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  * Given an array of non-normalised probabilities, this function will select
 334  * an element and return the appropriate key
 335  *
 336  * @param $weights array
 337  *
 338  * @return bool|int|string
 339  */
 340 function wfPickRandom( $weights ){
 341         if ( !is_array( $weights ) || count( $weights ) == 0 ) {
 342                 return false;
 343         }
 344
 345         $sum = array_sum( $weights );
 346         if ( $sum == 0 ) {
 347                 # No loads on any of them
 348                 # In previous versions, this triggered an unweighted random selection,
 349                 # but this feature has been removed as of April 2006 to allow for strict
 350                 # separation of query groups.
 351                 return false;
 352         }
 353         $max = mt_getrandmax();
 354         $rand = mt_rand( 0, $max ) / $max * $sum;
 355
 356         $sum = 0;
 357         foreach ( $weights as $i => $w ) {
 358                 $sum += $w;
 359                 if ( $sum >= $rand ) {
 360                         break;
 361                 }
 362         }
 363         return $i;
 364 }
 365
 366 /**
 367  * We want some things to be included as literal characters in our title URLs
 368  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 369  * all of the following should be safe:
 370  *
 371  * ;:@&=$-_.+!*'(),
 372  *
 373  * But + is not safe because it's used to indicate a space; &= are only safe in
 374  * paths and not in queries (and we don't distinguish here); ' seems kind of
 375  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 376  * is reserved, we don't care.  So the list we unescape is:
 377  *
 378  * ;:@$!*(),/
 379  *
 380  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 381  * so no fancy : for IIS7.
 382  *
 383  * %2F in the page titles seems to fatally break for some reason.
 384  *
 385  * @param $s String:
 386  * @return string
 387 */
 388 function wfUrlencode( $s ) {
 389         static $needle;
 390         if ( is_null( $s ) ) {
 391                 $needle = null;
 392                 return '';
 393         }
 394
 395         if ( is_null( $needle ) ) {
 396                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 397                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 398                         $needle[] = '%3A';
 399                 }
 400         }
 401
 402         $s = urlencode( $s );
 403         $s = str_ireplace(
 404                 $needle,
 405                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 406                 $s
 407         );
 408
 409         return $s;
 410 }
 411
 412 /**
 413  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 414  * "days=7&limit=100". Options in the first array override options in the second.
 415  * Options set to null or false will not be output.
 416  *
 417  * @param $array1 Array ( String|Array )
 418  * @param $array2 Array ( String|Array )
 419  * @param $prefix String
 420  * @return String
 421  */
 422 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 423         if ( !is_null( $array2 ) ) {
 424                 $array1 = $array1 + $array2;
 425         }
 426
 427         $cgi = '';
 428         foreach ( $array1 as $key => $value ) {
 429                 if ( !is_null( $value ) && $value !== false ) {
 430                         if ( $cgi != '' ) {
 431                                 $cgi .= '&';
 432                         }
 433                         if ( $prefix !== '' ) {
 434                                 $key = $prefix . "[$key]";
 435                         }
 436                         if ( is_array( $value ) ) {
 437                                 $firstTime = true;
 438                                 foreach ( $value as $k => $v ) {
 439                                         $cgi .= $firstTime ? '' : '&';
 440                                         if ( is_array( $v ) ) {
 441                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 442                                         } else {
 443                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 444                                         }
 445                                         $firstTime = false;
 446                                 }
 447                         } else {
 448                                 if ( is_object( $value ) ) {
 449                                         $value = $value->__toString();
 450                                 }
 451                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 452                         }
 453                 }
 454         }
 455         return $cgi;
 456 }
 457
 458 /**
 459  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 460  * its argument and returns the same string in array form.  This allows compa-
 461  * tibility with legacy functions that accept raw query strings instead of nice
 462  * arrays.  Of course, keys and values are urldecode()d.
 463  *
 464  * @param $query String: query string
 465  * @return array Array version of input
 466  */
 467 function wfCgiToArray( $query ) {
 468         if ( isset( $query[0] ) && $query[0] == '?' ) {
 469                 $query = substr( $query, 1 );
 470         }
 471         $bits = explode( '&', $query );
 472         $ret = array();
 473         foreach ( $bits as $bit ) {
 474                 if ( $bit === '' ) {
 475                         continue;
 476                 }
 477                 if ( strpos( $bit, '=' ) === false ) {
 478                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 479                         $key = $bit;
 480                         $value = '';
 481                 } else {
 482                         list( $key, $value ) = explode( '=', $bit );
 483                 }
 484                 $key = urldecode( $key );
 485                 $value = urldecode( $value );
 486                 if ( strpos( $key, '[' ) !== false ) {
 487                         $keys = array_reverse( explode( '[', $key ) );
 488                         $key = array_pop( $keys );
 489                         $temp = $value;
 490                         foreach ( $keys as $k ) {
 491                                 $k = substr( $k, 0, -1 );
 492                                 $temp = array( $k => $temp );
 493                         }
 494                         if ( isset( $ret[$key] ) ) {
 495                                 $ret[$key] = array_merge( $ret[$key], $temp );
 496                         } else {
 497                                 $ret[$key] = $temp;
 498                         }
 499                 } else {
 500                         $ret[$key] = $value;
 501                 }
 502         }
 503         return $ret;
 504 }
 505
 506 /**
 507  * Append a query string to an existing URL, which may or may not already
 508  * have query string parameters already. If so, they will be combined.
 509  *
 510  * @param $url String
 511  * @param $query Mixed: string or associative array
 512  * @return string
 513  */
 514 function wfAppendQuery( $url, $query ) {
 515         if ( is_array( $query ) ) {
 516                 $query = wfArrayToCgi( $query );
 517         }
 518         if( $query != '' ) {
 519                 if( false === strpos( $url, '?' ) ) {
 520                         $url .= '?';
 521                 } else {
 522                         $url .= '&';
 523                 }
 524                 $url .= $query;
 525         }
 526         return $url;
 527 }
 528
 529 /**
 530  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 531  * is correct.
 532  *
 533  * The meaning of the PROTO_* constants is as follows:
 534  * PROTO_HTTP: Output a URL starting with http://
 535  * PROTO_HTTPS: Output a URL starting with https://
 536  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 537  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 538  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 539  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 540  *
 541  * @todo this won't work with current-path-relative URLs
 542  * like "subdir/foo.html", etc.
 543  *
 544  * @param $url String: either fully-qualified or a local path + query
 545  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 546  *                             protocol to use if $url or $wgServer is
 547  *                             protocol-relative
 548  * @return string Fully-qualified URL, current-path-relative URL or false if
 549  *                no valid URL can be constructed
 550  */
 551 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 552         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 553         $serverUrl = $wgServer;
 554         if ( $defaultProto === PROTO_CANONICAL ) {
 555                 $serverUrl = $wgCanonicalServer;
 556         }
 557         // Make $wgInternalServer fall back to $wgServer if not set
 558         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 559                 $serverUrl = $wgInternalServer;
 560         }
 561         if ( $defaultProto === PROTO_CURRENT ) {
 562                 $defaultProto = WebRequest::detectProtocol() . '://';
 563         }
 564
 565         // Analyze $serverUrl to obtain its protocol
 566         $bits = wfParseUrl( $serverUrl );
 567         $serverHasProto = $bits && $bits['scheme'] != '';
 568
 569         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 570                 if ( $serverHasProto ) {
 571                         $defaultProto = $bits['scheme'] . '://';
 572                 } else {
 573                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 574                         // Fall back to HTTP in this ridiculous case
 575                         $defaultProto = PROTO_HTTP;
 576                 }
 577         }
 578
 579         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 580
 581         if ( substr( $url, 0, 2 ) == '//' ) {
 582                 $url = $defaultProtoWithoutSlashes . $url;
 583         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 584                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 585                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 586         }
 587
 588         $bits = wfParseUrl( $url );
 589         if ( $bits && isset( $bits['path'] ) ) {
 590                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 591                 return wfAssembleUrl( $bits );
 592         } elseif ( $bits ) {
 593                 # No path to expand
 594                 return $url;
 595         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 596                 # URL is a relative path
 597                 return wfRemoveDotSegments( $url );
 598         }
 599
 600         # Expanded URL is not valid.
 601         return false;
 602 }
 603
 604 /**
 605  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 606  * if you need to edit part of a URL and put it back together.
 607  *
 608  * This is the basic structure used (brackets contain keys for $urlParts):
 609  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 610  *
 611  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 612  *
 613  * @since 1.19
 614  * @param $urlParts Array URL parts, as output from wfParseUrl
 615  * @return string URL assembled from its component parts
 616  */
 617 function wfAssembleUrl( $urlParts ) {
 618         $result = '';
 619
 620         if ( isset( $urlParts['delimiter'] ) ) {
 621                 if ( isset( $urlParts['scheme'] ) ) {
 622                         $result .= $urlParts['scheme'];
 623                 }
 624
 625                 $result .= $urlParts['delimiter'];
 626         }
 627
 628         if ( isset( $urlParts['host'] ) ) {
 629                 if ( isset( $urlParts['user'] ) ) {
 630                         $result .= $urlParts['user'];
 631                         if ( isset( $urlParts['pass'] ) ) {
 632                                 $result .= ':' . $urlParts['pass'];
 633                         }
 634                         $result .= '@';
 635                 }
 636
 637                 $result .= $urlParts['host'];
 638
 639                 if ( isset( $urlParts['port'] ) ) {
 640                         $result .= ':' . $urlParts['port'];
 641                 }
 642         }
 643
 644         if ( isset( $urlParts['path'] ) ) {
 645                 $result .= $urlParts['path'];
 646         }
 647
 648         if ( isset( $urlParts['query'] ) ) {
 649                 $result .= '?' . $urlParts['query'];
 650         }
 651
 652         if ( isset( $urlParts['fragment'] ) ) {
 653                 $result .= '#' . $urlParts['fragment'];
 654         }
 655
 656         return $result;
 657 }
 658
 659 /**
 660  * Remove all dot-segments in the provided URL path.  For example,
 661  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 662  * RFC3986 section 5.2.4.
 663  *
 664  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 665  *
 666  * @param $urlPath String URL path, potentially containing dot-segments
 667  * @return string URL path with all dot-segments removed
 668  */
 669 function wfRemoveDotSegments( $urlPath ) {
 670         $output = '';
 671         $inputOffset = 0;
 672         $inputLength = strlen( $urlPath );
 673
 674         while ( $inputOffset < $inputLength ) {
 675                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 676                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 677                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 678                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 679                 $trimOutput = false;
 680
 681                 if ( $prefixLengthTwo == './' ) {
 682                         # Step A, remove leading "./"
 683                         $inputOffset += 2;
 684                 } elseif ( $prefixLengthThree == '../' ) {
 685                         # Step A, remove leading "../"
 686                         $inputOffset += 3;
 687                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 688                         # Step B, replace leading "/.$" with "/"
 689                         $inputOffset += 1;
 690                         $urlPath[$inputOffset] = '/';
 691                 } elseif ( $prefixLengthThree == '/./' ) {
 692                         # Step B, replace leading "/./" with "/"
 693                         $inputOffset += 2;
 694                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 695                         # Step C, replace leading "/..$" with "/" and
 696                         # remove last path component in output
 697                         $inputOffset += 2;
 698                         $urlPath[$inputOffset] = '/';
 699                         $trimOutput = true;
 700                 } elseif ( $prefixLengthFour == '/../' ) {
 701                         # Step C, replace leading "/../" with "/" and
 702                         # remove last path component in output
 703                         $inputOffset += 3;
 704                         $trimOutput = true;
 705                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 706                         # Step D, remove "^.$"
 707                         $inputOffset += 1;
 708                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 709                         # Step D, remove "^..$"
 710                         $inputOffset += 2;
 711                 } else {
 712                         # Step E, move leading path segment to output
 713                         if ( $prefixLengthOne == '/' ) {
 714                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 715                         } else {
 716                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 717                         }
 718                         if ( $slashPos === false ) {
 719                                 $output .= substr( $urlPath, $inputOffset );
 720                                 $inputOffset = $inputLength;
 721                         } else {
 722                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 723                                 $inputOffset += $slashPos - $inputOffset;
 724                         }
 725                 }
 726
 727                 if ( $trimOutput ) {
 728                         $slashPos = strrpos( $output, '/' );
 729                         if ( $slashPos === false ) {
 730                                 $output = '';
 731                         } else {
 732                                 $output = substr( $output, 0, $slashPos );
 733                         }
 734                 }
 735         }
 736
 737         return $output;
 738 }
 739
 740 /**
 741  * Returns a regular expression of url protocols
 742  *
 743  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 744  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 745  * @return String
 746  */
 747 function wfUrlProtocols( $includeProtocolRelative = true ) {
 748         global $wgUrlProtocols;
 749
 750         // Cache return values separately based on $includeProtocolRelative
 751         static $withProtRel = null, $withoutProtRel = null;
 752         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 753         if ( !is_null( $cachedValue ) ) {
 754                 return $cachedValue;
 755         }
 756
 757         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 758         // with LocalSettings files from 1.5
 759         if ( is_array( $wgUrlProtocols ) ) {
 760                 $protocols = array();
 761                 foreach ( $wgUrlProtocols as $protocol ) {
 762                         // Filter out '//' if !$includeProtocolRelative
 763                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 764                                 $protocols[] = preg_quote( $protocol, '/' );
 765                         }
 766                 }
 767
 768                 $retval = implode( '|', $protocols );
 769         } else {
 770                 // Ignore $includeProtocolRelative in this case
 771                 // This case exists for pre-1.6 compatibility, and we can safely assume
 772                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 773                 // URLs weren't supported until 1.18
 774                 $retval = $wgUrlProtocols;
 775         }
 776
 777         // Cache return value
 778         if ( $includeProtocolRelative ) {
 779                 $withProtRel = $retval;
 780         } else {
 781                 $withoutProtRel = $retval;
 782         }
 783         return $retval;
 784 }
 785
 786 /**
 787  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 788  * you need a regex that matches all URL protocols but does not match protocol-
 789  * relative URLs
 790  * @return String
 791  */
 792 function wfUrlProtocolsWithoutProtRel() {
 793         return wfUrlProtocols( false );
 794 }
 795
 796 /**
 797  * parse_url() work-alike, but non-broken.  Differences:
 798  *
 799  * 1) Does not raise warnings on bad URLs (just returns false)
 800  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 801  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 802  *
 803  * @param $url String: a URL to parse
 804  * @return Array: bits of the URL in an associative array, per PHP docs
 805  */
 806 function wfParseUrl( $url ) {
 807         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 808
 809         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 810         // way to handle them is to just prepend 'http:' and strip the protocol out later
 811         $wasRelative = substr( $url, 0, 2 ) == '//';
 812         if ( $wasRelative ) {
 813                 $url = "http:$url";
 814         }
 815         wfSuppressWarnings();
 816         $bits = parse_url( $url );
 817         wfRestoreWarnings();
 818         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 819         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 820         if ( !$bits || !isset( $bits['scheme'] ) ) {
 821                 return false;
 822         }
 823
 824         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 825         $bits['scheme'] = strtolower( $bits['scheme'] );
 826
 827         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 828         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 829                 $bits['delimiter'] = '://';
 830         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 831                 $bits['delimiter'] = ':';
 832                 // parse_url detects for news: and mailto: the host part of an url as path
 833                 // We have to correct this wrong detection
 834                 if ( isset( $bits['path'] ) ) {
 835                         $bits['host'] = $bits['path'];
 836                         $bits['path'] = '';
 837                 }
 838         } else {
 839                 return false;
 840         }
 841
 842         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 843         if ( !isset( $bits['host'] ) ) {
 844                 $bits['host'] = '';
 845
 846                 // bug 45069
 847                 if ( isset( $bits['path'] ) ) {
 848                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 849                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 850                                 $bits['path'] = '/' . $bits['path'];
 851                         }
 852                 } else {
 853                         $bits['path'] = '';
 854                 }
 855         }
 856
 857         // If the URL was protocol-relative, fix scheme and delimiter
 858         if ( $wasRelative ) {
 859                 $bits['scheme'] = '';
 860                 $bits['delimiter'] = '//';
 861         }
 862         return $bits;
 863 }
 864
 865 /**
 866  * Take a URL, make sure it's expanded to fully qualified, and replace any
 867  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 868  * for more compact display and legibility for local audiences.
 869  *
 870  * @todo handle punycode domains too
 871  *
 872  * @param $url string
 873  * @return string
 874  */
 875 function wfExpandIRI( $url ) {
 876         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 877 }
 878
 879 /**
 880  * Private callback for wfExpandIRI
 881  * @param array $matches
 882  * @return string
 883  */
 884 function wfExpandIRI_callback( $matches ) {
 885         return urldecode( $matches[1] );
 886 }
 887
 888
 889
 890 /**
 891  * Make URL indexes, appropriate for the el_index field of externallinks.
 892  *
 893  * @param $url String
 894  * @return array
 895  */
 896 function wfMakeUrlIndexes( $url ) {
 897         $bits = wfParseUrl( $url );
 898
 899         // Reverse the labels in the hostname, convert to lower case
 900         // For emails reverse domainpart only
 901         if ( $bits['scheme'] == 'mailto' ) {
 902                 $mailparts = explode( '@', $bits['host'], 2 );
 903                 if ( count( $mailparts ) === 2 ) {
 904                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 905                 } else {
 906                         // No domain specified, don't mangle it
 907                         $domainpart = '';
 908                 }
 909                 $reversedHost = $domainpart . '@' . $mailparts[0];
 910         } else {
 911                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 912         }
 913         // Add an extra dot to the end
 914         // Why? Is it in wrong place in mailto links?
 915         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 916                 $reversedHost .= '.';
 917         }
 918         // Reconstruct the pseudo-URL
 919         $prot = $bits['scheme'];
 920         $index = $prot . $bits['delimiter'] . $reversedHost;
 921         // Leave out user and password. Add the port, path, query and fragment
 922         if ( isset( $bits['port'] ) ) {
 923                 $index .= ':' . $bits['port'];
 924         }
 925         if ( isset( $bits['path'] ) ) {
 926                 $index .= $bits['path'];
 927         } else {
 928                 $index .= '/';
 929         }
 930         if ( isset( $bits['query'] ) ) {
 931                 $index .= '?' . $bits['query'];
 932         }
 933         if ( isset( $bits['fragment'] ) ) {
 934                 $index .= '#' . $bits['fragment'];
 935         }
 936
 937         if ( $prot == '' ) {
 938                 return array( "http:$index", "https:$index" );
 939         } else {
 940                 return array( $index );
 941         }
 942 }
 943
 944 /**
 945  * Check whether a given URL has a domain that occurs in a given set of domains
 946  * @param $url string URL
 947  * @param $domains array Array of domains (strings)
 948  * @return bool True if the host part of $url ends in one of the strings in $domains
 949  */
 950 function wfMatchesDomainList( $url, $domains ) {
 951         $bits = wfParseUrl( $url );
 952         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 953                 foreach ( (array)$domains as $domain ) {
 954                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 955                         // We should use something that interprets dots instead
 956                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 957                                 return true;
 958                         }
 959                 }
 960         }
 961         return false;
 962 }
 963
 964 /**
 965  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 966  * In normal operation this is a NOP.
 967  *
 968  * Controlling globals:
 969  * $wgDebugLogFile - points to the log file
 970  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 971  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 972  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 973  *
 974  * @param $text String
 975  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 976  */
 977 function wfDebug( $text, $logonly = false ) {
 978         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 979
 980         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 981                 return;
 982         }
 983
 984         $timer = wfDebugTimer();
 985         if ( $timer !== '' ) {
 986                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 987         }
 988
 989         if ( !$logonly ) {
 990                 MWDebug::debugMsg( $text );
 991         }
 992
 993         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 994                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 995                         # Strip unprintables; they can switch terminal modes when binary data
 996                         # gets dumped, which is pretty annoying.
 997                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 998                         $text = $wgDebugLogPrefix . $text;
 999                         wfErrorLog( $text, $wgDebugLogFile );
1000                 }
1001         }
1002 }
1003
1004 /**
1005  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1006  * @return bool
1007  */
1008 function wfIsDebugRawPage() {
1009         static $cache;
1010         if ( $cache !== null ) {
1011                 return $cache;
1012         }
1013         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1014         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1015                 || (
1016                         isset( $_SERVER['SCRIPT_NAME'] )
1017                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1018                 ) )
1019         {
1020                 $cache = true;
1021         } else {
1022                 $cache = false;
1023         }
1024         return $cache;
1025 }
1026
1027 /**
1028  * Get microsecond timestamps for debug logs
1029  *
1030  * @return string
1031  */
1032 function wfDebugTimer() {
1033         global $wgDebugTimestamps, $wgRequestTime;
1034
1035         if ( !$wgDebugTimestamps ) {
1036                 return '';
1037         }
1038
1039         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1040         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1041         return "$prefix $mem  ";
1042 }
1043
1044 /**
1045  * Send a line giving PHP memory usage.
1046  *
1047  * @param $exact Bool: print exact values instead of kilobytes (default: false)
1048  */
1049 function wfDebugMem( $exact = false ) {
1050         $mem = memory_get_usage();
1051         if( !$exact ) {
1052                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1053         } else {
1054                 $mem .= ' bytes';
1055         }
1056         wfDebug( "Memory usage: $mem\n" );
1057 }
1058
1059 /**
1060  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1061  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1062  *
1063  * @param $logGroup String
1064  * @param $text String
1065  * @param $public Bool: whether to log the event in the public log if no private
1066  *                     log file is specified, (default true)
1067  */
1068 function wfDebugLog( $logGroup, $text, $public = true ) {
1069         global $wgDebugLogGroups;
1070         $text = trim( $text ) . "\n";
1071         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
1072                 $time = wfTimestamp( TS_DB );
1073                 $wiki = wfWikiID();
1074                 $host = wfHostname();
1075                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1076                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1077                 }
1078         } elseif ( $public === true ) {
1079                 wfDebug( "[$logGroup] $text", true );
1080         }
1081 }
1082
1083 /**
1084  * Log for database errors
1085  *
1086  * @param $text String: database error message.
1087  */
1088 function wfLogDBError( $text ) {
1089         global $wgDBerrorLog, $wgDBerrorLogTZ;
1090         static $logDBErrorTimeZoneObject = null;
1091
1092         if ( $wgDBerrorLog ) {
1093                 $host = wfHostname();
1094                 $wiki = wfWikiID();
1095
1096                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1097                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1098                 }
1099
1100                 // Workaround for https://bugs.php.net/bug.php?id=52063
1101                 // Can be removed when min PHP > 5.3.2
1102                 if ( $logDBErrorTimeZoneObject === null ) {
1103                         $d = date_create( "now" );
1104                 } else {
1105                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1106                 }
1107
1108                 $date = $d->format( 'D M j G:i:s T Y' );
1109
1110                 $text = "$date\t$host\t$wiki\t$text";
1111                 wfErrorLog( $text, $wgDBerrorLog );
1112         }
1113 }
1114
1115 /**
1116  * Throws a warning that $function is deprecated
1117  *
1118  * @param $function String
1119  * @param $version String|bool: Version of MediaWiki that the function was deprecated in (Added in 1.19).
1120  * @param $component String|bool: Added in 1.19.
1121  * @param $callerOffset integer: How far up the callstack is the original
1122  *    caller. 2 = function that called the function that called
1123  *    wfDeprecated (Added in 1.20)
1124  *
1125  * @return null
1126  */
1127 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1128         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1129 }
1130
1131 /**
1132  * Send a warning either to the debug log or in a PHP error depending on
1133  * $wgDevelopmentWarnings
1134  *
1135  * @param $msg String: message to send
1136  * @param $callerOffset Integer: number of items to go back in the backtrace to
1137  *        find the correct caller (1 = function calling wfWarn, ...)
1138  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1139  *        is true
1140  */
1141 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1142         MWDebug::warning( $msg, $callerOffset + 1, $level );
1143 }
1144
1145 /**
1146  * Log to a file without getting "file size exceeded" signals.
1147  *
1148  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1149  * send lines to the specified port, prefixed by the specified prefix and a space.
1150  *
1151  * @param $text String
1152  * @param $file String filename
1153  * @throws MWException
1154  */
1155 function wfErrorLog( $text, $file ) {
1156         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1157                 # Needs the sockets extension
1158                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1159                         // IPv6 bracketed host
1160                         $host = $m[2];
1161                         $port = intval( $m[3] );
1162                         $prefix = isset( $m[4] ) ? $m[4] : false;
1163                         $domain = AF_INET6;
1164                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1165                         $host = $m[2];
1166                         if ( !IP::isIPv4( $host ) ) {
1167                                 $host = gethostbyname( $host );
1168                         }
1169                         $port = intval( $m[3] );
1170                         $prefix = isset( $m[4] ) ? $m[4] : false;
1171                         $domain = AF_INET;
1172                 } else {
1173                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1174                 }
1175
1176                 // Clean it up for the multiplexer
1177                 if ( strval( $prefix ) !== '' ) {
1178                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1179
1180                         // Limit to 64KB
1181                         if ( strlen( $text ) > 65506 ) {
1182                                 $text = substr( $text, 0, 65506 );
1183                         }
1184
1185                         if ( substr( $text, -1 ) != "\n" ) {
1186                                 $text .= "\n";
1187                         }
1188                 } elseif ( strlen( $text ) > 65507 ) {
1189                         $text = substr( $text, 0, 65507 );
1190                 }
1191
1192                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1193                 if ( !$sock ) {
1194                         return;
1195                 }
1196
1197                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1198                 socket_close( $sock );
1199         } else {
1200                 wfSuppressWarnings();
1201                 $exists = file_exists( $file );
1202                 $size = $exists ? filesize( $file ) : false;
1203                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1204                         file_put_contents( $file, $text, FILE_APPEND );
1205                 }
1206                 wfRestoreWarnings();
1207         }
1208 }
1209
1210 /**
1211  * @todo document
1212  */
1213 function wfLogProfilingData() {
1214         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1215         global $wgProfileLimit, $wgUser;
1216
1217         $profiler = Profiler::instance();
1218
1219         # Profiling must actually be enabled...
1220         if ( $profiler->isStub() ) {
1221                 return;
1222         }
1223
1224         // Get total page request time and only show pages that longer than
1225         // $wgProfileLimit time (default is 0)
1226         $elapsed = microtime( true ) - $wgRequestTime;
1227         if ( $elapsed <= $wgProfileLimit ) {
1228                 return;
1229         }
1230
1231         $profiler->logData();
1232
1233         // Check whether this should be logged in the debug file.
1234         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1235                 return;
1236         }
1237
1238         $forward = '';
1239         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1240                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1241         }
1242         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1243                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1244         }
1245         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1246                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1247         }
1248         if ( $forward ) {
1249                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1250         }
1251         // Don't load $wgUser at this late stage just for statistics purposes
1252         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1253         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1254                 $forward .= ' anon';
1255         }
1256
1257         // Command line script uses a FauxRequest object which does not have
1258         // any knowledge about an URL and throw an exception instead.
1259         try {
1260                 $requestUrl = $wgRequest->getRequestURL();
1261         } catch ( MWException $e ) {
1262                 $requestUrl = 'n/a';
1263         }
1264
1265         $log = sprintf( "%s\t%04.3f\t%s\n",
1266                 gmdate( 'YmdHis' ), $elapsed,
1267                 urldecode( $requestUrl . $forward ) );
1268
1269         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1270 }
1271
1272 /**
1273  * Increment a statistics counter
1274  *
1275  * @param $key String
1276  * @param $count Int
1277  * @return void
1278  */
1279 function wfIncrStats( $key, $count = 1 ) {
1280         global $wgStatsMethod;
1281
1282         $count = intval( $count );
1283         if ( $count == 0 ) {
1284                 return;
1285         }
1286
1287         if( $wgStatsMethod == 'udp' ) {
1288                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgAggregateStatsID;
1289                 static $socket;
1290
1291                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : wfWikiID();
1292
1293                 if ( !$socket ) {
1294                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1295                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1296                         socket_sendto(
1297                                 $socket,
1298                                 $statline,
1299                                 strlen( $statline ),
1300                                 0,
1301                                 $wgUDPProfilerHost,
1302                                 $wgUDPProfilerPort
1303                         );
1304                 }
1305                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1306                 wfSuppressWarnings();
1307                 socket_sendto(
1308                         $socket,
1309                         $statline,
1310                         strlen( $statline ),
1311                         0,
1312                         $wgUDPProfilerHost,
1313                         $wgUDPProfilerPort
1314                 );
1315                 wfRestoreWarnings();
1316         } elseif( $wgStatsMethod == 'cache' ) {
1317                 global $wgMemc;
1318                 $key = wfMemcKey( 'stats', $key );
1319                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1320                         $wgMemc->add( $key, $count );
1321                 }
1322         } else {
1323                 // Disabled
1324         }
1325 }
1326
1327 /**
1328  * Check if the wiki read-only lock file is present. This can be used to lock
1329  * off editing functions, but doesn't guarantee that the database will not be
1330  * modified.
1331  *
1332  * @return bool
1333  */
1334 function wfReadOnly() {
1335         global $wgReadOnlyFile, $wgReadOnly;
1336
1337         if ( !is_null( $wgReadOnly ) ) {
1338                 return (bool)$wgReadOnly;
1339         }
1340         if ( $wgReadOnlyFile == '' ) {
1341                 return false;
1342         }
1343         // Set $wgReadOnly for faster access next time
1344         if ( is_file( $wgReadOnlyFile ) ) {
1345                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1346         } else {
1347                 $wgReadOnly = false;
1348         }
1349         return (bool)$wgReadOnly;
1350 }
1351
1352 /**
1353  * @return bool
1354  */
1355 function wfReadOnlyReason() {
1356         global $wgReadOnly;
1357         wfReadOnly();
1358         return $wgReadOnly;
1359 }
1360
1361 /**
1362  * Return a Language object from $langcode
1363  *
1364  * @param $langcode Mixed: either:
1365  *                  - a Language object
1366  *                  - code of the language to get the message for, if it is
1367  *                    a valid code create a language for that language, if
1368  *                    it is a string but not a valid code then make a basic
1369  *                    language object
1370  *                  - a boolean: if it's false then use the global object for
1371  *                    the current user's language (as a fallback for the old parameter
1372  *                    functionality), or if it is true then use global object
1373  *                    for the wiki's content language.
1374  * @return Language object
1375  */
1376 function wfGetLangObj( $langcode = false ) {
1377         # Identify which language to get or create a language object for.
1378         # Using is_object here due to Stub objects.
1379         if( is_object( $langcode ) ) {
1380                 # Great, we already have the object (hopefully)!
1381                 return $langcode;
1382         }
1383
1384         global $wgContLang, $wgLanguageCode;
1385         if( $langcode === true || $langcode === $wgLanguageCode ) {
1386                 # $langcode is the language code of the wikis content language object.
1387                 # or it is a boolean and value is true
1388                 return $wgContLang;
1389         }
1390
1391         global $wgLang;
1392         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1393                 # $langcode is the language code of user language object.
1394                 # or it was a boolean and value is false
1395                 return $wgLang;
1396         }
1397
1398         $validCodes = array_keys( Language::fetchLanguageNames() );
1399         if( in_array( $langcode, $validCodes ) ) {
1400                 # $langcode corresponds to a valid language.
1401                 return Language::factory( $langcode );
1402         }
1403
1404         # $langcode is a string, but not a valid language code; use content language.
1405         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1406         return $wgContLang;
1407 }
1408
1409 /**
1410  * Old function when $wgBetterDirectionality existed
1411  * All usage removed, wfUILang can be removed in near future
1412  *
1413  * @deprecated since 1.18
1414  * @return Language
1415  */
1416 function wfUILang() {
1417         wfDeprecated( __METHOD__, '1.18' );
1418         global $wgLang;
1419         return $wgLang;
1420 }
1421
1422 /**
1423  * This is the function for getting translated interface messages.
1424  *
1425  * @see Message class for documentation how to use them.
1426  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1427  *
1428  * This function replaces all old wfMsg* functions.
1429  *
1430  * @param $key \string Message key.
1431  * Varargs: normal message parameters.
1432  * @return Message
1433  * @since 1.17
1434  */
1435 function wfMessage( $key /*...*/) {
1436         $params = func_get_args();
1437         array_shift( $params );
1438         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1439                 $params = $params[0];
1440         }
1441         return new Message( $key, $params );
1442 }
1443
1444 /**
1445  * This function accepts multiple message keys and returns a message instance
1446  * for the first message which is non-empty. If all messages are empty then an
1447  * instance of the first message key is returned.
1448  * @param varargs: message keys
1449  * @return Message
1450  * @since 1.18
1451  */
1452 function wfMessageFallback( /*...*/ ) {
1453         $args = func_get_args();
1454         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1455 }
1456
1457 /**
1458  * Get a message from anywhere, for the current user language.
1459  *
1460  * Use wfMsgForContent() instead if the message should NOT
1461  * change depending on the user preferences.
1462  *
1463  * @deprecated since 1.18
1464  *
1465  * @param $key String: lookup key for the message, usually
1466  *    defined in languages/Language.php
1467  *
1468  * Parameters to the message, which can be used to insert variable text into
1469  * it, can be passed to this function in the following formats:
1470  * - One per argument, starting at the second parameter
1471  * - As an array in the second parameter
1472  * These are not shown in the function definition.
1473  *
1474  * @return String
1475  */
1476 function wfMsg( $key ) {
1477         wfDeprecated( __METHOD__, '1.21' );
1478
1479         $args = func_get_args();
1480         array_shift( $args );
1481         return wfMsgReal( $key, $args );
1482 }
1483
1484 /**
1485  * Same as above except doesn't transform the message
1486  *
1487  * @deprecated since 1.18
1488  *
1489  * @param $key String
1490  * @return String
1491  */
1492 function wfMsgNoTrans( $key ) {
1493         wfDeprecated( __METHOD__, '1.21' );
1494
1495         $args = func_get_args();
1496         array_shift( $args );
1497         return wfMsgReal( $key, $args, true, false, false );
1498 }
1499
1500 /**
1501  * Get a message from anywhere, for the current global language
1502  * set with $wgLanguageCode.
1503  *
1504  * Use this if the message should NOT change dependent on the
1505  * language set in the user's preferences. This is the case for
1506  * most text written into logs, as well as link targets (such as
1507  * the name of the copyright policy page). Link titles, on the
1508  * other hand, should be shown in the UI language.
1509  *
1510  * Note that MediaWiki allows users to change the user interface
1511  * language in their preferences, but a single installation
1512  * typically only contains content in one language.
1513  *
1514  * Be wary of this distinction: If you use wfMsg() where you should
1515  * use wfMsgForContent(), a user of the software may have to
1516  * customize potentially hundreds of messages in
1517  * order to, e.g., fix a link in every possible language.
1518  *
1519  * @deprecated since 1.18
1520  *
1521  * @param $key String: lookup key for the message, usually
1522  *     defined in languages/Language.php
1523  * @return String
1524  */
1525 function wfMsgForContent( $key ) {
1526         wfDeprecated( __METHOD__, '1.21' );
1527
1528         global $wgForceUIMsgAsContentMsg;
1529         $args = func_get_args();
1530         array_shift( $args );
1531         $forcontent = true;
1532         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1533                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1534         {
1535                 $forcontent = false;
1536         }
1537         return wfMsgReal( $key, $args, true, $forcontent );
1538 }
1539
1540 /**
1541  * Same as above except doesn't transform the message
1542  *
1543  * @deprecated since 1.18
1544  *
1545  * @param $key String
1546  * @return String
1547  */
1548 function wfMsgForContentNoTrans( $key ) {
1549         wfDeprecated( __METHOD__, '1.21' );
1550
1551         global $wgForceUIMsgAsContentMsg;
1552         $args = func_get_args();
1553         array_shift( $args );
1554         $forcontent = true;
1555         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1556                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1557         {
1558                 $forcontent = false;
1559         }
1560         return wfMsgReal( $key, $args, true, $forcontent, false );
1561 }
1562
1563 /**
1564  * Really get a message
1565  *
1566  * @deprecated since 1.18
1567  *
1568  * @param $key String: key to get.
1569  * @param $args
1570  * @param $useDB Boolean
1571  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1572  * @param $transform Boolean: Whether or not to transform the message.
1573  * @return String: the requested message.
1574  */
1575 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1576         wfDeprecated( __METHOD__, '1.21' );
1577
1578         wfProfileIn( __METHOD__ );
1579         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1580         $message = wfMsgReplaceArgs( $message, $args );
1581         wfProfileOut( __METHOD__ );
1582         return $message;
1583 }
1584
1585 /**
1586  * Fetch a message string value, but don't replace any keys yet.
1587  *
1588  * @deprecated since 1.18
1589  *
1590  * @param $key String
1591  * @param $useDB Bool
1592  * @param $langCode String: Code of the language to get the message for, or
1593  *                  behaves as a content language switch if it is a boolean.
1594  * @param $transform Boolean: whether to parse magic words, etc.
1595  * @return string
1596  */
1597 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1598         wfDeprecated( __METHOD__, '1.21' );
1599
1600         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1601
1602         $cache = MessageCache::singleton();
1603         $message = $cache->get( $key, $useDB, $langCode );
1604         if( $message === false ) {
1605                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1606         } elseif ( $transform ) {
1607                 $message = $cache->transform( $message );
1608         }
1609         return $message;
1610 }
1611
1612 /**
1613  * Replace message parameter keys on the given formatted output.
1614  *
1615  * @param $message String
1616  * @param $args Array
1617  * @return string
1618  * @private
1619  */
1620 function wfMsgReplaceArgs( $message, $args ) {
1621         # Fix windows line-endings
1622         # Some messages are split with explode("\n", $msg)
1623         $message = str_replace( "\r", '', $message );
1624
1625         // Replace arguments
1626         if ( count( $args ) ) {
1627                 if ( is_array( $args[0] ) ) {
1628                         $args = array_values( $args[0] );
1629                 }
1630                 $replacementKeys = array();
1631                 foreach( $args as $n => $param ) {
1632                         $replacementKeys['$' . ( $n + 1 )] = $param;
1633                 }
1634                 $message = strtr( $message, $replacementKeys );
1635         }
1636
1637         return $message;
1638 }
1639
1640 /**
1641  * Return an HTML-escaped version of a message.
1642  * Parameter replacements, if any, are done *after* the HTML-escaping,
1643  * so parameters may contain HTML (eg links or form controls). Be sure
1644  * to pre-escape them if you really do want plaintext, or just wrap
1645  * the whole thing in htmlspecialchars().
1646  *
1647  * @deprecated since 1.18
1648  *
1649  * @param $key String
1650  * @param string ... parameters
1651  * @return string
1652  */
1653 function wfMsgHtml( $key ) {
1654         wfDeprecated( __METHOD__, '1.21' );
1655
1656         $args = func_get_args();
1657         array_shift( $args );
1658         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1659 }
1660
1661 /**
1662  * Return an HTML version of message
1663  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1664  * so parameters may contain HTML (eg links or form controls). Be sure
1665  * to pre-escape them if you really do want plaintext, or just wrap
1666  * the whole thing in htmlspecialchars().
1667  *
1668  * @deprecated since 1.18
1669  *
1670  * @param $key String
1671  * @param string ... parameters
1672  * @return string
1673  */
1674 function wfMsgWikiHtml( $key ) {
1675         wfDeprecated( __METHOD__, '1.21' );
1676
1677         $args = func_get_args();
1678         array_shift( $args );
1679         return wfMsgReplaceArgs(
1680                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1681                 /* can't be set to false */ true, /* interface */ true )->getText(),
1682                 $args );
1683 }
1684
1685 /**
1686  * Returns message in the requested format
1687  *
1688  * @deprecated since 1.18
1689  *
1690  * @param $key String: key of the message
1691  * @param $options Array: processing rules. Can take the following options:
1692  *   <i>parse</i>: parses wikitext to HTML
1693  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1694  *       p's added by parser or tidy
1695  *   <i>escape</i>: filters message through htmlspecialchars
1696  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1697  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1698  *   <i>parsemag</i>: transform the message using magic phrases
1699  *   <i>content</i>: fetch message for content language instead of interface
1700  * Also can accept a single associative argument, of the form 'language' => 'xx':
1701  *   <i>language</i>: Language object or language code to fetch message for
1702  *       (overriden by <i>content</i>).
1703  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1704  *
1705  * @return String
1706  */
1707 function wfMsgExt( $key, $options ) {
1708         wfDeprecated( __METHOD__, '1.21' );
1709
1710         $args = func_get_args();
1711         array_shift( $args );
1712         array_shift( $args );
1713         $options = (array)$options;
1714
1715         foreach( $options as $arrayKey => $option ) {
1716                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1717                         # An unknown index, neither numeric nor "language"
1718                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1719                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1720                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1721                 'replaceafter', 'parsemag', 'content' ) ) ) {
1722                         # A numeric index with unknown value
1723                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1724                 }
1725         }
1726
1727         if( in_array( 'content', $options, true ) ) {
1728                 $forContent = true;
1729                 $langCode = true;
1730                 $langCodeObj = null;
1731         } elseif( array_key_exists( 'language', $options ) ) {
1732                 $forContent = false;
1733                 $langCode = wfGetLangObj( $options['language'] );
1734                 $langCodeObj = $langCode;
1735         } else {
1736                 $forContent = false;
1737                 $langCode = false;
1738                 $langCodeObj = null;
1739         }
1740
1741         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1742
1743         if( !in_array( 'replaceafter', $options, true ) ) {
1744                 $string = wfMsgReplaceArgs( $string, $args );
1745         }
1746
1747         $messageCache = MessageCache::singleton();
1748         $parseInline = in_array( 'parseinline', $options, true );
1749         if( in_array( 'parse', $options, true ) || $parseInline ) {
1750                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1751                 if ( $string instanceof ParserOutput ) {
1752                         $string = $string->getText();
1753                 }
1754
1755                 if ( $parseInline ) {
1756                         $m = array();
1757                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1758                                 $string = $m[1];
1759                         }
1760                 }
1761         } elseif ( in_array( 'parsemag', $options, true ) ) {
1762                 $string = $messageCache->transform( $string,
1763                                 !$forContent, $langCodeObj );
1764         }
1765
1766         if ( in_array( 'escape', $options, true ) ) {
1767                 $string = htmlspecialchars ( $string );
1768         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1769                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1770         }
1771
1772         if( in_array( 'replaceafter', $options, true ) ) {
1773                 $string = wfMsgReplaceArgs( $string, $args );
1774         }
1775
1776         return $string;
1777 }
1778
1779 /**
1780  * Since wfMsg() and co suck, they don't return false if the message key they
1781  * looked up didn't exist but a XHTML string, this function checks for the
1782  * nonexistance of messages by checking the MessageCache::get() result directly.
1783  *
1784  * @deprecated since 1.18. Use Message::isDisabled().
1785  *
1786  * @param $key      String: the message key looked up
1787  * @return Boolean True if the message *doesn't* exist.
1788  */
1789 function wfEmptyMsg( $key ) {
1790         wfDeprecated( __METHOD__, '1.21' );
1791
1792         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1793 }
1794
1795 /**
1796  * Throw a debugging exception. This function previously once exited the process,
1797  * but now throws an exception instead, with similar results.
1798  *
1799  * @param $msg String: message shown when dying.
1800  * @throws MWException
1801  */
1802 function wfDebugDieBacktrace( $msg = '' ) {
1803         throw new MWException( $msg );
1804 }
1805
1806 /**
1807  * Fetch server name for use in error reporting etc.
1808  * Use real server name if available, so we know which machine
1809  * in a server farm generated the current page.
1810  *
1811  * @return string
1812  */
1813 function wfHostname() {
1814         static $host;
1815         if ( is_null( $host ) ) {
1816
1817                 # Hostname overriding
1818                 global $wgOverrideHostname;
1819                 if( $wgOverrideHostname !== false ) {
1820                         # Set static and skip any detection
1821                         $host = $wgOverrideHostname;
1822                         return $host;
1823                 }
1824
1825                 if ( function_exists( 'posix_uname' ) ) {
1826                         // This function not present on Windows
1827                         $uname = posix_uname();
1828                 } else {
1829                         $uname = false;
1830                 }
1831                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1832                         $host = $uname['nodename'];
1833                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1834                         # Windows computer name
1835                         $host = getenv( 'COMPUTERNAME' );
1836                 } else {
1837                         # This may be a virtual server.
1838                         $host = $_SERVER['SERVER_NAME'];
1839                 }
1840         }
1841         return $host;
1842 }
1843
1844 /**
1845  * Returns a HTML comment with the elapsed time since request.
1846  * This method has no side effects.
1847  *
1848  * @return string
1849  */
1850 function wfReportTime() {
1851         global $wgRequestTime, $wgShowHostnames;
1852
1853         $elapsed = microtime( true ) - $wgRequestTime;
1854
1855         return $wgShowHostnames
1856                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1857                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1858 }
1859
1860 /**
1861  * Safety wrapper for debug_backtrace().
1862  *
1863  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1864  * murky circumstances, which may be triggered in part by stub objects
1865  * or other fancy talkin'.
1866  *
1867  * Will return an empty array if Zend Optimizer is detected or if
1868  * debug_backtrace is disabled, otherwise the output from
1869  * debug_backtrace() (trimmed).
1870  *
1871  * @param $limit int This parameter can be used to limit the number of stack frames returned
1872  *
1873  * @return array of backtrace information
1874  */
1875 function wfDebugBacktrace( $limit = 0 ) {
1876         static $disabled = null;
1877
1878         if( extension_loaded( 'Zend Optimizer' ) ) {
1879                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1880                 return array();
1881         }
1882
1883         if ( is_null( $disabled ) ) {
1884                 $disabled = false;
1885                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1886                 $functions = array_map( 'trim', $functions );
1887                 $functions = array_map( 'strtolower', $functions );
1888                 if ( in_array( 'debug_backtrace', $functions ) ) {
1889                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1890                         $disabled = true;
1891                 }
1892         }
1893         if ( $disabled ) {
1894                 return array();
1895         }
1896
1897         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1898                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1899         } else {
1900                 return array_slice( debug_backtrace(), 1 );
1901         }
1902 }
1903
1904 /**
1905  * Get a debug backtrace as a string
1906  *
1907  * @return string
1908  */
1909 function wfBacktrace() {
1910         global $wgCommandLineMode;
1911
1912         if ( $wgCommandLineMode ) {
1913                 $msg = '';
1914         } else {
1915                 $msg = "<ul>\n";
1916         }
1917         $backtrace = wfDebugBacktrace();
1918         foreach( $backtrace as $call ) {
1919                 if( isset( $call['file'] ) ) {
1920                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1921                         $file = $f[count( $f ) - 1];
1922                 } else {
1923                         $file = '-';
1924                 }
1925                 if( isset( $call['line'] ) ) {
1926                         $line = $call['line'];
1927                 } else {
1928                         $line = '-';
1929                 }
1930                 if ( $wgCommandLineMode ) {
1931                         $msg .= "$file line $line calls ";
1932                 } else {
1933                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1934                 }
1935                 if( !empty( $call['class'] ) ) {
1936                         $msg .= $call['class'] . $call['type'];
1937                 }
1938                 $msg .= $call['function'] . '()';
1939
1940                 if ( $wgCommandLineMode ) {
1941                         $msg .= "\n";
1942                 } else {
1943                         $msg .= "</li>\n";
1944                 }
1945         }
1946         if ( $wgCommandLineMode ) {
1947                 $msg .= "\n";
1948         } else {
1949                 $msg .= "</ul>\n";
1950         }
1951
1952         return $msg;
1953 }
1954
1955 /**
1956  * Get the name of the function which called this function
1957  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1958  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1959  * wfGetCaller( 3 ) is the parent of that.
1960  *
1961  * @param $level Int
1962  * @return string
1963  */
1964 function wfGetCaller( $level = 2 ) {
1965         $backtrace = wfDebugBacktrace( $level + 1 );
1966         if ( isset( $backtrace[$level] ) ) {
1967                 return wfFormatStackFrame( $backtrace[$level] );
1968         } else {
1969                 return 'unknown';
1970         }
1971 }
1972
1973 /**
1974  * Return a string consisting of callers in the stack. Useful sometimes
1975  * for profiling specific points.
1976  *
1977  * @param $limit int The maximum depth of the stack frame to return, or false for
1978  *               the entire stack.
1979  * @return String
1980  */
1981 function wfGetAllCallers( $limit = 3 ) {
1982         $trace = array_reverse( wfDebugBacktrace() );
1983         if ( !$limit || $limit > count( $trace ) - 1 ) {
1984                 $limit = count( $trace ) - 1;
1985         }
1986         $trace = array_slice( $trace, -$limit - 1, $limit );
1987         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1988 }
1989
1990 /**
1991  * Return a string representation of frame
1992  *
1993  * @param $frame Array
1994  * @return string
1995  */
1996 function wfFormatStackFrame( $frame ) {
1997         return isset( $frame['class'] ) ?
1998                 $frame['class'] . '::' . $frame['function'] :
1999                 $frame['function'];
2000 }
2001
2002
2003 /* Some generic result counters, pulled out of SearchEngine */
2004
2005
2006 /**
2007  * @todo document
2008  *
2009  * @param $offset Int
2010  * @param $limit Int
2011  * @return String
2012  */
2013 function wfShowingResults( $offset, $limit ) {
2014         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
2015 }
2016
2017 /**
2018  * Generate (prev x| next x) (20|50|100...) type links for paging
2019  *
2020  * @param $offset String
2021  * @param $limit Integer
2022  * @param $link String
2023  * @param $query String: optional URL query parameter string
2024  * @param $atend Bool: optional param for specified if this is the last page
2025  * @return String
2026  * @deprecated in 1.19; use Language::viewPrevNext() instead
2027  */
2028 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
2029         wfDeprecated( __METHOD__, '1.19' );
2030
2031         global $wgLang;
2032
2033         $query = wfCgiToArray( $query );
2034
2035         if( is_object( $link ) ) {
2036                 $title = $link;
2037         } else {
2038                 $title = Title::newFromText( $link );
2039                 if( is_null( $title ) ) {
2040                         return false;
2041                 }
2042         }
2043
2044         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
2045 }
2046
2047 /**
2048  * Make a list item, used by various special pages
2049  *
2050  * @param $page String Page link
2051  * @param $details String Text between brackets
2052  * @param $oppositedm Boolean   Add the direction mark opposite to your
2053  *                                                              language, to display text properly
2054  * @return String
2055  * @deprecated since 1.19; use Language::specialList() instead
2056  */
2057 function wfSpecialList( $page, $details, $oppositedm = true ) {
2058         wfDeprecated( __METHOD__, '1.19' );
2059
2060         global $wgLang;
2061         return $wgLang->specialList( $page, $details, $oppositedm );
2062 }
2063
2064 /**
2065  * @todo document
2066  * @todo FIXME: We may want to blacklist some broken browsers
2067  *
2068  * @param $force Bool
2069  * @return bool Whereas client accept gzip compression
2070  */
2071 function wfClientAcceptsGzip( $force = false ) {
2072         static $result = null;
2073         if ( $result === null || $force ) {
2074                 $result = false;
2075                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2076                         # @todo FIXME: We may want to blacklist some broken browsers
2077                         $m = array();
2078                         if( preg_match(
2079                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2080                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
2081                                 $m )
2082                         )
2083                         {
2084                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2085                                         $result = false;
2086                                         return $result;
2087                                 }
2088                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2089                                 $result = true;
2090                         }
2091                 }
2092         }
2093         return $result;
2094 }
2095
2096 /**
2097  * Obtain the offset and limit values from the request string;
2098  * used in special pages
2099  *
2100  * @param $deflimit Int default limit if none supplied
2101  * @param $optionname String Name of a user preference to check against
2102  * @return array
2103  *
2104  */
2105 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2106         global $wgRequest;
2107         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2108 }
2109
2110 /**
2111  * Escapes the given text so that it may be output using addWikiText()
2112  * without any linking, formatting, etc. making its way through. This
2113  * is achieved by substituting certain characters with HTML entities.
2114  * As required by the callers, "<nowiki>" is not used.
2115  *
2116  * @param $text String: text to be escaped
2117  * @return String
2118  */
2119 function wfEscapeWikiText( $text ) {
2120         $text = strtr( "\n$text", array(
2121                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2122                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2123                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2124                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2125                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2126                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2127         ) );
2128         return substr( $text, 1 );
2129 }
2130
2131 /**
2132  * Get the current unix timetstamp with microseconds.  Useful for profiling
2133  * @return Float
2134  */
2135 function wfTime() {
2136         return microtime( true );
2137 }
2138
2139 /**
2140  * Sets dest to source and returns the original value of dest
2141  * If source is NULL, it just returns the value, it doesn't set the variable
2142  * If force is true, it will set the value even if source is NULL
2143  *
2144  * @param $dest Mixed
2145  * @param $source Mixed
2146  * @param $force Bool
2147  * @return Mixed
2148  */
2149 function wfSetVar( &$dest, $source, $force = false ) {
2150         $temp = $dest;
2151         if ( !is_null( $source ) || $force ) {
2152                 $dest = $source;
2153         }
2154         return $temp;
2155 }
2156
2157 /**
2158  * As for wfSetVar except setting a bit
2159  *
2160  * @param $dest Int
2161  * @param $bit Int
2162  * @param $state Bool
2163  *
2164  * @return bool
2165  */
2166 function wfSetBit( &$dest, $bit, $state = true ) {
2167         $temp = (bool)( $dest & $bit );
2168         if ( !is_null( $state ) ) {
2169                 if ( $state ) {
2170                         $dest |= $bit;
2171                 } else {
2172                         $dest &= ~$bit;
2173                 }
2174         }
2175         return $temp;
2176 }
2177
2178 /**
2179  * A wrapper around the PHP function var_export().
2180  * Either print it or add it to the regular output ($wgOut).
2181  *
2182  * @param $var mixed A PHP variable to dump.
2183  */
2184 function wfVarDump( $var ) {
2185         global $wgOut;
2186         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2187         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2188                 print $s;
2189         } else {
2190                 $wgOut->addHTML( $s );
2191         }
2192 }
2193
2194 /**
2195  * Provide a simple HTTP error.
2196  *
2197  * @param $code Int|String
2198  * @param $label String
2199  * @param $desc String
2200  */
2201 function wfHttpError( $code, $label, $desc ) {
2202         global $wgOut;
2203         $wgOut->disable();
2204         header( "HTTP/1.0 $code $label" );
2205         header( "Status: $code $label" );
2206         $wgOut->sendCacheControl();
2207
2208         header( 'Content-type: text/html; charset=utf-8' );
2209         print "<!doctype html>" .
2210                 '<html><head><title>' .
2211                 htmlspecialchars( $label ) .
2212                 '</title></head><body><h1>' .
2213                 htmlspecialchars( $label ) .
2214                 '</h1><p>' .
2215                 nl2br( htmlspecialchars( $desc ) ) .
2216                 "</p></body></html>\n";
2217 }
2218
2219 /**
2220  * Clear away any user-level output buffers, discarding contents.
2221  *
2222  * Suitable for 'starting afresh', for instance when streaming
2223  * relatively large amounts of data without buffering, or wanting to
2224  * output image files without ob_gzhandler's compression.
2225  *
2226  * The optional $resetGzipEncoding parameter controls suppression of
2227  * the Content-Encoding header sent by ob_gzhandler; by default it
2228  * is left. See comments for wfClearOutputBuffers() for why it would
2229  * be used.
2230  *
2231  * Note that some PHP configuration options may add output buffer
2232  * layers which cannot be removed; these are left in place.
2233  *
2234  * @param $resetGzipEncoding Bool
2235  */
2236 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2237         if( $resetGzipEncoding ) {
2238                 // Suppress Content-Encoding and Content-Length
2239                 // headers from 1.10+s wfOutputHandler
2240                 global $wgDisableOutputCompression;
2241                 $wgDisableOutputCompression = true;
2242         }
2243         while( $status = ob_get_status() ) {
2244                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2245                         // Probably from zlib.output_compression or other
2246                         // PHP-internal setting which can't be removed.
2247                         //
2248                         // Give up, and hope the result doesn't break
2249                         // output behavior.
2250                         break;
2251                 }
2252                 if( !ob_end_clean() ) {
2253                         // Could not remove output buffer handler; abort now
2254                         // to avoid getting in some kind of infinite loop.
2255                         break;
2256                 }
2257                 if( $resetGzipEncoding ) {
2258                         if( $status['name'] == 'ob_gzhandler' ) {
2259                                 // Reset the 'Content-Encoding' field set by this handler
2260                                 // so we can start fresh.
2261                                 header_remove( 'Content-Encoding' );
2262                                 break;
2263                         }
2264                 }
2265         }
2266 }
2267
2268 /**
2269  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2270  *
2271  * Clear away output buffers, but keep the Content-Encoding header
2272  * produced by ob_gzhandler, if any.
2273  *
2274  * This should be used for HTTP 304 responses, where you need to
2275  * preserve the Content-Encoding header of the real result, but
2276  * also need to suppress the output of ob_gzhandler to keep to spec
2277  * and avoid breaking Firefox in rare cases where the headers and
2278  * body are broken over two packets.
2279  */
2280 function wfClearOutputBuffers() {
2281         wfResetOutputBuffers( false );
2282 }
2283
2284 /**
2285  * Converts an Accept-* header into an array mapping string values to quality
2286  * factors
2287  *
2288  * @param $accept String
2289  * @param $def String default
2290  * @return Array
2291  */
2292 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2293         # No arg means accept anything (per HTTP spec)
2294         if( !$accept ) {
2295                 return array( $def => 1.0 );
2296         }
2297
2298         $prefs = array();
2299
2300         $parts = explode( ',', $accept );
2301
2302         foreach( $parts as $part ) {
2303                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2304                 $values = explode( ';', trim( $part ) );
2305                 $match = array();
2306                 if ( count( $values ) == 1 ) {
2307                         $prefs[$values[0]] = 1.0;
2308                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2309                         $prefs[$values[0]] = floatval( $match[1] );
2310                 }
2311         }
2312
2313         return $prefs;
2314 }
2315
2316 /**
2317  * Checks if a given MIME type matches any of the keys in the given
2318  * array. Basic wildcards are accepted in the array keys.
2319  *
2320  * Returns the matching MIME type (or wildcard) if a match, otherwise
2321  * NULL if no match.
2322  *
2323  * @param $type String
2324  * @param $avail Array
2325  * @return string
2326  * @private
2327  */
2328 function mimeTypeMatch( $type, $avail ) {
2329         if( array_key_exists( $type, $avail ) ) {
2330                 return $type;
2331         } else {
2332                 $parts = explode( '/', $type );
2333                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2334                         return $parts[0] . '/*';
2335                 } elseif( array_key_exists( '*/*', $avail ) ) {
2336                         return '*/*';
2337                 } else {
2338                         return null;
2339                 }
2340         }
2341 }
2342
2343 /**
2344  * Returns the 'best' match between a client's requested internet media types
2345  * and the server's list of available types. Each list should be an associative
2346  * array of type to preference (preference is a float between 0.0 and 1.0).
2347  * Wildcards in the types are acceptable.
2348  *
2349  * @param $cprefs Array: client's acceptable type list
2350  * @param $sprefs Array: server's offered types
2351  * @return string
2352  *
2353  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2354  * XXX: generalize to negotiate other stuff
2355  */
2356 function wfNegotiateType( $cprefs, $sprefs ) {
2357         $combine = array();
2358
2359         foreach( array_keys( $sprefs ) as $type ) {
2360                 $parts = explode( '/', $type );
2361                 if( $parts[1] != '*' ) {
2362                         $ckey = mimeTypeMatch( $type, $cprefs );
2363                         if( $ckey ) {
2364                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2365                         }
2366                 }
2367         }
2368
2369         foreach( array_keys( $cprefs ) as $type ) {
2370                 $parts = explode( '/', $type );
2371                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2372                         $skey = mimeTypeMatch( $type, $sprefs );
2373                         if( $skey ) {
2374                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2375                         }
2376                 }
2377         }
2378
2379         $bestq = 0;
2380         $besttype = null;
2381
2382         foreach( array_keys( $combine ) as $type ) {
2383                 if( $combine[$type] > $bestq ) {
2384                         $besttype = $type;
2385                         $bestq = $combine[$type];
2386                 }
2387         }
2388
2389         return $besttype;
2390 }
2391
2392 /**
2393  * Reference-counted warning suppression
2394  *
2395  * @param $end Bool
2396  */
2397 function wfSuppressWarnings( $end = false ) {
2398         static $suppressCount = 0;
2399         static $originalLevel = false;
2400
2401         if ( $end ) {
2402                 if ( $suppressCount ) {
2403                         --$suppressCount;
2404                         if ( !$suppressCount ) {
2405                                 error_reporting( $originalLevel );
2406                         }
2407                 }
2408         } else {
2409                 if ( !$suppressCount ) {
2410                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT ) );
2411                 }
2412                 ++$suppressCount;
2413         }
2414 }
2415
2416 /**
2417  * Restore error level to previous value
2418  */
2419 function wfRestoreWarnings() {
2420         wfSuppressWarnings( true );
2421 }
2422
2423 # Autodetect, convert and provide timestamps of various types
2424
2425 /**
2426  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2427  */
2428 define( 'TS_UNIX', 0 );
2429
2430 /**
2431  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2432  */
2433 define( 'TS_MW', 1 );
2434
2435 /**
2436  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2437  */
2438 define( 'TS_DB', 2 );
2439
2440 /**
2441  * RFC 2822 format, for E-mail and HTTP headers
2442  */
2443 define( 'TS_RFC2822', 3 );
2444
2445 /**
2446  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2447  *
2448  * This is used by Special:Export
2449  */
2450 define( 'TS_ISO_8601', 4 );
2451
2452 /**
2453  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2454  *
2455  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2456  *       DateTime tag and page 36 for the DateTimeOriginal and
2457  *       DateTimeDigitized tags.
2458  */
2459 define( 'TS_EXIF', 5 );
2460
2461 /**
2462  * Oracle format time.
2463  */
2464 define( 'TS_ORACLE', 6 );
2465
2466 /**
2467  * Postgres format time.
2468  */
2469 define( 'TS_POSTGRES', 7 );
2470
2471 /**
2472  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2473  */
2474 define( 'TS_ISO_8601_BASIC', 9 );
2475
2476 /**
2477  * Get a timestamp string in one of various formats
2478  *
2479  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2480  *                    function will autodetect which format is supplied and act
2481  *                    accordingly.
2482  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2483  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2484  */
2485 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2486         try {
2487                 $timestamp = new MWTimestamp( $ts );
2488                 return $timestamp->getTimestamp( $outputtype );
2489         } catch( TimestampException $e ) {
2490                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2491                 return false;
2492         }
2493 }
2494
2495 /**
2496  * Return a formatted timestamp, or null if input is null.
2497  * For dealing with nullable timestamp columns in the database.
2498  *
2499  * @param $outputtype Integer
2500  * @param $ts String
2501  * @return String
2502  */
2503 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2504         if( is_null( $ts ) ) {
2505                 return null;
2506         } else {
2507                 return wfTimestamp( $outputtype, $ts );
2508         }
2509 }
2510
2511 /**
2512  * Convenience function; returns MediaWiki timestamp for the present time.
2513  *
2514  * @return string
2515  */
2516 function wfTimestampNow() {
2517         # return NOW
2518         return wfTimestamp( TS_MW, time() );
2519 }
2520
2521 /**
2522  * Check if the operating system is Windows
2523  *
2524  * @return Bool: true if it's Windows, False otherwise.
2525  */
2526 function wfIsWindows() {
2527         static $isWindows = null;
2528         if ( $isWindows === null ) {
2529                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2530         }
2531         return $isWindows;
2532 }
2533
2534 /**
2535  * Check if we are running under HipHop
2536  *
2537  * @return Bool
2538  */
2539 function wfIsHipHop() {
2540         return function_exists( 'hphp_thread_set_warmup_enabled' );
2541 }
2542
2543 /**
2544  * Swap two variables
2545  *
2546  * @param $x Mixed
2547  * @param $y Mixed
2548  */
2549 function swap( &$x, &$y ) {
2550         $z = $x;
2551         $x = $y;
2552         $y = $z;
2553 }
2554
2555 /**
2556  * Tries to get the system directory for temporary files. First
2557  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2558  * environment variables are then checked in sequence, and if none are
2559  * set try sys_get_temp_dir().
2560  *
2561  * NOTE: When possible, use instead the tmpfile() function to create
2562  * temporary files to avoid race conditions on file creation, etc.
2563  *
2564  * @return String
2565  */
2566 function wfTempDir() {
2567         global $wgTmpDirectory;
2568
2569         if ( $wgTmpDirectory !== false ) {
2570                 return $wgTmpDirectory;
2571         }
2572
2573         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2574
2575         foreach( $tmpDir as $tmp ) {
2576                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2577                         return $tmp;
2578                 }
2579         }
2580         return sys_get_temp_dir();
2581 }
2582
2583 /**
2584  * Make directory, and make all parent directories if they don't exist
2585  *
2586  * @param $dir String: full path to directory to create
2587  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2588  * @param $caller String: optional caller param for debugging.
2589  * @throws MWException
2590  * @return bool
2591  */
2592 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2593         global $wgDirectoryMode;
2594
2595         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2596                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2597         }
2598
2599         if ( !is_null( $caller ) ) {
2600                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2601         }
2602
2603         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2604                 return true;
2605         }
2606
2607         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2608
2609         if ( is_null( $mode ) ) {
2610                 $mode = $wgDirectoryMode;
2611         }
2612
2613         // Turn off the normal warning, we're doing our own below
2614         wfSuppressWarnings();
2615         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2616         wfRestoreWarnings();
2617
2618         if( !$ok ) {
2619                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2620                 trigger_error( sprintf( "%s: failed to mkdir \"%s\" mode 0%o", __FUNCTION__, $dir, $mode ),
2621                         E_USER_WARNING );
2622         }
2623         return $ok;
2624 }
2625
2626 /**
2627  * Remove a directory and all its content.
2628  * Does not hide error.
2629  */
2630 function wfRecursiveRemoveDir( $dir ) {
2631         wfDebug( __FUNCTION__ . "( $dir )\n" );
2632         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2633         if ( is_dir( $dir ) ) {
2634                 $objects = scandir( $dir );
2635                 foreach ( $objects as $object ) {
2636                         if ( $object != "." && $object != ".." ) {
2637                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2638                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2639                                 } else {
2640                                         unlink( $dir . '/' . $object );
2641                                 }
2642                         }
2643                 }
2644                 reset( $objects );
2645                 rmdir( $dir );
2646         }
2647 }
2648
2649 /**
2650  * @param $nr Mixed: the number to format
2651  * @param $acc Integer: the number of digits after the decimal point, default 2
2652  * @param $round Boolean: whether or not to round the value, default true
2653  * @return float
2654  */
2655 function wfPercent( $nr, $acc = 2, $round = true ) {
2656         $ret = sprintf( "%.${acc}f", $nr );
2657         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2658 }
2659
2660 /**
2661  * Find out whether or not a mixed variable exists in a string
2662  *
2663  * @deprecated Just use str(i)pos
2664  * @param $needle String
2665  * @param $str String
2666  * @param $insensitive Boolean
2667  * @return Boolean
2668  */
2669 function in_string( $needle, $str, $insensitive = false ) {
2670         wfDeprecated( __METHOD__, '1.21' );
2671         $func = 'strpos';
2672         if( $insensitive ) $func = 'stripos';
2673
2674         return $func( $str, $needle ) !== false;
2675 }
2676
2677 /**
2678  * Safety wrapper around ini_get() for boolean settings.
2679  * The values returned from ini_get() are pre-normalized for settings
2680  * set via php.ini or php_flag/php_admin_flag... but *not*
2681  * for those set via php_value/php_admin_value.
2682  *
2683  * It's fairly common for people to use php_value instead of php_flag,
2684  * which can leave you with an 'off' setting giving a false positive
2685  * for code that just takes the ini_get() return value as a boolean.
2686  *
2687  * To make things extra interesting, setting via php_value accepts
2688  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2689  * Unrecognized values go false... again opposite PHP's own coercion
2690  * from string to bool.
2691  *
2692  * Luckily, 'properly' set settings will always come back as '0' or '1',
2693  * so we only have to worry about them and the 'improper' settings.
2694  *
2695  * I frickin' hate PHP... :P
2696  *
2697  * @param $setting String
2698  * @return Bool
2699  */
2700 function wfIniGetBool( $setting ) {
2701         $val = ini_get( $setting );
2702         // 'on' and 'true' can't have whitespace around them, but '1' can.
2703         return strtolower( $val ) == 'on'
2704                 || strtolower( $val ) == 'true'
2705                 || strtolower( $val ) == 'yes'
2706                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2707 }
2708
2709 /**
2710  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2711  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2712  *
2713  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2714  *                          should be omitted
2715  * @param $fileName String Name of the library, if not $extension.suffix
2716  * @return Bool - Whether or not the extension is loaded
2717  */
2718 function wfDl( $extension, $fileName = null ) {
2719         if( extension_loaded( $extension ) ) {
2720                 return true;
2721         }
2722
2723         $canDl = false;
2724         if( PHP_SAPI == 'cli' || PHP_SAPI == 'cgi' || PHP_SAPI == 'embed' ) {
2725                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2726                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2727         }
2728
2729         if( $canDl ) {
2730                 $fileName = $fileName ? $fileName : $extension;
2731                 if( wfIsWindows() ) {
2732                         $fileName = 'php_' . $fileName;
2733                 }
2734                 wfSuppressWarnings();
2735                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2736                 wfRestoreWarnings();
2737         }
2738         return extension_loaded( $extension );
2739 }
2740
2741 /**
2742  * Windows-compatible version of escapeshellarg()
2743  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2744  * function puts single quotes in regardless of OS.
2745  *
2746  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2747  * earlier distro releases of PHP)
2748  *
2749  * @param varargs
2750  * @return String
2751  */
2752 function wfEscapeShellArg( ) {
2753         wfInitShellLocale();
2754
2755         $args = func_get_args();
2756         $first = true;
2757         $retVal = '';
2758         foreach ( $args as $arg ) {
2759                 if ( !$first ) {
2760                         $retVal .= ' ';
2761                 } else {
2762                         $first = false;
2763                 }
2764
2765                 if ( wfIsWindows() ) {
2766                         // Escaping for an MSVC-style command line parser and CMD.EXE
2767                         // Refs:
2768                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2769                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2770                         //  * Bug #13518
2771                         //  * CR r63214
2772                         // Double the backslashes before any double quotes. Escape the double quotes.
2773                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2774                         $arg = '';
2775                         $iteration = 0;
2776                         foreach ( $tokens as $token ) {
2777                                 if ( $iteration % 2 == 1 ) {
2778                                         // Delimiter, a double quote preceded by zero or more slashes
2779                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2780                                 } elseif ( $iteration % 4 == 2 ) {
2781                                         // ^ in $token will be outside quotes, need to be escaped
2782                                         $arg .= str_replace( '^', '^^', $token );
2783                                 } else { // $iteration % 4 == 0
2784                                         // ^ in $token will appear inside double quotes, so leave as is
2785                                         $arg .= $token;
2786                                 }
2787                                 $iteration++;
2788                         }
2789                         // Double the backslashes before the end of the string, because
2790                         // we will soon add a quote
2791                         $m = array();
2792                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2793                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2794                         }
2795
2796                         // Add surrounding quotes
2797                         $retVal .= '"' . $arg . '"';
2798                 } else {
2799                         $retVal .= escapeshellarg( $arg );
2800                 }
2801         }
2802         return $retVal;
2803 }
2804
2805 /**
2806  * Execute a shell command, with time and memory limits mirrored from the PHP
2807  * configuration if supported.
2808  * @param $cmd String Command line, properly escaped for shell.
2809  * @param &$retval null|Mixed optional, will receive the program's exit code.
2810  *                 (non-zero is usually failure)
2811  * @param $environ Array optional environment variables which should be
2812  *                 added to the executed command environment.
2813  * @param $limits Array optional array with limits(filesize, memory, time, walltime)
2814  *                 this overwrites the global wgShellMax* limits.
2815  * @return string collected stdout as a string (trailing newlines stripped)
2816  */
2817 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2818         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2819                 $wgMaxShellWallClockTime, $wgShellCgroup;
2820
2821         static $disabled;
2822         if ( is_null( $disabled ) ) {
2823                 $disabled = false;
2824                 if( wfIniGetBool( 'safe_mode' ) ) {
2825                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2826                         $disabled = 'safemode';
2827                 } else {
2828                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2829                         $functions = array_map( 'trim', $functions );
2830                         $functions = array_map( 'strtolower', $functions );
2831                         if ( in_array( 'passthru', $functions ) ) {
2832                                 wfDebug( "passthru is in disabled_functions\n" );
2833                                 $disabled = 'passthru';
2834                         }
2835                 }
2836         }
2837         if ( $disabled ) {
2838                 $retval = 1;
2839                 return $disabled == 'safemode' ?
2840                         'Unable to run external programs in safe mode.' :
2841                         'Unable to run external programs, passthru() is disabled.';
2842         }
2843
2844         wfInitShellLocale();
2845
2846         $envcmd = '';
2847         foreach( $environ as $k => $v ) {
2848                 if ( wfIsWindows() ) {
2849                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2850                          * appear in the environment variable, so we must use carat escaping as documented in
2851                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2852                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2853                          * are listed there but doesn't appear to need it.
2854                          */
2855                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2856                 } else {
2857                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2858                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2859                          */
2860                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2861                 }
2862         }
2863         $cmd = $envcmd . $cmd;
2864
2865         if ( php_uname( 's' ) == 'Linux' ) {
2866                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2867                 if ( isset( $limits['walltime'] ) ) {
2868                         $wallTime = intval( $limits['walltime'] );
2869                 } elseif ( isset( $limits['time'] ) ) {
2870                         $wallTime = $time;
2871                 } else {
2872                         $wallTime = intval( $wgMaxShellWallClockTime );
2873                 }
2874                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2875                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2876
2877                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2878                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2879                                 escapeshellarg( $cmd ) . ' ' .
2880                                 escapeshellarg(
2881                                         "MW_CPU_LIMIT=$time; " .
2882                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2883                                         "MW_MEM_LIMIT=$mem; " .
2884                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2885                                         "MW_WALL_CLOCK_LIMIT=$wallTime"
2886                                 );
2887                 }
2888         }
2889         wfDebug( "wfShellExec: $cmd\n" );
2890
2891         $retval = 1; // error by default?
2892         ob_start();
2893         passthru( $cmd, $retval );
2894         $output = ob_get_contents();
2895         ob_end_clean();
2896
2897         if ( $retval == 127 ) {
2898                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2899         }
2900         return $output;
2901 }
2902
2903 /**
2904  * Workaround for http://bugs.php.net/bug.php?id=45132
2905  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2906  */
2907 function wfInitShellLocale() {
2908         static $done = false;
2909         if ( $done ) {
2910                 return;
2911         }
2912         $done = true;
2913         global $wgShellLocale;
2914         if ( !wfIniGetBool( 'safe_mode' ) ) {
2915                 putenv( "LC_CTYPE=$wgShellLocale" );
2916                 setlocale( LC_CTYPE, $wgShellLocale );
2917         }
2918 }
2919
2920 /**
2921  * Alias to wfShellWikiCmd()
2922  * @see wfShellWikiCmd()
2923  */
2924 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2925         return wfShellWikiCmd( $script, $parameters, $options );
2926 }
2927
2928 /**
2929  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2930  * Note that $parameters should be a flat array and an option with an argument
2931  * should consist of two consecutive items in the array (do not use "--option value").
2932  * @param $script string MediaWiki cli script path
2933  * @param $parameters Array Arguments and options to the script
2934  * @param $options Array Associative array of options:
2935  *              'php': The path to the php executable
2936  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2937  * @return Array
2938  */
2939 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2940         global $wgPhpCli;
2941         // Give site config file a chance to run the script in a wrapper.
2942         // The caller may likely want to call wfBasename() on $script.
2943         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2944         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2945         if ( isset( $options['wrapper'] ) ) {
2946                 $cmd[] = $options['wrapper'];
2947         }
2948         $cmd[] = $script;
2949         // Escape each parameter for shell
2950         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2951 }
2952
2953 /**
2954  * wfMerge attempts to merge differences between three texts.
2955  * Returns true for a clean merge and false for failure or a conflict.
2956  *
2957  * @param $old String
2958  * @param $mine String
2959  * @param $yours String
2960  * @param $result String
2961  * @return Bool
2962  */
2963 function wfMerge( $old, $mine, $yours, &$result ) {
2964         global $wgDiff3;
2965
2966         # This check may also protect against code injection in
2967         # case of broken installations.
2968         wfSuppressWarnings();
2969         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2970         wfRestoreWarnings();
2971
2972         if( !$haveDiff3 ) {
2973                 wfDebug( "diff3 not found\n" );
2974                 return false;
2975         }
2976
2977         # Make temporary files
2978         $td = wfTempDir();
2979         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2980         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2981         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2982
2983         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2984         #       a newline character. To avoid this, we normalize the trailing whitespace before
2985         #       creating the diff.
2986
2987         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2988         fclose( $oldtextFile );
2989         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2990         fclose( $mytextFile );
2991         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2992         fclose( $yourtextFile );
2993
2994         # Check for a conflict
2995         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
2996                 wfEscapeShellArg( $mytextName ) . ' ' .
2997                 wfEscapeShellArg( $oldtextName ) . ' ' .
2998                 wfEscapeShellArg( $yourtextName );
2999         $handle = popen( $cmd, 'r' );
3000
3001         if( fgets( $handle, 1024 ) ) {
3002                 $conflict = true;
3003         } else {
3004                 $conflict = false;
3005         }
3006         pclose( $handle );
3007
3008         # Merge differences
3009         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3010                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3011         $handle = popen( $cmd, 'r' );
3012         $result = '';
3013         do {
3014                 $data = fread( $handle, 8192 );
3015                 if ( strlen( $data ) == 0 ) {
3016                         break;
3017                 }
3018                 $result .= $data;
3019         } while ( true );
3020         pclose( $handle );
3021         unlink( $mytextName );
3022         unlink( $oldtextName );
3023         unlink( $yourtextName );
3024
3025         if ( $result === '' && $old !== '' && !$conflict ) {
3026                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3027                 $conflict = true;
3028         }
3029         return !$conflict;
3030 }
3031
3032 /**
3033  * Returns unified plain-text diff of two texts.
3034  * Useful for machine processing of diffs.
3035  *
3036  * @param $before String: the text before the changes.
3037  * @param $after String: the text after the changes.
3038  * @param $params String: command-line options for the diff command.
3039  * @return String: unified diff of $before and $after
3040  */
3041 function wfDiff( $before, $after, $params = '-u' ) {
3042         if ( $before == $after ) {
3043                 return '';
3044         }
3045
3046         global $wgDiff;
3047         wfSuppressWarnings();
3048         $haveDiff = $wgDiff && file_exists( $wgDiff );
3049         wfRestoreWarnings();
3050
3051         # This check may also protect against code injection in
3052         # case of broken installations.
3053         if( !$haveDiff ) {
3054                 wfDebug( "diff executable not found\n" );
3055                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3056                 $format = new UnifiedDiffFormatter();
3057                 return $format->format( $diffs );
3058         }
3059
3060         # Make temporary files
3061         $td = wfTempDir();
3062         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3063         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3064
3065         fwrite( $oldtextFile, $before );
3066         fclose( $oldtextFile );
3067         fwrite( $newtextFile, $after );
3068         fclose( $newtextFile );
3069
3070         // Get the diff of the two files
3071         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3072
3073         $h = popen( $cmd, 'r' );
3074
3075         $diff = '';
3076
3077         do {
3078                 $data = fread( $h, 8192 );
3079                 if ( strlen( $data ) == 0 ) {
3080                         break;
3081                 }
3082                 $diff .= $data;
3083         } while ( true );
3084
3085         // Clean up
3086         pclose( $h );
3087         unlink( $oldtextName );
3088         unlink( $newtextName );
3089
3090         // Kill the --- and +++ lines. They're not useful.
3091         $diff_lines = explode( "\n", $diff );
3092         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3093                 unset( $diff_lines[0] );
3094         }
3095         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3096                 unset( $diff_lines[1] );
3097         }
3098
3099         $diff = implode( "\n", $diff_lines );
3100
3101         return $diff;
3102 }
3103
3104 /**
3105  * This function works like "use VERSION" in Perl, the program will die with a
3106  * backtrace if the current version of PHP is less than the version provided
3107  *
3108  * This is useful for extensions which due to their nature are not kept in sync
3109  * with releases, and might depend on other versions of PHP than the main code
3110  *
3111  * Note: PHP might die due to parsing errors in some cases before it ever
3112  *       manages to call this function, such is life
3113  *
3114  * @see perldoc -f use
3115  *
3116  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3117  *                 a float
3118  * @throws MWException
3119  */
3120 function wfUsePHP( $req_ver ) {
3121         $php_ver = PHP_VERSION;
3122
3123         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3124                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3125         }
3126 }
3127
3128 /**
3129  * This function works like "use VERSION" in Perl except it checks the version
3130  * of MediaWiki, the program will die with a backtrace if the current version
3131  * of MediaWiki is less than the version provided.
3132  *
3133  * This is useful for extensions which due to their nature are not kept in sync
3134  * with releases
3135  *
3136  * @see perldoc -f use
3137  *
3138  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3139  *                 a float
3140  * @throws MWException
3141  */
3142 function wfUseMW( $req_ver ) {
3143         global $wgVersion;
3144
3145         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3146                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3147         }
3148 }
3149
3150 /**
3151  * Return the final portion of a pathname.
3152  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3153  * http://bugs.php.net/bug.php?id=33898
3154  *
3155  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3156  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3157  *
3158  * @param $path String
3159  * @param $suffix String: to remove if present
3160  * @return String
3161  */
3162 function wfBaseName( $path, $suffix = '' ) {
3163         $encSuffix = ( $suffix == '' )
3164                 ? ''
3165                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3166         $matches = array();
3167         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3168                 return $matches[1];
3169         } else {
3170                 return '';
3171         }
3172 }
3173
3174 /**
3175  * Generate a relative path name to the given file.
3176  * May explode on non-matching case-insensitive paths,
3177  * funky symlinks, etc.
3178  *
3179  * @param $path String: absolute destination path including target filename
3180  * @param $from String: Absolute source path, directory only
3181  * @return String
3182  */
3183 function wfRelativePath( $path, $from ) {
3184         // Normalize mixed input on Windows...
3185         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3186         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3187
3188         // Trim trailing slashes -- fix for drive root
3189         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3190         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3191
3192         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3193         $against = explode( DIRECTORY_SEPARATOR, $from );
3194
3195         if( $pieces[0] !== $against[0] ) {
3196                 // Non-matching Windows drive letters?
3197                 // Return a full path.
3198                 return $path;
3199         }
3200
3201         // Trim off common prefix
3202         while( count( $pieces ) && count( $against )
3203                 && $pieces[0] == $against[0] ) {
3204                 array_shift( $pieces );
3205                 array_shift( $against );
3206         }
3207
3208         // relative dots to bump us to the parent
3209         while( count( $against ) ) {
3210                 array_unshift( $pieces, '..' );
3211                 array_shift( $against );
3212         }
3213
3214         array_push( $pieces, wfBaseName( $path ) );
3215
3216         return implode( DIRECTORY_SEPARATOR, $pieces );
3217 }
3218
3219 /**
3220  * Do any deferred updates and clear the list
3221  *
3222  * @deprecated since 1.19
3223  * @see DeferredUpdates::doUpdate()
3224  * @param $commit string
3225  */
3226 function wfDoUpdates( $commit = '' ) {
3227         wfDeprecated( __METHOD__, '1.19' );
3228         DeferredUpdates::doUpdates( $commit );
3229 }
3230
3231 /**
3232  * Convert an arbitrarily-long digit string from one numeric base
3233  * to another, optionally zero-padding to a minimum column width.
3234  *
3235  * Supports base 2 through 36; digit values 10-36 are represented
3236  * as lowercase letters a-z. Input is case-insensitive.
3237  *
3238  * @param string $input Input number
3239  * @param int $sourceBase Base of the input number
3240  * @param int $destBase Desired base of the output
3241  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3242  * @param bool $lowercase Whether to output in lowercase or uppercase
3243  * @param string $engine Either "gmp", "bcmath", or "php"
3244  * @return string|bool The output number as a string, or false on error
3245  */
3246 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true, $engine = 'auto' ) {
3247         $input = (string)$input;
3248         if(
3249                 $sourceBase < 2 ||
3250                 $sourceBase > 36 ||
3251                 $destBase < 2 ||
3252                 $destBase > 36 ||
3253                 $sourceBase != (int) $sourceBase ||
3254                 $destBase != (int) $destBase ||
3255                 $pad != (int) $pad ||
3256                 !preg_match( "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i", $input )
3257         ) {
3258                 return false;
3259         }
3260
3261         static $baseChars = array (
3262                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3263                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3264                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3265                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3266                 34 => 'y', 35 => 'z',
3267
3268                 '0' => 0,  '1' => 1,  '2' => 2,  '3' => 3,  '4' => 4,  '5' => 5,
3269                 '6' => 6,  '7' => 7,  '8' => 8,  '9' => 9,  'a' => 10, 'b' => 11,
3270                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3271                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3272                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3273                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3274         );
3275
3276         if( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3277                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3278         } elseif( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3279                 $decimal = '0';
3280                 foreach( str_split( strtolower( $input ) ) as $char ) {
3281                         $decimal = bcmul( $decimal, $sourceBase );
3282                         $decimal = bcadd( $decimal, $baseChars[$char] );
3283                 }
3284
3285                 for( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3286                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3287                 }
3288
3289                 $result = strrev( $result );
3290         } else {
3291                 $inDigits = array();
3292                 foreach( str_split( strtolower( $input ) ) as $char ) {
3293                         $inDigits[] = $baseChars[$char];
3294                 }
3295
3296                 // Iterate over the input, modulo-ing out an output digit
3297                 // at a time until input is gone.
3298                 $result = '';
3299                 while( $inDigits ) {
3300                         $work = 0;
3301                         $workDigits = array();
3302
3303                         // Long division...
3304                         foreach( $inDigits as $digit ) {
3305                                 $work *= $sourceBase;
3306                                 $work += $digit;
3307
3308                                 if( $workDigits || $work >= $destBase ) {
3309                                         $workDigits[] = (int) ( $work / $destBase );
3310                                 }
3311                                 $work %= $destBase;
3312                         }
3313
3314                         // All that division leaves us with a remainder,
3315                         // which is conveniently our next output digit.
3316                         $result .= $baseChars[$work];
3317
3318                         // And we continue!
3319                         $inDigits = $workDigits;
3320                 }
3321
3322                 $result = strrev( $result );
3323         }
3324
3325         if( !$lowercase ) {
3326                 $result = strtoupper( $result );
3327         }
3328
3329         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3330 }
3331
3332 /**
3333  * Create an object with a given name and an array of construct parameters
3334  *
3335  * @param $name String
3336  * @param $p Array: parameters
3337  * @return object
3338  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3339  */
3340 function wfCreateObject( $name, $p ) {
3341         wfDeprecated( __FUNCTION__, '1.18' );
3342         return MWFunction::newObj( $name, $p );
3343 }
3344
3345 /**
3346  * @return bool
3347  */
3348 function wfHttpOnlySafe() {
3349         global $wgHttpOnlyBlacklist;
3350
3351         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3352                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3353                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3354                                 return false;
3355                         }
3356                 }
3357         }
3358
3359         return true;
3360 }
3361
3362 /**
3363  * Check if there is sufficent entropy in php's built-in session generation
3364  * @return bool true = there is sufficient entropy
3365  */
3366 function wfCheckEntropy() {
3367         return (
3368                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3369                         || ini_get( 'session.entropy_file' )
3370                 )
3371                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3372 }
3373
3374 /**
3375  * Override session_id before session startup if php's built-in
3376  * session generation code is not secure.
3377  */
3378 function wfFixSessionID() {
3379         // If the cookie or session id is already set we already have a session and should abort
3380         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3381                 return;
3382         }
3383
3384         // PHP's built-in session entropy is enabled if:
3385         // - entropy_file is set or you're on Windows with php 5.3.3+
3386         // - AND entropy_length is > 0
3387         // We treat it as disabled if it doesn't have an entropy length of at least 32
3388         $entropyEnabled = wfCheckEntropy();
3389
3390         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3391         if ( !$entropyEnabled ) {
3392                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3393                 session_id( MWCryptRand::generateHex( 32 ) );
3394         }
3395 }
3396
3397 /**
3398  * Initialise php session
3399  *
3400  * @param $sessionId Bool
3401  */
3402 function wfSetupSession( $sessionId = false ) {
3403         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3404                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3405         if( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3406                 ObjectCacheSessionHandler::install();
3407         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3408                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3409                 # hasn't already been set to the desired value (that causes errors)
3410                 ini_set( 'session.save_handler', $wgSessionHandler );
3411         }
3412         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3413         wfDebugLog( 'cookie',
3414                 'session_set_cookie_params: "' . implode( '", "',
3415                         array(
3416                                 0,
3417                                 $wgCookiePath,
3418                                 $wgCookieDomain,
3419                                 $wgCookieSecure,
3420                                 $httpOnlySafe ) ) . '"' );
3421         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3422         session_cache_limiter( 'private, must-revalidate' );
3423         if ( $sessionId ) {
3424                 session_id( $sessionId );
3425         } else {
3426                 wfFixSessionID();
3427         }
3428         wfSuppressWarnings();
3429         session_start();
3430         wfRestoreWarnings();
3431 }
3432
3433 /**
3434  * Get an object from the precompiled serialized directory
3435  *
3436  * @param $name String
3437  * @return Mixed: the variable on success, false on failure
3438  */
3439 function wfGetPrecompiledData( $name ) {
3440         global $IP;
3441
3442         $file = "$IP/serialized/$name";
3443         if ( file_exists( $file ) ) {
3444                 $blob = file_get_contents( $file );
3445                 if ( $blob ) {
3446                         return unserialize( $blob );
3447                 }
3448         }
3449         return false;
3450 }
3451
3452 /**
3453  * Get a cache key
3454  *
3455  * @param varargs
3456  * @return String
3457  */
3458 function wfMemcKey( /*... */ ) {
3459         global $wgCachePrefix;
3460         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3461         $args = func_get_args();
3462         $key = $prefix . ':' . implode( ':', $args );
3463         $key = str_replace( ' ', '_', $key );
3464         return $key;
3465 }
3466
3467 /**
3468  * Get a cache key for a foreign DB
3469  *
3470  * @param $db String
3471  * @param $prefix String
3472  * @param varargs String
3473  * @return String
3474  */
3475 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3476         $args = array_slice( func_get_args(), 2 );
3477         if ( $prefix ) {
3478                 $key = "$db-$prefix:" . implode( ':', $args );
3479         } else {
3480                 $key = $db . ':' . implode( ':', $args );
3481         }
3482         return $key;
3483 }
3484
3485 /**
3486  * Get an ASCII string identifying this wiki
3487  * This is used as a prefix in memcached keys
3488  *
3489  * @return String
3490  */
3491 function wfWikiID() {
3492         global $wgDBprefix, $wgDBname;
3493         if ( $wgDBprefix ) {
3494                 return "$wgDBname-$wgDBprefix";
3495         } else {
3496                 return $wgDBname;
3497         }
3498 }
3499
3500 /**
3501  * Split a wiki ID into DB name and table prefix
3502  *
3503  * @param $wiki String
3504  *
3505  * @return array
3506  */
3507 function wfSplitWikiID( $wiki ) {
3508         $bits = explode( '-', $wiki, 2 );
3509         if ( count( $bits ) < 2 ) {
3510                 $bits[] = '';
3511         }
3512         return $bits;
3513 }
3514
3515 /**
3516  * Get a Database object.
3517  *
3518  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3519  *            master (for write queries), DB_SLAVE for potentially lagged read
3520  *            queries, or an integer >= 0 for a particular server.
3521  *
3522  * @param $groups Mixed: query groups. An array of group names that this query
3523  *                belongs to. May contain a single string if the query is only
3524  *                in one group.
3525  *
3526  * @param $wiki String: the wiki ID, or false for the current wiki
3527  *
3528  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3529  * will always return the same object, unless the underlying connection or load
3530  * balancer is manually destroyed.
3531  *
3532  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3533  * updater to ensure that a proper database is being updated.
3534  *
3535  * @return DatabaseBase
3536  */
3537 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3538         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3539 }
3540
3541 /**
3542  * Get a load balancer object.
3543  *
3544  * @param $wiki String: wiki ID, or false for the current wiki
3545  * @return LoadBalancer
3546  */
3547 function wfGetLB( $wiki = false ) {
3548         return wfGetLBFactory()->getMainLB( $wiki );
3549 }
3550
3551 /**
3552  * Get the load balancer factory object
3553  *
3554  * @return LBFactory
3555  */
3556 function &wfGetLBFactory() {
3557         return LBFactory::singleton();
3558 }
3559
3560 /**
3561  * Find a file.
3562  * Shortcut for RepoGroup::singleton()->findFile()
3563  *
3564  * @param $title String or Title object
3565  * @param $options array Associative array of options:
3566  *     time:           requested time for an archived image, or false for the
3567  *                     current version. An image object will be returned which was
3568  *                     created at the specified time.
3569  *
3570  *     ignoreRedirect: If true, do not follow file redirects
3571  *
3572  *     private:        If true, return restricted (deleted) files if the current
3573  *                     user is allowed to view them. Otherwise, such files will not
3574  *                     be found.
3575  *
3576  *     bypassCache:    If true, do not use the process-local cache of File objects
3577  *
3578  * @return File, or false if the file does not exist
3579  */
3580 function wfFindFile( $title, $options = array() ) {
3581         return RepoGroup::singleton()->findFile( $title, $options );
3582 }
3583
3584 /**
3585  * Get an object referring to a locally registered file.
3586  * Returns a valid placeholder object if the file does not exist.
3587  *
3588  * @param $title Title|String
3589  * @return LocalFile|null A File, or null if passed an invalid Title
3590  */
3591 function wfLocalFile( $title ) {
3592         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3593 }
3594
3595 /**
3596  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3597  * @deprecated since 1.19
3598  */
3599 function wfStreamFile( $fname, $headers = array() ) {
3600         wfDeprecated( __FUNCTION__, '1.19' );
3601         StreamFile::stream( $fname, $headers );
3602 }
3603
3604 /**
3605  * Should low-performance queries be disabled?
3606  *
3607  * @return Boolean
3608  * @codeCoverageIgnore
3609  */
3610 function wfQueriesMustScale() {
3611         global $wgMiserMode;
3612         return $wgMiserMode
3613                 || ( SiteStats::pages() > 100000
3614                 && SiteStats::edits() > 1000000
3615                 && SiteStats::users() > 10000 );
3616 }
3617
3618 /**
3619  * Get the path to a specified script file, respecting file
3620  * extensions; this is a wrapper around $wgScriptExtension etc.
3621  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3622  *
3623  * @param $script String: script filename, sans extension
3624  * @return String
3625  */
3626 function wfScript( $script = 'index' ) {
3627         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3628         if ( $script === 'index' ) {
3629                 return $wgScript;
3630         } else if ( $script === 'load' ) {
3631                 return $wgLoadScript;
3632         } else {
3633                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3634         }
3635 }
3636
3637 /**
3638  * Get the script URL.
3639  *
3640  * @return string script URL
3641  */
3642 function wfGetScriptUrl() {
3643         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3644                 #
3645                 # as it was called, minus the query string.
3646                 #
3647                 # Some sites use Apache rewrite rules to handle subdomains,
3648                 # and have PHP set up in a weird way that causes PHP_SELF
3649                 # to contain the rewritten URL instead of the one that the
3650                 # outside world sees.
3651                 #
3652                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3653                 # provides containing the "before" URL.
3654                 return $_SERVER['SCRIPT_NAME'];
3655         } else {
3656                 return $_SERVER['URL'];
3657         }
3658 }
3659
3660 /**
3661  * Convenience function converts boolean values into "true"
3662  * or "false" (string) values
3663  *
3664  * @param $value Boolean
3665  * @return String
3666  */
3667 function wfBoolToStr( $value ) {
3668         return $value ? 'true' : 'false';
3669 }
3670
3671 /**
3672  * Get a platform-independent path to the null file, e.g. /dev/null
3673  *
3674  * @return string
3675  */
3676 function wfGetNull() {
3677         return wfIsWindows()
3678                 ? 'NUL'
3679                 : '/dev/null';
3680 }
3681
3682 /**
3683  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3684  * and waiting for it to go down, this waits for the slaves to catch up to the
3685  * master position. Use this when updating very large numbers of rows, as
3686  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3687  * a no-op if there are no slaves.
3688  *
3689  * @param $maxLag Integer (deprecated)
3690  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3691  */
3692 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3693         $lb = wfGetLB( $wiki );
3694         // bug 27975 - Don't try to wait for slaves if there are none
3695         // Prevents permission error when getting master position
3696         if ( $lb->getServerCount() > 1 ) {
3697                 $dbw = $lb->getConnection( DB_MASTER );
3698                 $pos = $dbw->getMasterPos();
3699                 $lb->waitForAll( $pos );
3700         }
3701 }
3702
3703 /**
3704  * Used to be used for outputting text in the installer/updater
3705  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3706  */
3707 function wfOut( $s ) {
3708         wfDeprecated( __FUNCTION__, '1.18' );
3709         global $wgCommandLineMode;
3710         if ( $wgCommandLineMode ) {
3711                 echo $s;
3712         } else {
3713                 echo htmlspecialchars( $s );
3714         }
3715         flush();
3716 }
3717
3718 /**
3719  * Count down from $n to zero on the terminal, with a one-second pause
3720  * between showing each number. For use in command-line scripts.
3721  * @codeCoverageIgnore
3722  * @param $n int
3723  */
3724 function wfCountDown( $n ) {
3725         for ( $i = $n; $i >= 0; $i-- ) {
3726                 if ( $i != $n ) {
3727                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3728                 }
3729                 echo $i;
3730                 flush();
3731                 if ( $i ) {
3732                         sleep( 1 );
3733                 }
3734         }
3735         echo "\n";
3736 }
3737
3738 /**
3739  * Generate a random 32-character hexadecimal token.
3740  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3741  *              characters before hashing.
3742  * @return string
3743  * @codeCoverageIgnore
3744  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pesudo-random strings
3745  * @warning This method is NOT secure. Additionally it has many callers that use it for pesudo-random purposes.
3746  */
3747 function wfGenerateToken( $salt = '' ) {
3748         wfDeprecated( __METHOD__, '1.20' );
3749         $salt = serialize( $salt );
3750         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3751 }
3752
3753 /**
3754  * Replace all invalid characters with -
3755  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3756  * By default, $wgIllegalFileChars = ':'
3757  *
3758  * @param $name Mixed: filename to process
3759  * @return String
3760  */
3761 function wfStripIllegalFilenameChars( $name ) {
3762         global $wgIllegalFileChars;
3763         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3764         $name = wfBaseName( $name );
3765         $name = preg_replace(
3766                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3767                 '-',
3768                 $name
3769         );
3770         return $name;
3771 }
3772
3773 /**
3774  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3775  *
3776  * @return Integer value memory was set to.
3777  */
3778 function wfMemoryLimit() {
3779         global $wgMemoryLimit;
3780         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3781         if( $memlimit != -1 ) {
3782                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3783                 if( $conflimit == -1 ) {
3784                         wfDebug( "Removing PHP's memory limit\n" );
3785                         wfSuppressWarnings();
3786                         ini_set( 'memory_limit', $conflimit );
3787                         wfRestoreWarnings();
3788                         return $conflimit;
3789                 } elseif ( $conflimit > $memlimit ) {
3790                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3791                         wfSuppressWarnings();
3792                         ini_set( 'memory_limit', $conflimit );
3793                         wfRestoreWarnings();
3794                         return $conflimit;
3795                 }
3796         }
3797         return $memlimit;
3798 }
3799
3800 /**
3801  * Converts shorthand byte notation to integer form
3802  *
3803  * @param $string String
3804  * @return Integer
3805  */
3806 function wfShorthandToInteger( $string = '' ) {
3807         $string = trim( $string );
3808         if( $string === '' ) {
3809                 return -1;
3810         }
3811         $last = $string[strlen( $string ) - 1];
3812         $val = intval( $string );
3813         switch( $last ) {
3814                 case 'g':
3815                 case 'G':
3816                         $val *= 1024;
3817                         // break intentionally missing
3818                 case 'm':
3819                 case 'M':
3820                         $val *= 1024;
3821                         // break intentionally missing
3822                 case 'k':
3823                 case 'K':
3824                         $val *= 1024;
3825         }
3826
3827         return $val;
3828 }
3829
3830 /**
3831  * Get the normalised IETF language tag
3832  * See unit test for examples.
3833  *
3834  * @param $code String: The language code.
3835  * @return String: The language code which complying with BCP 47 standards.
3836  */
3837 function wfBCP47( $code ) {
3838         $codeSegment = explode( '-', $code );
3839         $codeBCP = array();
3840         foreach ( $codeSegment as $segNo => $seg ) {
3841                 if ( count( $codeSegment ) > 0 ) {
3842                         // when previous segment is x, it is a private segment and should be lc
3843                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3844                                 $codeBCP[$segNo] = strtolower( $seg );
3845                         // ISO 3166 country code
3846                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3847                                 $codeBCP[$segNo] = strtoupper( $seg );
3848                         // ISO 15924 script code
3849                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3850                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3851                         // Use lowercase for other cases
3852                         } else {
3853                                 $codeBCP[$segNo] = strtolower( $seg );
3854                         }
3855                 } else {
3856                 // Use lowercase for single segment
3857                         $codeBCP[$segNo] = strtolower( $seg );
3858                 }
3859         }
3860         $langCode = implode( '-', $codeBCP );
3861         return $langCode;
3862 }
3863
3864 /**
3865  * Get a cache object.
3866  *
3867  * @param $inputType integer Cache type, one the the CACHE_* constants.
3868  * @return BagOStuff
3869  */
3870 function wfGetCache( $inputType ) {
3871         return ObjectCache::getInstance( $inputType );
3872 }
3873
3874 /**
3875  * Get the main cache object
3876  *
3877  * @return BagOStuff
3878  */
3879 function wfGetMainCache() {
3880         global $wgMainCacheType;
3881         return ObjectCache::getInstance( $wgMainCacheType );
3882 }
3883
3884 /**
3885  * Get the cache object used by the message cache
3886  *
3887  * @return BagOStuff
3888  */
3889 function wfGetMessageCacheStorage() {
3890         global $wgMessageCacheType;
3891         return ObjectCache::getInstance( $wgMessageCacheType );
3892 }
3893
3894 /**
3895  * Get the cache object used by the parser cache
3896  *
3897  * @return BagOStuff
3898  */
3899 function wfGetParserCacheStorage() {
3900         global $wgParserCacheType;
3901         return ObjectCache::getInstance( $wgParserCacheType );
3902 }
3903
3904 /**
3905  * Get the cache object used by the language converter
3906  *
3907  * @return BagOStuff
3908  */
3909 function wfGetLangConverterCacheStorage() {
3910         global $wgLanguageConverterCacheType;
3911         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3912 }
3913
3914 /**
3915  * Call hook functions defined in $wgHooks
3916  *
3917  * @param $event String: event name
3918  * @param $args Array: parameters passed to hook functions
3919  * @return Boolean True if no handler aborted the hook
3920  */
3921 function wfRunHooks( $event, $args = array() ) {
3922         return Hooks::run( $event, $args );
3923 }
3924
3925 /**
3926  * Wrapper around php's unpack.
3927  *
3928  * @param $format String: The format string (See php's docs)
3929  * @param $data: A binary string of binary data
3930  * @param $length integer or false: The minimun length of $data. This is to
3931  *      prevent reading beyond the end of $data. false to disable the check.
3932  *
3933  * Also be careful when using this function to read unsigned 32 bit integer
3934  * because php might make it negative.
3935  *
3936  * @throws MWException if $data not long enough, or if unpack fails
3937  * @return array Associative array of the extracted data
3938  */
3939 function wfUnpack( $format, $data, $length=false ) {
3940         if ( $length !== false ) {
3941                 $realLen = strlen( $data );
3942                 if ( $realLen < $length ) {
3943                         throw new MWException( "Tried to use wfUnpack on a "
3944                                 . "string of length $realLen, but needed one "
3945                                 . "of at least length $length."
3946                         );
3947                 }
3948         }
3949
3950         wfSuppressWarnings();
3951         $result = unpack( $format, $data );
3952         wfRestoreWarnings();
3953
3954         if ( $result === false ) {
3955                 // If it cannot extract the packed data.
3956                 throw new MWException( "unpack could not unpack binary data" );
3957         }
3958         return $result;
3959 }
3960
3961 /**
3962  * Determine if an image exists on the 'bad image list'.
3963  *
3964  * The format of MediaWiki:Bad_image_list is as follows:
3965  *    * Only list items (lines starting with "*") are considered
3966  *    * The first link on a line must be a link to a bad image
3967  *    * Any subsequent links on the same line are considered to be exceptions,
3968  *      i.e. articles where the image may occur inline.
3969  *
3970  * @param $name string the image name to check
3971  * @param $contextTitle Title|bool the page on which the image occurs, if known
3972  * @param $blacklist string wikitext of a file blacklist
3973  * @return bool
3974  */
3975 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3976         static $badImageCache = null; // based on bad_image_list msg
3977         wfProfileIn( __METHOD__ );
3978
3979         # Handle redirects
3980         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3981         if( $redirectTitle ) {
3982                 $name = $redirectTitle->getDbKey();
3983         }
3984
3985         # Run the extension hook
3986         $bad = false;
3987         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3988                 wfProfileOut( __METHOD__ );
3989                 return $bad;
3990         }
3991
3992         $cacheable = ( $blacklist === null );
3993         if( $cacheable && $badImageCache !== null ) {
3994                 $badImages = $badImageCache;
3995         } else { // cache miss
3996                 if ( $blacklist === null ) {
3997                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3998                 }
3999                 # Build the list now
4000                 $badImages = array();
4001                 $lines = explode( "\n", $blacklist );
4002                 foreach( $lines as $line ) {
4003                         # List items only
4004                         if ( substr( $line, 0, 1 ) !== '*' ) {
4005                                 continue;
4006                         }
4007
4008                         # Find all links
4009                         $m = array();
4010                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4011                                 continue;
4012                         }
4013
4014                         $exceptions = array();
4015                         $imageDBkey = false;
4016                         foreach ( $m[1] as $i => $titleText ) {
4017                                 $title = Title::newFromText( $titleText );
4018                                 if ( !is_null( $title ) ) {
4019                                         if ( $i == 0 ) {
4020                                                 $imageDBkey = $title->getDBkey();
4021                                         } else {
4022                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4023                                         }
4024                                 }
4025                         }
4026
4027                         if ( $imageDBkey !== false ) {
4028                                 $badImages[$imageDBkey] = $exceptions;
4029                         }
4030                 }
4031                 if ( $cacheable ) {
4032                         $badImageCache = $badImages;
4033                 }
4034         }
4035
4036         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4037         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4038         wfProfileOut( __METHOD__ );
4039         return $bad;
4040 }