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
  98 // Support for Wietse Venema's taint feature
  99 if ( !function_exists( 'istainted' ) ) {
 100         /**
 101          * @codeCoverageIgnore
 102          * @return int
 103          */
 104         function istainted( $var ) {
 105                 return 0;
 106         }
 107         /** @codeCoverageIgnore */
 108         function taint( $var, $level = 0 ) {}
 109         /** @codeCoverageIgnore */
 110         function untaint( $var, $level = 0 ) {}
 111         define( 'TC_HTML', 1 );
 112         define( 'TC_SHELL', 1 );
 113         define( 'TC_MYSQL', 1 );
 114         define( 'TC_PCRE', 1 );
 115         define( 'TC_SELF', 1 );
 116 }
 117 /// @endcond
 118
 119 /**
 120  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 121  * @param $a array
 122  * @param $b array
 123  * @return array
 124  */
 125 function wfArrayDiff2( $a, $b ) {
 126         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 127 }
 128
 129 /**
 130  * @param $a
 131  * @param $b
 132  * @return int
 133  */
 134 function wfArrayDiff2_cmp( $a, $b ) {
 135         if ( !is_array( $a ) ) {
 136                 return strcmp( $a, $b );
 137         } elseif ( count( $a ) !== count( $b ) ) {
 138                 return count( $a ) < count( $b ) ? -1 : 1;
 139         } else {
 140                 reset( $a );
 141                 reset( $b );
 142                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 143                         $cmp = strcmp( $valueA, $valueB );
 144                         if ( $cmp !== 0 ) {
 145                                 return $cmp;
 146                         }
 147                 }
 148                 return 0;
 149         }
 150 }
 151
 152 /**
 153  * Array lookup
 154  * Returns an array where the values in the first array are replaced by the
 155  * values in the second array with the corresponding keys
 156  *
 157  * @param $a Array
 158  * @param $b Array
 159  * @return array
 160  */
 161 function wfArrayLookup( $a, $b ) {
 162         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 163 }
 164
 165 /**
 166  * Appends to second array if $value differs from that in $default
 167  *
 168  * @param $key String|Int
 169  * @param $value Mixed
 170  * @param $default Mixed
 171  * @param $changed Array to alter
 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 $insert Array: 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 pesudo-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 $length int 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 $array1 Array ( String|Array )
 383  * @param $array2 Array ( 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 compa-
 426  * tibility with legacy functions that accept raw query strings instead of nice
 427  * arrays.  Of course, keys and values are urldecode()d.
 428  *
 429  * @param $query String: 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 $url String: 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 $urlParts Array 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 $urlPath String 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 $includeProtocolRelative bool 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 $url String: 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         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 790         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 791                 $bits['delimiter'] = '://';
 792         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 793                 $bits['delimiter'] = ':';
 794                 // parse_url detects for news: and mailto: the host part of an url as path
 795                 // We have to correct this wrong detection
 796                 if ( isset( $bits['path'] ) ) {
 797                         $bits['host'] = $bits['path'];
 798                         $bits['path'] = '';
 799                 }
 800         } else {
 801                 return false;
 802         }
 803
 804         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 805         if ( !isset( $bits['host'] ) ) {
 806                 $bits['host'] = '';
 807
 808                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 809                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 810                         $bits['path'] = '/' . $bits['path'];
 811                 }
 812         }
 813
 814         // If the URL was protocol-relative, fix scheme and delimiter
 815         if ( $wasRelative ) {
 816                 $bits['scheme'] = '';
 817                 $bits['delimiter'] = '//';
 818         }
 819         return $bits;
 820 }
 821
 822 /**
 823  * Take a URL, make sure it's expanded to fully qualified, and replace any
 824  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 825  * for more compact display and legibility for local audiences.
 826  *
 827  * @todo handle punycode domains too
 828  *
 829  * @param $url string
 830  * @return string
 831  */
 832 function wfExpandIRI( $url ) {
 833         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 834 }
 835
 836 /**
 837  * Private callback for wfExpandIRI
 838  * @param array $matches
 839  * @return string
 840  */
 841 function wfExpandIRI_callback( $matches ) {
 842         return urldecode( $matches[1] );
 843 }
 844
 845
 846
 847 /**
 848  * Make URL indexes, appropriate for the el_index field of externallinks.
 849  *
 850  * @param $url String
 851  * @return array
 852  */
 853 function wfMakeUrlIndexes( $url ) {
 854         $bits = wfParseUrl( $url );
 855
 856         // Reverse the labels in the hostname, convert to lower case
 857         // For emails reverse domainpart only
 858         if ( $bits['scheme'] == 'mailto' ) {
 859                 $mailparts = explode( '@', $bits['host'], 2 );
 860                 if ( count( $mailparts ) === 2 ) {
 861                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 862                 } else {
 863                         // No domain specified, don't mangle it
 864                         $domainpart = '';
 865                 }
 866                 $reversedHost = $domainpart . '@' . $mailparts[0];
 867         } else {
 868                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 869         }
 870         // Add an extra dot to the end
 871         // Why? Is it in wrong place in mailto links?
 872         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 873                 $reversedHost .= '.';
 874         }
 875         // Reconstruct the pseudo-URL
 876         $prot = $bits['scheme'];
 877         $index = $prot . $bits['delimiter'] . $reversedHost;
 878         // Leave out user and password. Add the port, path, query and fragment
 879         if ( isset( $bits['port'] ) ) {
 880                 $index .= ':' . $bits['port'];
 881         }
 882         if ( isset( $bits['path'] ) ) {
 883                 $index .= $bits['path'];
 884         } else {
 885                 $index .= '/';
 886         }
 887         if ( isset( $bits['query'] ) ) {
 888                 $index .= '?' . $bits['query'];
 889         }
 890         if ( isset( $bits['fragment'] ) ) {
 891                 $index .= '#' . $bits['fragment'];
 892         }
 893
 894         if ( $prot == '' ) {
 895                 return array( "http:$index", "https:$index" );
 896         } else {
 897                 return array( $index );
 898         }
 899 }
 900
 901 /**
 902  * Check whether a given URL has a domain that occurs in a given set of domains
 903  * @param $url string URL
 904  * @param $domains array Array of domains (strings)
 905  * @return bool True if the host part of $url ends in one of the strings in $domains
 906  */
 907 function wfMatchesDomainList( $url, $domains ) {
 908         $bits = wfParseUrl( $url );
 909         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 910                 foreach ( (array)$domains as $domain ) {
 911                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 912                         // We should use something that interprets dots instead
 913                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 914                                 return true;
 915                         }
 916                 }
 917         }
 918         return false;
 919 }
 920
 921 /**
 922  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 923  * In normal operation this is a NOP.
 924  *
 925  * Controlling globals:
 926  * $wgDebugLogFile - points to the log file
 927  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 928  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 929  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 930  *
 931  * @param $text String
 932  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 933  */
 934 function wfDebug( $text, $logonly = false ) {
 935         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 936
 937         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 938                 return;
 939         }
 940
 941         $timer = wfDebugTimer();
 942         if ( $timer !== '' ) {
 943                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 944         }
 945
 946         if ( !$logonly ) {
 947                 MWDebug::debugMsg( $text );
 948         }
 949
 950         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 951                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 952                         # Strip unprintables; they can switch terminal modes when binary data
 953                         # gets dumped, which is pretty annoying.
 954                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 955                         $text = $wgDebugLogPrefix . $text;
 956                         wfErrorLog( $text, $wgDebugLogFile );
 957                 }
 958         }
 959 }
 960
 961 /**
 962  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 963  * @return bool
 964  */
 965 function wfIsDebugRawPage() {
 966         static $cache;
 967         if ( $cache !== null ) {
 968                 return $cache;
 969         }
 970         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 971         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 972                 || (
 973                         isset( $_SERVER['SCRIPT_NAME'] )
 974                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 975                 ) )
 976         {
 977                 $cache = true;
 978         } else {
 979                 $cache = false;
 980         }
 981         return $cache;
 982 }
 983
 984 /**
 985  * Get microsecond timestamps for debug logs
 986  *
 987  * @return string
 988  */
 989 function wfDebugTimer() {
 990         global $wgDebugTimestamps, $wgRequestTime;
 991
 992         if ( !$wgDebugTimestamps ) {
 993                 return '';
 994         }
 995
 996         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 997         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 998         return "$prefix $mem  ";
 999 }
1000
1001 /**
1002  * Send a line giving PHP memory usage.
1003  *
1004  * @param $exact Bool: print exact values instead of kilobytes (default: false)
1005  */
1006 function wfDebugMem( $exact = false ) {
1007         $mem = memory_get_usage();
1008         if( !$exact ) {
1009                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1010         } else {
1011                 $mem .= ' bytes';
1012         }
1013         wfDebug( "Memory usage: $mem\n" );
1014 }
1015
1016 /**
1017  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1018  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1019  *
1020  * @param $logGroup String
1021  * @param $text String
1022  * @param $public Bool: whether to log the event in the public log if no private
1023  *                     log file is specified, (default true)
1024  */
1025 function wfDebugLog( $logGroup, $text, $public = true ) {
1026         global $wgDebugLogGroups;
1027         $text = trim( $text ) . "\n";
1028         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
1029                 $time = wfTimestamp( TS_DB );
1030                 $wiki = wfWikiID();
1031                 $host = wfHostname();
1032                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1033                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1034                 }
1035         } elseif ( $public === true ) {
1036                 wfDebug( $text, true );
1037         }
1038 }
1039
1040 /**
1041  * Log for database errors
1042  *
1043  * @param $text String: database error message.
1044  */
1045 function wfLogDBError( $text ) {
1046         global $wgDBerrorLog, $wgDBerrorLogTZ;
1047         static $logDBErrorTimeZoneObject = null;
1048
1049         if ( $wgDBerrorLog ) {
1050                 $host = wfHostname();
1051                 $wiki = wfWikiID();
1052
1053                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1054                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1055                 }
1056
1057                 // Workaround for https://bugs.php.net/bug.php?id=52063
1058                 // Can be removed when min PHP > 5.3.2
1059                 if ( $logDBErrorTimeZoneObject === null ) {
1060                         $d = date_create( "now" );
1061                 } else {
1062                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1063                 }
1064
1065                 $date = $d->format( 'D M j G:i:s T Y' );
1066
1067                 $text = "$date\t$host\t$wiki\t$text";
1068                 wfErrorLog( $text, $wgDBerrorLog );
1069         }
1070 }
1071
1072 /**
1073  * Throws a warning that $function is deprecated
1074  *
1075  * @param $function String
1076  * @param $version String|bool: Version of MediaWiki that the function was deprecated in (Added in 1.19).
1077  * @param $component String|bool: Added in 1.19.
1078  * @param $callerOffset integer: How far up the callstack is the original
1079  *    caller. 2 = function that called the function that called
1080  *    wfDeprecated (Added in 1.20)
1081  *
1082  * @return null
1083  */
1084 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1085         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1086 }
1087
1088 /**
1089  * Send a warning either to the debug log or in a PHP error depending on
1090  * $wgDevelopmentWarnings
1091  *
1092  * @param $msg String: message to send
1093  * @param $callerOffset Integer: number of items to go back in the backtrace to
1094  *        find the correct caller (1 = function calling wfWarn, ...)
1095  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1096  *        is true
1097  */
1098 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1099         MWDebug::warning( $msg, $callerOffset + 1, $level );
1100 }
1101
1102 /**
1103  * Log to a file without getting "file size exceeded" signals.
1104  *
1105  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1106  * send lines to the specified port, prefixed by the specified prefix and a space.
1107  *
1108  * @param $text String
1109  * @param $file String filename
1110  */
1111 function wfErrorLog( $text, $file ) {
1112         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1113                 # Needs the sockets extension
1114                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1115                         // IPv6 bracketed host
1116                         $host = $m[2];
1117                         $port = intval( $m[3] );
1118                         $prefix = isset( $m[4] ) ? $m[4] : false;
1119                         $domain = AF_INET6;
1120                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1121                         $host = $m[2];
1122                         if ( !IP::isIPv4( $host ) ) {
1123                                 $host = gethostbyname( $host );
1124                         }
1125                         $port = intval( $m[3] );
1126                         $prefix = isset( $m[4] ) ? $m[4] : false;
1127                         $domain = AF_INET;
1128                 } else {
1129                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1130                 }
1131
1132                 // Clean it up for the multiplexer
1133                 if ( strval( $prefix ) !== '' ) {
1134                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1135
1136                         // Limit to 64KB
1137                         if ( strlen( $text ) > 65506 ) {
1138                                 $text = substr( $text, 0, 65506 );
1139                         }
1140
1141                         if ( substr( $text, -1 ) != "\n" ) {
1142                                 $text .= "\n";
1143                         }
1144                 } elseif ( strlen( $text ) > 65507 ) {
1145                         $text = substr( $text, 0, 65507 );
1146                 }
1147
1148                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1149                 if ( !$sock ) {
1150                         return;
1151                 }
1152
1153                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1154                 socket_close( $sock );
1155         } else {
1156                 wfSuppressWarnings();
1157                 $exists = file_exists( $file );
1158                 $size = $exists ? filesize( $file ) : false;
1159                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1160                         file_put_contents( $file, $text, FILE_APPEND );
1161                 }
1162                 wfRestoreWarnings();
1163         }
1164 }
1165
1166 /**
1167  * @todo document
1168  */
1169 function wfLogProfilingData() {
1170         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1171         global $wgProfileLimit, $wgUser;
1172
1173         $profiler = Profiler::instance();
1174
1175         # Profiling must actually be enabled...
1176         if ( $profiler->isStub() ) {
1177                 return;
1178         }
1179
1180         // Get total page request time and only show pages that longer than
1181         // $wgProfileLimit time (default is 0)
1182         $elapsed = microtime( true ) - $wgRequestTime;
1183         if ( $elapsed <= $wgProfileLimit ) {
1184                 return;
1185         }
1186
1187         $profiler->logData();
1188
1189         // Check whether this should be logged in the debug file.
1190         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1191                 return;
1192         }
1193
1194         $forward = '';
1195         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1196                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1197         }
1198         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1199                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1200         }
1201         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1202                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1203         }
1204         if ( $forward ) {
1205                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1206         }
1207         // Don't load $wgUser at this late stage just for statistics purposes
1208         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1209         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1210                 $forward .= ' anon';
1211         }
1212         $log = sprintf( "%s\t%04.3f\t%s\n",
1213                 gmdate( 'YmdHis' ), $elapsed,
1214                 urldecode( $wgRequest->getRequestURL() . $forward ) );
1215
1216         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1217 }
1218
1219 /**
1220  * Increment a statistics counter
1221  *
1222  * @param $key String
1223  * @param $count Int
1224  */
1225 function wfIncrStats( $key, $count = 1 ) {
1226         global $wgStatsMethod;
1227
1228         $count = intval( $count );
1229
1230         if( $wgStatsMethod == 'udp' ) {
1231                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
1232                 static $socket;
1233
1234                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
1235
1236                 if ( !$socket ) {
1237                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1238                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1239                         socket_sendto(
1240                                 $socket,
1241                                 $statline,
1242                                 strlen( $statline ),
1243                                 0,
1244                                 $wgUDPProfilerHost,
1245                                 $wgUDPProfilerPort
1246                         );
1247                 }
1248                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1249                 wfSuppressWarnings();
1250                 socket_sendto(
1251                         $socket,
1252                         $statline,
1253                         strlen( $statline ),
1254                         0,
1255                         $wgUDPProfilerHost,
1256                         $wgUDPProfilerPort
1257                 );
1258                 wfRestoreWarnings();
1259         } elseif( $wgStatsMethod == 'cache' ) {
1260                 global $wgMemc;
1261                 $key = wfMemcKey( 'stats', $key );
1262                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1263                         $wgMemc->add( $key, $count );
1264                 }
1265         } else {
1266                 // Disabled
1267         }
1268 }
1269
1270 /**
1271  * Check if the wiki read-only lock file is present. This can be used to lock
1272  * off editing functions, but doesn't guarantee that the database will not be
1273  * modified.
1274  *
1275  * @return bool
1276  */
1277 function wfReadOnly() {
1278         global $wgReadOnlyFile, $wgReadOnly;
1279
1280         if ( !is_null( $wgReadOnly ) ) {
1281                 return (bool)$wgReadOnly;
1282         }
1283         if ( $wgReadOnlyFile == '' ) {
1284                 return false;
1285         }
1286         // Set $wgReadOnly for faster access next time
1287         if ( is_file( $wgReadOnlyFile ) ) {
1288                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1289         } else {
1290                 $wgReadOnly = false;
1291         }
1292         return (bool)$wgReadOnly;
1293 }
1294
1295 /**
1296  * @return bool
1297  */
1298 function wfReadOnlyReason() {
1299         global $wgReadOnly;
1300         wfReadOnly();
1301         return $wgReadOnly;
1302 }
1303
1304 /**
1305  * Return a Language object from $langcode
1306  *
1307  * @param $langcode Mixed: either:
1308  *                  - a Language object
1309  *                  - code of the language to get the message for, if it is
1310  *                    a valid code create a language for that language, if
1311  *                    it is a string but not a valid code then make a basic
1312  *                    language object
1313  *                  - a boolean: if it's false then use the global object for
1314  *                    the current user's language (as a fallback for the old parameter
1315  *                    functionality), or if it is true then use global object
1316  *                    for the wiki's content language.
1317  * @return Language object
1318  */
1319 function wfGetLangObj( $langcode = false ) {
1320         # Identify which language to get or create a language object for.
1321         # Using is_object here due to Stub objects.
1322         if( is_object( $langcode ) ) {
1323                 # Great, we already have the object (hopefully)!
1324                 return $langcode;
1325         }
1326
1327         global $wgContLang, $wgLanguageCode;
1328         if( $langcode === true || $langcode === $wgLanguageCode ) {
1329                 # $langcode is the language code of the wikis content language object.
1330                 # or it is a boolean and value is true
1331                 return $wgContLang;
1332         }
1333
1334         global $wgLang;
1335         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1336                 # $langcode is the language code of user language object.
1337                 # or it was a boolean and value is false
1338                 return $wgLang;
1339         }
1340
1341         $validCodes = array_keys( Language::fetchLanguageNames() );
1342         if( in_array( $langcode, $validCodes ) ) {
1343                 # $langcode corresponds to a valid language.
1344                 return Language::factory( $langcode );
1345         }
1346
1347         # $langcode is a string, but not a valid language code; use content language.
1348         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1349         return $wgContLang;
1350 }
1351
1352 /**
1353  * Old function when $wgBetterDirectionality existed
1354  * All usage removed, wfUILang can be removed in near future
1355  *
1356  * @deprecated since 1.18
1357  * @return Language
1358  */
1359 function wfUILang() {
1360         wfDeprecated( __METHOD__, '1.18' );
1361         global $wgLang;
1362         return $wgLang;
1363 }
1364
1365 /**
1366  * This is the new function for getting translated interface messages.
1367  * See the Message class for documentation how to use them.
1368  * The intention is that this function replaces all old wfMsg* functions.
1369  * @param $key \string Message key.
1370  * Varargs: normal message parameters.
1371  * @return Message
1372  * @since 1.17
1373  */
1374 function wfMessage( $key /*...*/) {
1375         $params = func_get_args();
1376         array_shift( $params );
1377         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1378                 $params = $params[0];
1379         }
1380         return new Message( $key, $params );
1381 }
1382
1383 /**
1384  * This function accepts multiple message keys and returns a message instance
1385  * for the first message which is non-empty. If all messages are empty then an
1386  * instance of the first message key is returned.
1387  * @param varargs: message keys
1388  * @return Message
1389  * @since 1.18
1390  */
1391 function wfMessageFallback( /*...*/ ) {
1392         $args = func_get_args();
1393         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1394 }
1395
1396 /**
1397  * Get a message from anywhere, for the current user language.
1398  *
1399  * Use wfMsgForContent() instead if the message should NOT
1400  * change depending on the user preferences.
1401  *
1402  * @deprecated since 1.18
1403  *
1404  * @param $key String: lookup key for the message, usually
1405  *    defined in languages/Language.php
1406  *
1407  * Parameters to the message, which can be used to insert variable text into
1408  * it, can be passed to this function in the following formats:
1409  * - One per argument, starting at the second parameter
1410  * - As an array in the second parameter
1411  * These are not shown in the function definition.
1412  *
1413  * @return String
1414  */
1415 function wfMsg( $key ) {
1416         $args = func_get_args();
1417         array_shift( $args );
1418         return wfMsgReal( $key, $args );
1419 }
1420
1421 /**
1422  * Same as above except doesn't transform the message
1423  *
1424  * @deprecated since 1.18
1425  *
1426  * @param $key String
1427  * @return String
1428  */
1429 function wfMsgNoTrans( $key ) {
1430         $args = func_get_args();
1431         array_shift( $args );
1432         return wfMsgReal( $key, $args, true, false, false );
1433 }
1434
1435 /**
1436  * Get a message from anywhere, for the current global language
1437  * set with $wgLanguageCode.
1438  *
1439  * Use this if the message should NOT change dependent on the
1440  * language set in the user's preferences. This is the case for
1441  * most text written into logs, as well as link targets (such as
1442  * the name of the copyright policy page). Link titles, on the
1443  * other hand, should be shown in the UI language.
1444  *
1445  * Note that MediaWiki allows users to change the user interface
1446  * language in their preferences, but a single installation
1447  * typically only contains content in one language.
1448  *
1449  * Be wary of this distinction: If you use wfMsg() where you should
1450  * use wfMsgForContent(), a user of the software may have to
1451  * customize potentially hundreds of messages in
1452  * order to, e.g., fix a link in every possible language.
1453  *
1454  * @deprecated since 1.18
1455  *
1456  * @param $key String: lookup key for the message, usually
1457  *     defined in languages/Language.php
1458  * @return String
1459  */
1460 function wfMsgForContent( $key ) {
1461         global $wgForceUIMsgAsContentMsg;
1462         $args = func_get_args();
1463         array_shift( $args );
1464         $forcontent = true;
1465         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1466                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1467         {
1468                 $forcontent = false;
1469         }
1470         return wfMsgReal( $key, $args, true, $forcontent );
1471 }
1472
1473 /**
1474  * Same as above except doesn't transform the message
1475  *
1476  * @deprecated since 1.18
1477  *
1478  * @param $key String
1479  * @return String
1480  */
1481 function wfMsgForContentNoTrans( $key ) {
1482         global $wgForceUIMsgAsContentMsg;
1483         $args = func_get_args();
1484         array_shift( $args );
1485         $forcontent = true;
1486         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1487                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1488         {
1489                 $forcontent = false;
1490         }
1491         return wfMsgReal( $key, $args, true, $forcontent, false );
1492 }
1493
1494 /**
1495  * Really get a message
1496  *
1497  * @deprecated since 1.18
1498  *
1499  * @param $key String: key to get.
1500  * @param $args
1501  * @param $useDB Boolean
1502  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1503  * @param $transform Boolean: Whether or not to transform the message.
1504  * @return String: the requested message.
1505  */
1506 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1507         wfProfileIn( __METHOD__ );
1508         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1509         $message = wfMsgReplaceArgs( $message, $args );
1510         wfProfileOut( __METHOD__ );
1511         return $message;
1512 }
1513
1514 /**
1515  * Fetch a message string value, but don't replace any keys yet.
1516  *
1517  * @deprecated since 1.18
1518  *
1519  * @param $key String
1520  * @param $useDB Bool
1521  * @param $langCode String: Code of the language to get the message for, or
1522  *                  behaves as a content language switch if it is a boolean.
1523  * @param $transform Boolean: whether to parse magic words, etc.
1524  * @return string
1525  */
1526 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1527         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1528
1529         $cache = MessageCache::singleton();
1530         $message = $cache->get( $key, $useDB, $langCode );
1531         if( $message === false ) {
1532                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1533         } elseif ( $transform ) {
1534                 $message = $cache->transform( $message );
1535         }
1536         return $message;
1537 }
1538
1539 /**
1540  * Replace message parameter keys on the given formatted output.
1541  *
1542  * @deprecated since 1.18
1543  *
1544  * @param $message String
1545  * @param $args Array
1546  * @return string
1547  * @private
1548  */
1549 function wfMsgReplaceArgs( $message, $args ) {
1550         # Fix windows line-endings
1551         # Some messages are split with explode("\n", $msg)
1552         $message = str_replace( "\r", '', $message );
1553
1554         // Replace arguments
1555         if ( count( $args ) ) {
1556                 if ( is_array( $args[0] ) ) {
1557                         $args = array_values( $args[0] );
1558                 }
1559                 $replacementKeys = array();
1560                 foreach( $args as $n => $param ) {
1561                         $replacementKeys['$' . ( $n + 1 )] = $param;
1562                 }
1563                 $message = strtr( $message, $replacementKeys );
1564         }
1565
1566         return $message;
1567 }
1568
1569 /**
1570  * Return an HTML-escaped version of a message.
1571  * Parameter replacements, if any, are done *after* the HTML-escaping,
1572  * so parameters may contain HTML (eg links or form controls). Be sure
1573  * to pre-escape them if you really do want plaintext, or just wrap
1574  * the whole thing in htmlspecialchars().
1575  *
1576  * @deprecated since 1.18
1577  *
1578  * @param $key String
1579  * @param string ... parameters
1580  * @return string
1581  */
1582 function wfMsgHtml( $key ) {
1583         $args = func_get_args();
1584         array_shift( $args );
1585         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1586 }
1587
1588 /**
1589  * Return an HTML version of message
1590  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1591  * so parameters may contain HTML (eg links or form controls). Be sure
1592  * to pre-escape them if you really do want plaintext, or just wrap
1593  * the whole thing in htmlspecialchars().
1594  *
1595  * @deprecated since 1.18
1596  *
1597  * @param $key String
1598  * @param string ... parameters
1599  * @return string
1600  */
1601 function wfMsgWikiHtml( $key ) {
1602         $args = func_get_args();
1603         array_shift( $args );
1604         return wfMsgReplaceArgs(
1605                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1606                 /* can't be set to false */ true, /* interface */ true )->getText(),
1607                 $args );
1608 }
1609
1610 /**
1611  * Returns message in the requested format
1612  *
1613  * @deprecated since 1.18
1614  *
1615  * @param $key String: key of the message
1616  * @param $options Array: processing rules. Can take the following options:
1617  *   <i>parse</i>: parses wikitext to HTML
1618  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1619  *       p's added by parser or tidy
1620  *   <i>escape</i>: filters message through htmlspecialchars
1621  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1622  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1623  *   <i>parsemag</i>: transform the message using magic phrases
1624  *   <i>content</i>: fetch message for content language instead of interface
1625  * Also can accept a single associative argument, of the form 'language' => 'xx':
1626  *   <i>language</i>: Language object or language code to fetch message for
1627  *       (overriden by <i>content</i>).
1628  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1629  *
1630  * @return String
1631  */
1632 function wfMsgExt( $key, $options ) {
1633         $args = func_get_args();
1634         array_shift( $args );
1635         array_shift( $args );
1636         $options = (array)$options;
1637
1638         foreach( $options as $arrayKey => $option ) {
1639                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1640                         # An unknown index, neither numeric nor "language"
1641                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1642                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1643                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1644                 'replaceafter', 'parsemag', 'content' ) ) ) {
1645                         # A numeric index with unknown value
1646                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1647                 }
1648         }
1649
1650         if( in_array( 'content', $options, true ) ) {
1651                 $forContent = true;
1652                 $langCode = true;
1653                 $langCodeObj = null;
1654         } elseif( array_key_exists( 'language', $options ) ) {
1655                 $forContent = false;
1656                 $langCode = wfGetLangObj( $options['language'] );
1657                 $langCodeObj = $langCode;
1658         } else {
1659                 $forContent = false;
1660                 $langCode = false;
1661                 $langCodeObj = null;
1662         }
1663
1664         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1665
1666         if( !in_array( 'replaceafter', $options, true ) ) {
1667                 $string = wfMsgReplaceArgs( $string, $args );
1668         }
1669
1670         $messageCache = MessageCache::singleton();
1671         $parseInline = in_array( 'parseinline', $options, true );
1672         if( in_array( 'parse', $options, true ) || $parseInline ) {
1673                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1674                 if ( $string instanceof ParserOutput ) {
1675                         $string = $string->getText();
1676                 }
1677
1678                 if ( $parseInline ) {
1679                         $m = array();
1680                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1681                                 $string = $m[1];
1682                         }
1683                 }
1684         } elseif ( in_array( 'parsemag', $options, true ) ) {
1685                 $string = $messageCache->transform( $string,
1686                                 !$forContent, $langCodeObj );
1687         }
1688
1689         if ( in_array( 'escape', $options, true ) ) {
1690                 $string = htmlspecialchars ( $string );
1691         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1692                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1693         }
1694
1695         if( in_array( 'replaceafter', $options, true ) ) {
1696                 $string = wfMsgReplaceArgs( $string, $args );
1697         }
1698
1699         return $string;
1700 }
1701
1702 /**
1703  * Since wfMsg() and co suck, they don't return false if the message key they
1704  * looked up didn't exist but a XHTML string, this function checks for the
1705  * nonexistance of messages by checking the MessageCache::get() result directly.
1706  *
1707  * @deprecated since 1.18. Use Message::isDisabled().
1708  *
1709  * @param $key      String: the message key looked up
1710  * @return Boolean True if the message *doesn't* exist.
1711  */
1712 function wfEmptyMsg( $key ) {
1713         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1714 }
1715
1716 /**
1717  * Throw a debugging exception. This function previously once exited the process,
1718  * but now throws an exception instead, with similar results.
1719  *
1720  * @param $msg String: message shown when dying.
1721  */
1722 function wfDebugDieBacktrace( $msg = '' ) {
1723         throw new MWException( $msg );
1724 }
1725
1726 /**
1727  * Fetch server name for use in error reporting etc.
1728  * Use real server name if available, so we know which machine
1729  * in a server farm generated the current page.
1730  *
1731  * @return string
1732  */
1733 function wfHostname() {
1734         static $host;
1735         if ( is_null( $host ) ) {
1736
1737                 # Hostname overriding
1738                 global $wgOverrideHostname;
1739                 if( $wgOverrideHostname !== false ) {
1740                         # Set static and skip any detection
1741                         $host = $wgOverrideHostname;
1742                         return $host;
1743                 }
1744
1745                 if ( function_exists( 'posix_uname' ) ) {
1746                         // This function not present on Windows
1747                         $uname = posix_uname();
1748                 } else {
1749                         $uname = false;
1750                 }
1751                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1752                         $host = $uname['nodename'];
1753                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1754                         # Windows computer name
1755                         $host = getenv( 'COMPUTERNAME' );
1756                 } else {
1757                         # This may be a virtual server.
1758                         $host = $_SERVER['SERVER_NAME'];
1759                 }
1760         }
1761         return $host;
1762 }
1763
1764 /**
1765  * Returns a HTML comment with the elapsed time since request.
1766  * This method has no side effects.
1767  *
1768  * @return string
1769  */
1770 function wfReportTime() {
1771         global $wgRequestTime, $wgShowHostnames;
1772
1773         $elapsed = microtime( true ) - $wgRequestTime;
1774
1775         return $wgShowHostnames
1776                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1777                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1778 }
1779
1780 /**
1781  * Safety wrapper for debug_backtrace().
1782  *
1783  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1784  * murky circumstances, which may be triggered in part by stub objects
1785  * or other fancy talkin'.
1786  *
1787  * Will return an empty array if Zend Optimizer is detected or if
1788  * debug_backtrace is disabled, otherwise the output from
1789  * debug_backtrace() (trimmed).
1790  *
1791  * @param $limit int This parameter can be used to limit the number of stack frames returned
1792  *
1793  * @return array of backtrace information
1794  */
1795 function wfDebugBacktrace( $limit = 0 ) {
1796         static $disabled = null;
1797
1798         if( extension_loaded( 'Zend Optimizer' ) ) {
1799                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1800                 return array();
1801         }
1802
1803         if ( is_null( $disabled ) ) {
1804                 $disabled = false;
1805                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1806                 $functions = array_map( 'trim', $functions );
1807                 $functions = array_map( 'strtolower', $functions );
1808                 if ( in_array( 'debug_backtrace', $functions ) ) {
1809                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1810                         $disabled = true;
1811                 }
1812         }
1813         if ( $disabled ) {
1814                 return array();
1815         }
1816
1817         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1818                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1819         } else {
1820                 return array_slice( debug_backtrace(), 1 );
1821         }
1822 }
1823
1824 /**
1825  * Get a debug backtrace as a string
1826  *
1827  * @return string
1828  */
1829 function wfBacktrace() {
1830         global $wgCommandLineMode;
1831
1832         if ( $wgCommandLineMode ) {
1833                 $msg = '';
1834         } else {
1835                 $msg = "<ul>\n";
1836         }
1837         $backtrace = wfDebugBacktrace();
1838         foreach( $backtrace as $call ) {
1839                 if( isset( $call['file'] ) ) {
1840                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1841                         $file = $f[count( $f ) - 1];
1842                 } else {
1843                         $file = '-';
1844                 }
1845                 if( isset( $call['line'] ) ) {
1846                         $line = $call['line'];
1847                 } else {
1848                         $line = '-';
1849                 }
1850                 if ( $wgCommandLineMode ) {
1851                         $msg .= "$file line $line calls ";
1852                 } else {
1853                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1854                 }
1855                 if( !empty( $call['class'] ) ) {
1856                         $msg .= $call['class'] . $call['type'];
1857                 }
1858                 $msg .= $call['function'] . '()';
1859
1860                 if ( $wgCommandLineMode ) {
1861                         $msg .= "\n";
1862                 } else {
1863                         $msg .= "</li>\n";
1864                 }
1865         }
1866         if ( $wgCommandLineMode ) {
1867                 $msg .= "\n";
1868         } else {
1869                 $msg .= "</ul>\n";
1870         }
1871
1872         return $msg;
1873 }
1874
1875 /**
1876  * Get the name of the function which called this function
1877  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1878  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1879  * wfGetCaller( 3 ) is the parent of that.
1880  *
1881  * @param $level Int
1882  * @return Bool|string
1883  */
1884 function wfGetCaller( $level = 2 ) {
1885         $backtrace = wfDebugBacktrace( $level + 1 );
1886         if ( isset( $backtrace[$level] ) ) {
1887                 return wfFormatStackFrame( $backtrace[$level] );
1888         } else {
1889                 $caller = 'unknown';
1890         }
1891         return $caller;
1892 }
1893
1894 /**
1895  * Return a string consisting of callers in the stack. Useful sometimes
1896  * for profiling specific points.
1897  *
1898  * @param $limit int The maximum depth of the stack frame to return, or false for
1899  *               the entire stack.
1900  * @return String
1901  */
1902 function wfGetAllCallers( $limit = 3 ) {
1903         $trace = array_reverse( wfDebugBacktrace() );
1904         if ( !$limit || $limit > count( $trace ) - 1 ) {
1905                 $limit = count( $trace ) - 1;
1906         }
1907         $trace = array_slice( $trace, -$limit - 1, $limit );
1908         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1909 }
1910
1911 /**
1912  * Return a string representation of frame
1913  *
1914  * @param $frame Array
1915  * @return Bool
1916  */
1917 function wfFormatStackFrame( $frame ) {
1918         return isset( $frame['class'] ) ?
1919                 $frame['class'] . '::' . $frame['function'] :
1920                 $frame['function'];
1921 }
1922
1923
1924 /* Some generic result counters, pulled out of SearchEngine */
1925
1926
1927 /**
1928  * @todo document
1929  *
1930  * @param $offset Int
1931  * @param $limit Int
1932  * @return String
1933  */
1934 function wfShowingResults( $offset, $limit ) {
1935         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1936 }
1937
1938 /**
1939  * Generate (prev x| next x) (20|50|100...) type links for paging
1940  *
1941  * @param $offset String
1942  * @param $limit Integer
1943  * @param $link String
1944  * @param $query String: optional URL query parameter string
1945  * @param $atend Bool: optional param for specified if this is the last page
1946  * @return String
1947  * @deprecated in 1.19; use Language::viewPrevNext() instead
1948  */
1949 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1950         wfDeprecated( __METHOD__, '1.19' );
1951
1952         global $wgLang;
1953
1954         $query = wfCgiToArray( $query );
1955
1956         if( is_object( $link ) ) {
1957                 $title = $link;
1958         } else {
1959                 $title = Title::newFromText( $link );
1960                 if( is_null( $title ) ) {
1961                         return false;
1962                 }
1963         }
1964
1965         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1966 }
1967
1968 /**
1969  * Make a list item, used by various special pages
1970  *
1971  * @param $page String Page link
1972  * @param $details String Text between brackets
1973  * @param $oppositedm Boolean   Add the direction mark opposite to your
1974  *                                                              language, to display text properly
1975  * @return String
1976  * @deprecated since 1.19; use Language::specialList() instead
1977  */
1978 function wfSpecialList( $page, $details, $oppositedm = true ) {
1979         wfDeprecated( __METHOD__, '1.19' );
1980
1981         global $wgLang;
1982         return $wgLang->specialList( $page, $details, $oppositedm );
1983 }
1984
1985 /**
1986  * @todo document
1987  * @todo FIXME: We may want to blacklist some broken browsers
1988  *
1989  * @param $force Bool
1990  * @return bool Whereas client accept gzip compression
1991  */
1992 function wfClientAcceptsGzip( $force = false ) {
1993         static $result = null;
1994         if ( $result === null || $force ) {
1995                 $result = false;
1996                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1997                         # @todo FIXME: We may want to blacklist some broken browsers
1998                         $m = array();
1999                         if( preg_match(
2000                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2001                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
2002                                 $m )
2003                         )
2004                         {
2005                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2006                                         $result = false;
2007                                         return $result;
2008                                 }
2009                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2010                                 $result = true;
2011                         }
2012                 }
2013         }
2014         return $result;
2015 }
2016
2017 /**
2018  * Obtain the offset and limit values from the request string;
2019  * used in special pages
2020  *
2021  * @param $deflimit Int default limit if none supplied
2022  * @param $optionname String Name of a user preference to check against
2023  * @return array
2024  *
2025  */
2026 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2027         global $wgRequest;
2028         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2029 }
2030
2031 /**
2032  * Escapes the given text so that it may be output using addWikiText()
2033  * without any linking, formatting, etc. making its way through. This
2034  * is achieved by substituting certain characters with HTML entities.
2035  * As required by the callers, "<nowiki>" is not used.
2036  *
2037  * @param $text String: text to be escaped
2038  * @return String
2039  */
2040 function wfEscapeWikiText( $text ) {
2041         $text = strtr( "\n$text", array(
2042                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2043                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2044                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2045                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2046                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2047                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2048         ) );
2049         return substr( $text, 1 );
2050 }
2051
2052 /**
2053  * Get the current unix timetstamp with microseconds.  Useful for profiling
2054  * @return Float
2055  */
2056 function wfTime() {
2057         return microtime( true );
2058 }
2059
2060 /**
2061  * Sets dest to source and returns the original value of dest
2062  * If source is NULL, it just returns the value, it doesn't set the variable
2063  * If force is true, it will set the value even if source is NULL
2064  *
2065  * @param $dest Mixed
2066  * @param $source Mixed
2067  * @param $force Bool
2068  * @return Mixed
2069  */
2070 function wfSetVar( &$dest, $source, $force = false ) {
2071         $temp = $dest;
2072         if ( !is_null( $source ) || $force ) {
2073                 $dest = $source;
2074         }
2075         return $temp;
2076 }
2077
2078 /**
2079  * As for wfSetVar except setting a bit
2080  *
2081  * @param $dest Int
2082  * @param $bit Int
2083  * @param $state Bool
2084  *
2085  * @return bool
2086  */
2087 function wfSetBit( &$dest, $bit, $state = true ) {
2088         $temp = (bool)( $dest & $bit );
2089         if ( !is_null( $state ) ) {
2090                 if ( $state ) {
2091                         $dest |= $bit;
2092                 } else {
2093                         $dest &= ~$bit;
2094                 }
2095         }
2096         return $temp;
2097 }
2098
2099 /**
2100  * A wrapper around the PHP function var_export().
2101  * Either print it or add it to the regular output ($wgOut).
2102  *
2103  * @param $var mixed A PHP variable to dump.
2104  */
2105 function wfVarDump( $var ) {
2106         global $wgOut;
2107         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2108         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2109                 print $s;
2110         } else {
2111                 $wgOut->addHTML( $s );
2112         }
2113 }
2114
2115 /**
2116  * Provide a simple HTTP error.
2117  *
2118  * @param $code Int|String
2119  * @param $label String
2120  * @param $desc String
2121  */
2122 function wfHttpError( $code, $label, $desc ) {
2123         global $wgOut;
2124         $wgOut->disable();
2125         header( "HTTP/1.0 $code $label" );
2126         header( "Status: $code $label" );
2127         $wgOut->sendCacheControl();
2128
2129         header( 'Content-type: text/html; charset=utf-8' );
2130         print "<!doctype html>" .
2131                 '<html><head><title>' .
2132                 htmlspecialchars( $label ) .
2133                 '</title></head><body><h1>' .
2134                 htmlspecialchars( $label ) .
2135                 '</h1><p>' .
2136                 nl2br( htmlspecialchars( $desc ) ) .
2137                 "</p></body></html>\n";
2138 }
2139
2140 /**
2141  * Clear away any user-level output buffers, discarding contents.
2142  *
2143  * Suitable for 'starting afresh', for instance when streaming
2144  * relatively large amounts of data without buffering, or wanting to
2145  * output image files without ob_gzhandler's compression.
2146  *
2147  * The optional $resetGzipEncoding parameter controls suppression of
2148  * the Content-Encoding header sent by ob_gzhandler; by default it
2149  * is left. See comments for wfClearOutputBuffers() for why it would
2150  * be used.
2151  *
2152  * Note that some PHP configuration options may add output buffer
2153  * layers which cannot be removed; these are left in place.
2154  *
2155  * @param $resetGzipEncoding Bool
2156  */
2157 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2158         if( $resetGzipEncoding ) {
2159                 // Suppress Content-Encoding and Content-Length
2160                 // headers from 1.10+s wfOutputHandler
2161                 global $wgDisableOutputCompression;
2162                 $wgDisableOutputCompression = true;
2163         }
2164         while( $status = ob_get_status() ) {
2165                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2166                         // Probably from zlib.output_compression or other
2167                         // PHP-internal setting which can't be removed.
2168                         //
2169                         // Give up, and hope the result doesn't break
2170                         // output behavior.
2171                         break;
2172                 }
2173                 if( !ob_end_clean() ) {
2174                         // Could not remove output buffer handler; abort now
2175                         // to avoid getting in some kind of infinite loop.
2176                         break;
2177                 }
2178                 if( $resetGzipEncoding ) {
2179                         if( $status['name'] == 'ob_gzhandler' ) {
2180                                 // Reset the 'Content-Encoding' field set by this handler
2181                                 // so we can start fresh.
2182                                 header_remove( 'Content-Encoding' );
2183                                 break;
2184                         }
2185                 }
2186         }
2187 }
2188
2189 /**
2190  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2191  *
2192  * Clear away output buffers, but keep the Content-Encoding header
2193  * produced by ob_gzhandler, if any.
2194  *
2195  * This should be used for HTTP 304 responses, where you need to
2196  * preserve the Content-Encoding header of the real result, but
2197  * also need to suppress the output of ob_gzhandler to keep to spec
2198  * and avoid breaking Firefox in rare cases where the headers and
2199  * body are broken over two packets.
2200  */
2201 function wfClearOutputBuffers() {
2202         wfResetOutputBuffers( false );
2203 }
2204
2205 /**
2206  * Converts an Accept-* header into an array mapping string values to quality
2207  * factors
2208  *
2209  * @param $accept String
2210  * @param $def String default
2211  * @return Array
2212  */
2213 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2214         # No arg means accept anything (per HTTP spec)
2215         if( !$accept ) {
2216                 return array( $def => 1.0 );
2217         }
2218
2219         $prefs = array();
2220
2221         $parts = explode( ',', $accept );
2222
2223         foreach( $parts as $part ) {
2224                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2225                 $values = explode( ';', trim( $part ) );
2226                 $match = array();
2227                 if ( count( $values ) == 1 ) {
2228                         $prefs[$values[0]] = 1.0;
2229                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2230                         $prefs[$values[0]] = floatval( $match[1] );
2231                 }
2232         }
2233
2234         return $prefs;
2235 }
2236
2237 /**
2238  * Checks if a given MIME type matches any of the keys in the given
2239  * array. Basic wildcards are accepted in the array keys.
2240  *
2241  * Returns the matching MIME type (or wildcard) if a match, otherwise
2242  * NULL if no match.
2243  *
2244  * @param $type String
2245  * @param $avail Array
2246  * @return string
2247  * @private
2248  */
2249 function mimeTypeMatch( $type, $avail ) {
2250         if( array_key_exists( $type, $avail ) ) {
2251                 return $type;
2252         } else {
2253                 $parts = explode( '/', $type );
2254                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2255                         return $parts[0] . '/*';
2256                 } elseif( array_key_exists( '*/*', $avail ) ) {
2257                         return '*/*';
2258                 } else {
2259                         return null;
2260                 }
2261         }
2262 }
2263
2264 /**
2265  * Returns the 'best' match between a client's requested internet media types
2266  * and the server's list of available types. Each list should be an associative
2267  * array of type to preference (preference is a float between 0.0 and 1.0).
2268  * Wildcards in the types are acceptable.
2269  *
2270  * @param $cprefs Array: client's acceptable type list
2271  * @param $sprefs Array: server's offered types
2272  * @return string
2273  *
2274  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2275  * XXX: generalize to negotiate other stuff
2276  */
2277 function wfNegotiateType( $cprefs, $sprefs ) {
2278         $combine = array();
2279
2280         foreach( array_keys( $sprefs ) as $type ) {
2281                 $parts = explode( '/', $type );
2282                 if( $parts[1] != '*' ) {
2283                         $ckey = mimeTypeMatch( $type, $cprefs );
2284                         if( $ckey ) {
2285                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2286                         }
2287                 }
2288         }
2289
2290         foreach( array_keys( $cprefs ) as $type ) {
2291                 $parts = explode( '/', $type );
2292                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2293                         $skey = mimeTypeMatch( $type, $sprefs );
2294                         if( $skey ) {
2295                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2296                         }
2297                 }
2298         }
2299
2300         $bestq = 0;
2301         $besttype = null;
2302
2303         foreach( array_keys( $combine ) as $type ) {
2304                 if( $combine[$type] > $bestq ) {
2305                         $besttype = $type;
2306                         $bestq = $combine[$type];
2307                 }
2308         }
2309
2310         return $besttype;
2311 }
2312
2313 /**
2314  * Reference-counted warning suppression
2315  *
2316  * @param $end Bool
2317  */
2318 function wfSuppressWarnings( $end = false ) {
2319         static $suppressCount = 0;
2320         static $originalLevel = false;
2321
2322         if ( $end ) {
2323                 if ( $suppressCount ) {
2324                         --$suppressCount;
2325                         if ( !$suppressCount ) {
2326                                 error_reporting( $originalLevel );
2327                         }
2328                 }
2329         } else {
2330                 if ( !$suppressCount ) {
2331                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED ) );
2332                 }
2333                 ++$suppressCount;
2334         }
2335 }
2336
2337 /**
2338  * Restore error level to previous value
2339  */
2340 function wfRestoreWarnings() {
2341         wfSuppressWarnings( true );
2342 }
2343
2344 # Autodetect, convert and provide timestamps of various types
2345
2346 /**
2347  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2348  */
2349 define( 'TS_UNIX', 0 );
2350
2351 /**
2352  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2353  */
2354 define( 'TS_MW', 1 );
2355
2356 /**
2357  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2358  */
2359 define( 'TS_DB', 2 );
2360
2361 /**
2362  * RFC 2822 format, for E-mail and HTTP headers
2363  */
2364 define( 'TS_RFC2822', 3 );
2365
2366 /**
2367  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2368  *
2369  * This is used by Special:Export
2370  */
2371 define( 'TS_ISO_8601', 4 );
2372
2373 /**
2374  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2375  *
2376  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2377  *       DateTime tag and page 36 for the DateTimeOriginal and
2378  *       DateTimeDigitized tags.
2379  */
2380 define( 'TS_EXIF', 5 );
2381
2382 /**
2383  * Oracle format time.
2384  */
2385 define( 'TS_ORACLE', 6 );
2386
2387 /**
2388  * Postgres format time.
2389  */
2390 define( 'TS_POSTGRES', 7 );
2391
2392 /**
2393  * DB2 format time
2394  */
2395 define( 'TS_DB2', 8 );
2396
2397 /**
2398  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2399  */
2400 define( 'TS_ISO_8601_BASIC', 9 );
2401
2402 /**
2403  * Get a timestamp string in one of various formats
2404  *
2405  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2406  *                    function will autodetect which format is supplied and act
2407  *                    accordingly.
2408  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2409  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2410  */
2411 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2412         $uts = 0;
2413         $da = array();
2414         $strtime = '';
2415
2416         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2417                 $uts = time();
2418                 $strtime = "@$uts";
2419         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2420                 # TS_DB
2421         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2422                 # TS_EXIF
2423         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2424                 # TS_MW
2425         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2426                 # TS_UNIX
2427                 $uts = $ts;
2428                 $strtime = "@$ts"; // http://php.net/manual/en/datetime.formats.compound.php
2429         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2430                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2431                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2432                                 str_replace( '+00:00', 'UTC', $ts ) );
2433         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2434                 # TS_ISO_8601
2435         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2436                 #TS_ISO_8601_BASIC
2437         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2438                 # TS_POSTGRES
2439         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2440                 # TS_POSTGRES
2441         } elseif (preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/', $ts, $da ) ) {
2442                 # TS_DB2
2443         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2444                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2445                                                         '[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d/S', $ts ) ) { # hh:mm:ss
2446                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2447                 # The regex is a superset of rfc2822 for readability
2448                 $strtime = strtok( $ts, ';' );
2449         } elseif ( preg_match( '/^[A-Z][a-z]{5,8}, \d\d-[A-Z][a-z]{2}-\d{2} \d\d:\d\d:\d\d/', $ts ) ) {
2450                 # TS_RFC850
2451                 $strtime = $ts;
2452         } elseif ( preg_match( '/^[A-Z][a-z]{2} [A-Z][a-z]{2} +\d{1,2} \d\d:\d\d:\d\d \d{4}/', $ts ) ) {
2453                 # asctime
2454                 $strtime = $ts;
2455         } else {
2456                 # Bogus value...
2457                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2458
2459                 return false;
2460         }
2461
2462         static $formats = array(
2463                 TS_UNIX => 'U',
2464                 TS_MW => 'YmdHis',
2465                 TS_DB => 'Y-m-d H:i:s',
2466                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2467                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2468                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2469                 TS_RFC2822 => 'D, d M Y H:i:s',
2470                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2471                 TS_POSTGRES => 'Y-m-d H:i:s',
2472                 TS_DB2 => 'Y-m-d H:i:s',
2473         );
2474
2475         if ( !isset( $formats[$outputtype] ) ) {
2476                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2477         }
2478
2479         if ( function_exists( "date_create" ) ) {
2480                 if ( count( $da ) ) {
2481                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2482                                 (int)$da[1], (int)$da[2], (int)$da[3],
2483                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2484
2485                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2486                 } elseif ( $strtime ) {
2487                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2488                 } else {
2489                         return false;
2490                 }
2491
2492                 if ( !$d ) {
2493                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2494                         return false;
2495                 }
2496
2497                 $output = $d->format( $formats[$outputtype] );
2498         } else {
2499                 if ( count( $da ) ) {
2500                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2501                         // We may want to handle that explicitly at some point
2502                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2503                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2504                 } elseif ( $strtime ) {
2505                         $uts = strtotime( $strtime );
2506                 }
2507
2508                 if ( $uts === false ) {
2509                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2510                         return false;
2511                 }
2512
2513                 if ( TS_UNIX == $outputtype ) {
2514                         return $uts;
2515                 }
2516                 $output = gmdate( $formats[$outputtype], $uts );
2517         }
2518
2519         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2520                 $output .= ' GMT';
2521         }
2522
2523         return $output;
2524 }
2525
2526 /**
2527  * Return a formatted timestamp, or null if input is null.
2528  * For dealing with nullable timestamp columns in the database.
2529  *
2530  * @param $outputtype Integer
2531  * @param $ts String
2532  * @return String
2533  */
2534 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2535         if( is_null( $ts ) ) {
2536                 return null;
2537         } else {
2538                 return wfTimestamp( $outputtype, $ts );
2539         }
2540 }
2541
2542 /**
2543  * Convenience function; returns MediaWiki timestamp for the present time.
2544  *
2545  * @return string
2546  */
2547 function wfTimestampNow() {
2548         # return NOW
2549         return wfTimestamp( TS_MW, time() );
2550 }
2551
2552 /**
2553  * Check if the operating system is Windows
2554  *
2555  * @return Bool: true if it's Windows, False otherwise.
2556  */
2557 function wfIsWindows() {
2558         static $isWindows = null;
2559         if ( $isWindows === null ) {
2560                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2561         }
2562         return $isWindows;
2563 }
2564
2565 /**
2566  * Check if we are running under HipHop
2567  *
2568  * @return Bool
2569  */
2570 function wfIsHipHop() {
2571         return function_exists( 'hphp_thread_set_warmup_enabled' );
2572 }
2573
2574 /**
2575  * Swap two variables
2576  *
2577  * @param $x Mixed
2578  * @param $y Mixed
2579  */
2580 function swap( &$x, &$y ) {
2581         $z = $x;
2582         $x = $y;
2583         $y = $z;
2584 }
2585
2586 /**
2587  * Tries to get the system directory for temporary files. First
2588  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2589  * environment variables are then checked in sequence, and if none are
2590  * set try sys_get_temp_dir().
2591  *
2592  * NOTE: When possible, use instead the tmpfile() function to create
2593  * temporary files to avoid race conditions on file creation, etc.
2594  *
2595  * @return String
2596  */
2597 function wfTempDir() {
2598         global $wgTmpDirectory;
2599
2600         if ( $wgTmpDirectory !== false ) {
2601                 return $wgTmpDirectory;
2602         }
2603
2604         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2605
2606         foreach( $tmpDir as $tmp ) {
2607                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2608                         return $tmp;
2609                 }
2610         }
2611         return sys_get_temp_dir();
2612 }
2613
2614 /**
2615  * Make directory, and make all parent directories if they don't exist
2616  *
2617  * @param $dir String: full path to directory to create
2618  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2619  * @param $caller String: optional caller param for debugging.
2620  * @return bool
2621  */
2622 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2623         global $wgDirectoryMode;
2624
2625         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2626                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2627         }
2628
2629         if ( !is_null( $caller ) ) {
2630                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2631         }
2632
2633         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2634                 return true;
2635         }
2636
2637         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2638
2639         if ( is_null( $mode ) ) {
2640                 $mode = $wgDirectoryMode;
2641         }
2642
2643         // Turn off the normal warning, we're doing our own below
2644         wfSuppressWarnings();
2645         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2646         wfRestoreWarnings();
2647
2648         if( !$ok ) {
2649                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2650                 trigger_error( sprintf( "%s: failed to mkdir \"%s\" mode 0%o", __FUNCTION__, $dir, $mode ),
2651                         E_USER_WARNING );
2652         }
2653         return $ok;
2654 }
2655
2656 /**
2657  * Remove a directory and all its content.
2658  * Does not hide error.
2659  */
2660 function wfRecursiveRemoveDir( $dir ) {
2661         wfDebug( __FUNCTION__ . "( $dir )\n" );
2662         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2663         if ( is_dir( $dir ) ) {
2664                 $objects = scandir( $dir );
2665                 foreach ( $objects as $object ) {
2666                         if ( $object != "." && $object != ".." ) {
2667                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2668                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2669                                 } else {
2670                                         unlink( $dir . '/' . $object );
2671                                 }
2672                         }
2673                 }
2674                 reset( $objects );
2675                 rmdir( $dir );
2676         }
2677 }
2678
2679 /**
2680  * @param $nr Mixed: the number to format
2681  * @param $acc Integer: the number of digits after the decimal point, default 2
2682  * @param $round Boolean: whether or not to round the value, default true
2683  * @return float
2684  */
2685 function wfPercent( $nr, $acc = 2, $round = true ) {
2686         $ret = sprintf( "%.${acc}f", $nr );
2687         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2688 }
2689
2690 /**
2691  * Find out whether or not a mixed variable exists in a string
2692  *
2693  * @param $needle String
2694  * @param $str String
2695  * @param $insensitive Boolean
2696  * @return Boolean
2697  */
2698 function in_string( $needle, $str, $insensitive = false ) {
2699         $func = 'strpos';
2700         if( $insensitive ) $func = 'stripos';
2701
2702         return $func( $str, $needle ) !== false;
2703 }
2704
2705 /**
2706  * Safety wrapper around ini_get() for boolean settings.
2707  * The values returned from ini_get() are pre-normalized for settings
2708  * set via php.ini or php_flag/php_admin_flag... but *not*
2709  * for those set via php_value/php_admin_value.
2710  *
2711  * It's fairly common for people to use php_value instead of php_flag,
2712  * which can leave you with an 'off' setting giving a false positive
2713  * for code that just takes the ini_get() return value as a boolean.
2714  *
2715  * To make things extra interesting, setting via php_value accepts
2716  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2717  * Unrecognized values go false... again opposite PHP's own coercion
2718  * from string to bool.
2719  *
2720  * Luckily, 'properly' set settings will always come back as '0' or '1',
2721  * so we only have to worry about them and the 'improper' settings.
2722  *
2723  * I frickin' hate PHP... :P
2724  *
2725  * @param $setting String
2726  * @return Bool
2727  */
2728 function wfIniGetBool( $setting ) {
2729         $val = ini_get( $setting );
2730         // 'on' and 'true' can't have whitespace around them, but '1' can.
2731         return strtolower( $val ) == 'on'
2732                 || strtolower( $val ) == 'true'
2733                 || strtolower( $val ) == 'yes'
2734                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2735 }
2736
2737 /**
2738  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2739  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2740  *
2741  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2742  *                          should be omitted
2743  * @param $fileName String Name of the library, if not $extension.suffix
2744  * @return Bool - Whether or not the extension is loaded
2745  */
2746 function wfDl( $extension, $fileName = null ) {
2747         if( extension_loaded( $extension ) ) {
2748                 return true;
2749         }
2750
2751         $canDl = false;
2752         $sapi = php_sapi_name();
2753         if( $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' ) {
2754                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2755                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2756         }
2757
2758         if( $canDl ) {
2759                 $fileName = $fileName ? $fileName : $extension;
2760                 if( wfIsWindows() ) {
2761                         $fileName = 'php_' . $fileName;
2762                 }
2763                 wfSuppressWarnings();
2764                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2765                 wfRestoreWarnings();
2766         }
2767         return extension_loaded( $extension );
2768 }
2769
2770 /**
2771  * Windows-compatible version of escapeshellarg()
2772  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2773  * function puts single quotes in regardless of OS.
2774  *
2775  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2776  * earlier distro releases of PHP)
2777  *
2778  * @param varargs
2779  * @return String
2780  */
2781 function wfEscapeShellArg( ) {
2782         wfInitShellLocale();
2783
2784         $args = func_get_args();
2785         $first = true;
2786         $retVal = '';
2787         foreach ( $args as $arg ) {
2788                 if ( !$first ) {
2789                         $retVal .= ' ';
2790                 } else {
2791                         $first = false;
2792                 }
2793
2794                 if ( wfIsWindows() ) {
2795                         // Escaping for an MSVC-style command line parser and CMD.EXE
2796                         // Refs:
2797                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2798                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2799                         //  * Bug #13518
2800                         //  * CR r63214
2801                         // Double the backslashes before any double quotes. Escape the double quotes.
2802                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2803                         $arg = '';
2804                         $iteration = 0;
2805                         foreach ( $tokens as $token ) {
2806                                 if ( $iteration % 2 == 1 ) {
2807                                         // Delimiter, a double quote preceded by zero or more slashes
2808                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2809                                 } elseif ( $iteration % 4 == 2 ) {
2810                                         // ^ in $token will be outside quotes, need to be escaped
2811                                         $arg .= str_replace( '^', '^^', $token );
2812                                 } else { // $iteration % 4 == 0
2813                                         // ^ in $token will appear inside double quotes, so leave as is
2814                                         $arg .= $token;
2815                                 }
2816                                 $iteration++;
2817                         }
2818                         // Double the backslashes before the end of the string, because
2819                         // we will soon add a quote
2820                         $m = array();
2821                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2822                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2823                         }
2824
2825                         // Add surrounding quotes
2826                         $retVal .= '"' . $arg . '"';
2827                 } else {
2828                         $retVal .= escapeshellarg( $arg );
2829                 }
2830         }
2831         return $retVal;
2832 }
2833
2834 /**
2835  * Execute a shell command, with time and memory limits mirrored from the PHP
2836  * configuration if supported.
2837  * @param $cmd String Command line, properly escaped for shell.
2838  * @param &$retval null|Mixed optional, will receive the program's exit code.
2839  *                 (non-zero is usually failure)
2840  * @param $environ Array optional environment variables which should be
2841  *                 added to the executed command environment.
2842  * @param $limits Array optional array with limits(filesize, memory, time)
2843  *                 this overwrites the global wgShellMax* limits.
2844  * @return string collected stdout as a string (trailing newlines stripped)
2845  */
2846 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2847         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2848
2849         static $disabled;
2850         if ( is_null( $disabled ) ) {
2851                 $disabled = false;
2852                 if( wfIniGetBool( 'safe_mode' ) ) {
2853                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2854                         $disabled = 'safemode';
2855                 } else {
2856                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2857                         $functions = array_map( 'trim', $functions );
2858                         $functions = array_map( 'strtolower', $functions );
2859                         if ( in_array( 'passthru', $functions ) ) {
2860                                 wfDebug( "passthru is in disabled_functions\n" );
2861                                 $disabled = 'passthru';
2862                         }
2863                 }
2864         }
2865         if ( $disabled ) {
2866                 $retval = 1;
2867                 return $disabled == 'safemode' ?
2868                         'Unable to run external programs in safe mode.' :
2869                         'Unable to run external programs, passthru() is disabled.';
2870         }
2871
2872         wfInitShellLocale();
2873
2874         $envcmd = '';
2875         foreach( $environ as $k => $v ) {
2876                 if ( wfIsWindows() ) {
2877                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2878                          * appear in the environment variable, so we must use carat escaping as documented in
2879                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2880                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2881                          * are listed there but doesn't appear to need it.
2882                          */
2883                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2884                 } else {
2885                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2886                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2887                          */
2888                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2889                 }
2890         }
2891         $cmd = $envcmd . $cmd;
2892
2893         if ( php_uname( 's' ) == 'Linux' ) {
2894                 $time = intval ( isset($limits['time']) ? $limits['time'] : $wgMaxShellTime );
2895                 $mem = intval ( isset($limits['memory']) ? $limits['memory'] : $wgMaxShellMemory );
2896                 $filesize = intval ( isset($limits['filesize']) ? $limits['filesize'] : $wgMaxShellFileSize );
2897
2898                 if ( $time > 0 && $mem > 0 ) {
2899                         $script = "$IP/bin/ulimit4.sh";
2900                         if ( is_executable( $script ) ) {
2901                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2902                         }
2903                 }
2904         }
2905         wfDebug( "wfShellExec: $cmd\n" );
2906
2907         $retval = 1; // error by default?
2908         ob_start();
2909         passthru( $cmd, $retval );
2910         $output = ob_get_contents();
2911         ob_end_clean();
2912
2913         if ( $retval == 127 ) {
2914                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2915         }
2916         return $output;
2917 }
2918
2919 /**
2920  * Workaround for http://bugs.php.net/bug.php?id=45132
2921  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2922  */
2923 function wfInitShellLocale() {
2924         static $done = false;
2925         if ( $done ) {
2926                 return;
2927         }
2928         $done = true;
2929         global $wgShellLocale;
2930         if ( !wfIniGetBool( 'safe_mode' ) ) {
2931                 putenv( "LC_CTYPE=$wgShellLocale" );
2932                 setlocale( LC_CTYPE, $wgShellLocale );
2933         }
2934 }
2935
2936 /**
2937  * Alias to wfShellWikiCmd()
2938  * @see wfShellWikiCmd()
2939  */
2940 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2941         return wfShellWikiCmd( $script, $parameters, $options );
2942 }
2943
2944 /**
2945  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2946  * Note that $parameters should be a flat array and an option with an argument
2947  * should consist of two consecutive items in the array (do not use "--option value").
2948  * @param $script string MediaWiki cli script path
2949  * @param $parameters Array Arguments and options to the script
2950  * @param $options Array Associative array of options:
2951  *              'php': The path to the php executable
2952  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2953  * @return Array
2954  */
2955 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2956         global $wgPhpCli;
2957         // Give site config file a chance to run the script in a wrapper.
2958         // The caller may likely want to call wfBasename() on $script.
2959         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2960         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2961         if ( isset( $options['wrapper'] ) ) {
2962                 $cmd[] = $options['wrapper'];
2963         }
2964         $cmd[] = $script;
2965         // Escape each parameter for shell
2966         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2967 }
2968
2969 /**
2970  * wfMerge attempts to merge differences between three texts.
2971  * Returns true for a clean merge and false for failure or a conflict.
2972  *
2973  * @param $old String
2974  * @param $mine String
2975  * @param $yours String
2976  * @param $result String
2977  * @return Bool
2978  */
2979 function wfMerge( $old, $mine, $yours, &$result ) {
2980         global $wgDiff3;
2981
2982         # This check may also protect against code injection in
2983         # case of broken installations.
2984         wfSuppressWarnings();
2985         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2986         wfRestoreWarnings();
2987
2988         if( !$haveDiff3 ) {
2989                 wfDebug( "diff3 not found\n" );
2990                 return false;
2991         }
2992
2993         # Make temporary files
2994         $td = wfTempDir();
2995         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2996         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2997         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2998
2999         fwrite( $oldtextFile, $old );
3000         fclose( $oldtextFile );
3001         fwrite( $mytextFile, $mine );
3002         fclose( $mytextFile );
3003         fwrite( $yourtextFile, $yours );
3004         fclose( $yourtextFile );
3005
3006         # Check for a conflict
3007         $cmd = $wgDiff3 . ' -a --overlap-only ' .
3008                 wfEscapeShellArg( $mytextName ) . ' ' .
3009                 wfEscapeShellArg( $oldtextName ) . ' ' .
3010                 wfEscapeShellArg( $yourtextName );
3011         $handle = popen( $cmd, 'r' );
3012
3013         if( fgets( $handle, 1024 ) ) {
3014                 $conflict = true;
3015         } else {
3016                 $conflict = false;
3017         }
3018         pclose( $handle );
3019
3020         # Merge differences
3021         $cmd = $wgDiff3 . ' -a -e --merge ' .
3022                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3023         $handle = popen( $cmd, 'r' );
3024         $result = '';
3025         do {
3026                 $data = fread( $handle, 8192 );
3027                 if ( strlen( $data ) == 0 ) {
3028                         break;
3029                 }
3030                 $result .= $data;
3031         } while ( true );
3032         pclose( $handle );
3033         unlink( $mytextName );
3034         unlink( $oldtextName );
3035         unlink( $yourtextName );
3036
3037         if ( $result === '' && $old !== '' && !$conflict ) {
3038                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3039                 $conflict = true;
3040         }
3041         return !$conflict;
3042 }
3043
3044 /**
3045  * Returns unified plain-text diff of two texts.
3046  * Useful for machine processing of diffs.
3047  *
3048  * @param $before String: the text before the changes.
3049  * @param $after String: the text after the changes.
3050  * @param $params String: command-line options for the diff command.
3051  * @return String: unified diff of $before and $after
3052  */
3053 function wfDiff( $before, $after, $params = '-u' ) {
3054         if ( $before == $after ) {
3055                 return '';
3056         }
3057
3058         global $wgDiff;
3059         wfSuppressWarnings();
3060         $haveDiff = $wgDiff && file_exists( $wgDiff );
3061         wfRestoreWarnings();
3062
3063         # This check may also protect against code injection in
3064         # case of broken installations.
3065         if( !$haveDiff ) {
3066                 wfDebug( "diff executable not found\n" );
3067                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3068                 $format = new UnifiedDiffFormatter();
3069                 return $format->format( $diffs );
3070         }
3071
3072         # Make temporary files
3073         $td = wfTempDir();
3074         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3075         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3076
3077         fwrite( $oldtextFile, $before );
3078         fclose( $oldtextFile );
3079         fwrite( $newtextFile, $after );
3080         fclose( $newtextFile );
3081
3082         // Get the diff of the two files
3083         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3084
3085         $h = popen( $cmd, 'r' );
3086
3087         $diff = '';
3088
3089         do {
3090                 $data = fread( $h, 8192 );
3091                 if ( strlen( $data ) == 0 ) {
3092                         break;
3093                 }
3094                 $diff .= $data;
3095         } while ( true );
3096
3097         // Clean up
3098         pclose( $h );
3099         unlink( $oldtextName );
3100         unlink( $newtextName );
3101
3102         // Kill the --- and +++ lines. They're not useful.
3103         $diff_lines = explode( "\n", $diff );
3104         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3105                 unset( $diff_lines[0] );
3106         }
3107         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3108                 unset( $diff_lines[1] );
3109         }
3110
3111         $diff = implode( "\n", $diff_lines );
3112
3113         return $diff;
3114 }
3115
3116 /**
3117  * This function works like "use VERSION" in Perl, the program will die with a
3118  * backtrace if the current version of PHP is less than the version provided
3119  *
3120  * This is useful for extensions which due to their nature are not kept in sync
3121  * with releases, and might depend on other versions of PHP than the main code
3122  *
3123  * Note: PHP might die due to parsing errors in some cases before it ever
3124  *       manages to call this function, such is life
3125  *
3126  * @see perldoc -f use
3127  *
3128  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3129  *                 a float
3130  */
3131 function wfUsePHP( $req_ver ) {
3132         $php_ver = PHP_VERSION;
3133
3134         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3135                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3136         }
3137 }
3138
3139 /**
3140  * This function works like "use VERSION" in Perl except it checks the version
3141  * of MediaWiki, the program will die with a backtrace if the current version
3142  * of MediaWiki is less than the version provided.
3143  *
3144  * This is useful for extensions which due to their nature are not kept in sync
3145  * with releases
3146  *
3147  * @see perldoc -f use
3148  *
3149  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3150  *                 a float
3151  */
3152 function wfUseMW( $req_ver ) {
3153         global $wgVersion;
3154
3155         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3156                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3157         }
3158 }
3159
3160 /**
3161  * Return the final portion of a pathname.
3162  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3163  * http://bugs.php.net/bug.php?id=33898
3164  *
3165  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3166  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3167  *
3168  * @param $path String
3169  * @param $suffix String: to remove if present
3170  * @return String
3171  */
3172 function wfBaseName( $path, $suffix = '' ) {
3173         $encSuffix = ( $suffix == '' )
3174                 ? ''
3175                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3176         $matches = array();
3177         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3178                 return $matches[1];
3179         } else {
3180                 return '';
3181         }
3182 }
3183
3184 /**
3185  * Generate a relative path name to the given file.
3186  * May explode on non-matching case-insensitive paths,
3187  * funky symlinks, etc.
3188  *
3189  * @param $path String: absolute destination path including target filename
3190  * @param $from String: Absolute source path, directory only
3191  * @return String
3192  */
3193 function wfRelativePath( $path, $from ) {
3194         // Normalize mixed input on Windows...
3195         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3196         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3197
3198         // Trim trailing slashes -- fix for drive root
3199         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3200         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3201
3202         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3203         $against = explode( DIRECTORY_SEPARATOR, $from );
3204
3205         if( $pieces[0] !== $against[0] ) {
3206                 // Non-matching Windows drive letters?
3207                 // Return a full path.
3208                 return $path;
3209         }
3210
3211         // Trim off common prefix
3212         while( count( $pieces ) && count( $against )
3213                 && $pieces[0] == $against[0] ) {
3214                 array_shift( $pieces );
3215                 array_shift( $against );
3216         }
3217
3218         // relative dots to bump us to the parent
3219         while( count( $against ) ) {
3220                 array_unshift( $pieces, '..' );
3221                 array_shift( $against );
3222         }
3223
3224         array_push( $pieces, wfBaseName( $path ) );
3225
3226         return implode( DIRECTORY_SEPARATOR, $pieces );
3227 }
3228
3229 /**
3230  * Do any deferred updates and clear the list
3231  *
3232  * @deprecated since 1.19
3233  * @see DeferredUpdates::doUpdate()
3234  * @param $commit string
3235  */
3236 function wfDoUpdates( $commit = '' ) {
3237         wfDeprecated( __METHOD__, '1.19' );
3238         DeferredUpdates::doUpdates( $commit );
3239 }
3240
3241 /**
3242  * Convert an arbitrarily-long digit string from one numeric base
3243  * to another, optionally zero-padding to a minimum column width.
3244  *
3245  * Supports base 2 through 36; digit values 10-36 are represented
3246  * as lowercase letters a-z. Input is case-insensitive.
3247  *
3248  * @param $input String: of digits
3249  * @param $sourceBase Integer: 2-36
3250  * @param $destBase Integer: 2-36
3251  * @param $pad Integer: 1 or greater
3252  * @param $lowercase Boolean
3253  * @return String or false on invalid input
3254  */
3255 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3256         $input = strval( $input );
3257         if( $sourceBase < 2 ||
3258                 $sourceBase > 36 ||
3259                 $destBase < 2 ||
3260                 $destBase > 36 ||
3261                 $pad < 1 ||
3262                 $sourceBase != intval( $sourceBase ) ||
3263                 $destBase != intval( $destBase ) ||
3264                 $pad != intval( $pad ) ||
3265                 !is_string( $input ) ||
3266                 $input == '' ) {
3267                 return false;
3268         }
3269         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3270         $inDigits = array();
3271         $outChars = '';
3272
3273         // Decode and validate input string
3274         $input = strtolower( $input );
3275         for( $i = 0; $i < strlen( $input ); $i++ ) {
3276                 $n = strpos( $digitChars, $input[$i] );
3277                 if( $n === false || $n > $sourceBase ) {
3278                         return false;
3279                 }
3280                 $inDigits[] = $n;
3281         }
3282
3283         // Iterate over the input, modulo-ing out an output digit
3284         // at a time until input is gone.
3285         while( count( $inDigits ) ) {
3286                 $work = 0;
3287                 $workDigits = array();
3288
3289                 // Long division...
3290                 foreach( $inDigits as $digit ) {
3291                         $work *= $sourceBase;
3292                         $work += $digit;
3293
3294                         if( $work < $destBase ) {
3295                                 // Gonna need to pull another digit.
3296                                 if( count( $workDigits ) ) {
3297                                         // Avoid zero-padding; this lets us find
3298                                         // the end of the input very easily when
3299                                         // length drops to zero.
3300                                         $workDigits[] = 0;
3301                                 }
3302                         } else {
3303                                 // Finally! Actual division!
3304                                 $workDigits[] = intval( $work / $destBase );
3305
3306                                 // Isn't it annoying that most programming languages
3307                                 // don't have a single divide-and-remainder operator,
3308                                 // even though the CPU implements it that way?
3309                                 $work = $work % $destBase;
3310                         }
3311                 }
3312
3313                 // All that division leaves us with a remainder,
3314                 // which is conveniently our next output digit.
3315                 $outChars .= $digitChars[$work];
3316
3317                 // And we continue!
3318                 $inDigits = $workDigits;
3319         }
3320
3321         while( strlen( $outChars ) < $pad ) {
3322                 $outChars .= '0';
3323         }
3324
3325         return strrev( $outChars );
3326 }
3327
3328 /**
3329  * Create an object with a given name and an array of construct parameters
3330  *
3331  * @param $name String
3332  * @param $p Array: parameters
3333  * @return object
3334  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3335  */
3336 function wfCreateObject( $name, $p ) {
3337         wfDeprecated( __FUNCTION__, '1.18' );
3338         return MWFunction::newObj( $name, $p );
3339 }
3340
3341 /**
3342  * @return bool
3343  */
3344 function wfHttpOnlySafe() {
3345         global $wgHttpOnlyBlacklist;
3346
3347         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3348                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3349                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3350                                 return false;
3351                         }
3352                 }
3353         }
3354
3355         return true;
3356 }
3357
3358 /**
3359  * Override session_id before session startup if php's built-in
3360  * session generation code is not secure.
3361  */
3362 function wfFixSessionID() {
3363         // If the cookie or session id is already set we already have a session and should abort
3364         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3365                 return;
3366         }
3367
3368         // PHP's built-in session entropy is enabled if:
3369         // - entropy_file is set or you're on Windows with php 5.3.3+
3370         // - AND entropy_length is > 0
3371         // We treat it as disabled if it doesn't have an entropy length of at least 32
3372         $entropyEnabled = (
3373                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3374                         || ini_get( 'session.entropy_file' )
3375                 )
3376                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3377
3378         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3379         if ( !$entropyEnabled ) {
3380                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3381                 session_id( MWCryptRand::generateHex( 32 ) );
3382         }
3383 }
3384
3385 /**
3386  * Initialise php session
3387  *
3388  * @param $sessionId Bool
3389  */
3390 function wfSetupSession( $sessionId = false ) {
3391         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3392                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3393         if( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3394                 ObjectCacheSessionHandler::install();
3395         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3396                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3397                 # hasn't already been set to the desired value (that causes errors)
3398                 ini_set( 'session.save_handler', $wgSessionHandler );
3399         }
3400         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3401         wfDebugLog( 'cookie',
3402                 'session_set_cookie_params: "' . implode( '", "',
3403                         array(
3404                                 0,
3405                                 $wgCookiePath,
3406                                 $wgCookieDomain,
3407                                 $wgCookieSecure,
3408                                 $httpOnlySafe ) ) . '"' );
3409         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3410         session_cache_limiter( 'private, must-revalidate' );
3411         if ( $sessionId ) {
3412                 session_id( $sessionId );
3413         } else {
3414                 wfFixSessionID();
3415         }
3416         wfSuppressWarnings();
3417         session_start();
3418         wfRestoreWarnings();
3419 }
3420
3421 /**
3422  * Get an object from the precompiled serialized directory
3423  *
3424  * @param $name String
3425  * @return Mixed: the variable on success, false on failure
3426  */
3427 function wfGetPrecompiledData( $name ) {
3428         global $IP;
3429
3430         $file = "$IP/serialized/$name";
3431         if ( file_exists( $file ) ) {
3432                 $blob = file_get_contents( $file );
3433                 if ( $blob ) {
3434                         return unserialize( $blob );
3435                 }
3436         }
3437         return false;
3438 }
3439
3440 /**
3441  * Get a cache key
3442  *
3443  * @param varargs
3444  * @return String
3445  */
3446 function wfMemcKey( /*... */ ) {
3447         global $wgCachePrefix;
3448         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3449         $args = func_get_args();
3450         $key = $prefix . ':' . implode( ':', $args );
3451         $key = str_replace( ' ', '_', $key );
3452         return $key;
3453 }
3454
3455 /**
3456  * Get a cache key for a foreign DB
3457  *
3458  * @param $db String
3459  * @param $prefix String
3460  * @param varargs String
3461  * @return String
3462  */
3463 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3464         $args = array_slice( func_get_args(), 2 );
3465         if ( $prefix ) {
3466                 $key = "$db-$prefix:" . implode( ':', $args );
3467         } else {
3468                 $key = $db . ':' . implode( ':', $args );
3469         }
3470         return $key;
3471 }
3472
3473 /**
3474  * Get an ASCII string identifying this wiki
3475  * This is used as a prefix in memcached keys
3476  *
3477  * @return String
3478  */
3479 function wfWikiID() {
3480         global $wgDBprefix, $wgDBname;
3481         if ( $wgDBprefix ) {
3482                 return "$wgDBname-$wgDBprefix";
3483         } else {
3484                 return $wgDBname;
3485         }
3486 }
3487
3488 /**
3489  * Split a wiki ID into DB name and table prefix
3490  *
3491  * @param $wiki String
3492  *
3493  * @return array
3494  */
3495 function wfSplitWikiID( $wiki ) {
3496         $bits = explode( '-', $wiki, 2 );
3497         if ( count( $bits ) < 2 ) {
3498                 $bits[] = '';
3499         }
3500         return $bits;
3501 }
3502
3503 /**
3504  * Get a Database object.
3505  *
3506  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3507  *            master (for write queries), DB_SLAVE for potentially lagged read
3508  *            queries, or an integer >= 0 for a particular server.
3509  *
3510  * @param $groups Mixed: query groups. An array of group names that this query
3511  *                belongs to. May contain a single string if the query is only
3512  *                in one group.
3513  *
3514  * @param $wiki String: the wiki ID, or false for the current wiki
3515  *
3516  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3517  * will always return the same object, unless the underlying connection or load
3518  * balancer is manually destroyed.
3519  *
3520  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3521  * updater to ensure that a proper database is being updated.
3522  *
3523  * @return DatabaseBase
3524  */
3525 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3526         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3527 }
3528
3529 /**
3530  * Get a load balancer object.
3531  *
3532  * @param $wiki String: wiki ID, or false for the current wiki
3533  * @return LoadBalancer
3534  */
3535 function wfGetLB( $wiki = false ) {
3536         return wfGetLBFactory()->getMainLB( $wiki );
3537 }
3538
3539 /**
3540  * Get the load balancer factory object
3541  *
3542  * @return LBFactory
3543  */
3544 function &wfGetLBFactory() {
3545         return LBFactory::singleton();
3546 }
3547
3548 /**
3549  * Find a file.
3550  * Shortcut for RepoGroup::singleton()->findFile()
3551  *
3552  * @param $title String or Title object
3553  * @param $options array Associative array of options:
3554  *     time:           requested time for an archived image, or false for the
3555  *                     current version. An image object will be returned which was
3556  *                     created at the specified time.
3557  *
3558  *     ignoreRedirect: If true, do not follow file redirects
3559  *
3560  *     private:        If true, return restricted (deleted) files if the current
3561  *                     user is allowed to view them. Otherwise, such files will not
3562  *                     be found.
3563  *
3564  *     bypassCache:    If true, do not use the process-local cache of File objects
3565  *
3566  * @return File, or false if the file does not exist
3567  */
3568 function wfFindFile( $title, $options = array() ) {
3569         return RepoGroup::singleton()->findFile( $title, $options );
3570 }
3571
3572 /**
3573  * Get an object referring to a locally registered file.
3574  * Returns a valid placeholder object if the file does not exist.
3575  *
3576  * @param $title Title|String
3577  * @return LocalFile|null A File, or null if passed an invalid Title
3578  */
3579 function wfLocalFile( $title ) {
3580         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3581 }
3582
3583 /**
3584  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3585  * @deprecated since 1.19
3586  */
3587 function wfStreamFile( $fname, $headers = array() ) {
3588         wfDeprecated( __FUNCTION__, '1.19' );
3589         StreamFile::stream( $fname, $headers );
3590 }
3591
3592 /**
3593  * Should low-performance queries be disabled?
3594  *
3595  * @return Boolean
3596  * @codeCoverageIgnore
3597  */
3598 function wfQueriesMustScale() {
3599         global $wgMiserMode;
3600         return $wgMiserMode
3601                 || ( SiteStats::pages() > 100000
3602                 && SiteStats::edits() > 1000000
3603                 && SiteStats::users() > 10000 );
3604 }
3605
3606 /**
3607  * Get the path to a specified script file, respecting file
3608  * extensions; this is a wrapper around $wgScriptExtension etc.
3609  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3610  *
3611  * @param $script String: script filename, sans extension
3612  * @return String
3613  */
3614 function wfScript( $script = 'index' ) {
3615         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3616         if ( $script === 'index' ) {
3617                 return $wgScript;
3618         } else if ( $script === 'load' ) {
3619                 return $wgLoadScript;
3620         } else {
3621                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3622         }
3623 }
3624
3625 /**
3626  * Get the script URL.
3627  *
3628  * @return string script URL
3629  */
3630 function wfGetScriptUrl() {
3631         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3632                 #
3633                 # as it was called, minus the query string.
3634                 #
3635                 # Some sites use Apache rewrite rules to handle subdomains,
3636                 # and have PHP set up in a weird way that causes PHP_SELF
3637                 # to contain the rewritten URL instead of the one that the
3638                 # outside world sees.
3639                 #
3640                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3641                 # provides containing the "before" URL.
3642                 return $_SERVER['SCRIPT_NAME'];
3643         } else {
3644                 return $_SERVER['URL'];
3645         }
3646 }
3647
3648 /**
3649  * Convenience function converts boolean values into "true"
3650  * or "false" (string) values
3651  *
3652  * @param $value Boolean
3653  * @return String
3654  */
3655 function wfBoolToStr( $value ) {
3656         return $value ? 'true' : 'false';
3657 }
3658
3659 /**
3660  * Load an extension messages file
3661  *
3662  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3663  * @codeCoverageIgnore
3664  */
3665 function wfLoadExtensionMessages() {
3666         wfDeprecated( __FUNCTION__, '1.16' );
3667 }
3668
3669 /**
3670  * Get a platform-independent path to the null file, e.g. /dev/null
3671  *
3672  * @return string
3673  */
3674 function wfGetNull() {
3675         return wfIsWindows()
3676                 ? 'NUL'
3677                 : '/dev/null';
3678 }
3679
3680 /**
3681  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3682  * and waiting for it to go down, this waits for the slaves to catch up to the
3683  * master position. Use this when updating very large numbers of rows, as
3684  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3685  * a no-op if there are no slaves.
3686  *
3687  * @param $maxLag Integer (deprecated)
3688  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3689  */
3690 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3691         $lb = wfGetLB( $wiki );
3692         // bug 27975 - Don't try to wait for slaves if there are none
3693         // Prevents permission error when getting master position
3694         if ( $lb->getServerCount() > 1 ) {
3695                 $dbw = $lb->getConnection( DB_MASTER );
3696                 $pos = $dbw->getMasterPos();
3697                 $lb->waitForAll( $pos );
3698         }
3699 }
3700
3701 /**
3702  * Used to be used for outputting text in the installer/updater
3703  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3704  */
3705 function wfOut( $s ) {
3706         wfDeprecated( __FUNCTION__, '1.18' );
3707         global $wgCommandLineMode;
3708         if ( $wgCommandLineMode ) {
3709                 echo $s;
3710         } else {
3711                 echo htmlspecialchars( $s );
3712         }
3713         flush();
3714 }
3715
3716 /**
3717  * Count down from $n to zero on the terminal, with a one-second pause
3718  * between showing each number. For use in command-line scripts.
3719  * @codeCoverageIgnore
3720  * @param $n int
3721  */
3722 function wfCountDown( $n ) {
3723         for ( $i = $n; $i >= 0; $i-- ) {
3724                 if ( $i != $n ) {
3725                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3726                 }
3727                 echo $i;
3728                 flush();
3729                 if ( $i ) {
3730                         sleep( 1 );
3731                 }
3732         }
3733         echo "\n";
3734 }
3735
3736 /**
3737  * Generate a random 32-character hexadecimal token.
3738  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3739  *              characters before hashing.
3740  * @return string
3741  * @codeCoverageIgnore
3742  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pesudo-random strings
3743  * @warning This method is NOT secure. Additionally it has many callers that use it for pesudo-random purposes.
3744  */
3745 function wfGenerateToken( $salt = '' ) {
3746         wfDeprecated( __METHOD__, '1.20' );
3747         $salt = serialize( $salt );
3748         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3749 }
3750
3751 /**
3752  * Replace all invalid characters with -
3753  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3754  * By default, $wgIllegalFileChars = ':'
3755  *
3756  * @param $name Mixed: filename to process
3757  * @return String
3758  */
3759 function wfStripIllegalFilenameChars( $name ) {
3760         global $wgIllegalFileChars;
3761         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3762         $name = wfBaseName( $name );
3763         $name = preg_replace(
3764                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3765                 '-',
3766                 $name
3767         );
3768         return $name;
3769 }
3770
3771 /**
3772  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3773  *
3774  * @return Integer value memory was set to.
3775  */
3776 function wfMemoryLimit() {
3777         global $wgMemoryLimit;
3778         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3779         if( $memlimit != -1 ) {
3780                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3781                 if( $conflimit == -1 ) {
3782                         wfDebug( "Removing PHP's memory limit\n" );
3783                         wfSuppressWarnings();
3784                         ini_set( 'memory_limit', $conflimit );
3785                         wfRestoreWarnings();
3786                         return $conflimit;
3787                 } elseif ( $conflimit > $memlimit ) {
3788                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3789                         wfSuppressWarnings();
3790                         ini_set( 'memory_limit', $conflimit );
3791                         wfRestoreWarnings();
3792                         return $conflimit;
3793                 }
3794         }
3795         return $memlimit;
3796 }
3797
3798 /**
3799  * Converts shorthand byte notation to integer form
3800  *
3801  * @param $string String
3802  * @return Integer
3803  */
3804 function wfShorthandToInteger( $string = '' ) {
3805         $string = trim( $string );
3806         if( $string === '' ) {
3807                 return -1;
3808         }
3809         $last = $string[strlen( $string ) - 1];
3810         $val = intval( $string );
3811         switch( $last ) {
3812                 case 'g':
3813                 case 'G':
3814                         $val *= 1024;
3815                         // break intentionally missing
3816                 case 'm':
3817                 case 'M':
3818                         $val *= 1024;
3819                         // break intentionally missing
3820                 case 'k':
3821                 case 'K':
3822                         $val *= 1024;
3823         }
3824
3825         return $val;
3826 }
3827
3828 /**
3829  * Get the normalised IETF language tag
3830  * See unit test for examples.
3831  *
3832  * @param $code String: The language code.
3833  * @return String: The language code which complying with BCP 47 standards.
3834  */
3835 function wfBCP47( $code ) {
3836         $codeSegment = explode( '-', $code );
3837         $codeBCP = array();
3838         foreach ( $codeSegment as $segNo => $seg ) {
3839                 if ( count( $codeSegment ) > 0 ) {
3840                         // when previous segment is x, it is a private segment and should be lc
3841                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3842                                 $codeBCP[$segNo] = strtolower( $seg );
3843                         // ISO 3166 country code
3844                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3845                                 $codeBCP[$segNo] = strtoupper( $seg );
3846                         // ISO 15924 script code
3847                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3848                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3849                         // Use lowercase for other cases
3850                         } else {
3851                                 $codeBCP[$segNo] = strtolower( $seg );
3852                         }
3853                 } else {
3854                 // Use lowercase for single segment
3855                         $codeBCP[$segNo] = strtolower( $seg );
3856                 }
3857         }
3858         $langCode = implode( '-', $codeBCP );
3859         return $langCode;
3860 }
3861
3862 /**
3863  * Get a cache object.
3864  *
3865  * @param $inputType integer Cache type, one the the CACHE_* constants.
3866  * @return BagOStuff
3867  */
3868 function wfGetCache( $inputType ) {
3869         return ObjectCache::getInstance( $inputType );
3870 }
3871
3872 /**
3873  * Get the main cache object
3874  *
3875  * @return BagOStuff
3876  */
3877 function wfGetMainCache() {
3878         global $wgMainCacheType;
3879         return ObjectCache::getInstance( $wgMainCacheType );
3880 }
3881
3882 /**
3883  * Get the cache object used by the message cache
3884  *
3885  * @return BagOStuff
3886  */
3887 function wfGetMessageCacheStorage() {
3888         global $wgMessageCacheType;
3889         return ObjectCache::getInstance( $wgMessageCacheType );
3890 }
3891
3892 /**
3893  * Get the cache object used by the parser cache
3894  *
3895  * @return BagOStuff
3896  */
3897 function wfGetParserCacheStorage() {
3898         global $wgParserCacheType;
3899         return ObjectCache::getInstance( $wgParserCacheType );
3900 }
3901
3902 /**
3903  * Get the cache object used by the language converter
3904  *
3905  * @return BagOStuff
3906  */
3907 function wfGetLangConverterCacheStorage() {
3908         global $wgLanguageConverterCacheType;
3909         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3910 }
3911
3912 /**
3913  * Call hook functions defined in $wgHooks
3914  *
3915  * @param $event String: event name
3916  * @param $args Array: parameters passed to hook functions
3917  * @return Boolean True if no handler aborted the hook
3918  */
3919 function wfRunHooks( $event, $args = array() ) {
3920         return Hooks::run( $event, $args );
3921 }
3922
3923 /**
3924  * Wrapper around php's unpack.
3925  *
3926  * @param $format String: The format string (See php's docs)
3927  * @param $data: A binary string of binary data
3928  * @param $length integer or false: The minimun length of $data. This is to
3929  *      prevent reading beyond the end of $data. false to disable the check.
3930  *
3931  * Also be careful when using this function to read unsigned 32 bit integer
3932  * because php might make it negative.
3933  *
3934  * @throws MWException if $data not long enough, or if unpack fails
3935  * @return array Associative array of the extracted data
3936  */
3937 function wfUnpack( $format, $data, $length=false ) {
3938         if ( $length !== false ) {
3939                 $realLen = strlen( $data );
3940                 if ( $realLen < $length ) {
3941                         throw new MWException( "Tried to use wfUnpack on a "
3942                                 . "string of length $realLen, but needed one "
3943                                 . "of at least length $length."
3944                         );
3945                 }
3946         }
3947
3948         wfSuppressWarnings();
3949         $result = unpack( $format, $data );
3950         wfRestoreWarnings();
3951
3952         if ( $result === false ) {
3953                 // If it cannot extract the packed data.
3954                 throw new MWException( "unpack could not unpack binary data" );
3955         }
3956         return $result;
3957 }
3958
3959 /**
3960  * Determine if an image exists on the 'bad image list'.
3961  *
3962  * The format of MediaWiki:Bad_image_list is as follows:
3963  *    * Only list items (lines starting with "*") are considered
3964  *    * The first link on a line must be a link to a bad image
3965  *    * Any subsequent links on the same line are considered to be exceptions,
3966  *      i.e. articles where the image may occur inline.
3967  *
3968  * @param $name string the image name to check
3969  * @param $contextTitle Title|bool the page on which the image occurs, if known
3970  * @param $blacklist string wikitext of a file blacklist
3971  * @return bool
3972  */
3973 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3974         static $badImageCache = null; // based on bad_image_list msg
3975         wfProfileIn( __METHOD__ );
3976
3977         # Handle redirects
3978         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3979         if( $redirectTitle ) {
3980                 $name = $redirectTitle->getDbKey();
3981         }
3982
3983         # Run the extension hook
3984         $bad = false;
3985         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3986                 wfProfileOut( __METHOD__ );
3987                 return $bad;
3988         }
3989
3990         $cacheable = ( $blacklist === null );
3991         if( $cacheable && $badImageCache !== null ) {
3992                 $badImages = $badImageCache;
3993         } else { // cache miss
3994                 if ( $blacklist === null ) {
3995                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3996                 }
3997                 # Build the list now
3998                 $badImages = array();
3999                 $lines = explode( "\n", $blacklist );
4000                 foreach( $lines as $line ) {
4001                         # List items only
4002                         if ( substr( $line, 0, 1 ) !== '*' ) {
4003                                 continue;
4004                         }
4005
4006                         # Find all links
4007                         $m = array();
4008                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4009                                 continue;
4010                         }
4011
4012                         $exceptions = array();
4013                         $imageDBkey = false;
4014                         foreach ( $m[1] as $i => $titleText ) {
4015                                 $title = Title::newFromText( $titleText );
4016                                 if ( !is_null( $title ) ) {
4017                                         if ( $i == 0 ) {
4018                                                 $imageDBkey = $title->getDBkey();
4019                                         } else {
4020                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4021                                         }
4022                                 }
4023                         }
4024
4025                         if ( $imageDBkey !== false ) {
4026                                 $badImages[$imageDBkey] = $exceptions;
4027                         }
4028                 }
4029                 if ( $cacheable ) {
4030                         $badImageCache = $badImages;
4031                 }
4032         }
4033
4034         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4035         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4036         wfProfileOut( __METHOD__ );
4037         return $bad;
4038 }