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 /// @endcond
  97
  98 /**
  99  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 100  * @param $a array
 101  * @param $b array
 102  * @return array
 103  */
 104 function wfArrayDiff2( $a, $b ) {
 105         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 106 }
 107
 108 /**
 109  * @param $a
 110  * @param $b
 111  * @return int
 112  */
 113 function wfArrayDiff2_cmp( $a, $b ) {
 114         if ( !is_array( $a ) ) {
 115                 return strcmp( $a, $b );
 116         } elseif ( count( $a ) !== count( $b ) ) {
 117                 return count( $a ) < count( $b ) ? -1 : 1;
 118         } else {
 119                 reset( $a );
 120                 reset( $b );
 121                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 122                         $cmp = strcmp( $valueA, $valueB );
 123                         if ( $cmp !== 0 ) {
 124                                 return $cmp;
 125                         }
 126                 }
 127                 return 0;
 128         }
 129 }
 130
 131 /**
 132  * Array lookup
 133  * Returns an array where the values in array $b are replaced by the
 134  * values in array $a with the corresponding keys
 135  *
 136  * @deprecated since 1.22; use array_intersect_key()
 137  * @param $a Array
 138  * @param $b Array
 139  * @return array
 140  */
 141 function wfArrayLookup( $a, $b ) {
 142         wfDeprecated( __FUNCTION__, '1.22' );
 143         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 144 }
 145
 146 /**
 147  * Appends to second array if $value differs from that in $default
 148  *
 149  * @param $key String|Int
 150  * @param $value Mixed
 151  * @param $default Mixed
 152  * @param array $changed to alter
 153  * @throws MWException
 154  */
 155 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 156         if ( is_null( $changed ) ) {
 157                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 158         }
 159         if ( $default[$key] !== $value ) {
 160                 $changed[$key] = $value;
 161         }
 162 }
 163
 164 /**
 165  * Backwards array plus for people who haven't bothered to read the PHP manual
 166  * XXX: will not darn your socks for you.
 167  *
 168  * @deprecated since 1.22; use array_replace()
 169  * @param $array1 Array
 170  * @param [$array2, [...]] Arrays
 171  * @return Array
 172  */
 173 function wfArrayMerge( $array1/* ... */ ) {
 174         wfDeprecated( __FUNCTION__, '1.22' );
 175         $args = func_get_args();
 176         $args = array_reverse( $args, true );
 177         $out = array();
 178         foreach ( $args as $arg ) {
 179                 $out += $arg;
 180         }
 181         return $out;
 182 }
 183
 184 /**
 185  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 186  * e.g.
 187  *      wfMergeErrorArrays(
 188  *              array( array( 'x' ) ),
 189  *              array( array( 'x', '2' ) ),
 190  *              array( array( 'x' ) ),
 191  *              array( array( 'y' ) )
 192  *      );
 193  * returns:
 194  *              array(
 195  *              array( 'x', '2' ),
 196  *              array( 'x' ),
 197  *              array( 'y' )
 198  *      )
 199  * @param varargs
 200  * @return Array
 201  */
 202 function wfMergeErrorArrays( /*...*/ ) {
 203         $args = func_get_args();
 204         $out = array();
 205         foreach ( $args as $errors ) {
 206                 foreach ( $errors as $params ) {
 207                         # @todo FIXME: Sometimes get nested arrays for $params,
 208                         # which leads to E_NOTICEs
 209                         $spec = implode( "\t", $params );
 210                         $out[$spec] = $params;
 211                 }
 212         }
 213         return array_values( $out );
 214 }
 215
 216 /**
 217  * Insert array into another array after the specified *KEY*
 218  *
 219  * @param array $array The array.
 220  * @param array $insert The array to insert.
 221  * @param $after Mixed: The key to insert after
 222  * @return Array
 223  */
 224 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 225         // Find the offset of the element to insert after.
 226         $keys = array_keys( $array );
 227         $offsetByKey = array_flip( $keys );
 228
 229         $offset = $offsetByKey[$after];
 230
 231         // Insert at the specified offset
 232         $before = array_slice( $array, 0, $offset + 1, true );
 233         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 234
 235         $output = $before + $insert + $after;
 236
 237         return $output;
 238 }
 239
 240 /**
 241  * Recursively converts the parameter (an object) to an array with the same data
 242  *
 243  * @param $objOrArray Object|Array
 244  * @param $recursive Bool
 245  * @return Array
 246  */
 247 function wfObjectToArray( $objOrArray, $recursive = true ) {
 248         $array = array();
 249         if ( is_object( $objOrArray ) ) {
 250                 $objOrArray = get_object_vars( $objOrArray );
 251         }
 252         foreach ( $objOrArray as $key => $value ) {
 253                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 254                         $value = wfObjectToArray( $value );
 255                 }
 256
 257                 $array[$key] = $value;
 258         }
 259
 260         return $array;
 261 }
 262
 263 /**
 264  * Get a random decimal value between 0 and 1, in a way
 265  * not likely to give duplicate values for any realistic
 266  * number of articles.
 267  *
 268  * @return string
 269  */
 270 function wfRandom() {
 271         # The maximum random value is "only" 2^31-1, so get two random
 272         # values to reduce the chance of dupes
 273         $max = mt_getrandmax() + 1;
 274         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 275                 / $max / $max, 12, '.', '' );
 276         return $rand;
 277 }
 278
 279 /**
 280  * Get a random string containing a number of pseudo-random hex
 281  * characters.
 282  * @note This is not secure, if you are trying to generate some sort
 283  *       of token please use MWCryptRand instead.
 284  *
 285  * @param int $length The length of the string to generate
 286  * @return String
 287  * @since 1.20
 288  */
 289 function wfRandomString( $length = 32 ) {
 290         $str = '';
 291         for ( $n = 0; $n < $length; $n += 7 ) {
 292                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 293         }
 294         return substr( $str, 0, $length );
 295 }
 296
 297 /**
 298  * We want some things to be included as literal characters in our title URLs
 299  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 300  * all of the following should be safe:
 301  *
 302  * ;:@&=$-_.+!*'(),
 303  *
 304  * But + is not safe because it's used to indicate a space; &= are only safe in
 305  * paths and not in queries (and we don't distinguish here); ' seems kind of
 306  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 307  * is reserved, we don't care.  So the list we unescape is:
 308  *
 309  * ;:@$!*(),/
 310  *
 311  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 312  * so no fancy : for IIS7.
 313  *
 314  * %2F in the page titles seems to fatally break for some reason.
 315  *
 316  * @param $s String:
 317  * @return string
 318  */
 319 function wfUrlencode( $s ) {
 320         static $needle;
 321         if ( is_null( $s ) ) {
 322                 $needle = null;
 323                 return '';
 324         }
 325
 326         if ( is_null( $needle ) ) {
 327                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 328                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 329                         $needle[] = '%3A';
 330                 }
 331         }
 332
 333         $s = urlencode( $s );
 334         $s = str_ireplace(
 335                 $needle,
 336                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 337                 $s
 338         );
 339
 340         return $s;
 341 }
 342
 343 /**
 344  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 345  * "days=7&limit=100". Options in the first array override options in the second.
 346  * Options set to null or false will not be output.
 347  *
 348  * @param array $array1 ( String|Array )
 349  * @param array $array2 ( String|Array )
 350  * @param $prefix String
 351  * @return String
 352  */
 353 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 354         if ( !is_null( $array2 ) ) {
 355                 $array1 = $array1 + $array2;
 356         }
 357
 358         $cgi = '';
 359         foreach ( $array1 as $key => $value ) {
 360                 if ( !is_null( $value ) && $value !== false ) {
 361                         if ( $cgi != '' ) {
 362                                 $cgi .= '&';
 363                         }
 364                         if ( $prefix !== '' ) {
 365                                 $key = $prefix . "[$key]";
 366                         }
 367                         if ( is_array( $value ) ) {
 368                                 $firstTime = true;
 369                                 foreach ( $value as $k => $v ) {
 370                                         $cgi .= $firstTime ? '' : '&';
 371                                         if ( is_array( $v ) ) {
 372                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 373                                         } else {
 374                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 375                                         }
 376                                         $firstTime = false;
 377                                 }
 378                         } else {
 379                                 if ( is_object( $value ) ) {
 380                                         $value = $value->__toString();
 381                                 }
 382                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 383                         }
 384                 }
 385         }
 386         return $cgi;
 387 }
 388
 389 /**
 390  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 391  * its argument and returns the same string in array form.  This allows compatibility
 392  * with legacy functions that accept raw query strings instead of nice
 393  * arrays.  Of course, keys and values are urldecode()d.
 394  *
 395  * @param string $query query string
 396  * @return array Array version of input
 397  */
 398 function wfCgiToArray( $query ) {
 399         if ( isset( $query[0] ) && $query[0] == '?' ) {
 400                 $query = substr( $query, 1 );
 401         }
 402         $bits = explode( '&', $query );
 403         $ret = array();
 404         foreach ( $bits as $bit ) {
 405                 if ( $bit === '' ) {
 406                         continue;
 407                 }
 408                 if ( strpos( $bit, '=' ) === false ) {
 409                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 410                         $key = $bit;
 411                         $value = '';
 412                 } else {
 413                         list( $key, $value ) = explode( '=', $bit );
 414                 }
 415                 $key = urldecode( $key );
 416                 $value = urldecode( $value );
 417                 if ( strpos( $key, '[' ) !== false ) {
 418                         $keys = array_reverse( explode( '[', $key ) );
 419                         $key = array_pop( $keys );
 420                         $temp = $value;
 421                         foreach ( $keys as $k ) {
 422                                 $k = substr( $k, 0, -1 );
 423                                 $temp = array( $k => $temp );
 424                         }
 425                         if ( isset( $ret[$key] ) ) {
 426                                 $ret[$key] = array_merge( $ret[$key], $temp );
 427                         } else {
 428                                 $ret[$key] = $temp;
 429                         }
 430                 } else {
 431                         $ret[$key] = $value;
 432                 }
 433         }
 434         return $ret;
 435 }
 436
 437 /**
 438  * Append a query string to an existing URL, which may or may not already
 439  * have query string parameters already. If so, they will be combined.
 440  *
 441  * @param $url String
 442  * @param $query Mixed: string or associative array
 443  * @return string
 444  */
 445 function wfAppendQuery( $url, $query ) {
 446         if ( is_array( $query ) ) {
 447                 $query = wfArrayToCgi( $query );
 448         }
 449         if ( $query != '' ) {
 450                 if ( false === strpos( $url, '?' ) ) {
 451                         $url .= '?';
 452                 } else {
 453                         $url .= '&';
 454                 }
 455                 $url .= $query;
 456         }
 457         return $url;
 458 }
 459
 460 /**
 461  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 462  * is correct.
 463  *
 464  * The meaning of the PROTO_* constants is as follows:
 465  * PROTO_HTTP: Output a URL starting with http://
 466  * PROTO_HTTPS: Output a URL starting with https://
 467  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 468  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 469  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 470  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 471  *
 472  * @todo this won't work with current-path-relative URLs
 473  * like "subdir/foo.html", etc.
 474  *
 475  * @param string $url either fully-qualified or a local path + query
 476  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 477  *                             protocol to use if $url or $wgServer is
 478  *                             protocol-relative
 479  * @return string Fully-qualified URL, current-path-relative URL or false if
 480  *                no valid URL can be constructed
 481  */
 482 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 483         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 484         $serverUrl = $wgServer;
 485         if ( $defaultProto === PROTO_CANONICAL ) {
 486                 $serverUrl = $wgCanonicalServer;
 487         }
 488         // Make $wgInternalServer fall back to $wgServer if not set
 489         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 490                 $serverUrl = $wgInternalServer;
 491         }
 492         if ( $defaultProto === PROTO_CURRENT ) {
 493                 $defaultProto = WebRequest::detectProtocol() . '://';
 494         }
 495
 496         // Analyze $serverUrl to obtain its protocol
 497         $bits = wfParseUrl( $serverUrl );
 498         $serverHasProto = $bits && $bits['scheme'] != '';
 499
 500         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 501                 if ( $serverHasProto ) {
 502                         $defaultProto = $bits['scheme'] . '://';
 503                 } else {
 504                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 505                         // Fall back to HTTP in this ridiculous case
 506                         $defaultProto = PROTO_HTTP;
 507                 }
 508         }
 509
 510         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 511
 512         if ( substr( $url, 0, 2 ) == '//' ) {
 513                 $url = $defaultProtoWithoutSlashes . $url;
 514         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 515                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 516                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 517         }
 518
 519         $bits = wfParseUrl( $url );
 520         if ( $bits && isset( $bits['path'] ) ) {
 521                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 522                 return wfAssembleUrl( $bits );
 523         } elseif ( $bits ) {
 524                 # No path to expand
 525                 return $url;
 526         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 527                 # URL is a relative path
 528                 return wfRemoveDotSegments( $url );
 529         }
 530
 531         # Expanded URL is not valid.
 532         return false;
 533 }
 534
 535 /**
 536  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 537  * if you need to edit part of a URL and put it back together.
 538  *
 539  * This is the basic structure used (brackets contain keys for $urlParts):
 540  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 541  *
 542  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 543  *
 544  * @since 1.19
 545  * @param array $urlParts URL parts, as output from wfParseUrl
 546  * @return string URL assembled from its component parts
 547  */
 548 function wfAssembleUrl( $urlParts ) {
 549         $result = '';
 550
 551         if ( isset( $urlParts['delimiter'] ) ) {
 552                 if ( isset( $urlParts['scheme'] ) ) {
 553                         $result .= $urlParts['scheme'];
 554                 }
 555
 556                 $result .= $urlParts['delimiter'];
 557         }
 558
 559         if ( isset( $urlParts['host'] ) ) {
 560                 if ( isset( $urlParts['user'] ) ) {
 561                         $result .= $urlParts['user'];
 562                         if ( isset( $urlParts['pass'] ) ) {
 563                                 $result .= ':' . $urlParts['pass'];
 564                         }
 565                         $result .= '@';
 566                 }
 567
 568                 $result .= $urlParts['host'];
 569
 570                 if ( isset( $urlParts['port'] ) ) {
 571                         $result .= ':' . $urlParts['port'];
 572                 }
 573         }
 574
 575         if ( isset( $urlParts['path'] ) ) {
 576                 $result .= $urlParts['path'];
 577         }
 578
 579         if ( isset( $urlParts['query'] ) ) {
 580                 $result .= '?' . $urlParts['query'];
 581         }
 582
 583         if ( isset( $urlParts['fragment'] ) ) {
 584                 $result .= '#' . $urlParts['fragment'];
 585         }
 586
 587         return $result;
 588 }
 589
 590 /**
 591  * Remove all dot-segments in the provided URL path.  For example,
 592  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 593  * RFC3986 section 5.2.4.
 594  *
 595  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 596  *
 597  * @param string $urlPath URL path, potentially containing dot-segments
 598  * @return string URL path with all dot-segments removed
 599  */
 600 function wfRemoveDotSegments( $urlPath ) {
 601         $output = '';
 602         $inputOffset = 0;
 603         $inputLength = strlen( $urlPath );
 604
 605         while ( $inputOffset < $inputLength ) {
 606                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 607                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 608                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 609                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 610                 $trimOutput = false;
 611
 612                 if ( $prefixLengthTwo == './' ) {
 613                         # Step A, remove leading "./"
 614                         $inputOffset += 2;
 615                 } elseif ( $prefixLengthThree == '../' ) {
 616                         # Step A, remove leading "../"
 617                         $inputOffset += 3;
 618                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 619                         # Step B, replace leading "/.$" with "/"
 620                         $inputOffset += 1;
 621                         $urlPath[$inputOffset] = '/';
 622                 } elseif ( $prefixLengthThree == '/./' ) {
 623                         # Step B, replace leading "/./" with "/"
 624                         $inputOffset += 2;
 625                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 626                         # Step C, replace leading "/..$" with "/" and
 627                         # remove last path component in output
 628                         $inputOffset += 2;
 629                         $urlPath[$inputOffset] = '/';
 630                         $trimOutput = true;
 631                 } elseif ( $prefixLengthFour == '/../' ) {
 632                         # Step C, replace leading "/../" with "/" and
 633                         # remove last path component in output
 634                         $inputOffset += 3;
 635                         $trimOutput = true;
 636                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 637                         # Step D, remove "^.$"
 638                         $inputOffset += 1;
 639                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 640                         # Step D, remove "^..$"
 641                         $inputOffset += 2;
 642                 } else {
 643                         # Step E, move leading path segment to output
 644                         if ( $prefixLengthOne == '/' ) {
 645                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 646                         } else {
 647                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 648                         }
 649                         if ( $slashPos === false ) {
 650                                 $output .= substr( $urlPath, $inputOffset );
 651                                 $inputOffset = $inputLength;
 652                         } else {
 653                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 654                                 $inputOffset += $slashPos - $inputOffset;
 655                         }
 656                 }
 657
 658                 if ( $trimOutput ) {
 659                         $slashPos = strrpos( $output, '/' );
 660                         if ( $slashPos === false ) {
 661                                 $output = '';
 662                         } else {
 663                                 $output = substr( $output, 0, $slashPos );
 664                         }
 665                 }
 666         }
 667
 668         return $output;
 669 }
 670
 671 /**
 672  * Returns a regular expression of url protocols
 673  *
 674  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 675  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 676  * @return String
 677  */
 678 function wfUrlProtocols( $includeProtocolRelative = true ) {
 679         global $wgUrlProtocols;
 680
 681         // Cache return values separately based on $includeProtocolRelative
 682         static $withProtRel = null, $withoutProtRel = null;
 683         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 684         if ( !is_null( $cachedValue ) ) {
 685                 return $cachedValue;
 686         }
 687
 688         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 689         // with LocalSettings files from 1.5
 690         if ( is_array( $wgUrlProtocols ) ) {
 691                 $protocols = array();
 692                 foreach ( $wgUrlProtocols as $protocol ) {
 693                         // Filter out '//' if !$includeProtocolRelative
 694                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 695                                 $protocols[] = preg_quote( $protocol, '/' );
 696                         }
 697                 }
 698
 699                 $retval = implode( '|', $protocols );
 700         } else {
 701                 // Ignore $includeProtocolRelative in this case
 702                 // This case exists for pre-1.6 compatibility, and we can safely assume
 703                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 704                 // URLs weren't supported until 1.18
 705                 $retval = $wgUrlProtocols;
 706         }
 707
 708         // Cache return value
 709         if ( $includeProtocolRelative ) {
 710                 $withProtRel = $retval;
 711         } else {
 712                 $withoutProtRel = $retval;
 713         }
 714         return $retval;
 715 }
 716
 717 /**
 718  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 719  * you need a regex that matches all URL protocols but does not match protocol-
 720  * relative URLs
 721  * @return String
 722  */
 723 function wfUrlProtocolsWithoutProtRel() {
 724         return wfUrlProtocols( false );
 725 }
 726
 727 /**
 728  * parse_url() work-alike, but non-broken.  Differences:
 729  *
 730  * 1) Does not raise warnings on bad URLs (just returns false)
 731  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 732  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 733  *
 734  * @param string $url a URL to parse
 735  * @return Array: bits of the URL in an associative array, per PHP docs
 736  */
 737 function wfParseUrl( $url ) {
 738         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 739
 740         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 741         // way to handle them is to just prepend 'http:' and strip the protocol out later
 742         $wasRelative = substr( $url, 0, 2 ) == '//';
 743         if ( $wasRelative ) {
 744                 $url = "http:$url";
 745         }
 746         wfSuppressWarnings();
 747         $bits = parse_url( $url );
 748         wfRestoreWarnings();
 749         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 750         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 751         if ( !$bits || !isset( $bits['scheme'] ) ) {
 752                 return false;
 753         }
 754
 755         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 756         $bits['scheme'] = strtolower( $bits['scheme'] );
 757
 758         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 759         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 760                 $bits['delimiter'] = '://';
 761         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 762                 $bits['delimiter'] = ':';
 763                 // parse_url detects for news: and mailto: the host part of an url as path
 764                 // We have to correct this wrong detection
 765                 if ( isset( $bits['path'] ) ) {
 766                         $bits['host'] = $bits['path'];
 767                         $bits['path'] = '';
 768                 }
 769         } else {
 770                 return false;
 771         }
 772
 773         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 774         if ( !isset( $bits['host'] ) ) {
 775                 $bits['host'] = '';
 776
 777                 // bug 45069
 778                 if ( isset( $bits['path'] ) ) {
 779                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 780                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 781                                 $bits['path'] = '/' . $bits['path'];
 782                         }
 783                 } else {
 784                         $bits['path'] = '';
 785                 }
 786         }
 787
 788         // If the URL was protocol-relative, fix scheme and delimiter
 789         if ( $wasRelative ) {
 790                 $bits['scheme'] = '';
 791                 $bits['delimiter'] = '//';
 792         }
 793         return $bits;
 794 }
 795
 796 /**
 797  * Take a URL, make sure it's expanded to fully qualified, and replace any
 798  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 799  * for more compact display and legibility for local audiences.
 800  *
 801  * @todo handle punycode domains too
 802  *
 803  * @param $url string
 804  * @return string
 805  */
 806 function wfExpandIRI( $url ) {
 807         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 808 }
 809
 810 /**
 811  * Private callback for wfExpandIRI
 812  * @param array $matches
 813  * @return string
 814  */
 815 function wfExpandIRI_callback( $matches ) {
 816         return urldecode( $matches[1] );
 817 }
 818
 819 /**
 820  * Make URL indexes, appropriate for the el_index field of externallinks.
 821  *
 822  * @param $url String
 823  * @return array
 824  */
 825 function wfMakeUrlIndexes( $url ) {
 826         $bits = wfParseUrl( $url );
 827
 828         // Reverse the labels in the hostname, convert to lower case
 829         // For emails reverse domainpart only
 830         if ( $bits['scheme'] == 'mailto' ) {
 831                 $mailparts = explode( '@', $bits['host'], 2 );
 832                 if ( count( $mailparts ) === 2 ) {
 833                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 834                 } else {
 835                         // No domain specified, don't mangle it
 836                         $domainpart = '';
 837                 }
 838                 $reversedHost = $domainpart . '@' . $mailparts[0];
 839         } else {
 840                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 841         }
 842         // Add an extra dot to the end
 843         // Why? Is it in wrong place in mailto links?
 844         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 845                 $reversedHost .= '.';
 846         }
 847         // Reconstruct the pseudo-URL
 848         $prot = $bits['scheme'];
 849         $index = $prot . $bits['delimiter'] . $reversedHost;
 850         // Leave out user and password. Add the port, path, query and fragment
 851         if ( isset( $bits['port'] ) ) {
 852                 $index .= ':' . $bits['port'];
 853         }
 854         if ( isset( $bits['path'] ) ) {
 855                 $index .= $bits['path'];
 856         } else {
 857                 $index .= '/';
 858         }
 859         if ( isset( $bits['query'] ) ) {
 860                 $index .= '?' . $bits['query'];
 861         }
 862         if ( isset( $bits['fragment'] ) ) {
 863                 $index .= '#' . $bits['fragment'];
 864         }
 865
 866         if ( $prot == '' ) {
 867                 return array( "http:$index", "https:$index" );
 868         } else {
 869                 return array( $index );
 870         }
 871 }
 872
 873 /**
 874  * Check whether a given URL has a domain that occurs in a given set of domains
 875  * @param string $url URL
 876  * @param array $domains Array of domains (strings)
 877  * @return bool True if the host part of $url ends in one of the strings in $domains
 878  */
 879 function wfMatchesDomainList( $url, $domains ) {
 880         $bits = wfParseUrl( $url );
 881         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 882                 $host = '.' . $bits['host'];
 883                 foreach ( (array)$domains as $domain ) {
 884                         $domain = '.' . $domain;
 885                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 886                                 return true;
 887                         }
 888                 }
 889         }
 890         return false;
 891 }
 892
 893 /**
 894  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 895  * In normal operation this is a NOP.
 896  *
 897  * Controlling globals:
 898  * $wgDebugLogFile - points to the log file
 899  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 900  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 901  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 902  *
 903  * @param $text String
 904  * @param bool $logonly set true to avoid appearing in HTML when $wgDebugComments is set
 905  */
 906 function wfDebug( $text, $logonly = false ) {
 907         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 908
 909         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 910                 return;
 911         }
 912
 913         $timer = wfDebugTimer();
 914         if ( $timer !== '' ) {
 915                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 916         }
 917
 918         if ( !$logonly ) {
 919                 MWDebug::debugMsg( $text );
 920         }
 921
 922         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 923                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 924                         # Strip unprintables; they can switch terminal modes when binary data
 925                         # gets dumped, which is pretty annoying.
 926                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 927                         $text = $wgDebugLogPrefix . $text;
 928                         wfErrorLog( $text, $wgDebugLogFile );
 929                 }
 930         }
 931 }
 932
 933 /**
 934  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 935  * @return bool
 936  */
 937 function wfIsDebugRawPage() {
 938         static $cache;
 939         if ( $cache !== null ) {
 940                 return $cache;
 941         }
 942         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 943         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 944                 || (
 945                         isset( $_SERVER['SCRIPT_NAME'] )
 946                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 947                 ) )
 948         {
 949                 $cache = true;
 950         } else {
 951                 $cache = false;
 952         }
 953         return $cache;
 954 }
 955
 956 /**
 957  * Get microsecond timestamps for debug logs
 958  *
 959  * @return string
 960  */
 961 function wfDebugTimer() {
 962         global $wgDebugTimestamps, $wgRequestTime;
 963
 964         if ( !$wgDebugTimestamps ) {
 965                 return '';
 966         }
 967
 968         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 969         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 970         return "$prefix $mem  ";
 971 }
 972
 973 /**
 974  * Send a line giving PHP memory usage.
 975  *
 976  * @param bool $exact print exact values instead of kilobytes (default: false)
 977  */
 978 function wfDebugMem( $exact = false ) {
 979         $mem = memory_get_usage();
 980         if ( !$exact ) {
 981                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 982         } else {
 983                 $mem .= ' bytes';
 984         }
 985         wfDebug( "Memory usage: $mem\n" );
 986 }
 987
 988 /**
 989  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 990  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 991  *
 992  * @param $logGroup String
 993  * @param $text String
 994  * @param bool $public whether to log the event in the public log if no private
 995  *                     log file is specified, (default true)
 996  */
 997 function wfDebugLog( $logGroup, $text, $public = true ) {
 998         global $wgDebugLogGroups;
 999         $text = trim( $text ) . "\n";
1000         if ( isset( $wgDebugLogGroups[$logGroup] ) ) {
1001                 $time = wfTimestamp( TS_DB );
1002                 $wiki = wfWikiID();
1003                 $host = wfHostname();
1004                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1005                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1006                 }
1007         } elseif ( $public === true ) {
1008                 wfDebug( "[$logGroup] $text", false );
1009         }
1010 }
1011
1012 /**
1013  * Log for database errors
1014  *
1015  * @param string $text database error message.
1016  */
1017 function wfLogDBError( $text ) {
1018         global $wgDBerrorLog, $wgDBerrorLogTZ;
1019         static $logDBErrorTimeZoneObject = null;
1020
1021         if ( $wgDBerrorLog ) {
1022                 $host = wfHostname();
1023                 $wiki = wfWikiID();
1024
1025                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1026                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1027                 }
1028
1029                 // Workaround for https://bugs.php.net/bug.php?id=52063
1030                 // Can be removed when min PHP > 5.3.2
1031                 if ( $logDBErrorTimeZoneObject === null ) {
1032                         $d = date_create( "now" );
1033                 } else {
1034                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1035                 }
1036
1037                 $date = $d->format( 'D M j G:i:s T Y' );
1038
1039                 $text = "$date\t$host\t$wiki\t$text";
1040                 wfErrorLog( $text, $wgDBerrorLog );
1041         }
1042 }
1043
1044 /**
1045  * Throws a warning that $function is deprecated
1046  *
1047  * @param $function String
1048  * @param string|bool $version Version of MediaWiki that the function was deprecated in (Added in 1.19).
1049  * @param string|bool $component Added in 1.19.
1050  * @param $callerOffset integer: How far up the call stack is the original
1051  *    caller. 2 = function that called the function that called
1052  *    wfDeprecated (Added in 1.20)
1053  *
1054  * @return null
1055  */
1056 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1057         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1058 }
1059
1060 /**
1061  * Send a warning either to the debug log or in a PHP error depending on
1062  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1063  *
1064  * @param string $msg message to send
1065  * @param $callerOffset Integer: number of items to go back in the backtrace to
1066  *        find the correct caller (1 = function calling wfWarn, ...)
1067  * @param $level Integer: PHP error level; defaults to E_USER_NOTICE;
1068  *        only used when $wgDevelopmentWarnings is true
1069  */
1070 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1071         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1072 }
1073
1074 /**
1075  * Send a warning as a PHP error and the debug log. This is intended for logging
1076  * warnings in production. For logging development warnings, use WfWarn instead.
1077  *
1078  * @param $msg String: message to send
1079  * @param $callerOffset Integer: number of items to go back in the backtrace to
1080  *        find the correct caller (1 = function calling wfLogWarning, ...)
1081  * @param $level Integer: PHP error level; defaults to E_USER_WARNING
1082  */
1083 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1084         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1085 }
1086
1087 /**
1088  * Log to a file without getting "file size exceeded" signals.
1089  *
1090  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1091  * send lines to the specified port, prefixed by the specified prefix and a space.
1092  *
1093  * @param $text String
1094  * @param string $file filename
1095  * @throws MWException
1096  */
1097 function wfErrorLog( $text, $file ) {
1098         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1099                 # Needs the sockets extension
1100                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1101                         // IPv6 bracketed host
1102                         $host = $m[2];
1103                         $port = intval( $m[3] );
1104                         $prefix = isset( $m[4] ) ? $m[4] : false;
1105                         $domain = AF_INET6;
1106                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1107                         $host = $m[2];
1108                         if ( !IP::isIPv4( $host ) ) {
1109                                 $host = gethostbyname( $host );
1110                         }
1111                         $port = intval( $m[3] );
1112                         $prefix = isset( $m[4] ) ? $m[4] : false;
1113                         $domain = AF_INET;
1114                 } else {
1115                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1116                 }
1117
1118                 // Clean it up for the multiplexer
1119                 if ( strval( $prefix ) !== '' ) {
1120                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1121
1122                         // Limit to 64KB
1123                         if ( strlen( $text ) > 65506 ) {
1124                                 $text = substr( $text, 0, 65506 );
1125                         }
1126
1127                         if ( substr( $text, -1 ) != "\n" ) {
1128                                 $text .= "\n";
1129                         }
1130                 } elseif ( strlen( $text ) > 65507 ) {
1131                         $text = substr( $text, 0, 65507 );
1132                 }
1133
1134                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1135                 if ( !$sock ) {
1136                         return;
1137                 }
1138
1139                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1140                 socket_close( $sock );
1141         } else {
1142                 wfSuppressWarnings();
1143                 $exists = file_exists( $file );
1144                 $size = $exists ? filesize( $file ) : false;
1145                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1146                         file_put_contents( $file, $text, FILE_APPEND );
1147                 }
1148                 wfRestoreWarnings();
1149         }
1150 }
1151
1152 /**
1153  * @todo document
1154  */
1155 function wfLogProfilingData() {
1156         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1157         global $wgProfileLimit, $wgUser;
1158
1159         StatCounter::singleton()->flush();
1160
1161         $profiler = Profiler::instance();
1162
1163         # Profiling must actually be enabled...
1164         if ( $profiler->isStub() ) {
1165                 return;
1166         }
1167
1168         // Get total page request time and only show pages that longer than
1169         // $wgProfileLimit time (default is 0)
1170         $elapsed = microtime( true ) - $wgRequestTime;
1171         if ( $elapsed <= $wgProfileLimit ) {
1172                 return;
1173         }
1174
1175         $profiler->logData();
1176
1177         // Check whether this should be logged in the debug file.
1178         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1179                 return;
1180         }
1181
1182         $forward = '';
1183         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1184                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1185         }
1186         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1187                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1188         }
1189         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1190                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1191         }
1192         if ( $forward ) {
1193                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1194         }
1195         // Don't load $wgUser at this late stage just for statistics purposes
1196         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1197         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1198                 $forward .= ' anon';
1199         }
1200
1201         // Command line script uses a FauxRequest object which does not have
1202         // any knowledge about an URL and throw an exception instead.
1203         try {
1204                 $requestUrl = $wgRequest->getRequestURL();
1205         } catch ( MWException $e ) {
1206                 $requestUrl = 'n/a';
1207         }
1208
1209         $log = sprintf( "%s\t%04.3f\t%s\n",
1210                 gmdate( 'YmdHis' ), $elapsed,
1211                 urldecode( $requestUrl . $forward ) );
1212
1213         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1214 }
1215
1216 /**
1217  * Increment a statistics counter
1218  *
1219  * @param $key String
1220  * @param $count Int
1221  * @return void
1222  */
1223 function wfIncrStats( $key, $count = 1 ) {
1224         StatCounter::singleton()->incr( $key, $count );
1225 }
1226
1227 /**
1228  * Check whether the wiki is in read-only mode.
1229  *
1230  * @return bool
1231  */
1232 function wfReadOnly() {
1233         return wfReadOnlyReason() !== false;
1234 }
1235
1236 /**
1237  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1238  *
1239  * @return string|bool: String when in read-only mode; false otherwise
1240  */
1241 function wfReadOnlyReason() {
1242         global $wgReadOnly, $wgReadOnlyFile;
1243
1244         if ( $wgReadOnly === null ) {
1245                 // Set $wgReadOnly for faster access next time
1246                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1247                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1248                 } else {
1249                         $wgReadOnly = false;
1250                 }
1251         }
1252
1253         return $wgReadOnly;
1254 }
1255
1256 /**
1257  * Return a Language object from $langcode
1258  *
1259  * @param $langcode Mixed: either:
1260  *                  - a Language object
1261  *                  - code of the language to get the message for, if it is
1262  *                    a valid code create a language for that language, if
1263  *                    it is a string but not a valid code then make a basic
1264  *                    language object
1265  *                  - a boolean: if it's false then use the global object for
1266  *                    the current user's language (as a fallback for the old parameter
1267  *                    functionality), or if it is true then use global object
1268  *                    for the wiki's content language.
1269  * @return Language object
1270  */
1271 function wfGetLangObj( $langcode = false ) {
1272         # Identify which language to get or create a language object for.
1273         # Using is_object here due to Stub objects.
1274         if ( is_object( $langcode ) ) {
1275                 # Great, we already have the object (hopefully)!
1276                 return $langcode;
1277         }
1278
1279         global $wgContLang, $wgLanguageCode;
1280         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1281                 # $langcode is the language code of the wikis content language object.
1282                 # or it is a boolean and value is true
1283                 return $wgContLang;
1284         }
1285
1286         global $wgLang;
1287         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1288                 # $langcode is the language code of user language object.
1289                 # or it was a boolean and value is false
1290                 return $wgLang;
1291         }
1292
1293         $validCodes = array_keys( Language::fetchLanguageNames() );
1294         if ( in_array( $langcode, $validCodes ) ) {
1295                 # $langcode corresponds to a valid language.
1296                 return Language::factory( $langcode );
1297         }
1298
1299         # $langcode is a string, but not a valid language code; use content language.
1300         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1301         return $wgContLang;
1302 }
1303
1304 /**
1305  * Old function when $wgBetterDirectionality existed
1306  * All usage removed, wfUILang can be removed in near future
1307  *
1308  * @deprecated since 1.18
1309  * @return Language
1310  */
1311 function wfUILang() {
1312         wfDeprecated( __METHOD__, '1.18' );
1313         global $wgLang;
1314         return $wgLang;
1315 }
1316
1317 /**
1318  * This is the function for getting translated interface messages.
1319  *
1320  * @see Message class for documentation how to use them.
1321  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1322  *
1323  * This function replaces all old wfMsg* functions.
1324  *
1325  * @param $key \string Message key.
1326  * Varargs: normal message parameters.
1327  * @return Message
1328  * @since 1.17
1329  */
1330 function wfMessage( $key /*...*/) {
1331         $params = func_get_args();
1332         array_shift( $params );
1333         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1334                 $params = $params[0];
1335         }
1336         return new Message( $key, $params );
1337 }
1338
1339 /**
1340  * This function accepts multiple message keys and returns a message instance
1341  * for the first message which is non-empty. If all messages are empty then an
1342  * instance of the first message key is returned.
1343  * @param varargs: message keys
1344  * @return Message
1345  * @since 1.18
1346  */
1347 function wfMessageFallback( /*...*/ ) {
1348         $args = func_get_args();
1349         return call_user_func_array( 'Message::newFallbackSequence', $args );
1350 }
1351
1352 /**
1353  * Get a message from anywhere, for the current user language.
1354  *
1355  * Use wfMsgForContent() instead if the message should NOT
1356  * change depending on the user preferences.
1357  *
1358  * @deprecated since 1.18
1359  *
1360  * @param string $key lookup key for the message, usually
1361  *    defined in languages/Language.php
1362  *
1363  * Parameters to the message, which can be used to insert variable text into
1364  * it, can be passed to this function in the following formats:
1365  * - One per argument, starting at the second parameter
1366  * - As an array in the second parameter
1367  * These are not shown in the function definition.
1368  *
1369  * @return String
1370  */
1371 function wfMsg( $key ) {
1372         wfDeprecated( __METHOD__, '1.21' );
1373
1374         $args = func_get_args();
1375         array_shift( $args );
1376         return wfMsgReal( $key, $args );
1377 }
1378
1379 /**
1380  * Same as above except doesn't transform the message
1381  *
1382  * @deprecated since 1.18
1383  *
1384  * @param $key String
1385  * @return String
1386  */
1387 function wfMsgNoTrans( $key ) {
1388         wfDeprecated( __METHOD__, '1.21' );
1389
1390         $args = func_get_args();
1391         array_shift( $args );
1392         return wfMsgReal( $key, $args, true, false, false );
1393 }
1394
1395 /**
1396  * Get a message from anywhere, for the current global language
1397  * set with $wgLanguageCode.
1398  *
1399  * Use this if the message should NOT change dependent on the
1400  * language set in the user's preferences. This is the case for
1401  * most text written into logs, as well as link targets (such as
1402  * the name of the copyright policy page). Link titles, on the
1403  * other hand, should be shown in the UI language.
1404  *
1405  * Note that MediaWiki allows users to change the user interface
1406  * language in their preferences, but a single installation
1407  * typically only contains content in one language.
1408  *
1409  * Be wary of this distinction: If you use wfMsg() where you should
1410  * use wfMsgForContent(), a user of the software may have to
1411  * customize potentially hundreds of messages in
1412  * order to, e.g., fix a link in every possible language.
1413  *
1414  * @deprecated since 1.18
1415  *
1416  * @param string $key lookup key for the message, usually
1417  *     defined in languages/Language.php
1418  * @return String
1419  */
1420 function wfMsgForContent( $key ) {
1421         wfDeprecated( __METHOD__, '1.21' );
1422
1423         global $wgForceUIMsgAsContentMsg;
1424         $args = func_get_args();
1425         array_shift( $args );
1426         $forcontent = true;
1427         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1428                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1429         {
1430                 $forcontent = false;
1431         }
1432         return wfMsgReal( $key, $args, true, $forcontent );
1433 }
1434
1435 /**
1436  * Same as above except doesn't transform the message
1437  *
1438  * @deprecated since 1.18
1439  *
1440  * @param $key String
1441  * @return String
1442  */
1443 function wfMsgForContentNoTrans( $key ) {
1444         wfDeprecated( __METHOD__, '1.21' );
1445
1446         global $wgForceUIMsgAsContentMsg;
1447         $args = func_get_args();
1448         array_shift( $args );
1449         $forcontent = true;
1450         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1451                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1452         {
1453                 $forcontent = false;
1454         }
1455         return wfMsgReal( $key, $args, true, $forcontent, false );
1456 }
1457
1458 /**
1459  * Really get a message
1460  *
1461  * @deprecated since 1.18
1462  *
1463  * @param string $key key to get.
1464  * @param $args
1465  * @param $useDB Boolean
1466  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1467  * @param $transform Boolean: Whether or not to transform the message.
1468  * @return String: the requested message.
1469  */
1470 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1471         wfDeprecated( __METHOD__, '1.21' );
1472
1473         wfProfileIn( __METHOD__ );
1474         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1475         $message = wfMsgReplaceArgs( $message, $args );
1476         wfProfileOut( __METHOD__ );
1477         return $message;
1478 }
1479
1480 /**
1481  * Fetch a message string value, but don't replace any keys yet.
1482  *
1483  * @deprecated since 1.18
1484  *
1485  * @param $key String
1486  * @param $useDB Bool
1487  * @param string $langCode Code of the language to get the message for, or
1488  *                  behaves as a content language switch if it is a boolean.
1489  * @param $transform Boolean: whether to parse magic words, etc.
1490  * @return string
1491  */
1492 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1493         wfDeprecated( __METHOD__, '1.21' );
1494
1495         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1496
1497         $cache = MessageCache::singleton();
1498         $message = $cache->get( $key, $useDB, $langCode );
1499         if ( $message === false ) {
1500                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1501         } elseif ( $transform ) {
1502                 $message = $cache->transform( $message );
1503         }
1504         return $message;
1505 }
1506
1507 /**
1508  * Replace message parameter keys on the given formatted output.
1509  *
1510  * @param $message String
1511  * @param $args Array
1512  * @return string
1513  * @private
1514  */
1515 function wfMsgReplaceArgs( $message, $args ) {
1516         # Fix windows line-endings
1517         # Some messages are split with explode("\n", $msg)
1518         $message = str_replace( "\r", '', $message );
1519
1520         // Replace arguments
1521         if ( count( $args ) ) {
1522                 if ( is_array( $args[0] ) ) {
1523                         $args = array_values( $args[0] );
1524                 }
1525                 $replacementKeys = array();
1526                 foreach ( $args as $n => $param ) {
1527                         $replacementKeys['$' . ( $n + 1 )] = $param;
1528                 }
1529                 $message = strtr( $message, $replacementKeys );
1530         }
1531
1532         return $message;
1533 }
1534
1535 /**
1536  * Return an HTML-escaped version of a message.
1537  * Parameter replacements, if any, are done *after* the HTML-escaping,
1538  * so parameters may contain HTML (eg links or form controls). Be sure
1539  * to pre-escape them if you really do want plaintext, or just wrap
1540  * the whole thing in htmlspecialchars().
1541  *
1542  * @deprecated since 1.18
1543  *
1544  * @param $key String
1545  * @param string ... parameters
1546  * @return string
1547  */
1548 function wfMsgHtml( $key ) {
1549         wfDeprecated( __METHOD__, '1.21' );
1550
1551         $args = func_get_args();
1552         array_shift( $args );
1553         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1554 }
1555
1556 /**
1557  * Return an HTML version of message
1558  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1559  * so parameters may contain HTML (eg links or form controls). Be sure
1560  * to pre-escape them if you really do want plaintext, or just wrap
1561  * the whole thing in htmlspecialchars().
1562  *
1563  * @deprecated since 1.18
1564  *
1565  * @param $key String
1566  * @param string ... parameters
1567  * @return string
1568  */
1569 function wfMsgWikiHtml( $key ) {
1570         wfDeprecated( __METHOD__, '1.21' );
1571
1572         $args = func_get_args();
1573         array_shift( $args );
1574         return wfMsgReplaceArgs(
1575                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1576                 /* can't be set to false */ true, /* interface */ true )->getText(),
1577                 $args );
1578 }
1579
1580 /**
1581  * Returns message in the requested format
1582  *
1583  * @deprecated since 1.18
1584  *
1585  * @param string $key key of the message
1586  * @param array $options processing rules. Can take the following options:
1587  *   <i>parse</i>: parses wikitext to HTML
1588  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1589  *       p's added by parser or tidy
1590  *   <i>escape</i>: filters message through htmlspecialchars
1591  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1592  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1593  *   <i>parsemag</i>: transform the message using magic phrases
1594  *   <i>content</i>: fetch message for content language instead of interface
1595  * Also can accept a single associative argument, of the form 'language' => 'xx':
1596  *   <i>language</i>: Language object or language code to fetch message for
1597  *       (overridden by <i>content</i>).
1598  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1599  *
1600  * @return String
1601  */
1602 function wfMsgExt( $key, $options ) {
1603         wfDeprecated( __METHOD__, '1.21' );
1604
1605         $args = func_get_args();
1606         array_shift( $args );
1607         array_shift( $args );
1608         $options = (array)$options;
1609
1610         foreach ( $options as $arrayKey => $option ) {
1611                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1612                         # An unknown index, neither numeric nor "language"
1613                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1614                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1615                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1616                 'replaceafter', 'parsemag', 'content' ) ) ) {
1617                         # A numeric index with unknown value
1618                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1619                 }
1620         }
1621
1622         if ( in_array( 'content', $options, true ) ) {
1623                 $forContent = true;
1624                 $langCode = true;
1625                 $langCodeObj = null;
1626         } elseif ( array_key_exists( 'language', $options ) ) {
1627                 $forContent = false;
1628                 $langCode = wfGetLangObj( $options['language'] );
1629                 $langCodeObj = $langCode;
1630         } else {
1631                 $forContent = false;
1632                 $langCode = false;
1633                 $langCodeObj = null;
1634         }
1635
1636         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1637
1638         if ( !in_array( 'replaceafter', $options, true ) ) {
1639                 $string = wfMsgReplaceArgs( $string, $args );
1640         }
1641
1642         $messageCache = MessageCache::singleton();
1643         $parseInline = in_array( 'parseinline', $options, true );
1644         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1645                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1646                 if ( $string instanceof ParserOutput ) {
1647                         $string = $string->getText();
1648                 }
1649
1650                 if ( $parseInline ) {
1651                         $m = array();
1652                         if ( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1653                                 $string = $m[1];
1654                         }
1655                 }
1656         } elseif ( in_array( 'parsemag', $options, true ) ) {
1657                 $string = $messageCache->transform( $string,
1658                                 !$forContent, $langCodeObj );
1659         }
1660
1661         if ( in_array( 'escape', $options, true ) ) {
1662                 $string = htmlspecialchars ( $string );
1663         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1664                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1665         }
1666
1667         if ( in_array( 'replaceafter', $options, true ) ) {
1668                 $string = wfMsgReplaceArgs( $string, $args );
1669         }
1670
1671         return $string;
1672 }
1673
1674 /**
1675  * Since wfMsg() and co suck, they don't return false if the message key they
1676  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1677  * nonexistence of messages by checking the MessageCache::get() result directly.
1678  *
1679  * @deprecated since 1.18. Use Message::isDisabled().
1680  *
1681  * @param $key      String: the message key looked up
1682  * @return Boolean True if the message *doesn't* exist.
1683  */
1684 function wfEmptyMsg( $key ) {
1685         wfDeprecated( __METHOD__, '1.21' );
1686
1687         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1688 }
1689
1690 /**
1691  * Throw a debugging exception. This function previously once exited the process,
1692  * but now throws an exception instead, with similar results.
1693  *
1694  * @param string $msg message shown when dying.
1695  * @throws MWException
1696  */
1697 function wfDebugDieBacktrace( $msg = '' ) {
1698         throw new MWException( $msg );
1699 }
1700
1701 /**
1702  * Fetch server name for use in error reporting etc.
1703  * Use real server name if available, so we know which machine
1704  * in a server farm generated the current page.
1705  *
1706  * @return string
1707  */
1708 function wfHostname() {
1709         static $host;
1710         if ( is_null( $host ) ) {
1711
1712                 # Hostname overriding
1713                 global $wgOverrideHostname;
1714                 if ( $wgOverrideHostname !== false ) {
1715                         # Set static and skip any detection
1716                         $host = $wgOverrideHostname;
1717                         return $host;
1718                 }
1719
1720                 if ( function_exists( 'posix_uname' ) ) {
1721                         // This function not present on Windows
1722                         $uname = posix_uname();
1723                 } else {
1724                         $uname = false;
1725                 }
1726                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1727                         $host = $uname['nodename'];
1728                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1729                         # Windows computer name
1730                         $host = getenv( 'COMPUTERNAME' );
1731                 } else {
1732                         # This may be a virtual server.
1733                         $host = $_SERVER['SERVER_NAME'];
1734                 }
1735         }
1736         return $host;
1737 }
1738
1739 /**
1740  * Returns a HTML comment with the elapsed time since request.
1741  * This method has no side effects.
1742  *
1743  * @return string
1744  */
1745 function wfReportTime() {
1746         global $wgRequestTime, $wgShowHostnames;
1747
1748         $elapsed = microtime( true ) - $wgRequestTime;
1749
1750         return $wgShowHostnames
1751                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1752                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1753 }
1754
1755 /**
1756  * Safety wrapper for debug_backtrace().
1757  *
1758  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1759  * murky circumstances, which may be triggered in part by stub objects
1760  * or other fancy talking'.
1761  *
1762  * Will return an empty array if Zend Optimizer is detected or if
1763  * debug_backtrace is disabled, otherwise the output from
1764  * debug_backtrace() (trimmed).
1765  *
1766  * @param int $limit This parameter can be used to limit the number of stack frames returned
1767  *
1768  * @return array of backtrace information
1769  */
1770 function wfDebugBacktrace( $limit = 0 ) {
1771         static $disabled = null;
1772
1773         if ( extension_loaded( 'Zend Optimizer' ) ) {
1774                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1775                 return array();
1776         }
1777
1778         if ( is_null( $disabled ) ) {
1779                 $disabled = false;
1780                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1781                 $functions = array_map( 'trim', $functions );
1782                 $functions = array_map( 'strtolower', $functions );
1783                 if ( in_array( 'debug_backtrace', $functions ) ) {
1784                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1785                         $disabled = true;
1786                 }
1787         }
1788         if ( $disabled ) {
1789                 return array();
1790         }
1791
1792         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1793                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1794         } else {
1795                 return array_slice( debug_backtrace(), 1 );
1796         }
1797 }
1798
1799 /**
1800  * Get a debug backtrace as a string
1801  *
1802  * @return string
1803  */
1804 function wfBacktrace() {
1805         global $wgCommandLineMode;
1806
1807         if ( $wgCommandLineMode ) {
1808                 $msg = '';
1809         } else {
1810                 $msg = "<ul>\n";
1811         }
1812         $backtrace = wfDebugBacktrace();
1813         foreach ( $backtrace as $call ) {
1814                 if ( isset( $call['file'] ) ) {
1815                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1816                         $file = $f[count( $f ) - 1];
1817                 } else {
1818                         $file = '-';
1819                 }
1820                 if ( isset( $call['line'] ) ) {
1821                         $line = $call['line'];
1822                 } else {
1823                         $line = '-';
1824                 }
1825                 if ( $wgCommandLineMode ) {
1826                         $msg .= "$file line $line calls ";
1827                 } else {
1828                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1829                 }
1830                 if ( !empty( $call['class'] ) ) {
1831                         $msg .= $call['class'] . $call['type'];
1832                 }
1833                 $msg .= $call['function'] . '()';
1834
1835                 if ( $wgCommandLineMode ) {
1836                         $msg .= "\n";
1837                 } else {
1838                         $msg .= "</li>\n";
1839                 }
1840         }
1841         if ( $wgCommandLineMode ) {
1842                 $msg .= "\n";
1843         } else {
1844                 $msg .= "</ul>\n";
1845         }
1846
1847         return $msg;
1848 }
1849
1850 /**
1851  * Get the name of the function which called this function
1852  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1853  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1854  * wfGetCaller( 3 ) is the parent of that.
1855  *
1856  * @param $level Int
1857  * @return string
1858  */
1859 function wfGetCaller( $level = 2 ) {
1860         $backtrace = wfDebugBacktrace( $level + 1 );
1861         if ( isset( $backtrace[$level] ) ) {
1862                 return wfFormatStackFrame( $backtrace[$level] );
1863         } else {
1864                 return 'unknown';
1865         }
1866 }
1867
1868 /**
1869  * Return a string consisting of callers in the stack. Useful sometimes
1870  * for profiling specific points.
1871  *
1872  * @param int $limit The maximum depth of the stack frame to return, or false for
1873  *               the entire stack.
1874  * @return String
1875  */
1876 function wfGetAllCallers( $limit = 3 ) {
1877         $trace = array_reverse( wfDebugBacktrace() );
1878         if ( !$limit || $limit > count( $trace ) - 1 ) {
1879                 $limit = count( $trace ) - 1;
1880         }
1881         $trace = array_slice( $trace, -$limit - 1, $limit );
1882         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1883 }
1884
1885 /**
1886  * Return a string representation of frame
1887  *
1888  * @param $frame Array
1889  * @return string
1890  */
1891 function wfFormatStackFrame( $frame ) {
1892         return isset( $frame['class'] ) ?
1893                 $frame['class'] . '::' . $frame['function'] :
1894                 $frame['function'];
1895 }
1896
1897 /* Some generic result counters, pulled out of SearchEngine */
1898
1899 /**
1900  * @todo document
1901  *
1902  * @param $offset Int
1903  * @param $limit Int
1904  * @return String
1905  */
1906 function wfShowingResults( $offset, $limit ) {
1907         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1908 }
1909
1910 /**
1911  * Generate (prev x| next x) (20|50|100...) type links for paging
1912  *
1913  * @param $offset String
1914  * @param $limit Integer
1915  * @param $link String
1916  * @param string $query optional URL query parameter string
1917  * @param bool $atend optional param for specified if this is the last page
1918  * @return String
1919  * @deprecated in 1.19; use Language::viewPrevNext() instead
1920  */
1921 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1922         wfDeprecated( __METHOD__, '1.19' );
1923
1924         global $wgLang;
1925
1926         $query = wfCgiToArray( $query );
1927
1928         if ( is_object( $link ) ) {
1929                 $title = $link;
1930         } else {
1931                 $title = Title::newFromText( $link );
1932                 if ( is_null( $title ) ) {
1933                         return false;
1934                 }
1935         }
1936
1937         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1938 }
1939
1940 /**
1941  * Make a list item, used by various special pages
1942  *
1943  * @param string $page Page link
1944  * @param string $details Text between brackets
1945  * @param $oppositedm Boolean   Add the direction mark opposite to your
1946  *                                                              language, to display text properly
1947  * @return String
1948  * @deprecated since 1.19; use Language::specialList() instead
1949  */
1950 function wfSpecialList( $page, $details, $oppositedm = true ) {
1951         wfDeprecated( __METHOD__, '1.19' );
1952
1953         global $wgLang;
1954         return $wgLang->specialList( $page, $details, $oppositedm );
1955 }
1956
1957 /**
1958  * @todo document
1959  * @todo FIXME: We may want to blacklist some broken browsers
1960  *
1961  * @param $force Bool
1962  * @return bool Whereas client accept gzip compression
1963  */
1964 function wfClientAcceptsGzip( $force = false ) {
1965         static $result = null;
1966         if ( $result === null || $force ) {
1967                 $result = false;
1968                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1969                         # @todo FIXME: We may want to blacklist some broken browsers
1970                         $m = array();
1971                         if ( preg_match(
1972                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1973                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1974                                 $m )
1975                         )
1976                         {
1977                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1978                                         $result = false;
1979                                         return $result;
1980                                 }
1981                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1982                                 $result = true;
1983                         }
1984                 }
1985         }
1986         return $result;
1987 }
1988
1989 /**
1990  * Obtain the offset and limit values from the request string;
1991  * used in special pages
1992  *
1993  * @param int $deflimit default limit if none supplied
1994  * @param string $optionname Name of a user preference to check against
1995  * @return array
1996  *
1997  */
1998 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1999         global $wgRequest;
2000         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2001 }
2002
2003 /**
2004  * Escapes the given text so that it may be output using addWikiText()
2005  * without any linking, formatting, etc. making its way through. This
2006  * is achieved by substituting certain characters with HTML entities.
2007  * As required by the callers, "<nowiki>" is not used.
2008  *
2009  * @param string $text text to be escaped
2010  * @return String
2011  */
2012 function wfEscapeWikiText( $text ) {
2013         static $repl = null, $repl2 = null;
2014         if ( $repl === null ) {
2015                 $repl = array(
2016                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2017                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2018                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2019                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2020                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2021                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2022                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2023                         '__' => '_&#95;', '://' => '&#58;//',
2024                 );
2025
2026                 // We have to catch everything "\s" matches in PCRE
2027                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2028                         $repl["$magic "] = "$magic&#32;";
2029                         $repl["$magic\t"] = "$magic&#9;";
2030                         $repl["$magic\r"] = "$magic&#13;";
2031                         $repl["$magic\n"] = "$magic&#10;";
2032                         $repl["$magic\f"] = "$magic&#12;";
2033                 }
2034
2035                 // And handle protocols that don't use "://"
2036                 global $wgUrlProtocols;
2037                 $repl2 = array();
2038                 foreach ( $wgUrlProtocols as $prot ) {
2039                         if ( substr( $prot, -1 ) === ':' ) {
2040                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2041                         }
2042                 }
2043                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2044         }
2045         $text = substr( strtr( "\n$text", $repl ), 1 );
2046         $text = preg_replace( $repl2, '$1&#58;', $text );
2047         return $text;
2048 }
2049
2050 /**
2051  * Get the current unix timestamp with microseconds.  Useful for profiling
2052  * @deprecated since 1.22; call microtime() directly
2053  * @return Float
2054  */
2055 function wfTime() {
2056         wfDeprecated( __FUNCTION__, '1.22' );
2057         return microtime( true );
2058 }
2059
2060 /**
2061  * Sets dest to source and returns the original value of dest
2062  * If source is NULL, it just returns the value, it doesn't set the variable
2063  * If force is true, it will set the value even if source is NULL
2064  *
2065  * @param $dest Mixed
2066  * @param $source Mixed
2067  * @param $force Bool
2068  * @return Mixed
2069  */
2070 function wfSetVar( &$dest, $source, $force = false ) {
2071         $temp = $dest;
2072         if ( !is_null( $source ) || $force ) {
2073                 $dest = $source;
2074         }
2075         return $temp;
2076 }
2077
2078 /**
2079  * As for wfSetVar except setting a bit
2080  *
2081  * @param $dest Int
2082  * @param $bit Int
2083  * @param $state Bool
2084  *
2085  * @return bool
2086  */
2087 function wfSetBit( &$dest, $bit, $state = true ) {
2088         $temp = (bool)( $dest & $bit );
2089         if ( !is_null( $state ) ) {
2090                 if ( $state ) {
2091                         $dest |= $bit;
2092                 } else {
2093                         $dest &= ~$bit;
2094                 }
2095         }
2096         return $temp;
2097 }
2098
2099 /**
2100  * A wrapper around the PHP function var_export().
2101  * Either print it or add it to the regular output ($wgOut).
2102  *
2103  * @param $var mixed A PHP variable to dump.
2104  */
2105 function wfVarDump( $var ) {
2106         global $wgOut;
2107         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2108         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2109                 print $s;
2110         } else {
2111                 $wgOut->addHTML( $s );
2112         }
2113 }
2114
2115 /**
2116  * Provide a simple HTTP error.
2117  *
2118  * @param $code Int|String
2119  * @param $label String
2120  * @param $desc String
2121  */
2122 function wfHttpError( $code, $label, $desc ) {
2123         global $wgOut;
2124         $wgOut->disable();
2125         header( "HTTP/1.0 $code $label" );
2126         header( "Status: $code $label" );
2127         $wgOut->sendCacheControl();
2128
2129         header( 'Content-type: text/html; charset=utf-8' );
2130         print "<!doctype html>" .
2131                 '<html><head><title>' .
2132                 htmlspecialchars( $label ) .
2133                 '</title></head><body><h1>' .
2134                 htmlspecialchars( $label ) .
2135                 '</h1><p>' .
2136                 nl2br( htmlspecialchars( $desc ) ) .
2137                 "</p></body></html>\n";
2138 }
2139
2140 /**
2141  * Clear away any user-level output buffers, discarding contents.
2142  *
2143  * Suitable for 'starting afresh', for instance when streaming
2144  * relatively large amounts of data without buffering, or wanting to
2145  * output image files without ob_gzhandler's compression.
2146  *
2147  * The optional $resetGzipEncoding parameter controls suppression of
2148  * the Content-Encoding header sent by ob_gzhandler; by default it
2149  * is left. See comments for wfClearOutputBuffers() for why it would
2150  * be used.
2151  *
2152  * Note that some PHP configuration options may add output buffer
2153  * layers which cannot be removed; these are left in place.
2154  *
2155  * @param $resetGzipEncoding Bool
2156  */
2157 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2158         if ( $resetGzipEncoding ) {
2159                 // Suppress Content-Encoding and Content-Length
2160                 // headers from 1.10+s wfOutputHandler
2161                 global $wgDisableOutputCompression;
2162                 $wgDisableOutputCompression = true;
2163         }
2164         while ( $status = ob_get_status() ) {
2165                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2166                         // Probably from zlib.output_compression or other
2167                         // PHP-internal setting which can't be removed.
2168                         //
2169                         // Give up, and hope the result doesn't break
2170                         // output behavior.
2171                         break;
2172                 }
2173                 if ( !ob_end_clean() ) {
2174                         // Could not remove output buffer handler; abort now
2175                         // to avoid getting in some kind of infinite loop.
2176                         break;
2177                 }
2178                 if ( $resetGzipEncoding ) {
2179                         if ( $status['name'] == 'ob_gzhandler' ) {
2180                                 // Reset the 'Content-Encoding' field set by this handler
2181                                 // so we can start fresh.
2182                                 header_remove( 'Content-Encoding' );
2183                                 break;
2184                         }
2185                 }
2186         }
2187 }
2188
2189 /**
2190  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2191  *
2192  * Clear away output buffers, but keep the Content-Encoding header
2193  * produced by ob_gzhandler, if any.
2194  *
2195  * This should be used for HTTP 304 responses, where you need to
2196  * preserve the Content-Encoding header of the real result, but
2197  * also need to suppress the output of ob_gzhandler to keep to spec
2198  * and avoid breaking Firefox in rare cases where the headers and
2199  * body are broken over two packets.
2200  */
2201 function wfClearOutputBuffers() {
2202         wfResetOutputBuffers( false );
2203 }
2204
2205 /**
2206  * Converts an Accept-* header into an array mapping string values to quality
2207  * factors
2208  *
2209  * @param $accept String
2210  * @param string $def default
2211  * @return Array
2212  */
2213 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2214         # No arg means accept anything (per HTTP spec)
2215         if ( !$accept ) {
2216                 return array( $def => 1.0 );
2217         }
2218
2219         $prefs = array();
2220
2221         $parts = explode( ',', $accept );
2222
2223         foreach ( $parts as $part ) {
2224                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2225                 $values = explode( ';', trim( $part ) );
2226                 $match = array();
2227                 if ( count( $values ) == 1 ) {
2228                         $prefs[$values[0]] = 1.0;
2229                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2230                         $prefs[$values[0]] = floatval( $match[1] );
2231                 }
2232         }
2233
2234         return $prefs;
2235 }
2236
2237 /**
2238  * Checks if a given MIME type matches any of the keys in the given
2239  * array. Basic wildcards are accepted in the array keys.
2240  *
2241  * Returns the matching MIME type (or wildcard) if a match, otherwise
2242  * NULL if no match.
2243  *
2244  * @param $type String
2245  * @param $avail Array
2246  * @return string
2247  * @private
2248  */
2249 function mimeTypeMatch( $type, $avail ) {
2250         if ( array_key_exists( $type, $avail ) ) {
2251                 return $type;
2252         } else {
2253                 $parts = explode( '/', $type );
2254                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2255                         return $parts[0] . '/*';
2256                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2257                         return '*/*';
2258                 } else {
2259                         return null;
2260                 }
2261         }
2262 }
2263
2264 /**
2265  * Returns the 'best' match between a client's requested internet media types
2266  * and the server's list of available types. Each list should be an associative
2267  * array of type to preference (preference is a float between 0.0 and 1.0).
2268  * Wildcards in the types are acceptable.
2269  *
2270  * @param array $cprefs client's acceptable type list
2271  * @param array $sprefs server's offered types
2272  * @return string
2273  *
2274  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2275  * XXX: generalize to negotiate other stuff
2276  */
2277 function wfNegotiateType( $cprefs, $sprefs ) {
2278         $combine = array();
2279
2280         foreach ( array_keys( $sprefs ) as $type ) {
2281                 $parts = explode( '/', $type );
2282                 if ( $parts[1] != '*' ) {
2283                         $ckey = mimeTypeMatch( $type, $cprefs );
2284                         if ( $ckey ) {
2285                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2286                         }
2287                 }
2288         }
2289
2290         foreach ( array_keys( $cprefs ) as $type ) {
2291                 $parts = explode( '/', $type );
2292                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2293                         $skey = mimeTypeMatch( $type, $sprefs );
2294                         if ( $skey ) {
2295                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2296                         }
2297                 }
2298         }
2299
2300         $bestq = 0;
2301         $besttype = null;
2302
2303         foreach ( array_keys( $combine ) as $type ) {
2304                 if ( $combine[$type] > $bestq ) {
2305                         $besttype = $type;
2306                         $bestq = $combine[$type];
2307                 }
2308         }
2309
2310         return $besttype;
2311 }
2312
2313 /**
2314  * Reference-counted warning suppression
2315  *
2316  * @param $end Bool
2317  */
2318 function wfSuppressWarnings( $end = false ) {
2319         static $suppressCount = 0;
2320         static $originalLevel = false;
2321
2322         if ( $end ) {
2323                 if ( $suppressCount ) {
2324                         --$suppressCount;
2325                         if ( !$suppressCount ) {
2326                                 error_reporting( $originalLevel );
2327                         }
2328                 }
2329         } else {
2330                 if ( !$suppressCount ) {
2331                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT ) );
2332                 }
2333                 ++$suppressCount;
2334         }
2335 }
2336
2337 /**
2338  * Restore error level to previous value
2339  */
2340 function wfRestoreWarnings() {
2341         wfSuppressWarnings( true );
2342 }
2343
2344 # Autodetect, convert and provide timestamps of various types
2345
2346 /**
2347  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2348  */
2349 define( 'TS_UNIX', 0 );
2350
2351 /**
2352  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2353  */
2354 define( 'TS_MW', 1 );
2355
2356 /**
2357  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2358  */
2359 define( 'TS_DB', 2 );
2360
2361 /**
2362  * RFC 2822 format, for E-mail and HTTP headers
2363  */
2364 define( 'TS_RFC2822', 3 );
2365
2366 /**
2367  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2368  *
2369  * This is used by Special:Export
2370  */
2371 define( 'TS_ISO_8601', 4 );
2372
2373 /**
2374  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2375  *
2376  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2377  *       DateTime tag and page 36 for the DateTimeOriginal and
2378  *       DateTimeDigitized tags.
2379  */
2380 define( 'TS_EXIF', 5 );
2381
2382 /**
2383  * Oracle format time.
2384  */
2385 define( 'TS_ORACLE', 6 );
2386
2387 /**
2388  * Postgres format time.
2389  */
2390 define( 'TS_POSTGRES', 7 );
2391
2392 /**
2393  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2394  */
2395 define( 'TS_ISO_8601_BASIC', 9 );
2396
2397 /**
2398  * Get a timestamp string in one of various formats
2399  *
2400  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2401  *                    function will autodetect which format is supplied and act
2402  *                    accordingly.
2403  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2404  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2405  */
2406 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2407         try {
2408                 $timestamp = new MWTimestamp( $ts );
2409                 return $timestamp->getTimestamp( $outputtype );
2410         } catch ( TimestampException $e ) {
2411                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2412                 return false;
2413         }
2414 }
2415
2416 /**
2417  * Return a formatted timestamp, or null if input is null.
2418  * For dealing with nullable timestamp columns in the database.
2419  *
2420  * @param $outputtype Integer
2421  * @param $ts String
2422  * @return String
2423  */
2424 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2425         if ( is_null( $ts ) ) {
2426                 return null;
2427         } else {
2428                 return wfTimestamp( $outputtype, $ts );
2429         }
2430 }
2431
2432 /**
2433  * Convenience function; returns MediaWiki timestamp for the present time.
2434  *
2435  * @return string
2436  */
2437 function wfTimestampNow() {
2438         # return NOW
2439         return wfTimestamp( TS_MW, time() );
2440 }
2441
2442 /**
2443  * Check if the operating system is Windows
2444  *
2445  * @return Bool: true if it's Windows, False otherwise.
2446  */
2447 function wfIsWindows() {
2448         static $isWindows = null;
2449         if ( $isWindows === null ) {
2450                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2451         }
2452         return $isWindows;
2453 }
2454
2455 /**
2456  * Check if we are running under HipHop
2457  *
2458  * @return Bool
2459  */
2460 function wfIsHipHop() {
2461         return function_exists( 'hphp_thread_set_warmup_enabled' );
2462 }
2463
2464 /**
2465  * Swap two variables
2466  *
2467  * @param $x Mixed
2468  * @param $y Mixed
2469  */
2470 function swap( &$x, &$y ) {
2471         $z = $x;
2472         $x = $y;
2473         $y = $z;
2474 }
2475
2476 /**
2477  * Tries to get the system directory for temporary files. First
2478  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2479  * environment variables are then checked in sequence, and if none are
2480  * set try sys_get_temp_dir().
2481  *
2482  * NOTE: When possible, use instead the tmpfile() function to create
2483  * temporary files to avoid race conditions on file creation, etc.
2484  *
2485  * @return String
2486  */
2487 function wfTempDir() {
2488         global $wgTmpDirectory;
2489
2490         if ( $wgTmpDirectory !== false ) {
2491                 return $wgTmpDirectory;
2492         }
2493
2494         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2495
2496         foreach ( $tmpDir as $tmp ) {
2497                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2498                         return $tmp;
2499                 }
2500         }
2501         return sys_get_temp_dir();
2502 }
2503
2504 /**
2505  * Make directory, and make all parent directories if they don't exist
2506  *
2507  * @param string $dir full path to directory to create
2508  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2509  * @param string $caller optional caller param for debugging.
2510  * @throws MWException
2511  * @return bool
2512  */
2513 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2514         global $wgDirectoryMode;
2515
2516         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2517                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2518         }
2519
2520         if ( !is_null( $caller ) ) {
2521                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2522         }
2523
2524         if ( strval( $dir ) === '' || file_exists( $dir ) ) {
2525                 return true;
2526         }
2527
2528         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2529
2530         if ( is_null( $mode ) ) {
2531                 $mode = $wgDirectoryMode;
2532         }
2533
2534         // Turn off the normal warning, we're doing our own below
2535         wfSuppressWarnings();
2536         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2537         wfRestoreWarnings();
2538
2539         if ( !$ok ) {
2540                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2541                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2542         }
2543         return $ok;
2544 }
2545
2546 /**
2547  * Remove a directory and all its content.
2548  * Does not hide error.
2549  */
2550 function wfRecursiveRemoveDir( $dir ) {
2551         wfDebug( __FUNCTION__ . "( $dir )\n" );
2552         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2553         if ( is_dir( $dir ) ) {
2554                 $objects = scandir( $dir );
2555                 foreach ( $objects as $object ) {
2556                         if ( $object != "." && $object != ".." ) {
2557                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2558                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2559                                 } else {
2560                                         unlink( $dir . '/' . $object );
2561                                 }
2562                         }
2563                 }
2564                 reset( $objects );
2565                 rmdir( $dir );
2566         }
2567 }
2568
2569 /**
2570  * @param $nr Mixed: the number to format
2571  * @param $acc Integer: the number of digits after the decimal point, default 2
2572  * @param $round Boolean: whether or not to round the value, default true
2573  * @return float
2574  */
2575 function wfPercent( $nr, $acc = 2, $round = true ) {
2576         $ret = sprintf( "%.${acc}f", $nr );
2577         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2578 }
2579
2580 /**
2581  * Find out whether or not a mixed variable exists in a string
2582  *
2583  * @deprecated Just use str(i)pos
2584  * @param $needle String
2585  * @param $str String
2586  * @param $insensitive Boolean
2587  * @return Boolean
2588  */
2589 function in_string( $needle, $str, $insensitive = false ) {
2590         wfDeprecated( __METHOD__, '1.21' );
2591         $func = 'strpos';
2592         if ( $insensitive ) {
2593                 $func = 'stripos';
2594         }
2595
2596         return $func( $str, $needle ) !== false;
2597 }
2598
2599 /**
2600  * Safety wrapper around ini_get() for boolean settings.
2601  * The values returned from ini_get() are pre-normalized for settings
2602  * set via php.ini or php_flag/php_admin_flag... but *not*
2603  * for those set via php_value/php_admin_value.
2604  *
2605  * It's fairly common for people to use php_value instead of php_flag,
2606  * which can leave you with an 'off' setting giving a false positive
2607  * for code that just takes the ini_get() return value as a boolean.
2608  *
2609  * To make things extra interesting, setting via php_value accepts
2610  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2611  * Unrecognized values go false... again opposite PHP's own coercion
2612  * from string to bool.
2613  *
2614  * Luckily, 'properly' set settings will always come back as '0' or '1',
2615  * so we only have to worry about them and the 'improper' settings.
2616  *
2617  * I frickin' hate PHP... :P
2618  *
2619  * @param $setting String
2620  * @return Bool
2621  */
2622 function wfIniGetBool( $setting ) {
2623         $val = strtolower( ini_get( $setting ) );
2624         // 'on' and 'true' can't have whitespace around them, but '1' can.
2625         return $val == 'on'
2626                 || $val == 'true'
2627                 || $val == 'yes'
2628                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2629 }
2630
2631 /**
2632  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2633  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2634  *
2635  * @param string $extension A PHP extension. The file suffix (.so or .dll)
2636  *                          should be omitted
2637  * @param string $fileName Name of the library, if not $extension.suffix
2638  * @return Bool - Whether or not the extension is loaded
2639  */
2640 function wfDl( $extension, $fileName = null ) {
2641         if ( extension_loaded( $extension ) ) {
2642                 return true;
2643         }
2644
2645         $canDl = false;
2646         if ( PHP_SAPI == 'cli' || PHP_SAPI == 'cgi' || PHP_SAPI == 'embed' ) {
2647                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2648                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2649         }
2650
2651         if ( $canDl ) {
2652                 $fileName = $fileName ? $fileName : $extension;
2653                 if ( wfIsWindows() ) {
2654                         $fileName = 'php_' . $fileName;
2655                 }
2656                 wfSuppressWarnings();
2657                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2658                 wfRestoreWarnings();
2659         }
2660         return extension_loaded( $extension );
2661 }
2662
2663 /**
2664  * Windows-compatible version of escapeshellarg()
2665  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2666  * function puts single quotes in regardless of OS.
2667  *
2668  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2669  * earlier distro releases of PHP)
2670  *
2671  * @param varargs
2672  * @return String
2673  */
2674 function wfEscapeShellArg() {
2675         wfInitShellLocale();
2676
2677         $args = func_get_args();
2678         $first = true;
2679         $retVal = '';
2680         foreach ( $args as $arg ) {
2681                 if ( !$first ) {
2682                         $retVal .= ' ';
2683                 } else {
2684                         $first = false;
2685                 }
2686
2687                 if ( wfIsWindows() ) {
2688                         // Escaping for an MSVC-style command line parser and CMD.EXE
2689                         // Refs:
2690                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2691                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2692                         //  * Bug #13518
2693                         //  * CR r63214
2694                         // Double the backslashes before any double quotes. Escape the double quotes.
2695                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2696                         $arg = '';
2697                         $iteration = 0;
2698                         foreach ( $tokens as $token ) {
2699                                 if ( $iteration % 2 == 1 ) {
2700                                         // Delimiter, a double quote preceded by zero or more slashes
2701                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2702                                 } elseif ( $iteration % 4 == 2 ) {
2703                                         // ^ in $token will be outside quotes, need to be escaped
2704                                         $arg .= str_replace( '^', '^^', $token );
2705                                 } else { // $iteration % 4 == 0
2706                                         // ^ in $token will appear inside double quotes, so leave as is
2707                                         $arg .= $token;
2708                                 }
2709                                 $iteration++;
2710                         }
2711                         // Double the backslashes before the end of the string, because
2712                         // we will soon add a quote
2713                         $m = array();
2714                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2715                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2716                         }
2717
2718                         // Add surrounding quotes
2719                         $retVal .= '"' . $arg . '"';
2720                 } else {
2721                         $retVal .= escapeshellarg( $arg );
2722                 }
2723         }
2724         return $retVal;
2725 }
2726
2727 /**
2728  * Check if wfShellExec() is effectively disabled via php.ini config
2729  * @return bool|string False or one of (safemode,disabled)
2730  * @since 1.22
2731  */
2732 function wfShellExecDisabled() {
2733         static $disabled = null;
2734         if ( is_null( $disabled ) ) {
2735                 $disabled = false;
2736                 if ( wfIniGetBool( 'safe_mode' ) ) {
2737                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2738                         $disabled = 'safemode';
2739                 } else {
2740                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2741                         $functions = array_map( 'trim', $functions );
2742                         $functions = array_map( 'strtolower', $functions );
2743                         if ( in_array( 'passthru', $functions ) ) {
2744                                 wfDebug( "passthru is in disabled_functions\n" );
2745                                 $disabled = 'passthru';
2746                         }
2747                 }
2748         }
2749         return $disabled;
2750 }
2751
2752 /**
2753  * Execute a shell command, with time and memory limits mirrored from the PHP
2754  * configuration if supported.
2755  * @param string $cmd Command line, properly escaped for shell.
2756  * @param &$retval null|Mixed optional, will receive the program's exit code.
2757  *                 (non-zero is usually failure)
2758  * @param array $environ optional environment variables which should be
2759  *                 added to the executed command environment.
2760  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2761  *                 this overwrites the global wgShellMax* limits.
2762  * @return string collected stdout as a string (trailing newlines stripped)
2763  */
2764 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2765         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2766                 $wgMaxShellWallClockTime, $wgShellCgroup;
2767
2768         $disabled = wfShellExecDisabled();
2769         if ( $disabled ) {
2770                 $retval = 1;
2771                 return $disabled == 'safemode' ?
2772                         'Unable to run external programs in safe mode.' :
2773                         'Unable to run external programs, passthru() is disabled.';
2774         }
2775
2776         wfInitShellLocale();
2777
2778         $envcmd = '';
2779         foreach ( $environ as $k => $v ) {
2780                 if ( wfIsWindows() ) {
2781                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2782                          * appear in the environment variable, so we must use carat escaping as documented in
2783                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2784                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2785                          * are listed there but doesn't appear to need it.
2786                          */
2787                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2788                 } else {
2789                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2790                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2791                          */
2792                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2793                 }
2794         }
2795         $cmd = $envcmd . $cmd;
2796
2797         if ( php_uname( 's' ) == 'Linux' ) {
2798                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2799                 if ( isset( $limits['walltime'] ) ) {
2800                         $wallTime = intval( $limits['walltime'] );
2801                 } elseif ( isset( $limits['time'] ) ) {
2802                         $wallTime = $time;
2803                 } else {
2804                         $wallTime = intval( $wgMaxShellWallClockTime );
2805                 }
2806                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2807                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2808
2809                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2810                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2811                                 escapeshellarg( $cmd ) . ' ' .
2812                                 escapeshellarg(
2813                                         "MW_CPU_LIMIT=$time; " .
2814                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2815                                         "MW_MEM_LIMIT=$mem; " .
2816                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2817                                         "MW_WALL_CLOCK_LIMIT=$wallTime"
2818                                 );
2819                 }
2820         }
2821         wfDebug( "wfShellExec: $cmd\n" );
2822
2823         $retval = 1; // error by default?
2824         ob_start();
2825         passthru( $cmd, $retval );
2826         $output = ob_get_contents();
2827         ob_end_clean();
2828
2829         if ( $retval == 127 ) {
2830                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2831         }
2832         return $output;
2833 }
2834
2835 /**
2836  * Workaround for http://bugs.php.net/bug.php?id=45132
2837  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2838  */
2839 function wfInitShellLocale() {
2840         static $done = false;
2841         if ( $done ) {
2842                 return;
2843         }
2844         $done = true;
2845         global $wgShellLocale;
2846         if ( !wfIniGetBool( 'safe_mode' ) ) {
2847                 putenv( "LC_CTYPE=$wgShellLocale" );
2848                 setlocale( LC_CTYPE, $wgShellLocale );
2849         }
2850 }
2851
2852 /**
2853  * Alias to wfShellWikiCmd()
2854  * @see wfShellWikiCmd()
2855  */
2856 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2857         return wfShellWikiCmd( $script, $parameters, $options );
2858 }
2859
2860 /**
2861  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2862  * Note that $parameters should be a flat array and an option with an argument
2863  * should consist of two consecutive items in the array (do not use "--option value").
2864  * @param string $script MediaWiki cli script path
2865  * @param array $parameters Arguments and options to the script
2866  * @param array $options Associative array of options:
2867  *              'php': The path to the php executable
2868  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2869  * @return Array
2870  */
2871 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2872         global $wgPhpCli;
2873         // Give site config file a chance to run the script in a wrapper.
2874         // The caller may likely want to call wfBasename() on $script.
2875         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2876         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2877         if ( isset( $options['wrapper'] ) ) {
2878                 $cmd[] = $options['wrapper'];
2879         }
2880         $cmd[] = $script;
2881         // Escape each parameter for shell
2882         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2883 }
2884
2885 /**
2886  * wfMerge attempts to merge differences between three texts.
2887  * Returns true for a clean merge and false for failure or a conflict.
2888  *
2889  * @param $old String
2890  * @param $mine String
2891  * @param $yours String
2892  * @param $result String
2893  * @return Bool
2894  */
2895 function wfMerge( $old, $mine, $yours, &$result ) {
2896         global $wgDiff3;
2897
2898         # This check may also protect against code injection in
2899         # case of broken installations.
2900         wfSuppressWarnings();
2901         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2902         wfRestoreWarnings();
2903
2904         if ( !$haveDiff3 ) {
2905                 wfDebug( "diff3 not found\n" );
2906                 return false;
2907         }
2908
2909         # Make temporary files
2910         $td = wfTempDir();
2911         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2912         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2913         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2914
2915         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2916         #       a newline character. To avoid this, we normalize the trailing whitespace before
2917         #       creating the diff.
2918
2919         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2920         fclose( $oldtextFile );
2921         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2922         fclose( $mytextFile );
2923         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2924         fclose( $yourtextFile );
2925
2926         # Check for a conflict
2927         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
2928                 wfEscapeShellArg( $mytextName ) . ' ' .
2929                 wfEscapeShellArg( $oldtextName ) . ' ' .
2930                 wfEscapeShellArg( $yourtextName );
2931         $handle = popen( $cmd, 'r' );
2932
2933         if ( fgets( $handle, 1024 ) ) {
2934                 $conflict = true;
2935         } else {
2936                 $conflict = false;
2937         }
2938         pclose( $handle );
2939
2940         # Merge differences
2941         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
2942                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2943         $handle = popen( $cmd, 'r' );
2944         $result = '';
2945         do {
2946                 $data = fread( $handle, 8192 );
2947                 if ( strlen( $data ) == 0 ) {
2948                         break;
2949                 }
2950                 $result .= $data;
2951         } while ( true );
2952         pclose( $handle );
2953         unlink( $mytextName );
2954         unlink( $oldtextName );
2955         unlink( $yourtextName );
2956
2957         if ( $result === '' && $old !== '' && !$conflict ) {
2958                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2959                 $conflict = true;
2960         }
2961         return !$conflict;
2962 }
2963
2964 /**
2965  * Returns unified plain-text diff of two texts.
2966  * Useful for machine processing of diffs.
2967  *
2968  * @param string $before the text before the changes.
2969  * @param string $after the text after the changes.
2970  * @param string $params command-line options for the diff command.
2971  * @return String: unified diff of $before and $after
2972  */
2973 function wfDiff( $before, $after, $params = '-u' ) {
2974         if ( $before == $after ) {
2975                 return '';
2976         }
2977
2978         global $wgDiff;
2979         wfSuppressWarnings();
2980         $haveDiff = $wgDiff && file_exists( $wgDiff );
2981         wfRestoreWarnings();
2982
2983         # This check may also protect against code injection in
2984         # case of broken installations.
2985         if ( !$haveDiff ) {
2986                 wfDebug( "diff executable not found\n" );
2987                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2988                 $format = new UnifiedDiffFormatter();
2989                 return $format->format( $diffs );
2990         }
2991
2992         # Make temporary files
2993         $td = wfTempDir();
2994         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2995         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2996
2997         fwrite( $oldtextFile, $before );
2998         fclose( $oldtextFile );
2999         fwrite( $newtextFile, $after );
3000         fclose( $newtextFile );
3001
3002         // Get the diff of the two files
3003         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3004
3005         $h = popen( $cmd, 'r' );
3006
3007         $diff = '';
3008
3009         do {
3010                 $data = fread( $h, 8192 );
3011                 if ( strlen( $data ) == 0 ) {
3012                         break;
3013                 }
3014                 $diff .= $data;
3015         } while ( true );
3016
3017         // Clean up
3018         pclose( $h );
3019         unlink( $oldtextName );
3020         unlink( $newtextName );
3021
3022         // Kill the --- and +++ lines. They're not useful.
3023         $diff_lines = explode( "\n", $diff );
3024         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3025                 unset( $diff_lines[0] );
3026         }
3027         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3028                 unset( $diff_lines[1] );
3029         }
3030
3031         $diff = implode( "\n", $diff_lines );
3032
3033         return $diff;
3034 }
3035
3036 /**
3037  * This function works like "use VERSION" in Perl, the program will die with a
3038  * backtrace if the current version of PHP is less than the version provided
3039  *
3040  * This is useful for extensions which due to their nature are not kept in sync
3041  * with releases, and might depend on other versions of PHP than the main code
3042  *
3043  * Note: PHP might die due to parsing errors in some cases before it ever
3044  *       manages to call this function, such is life
3045  *
3046  * @see perldoc -f use
3047  *
3048  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3049  *                 a float
3050  * @throws MWException
3051  */
3052 function wfUsePHP( $req_ver ) {
3053         $php_ver = PHP_VERSION;
3054
3055         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3056                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3057         }
3058 }
3059
3060 /**
3061  * This function works like "use VERSION" in Perl except it checks the version
3062  * of MediaWiki, the program will die with a backtrace if the current version
3063  * of MediaWiki is less than the version provided.
3064  *
3065  * This is useful for extensions which due to their nature are not kept in sync
3066  * with releases
3067  *
3068  * @see perldoc -f use
3069  *
3070  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3071  *                 a float
3072  * @throws MWException
3073  */
3074 function wfUseMW( $req_ver ) {
3075         global $wgVersion;
3076
3077         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3078                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3079         }
3080 }
3081
3082 /**
3083  * Return the final portion of a pathname.
3084  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3085  * http://bugs.php.net/bug.php?id=33898
3086  *
3087  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3088  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3089  *
3090  * @param $path String
3091  * @param string $suffix to remove if present
3092  * @return String
3093  */
3094 function wfBaseName( $path, $suffix = '' ) {
3095         $encSuffix = ( $suffix == '' )
3096                 ? ''
3097                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3098         $matches = array();
3099         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3100                 return $matches[1];
3101         } else {
3102                 return '';
3103         }
3104 }
3105
3106 /**
3107  * Generate a relative path name to the given file.
3108  * May explode on non-matching case-insensitive paths,
3109  * funky symlinks, etc.
3110  *
3111  * @param string $path absolute destination path including target filename
3112  * @param string $from Absolute source path, directory only
3113  * @return String
3114  */
3115 function wfRelativePath( $path, $from ) {
3116         // Normalize mixed input on Windows...
3117         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3118         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3119
3120         // Trim trailing slashes -- fix for drive root
3121         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3122         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3123
3124         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3125         $against = explode( DIRECTORY_SEPARATOR, $from );
3126
3127         if ( $pieces[0] !== $against[0] ) {
3128                 // Non-matching Windows drive letters?
3129                 // Return a full path.
3130                 return $path;
3131         }
3132
3133         // Trim off common prefix
3134         while ( count( $pieces ) && count( $against )
3135                 && $pieces[0] == $against[0] ) {
3136                 array_shift( $pieces );
3137                 array_shift( $against );
3138         }
3139
3140         // relative dots to bump us to the parent
3141         while ( count( $against ) ) {
3142                 array_unshift( $pieces, '..' );
3143                 array_shift( $against );
3144         }
3145
3146         array_push( $pieces, wfBaseName( $path ) );
3147
3148         return implode( DIRECTORY_SEPARATOR, $pieces );
3149 }
3150
3151 /**
3152  * Do any deferred updates and clear the list
3153  *
3154  * @deprecated since 1.19
3155  * @see DeferredUpdates::doUpdate()
3156  * @param $commit string
3157  */
3158 function wfDoUpdates( $commit = '' ) {
3159         wfDeprecated( __METHOD__, '1.19' );
3160         DeferredUpdates::doUpdates( $commit );
3161 }
3162
3163 /**
3164  * Convert an arbitrarily-long digit string from one numeric base
3165  * to another, optionally zero-padding to a minimum column width.
3166  *
3167  * Supports base 2 through 36; digit values 10-36 are represented
3168  * as lowercase letters a-z. Input is case-insensitive.
3169  *
3170  * @param string $input Input number
3171  * @param int $sourceBase Base of the input number
3172  * @param int $destBase Desired base of the output
3173  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3174  * @param bool $lowercase Whether to output in lowercase or uppercase
3175  * @param string $engine Either "gmp", "bcmath", or "php"
3176  * @return string|bool The output number as a string, or false on error
3177  */
3178 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true, $engine = 'auto' ) {
3179         $input = (string)$input;
3180         if (
3181                 $sourceBase < 2 ||
3182                 $sourceBase > 36 ||
3183                 $destBase < 2 ||
3184                 $destBase > 36 ||
3185                 $sourceBase != (int)$sourceBase ||
3186                 $destBase != (int)$destBase ||
3187                 $pad != (int)$pad ||
3188                 !preg_match( "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i", $input )
3189         ) {
3190                 return false;
3191         }
3192
3193         static $baseChars = array(
3194                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3195                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3196                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3197                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3198                 34 => 'y', 35 => 'z',
3199
3200                 '0' => 0,  '1' => 1,  '2' => 2,  '3' => 3,  '4' => 4,  '5' => 5,
3201                 '6' => 6,  '7' => 7,  '8' => 8,  '9' => 9,  'a' => 10, 'b' => 11,
3202                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3203                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3204                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3205                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3206         );
3207
3208         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3209                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3210         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3211                 $decimal = '0';
3212                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3213                         $decimal = bcmul( $decimal, $sourceBase );
3214                         $decimal = bcadd( $decimal, $baseChars[$char] );
3215                 }
3216
3217                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3218                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3219                 }
3220
3221                 $result = strrev( $result );
3222         } else {
3223                 $inDigits = array();
3224                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3225                         $inDigits[] = $baseChars[$char];
3226                 }
3227
3228                 // Iterate over the input, modulo-ing out an output digit
3229                 // at a time until input is gone.
3230                 $result = '';
3231                 while ( $inDigits ) {
3232                         $work = 0;
3233                         $workDigits = array();
3234
3235                         // Long division...
3236                         foreach ( $inDigits as $digit ) {
3237                                 $work *= $sourceBase;
3238                                 $work += $digit;
3239
3240                                 if ( $workDigits || $work >= $destBase ) {
3241                                         $workDigits[] = (int)( $work / $destBase );
3242                                 }
3243                                 $work %= $destBase;
3244                         }
3245
3246                         // All that division leaves us with a remainder,
3247                         // which is conveniently our next output digit.
3248                         $result .= $baseChars[$work];
3249
3250                         // And we continue!
3251                         $inDigits = $workDigits;
3252                 }
3253
3254                 $result = strrev( $result );
3255         }
3256
3257         if ( !$lowercase ) {
3258                 $result = strtoupper( $result );
3259         }
3260
3261         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3262 }
3263
3264 /**
3265  * Create an object with a given name and an array of construct parameters
3266  *
3267  * @param $name String
3268  * @param array $p parameters
3269  * @return object
3270  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3271  */
3272 function wfCreateObject( $name, $p ) {
3273         wfDeprecated( __FUNCTION__, '1.18' );
3274         return MWFunction::newObj( $name, $p );
3275 }
3276
3277 /**
3278  * @return bool
3279  */
3280 function wfHttpOnlySafe() {
3281         global $wgHttpOnlyBlacklist;
3282
3283         if ( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3284                 foreach ( $wgHttpOnlyBlacklist as $regex ) {
3285                         if ( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3286                                 return false;
3287                         }
3288                 }
3289         }
3290
3291         return true;
3292 }
3293
3294 /**
3295  * Check if there is sufficient entropy in php's built-in session generation
3296  * @return bool true = there is sufficient entropy
3297  */
3298 function wfCheckEntropy() {
3299         return (
3300                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3301                         || ini_get( 'session.entropy_file' )
3302                 )
3303                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3304 }
3305
3306 /**
3307  * Override session_id before session startup if php's built-in
3308  * session generation code is not secure.
3309  */
3310 function wfFixSessionID() {
3311         // If the cookie or session id is already set we already have a session and should abort
3312         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3313                 return;
3314         }
3315
3316         // PHP's built-in session entropy is enabled if:
3317         // - entropy_file is set or you're on Windows with php 5.3.3+
3318         // - AND entropy_length is > 0
3319         // We treat it as disabled if it doesn't have an entropy length of at least 32
3320         $entropyEnabled = wfCheckEntropy();
3321
3322         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3323         if ( !$entropyEnabled ) {
3324                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3325                 session_id( MWCryptRand::generateHex( 32 ) );
3326         }
3327 }
3328
3329 /**
3330  * Reset the session_id
3331  * @since 1.22
3332  */
3333 function wfResetSessionID() {
3334         global $wgCookieSecure;
3335         $oldSessionId = session_id();
3336         $cookieParams = session_get_cookie_params();
3337         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3338                 session_regenerate_id( false );
3339         } else {
3340                 $tmp = $_SESSION;
3341                 session_destroy();
3342                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3343                 $_SESSION = $tmp;
3344         }
3345         $newSessionId = session_id();
3346         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3347 }
3348
3349
3350 /**
3351  * Initialise php session
3352  *
3353  * @param $sessionId Bool
3354  */
3355 function wfSetupSession( $sessionId = false ) {
3356         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3357                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3358         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3359                 ObjectCacheSessionHandler::install();
3360         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3361                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3362                 # hasn't already been set to the desired value (that causes errors)
3363                 ini_set( 'session.save_handler', $wgSessionHandler );
3364         }
3365         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3366         wfDebugLog( 'cookie',
3367                 'session_set_cookie_params: "' . implode( '", "',
3368                         array(
3369                                 0,
3370                                 $wgCookiePath,
3371                                 $wgCookieDomain,
3372                                 $wgCookieSecure,
3373                                 $httpOnlySafe ) ) . '"' );
3374         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3375         session_cache_limiter( 'private, must-revalidate' );
3376         if ( $sessionId ) {
3377                 session_id( $sessionId );
3378         } else {
3379                 wfFixSessionID();
3380         }
3381         wfSuppressWarnings();
3382         session_start();
3383         wfRestoreWarnings();
3384 }
3385
3386 /**
3387  * Get an object from the precompiled serialized directory
3388  *
3389  * @param $name String
3390  * @return Mixed: the variable on success, false on failure
3391  */
3392 function wfGetPrecompiledData( $name ) {
3393         global $IP;
3394
3395         $file = "$IP/serialized/$name";
3396         if ( file_exists( $file ) ) {
3397                 $blob = file_get_contents( $file );
3398                 if ( $blob ) {
3399                         return unserialize( $blob );
3400                 }
3401         }
3402         return false;
3403 }
3404
3405 /**
3406  * Get a cache key
3407  *
3408  * @param varargs
3409  * @return String
3410  */
3411 function wfMemcKey( /*... */ ) {
3412         global $wgCachePrefix;
3413         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3414         $args = func_get_args();
3415         $key = $prefix . ':' . implode( ':', $args );
3416         $key = str_replace( ' ', '_', $key );
3417         return $key;
3418 }
3419
3420 /**
3421  * Get a cache key for a foreign DB
3422  *
3423  * @param $db String
3424  * @param $prefix String
3425  * @param varargs String
3426  * @return String
3427  */
3428 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3429         $args = array_slice( func_get_args(), 2 );
3430         if ( $prefix ) {
3431                 $key = "$db-$prefix:" . implode( ':', $args );
3432         } else {
3433                 $key = $db . ':' . implode( ':', $args );
3434         }
3435         return str_replace( ' ', '_', $key );
3436 }
3437
3438 /**
3439  * Get an ASCII string identifying this wiki
3440  * This is used as a prefix in memcached keys
3441  *
3442  * @return String
3443  */
3444 function wfWikiID() {
3445         global $wgDBprefix, $wgDBname;
3446         if ( $wgDBprefix ) {
3447                 return "$wgDBname-$wgDBprefix";
3448         } else {
3449                 return $wgDBname;
3450         }
3451 }
3452
3453 /**
3454  * Split a wiki ID into DB name and table prefix
3455  *
3456  * @param $wiki String
3457  *
3458  * @return array
3459  */
3460 function wfSplitWikiID( $wiki ) {
3461         $bits = explode( '-', $wiki, 2 );
3462         if ( count( $bits ) < 2 ) {
3463                 $bits[] = '';
3464         }
3465         return $bits;
3466 }
3467
3468 /**
3469  * Get a Database object.
3470  *
3471  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3472  *            master (for write queries), DB_SLAVE for potentially lagged read
3473  *            queries, or an integer >= 0 for a particular server.
3474  *
3475  * @param $groups Mixed: query groups. An array of group names that this query
3476  *                belongs to. May contain a single string if the query is only
3477  *                in one group.
3478  *
3479  * @param string $wiki the wiki ID, or false for the current wiki
3480  *
3481  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3482  * will always return the same object, unless the underlying connection or load
3483  * balancer is manually destroyed.
3484  *
3485  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3486  * updater to ensure that a proper database is being updated.
3487  *
3488  * @return DatabaseBase
3489  */
3490 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3491         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3492 }
3493
3494 /**
3495  * Get a load balancer object.
3496  *
3497  * @param string $wiki wiki ID, or false for the current wiki
3498  * @return LoadBalancer
3499  */
3500 function wfGetLB( $wiki = false ) {
3501         return wfGetLBFactory()->getMainLB( $wiki );
3502 }
3503
3504 /**
3505  * Get the load balancer factory object
3506  *
3507  * @return LBFactory
3508  */
3509 function &wfGetLBFactory() {
3510         return LBFactory::singleton();
3511 }
3512
3513 /**
3514  * Find a file.
3515  * Shortcut for RepoGroup::singleton()->findFile()
3516  *
3517  * @param string $title or Title object
3518  * @param array $options Associative array of options:
3519  *     time:           requested time for an archived image, or false for the
3520  *                     current version. An image object will be returned which was
3521  *                     created at the specified time.
3522  *
3523  *     ignoreRedirect: If true, do not follow file redirects
3524  *
3525  *     private:        If true, return restricted (deleted) files if the current
3526  *                     user is allowed to view them. Otherwise, such files will not
3527  *                     be found.
3528  *
3529  *     bypassCache:    If true, do not use the process-local cache of File objects
3530  *
3531  * @return File, or false if the file does not exist
3532  */
3533 function wfFindFile( $title, $options = array() ) {
3534         return RepoGroup::singleton()->findFile( $title, $options );
3535 }
3536
3537 /**
3538  * Get an object referring to a locally registered file.
3539  * Returns a valid placeholder object if the file does not exist.
3540  *
3541  * @param $title Title|String
3542  * @return LocalFile|null A File, or null if passed an invalid Title
3543  */
3544 function wfLocalFile( $title ) {
3545         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3546 }
3547
3548 /**
3549  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3550  * @deprecated since 1.19
3551  */
3552 function wfStreamFile( $fname, $headers = array() ) {
3553         wfDeprecated( __FUNCTION__, '1.19' );
3554         StreamFile::stream( $fname, $headers );
3555 }
3556
3557 /**
3558  * Should low-performance queries be disabled?
3559  *
3560  * @return Boolean
3561  * @codeCoverageIgnore
3562  */
3563 function wfQueriesMustScale() {
3564         global $wgMiserMode;
3565         return $wgMiserMode
3566                 || ( SiteStats::pages() > 100000
3567                 && SiteStats::edits() > 1000000
3568                 && SiteStats::users() > 10000 );
3569 }
3570
3571 /**
3572  * Get the path to a specified script file, respecting file
3573  * extensions; this is a wrapper around $wgScriptExtension etc.
3574  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3575  *
3576  * @param string $script script filename, sans extension
3577  * @return String
3578  */
3579 function wfScript( $script = 'index' ) {
3580         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3581         if ( $script === 'index' ) {
3582                 return $wgScript;
3583         } elseif ( $script === 'load' ) {
3584                 return $wgLoadScript;
3585         } else {
3586                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3587         }
3588 }
3589
3590 /**
3591  * Get the script URL.
3592  *
3593  * @return string script URL
3594  */
3595 function wfGetScriptUrl() {
3596         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3597                 #
3598                 # as it was called, minus the query string.
3599                 #
3600                 # Some sites use Apache rewrite rules to handle subdomains,
3601                 # and have PHP set up in a weird way that causes PHP_SELF
3602                 # to contain the rewritten URL instead of the one that the
3603                 # outside world sees.
3604                 #
3605                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3606                 # provides containing the "before" URL.
3607                 return $_SERVER['SCRIPT_NAME'];
3608         } else {
3609                 return $_SERVER['URL'];
3610         }
3611 }
3612
3613 /**
3614  * Convenience function converts boolean values into "true"
3615  * or "false" (string) values
3616  *
3617  * @param $value Boolean
3618  * @return String
3619  */
3620 function wfBoolToStr( $value ) {
3621         return $value ? 'true' : 'false';
3622 }
3623
3624 /**
3625  * Get a platform-independent path to the null file, e.g. /dev/null
3626  *
3627  * @return string
3628  */
3629 function wfGetNull() {
3630         return wfIsWindows()
3631                 ? 'NUL'
3632                 : '/dev/null';
3633 }
3634
3635 /**
3636  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3637  * and waiting for it to go down, this waits for the slaves to catch up to the
3638  * master position. Use this when updating very large numbers of rows, as
3639  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3640  * a no-op if there are no slaves.
3641  *
3642  * @param $maxLag Integer (deprecated)
3643  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3644  * @param $cluster string cluster name accepted by LBFactory
3645  */
3646 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3647         $lb = ( $cluster !== false )
3648                 ? wfGetLBFactory()->getExternalLB( $cluster )
3649                 : wfGetLB( $wiki );
3650         // bug 27975 - Don't try to wait for slaves if there are none
3651         // Prevents permission error when getting master position
3652         if ( $lb->getServerCount() > 1 ) {
3653                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3654                 $pos = $dbw->getMasterPos();
3655                 // The DBMS may not support getMasterPos() or the whole
3656                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3657                 if ( $pos !== false ) {
3658                         $lb->waitForAll( $pos );
3659                 }
3660         }
3661 }
3662
3663 /**
3664  * Used to be used for outputting text in the installer/updater
3665  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3666  */
3667 function wfOut( $s ) {
3668         wfDeprecated( __FUNCTION__, '1.18' );
3669         global $wgCommandLineMode;
3670         if ( $wgCommandLineMode ) {
3671                 echo $s;
3672         } else {
3673                 echo htmlspecialchars( $s );
3674         }
3675         flush();
3676 }
3677
3678 /**
3679  * Count down from $n to zero on the terminal, with a one-second pause
3680  * between showing each number. For use in command-line scripts.
3681  * @codeCoverageIgnore
3682  * @param $n int
3683  */
3684 function wfCountDown( $n ) {
3685         for ( $i = $n; $i >= 0; $i-- ) {
3686                 if ( $i != $n ) {
3687                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3688                 }
3689                 echo $i;
3690                 flush();
3691                 if ( $i ) {
3692                         sleep( 1 );
3693                 }
3694         }
3695         echo "\n";
3696 }
3697
3698 /**
3699  * Generate a random 32-character hexadecimal token.
3700  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3701  *              characters before hashing.
3702  * @return string
3703  * @codeCoverageIgnore
3704  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pseudo-random strings
3705  * @warning This method is NOT secure. Additionally it has many callers that use it for pseudo-random purposes.
3706  */
3707 function wfGenerateToken( $salt = '' ) {
3708         wfDeprecated( __METHOD__, '1.20' );
3709         $salt = serialize( $salt );
3710         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3711 }
3712
3713 /**
3714  * Replace all invalid characters with -
3715  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3716  * By default, $wgIllegalFileChars = ':'
3717  *
3718  * @param $name Mixed: filename to process
3719  * @return String
3720  */
3721 function wfStripIllegalFilenameChars( $name ) {
3722         global $wgIllegalFileChars;
3723         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3724         $name = wfBaseName( $name );
3725         $name = preg_replace(
3726                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3727                 '-',
3728                 $name
3729         );
3730         return $name;
3731 }
3732
3733 /**
3734  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3735  *
3736  * @return Integer value memory was set to.
3737  */
3738 function wfMemoryLimit() {
3739         global $wgMemoryLimit;
3740         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3741         if ( $memlimit != -1 ) {
3742                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3743                 if ( $conflimit == -1 ) {
3744                         wfDebug( "Removing PHP's memory limit\n" );
3745                         wfSuppressWarnings();
3746                         ini_set( 'memory_limit', $conflimit );
3747                         wfRestoreWarnings();
3748                         return $conflimit;
3749                 } elseif ( $conflimit > $memlimit ) {
3750                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3751                         wfSuppressWarnings();
3752                         ini_set( 'memory_limit', $conflimit );
3753                         wfRestoreWarnings();
3754                         return $conflimit;
3755                 }
3756         }
3757         return $memlimit;
3758 }
3759
3760 /**
3761  * Converts shorthand byte notation to integer form
3762  *
3763  * @param $string String
3764  * @return Integer
3765  */
3766 function wfShorthandToInteger( $string = '' ) {
3767         $string = trim( $string );
3768         if ( $string === '' ) {
3769                 return -1;
3770         }
3771         $last = $string[strlen( $string ) - 1];
3772         $val = intval( $string );
3773         switch ( $last ) {
3774                 case 'g':
3775                 case 'G':
3776                         $val *= 1024;
3777                         // break intentionally missing
3778                 case 'm':
3779                 case 'M':
3780                         $val *= 1024;
3781                         // break intentionally missing
3782                 case 'k':
3783                 case 'K':
3784                         $val *= 1024;
3785         }
3786
3787         return $val;
3788 }
3789
3790 /**
3791  * Get the normalised IETF language tag
3792  * See unit test for examples.
3793  *
3794  * @param string $code The language code.
3795  * @return String: The language code which complying with BCP 47 standards.
3796  */
3797 function wfBCP47( $code ) {
3798         $codeSegment = explode( '-', $code );
3799         $codeBCP = array();
3800         foreach ( $codeSegment as $segNo => $seg ) {
3801                 // when previous segment is x, it is a private segment and should be lc
3802                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3803                         $codeBCP[$segNo] = strtolower( $seg );
3804                 // ISO 3166 country code
3805                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3806                         $codeBCP[$segNo] = strtoupper( $seg );
3807                 // ISO 15924 script code
3808                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3809                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3810                 // Use lowercase for other cases
3811                 } else {
3812                         $codeBCP[$segNo] = strtolower( $seg );
3813                 }
3814         }
3815         $langCode = implode( '-', $codeBCP );
3816         return $langCode;
3817 }
3818
3819 /**
3820  * Get a cache object.
3821  *
3822  * @param $inputType integer Cache type, one the the CACHE_* constants.
3823  * @return BagOStuff
3824  */
3825 function wfGetCache( $inputType ) {
3826         return ObjectCache::getInstance( $inputType );
3827 }
3828
3829 /**
3830  * Get the main cache object
3831  *
3832  * @return BagOStuff
3833  */
3834 function wfGetMainCache() {
3835         global $wgMainCacheType;
3836         return ObjectCache::getInstance( $wgMainCacheType );
3837 }
3838
3839 /**
3840  * Get the cache object used by the message cache
3841  *
3842  * @return BagOStuff
3843  */
3844 function wfGetMessageCacheStorage() {
3845         global $wgMessageCacheType;
3846         return ObjectCache::getInstance( $wgMessageCacheType );
3847 }
3848
3849 /**
3850  * Get the cache object used by the parser cache
3851  *
3852  * @return BagOStuff
3853  */
3854 function wfGetParserCacheStorage() {
3855         global $wgParserCacheType;
3856         return ObjectCache::getInstance( $wgParserCacheType );
3857 }
3858
3859 /**
3860  * Get the cache object used by the language converter
3861  *
3862  * @return BagOStuff
3863  */
3864 function wfGetLangConverterCacheStorage() {
3865         global $wgLanguageConverterCacheType;
3866         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3867 }
3868
3869 /**
3870  * Call hook functions defined in $wgHooks
3871  *
3872  * @param string $event event name
3873  * @param array $args parameters passed to hook functions
3874  * @return Boolean True if no handler aborted the hook
3875  */
3876 function wfRunHooks( $event, array $args = array() ) {
3877         return Hooks::run( $event, $args );
3878 }
3879
3880 /**
3881  * Wrapper around php's unpack.
3882  *
3883  * @param string $format The format string (See php's docs)
3884  * @param $data: A binary string of binary data
3885  * @param $length integer or false: The minimum length of $data. This is to
3886  *      prevent reading beyond the end of $data. false to disable the check.
3887  *
3888  * Also be careful when using this function to read unsigned 32 bit integer
3889  * because php might make it negative.
3890  *
3891  * @throws MWException if $data not long enough, or if unpack fails
3892  * @return array Associative array of the extracted data
3893  */
3894 function wfUnpack( $format, $data, $length = false ) {
3895         if ( $length !== false ) {
3896                 $realLen = strlen( $data );
3897                 if ( $realLen < $length ) {
3898                         throw new MWException( "Tried to use wfUnpack on a "
3899                                 . "string of length $realLen, but needed one "
3900                                 . "of at least length $length."
3901                         );
3902                 }
3903         }
3904
3905         wfSuppressWarnings();
3906         $result = unpack( $format, $data );
3907         wfRestoreWarnings();
3908
3909         if ( $result === false ) {
3910                 // If it cannot extract the packed data.
3911                 throw new MWException( "unpack could not unpack binary data" );
3912         }
3913         return $result;
3914 }
3915
3916 /**
3917  * Determine if an image exists on the 'bad image list'.
3918  *
3919  * The format of MediaWiki:Bad_image_list is as follows:
3920  *    * Only list items (lines starting with "*") are considered
3921  *    * The first link on a line must be a link to a bad image
3922  *    * Any subsequent links on the same line are considered to be exceptions,
3923  *      i.e. articles where the image may occur inline.
3924  *
3925  * @param string $name the image name to check
3926  * @param $contextTitle Title|bool the page on which the image occurs, if known
3927  * @param string $blacklist wikitext of a file blacklist
3928  * @return bool
3929  */
3930 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3931         static $badImageCache = null; // based on bad_image_list msg
3932         wfProfileIn( __METHOD__ );
3933
3934         # Handle redirects
3935         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3936         if ( $redirectTitle ) {
3937                 $name = $redirectTitle->getDBkey();
3938         }
3939
3940         # Run the extension hook
3941         $bad = false;
3942         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3943                 wfProfileOut( __METHOD__ );
3944                 return $bad;
3945         }
3946
3947         $cacheable = ( $blacklist === null );
3948         if ( $cacheable && $badImageCache !== null ) {
3949                 $badImages = $badImageCache;
3950         } else { // cache miss
3951                 if ( $blacklist === null ) {
3952                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3953                 }
3954                 # Build the list now
3955                 $badImages = array();
3956                 $lines = explode( "\n", $blacklist );
3957                 foreach ( $lines as $line ) {
3958                         # List items only
3959                         if ( substr( $line, 0, 1 ) !== '*' ) {
3960                                 continue;
3961                         }
3962
3963                         # Find all links
3964                         $m = array();
3965                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3966                                 continue;
3967                         }
3968
3969                         $exceptions = array();
3970                         $imageDBkey = false;
3971                         foreach ( $m[1] as $i => $titleText ) {
3972                                 $title = Title::newFromText( $titleText );
3973                                 if ( !is_null( $title ) ) {
3974                                         if ( $i == 0 ) {
3975                                                 $imageDBkey = $title->getDBkey();
3976                                         } else {
3977                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3978                                         }
3979                                 }
3980                         }
3981
3982                         if ( $imageDBkey !== false ) {
3983                                 $badImages[$imageDBkey] = $exceptions;
3984                         }
3985                 }
3986                 if ( $cacheable ) {
3987                         $badImageCache = $badImages;
3988                 }
3989         }
3990
3991         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3992         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3993         wfProfileOut( __METHOD__ );
3994         return $bad;
3995 }
3996
3997 /**
3998  * Determine whether the client at a given source IP is likely to be able to
3999  * access the wiki via HTTPS.
4000  *
4001  * @param string $ip The IPv4/6 address in the normal human-readable form
4002  * @return boolean
4003  */
4004 function wfCanIPUseHTTPS( $ip ) {
4005         $canDo = true;
4006         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4007         return !!$canDo;
4008 }