includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 // Hide compatibility functions from Doxygen
  28 /// @cond
  29
  30 /**
  31  * Compatibility functions
  32  *
  33  * We support PHP 5.3.2 and up.
  34  * Re-implementations of newer functions or functions in non-standard
  35  * PHP extensions may be included here.
  36  */
  37
  38 if( !function_exists( 'iconv' ) ) {
  39         /**
  40          * @codeCoverageIgnore
  41          * @return string
  42          */
  43         function iconv( $from, $to, $string ) {
  44                 return Fallback::iconv( $from, $to, $string );
  45         }
  46 }
  47
  48 if ( !function_exists( 'mb_substr' ) ) {
  49         /**
  50          * @codeCoverageIgnore
  51          * @return string
  52          */
  53         function mb_substr( $str, $start, $count='end' ) {
  54                 return Fallback::mb_substr( $str, $start, $count );
  55         }
  56
  57         /**
  58          * @codeCoverageIgnore
  59          * @return int
  60          */
  61         function mb_substr_split_unicode( $str, $splitPos ) {
  62                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  63         }
  64 }
  65
  66 if ( !function_exists( 'mb_strlen' ) ) {
  67         /**
  68          * @codeCoverageIgnore
  69          * @return int
  70          */
  71         function mb_strlen( $str, $enc = '' ) {
  72                 return Fallback::mb_strlen( $str, $enc );
  73         }
  74 }
  75
  76 if( !function_exists( 'mb_strpos' ) ) {
  77         /**
  78          * @codeCoverageIgnore
  79          * @return int
  80          */
  81         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  82                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  83         }
  84
  85 }
  86
  87 if( !function_exists( 'mb_strrpos' ) ) {
  88         /**
  89          * @codeCoverageIgnore
  90          * @return int
  91          */
  92         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  93                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  94         }
  95 }
  96
  97
  98 // Support for Wietse Venema's taint feature
  99 if ( !function_exists( 'istainted' ) ) {
 100         /**
 101          * @codeCoverageIgnore
 102          * @return int
 103          */
 104         function istainted( $var ) {
 105                 return 0;
 106         }
 107         /** @codeCoverageIgnore */
 108         function taint( $var, $level = 0 ) {}
 109         /** @codeCoverageIgnore */
 110         function untaint( $var, $level = 0 ) {}
 111         define( 'TC_HTML', 1 );
 112         define( 'TC_SHELL', 1 );
 113         define( 'TC_MYSQL', 1 );
 114         define( 'TC_PCRE', 1 );
 115         define( 'TC_SELF', 1 );
 116 }
 117 /// @endcond
 118
 119 /**
 120  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 121  * @param $a array
 122  * @param $b array
 123  * @return array
 124  */
 125 function wfArrayDiff2( $a, $b ) {
 126         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 127 }
 128
 129 /**
 130  * @param $a
 131  * @param $b
 132  * @return int
 133  */
 134 function wfArrayDiff2_cmp( $a, $b ) {
 135         if ( !is_array( $a ) ) {
 136                 return strcmp( $a, $b );
 137         } elseif ( count( $a ) !== count( $b ) ) {
 138                 return count( $a ) < count( $b ) ? -1 : 1;
 139         } else {
 140                 reset( $a );
 141                 reset( $b );
 142                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 143                         $cmp = strcmp( $valueA, $valueB );
 144                         if ( $cmp !== 0 ) {
 145                                 return $cmp;
 146                         }
 147                 }
 148                 return 0;
 149         }
 150 }
 151
 152 /**
 153  * Array lookup
 154  * Returns an array where the values in the first array are replaced by the
 155  * values in the second array with the corresponding keys
 156  *
 157  * @param $a Array
 158  * @param $b Array
 159  * @return array
 160  */
 161 function wfArrayLookup( $a, $b ) {
 162         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 163 }
 164
 165 /**
 166  * Appends to second array if $value differs from that in $default
 167  *
 168  * @param $key String|Int
 169  * @param $value Mixed
 170  * @param $default Mixed
 171  * @param $changed Array to alter
 172  */
 173 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 174         if ( is_null( $changed ) ) {
 175                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 176         }
 177         if ( $default[$key] !== $value ) {
 178                 $changed[$key] = $value;
 179         }
 180 }
 181
 182 /**
 183  * Backwards array plus for people who haven't bothered to read the PHP manual
 184  * XXX: will not darn your socks for you.
 185  *
 186  * @param $array1 Array
 187  * @param [$array2, [...]] Arrays
 188  * @return Array
 189  */
 190 function wfArrayMerge( $array1/* ... */ ) {
 191         $args = func_get_args();
 192         $args = array_reverse( $args, true );
 193         $out = array();
 194         foreach ( $args as $arg ) {
 195                 $out += $arg;
 196         }
 197         return $out;
 198 }
 199
 200 /**
 201  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 202  * e.g.
 203  *      wfMergeErrorArrays(
 204  *              array( array( 'x' ) ),
 205  *              array( array( 'x', '2' ) ),
 206  *              array( array( 'x' ) ),
 207  *              array( array( 'y' ) )
 208  *      );
 209  * returns:
 210  *              array(
 211  *              array( 'x', '2' ),
 212  *              array( 'x' ),
 213  *              array( 'y' )
 214  *      )
 215  * @param varargs
 216  * @return Array
 217  */
 218 function wfMergeErrorArrays( /*...*/ ) {
 219         $args = func_get_args();
 220         $out = array();
 221         foreach ( $args as $errors ) {
 222                 foreach ( $errors as $params ) {
 223                         # @todo FIXME: Sometimes get nested arrays for $params,
 224                         # which leads to E_NOTICEs
 225                         $spec = implode( "\t", $params );
 226                         $out[$spec] = $params;
 227                 }
 228         }
 229         return array_values( $out );
 230 }
 231
 232 /**
 233  * Insert array into another array after the specified *KEY*
 234  *
 235  * @param $array Array: The array.
 236  * @param $insert Array: The array to insert.
 237  * @param $after Mixed: The key to insert after
 238  * @return Array
 239  */
 240 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 241         // Find the offset of the element to insert after.
 242         $keys = array_keys( $array );
 243         $offsetByKey = array_flip( $keys );
 244
 245         $offset = $offsetByKey[$after];
 246
 247         // Insert at the specified offset
 248         $before = array_slice( $array, 0, $offset + 1, true );
 249         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 250
 251         $output = $before + $insert + $after;
 252
 253         return $output;
 254 }
 255
 256 /**
 257  * Recursively converts the parameter (an object) to an array with the same data
 258  *
 259  * @param $objOrArray Object|Array
 260  * @param $recursive Bool
 261  * @return Array
 262  */
 263 function wfObjectToArray( $objOrArray, $recursive = true ) {
 264         $array = array();
 265         if( is_object( $objOrArray ) ) {
 266                 $objOrArray = get_object_vars( $objOrArray );
 267         }
 268         foreach ( $objOrArray as $key => $value ) {
 269                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 270                         $value = wfObjectToArray( $value );
 271                 }
 272
 273                 $array[$key] = $value;
 274         }
 275
 276         return $array;
 277 }
 278
 279 /**
 280  * Wrapper around array_map() which also taints variables
 281  *
 282  * @param  $function Callback
 283  * @param  $input Array
 284  * @return Array
 285  */
 286 function wfArrayMap( $function, $input ) {
 287         $ret = array_map( $function, $input );
 288         foreach ( $ret as $key => $value ) {
 289                 $taint = istainted( $input[$key] );
 290                 if ( $taint ) {
 291                         taint( $ret[$key], $taint );
 292                 }
 293         }
 294         return $ret;
 295 }
 296
 297 /**
 298  * Get a random decimal value between 0 and 1, in a way
 299  * not likely to give duplicate values for any realistic
 300  * number of articles.
 301  *
 302  * @return string
 303  */
 304 function wfRandom() {
 305         # The maximum random value is "only" 2^31-1, so get two random
 306         # values to reduce the chance of dupes
 307         $max = mt_getrandmax() + 1;
 308         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 309                 / $max / $max, 12, '.', '' );
 310         return $rand;
 311 }
 312
 313 /**
 314  * Get a random string containing a number of pesudo-random hex
 315  * characters.
 316  * @note This is not secure, if you are trying to generate some sort
 317  *       of token please use MWCryptRand instead.
 318  *
 319  * @param $length int The length of the string to generate
 320  * @return String
 321  * @since 1.20
 322  */
 323 function wfRandomString( $length = 32 ) {
 324         $str = '';
 325         while ( strlen( $str ) < $length ) {
 326                 $str .= dechex( mt_rand() );
 327         }
 328         return substr( $str, 0, $length );
 329 }
 330
 331 /**
 332  * We want some things to be included as literal characters in our title URLs
 333  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 334  * all of the following should be safe:
 335  *
 336  * ;:@&=$-_.+!*'(),
 337  *
 338  * But + is not safe because it's used to indicate a space; &= are only safe in
 339  * paths and not in queries (and we don't distinguish here); ' seems kind of
 340  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 341  * is reserved, we don't care.  So the list we unescape is:
 342  *
 343  * ;:@$!*(),/
 344  *
 345  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 346  * so no fancy : for IIS7.
 347  *
 348  * %2F in the page titles seems to fatally break for some reason.
 349  *
 350  * @param $s String:
 351  * @return string
 352 */
 353 function wfUrlencode( $s ) {
 354         static $needle;
 355         if ( is_null( $s ) ) {
 356                 $needle = null;
 357                 return '';
 358         }
 359
 360         if ( is_null( $needle ) ) {
 361                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 362                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 363                         $needle[] = '%3A';
 364                 }
 365         }
 366
 367         $s = urlencode( $s );
 368         $s = str_ireplace(
 369                 $needle,
 370                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 371                 $s
 372         );
 373
 374         return $s;
 375 }
 376
 377 /**
 378  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 379  * "days=7&limit=100". Options in the first array override options in the second.
 380  * Options set to null or false will not be output.
 381  *
 382  * @param $array1 Array ( String|Array )
 383  * @param $array2 Array ( String|Array )
 384  * @param $prefix String
 385  * @return String
 386  */
 387 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 388         if ( !is_null( $array2 ) ) {
 389                 $array1 = $array1 + $array2;
 390         }
 391
 392         $cgi = '';
 393         foreach ( $array1 as $key => $value ) {
 394                 if ( $value !== false ) {
 395                         if ( $cgi != '' ) {
 396                                 $cgi .= '&';
 397                         }
 398                         if ( $prefix !== '' ) {
 399                                 $key = $prefix . "[$key]";
 400                         }
 401                         if ( is_array( $value ) ) {
 402                                 $firstTime = true;
 403                                 foreach ( $value as $k => $v ) {
 404                                         $cgi .= $firstTime ? '' : '&';
 405                                         if ( is_array( $v ) ) {
 406                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 407                                         } else {
 408                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 409                                         }
 410                                         $firstTime = false;
 411                                 }
 412                         } else {
 413                                 if ( is_object( $value ) ) {
 414                                         $value = $value->__toString();
 415                                 } elseif( !is_null( $value ) ) {
 416                                         $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 417                                 } else {
 418                                         $cgi .= urlencode( $key );
 419                                 }
 420                         }
 421                 }
 422         }
 423         return $cgi;
 424 }
 425
 426 /**
 427  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 428  * its argument and returns the same string in array form.  This allows compa-
 429  * tibility with legacy functions that accept raw query strings instead of nice
 430  * arrays.  Of course, keys and values are urldecode()d.
 431  *
 432  * @param $query String: query string
 433  * @return array Array version of input
 434  */
 435 function wfCgiToArray( $query ) {
 436         if ( isset( $query[0] ) && $query[0] == '?' ) {
 437                 $query = substr( $query, 1 );
 438         }
 439         $bits = explode( '&', $query );
 440         $ret = array();
 441         foreach ( $bits as $bit ) {
 442                 if ( $bit === '' ) {
 443                         continue;
 444                 }
 445                 if ( strpos( $bit, '=' ) === false ) {
 446                         // Pieces like &qwerty become 'qwerty' => null
 447                         $key = urldecode( $bit );
 448                         $value = null;
 449                 } else {
 450                         list( $key, $value ) = explode( '=', $bit );
 451                         $key = urldecode( $key );
 452                         $value = urldecode( $value );
 453                 }
 454
 455                 if ( strpos( $key, '[' ) !== false ) {
 456                         $keys = array_reverse( explode( '[', $key ) );
 457                         $key = array_pop( $keys );
 458                         $temp = $value;
 459                         foreach ( $keys as $k ) {
 460                                 $k = substr( $k, 0, -1 );
 461                                 $temp = array( $k => $temp );
 462                         }
 463                         if ( isset( $ret[$key] ) ) {
 464                                 $ret[$key] = array_merge( $ret[$key], $temp );
 465                         } else {
 466                                 $ret[$key] = $temp;
 467                         }
 468                 } else {
 469                         $ret[$key] = $value;
 470                 }
 471         }
 472         return $ret;
 473 }
 474
 475 /**
 476  * Append a query string to an existing URL, which may or may not already
 477  * have query string parameters already. If so, they will be combined.
 478  *
 479  * @deprecated
 480  * @param $url String
 481  * @param $query Mixed: string or associative array
 482  * @return string
 483  */
 484 function wfAppendQuery( $url, $query ) {
 485         $obj = new Uri( $url );
 486         $obj->extendQuery( $query );
 487         return $obj->toString();
 488 }
 489
 490 /**
 491  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 492  * is correct.
 493  *
 494  * The meaning of the PROTO_* constants is as follows:
 495  * PROTO_HTTP: Output a URL starting with http://
 496  * PROTO_HTTPS: Output a URL starting with https://
 497  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 498  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 499  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 500  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 501  *
 502  * @todo this won't work with current-path-relative URLs
 503  * like "subdir/foo.html", etc.
 504  *
 505  * @param $url String: either fully-qualified or a local path + query
 506  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 507  *                             protocol to use if $url or $wgServer is
 508  *                             protocol-relative
 509  * @return string Fully-qualified URL, current-path-relative URL or false if
 510  *                no valid URL can be constructed
 511  */
 512 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 513         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 514         $serverUrl = $wgServer;
 515         if ( $defaultProto === PROTO_CANONICAL ) {
 516                 $serverUrl = $wgCanonicalServer;
 517         }
 518         // Make $wgInternalServer fall back to $wgServer if not set
 519         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 520                 $serverUrl = $wgInternalServer;
 521         }
 522         if ( $defaultProto === PROTO_CURRENT ) {
 523                 $defaultProto = WebRequest::detectProtocol() . '://';
 524         }
 525
 526         // Analyze $serverUrl to obtain its protocol
 527         $bits = wfParseUrl( $serverUrl );
 528         $serverHasProto = $bits && $bits['scheme'] != '';
 529
 530         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 531                 if ( $serverHasProto ) {
 532                         $defaultProto = $bits['scheme'] . '://';
 533                 } else {
 534                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 535                         // Fall back to HTTP in this ridiculous case
 536                         $defaultProto = PROTO_HTTP;
 537                 }
 538         }
 539
 540         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 541
 542         if ( substr( $url, 0, 2 ) == '//' ) {
 543                 $url = $defaultProtoWithoutSlashes . $url;
 544         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 545                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 546                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 547         }
 548
 549         $bits = wfParseUrl( $url );
 550         if ( $bits && isset( $bits['path'] ) ) {
 551                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 552                 return wfAssembleUrl( $bits );
 553         } elseif ( $bits ) {
 554                 # No path to expand
 555                 return $url;
 556         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 557                 # URL is a relative path
 558                 return wfRemoveDotSegments( $url );
 559         }
 560
 561         # Expanded URL is not valid.
 562         return false;
 563 }
 564
 565 /**
 566  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 567  * if you need to edit part of a URL and put it back together.
 568  *
 569  * This is the basic structure used (brackets contain keys for $urlParts):
 570  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 571  *
 572  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 573  *
 574  * @since 1.19
 575  * @deprecated
 576  * @param $urlParts Array URL parts, as output from wfParseUrl
 577  * @return string URL assembled from its component parts
 578  */
 579 function wfAssembleUrl( $urlParts ) {
 580         $obj = new Uri( $urlParts );
 581         return $obj->toString();
 582 }
 583
 584 /**
 585  * Remove all dot-segments in the provided URL path.  For example,
 586  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 587  * RFC3986 section 5.2.4.
 588  *
 589  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 590  *
 591  * @param $urlPath String URL path, potentially containing dot-segments
 592  * @return string URL path with all dot-segments removed
 593  */
 594 function wfRemoveDotSegments( $urlPath ) {
 595         $output = '';
 596         $inputOffset = 0;
 597         $inputLength = strlen( $urlPath );
 598
 599         while ( $inputOffset < $inputLength ) {
 600                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 601                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 602                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 603                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 604                 $trimOutput = false;
 605
 606                 if ( $prefixLengthTwo == './' ) {
 607                         # Step A, remove leading "./"
 608                         $inputOffset += 2;
 609                 } elseif ( $prefixLengthThree == '../' ) {
 610                         # Step A, remove leading "../"
 611                         $inputOffset += 3;
 612                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 613                         # Step B, replace leading "/.$" with "/"
 614                         $inputOffset += 1;
 615                         $urlPath[$inputOffset] = '/';
 616                 } elseif ( $prefixLengthThree == '/./' ) {
 617                         # Step B, replace leading "/./" with "/"
 618                         $inputOffset += 2;
 619                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 620                         # Step C, replace leading "/..$" with "/" and
 621                         # remove last path component in output
 622                         $inputOffset += 2;
 623                         $urlPath[$inputOffset] = '/';
 624                         $trimOutput = true;
 625                 } elseif ( $prefixLengthFour == '/../' ) {
 626                         # Step C, replace leading "/../" with "/" and
 627                         # remove last path component in output
 628                         $inputOffset += 3;
 629                         $trimOutput = true;
 630                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 631                         # Step D, remove "^.$"
 632                         $inputOffset += 1;
 633                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 634                         # Step D, remove "^..$"
 635                         $inputOffset += 2;
 636                 } else {
 637                         # Step E, move leading path segment to output
 638                         if ( $prefixLengthOne == '/' ) {
 639                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 640                         } else {
 641                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 642                         }
 643                         if ( $slashPos === false ) {
 644                                 $output .= substr( $urlPath, $inputOffset );
 645                                 $inputOffset = $inputLength;
 646                         } else {
 647                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 648                                 $inputOffset += $slashPos - $inputOffset;
 649                         }
 650                 }
 651
 652                 if ( $trimOutput ) {
 653                         $slashPos = strrpos( $output, '/' );
 654                         if ( $slashPos === false ) {
 655                                 $output = '';
 656                         } else {
 657                                 $output = substr( $output, 0, $slashPos );
 658                         }
 659                 }
 660         }
 661
 662         return $output;
 663 }
 664
 665 /**
 666  * Returns a regular expression of url protocols
 667  *
 668  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 669  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 670  * @return String
 671  */
 672 function wfUrlProtocols( $includeProtocolRelative = true ) {
 673         global $wgUrlProtocols;
 674
 675         // Cache return values separately based on $includeProtocolRelative
 676         static $withProtRel = null, $withoutProtRel = null;
 677         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 678         if ( !is_null( $cachedValue ) ) {
 679                 return $cachedValue;
 680         }
 681
 682         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 683         // with LocalSettings files from 1.5
 684         if ( is_array( $wgUrlProtocols ) ) {
 685                 $protocols = array();
 686                 foreach ( $wgUrlProtocols as $protocol ) {
 687                         // Filter out '//' if !$includeProtocolRelative
 688                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 689                                 $protocols[] = preg_quote( $protocol, '/' );
 690                         }
 691                 }
 692
 693                 $retval = implode( '|', $protocols );
 694         } else {
 695                 // Ignore $includeProtocolRelative in this case
 696                 // This case exists for pre-1.6 compatibility, and we can safely assume
 697                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 698                 // URLs weren't supported until 1.18
 699                 $retval = $wgUrlProtocols;
 700         }
 701
 702         // Cache return value
 703         if ( $includeProtocolRelative ) {
 704                 $withProtRel = $retval;
 705         } else {
 706                 $withoutProtRel = $retval;
 707         }
 708         return $retval;
 709 }
 710
 711 /**
 712  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 713  * you need a regex that matches all URL protocols but does not match protocol-
 714  * relative URLs
 715  * @return String
 716  */
 717 function wfUrlProtocolsWithoutProtRel() {
 718         return wfUrlProtocols( false );
 719 }
 720
 721 /**
 722  * parse_url() work-alike, but non-broken.  Differences:
 723  *
 724  * 1) Does not raise warnings on bad URLs (just returns false)
 725  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 726  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 727  *
 728  * @deprecated
 729  * @param $url String: a URL to parse
 730  * @return Array: bits of the URL in an associative array, per PHP docs
 731  */
 732 function wfParseUrl( $url ) {
 733         $obj = new Uri( $url );
 734         return $obj->getComponents();
 735 }
 736
 737 /**
 738  * Take a URL, make sure it's expanded to fully qualified, and replace any
 739  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 740  * for more compact display and legibility for local audiences.
 741  *
 742  * @todo handle punycode domains too
 743  *
 744  * @param $url string
 745  * @return string
 746  */
 747 function wfExpandIRI( $url ) {
 748         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 749 }
 750
 751 /**
 752  * Private callback for wfExpandIRI
 753  * @param array $matches
 754  * @return string
 755  */
 756 function wfExpandIRI_callback( $matches ) {
 757         return urldecode( $matches[1] );
 758 }
 759
 760
 761
 762 /**
 763  * Make URL indexes, appropriate for the el_index field of externallinks.
 764  *
 765  * @param $url String
 766  * @return array
 767  */
 768 function wfMakeUrlIndexes( $url ) {
 769         $bits = wfParseUrl( $url );
 770
 771         // Reverse the labels in the hostname, convert to lower case
 772         // For emails reverse domainpart only
 773         if ( $bits['scheme'] == 'mailto' ) {
 774                 $mailparts = explode( '@', $bits['host'], 2 );
 775                 if ( count( $mailparts ) === 2 ) {
 776                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 777                 } else {
 778                         // No domain specified, don't mangle it
 779                         $domainpart = '';
 780                 }
 781                 $reversedHost = $domainpart . '@' . $mailparts[0];
 782         } else {
 783                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 784         }
 785         // Add an extra dot to the end
 786         // Why? Is it in wrong place in mailto links?
 787         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 788                 $reversedHost .= '.';
 789         }
 790         // Reconstruct the pseudo-URL
 791         $prot = $bits['scheme'];
 792         $index = $prot . $bits['delimiter'] . $reversedHost;
 793         // Leave out user and password. Add the port, path, query and fragment
 794         if ( isset( $bits['port'] ) ) {
 795                 $index .= ':' . $bits['port'];
 796         }
 797         if ( isset( $bits['path'] ) ) {
 798                 $index .= $bits['path'];
 799         } else {
 800                 $index .= '/';
 801         }
 802         if ( isset( $bits['query'] ) ) {
 803                 $index .= '?' . $bits['query'];
 804         }
 805         if ( isset( $bits['fragment'] ) ) {
 806                 $index .= '#' . $bits['fragment'];
 807         }
 808
 809         if ( $prot == '' ) {
 810                 return array( "http:$index", "https:$index" );
 811         } else {
 812                 return array( $index );
 813         }
 814 }
 815
 816 /**
 817  * Check whether a given URL has a domain that occurs in a given set of domains
 818  * @param $url string URL
 819  * @param $domains array Array of domains (strings)
 820  * @return bool True if the host part of $url ends in one of the strings in $domains
 821  */
 822 function wfMatchesDomainList( $url, $domains ) {
 823         $bits = wfParseUrl( $url );
 824         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 825                 foreach ( (array)$domains as $domain ) {
 826                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 827                         // We should use something that interprets dots instead
 828                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 829                                 return true;
 830                         }
 831                 }
 832         }
 833         return false;
 834 }
 835
 836 /**
 837  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 838  * In normal operation this is a NOP.
 839  *
 840  * Controlling globals:
 841  * $wgDebugLogFile - points to the log file
 842  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 843  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 844  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 845  *
 846  * @param $text String
 847  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 848  */
 849 function wfDebug( $text, $logonly = false ) {
 850         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 851         global $wgDebugLogPrefix, $wgShowDebug;
 852
 853         static $cache = array(); // Cache of unoutputted messages
 854
 855         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 856                 return;
 857         }
 858
 859         $timer = wfDebugTimer();
 860         if ( $timer !== '' ) {
 861                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 862         }
 863
 864         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 865                 $cache[] = $text;
 866
 867                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 868                         // add the message and any cached messages to the output
 869                         array_map( array( $wgOut, 'debug' ), $cache );
 870                         $cache = array();
 871                 }
 872         }
 873         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 874                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 875                         # Strip unprintables; they can switch terminal modes when binary data
 876                         # gets dumped, which is pretty annoying.
 877                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 878                         $text = $wgDebugLogPrefix . $text;
 879                         wfErrorLog( $text, $wgDebugLogFile );
 880                 }
 881         }
 882
 883         MWDebug::debugMsg( $text );
 884 }
 885
 886 /**
 887  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 888  * @return bool
 889  */
 890 function wfIsDebugRawPage() {
 891         static $cache;
 892         if ( $cache !== null ) {
 893                 return $cache;
 894         }
 895         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 896         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 897                 || (
 898                         isset( $_SERVER['SCRIPT_NAME'] )
 899                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 900                 ) )
 901         {
 902                 $cache = true;
 903         } else {
 904                 $cache = false;
 905         }
 906         return $cache;
 907 }
 908
 909 /**
 910  * Get microsecond timestamps for debug logs
 911  *
 912  * @return string
 913  */
 914 function wfDebugTimer() {
 915         global $wgDebugTimestamps, $wgRequestTime;
 916
 917         if ( !$wgDebugTimestamps ) {
 918                 return '';
 919         }
 920
 921         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 922         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 923         return "$prefix $mem  ";
 924 }
 925
 926 /**
 927  * Send a line giving PHP memory usage.
 928  *
 929  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 930  */
 931 function wfDebugMem( $exact = false ) {
 932         $mem = memory_get_usage();
 933         if( !$exact ) {
 934                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 935         } else {
 936                 $mem .= ' bytes';
 937         }
 938         wfDebug( "Memory usage: $mem\n" );
 939 }
 940
 941 /**
 942  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 943  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 944  *
 945  * @param $logGroup String
 946  * @param $text String
 947  * @param $public Bool: whether to log the event in the public log if no private
 948  *                     log file is specified, (default true)
 949  */
 950 function wfDebugLog( $logGroup, $text, $public = true ) {
 951         global $wgDebugLogGroups;
 952         $text = trim( $text ) . "\n";
 953         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 954                 $time = wfTimestamp( TS_DB );
 955                 $wiki = wfWikiID();
 956                 $host = wfHostname();
 957                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 958                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 959                 }
 960         } elseif ( $public === true ) {
 961                 wfDebug( $text, true );
 962         }
 963 }
 964
 965 /**
 966  * Log for database errors
 967  *
 968  * @param $text String: database error message.
 969  */
 970 function wfLogDBError( $text ) {
 971         global $wgDBerrorLog, $wgDBerrorLogInUTC;
 972         if ( $wgDBerrorLog ) {
 973                 $host = wfHostname();
 974                 $wiki = wfWikiID();
 975
 976                 if( $wgDBerrorLogInUTC ) {
 977                         $wikiTimezone = date_default_timezone_get();
 978                         date_default_timezone_set( 'UTC' );
 979                 }
 980                 $date = date( 'D M j G:i:s T Y' );
 981                 if( $wgDBerrorLogInUTC ) {
 982                         // Restore timezone
 983                         date_default_timezone_set( $wikiTimezone );
 984                 }
 985
 986                 $text = "$date\t$host\t$wiki\t$text";
 987                 wfErrorLog( $text, $wgDBerrorLog );
 988         }
 989 }
 990
 991 /**
 992  * Throws a warning that $function is deprecated
 993  *
 994  * @param $function String
 995  * @param $version String|bool: Version of MediaWiki that the function was deprecated in (Added in 1.19).
 996  * @param $component String|bool: Added in 1.19.
 997  * @param $callerOffset integer: How far up the callstack is the original
 998  *    caller. 2 = function that called the function that called
 999  *    wfDeprecated (Added in 1.20)
1000  *
1001  * @return null
1002  */
1003 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1004         static $functionsWarned = array();
1005
1006         MWDebug::deprecated( $function, $version, $component );
1007
1008         if ( !isset( $functionsWarned[$function] ) ) {
1009                 $functionsWarned[$function] = true;
1010
1011                 if ( $version ) {
1012                         global $wgDeprecationReleaseLimit;
1013
1014                         if ( $wgDeprecationReleaseLimit && $component === false ) {
1015                                 # Strip -* off the end of $version so that branches can use the
1016                                 # format #.##-branchname to avoid issues if the branch is merged into
1017                                 # a version of MediaWiki later than what it was branched from
1018                                 $comparableVersion = preg_replace( '/-.*$/', '', $version );
1019
1020                                 # If the comparableVersion is larger than our release limit then
1021                                 # skip the warning message for the deprecation
1022                                 if ( version_compare( $wgDeprecationReleaseLimit, $comparableVersion, '<' ) ) {
1023                                         return;
1024                                 }
1025                         }
1026
1027                         $component = $component === false ? 'MediaWiki' : $component;
1028                         wfWarn( "Use of $function was deprecated in $component $version.", $callerOffset );
1029                 } else {
1030                         wfWarn( "Use of $function is deprecated.", $callerOffset );
1031                 }
1032         }
1033 }
1034
1035 /**
1036  * Send a warning either to the debug log or in a PHP error depending on
1037  * $wgDevelopmentWarnings
1038  *
1039  * @param $msg String: message to send
1040  * @param $callerOffset Integer: number of items to go back in the backtrace to
1041  *        find the correct caller (1 = function calling wfWarn, ...)
1042  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1043  *        is true
1044  */
1045 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1046         global $wgDevelopmentWarnings;
1047
1048         MWDebug::warning( $msg, $callerOffset + 2 );
1049
1050         $callers = wfDebugBacktrace();
1051         if ( isset( $callers[$callerOffset + 1] ) ) {
1052                 $callerfunc = $callers[$callerOffset + 1];
1053                 $callerfile = $callers[$callerOffset];
1054                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
1055                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
1056                 } else {
1057                         $file = '(internal function)';
1058                 }
1059                 $func = '';
1060                 if ( isset( $callerfunc['class'] ) ) {
1061                         $func .= $callerfunc['class'] . '::';
1062                 }
1063                 if ( isset( $callerfunc['function'] ) ) {
1064                         $func .= $callerfunc['function'];
1065                 }
1066                 $msg .= " [Called from $func in $file]";
1067         }
1068
1069         if ( $wgDevelopmentWarnings ) {
1070                 trigger_error( $msg, $level );
1071         } else {
1072                 wfDebug( "$msg\n" );
1073         }
1074 }
1075
1076 /**
1077  * Log to a file without getting "file size exceeded" signals.
1078  *
1079  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1080  * send lines to the specified port, prefixed by the specified prefix and a space.
1081  *
1082  * @param $text String
1083  * @param $file String filename
1084  */
1085 function wfErrorLog( $text, $file ) {
1086         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1087                 # Needs the sockets extension
1088                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1089                         // IPv6 bracketed host
1090                         $host = $m[2];
1091                         $port = intval( $m[3] );
1092                         $prefix = isset( $m[4] ) ? $m[4] : false;
1093                         $domain = AF_INET6;
1094                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1095                         $host = $m[2];
1096                         if ( !IP::isIPv4( $host ) ) {
1097                                 $host = gethostbyname( $host );
1098                         }
1099                         $port = intval( $m[3] );
1100                         $prefix = isset( $m[4] ) ? $m[4] : false;
1101                         $domain = AF_INET;
1102                 } else {
1103                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1104                 }
1105
1106                 // Clean it up for the multiplexer
1107                 if ( strval( $prefix ) !== '' ) {
1108                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1109
1110                         // Limit to 64KB
1111                         if ( strlen( $text ) > 65506 ) {
1112                                 $text = substr( $text, 0, 65506 );
1113                         }
1114
1115                         if ( substr( $text, -1 ) != "\n" ) {
1116                                 $text .= "\n";
1117                         }
1118                 } elseif ( strlen( $text ) > 65507 ) {
1119                         $text = substr( $text, 0, 65507 );
1120                 }
1121
1122                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1123                 if ( !$sock ) {
1124                         return;
1125                 }
1126
1127                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1128                 socket_close( $sock );
1129         } else {
1130                 wfSuppressWarnings();
1131                 $exists = file_exists( $file );
1132                 $size = $exists ? filesize( $file ) : false;
1133                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1134                         file_put_contents( $file, $text, FILE_APPEND );
1135                 }
1136                 wfRestoreWarnings();
1137         }
1138 }
1139
1140 /**
1141  * @todo document
1142  */
1143 function wfLogProfilingData() {
1144         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1145         global $wgProfileLimit, $wgUser;
1146
1147         $profiler = Profiler::instance();
1148
1149         # Profiling must actually be enabled...
1150         if ( $profiler->isStub() ) {
1151                 return;
1152         }
1153
1154         // Get total page request time and only show pages that longer than
1155         // $wgProfileLimit time (default is 0)
1156         $elapsed = microtime( true ) - $wgRequestTime;
1157         if ( $elapsed <= $wgProfileLimit ) {
1158                 return;
1159         }
1160
1161         $profiler->logData();
1162
1163         // Check whether this should be logged in the debug file.
1164         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1165                 return;
1166         }
1167
1168         $forward = '';
1169         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1170                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1171         }
1172         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1173                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1174         }
1175         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1176                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1177         }
1178         if ( $forward ) {
1179                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1180         }
1181         // Don't load $wgUser at this late stage just for statistics purposes
1182         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1183         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1184                 $forward .= ' anon';
1185         }
1186         $log = sprintf( "%s\t%04.3f\t%s\n",
1187                 gmdate( 'YmdHis' ), $elapsed,
1188                 urldecode( $wgRequest->getRequestURL() . $forward ) );
1189
1190         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1191 }
1192
1193 /**
1194  * Increment a statistics counter
1195  *
1196  * @param $key String
1197  * @param $count Int
1198  */
1199 function wfIncrStats( $key, $count = 1 ) {
1200         global $wgStatsMethod;
1201
1202         $count = intval( $count );
1203
1204         if( $wgStatsMethod == 'udp' ) {
1205                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
1206                 static $socket;
1207
1208                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
1209
1210                 if ( !$socket ) {
1211                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1212                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1213                         socket_sendto(
1214                                 $socket,
1215                                 $statline,
1216                                 strlen( $statline ),
1217                                 0,
1218                                 $wgUDPProfilerHost,
1219                                 $wgUDPProfilerPort
1220                         );
1221                 }
1222                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1223                 wfSuppressWarnings();
1224                 socket_sendto(
1225                         $socket,
1226                         $statline,
1227                         strlen( $statline ),
1228                         0,
1229                         $wgUDPProfilerHost,
1230                         $wgUDPProfilerPort
1231                 );
1232                 wfRestoreWarnings();
1233         } elseif( $wgStatsMethod == 'cache' ) {
1234                 global $wgMemc;
1235                 $key = wfMemcKey( 'stats', $key );
1236                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1237                         $wgMemc->add( $key, $count );
1238                 }
1239         } else {
1240                 // Disabled
1241         }
1242 }
1243
1244 /**
1245  * Check if the wiki read-only lock file is present. This can be used to lock
1246  * off editing functions, but doesn't guarantee that the database will not be
1247  * modified.
1248  *
1249  * @return bool
1250  */
1251 function wfReadOnly() {
1252         global $wgReadOnlyFile, $wgReadOnly;
1253
1254         if ( !is_null( $wgReadOnly ) ) {
1255                 return (bool)$wgReadOnly;
1256         }
1257         if ( $wgReadOnlyFile == '' ) {
1258                 return false;
1259         }
1260         // Set $wgReadOnly for faster access next time
1261         if ( is_file( $wgReadOnlyFile ) ) {
1262                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1263         } else {
1264                 $wgReadOnly = false;
1265         }
1266         return (bool)$wgReadOnly;
1267 }
1268
1269 /**
1270  * @return bool
1271  */
1272 function wfReadOnlyReason() {
1273         global $wgReadOnly;
1274         wfReadOnly();
1275         return $wgReadOnly;
1276 }
1277
1278 /**
1279  * Return a Language object from $langcode
1280  *
1281  * @param $langcode Mixed: either:
1282  *                  - a Language object
1283  *                  - code of the language to get the message for, if it is
1284  *                    a valid code create a language for that language, if
1285  *                    it is a string but not a valid code then make a basic
1286  *                    language object
1287  *                  - a boolean: if it's false then use the global object for
1288  *                    the current user's language (as a fallback for the old parameter
1289  *                    functionality), or if it is true then use global object
1290  *                    for the wiki's content language.
1291  * @return Language object
1292  */
1293 function wfGetLangObj( $langcode = false ) {
1294         # Identify which language to get or create a language object for.
1295         # Using is_object here due to Stub objects.
1296         if( is_object( $langcode ) ) {
1297                 # Great, we already have the object (hopefully)!
1298                 return $langcode;
1299         }
1300
1301         global $wgContLang, $wgLanguageCode;
1302         if( $langcode === true || $langcode === $wgLanguageCode ) {
1303                 # $langcode is the language code of the wikis content language object.
1304                 # or it is a boolean and value is true
1305                 return $wgContLang;
1306         }
1307
1308         global $wgLang;
1309         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1310                 # $langcode is the language code of user language object.
1311                 # or it was a boolean and value is false
1312                 return $wgLang;
1313         }
1314
1315         $validCodes = array_keys( Language::fetchLanguageNames() );
1316         if( in_array( $langcode, $validCodes ) ) {
1317                 # $langcode corresponds to a valid language.
1318                 return Language::factory( $langcode );
1319         }
1320
1321         # $langcode is a string, but not a valid language code; use content language.
1322         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1323         return $wgContLang;
1324 }
1325
1326 /**
1327  * Old function when $wgBetterDirectionality existed
1328  * All usage removed, wfUILang can be removed in near future
1329  *
1330  * @deprecated since 1.18
1331  * @return Language
1332  */
1333 function wfUILang() {
1334         wfDeprecated( __METHOD__, '1.18' );
1335         global $wgLang;
1336         return $wgLang;
1337 }
1338
1339 /**
1340  * This is the new function for getting translated interface messages.
1341  * See the Message class for documentation how to use them.
1342  * The intention is that this function replaces all old wfMsg* functions.
1343  * @param $key \string Message key.
1344  * Varargs: normal message parameters.
1345  * @return Message
1346  * @since 1.17
1347  */
1348 function wfMessage( $key /*...*/) {
1349         $params = func_get_args();
1350         array_shift( $params );
1351         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1352                 $params = $params[0];
1353         }
1354         return new Message( $key, $params );
1355 }
1356
1357 /**
1358  * This function accepts multiple message keys and returns a message instance
1359  * for the first message which is non-empty. If all messages are empty then an
1360  * instance of the first message key is returned.
1361  * @param varargs: message keys
1362  * @return Message
1363  * @since 1.18
1364  */
1365 function wfMessageFallback( /*...*/ ) {
1366         $args = func_get_args();
1367         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1368 }
1369
1370 /**
1371  * Get a message from anywhere, for the current user language.
1372  *
1373  * Use wfMsgForContent() instead if the message should NOT
1374  * change depending on the user preferences.
1375  *
1376  * @deprecated since 1.18
1377  *
1378  * @param $key String: lookup key for the message, usually
1379  *    defined in languages/Language.php
1380  *
1381  * Parameters to the message, which can be used to insert variable text into
1382  * it, can be passed to this function in the following formats:
1383  * - One per argument, starting at the second parameter
1384  * - As an array in the second parameter
1385  * These are not shown in the function definition.
1386  *
1387  * @return String
1388  */
1389 function wfMsg( $key ) {
1390         $args = func_get_args();
1391         array_shift( $args );
1392         return wfMsgReal( $key, $args );
1393 }
1394
1395 /**
1396  * Same as above except doesn't transform the message
1397  *
1398  * @deprecated since 1.18
1399  *
1400  * @param $key String
1401  * @return String
1402  */
1403 function wfMsgNoTrans( $key ) {
1404         $args = func_get_args();
1405         array_shift( $args );
1406         return wfMsgReal( $key, $args, true, false, false );
1407 }
1408
1409 /**
1410  * Get a message from anywhere, for the current global language
1411  * set with $wgLanguageCode.
1412  *
1413  * Use this if the message should NOT change dependent on the
1414  * language set in the user's preferences. This is the case for
1415  * most text written into logs, as well as link targets (such as
1416  * the name of the copyright policy page). Link titles, on the
1417  * other hand, should be shown in the UI language.
1418  *
1419  * Note that MediaWiki allows users to change the user interface
1420  * language in their preferences, but a single installation
1421  * typically only contains content in one language.
1422  *
1423  * Be wary of this distinction: If you use wfMsg() where you should
1424  * use wfMsgForContent(), a user of the software may have to
1425  * customize potentially hundreds of messages in
1426  * order to, e.g., fix a link in every possible language.
1427  *
1428  * @deprecated since 1.18
1429  *
1430  * @param $key String: lookup key for the message, usually
1431  *     defined in languages/Language.php
1432  * @return String
1433  */
1434 function wfMsgForContent( $key ) {
1435         global $wgForceUIMsgAsContentMsg;
1436         $args = func_get_args();
1437         array_shift( $args );
1438         $forcontent = true;
1439         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1440                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1441         {
1442                 $forcontent = false;
1443         }
1444         return wfMsgReal( $key, $args, true, $forcontent );
1445 }
1446
1447 /**
1448  * Same as above except doesn't transform the message
1449  *
1450  * @deprecated since 1.18
1451  *
1452  * @param $key String
1453  * @return String
1454  */
1455 function wfMsgForContentNoTrans( $key ) {
1456         global $wgForceUIMsgAsContentMsg;
1457         $args = func_get_args();
1458         array_shift( $args );
1459         $forcontent = true;
1460         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1461                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1462         {
1463                 $forcontent = false;
1464         }
1465         return wfMsgReal( $key, $args, true, $forcontent, false );
1466 }
1467
1468 /**
1469  * Really get a message
1470  *
1471  * @deprecated since 1.18
1472  *
1473  * @param $key String: key to get.
1474  * @param $args
1475  * @param $useDB Boolean
1476  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1477  * @param $transform Boolean: Whether or not to transform the message.
1478  * @return String: the requested message.
1479  */
1480 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1481         wfProfileIn( __METHOD__ );
1482         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1483         $message = wfMsgReplaceArgs( $message, $args );
1484         wfProfileOut( __METHOD__ );
1485         return $message;
1486 }
1487
1488 /**
1489  * Fetch a message string value, but don't replace any keys yet.
1490  *
1491  * @deprecated since 1.18
1492  *
1493  * @param $key String
1494  * @param $useDB Bool
1495  * @param $langCode String: Code of the language to get the message for, or
1496  *                  behaves as a content language switch if it is a boolean.
1497  * @param $transform Boolean: whether to parse magic words, etc.
1498  * @return string
1499  */
1500 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1501         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1502
1503         $cache = MessageCache::singleton();
1504         $message = $cache->get( $key, $useDB, $langCode );
1505         if( $message === false ) {
1506                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1507         } elseif ( $transform ) {
1508                 $message = $cache->transform( $message );
1509         }
1510         return $message;
1511 }
1512
1513 /**
1514  * Replace message parameter keys on the given formatted output.
1515  *
1516  * @deprecated since 1.18
1517  *
1518  * @param $message String
1519  * @param $args Array
1520  * @return string
1521  * @private
1522  */
1523 function wfMsgReplaceArgs( $message, $args ) {
1524         # Fix windows line-endings
1525         # Some messages are split with explode("\n", $msg)
1526         $message = str_replace( "\r", '', $message );
1527
1528         // Replace arguments
1529         if ( count( $args ) ) {
1530                 if ( is_array( $args[0] ) ) {
1531                         $args = array_values( $args[0] );
1532                 }
1533                 $replacementKeys = array();
1534                 foreach( $args as $n => $param ) {
1535                         $replacementKeys['$' . ( $n + 1 )] = $param;
1536                 }
1537                 $message = strtr( $message, $replacementKeys );
1538         }
1539
1540         return $message;
1541 }
1542
1543 /**
1544  * Return an HTML-escaped version of a message.
1545  * Parameter replacements, if any, are done *after* the HTML-escaping,
1546  * so parameters may contain HTML (eg links or form controls). Be sure
1547  * to pre-escape them if you really do want plaintext, or just wrap
1548  * the whole thing in htmlspecialchars().
1549  *
1550  * @deprecated since 1.18
1551  *
1552  * @param $key String
1553  * @param string ... parameters
1554  * @return string
1555  */
1556 function wfMsgHtml( $key ) {
1557         $args = func_get_args();
1558         array_shift( $args );
1559         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1560 }
1561
1562 /**
1563  * Return an HTML version of message
1564  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1565  * so parameters may contain HTML (eg links or form controls). Be sure
1566  * to pre-escape them if you really do want plaintext, or just wrap
1567  * the whole thing in htmlspecialchars().
1568  *
1569  * @deprecated since 1.18
1570  *
1571  * @param $key String
1572  * @param string ... parameters
1573  * @return string
1574  */
1575 function wfMsgWikiHtml( $key ) {
1576         $args = func_get_args();
1577         array_shift( $args );
1578         return wfMsgReplaceArgs(
1579                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1580                 /* can't be set to false */ true, /* interface */ true )->getText(),
1581                 $args );
1582 }
1583
1584 /**
1585  * Returns message in the requested format
1586  *
1587  * @deprecated since 1.18
1588  *
1589  * @param $key String: key of the message
1590  * @param $options Array: processing rules. Can take the following options:
1591  *   <i>parse</i>: parses wikitext to HTML
1592  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1593  *       p's added by parser or tidy
1594  *   <i>escape</i>: filters message through htmlspecialchars
1595  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1596  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1597  *   <i>parsemag</i>: transform the message using magic phrases
1598  *   <i>content</i>: fetch message for content language instead of interface
1599  * Also can accept a single associative argument, of the form 'language' => 'xx':
1600  *   <i>language</i>: Language object or language code to fetch message for
1601  *       (overriden by <i>content</i>).
1602  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1603  *
1604  * @return String
1605  */
1606 function wfMsgExt( $key, $options ) {
1607         $args = func_get_args();
1608         array_shift( $args );
1609         array_shift( $args );
1610         $options = (array)$options;
1611
1612         foreach( $options as $arrayKey => $option ) {
1613                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1614                         # An unknown index, neither numeric nor "language"
1615                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1616                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1617                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1618                 'replaceafter', 'parsemag', 'content' ) ) ) {
1619                         # A numeric index with unknown value
1620                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1621                 }
1622         }
1623
1624         if( in_array( 'content', $options, true ) ) {
1625                 $forContent = true;
1626                 $langCode = true;
1627                 $langCodeObj = null;
1628         } elseif( array_key_exists( 'language', $options ) ) {
1629                 $forContent = false;
1630                 $langCode = wfGetLangObj( $options['language'] );
1631                 $langCodeObj = $langCode;
1632         } else {
1633                 $forContent = false;
1634                 $langCode = false;
1635                 $langCodeObj = null;
1636         }
1637
1638         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1639
1640         if( !in_array( 'replaceafter', $options, true ) ) {
1641                 $string = wfMsgReplaceArgs( $string, $args );
1642         }
1643
1644         $messageCache = MessageCache::singleton();
1645         $parseInline = in_array( 'parseinline', $options, true );
1646         if( in_array( 'parse', $options, true ) || $parseInline ) {
1647                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1648                 if ( $string instanceof ParserOutput ) {
1649                         $string = $string->getText();
1650                 }
1651
1652                 if ( $parseInline ) {
1653                         $m = array();
1654                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1655                                 $string = $m[1];
1656                         }
1657                 }
1658         } elseif ( in_array( 'parsemag', $options, true ) ) {
1659                 $string = $messageCache->transform( $string,
1660                                 !$forContent, $langCodeObj );
1661         }
1662
1663         if ( in_array( 'escape', $options, true ) ) {
1664                 $string = htmlspecialchars ( $string );
1665         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1666                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1667         }
1668
1669         if( in_array( 'replaceafter', $options, true ) ) {
1670                 $string = wfMsgReplaceArgs( $string, $args );
1671         }
1672
1673         return $string;
1674 }
1675
1676 /**
1677  * Since wfMsg() and co suck, they don't return false if the message key they
1678  * looked up didn't exist but a XHTML string, this function checks for the
1679  * nonexistance of messages by checking the MessageCache::get() result directly.
1680  *
1681  * @deprecated since 1.18
1682  *
1683  * @param $key      String: the message key looked up
1684  * @return Boolean True if the message *doesn't* exist.
1685  */
1686 function wfEmptyMsg( $key ) {
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 $msg String: message shown when dying.
1695  */
1696 function wfDebugDieBacktrace( $msg = '' ) {
1697         throw new MWException( $msg );
1698 }
1699
1700 /**
1701  * Fetch server name for use in error reporting etc.
1702  * Use real server name if available, so we know which machine
1703  * in a server farm generated the current page.
1704  *
1705  * @return string
1706  */
1707 function wfHostname() {
1708         static $host;
1709         if ( is_null( $host ) ) {
1710
1711                 # Hostname overriding
1712                 global $wgOverrideHostname;
1713                 if( $wgOverrideHostname !== false ) {
1714                         # Set static and skip any detection
1715                         $host = $wgOverrideHostname;
1716                         return $host;
1717                 }
1718
1719                 if ( function_exists( 'posix_uname' ) ) {
1720                         // This function not present on Windows
1721                         $uname = posix_uname();
1722                 } else {
1723                         $uname = false;
1724                 }
1725                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1726                         $host = $uname['nodename'];
1727                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1728                         # Windows computer name
1729                         $host = getenv( 'COMPUTERNAME' );
1730                 } else {
1731                         # This may be a virtual server.
1732                         $host = $_SERVER['SERVER_NAME'];
1733                 }
1734         }
1735         return $host;
1736 }
1737
1738 /**
1739  * Returns a HTML comment with the elapsed time since request.
1740  * This method has no side effects.
1741  *
1742  * @return string
1743  */
1744 function wfReportTime() {
1745         global $wgRequestTime, $wgShowHostnames;
1746
1747         $elapsed = microtime( true ) - $wgRequestTime;
1748
1749         return $wgShowHostnames
1750                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1751                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1752 }
1753
1754 /**
1755  * Safety wrapper for debug_backtrace().
1756  *
1757  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1758  * murky circumstances, which may be triggered in part by stub objects
1759  * or other fancy talkin'.
1760  *
1761  * Will return an empty array if Zend Optimizer is detected or if
1762  * debug_backtrace is disabled, otherwise the output from
1763  * debug_backtrace() (trimmed).
1764  *
1765  * @param $limit int This parameter can be used to limit the number of stack frames returned
1766  *
1767  * @return array of backtrace information
1768  */
1769 function wfDebugBacktrace( $limit = 0 ) {
1770         static $disabled = null;
1771
1772         if( extension_loaded( 'Zend Optimizer' ) ) {
1773                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1774                 return array();
1775         }
1776
1777         if ( is_null( $disabled ) ) {
1778                 $disabled = false;
1779                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1780                 $functions = array_map( 'trim', $functions );
1781                 $functions = array_map( 'strtolower', $functions );
1782                 if ( in_array( 'debug_backtrace', $functions ) ) {
1783                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1784                         $disabled = true;
1785                 }
1786         }
1787         if ( $disabled ) {
1788                 return array();
1789         }
1790
1791         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1792                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1793         } else {
1794                 return array_slice( debug_backtrace(), 1 );
1795         }
1796 }
1797
1798 /**
1799  * Get a debug backtrace as a string
1800  *
1801  * @return string
1802  */
1803 function wfBacktrace() {
1804         global $wgCommandLineMode;
1805
1806         if ( $wgCommandLineMode ) {
1807                 $msg = '';
1808         } else {
1809                 $msg = "<ul>\n";
1810         }
1811         $backtrace = wfDebugBacktrace();
1812         foreach( $backtrace as $call ) {
1813                 if( isset( $call['file'] ) ) {
1814                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1815                         $file = $f[count( $f ) - 1];
1816                 } else {
1817                         $file = '-';
1818                 }
1819                 if( isset( $call['line'] ) ) {
1820                         $line = $call['line'];
1821                 } else {
1822                         $line = '-';
1823                 }
1824                 if ( $wgCommandLineMode ) {
1825                         $msg .= "$file line $line calls ";
1826                 } else {
1827                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1828                 }
1829                 if( !empty( $call['class'] ) ) {
1830                         $msg .= $call['class'] . $call['type'];
1831                 }
1832                 $msg .= $call['function'] . '()';
1833
1834                 if ( $wgCommandLineMode ) {
1835                         $msg .= "\n";
1836                 } else {
1837                         $msg .= "</li>\n";
1838                 }
1839         }
1840         if ( $wgCommandLineMode ) {
1841                 $msg .= "\n";
1842         } else {
1843                 $msg .= "</ul>\n";
1844         }
1845
1846         return $msg;
1847 }
1848
1849 /**
1850  * Get the name of the function which called this function
1851  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1852  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1853  * wfGetCaller( 3 ) is the parent of that.
1854  *
1855  * @param $level Int
1856  * @return Bool|string
1857  */
1858 function wfGetCaller( $level = 2 ) {
1859         $backtrace = wfDebugBacktrace( $level + 1 );
1860         if ( isset( $backtrace[$level] ) ) {
1861                 return wfFormatStackFrame( $backtrace[$level] );
1862         } else {
1863                 $caller = 'unknown';
1864         }
1865         return $caller;
1866 }
1867
1868 /**
1869  * Return a string consisting of callers in the stack. Useful sometimes
1870  * for profiling specific points.
1871  *
1872  * @param $limit int 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 Bool
1890  */
1891 function wfFormatStackFrame( $frame ) {
1892         return isset( $frame['class'] ) ?
1893                 $frame['class'] . '::' . $frame['function'] :
1894                 $frame['function'];
1895 }
1896
1897
1898 /* Some generic result counters, pulled out of SearchEngine */
1899
1900
1901 /**
1902  * @todo document
1903  *
1904  * @param $offset Int
1905  * @param $limit Int
1906  * @return String
1907  */
1908 function wfShowingResults( $offset, $limit ) {
1909         global $wgLang;
1910         return wfMsgExt(
1911                 'showingresults',
1912                 array( 'parseinline' ),
1913                 $wgLang->formatNum( $limit ),
1914                 $wgLang->formatNum( $offset + 1 )
1915         );
1916 }
1917
1918 /**
1919  * Generate (prev x| next x) (20|50|100...) type links for paging
1920  *
1921  * @param $offset String
1922  * @param $limit Integer
1923  * @param $link String
1924  * @param $query String: optional URL query parameter string
1925  * @param $atend Bool: optional param for specified if this is the last page
1926  * @return String
1927  * @deprecated in 1.19; use Language::viewPrevNext() instead
1928  */
1929 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1930         wfDeprecated( __METHOD__, '1.19' );
1931
1932         global $wgLang;
1933
1934         $query = wfCgiToArray( $query );
1935
1936         if( is_object( $link ) ) {
1937                 $title = $link;
1938         } else {
1939                 $title = Title::newFromText( $link );
1940                 if( is_null( $title ) ) {
1941                         return false;
1942                 }
1943         }
1944
1945         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1946 }
1947
1948 /**
1949  * Make a list item, used by various special pages
1950  *
1951  * @param $page String Page link
1952  * @param $details String Text between brackets
1953  * @param $oppositedm Boolean   Add the direction mark opposite to your
1954  *                                                              language, to display text properly
1955  * @return String
1956  * @deprecated since 1.19; use Language::specialList() instead
1957  */
1958 function wfSpecialList( $page, $details, $oppositedm = true ) {
1959         wfDeprecated( __METHOD__, '1.19' );
1960
1961         global $wgLang;
1962         return $wgLang->specialList( $page, $details, $oppositedm );
1963 }
1964
1965 /**
1966  * @todo document
1967  * @todo FIXME: We may want to blacklist some broken browsers
1968  *
1969  * @param $force Bool
1970  * @return bool Whereas client accept gzip compression
1971  */
1972 function wfClientAcceptsGzip( $force = false ) {
1973         static $result = null;
1974         if ( $result === null || $force ) {
1975                 $result = false;
1976                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1977                         # @todo FIXME: We may want to blacklist some broken browsers
1978                         $m = array();
1979                         if( preg_match(
1980                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1981                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1982                                 $m )
1983                         )
1984                         {
1985                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1986                                         $result = false;
1987                                         return $result;
1988                                 }
1989                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1990                                 $result = true;
1991                         }
1992                 }
1993         }
1994         return $result;
1995 }
1996
1997 /**
1998  * Obtain the offset and limit values from the request string;
1999  * used in special pages
2000  *
2001  * @param $deflimit Int default limit if none supplied
2002  * @param $optionname String Name of a user preference to check against
2003  * @return array
2004  *
2005  */
2006 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2007         global $wgRequest;
2008         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2009 }
2010
2011 /**
2012  * Escapes the given text so that it may be output using addWikiText()
2013  * without any linking, formatting, etc. making its way through. This
2014  * is achieved by substituting certain characters with HTML entities.
2015  * As required by the callers, "<nowiki>" is not used.
2016  *
2017  * @param $text String: text to be escaped
2018  * @return String
2019  */
2020 function wfEscapeWikiText( $text ) {
2021         $text = strtr( "\n$text", array(
2022                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2023                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2024                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2025                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2026                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2027                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2028         ) );
2029         return substr( $text, 1 );
2030 }
2031
2032 /**
2033  * Get the current unix timetstamp with microseconds.  Useful for profiling
2034  * @return Float
2035  */
2036 function wfTime() {
2037         return microtime( true );
2038 }
2039
2040 /**
2041  * Sets dest to source and returns the original value of dest
2042  * If source is NULL, it just returns the value, it doesn't set the variable
2043  * If force is true, it will set the value even if source is NULL
2044  *
2045  * @param $dest Mixed
2046  * @param $source Mixed
2047  * @param $force Bool
2048  * @return Mixed
2049  */
2050 function wfSetVar( &$dest, $source, $force = false ) {
2051         $temp = $dest;
2052         if ( !is_null( $source ) || $force ) {
2053                 $dest = $source;
2054         }
2055         return $temp;
2056 }
2057
2058 /**
2059  * As for wfSetVar except setting a bit
2060  *
2061  * @param $dest Int
2062  * @param $bit Int
2063  * @param $state Bool
2064  *
2065  * @return bool
2066  */
2067 function wfSetBit( &$dest, $bit, $state = true ) {
2068         $temp = (bool)( $dest & $bit );
2069         if ( !is_null( $state ) ) {
2070                 if ( $state ) {
2071                         $dest |= $bit;
2072                 } else {
2073                         $dest &= ~$bit;
2074                 }
2075         }
2076         return $temp;
2077 }
2078
2079 /**
2080  * A wrapper around the PHP function var_export().
2081  * Either print it or add it to the regular output ($wgOut).
2082  *
2083  * @param $var mixed A PHP variable to dump.
2084  */
2085 function wfVarDump( $var ) {
2086         global $wgOut;
2087         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2088         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2089                 print $s;
2090         } else {
2091                 $wgOut->addHTML( $s );
2092         }
2093 }
2094
2095 /**
2096  * Provide a simple HTTP error.
2097  *
2098  * @param $code Int|String
2099  * @param $label String
2100  * @param $desc String
2101  */
2102 function wfHttpError( $code, $label, $desc ) {
2103         global $wgOut;
2104         $wgOut->disable();
2105         header( "HTTP/1.0 $code $label" );
2106         header( "Status: $code $label" );
2107         $wgOut->sendCacheControl();
2108
2109         header( 'Content-type: text/html; charset=utf-8' );
2110         print "<!doctype html>" .
2111                 '<html><head><title>' .
2112                 htmlspecialchars( $label ) .
2113                 '</title></head><body><h1>' .
2114                 htmlspecialchars( $label ) .
2115                 '</h1><p>' .
2116                 nl2br( htmlspecialchars( $desc ) ) .
2117                 "</p></body></html>\n";
2118 }
2119
2120 /**
2121  * Clear away any user-level output buffers, discarding contents.
2122  *
2123  * Suitable for 'starting afresh', for instance when streaming
2124  * relatively large amounts of data without buffering, or wanting to
2125  * output image files without ob_gzhandler's compression.
2126  *
2127  * The optional $resetGzipEncoding parameter controls suppression of
2128  * the Content-Encoding header sent by ob_gzhandler; by default it
2129  * is left. See comments for wfClearOutputBuffers() for why it would
2130  * be used.
2131  *
2132  * Note that some PHP configuration options may add output buffer
2133  * layers which cannot be removed; these are left in place.
2134  *
2135  * @param $resetGzipEncoding Bool
2136  */
2137 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2138         if( $resetGzipEncoding ) {
2139                 // Suppress Content-Encoding and Content-Length
2140                 // headers from 1.10+s wfOutputHandler
2141                 global $wgDisableOutputCompression;
2142                 $wgDisableOutputCompression = true;
2143         }
2144         while( $status = ob_get_status() ) {
2145                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2146                         // Probably from zlib.output_compression or other
2147                         // PHP-internal setting which can't be removed.
2148                         //
2149                         // Give up, and hope the result doesn't break
2150                         // output behavior.
2151                         break;
2152                 }
2153                 if( !ob_end_clean() ) {
2154                         // Could not remove output buffer handler; abort now
2155                         // to avoid getting in some kind of infinite loop.
2156                         break;
2157                 }
2158                 if( $resetGzipEncoding ) {
2159                         if( $status['name'] == 'ob_gzhandler' ) {
2160                                 // Reset the 'Content-Encoding' field set by this handler
2161                                 // so we can start fresh.
2162                                 header_remove( 'Content-Encoding' );
2163                                 break;
2164                         }
2165                 }
2166         }
2167 }
2168
2169 /**
2170  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2171  *
2172  * Clear away output buffers, but keep the Content-Encoding header
2173  * produced by ob_gzhandler, if any.
2174  *
2175  * This should be used for HTTP 304 responses, where you need to
2176  * preserve the Content-Encoding header of the real result, but
2177  * also need to suppress the output of ob_gzhandler to keep to spec
2178  * and avoid breaking Firefox in rare cases where the headers and
2179  * body are broken over two packets.
2180  */
2181 function wfClearOutputBuffers() {
2182         wfResetOutputBuffers( false );
2183 }
2184
2185 /**
2186  * Converts an Accept-* header into an array mapping string values to quality
2187  * factors
2188  *
2189  * @param $accept String
2190  * @param $def String default
2191  * @return Array
2192  */
2193 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2194         # No arg means accept anything (per HTTP spec)
2195         if( !$accept ) {
2196                 return array( $def => 1.0 );
2197         }
2198
2199         $prefs = array();
2200
2201         $parts = explode( ',', $accept );
2202
2203         foreach( $parts as $part ) {
2204                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2205                 $values = explode( ';', trim( $part ) );
2206                 $match = array();
2207                 if ( count( $values ) == 1 ) {
2208                         $prefs[$values[0]] = 1.0;
2209                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2210                         $prefs[$values[0]] = floatval( $match[1] );
2211                 }
2212         }
2213
2214         return $prefs;
2215 }
2216
2217 /**
2218  * Checks if a given MIME type matches any of the keys in the given
2219  * array. Basic wildcards are accepted in the array keys.
2220  *
2221  * Returns the matching MIME type (or wildcard) if a match, otherwise
2222  * NULL if no match.
2223  *
2224  * @param $type String
2225  * @param $avail Array
2226  * @return string
2227  * @private
2228  */
2229 function mimeTypeMatch( $type, $avail ) {
2230         if( array_key_exists( $type, $avail ) ) {
2231                 return $type;
2232         } else {
2233                 $parts = explode( '/', $type );
2234                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2235                         return $parts[0] . '/*';
2236                 } elseif( array_key_exists( '*/*', $avail ) ) {
2237                         return '*/*';
2238                 } else {
2239                         return null;
2240                 }
2241         }
2242 }
2243
2244 /**
2245  * Returns the 'best' match between a client's requested internet media types
2246  * and the server's list of available types. Each list should be an associative
2247  * array of type to preference (preference is a float between 0.0 and 1.0).
2248  * Wildcards in the types are acceptable.
2249  *
2250  * @param $cprefs Array: client's acceptable type list
2251  * @param $sprefs Array: server's offered types
2252  * @return string
2253  *
2254  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2255  * XXX: generalize to negotiate other stuff
2256  */
2257 function wfNegotiateType( $cprefs, $sprefs ) {
2258         $combine = array();
2259
2260         foreach( array_keys( $sprefs ) as $type ) {
2261                 $parts = explode( '/', $type );
2262                 if( $parts[1] != '*' ) {
2263                         $ckey = mimeTypeMatch( $type, $cprefs );
2264                         if( $ckey ) {
2265                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2266                         }
2267                 }
2268         }
2269
2270         foreach( array_keys( $cprefs ) as $type ) {
2271                 $parts = explode( '/', $type );
2272                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2273                         $skey = mimeTypeMatch( $type, $sprefs );
2274                         if( $skey ) {
2275                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2276                         }
2277                 }
2278         }
2279
2280         $bestq = 0;
2281         $besttype = null;
2282
2283         foreach( array_keys( $combine ) as $type ) {
2284                 if( $combine[$type] > $bestq ) {
2285                         $besttype = $type;
2286                         $bestq = $combine[$type];
2287                 }
2288         }
2289
2290         return $besttype;
2291 }
2292
2293 /**
2294  * Reference-counted warning suppression
2295  *
2296  * @param $end Bool
2297  */
2298 function wfSuppressWarnings( $end = false ) {
2299         static $suppressCount = 0;
2300         static $originalLevel = false;
2301
2302         if ( $end ) {
2303                 if ( $suppressCount ) {
2304                         --$suppressCount;
2305                         if ( !$suppressCount ) {
2306                                 error_reporting( $originalLevel );
2307                         }
2308                 }
2309         } else {
2310                 if ( !$suppressCount ) {
2311                         // E_DEPRECATED is undefined in PHP 5.2
2312                         if( !defined( 'E_DEPRECATED' ) ) {
2313                                 define( 'E_DEPRECATED', 8192 );
2314                         }
2315                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2316                 }
2317                 ++$suppressCount;
2318         }
2319 }
2320
2321 /**
2322  * Restore error level to previous value
2323  */
2324 function wfRestoreWarnings() {
2325         wfSuppressWarnings( true );
2326 }
2327
2328 # Autodetect, convert and provide timestamps of various types
2329
2330 /**
2331  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2332  */
2333 define( 'TS_UNIX', 0 );
2334
2335 /**
2336  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2337  */
2338 define( 'TS_MW', 1 );
2339
2340 /**
2341  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2342  */
2343 define( 'TS_DB', 2 );
2344
2345 /**
2346  * RFC 2822 format, for E-mail and HTTP headers
2347  */
2348 define( 'TS_RFC2822', 3 );
2349
2350 /**
2351  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2352  *
2353  * This is used by Special:Export
2354  */
2355 define( 'TS_ISO_8601', 4 );
2356
2357 /**
2358  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2359  *
2360  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2361  *       DateTime tag and page 36 for the DateTimeOriginal and
2362  *       DateTimeDigitized tags.
2363  */
2364 define( 'TS_EXIF', 5 );
2365
2366 /**
2367  * Oracle format time.
2368  */
2369 define( 'TS_ORACLE', 6 );
2370
2371 /**
2372  * Postgres format time.
2373  */
2374 define( 'TS_POSTGRES', 7 );
2375
2376 /**
2377  * DB2 format time
2378  */
2379 define( 'TS_DB2', 8 );
2380
2381 /**
2382  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2383  */
2384 define( 'TS_ISO_8601_BASIC', 9 );
2385
2386 /**
2387  * Get a timestamp string in one of various formats
2388  *
2389  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2390  *                    function will autodetect which format is supplied and act
2391  *                    accordingly.
2392  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2393  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2394  */
2395 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2396         $uts = 0;
2397         $da = array();
2398         $strtime = '';
2399
2400         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2401                 $uts = time();
2402                 $strtime = "@$uts";
2403         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2404                 # TS_DB
2405         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2406                 # TS_EXIF
2407         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2408                 # TS_MW
2409         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2410                 # TS_UNIX
2411                 $uts = $ts;
2412                 $strtime = "@$ts"; // http://php.net/manual/en/datetime.formats.compound.php
2413         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2414                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2415                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2416                                 str_replace( '+00:00', 'UTC', $ts ) );
2417         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2418                 # TS_ISO_8601
2419         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2420                 #TS_ISO_8601_BASIC
2421         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2422                 # TS_POSTGRES
2423         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2424                 # TS_POSTGRES
2425         } elseif (preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/', $ts, $da ) ) {
2426                 # TS_DB2
2427         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2428                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2429                                                         '[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d/S', $ts ) ) { # hh:mm:ss
2430                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2431                 # The regex is a superset of rfc2822 for readability
2432                 $strtime = strtok( $ts, ';' );
2433         } elseif ( preg_match( '/^[A-Z][a-z]{5,8}, \d\d-[A-Z][a-z]{2}-\d{2} \d\d:\d\d:\d\d/', $ts ) ) {
2434                 # TS_RFC850
2435                 $strtime = $ts;
2436         } elseif ( preg_match( '/^[A-Z][a-z]{2} [A-Z][a-z]{2} +\d{1,2} \d\d:\d\d:\d\d \d{4}/', $ts ) ) {
2437                 # asctime
2438                 $strtime = $ts;
2439         } else {
2440                 # Bogus value...
2441                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2442
2443                 return false;
2444         }
2445
2446         static $formats = array(
2447                 TS_UNIX => 'U',
2448                 TS_MW => 'YmdHis',
2449                 TS_DB => 'Y-m-d H:i:s',
2450                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2451                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2452                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2453                 TS_RFC2822 => 'D, d M Y H:i:s',
2454                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2455                 TS_POSTGRES => 'Y-m-d H:i:s',
2456                 TS_DB2 => 'Y-m-d H:i:s',
2457         );
2458
2459         if ( !isset( $formats[$outputtype] ) ) {
2460                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2461         }
2462
2463         if ( function_exists( "date_create" ) ) {
2464                 if ( count( $da ) ) {
2465                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2466                                 (int)$da[1], (int)$da[2], (int)$da[3],
2467                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2468
2469                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2470                 } elseif ( $strtime ) {
2471                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2472                 } else {
2473                         return false;
2474                 }
2475
2476                 if ( !$d ) {
2477                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2478                         return false;
2479                 }
2480
2481                 $output = $d->format( $formats[$outputtype] );
2482         } else {
2483                 if ( count( $da ) ) {
2484                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2485                         // We may want to handle that explicitly at some point
2486                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2487                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2488                 } elseif ( $strtime ) {
2489                         $uts = strtotime( $strtime );
2490                 }
2491
2492                 if ( $uts === false ) {
2493                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2494                         return false;
2495                 }
2496
2497                 if ( TS_UNIX == $outputtype ) {
2498                         return $uts;
2499                 }
2500                 $output = gmdate( $formats[$outputtype], $uts );
2501         }
2502
2503         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2504                 $output .= ' GMT';
2505         }
2506
2507         return $output;
2508 }
2509
2510 /**
2511  * Return a formatted timestamp, or null if input is null.
2512  * For dealing with nullable timestamp columns in the database.
2513  *
2514  * @param $outputtype Integer
2515  * @param $ts String
2516  * @return String
2517  */
2518 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2519         if( is_null( $ts ) ) {
2520                 return null;
2521         } else {
2522                 return wfTimestamp( $outputtype, $ts );
2523         }
2524 }
2525
2526 /**
2527  * Convenience function; returns MediaWiki timestamp for the present time.
2528  *
2529  * @return string
2530  */
2531 function wfTimestampNow() {
2532         # return NOW
2533         return wfTimestamp( TS_MW, time() );
2534 }
2535
2536 /**
2537  * Check if the operating system is Windows
2538  *
2539  * @return Bool: true if it's Windows, False otherwise.
2540  */
2541 function wfIsWindows() {
2542         static $isWindows = null;
2543         if ( $isWindows === null ) {
2544                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2545         }
2546         return $isWindows;
2547 }
2548
2549 /**
2550  * Check if we are running under HipHop
2551  *
2552  * @return Bool
2553  */
2554 function wfIsHipHop() {
2555         return function_exists( 'hphp_thread_set_warmup_enabled' );
2556 }
2557
2558 /**
2559  * Swap two variables
2560  *
2561  * @param $x Mixed
2562  * @param $y Mixed
2563  */
2564 function swap( &$x, &$y ) {
2565         $z = $x;
2566         $x = $y;
2567         $y = $z;
2568 }
2569
2570 /**
2571  * Tries to get the system directory for temporary files. First
2572  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2573  * environment variables are then checked in sequence, and if none are
2574  * set try sys_get_temp_dir().
2575  *
2576  * NOTE: When possible, use instead the tmpfile() function to create
2577  * temporary files to avoid race conditions on file creation, etc.
2578  *
2579  * @return String
2580  */
2581 function wfTempDir() {
2582         global $wgTmpDirectory;
2583
2584         if ( $wgTmpDirectory !== false ) {
2585                 return $wgTmpDirectory;
2586         }
2587
2588         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2589
2590         foreach( $tmpDir as $tmp ) {
2591                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2592                         return $tmp;
2593                 }
2594         }
2595         return sys_get_temp_dir();
2596 }
2597
2598 /**
2599  * Make directory, and make all parent directories if they don't exist
2600  *
2601  * @param $dir String: full path to directory to create
2602  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2603  * @param $caller String: optional caller param for debugging.
2604  * @return bool
2605  */
2606 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2607         global $wgDirectoryMode;
2608
2609         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2610                 throw new MWException( __FUNCTION__ . " given storage path `$dir`.");
2611         }
2612
2613         if ( !is_null( $caller ) ) {
2614                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2615         }
2616
2617         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2618                 return true;
2619         }
2620
2621         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2622
2623         if ( is_null( $mode ) ) {
2624                 $mode = $wgDirectoryMode;
2625         }
2626
2627         // Turn off the normal warning, we're doing our own below
2628         wfSuppressWarnings();
2629         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2630         wfRestoreWarnings();
2631
2632         if( !$ok ) {
2633                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2634                 trigger_error( sprintf( "%s: failed to mkdir \"%s\" mode 0%o", __FUNCTION__, $dir, $mode ),
2635                         E_USER_WARNING );
2636         }
2637         return $ok;
2638 }
2639
2640 /**
2641  * Remove a directory and all its content.
2642  * Does not hide error.
2643  */
2644 function wfRecursiveRemoveDir( $dir ) {
2645         wfDebug( __FUNCTION__ . "( $dir )\n" );
2646         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2647         if ( is_dir( $dir ) ) {
2648                 $objects = scandir( $dir );
2649                 foreach ( $objects as $object ) {
2650                         if ( $object != "." && $object != ".." ) {
2651                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2652                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2653                                 } else {
2654                                         unlink( $dir . '/' . $object );
2655                                 }
2656                         }
2657                 }
2658                 reset( $objects );
2659                 rmdir( $dir );
2660         }
2661 }
2662
2663 /**
2664  * @param $nr Mixed: the number to format
2665  * @param $acc Integer: the number of digits after the decimal point, default 2
2666  * @param $round Boolean: whether or not to round the value, default true
2667  * @return float
2668  */
2669 function wfPercent( $nr, $acc = 2, $round = true ) {
2670         $ret = sprintf( "%.${acc}f", $nr );
2671         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2672 }
2673
2674 /**
2675  * Find out whether or not a mixed variable exists in a string
2676  *
2677  * @param $needle String
2678  * @param $str String
2679  * @param $insensitive Boolean
2680  * @return Boolean
2681  */
2682 function in_string( $needle, $str, $insensitive = false ) {
2683         $func = 'strpos';
2684         if( $insensitive ) $func = 'stripos';
2685
2686         return $func( $str, $needle ) !== false;
2687 }
2688
2689 /**
2690  * Safety wrapper around ini_get() for boolean settings.
2691  * The values returned from ini_get() are pre-normalized for settings
2692  * set via php.ini or php_flag/php_admin_flag... but *not*
2693  * for those set via php_value/php_admin_value.
2694  *
2695  * It's fairly common for people to use php_value instead of php_flag,
2696  * which can leave you with an 'off' setting giving a false positive
2697  * for code that just takes the ini_get() return value as a boolean.
2698  *
2699  * To make things extra interesting, setting via php_value accepts
2700  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2701  * Unrecognized values go false... again opposite PHP's own coercion
2702  * from string to bool.
2703  *
2704  * Luckily, 'properly' set settings will always come back as '0' or '1',
2705  * so we only have to worry about them and the 'improper' settings.
2706  *
2707  * I frickin' hate PHP... :P
2708  *
2709  * @param $setting String
2710  * @return Bool
2711  */
2712 function wfIniGetBool( $setting ) {
2713         $val = ini_get( $setting );
2714         // 'on' and 'true' can't have whitespace around them, but '1' can.
2715         return strtolower( $val ) == 'on'
2716                 || strtolower( $val ) == 'true'
2717                 || strtolower( $val ) == 'yes'
2718                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2719 }
2720
2721 /**
2722  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2723  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2724  *
2725  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2726  *                          should be omitted
2727  * @param $fileName String Name of the library, if not $extension.suffix
2728  * @return Bool - Whether or not the extension is loaded
2729  */
2730 function wfDl( $extension, $fileName = null ) {
2731         if( extension_loaded( $extension ) ) {
2732                 return true;
2733         }
2734
2735         $canDl = false;
2736         $sapi = php_sapi_name();
2737         if( $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' ) {
2738                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2739                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2740         }
2741
2742         if( $canDl ) {
2743                 $fileName = $fileName ? $fileName : $extension;
2744                 if( wfIsWindows() ) {
2745                         $fileName = 'php_' . $fileName;
2746                 }
2747                 wfSuppressWarnings();
2748                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2749                 wfRestoreWarnings();
2750         }
2751         return extension_loaded( $extension );
2752 }
2753
2754 /**
2755  * Windows-compatible version of escapeshellarg()
2756  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2757  * function puts single quotes in regardless of OS.
2758  *
2759  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2760  * earlier distro releases of PHP)
2761  *
2762  * @param varargs
2763  * @return String
2764  */
2765 function wfEscapeShellArg( ) {
2766         wfInitShellLocale();
2767
2768         $args = func_get_args();
2769         $first = true;
2770         $retVal = '';
2771         foreach ( $args as $arg ) {
2772                 if ( !$first ) {
2773                         $retVal .= ' ';
2774                 } else {
2775                         $first = false;
2776                 }
2777
2778                 if ( wfIsWindows() ) {
2779                         // Escaping for an MSVC-style command line parser and CMD.EXE
2780                         // Refs:
2781                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2782                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2783                         //  * Bug #13518
2784                         //  * CR r63214
2785                         // Double the backslashes before any double quotes. Escape the double quotes.
2786                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2787                         $arg = '';
2788                         $iteration = 0;
2789                         foreach ( $tokens as $token ) {
2790                                 if ( $iteration % 2 == 1 ) {
2791                                         // Delimiter, a double quote preceded by zero or more slashes
2792                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2793                                 } elseif ( $iteration % 4 == 2 ) {
2794                                         // ^ in $token will be outside quotes, need to be escaped
2795                                         $arg .= str_replace( '^', '^^', $token );
2796                                 } else { // $iteration % 4 == 0
2797                                         // ^ in $token will appear inside double quotes, so leave as is
2798                                         $arg .= $token;
2799                                 }
2800                                 $iteration++;
2801                         }
2802                         // Double the backslashes before the end of the string, because
2803                         // we will soon add a quote
2804                         $m = array();
2805                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2806                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2807                         }
2808
2809                         // Add surrounding quotes
2810                         $retVal .= '"' . $arg . '"';
2811                 } else {
2812                         $retVal .= escapeshellarg( $arg );
2813                 }
2814         }
2815         return $retVal;
2816 }
2817
2818 /**
2819  * Execute a shell command, with time and memory limits mirrored from the PHP
2820  * configuration if supported.
2821  * @param $cmd String Command line, properly escaped for shell.
2822  * @param &$retval null|Mixed optional, will receive the program's exit code.
2823  *                 (non-zero is usually failure)
2824  * @param $environ Array optional environment variables which should be
2825  *                 added to the executed command environment.
2826  * @param $limits Array optional array with limits(filesize, memory, time)
2827  *                 this overwrites the global wgShellMax* limits.
2828  * @return string collected stdout as a string (trailing newlines stripped)
2829  */
2830 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2831         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2832
2833         static $disabled;
2834         if ( is_null( $disabled ) ) {
2835                 $disabled = false;
2836                 if( wfIniGetBool( 'safe_mode' ) ) {
2837                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2838                         $disabled = 'safemode';
2839                 } else {
2840                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2841                         $functions = array_map( 'trim', $functions );
2842                         $functions = array_map( 'strtolower', $functions );
2843                         if ( in_array( 'passthru', $functions ) ) {
2844                                 wfDebug( "passthru is in disabled_functions\n" );
2845                                 $disabled = 'passthru';
2846                         }
2847                 }
2848         }
2849         if ( $disabled ) {
2850                 $retval = 1;
2851                 return $disabled == 'safemode' ?
2852                         'Unable to run external programs in safe mode.' :
2853                         'Unable to run external programs, passthru() is disabled.';
2854         }
2855
2856         wfInitShellLocale();
2857
2858         $envcmd = '';
2859         foreach( $environ as $k => $v ) {
2860                 if ( wfIsWindows() ) {
2861                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2862                          * appear in the environment variable, so we must use carat escaping as documented in
2863                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2864                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2865                          * are listed there but doesn't appear to need it.
2866                          */
2867                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2868                 } else {
2869                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2870                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2871                          */
2872                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2873                 }
2874         }
2875         $cmd = $envcmd . $cmd;
2876
2877         if ( php_uname( 's' ) == 'Linux' ) {
2878                 $time = intval ( isset($limits['time']) ? $limits['time'] : $wgMaxShellTime );
2879                 $mem = intval ( isset($limits['memory']) ? $limits['memory'] : $wgMaxShellMemory );
2880                 $filesize = intval ( isset($limits['filesize']) ? $limits['filesize'] : $wgMaxShellFileSize );
2881
2882                 if ( $time > 0 && $mem > 0 ) {
2883                         $script = "$IP/bin/ulimit4.sh";
2884                         if ( is_executable( $script ) ) {
2885                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2886                         }
2887                 }
2888         }
2889         wfDebug( "wfShellExec: $cmd\n" );
2890
2891         $retval = 1; // error by default?
2892         ob_start();
2893         passthru( $cmd, $retval );
2894         $output = ob_get_contents();
2895         ob_end_clean();
2896
2897         if ( $retval == 127 ) {
2898                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2899         }
2900         return $output;
2901 }
2902
2903 /**
2904  * Workaround for http://bugs.php.net/bug.php?id=45132
2905  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2906  */
2907 function wfInitShellLocale() {
2908         static $done = false;
2909         if ( $done ) {
2910                 return;
2911         }
2912         $done = true;
2913         global $wgShellLocale;
2914         if ( !wfIniGetBool( 'safe_mode' ) ) {
2915                 putenv( "LC_CTYPE=$wgShellLocale" );
2916                 setlocale( LC_CTYPE, $wgShellLocale );
2917         }
2918 }
2919
2920 /**
2921  * Alias to wfShellWikiCmd()
2922  * @see wfShellWikiCmd()
2923  */
2924 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2925         return wfShellWikiCmd( $script, $parameters, $options );
2926 }
2927
2928 /**
2929  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2930  * Note that $parameters should be a flat array and an option with an argument
2931  * should consist of two consecutive items in the array (do not use "--option value").
2932  * @param $script string MediaWiki cli script path
2933  * @param $parameters Array Arguments and options to the script
2934  * @param $options Array Associative array of options:
2935  *              'php': The path to the php executable
2936  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2937  * @return Array
2938  */
2939 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2940         global $wgPhpCli;
2941         // Give site config file a chance to run the script in a wrapper.
2942         // The caller may likely want to call wfBasename() on $script.
2943         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2944         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2945         if ( isset( $options['wrapper'] ) ) {
2946                 $cmd[] = $options['wrapper'];
2947         }
2948         $cmd[] = $script;
2949         // Escape each parameter for shell
2950         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2951 }
2952
2953 /**
2954  * wfMerge attempts to merge differences between three texts.
2955  * Returns true for a clean merge and false for failure or a conflict.
2956  *
2957  * @param $old String
2958  * @param $mine String
2959  * @param $yours String
2960  * @param $result String
2961  * @return Bool
2962  */
2963 function wfMerge( $old, $mine, $yours, &$result ) {
2964         global $wgDiff3;
2965
2966         # This check may also protect against code injection in
2967         # case of broken installations.
2968         wfSuppressWarnings();
2969         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2970         wfRestoreWarnings();
2971
2972         if( !$haveDiff3 ) {
2973                 wfDebug( "diff3 not found\n" );
2974                 return false;
2975         }
2976
2977         # Make temporary files
2978         $td = wfTempDir();
2979         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2980         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2981         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2982
2983         fwrite( $oldtextFile, $old );
2984         fclose( $oldtextFile );
2985         fwrite( $mytextFile, $mine );
2986         fclose( $mytextFile );
2987         fwrite( $yourtextFile, $yours );
2988         fclose( $yourtextFile );
2989
2990         # Check for a conflict
2991         $cmd = $wgDiff3 . ' -a --overlap-only ' .
2992                 wfEscapeShellArg( $mytextName ) . ' ' .
2993                 wfEscapeShellArg( $oldtextName ) . ' ' .
2994                 wfEscapeShellArg( $yourtextName );
2995         $handle = popen( $cmd, 'r' );
2996
2997         if( fgets( $handle, 1024 ) ) {
2998                 $conflict = true;
2999         } else {
3000                 $conflict = false;
3001         }
3002         pclose( $handle );
3003
3004         # Merge differences
3005         $cmd = $wgDiff3 . ' -a -e --merge ' .
3006                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3007         $handle = popen( $cmd, 'r' );
3008         $result = '';
3009         do {
3010                 $data = fread( $handle, 8192 );
3011                 if ( strlen( $data ) == 0 ) {
3012                         break;
3013                 }
3014                 $result .= $data;
3015         } while ( true );
3016         pclose( $handle );
3017         unlink( $mytextName );
3018         unlink( $oldtextName );
3019         unlink( $yourtextName );
3020
3021         if ( $result === '' && $old !== '' && !$conflict ) {
3022                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3023                 $conflict = true;
3024         }
3025         return !$conflict;
3026 }
3027
3028 /**
3029  * Returns unified plain-text diff of two texts.
3030  * Useful for machine processing of diffs.
3031  *
3032  * @param $before String: the text before the changes.
3033  * @param $after String: the text after the changes.
3034  * @param $params String: command-line options for the diff command.
3035  * @return String: unified diff of $before and $after
3036  */
3037 function wfDiff( $before, $after, $params = '-u' ) {
3038         if ( $before == $after ) {
3039                 return '';
3040         }
3041
3042         global $wgDiff;
3043         wfSuppressWarnings();
3044         $haveDiff = $wgDiff && file_exists( $wgDiff );
3045         wfRestoreWarnings();
3046
3047         # This check may also protect against code injection in
3048         # case of broken installations.
3049         if( !$haveDiff ) {
3050                 wfDebug( "diff executable not found\n" );
3051                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3052                 $format = new UnifiedDiffFormatter();
3053                 return $format->format( $diffs );
3054         }
3055
3056         # Make temporary files
3057         $td = wfTempDir();
3058         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3059         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3060
3061         fwrite( $oldtextFile, $before );
3062         fclose( $oldtextFile );
3063         fwrite( $newtextFile, $after );
3064         fclose( $newtextFile );
3065
3066         // Get the diff of the two files
3067         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3068
3069         $h = popen( $cmd, 'r' );
3070
3071         $diff = '';
3072
3073         do {
3074                 $data = fread( $h, 8192 );
3075                 if ( strlen( $data ) == 0 ) {
3076                         break;
3077                 }
3078                 $diff .= $data;
3079         } while ( true );
3080
3081         // Clean up
3082         pclose( $h );
3083         unlink( $oldtextName );
3084         unlink( $newtextName );
3085
3086         // Kill the --- and +++ lines. They're not useful.
3087         $diff_lines = explode( "\n", $diff );
3088         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3089                 unset( $diff_lines[0] );
3090         }
3091         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3092                 unset( $diff_lines[1] );
3093         }
3094
3095         $diff = implode( "\n", $diff_lines );
3096
3097         return $diff;
3098 }
3099
3100 /**
3101  * This function works like "use VERSION" in Perl, the program will die with a
3102  * backtrace if the current version of PHP is less than the version provided
3103  *
3104  * This is useful for extensions which due to their nature are not kept in sync
3105  * with releases, and might depend on other versions of PHP than the main code
3106  *
3107  * Note: PHP might die due to parsing errors in some cases before it ever
3108  *       manages to call this function, such is life
3109  *
3110  * @see perldoc -f use
3111  *
3112  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3113  *                 a float
3114  */
3115 function wfUsePHP( $req_ver ) {
3116         $php_ver = PHP_VERSION;
3117
3118         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3119                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3120         }
3121 }
3122
3123 /**
3124  * This function works like "use VERSION" in Perl except it checks the version
3125  * of MediaWiki, the program will die with a backtrace if the current version
3126  * of MediaWiki is less than the version provided.
3127  *
3128  * This is useful for extensions which due to their nature are not kept in sync
3129  * with releases
3130  *
3131  * @see perldoc -f use
3132  *
3133  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3134  *                 a float
3135  */
3136 function wfUseMW( $req_ver ) {
3137         global $wgVersion;
3138
3139         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3140                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3141         }
3142 }
3143
3144 /**
3145  * Return the final portion of a pathname.
3146  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3147  * http://bugs.php.net/bug.php?id=33898
3148  *
3149  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3150  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3151  *
3152  * @param $path String
3153  * @param $suffix String: to remove if present
3154  * @return String
3155  */
3156 function wfBaseName( $path, $suffix = '' ) {
3157         $encSuffix = ( $suffix == '' )
3158                 ? ''
3159                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3160         $matches = array();
3161         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3162                 return $matches[1];
3163         } else {
3164                 return '';
3165         }
3166 }
3167
3168 /**
3169  * Generate a relative path name to the given file.
3170  * May explode on non-matching case-insensitive paths,
3171  * funky symlinks, etc.
3172  *
3173  * @param $path String: absolute destination path including target filename
3174  * @param $from String: Absolute source path, directory only
3175  * @return String
3176  */
3177 function wfRelativePath( $path, $from ) {
3178         // Normalize mixed input on Windows...
3179         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3180         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3181
3182         // Trim trailing slashes -- fix for drive root
3183         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3184         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3185
3186         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3187         $against = explode( DIRECTORY_SEPARATOR, $from );
3188
3189         if( $pieces[0] !== $against[0] ) {
3190                 // Non-matching Windows drive letters?
3191                 // Return a full path.
3192                 return $path;
3193         }
3194
3195         // Trim off common prefix
3196         while( count( $pieces ) && count( $against )
3197                 && $pieces[0] == $against[0] ) {
3198                 array_shift( $pieces );
3199                 array_shift( $against );
3200         }
3201
3202         // relative dots to bump us to the parent
3203         while( count( $against ) ) {
3204                 array_unshift( $pieces, '..' );
3205                 array_shift( $against );
3206         }
3207
3208         array_push( $pieces, wfBaseName( $path ) );
3209
3210         return implode( DIRECTORY_SEPARATOR, $pieces );
3211 }
3212
3213 /**
3214  * Do any deferred updates and clear the list
3215  *
3216  * @deprecated since 1.19
3217  * @see DeferredUpdates::doUpdate()
3218  * @param $commit string
3219  */
3220 function wfDoUpdates( $commit = '' ) {
3221         wfDeprecated( __METHOD__, '1.19' );
3222         DeferredUpdates::doUpdates( $commit );
3223 }
3224
3225 /**
3226  * Convert an arbitrarily-long digit string from one numeric base
3227  * to another, optionally zero-padding to a minimum column width.
3228  *
3229  * Supports base 2 through 36; digit values 10-36 are represented
3230  * as lowercase letters a-z. Input is case-insensitive.
3231  *
3232  * @param $input String: of digits
3233  * @param $sourceBase Integer: 2-36
3234  * @param $destBase Integer: 2-36
3235  * @param $pad Integer: 1 or greater
3236  * @param $lowercase Boolean
3237  * @return String or false on invalid input
3238  */
3239 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3240         $input = strval( $input );
3241         if( $sourceBase < 2 ||
3242                 $sourceBase > 36 ||
3243                 $destBase < 2 ||
3244                 $destBase > 36 ||
3245                 $pad < 1 ||
3246                 $sourceBase != intval( $sourceBase ) ||
3247                 $destBase != intval( $destBase ) ||
3248                 $pad != intval( $pad ) ||
3249                 !is_string( $input ) ||
3250                 $input == '' ) {
3251                 return false;
3252         }
3253         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3254         $inDigits = array();
3255         $outChars = '';
3256
3257         // Decode and validate input string
3258         $input = strtolower( $input );
3259         for( $i = 0; $i < strlen( $input ); $i++ ) {
3260                 $n = strpos( $digitChars, $input[$i] );
3261                 if( $n === false || $n > $sourceBase ) {
3262                         return false;
3263                 }
3264                 $inDigits[] = $n;
3265         }
3266
3267         // Iterate over the input, modulo-ing out an output digit
3268         // at a time until input is gone.
3269         while( count( $inDigits ) ) {
3270                 $work = 0;
3271                 $workDigits = array();
3272
3273                 // Long division...
3274                 foreach( $inDigits as $digit ) {
3275                         $work *= $sourceBase;
3276                         $work += $digit;
3277
3278                         if( $work < $destBase ) {
3279                                 // Gonna need to pull another digit.
3280                                 if( count( $workDigits ) ) {
3281                                         // Avoid zero-padding; this lets us find
3282                                         // the end of the input very easily when
3283                                         // length drops to zero.
3284                                         $workDigits[] = 0;
3285                                 }
3286                         } else {
3287                                 // Finally! Actual division!
3288                                 $workDigits[] = intval( $work / $destBase );
3289
3290                                 // Isn't it annoying that most programming languages
3291                                 // don't have a single divide-and-remainder operator,
3292                                 // even though the CPU implements it that way?
3293                                 $work = $work % $destBase;
3294                         }
3295                 }
3296
3297                 // All that division leaves us with a remainder,
3298                 // which is conveniently our next output digit.
3299                 $outChars .= $digitChars[$work];
3300
3301                 // And we continue!
3302                 $inDigits = $workDigits;
3303         }
3304
3305         while( strlen( $outChars ) < $pad ) {
3306                 $outChars .= '0';
3307         }
3308
3309         return strrev( $outChars );
3310 }
3311
3312 /**
3313  * Create an object with a given name and an array of construct parameters
3314  *
3315  * @param $name String
3316  * @param $p Array: parameters
3317  * @return object
3318  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3319  */
3320 function wfCreateObject( $name, $p ) {
3321         wfDeprecated( __FUNCTION__, '1.18' );
3322         return MWFunction::newObj( $name, $p );
3323 }
3324
3325 /**
3326  * @return bool
3327  */
3328 function wfHttpOnlySafe() {
3329         global $wgHttpOnlyBlacklist;
3330
3331         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3332                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3333                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3334                                 return false;
3335                         }
3336                 }
3337         }
3338
3339         return true;
3340 }
3341
3342 /**
3343  * Override session_id before session startup if php's built-in
3344  * session generation code is not secure.
3345  */
3346 function wfFixSessionID() {
3347         // If the cookie or session id is already set we already have a session and should abort
3348         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3349                 return;
3350         }
3351
3352         // PHP's built-in session entropy is enabled if:
3353         // - entropy_file is set or you're on Windows with php 5.3.3+
3354         // - AND entropy_length is > 0
3355         // We treat it as disabled if it doesn't have an entropy length of at least 32
3356         $entropyEnabled = (
3357                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3358                         || ini_get( 'session.entropy_file' )
3359                 )
3360                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3361
3362         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3363         if ( !$entropyEnabled ) {
3364                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3365                 session_id( MWCryptRand::generateHex( 32 ) );
3366         }
3367 }
3368
3369 /**
3370  * Initialise php session
3371  *
3372  * @param $sessionId Bool
3373  */
3374 function wfSetupSession( $sessionId = false ) {
3375         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3376                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3377         if( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3378                 ObjectCacheSessionHandler::install();
3379         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3380                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3381                 # hasn't already been set to the desired value (that causes errors)
3382                 ini_set( 'session.save_handler', $wgSessionHandler );
3383         }
3384         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3385         wfDebugLog( 'cookie',
3386                 'session_set_cookie_params: "' . implode( '", "',
3387                         array(
3388                                 0,
3389                                 $wgCookiePath,
3390                                 $wgCookieDomain,
3391                                 $wgCookieSecure,
3392                                 $httpOnlySafe ) ) . '"' );
3393         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3394         session_cache_limiter( 'private, must-revalidate' );
3395         if ( $sessionId ) {
3396                 session_id( $sessionId );
3397         } else {
3398                 wfFixSessionID();
3399         }
3400         wfSuppressWarnings();
3401         session_start();
3402         wfRestoreWarnings();
3403 }
3404
3405 /**
3406  * Get an object from the precompiled serialized directory
3407  *
3408  * @param $name String
3409  * @return Mixed: the variable on success, false on failure
3410  */
3411 function wfGetPrecompiledData( $name ) {
3412         global $IP;
3413
3414         $file = "$IP/serialized/$name";
3415         if ( file_exists( $file ) ) {
3416                 $blob = file_get_contents( $file );
3417                 if ( $blob ) {
3418                         return unserialize( $blob );
3419                 }
3420         }
3421         return false;
3422 }
3423
3424 /**
3425  * Get a cache key
3426  *
3427  * @param varargs
3428  * @return String
3429  */
3430 function wfMemcKey( /*... */ ) {
3431         global $wgCachePrefix;
3432         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3433         $args = func_get_args();
3434         $key = $prefix . ':' . implode( ':', $args );
3435         $key = str_replace( ' ', '_', $key );
3436         return $key;
3437 }
3438
3439 /**
3440  * Get a cache key for a foreign DB
3441  *
3442  * @param $db String
3443  * @param $prefix String
3444  * @param varargs String
3445  * @return String
3446  */
3447 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3448         $args = array_slice( func_get_args(), 2 );
3449         if ( $prefix ) {
3450                 $key = "$db-$prefix:" . implode( ':', $args );
3451         } else {
3452                 $key = $db . ':' . implode( ':', $args );
3453         }
3454         return $key;
3455 }
3456
3457 /**
3458  * Get an ASCII string identifying this wiki
3459  * This is used as a prefix in memcached keys
3460  *
3461  * @return String
3462  */
3463 function wfWikiID() {
3464         global $wgDBprefix, $wgDBname;
3465         if ( $wgDBprefix ) {
3466                 return "$wgDBname-$wgDBprefix";
3467         } else {
3468                 return $wgDBname;
3469         }
3470 }
3471
3472 /**
3473  * Split a wiki ID into DB name and table prefix
3474  *
3475  * @param $wiki String
3476  *
3477  * @return array
3478  */
3479 function wfSplitWikiID( $wiki ) {
3480         $bits = explode( '-', $wiki, 2 );
3481         if ( count( $bits ) < 2 ) {
3482                 $bits[] = '';
3483         }
3484         return $bits;
3485 }
3486
3487 /**
3488  * Get a Database object.
3489  *
3490  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3491  *            master (for write queries), DB_SLAVE for potentially lagged read
3492  *            queries, or an integer >= 0 for a particular server.
3493  *
3494  * @param $groups Mixed: query groups. An array of group names that this query
3495  *                belongs to. May contain a single string if the query is only
3496  *                in one group.
3497  *
3498  * @param $wiki String: the wiki ID, or false for the current wiki
3499  *
3500  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3501  * will always return the same object, unless the underlying connection or load
3502  * balancer is manually destroyed.
3503  *
3504  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3505  * updater to ensure that a proper database is being updated.
3506  *
3507  * @return DatabaseBase
3508  */
3509 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3510         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3511 }
3512
3513 /**
3514  * Get a load balancer object.
3515  *
3516  * @param $wiki String: wiki ID, or false for the current wiki
3517  * @return LoadBalancer
3518  */
3519 function wfGetLB( $wiki = false ) {
3520         return wfGetLBFactory()->getMainLB( $wiki );
3521 }
3522
3523 /**
3524  * Get the load balancer factory object
3525  *
3526  * @return LBFactory
3527  */
3528 function &wfGetLBFactory() {
3529         return LBFactory::singleton();
3530 }
3531
3532 /**
3533  * Find a file.
3534  * Shortcut for RepoGroup::singleton()->findFile()
3535  *
3536  * @param $title String or Title object
3537  * @param $options array Associative array of options:
3538  *     time:           requested time for an archived image, or false for the
3539  *                     current version. An image object will be returned which was
3540  *                     created at the specified time.
3541  *
3542  *     ignoreRedirect: If true, do not follow file redirects
3543  *
3544  *     private:        If true, return restricted (deleted) files if the current
3545  *                     user is allowed to view them. Otherwise, such files will not
3546  *                     be found.
3547  *
3548  *     bypassCache:    If true, do not use the process-local cache of File objects
3549  *
3550  * @return File, or false if the file does not exist
3551  */
3552 function wfFindFile( $title, $options = array() ) {
3553         return RepoGroup::singleton()->findFile( $title, $options );
3554 }
3555
3556 /**
3557  * Get an object referring to a locally registered file.
3558  * Returns a valid placeholder object if the file does not exist.
3559  *
3560  * @param $title Title|String
3561  * @return LocalFile|null A File, or null if passed an invalid Title
3562  */
3563 function wfLocalFile( $title ) {
3564         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3565 }
3566
3567 /**
3568  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3569  * @deprecated since 1.19
3570  */
3571 function wfStreamFile( $fname, $headers = array() ) {
3572         wfDeprecated( __FUNCTION__, '1.19' );
3573         StreamFile::stream( $fname, $headers );
3574 }
3575
3576 /**
3577  * Should low-performance queries be disabled?
3578  *
3579  * @return Boolean
3580  * @codeCoverageIgnore
3581  */
3582 function wfQueriesMustScale() {
3583         global $wgMiserMode;
3584         return $wgMiserMode
3585                 || ( SiteStats::pages() > 100000
3586                 && SiteStats::edits() > 1000000
3587                 && SiteStats::users() > 10000 );
3588 }
3589
3590 /**
3591  * Get the path to a specified script file, respecting file
3592  * extensions; this is a wrapper around $wgScriptExtension etc.
3593  *
3594  * @param $script String: script filename, sans extension
3595  * @return String
3596  */
3597 function wfScript( $script = 'index' ) {
3598         global $wgScriptPath, $wgScriptExtension;
3599         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3600 }
3601
3602 /**
3603  * Get the script URL.
3604  *
3605  * @return string script URL
3606  */
3607 function wfGetScriptUrl() {
3608         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3609                 #
3610                 # as it was called, minus the query string.
3611                 #
3612                 # Some sites use Apache rewrite rules to handle subdomains,
3613                 # and have PHP set up in a weird way that causes PHP_SELF
3614                 # to contain the rewritten URL instead of the one that the
3615                 # outside world sees.
3616                 #
3617                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3618                 # provides containing the "before" URL.
3619                 return $_SERVER['SCRIPT_NAME'];
3620         } else {
3621                 return $_SERVER['URL'];
3622         }
3623 }
3624
3625 /**
3626  * Convenience function converts boolean values into "true"
3627  * or "false" (string) values
3628  *
3629  * @param $value Boolean
3630  * @return String
3631  */
3632 function wfBoolToStr( $value ) {
3633         return $value ? 'true' : 'false';
3634 }
3635
3636 /**
3637  * Load an extension messages file
3638  *
3639  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3640  * @codeCoverageIgnore
3641  */
3642 function wfLoadExtensionMessages() {
3643         wfDeprecated( __FUNCTION__, '1.16' );
3644 }
3645
3646 /**
3647  * Get a platform-independent path to the null file, e.g. /dev/null
3648  *
3649  * @return string
3650  */
3651 function wfGetNull() {
3652         return wfIsWindows()
3653                 ? 'NUL'
3654                 : '/dev/null';
3655 }
3656
3657 /**
3658  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3659  * and waiting for it to go down, this waits for the slaves to catch up to the
3660  * master position. Use this when updating very large numbers of rows, as
3661  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3662  * a no-op if there are no slaves.
3663  *
3664  * @param $maxLag Integer (deprecated)
3665  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3666  */
3667 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3668         $lb = wfGetLB( $wiki );
3669         // bug 27975 - Don't try to wait for slaves if there are none
3670         // Prevents permission error when getting master position
3671         if ( $lb->getServerCount() > 1 ) {
3672                 $dbw = $lb->getConnection( DB_MASTER );
3673                 $pos = $dbw->getMasterPos();
3674                 $lb->waitForAll( $pos );
3675         }
3676 }
3677
3678 /**
3679  * Used to be used for outputting text in the installer/updater
3680  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3681  */
3682 function wfOut( $s ) {
3683         wfDeprecated( __FUNCTION__, '1.18' );
3684         global $wgCommandLineMode;
3685         if ( $wgCommandLineMode ) {
3686                 echo $s;
3687         } else {
3688                 echo htmlspecialchars( $s );
3689         }
3690         flush();
3691 }
3692
3693 /**
3694  * Count down from $n to zero on the terminal, with a one-second pause
3695  * between showing each number. For use in command-line scripts.
3696  * @codeCoverageIgnore
3697  * @param $n int
3698  */
3699 function wfCountDown( $n ) {
3700         for ( $i = $n; $i >= 0; $i-- ) {
3701                 if ( $i != $n ) {
3702                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3703                 }
3704                 echo $i;
3705                 flush();
3706                 if ( $i ) {
3707                         sleep( 1 );
3708                 }
3709         }
3710         echo "\n";
3711 }
3712
3713 /**
3714  * Generate a random 32-character hexadecimal token.
3715  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3716  *              characters before hashing.
3717  * @return string
3718  * @codeCoverageIgnore
3719  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pesudo-random strings
3720  * @warning This method is NOT secure. Additionally it has many callers that use it for pesudo-random purposes.
3721  */
3722 function wfGenerateToken( $salt = '' ) {
3723         wfDeprecated( __METHOD__, '1.20' );
3724         $salt = serialize( $salt );
3725         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3726 }
3727
3728 /**
3729  * Replace all invalid characters with -
3730  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3731  * By default, $wgIllegalFileChars = ':'
3732  *
3733  * @param $name Mixed: filename to process
3734  * @return String
3735  */
3736 function wfStripIllegalFilenameChars( $name ) {
3737         global $wgIllegalFileChars;
3738         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3739         $name = wfBaseName( $name );
3740         $name = preg_replace(
3741                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3742                 '-',
3743                 $name
3744         );
3745         return $name;
3746 }
3747
3748 /**
3749  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3750  *
3751  * @return Integer value memory was set to.
3752  */
3753 function wfMemoryLimit() {
3754         global $wgMemoryLimit;
3755         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3756         if( $memlimit != -1 ) {
3757                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3758                 if( $conflimit == -1 ) {
3759                         wfDebug( "Removing PHP's memory limit\n" );
3760                         wfSuppressWarnings();
3761                         ini_set( 'memory_limit', $conflimit );
3762                         wfRestoreWarnings();
3763                         return $conflimit;
3764                 } elseif ( $conflimit > $memlimit ) {
3765                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3766                         wfSuppressWarnings();
3767                         ini_set( 'memory_limit', $conflimit );
3768                         wfRestoreWarnings();
3769                         return $conflimit;
3770                 }
3771         }
3772         return $memlimit;
3773 }
3774
3775 /**
3776  * Converts shorthand byte notation to integer form
3777  *
3778  * @param $string String
3779  * @return Integer
3780  */
3781 function wfShorthandToInteger( $string = '' ) {
3782         $string = trim( $string );
3783         if( $string === '' ) {
3784                 return -1;
3785         }
3786         $last = $string[strlen( $string ) - 1];
3787         $val = intval( $string );
3788         switch( $last ) {
3789                 case 'g':
3790                 case 'G':
3791                         $val *= 1024;
3792                         // break intentionally missing
3793                 case 'm':
3794                 case 'M':
3795                         $val *= 1024;
3796                         // break intentionally missing
3797                 case 'k':
3798                 case 'K':
3799                         $val *= 1024;
3800         }
3801
3802         return $val;
3803 }
3804
3805 /**
3806  * Get the normalised IETF language tag
3807  * See unit test for examples.
3808  *
3809  * @param $code String: The language code.
3810  * @return String: The language code which complying with BCP 47 standards.
3811  */
3812 function wfBCP47( $code ) {
3813         $codeSegment = explode( '-', $code );
3814         $codeBCP = array();
3815         foreach ( $codeSegment as $segNo => $seg ) {
3816                 if ( count( $codeSegment ) > 0 ) {
3817                         // when previous segment is x, it is a private segment and should be lc
3818                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3819                                 $codeBCP[$segNo] = strtolower( $seg );
3820                         // ISO 3166 country code
3821                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3822                                 $codeBCP[$segNo] = strtoupper( $seg );
3823                         // ISO 15924 script code
3824                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3825                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3826                         // Use lowercase for other cases
3827                         } else {
3828                                 $codeBCP[$segNo] = strtolower( $seg );
3829                         }
3830                 } else {
3831                 // Use lowercase for single segment
3832                         $codeBCP[$segNo] = strtolower( $seg );
3833                 }
3834         }
3835         $langCode = implode( '-', $codeBCP );
3836         return $langCode;
3837 }
3838
3839 /**
3840  * Get a cache object.
3841  *
3842  * @param $inputType integer Cache type, one the the CACHE_* constants.
3843  * @return BagOStuff
3844  */
3845 function wfGetCache( $inputType ) {
3846         return ObjectCache::getInstance( $inputType );
3847 }
3848
3849 /**
3850  * Get the main cache object
3851  *
3852  * @return BagOStuff
3853  */
3854 function wfGetMainCache() {
3855         global $wgMainCacheType;
3856         return ObjectCache::getInstance( $wgMainCacheType );
3857 }
3858
3859 /**
3860  * Get the cache object used by the message cache
3861  *
3862  * @return BagOStuff
3863  */
3864 function wfGetMessageCacheStorage() {
3865         global $wgMessageCacheType;
3866         return ObjectCache::getInstance( $wgMessageCacheType );
3867 }
3868
3869 /**
3870  * Get the cache object used by the parser cache
3871  *
3872  * @return BagOStuff
3873  */
3874 function wfGetParserCacheStorage() {
3875         global $wgParserCacheType;
3876         return ObjectCache::getInstance( $wgParserCacheType );
3877 }
3878
3879 /**
3880  * Get the cache object used by the language converter
3881  *
3882  * @return BagOStuff
3883  */
3884 function wfGetLangConverterCacheStorage() {
3885         global $wgLanguageConverterCacheType;
3886         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3887 }
3888
3889 /**
3890  * Call hook functions defined in $wgHooks
3891  *
3892  * @param $event String: event name
3893  * @param $args Array: parameters passed to hook functions
3894  * @return Boolean True if no handler aborted the hook
3895  */
3896 function wfRunHooks( $event, $args = array() ) {
3897         return Hooks::run( $event, $args );
3898 }
3899
3900 /**
3901  * Wrapper around php's unpack.
3902  *
3903  * @param $format String: The format string (See php's docs)
3904  * @param $data: A binary string of binary data
3905  * @param $length integer or false: The minimun length of $data. This is to
3906  *      prevent reading beyond the end of $data. false to disable the check.
3907  *
3908  * Also be careful when using this function to read unsigned 32 bit integer
3909  * because php might make it negative.
3910  *
3911  * @throws MWException if $data not long enough, or if unpack fails
3912  * @return array Associative array of the extracted data
3913  */
3914 function wfUnpack( $format, $data, $length=false ) {
3915         if ( $length !== false ) {
3916                 $realLen = strlen( $data );
3917                 if ( $realLen < $length ) {
3918                         throw new MWException( "Tried to use wfUnpack on a "
3919                                 . "string of length $realLen, but needed one "
3920                                 . "of at least length $length."
3921                         );
3922                 }
3923         }
3924
3925         wfSuppressWarnings();
3926         $result = unpack( $format, $data );
3927         wfRestoreWarnings();
3928
3929         if ( $result === false ) {
3930                 // If it cannot extract the packed data.
3931                 throw new MWException( "unpack could not unpack binary data" );
3932         }
3933         return $result;
3934 }
3935
3936 /**
3937  * Determine if an image exists on the 'bad image list'.
3938  *
3939  * The format of MediaWiki:Bad_image_list is as follows:
3940  *    * Only list items (lines starting with "*") are considered
3941  *    * The first link on a line must be a link to a bad image
3942  *    * Any subsequent links on the same line are considered to be exceptions,
3943  *      i.e. articles where the image may occur inline.
3944  *
3945  * @param $name string the image name to check
3946  * @param $contextTitle Title|bool the page on which the image occurs, if known
3947  * @param $blacklist string wikitext of a file blacklist
3948  * @return bool
3949  */
3950 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3951         static $badImageCache = null; // based on bad_image_list msg
3952         wfProfileIn( __METHOD__ );
3953
3954         # Handle redirects
3955         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3956         if( $redirectTitle ) {
3957                 $name = $redirectTitle->getDbKey();
3958         }
3959
3960         # Run the extension hook
3961         $bad = false;
3962         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3963                 wfProfileOut( __METHOD__ );
3964                 return $bad;
3965         }
3966
3967         $cacheable = ( $blacklist === null );
3968         if( $cacheable && $badImageCache !== null ) {
3969                 $badImages = $badImageCache;
3970         } else { // cache miss
3971                 if ( $blacklist === null ) {
3972                         $blacklist = wfMsgForContentNoTrans( 'bad_image_list' ); // site list
3973                 }
3974                 # Build the list now
3975                 $badImages = array();
3976                 $lines = explode( "\n", $blacklist );
3977                 foreach( $lines as $line ) {
3978                         # List items only
3979                         if ( substr( $line, 0, 1 ) !== '*' ) {
3980                                 continue;
3981                         }
3982
3983                         # Find all links
3984                         $m = array();
3985                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3986                                 continue;
3987                         }
3988
3989                         $exceptions = array();
3990                         $imageDBkey = false;
3991                         foreach ( $m[1] as $i => $titleText ) {
3992                                 $title = Title::newFromText( $titleText );
3993                                 if ( !is_null( $title ) ) {
3994                                         if ( $i == 0 ) {
3995                                                 $imageDBkey = $title->getDBkey();
3996                                         } else {
3997                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3998                                         }
3999                                 }
4000                         }
4001
4002                         if ( $imageDBkey !== false ) {
4003                                 $badImages[$imageDBkey] = $exceptions;
4004                         }
4005                 }
4006                 if ( $cacheable ) {
4007                         $badImageCache = $badImages;
4008                 }
4009         }
4010
4011         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4012         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4013         wfProfileOut( __METHOD__ );
4014         return $bad;
4015 }