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  * @throws MWException
 173  */
 174 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 175         if ( is_null( $changed ) ) {
 176                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 177         }
 178         if ( $default[$key] !== $value ) {
 179                 $changed[$key] = $value;
 180         }
 181 }
 182
 183 /**
 184  * Backwards array plus for people who haven't bothered to read the PHP manual
 185  * XXX: will not darn your socks for you.
 186  *
 187  * @param $array1 Array
 188  * @param [$array2, [...]] Arrays
 189  * @return Array
 190  */
 191 function wfArrayMerge( $array1/* ... */ ) {
 192         $args = func_get_args();
 193         $args = array_reverse( $args, true );
 194         $out = array();
 195         foreach ( $args as $arg ) {
 196                 $out += $arg;
 197         }
 198         return $out;
 199 }
 200
 201 /**
 202  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 203  * e.g.
 204  *      wfMergeErrorArrays(
 205  *              array( array( 'x' ) ),
 206  *              array( array( 'x', '2' ) ),
 207  *              array( array( 'x' ) ),
 208  *              array( array( 'y' ) )
 209  *      );
 210  * returns:
 211  *              array(
 212  *              array( 'x', '2' ),
 213  *              array( 'x' ),
 214  *              array( 'y' )
 215  *      )
 216  * @param varargs
 217  * @return Array
 218  */
 219 function wfMergeErrorArrays( /*...*/ ) {
 220         $args = func_get_args();
 221         $out = array();
 222         foreach ( $args as $errors ) {
 223                 foreach ( $errors as $params ) {
 224                         # @todo FIXME: Sometimes get nested arrays for $params,
 225                         # which leads to E_NOTICEs
 226                         $spec = implode( "\t", $params );
 227                         $out[$spec] = $params;
 228                 }
 229         }
 230         return array_values( $out );
 231 }
 232
 233 /**
 234  * Insert array into another array after the specified *KEY*
 235  *
 236  * @param $array Array: The array.
 237  * @param $insert Array: The array to insert.
 238  * @param $after Mixed: The key to insert after
 239  * @return Array
 240  */
 241 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 242         // Find the offset of the element to insert after.
 243         $keys = array_keys( $array );
 244         $offsetByKey = array_flip( $keys );
 245
 246         $offset = $offsetByKey[$after];
 247
 248         // Insert at the specified offset
 249         $before = array_slice( $array, 0, $offset + 1, true );
 250         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 251
 252         $output = $before + $insert + $after;
 253
 254         return $output;
 255 }
 256
 257 /**
 258  * Recursively converts the parameter (an object) to an array with the same data
 259  *
 260  * @param $objOrArray Object|Array
 261  * @param $recursive Bool
 262  * @return Array
 263  */
 264 function wfObjectToArray( $objOrArray, $recursive = true ) {
 265         $array = array();
 266         if( is_object( $objOrArray ) ) {
 267                 $objOrArray = get_object_vars( $objOrArray );
 268         }
 269         foreach ( $objOrArray as $key => $value ) {
 270                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 271                         $value = wfObjectToArray( $value );
 272                 }
 273
 274                 $array[$key] = $value;
 275         }
 276
 277         return $array;
 278 }
 279
 280 /**
 281  * Wrapper around array_map() which also taints variables
 282  *
 283  * @param  $function Callback
 284  * @param  $input Array
 285  * @return Array
 286  */
 287 function wfArrayMap( $function, $input ) {
 288         $ret = array_map( $function, $input );
 289         foreach ( $ret as $key => $value ) {
 290                 $taint = istainted( $input[$key] );
 291                 if ( $taint ) {
 292                         taint( $ret[$key], $taint );
 293                 }
 294         }
 295         return $ret;
 296 }
 297
 298 /**
 299  * Get a random decimal value between 0 and 1, in a way
 300  * not likely to give duplicate values for any realistic
 301  * number of articles.
 302  *
 303  * @return string
 304  */
 305 function wfRandom() {
 306         # The maximum random value is "only" 2^31-1, so get two random
 307         # values to reduce the chance of dupes
 308         $max = mt_getrandmax() + 1;
 309         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 310                 / $max / $max, 12, '.', '' );
 311         return $rand;
 312 }
 313
 314 /**
 315  * Get a random string containing a number of pesudo-random hex
 316  * characters.
 317  * @note This is not secure, if you are trying to generate some sort
 318  *       of token please use MWCryptRand instead.
 319  *
 320  * @param $length int The length of the string to generate
 321  * @return String
 322  * @since 1.20
 323  */
 324 function wfRandomString( $length = 32 ) {
 325         $str = '';
 326         while ( strlen( $str ) < $length ) {
 327                 $str .= dechex( mt_rand() );
 328         }
 329         return substr( $str, 0, $length );
 330 }
 331
 332 /**
 333  * We want some things to be included as literal characters in our title URLs
 334  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 335  * all of the following should be safe:
 336  *
 337  * ;:@&=$-_.+!*'(),
 338  *
 339  * But + is not safe because it's used to indicate a space; &= are only safe in
 340  * paths and not in queries (and we don't distinguish here); ' seems kind of
 341  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 342  * is reserved, we don't care.  So the list we unescape is:
 343  *
 344  * ;:@$!*(),/
 345  *
 346  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 347  * so no fancy : for IIS7.
 348  *
 349  * %2F in the page titles seems to fatally break for some reason.
 350  *
 351  * @param $s String:
 352  * @return string
 353 */
 354 function wfUrlencode( $s ) {
 355         static $needle;
 356         if ( is_null( $s ) ) {
 357                 $needle = null;
 358                 return '';
 359         }
 360
 361         if ( is_null( $needle ) ) {
 362                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 363                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 364                         $needle[] = '%3A';
 365                 }
 366         }
 367
 368         $s = urlencode( $s );
 369         $s = str_ireplace(
 370                 $needle,
 371                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 372                 $s
 373         );
 374
 375         return $s;
 376 }
 377
 378 /**
 379  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 380  * "days=7&limit=100". Options in the first array override options in the second.
 381  * Options set to null or false will not be output.
 382  *
 383  * @param $array1 Array ( String|Array )
 384  * @param $array2 Array ( String|Array )
 385  * @param $prefix String
 386  * @return String
 387  */
 388 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 389         if ( !is_null( $array2 ) ) {
 390                 $array1 = $array1 + $array2;
 391         }
 392
 393         $cgi = '';
 394         foreach ( $array1 as $key => $value ) {
 395                 if ( !is_null( $value ) && $value !== false ) {
 396                         if ( $cgi != '' ) {
 397                                 $cgi .= '&';
 398                         }
 399                         if ( $prefix !== '' ) {
 400                                 $key = $prefix . "[$key]";
 401                         }
 402                         if ( is_array( $value ) ) {
 403                                 $firstTime = true;
 404                                 foreach ( $value as $k => $v ) {
 405                                         $cgi .= $firstTime ? '' : '&';
 406                                         if ( is_array( $v ) ) {
 407                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 408                                         } else {
 409                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 410                                         }
 411                                         $firstTime = false;
 412                                 }
 413                         } else {
 414                                 if ( is_object( $value ) ) {
 415                                         $value = $value->__toString();
 416                                 }
 417                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 418                         }
 419                 }
 420         }
 421         return $cgi;
 422 }
 423
 424 /**
 425  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 426  * its argument and returns the same string in array form.  This allows compa-
 427  * tibility with legacy functions that accept raw query strings instead of nice
 428  * arrays.  Of course, keys and values are urldecode()d.
 429  *
 430  * @param $query String: query string
 431  * @return array Array version of input
 432  */
 433 function wfCgiToArray( $query ) {
 434         if ( isset( $query[0] ) && $query[0] == '?' ) {
 435                 $query = substr( $query, 1 );
 436         }
 437         $bits = explode( '&', $query );
 438         $ret = array();
 439         foreach ( $bits as $bit ) {
 440                 if ( $bit === '' ) {
 441                         continue;
 442                 }
 443                 if ( strpos( $bit, '=' ) === false ) {
 444                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 445                         $key = $bit;
 446                         $value = '';
 447                 } else {
 448                         list( $key, $value ) = explode( '=', $bit );
 449                 }
 450                 $key = urldecode( $key );
 451                 $value = urldecode( $value );
 452                 if ( strpos( $key, '[' ) !== false ) {
 453                         $keys = array_reverse( explode( '[', $key ) );
 454                         $key = array_pop( $keys );
 455                         $temp = $value;
 456                         foreach ( $keys as $k ) {
 457                                 $k = substr( $k, 0, -1 );
 458                                 $temp = array( $k => $temp );
 459                         }
 460                         if ( isset( $ret[$key] ) ) {
 461                                 $ret[$key] = array_merge( $ret[$key], $temp );
 462                         } else {
 463                                 $ret[$key] = $temp;
 464                         }
 465                 } else {
 466                         $ret[$key] = $value;
 467                 }
 468         }
 469         return $ret;
 470 }
 471
 472 /**
 473  * Append a query string to an existing URL, which may or may not already
 474  * have query string parameters already. If so, they will be combined.
 475  *
 476  * @param $url String
 477  * @param $query Mixed: string or associative array
 478  * @return string
 479  */
 480 function wfAppendQuery( $url, $query ) {
 481         if ( is_array( $query ) ) {
 482                 $query = wfArrayToCgi( $query );
 483         }
 484         if( $query != '' ) {
 485                 if( false === strpos( $url, '?' ) ) {
 486                         $url .= '?';
 487                 } else {
 488                         $url .= '&';
 489                 }
 490                 $url .= $query;
 491         }
 492         return $url;
 493 }
 494
 495 /**
 496  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 497  * is correct.
 498  *
 499  * The meaning of the PROTO_* constants is as follows:
 500  * PROTO_HTTP: Output a URL starting with http://
 501  * PROTO_HTTPS: Output a URL starting with https://
 502  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 503  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 504  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 505  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 506  *
 507  * @todo this won't work with current-path-relative URLs
 508  * like "subdir/foo.html", etc.
 509  *
 510  * @param $url String: either fully-qualified or a local path + query
 511  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 512  *                             protocol to use if $url or $wgServer is
 513  *                             protocol-relative
 514  * @return string Fully-qualified URL, current-path-relative URL or false if
 515  *                no valid URL can be constructed
 516  */
 517 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 518         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 519         $serverUrl = $wgServer;
 520         if ( $defaultProto === PROTO_CANONICAL ) {
 521                 $serverUrl = $wgCanonicalServer;
 522         }
 523         // Make $wgInternalServer fall back to $wgServer if not set
 524         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 525                 $serverUrl = $wgInternalServer;
 526         }
 527         if ( $defaultProto === PROTO_CURRENT ) {
 528                 $defaultProto = WebRequest::detectProtocol() . '://';
 529         }
 530
 531         // Analyze $serverUrl to obtain its protocol
 532         $bits = wfParseUrl( $serverUrl );
 533         $serverHasProto = $bits && $bits['scheme'] != '';
 534
 535         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 536                 if ( $serverHasProto ) {
 537                         $defaultProto = $bits['scheme'] . '://';
 538                 } else {
 539                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 540                         // Fall back to HTTP in this ridiculous case
 541                         $defaultProto = PROTO_HTTP;
 542                 }
 543         }
 544
 545         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 546
 547         if ( substr( $url, 0, 2 ) == '//' ) {
 548                 $url = $defaultProtoWithoutSlashes . $url;
 549         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 550                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 551                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 552         }
 553
 554         $bits = wfParseUrl( $url );
 555         if ( $bits && isset( $bits['path'] ) ) {
 556                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 557                 return wfAssembleUrl( $bits );
 558         } elseif ( $bits ) {
 559                 # No path to expand
 560                 return $url;
 561         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 562                 # URL is a relative path
 563                 return wfRemoveDotSegments( $url );
 564         }
 565
 566         # Expanded URL is not valid.
 567         return false;
 568 }
 569
 570 /**
 571  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 572  * if you need to edit part of a URL and put it back together.
 573  *
 574  * This is the basic structure used (brackets contain keys for $urlParts):
 575  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 576  *
 577  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 578  *
 579  * @since 1.19
 580  * @param $urlParts Array URL parts, as output from wfParseUrl
 581  * @return string URL assembled from its component parts
 582  */
 583 function wfAssembleUrl( $urlParts ) {
 584         $result = '';
 585
 586         if ( isset( $urlParts['delimiter'] ) ) {
 587                 if ( isset( $urlParts['scheme'] ) ) {
 588                         $result .= $urlParts['scheme'];
 589                 }
 590
 591                 $result .= $urlParts['delimiter'];
 592         }
 593
 594         if ( isset( $urlParts['host'] ) ) {
 595                 if ( isset( $urlParts['user'] ) ) {
 596                         $result .= $urlParts['user'];
 597                         if ( isset( $urlParts['pass'] ) ) {
 598                                 $result .= ':' . $urlParts['pass'];
 599                         }
 600                         $result .= '@';
 601                 }
 602
 603                 $result .= $urlParts['host'];
 604
 605                 if ( isset( $urlParts['port'] ) ) {
 606                         $result .= ':' . $urlParts['port'];
 607                 }
 608         }
 609
 610         if ( isset( $urlParts['path'] ) ) {
 611                 $result .= $urlParts['path'];
 612         }
 613
 614         if ( isset( $urlParts['query'] ) ) {
 615                 $result .= '?' . $urlParts['query'];
 616         }
 617
 618         if ( isset( $urlParts['fragment'] ) ) {
 619                 $result .= '#' . $urlParts['fragment'];
 620         }
 621
 622         return $result;
 623 }
 624
 625 /**
 626  * Remove all dot-segments in the provided URL path.  For example,
 627  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 628  * RFC3986 section 5.2.4.
 629  *
 630  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 631  *
 632  * @param $urlPath String URL path, potentially containing dot-segments
 633  * @return string URL path with all dot-segments removed
 634  */
 635 function wfRemoveDotSegments( $urlPath ) {
 636         $output = '';
 637         $inputOffset = 0;
 638         $inputLength = strlen( $urlPath );
 639
 640         while ( $inputOffset < $inputLength ) {
 641                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 642                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 643                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 644                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 645                 $trimOutput = false;
 646
 647                 if ( $prefixLengthTwo == './' ) {
 648                         # Step A, remove leading "./"
 649                         $inputOffset += 2;
 650                 } elseif ( $prefixLengthThree == '../' ) {
 651                         # Step A, remove leading "../"
 652                         $inputOffset += 3;
 653                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 654                         # Step B, replace leading "/.$" with "/"
 655                         $inputOffset += 1;
 656                         $urlPath[$inputOffset] = '/';
 657                 } elseif ( $prefixLengthThree == '/./' ) {
 658                         # Step B, replace leading "/./" with "/"
 659                         $inputOffset += 2;
 660                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 661                         # Step C, replace leading "/..$" with "/" and
 662                         # remove last path component in output
 663                         $inputOffset += 2;
 664                         $urlPath[$inputOffset] = '/';
 665                         $trimOutput = true;
 666                 } elseif ( $prefixLengthFour == '/../' ) {
 667                         # Step C, replace leading "/../" with "/" and
 668                         # remove last path component in output
 669                         $inputOffset += 3;
 670                         $trimOutput = true;
 671                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 672                         # Step D, remove "^.$"
 673                         $inputOffset += 1;
 674                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 675                         # Step D, remove "^..$"
 676                         $inputOffset += 2;
 677                 } else {
 678                         # Step E, move leading path segment to output
 679                         if ( $prefixLengthOne == '/' ) {
 680                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 681                         } else {
 682                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 683                         }
 684                         if ( $slashPos === false ) {
 685                                 $output .= substr( $urlPath, $inputOffset );
 686                                 $inputOffset = $inputLength;
 687                         } else {
 688                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 689                                 $inputOffset += $slashPos - $inputOffset;
 690                         }
 691                 }
 692
 693                 if ( $trimOutput ) {
 694                         $slashPos = strrpos( $output, '/' );
 695                         if ( $slashPos === false ) {
 696                                 $output = '';
 697                         } else {
 698                                 $output = substr( $output, 0, $slashPos );
 699                         }
 700                 }
 701         }
 702
 703         return $output;
 704 }
 705
 706 /**
 707  * Returns a regular expression of url protocols
 708  *
 709  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 710  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 711  * @return String
 712  */
 713 function wfUrlProtocols( $includeProtocolRelative = true ) {
 714         global $wgUrlProtocols;
 715
 716         // Cache return values separately based on $includeProtocolRelative
 717         static $withProtRel = null, $withoutProtRel = null;
 718         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 719         if ( !is_null( $cachedValue ) ) {
 720                 return $cachedValue;
 721         }
 722
 723         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 724         // with LocalSettings files from 1.5
 725         if ( is_array( $wgUrlProtocols ) ) {
 726                 $protocols = array();
 727                 foreach ( $wgUrlProtocols as $protocol ) {
 728                         // Filter out '//' if !$includeProtocolRelative
 729                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 730                                 $protocols[] = preg_quote( $protocol, '/' );
 731                         }
 732                 }
 733
 734                 $retval = implode( '|', $protocols );
 735         } else {
 736                 // Ignore $includeProtocolRelative in this case
 737                 // This case exists for pre-1.6 compatibility, and we can safely assume
 738                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 739                 // URLs weren't supported until 1.18
 740                 $retval = $wgUrlProtocols;
 741         }
 742
 743         // Cache return value
 744         if ( $includeProtocolRelative ) {
 745                 $withProtRel = $retval;
 746         } else {
 747                 $withoutProtRel = $retval;
 748         }
 749         return $retval;
 750 }
 751
 752 /**
 753  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 754  * you need a regex that matches all URL protocols but does not match protocol-
 755  * relative URLs
 756  * @return String
 757  */
 758 function wfUrlProtocolsWithoutProtRel() {
 759         return wfUrlProtocols( false );
 760 }
 761
 762 /**
 763  * parse_url() work-alike, but non-broken.  Differences:
 764  *
 765  * 1) Does not raise warnings on bad URLs (just returns false)
 766  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 767  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 768  *
 769  * @param $url String: a URL to parse
 770  * @return Array: bits of the URL in an associative array, per PHP docs
 771  */
 772 function wfParseUrl( $url ) {
 773         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 774
 775         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 776         // way to handle them is to just prepend 'http:' and strip the protocol out later
 777         $wasRelative = substr( $url, 0, 2 ) == '//';
 778         if ( $wasRelative ) {
 779                 $url = "http:$url";
 780         }
 781         wfSuppressWarnings();
 782         $bits = parse_url( $url );
 783         wfRestoreWarnings();
 784         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 785         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 786         if ( !$bits || !isset( $bits['scheme'] ) ) {
 787                 return false;
 788         }
 789
 790         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 791         $bits['scheme'] = strtolower( $bits['scheme'] );
 792
 793         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 794         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 795                 $bits['delimiter'] = '://';
 796         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 797                 $bits['delimiter'] = ':';
 798                 // parse_url detects for news: and mailto: the host part of an url as path
 799                 // We have to correct this wrong detection
 800                 if ( isset( $bits['path'] ) ) {
 801                         $bits['host'] = $bits['path'];
 802                         $bits['path'] = '';
 803                 }
 804         } else {
 805                 return false;
 806         }
 807
 808         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 809         if ( !isset( $bits['host'] ) ) {
 810                 $bits['host'] = '';
 811
 812                 // bug 45069
 813                 if ( isset( $bits['path'] ) ) {
 814                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 815                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 816                                 $bits['path'] = '/' . $bits['path'];
 817                         }
 818                 } else {
 819                         $bits['path'] = '';
 820                 }
 821         }
 822
 823         // If the URL was protocol-relative, fix scheme and delimiter
 824         if ( $wasRelative ) {
 825                 $bits['scheme'] = '';
 826                 $bits['delimiter'] = '//';
 827         }
 828         return $bits;
 829 }
 830
 831 /**
 832  * Take a URL, make sure it's expanded to fully qualified, and replace any
 833  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 834  * for more compact display and legibility for local audiences.
 835  *
 836  * @todo handle punycode domains too
 837  *
 838  * @param $url string
 839  * @return string
 840  */
 841 function wfExpandIRI( $url ) {
 842         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 843 }
 844
 845 /**
 846  * Private callback for wfExpandIRI
 847  * @param array $matches
 848  * @return string
 849  */
 850 function wfExpandIRI_callback( $matches ) {
 851         return urldecode( $matches[1] );
 852 }
 853
 854
 855
 856 /**
 857  * Make URL indexes, appropriate for the el_index field of externallinks.
 858  *
 859  * @param $url String
 860  * @return array
 861  */
 862 function wfMakeUrlIndexes( $url ) {
 863         $bits = wfParseUrl( $url );
 864
 865         // Reverse the labels in the hostname, convert to lower case
 866         // For emails reverse domainpart only
 867         if ( $bits['scheme'] == 'mailto' ) {
 868                 $mailparts = explode( '@', $bits['host'], 2 );
 869                 if ( count( $mailparts ) === 2 ) {
 870                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 871                 } else {
 872                         // No domain specified, don't mangle it
 873                         $domainpart = '';
 874                 }
 875                 $reversedHost = $domainpart . '@' . $mailparts[0];
 876         } else {
 877                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 878         }
 879         // Add an extra dot to the end
 880         // Why? Is it in wrong place in mailto links?
 881         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 882                 $reversedHost .= '.';
 883         }
 884         // Reconstruct the pseudo-URL
 885         $prot = $bits['scheme'];
 886         $index = $prot . $bits['delimiter'] . $reversedHost;
 887         // Leave out user and password. Add the port, path, query and fragment
 888         if ( isset( $bits['port'] ) ) {
 889                 $index .= ':' . $bits['port'];
 890         }
 891         if ( isset( $bits['path'] ) ) {
 892                 $index .= $bits['path'];
 893         } else {
 894                 $index .= '/';
 895         }
 896         if ( isset( $bits['query'] ) ) {
 897                 $index .= '?' . $bits['query'];
 898         }
 899         if ( isset( $bits['fragment'] ) ) {
 900                 $index .= '#' . $bits['fragment'];
 901         }
 902
 903         if ( $prot == '' ) {
 904                 return array( "http:$index", "https:$index" );
 905         } else {
 906                 return array( $index );
 907         }
 908 }
 909
 910 /**
 911  * Check whether a given URL has a domain that occurs in a given set of domains
 912  * @param $url string URL
 913  * @param $domains array Array of domains (strings)
 914  * @return bool True if the host part of $url ends in one of the strings in $domains
 915  */
 916 function wfMatchesDomainList( $url, $domains ) {
 917         $bits = wfParseUrl( $url );
 918         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 919                 foreach ( (array)$domains as $domain ) {
 920                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 921                         // We should use something that interprets dots instead
 922                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 923                                 return true;
 924                         }
 925                 }
 926         }
 927         return false;
 928 }
 929
 930 /**
 931  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 932  * In normal operation this is a NOP.
 933  *
 934  * Controlling globals:
 935  * $wgDebugLogFile - points to the log file
 936  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 937  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 938  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 939  *
 940  * @param $text String
 941  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 942  */
 943 function wfDebug( $text, $logonly = false ) {
 944         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 945
 946         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 947                 return;
 948         }
 949
 950         $timer = wfDebugTimer();
 951         if ( $timer !== '' ) {
 952                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 953         }
 954
 955         if ( !$logonly ) {
 956                 MWDebug::debugMsg( $text );
 957         }
 958
 959         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 960                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 961                         # Strip unprintables; they can switch terminal modes when binary data
 962                         # gets dumped, which is pretty annoying.
 963                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 964                         $text = $wgDebugLogPrefix . $text;
 965                         wfErrorLog( $text, $wgDebugLogFile );
 966                 }
 967         }
 968 }
 969
 970 /**
 971  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 972  * @return bool
 973  */
 974 function wfIsDebugRawPage() {
 975         static $cache;
 976         if ( $cache !== null ) {
 977                 return $cache;
 978         }
 979         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 980         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 981                 || (
 982                         isset( $_SERVER['SCRIPT_NAME'] )
 983                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 984                 ) )
 985         {
 986                 $cache = true;
 987         } else {
 988                 $cache = false;
 989         }
 990         return $cache;
 991 }
 992
 993 /**
 994  * Get microsecond timestamps for debug logs
 995  *
 996  * @return string
 997  */
 998 function wfDebugTimer() {
 999         global $wgDebugTimestamps, $wgRequestTime;
1000
1001         if ( !$wgDebugTimestamps ) {
1002                 return '';
1003         }
1004
1005         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1006         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1007         return "$prefix $mem  ";
1008 }
1009
1010 /**
1011  * Send a line giving PHP memory usage.
1012  *
1013  * @param $exact Bool: print exact values instead of kilobytes (default: false)
1014  */
1015 function wfDebugMem( $exact = false ) {
1016         $mem = memory_get_usage();
1017         if( !$exact ) {
1018                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1019         } else {
1020                 $mem .= ' bytes';
1021         }
1022         wfDebug( "Memory usage: $mem\n" );
1023 }
1024
1025 /**
1026  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1027  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1028  *
1029  * @param $logGroup String
1030  * @param $text String
1031  * @param $public Bool: whether to log the event in the public log if no private
1032  *                     log file is specified, (default true)
1033  */
1034 function wfDebugLog( $logGroup, $text, $public = true ) {
1035         global $wgDebugLogGroups;
1036         $text = trim( $text ) . "\n";
1037         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
1038                 $time = wfTimestamp( TS_DB );
1039                 $wiki = wfWikiID();
1040                 $host = wfHostname();
1041                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1042                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1043                 }
1044         } elseif ( $public === true ) {
1045                 wfDebug( "[$logGroup] $text", true );
1046         }
1047 }
1048
1049 /**
1050  * Log for database errors
1051  *
1052  * @param $text String: database error message.
1053  */
1054 function wfLogDBError( $text ) {
1055         global $wgDBerrorLog, $wgDBerrorLogTZ;
1056         static $logDBErrorTimeZoneObject = null;
1057
1058         if ( $wgDBerrorLog ) {
1059                 $host = wfHostname();
1060                 $wiki = wfWikiID();
1061
1062                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1063                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1064                 }
1065
1066                 // Workaround for https://bugs.php.net/bug.php?id=52063
1067                 // Can be removed when min PHP > 5.3.2
1068                 if ( $logDBErrorTimeZoneObject === null ) {
1069                         $d = date_create( "now" );
1070                 } else {
1071                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1072                 }
1073
1074                 $date = $d->format( 'D M j G:i:s T Y' );
1075
1076                 $text = "$date\t$host\t$wiki\t$text";
1077                 wfErrorLog( $text, $wgDBerrorLog );
1078         }
1079 }
1080
1081 /**
1082  * Throws a warning that $function is deprecated
1083  *
1084  * @param $function String
1085  * @param $version String|bool: Version of MediaWiki that the function was deprecated in (Added in 1.19).
1086  * @param $component String|bool: Added in 1.19.
1087  * @param $callerOffset integer: How far up the callstack is the original
1088  *    caller. 2 = function that called the function that called
1089  *    wfDeprecated (Added in 1.20)
1090  *
1091  * @return null
1092  */
1093 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1094         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1095 }
1096
1097 /**
1098  * Send a warning either to the debug log or in a PHP error depending on
1099  * $wgDevelopmentWarnings
1100  *
1101  * @param $msg String: message to send
1102  * @param $callerOffset Integer: number of items to go back in the backtrace to
1103  *        find the correct caller (1 = function calling wfWarn, ...)
1104  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1105  *        is true
1106  */
1107 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1108         MWDebug::warning( $msg, $callerOffset + 1, $level );
1109 }
1110
1111 /**
1112  * Log to a file without getting "file size exceeded" signals.
1113  *
1114  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1115  * send lines to the specified port, prefixed by the specified prefix and a space.
1116  *
1117  * @param $text String
1118  * @param $file String filename
1119  * @throws MWException
1120  */
1121 function wfErrorLog( $text, $file ) {
1122         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1123                 # Needs the sockets extension
1124                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1125                         // IPv6 bracketed host
1126                         $host = $m[2];
1127                         $port = intval( $m[3] );
1128                         $prefix = isset( $m[4] ) ? $m[4] : false;
1129                         $domain = AF_INET6;
1130                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1131                         $host = $m[2];
1132                         if ( !IP::isIPv4( $host ) ) {
1133                                 $host = gethostbyname( $host );
1134                         }
1135                         $port = intval( $m[3] );
1136                         $prefix = isset( $m[4] ) ? $m[4] : false;
1137                         $domain = AF_INET;
1138                 } else {
1139                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1140                 }
1141
1142                 // Clean it up for the multiplexer
1143                 if ( strval( $prefix ) !== '' ) {
1144                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1145
1146                         // Limit to 64KB
1147                         if ( strlen( $text ) > 65506 ) {
1148                                 $text = substr( $text, 0, 65506 );
1149                         }
1150
1151                         if ( substr( $text, -1 ) != "\n" ) {
1152                                 $text .= "\n";
1153                         }
1154                 } elseif ( strlen( $text ) > 65507 ) {
1155                         $text = substr( $text, 0, 65507 );
1156                 }
1157
1158                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1159                 if ( !$sock ) {
1160                         return;
1161                 }
1162
1163                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1164                 socket_close( $sock );
1165         } else {
1166                 wfSuppressWarnings();
1167                 $exists = file_exists( $file );
1168                 $size = $exists ? filesize( $file ) : false;
1169                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1170                         file_put_contents( $file, $text, FILE_APPEND );
1171                 }
1172                 wfRestoreWarnings();
1173         }
1174 }
1175
1176 /**
1177  * @todo document
1178  */
1179 function wfLogProfilingData() {
1180         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1181         global $wgProfileLimit, $wgUser;
1182
1183         $profiler = Profiler::instance();
1184
1185         # Profiling must actually be enabled...
1186         if ( $profiler->isStub() ) {
1187                 return;
1188         }
1189
1190         // Get total page request time and only show pages that longer than
1191         // $wgProfileLimit time (default is 0)
1192         $elapsed = microtime( true ) - $wgRequestTime;
1193         if ( $elapsed <= $wgProfileLimit ) {
1194                 return;
1195         }
1196
1197         $profiler->logData();
1198
1199         // Check whether this should be logged in the debug file.
1200         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1201                 return;
1202         }
1203
1204         $forward = '';
1205         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1206                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1207         }
1208         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1209                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1210         }
1211         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1212                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1213         }
1214         if ( $forward ) {
1215                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1216         }
1217         // Don't load $wgUser at this late stage just for statistics purposes
1218         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1219         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1220                 $forward .= ' anon';
1221         }
1222
1223         // Command line script uses a FauxRequest object which does not have
1224         // any knowledge about an URL and throw an exception instead.
1225         try {
1226                 $requestUrl = $wgRequest->getRequestURL();
1227         } catch ( MWException $e ) {
1228                 $requestUrl = 'n/a';
1229         }
1230
1231         $log = sprintf( "%s\t%04.3f\t%s\n",
1232                 gmdate( 'YmdHis' ), $elapsed,
1233                 urldecode( $requestUrl . $forward ) );
1234
1235         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1236 }
1237
1238 /**
1239  * Increment a statistics counter
1240  *
1241  * @param $key String
1242  * @param $count Int
1243  * @return void
1244  */
1245 function wfIncrStats( $key, $count = 1 ) {
1246         global $wgStatsMethod;
1247
1248         $count = intval( $count );
1249         if ( $count == 0 ) {
1250                 return;
1251         }
1252
1253         if( $wgStatsMethod == 'udp' ) {
1254                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgAggregateStatsID;
1255                 static $socket;
1256
1257                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : wfWikiID();
1258
1259                 if ( !$socket ) {
1260                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1261                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1262                         socket_sendto(
1263                                 $socket,
1264                                 $statline,
1265                                 strlen( $statline ),
1266                                 0,
1267                                 $wgUDPProfilerHost,
1268                                 $wgUDPProfilerPort
1269                         );
1270                 }
1271                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1272                 wfSuppressWarnings();
1273                 socket_sendto(
1274                         $socket,
1275                         $statline,
1276                         strlen( $statline ),
1277                         0,
1278                         $wgUDPProfilerHost,
1279                         $wgUDPProfilerPort
1280                 );
1281                 wfRestoreWarnings();
1282         } elseif( $wgStatsMethod == 'cache' ) {
1283                 global $wgMemc;
1284                 $key = wfMemcKey( 'stats', $key );
1285                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1286                         $wgMemc->add( $key, $count );
1287                 }
1288         } else {
1289                 // Disabled
1290         }
1291 }
1292
1293 /**
1294  * Check if the wiki read-only lock file is present. This can be used to lock
1295  * off editing functions, but doesn't guarantee that the database will not be
1296  * modified.
1297  *
1298  * @return bool
1299  */
1300 function wfReadOnly() {
1301         global $wgReadOnlyFile, $wgReadOnly;
1302
1303         if ( !is_null( $wgReadOnly ) ) {
1304                 return (bool)$wgReadOnly;
1305         }
1306         if ( $wgReadOnlyFile == '' ) {
1307                 return false;
1308         }
1309         // Set $wgReadOnly for faster access next time
1310         if ( is_file( $wgReadOnlyFile ) ) {
1311                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1312         } else {
1313                 $wgReadOnly = false;
1314         }
1315         return (bool)$wgReadOnly;
1316 }
1317
1318 /**
1319  * @return bool
1320  */
1321 function wfReadOnlyReason() {
1322         global $wgReadOnly;
1323         wfReadOnly();
1324         return $wgReadOnly;
1325 }
1326
1327 /**
1328  * Return a Language object from $langcode
1329  *
1330  * @param $langcode Mixed: either:
1331  *                  - a Language object
1332  *                  - code of the language to get the message for, if it is
1333  *                    a valid code create a language for that language, if
1334  *                    it is a string but not a valid code then make a basic
1335  *                    language object
1336  *                  - a boolean: if it's false then use the global object for
1337  *                    the current user's language (as a fallback for the old parameter
1338  *                    functionality), or if it is true then use global object
1339  *                    for the wiki's content language.
1340  * @return Language object
1341  */
1342 function wfGetLangObj( $langcode = false ) {
1343         # Identify which language to get or create a language object for.
1344         # Using is_object here due to Stub objects.
1345         if( is_object( $langcode ) ) {
1346                 # Great, we already have the object (hopefully)!
1347                 return $langcode;
1348         }
1349
1350         global $wgContLang, $wgLanguageCode;
1351         if( $langcode === true || $langcode === $wgLanguageCode ) {
1352                 # $langcode is the language code of the wikis content language object.
1353                 # or it is a boolean and value is true
1354                 return $wgContLang;
1355         }
1356
1357         global $wgLang;
1358         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1359                 # $langcode is the language code of user language object.
1360                 # or it was a boolean and value is false
1361                 return $wgLang;
1362         }
1363
1364         $validCodes = array_keys( Language::fetchLanguageNames() );
1365         if( in_array( $langcode, $validCodes ) ) {
1366                 # $langcode corresponds to a valid language.
1367                 return Language::factory( $langcode );
1368         }
1369
1370         # $langcode is a string, but not a valid language code; use content language.
1371         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1372         return $wgContLang;
1373 }
1374
1375 /**
1376  * Old function when $wgBetterDirectionality existed
1377  * All usage removed, wfUILang can be removed in near future
1378  *
1379  * @deprecated since 1.18
1380  * @return Language
1381  */
1382 function wfUILang() {
1383         wfDeprecated( __METHOD__, '1.18' );
1384         global $wgLang;
1385         return $wgLang;
1386 }
1387
1388 /**
1389  * This is the function for getting translated interface messages.
1390  *
1391  * @see Message class for documentation how to use them.
1392  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1393  *
1394  * This function replaces all old wfMsg* functions.
1395  *
1396  * @param $key \string Message key.
1397  * Varargs: normal message parameters.
1398  * @return Message
1399  * @since 1.17
1400  */
1401 function wfMessage( $key /*...*/) {
1402         $params = func_get_args();
1403         array_shift( $params );
1404         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1405                 $params = $params[0];
1406         }
1407         return new Message( $key, $params );
1408 }
1409
1410 /**
1411  * This function accepts multiple message keys and returns a message instance
1412  * for the first message which is non-empty. If all messages are empty then an
1413  * instance of the first message key is returned.
1414  * @param varargs: message keys
1415  * @return Message
1416  * @since 1.18
1417  */
1418 function wfMessageFallback( /*...*/ ) {
1419         $args = func_get_args();
1420         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1421 }
1422
1423 /**
1424  * Get a message from anywhere, for the current user language.
1425  *
1426  * Use wfMsgForContent() instead if the message should NOT
1427  * change depending on the user preferences.
1428  *
1429  * @deprecated since 1.18
1430  *
1431  * @param $key String: lookup key for the message, usually
1432  *    defined in languages/Language.php
1433  *
1434  * Parameters to the message, which can be used to insert variable text into
1435  * it, can be passed to this function in the following formats:
1436  * - One per argument, starting at the second parameter
1437  * - As an array in the second parameter
1438  * These are not shown in the function definition.
1439  *
1440  * @return String
1441  */
1442 function wfMsg( $key ) {
1443         wfDeprecated( __METHOD__, '1.21' );
1444
1445         $args = func_get_args();
1446         array_shift( $args );
1447         return wfMsgReal( $key, $args );
1448 }
1449
1450 /**
1451  * Same as above except doesn't transform the message
1452  *
1453  * @deprecated since 1.18
1454  *
1455  * @param $key String
1456  * @return String
1457  */
1458 function wfMsgNoTrans( $key ) {
1459         wfDeprecated( __METHOD__, '1.21' );
1460
1461         $args = func_get_args();
1462         array_shift( $args );
1463         return wfMsgReal( $key, $args, true, false, false );
1464 }
1465
1466 /**
1467  * Get a message from anywhere, for the current global language
1468  * set with $wgLanguageCode.
1469  *
1470  * Use this if the message should NOT change dependent on the
1471  * language set in the user's preferences. This is the case for
1472  * most text written into logs, as well as link targets (such as
1473  * the name of the copyright policy page). Link titles, on the
1474  * other hand, should be shown in the UI language.
1475  *
1476  * Note that MediaWiki allows users to change the user interface
1477  * language in their preferences, but a single installation
1478  * typically only contains content in one language.
1479  *
1480  * Be wary of this distinction: If you use wfMsg() where you should
1481  * use wfMsgForContent(), a user of the software may have to
1482  * customize potentially hundreds of messages in
1483  * order to, e.g., fix a link in every possible language.
1484  *
1485  * @deprecated since 1.18
1486  *
1487  * @param $key String: lookup key for the message, usually
1488  *     defined in languages/Language.php
1489  * @return String
1490  */
1491 function wfMsgForContent( $key ) {
1492         wfDeprecated( __METHOD__, '1.21' );
1493
1494         global $wgForceUIMsgAsContentMsg;
1495         $args = func_get_args();
1496         array_shift( $args );
1497         $forcontent = true;
1498         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1499                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1500         {
1501                 $forcontent = false;
1502         }
1503         return wfMsgReal( $key, $args, true, $forcontent );
1504 }
1505
1506 /**
1507  * Same as above except doesn't transform the message
1508  *
1509  * @deprecated since 1.18
1510  *
1511  * @param $key String
1512  * @return String
1513  */
1514 function wfMsgForContentNoTrans( $key ) {
1515         wfDeprecated( __METHOD__, '1.21' );
1516
1517         global $wgForceUIMsgAsContentMsg;
1518         $args = func_get_args();
1519         array_shift( $args );
1520         $forcontent = true;
1521         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1522                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1523         {
1524                 $forcontent = false;
1525         }
1526         return wfMsgReal( $key, $args, true, $forcontent, false );
1527 }
1528
1529 /**
1530  * Really get a message
1531  *
1532  * @deprecated since 1.18
1533  *
1534  * @param $key String: key to get.
1535  * @param $args
1536  * @param $useDB Boolean
1537  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1538  * @param $transform Boolean: Whether or not to transform the message.
1539  * @return String: the requested message.
1540  */
1541 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1542         wfDeprecated( __METHOD__, '1.21' );
1543
1544         wfProfileIn( __METHOD__ );
1545         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1546         $message = wfMsgReplaceArgs( $message, $args );
1547         wfProfileOut( __METHOD__ );
1548         return $message;
1549 }
1550
1551 /**
1552  * Fetch a message string value, but don't replace any keys yet.
1553  *
1554  * @deprecated since 1.18
1555  *
1556  * @param $key String
1557  * @param $useDB Bool
1558  * @param $langCode String: Code of the language to get the message for, or
1559  *                  behaves as a content language switch if it is a boolean.
1560  * @param $transform Boolean: whether to parse magic words, etc.
1561  * @return string
1562  */
1563 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1564         wfDeprecated( __METHOD__, '1.21' );
1565
1566         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1567
1568         $cache = MessageCache::singleton();
1569         $message = $cache->get( $key, $useDB, $langCode );
1570         if( $message === false ) {
1571                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1572         } elseif ( $transform ) {
1573                 $message = $cache->transform( $message );
1574         }
1575         return $message;
1576 }
1577
1578 /**
1579  * Replace message parameter keys on the given formatted output.
1580  *
1581  * @param $message String
1582  * @param $args Array
1583  * @return string
1584  * @private
1585  */
1586 function wfMsgReplaceArgs( $message, $args ) {
1587         # Fix windows line-endings
1588         # Some messages are split with explode("\n", $msg)
1589         $message = str_replace( "\r", '', $message );
1590
1591         // Replace arguments
1592         if ( count( $args ) ) {
1593                 if ( is_array( $args[0] ) ) {
1594                         $args = array_values( $args[0] );
1595                 }
1596                 $replacementKeys = array();
1597                 foreach( $args as $n => $param ) {
1598                         $replacementKeys['$' . ( $n + 1 )] = $param;
1599                 }
1600                 $message = strtr( $message, $replacementKeys );
1601         }
1602
1603         return $message;
1604 }
1605
1606 /**
1607  * Return an HTML-escaped version of a message.
1608  * Parameter replacements, if any, are done *after* the HTML-escaping,
1609  * so parameters may contain HTML (eg links or form controls). Be sure
1610  * to pre-escape them if you really do want plaintext, or just wrap
1611  * the whole thing in htmlspecialchars().
1612  *
1613  * @deprecated since 1.18
1614  *
1615  * @param $key String
1616  * @param string ... parameters
1617  * @return string
1618  */
1619 function wfMsgHtml( $key ) {
1620         wfDeprecated( __METHOD__, '1.21' );
1621
1622         $args = func_get_args();
1623         array_shift( $args );
1624         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1625 }
1626
1627 /**
1628  * Return an HTML version of message
1629  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1630  * so parameters may contain HTML (eg links or form controls). Be sure
1631  * to pre-escape them if you really do want plaintext, or just wrap
1632  * the whole thing in htmlspecialchars().
1633  *
1634  * @deprecated since 1.18
1635  *
1636  * @param $key String
1637  * @param string ... parameters
1638  * @return string
1639  */
1640 function wfMsgWikiHtml( $key ) {
1641         wfDeprecated( __METHOD__, '1.21' );
1642
1643         $args = func_get_args();
1644         array_shift( $args );
1645         return wfMsgReplaceArgs(
1646                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1647                 /* can't be set to false */ true, /* interface */ true )->getText(),
1648                 $args );
1649 }
1650
1651 /**
1652  * Returns message in the requested format
1653  *
1654  * @deprecated since 1.18
1655  *
1656  * @param $key String: key of the message
1657  * @param $options Array: processing rules. Can take the following options:
1658  *   <i>parse</i>: parses wikitext to HTML
1659  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1660  *       p's added by parser or tidy
1661  *   <i>escape</i>: filters message through htmlspecialchars
1662  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1663  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1664  *   <i>parsemag</i>: transform the message using magic phrases
1665  *   <i>content</i>: fetch message for content language instead of interface
1666  * Also can accept a single associative argument, of the form 'language' => 'xx':
1667  *   <i>language</i>: Language object or language code to fetch message for
1668  *       (overriden by <i>content</i>).
1669  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1670  *
1671  * @return String
1672  */
1673 function wfMsgExt( $key, $options ) {
1674         wfDeprecated( __METHOD__, '1.21' );
1675
1676         $args = func_get_args();
1677         array_shift( $args );
1678         array_shift( $args );
1679         $options = (array)$options;
1680
1681         foreach( $options as $arrayKey => $option ) {
1682                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1683                         # An unknown index, neither numeric nor "language"
1684                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1685                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1686                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1687                 'replaceafter', 'parsemag', 'content' ) ) ) {
1688                         # A numeric index with unknown value
1689                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1690                 }
1691         }
1692
1693         if( in_array( 'content', $options, true ) ) {
1694                 $forContent = true;
1695                 $langCode = true;
1696                 $langCodeObj = null;
1697         } elseif( array_key_exists( 'language', $options ) ) {
1698                 $forContent = false;
1699                 $langCode = wfGetLangObj( $options['language'] );
1700                 $langCodeObj = $langCode;
1701         } else {
1702                 $forContent = false;
1703                 $langCode = false;
1704                 $langCodeObj = null;
1705         }
1706
1707         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1708
1709         if( !in_array( 'replaceafter', $options, true ) ) {
1710                 $string = wfMsgReplaceArgs( $string, $args );
1711         }
1712
1713         $messageCache = MessageCache::singleton();
1714         $parseInline = in_array( 'parseinline', $options, true );
1715         if( in_array( 'parse', $options, true ) || $parseInline ) {
1716                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1717                 if ( $string instanceof ParserOutput ) {
1718                         $string = $string->getText();
1719                 }
1720
1721                 if ( $parseInline ) {
1722                         $m = array();
1723                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1724                                 $string = $m[1];
1725                         }
1726                 }
1727         } elseif ( in_array( 'parsemag', $options, true ) ) {
1728                 $string = $messageCache->transform( $string,
1729                                 !$forContent, $langCodeObj );
1730         }
1731
1732         if ( in_array( 'escape', $options, true ) ) {
1733                 $string = htmlspecialchars ( $string );
1734         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1735                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1736         }
1737
1738         if( in_array( 'replaceafter', $options, true ) ) {
1739                 $string = wfMsgReplaceArgs( $string, $args );
1740         }
1741
1742         return $string;
1743 }
1744
1745 /**
1746  * Since wfMsg() and co suck, they don't return false if the message key they
1747  * looked up didn't exist but a XHTML string, this function checks for the
1748  * nonexistance of messages by checking the MessageCache::get() result directly.
1749  *
1750  * @deprecated since 1.18. Use Message::isDisabled().
1751  *
1752  * @param $key      String: the message key looked up
1753  * @return Boolean True if the message *doesn't* exist.
1754  */
1755 function wfEmptyMsg( $key ) {
1756         wfDeprecated( __METHOD__, '1.21' );
1757
1758         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1759 }
1760
1761 /**
1762  * Throw a debugging exception. This function previously once exited the process,
1763  * but now throws an exception instead, with similar results.
1764  *
1765  * @param $msg String: message shown when dying.
1766  * @throws MWException
1767  */
1768 function wfDebugDieBacktrace( $msg = '' ) {
1769         throw new MWException( $msg );
1770 }
1771
1772 /**
1773  * Fetch server name for use in error reporting etc.
1774  * Use real server name if available, so we know which machine
1775  * in a server farm generated the current page.
1776  *
1777  * @return string
1778  */
1779 function wfHostname() {
1780         static $host;
1781         if ( is_null( $host ) ) {
1782
1783                 # Hostname overriding
1784                 global $wgOverrideHostname;
1785                 if( $wgOverrideHostname !== false ) {
1786                         # Set static and skip any detection
1787                         $host = $wgOverrideHostname;
1788                         return $host;
1789                 }
1790
1791                 if ( function_exists( 'posix_uname' ) ) {
1792                         // This function not present on Windows
1793                         $uname = posix_uname();
1794                 } else {
1795                         $uname = false;
1796                 }
1797                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1798                         $host = $uname['nodename'];
1799                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1800                         # Windows computer name
1801                         $host = getenv( 'COMPUTERNAME' );
1802                 } else {
1803                         # This may be a virtual server.
1804                         $host = $_SERVER['SERVER_NAME'];
1805                 }
1806         }
1807         return $host;
1808 }
1809
1810 /**
1811  * Returns a HTML comment with the elapsed time since request.
1812  * This method has no side effects.
1813  *
1814  * @return string
1815  */
1816 function wfReportTime() {
1817         global $wgRequestTime, $wgShowHostnames;
1818
1819         $elapsed = microtime( true ) - $wgRequestTime;
1820
1821         return $wgShowHostnames
1822                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1823                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1824 }
1825
1826 /**
1827  * Safety wrapper for debug_backtrace().
1828  *
1829  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1830  * murky circumstances, which may be triggered in part by stub objects
1831  * or other fancy talkin'.
1832  *
1833  * Will return an empty array if Zend Optimizer is detected or if
1834  * debug_backtrace is disabled, otherwise the output from
1835  * debug_backtrace() (trimmed).
1836  *
1837  * @param $limit int This parameter can be used to limit the number of stack frames returned
1838  *
1839  * @return array of backtrace information
1840  */
1841 function wfDebugBacktrace( $limit = 0 ) {
1842         static $disabled = null;
1843
1844         if( extension_loaded( 'Zend Optimizer' ) ) {
1845                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1846                 return array();
1847         }
1848
1849         if ( is_null( $disabled ) ) {
1850                 $disabled = false;
1851                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1852                 $functions = array_map( 'trim', $functions );
1853                 $functions = array_map( 'strtolower', $functions );
1854                 if ( in_array( 'debug_backtrace', $functions ) ) {
1855                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1856                         $disabled = true;
1857                 }
1858         }
1859         if ( $disabled ) {
1860                 return array();
1861         }
1862
1863         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1864                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1865         } else {
1866                 return array_slice( debug_backtrace(), 1 );
1867         }
1868 }
1869
1870 /**
1871  * Get a debug backtrace as a string
1872  *
1873  * @return string
1874  */
1875 function wfBacktrace() {
1876         global $wgCommandLineMode;
1877
1878         if ( $wgCommandLineMode ) {
1879                 $msg = '';
1880         } else {
1881                 $msg = "<ul>\n";
1882         }
1883         $backtrace = wfDebugBacktrace();
1884         foreach( $backtrace as $call ) {
1885                 if( isset( $call['file'] ) ) {
1886                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1887                         $file = $f[count( $f ) - 1];
1888                 } else {
1889                         $file = '-';
1890                 }
1891                 if( isset( $call['line'] ) ) {
1892                         $line = $call['line'];
1893                 } else {
1894                         $line = '-';
1895                 }
1896                 if ( $wgCommandLineMode ) {
1897                         $msg .= "$file line $line calls ";
1898                 } else {
1899                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1900                 }
1901                 if( !empty( $call['class'] ) ) {
1902                         $msg .= $call['class'] . $call['type'];
1903                 }
1904                 $msg .= $call['function'] . '()';
1905
1906                 if ( $wgCommandLineMode ) {
1907                         $msg .= "\n";
1908                 } else {
1909                         $msg .= "</li>\n";
1910                 }
1911         }
1912         if ( $wgCommandLineMode ) {
1913                 $msg .= "\n";
1914         } else {
1915                 $msg .= "</ul>\n";
1916         }
1917
1918         return $msg;
1919 }
1920
1921 /**
1922  * Get the name of the function which called this function
1923  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1924  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1925  * wfGetCaller( 3 ) is the parent of that.
1926  *
1927  * @param $level Int
1928  * @return string
1929  */
1930 function wfGetCaller( $level = 2 ) {
1931         $backtrace = wfDebugBacktrace( $level + 1 );
1932         if ( isset( $backtrace[$level] ) ) {
1933                 return wfFormatStackFrame( $backtrace[$level] );
1934         } else {
1935                 return 'unknown';
1936         }
1937 }
1938
1939 /**
1940  * Return a string consisting of callers in the stack. Useful sometimes
1941  * for profiling specific points.
1942  *
1943  * @param $limit int The maximum depth of the stack frame to return, or false for
1944  *               the entire stack.
1945  * @return String
1946  */
1947 function wfGetAllCallers( $limit = 3 ) {
1948         $trace = array_reverse( wfDebugBacktrace() );
1949         if ( !$limit || $limit > count( $trace ) - 1 ) {
1950                 $limit = count( $trace ) - 1;
1951         }
1952         $trace = array_slice( $trace, -$limit - 1, $limit );
1953         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1954 }
1955
1956 /**
1957  * Return a string representation of frame
1958  *
1959  * @param $frame Array
1960  * @return string
1961  */
1962 function wfFormatStackFrame( $frame ) {
1963         return isset( $frame['class'] ) ?
1964                 $frame['class'] . '::' . $frame['function'] :
1965                 $frame['function'];
1966 }
1967
1968
1969 /* Some generic result counters, pulled out of SearchEngine */
1970
1971
1972 /**
1973  * @todo document
1974  *
1975  * @param $offset Int
1976  * @param $limit Int
1977  * @return String
1978  */
1979 function wfShowingResults( $offset, $limit ) {
1980         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1981 }
1982
1983 /**
1984  * Generate (prev x| next x) (20|50|100...) type links for paging
1985  *
1986  * @param $offset String
1987  * @param $limit Integer
1988  * @param $link String
1989  * @param $query String: optional URL query parameter string
1990  * @param $atend Bool: optional param for specified if this is the last page
1991  * @return String
1992  * @deprecated in 1.19; use Language::viewPrevNext() instead
1993  */
1994 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1995         wfDeprecated( __METHOD__, '1.19' );
1996
1997         global $wgLang;
1998
1999         $query = wfCgiToArray( $query );
2000
2001         if( is_object( $link ) ) {
2002                 $title = $link;
2003         } else {
2004                 $title = Title::newFromText( $link );
2005                 if( is_null( $title ) ) {
2006                         return false;
2007                 }
2008         }
2009
2010         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
2011 }
2012
2013 /**
2014  * Make a list item, used by various special pages
2015  *
2016  * @param $page String Page link
2017  * @param $details String Text between brackets
2018  * @param $oppositedm Boolean   Add the direction mark opposite to your
2019  *                                                              language, to display text properly
2020  * @return String
2021  * @deprecated since 1.19; use Language::specialList() instead
2022  */
2023 function wfSpecialList( $page, $details, $oppositedm = true ) {
2024         wfDeprecated( __METHOD__, '1.19' );
2025
2026         global $wgLang;
2027         return $wgLang->specialList( $page, $details, $oppositedm );
2028 }
2029
2030 /**
2031  * @todo document
2032  * @todo FIXME: We may want to blacklist some broken browsers
2033  *
2034  * @param $force Bool
2035  * @return bool Whereas client accept gzip compression
2036  */
2037 function wfClientAcceptsGzip( $force = false ) {
2038         static $result = null;
2039         if ( $result === null || $force ) {
2040                 $result = false;
2041                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2042                         # @todo FIXME: We may want to blacklist some broken browsers
2043                         $m = array();
2044                         if( preg_match(
2045                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2046                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
2047                                 $m )
2048                         )
2049                         {
2050                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2051                                         $result = false;
2052                                         return $result;
2053                                 }
2054                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2055                                 $result = true;
2056                         }
2057                 }
2058         }
2059         return $result;
2060 }
2061
2062 /**
2063  * Obtain the offset and limit values from the request string;
2064  * used in special pages
2065  *
2066  * @param $deflimit Int default limit if none supplied
2067  * @param $optionname String Name of a user preference to check against
2068  * @return array
2069  *
2070  */
2071 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2072         global $wgRequest;
2073         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2074 }
2075
2076 /**
2077  * Escapes the given text so that it may be output using addWikiText()
2078  * without any linking, formatting, etc. making its way through. This
2079  * is achieved by substituting certain characters with HTML entities.
2080  * As required by the callers, "<nowiki>" is not used.
2081  *
2082  * @param $text String: text to be escaped
2083  * @return String
2084  */
2085 function wfEscapeWikiText( $text ) {
2086         $text = strtr( "\n$text", array(
2087                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2088                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2089                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2090                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2091                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2092                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2093         ) );
2094         return substr( $text, 1 );
2095 }
2096
2097 /**
2098  * Get the current unix timetstamp with microseconds.  Useful for profiling
2099  * @return Float
2100  */
2101 function wfTime() {
2102         return microtime( true );
2103 }
2104
2105 /**
2106  * Sets dest to source and returns the original value of dest
2107  * If source is NULL, it just returns the value, it doesn't set the variable
2108  * If force is true, it will set the value even if source is NULL
2109  *
2110  * @param $dest Mixed
2111  * @param $source Mixed
2112  * @param $force Bool
2113  * @return Mixed
2114  */
2115 function wfSetVar( &$dest, $source, $force = false ) {
2116         $temp = $dest;
2117         if ( !is_null( $source ) || $force ) {
2118                 $dest = $source;
2119         }
2120         return $temp;
2121 }
2122
2123 /**
2124  * As for wfSetVar except setting a bit
2125  *
2126  * @param $dest Int
2127  * @param $bit Int
2128  * @param $state Bool
2129  *
2130  * @return bool
2131  */
2132 function wfSetBit( &$dest, $bit, $state = true ) {
2133         $temp = (bool)( $dest & $bit );
2134         if ( !is_null( $state ) ) {
2135                 if ( $state ) {
2136                         $dest |= $bit;
2137                 } else {
2138                         $dest &= ~$bit;
2139                 }
2140         }
2141         return $temp;
2142 }
2143
2144 /**
2145  * A wrapper around the PHP function var_export().
2146  * Either print it or add it to the regular output ($wgOut).
2147  *
2148  * @param $var mixed A PHP variable to dump.
2149  */
2150 function wfVarDump( $var ) {
2151         global $wgOut;
2152         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2153         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2154                 print $s;
2155         } else {
2156                 $wgOut->addHTML( $s );
2157         }
2158 }
2159
2160 /**
2161  * Provide a simple HTTP error.
2162  *
2163  * @param $code Int|String
2164  * @param $label String
2165  * @param $desc String
2166  */
2167 function wfHttpError( $code, $label, $desc ) {
2168         global $wgOut;
2169         $wgOut->disable();
2170         header( "HTTP/1.0 $code $label" );
2171         header( "Status: $code $label" );
2172         $wgOut->sendCacheControl();
2173
2174         header( 'Content-type: text/html; charset=utf-8' );
2175         print "<!doctype html>" .
2176                 '<html><head><title>' .
2177                 htmlspecialchars( $label ) .
2178                 '</title></head><body><h1>' .
2179                 htmlspecialchars( $label ) .
2180                 '</h1><p>' .
2181                 nl2br( htmlspecialchars( $desc ) ) .
2182                 "</p></body></html>\n";
2183 }
2184
2185 /**
2186  * Clear away any user-level output buffers, discarding contents.
2187  *
2188  * Suitable for 'starting afresh', for instance when streaming
2189  * relatively large amounts of data without buffering, or wanting to
2190  * output image files without ob_gzhandler's compression.
2191  *
2192  * The optional $resetGzipEncoding parameter controls suppression of
2193  * the Content-Encoding header sent by ob_gzhandler; by default it
2194  * is left. See comments for wfClearOutputBuffers() for why it would
2195  * be used.
2196  *
2197  * Note that some PHP configuration options may add output buffer
2198  * layers which cannot be removed; these are left in place.
2199  *
2200  * @param $resetGzipEncoding Bool
2201  */
2202 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2203         if( $resetGzipEncoding ) {
2204                 // Suppress Content-Encoding and Content-Length
2205                 // headers from 1.10+s wfOutputHandler
2206                 global $wgDisableOutputCompression;
2207                 $wgDisableOutputCompression = true;
2208         }
2209         while( $status = ob_get_status() ) {
2210                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2211                         // Probably from zlib.output_compression or other
2212                         // PHP-internal setting which can't be removed.
2213                         //
2214                         // Give up, and hope the result doesn't break
2215                         // output behavior.
2216                         break;
2217                 }
2218                 if( !ob_end_clean() ) {
2219                         // Could not remove output buffer handler; abort now
2220                         // to avoid getting in some kind of infinite loop.
2221                         break;
2222                 }
2223                 if( $resetGzipEncoding ) {
2224                         if( $status['name'] == 'ob_gzhandler' ) {
2225                                 // Reset the 'Content-Encoding' field set by this handler
2226                                 // so we can start fresh.
2227                                 header_remove( 'Content-Encoding' );
2228                                 break;
2229                         }
2230                 }
2231         }
2232 }
2233
2234 /**
2235  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2236  *
2237  * Clear away output buffers, but keep the Content-Encoding header
2238  * produced by ob_gzhandler, if any.
2239  *
2240  * This should be used for HTTP 304 responses, where you need to
2241  * preserve the Content-Encoding header of the real result, but
2242  * also need to suppress the output of ob_gzhandler to keep to spec
2243  * and avoid breaking Firefox in rare cases where the headers and
2244  * body are broken over two packets.
2245  */
2246 function wfClearOutputBuffers() {
2247         wfResetOutputBuffers( false );
2248 }
2249
2250 /**
2251  * Converts an Accept-* header into an array mapping string values to quality
2252  * factors
2253  *
2254  * @param $accept String
2255  * @param $def String default
2256  * @return Array
2257  */
2258 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2259         # No arg means accept anything (per HTTP spec)
2260         if( !$accept ) {
2261                 return array( $def => 1.0 );
2262         }
2263
2264         $prefs = array();
2265
2266         $parts = explode( ',', $accept );
2267
2268         foreach( $parts as $part ) {
2269                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2270                 $values = explode( ';', trim( $part ) );
2271                 $match = array();
2272                 if ( count( $values ) == 1 ) {
2273                         $prefs[$values[0]] = 1.0;
2274                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2275                         $prefs[$values[0]] = floatval( $match[1] );
2276                 }
2277         }
2278
2279         return $prefs;
2280 }
2281
2282 /**
2283  * Checks if a given MIME type matches any of the keys in the given
2284  * array. Basic wildcards are accepted in the array keys.
2285  *
2286  * Returns the matching MIME type (or wildcard) if a match, otherwise
2287  * NULL if no match.
2288  *
2289  * @param $type String
2290  * @param $avail Array
2291  * @return string
2292  * @private
2293  */
2294 function mimeTypeMatch( $type, $avail ) {
2295         if( array_key_exists( $type, $avail ) ) {
2296                 return $type;
2297         } else {
2298                 $parts = explode( '/', $type );
2299                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2300                         return $parts[0] . '/*';
2301                 } elseif( array_key_exists( '*/*', $avail ) ) {
2302                         return '*/*';
2303                 } else {
2304                         return null;
2305                 }
2306         }
2307 }
2308
2309 /**
2310  * Returns the 'best' match between a client's requested internet media types
2311  * and the server's list of available types. Each list should be an associative
2312  * array of type to preference (preference is a float between 0.0 and 1.0).
2313  * Wildcards in the types are acceptable.
2314  *
2315  * @param $cprefs Array: client's acceptable type list
2316  * @param $sprefs Array: server's offered types
2317  * @return string
2318  *
2319  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2320  * XXX: generalize to negotiate other stuff
2321  */
2322 function wfNegotiateType( $cprefs, $sprefs ) {
2323         $combine = array();
2324
2325         foreach( array_keys( $sprefs ) as $type ) {
2326                 $parts = explode( '/', $type );
2327                 if( $parts[1] != '*' ) {
2328                         $ckey = mimeTypeMatch( $type, $cprefs );
2329                         if( $ckey ) {
2330                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2331                         }
2332                 }
2333         }
2334
2335         foreach( array_keys( $cprefs ) as $type ) {
2336                 $parts = explode( '/', $type );
2337                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2338                         $skey = mimeTypeMatch( $type, $sprefs );
2339                         if( $skey ) {
2340                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2341                         }
2342                 }
2343         }
2344
2345         $bestq = 0;
2346         $besttype = null;
2347
2348         foreach( array_keys( $combine ) as $type ) {
2349                 if( $combine[$type] > $bestq ) {
2350                         $besttype = $type;
2351                         $bestq = $combine[$type];
2352                 }
2353         }
2354
2355         return $besttype;
2356 }
2357
2358 /**
2359  * Reference-counted warning suppression
2360  *
2361  * @param $end Bool
2362  */
2363 function wfSuppressWarnings( $end = false ) {
2364         static $suppressCount = 0;
2365         static $originalLevel = false;
2366
2367         if ( $end ) {
2368                 if ( $suppressCount ) {
2369                         --$suppressCount;
2370                         if ( !$suppressCount ) {
2371                                 error_reporting( $originalLevel );
2372                         }
2373                 }
2374         } else {
2375                 if ( !$suppressCount ) {
2376                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT ) );
2377                 }
2378                 ++$suppressCount;
2379         }
2380 }
2381
2382 /**
2383  * Restore error level to previous value
2384  */
2385 function wfRestoreWarnings() {
2386         wfSuppressWarnings( true );
2387 }
2388
2389 # Autodetect, convert and provide timestamps of various types
2390
2391 /**
2392  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2393  */
2394 define( 'TS_UNIX', 0 );
2395
2396 /**
2397  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2398  */
2399 define( 'TS_MW', 1 );
2400
2401 /**
2402  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2403  */
2404 define( 'TS_DB', 2 );
2405
2406 /**
2407  * RFC 2822 format, for E-mail and HTTP headers
2408  */
2409 define( 'TS_RFC2822', 3 );
2410
2411 /**
2412  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2413  *
2414  * This is used by Special:Export
2415  */
2416 define( 'TS_ISO_8601', 4 );
2417
2418 /**
2419  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2420  *
2421  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2422  *       DateTime tag and page 36 for the DateTimeOriginal and
2423  *       DateTimeDigitized tags.
2424  */
2425 define( 'TS_EXIF', 5 );
2426
2427 /**
2428  * Oracle format time.
2429  */
2430 define( 'TS_ORACLE', 6 );
2431
2432 /**
2433  * Postgres format time.
2434  */
2435 define( 'TS_POSTGRES', 7 );
2436
2437 /**
2438  * DB2 format time
2439  */
2440 define( 'TS_DB2', 8 );
2441
2442 /**
2443  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2444  */
2445 define( 'TS_ISO_8601_BASIC', 9 );
2446
2447 /**
2448  * Get a timestamp string in one of various formats
2449  *
2450  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2451  *                    function will autodetect which format is supplied and act
2452  *                    accordingly.
2453  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2454  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2455  */
2456 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2457         try {
2458                 $timestamp = new MWTimestamp( $ts );
2459                 return $timestamp->getTimestamp( $outputtype );
2460         } catch( TimestampException $e ) {
2461                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2462                 return false;
2463         }
2464 }
2465
2466 /**
2467  * Return a formatted timestamp, or null if input is null.
2468  * For dealing with nullable timestamp columns in the database.
2469  *
2470  * @param $outputtype Integer
2471  * @param $ts String
2472  * @return String
2473  */
2474 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2475         if( is_null( $ts ) ) {
2476                 return null;
2477         } else {
2478                 return wfTimestamp( $outputtype, $ts );
2479         }
2480 }
2481
2482 /**
2483  * Convenience function; returns MediaWiki timestamp for the present time.
2484  *
2485  * @return string
2486  */
2487 function wfTimestampNow() {
2488         # return NOW
2489         return wfTimestamp( TS_MW, time() );
2490 }
2491
2492 /**
2493  * Check if the operating system is Windows
2494  *
2495  * @return Bool: true if it's Windows, False otherwise.
2496  */
2497 function wfIsWindows() {
2498         static $isWindows = null;
2499         if ( $isWindows === null ) {
2500                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2501         }
2502         return $isWindows;
2503 }
2504
2505 /**
2506  * Check if we are running under HipHop
2507  *
2508  * @return Bool
2509  */
2510 function wfIsHipHop() {
2511         return function_exists( 'hphp_thread_set_warmup_enabled' );
2512 }
2513
2514 /**
2515  * Swap two variables
2516  *
2517  * @param $x Mixed
2518  * @param $y Mixed
2519  */
2520 function swap( &$x, &$y ) {
2521         $z = $x;
2522         $x = $y;
2523         $y = $z;
2524 }
2525
2526 /**
2527  * Tries to get the system directory for temporary files. First
2528  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2529  * environment variables are then checked in sequence, and if none are
2530  * set try sys_get_temp_dir().
2531  *
2532  * NOTE: When possible, use instead the tmpfile() function to create
2533  * temporary files to avoid race conditions on file creation, etc.
2534  *
2535  * @return String
2536  */
2537 function wfTempDir() {
2538         global $wgTmpDirectory;
2539
2540         if ( $wgTmpDirectory !== false ) {
2541                 return $wgTmpDirectory;
2542         }
2543
2544         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2545
2546         foreach( $tmpDir as $tmp ) {
2547                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2548                         return $tmp;
2549                 }
2550         }
2551         return sys_get_temp_dir();
2552 }
2553
2554 /**
2555  * Make directory, and make all parent directories if they don't exist
2556  *
2557  * @param $dir String: full path to directory to create
2558  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2559  * @param $caller String: optional caller param for debugging.
2560  * @throws MWException
2561  * @return bool
2562  */
2563 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2564         global $wgDirectoryMode;
2565
2566         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2567                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2568         }
2569
2570         if ( !is_null( $caller ) ) {
2571                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2572         }
2573
2574         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2575                 return true;
2576         }
2577
2578         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2579
2580         if ( is_null( $mode ) ) {
2581                 $mode = $wgDirectoryMode;
2582         }
2583
2584         // Turn off the normal warning, we're doing our own below
2585         wfSuppressWarnings();
2586         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2587         wfRestoreWarnings();
2588
2589         if( !$ok ) {
2590                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2591                 trigger_error( sprintf( "%s: failed to mkdir \"%s\" mode 0%o", __FUNCTION__, $dir, $mode ),
2592                         E_USER_WARNING );
2593         }
2594         return $ok;
2595 }
2596
2597 /**
2598  * Remove a directory and all its content.
2599  * Does not hide error.
2600  */
2601 function wfRecursiveRemoveDir( $dir ) {
2602         wfDebug( __FUNCTION__ . "( $dir )\n" );
2603         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2604         if ( is_dir( $dir ) ) {
2605                 $objects = scandir( $dir );
2606                 foreach ( $objects as $object ) {
2607                         if ( $object != "." && $object != ".." ) {
2608                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2609                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2610                                 } else {
2611                                         unlink( $dir . '/' . $object );
2612                                 }
2613                         }
2614                 }
2615                 reset( $objects );
2616                 rmdir( $dir );
2617         }
2618 }
2619
2620 /**
2621  * @param $nr Mixed: the number to format
2622  * @param $acc Integer: the number of digits after the decimal point, default 2
2623  * @param $round Boolean: whether or not to round the value, default true
2624  * @return float
2625  */
2626 function wfPercent( $nr, $acc = 2, $round = true ) {
2627         $ret = sprintf( "%.${acc}f", $nr );
2628         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2629 }
2630
2631 /**
2632  * Find out whether or not a mixed variable exists in a string
2633  *
2634  * @deprecated Just use str(i)pos
2635  * @param $needle String
2636  * @param $str String
2637  * @param $insensitive Boolean
2638  * @return Boolean
2639  */
2640 function in_string( $needle, $str, $insensitive = false ) {
2641         wfDeprecated( __METHOD__, '1.21' );
2642         $func = 'strpos';
2643         if( $insensitive ) $func = 'stripos';
2644
2645         return $func( $str, $needle ) !== false;
2646 }
2647
2648 /**
2649  * Safety wrapper around ini_get() for boolean settings.
2650  * The values returned from ini_get() are pre-normalized for settings
2651  * set via php.ini or php_flag/php_admin_flag... but *not*
2652  * for those set via php_value/php_admin_value.
2653  *
2654  * It's fairly common for people to use php_value instead of php_flag,
2655  * which can leave you with an 'off' setting giving a false positive
2656  * for code that just takes the ini_get() return value as a boolean.
2657  *
2658  * To make things extra interesting, setting via php_value accepts
2659  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2660  * Unrecognized values go false... again opposite PHP's own coercion
2661  * from string to bool.
2662  *
2663  * Luckily, 'properly' set settings will always come back as '0' or '1',
2664  * so we only have to worry about them and the 'improper' settings.
2665  *
2666  * I frickin' hate PHP... :P
2667  *
2668  * @param $setting String
2669  * @return Bool
2670  */
2671 function wfIniGetBool( $setting ) {
2672         $val = ini_get( $setting );
2673         // 'on' and 'true' can't have whitespace around them, but '1' can.
2674         return strtolower( $val ) == 'on'
2675                 || strtolower( $val ) == 'true'
2676                 || strtolower( $val ) == 'yes'
2677                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2678 }
2679
2680 /**
2681  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2682  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2683  *
2684  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2685  *                          should be omitted
2686  * @param $fileName String Name of the library, if not $extension.suffix
2687  * @return Bool - Whether or not the extension is loaded
2688  */
2689 function wfDl( $extension, $fileName = null ) {
2690         if( extension_loaded( $extension ) ) {
2691                 return true;
2692         }
2693
2694         $canDl = false;
2695         if( PHP_SAPI == 'cli' || PHP_SAPI == 'cgi' || PHP_SAPI == 'embed' ) {
2696                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2697                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2698         }
2699
2700         if( $canDl ) {
2701                 $fileName = $fileName ? $fileName : $extension;
2702                 if( wfIsWindows() ) {
2703                         $fileName = 'php_' . $fileName;
2704                 }
2705                 wfSuppressWarnings();
2706                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2707                 wfRestoreWarnings();
2708         }
2709         return extension_loaded( $extension );
2710 }
2711
2712 /**
2713  * Windows-compatible version of escapeshellarg()
2714  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2715  * function puts single quotes in regardless of OS.
2716  *
2717  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2718  * earlier distro releases of PHP)
2719  *
2720  * @param varargs
2721  * @return String
2722  */
2723 function wfEscapeShellArg( ) {
2724         wfInitShellLocale();
2725
2726         $args = func_get_args();
2727         $first = true;
2728         $retVal = '';
2729         foreach ( $args as $arg ) {
2730                 if ( !$first ) {
2731                         $retVal .= ' ';
2732                 } else {
2733                         $first = false;
2734                 }
2735
2736                 if ( wfIsWindows() ) {
2737                         // Escaping for an MSVC-style command line parser and CMD.EXE
2738                         // Refs:
2739                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2740                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2741                         //  * Bug #13518
2742                         //  * CR r63214
2743                         // Double the backslashes before any double quotes. Escape the double quotes.
2744                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2745                         $arg = '';
2746                         $iteration = 0;
2747                         foreach ( $tokens as $token ) {
2748                                 if ( $iteration % 2 == 1 ) {
2749                                         // Delimiter, a double quote preceded by zero or more slashes
2750                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2751                                 } elseif ( $iteration % 4 == 2 ) {
2752                                         // ^ in $token will be outside quotes, need to be escaped
2753                                         $arg .= str_replace( '^', '^^', $token );
2754                                 } else { // $iteration % 4 == 0
2755                                         // ^ in $token will appear inside double quotes, so leave as is
2756                                         $arg .= $token;
2757                                 }
2758                                 $iteration++;
2759                         }
2760                         // Double the backslashes before the end of the string, because
2761                         // we will soon add a quote
2762                         $m = array();
2763                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2764                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2765                         }
2766
2767                         // Add surrounding quotes
2768                         $retVal .= '"' . $arg . '"';
2769                 } else {
2770                         $retVal .= escapeshellarg( $arg );
2771                 }
2772         }
2773         return $retVal;
2774 }
2775
2776 /**
2777  * Execute a shell command, with time and memory limits mirrored from the PHP
2778  * configuration if supported.
2779  * @param $cmd String Command line, properly escaped for shell.
2780  * @param &$retval null|Mixed optional, will receive the program's exit code.
2781  *                 (non-zero is usually failure)
2782  * @param $environ Array optional environment variables which should be
2783  *                 added to the executed command environment.
2784  * @param $limits Array optional array with limits(filesize, memory, time, walltime)
2785  *                 this overwrites the global wgShellMax* limits.
2786  * @return string collected stdout as a string (trailing newlines stripped)
2787  */
2788 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2789         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2790                 $wgMaxShellWallClockTime, $wgShellCgroup;
2791
2792         static $disabled;
2793         if ( is_null( $disabled ) ) {
2794                 $disabled = false;
2795                 if( wfIniGetBool( 'safe_mode' ) ) {
2796                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2797                         $disabled = 'safemode';
2798                 } else {
2799                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2800                         $functions = array_map( 'trim', $functions );
2801                         $functions = array_map( 'strtolower', $functions );
2802                         if ( in_array( 'passthru', $functions ) ) {
2803                                 wfDebug( "passthru is in disabled_functions\n" );
2804                                 $disabled = 'passthru';
2805                         }
2806                 }
2807         }
2808         if ( $disabled ) {
2809                 $retval = 1;
2810                 return $disabled == 'safemode' ?
2811                         'Unable to run external programs in safe mode.' :
2812                         'Unable to run external programs, passthru() is disabled.';
2813         }
2814
2815         wfInitShellLocale();
2816
2817         $envcmd = '';
2818         foreach( $environ as $k => $v ) {
2819                 if ( wfIsWindows() ) {
2820                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2821                          * appear in the environment variable, so we must use carat escaping as documented in
2822                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2823                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2824                          * are listed there but doesn't appear to need it.
2825                          */
2826                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2827                 } else {
2828                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2829                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2830                          */
2831                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2832                 }
2833         }
2834         $cmd = $envcmd . $cmd;
2835
2836         if ( php_uname( 's' ) == 'Linux' ) {
2837                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2838                 if ( isset( $limits['walltime'] ) ) {
2839                         $wallTime = intval( $limits['walltime'] );
2840                 } elseif ( isset( $limits['time'] ) ) {
2841                         $wallTime = $time;
2842                 } else {
2843                         $wallTime = intval( $wgMaxShellWallClockTime );
2844                 }
2845                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2846                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2847
2848                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2849                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2850                                 escapeshellarg( $cmd ) . ' ' .
2851                                 escapeshellarg(
2852                                         "MW_CPU_LIMIT=$time; " .
2853                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2854                                         "MW_MEM_LIMIT=$mem; " .
2855                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2856                                         "MW_WALL_CLOCK_LIMIT=$wallTime"
2857                                 );
2858                 }
2859         }
2860         wfDebug( "wfShellExec: $cmd\n" );
2861
2862         $retval = 1; // error by default?
2863         ob_start();
2864         passthru( $cmd, $retval );
2865         $output = ob_get_contents();
2866         ob_end_clean();
2867
2868         if ( $retval == 127 ) {
2869                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2870         }
2871         return $output;
2872 }
2873
2874 /**
2875  * Workaround for http://bugs.php.net/bug.php?id=45132
2876  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2877  */
2878 function wfInitShellLocale() {
2879         static $done = false;
2880         if ( $done ) {
2881                 return;
2882         }
2883         $done = true;
2884         global $wgShellLocale;
2885         if ( !wfIniGetBool( 'safe_mode' ) ) {
2886                 putenv( "LC_CTYPE=$wgShellLocale" );
2887                 setlocale( LC_CTYPE, $wgShellLocale );
2888         }
2889 }
2890
2891 /**
2892  * Alias to wfShellWikiCmd()
2893  * @see wfShellWikiCmd()
2894  */
2895 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2896         return wfShellWikiCmd( $script, $parameters, $options );
2897 }
2898
2899 /**
2900  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2901  * Note that $parameters should be a flat array and an option with an argument
2902  * should consist of two consecutive items in the array (do not use "--option value").
2903  * @param $script string MediaWiki cli script path
2904  * @param $parameters Array Arguments and options to the script
2905  * @param $options Array Associative array of options:
2906  *              'php': The path to the php executable
2907  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2908  * @return Array
2909  */
2910 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2911         global $wgPhpCli;
2912         // Give site config file a chance to run the script in a wrapper.
2913         // The caller may likely want to call wfBasename() on $script.
2914         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2915         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2916         if ( isset( $options['wrapper'] ) ) {
2917                 $cmd[] = $options['wrapper'];
2918         }
2919         $cmd[] = $script;
2920         // Escape each parameter for shell
2921         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2922 }
2923
2924 /**
2925  * wfMerge attempts to merge differences between three texts.
2926  * Returns true for a clean merge and false for failure or a conflict.
2927  *
2928  * @param $old String
2929  * @param $mine String
2930  * @param $yours String
2931  * @param $result String
2932  * @return Bool
2933  */
2934 function wfMerge( $old, $mine, $yours, &$result ) {
2935         global $wgDiff3;
2936
2937         # This check may also protect against code injection in
2938         # case of broken installations.
2939         wfSuppressWarnings();
2940         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2941         wfRestoreWarnings();
2942
2943         if( !$haveDiff3 ) {
2944                 wfDebug( "diff3 not found\n" );
2945                 return false;
2946         }
2947
2948         # Make temporary files
2949         $td = wfTempDir();
2950         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2951         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2952         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2953
2954         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2955         #       a newline character. To avoid this, we normalize the trailing whitespace before
2956         #       creating the diff.
2957
2958         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2959         fclose( $oldtextFile );
2960         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2961         fclose( $mytextFile );
2962         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2963         fclose( $yourtextFile );
2964
2965         # Check for a conflict
2966         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
2967                 wfEscapeShellArg( $mytextName ) . ' ' .
2968                 wfEscapeShellArg( $oldtextName ) . ' ' .
2969                 wfEscapeShellArg( $yourtextName );
2970         $handle = popen( $cmd, 'r' );
2971
2972         if( fgets( $handle, 1024 ) ) {
2973                 $conflict = true;
2974         } else {
2975                 $conflict = false;
2976         }
2977         pclose( $handle );
2978
2979         # Merge differences
2980         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
2981                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2982         $handle = popen( $cmd, 'r' );
2983         $result = '';
2984         do {
2985                 $data = fread( $handle, 8192 );
2986                 if ( strlen( $data ) == 0 ) {
2987                         break;
2988                 }
2989                 $result .= $data;
2990         } while ( true );
2991         pclose( $handle );
2992         unlink( $mytextName );
2993         unlink( $oldtextName );
2994         unlink( $yourtextName );
2995
2996         if ( $result === '' && $old !== '' && !$conflict ) {
2997                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2998                 $conflict = true;
2999         }
3000         return !$conflict;
3001 }
3002
3003 /**
3004  * Returns unified plain-text diff of two texts.
3005  * Useful for machine processing of diffs.
3006  *
3007  * @param $before String: the text before the changes.
3008  * @param $after String: the text after the changes.
3009  * @param $params String: command-line options for the diff command.
3010  * @return String: unified diff of $before and $after
3011  */
3012 function wfDiff( $before, $after, $params = '-u' ) {
3013         if ( $before == $after ) {
3014                 return '';
3015         }
3016
3017         global $wgDiff;
3018         wfSuppressWarnings();
3019         $haveDiff = $wgDiff && file_exists( $wgDiff );
3020         wfRestoreWarnings();
3021
3022         # This check may also protect against code injection in
3023         # case of broken installations.
3024         if( !$haveDiff ) {
3025                 wfDebug( "diff executable not found\n" );
3026                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3027                 $format = new UnifiedDiffFormatter();
3028                 return $format->format( $diffs );
3029         }
3030
3031         # Make temporary files
3032         $td = wfTempDir();
3033         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3034         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3035
3036         fwrite( $oldtextFile, $before );
3037         fclose( $oldtextFile );
3038         fwrite( $newtextFile, $after );
3039         fclose( $newtextFile );
3040
3041         // Get the diff of the two files
3042         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3043
3044         $h = popen( $cmd, 'r' );
3045
3046         $diff = '';
3047
3048         do {
3049                 $data = fread( $h, 8192 );
3050                 if ( strlen( $data ) == 0 ) {
3051                         break;
3052                 }
3053                 $diff .= $data;
3054         } while ( true );
3055
3056         // Clean up
3057         pclose( $h );
3058         unlink( $oldtextName );
3059         unlink( $newtextName );
3060
3061         // Kill the --- and +++ lines. They're not useful.
3062         $diff_lines = explode( "\n", $diff );
3063         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3064                 unset( $diff_lines[0] );
3065         }
3066         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3067                 unset( $diff_lines[1] );
3068         }
3069
3070         $diff = implode( "\n", $diff_lines );
3071
3072         return $diff;
3073 }
3074
3075 /**
3076  * This function works like "use VERSION" in Perl, the program will die with a
3077  * backtrace if the current version of PHP is less than the version provided
3078  *
3079  * This is useful for extensions which due to their nature are not kept in sync
3080  * with releases, and might depend on other versions of PHP than the main code
3081  *
3082  * Note: PHP might die due to parsing errors in some cases before it ever
3083  *       manages to call this function, such is life
3084  *
3085  * @see perldoc -f use
3086  *
3087  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3088  *                 a float
3089  * @throws MWException
3090  */
3091 function wfUsePHP( $req_ver ) {
3092         $php_ver = PHP_VERSION;
3093
3094         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3095                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3096         }
3097 }
3098
3099 /**
3100  * This function works like "use VERSION" in Perl except it checks the version
3101  * of MediaWiki, the program will die with a backtrace if the current version
3102  * of MediaWiki is less than the version provided.
3103  *
3104  * This is useful for extensions which due to their nature are not kept in sync
3105  * with releases
3106  *
3107  * @see perldoc -f use
3108  *
3109  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3110  *                 a float
3111  * @throws MWException
3112  */
3113 function wfUseMW( $req_ver ) {
3114         global $wgVersion;
3115
3116         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3117                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3118         }
3119 }
3120
3121 /**
3122  * Return the final portion of a pathname.
3123  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3124  * http://bugs.php.net/bug.php?id=33898
3125  *
3126  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3127  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3128  *
3129  * @param $path String
3130  * @param $suffix String: to remove if present
3131  * @return String
3132  */
3133 function wfBaseName( $path, $suffix = '' ) {
3134         $encSuffix = ( $suffix == '' )
3135                 ? ''
3136                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3137         $matches = array();
3138         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3139                 return $matches[1];
3140         } else {
3141                 return '';
3142         }
3143 }
3144
3145 /**
3146  * Generate a relative path name to the given file.
3147  * May explode on non-matching case-insensitive paths,
3148  * funky symlinks, etc.
3149  *
3150  * @param $path String: absolute destination path including target filename
3151  * @param $from String: Absolute source path, directory only
3152  * @return String
3153  */
3154 function wfRelativePath( $path, $from ) {
3155         // Normalize mixed input on Windows...
3156         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3157         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3158
3159         // Trim trailing slashes -- fix for drive root
3160         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3161         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3162
3163         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3164         $against = explode( DIRECTORY_SEPARATOR, $from );
3165
3166         if( $pieces[0] !== $against[0] ) {
3167                 // Non-matching Windows drive letters?
3168                 // Return a full path.
3169                 return $path;
3170         }
3171
3172         // Trim off common prefix
3173         while( count( $pieces ) && count( $against )
3174                 && $pieces[0] == $against[0] ) {
3175                 array_shift( $pieces );
3176                 array_shift( $against );
3177         }
3178
3179         // relative dots to bump us to the parent
3180         while( count( $against ) ) {
3181                 array_unshift( $pieces, '..' );
3182                 array_shift( $against );
3183         }
3184
3185         array_push( $pieces, wfBaseName( $path ) );
3186
3187         return implode( DIRECTORY_SEPARATOR, $pieces );
3188 }
3189
3190 /**
3191  * Do any deferred updates and clear the list
3192  *
3193  * @deprecated since 1.19
3194  * @see DeferredUpdates::doUpdate()
3195  * @param $commit string
3196  */
3197 function wfDoUpdates( $commit = '' ) {
3198         wfDeprecated( __METHOD__, '1.19' );
3199         DeferredUpdates::doUpdates( $commit );
3200 }
3201
3202 /**
3203  * Convert an arbitrarily-long digit string from one numeric base
3204  * to another, optionally zero-padding to a minimum column width.
3205  *
3206  * Supports base 2 through 36; digit values 10-36 are represented
3207  * as lowercase letters a-z. Input is case-insensitive.
3208  *
3209  * @param string $input Input number
3210  * @param int $sourceBase Base of the input number
3211  * @param int $destBase Desired base of the output
3212  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3213  * @param bool $lowercase Whether to output in lowercase or uppercase
3214  * @param string $engine Either "gmp", "bcmath", or "php"
3215  * @return string|bool The output number as a string, or false on error
3216  */
3217 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true, $engine = 'auto' ) {
3218         $input = (string)$input;
3219         if(
3220                 $sourceBase < 2 ||
3221                 $sourceBase > 36 ||
3222                 $destBase < 2 ||
3223                 $destBase > 36 ||
3224                 $sourceBase != (int) $sourceBase ||
3225                 $destBase != (int) $destBase ||
3226                 $pad != (int) $pad ||
3227                 !preg_match( "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i", $input )
3228         ) {
3229                 return false;
3230         }
3231
3232         static $baseChars = array (
3233                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3234                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3235                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3236                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3237                 34 => 'y', 35 => 'z',
3238
3239                 '0' => 0,  '1' => 1,  '2' => 2,  '3' => 3,  '4' => 4,  '5' => 5,
3240                 '6' => 6,  '7' => 7,  '8' => 8,  '9' => 9,  'a' => 10, 'b' => 11,
3241                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3242                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3243                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3244                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3245         );
3246
3247         if( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3248                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3249         } elseif( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3250                 $decimal = '0';
3251                 foreach( str_split( strtolower( $input ) ) as $char ) {
3252                         $decimal = bcmul( $decimal, $sourceBase );
3253                         $decimal = bcadd( $decimal, $baseChars[$char] );
3254                 }
3255
3256                 for( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3257                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3258                 }
3259
3260                 $result = strrev( $result );
3261         } else {
3262                 $inDigits = array();
3263                 foreach( str_split( strtolower( $input ) ) as $char ) {
3264                         $inDigits[] = $baseChars[$char];
3265                 }
3266
3267                 // Iterate over the input, modulo-ing out an output digit
3268                 // at a time until input is gone.
3269                 $result = '';
3270                 while( $inDigits ) {
3271                         $work = 0;
3272                         $workDigits = array();
3273
3274                         // Long division...
3275                         foreach( $inDigits as $digit ) {
3276                                 $work *= $sourceBase;
3277                                 $work += $digit;
3278
3279                                 if( $workDigits || $work >= $destBase ) {
3280                                         $workDigits[] = (int) ( $work / $destBase );
3281                                 }
3282                                 $work %= $destBase;
3283                         }
3284
3285                         // All that division leaves us with a remainder,
3286                         // which is conveniently our next output digit.
3287                         $result .= $baseChars[$work];
3288
3289                         // And we continue!
3290                         $inDigits = $workDigits;
3291                 }
3292
3293                 $result = strrev( $result );
3294         }
3295
3296         if( !$lowercase ) {
3297                 $result = strtoupper( $result );
3298         }
3299
3300         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3301 }
3302
3303 /**
3304  * Create an object with a given name and an array of construct parameters
3305  *
3306  * @param $name String
3307  * @param $p Array: parameters
3308  * @return object
3309  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3310  */
3311 function wfCreateObject( $name, $p ) {
3312         wfDeprecated( __FUNCTION__, '1.18' );
3313         return MWFunction::newObj( $name, $p );
3314 }
3315
3316 /**
3317  * @return bool
3318  */
3319 function wfHttpOnlySafe() {
3320         global $wgHttpOnlyBlacklist;
3321
3322         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3323                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3324                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3325                                 return false;
3326                         }
3327                 }
3328         }
3329
3330         return true;
3331 }
3332
3333 /**
3334  * Check if there is sufficent entropy in php's built-in session generation
3335  * @return bool true = there is sufficient entropy
3336  */
3337 function wfCheckEntropy() {
3338         return (
3339                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3340                         || ini_get( 'session.entropy_file' )
3341                 )
3342                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3343 }
3344
3345 /**
3346  * Override session_id before session startup if php's built-in
3347  * session generation code is not secure.
3348  */
3349 function wfFixSessionID() {
3350         // If the cookie or session id is already set we already have a session and should abort
3351         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3352                 return;
3353         }
3354
3355         // PHP's built-in session entropy is enabled if:
3356         // - entropy_file is set or you're on Windows with php 5.3.3+
3357         // - AND entropy_length is > 0
3358         // We treat it as disabled if it doesn't have an entropy length of at least 32
3359         $entropyEnabled = wfCheckEntropy();
3360
3361         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3362         if ( !$entropyEnabled ) {
3363                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3364                 session_id( MWCryptRand::generateHex( 32 ) );
3365         }
3366 }
3367
3368 /**
3369  * Initialise php session
3370  *
3371  * @param $sessionId Bool
3372  */
3373 function wfSetupSession( $sessionId = false ) {
3374         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3375                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3376         if( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3377                 ObjectCacheSessionHandler::install();
3378         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3379                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3380                 # hasn't already been set to the desired value (that causes errors)
3381                 ini_set( 'session.save_handler', $wgSessionHandler );
3382         }
3383         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3384         wfDebugLog( 'cookie',
3385                 'session_set_cookie_params: "' . implode( '", "',
3386                         array(
3387                                 0,
3388                                 $wgCookiePath,
3389                                 $wgCookieDomain,
3390                                 $wgCookieSecure,
3391                                 $httpOnlySafe ) ) . '"' );
3392         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3393         session_cache_limiter( 'private, must-revalidate' );
3394         if ( $sessionId ) {
3395                 session_id( $sessionId );
3396         } else {
3397                 wfFixSessionID();
3398         }
3399         wfSuppressWarnings();
3400         session_start();
3401         wfRestoreWarnings();
3402 }
3403
3404 /**
3405  * Get an object from the precompiled serialized directory
3406  *
3407  * @param $name String
3408  * @return Mixed: the variable on success, false on failure
3409  */
3410 function wfGetPrecompiledData( $name ) {
3411         global $IP;
3412
3413         $file = "$IP/serialized/$name";
3414         if ( file_exists( $file ) ) {
3415                 $blob = file_get_contents( $file );
3416                 if ( $blob ) {
3417                         return unserialize( $blob );
3418                 }
3419         }
3420         return false;
3421 }
3422
3423 /**
3424  * Get a cache key
3425  *
3426  * @param varargs
3427  * @return String
3428  */
3429 function wfMemcKey( /*... */ ) {
3430         global $wgCachePrefix;
3431         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3432         $args = func_get_args();
3433         $key = $prefix . ':' . implode( ':', $args );
3434         $key = str_replace( ' ', '_', $key );
3435         return $key;
3436 }
3437
3438 /**
3439  * Get a cache key for a foreign DB
3440  *
3441  * @param $db String
3442  * @param $prefix String
3443  * @param varargs String
3444  * @return String
3445  */
3446 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3447         $args = array_slice( func_get_args(), 2 );
3448         if ( $prefix ) {
3449                 $key = "$db-$prefix:" . implode( ':', $args );
3450         } else {
3451                 $key = $db . ':' . implode( ':', $args );
3452         }
3453         return $key;
3454 }
3455
3456 /**
3457  * Get an ASCII string identifying this wiki
3458  * This is used as a prefix in memcached keys
3459  *
3460  * @return String
3461  */
3462 function wfWikiID() {
3463         global $wgDBprefix, $wgDBname;
3464         if ( $wgDBprefix ) {
3465                 return "$wgDBname-$wgDBprefix";
3466         } else {
3467                 return $wgDBname;
3468         }
3469 }
3470
3471 /**
3472  * Split a wiki ID into DB name and table prefix
3473  *
3474  * @param $wiki String
3475  *
3476  * @return array
3477  */
3478 function wfSplitWikiID( $wiki ) {
3479         $bits = explode( '-', $wiki, 2 );
3480         if ( count( $bits ) < 2 ) {
3481                 $bits[] = '';
3482         }
3483         return $bits;
3484 }
3485
3486 /**
3487  * Get a Database object.
3488  *
3489  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3490  *            master (for write queries), DB_SLAVE for potentially lagged read
3491  *            queries, or an integer >= 0 for a particular server.
3492  *
3493  * @param $groups Mixed: query groups. An array of group names that this query
3494  *                belongs to. May contain a single string if the query is only
3495  *                in one group.
3496  *
3497  * @param $wiki String: the wiki ID, or false for the current wiki
3498  *
3499  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3500  * will always return the same object, unless the underlying connection or load
3501  * balancer is manually destroyed.
3502  *
3503  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3504  * updater to ensure that a proper database is being updated.
3505  *
3506  * @return DatabaseBase
3507  */
3508 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3509         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3510 }
3511
3512 /**
3513  * Get a load balancer object.
3514  *
3515  * @param $wiki String: wiki ID, or false for the current wiki
3516  * @return LoadBalancer
3517  */
3518 function wfGetLB( $wiki = false ) {
3519         return wfGetLBFactory()->getMainLB( $wiki );
3520 }
3521
3522 /**
3523  * Get the load balancer factory object
3524  *
3525  * @return LBFactory
3526  */
3527 function &wfGetLBFactory() {
3528         return LBFactory::singleton();
3529 }
3530
3531 /**
3532  * Find a file.
3533  * Shortcut for RepoGroup::singleton()->findFile()
3534  *
3535  * @param $title String or Title object
3536  * @param $options array Associative array of options:
3537  *     time:           requested time for an archived image, or false for the
3538  *                     current version. An image object will be returned which was
3539  *                     created at the specified time.
3540  *
3541  *     ignoreRedirect: If true, do not follow file redirects
3542  *
3543  *     private:        If true, return restricted (deleted) files if the current
3544  *                     user is allowed to view them. Otherwise, such files will not
3545  *                     be found.
3546  *
3547  *     bypassCache:    If true, do not use the process-local cache of File objects
3548  *
3549  * @return File, or false if the file does not exist
3550  */
3551 function wfFindFile( $title, $options = array() ) {
3552         return RepoGroup::singleton()->findFile( $title, $options );
3553 }
3554
3555 /**
3556  * Get an object referring to a locally registered file.
3557  * Returns a valid placeholder object if the file does not exist.
3558  *
3559  * @param $title Title|String
3560  * @return LocalFile|null A File, or null if passed an invalid Title
3561  */
3562 function wfLocalFile( $title ) {
3563         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3564 }
3565
3566 /**
3567  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3568  * @deprecated since 1.19
3569  */
3570 function wfStreamFile( $fname, $headers = array() ) {
3571         wfDeprecated( __FUNCTION__, '1.19' );
3572         StreamFile::stream( $fname, $headers );
3573 }
3574
3575 /**
3576  * Should low-performance queries be disabled?
3577  *
3578  * @return Boolean
3579  * @codeCoverageIgnore
3580  */
3581 function wfQueriesMustScale() {
3582         global $wgMiserMode;
3583         return $wgMiserMode
3584                 || ( SiteStats::pages() > 100000
3585                 && SiteStats::edits() > 1000000
3586                 && SiteStats::users() > 10000 );
3587 }
3588
3589 /**
3590  * Get the path to a specified script file, respecting file
3591  * extensions; this is a wrapper around $wgScriptExtension etc.
3592  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3593  *
3594  * @param $script String: script filename, sans extension
3595  * @return String
3596  */
3597 function wfScript( $script = 'index' ) {
3598         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3599         if ( $script === 'index' ) {
3600                 return $wgScript;
3601         } else if ( $script === 'load' ) {
3602                 return $wgLoadScript;
3603         } else {
3604                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3605         }
3606 }
3607
3608 /**
3609  * Get the script URL.
3610  *
3611  * @return string script URL
3612  */
3613 function wfGetScriptUrl() {
3614         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3615                 #
3616                 # as it was called, minus the query string.
3617                 #
3618                 # Some sites use Apache rewrite rules to handle subdomains,
3619                 # and have PHP set up in a weird way that causes PHP_SELF
3620                 # to contain the rewritten URL instead of the one that the
3621                 # outside world sees.
3622                 #
3623                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3624                 # provides containing the "before" URL.
3625                 return $_SERVER['SCRIPT_NAME'];
3626         } else {
3627                 return $_SERVER['URL'];
3628         }
3629 }
3630
3631 /**
3632  * Convenience function converts boolean values into "true"
3633  * or "false" (string) values
3634  *
3635  * @param $value Boolean
3636  * @return String
3637  */
3638 function wfBoolToStr( $value ) {
3639         return $value ? 'true' : 'false';
3640 }
3641
3642 /**
3643  * Get a platform-independent path to the null file, e.g. /dev/null
3644  *
3645  * @return string
3646  */
3647 function wfGetNull() {
3648         return wfIsWindows()
3649                 ? 'NUL'
3650                 : '/dev/null';
3651 }
3652
3653 /**
3654  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3655  * and waiting for it to go down, this waits for the slaves to catch up to the
3656  * master position. Use this when updating very large numbers of rows, as
3657  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3658  * a no-op if there are no slaves.
3659  *
3660  * @param $maxLag Integer (deprecated)
3661  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3662  */
3663 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3664         $lb = wfGetLB( $wiki );
3665         // bug 27975 - Don't try to wait for slaves if there are none
3666         // Prevents permission error when getting master position
3667         if ( $lb->getServerCount() > 1 ) {
3668                 $dbw = $lb->getConnection( DB_MASTER );
3669                 $pos = $dbw->getMasterPos();
3670                 $lb->waitForAll( $pos );
3671         }
3672 }
3673
3674 /**
3675  * Used to be used for outputting text in the installer/updater
3676  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3677  */
3678 function wfOut( $s ) {
3679         wfDeprecated( __FUNCTION__, '1.18' );
3680         global $wgCommandLineMode;
3681         if ( $wgCommandLineMode ) {
3682                 echo $s;
3683         } else {
3684                 echo htmlspecialchars( $s );
3685         }
3686         flush();
3687 }
3688
3689 /**
3690  * Count down from $n to zero on the terminal, with a one-second pause
3691  * between showing each number. For use in command-line scripts.
3692  * @codeCoverageIgnore
3693  * @param $n int
3694  */
3695 function wfCountDown( $n ) {
3696         for ( $i = $n; $i >= 0; $i-- ) {
3697                 if ( $i != $n ) {
3698                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3699                 }
3700                 echo $i;
3701                 flush();
3702                 if ( $i ) {
3703                         sleep( 1 );
3704                 }
3705         }
3706         echo "\n";
3707 }
3708
3709 /**
3710  * Generate a random 32-character hexadecimal token.
3711  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3712  *              characters before hashing.
3713  * @return string
3714  * @codeCoverageIgnore
3715  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pesudo-random strings
3716  * @warning This method is NOT secure. Additionally it has many callers that use it for pesudo-random purposes.
3717  */
3718 function wfGenerateToken( $salt = '' ) {
3719         wfDeprecated( __METHOD__, '1.20' );
3720         $salt = serialize( $salt );
3721         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3722 }
3723
3724 /**
3725  * Replace all invalid characters with -
3726  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3727  * By default, $wgIllegalFileChars = ':'
3728  *
3729  * @param $name Mixed: filename to process
3730  * @return String
3731  */
3732 function wfStripIllegalFilenameChars( $name ) {
3733         global $wgIllegalFileChars;
3734         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3735         $name = wfBaseName( $name );
3736         $name = preg_replace(
3737                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3738                 '-',
3739                 $name
3740         );
3741         return $name;
3742 }
3743
3744 /**
3745  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3746  *
3747  * @return Integer value memory was set to.
3748  */
3749 function wfMemoryLimit() {
3750         global $wgMemoryLimit;
3751         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3752         if( $memlimit != -1 ) {
3753                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3754                 if( $conflimit == -1 ) {
3755                         wfDebug( "Removing PHP's memory limit\n" );
3756                         wfSuppressWarnings();
3757                         ini_set( 'memory_limit', $conflimit );
3758                         wfRestoreWarnings();
3759                         return $conflimit;
3760                 } elseif ( $conflimit > $memlimit ) {
3761                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3762                         wfSuppressWarnings();
3763                         ini_set( 'memory_limit', $conflimit );
3764                         wfRestoreWarnings();
3765                         return $conflimit;
3766                 }
3767         }
3768         return $memlimit;
3769 }
3770
3771 /**
3772  * Converts shorthand byte notation to integer form
3773  *
3774  * @param $string String
3775  * @return Integer
3776  */
3777 function wfShorthandToInteger( $string = '' ) {
3778         $string = trim( $string );
3779         if( $string === '' ) {
3780                 return -1;
3781         }
3782         $last = $string[strlen( $string ) - 1];
3783         $val = intval( $string );
3784         switch( $last ) {
3785                 case 'g':
3786                 case 'G':
3787                         $val *= 1024;
3788                         // break intentionally missing
3789                 case 'm':
3790                 case 'M':
3791                         $val *= 1024;
3792                         // break intentionally missing
3793                 case 'k':
3794                 case 'K':
3795                         $val *= 1024;
3796         }
3797
3798         return $val;
3799 }
3800
3801 /**
3802  * Get the normalised IETF language tag
3803  * See unit test for examples.
3804  *
3805  * @param $code String: The language code.
3806  * @return String: The language code which complying with BCP 47 standards.
3807  */
3808 function wfBCP47( $code ) {
3809         $codeSegment = explode( '-', $code );
3810         $codeBCP = array();
3811         foreach ( $codeSegment as $segNo => $seg ) {
3812                 if ( count( $codeSegment ) > 0 ) {
3813                         // when previous segment is x, it is a private segment and should be lc
3814                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3815                                 $codeBCP[$segNo] = strtolower( $seg );
3816                         // ISO 3166 country code
3817                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3818                                 $codeBCP[$segNo] = strtoupper( $seg );
3819                         // ISO 15924 script code
3820                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3821                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3822                         // Use lowercase for other cases
3823                         } else {
3824                                 $codeBCP[$segNo] = strtolower( $seg );
3825                         }
3826                 } else {
3827                 // Use lowercase for single segment
3828                         $codeBCP[$segNo] = strtolower( $seg );
3829                 }
3830         }
3831         $langCode = implode( '-', $codeBCP );
3832         return $langCode;
3833 }
3834
3835 /**
3836  * Get a cache object.
3837  *
3838  * @param $inputType integer Cache type, one the the CACHE_* constants.
3839  * @return BagOStuff
3840  */
3841 function wfGetCache( $inputType ) {
3842         return ObjectCache::getInstance( $inputType );
3843 }
3844
3845 /**
3846  * Get the main cache object
3847  *
3848  * @return BagOStuff
3849  */
3850 function wfGetMainCache() {
3851         global $wgMainCacheType;
3852         return ObjectCache::getInstance( $wgMainCacheType );
3853 }
3854
3855 /**
3856  * Get the cache object used by the message cache
3857  *
3858  * @return BagOStuff
3859  */
3860 function wfGetMessageCacheStorage() {
3861         global $wgMessageCacheType;
3862         return ObjectCache::getInstance( $wgMessageCacheType );
3863 }
3864
3865 /**
3866  * Get the cache object used by the parser cache
3867  *
3868  * @return BagOStuff
3869  */
3870 function wfGetParserCacheStorage() {
3871         global $wgParserCacheType;
3872         return ObjectCache::getInstance( $wgParserCacheType );
3873 }
3874
3875 /**
3876  * Get the cache object used by the language converter
3877  *
3878  * @return BagOStuff
3879  */
3880 function wfGetLangConverterCacheStorage() {
3881         global $wgLanguageConverterCacheType;
3882         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3883 }
3884
3885 /**
3886  * Call hook functions defined in $wgHooks
3887  *
3888  * @param $event String: event name
3889  * @param $args Array: parameters passed to hook functions
3890  * @return Boolean True if no handler aborted the hook
3891  */
3892 function wfRunHooks( $event, $args = array() ) {
3893         return Hooks::run( $event, $args );
3894 }
3895
3896 /**
3897  * Wrapper around php's unpack.
3898  *
3899  * @param $format String: The format string (See php's docs)
3900  * @param $data: A binary string of binary data
3901  * @param $length integer or false: The minimun length of $data. This is to
3902  *      prevent reading beyond the end of $data. false to disable the check.
3903  *
3904  * Also be careful when using this function to read unsigned 32 bit integer
3905  * because php might make it negative.
3906  *
3907  * @throws MWException if $data not long enough, or if unpack fails
3908  * @return array Associative array of the extracted data
3909  */
3910 function wfUnpack( $format, $data, $length=false ) {
3911         if ( $length !== false ) {
3912                 $realLen = strlen( $data );
3913                 if ( $realLen < $length ) {
3914                         throw new MWException( "Tried to use wfUnpack on a "
3915                                 . "string of length $realLen, but needed one "
3916                                 . "of at least length $length."
3917                         );
3918                 }
3919         }
3920
3921         wfSuppressWarnings();
3922         $result = unpack( $format, $data );
3923         wfRestoreWarnings();
3924
3925         if ( $result === false ) {
3926                 // If it cannot extract the packed data.
3927                 throw new MWException( "unpack could not unpack binary data" );
3928         }
3929         return $result;
3930 }
3931
3932 /**
3933  * Determine if an image exists on the 'bad image list'.
3934  *
3935  * The format of MediaWiki:Bad_image_list is as follows:
3936  *    * Only list items (lines starting with "*") are considered
3937  *    * The first link on a line must be a link to a bad image
3938  *    * Any subsequent links on the same line are considered to be exceptions,
3939  *      i.e. articles where the image may occur inline.
3940  *
3941  * @param $name string the image name to check
3942  * @param $contextTitle Title|bool the page on which the image occurs, if known
3943  * @param $blacklist string wikitext of a file blacklist
3944  * @return bool
3945  */
3946 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3947         static $badImageCache = null; // based on bad_image_list msg
3948         wfProfileIn( __METHOD__ );
3949
3950         # Handle redirects
3951         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3952         if( $redirectTitle ) {
3953                 $name = $redirectTitle->getDbKey();
3954         }
3955
3956         # Run the extension hook
3957         $bad = false;
3958         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3959                 wfProfileOut( __METHOD__ );
3960                 return $bad;
3961         }
3962
3963         $cacheable = ( $blacklist === null );
3964         if( $cacheable && $badImageCache !== null ) {
3965                 $badImages = $badImageCache;
3966         } else { // cache miss
3967                 if ( $blacklist === null ) {
3968                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3969                 }
3970                 # Build the list now
3971                 $badImages = array();
3972                 $lines = explode( "\n", $blacklist );
3973                 foreach( $lines as $line ) {
3974                         # List items only
3975                         if ( substr( $line, 0, 1 ) !== '*' ) {
3976                                 continue;
3977                         }
3978
3979                         # Find all links
3980                         $m = array();
3981                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3982                                 continue;
3983                         }
3984
3985                         $exceptions = array();
3986                         $imageDBkey = false;
3987                         foreach ( $m[1] as $i => $titleText ) {
3988                                 $title = Title::newFromText( $titleText );
3989                                 if ( !is_null( $title ) ) {
3990                                         if ( $i == 0 ) {
3991                                                 $imageDBkey = $title->getDBkey();
3992                                         } else {
3993                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3994                                         }
3995                                 }
3996                         }
3997
3998                         if ( $imageDBkey !== false ) {
3999                                 $badImages[$imageDBkey] = $exceptions;
4000                         }
4001                 }
4002                 if ( $cacheable ) {
4003                         $badImageCache = $badImages;
4004                 }
4005         }
4006
4007         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4008         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4009         wfProfileOut( __METHOD__ );
4010         return $bad;
4011 }