includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere
   4  * @file
   5  */
   6
   7 if ( !defined( 'MEDIAWIKI' ) ) {
   8         die( "This file is part of MediaWiki, it is not a valid entry point" );
   9 }
  10
  11 // Hide compatibility functions from Doxygen
  12 /// @cond
  13
  14 /**
  15  * Compatibility functions
  16  *
  17  * We support PHP 5.2.3 and up.
  18  * Re-implementations of newer functions or functions in non-standard
  19  * PHP extensions may be included here.
  20  */
  21
  22 if( !function_exists( 'iconv' ) ) {
  23         /**
  24          * @codeCoverageIgnore
  25          * @return string
  26          */
  27         function iconv( $from, $to, $string ) {
  28                 return Fallback::iconv( $from, $to, $string );
  29         }
  30 }
  31
  32 if ( !function_exists( 'mb_substr' ) ) {
  33         /**
  34          * @codeCoverageIgnore
  35          * @return string
  36          */
  37         function mb_substr( $str, $start, $count='end' ) {
  38                 return Fallback::mb_substr( $str, $start, $count );
  39         }
  40
  41         /**
  42          * @codeCoverageIgnore
  43          * @return int
  44          */
  45         function mb_substr_split_unicode( $str, $splitPos ) {
  46                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  47         }
  48 }
  49
  50 if ( !function_exists( 'mb_strlen' ) ) {
  51         /**
  52          * @codeCoverageIgnore
  53          * @return int
  54          */
  55         function mb_strlen( $str, $enc = '' ) {
  56                 return Fallback::mb_strlen( $str, $enc );
  57         }
  58 }
  59
  60 if( !function_exists( 'mb_strpos' ) ) {
  61         /**
  62          * @codeCoverageIgnore
  63          * @return int
  64          */
  65         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  66                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  67         }
  68
  69 }
  70
  71 if( !function_exists( 'mb_strrpos' ) ) {
  72         /**
  73          * @codeCoverageIgnore
  74          * @return int
  75          */
  76         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  77                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  78         }
  79 }
  80
  81
  82 // Support for Wietse Venema's taint feature
  83 if ( !function_exists( 'istainted' ) ) {
  84         /**
  85          * @codeCoverageIgnore
  86          * @return int
  87          */
  88         function istainted( $var ) {
  89                 return 0;
  90         }
  91         /** @codeCoverageIgnore */
  92         function taint( $var, $level = 0 ) {}
  93         /** @codeCoverageIgnore */
  94         function untaint( $var, $level = 0 ) {}
  95         define( 'TC_HTML', 1 );
  96         define( 'TC_SHELL', 1 );
  97         define( 'TC_MYSQL', 1 );
  98         define( 'TC_PCRE', 1 );
  99         define( 'TC_SELF', 1 );
 100 }
 101 /// @endcond
 102
 103 /**
 104  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 105  * @param $a array
 106  * @param $b array
 107  * @return array
 108  */
 109 function wfArrayDiff2( $a, $b ) {
 110         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 111 }
 112
 113 /**
 114  * @param $a
 115  * @param $b
 116  * @return int
 117  */
 118 function wfArrayDiff2_cmp( $a, $b ) {
 119         if ( !is_array( $a ) ) {
 120                 return strcmp( $a, $b );
 121         } elseif ( count( $a ) !== count( $b ) ) {
 122                 return count( $a ) < count( $b ) ? -1 : 1;
 123         } else {
 124                 reset( $a );
 125                 reset( $b );
 126                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 127                         $cmp = strcmp( $valueA, $valueB );
 128                         if ( $cmp !== 0 ) {
 129                                 return $cmp;
 130                         }
 131                 }
 132                 return 0;
 133         }
 134 }
 135
 136 /**
 137  * Array lookup
 138  * Returns an array where the values in the first array are replaced by the
 139  * values in the second array with the corresponding keys
 140  *
 141  * @param $a Array
 142  * @param $b Array
 143  * @return array
 144  */
 145 function wfArrayLookup( $a, $b ) {
 146         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 147 }
 148
 149 /**
 150  * Appends to second array if $value differs from that in $default
 151  *
 152  * @param $key String|Int
 153  * @param $value Mixed
 154  * @param $default Mixed
 155  * @param $changed Array to alter
 156  */
 157 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 158         if ( is_null( $changed ) ) {
 159                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 160         }
 161         if ( $default[$key] !== $value ) {
 162                 $changed[$key] = $value;
 163         }
 164 }
 165
 166 /**
 167  * Backwards array plus for people who haven't bothered to read the PHP manual
 168  * XXX: will not darn your socks for you.
 169  *
 170  * @param $array1 Array
 171  * @param [$array2, [...]] Arrays
 172  * @return Array
 173  */
 174 function wfArrayMerge( $array1/* ... */ ) {
 175         $args = func_get_args();
 176         $args = array_reverse( $args, true );
 177         $out = array();
 178         foreach ( $args as $arg ) {
 179                 $out += $arg;
 180         }
 181         return $out;
 182 }
 183
 184 /**
 185  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 186  * e.g.
 187  *      wfMergeErrorArrays(
 188  *              array( array( 'x' ) ),
 189  *              array( array( 'x', '2' ) ),
 190  *              array( array( 'x' ) ),
 191  *              array( array( 'y' ) )
 192  *      );
 193  * returns:
 194  *              array(
 195  *              array( 'x', '2' ),
 196  *              array( 'x' ),
 197  *              array( 'y' )
 198  *      )
 199  * @param varargs
 200  * @return Array
 201  */
 202 function wfMergeErrorArrays( /*...*/ ) {
 203         $args = func_get_args();
 204         $out = array();
 205         foreach ( $args as $errors ) {
 206                 foreach ( $errors as $params ) {
 207                         # @todo FIXME: Sometimes get nested arrays for $params,
 208                         # which leads to E_NOTICEs
 209                         $spec = implode( "\t", $params );
 210                         $out[$spec] = $params;
 211                 }
 212         }
 213         return array_values( $out );
 214 }
 215
 216 /**
 217  * Insert array into another array after the specified *KEY*
 218  *
 219  * @param $array Array: The array.
 220  * @param $insert Array: The array to insert.
 221  * @param $after Mixed: The key to insert after
 222  * @return Array
 223  */
 224 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 225         // Find the offset of the element to insert after.
 226         $keys = array_keys( $array );
 227         $offsetByKey = array_flip( $keys );
 228
 229         $offset = $offsetByKey[$after];
 230
 231         // Insert at the specified offset
 232         $before = array_slice( $array, 0, $offset + 1, true );
 233         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 234
 235         $output = $before + $insert + $after;
 236
 237         return $output;
 238 }
 239
 240 /**
 241  * Recursively converts the parameter (an object) to an array with the same data
 242  *
 243  * @param $objOrArray Object|Array
 244  * @param $recursive Bool
 245  * @return Array
 246  */
 247 function wfObjectToArray( $objOrArray, $recursive = true ) {
 248         $array = array();
 249         if( is_object( $objOrArray ) ) {
 250                 $objOrArray = get_object_vars( $objOrArray );
 251         }
 252         foreach ( $objOrArray as $key => $value ) {
 253                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 254                         $value = wfObjectToArray( $value );
 255                 }
 256
 257                 $array[$key] = $value;
 258         }
 259
 260         return $array;
 261 }
 262
 263 /**
 264  * Wrapper around array_map() which also taints variables
 265  *
 266  * @param  $function Callback
 267  * @param  $input Array
 268  * @return Array
 269  */
 270 function wfArrayMap( $function, $input ) {
 271         $ret = array_map( $function, $input );
 272         foreach ( $ret as $key => $value ) {
 273                 $taint = istainted( $input[$key] );
 274                 if ( $taint ) {
 275                         taint( $ret[$key], $taint );
 276                 }
 277         }
 278         return $ret;
 279 }
 280
 281 /**
 282  * Get a random decimal value between 0 and 1, in a way
 283  * not likely to give duplicate values for any realistic
 284  * number of articles.
 285  *
 286  * @return string
 287  */
 288 function wfRandom() {
 289         # The maximum random value is "only" 2^31-1, so get two random
 290         # values to reduce the chance of dupes
 291         $max = mt_getrandmax() + 1;
 292         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 293                 / $max / $max, 12, '.', '' );
 294         return $rand;
 295 }
 296
 297 /**
 298  * Get a random string containing a number of pesudo-random hex
 299  * characters.
 300  * @note This is not secure, if you are trying to generate some sort
 301  *       of token please use MWCryptRand instead.
 302  *
 303  * @param $length int The length of the string to generate
 304  * @return String
 305  * @since 1.20
 306  */
 307 function wfRandomString( $length = 32 ) {
 308         $str = '';
 309         while ( strlen( $str ) < $length ) {
 310                 $str .= dechex( mt_rand() );
 311         }
 312         return substr( $str, 0, $length );
 313 }
 314
 315 /**
 316  * We want some things to be included as literal characters in our title URLs
 317  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 318  * all of the following should be safe:
 319  *
 320  * ;:@&=$-_.+!*'(),
 321  *
 322  * But + is not safe because it's used to indicate a space; &= are only safe in
 323  * paths and not in queries (and we don't distinguish here); ' seems kind of
 324  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 325  * is reserved, we don't care.  So the list we unescape is:
 326  *
 327  * ;:@$!*(),/
 328  *
 329  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 330  * so no fancy : for IIS7.
 331  *
 332  * %2F in the page titles seems to fatally break for some reason.
 333  *
 334  * @param $s String:
 335  * @return string
 336 */
 337 function wfUrlencode( $s ) {
 338         static $needle;
 339         if ( is_null( $s ) ) {
 340                 $needle = null;
 341                 return '';
 342         }
 343
 344         if ( is_null( $needle ) ) {
 345                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 346                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 347                         $needle[] = '%3A';
 348                 }
 349         }
 350
 351         $s = urlencode( $s );
 352         $s = str_ireplace(
 353                 $needle,
 354                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 355                 $s
 356         );
 357
 358         return $s;
 359 }
 360
 361 /**
 362  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 363  * "days=7&limit=100". Options in the first array override options in the second.
 364  * Options set to null or false will not be output.
 365  *
 366  * @param $array1 Array ( String|Array )
 367  * @param $array2 Array ( String|Array )
 368  * @param $prefix String
 369  * @return String
 370  */
 371 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 372         if ( !is_null( $array2 ) ) {
 373                 $array1 = $array1 + $array2;
 374         }
 375
 376         $cgi = '';
 377         foreach ( $array1 as $key => $value ) {
 378                 if ( !is_null($value) && $value !== false ) {
 379                         if ( $cgi != '' ) {
 380                                 $cgi .= '&';
 381                         }
 382                         if ( $prefix !== '' ) {
 383                                 $key = $prefix . "[$key]";
 384                         }
 385                         if ( is_array( $value ) ) {
 386                                 $firstTime = true;
 387                                 foreach ( $value as $k => $v ) {
 388                                         $cgi .= $firstTime ? '' : '&';
 389                                         if ( is_array( $v ) ) {
 390                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 391                                         } else {
 392                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 393                                         }
 394                                         $firstTime = false;
 395                                 }
 396                         } else {
 397                                 if ( is_object( $value ) ) {
 398                                         $value = $value->__toString();
 399                                 }
 400                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 401                         }
 402                 }
 403         }
 404         return $cgi;
 405 }
 406
 407 /**
 408  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 409  * its argument and returns the same string in array form.  This allows compa-
 410  * tibility with legacy functions that accept raw query strings instead of nice
 411  * arrays.  Of course, keys and values are urldecode()d.
 412  *
 413  * @param $query String: query string
 414  * @return array Array version of input
 415  */
 416 function wfCgiToArray( $query ) {
 417         if ( isset( $query[0] ) && $query[0] == '?' ) {
 418                 $query = substr( $query, 1 );
 419         }
 420         $bits = explode( '&', $query );
 421         $ret = array();
 422         foreach ( $bits as $bit ) {
 423                 if ( $bit === '' ) {
 424                         continue;
 425                 }
 426                 if ( strpos( $bit, '=' ) === false ) {
 427                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 428                         $key = $bit;
 429                         $value = '';
 430                 } else {
 431                         list( $key, $value ) = explode( '=', $bit );
 432                 }
 433                 $key = urldecode( $key );
 434                 $value = urldecode( $value );
 435                 if ( strpos( $key, '[' ) !== false ) {
 436                         $keys = array_reverse( explode( '[', $key ) );
 437                         $key = array_pop( $keys );
 438                         $temp = $value;
 439                         foreach ( $keys as $k ) {
 440                                 $k = substr( $k, 0, -1 );
 441                                 $temp = array( $k => $temp );
 442                         }
 443                         if ( isset( $ret[$key] ) ) {
 444                                 $ret[$key] = array_merge( $ret[$key], $temp );
 445                         } else {
 446                                 $ret[$key] = $temp;
 447                         }
 448                 } else {
 449                         $ret[$key] = $value;
 450                 }
 451         }
 452         return $ret;
 453 }
 454
 455 /**
 456  * Append a query string to an existing URL, which may or may not already
 457  * have query string parameters already. If so, they will be combined.
 458  *
 459  * @param $url String
 460  * @param $query Mixed: string or associative array
 461  * @return string
 462  */
 463 function wfAppendQuery( $url, $query ) {
 464         if ( is_array( $query ) ) {
 465                 $query = wfArrayToCgi( $query );
 466         }
 467         if( $query != '' ) {
 468                 if( false === strpos( $url, '?' ) ) {
 469                         $url .= '?';
 470                 } else {
 471                         $url .= '&';
 472                 }
 473                 $url .= $query;
 474         }
 475         return $url;
 476 }
 477
 478 /**
 479  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 480  * is correct.
 481  *
 482  * The meaning of the PROTO_* constants is as follows:
 483  * PROTO_HTTP: Output a URL starting with http://
 484  * PROTO_HTTPS: Output a URL starting with https://
 485  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 486  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 487  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 488  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 489  *
 490  * @todo this won't work with current-path-relative URLs
 491  * like "subdir/foo.html", etc.
 492  *
 493  * @param $url String: either fully-qualified or a local path + query
 494  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 495  *                             protocol to use if $url or $wgServer is
 496  *                             protocol-relative
 497  * @return string Fully-qualified URL, current-path-relative URL or false if
 498  *                no valid URL can be constructed
 499  */
 500 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 501         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 502         $serverUrl = $wgServer;
 503         if ( $defaultProto === PROTO_CANONICAL ) {
 504                 $serverUrl = $wgCanonicalServer;
 505         }
 506         // Make $wgInternalServer fall back to $wgServer if not set
 507         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 508                 $serverUrl = $wgInternalServer;
 509         }
 510         if ( $defaultProto === PROTO_CURRENT ) {
 511                 $defaultProto = WebRequest::detectProtocol() . '://';
 512         }
 513
 514         // Analyze $serverUrl to obtain its protocol
 515         $bits = wfParseUrl( $serverUrl );
 516         $serverHasProto = $bits && $bits['scheme'] != '';
 517
 518         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 519                 if ( $serverHasProto ) {
 520                         $defaultProto = $bits['scheme'] . '://';
 521                 } else {
 522                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 523                         // Fall back to HTTP in this ridiculous case
 524                         $defaultProto = PROTO_HTTP;
 525                 }
 526         }
 527
 528         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 529
 530         if ( substr( $url, 0, 2 ) == '//' ) {
 531                 $url = $defaultProtoWithoutSlashes . $url;
 532         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 533                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 534                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 535         }
 536
 537         $bits = wfParseUrl( $url );
 538         if ( $bits && isset( $bits['path'] ) ) {
 539                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 540                 return wfAssembleUrl( $bits );
 541         } elseif ( $bits ) {
 542                 # No path to expand
 543                 return $url;
 544         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 545                 # URL is a relative path
 546                 return wfRemoveDotSegments( $url );
 547         }
 548
 549         # Expanded URL is not valid.
 550         return false;
 551 }
 552
 553 /**
 554  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 555  * if you need to edit part of a URL and put it back together.
 556  *
 557  * This is the basic structure used (brackets contain keys for $urlParts):
 558  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 559  *
 560  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 561  *
 562  * @since 1.19
 563  * @param $urlParts Array URL parts, as output from wfParseUrl
 564  * @return string URL assembled from its component parts
 565  */
 566 function wfAssembleUrl( $urlParts ) {
 567         $result = '';
 568
 569         if ( isset( $urlParts['delimiter'] ) ) {
 570                 if ( isset( $urlParts['scheme'] ) ) {
 571                         $result .= $urlParts['scheme'];
 572                 }
 573
 574                 $result .= $urlParts['delimiter'];
 575         }
 576
 577         if ( isset( $urlParts['host'] ) ) {
 578                 if ( isset( $urlParts['user'] ) ) {
 579                         $result .= $urlParts['user'];
 580                         if ( isset( $urlParts['pass'] ) ) {
 581                                 $result .= ':' . $urlParts['pass'];
 582                         }
 583                         $result .= '@';
 584                 }
 585
 586                 $result .= $urlParts['host'];
 587
 588                 if ( isset( $urlParts['port'] ) ) {
 589                         $result .= ':' . $urlParts['port'];
 590                 }
 591         }
 592
 593         if ( isset( $urlParts['path'] ) ) {
 594                 $result .= $urlParts['path'];
 595         }
 596
 597         if ( isset( $urlParts['query'] ) ) {
 598                 $result .= '?' . $urlParts['query'];
 599         }
 600
 601         if ( isset( $urlParts['fragment'] ) ) {
 602                 $result .= '#' . $urlParts['fragment'];
 603         }
 604
 605         return $result;
 606 }
 607
 608 /**
 609  * Remove all dot-segments in the provided URL path.  For example,
 610  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 611  * RFC3986 section 5.2.4.
 612  *
 613  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 614  *
 615  * @param $urlPath String URL path, potentially containing dot-segments
 616  * @return string URL path with all dot-segments removed
 617  */
 618 function wfRemoveDotSegments( $urlPath ) {
 619         $output = '';
 620         $inputOffset = 0;
 621         $inputLength = strlen( $urlPath );
 622
 623         while ( $inputOffset < $inputLength ) {
 624                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 625                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 626                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 627                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 628                 $trimOutput = false;
 629
 630                 if ( $prefixLengthTwo == './' ) {
 631                         # Step A, remove leading "./"
 632                         $inputOffset += 2;
 633                 } elseif ( $prefixLengthThree == '../' ) {
 634                         # Step A, remove leading "../"
 635                         $inputOffset += 3;
 636                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 637                         # Step B, replace leading "/.$" with "/"
 638                         $inputOffset += 1;
 639                         $urlPath[$inputOffset] = '/';
 640                 } elseif ( $prefixLengthThree == '/./' ) {
 641                         # Step B, replace leading "/./" with "/"
 642                         $inputOffset += 2;
 643                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 644                         # Step C, replace leading "/..$" with "/" and
 645                         # remove last path component in output
 646                         $inputOffset += 2;
 647                         $urlPath[$inputOffset] = '/';
 648                         $trimOutput = true;
 649                 } elseif ( $prefixLengthFour == '/../' ) {
 650                         # Step C, replace leading "/../" with "/" and
 651                         # remove last path component in output
 652                         $inputOffset += 3;
 653                         $trimOutput = true;
 654                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 655                         # Step D, remove "^.$"
 656                         $inputOffset += 1;
 657                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 658                         # Step D, remove "^..$"
 659                         $inputOffset += 2;
 660                 } else {
 661                         # Step E, move leading path segment to output
 662                         if ( $prefixLengthOne == '/' ) {
 663                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 664                         } else {
 665                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 666                         }
 667                         if ( $slashPos === false ) {
 668                                 $output .= substr( $urlPath, $inputOffset );
 669                                 $inputOffset = $inputLength;
 670                         } else {
 671                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 672                                 $inputOffset += $slashPos - $inputOffset;
 673                         }
 674                 }
 675
 676                 if ( $trimOutput ) {
 677                         $slashPos = strrpos( $output, '/' );
 678                         if ( $slashPos === false ) {
 679                                 $output = '';
 680                         } else {
 681                                 $output = substr( $output, 0, $slashPos );
 682                         }
 683                 }
 684         }
 685
 686         return $output;
 687 }
 688
 689 /**
 690  * Returns a regular expression of url protocols
 691  *
 692  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 693  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 694  * @return String
 695  */
 696 function wfUrlProtocols( $includeProtocolRelative = true ) {
 697         global $wgUrlProtocols;
 698
 699         // Cache return values separately based on $includeProtocolRelative
 700         static $withProtRel = null, $withoutProtRel = null;
 701         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 702         if ( !is_null( $cachedValue ) ) {
 703                 return $cachedValue;
 704         }
 705
 706         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 707         // with LocalSettings files from 1.5
 708         if ( is_array( $wgUrlProtocols ) ) {
 709                 $protocols = array();
 710                 foreach ( $wgUrlProtocols as $protocol ) {
 711                         // Filter out '//' if !$includeProtocolRelative
 712                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 713                                 $protocols[] = preg_quote( $protocol, '/' );
 714                         }
 715                 }
 716
 717                 $retval = implode( '|', $protocols );
 718         } else {
 719                 // Ignore $includeProtocolRelative in this case
 720                 // This case exists for pre-1.6 compatibility, and we can safely assume
 721                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 722                 // URLs weren't supported until 1.18
 723                 $retval = $wgUrlProtocols;
 724         }
 725
 726         // Cache return value
 727         if ( $includeProtocolRelative ) {
 728                 $withProtRel = $retval;
 729         } else {
 730                 $withoutProtRel = $retval;
 731         }
 732         return $retval;
 733 }
 734
 735 /**
 736  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 737  * you need a regex that matches all URL protocols but does not match protocol-
 738  * relative URLs
 739  * @return String
 740  */
 741 function wfUrlProtocolsWithoutProtRel() {
 742         return wfUrlProtocols( false );
 743 }
 744
 745 /**
 746  * parse_url() work-alike, but non-broken.  Differences:
 747  *
 748  * 1) Does not raise warnings on bad URLs (just returns false)
 749  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 750  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 751  *
 752  * @param $url String: a URL to parse
 753  * @return Array: bits of the URL in an associative array, per PHP docs
 754  */
 755 function wfParseUrl( $url ) {
 756         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 757
 758         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 759         // way to handle them is to just prepend 'http:' and strip the protocol out later
 760         $wasRelative = substr( $url, 0, 2 ) == '//';
 761         if ( $wasRelative ) {
 762                 $url = "http:$url";
 763         }
 764         wfSuppressWarnings();
 765         $bits = parse_url( $url );
 766         wfRestoreWarnings();
 767         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 768         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 769         if ( !$bits || !isset( $bits['scheme'] ) ) {
 770                 return false;
 771         }
 772
 773         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 774         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 775                 $bits['delimiter'] = '://';
 776         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 777                 $bits['delimiter'] = ':';
 778                 // parse_url detects for news: and mailto: the host part of an url as path
 779                 // We have to correct this wrong detection
 780                 if ( isset( $bits['path'] ) ) {
 781                         $bits['host'] = $bits['path'];
 782                         $bits['path'] = '';
 783                 }
 784         } else {
 785                 return false;
 786         }
 787
 788         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 789         if ( !isset( $bits['host'] ) ) {
 790                 $bits['host'] = '';
 791
 792                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 793                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 794                         $bits['path'] = '/' . $bits['path'];
 795                 }
 796         }
 797
 798         // If the URL was protocol-relative, fix scheme and delimiter
 799         if ( $wasRelative ) {
 800                 $bits['scheme'] = '';
 801                 $bits['delimiter'] = '//';
 802         }
 803         return $bits;
 804 }
 805
 806 /**
 807  * Take a URL, make sure it's expanded to fully qualified, and replace any
 808  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 809  * for more compact display and legibility for local audiences.
 810  *
 811  * @todo handle punycode domains too
 812  *
 813  * @param $url string
 814  * @return string
 815  */
 816 function wfExpandIRI( $url ) {
 817         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 818 }
 819
 820 /**
 821  * Private callback for wfExpandIRI
 822  * @param array $matches
 823  * @return string
 824  */
 825 function wfExpandIRI_callback( $matches ) {
 826         return urldecode( $matches[1] );
 827 }
 828
 829
 830
 831 /**
 832  * Make URL indexes, appropriate for the el_index field of externallinks.
 833  *
 834  * @param $url String
 835  * @return array
 836  */
 837 function wfMakeUrlIndexes( $url ) {
 838         $bits = wfParseUrl( $url );
 839
 840         // Reverse the labels in the hostname, convert to lower case
 841         // For emails reverse domainpart only
 842         if ( $bits['scheme'] == 'mailto' ) {
 843                 $mailparts = explode( '@', $bits['host'], 2 );
 844                 if ( count( $mailparts ) === 2 ) {
 845                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 846                 } else {
 847                         // No domain specified, don't mangle it
 848                         $domainpart = '';
 849                 }
 850                 $reversedHost = $domainpart . '@' . $mailparts[0];
 851         } else {
 852                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 853         }
 854         // Add an extra dot to the end
 855         // Why? Is it in wrong place in mailto links?
 856         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 857                 $reversedHost .= '.';
 858         }
 859         // Reconstruct the pseudo-URL
 860         $prot = $bits['scheme'];
 861         $index = $prot . $bits['delimiter'] . $reversedHost;
 862         // Leave out user and password. Add the port, path, query and fragment
 863         if ( isset( $bits['port'] ) ) {
 864                 $index .= ':' . $bits['port'];
 865         }
 866         if ( isset( $bits['path'] ) ) {
 867                 $index .= $bits['path'];
 868         } else {
 869                 $index .= '/';
 870         }
 871         if ( isset( $bits['query'] ) ) {
 872                 $index .= '?' . $bits['query'];
 873         }
 874         if ( isset( $bits['fragment'] ) ) {
 875                 $index .= '#' . $bits['fragment'];
 876         }
 877
 878         if ( $prot == '' ) {
 879                 return array( "http:$index", "https:$index" );
 880         } else {
 881                 return array( $index );
 882         }
 883 }
 884
 885 /**
 886  * Check whether a given URL has a domain that occurs in a given set of domains
 887  * @param $url string URL
 888  * @param $domains array Array of domains (strings)
 889  * @return bool True if the host part of $url ends in one of the strings in $domains
 890  */
 891 function wfMatchesDomainList( $url, $domains ) {
 892         $bits = wfParseUrl( $url );
 893         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 894                 foreach ( (array)$domains as $domain ) {
 895                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 896                         // We should use something that interprets dots instead
 897                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 898                                 return true;
 899                         }
 900                 }
 901         }
 902         return false;
 903 }
 904
 905 /**
 906  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 907  * In normal operation this is a NOP.
 908  *
 909  * Controlling globals:
 910  * $wgDebugLogFile - points to the log file
 911  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 912  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 913  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 914  *
 915  * @param $text String
 916  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 917  */
 918 function wfDebug( $text, $logonly = false ) {
 919         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 920         global $wgDebugLogPrefix, $wgShowDebug;
 921
 922         static $cache = array(); // Cache of unoutputted messages
 923
 924         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 925                 return;
 926         }
 927
 928         $timer = wfDebugTimer();
 929         if ( $timer !== '' ) {
 930                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 931         }
 932
 933         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 934                 $cache[] = $text;
 935
 936                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 937                         // add the message and any cached messages to the output
 938                         array_map( array( $wgOut, 'debug' ), $cache );
 939                         $cache = array();
 940                 }
 941         }
 942         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 943                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 944                         # Strip unprintables; they can switch terminal modes when binary data
 945                         # gets dumped, which is pretty annoying.
 946                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 947                         $text = $wgDebugLogPrefix . $text;
 948                         wfErrorLog( $text, $wgDebugLogFile );
 949                 }
 950         }
 951
 952         MWDebug::debugMsg( $text );
 953 }
 954
 955 /**
 956  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 957  * @return bool
 958  */
 959 function wfIsDebugRawPage() {
 960         static $cache;
 961         if ( $cache !== null ) {
 962                 return $cache;
 963         }
 964         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 965         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 966                 || (
 967                         isset( $_SERVER['SCRIPT_NAME'] )
 968                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 969                 ) )
 970         {
 971                 $cache = true;
 972         } else {
 973                 $cache = false;
 974         }
 975         return $cache;
 976 }
 977
 978 /**
 979  * Get microsecond timestamps for debug logs
 980  *
 981  * @return string
 982  */
 983 function wfDebugTimer() {
 984         global $wgDebugTimestamps, $wgRequestTime;
 985
 986         if ( !$wgDebugTimestamps ) {
 987                 return '';
 988         }
 989
 990         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 991         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 992         return "$prefix $mem  ";
 993 }
 994
 995 /**
 996  * Send a line giving PHP memory usage.
 997  *
 998  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 999  */
1000 function wfDebugMem( $exact = false ) {
1001         $mem = memory_get_usage();
1002         if( !$exact ) {
1003                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1004         } else {
1005                 $mem .= ' bytes';
1006         }
1007         wfDebug( "Memory usage: $mem\n" );
1008 }
1009
1010 /**
1011  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1012  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1013  *
1014  * @param $logGroup String
1015  * @param $text String
1016  * @param $public Bool: whether to log the event in the public log if no private
1017  *                     log file is specified, (default true)
1018  */
1019 function wfDebugLog( $logGroup, $text, $public = true ) {
1020         global $wgDebugLogGroups;
1021         $text = trim( $text ) . "\n";
1022         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
1023                 $time = wfTimestamp( TS_DB );
1024                 $wiki = wfWikiID();
1025                 $host = wfHostname();
1026                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1027                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1028                 }
1029         } elseif ( $public === true ) {
1030                 wfDebug( $text, true );
1031         }
1032 }
1033
1034 /**
1035  * Log for database errors
1036  *
1037  * @param $text String: database error message.
1038  */
1039 function wfLogDBError( $text ) {
1040         global $wgDBerrorLog;
1041         if ( $wgDBerrorLog ) {
1042                 $host = wfHostname();
1043                 $wiki = wfWikiID();
1044                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wiki\t$text";
1045                 wfErrorLog( $text, $wgDBerrorLog );
1046         }
1047 }
1048
1049 /**
1050  * Throws a warning that $function is deprecated
1051  *
1052  * @param $function String
1053  * @param $version String|bool: Version of MediaWiki that the function was deprecated in (Added in 1.19).
1054  * @param $component String|bool: Added in 1.19.
1055  * @param $callerOffset integer: How far up the callstack is the original
1056  *    caller. 2 = function that called the function that called
1057  *    wfDeprecated (Added in 1.20)
1058  *
1059  * @return null
1060  */
1061 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1062         static $functionsWarned = array();
1063
1064         MWDebug::deprecated( $function, $version, $component );
1065
1066         if ( !isset( $functionsWarned[$function] ) ) {
1067                 $functionsWarned[$function] = true;
1068
1069                 if ( $version ) {
1070                         global $wgDeprecationReleaseLimit;
1071
1072                         if ( $wgDeprecationReleaseLimit && $component === false ) {
1073                                 # Strip -* off the end of $version so that branches can use the
1074                                 # format #.##-branchname to avoid issues if the branch is merged into
1075                                 # a version of MediaWiki later than what it was branched from
1076                                 $comparableVersion = preg_replace( '/-.*$/', '', $version );
1077
1078                                 # If the comparableVersion is larger than our release limit then
1079                                 # skip the warning message for the deprecation
1080                                 if ( version_compare( $wgDeprecationReleaseLimit, $comparableVersion, '<' ) ) {
1081                                         return;
1082                                 }
1083                         }
1084
1085                         $component = $component === false ? 'MediaWiki' : $component;
1086                         wfWarn( "Use of $function was deprecated in $component $version.", $callerOffset );
1087                 } else {
1088                         wfWarn( "Use of $function is deprecated.", $callerOffset );
1089                 }
1090         }
1091 }
1092
1093 /**
1094  * Send a warning either to the debug log or in a PHP error depending on
1095  * $wgDevelopmentWarnings
1096  *
1097  * @param $msg String: message to send
1098  * @param $callerOffset Integer: number of items to go back in the backtrace to
1099  *        find the correct caller (1 = function calling wfWarn, ...)
1100  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1101  *        is true
1102  */
1103 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1104         global $wgDevelopmentWarnings;
1105
1106         MWDebug::warning( $msg, $callerOffset + 2 );
1107
1108         $callers = wfDebugBacktrace();
1109         if ( isset( $callers[$callerOffset + 1] ) ) {
1110                 $callerfunc = $callers[$callerOffset + 1];
1111                 $callerfile = $callers[$callerOffset];
1112                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
1113                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
1114                 } else {
1115                         $file = '(internal function)';
1116                 }
1117                 $func = '';
1118                 if ( isset( $callerfunc['class'] ) ) {
1119                         $func .= $callerfunc['class'] . '::';
1120                 }
1121                 if ( isset( $callerfunc['function'] ) ) {
1122                         $func .= $callerfunc['function'];
1123                 }
1124                 $msg .= " [Called from $func in $file]";
1125         }
1126
1127         if ( $wgDevelopmentWarnings ) {
1128                 trigger_error( $msg, $level );
1129         } else {
1130                 wfDebug( "$msg\n" );
1131         }
1132 }
1133
1134 /**
1135  * Log to a file without getting "file size exceeded" signals.
1136  *
1137  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1138  * send lines to the specified port, prefixed by the specified prefix and a space.
1139  *
1140  * @param $text String
1141  * @param $file String filename
1142  */
1143 function wfErrorLog( $text, $file ) {
1144         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1145                 # Needs the sockets extension
1146                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1147                         // IPv6 bracketed host
1148                         $host = $m[2];
1149                         $port = intval( $m[3] );
1150                         $prefix = isset( $m[4] ) ? $m[4] : false;
1151                         $domain = AF_INET6;
1152                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1153                         $host = $m[2];
1154                         if ( !IP::isIPv4( $host ) ) {
1155                                 $host = gethostbyname( $host );
1156                         }
1157                         $port = intval( $m[3] );
1158                         $prefix = isset( $m[4] ) ? $m[4] : false;
1159                         $domain = AF_INET;
1160                 } else {
1161                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1162                 }
1163
1164                 // Clean it up for the multiplexer
1165                 if ( strval( $prefix ) !== '' ) {
1166                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1167
1168                         // Limit to 64KB
1169                         if ( strlen( $text ) > 65506 ) {
1170                                 $text = substr( $text, 0, 65506 );
1171                         }
1172
1173                         if ( substr( $text, -1 ) != "\n" ) {
1174                                 $text .= "\n";
1175                         }
1176                 } elseif ( strlen( $text ) > 65507 ) {
1177                         $text = substr( $text, 0, 65507 );
1178                 }
1179
1180                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1181                 if ( !$sock ) {
1182                         return;
1183                 }
1184
1185                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1186                 socket_close( $sock );
1187         } else {
1188                 wfSuppressWarnings();
1189                 $exists = file_exists( $file );
1190                 $size = $exists ? filesize( $file ) : false;
1191                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1192                         file_put_contents( $file, $text, FILE_APPEND );
1193                 }
1194                 wfRestoreWarnings();
1195         }
1196 }
1197
1198 /**
1199  * @todo document
1200  */
1201 function wfLogProfilingData() {
1202         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1203         global $wgProfileLimit, $wgUser;
1204
1205         $profiler = Profiler::instance();
1206
1207         # Profiling must actually be enabled...
1208         if ( $profiler->isStub() ) {
1209                 return;
1210         }
1211
1212         // Get total page request time and only show pages that longer than
1213         // $wgProfileLimit time (default is 0)
1214         $elapsed = microtime( true ) - $wgRequestTime;
1215         if ( $elapsed <= $wgProfileLimit ) {
1216                 return;
1217         }
1218
1219         $profiler->logData();
1220
1221         // Check whether this should be logged in the debug file.
1222         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1223                 return;
1224         }
1225
1226         $forward = '';
1227         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1228                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1229         }
1230         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1231                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1232         }
1233         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1234                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1235         }
1236         if ( $forward ) {
1237                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1238         }
1239         // Don't load $wgUser at this late stage just for statistics purposes
1240         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1241         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1242                 $forward .= ' anon';
1243         }
1244         $log = sprintf( "%s\t%04.3f\t%s\n",
1245                 gmdate( 'YmdHis' ), $elapsed,
1246                 urldecode( $wgRequest->getRequestURL() . $forward ) );
1247
1248         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1249 }
1250
1251 /**
1252  * Increment a statistics counter
1253  *
1254  * @param $key String
1255  * @param $count Int
1256  */
1257 function wfIncrStats( $key, $count = 1 ) {
1258         global $wgStatsMethod;
1259
1260         $count = intval( $count );
1261
1262         if( $wgStatsMethod == 'udp' ) {
1263                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
1264                 static $socket;
1265
1266                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
1267
1268                 if ( !$socket ) {
1269                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1270                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1271                         socket_sendto(
1272                                 $socket,
1273                                 $statline,
1274                                 strlen( $statline ),
1275                                 0,
1276                                 $wgUDPProfilerHost,
1277                                 $wgUDPProfilerPort
1278                         );
1279                 }
1280                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1281                 wfSuppressWarnings();
1282                 socket_sendto(
1283                         $socket,
1284                         $statline,
1285                         strlen( $statline ),
1286                         0,
1287                         $wgUDPProfilerHost,
1288                         $wgUDPProfilerPort
1289                 );
1290                 wfRestoreWarnings();
1291         } elseif( $wgStatsMethod == 'cache' ) {
1292                 global $wgMemc;
1293                 $key = wfMemcKey( 'stats', $key );
1294                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1295                         $wgMemc->add( $key, $count );
1296                 }
1297         } else {
1298                 // Disabled
1299         }
1300 }
1301
1302 /**
1303  * Check if the wiki read-only lock file is present. This can be used to lock
1304  * off editing functions, but doesn't guarantee that the database will not be
1305  * modified.
1306  *
1307  * @return bool
1308  */
1309 function wfReadOnly() {
1310         global $wgReadOnlyFile, $wgReadOnly;
1311
1312         if ( !is_null( $wgReadOnly ) ) {
1313                 return (bool)$wgReadOnly;
1314         }
1315         if ( $wgReadOnlyFile == '' ) {
1316                 return false;
1317         }
1318         // Set $wgReadOnly for faster access next time
1319         if ( is_file( $wgReadOnlyFile ) ) {
1320                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1321         } else {
1322                 $wgReadOnly = false;
1323         }
1324         return (bool)$wgReadOnly;
1325 }
1326
1327 /**
1328  * @return bool
1329  */
1330 function wfReadOnlyReason() {
1331         global $wgReadOnly;
1332         wfReadOnly();
1333         return $wgReadOnly;
1334 }
1335
1336 /**
1337  * Return a Language object from $langcode
1338  *
1339  * @param $langcode Mixed: either:
1340  *                  - a Language object
1341  *                  - code of the language to get the message for, if it is
1342  *                    a valid code create a language for that language, if
1343  *                    it is a string but not a valid code then make a basic
1344  *                    language object
1345  *                  - a boolean: if it's false then use the global object for
1346  *                    the current user's language (as a fallback for the old parameter
1347  *                    functionality), or if it is true then use global object
1348  *                    for the wiki's content language.
1349  * @return Language object
1350  */
1351 function wfGetLangObj( $langcode = false ) {
1352         # Identify which language to get or create a language object for.
1353         # Using is_object here due to Stub objects.
1354         if( is_object( $langcode ) ) {
1355                 # Great, we already have the object (hopefully)!
1356                 return $langcode;
1357         }
1358
1359         global $wgContLang, $wgLanguageCode;
1360         if( $langcode === true || $langcode === $wgLanguageCode ) {
1361                 # $langcode is the language code of the wikis content language object.
1362                 # or it is a boolean and value is true
1363                 return $wgContLang;
1364         }
1365
1366         global $wgLang;
1367         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1368                 # $langcode is the language code of user language object.
1369                 # or it was a boolean and value is false
1370                 return $wgLang;
1371         }
1372
1373         $validCodes = array_keys( Language::fetchLanguageNames() );
1374         if( in_array( $langcode, $validCodes ) ) {
1375                 # $langcode corresponds to a valid language.
1376                 return Language::factory( $langcode );
1377         }
1378
1379         # $langcode is a string, but not a valid language code; use content language.
1380         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1381         return $wgContLang;
1382 }
1383
1384 /**
1385  * Old function when $wgBetterDirectionality existed
1386  * All usage removed, wfUILang can be removed in near future
1387  *
1388  * @deprecated since 1.18
1389  * @return Language
1390  */
1391 function wfUILang() {
1392         wfDeprecated( __METHOD__, '1.18' );
1393         global $wgLang;
1394         return $wgLang;
1395 }
1396
1397 /**
1398  * This is the new function for getting translated interface messages.
1399  * See the Message class for documentation how to use them.
1400  * The intention is that this function replaces all old wfMsg* functions.
1401  * @param $key \string Message key.
1402  * Varargs: normal message parameters.
1403  * @return Message
1404  * @since 1.17
1405  */
1406 function wfMessage( $key /*...*/) {
1407         $params = func_get_args();
1408         array_shift( $params );
1409         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1410                 $params = $params[0];
1411         }
1412         return new Message( $key, $params );
1413 }
1414
1415 /**
1416  * This function accepts multiple message keys and returns a message instance
1417  * for the first message which is non-empty. If all messages are empty then an
1418  * instance of the first message key is returned.
1419  * @param varargs: message keys
1420  * @return Message
1421  * @since 1.18
1422  */
1423 function wfMessageFallback( /*...*/ ) {
1424         $args = func_get_args();
1425         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1426 }
1427
1428 /**
1429  * Get a message from anywhere, for the current user language.
1430  *
1431  * Use wfMsgForContent() instead if the message should NOT
1432  * change depending on the user preferences.
1433  *
1434  * @param $key String: lookup key for the message, usually
1435  *    defined in languages/Language.php
1436  *
1437  * Parameters to the message, which can be used to insert variable text into
1438  * it, can be passed to this function in the following formats:
1439  * - One per argument, starting at the second parameter
1440  * - As an array in the second parameter
1441  * These are not shown in the function definition.
1442  *
1443  * @return String
1444  */
1445 function wfMsg( $key ) {
1446         $args = func_get_args();
1447         array_shift( $args );
1448         return wfMsgReal( $key, $args );
1449 }
1450
1451 /**
1452  * Same as above except doesn't transform the message
1453  *
1454  * @param $key String
1455  * @return String
1456  */
1457 function wfMsgNoTrans( $key ) {
1458         $args = func_get_args();
1459         array_shift( $args );
1460         return wfMsgReal( $key, $args, true, false, false );
1461 }
1462
1463 /**
1464  * Get a message from anywhere, for the current global language
1465  * set with $wgLanguageCode.
1466  *
1467  * Use this if the message should NOT change dependent on the
1468  * language set in the user's preferences. This is the case for
1469  * most text written into logs, as well as link targets (such as
1470  * the name of the copyright policy page). Link titles, on the
1471  * other hand, should be shown in the UI language.
1472  *
1473  * Note that MediaWiki allows users to change the user interface
1474  * language in their preferences, but a single installation
1475  * typically only contains content in one language.
1476  *
1477  * Be wary of this distinction: If you use wfMsg() where you should
1478  * use wfMsgForContent(), a user of the software may have to
1479  * customize potentially hundreds of messages in
1480  * order to, e.g., fix a link in every possible language.
1481  *
1482  * @param $key String: lookup key for the message, usually
1483  *     defined in languages/Language.php
1484  * @return String
1485  */
1486 function wfMsgForContent( $key ) {
1487         global $wgForceUIMsgAsContentMsg;
1488         $args = func_get_args();
1489         array_shift( $args );
1490         $forcontent = true;
1491         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1492                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1493         {
1494                 $forcontent = false;
1495         }
1496         return wfMsgReal( $key, $args, true, $forcontent );
1497 }
1498
1499 /**
1500  * Same as above except doesn't transform the message
1501  *
1502  * @param $key String
1503  * @return String
1504  */
1505 function wfMsgForContentNoTrans( $key ) {
1506         global $wgForceUIMsgAsContentMsg;
1507         $args = func_get_args();
1508         array_shift( $args );
1509         $forcontent = true;
1510         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1511                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1512         {
1513                 $forcontent = false;
1514         }
1515         return wfMsgReal( $key, $args, true, $forcontent, false );
1516 }
1517
1518 /**
1519  * Really get a message
1520  *
1521  * @param $key String: key to get.
1522  * @param $args
1523  * @param $useDB Boolean
1524  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1525  * @param $transform Boolean: Whether or not to transform the message.
1526  * @return String: the requested message.
1527  */
1528 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1529         wfProfileIn( __METHOD__ );
1530         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1531         $message = wfMsgReplaceArgs( $message, $args );
1532         wfProfileOut( __METHOD__ );
1533         return $message;
1534 }
1535
1536 /**
1537  * Fetch a message string value, but don't replace any keys yet.
1538  *
1539  * @param $key String
1540  * @param $useDB Bool
1541  * @param $langCode String: Code of the language to get the message for, or
1542  *                  behaves as a content language switch if it is a boolean.
1543  * @param $transform Boolean: whether to parse magic words, etc.
1544  * @return string
1545  */
1546 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1547         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1548
1549         $cache = MessageCache::singleton();
1550         $message = $cache->get( $key, $useDB, $langCode );
1551         if( $message === false ) {
1552                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1553         } elseif ( $transform ) {
1554                 $message = $cache->transform( $message );
1555         }
1556         return $message;
1557 }
1558
1559 /**
1560  * Replace message parameter keys on the given formatted output.
1561  *
1562  * @param $message String
1563  * @param $args Array
1564  * @return string
1565  * @private
1566  */
1567 function wfMsgReplaceArgs( $message, $args ) {
1568         # Fix windows line-endings
1569         # Some messages are split with explode("\n", $msg)
1570         $message = str_replace( "\r", '', $message );
1571
1572         // Replace arguments
1573         if ( count( $args ) ) {
1574                 if ( is_array( $args[0] ) ) {
1575                         $args = array_values( $args[0] );
1576                 }
1577                 $replacementKeys = array();
1578                 foreach( $args as $n => $param ) {
1579                         $replacementKeys['$' . ( $n + 1 )] = $param;
1580                 }
1581                 $message = strtr( $message, $replacementKeys );
1582         }
1583
1584         return $message;
1585 }
1586
1587 /**
1588  * Return an HTML-escaped version of a message.
1589  * Parameter replacements, if any, are done *after* the HTML-escaping,
1590  * so parameters may contain HTML (eg links or form controls). Be sure
1591  * to pre-escape them if you really do want plaintext, or just wrap
1592  * the whole thing in htmlspecialchars().
1593  *
1594  * @param $key String
1595  * @param string ... parameters
1596  * @return string
1597  */
1598 function wfMsgHtml( $key ) {
1599         $args = func_get_args();
1600         array_shift( $args );
1601         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1602 }
1603
1604 /**
1605  * Return an HTML version of message
1606  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1607  * so parameters may contain HTML (eg links or form controls). Be sure
1608  * to pre-escape them if you really do want plaintext, or just wrap
1609  * the whole thing in htmlspecialchars().
1610  *
1611  * @param $key String
1612  * @param string ... parameters
1613  * @return string
1614  */
1615 function wfMsgWikiHtml( $key ) {
1616         $args = func_get_args();
1617         array_shift( $args );
1618         return wfMsgReplaceArgs(
1619                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1620                 /* can't be set to false */ true, /* interface */ true )->getText(),
1621                 $args );
1622 }
1623
1624 /**
1625  * Returns message in the requested format
1626  * @param $key String: key of the message
1627  * @param $options Array: processing rules. Can take the following options:
1628  *   <i>parse</i>: parses wikitext to HTML
1629  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1630  *       p's added by parser or tidy
1631  *   <i>escape</i>: filters message through htmlspecialchars
1632  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1633  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1634  *   <i>parsemag</i>: transform the message using magic phrases
1635  *   <i>content</i>: fetch message for content language instead of interface
1636  * Also can accept a single associative argument, of the form 'language' => 'xx':
1637  *   <i>language</i>: Language object or language code to fetch message for
1638  *       (overriden by <i>content</i>).
1639  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1640  *
1641  * @return String
1642  */
1643 function wfMsgExt( $key, $options ) {
1644         $args = func_get_args();
1645         array_shift( $args );
1646         array_shift( $args );
1647         $options = (array)$options;
1648
1649         foreach( $options as $arrayKey => $option ) {
1650                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1651                         # An unknown index, neither numeric nor "language"
1652                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1653                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1654                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1655                 'replaceafter', 'parsemag', 'content' ) ) ) {
1656                         # A numeric index with unknown value
1657                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1658                 }
1659         }
1660
1661         if( in_array( 'content', $options, true ) ) {
1662                 $forContent = true;
1663                 $langCode = true;
1664                 $langCodeObj = null;
1665         } elseif( array_key_exists( 'language', $options ) ) {
1666                 $forContent = false;
1667                 $langCode = wfGetLangObj( $options['language'] );
1668                 $langCodeObj = $langCode;
1669         } else {
1670                 $forContent = false;
1671                 $langCode = false;
1672                 $langCodeObj = null;
1673         }
1674
1675         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1676
1677         if( !in_array( 'replaceafter', $options, true ) ) {
1678                 $string = wfMsgReplaceArgs( $string, $args );
1679         }
1680
1681         $messageCache = MessageCache::singleton();
1682         $parseInline = in_array( 'parseinline', $options, true );
1683         if( in_array( 'parse', $options, true ) || $parseInline ) {
1684                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1685                 if ( $string instanceof ParserOutput ) {
1686                         $string = $string->getText();
1687                 }
1688
1689                 if ( $parseInline ) {
1690                         $m = array();
1691                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1692                                 $string = $m[1];
1693                         }
1694                 }
1695         } elseif ( in_array( 'parsemag', $options, true ) ) {
1696                 $string = $messageCache->transform( $string,
1697                                 !$forContent, $langCodeObj );
1698         }
1699
1700         if ( in_array( 'escape', $options, true ) ) {
1701                 $string = htmlspecialchars ( $string );
1702         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1703                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1704         }
1705
1706         if( in_array( 'replaceafter', $options, true ) ) {
1707                 $string = wfMsgReplaceArgs( $string, $args );
1708         }
1709
1710         return $string;
1711 }
1712
1713 /**
1714  * Since wfMsg() and co suck, they don't return false if the message key they
1715  * looked up didn't exist but a XHTML string, this function checks for the
1716  * nonexistance of messages by checking the MessageCache::get() result directly.
1717  *
1718  * @param $key      String: the message key looked up
1719  * @return Boolean True if the message *doesn't* exist.
1720  */
1721 function wfEmptyMsg( $key ) {
1722         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1723 }
1724
1725 /**
1726  * Throw a debugging exception. This function previously once exited the process,
1727  * but now throws an exception instead, with similar results.
1728  *
1729  * @param $msg String: message shown when dying.
1730  */
1731 function wfDebugDieBacktrace( $msg = '' ) {
1732         throw new MWException( $msg );
1733 }
1734
1735 /**
1736  * Fetch server name for use in error reporting etc.
1737  * Use real server name if available, so we know which machine
1738  * in a server farm generated the current page.
1739  *
1740  * @return string
1741  */
1742 function wfHostname() {
1743         static $host;
1744         if ( is_null( $host ) ) {
1745                 if ( function_exists( 'posix_uname' ) ) {
1746                         // This function not present on Windows
1747                         $uname = posix_uname();
1748                 } else {
1749                         $uname = false;
1750                 }
1751                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1752                         $host = $uname['nodename'];
1753                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1754                         # Windows computer name
1755                         $host = getenv( 'COMPUTERNAME' );
1756                 } else {
1757                         # This may be a virtual server.
1758                         $host = $_SERVER['SERVER_NAME'];
1759                 }
1760         }
1761         return $host;
1762 }
1763
1764 /**
1765  * Returns a HTML comment with the elapsed time since request.
1766  * This method has no side effects.
1767  *
1768  * @return string
1769  */
1770 function wfReportTime() {
1771         global $wgRequestTime, $wgShowHostnames;
1772
1773         $elapsed = microtime( true ) - $wgRequestTime;
1774
1775         return $wgShowHostnames
1776                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1777                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1778 }
1779
1780 /**
1781  * Safety wrapper for debug_backtrace().
1782  *
1783  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1784  * murky circumstances, which may be triggered in part by stub objects
1785  * or other fancy talkin'.
1786  *
1787  * Will return an empty array if Zend Optimizer is detected or if
1788  * debug_backtrace is disabled, otherwise the output from
1789  * debug_backtrace() (trimmed).
1790  *
1791  * @param $limit int This parameter can be used to limit the number of stack frames returned
1792  *
1793  * @return array of backtrace information
1794  */
1795 function wfDebugBacktrace( $limit = 0 ) {
1796         static $disabled = null;
1797
1798         if( extension_loaded( 'Zend Optimizer' ) ) {
1799                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1800                 return array();
1801         }
1802
1803         if ( is_null( $disabled ) ) {
1804                 $disabled = false;
1805                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1806                 $functions = array_map( 'trim', $functions );
1807                 $functions = array_map( 'strtolower', $functions );
1808                 if ( in_array( 'debug_backtrace', $functions ) ) {
1809                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1810                         $disabled = true;
1811                 }
1812         }
1813         if ( $disabled ) {
1814                 return array();
1815         }
1816
1817         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1818                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit ), 1 );
1819         } else {
1820                 return array_slice( debug_backtrace(), 1 );
1821         }
1822 }
1823
1824 /**
1825  * Get a debug backtrace as a string
1826  *
1827  * @return string
1828  */
1829 function wfBacktrace() {
1830         global $wgCommandLineMode;
1831
1832         if ( $wgCommandLineMode ) {
1833                 $msg = '';
1834         } else {
1835                 $msg = "<ul>\n";
1836         }
1837         $backtrace = wfDebugBacktrace();
1838         foreach( $backtrace as $call ) {
1839                 if( isset( $call['file'] ) ) {
1840                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1841                         $file = $f[count( $f ) - 1];
1842                 } else {
1843                         $file = '-';
1844                 }
1845                 if( isset( $call['line'] ) ) {
1846                         $line = $call['line'];
1847                 } else {
1848                         $line = '-';
1849                 }
1850                 if ( $wgCommandLineMode ) {
1851                         $msg .= "$file line $line calls ";
1852                 } else {
1853                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1854                 }
1855                 if( !empty( $call['class'] ) ) {
1856                         $msg .= $call['class'] . $call['type'];
1857                 }
1858                 $msg .= $call['function'] . '()';
1859
1860                 if ( $wgCommandLineMode ) {
1861                         $msg .= "\n";
1862                 } else {
1863                         $msg .= "</li>\n";
1864                 }
1865         }
1866         if ( $wgCommandLineMode ) {
1867                 $msg .= "\n";
1868         } else {
1869                 $msg .= "</ul>\n";
1870         }
1871
1872         return $msg;
1873 }
1874
1875 /**
1876  * Get the name of the function which called this function
1877  *
1878  * @param $level Int
1879  * @return Bool|string
1880  */
1881 function wfGetCaller( $level = 2 ) {
1882         $backtrace = wfDebugBacktrace( $level );
1883         if ( isset( $backtrace[$level] ) ) {
1884                 return wfFormatStackFrame( $backtrace[$level] );
1885         } else {
1886                 $caller = 'unknown';
1887         }
1888         return $caller;
1889 }
1890
1891 /**
1892  * Return a string consisting of callers in the stack. Useful sometimes
1893  * for profiling specific points.
1894  *
1895  * @param $limit int The maximum depth of the stack frame to return, or false for
1896  *               the entire stack.
1897  * @return String
1898  */
1899 function wfGetAllCallers( $limit = 3 ) {
1900         $trace = array_reverse( wfDebugBacktrace() );
1901         if ( !$limit || $limit > count( $trace ) - 1 ) {
1902                 $limit = count( $trace ) - 1;
1903         }
1904         $trace = array_slice( $trace, -$limit - 1, $limit );
1905         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1906 }
1907
1908 /**
1909  * Return a string representation of frame
1910  *
1911  * @param $frame Array
1912  * @return Bool
1913  */
1914 function wfFormatStackFrame( $frame ) {
1915         return isset( $frame['class'] ) ?
1916                 $frame['class'] . '::' . $frame['function'] :
1917                 $frame['function'];
1918 }
1919
1920
1921 /* Some generic result counters, pulled out of SearchEngine */
1922
1923
1924 /**
1925  * @todo document
1926  *
1927  * @param $offset Int
1928  * @param $limit Int
1929  * @return String
1930  */
1931 function wfShowingResults( $offset, $limit ) {
1932         global $wgLang;
1933         return wfMsgExt(
1934                 'showingresults',
1935                 array( 'parseinline' ),
1936                 $wgLang->formatNum( $limit ),
1937                 $wgLang->formatNum( $offset + 1 )
1938         );
1939 }
1940
1941 /**
1942  * Generate (prev x| next x) (20|50|100...) type links for paging
1943  *
1944  * @param $offset String
1945  * @param $limit Integer
1946  * @param $link String
1947  * @param $query String: optional URL query parameter string
1948  * @param $atend Bool: optional param for specified if this is the last page
1949  * @return String
1950  * @deprecated in 1.19; use Language::viewPrevNext() instead
1951  */
1952 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1953         wfDeprecated( __METHOD__, '1.19' );
1954
1955         global $wgLang;
1956
1957         $query = wfCgiToArray( $query );
1958
1959         if( is_object( $link ) ) {
1960                 $title = $link;
1961         } else {
1962                 $title = Title::newFromText( $link );
1963                 if( is_null( $title ) ) {
1964                         return false;
1965                 }
1966         }
1967
1968         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1969 }
1970
1971 /**
1972  * Make a list item, used by various special pages
1973  *
1974  * @param $page String Page link
1975  * @param $details String Text between brackets
1976  * @param $oppositedm Boolean   Add the direction mark opposite to your
1977  *                                                              language, to display text properly
1978  * @return String
1979  * @deprecated since 1.19; use Language::specialList() instead
1980  */
1981 function wfSpecialList( $page, $details, $oppositedm = true ) {
1982         wfDeprecated( __METHOD__, '1.19' );
1983
1984         global $wgLang;
1985         return $wgLang->specialList( $page, $details, $oppositedm );
1986 }
1987
1988 /**
1989  * @todo document
1990  * @todo FIXME: We may want to blacklist some broken browsers
1991  *
1992  * @param $force Bool
1993  * @return bool Whereas client accept gzip compression
1994  */
1995 function wfClientAcceptsGzip( $force = false ) {
1996         static $result = null;
1997         if ( $result === null || $force ) {
1998                 $result = false;
1999                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2000                         # @todo FIXME: We may want to blacklist some broken browsers
2001                         $m = array();
2002                         if( preg_match(
2003                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2004                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
2005                                 $m )
2006                         )
2007                         {
2008                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2009                                         $result = false;
2010                                         return $result;
2011                                 }
2012                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2013                                 $result = true;
2014                         }
2015                 }
2016         }
2017         return $result;
2018 }
2019
2020 /**
2021  * Obtain the offset and limit values from the request string;
2022  * used in special pages
2023  *
2024  * @param $deflimit Int default limit if none supplied
2025  * @param $optionname String Name of a user preference to check against
2026  * @return array
2027  *
2028  */
2029 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2030         global $wgRequest;
2031         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2032 }
2033
2034 /**
2035  * Escapes the given text so that it may be output using addWikiText()
2036  * without any linking, formatting, etc. making its way through. This
2037  * is achieved by substituting certain characters with HTML entities.
2038  * As required by the callers, <nowiki> is not used.
2039  *
2040  * @param $text String: text to be escaped
2041  * @return String
2042  */
2043 function wfEscapeWikiText( $text ) {
2044         $text = strtr( "\n$text", array(
2045                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2046                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2047                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2048                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2049                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2050                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2051         ) );
2052         return substr( $text, 1 );
2053 }
2054
2055 /**
2056  * Get the current unix timetstamp with microseconds.  Useful for profiling
2057  * @return Float
2058  */
2059 function wfTime() {
2060         return microtime( true );
2061 }
2062
2063 /**
2064  * Sets dest to source and returns the original value of dest
2065  * If source is NULL, it just returns the value, it doesn't set the variable
2066  * If force is true, it will set the value even if source is NULL
2067  *
2068  * @param $dest Mixed
2069  * @param $source Mixed
2070  * @param $force Bool
2071  * @return Mixed
2072  */
2073 function wfSetVar( &$dest, $source, $force = false ) {
2074         $temp = $dest;
2075         if ( !is_null( $source ) || $force ) {
2076                 $dest = $source;
2077         }
2078         return $temp;
2079 }
2080
2081 /**
2082  * As for wfSetVar except setting a bit
2083  *
2084  * @param $dest Int
2085  * @param $bit Int
2086  * @param $state Bool
2087  *
2088  * @return bool
2089  */
2090 function wfSetBit( &$dest, $bit, $state = true ) {
2091         $temp = (bool)( $dest & $bit );
2092         if ( !is_null( $state ) ) {
2093                 if ( $state ) {
2094                         $dest |= $bit;
2095                 } else {
2096                         $dest &= ~$bit;
2097                 }
2098         }
2099         return $temp;
2100 }
2101
2102 /**
2103  * A wrapper around the PHP function var_export().
2104  * Either print it or add it to the regular output ($wgOut).
2105  *
2106  * @param $var mixed A PHP variable to dump.
2107  */
2108 function wfVarDump( $var ) {
2109         global $wgOut;
2110         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2111         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2112                 print $s;
2113         } else {
2114                 $wgOut->addHTML( $s );
2115         }
2116 }
2117
2118 /**
2119  * Provide a simple HTTP error.
2120  *
2121  * @param $code Int|String
2122  * @param $label String
2123  * @param $desc String
2124  */
2125 function wfHttpError( $code, $label, $desc ) {
2126         global $wgOut;
2127         $wgOut->disable();
2128         header( "HTTP/1.0 $code $label" );
2129         header( "Status: $code $label" );
2130         $wgOut->sendCacheControl();
2131
2132         header( 'Content-type: text/html; charset=utf-8' );
2133         print "<!doctype html>" .
2134                 '<html><head><title>' .
2135                 htmlspecialchars( $label ) .
2136                 '</title></head><body><h1>' .
2137                 htmlspecialchars( $label ) .
2138                 '</h1><p>' .
2139                 nl2br( htmlspecialchars( $desc ) ) .
2140                 "</p></body></html>\n";
2141 }
2142
2143 /**
2144  * Clear away any user-level output buffers, discarding contents.
2145  *
2146  * Suitable for 'starting afresh', for instance when streaming
2147  * relatively large amounts of data without buffering, or wanting to
2148  * output image files without ob_gzhandler's compression.
2149  *
2150  * The optional $resetGzipEncoding parameter controls suppression of
2151  * the Content-Encoding header sent by ob_gzhandler; by default it
2152  * is left. See comments for wfClearOutputBuffers() for why it would
2153  * be used.
2154  *
2155  * Note that some PHP configuration options may add output buffer
2156  * layers which cannot be removed; these are left in place.
2157  *
2158  * @param $resetGzipEncoding Bool
2159  */
2160 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2161         if( $resetGzipEncoding ) {
2162                 // Suppress Content-Encoding and Content-Length
2163                 // headers from 1.10+s wfOutputHandler
2164                 global $wgDisableOutputCompression;
2165                 $wgDisableOutputCompression = true;
2166         }
2167         while( $status = ob_get_status() ) {
2168                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2169                         // Probably from zlib.output_compression or other
2170                         // PHP-internal setting which can't be removed.
2171                         //
2172                         // Give up, and hope the result doesn't break
2173                         // output behavior.
2174                         break;
2175                 }
2176                 if( !ob_end_clean() ) {
2177                         // Could not remove output buffer handler; abort now
2178                         // to avoid getting in some kind of infinite loop.
2179                         break;
2180                 }
2181                 if( $resetGzipEncoding ) {
2182                         if( $status['name'] == 'ob_gzhandler' ) {
2183                                 // Reset the 'Content-Encoding' field set by this handler
2184                                 // so we can start fresh.
2185                                 if ( function_exists( 'header_remove' ) ) {
2186                                         // Available since PHP 5.3.0
2187                                         header_remove( 'Content-Encoding' );
2188                                 } else {
2189                                         // We need to provide a valid content-coding. See bug 28069
2190                                         header( 'Content-Encoding: identity' );
2191                                 }
2192                                 break;
2193                         }
2194                 }
2195         }
2196 }
2197
2198 /**
2199  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2200  *
2201  * Clear away output buffers, but keep the Content-Encoding header
2202  * produced by ob_gzhandler, if any.
2203  *
2204  * This should be used for HTTP 304 responses, where you need to
2205  * preserve the Content-Encoding header of the real result, but
2206  * also need to suppress the output of ob_gzhandler to keep to spec
2207  * and avoid breaking Firefox in rare cases where the headers and
2208  * body are broken over two packets.
2209  */
2210 function wfClearOutputBuffers() {
2211         wfResetOutputBuffers( false );
2212 }
2213
2214 /**
2215  * Converts an Accept-* header into an array mapping string values to quality
2216  * factors
2217  *
2218  * @param $accept String
2219  * @param $def String default
2220  * @return Array
2221  */
2222 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2223         # No arg means accept anything (per HTTP spec)
2224         if( !$accept ) {
2225                 return array( $def => 1.0 );
2226         }
2227
2228         $prefs = array();
2229
2230         $parts = explode( ',', $accept );
2231
2232         foreach( $parts as $part ) {
2233                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2234                 $values = explode( ';', trim( $part ) );
2235                 $match = array();
2236                 if ( count( $values ) == 1 ) {
2237                         $prefs[$values[0]] = 1.0;
2238                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2239                         $prefs[$values[0]] = floatval( $match[1] );
2240                 }
2241         }
2242
2243         return $prefs;
2244 }
2245
2246 /**
2247  * Checks if a given MIME type matches any of the keys in the given
2248  * array. Basic wildcards are accepted in the array keys.
2249  *
2250  * Returns the matching MIME type (or wildcard) if a match, otherwise
2251  * NULL if no match.
2252  *
2253  * @param $type String
2254  * @param $avail Array
2255  * @return string
2256  * @private
2257  */
2258 function mimeTypeMatch( $type, $avail ) {
2259         if( array_key_exists( $type, $avail ) ) {
2260                 return $type;
2261         } else {
2262                 $parts = explode( '/', $type );
2263                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2264                         return $parts[0] . '/*';
2265                 } elseif( array_key_exists( '*/*', $avail ) ) {
2266                         return '*/*';
2267                 } else {
2268                         return null;
2269                 }
2270         }
2271 }
2272
2273 /**
2274  * Returns the 'best' match between a client's requested internet media types
2275  * and the server's list of available types. Each list should be an associative
2276  * array of type to preference (preference is a float between 0.0 and 1.0).
2277  * Wildcards in the types are acceptable.
2278  *
2279  * @param $cprefs Array: client's acceptable type list
2280  * @param $sprefs Array: server's offered types
2281  * @return string
2282  *
2283  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2284  * XXX: generalize to negotiate other stuff
2285  */
2286 function wfNegotiateType( $cprefs, $sprefs ) {
2287         $combine = array();
2288
2289         foreach( array_keys( $sprefs ) as $type ) {
2290                 $parts = explode( '/', $type );
2291                 if( $parts[1] != '*' ) {
2292                         $ckey = mimeTypeMatch( $type, $cprefs );
2293                         if( $ckey ) {
2294                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2295                         }
2296                 }
2297         }
2298
2299         foreach( array_keys( $cprefs ) as $type ) {
2300                 $parts = explode( '/', $type );
2301                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2302                         $skey = mimeTypeMatch( $type, $sprefs );
2303                         if( $skey ) {
2304                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2305                         }
2306                 }
2307         }
2308
2309         $bestq = 0;
2310         $besttype = null;
2311
2312         foreach( array_keys( $combine ) as $type ) {
2313                 if( $combine[$type] > $bestq ) {
2314                         $besttype = $type;
2315                         $bestq = $combine[$type];
2316                 }
2317         }
2318
2319         return $besttype;
2320 }
2321
2322 /**
2323  * Reference-counted warning suppression
2324  *
2325  * @param $end Bool
2326  */
2327 function wfSuppressWarnings( $end = false ) {
2328         static $suppressCount = 0;
2329         static $originalLevel = false;
2330
2331         if ( $end ) {
2332                 if ( $suppressCount ) {
2333                         --$suppressCount;
2334                         if ( !$suppressCount ) {
2335                                 error_reporting( $originalLevel );
2336                         }
2337                 }
2338         } else {
2339                 if ( !$suppressCount ) {
2340                         // E_DEPRECATED is undefined in PHP 5.2
2341                         if( !defined( 'E_DEPRECATED' ) ) {
2342                                 define( 'E_DEPRECATED', 8192 );
2343                         }
2344                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2345                 }
2346                 ++$suppressCount;
2347         }
2348 }
2349
2350 /**
2351  * Restore error level to previous value
2352  */
2353 function wfRestoreWarnings() {
2354         wfSuppressWarnings( true );
2355 }
2356
2357 # Autodetect, convert and provide timestamps of various types
2358
2359 /**
2360  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2361  */
2362 define( 'TS_UNIX', 0 );
2363
2364 /**
2365  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2366  */
2367 define( 'TS_MW', 1 );
2368
2369 /**
2370  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2371  */
2372 define( 'TS_DB', 2 );
2373
2374 /**
2375  * RFC 2822 format, for E-mail and HTTP headers
2376  */
2377 define( 'TS_RFC2822', 3 );
2378
2379 /**
2380  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2381  *
2382  * This is used by Special:Export
2383  */
2384 define( 'TS_ISO_8601', 4 );
2385
2386 /**
2387  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2388  *
2389  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2390  *       DateTime tag and page 36 for the DateTimeOriginal and
2391  *       DateTimeDigitized tags.
2392  */
2393 define( 'TS_EXIF', 5 );
2394
2395 /**
2396  * Oracle format time.
2397  */
2398 define( 'TS_ORACLE', 6 );
2399
2400 /**
2401  * Postgres format time.
2402  */
2403 define( 'TS_POSTGRES', 7 );
2404
2405 /**
2406  * DB2 format time
2407  */
2408 define( 'TS_DB2', 8 );
2409
2410 /**
2411  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2412  */
2413 define( 'TS_ISO_8601_BASIC', 9 );
2414
2415 /**
2416  * Get a timestamp string in one of various formats
2417  *
2418  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2419  *                    function will autodetect which format is supplied and act
2420  *                    accordingly.
2421  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2422  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2423  */
2424 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2425         $uts = 0;
2426         $da = array();
2427         $strtime = '';
2428
2429         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2430                 $uts = time();
2431                 $strtime = "@$uts";
2432         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2433                 # TS_DB
2434         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2435                 # TS_EXIF
2436         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2437                 # TS_MW
2438         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2439                 # TS_UNIX
2440                 $uts = $ts;
2441                 $strtime = "@$ts"; // http://php.net/manual/en/datetime.formats.compound.php
2442         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2443                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2444                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2445                                 str_replace( '+00:00', 'UTC', $ts ) );
2446         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2447                 # TS_ISO_8601
2448         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2449                 #TS_ISO_8601_BASIC
2450         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2451                 # TS_POSTGRES
2452         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2453                 # TS_POSTGRES
2454         } elseif (preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/', $ts, $da ) ) {
2455                 # TS_DB2
2456         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2457                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2458                                                         '[ \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
2459                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2460                 # The regex is a superset of rfc2822 for readability
2461                 $strtime = strtok( $ts, ';' );
2462         } 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 ) ) {
2463                 # TS_RFC850
2464                 $strtime = $ts;
2465         } 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 ) ) {
2466                 # asctime
2467                 $strtime = $ts;
2468         } else {
2469                 # Bogus value...
2470                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2471
2472                 return false;
2473         }
2474
2475         static $formats = array(
2476                 TS_UNIX => 'U',
2477                 TS_MW => 'YmdHis',
2478                 TS_DB => 'Y-m-d H:i:s',
2479                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2480                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2481                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2482                 TS_RFC2822 => 'D, d M Y H:i:s',
2483                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2484                 TS_POSTGRES => 'Y-m-d H:i:s',
2485                 TS_DB2 => 'Y-m-d H:i:s',
2486         );
2487
2488         if ( !isset( $formats[$outputtype] ) ) {
2489                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2490         }
2491
2492         if ( function_exists( "date_create" ) ) {
2493                 if ( count( $da ) ) {
2494                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2495                                 (int)$da[1], (int)$da[2], (int)$da[3],
2496                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2497
2498                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2499                 } elseif ( $strtime ) {
2500                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2501                 } else {
2502                         return false;
2503                 }
2504
2505                 if ( !$d ) {
2506                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2507                         return false;
2508                 }
2509
2510                 $output = $d->format( $formats[$outputtype] );
2511         } else {
2512                 if ( count( $da ) ) {
2513                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2514                         // We may want to handle that explicitly at some point
2515                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2516                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2517                 } elseif ( $strtime ) {
2518                         $uts = strtotime( $strtime );
2519                 }
2520
2521                 if ( $uts === false ) {
2522                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2523                         return false;
2524                 }
2525
2526                 if ( TS_UNIX == $outputtype ) {
2527                         return $uts;
2528                 }
2529                 $output = gmdate( $formats[$outputtype], $uts );
2530         }
2531
2532         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2533                 $output .= ' GMT';
2534         }
2535
2536         return $output;
2537 }
2538
2539 /**
2540  * Return a formatted timestamp, or null if input is null.
2541  * For dealing with nullable timestamp columns in the database.
2542  *
2543  * @param $outputtype Integer
2544  * @param $ts String
2545  * @return String
2546  */
2547 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2548         if( is_null( $ts ) ) {
2549                 return null;
2550         } else {
2551                 return wfTimestamp( $outputtype, $ts );
2552         }
2553 }
2554
2555 /**
2556  * Convenience function; returns MediaWiki timestamp for the present time.
2557  *
2558  * @return string
2559  */
2560 function wfTimestampNow() {
2561         # return NOW
2562         return wfTimestamp( TS_MW, time() );
2563 }
2564
2565 /**
2566  * Check if the operating system is Windows
2567  *
2568  * @return Bool: true if it's Windows, False otherwise.
2569  */
2570 function wfIsWindows() {
2571         static $isWindows = null;
2572         if ( $isWindows === null ) {
2573                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2574         }
2575         return $isWindows;
2576 }
2577
2578 /**
2579  * Check if we are running under HipHop
2580  *
2581  * @return Bool
2582  */
2583 function wfIsHipHop() {
2584         return function_exists( 'hphp_thread_set_warmup_enabled' );
2585 }
2586
2587 /**
2588  * Swap two variables
2589  *
2590  * @param $x Mixed
2591  * @param $y Mixed
2592  */
2593 function swap( &$x, &$y ) {
2594         $z = $x;
2595         $x = $y;
2596         $y = $z;
2597 }
2598
2599 /**
2600  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2601  * TEMP environment variables are then checked in sequence, and if none are set
2602  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2603  * or C:\Windows\Temp for Windows and hope for the best.
2604  * It is common to call it with tempnam().
2605  *
2606  * NOTE: When possible, use instead the tmpfile() function to create
2607  * temporary files to avoid race conditions on file creation, etc.
2608  *
2609  * @return String
2610  */
2611 function wfTempDir() {
2612         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2613                 $tmp = getenv( $var );
2614                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2615                         return $tmp;
2616                 }
2617         }
2618         if( function_exists( 'sys_get_temp_dir' ) ) {
2619                 return sys_get_temp_dir();
2620         }
2621         # Usual defaults
2622         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2623 }
2624
2625 /**
2626  * Make directory, and make all parent directories if they don't exist
2627  *
2628  * @param $dir String: full path to directory to create
2629  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2630  * @param $caller String: optional caller param for debugging.
2631  * @return bool
2632  */
2633 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2634         global $wgDirectoryMode;
2635
2636         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2637                 throw new MWException( __FUNCTION__ . " given storage path `$dir`.");
2638         }
2639
2640         if ( !is_null( $caller ) ) {
2641                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2642         }
2643
2644         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2645                 return true;
2646         }
2647
2648         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2649
2650         if ( is_null( $mode ) ) {
2651                 $mode = $wgDirectoryMode;
2652         }
2653
2654         // Turn off the normal warning, we're doing our own below
2655         wfSuppressWarnings();
2656         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2657         wfRestoreWarnings();
2658
2659         if( !$ok ) {
2660                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2661                 trigger_error( sprintf( "%s: failed to mkdir \"%s\" mode 0%o", __FUNCTION__, $dir, $mode ),
2662                         E_USER_WARNING );
2663         }
2664         return $ok;
2665 }
2666
2667 /**
2668  * Remove a directory and all its content.
2669  * Does not hide error.
2670  */
2671 function wfRecursiveRemoveDir( $dir ) {
2672         wfDebug( __FUNCTION__ . "( $dir )\n" );
2673         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2674         if ( is_dir( $dir ) ) {
2675                 $objects = scandir( $dir );
2676                 foreach ( $objects as $object ) {
2677                         if ( $object != "." && $object != ".." ) {
2678                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2679                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2680                                 } else {
2681                                         unlink( $dir . '/' . $object );
2682                                 }
2683                         }
2684                 }
2685                 reset( $objects );
2686                 rmdir( $dir );
2687         }
2688 }
2689
2690 /**
2691  * @param $nr Mixed: the number to format
2692  * @param $acc Integer: the number of digits after the decimal point, default 2
2693  * @param $round Boolean: whether or not to round the value, default true
2694  * @return float
2695  */
2696 function wfPercent( $nr, $acc = 2, $round = true ) {
2697         $ret = sprintf( "%.${acc}f", $nr );
2698         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2699 }
2700
2701 /**
2702  * Find out whether or not a mixed variable exists in a string
2703  *
2704  * @param $needle String
2705  * @param $str String
2706  * @param $insensitive Boolean
2707  * @return Boolean
2708  */
2709 function in_string( $needle, $str, $insensitive = false ) {
2710         $func = 'strpos';
2711         if( $insensitive ) $func = 'stripos';
2712
2713         return $func( $str, $needle ) !== false;
2714 }
2715
2716 /**
2717  * Safety wrapper around ini_get() for boolean settings.
2718  * The values returned from ini_get() are pre-normalized for settings
2719  * set via php.ini or php_flag/php_admin_flag... but *not*
2720  * for those set via php_value/php_admin_value.
2721  *
2722  * It's fairly common for people to use php_value instead of php_flag,
2723  * which can leave you with an 'off' setting giving a false positive
2724  * for code that just takes the ini_get() return value as a boolean.
2725  *
2726  * To make things extra interesting, setting via php_value accepts
2727  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2728  * Unrecognized values go false... again opposite PHP's own coercion
2729  * from string to bool.
2730  *
2731  * Luckily, 'properly' set settings will always come back as '0' or '1',
2732  * so we only have to worry about them and the 'improper' settings.
2733  *
2734  * I frickin' hate PHP... :P
2735  *
2736  * @param $setting String
2737  * @return Bool
2738  */
2739 function wfIniGetBool( $setting ) {
2740         $val = ini_get( $setting );
2741         // 'on' and 'true' can't have whitespace around them, but '1' can.
2742         return strtolower( $val ) == 'on'
2743                 || strtolower( $val ) == 'true'
2744                 || strtolower( $val ) == 'yes'
2745                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2746 }
2747
2748 /**
2749  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2750  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2751  *
2752  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2753  *                          should be omitted
2754  * @param $fileName String Name of the library, if not $extension.suffix
2755  * @return Bool - Whether or not the extension is loaded
2756  */
2757 function wfDl( $extension, $fileName = null ) {
2758         if( extension_loaded( $extension ) ) {
2759                 return true;
2760         }
2761
2762         $canDl = false;
2763         $sapi = php_sapi_name();
2764         if( $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' ) {
2765                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2766                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2767         }
2768
2769         if( $canDl ) {
2770                 $fileName = $fileName ? $fileName : $extension;
2771                 if( wfIsWindows() ) {
2772                         $fileName = 'php_' . $fileName;
2773                 }
2774                 wfSuppressWarnings();
2775                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2776                 wfRestoreWarnings();
2777         }
2778         return extension_loaded( $extension );
2779 }
2780
2781 /**
2782  * Windows-compatible version of escapeshellarg()
2783  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2784  * function puts single quotes in regardless of OS.
2785  *
2786  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2787  * earlier distro releases of PHP)
2788  *
2789  * @param varargs
2790  * @return String
2791  */
2792 function wfEscapeShellArg( ) {
2793         wfInitShellLocale();
2794
2795         $args = func_get_args();
2796         $first = true;
2797         $retVal = '';
2798         foreach ( $args as $arg ) {
2799                 if ( !$first ) {
2800                         $retVal .= ' ';
2801                 } else {
2802                         $first = false;
2803                 }
2804
2805                 if ( wfIsWindows() ) {
2806                         // Escaping for an MSVC-style command line parser and CMD.EXE
2807                         // Refs:
2808                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2809                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2810                         //  * Bug #13518
2811                         //  * CR r63214
2812                         // Double the backslashes before any double quotes. Escape the double quotes.
2813                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2814                         $arg = '';
2815                         $iteration = 0;
2816                         foreach ( $tokens as $token ) {
2817                                 if ( $iteration % 2 == 1 ) {
2818                                         // Delimiter, a double quote preceded by zero or more slashes
2819                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2820                                 } elseif ( $iteration % 4 == 2 ) {
2821                                         // ^ in $token will be outside quotes, need to be escaped
2822                                         $arg .= str_replace( '^', '^^', $token );
2823                                 } else { // $iteration % 4 == 0
2824                                         // ^ in $token will appear inside double quotes, so leave as is
2825                                         $arg .= $token;
2826                                 }
2827                                 $iteration++;
2828                         }
2829                         // Double the backslashes before the end of the string, because
2830                         // we will soon add a quote
2831                         $m = array();
2832                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2833                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2834                         }
2835
2836                         // Add surrounding quotes
2837                         $retVal .= '"' . $arg . '"';
2838                 } else {
2839                         $retVal .= escapeshellarg( $arg );
2840                 }
2841         }
2842         return $retVal;
2843 }
2844
2845 /**
2846  * Execute a shell command, with time and memory limits mirrored from the PHP
2847  * configuration if supported.
2848  * @param $cmd String Command line, properly escaped for shell.
2849  * @param &$retval null|Mixed optional, will receive the program's exit code.
2850  *                 (non-zero is usually failure)
2851  * @param $environ Array optional environment variables which should be
2852  *                 added to the executed command environment.
2853  * @return string collected stdout as a string (trailing newlines stripped)
2854  */
2855 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2856         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2857
2858         static $disabled;
2859         if ( is_null( $disabled ) ) {
2860                 $disabled = false;
2861                 if( wfIniGetBool( 'safe_mode' ) ) {
2862                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2863                         $disabled = 'safemode';
2864                 } else {
2865                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2866                         $functions = array_map( 'trim', $functions );
2867                         $functions = array_map( 'strtolower', $functions );
2868                         if ( in_array( 'passthru', $functions ) ) {
2869                                 wfDebug( "passthru is in disabled_functions\n" );
2870                                 $disabled = 'passthru';
2871                         }
2872                 }
2873         }
2874         if ( $disabled ) {
2875                 $retval = 1;
2876                 return $disabled == 'safemode' ?
2877                         'Unable to run external programs in safe mode.' :
2878                         'Unable to run external programs, passthru() is disabled.';
2879         }
2880
2881         wfInitShellLocale();
2882
2883         $envcmd = '';
2884         foreach( $environ as $k => $v ) {
2885                 if ( wfIsWindows() ) {
2886                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2887                          * appear in the environment variable, so we must use carat escaping as documented in
2888                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2889                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2890                          * are listed there but doesn't appear to need it.
2891                          */
2892                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2893                 } else {
2894                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2895                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2896                          */
2897                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2898                 }
2899         }
2900         $cmd = $envcmd . $cmd;
2901
2902         if ( php_uname( 's' ) == 'Linux' ) {
2903                 $time = intval( $wgMaxShellTime );
2904                 $mem = intval( $wgMaxShellMemory );
2905                 $filesize = intval( $wgMaxShellFileSize );
2906
2907                 if ( $time > 0 && $mem > 0 ) {
2908                         $script = "$IP/bin/ulimit4.sh";
2909                         if ( is_executable( $script ) ) {
2910                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2911                         }
2912                 }
2913         }
2914         wfDebug( "wfShellExec: $cmd\n" );
2915
2916         $retval = 1; // error by default?
2917         ob_start();
2918         passthru( $cmd, $retval );
2919         $output = ob_get_contents();
2920         ob_end_clean();
2921
2922         if ( $retval == 127 ) {
2923                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2924         }
2925         return $output;
2926 }
2927
2928 /**
2929  * Workaround for http://bugs.php.net/bug.php?id=45132
2930  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2931  */
2932 function wfInitShellLocale() {
2933         static $done = false;
2934         if ( $done ) {
2935                 return;
2936         }
2937         $done = true;
2938         global $wgShellLocale;
2939         if ( !wfIniGetBool( 'safe_mode' ) ) {
2940                 putenv( "LC_CTYPE=$wgShellLocale" );
2941                 setlocale( LC_CTYPE, $wgShellLocale );
2942         }
2943 }
2944
2945 /**
2946  * Alias to wfShellWikiCmd()
2947  * @see wfShellWikiCmd()
2948  */
2949 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2950         return wfShellWikiCmd( $script, $parameters, $options );
2951 }
2952
2953 /**
2954  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2955  * Note that $parameters should be a flat array and an option with an argument
2956  * should consist of two consecutive items in the array (do not use "--option value").
2957  * @param $script string MediaWiki cli script path
2958  * @param $parameters Array Arguments and options to the script
2959  * @param $options Array Associative array of options:
2960  *              'php': The path to the php executable
2961  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2962  * @return Array
2963  */
2964 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2965         global $wgPhpCli;
2966         // Give site config file a chance to run the script in a wrapper.
2967         // The caller may likely want to call wfBasename() on $script.
2968         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2969         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2970         if ( isset( $options['wrapper'] ) ) {
2971                 $cmd[] = $options['wrapper'];
2972         }
2973         $cmd[] = $script;
2974         // Escape each parameter for shell
2975         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2976 }
2977
2978 /**
2979  * wfMerge attempts to merge differences between three texts.
2980  * Returns true for a clean merge and false for failure or a conflict.
2981  *
2982  * @param $old String
2983  * @param $mine String
2984  * @param $yours String
2985  * @param $result String
2986  * @return Bool
2987  */
2988 function wfMerge( $old, $mine, $yours, &$result ) {
2989         global $wgDiff3;
2990
2991         # This check may also protect against code injection in
2992         # case of broken installations.
2993         wfSuppressWarnings();
2994         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2995         wfRestoreWarnings();
2996
2997         if( !$haveDiff3 ) {
2998                 wfDebug( "diff3 not found\n" );
2999                 return false;
3000         }
3001
3002         # Make temporary files
3003         $td = wfTempDir();
3004         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3005         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3006         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3007
3008         fwrite( $oldtextFile, $old );
3009         fclose( $oldtextFile );
3010         fwrite( $mytextFile, $mine );
3011         fclose( $mytextFile );
3012         fwrite( $yourtextFile, $yours );
3013         fclose( $yourtextFile );
3014
3015         # Check for a conflict
3016         $cmd = $wgDiff3 . ' -a --overlap-only ' .
3017                 wfEscapeShellArg( $mytextName ) . ' ' .
3018                 wfEscapeShellArg( $oldtextName ) . ' ' .
3019                 wfEscapeShellArg( $yourtextName );
3020         $handle = popen( $cmd, 'r' );
3021
3022         if( fgets( $handle, 1024 ) ) {
3023                 $conflict = true;
3024         } else {
3025                 $conflict = false;
3026         }
3027         pclose( $handle );
3028
3029         # Merge differences
3030         $cmd = $wgDiff3 . ' -a -e --merge ' .
3031                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3032         $handle = popen( $cmd, 'r' );
3033         $result = '';
3034         do {
3035                 $data = fread( $handle, 8192 );
3036                 if ( strlen( $data ) == 0 ) {
3037                         break;
3038                 }
3039                 $result .= $data;
3040         } while ( true );
3041         pclose( $handle );
3042         unlink( $mytextName );
3043         unlink( $oldtextName );
3044         unlink( $yourtextName );
3045
3046         if ( $result === '' && $old !== '' && !$conflict ) {
3047                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3048                 $conflict = true;
3049         }
3050         return !$conflict;
3051 }
3052
3053 /**
3054  * Returns unified plain-text diff of two texts.
3055  * Useful for machine processing of diffs.
3056  *
3057  * @param $before String: the text before the changes.
3058  * @param $after String: the text after the changes.
3059  * @param $params String: command-line options for the diff command.
3060  * @return String: unified diff of $before and $after
3061  */
3062 function wfDiff( $before, $after, $params = '-u' ) {
3063         if ( $before == $after ) {
3064                 return '';
3065         }
3066
3067         global $wgDiff;
3068         wfSuppressWarnings();
3069         $haveDiff = $wgDiff && file_exists( $wgDiff );
3070         wfRestoreWarnings();
3071
3072         # This check may also protect against code injection in
3073         # case of broken installations.
3074         if( !$haveDiff ) {
3075                 wfDebug( "diff executable not found\n" );
3076                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3077                 $format = new UnifiedDiffFormatter();
3078                 return $format->format( $diffs );
3079         }
3080
3081         # Make temporary files
3082         $td = wfTempDir();
3083         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3084         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3085
3086         fwrite( $oldtextFile, $before );
3087         fclose( $oldtextFile );
3088         fwrite( $newtextFile, $after );
3089         fclose( $newtextFile );
3090
3091         // Get the diff of the two files
3092         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3093
3094         $h = popen( $cmd, 'r' );
3095
3096         $diff = '';
3097
3098         do {
3099                 $data = fread( $h, 8192 );
3100                 if ( strlen( $data ) == 0 ) {
3101                         break;
3102                 }
3103                 $diff .= $data;
3104         } while ( true );
3105
3106         // Clean up
3107         pclose( $h );
3108         unlink( $oldtextName );
3109         unlink( $newtextName );
3110
3111         // Kill the --- and +++ lines. They're not useful.
3112         $diff_lines = explode( "\n", $diff );
3113         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3114                 unset( $diff_lines[0] );
3115         }
3116         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3117                 unset( $diff_lines[1] );
3118         }
3119
3120         $diff = implode( "\n", $diff_lines );
3121
3122         return $diff;
3123 }
3124
3125 /**
3126  * This function works like "use VERSION" in Perl, the program will die with a
3127  * backtrace if the current version of PHP is less than the version provided
3128  *
3129  * This is useful for extensions which due to their nature are not kept in sync
3130  * with releases, and might depend on other versions of PHP than the main code
3131  *
3132  * Note: PHP might die due to parsing errors in some cases before it ever
3133  *       manages to call this function, such is life
3134  *
3135  * @see perldoc -f use
3136  *
3137  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3138  *                 a float
3139  */
3140 function wfUsePHP( $req_ver ) {
3141         $php_ver = PHP_VERSION;
3142
3143         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3144                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3145         }
3146 }
3147
3148 /**
3149  * This function works like "use VERSION" in Perl except it checks the version
3150  * of MediaWiki, the program will die with a backtrace if the current version
3151  * of MediaWiki is less than the version provided.
3152  *
3153  * This is useful for extensions which due to their nature are not kept in sync
3154  * with releases
3155  *
3156  * @see perldoc -f use
3157  *
3158  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3159  *                 a float
3160  */
3161 function wfUseMW( $req_ver ) {
3162         global $wgVersion;
3163
3164         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3165                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3166         }
3167 }
3168
3169 /**
3170  * Return the final portion of a pathname.
3171  * Reimplemented because PHP5's basename() is buggy with multibyte text.
3172  * http://bugs.php.net/bug.php?id=33898
3173  *
3174  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3175  * We'll consider it so always, as we don't want \s in our Unix paths either.
3176  *
3177  * @param $path String
3178  * @param $suffix String: to remove if present
3179  * @return String
3180  */
3181 function wfBaseName( $path, $suffix = '' ) {
3182         $encSuffix = ( $suffix == '' )
3183                 ? ''
3184                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3185         $matches = array();
3186         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3187                 return $matches[1];
3188         } else {
3189                 return '';
3190         }
3191 }
3192
3193 /**
3194  * Generate a relative path name to the given file.
3195  * May explode on non-matching case-insensitive paths,
3196  * funky symlinks, etc.
3197  *
3198  * @param $path String: absolute destination path including target filename
3199  * @param $from String: Absolute source path, directory only
3200  * @return String
3201  */
3202 function wfRelativePath( $path, $from ) {
3203         // Normalize mixed input on Windows...
3204         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3205         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3206
3207         // Trim trailing slashes -- fix for drive root
3208         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3209         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3210
3211         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3212         $against = explode( DIRECTORY_SEPARATOR, $from );
3213
3214         if( $pieces[0] !== $against[0] ) {
3215                 // Non-matching Windows drive letters?
3216                 // Return a full path.
3217                 return $path;
3218         }
3219
3220         // Trim off common prefix
3221         while( count( $pieces ) && count( $against )
3222                 && $pieces[0] == $against[0] ) {
3223                 array_shift( $pieces );
3224                 array_shift( $against );
3225         }
3226
3227         // relative dots to bump us to the parent
3228         while( count( $against ) ) {
3229                 array_unshift( $pieces, '..' );
3230                 array_shift( $against );
3231         }
3232
3233         array_push( $pieces, wfBaseName( $path ) );
3234
3235         return implode( DIRECTORY_SEPARATOR, $pieces );
3236 }
3237
3238 /**
3239  * Do any deferred updates and clear the list
3240  *
3241  * @deprecated since 1.19
3242  * @see DeferredUpdates::doUpdate()
3243  * @param $commit string
3244  */
3245 function wfDoUpdates( $commit = '' ) {
3246         wfDeprecated( __METHOD__, '1.19' );
3247         DeferredUpdates::doUpdates( $commit );
3248 }
3249
3250 /**
3251  * Convert an arbitrarily-long digit string from one numeric base
3252  * to another, optionally zero-padding to a minimum column width.
3253  *
3254  * Supports base 2 through 36; digit values 10-36 are represented
3255  * as lowercase letters a-z. Input is case-insensitive.
3256  *
3257  * @param $input String: of digits
3258  * @param $sourceBase Integer: 2-36
3259  * @param $destBase Integer: 2-36
3260  * @param $pad Integer: 1 or greater
3261  * @param $lowercase Boolean
3262  * @return String or false on invalid input
3263  */
3264 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3265         $input = strval( $input );
3266         if( $sourceBase < 2 ||
3267                 $sourceBase > 36 ||
3268                 $destBase < 2 ||
3269                 $destBase > 36 ||
3270                 $pad < 1 ||
3271                 $sourceBase != intval( $sourceBase ) ||
3272                 $destBase != intval( $destBase ) ||
3273                 $pad != intval( $pad ) ||
3274                 !is_string( $input ) ||
3275                 $input == '' ) {
3276                 return false;
3277         }
3278         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3279         $inDigits = array();
3280         $outChars = '';
3281
3282         // Decode and validate input string
3283         $input = strtolower( $input );
3284         for( $i = 0; $i < strlen( $input ); $i++ ) {
3285                 $n = strpos( $digitChars, $input[$i] );
3286                 if( $n === false || $n > $sourceBase ) {
3287                         return false;
3288                 }
3289                 $inDigits[] = $n;
3290         }
3291
3292         // Iterate over the input, modulo-ing out an output digit
3293         // at a time until input is gone.
3294         while( count( $inDigits ) ) {
3295                 $work = 0;
3296                 $workDigits = array();
3297
3298                 // Long division...
3299                 foreach( $inDigits as $digit ) {
3300                         $work *= $sourceBase;
3301                         $work += $digit;
3302
3303                         if( $work < $destBase ) {
3304                                 // Gonna need to pull another digit.
3305                                 if( count( $workDigits ) ) {
3306                                         // Avoid zero-padding; this lets us find
3307                                         // the end of the input very easily when
3308                                         // length drops to zero.
3309                                         $workDigits[] = 0;
3310                                 }
3311                         } else {
3312                                 // Finally! Actual division!
3313                                 $workDigits[] = intval( $work / $destBase );
3314
3315                                 // Isn't it annoying that most programming languages
3316                                 // don't have a single divide-and-remainder operator,
3317                                 // even though the CPU implements it that way?
3318                                 $work = $work % $destBase;
3319                         }
3320                 }
3321
3322                 // All that division leaves us with a remainder,
3323                 // which is conveniently our next output digit.
3324                 $outChars .= $digitChars[$work];
3325
3326                 // And we continue!
3327                 $inDigits = $workDigits;
3328         }
3329
3330         while( strlen( $outChars ) < $pad ) {
3331                 $outChars .= '0';
3332         }
3333
3334         return strrev( $outChars );
3335 }
3336
3337 /**
3338  * Create an object with a given name and an array of construct parameters
3339  *
3340  * @param $name String
3341  * @param $p Array: parameters
3342  * @return object
3343  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3344  */
3345 function wfCreateObject( $name, $p ) {
3346         wfDeprecated( __FUNCTION__, '1.18' );
3347         return MWFunction::newObj( $name, $p );
3348 }
3349
3350 /**
3351  * @return bool
3352  */
3353 function wfHttpOnlySafe() {
3354         global $wgHttpOnlyBlacklist;
3355
3356         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3357                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3358                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3359                                 return false;
3360                         }
3361                 }
3362         }
3363
3364         return true;
3365 }
3366
3367 /**
3368  * Override session_id before session startup if php's built-in
3369  * session generation code is not secure.
3370  */
3371 function wfFixSessionID() {
3372         // If the cookie or session id is already set we already have a session and should abort
3373         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3374                 return;
3375         }
3376
3377         // PHP's built-in session entropy is enabled if:
3378         // - entropy_file is set or you're on Windows with php 5.3.3+
3379         // - AND entropy_length is > 0
3380         // We treat it as disabled if it doesn't have an entropy length of at least 32
3381         $entropyEnabled = (
3382                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3383                         || ini_get( 'session.entropy_file' )
3384                 )
3385                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3386
3387         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3388         if ( !$entropyEnabled ) {
3389                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3390                 session_id( MWCryptRand::generateHex( 32 ) );
3391         }
3392 }
3393
3394 /**
3395  * Initialise php session
3396  *
3397  * @param $sessionId Bool
3398  */
3399 function wfSetupSession( $sessionId = false ) {
3400         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3401                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3402         if( $wgSessionsInMemcached ) {
3403                 if ( !defined( 'MW_COMPILED' ) ) {
3404                         global $IP;
3405                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
3406                 }
3407                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3408                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3409
3410                 // It's necessary to register a shutdown function to call session_write_close(),
3411                 // because by the time the request shutdown function for the session module is
3412                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3413                 // this way are called before object destruction.
3414                 register_shutdown_function( 'memsess_write_close' );
3415         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3416                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3417                 # hasn't already been set to the desired value (that causes errors)
3418                 ini_set( 'session.save_handler', $wgSessionHandler );
3419         }
3420         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3421         wfDebugLog( 'cookie',
3422                 'session_set_cookie_params: "' . implode( '", "',
3423                         array(
3424                                 0,
3425                                 $wgCookiePath,
3426                                 $wgCookieDomain,
3427                                 $wgCookieSecure,
3428                                 $httpOnlySafe ) ) . '"' );
3429         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3430         session_cache_limiter( 'private, must-revalidate' );
3431         if ( $sessionId ) {
3432                 session_id( $sessionId );
3433         } else {
3434                 wfFixSessionID();
3435         }
3436         wfSuppressWarnings();
3437         session_start();
3438         wfRestoreWarnings();
3439 }
3440
3441 /**
3442  * Get an object from the precompiled serialized directory
3443  *
3444  * @param $name String
3445  * @return Mixed: the variable on success, false on failure
3446  */
3447 function wfGetPrecompiledData( $name ) {
3448         global $IP;
3449
3450         $file = "$IP/serialized/$name";
3451         if ( file_exists( $file ) ) {
3452                 $blob = file_get_contents( $file );
3453                 if ( $blob ) {
3454                         return unserialize( $blob );
3455                 }
3456         }
3457         return false;
3458 }
3459
3460 /**
3461  * Get a cache key
3462  *
3463  * @param varargs
3464  * @return String
3465  */
3466 function wfMemcKey( /*... */ ) {
3467         global $wgCachePrefix;
3468         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3469         $args = func_get_args();
3470         $key = $prefix . ':' . implode( ':', $args );
3471         $key = str_replace( ' ', '_', $key );
3472         return $key;
3473 }
3474
3475 /**
3476  * Get a cache key for a foreign DB
3477  *
3478  * @param $db String
3479  * @param $prefix String
3480  * @param varargs String
3481  * @return String
3482  */
3483 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3484         $args = array_slice( func_get_args(), 2 );
3485         if ( $prefix ) {
3486                 $key = "$db-$prefix:" . implode( ':', $args );
3487         } else {
3488                 $key = $db . ':' . implode( ':', $args );
3489         }
3490         return $key;
3491 }
3492
3493 /**
3494  * Get an ASCII string identifying this wiki
3495  * This is used as a prefix in memcached keys
3496  *
3497  * @return String
3498  */
3499 function wfWikiID() {
3500         global $wgDBprefix, $wgDBname;
3501         if ( $wgDBprefix ) {
3502                 return "$wgDBname-$wgDBprefix";
3503         } else {
3504                 return $wgDBname;
3505         }
3506 }
3507
3508 /**
3509  * Split a wiki ID into DB name and table prefix
3510  *
3511  * @param $wiki String
3512  *
3513  * @return array
3514  */
3515 function wfSplitWikiID( $wiki ) {
3516         $bits = explode( '-', $wiki, 2 );
3517         if ( count( $bits ) < 2 ) {
3518                 $bits[] = '';
3519         }
3520         return $bits;
3521 }
3522
3523 /**
3524  * Get a Database object.
3525  *
3526  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3527  *            master (for write queries), DB_SLAVE for potentially lagged read
3528  *            queries, or an integer >= 0 for a particular server.
3529  *
3530  * @param $groups Mixed: query groups. An array of group names that this query
3531  *                belongs to. May contain a single string if the query is only
3532  *                in one group.
3533  *
3534  * @param $wiki String: the wiki ID, or false for the current wiki
3535  *
3536  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3537  * will always return the same object, unless the underlying connection or load
3538  * balancer is manually destroyed.
3539  *
3540  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3541  * updater to ensure that a proper database is being updated.
3542  *
3543  * @return DatabaseBase
3544  */
3545 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3546         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3547 }
3548
3549 /**
3550  * Get a load balancer object.
3551  *
3552  * @param $wiki String: wiki ID, or false for the current wiki
3553  * @return LoadBalancer
3554  */
3555 function wfGetLB( $wiki = false ) {
3556         return wfGetLBFactory()->getMainLB( $wiki );
3557 }
3558
3559 /**
3560  * Get the load balancer factory object
3561  *
3562  * @return LBFactory
3563  */
3564 function &wfGetLBFactory() {
3565         return LBFactory::singleton();
3566 }
3567
3568 /**
3569  * Find a file.
3570  * Shortcut for RepoGroup::singleton()->findFile()
3571  *
3572  * @param $title String or Title object
3573  * @param $options array Associative array of options:
3574  *     time:           requested time for an archived image, or false for the
3575  *                     current version. An image object will be returned which was
3576  *                     created at the specified time.
3577  *
3578  *     ignoreRedirect: If true, do not follow file redirects
3579  *
3580  *     private:        If true, return restricted (deleted) files if the current
3581  *                     user is allowed to view them. Otherwise, such files will not
3582  *                     be found.
3583  *
3584  *     bypassCache:    If true, do not use the process-local cache of File objects
3585  *
3586  * @return File, or false if the file does not exist
3587  */
3588 function wfFindFile( $title, $options = array() ) {
3589         return RepoGroup::singleton()->findFile( $title, $options );
3590 }
3591
3592 /**
3593  * Get an object referring to a locally registered file.
3594  * Returns a valid placeholder object if the file does not exist.
3595  *
3596  * @param $title Title|String
3597  * @return LocalFile|null A File, or null if passed an invalid Title
3598  */
3599 function wfLocalFile( $title ) {
3600         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3601 }
3602
3603 /**
3604  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3605  * @deprecated since 1.19
3606  */
3607 function wfStreamFile( $fname, $headers = array() ) {
3608         wfDeprecated( __FUNCTION__, '1.19' );
3609         StreamFile::stream( $fname, $headers );
3610 }
3611
3612 /**
3613  * Should low-performance queries be disabled?
3614  *
3615  * @return Boolean
3616  * @codeCoverageIgnore
3617  */
3618 function wfQueriesMustScale() {
3619         global $wgMiserMode;
3620         return $wgMiserMode
3621                 || ( SiteStats::pages() > 100000
3622                 && SiteStats::edits() > 1000000
3623                 && SiteStats::users() > 10000 );
3624 }
3625
3626 /**
3627  * Get the path to a specified script file, respecting file
3628  * extensions; this is a wrapper around $wgScriptExtension etc.
3629  *
3630  * @param $script String: script filename, sans extension
3631  * @return String
3632  */
3633 function wfScript( $script = 'index' ) {
3634         global $wgScriptPath, $wgScriptExtension;
3635         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3636 }
3637
3638 /**
3639  * Get the script URL.
3640  *
3641  * @return string script URL
3642  */
3643 function wfGetScriptUrl() {
3644         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3645                 #
3646                 # as it was called, minus the query string.
3647                 #
3648                 # Some sites use Apache rewrite rules to handle subdomains,
3649                 # and have PHP set up in a weird way that causes PHP_SELF
3650                 # to contain the rewritten URL instead of the one that the
3651                 # outside world sees.
3652                 #
3653                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3654                 # provides containing the "before" URL.
3655                 return $_SERVER['SCRIPT_NAME'];
3656         } else {
3657                 return $_SERVER['URL'];
3658         }
3659 }
3660
3661 /**
3662  * Convenience function converts boolean values into "true"
3663  * or "false" (string) values
3664  *
3665  * @param $value Boolean
3666  * @return String
3667  */
3668 function wfBoolToStr( $value ) {
3669         return $value ? 'true' : 'false';
3670 }
3671
3672 /**
3673  * Load an extension messages file
3674  *
3675  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3676  * @codeCoverageIgnore
3677  */
3678 function wfLoadExtensionMessages() {
3679         wfDeprecated( __FUNCTION__, '1.16' );
3680 }
3681
3682 /**
3683  * Get a platform-independent path to the null file, e.g. /dev/null
3684  *
3685  * @return string
3686  */
3687 function wfGetNull() {
3688         return wfIsWindows()
3689                 ? 'NUL'
3690                 : '/dev/null';
3691 }
3692
3693 /**
3694  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3695  * and waiting for it to go down, this waits for the slaves to catch up to the
3696  * master position. Use this when updating very large numbers of rows, as
3697  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3698  * a no-op if there are no slaves.
3699  *
3700  * @param $maxLag Integer (deprecated)
3701  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3702  */
3703 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3704         $lb = wfGetLB( $wiki );
3705         // bug 27975 - Don't try to wait for slaves if there are none
3706         // Prevents permission error when getting master position
3707         if ( $lb->getServerCount() > 1 ) {
3708                 $dbw = $lb->getConnection( DB_MASTER );
3709                 $pos = $dbw->getMasterPos();
3710                 $lb->waitForAll( $pos );
3711         }
3712 }
3713
3714 /**
3715  * Used to be used for outputting text in the installer/updater
3716  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3717  */
3718 function wfOut( $s ) {
3719         wfDeprecated( __FUNCTION__, '1.18' );
3720         global $wgCommandLineMode;
3721         if ( $wgCommandLineMode ) {
3722                 echo $s;
3723         } else {
3724                 echo htmlspecialchars( $s );
3725         }
3726         flush();
3727 }
3728
3729 /**
3730  * Count down from $n to zero on the terminal, with a one-second pause
3731  * between showing each number. For use in command-line scripts.
3732  * @codeCoverageIgnore
3733  * @param $n int
3734  */
3735 function wfCountDown( $n ) {
3736         for ( $i = $n; $i >= 0; $i-- ) {
3737                 if ( $i != $n ) {
3738                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3739                 }
3740                 echo $i;
3741                 flush();
3742                 if ( $i ) {
3743                         sleep( 1 );
3744                 }
3745         }
3746         echo "\n";
3747 }
3748
3749 /**
3750  * Generate a random 32-character hexadecimal token.
3751  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3752  *              characters before hashing.
3753  * @return string
3754  * @codeCoverageIgnore
3755  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pesudo-random strings
3756  * @warning This method is NOT secure. Additionally it has many callers that use it for pesudo-random purposes.
3757  */
3758 function wfGenerateToken( $salt = '' ) {
3759         wfDeprecated( __METHOD__, '1.20' );
3760         $salt = serialize( $salt );
3761         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3762 }
3763
3764 /**
3765  * Replace all invalid characters with -
3766  *
3767  * @param $name Mixed: filename to process
3768  * @return String
3769  */
3770 function wfStripIllegalFilenameChars( $name ) {
3771         global $wgIllegalFileChars;
3772         $name = wfBaseName( $name );
3773         $name = preg_replace(
3774                 "/[^" . Title::legalChars() . "]" .
3775                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3776                         "/",
3777                 '-',
3778                 $name
3779         );
3780         return $name;
3781 }
3782
3783 /**
3784  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3785  *
3786  * @return Integer value memory was set to.
3787  */
3788 function wfMemoryLimit() {
3789         global $wgMemoryLimit;
3790         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3791         if( $memlimit != -1 ) {
3792                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3793                 if( $conflimit == -1 ) {
3794                         wfDebug( "Removing PHP's memory limit\n" );
3795                         wfSuppressWarnings();
3796                         ini_set( 'memory_limit', $conflimit );
3797                         wfRestoreWarnings();
3798                         return $conflimit;
3799                 } elseif ( $conflimit > $memlimit ) {
3800                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3801                         wfSuppressWarnings();
3802                         ini_set( 'memory_limit', $conflimit );
3803                         wfRestoreWarnings();
3804                         return $conflimit;
3805                 }
3806         }
3807         return $memlimit;
3808 }
3809
3810 /**
3811  * Converts shorthand byte notation to integer form
3812  *
3813  * @param $string String
3814  * @return Integer
3815  */
3816 function wfShorthandToInteger( $string = '' ) {
3817         $string = trim( $string );
3818         if( $string === '' ) {
3819                 return -1;
3820         }
3821         $last = $string[strlen( $string ) - 1];
3822         $val = intval( $string );
3823         switch( $last ) {
3824                 case 'g':
3825                 case 'G':
3826                         $val *= 1024;
3827                         // break intentionally missing
3828                 case 'm':
3829                 case 'M':
3830                         $val *= 1024;
3831                         // break intentionally missing
3832                 case 'k':
3833                 case 'K':
3834                         $val *= 1024;
3835         }
3836
3837         return $val;
3838 }
3839
3840 /**
3841  * Get the normalised IETF language tag
3842  * See unit test for examples.
3843  *
3844  * @param $code String: The language code.
3845  * @return String: The language code which complying with BCP 47 standards.
3846  */
3847 function wfBCP47( $code ) {
3848         $codeSegment = explode( '-', $code );
3849         $codeBCP = array();
3850         foreach ( $codeSegment as $segNo => $seg ) {
3851                 if ( count( $codeSegment ) > 0 ) {
3852                         // when previous segment is x, it is a private segment and should be lc
3853                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3854                                 $codeBCP[$segNo] = strtolower( $seg );
3855                         // ISO 3166 country code
3856                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3857                                 $codeBCP[$segNo] = strtoupper( $seg );
3858                         // ISO 15924 script code
3859                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3860                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3861                         // Use lowercase for other cases
3862                         } else {
3863                                 $codeBCP[$segNo] = strtolower( $seg );
3864                         }
3865                 } else {
3866                 // Use lowercase for single segment
3867                         $codeBCP[$segNo] = strtolower( $seg );
3868                 }
3869         }
3870         $langCode = implode( '-', $codeBCP );
3871         return $langCode;
3872 }
3873
3874 /**
3875  * Get a cache object.
3876  *
3877  * @param $inputType integer Cache type, one the the CACHE_* constants.
3878  * @return BagOStuff
3879  */
3880 function wfGetCache( $inputType ) {
3881         return ObjectCache::getInstance( $inputType );
3882 }
3883
3884 /**
3885  * Get the main cache object
3886  *
3887  * @return BagOStuff
3888  */
3889 function wfGetMainCache() {
3890         global $wgMainCacheType;
3891         return ObjectCache::getInstance( $wgMainCacheType );
3892 }
3893
3894 /**
3895  * Get the cache object used by the message cache
3896  *
3897  * @return BagOStuff
3898  */
3899 function wfGetMessageCacheStorage() {
3900         global $wgMessageCacheType;
3901         return ObjectCache::getInstance( $wgMessageCacheType );
3902 }
3903
3904 /**
3905  * Get the cache object used by the parser cache
3906  *
3907  * @return BagOStuff
3908  */
3909 function wfGetParserCacheStorage() {
3910         global $wgParserCacheType;
3911         return ObjectCache::getInstance( $wgParserCacheType );
3912 }
3913
3914 /**
3915  * Get the cache object used by the language converter
3916  *
3917  * @return BagOStuff
3918  */
3919 function wfGetLangConverterCacheStorage() {
3920         global $wgLanguageConverterCacheType;
3921         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3922 }
3923
3924 /**
3925  * Call hook functions defined in $wgHooks
3926  *
3927  * @param $event String: event name
3928  * @param $args Array: parameters passed to hook functions
3929  * @return Boolean True if no handler aborted the hook
3930  */
3931 function wfRunHooks( $event, $args = array() ) {
3932         return Hooks::run( $event, $args );
3933 }
3934
3935 /**
3936  * Wrapper around php's unpack.
3937  *
3938  * @param $format String: The format string (See php's docs)
3939  * @param $data: A binary string of binary data
3940  * @param $length integer or false: The minimun length of $data. This is to
3941  *      prevent reading beyond the end of $data. false to disable the check.
3942  *
3943  * Also be careful when using this function to read unsigned 32 bit integer
3944  * because php might make it negative.
3945  *
3946  * @throws MWException if $data not long enough, or if unpack fails
3947  * @return array Associative array of the extracted data
3948  */
3949 function wfUnpack( $format, $data, $length=false ) {
3950         if ( $length !== false ) {
3951                 $realLen = strlen( $data );
3952                 if ( $realLen < $length ) {
3953                         throw new MWException( "Tried to use wfUnpack on a "
3954                                 . "string of length $realLen, but needed one "
3955                                 . "of at least length $length."
3956                         );
3957                 }
3958         }
3959
3960         wfSuppressWarnings();
3961         $result = unpack( $format, $data );
3962         wfRestoreWarnings();
3963
3964         if ( $result === false ) {
3965                 // If it cannot extract the packed data.
3966                 throw new MWException( "unpack could not unpack binary data" );
3967         }
3968         return $result;
3969 }
3970
3971 /**
3972  * Determine if an image exists on the 'bad image list'.
3973  *
3974  * The format of MediaWiki:Bad_image_list is as follows:
3975  *    * Only list items (lines starting with "*") are considered
3976  *    * The first link on a line must be a link to a bad image
3977  *    * Any subsequent links on the same line are considered to be exceptions,
3978  *      i.e. articles where the image may occur inline.
3979  *
3980  * @param $name string the image name to check
3981  * @param $contextTitle Title|bool the page on which the image occurs, if known
3982  * @param $blacklist string wikitext of a file blacklist
3983  * @return bool
3984  */
3985 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3986         static $badImageCache = null; // based on bad_image_list msg
3987         wfProfileIn( __METHOD__ );
3988
3989         # Handle redirects
3990         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3991         if( $redirectTitle ) {
3992                 $name = $redirectTitle->getDbKey();
3993         }
3994
3995         # Run the extension hook
3996         $bad = false;
3997         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3998                 wfProfileOut( __METHOD__ );
3999                 return $bad;
4000         }
4001
4002         $cacheable = ( $blacklist === null );
4003         if( $cacheable && $badImageCache !== null ) {
4004                 $badImages = $badImageCache;
4005         } else { // cache miss
4006                 if ( $blacklist === null ) {
4007                         $blacklist = wfMsgForContentNoTrans( 'bad_image_list' ); // site list
4008                 }
4009                 # Build the list now
4010                 $badImages = array();
4011                 $lines = explode( "\n", $blacklist );
4012                 foreach( $lines as $line ) {
4013                         # List items only
4014                         if ( substr( $line, 0, 1 ) !== '*' ) {
4015                                 continue;
4016                         }
4017
4018                         # Find all links
4019                         $m = array();
4020                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4021                                 continue;
4022                         }
4023
4024                         $exceptions = array();
4025                         $imageDBkey = false;
4026                         foreach ( $m[1] as $i => $titleText ) {
4027                                 $title = Title::newFromText( $titleText );
4028                                 if ( !is_null( $title ) ) {
4029                                         if ( $i == 0 ) {
4030                                                 $imageDBkey = $title->getDBkey();
4031                                         } else {
4032                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4033                                         }
4034                                 }
4035                         }
4036
4037                         if ( $imageDBkey !== false ) {
4038                                 $badImages[$imageDBkey] = $exceptions;
4039                         }
4040                 }
4041                 if ( $cacheable ) {
4042                         $badImageCache = $badImages;
4043                 }
4044         }
4045
4046         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4047         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4048         wfProfileOut( __METHOD__ );
4049         return $bad;
4050 }