matches[1];
3130         } else {
3131                 return '';
3132         }
3133 }
3134
3135 /**
3136  * Generate a relative path name to the given file.
3137  * May explode on non-matching case-insensitive paths,
3138  * funky symlinks, etc.
3139  *
3140  * @param string $path absolute destination path including target filename
3141  * @param string $from Absolute source path, directory only
3142  * @return String
3143  */
3144 function wfRelativePath( $path, $from ) {
3145         // Normalize mixed input on Windows...
3146         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3147         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3148
3149         // Trim trailing slashes -- fix for drive root
3150         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3151         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3152
3153         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3154         $against = explode( DIRECTORY_SEPARATOR, $from );
3155
3156         if( $pieces[0] !== $against[0] ) {
3157                 // Non-matching Windows drive letters?
3158                 // Return a full path.
3159                 return $path;
3160         }
3161
3162         // Trim off common prefix
3163         while( count( $pieces ) && count( $against )
3164                 && $pieces[0] == $against[0] ) {
3165                 array_shift( $pieces );
3166                 array_shift( $against );
3167         }
3168
3169         // relative dots to bump us to the parent
3170         while( count( $against ) ) {
3171                 array_unshift( $pieces, '..' );
3172                 array_shift( $against );
3173         }
3174
3175         array_push( $pieces, wfBaseName( $path ) );
3176
3177         return implode( DIRECTORY_SEPARATOR, $pieces );
3178 }
3179
3180 /**
3181  * Do any deferred updates and clear the list
3182  *
3183  * @deprecated since 1.19
3184  * @see DeferredUpdates::doUpdate()
3185  * @param $commit string
3186  */
3187 function wfDoUpdates( $commit = '' ) {
3188         wfDeprecated( __METHOD__, '1.19' );
3189         DeferredUpdates::doUpdates( $commit );
3190 }
3191
3192 /**
3193  * Convert an arbitrarily-long digit string from one numeric base
3194  * to another, optionally zero-padding to a minimum column width.
3195  *
3196  * Supports base 2 through 36; digit values 10-36 are represented
3197  * as lowercase letters a-z. Input is case-insensitive.
3198  *
3199  * @param string $input Input number
3200  * @param int $sourceBase Base of the input number
3201  * @param int $destBase Desired base of the output
3202  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3203  * @param bool $lowercase Whether to output in lowercase or uppercase
3204  * @param string $engine Either "gmp", "bcmath", or "php"
3205  * @return string|bool The output number as a string, or false on error
3206  */
3207 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true, $engine = 'auto' ) {
3208         $input = (string)$input;
3209         if(
3210                 $sourceBase < 2 ||
3211                 $sourceBase > 36 ||
3212                 $destBase < 2 ||
3213                 $destBase > 36 ||
3214                 $sourceBase != (int) $sourceBase ||
3215                 $destBase != (int) $destBase ||
3216                 $pad != (int) $pad ||
3217                 !preg_match( "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i", $input )
3218         ) {
3219                 return false;
3220         }
3221
3222         static $baseChars = array (
3223                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3224                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3225                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3226                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3227                 34 => 'y', 35 => 'z',
3228
3229                 '0' => 0,  '1' => 1,  '2' => 2,  '3' => 3,  '4' => 4,  '5' => 5,
3230                 '6' => 6,  '7' => 7,  '8' => 8,  '9' => 9,  'a' => 10, 'b' => 11,
3231                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3232                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3233                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3234                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3235         );
3236
3237         if( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3238                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3239         } elseif( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3240                 $decimal = '0';
3241                 foreach( str_split( strtolower( $input ) ) as $char ) {
3242                         $decimal = bcmul( $decimal, $sourceBase );
3243                         $decimal = bcadd( $decimal, $baseChars[$char] );
3244                 }
3245
3246                 for( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3247                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3248                 }
3249
3250                 $result = strrev( $result );
3251         } else {
3252                 $inDigits = array();
3253                 foreach( str_split( strtolower( $input ) ) as $char ) {
3254                         $inDigits[] = $baseChars[$char];
3255                 }
3256
3257                 // Iterate over the input, modulo-ing out an output digit
3258                 // at a time until input is gone.
3259                 $result = '';
3260                 while( $inDigits ) {
3261                         $work = 0;
3262                         $workDigits = array();
3263
3264                         // Long division...
3265                         foreach( $inDigits as $digit ) {
3266                                 $work *= $sourceBase;
3267                                 $work += $digit;
3268
3269                                 if( $workDigits || $work >= $destBase ) {
3270                                         $workDigits[] = (int) ( $work / $destBase );
3271                                 }
3272                                 $work %= $destBase;
3273                         }
3274
3275                         // All that division leaves us with a remainder,
3276                         // which is conveniently our next output digit.
3277                         $result .= $baseChars[$work];
3278
3279                         // And we continue!
3280                         $inDigits = $workDigits;
3281                 }
3282
3283                 $result = strrev( $result );
3284         }
3285
3286         if( !$lowercase ) {
3287                 $result = strtoupper( $result );
3288         }
3289
3290         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3291 }
3292
3293 /**
3294  * Create an object with a given name and an array of construct parameters
3295  *
3296  * @param $name String
3297  * @param array $p parameters
3298  * @return object
3299  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3300  */
3301 function wfCreateObject( $name, $p ) {
3302         wfDeprecated( __FUNCTION__, '1.18' );
3303         return MWFunction::newObj( $name, $p );
3304 }
3305
3306 /**
3307  * @return bool
3308  */
3309 function wfHttpOnlySafe() {
3310         global $wgHttpOnlyBlacklist;
3311
3312         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3313                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3314                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3315                                 return false;
3316                         }
3317                 }
3318         }
3319
3320         return true;
3321 }
3322
3323 /**
3324  * Check if there is sufficient entropy in php's built-in session generation
3325  * @return bool true = there is sufficient entropy
3326  */
3327 function wfCheckEntropy() {
3328         return (
3329                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3330                         || ini_get( 'session.entropy_file' )
3331                 )
3332                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3333 }
3334
3335 /**
3336  * Override session_id before session startup if php's built-in
3337  * session generation code is not secure.
3338  */
3339 function wfFixSessionID() {
3340         // If the cookie or session id is already set we already have a session and should abort
3341         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3342                 return;
3343         }
3344
3345         // PHP's built-in session entropy is enabled if:
3346         // - entropy_file is set or you're on Windows with php 5.3.3+
3347         // - AND entropy_length is > 0
3348         // We treat it as disabled if it doesn't have an entropy length of at least 32
3349         $entropyEnabled = wfCheckEntropy();
3350
3351         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3352         if ( !$entropyEnabled ) {
3353                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3354                 session_id( MWCryptRand::generateHex( 32 ) );
3355         }
3356 }
3357
3358 /**
3359  * Initialise php session
3360  *
3361  * @param $sessionId Bool
3362  */
3363 function wfSetupSession( $sessionId = false ) {
3364         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3365                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3366         if( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3367                 ObjectCacheSessionHandler::install();
3368         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3369                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3370                 # hasn't already been set to the desired value (that causes errors)
3371                 ini_set( 'session.save_handler', $wgSessionHandler );
3372         }
3373         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3374         wfDebugLog( 'cookie',
3375                 'session_set_cookie_params: "' . implode( '", "',
3376                         array(
3377                                 0,
3378                                 $wgCookiePath,
3379                                 $wgCookieDomain,
3380                                 $wgCookieSecure,
3381                                 $httpOnlySafe ) ) . '"' );
3382         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3383         session_cache_limiter( 'private, must-revalidate' );
3384         if ( $sessionId ) {
3385                 session_id( $sessionId );
3386         } else {
3387                 wfFixSessionID();
3388         }
3389         wfSuppressWarnings();
3390         session_start();
3391         wfRestoreWarnings();
3392 }
3393
3394 /**
3395  * Get an object from the precompiled serialized directory
3396  *
3397  * @param $name String
3398  * @return Mixed: the variable on success, false on failure
3399  */
3400 function wfGetPrecompiledData( $name ) {
3401         global $IP;
3402
3403         $file = "$IP/serialized/$name";
3404         if ( file_exists( $file ) ) {
3405                 $blob = file_get_contents( $file );
3406                 if ( $blob ) {
3407                         return unserialize( $blob );
3408                 }
3409         }
3410         return false;
3411 }
3412
3413 /**
3414  * Get a cache key
3415  *
3416  * @param varargs
3417  * @return String
3418  */
3419 function wfMemcKey( /*... */ ) {
3420         global $wgCachePrefix;
3421         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3422         $args = func_get_args();
3423         $key = $prefix . ':' . implode( ':', $args );
3424         $key = str_replace( ' ', '_', $key );
3425         return $key;
3426 }
3427
3428 /**
3429  * Get a cache key for a foreign DB
3430  *
3431  * @param $db String
3432  * @param $prefix String
3433  * @param varargs String
3434  * @return String
3435  */
3436 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3437         $args = array_slice( func_get_args(), 2 );
3438         if ( $prefix ) {
3439                 $key = "$db-$prefix:" . implode( ':', $args );
3440         } else {
3441                 $key = $db . ':' . implode( ':', $args );
3442         }
3443         return $key;
3444 }
3445
3446 /**
3447  * Get an ASCII string identifying this wiki
3448  * This is used as a prefix in memcached keys
3449  *
3450  * @return String
3451  */
3452 function wfWikiID() {
3453         global $wgDBprefix, $wgDBname;
3454         if ( $wgDBprefix ) {
3455                 return "$wgDBname-$wgDBprefix";
3456         } else {
3457                 return $wgDBname;
3458         }
3459 }
3460
3461 /**
3462  * Split a wiki ID into DB name and table prefix
3463  *
3464  * @param $wiki String
3465  *
3466  * @return array
3467  */
3468 function wfSplitWikiID( $wiki ) {
3469         $bits = explode( '-', $wiki, 2 );
3470         if ( count( $bits ) < 2 ) {
3471                 $bits[] = '';
3472         }
3473         return $bits;
3474 }
3475
3476 /**
3477  * Get a Database object.
3478  *
3479  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3480  *            master (for write queries), DB_SLAVE for potentially lagged read
3481  *            queries, or an integer >= 0 for a particular server.
3482  *
3483  * @param $groups Mixed: query groups. An array of group names that this query
3484  *                belongs to. May contain a single string if the query is only
3485  *                in one group.
3486  *
3487  * @param string $wiki the wiki ID, or false for the current wiki
3488  *
3489  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3490  * will always return the same object, unless the underlying connection or load
3491  * balancer is manually destroyed.
3492  *
3493  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3494  * updater to ensure that a proper database is being updated.
3495  *
3496  * @return DatabaseBase
3497  */
3498 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3499         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3500 }
3501
3502 /**
3503  * Get a load balancer object.
3504  *
3505  * @param string $wiki wiki ID, or false for the current wiki
3506  * @return LoadBalancer
3507  */
3508 function wfGetLB( $wiki = false ) {
3509         return wfGetLBFactory()->getMainLB( $wiki );
3510 }
3511
3512 /**
3513  * Get the load balancer factory object
3514  *
3515  * @return LBFactory
3516  */
3517 function &wfGetLBFactory() {
3518         return LBFactory::singleton();
3519 }
3520
3521 /**
3522  * Find a file.
3523  * Shortcut for RepoGroup::singleton()->findFile()
3524  *
3525  * @param string $title or Title object
3526  * @param array $options Associative array of options:
3527  *     time:           requested time for an archived image, or false for the
3528  *                     current version. An image object will be returned which was
3529  *                     created at the specified time.
3530  *
3531  *     ignoreRedirect: If true, do not follow file redirects
3532  *
3533  *     private:        If true, return restricted (deleted) files if the current
3534  *                     user is allowed to view them. Otherwise, such files will not
3535  *                     be found.
3536  *
3537  *     bypassCache:    If true, do not use the process-local cache of File objects
3538  *
3539  * @return File, or false if the file does not exist
3540  */
3541 function wfFindFile( $title, $options = array() ) {
3542         return RepoGroup::singleton()->findFile( $title, $options );
3543 }
3544
3545 /**
3546  * Get an object referring to a locally registered file.
3547  * Returns a valid placeholder object if the file does not exist.
3548  *
3549  * @param $title Title|String
3550  * @return LocalFile|null A File, or null if passed an invalid Title
3551  */
3552 function wfLocalFile( $title ) {
3553         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3554 }
3555
3556 /**
3557  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3558  * @deprecated since 1.19
3559  */
3560 function wfStreamFile( $fname, $headers = array() ) {
3561         wfDeprecated( __FUNCTION__, '1.19' );
3562         StreamFile::stream( $fname, $headers );
3563 }
3564
3565 /**
3566  * Should low-performance queries be disabled?
3567  *
3568  * @return Boolean
3569  * @codeCoverageIgnore
3570  */
3571 function wfQueriesMustScale() {
3572         global $wgMiserMode;
3573         return $wgMiserMode
3574                 || ( SiteStats::pages() > 100000
3575                 && SiteStats::edits() > 1000000
3576                 && SiteStats::users() > 10000 );
3577 }
3578
3579 /**
3580  * Get the path to a specified script file, respecting file
3581  * extensions; this is a wrapper around $wgScriptExtension etc.
3582  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3583  *
3584  * @param string $script script filename, sans extension
3585  * @return String
3586  */
3587 function wfScript( $script = 'index' ) {
3588         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3589         if ( $script === 'index' ) {
3590                 return $wgScript;
3591         } else if ( $script === 'load' ) {
3592                 return $wgLoadScript;
3593         } else {
3594                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3595         }
3596 }
3597
3598 /**
3599  * Get the script URL.
3600  *
3601  * @return string script URL
3602  */
3603 function wfGetScriptUrl() {
3604         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3605                 #
3606                 # as it was called, minus the query string.
3607                 #
3608                 # Some sites use Apache rewrite rules to handle subdomains,
3609                 # and have PHP set up in a weird way that causes PHP_SELF
3610                 # to contain the rewritten URL instead of the one that the
3611                 # outside world sees.
3612                 #
3613                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3614                 # provides containing the "before" URL.
3615                 return $_SERVER['SCRIPT_NAME'];
3616         } else {
3617                 return $_SERVER['URL'];
3618         }
3619 }
3620
3621 /**
3622  * Convenience function converts boolean values into "true"
3623  * or "false" (string) values
3624  *
3625  * @param $value Boolean
3626  * @return String
3627  */
3628 function wfBoolToStr( $value ) {
3629         return $value ? 'true' : 'false';
3630 }
3631
3632 /**
3633  * Get a platform-independent path to the null file, e.g. /dev/null
3634  *
3635  * @return string
3636  */
3637 function wfGetNull() {
3638         return wfIsWindows()
3639                 ? 'NUL'
3640                 : '/dev/null';
3641 }
3642
3643 /**
3644  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3645  * and waiting for it to go down, this waits for the slaves to catch up to the
3646  * master position. Use this when updating very large numbers of rows, as
3647  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3648  * a no-op if there are no slaves.
3649  *
3650  * @param $maxLag Integer (deprecated)
3651  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3652  */
3653 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3654         $lb = wfGetLB( $wiki );
3655         // bug 27975 - Don't try to wait for slaves if there are none
3656         // Prevents permission error when getting master position
3657         if ( $lb->getServerCount() > 1 ) {
3658                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3659                 $pos = $dbw->getMasterPos();
3660                 $lb->waitForAll( $pos );
3661         }
3662 }
3663
3664 /**
3665  * Used to be used for outputting text in the installer/updater
3666  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3667  */
3668 function wfOut( $s ) {
3669         wfDeprecated( __FUNCTION__, '1.18' );
3670         global $wgCommandLineMode;
3671         if ( $wgCommandLineMode ) {
3672                 echo $s;
3673         } else {
3674                 echo htmlspecialchars( $s );
3675         }
3676         flush();
3677 }
3678
3679 /**
3680  * Count down from $n to zero on the terminal, with a one-second pause
3681  * between showing each number. For use in command-line scripts.
3682  * @codeCoverageIgnore
3683  * @param $n int
3684  */
3685 function wfCountDown( $n ) {
3686         for ( $i = $n; $i >= 0; $i-- ) {
3687                 if ( $i != $n ) {
3688                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3689                 }
3690                 echo $i;
3691                 flush();
3692                 if ( $i ) {
3693                         sleep( 1 );
3694                 }
3695         }
3696         echo "\n";
3697 }
3698
3699 /**
3700  * Generate a random 32-character hexadecimal token.
3701  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3702  *              characters before hashing.
3703  * @return string
3704  * @codeCoverageIgnore
3705  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pseudo-random strings
3706  * @warning This method is NOT secure. Additionally it has many callers that use it for pseudo-random purposes.
3707  */
3708 function wfGenerateToken( $salt = '' ) {
3709         wfDeprecated( __METHOD__, '1.20' );
3710         $salt = serialize( $salt );
3711         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3712 }
3713
3714 /**
3715  * Replace all invalid characters with -
3716  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3717  * By default, $wgIllegalFileChars = ':'
3718  *
3719  * @param $name Mixed: filename to process
3720  * @return String
3721  */
3722 function wfStripIllegalFilenameChars( $name ) {
3723         global $wgIllegalFileChars;
3724         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3725         $name = wfBaseName( $name );
3726         $name = preg_replace(
3727                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3728                 '-',
3729                 $name
3730         );
3731         return $name;
3732 }
3733
3734 /**
3735  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3736  *
3737  * @return Integer value memory was set to.
3738  */
3739 function wfMemoryLimit() {
3740         global $wgMemoryLimit;
3741         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3742         if( $memlimit != -1 ) {
3743                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3744                 if( $conflimit == -1 ) {
3745                         wfDebug( "Removing PHP's memory limit\n" );
3746                         wfSuppressWarnings();
3747                         ini_set( 'memory_limit', $conflimit );
3748                         wfRestoreWarnings();
3749                         return $conflimit;
3750                 } elseif ( $conflimit > $memlimit ) {
3751                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3752                         wfSuppressWarnings();
3753                         ini_set( 'memory_limit', $conflimit );
3754                         wfRestoreWarnings();
3755                         return $conflimit;
3756                 }
3757         }
3758         return $memlimit;
3759 }
3760
3761 /**
3762  * Converts shorthand byte notation to integer form
3763  *
3764  * @param $string String
3765  * @return Integer
3766  */
3767 function wfShorthandToInteger( $string = '' ) {
3768         $string = trim( $string );
3769         if( $string === '' ) {
3770                 return -1;
3771         }
3772         $last = $string[strlen( $string ) - 1];
3773         $val = intval( $string );
3774         switch( $last ) {
3775                 case 'g':
3776                 case 'G':
3777                         $val *= 1024;
3778                         // break intentionally missing
3779                 case 'm':
3780                 case 'M':
3781                         $val *= 1024;
3782                         // break intentionally missing
3783                 case 'k':
3784                 case 'K':
3785                         $val *= 1024;
3786         }
3787
3788         return $val;
3789 }
3790
3791 /**
3792  * Get the normalised IETF language tag
3793  * See unit test for examples.
3794  *
3795  * @param string $code The language code.
3796  * @return String: The language code which complying with BCP 47 standards.
3797  */
3798 function wfBCP47( $code ) {
3799         $codeSegment = explode( '-', $code );
3800         $codeBCP = array();
3801         foreach ( $codeSegment as $segNo => $seg ) {
3802                 if ( count( $codeSegment ) > 0 ) {
3803                         // when previous segment is x, it is a private segment and should be lc
3804                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3805                                 $codeBCP[$segNo] = strtolower( $seg );
3806                         // ISO 3166 country code
3807                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3808                                 $codeBCP[$segNo] = strtoupper( $seg );
3809                         // ISO 15924 script code
3810                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3811                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3812                         // Use lowercase for other cases
3813                         } else {
3814                                 $codeBCP[$segNo] = strtolower( $seg );
3815                         }
3816                 } else {
3817                 // Use lowercase for single segment
3818                         $codeBCP[$segNo] = strtolower( $seg );
3819                 }
3820         }
3821         $langCode = implode( '-', $codeBCP );
3822         return $langCode;
3823 }
3824
3825 /**
3826  * Get a cache object.
3827  *
3828  * @param $inputType integer Cache type, one the the CACHE_* constants.
3829  * @return BagOStuff
3830  */
3831 function wfGetCache( $inputType ) {
3832         return ObjectCache::getInstance( $inputType );
3833 }
3834
3835 /**
3836  * Get the main cache object
3837  *
3838  * @return BagOStuff
3839  */
3840 function wfGetMainCache() {
3841         global $wgMainCacheType;
3842         return ObjectCache::getInstance( $wgMainCacheType );
3843 }
3844
3845 /**
3846  * Get the cache object used by the message cache
3847  *
3848  * @return BagOStuff
3849  */
3850 function wfGetMessageCacheStorage() {
3851         global $wgMessageCacheType;
3852         return ObjectCache::getInstance( $wgMessageCacheType );
3853 }
3854
3855 /**
3856  * Get the cache object used by the parser cache
3857  *
3858  * @return BagOStuff
3859  */
3860 function wfGetParserCacheStorage() {
3861         global $wgParserCacheType;
3862         return ObjectCache::getInstance( $wgParserCacheType );
3863 }
3864
3865 /**
3866  * Get the cache object used by the language converter
3867  *
3868  * @return BagOStuff
3869  */
3870 function wfGetLangConverterCacheStorage() {
3871         global $wgLanguageConverterCacheType;
3872         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3873 }
3874
3875 /**
3876  * Call hook functions defined in $wgHooks
3877  *
3878  * @param string $event event name
3879  * @param array $args parameters passed to hook functions
3880  * @return Boolean True if no handler aborted the hook
3881  */
3882 function wfRunHooks( $event, $args = array() ) {
3883         return Hooks::run( $event, $args );
3884 }
3885
3886 /**
3887  * Wrapper around php's unpack.
3888  *
3889  * @param string $format The format string (See php's docs)
3890  * @param $data: A binary string of binary data
3891  * @param $length integer or false: The minimum length of $data. This is to
3892  *      prevent reading beyond the end of $data. false to disable the check.
3893  *
3894  * Also be careful when using this function to read unsigned 32 bit integer
3895  * because php might make it negative.
3896  *
3897  * @throws MWException if $data not long enough, or if unpack fails
3898  * @return array Associative array of the extracted data
3899  */
3900 function wfUnpack( $format, $data, $length=false ) {
3901         if ( $length !== false ) {
3902                 $realLen = strlen( $data );
3903                 if ( $realLen < $length ) {
3904                         throw new MWException( "Tried to use wfUnpack on a "
3905                                 . "string of length $realLen, but needed one "
3906                                 . "of at least length $length."
3907                         );
3908                 }
3909         }
3910
3911         wfSuppressWarnings();
3912         $result = unpack( $format, $data );
3913         wfRestoreWarnings();
3914
3915         if ( $result === false ) {
3916                 // If it cannot extract the packed data.
3917                 throw new MWException( "unpack could not unpack binary data" );
3918         }
3919         return $result;
3920 }
3921
3922 /**
3923  * Determine if an image exists on the 'bad image list'.
3924  *
3925  * The format of MediaWiki:Bad_image_list is as follows:
3926  *    * Only list items (lines starting with "*") are considered
3927  *    * The first link on a line must be a link to a bad image
3928  *    * Any subsequent links on the same line are considered to be exceptions,
3929  *      i.e. articles where the image may occur inline.
3930  *
3931  * @param string $name the image name to check
3932  * @param $contextTitle Title|bool the page on which the image occurs, if known
3933  * @param string $blacklist wikitext of a file blacklist
3934  * @return bool
3935  */
3936 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3937         static $badImageCache = null; // based on bad_image_list msg
3938         wfProfileIn( __METHOD__ );
3939
3940         # Handle redirects
3941         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3942         if( $redirectTitle ) {
3943                 $name = $redirectTitle->getDbKey();
3944         }
3945
3946         # Run the extension hook
3947         $bad = false;
3948         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3949                 wfProfileOut( __METHOD__ );
3950                 return $bad;
3951         }
3952
3953         $cacheable = ( $blacklist === null );
3954         if( $cacheable && $badImageCache !== null ) {
3955                 $badImages = $badImageCache;
3956         } else { // cache miss
3957                 if ( $blacklist === null ) {
3958                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3959                 }
3960                 # Build the list now
3961                 $badImages = array();
3962                 $lines = explode( "\n", $blacklist );
3963                 foreach( $lines as $line ) {
3964                         # List items only
3965                         if ( substr( $line, 0, 1 ) !== '*' ) {
3966                                 continue;
3967                         }
3968
3969                         # Find all links
3970                         $m = array();
3971                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3972                                 continue;
3973                         }
3974
3975                         $exceptions = array();
3976                         $imageDBkey = false;
3977                         foreach ( $m[1] as $i => $titleText ) {
3978                                 $title = Title::newFromText( $titleText );
3979                                 if ( !is_null( $title ) ) {
3980                                         if ( $i == 0 ) {
3981                                                 $imageDBkey = $title->getDBkey();
3982                                         } else {
3983                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3984                                         }
3985                                 }
3986                         }
3987
3988                         if ( $imageDBkey !== false ) {
3989                                 $badImages[$imageDBkey] = $exceptions;
3990                         }
3991                 }
3992                 if ( $cacheable ) {
3993                         $badImageCache = $badImages;
3994                 }
3995         }
3996
3997         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3998         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3999         wfProfileOut( __METHOD__ );
4000         return $bad;
4001 }