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  * @param $urlParts Array URL parts, as output from wfParseUrl
 563  * @return string URL assembled from its component parts
 564  */
 565 function wfAssembleUrl( $urlParts ) {
 566         $result = '';
 567
 568         if ( isset( $urlParts['delimiter'] ) ) {
 569                 if ( isset( $urlParts['scheme'] ) ) {
 570                         $result .= $urlParts['scheme'];
 571                 }
 572
 573                 $result .= $urlParts['delimiter'];
 574         }
 575
 576         if ( isset( $urlParts['host'] ) ) {
 577                 if ( isset( $urlParts['user'] ) ) {
 578                         $result .= $urlParts['user'];
 579                         if ( isset( $urlParts['pass'] ) ) {
 580                                 $result .= ':' . $urlParts['pass'];
 581                         }
 582                         $result .= '@';
 583                 }
 584
 585                 $result .= $urlParts['host'];
 586
 587                 if ( isset( $urlParts['port'] ) ) {
 588                         $result .= ':' . $urlParts['port'];
 589                 }
 590         }
 591
 592         if ( isset( $urlParts['path'] ) ) {
 593                 $result .= $urlParts['path'];
 594         }
 595
 596         if ( isset( $urlParts['query'] ) ) {
 597                 $result .= '?' . $urlParts['query'];
 598         }
 599
 600         if ( isset( $urlParts['fragment'] ) ) {
 601                 $result .= '#' . $urlParts['fragment'];
 602         }
 603
 604         return $result;
 605 }
 606
 607 /**
 608  * Remove all dot-segments in the provided URL path.  For example,
 609  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 610  * RFC3986 section 5.2.4.
 611  *
 612  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 613  *
 614  * @param $urlPath String URL path, potentially containing dot-segments
 615  * @return string URL path with all dot-segments removed
 616  */
 617 function wfRemoveDotSegments( $urlPath ) {
 618         $output = '';
 619         $inputOffset = 0;
 620         $inputLength = strlen( $urlPath );
 621
 622         while ( $inputOffset < $inputLength ) {
 623                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 624                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 625                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 626                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 627                 $trimOutput = false;
 628
 629                 if ( $prefixLengthTwo == './' ) {
 630                         # Step A, remove leading "./"
 631                         $inputOffset += 2;
 632                 } elseif ( $prefixLengthThree == '../' ) {
 633                         # Step A, remove leading "../"
 634                         $inputOffset += 3;
 635                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 636                         # Step B, replace leading "/.$" with "/"
 637                         $inputOffset += 1;
 638                         $urlPath[$inputOffset] = '/';
 639                 } elseif ( $prefixLengthThree == '/./' ) {
 640                         # Step B, replace leading "/./" with "/"
 641                         $inputOffset += 2;
 642                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 643                         # Step C, replace leading "/..$" with "/" and
 644                         # remove last path component in output
 645                         $inputOffset += 2;
 646                         $urlPath[$inputOffset] = '/';
 647                         $trimOutput = true;
 648                 } elseif ( $prefixLengthFour == '/../' ) {
 649                         # Step C, replace leading "/../" with "/" and
 650                         # remove last path component in output
 651                         $inputOffset += 3;
 652                         $trimOutput = true;
 653                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 654                         # Step D, remove "^.$"
 655                         $inputOffset += 1;
 656                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 657                         # Step D, remove "^..$"
 658                         $inputOffset += 2;
 659                 } else {
 660                         # Step E, move leading path segment to output
 661                         if ( $prefixLengthOne == '/' ) {
 662                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 663                         } else {
 664                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 665                         }
 666                         if ( $slashPos === false ) {
 667                                 $output .= substr( $urlPath, $inputOffset );
 668                                 $inputOffset = $inputLength;
 669                         } else {
 670                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 671                                 $inputOffset += $slashPos - $inputOffset;
 672                         }
 673                 }
 674
 675                 if ( $trimOutput ) {
 676                         $slashPos = strrpos( $output, '/' );
 677                         if ( $slashPos === false ) {
 678                                 $output = '';
 679                         } else {
 680                                 $output = substr( $output, 0, $slashPos );
 681                         }
 682                 }
 683         }
 684
 685         return $output;
 686 }
 687
 688 /**
 689  * Returns a regular expression of url protocols
 690  *
 691  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 692  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 693  * @return String
 694  */
 695 function wfUrlProtocols( $includeProtocolRelative = true ) {
 696         global $wgUrlProtocols;
 697
 698         // Cache return values separately based on $includeProtocolRelative
 699         static $withProtRel = null, $withoutProtRel = null;
 700         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 701         if ( !is_null( $cachedValue ) ) {
 702                 return $cachedValue;
 703         }
 704
 705         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 706         // with LocalSettings files from 1.5
 707         if ( is_array( $wgUrlProtocols ) ) {
 708                 $protocols = array();
 709                 foreach ( $wgUrlProtocols as $protocol ) {
 710                         // Filter out '//' if !$includeProtocolRelative
 711                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 712                                 $protocols[] = preg_quote( $protocol, '/' );
 713                         }
 714                 }
 715
 716                 $retval = implode( '|', $protocols );
 717         } else {
 718                 // Ignore $includeProtocolRelative in this case
 719                 // This case exists for pre-1.6 compatibility, and we can safely assume
 720                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 721                 // URLs weren't supported until 1.18
 722                 $retval = $wgUrlProtocols;
 723         }
 724
 725         // Cache return value
 726         if ( $includeProtocolRelative ) {
 727                 $withProtRel = $retval;
 728         } else {
 729                 $withoutProtRel = $retval;
 730         }
 731         return $retval;
 732 }
 733
 734 /**
 735  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 736  * you need a regex that matches all URL protocols but does not match protocol-
 737  * relative URLs
 738  * @return String
 739  */
 740 function wfUrlProtocolsWithoutProtRel() {
 741         return wfUrlProtocols( false );
 742 }
 743
 744 /**
 745  * parse_url() work-alike, but non-broken.  Differences:
 746  *
 747  * 1) Does not raise warnings on bad URLs (just returns false)
 748  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 749  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 750  *
 751  * @param $url String: a URL to parse
 752  * @return Array: bits of the URL in an associative array, per PHP docs
 753  */
 754 function wfParseUrl( $url ) {
 755         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 756
 757         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 758         // way to handle them is to just prepend 'http:' and strip the protocol out later
 759         $wasRelative = substr( $url, 0, 2 ) == '//';
 760         if ( $wasRelative ) {
 761                 $url = "http:$url";
 762         }
 763         wfSuppressWarnings();
 764         $bits = parse_url( $url );
 765         wfRestoreWarnings();
 766         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 767         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 768         if ( !$bits || !isset( $bits['scheme'] ) ) {
 769                 return false;
 770         }
 771
 772         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 773         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 774                 $bits['delimiter'] = '://';
 775         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 776                 $bits['delimiter'] = ':';
 777                 // parse_url detects for news: and mailto: the host part of an url as path
 778                 // We have to correct this wrong detection
 779                 if ( isset( $bits['path'] ) ) {
 780                         $bits['host'] = $bits['path'];
 781                         $bits['path'] = '';
 782                 }
 783         } else {
 784                 return false;
 785         }
 786
 787         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 788         if ( !isset( $bits['host'] ) ) {
 789                 $bits['host'] = '';
 790
 791                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 792                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 793                         $bits['path'] = '/' . $bits['path'];
 794                 }
 795         }
 796
 797         // If the URL was protocol-relative, fix scheme and delimiter
 798         if ( $wasRelative ) {
 799                 $bits['scheme'] = '';
 800                 $bits['delimiter'] = '//';
 801         }
 802         return $bits;
 803 }
 804
 805 /**
 806  * Make URL indexes, appropriate for the el_index field of externallinks.
 807  *
 808  * @param $url String
 809  * @return array
 810  */
 811 function wfMakeUrlIndexes( $url ) {
 812         $bits = wfParseUrl( $url );
 813
 814         // Reverse the labels in the hostname, convert to lower case
 815         // For emails reverse domainpart only
 816         if ( $bits['scheme'] == 'mailto' ) {
 817                 $mailparts = explode( '@', $bits['host'], 2 );
 818                 if ( count( $mailparts ) === 2 ) {
 819                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 820                 } else {
 821                         // No domain specified, don't mangle it
 822                         $domainpart = '';
 823                 }
 824                 $reversedHost = $domainpart . '@' . $mailparts[0];
 825         } else {
 826                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 827         }
 828         // Add an extra dot to the end
 829         // Why? Is it in wrong place in mailto links?
 830         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 831                 $reversedHost .= '.';
 832         }
 833         // Reconstruct the pseudo-URL
 834         $prot = $bits['scheme'];
 835         $index = $prot . $bits['delimiter'] . $reversedHost;
 836         // Leave out user and password. Add the port, path, query and fragment
 837         if ( isset( $bits['port'] ) ) {
 838                 $index .= ':' . $bits['port'];
 839         }
 840         if ( isset( $bits['path'] ) ) {
 841                 $index .= $bits['path'];
 842         } else {
 843                 $index .= '/';
 844         }
 845         if ( isset( $bits['query'] ) ) {
 846                 $index .= '?' . $bits['query'];
 847         }
 848         if ( isset( $bits['fragment'] ) ) {
 849                 $index .= '#' . $bits['fragment'];
 850         }
 851
 852         if ( $prot == '' ) {
 853                 return array( "http:$index", "https:$index" );
 854         } else {
 855                 return array( $index );
 856         }
 857 }
 858
 859 /**
 860  * Check whether a given URL has a domain that occurs in a given set of domains
 861  * @param $url string URL
 862  * @param $domains array Array of domains (strings)
 863  * @return bool True if the host part of $url ends in one of the strings in $domains
 864  */
 865 function wfMatchesDomainList( $url, $domains ) {
 866         $bits = wfParseUrl( $url );
 867         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 868                 foreach ( (array)$domains as $domain ) {
 869                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 870                         // We should use something that interprets dots instead
 871                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 872                                 return true;
 873                         }
 874                 }
 875         }
 876         return false;
 877 }
 878
 879 /**
 880  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 881  * In normal operation this is a NOP.
 882  *
 883  * Controlling globals:
 884  * $wgDebugLogFile - points to the log file
 885  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 886  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 887  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 888  *
 889  * @param $text String
 890  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 891  */
 892 function wfDebug( $text, $logonly = false ) {
 893         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 894         global $wgDebugLogPrefix, $wgShowDebug;
 895
 896         static $cache = array(); // Cache of unoutputted messages
 897
 898         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 899                 return;
 900         }
 901
 902         $timer = wfDebugTimer();
 903         if ( $timer !== '' ) {
 904                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 905         }
 906
 907         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 908                 $cache[] = $text;
 909
 910                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 911                         // add the message and any cached messages to the output
 912                         array_map( array( $wgOut, 'debug' ), $cache );
 913                         $cache = array();
 914                 }
 915         }
 916         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 917                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 918                         # Strip unprintables; they can switch terminal modes when binary data
 919                         # gets dumped, which is pretty annoying.
 920                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 921                         $text = $wgDebugLogPrefix . $text;
 922                         wfErrorLog( $text, $wgDebugLogFile );
 923                 }
 924         }
 925
 926         MWDebug::debugMsg( $text );
 927 }
 928
 929 /**
 930  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 931  * @return bool
 932  */
 933 function wfIsDebugRawPage() {
 934         static $cache;
 935         if ( $cache !== null ) {
 936                 return $cache;
 937         }
 938         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 939         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 940                 || (
 941                         isset( $_SERVER['SCRIPT_NAME'] )
 942                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 943                 ) )
 944         {
 945                 $cache = true;
 946         } else {
 947                 $cache = false;
 948         }
 949         return $cache;
 950 }
 951
 952 /**
 953  * Get microsecond timestamps for debug logs
 954  *
 955  * @return string
 956  */
 957 function wfDebugTimer() {
 958         global $wgDebugTimestamps, $wgRequestTime;
 959
 960         if ( !$wgDebugTimestamps ) {
 961                 return '';
 962         }
 963
 964         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 965         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 966         return "$prefix $mem  ";
 967 }
 968
 969 /**
 970  * Send a line giving PHP memory usage.
 971  *
 972  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 973  */
 974 function wfDebugMem( $exact = false ) {
 975         $mem = memory_get_usage();
 976         if( !$exact ) {
 977                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 978         } else {
 979                 $mem .= ' bytes';
 980         }
 981         wfDebug( "Memory usage: $mem\n" );
 982 }
 983
 984 /**
 985  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 986  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 987  *
 988  * @param $logGroup String
 989  * @param $text String
 990  * @param $public Bool: whether to log the event in the public log if no private
 991  *                     log file is specified, (default true)
 992  */
 993 function wfDebugLog( $logGroup, $text, $public = true ) {
 994         global $wgDebugLogGroups;
 995         $text = trim( $text ) . "\n";
 996         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 997                 $time = wfTimestamp( TS_DB );
 998                 $wiki = wfWikiID();
 999                 $host = wfHostname();
1000                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1001                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1002                 }
1003         } elseif ( $public === true ) {
1004                 wfDebug( $text, true );
1005         }
1006 }
1007
1008 /**
1009  * Log for database errors
1010  *
1011  * @param $text String: database error message.
1012  */
1013 function wfLogDBError( $text ) {
1014         global $wgDBerrorLog;
1015         if ( $wgDBerrorLog ) {
1016                 $host = wfHostname();
1017                 $wiki = wfWikiID();
1018                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wiki\t$text";
1019                 wfErrorLog( $text, $wgDBerrorLog );
1020         }
1021 }
1022
1023 /**
1024  * Throws a warning that $function is deprecated
1025  *
1026  * @param $function String
1027  * @param $version String|bool: Version of MediaWiki that the function was deprecated in (Added in 1.19).
1028  * @param $component String|bool: Added in 1.19.
1029  * @param $callerOffset integer: How far up the callstack is the original
1030  *    caller. 2 = function that called the function that called
1031  *    wfDeprecated (Added in 1.20)
1032  *
1033  * @return null
1034  */
1035 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1036         static $functionsWarned = array();
1037
1038         MWDebug::deprecated( $function, $version, $component );
1039
1040         if ( !isset( $functionsWarned[$function] ) ) {
1041                 $functionsWarned[$function] = true;
1042
1043                 if ( $version ) {
1044                         global $wgDeprecationReleaseLimit;
1045
1046                         if ( $wgDeprecationReleaseLimit && $component === false ) {
1047                                 # Strip -* off the end of $version so that branches can use the
1048                                 # format #.##-branchname to avoid issues if the branch is merged into
1049                                 # a version of MediaWiki later than what it was branched from
1050                                 $comparableVersion = preg_replace( '/-.*$/', '', $version );
1051
1052                                 # If the comparableVersion is larger than our release limit then
1053                                 # skip the warning message for the deprecation
1054                                 if ( version_compare( $wgDeprecationReleaseLimit, $comparableVersion, '<' ) ) {
1055                                         return;
1056                                 }
1057                         }
1058
1059                         $component = $component === false ? 'MediaWiki' : $component;
1060                         wfWarn( "Use of $function was deprecated in $component $version.", $callerOffset );
1061                 } else {
1062                         wfWarn( "Use of $function is deprecated.", $callerOffset );
1063                 }
1064         }
1065 }
1066
1067 /**
1068  * Send a warning either to the debug log or in a PHP error depending on
1069  * $wgDevelopmentWarnings
1070  *
1071  * @param $msg String: message to send
1072  * @param $callerOffset Integer: number of items to go back in the backtrace to
1073  *        find the correct caller (1 = function calling wfWarn, ...)
1074  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1075  *        is true
1076  */
1077 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1078         global $wgDevelopmentWarnings;
1079
1080         MWDebug::warning( $msg, $callerOffset + 2 );
1081
1082         $callers = wfDebugBacktrace();
1083         if ( isset( $callers[$callerOffset + 1] ) ) {
1084                 $callerfunc = $callers[$callerOffset + 1];
1085                 $callerfile = $callers[$callerOffset];
1086                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
1087                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
1088                 } else {
1089                         $file = '(internal function)';
1090                 }
1091                 $func = '';
1092                 if ( isset( $callerfunc['class'] ) ) {
1093                         $func .= $callerfunc['class'] . '::';
1094                 }
1095                 if ( isset( $callerfunc['function'] ) ) {
1096                         $func .= $callerfunc['function'];
1097                 }
1098                 $msg .= " [Called from $func in $file]";
1099         }
1100
1101         if ( $wgDevelopmentWarnings ) {
1102                 trigger_error( $msg, $level );
1103         } else {
1104                 wfDebug( "$msg\n" );
1105         }
1106 }
1107
1108 /**
1109  * Log to a file without getting "file size exceeded" signals.
1110  *
1111  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1112  * send lines to the specified port, prefixed by the specified prefix and a space.
1113  *
1114  * @param $text String
1115  * @param $file String filename
1116  */
1117 function wfErrorLog( $text, $file ) {
1118         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1119                 # Needs the sockets extension
1120                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1121                         // IPv6 bracketed host
1122                         $host = $m[2];
1123                         $port = intval( $m[3] );
1124                         $prefix = isset( $m[4] ) ? $m[4] : false;
1125                         $domain = AF_INET6;
1126                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1127                         $host = $m[2];
1128                         if ( !IP::isIPv4( $host ) ) {
1129                                 $host = gethostbyname( $host );
1130                         }
1131                         $port = intval( $m[3] );
1132                         $prefix = isset( $m[4] ) ? $m[4] : false;
1133                         $domain = AF_INET;
1134                 } else {
1135                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1136                 }
1137
1138                 // Clean it up for the multiplexer
1139                 if ( strval( $prefix ) !== '' ) {
1140                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1141
1142                         // Limit to 64KB
1143                         if ( strlen( $text ) > 65506 ) {
1144                                 $text = substr( $text, 0, 65506 );
1145                         }
1146
1147                         if ( substr( $text, -1 ) != "\n" ) {
1148                                 $text .= "\n";
1149                         }
1150                 } elseif ( strlen( $text ) > 65507 ) {
1151                         $text = substr( $text, 0, 65507 );
1152                 }
1153
1154                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1155                 if ( !$sock ) {
1156                         return;
1157                 }
1158
1159                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1160                 socket_close( $sock );
1161         } else {
1162                 wfSuppressWarnings();
1163                 $exists = file_exists( $file );
1164                 $size = $exists ? filesize( $file ) : false;
1165                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1166                         file_put_contents( $file, $text, FILE_APPEND );
1167                 }
1168                 wfRestoreWarnings();
1169         }
1170 }
1171
1172 /**
1173  * @todo document
1174  */
1175 function wfLogProfilingData() {
1176         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1177         global $wgProfileLimit, $wgUser;
1178
1179         $profiler = Profiler::instance();
1180
1181         # Profiling must actually be enabled...
1182         if ( $profiler->isStub() ) {
1183                 return;
1184         }
1185
1186         // Get total page request time and only show pages that longer than
1187         // $wgProfileLimit time (default is 0)
1188         $elapsed = microtime( true ) - $wgRequestTime;
1189         if ( $elapsed <= $wgProfileLimit ) {
1190                 return;
1191         }
1192
1193         $profiler->logData();
1194
1195         // Check whether this should be logged in the debug file.
1196         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1197                 return;
1198         }
1199
1200         $forward = '';
1201         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1202                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1203         }
1204         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1205                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1206         }
1207         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1208                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1209         }
1210         if ( $forward ) {
1211                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1212         }
1213         // Don't load $wgUser at this late stage just for statistics purposes
1214         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1215         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1216                 $forward .= ' anon';
1217         }
1218         $log = sprintf( "%s\t%04.3f\t%s\n",
1219                 gmdate( 'YmdHis' ), $elapsed,
1220                 urldecode( $wgRequest->getRequestURL() . $forward ) );
1221
1222         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1223 }
1224
1225 /**
1226  * Increment a statistics counter
1227  *
1228  * @param $key String
1229  * @param $count Int
1230  */
1231 function wfIncrStats( $key, $count = 1 ) {
1232         global $wgStatsMethod;
1233
1234         $count = intval( $count );
1235
1236         if( $wgStatsMethod == 'udp' ) {
1237                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
1238                 static $socket;
1239
1240                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
1241
1242                 if ( !$socket ) {
1243                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1244                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1245                         socket_sendto(
1246                                 $socket,
1247                                 $statline,
1248                                 strlen( $statline ),
1249                                 0,
1250                                 $wgUDPProfilerHost,
1251                                 $wgUDPProfilerPort
1252                         );
1253                 }
1254                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1255                 wfSuppressWarnings();
1256                 socket_sendto(
1257                         $socket,
1258                         $statline,
1259                         strlen( $statline ),
1260                         0,
1261                         $wgUDPProfilerHost,
1262                         $wgUDPProfilerPort
1263                 );
1264                 wfRestoreWarnings();
1265         } elseif( $wgStatsMethod == 'cache' ) {
1266                 global $wgMemc;
1267                 $key = wfMemcKey( 'stats', $key );
1268                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1269                         $wgMemc->add( $key, $count );
1270                 }
1271         } else {
1272                 // Disabled
1273         }
1274 }
1275
1276 /**
1277  * Check if the wiki read-only lock file is present. This can be used to lock
1278  * off editing functions, but doesn't guarantee that the database will not be
1279  * modified.
1280  *
1281  * @return bool
1282  */
1283 function wfReadOnly() {
1284         global $wgReadOnlyFile, $wgReadOnly;
1285
1286         if ( !is_null( $wgReadOnly ) ) {
1287                 return (bool)$wgReadOnly;
1288         }
1289         if ( $wgReadOnlyFile == '' ) {
1290                 return false;
1291         }
1292         // Set $wgReadOnly for faster access next time
1293         if ( is_file( $wgReadOnlyFile ) ) {
1294                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1295         } else {
1296                 $wgReadOnly = false;
1297         }
1298         return (bool)$wgReadOnly;
1299 }
1300
1301 /**
1302  * @return bool
1303  */
1304 function wfReadOnlyReason() {
1305         global $wgReadOnly;
1306         wfReadOnly();
1307         return $wgReadOnly;
1308 }
1309
1310 /**
1311  * Return a Language object from $langcode
1312  *
1313  * @param $langcode Mixed: either:
1314  *                  - a Language object
1315  *                  - code of the language to get the message for, if it is
1316  *                    a valid code create a language for that language, if
1317  *                    it is a string but not a valid code then make a basic
1318  *                    language object
1319  *                  - a boolean: if it's false then use the global object for
1320  *                    the current user's language (as a fallback for the old parameter
1321  *                    functionality), or if it is true then use global object
1322  *                    for the wiki's content language.
1323  * @return Language object
1324  */
1325 function wfGetLangObj( $langcode = false ) {
1326         # Identify which language to get or create a language object for.
1327         # Using is_object here due to Stub objects.
1328         if( is_object( $langcode ) ) {
1329                 # Great, we already have the object (hopefully)!
1330                 return $langcode;
1331         }
1332
1333         global $wgContLang, $wgLanguageCode;
1334         if( $langcode === true || $langcode === $wgLanguageCode ) {
1335                 # $langcode is the language code of the wikis content language object.
1336                 # or it is a boolean and value is true
1337                 return $wgContLang;
1338         }
1339
1340         global $wgLang;
1341         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1342                 # $langcode is the language code of user language object.
1343                 # or it was a boolean and value is false
1344                 return $wgLang;
1345         }
1346
1347         $validCodes = array_keys( Language::fetchLanguageNames() );
1348         if( in_array( $langcode, $validCodes ) ) {
1349                 # $langcode corresponds to a valid language.
1350                 return Language::factory( $langcode );
1351         }
1352
1353         # $langcode is a string, but not a valid language code; use content language.
1354         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1355         return $wgContLang;
1356 }
1357
1358 /**
1359  * Old function when $wgBetterDirectionality existed
1360  * All usage removed, wfUILang can be removed in near future
1361  *
1362  * @deprecated since 1.18
1363  * @return Language
1364  */
1365 function wfUILang() {
1366         wfDeprecated( __METHOD__, '1.18' );
1367         global $wgLang;
1368         return $wgLang;
1369 }
1370
1371 /**
1372  * This is the new function for getting translated interface messages.
1373  * See the Message class for documentation how to use them.
1374  * The intention is that this function replaces all old wfMsg* functions.
1375  * @param $key \string Message key.
1376  * Varargs: normal message parameters.
1377  * @return Message
1378  * @since 1.17
1379  */
1380 function wfMessage( $key /*...*/) {
1381         $params = func_get_args();
1382         array_shift( $params );
1383         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1384                 $params = $params[0];
1385         }
1386         return new Message( $key, $params );
1387 }
1388
1389 /**
1390  * This function accepts multiple message keys and returns a message instance
1391  * for the first message which is non-empty. If all messages are empty then an
1392  * instance of the first message key is returned.
1393  * @param varargs: message keys
1394  * @return Message
1395  * @since 1.18
1396  */
1397 function wfMessageFallback( /*...*/ ) {
1398         $args = func_get_args();
1399         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1400 }
1401
1402 /**
1403  * Get a message from anywhere, for the current user language.
1404  *
1405  * Use wfMsgForContent() instead if the message should NOT
1406  * change depending on the user preferences.
1407  *
1408  * @param $key String: lookup key for the message, usually
1409  *    defined in languages/Language.php
1410  *
1411  * Parameters to the message, which can be used to insert variable text into
1412  * it, can be passed to this function in the following formats:
1413  * - One per argument, starting at the second parameter
1414  * - As an array in the second parameter
1415  * These are not shown in the function definition.
1416  *
1417  * @return String
1418  */
1419 function wfMsg( $key ) {
1420         $args = func_get_args();
1421         array_shift( $args );
1422         return wfMsgReal( $key, $args );
1423 }
1424
1425 /**
1426  * Same as above except doesn't transform the message
1427  *
1428  * @param $key String
1429  * @return String
1430  */
1431 function wfMsgNoTrans( $key ) {
1432         $args = func_get_args();
1433         array_shift( $args );
1434         return wfMsgReal( $key, $args, true, false, false );
1435 }
1436
1437 /**
1438  * Get a message from anywhere, for the current global language
1439  * set with $wgLanguageCode.
1440  *
1441  * Use this if the message should NOT change dependent on the
1442  * language set in the user's preferences. This is the case for
1443  * most text written into logs, as well as link targets (such as
1444  * the name of the copyright policy page). Link titles, on the
1445  * other hand, should be shown in the UI language.
1446  *
1447  * Note that MediaWiki allows users to change the user interface
1448  * language in their preferences, but a single installation
1449  * typically only contains content in one language.
1450  *
1451  * Be wary of this distinction: If you use wfMsg() where you should
1452  * use wfMsgForContent(), a user of the software may have to
1453  * customize potentially hundreds of messages in
1454  * order to, e.g., fix a link in every possible language.
1455  *
1456  * @param $key String: lookup key for the message, usually
1457  *     defined in languages/Language.php
1458  * @return String
1459  */
1460 function wfMsgForContent( $key ) {
1461         global $wgForceUIMsgAsContentMsg;
1462         $args = func_get_args();
1463         array_shift( $args );
1464         $forcontent = true;
1465         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1466                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1467         {
1468                 $forcontent = false;
1469         }
1470         return wfMsgReal( $key, $args, true, $forcontent );
1471 }
1472
1473 /**
1474  * Same as above except doesn't transform the message
1475  *
1476  * @param $key String
1477  * @return String
1478  */
1479 function wfMsgForContentNoTrans( $key ) {
1480         global $wgForceUIMsgAsContentMsg;
1481         $args = func_get_args();
1482         array_shift( $args );
1483         $forcontent = true;
1484         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1485                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1486         {
1487                 $forcontent = false;
1488         }
1489         return wfMsgReal( $key, $args, true, $forcontent, false );
1490 }
1491
1492 /**
1493  * Really get a message
1494  *
1495  * @param $key String: key to get.
1496  * @param $args
1497  * @param $useDB Boolean
1498  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1499  * @param $transform Boolean: Whether or not to transform the message.
1500  * @return String: the requested message.
1501  */
1502 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1503         wfProfileIn( __METHOD__ );
1504         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1505         $message = wfMsgReplaceArgs( $message, $args );
1506         wfProfileOut( __METHOD__ );
1507         return $message;
1508 }
1509
1510 /**
1511  * Fetch a message string value, but don't replace any keys yet.
1512  *
1513  * @param $key String
1514  * @param $useDB Bool
1515  * @param $langCode String: Code of the language to get the message for, or
1516  *                  behaves as a content language switch if it is a boolean.
1517  * @param $transform Boolean: whether to parse magic words, etc.
1518  * @return string
1519  */
1520 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1521         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1522
1523         $cache = MessageCache::singleton();
1524         $message = $cache->get( $key, $useDB, $langCode );
1525         if( $message === false ) {
1526                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1527         } elseif ( $transform ) {
1528                 $message = $cache->transform( $message );
1529         }
1530         return $message;
1531 }
1532
1533 /**
1534  * Replace message parameter keys on the given formatted output.
1535  *
1536  * @param $message String
1537  * @param $args Array
1538  * @return string
1539  * @private
1540  */
1541 function wfMsgReplaceArgs( $message, $args ) {
1542         # Fix windows line-endings
1543         # Some messages are split with explode("\n", $msg)
1544         $message = str_replace( "\r", '', $message );
1545
1546         // Replace arguments
1547         if ( count( $args ) ) {
1548                 if ( is_array( $args[0] ) ) {
1549                         $args = array_values( $args[0] );
1550                 }
1551                 $replacementKeys = array();
1552                 foreach( $args as $n => $param ) {
1553                         $replacementKeys['$' . ( $n + 1 )] = $param;
1554                 }
1555                 $message = strtr( $message, $replacementKeys );
1556         }
1557
1558         return $message;
1559 }
1560
1561 /**
1562  * Return an HTML-escaped version of a message.
1563  * Parameter replacements, if any, are done *after* the HTML-escaping,
1564  * so parameters may contain HTML (eg links or form controls). Be sure
1565  * to pre-escape them if you really do want plaintext, or just wrap
1566  * the whole thing in htmlspecialchars().
1567  *
1568  * @param $key String
1569  * @param string ... parameters
1570  * @return string
1571  */
1572 function wfMsgHtml( $key ) {
1573         $args = func_get_args();
1574         array_shift( $args );
1575         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1576 }
1577
1578 /**
1579  * Return an HTML version of message
1580  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1581  * so parameters may contain HTML (eg links or form controls). Be sure
1582  * to pre-escape them if you really do want plaintext, or just wrap
1583  * the whole thing in htmlspecialchars().
1584  *
1585  * @param $key String
1586  * @param string ... parameters
1587  * @return string
1588  */
1589 function wfMsgWikiHtml( $key ) {
1590         $args = func_get_args();
1591         array_shift( $args );
1592         return wfMsgReplaceArgs(
1593                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1594                 /* can't be set to false */ true, /* interface */ true )->getText(),
1595                 $args );
1596 }
1597
1598 /**
1599  * Returns message in the requested format
1600  * @param $key String: key of the message
1601  * @param $options Array: processing rules. Can take the following options:
1602  *   <i>parse</i>: parses wikitext to HTML
1603  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1604  *       p's added by parser or tidy
1605  *   <i>escape</i>: filters message through htmlspecialchars
1606  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1607  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1608  *   <i>parsemag</i>: transform the message using magic phrases
1609  *   <i>content</i>: fetch message for content language instead of interface
1610  * Also can accept a single associative argument, of the form 'language' => 'xx':
1611  *   <i>language</i>: Language object or language code to fetch message for
1612  *       (overriden by <i>content</i>).
1613  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1614  *
1615  * @return String
1616  */
1617 function wfMsgExt( $key, $options ) {
1618         $args = func_get_args();
1619         array_shift( $args );
1620         array_shift( $args );
1621         $options = (array)$options;
1622
1623         foreach( $options as $arrayKey => $option ) {
1624                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1625                         # An unknown index, neither numeric nor "language"
1626                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1627                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1628                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1629                 'replaceafter', 'parsemag', 'content' ) ) ) {
1630                         # A numeric index with unknown value
1631                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1632                 }
1633         }
1634
1635         if( in_array( 'content', $options, true ) ) {
1636                 $forContent = true;
1637                 $langCode = true;
1638                 $langCodeObj = null;
1639         } elseif( array_key_exists( 'language', $options ) ) {
1640                 $forContent = false;
1641                 $langCode = wfGetLangObj( $options['language'] );
1642                 $langCodeObj = $langCode;
1643         } else {
1644                 $forContent = false;
1645                 $langCode = false;
1646                 $langCodeObj = null;
1647         }
1648
1649         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1650
1651         if( !in_array( 'replaceafter', $options, true ) ) {
1652                 $string = wfMsgReplaceArgs( $string, $args );
1653         }
1654
1655         $messageCache = MessageCache::singleton();
1656         $parseInline = in_array( 'parseinline', $options, true );
1657         if( in_array( 'parse', $options, true ) || $parseInline ) {
1658                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1659                 if ( $string instanceof ParserOutput ) {
1660                         $string = $string->getText();
1661                 }
1662
1663                 if ( $parseInline ) {
1664                         $m = array();
1665                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1666                                 $string = $m[1];
1667                         }
1668                 }
1669         } elseif ( in_array( 'parsemag', $options, true ) ) {
1670                 $string = $messageCache->transform( $string,
1671                                 !$forContent, $langCodeObj );
1672         }
1673
1674         if ( in_array( 'escape', $options, true ) ) {
1675                 $string = htmlspecialchars ( $string );
1676         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1677                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1678         }
1679
1680         if( in_array( 'replaceafter', $options, true ) ) {
1681                 $string = wfMsgReplaceArgs( $string, $args );
1682         }
1683
1684         return $string;
1685 }
1686
1687 /**
1688  * Since wfMsg() and co suck, they don't return false if the message key they
1689  * looked up didn't exist but a XHTML string, this function checks for the
1690  * nonexistance of messages by checking the MessageCache::get() result directly.
1691  *
1692  * @param $key      String: the message key looked up
1693  * @return Boolean True if the message *doesn't* exist.
1694  */
1695 function wfEmptyMsg( $key ) {
1696         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1697 }
1698
1699 /**
1700  * Throw a debugging exception. This function previously once exited the process,
1701  * but now throws an exception instead, with similar results.
1702  *
1703  * @param $msg String: message shown when dying.
1704  */
1705 function wfDebugDieBacktrace( $msg = '' ) {
1706         throw new MWException( $msg );
1707 }
1708
1709 /**
1710  * Fetch server name for use in error reporting etc.
1711  * Use real server name if available, so we know which machine
1712  * in a server farm generated the current page.
1713  *
1714  * @return string
1715  */
1716 function wfHostname() {
1717         static $host;
1718         if ( is_null( $host ) ) {
1719                 if ( function_exists( 'posix_uname' ) ) {
1720                         // This function not present on Windows
1721                         $uname = posix_uname();
1722                 } else {
1723                         $uname = false;
1724                 }
1725                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1726                         $host = $uname['nodename'];
1727                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1728                         # Windows computer name
1729                         $host = getenv( 'COMPUTERNAME' );
1730                 } else {
1731                         # This may be a virtual server.
1732                         $host = $_SERVER['SERVER_NAME'];
1733                 }
1734         }
1735         return $host;
1736 }
1737
1738 /**
1739  * Returns a HTML comment with the elapsed time since request.
1740  * This method has no side effects.
1741  *
1742  * @return string
1743  */
1744 function wfReportTime() {
1745         global $wgRequestTime, $wgShowHostnames;
1746
1747         $elapsed = microtime( true ) - $wgRequestTime;
1748
1749         return $wgShowHostnames
1750                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1751                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1752 }
1753
1754 /**
1755  * Safety wrapper for debug_backtrace().
1756  *
1757  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1758  * murky circumstances, which may be triggered in part by stub objects
1759  * or other fancy talkin'.
1760  *
1761  * Will return an empty array if Zend Optimizer is detected or if
1762  * debug_backtrace is disabled, otherwise the output from
1763  * debug_backtrace() (trimmed).
1764  *
1765  * @param $limit int This parameter can be used to limit the number of stack frames returned
1766  *
1767  * @return array of backtrace information
1768  */
1769 function wfDebugBacktrace( $limit = 0 ) {
1770         static $disabled = null;
1771
1772         if( extension_loaded( 'Zend Optimizer' ) ) {
1773                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1774                 return array();
1775         }
1776
1777         if ( is_null( $disabled ) ) {
1778                 $disabled = false;
1779                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1780                 $functions = array_map( 'trim', $functions );
1781                 $functions = array_map( 'strtolower', $functions );
1782                 if ( in_array( 'debug_backtrace', $functions ) ) {
1783                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1784                         $disabled = true;
1785                 }
1786         }
1787         if ( $disabled ) {
1788                 return array();
1789         }
1790
1791         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1792                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit ), 1 );
1793         } else {
1794                 return array_slice( debug_backtrace(), 1 );
1795         }
1796 }
1797
1798 /**
1799  * Get a debug backtrace as a string
1800  *
1801  * @return string
1802  */
1803 function wfBacktrace() {
1804         global $wgCommandLineMode;
1805
1806         if ( $wgCommandLineMode ) {
1807                 $msg = '';
1808         } else {
1809                 $msg = "<ul>\n";
1810         }
1811         $backtrace = wfDebugBacktrace();
1812         foreach( $backtrace as $call ) {
1813                 if( isset( $call['file'] ) ) {
1814                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1815                         $file = $f[count( $f ) - 1];
1816                 } else {
1817                         $file = '-';
1818                 }
1819                 if( isset( $call['line'] ) ) {
1820                         $line = $call['line'];
1821                 } else {
1822                         $line = '-';
1823                 }
1824                 if ( $wgCommandLineMode ) {
1825                         $msg .= "$file line $line calls ";
1826                 } else {
1827                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1828                 }
1829                 if( !empty( $call['class'] ) ) {
1830                         $msg .= $call['class'] . $call['type'];
1831                 }
1832                 $msg .= $call['function'] . '()';
1833
1834                 if ( $wgCommandLineMode ) {
1835                         $msg .= "\n";
1836                 } else {
1837                         $msg .= "</li>\n";
1838                 }
1839         }
1840         if ( $wgCommandLineMode ) {
1841                 $msg .= "\n";
1842         } else {
1843                 $msg .= "</ul>\n";
1844         }
1845
1846         return $msg;
1847 }
1848
1849 /**
1850  * Get the name of the function which called this function
1851  *
1852  * @param $level Int
1853  * @return Bool|string
1854  */
1855 function wfGetCaller( $level = 2 ) {
1856         $backtrace = wfDebugBacktrace( $level );
1857         if ( isset( $backtrace[$level] ) ) {
1858                 return wfFormatStackFrame( $backtrace[$level] );
1859         } else {
1860                 $caller = 'unknown';
1861         }
1862         return $caller;
1863 }
1864
1865 /**
1866  * Return a string consisting of callers in the stack. Useful sometimes
1867  * for profiling specific points.
1868  *
1869  * @param $limit int The maximum depth of the stack frame to return, or false for
1870  *               the entire stack.
1871  * @return String
1872  */
1873 function wfGetAllCallers( $limit = 3 ) {
1874         $trace = array_reverse( wfDebugBacktrace() );
1875         if ( !$limit || $limit > count( $trace ) - 1 ) {
1876                 $limit = count( $trace ) - 1;
1877         }
1878         $trace = array_slice( $trace, -$limit - 1, $limit );
1879         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1880 }
1881
1882 /**
1883  * Return a string representation of frame
1884  *
1885  * @param $frame Array
1886  * @return Bool
1887  */
1888 function wfFormatStackFrame( $frame ) {
1889         return isset( $frame['class'] ) ?
1890                 $frame['class'] . '::' . $frame['function'] :
1891                 $frame['function'];
1892 }
1893
1894
1895 /* Some generic result counters, pulled out of SearchEngine */
1896
1897
1898 /**
1899  * @todo document
1900  *
1901  * @param $offset Int
1902  * @param $limit Int
1903  * @return String
1904  */
1905 function wfShowingResults( $offset, $limit ) {
1906         global $wgLang;
1907         return wfMsgExt(
1908                 'showingresults',
1909                 array( 'parseinline' ),
1910                 $wgLang->formatNum( $limit ),
1911                 $wgLang->formatNum( $offset + 1 )
1912         );
1913 }
1914
1915 /**
1916  * Generate (prev x| next x) (20|50|100...) type links for paging
1917  *
1918  * @param $offset String
1919  * @param $limit Integer
1920  * @param $link String
1921  * @param $query String: optional URL query parameter string
1922  * @param $atend Bool: optional param for specified if this is the last page
1923  * @return String
1924  * @deprecated in 1.19; use Language::viewPrevNext() instead
1925  */
1926 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1927         wfDeprecated( __METHOD__, '1.19' );
1928
1929         global $wgLang;
1930
1931         $query = wfCgiToArray( $query );
1932
1933         if( is_object( $link ) ) {
1934                 $title = $link;
1935         } else {
1936                 $title = Title::newFromText( $link );
1937                 if( is_null( $title ) ) {
1938                         return false;
1939                 }
1940         }
1941
1942         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1943 }
1944
1945 /**
1946  * Make a list item, used by various special pages
1947  *
1948  * @param $page String Page link
1949  * @param $details String Text between brackets
1950  * @param $oppositedm Boolean   Add the direction mark opposite to your
1951  *                                                              language, to display text properly
1952  * @return String
1953  * @deprecated since 1.19; use Language::specialList() instead
1954  */
1955 function wfSpecialList( $page, $details, $oppositedm = true ) {
1956         wfDeprecated( __METHOD__, '1.19' );
1957
1958         global $wgLang;
1959         return $wgLang->specialList( $page, $details, $oppositedm );
1960 }
1961
1962 /**
1963  * @todo document
1964  * @todo FIXME: We may want to blacklist some broken browsers
1965  *
1966  * @param $force Bool
1967  * @return bool Whereas client accept gzip compression
1968  */
1969 function wfClientAcceptsGzip( $force = false ) {
1970         static $result = null;
1971         if ( $result === null || $force ) {
1972                 $result = false;
1973                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1974                         # @todo FIXME: We may want to blacklist some broken browsers
1975                         $m = array();
1976                         if( preg_match(
1977                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1978                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1979                                 $m )
1980                         )
1981                         {
1982                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1983                                         $result = false;
1984                                         return $result;
1985                                 }
1986                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1987                                 $result = true;
1988                         }
1989                 }
1990         }
1991         return $result;
1992 }
1993
1994 /**
1995  * Obtain the offset and limit values from the request string;
1996  * used in special pages
1997  *
1998  * @param $deflimit Int default limit if none supplied
1999  * @param $optionname String Name of a user preference to check against
2000  * @return array
2001  *
2002  */
2003 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2004         global $wgRequest;
2005         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2006 }
2007
2008 /**
2009  * Escapes the given text so that it may be output using addWikiText()
2010  * without any linking, formatting, etc. making its way through. This
2011  * is achieved by substituting certain characters with HTML entities.
2012  * As required by the callers, <nowiki> is not used.
2013  *
2014  * @param $text String: text to be escaped
2015  * @return String
2016  */
2017 function wfEscapeWikiText( $text ) {
2018         $text = strtr( "\n$text", array(
2019                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2020                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2021                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2022                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2023                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2024                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2025         ) );
2026         return substr( $text, 1 );
2027 }
2028
2029 /**
2030  * Get the current unix timetstamp with microseconds.  Useful for profiling
2031  * @return Float
2032  */
2033 function wfTime() {
2034         return microtime( true );
2035 }
2036
2037 /**
2038  * Sets dest to source and returns the original value of dest
2039  * If source is NULL, it just returns the value, it doesn't set the variable
2040  * If force is true, it will set the value even if source is NULL
2041  *
2042  * @param $dest Mixed
2043  * @param $source Mixed
2044  * @param $force Bool
2045  * @return Mixed
2046  */
2047 function wfSetVar( &$dest, $source, $force = false ) {
2048         $temp = $dest;
2049         if ( !is_null( $source ) || $force ) {
2050                 $dest = $source;
2051         }
2052         return $temp;
2053 }
2054
2055 /**
2056  * As for wfSetVar except setting a bit
2057  *
2058  * @param $dest Int
2059  * @param $bit Int
2060  * @param $state Bool
2061  *
2062  * @return bool
2063  */
2064 function wfSetBit( &$dest, $bit, $state = true ) {
2065         $temp = (bool)( $dest & $bit );
2066         if ( !is_null( $state ) ) {
2067                 if ( $state ) {
2068                         $dest |= $bit;
2069                 } else {
2070                         $dest &= ~$bit;
2071                 }
2072         }
2073         return $temp;
2074 }
2075
2076 /**
2077  * A wrapper around the PHP function var_export().
2078  * Either print it or add it to the regular output ($wgOut).
2079  *
2080  * @param $var mixed A PHP variable to dump.
2081  */
2082 function wfVarDump( $var ) {
2083         global $wgOut;
2084         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2085         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2086                 print $s;
2087         } else {
2088                 $wgOut->addHTML( $s );
2089         }
2090 }
2091
2092 /**
2093  * Provide a simple HTTP error.
2094  *
2095  * @param $code Int|String
2096  * @param $label String
2097  * @param $desc String
2098  */
2099 function wfHttpError( $code, $label, $desc ) {
2100         global $wgOut;
2101         $wgOut->disable();
2102         header( "HTTP/1.0 $code $label" );
2103         header( "Status: $code $label" );
2104         $wgOut->sendCacheControl();
2105
2106         header( 'Content-type: text/html; charset=utf-8' );
2107         print "<!doctype html>" .
2108                 '<html><head><title>' .
2109                 htmlspecialchars( $label ) .
2110                 '</title></head><body><h1>' .
2111                 htmlspecialchars( $label ) .
2112                 '</h1><p>' .
2113                 nl2br( htmlspecialchars( $desc ) ) .
2114                 "</p></body></html>\n";
2115 }
2116
2117 /**
2118  * Clear away any user-level output buffers, discarding contents.
2119  *
2120  * Suitable for 'starting afresh', for instance when streaming
2121  * relatively large amounts of data without buffering, or wanting to
2122  * output image files without ob_gzhandler's compression.
2123  *
2124  * The optional $resetGzipEncoding parameter controls suppression of
2125  * the Content-Encoding header sent by ob_gzhandler; by default it
2126  * is left. See comments for wfClearOutputBuffers() for why it would
2127  * be used.
2128  *
2129  * Note that some PHP configuration options may add output buffer
2130  * layers which cannot be removed; these are left in place.
2131  *
2132  * @param $resetGzipEncoding Bool
2133  */
2134 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2135         if( $resetGzipEncoding ) {
2136                 // Suppress Content-Encoding and Content-Length
2137                 // headers from 1.10+s wfOutputHandler
2138                 global $wgDisableOutputCompression;
2139                 $wgDisableOutputCompression = true;
2140         }
2141         while( $status = ob_get_status() ) {
2142                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2143                         // Probably from zlib.output_compression or other
2144                         // PHP-internal setting which can't be removed.
2145                         //
2146                         // Give up, and hope the result doesn't break
2147                         // output behavior.
2148                         break;
2149                 }
2150                 if( !ob_end_clean() ) {
2151                         // Could not remove output buffer handler; abort now
2152                         // to avoid getting in some kind of infinite loop.
2153                         break;
2154                 }
2155                 if( $resetGzipEncoding ) {
2156                         if( $status['name'] == 'ob_gzhandler' ) {
2157                                 // Reset the 'Content-Encoding' field set by this handler
2158                                 // so we can start fresh.
2159                                 if ( function_exists( 'header_remove' ) ) {
2160                                         // Available since PHP 5.3.0
2161                                         header_remove( 'Content-Encoding' );
2162                                 } else {
2163                                         // We need to provide a valid content-coding. See bug 28069
2164                                         header( 'Content-Encoding: identity' );
2165                                 }
2166                                 break;
2167                         }
2168                 }
2169         }
2170 }
2171
2172 /**
2173  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2174  *
2175  * Clear away output buffers, but keep the Content-Encoding header
2176  * produced by ob_gzhandler, if any.
2177  *
2178  * This should be used for HTTP 304 responses, where you need to
2179  * preserve the Content-Encoding header of the real result, but
2180  * also need to suppress the output of ob_gzhandler to keep to spec
2181  * and avoid breaking Firefox in rare cases where the headers and
2182  * body are broken over two packets.
2183  */
2184 function wfClearOutputBuffers() {
2185         wfResetOutputBuffers( false );
2186 }
2187
2188 /**
2189  * Converts an Accept-* header into an array mapping string values to quality
2190  * factors
2191  *
2192  * @param $accept String
2193  * @param $def String default
2194  * @return Array
2195  */
2196 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2197         # No arg means accept anything (per HTTP spec)
2198         if( !$accept ) {
2199                 return array( $def => 1.0 );
2200         }
2201
2202         $prefs = array();
2203
2204         $parts = explode( ',', $accept );
2205
2206         foreach( $parts as $part ) {
2207                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2208                 $values = explode( ';', trim( $part ) );
2209                 $match = array();
2210                 if ( count( $values ) == 1 ) {
2211                         $prefs[$values[0]] = 1.0;
2212                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2213                         $prefs[$values[0]] = floatval( $match[1] );
2214                 }
2215         }
2216
2217         return $prefs;
2218 }
2219
2220 /**
2221  * Checks if a given MIME type matches any of the keys in the given
2222  * array. Basic wildcards are accepted in the array keys.
2223  *
2224  * Returns the matching MIME type (or wildcard) if a match, otherwise
2225  * NULL if no match.
2226  *
2227  * @param $type String
2228  * @param $avail Array
2229  * @return string
2230  * @private
2231  */
2232 function mimeTypeMatch( $type, $avail ) {
2233         if( array_key_exists( $type, $avail ) ) {
2234                 return $type;
2235         } else {
2236                 $parts = explode( '/', $type );
2237                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2238                         return $parts[0] . '/*';
2239                 } elseif( array_key_exists( '*/*', $avail ) ) {
2240                         return '*/*';
2241                 } else {
2242                         return null;
2243                 }
2244         }
2245 }
2246
2247 /**
2248  * Returns the 'best' match between a client's requested internet media types
2249  * and the server's list of available types. Each list should be an associative
2250  * array of type to preference (preference is a float between 0.0 and 1.0).
2251  * Wildcards in the types are acceptable.
2252  *
2253  * @param $cprefs Array: client's acceptable type list
2254  * @param $sprefs Array: server's offered types
2255  * @return string
2256  *
2257  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2258  * XXX: generalize to negotiate other stuff
2259  */
2260 function wfNegotiateType( $cprefs, $sprefs ) {
2261         $combine = array();
2262
2263         foreach( array_keys( $sprefs ) as $type ) {
2264                 $parts = explode( '/', $type );
2265                 if( $parts[1] != '*' ) {
2266                         $ckey = mimeTypeMatch( $type, $cprefs );
2267                         if( $ckey ) {
2268                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2269                         }
2270                 }
2271         }
2272
2273         foreach( array_keys( $cprefs ) as $type ) {
2274                 $parts = explode( '/', $type );
2275                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2276                         $skey = mimeTypeMatch( $type, $sprefs );
2277                         if( $skey ) {
2278                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2279                         }
2280                 }
2281         }
2282
2283         $bestq = 0;
2284         $besttype = null;
2285
2286         foreach( array_keys( $combine ) as $type ) {
2287                 if( $combine[$type] > $bestq ) {
2288                         $besttype = $type;
2289                         $bestq = $combine[$type];
2290                 }
2291         }
2292
2293         return $besttype;
2294 }
2295
2296 /**
2297  * Reference-counted warning suppression
2298  *
2299  * @param $end Bool
2300  */
2301 function wfSuppressWarnings( $end = false ) {
2302         static $suppressCount = 0;
2303         static $originalLevel = false;
2304
2305         if ( $end ) {
2306                 if ( $suppressCount ) {
2307                         --$suppressCount;
2308                         if ( !$suppressCount ) {
2309                                 error_reporting( $originalLevel );
2310                         }
2311                 }
2312         } else {
2313                 if ( !$suppressCount ) {
2314                         // E_DEPRECATED is undefined in PHP 5.2
2315                         if( !defined( 'E_DEPRECATED' ) ) {
2316                                 define( 'E_DEPRECATED', 8192 );
2317                         }
2318                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2319                 }
2320                 ++$suppressCount;
2321         }
2322 }
2323
2324 /**
2325  * Restore error level to previous value
2326  */
2327 function wfRestoreWarnings() {
2328         wfSuppressWarnings( true );
2329 }
2330
2331 # Autodetect, convert and provide timestamps of various types
2332
2333 /**
2334  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2335  */
2336 define( 'TS_UNIX', 0 );
2337
2338 /**
2339  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2340  */
2341 define( 'TS_MW', 1 );
2342
2343 /**
2344  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2345  */
2346 define( 'TS_DB', 2 );
2347
2348 /**
2349  * RFC 2822 format, for E-mail and HTTP headers
2350  */
2351 define( 'TS_RFC2822', 3 );
2352
2353 /**
2354  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2355  *
2356  * This is used by Special:Export
2357  */
2358 define( 'TS_ISO_8601', 4 );
2359
2360 /**
2361  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2362  *
2363  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2364  *       DateTime tag and page 36 for the DateTimeOriginal and
2365  *       DateTimeDigitized tags.
2366  */
2367 define( 'TS_EXIF', 5 );
2368
2369 /**
2370  * Oracle format time.
2371  */
2372 define( 'TS_ORACLE', 6 );
2373
2374 /**
2375  * Postgres format time.
2376  */
2377 define( 'TS_POSTGRES', 7 );
2378
2379 /**
2380  * DB2 format time
2381  */
2382 define( 'TS_DB2', 8 );
2383
2384 /**
2385  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2386  */
2387 define( 'TS_ISO_8601_BASIC', 9 );
2388
2389 /**
2390  * Get a timestamp string in one of various formats
2391  *
2392  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2393  *                    function will autodetect which format is supplied and act
2394  *                    accordingly.
2395  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2396  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2397  */
2398 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2399         $uts = 0;
2400         $da = array();
2401         $strtime = '';
2402
2403         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2404                 $uts = time();
2405                 $strtime = "@$uts";
2406         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2407                 # TS_DB
2408         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2409                 # TS_EXIF
2410         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2411                 # TS_MW
2412         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2413                 # TS_UNIX
2414                 $uts = $ts;
2415                 $strtime = "@$ts"; // http://php.net/manual/en/datetime.formats.compound.php
2416         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2417                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2418                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2419                                 str_replace( '+00:00', 'UTC', $ts ) );
2420         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2421                 # TS_ISO_8601
2422         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2423                 #TS_ISO_8601_BASIC
2424         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2425                 # TS_POSTGRES
2426         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2427                 # TS_POSTGRES
2428         } elseif (preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/', $ts, $da ) ) {
2429                 # TS_DB2
2430         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2431                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2432                                                         '[ \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
2433                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2434                 # The regex is a superset of rfc2822 for readability
2435                 $strtime = strtok( $ts, ';' );
2436         } 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 ) ) {
2437                 # TS_RFC850
2438                 $strtime = $ts;
2439         } 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 ) ) {
2440                 # asctime
2441                 $strtime = $ts;
2442         } else {
2443                 # Bogus value...
2444                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2445
2446                 return false;
2447         }
2448
2449         static $formats = array(
2450                 TS_UNIX => 'U',
2451                 TS_MW => 'YmdHis',
2452                 TS_DB => 'Y-m-d H:i:s',
2453                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2454                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2455                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2456                 TS_RFC2822 => 'D, d M Y H:i:s',
2457                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2458                 TS_POSTGRES => 'Y-m-d H:i:s',
2459                 TS_DB2 => 'Y-m-d H:i:s',
2460         );
2461
2462         if ( !isset( $formats[$outputtype] ) ) {
2463                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2464         }
2465
2466         if ( function_exists( "date_create" ) ) {
2467                 if ( count( $da ) ) {
2468                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2469                                 (int)$da[1], (int)$da[2], (int)$da[3],
2470                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2471
2472                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2473                 } elseif ( $strtime ) {
2474                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2475                 } else {
2476                         return false;
2477                 }
2478
2479                 if ( !$d ) {
2480                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2481                         return false;
2482                 }
2483
2484                 $output = $d->format( $formats[$outputtype] );
2485         } else {
2486                 if ( count( $da ) ) {
2487                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2488                         // We may want to handle that explicitly at some point
2489                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2490                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2491                 } elseif ( $strtime ) {
2492                         $uts = strtotime( $strtime );
2493                 }
2494
2495                 if ( $uts === false ) {
2496                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2497                         return false;
2498                 }
2499
2500                 if ( TS_UNIX == $outputtype ) {
2501                         return $uts;
2502                 }
2503                 $output = gmdate( $formats[$outputtype], $uts );
2504         }
2505
2506         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2507                 $output .= ' GMT';
2508         }
2509
2510         return $output;
2511 }
2512
2513 /**
2514  * Return a formatted timestamp, or null if input is null.
2515  * For dealing with nullable timestamp columns in the database.
2516  *
2517  * @param $outputtype Integer
2518  * @param $ts String
2519  * @return String
2520  */
2521 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2522         if( is_null( $ts ) ) {
2523                 return null;
2524         } else {
2525                 return wfTimestamp( $outputtype, $ts );
2526         }
2527 }
2528
2529 /**
2530  * Convenience function; returns MediaWiki timestamp for the present time.
2531  *
2532  * @return string
2533  */
2534 function wfTimestampNow() {
2535         # return NOW
2536         return wfTimestamp( TS_MW, time() );
2537 }
2538
2539 /**
2540  * Check if the operating system is Windows
2541  *
2542  * @return Bool: true if it's Windows, False otherwise.
2543  */
2544 function wfIsWindows() {
2545         static $isWindows = null;
2546         if ( $isWindows === null ) {
2547                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2548         }
2549         return $isWindows;
2550 }
2551
2552 /**
2553  * Check if we are running under HipHop
2554  *
2555  * @return Bool
2556  */
2557 function wfIsHipHop() {
2558         return function_exists( 'hphp_thread_set_warmup_enabled' );
2559 }
2560
2561 /**
2562  * Swap two variables
2563  *
2564  * @param $x Mixed
2565  * @param $y Mixed
2566  */
2567 function swap( &$x, &$y ) {
2568         $z = $x;
2569         $x = $y;
2570         $y = $z;
2571 }
2572
2573 /**
2574  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2575  * TEMP environment variables are then checked in sequence, and if none are set
2576  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2577  * or C:\Windows\Temp for Windows and hope for the best.
2578  * It is common to call it with tempnam().
2579  *
2580  * NOTE: When possible, use instead the tmpfile() function to create
2581  * temporary files to avoid race conditions on file creation, etc.
2582  *
2583  * @return String
2584  */
2585 function wfTempDir() {
2586         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2587                 $tmp = getenv( $var );
2588                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2589                         return $tmp;
2590                 }
2591         }
2592         if( function_exists( 'sys_get_temp_dir' ) ) {
2593                 return sys_get_temp_dir();
2594         }
2595         # Usual defaults
2596         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2597 }
2598
2599 /**
2600  * Make directory, and make all parent directories if they don't exist
2601  *
2602  * @param $dir String: full path to directory to create
2603  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2604  * @param $caller String: optional caller param for debugging.
2605  * @return bool
2606  */
2607 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2608         global $wgDirectoryMode;
2609
2610         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2611                 throw new MWException( __FUNCTION__ . " given storage path `$dir`.");
2612         }
2613
2614         if ( !is_null( $caller ) ) {
2615                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2616         }
2617
2618         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2619                 return true;
2620         }
2621
2622         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2623
2624         if ( is_null( $mode ) ) {
2625                 $mode = $wgDirectoryMode;
2626         }
2627
2628         // Turn off the normal warning, we're doing our own below
2629         wfSuppressWarnings();
2630         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2631         wfRestoreWarnings();
2632
2633         if( !$ok ) {
2634                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2635                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2636         }
2637         return $ok;
2638 }
2639
2640 /**
2641  * Remove a directory and all its content.
2642  * Does not hide error.
2643  */
2644 function wfRecursiveRemoveDir( $dir ) {
2645         wfDebug( __FUNCTION__ . "( $dir )\n" );
2646         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2647         if ( is_dir( $dir ) ) {
2648                 $objects = scandir( $dir );
2649                 foreach ( $objects as $object ) {
2650                         if ( $object != "." && $object != ".." ) {
2651                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2652                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2653                                 } else {
2654                                         unlink( $dir . '/' . $object );
2655                                 }
2656                         }
2657                 }
2658                 reset( $objects );
2659                 rmdir( $dir );
2660         }
2661 }
2662
2663 /**
2664  * @param $nr Mixed: the number to format
2665  * @param $acc Integer: the number of digits after the decimal point, default 2
2666  * @param $round Boolean: whether or not to round the value, default true
2667  * @return float
2668  */
2669 function wfPercent( $nr, $acc = 2, $round = true ) {
2670         $ret = sprintf( "%.${acc}f", $nr );
2671         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2672 }
2673
2674 /**
2675  * Find out whether or not a mixed variable exists in a string
2676  *
2677  * @param $needle String
2678  * @param $str String
2679  * @param $insensitive Boolean
2680  * @return Boolean
2681  */
2682 function in_string( $needle, $str, $insensitive = false ) {
2683         $func = 'strpos';
2684         if( $insensitive ) $func = 'stripos';
2685
2686         return $func( $str, $needle ) !== false;
2687 }
2688
2689 /**
2690  * Safety wrapper around ini_get() for boolean settings.
2691  * The values returned from ini_get() are pre-normalized for settings
2692  * set via php.ini or php_flag/php_admin_flag... but *not*
2693  * for those set via php_value/php_admin_value.
2694  *
2695  * It's fairly common for people to use php_value instead of php_flag,
2696  * which can leave you with an 'off' setting giving a false positive
2697  * for code that just takes the ini_get() return value as a boolean.
2698  *
2699  * To make things extra interesting, setting via php_value accepts
2700  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2701  * Unrecognized values go false... again opposite PHP's own coercion
2702  * from string to bool.
2703  *
2704  * Luckily, 'properly' set settings will always come back as '0' or '1',
2705  * so we only have to worry about them and the 'improper' settings.
2706  *
2707  * I frickin' hate PHP... :P
2708  *
2709  * @param $setting String
2710  * @return Bool
2711  */
2712 function wfIniGetBool( $setting ) {
2713         $val = ini_get( $setting );
2714         // 'on' and 'true' can't have whitespace around them, but '1' can.
2715         return strtolower( $val ) == 'on'
2716                 || strtolower( $val ) == 'true'
2717                 || strtolower( $val ) == 'yes'
2718                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2719 }
2720
2721 /**
2722  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2723  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2724  *
2725  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2726  *                          should be omitted
2727  * @param $fileName String Name of the library, if not $extension.suffix
2728  * @return Bool - Whether or not the extension is loaded
2729  */
2730 function wfDl( $extension, $fileName = null ) {
2731         if( extension_loaded( $extension ) ) {
2732                 return true;
2733         }
2734
2735         $canDl = false;
2736         $sapi = php_sapi_name();
2737         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2738                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2739         {
2740                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2741                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2742         }
2743
2744         if( $canDl ) {
2745                 $fileName = $fileName ? $fileName : $extension;
2746                 if( wfIsWindows() ) {
2747                         $fileName = 'php_' . $fileName;
2748                 }
2749                 wfSuppressWarnings();
2750                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2751                 wfRestoreWarnings();
2752         }
2753         return extension_loaded( $extension );
2754 }
2755
2756 /**
2757  * Windows-compatible version of escapeshellarg()
2758  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2759  * function puts single quotes in regardless of OS.
2760  *
2761  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2762  * earlier distro releases of PHP)
2763  *
2764  * @param varargs
2765  * @return String
2766  */
2767 function wfEscapeShellArg( ) {
2768         wfInitShellLocale();
2769
2770         $args = func_get_args();
2771         $first = true;
2772         $retVal = '';
2773         foreach ( $args as $arg ) {
2774                 if ( !$first ) {
2775                         $retVal .= ' ';
2776                 } else {
2777                         $first = false;
2778                 }
2779
2780                 if ( wfIsWindows() ) {
2781                         // Escaping for an MSVC-style command line parser and CMD.EXE
2782                         // Refs:
2783                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2784                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2785                         //  * Bug #13518
2786                         //  * CR r63214
2787                         // Double the backslashes before any double quotes. Escape the double quotes.
2788                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2789                         $arg = '';
2790                         $iteration = 0;
2791                         foreach ( $tokens as $token ) {
2792                                 if ( $iteration % 2 == 1 ) {
2793                                         // Delimiter, a double quote preceded by zero or more slashes
2794                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2795                                 } elseif ( $iteration % 4 == 2 ) {
2796                                         // ^ in $token will be outside quotes, need to be escaped
2797                                         $arg .= str_replace( '^', '^^', $token );
2798                                 } else { // $iteration % 4 == 0
2799                                         // ^ in $token will appear inside double quotes, so leave as is
2800                                         $arg .= $token;
2801                                 }
2802                                 $iteration++;
2803                         }
2804                         // Double the backslashes before the end of the string, because
2805                         // we will soon add a quote
2806                         $m = array();
2807                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2808                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2809                         }
2810
2811                         // Add surrounding quotes
2812                         $retVal .= '"' . $arg . '"';
2813                 } else {
2814                         $retVal .= escapeshellarg( $arg );
2815                 }
2816         }
2817         return $retVal;
2818 }
2819
2820 /**
2821  * Execute a shell command, with time and memory limits mirrored from the PHP
2822  * configuration if supported.
2823  * @param $cmd String Command line, properly escaped for shell.
2824  * @param &$retval null|Mixed optional, will receive the program's exit code.
2825  *                 (non-zero is usually failure)
2826  * @param $environ Array optional environment variables which should be
2827  *                 added to the executed command environment.
2828  * @return string collected stdout as a string (trailing newlines stripped)
2829  */
2830 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2831         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2832
2833         static $disabled;
2834         if ( is_null( $disabled ) ) {
2835                 $disabled = false;
2836                 if( wfIniGetBool( 'safe_mode' ) ) {
2837                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2838                         $disabled = 'safemode';
2839                 } else {
2840                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2841                         $functions = array_map( 'trim', $functions );
2842                         $functions = array_map( 'strtolower', $functions );
2843                         if ( in_array( 'passthru', $functions ) ) {
2844                                 wfDebug( "passthru is in disabled_functions\n" );
2845                                 $disabled = 'passthru';
2846                         }
2847                 }
2848         }
2849         if ( $disabled ) {
2850                 $retval = 1;
2851                 return $disabled == 'safemode' ?
2852                         'Unable to run external programs in safe mode.' :
2853                         'Unable to run external programs, passthru() is disabled.';
2854         }
2855
2856         wfInitShellLocale();
2857
2858         $envcmd = '';
2859         foreach( $environ as $k => $v ) {
2860                 if ( wfIsWindows() ) {
2861                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2862                          * appear in the environment variable, so we must use carat escaping as documented in
2863                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2864                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2865                          * are listed there but doesn't appear to need it.
2866                          */
2867                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2868                 } else {
2869                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2870                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2871                          */
2872                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2873                 }
2874         }
2875         $cmd = $envcmd . $cmd;
2876
2877         if ( wfIsWindows() ) {
2878                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2879                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2880                 {
2881                         # Hack to work around PHP's flawed invocation of cmd.exe
2882                         # http://news.php.net/php.internals/21796
2883                         # Windows 9x doesn't accept any kind of quotes
2884                         $cmd = '"' . $cmd . '"';
2885                 }
2886         } elseif ( php_uname( 's' ) == 'Linux' ) {
2887                 $time = intval( $wgMaxShellTime );
2888                 $mem = intval( $wgMaxShellMemory );
2889                 $filesize = intval( $wgMaxShellFileSize );
2890
2891                 if ( $time > 0 && $mem > 0 ) {
2892                         $script = "$IP/bin/ulimit4.sh";
2893                         if ( is_executable( $script ) ) {
2894                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2895                         }
2896                 }
2897         }
2898         wfDebug( "wfShellExec: $cmd\n" );
2899
2900         $retval = 1; // error by default?
2901         ob_start();
2902         passthru( $cmd, $retval );
2903         $output = ob_get_contents();
2904         ob_end_clean();
2905
2906         if ( $retval == 127 ) {
2907                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2908         }
2909         return $output;
2910 }
2911
2912 /**
2913  * Workaround for http://bugs.php.net/bug.php?id=45132
2914  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2915  */
2916 function wfInitShellLocale() {
2917         static $done = false;
2918         if ( $done ) {
2919                 return;
2920         }
2921         $done = true;
2922         global $wgShellLocale;
2923         if ( !wfIniGetBool( 'safe_mode' ) ) {
2924                 putenv( "LC_CTYPE=$wgShellLocale" );
2925                 setlocale( LC_CTYPE, $wgShellLocale );
2926         }
2927 }
2928
2929 /**
2930  * Generate a shell-escaped command line string to run a maintenance script.
2931  * Note that $parameters should be a flat array and an option with an argument
2932  * should consist of two consecutive items in the array (do not use "--option value").
2933  * @param $script string MediaWiki maintenance script path
2934  * @param $parameters Array Arguments and options to the script
2935  * @param $options Array Associative array of options:
2936  *              'php': The path to the php executable
2937  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2938  * @return Array
2939  */
2940 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2941         global $wgPhpCli;
2942         // Give site config file a chance to run the script in a wrapper.
2943         // The caller may likely want to call wfBasename() on $script.
2944         wfRunHooks( 'wfShellMaintenanceCmd', array( &$script, &$parameters, &$options ) );
2945         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2946         if ( isset( $options['wrapper'] ) ) {
2947                 $cmd[] = $options['wrapper'];
2948         }
2949         $cmd[] = $script;
2950         // Escape each parameter for shell
2951         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2952 }
2953
2954 /**
2955  * wfMerge attempts to merge differences between three texts.
2956  * Returns true for a clean merge and false for failure or a conflict.
2957  *
2958  * @param $old String
2959  * @param $mine String
2960  * @param $yours String
2961  * @param $result String
2962  * @return Bool
2963  */
2964 function wfMerge( $old, $mine, $yours, &$result ) {
2965         global $wgDiff3;
2966
2967         # This check may also protect against code injection in
2968         # case of broken installations.
2969         wfSuppressWarnings();
2970         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2971         wfRestoreWarnings();
2972
2973         if( !$haveDiff3 ) {
2974                 wfDebug( "diff3 not found\n" );
2975                 return false;
2976         }
2977
2978         # Make temporary files
2979         $td = wfTempDir();
2980         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2981         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2982         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2983
2984         fwrite( $oldtextFile, $old );
2985         fclose( $oldtextFile );
2986         fwrite( $mytextFile, $mine );
2987         fclose( $mytextFile );
2988         fwrite( $yourtextFile, $yours );
2989         fclose( $yourtextFile );
2990
2991         # Check for a conflict
2992         $cmd = $wgDiff3 . ' -a --overlap-only ' .
2993                 wfEscapeShellArg( $mytextName ) . ' ' .
2994                 wfEscapeShellArg( $oldtextName ) . ' ' .
2995                 wfEscapeShellArg( $yourtextName );
2996         $handle = popen( $cmd, 'r' );
2997
2998         if( fgets( $handle, 1024 ) ) {
2999                 $conflict = true;
3000         } else {
3001                 $conflict = false;
3002         }
3003         pclose( $handle );
3004
3005         # Merge differences
3006         $cmd = $wgDiff3 . ' -a -e --merge ' .
3007                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3008         $handle = popen( $cmd, 'r' );
3009         $result = '';
3010         do {
3011                 $data = fread( $handle, 8192 );
3012                 if ( strlen( $data ) == 0 ) {
3013                         break;
3014                 }
3015                 $result .= $data;
3016         } while ( true );
3017         pclose( $handle );
3018         unlink( $mytextName );
3019         unlink( $oldtextName );
3020         unlink( $yourtextName );
3021
3022         if ( $result === '' && $old !== '' && !$conflict ) {
3023                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3024                 $conflict = true;
3025         }
3026         return !$conflict;
3027 }
3028
3029 /**
3030  * Returns unified plain-text diff of two texts.
3031  * Useful for machine processing of diffs.
3032  *
3033  * @param $before String: the text before the changes.
3034  * @param $after String: the text after the changes.
3035  * @param $params String: command-line options for the diff command.
3036  * @return String: unified diff of $before and $after
3037  */
3038 function wfDiff( $before, $after, $params = '-u' ) {
3039         if ( $before == $after ) {
3040                 return '';
3041         }
3042
3043         global $wgDiff;
3044         wfSuppressWarnings();
3045         $haveDiff = $wgDiff && file_exists( $wgDiff );
3046         wfRestoreWarnings();
3047
3048         # This check may also protect against code injection in
3049         # case of broken installations.
3050         if( !$haveDiff ) {
3051                 wfDebug( "diff executable not found\n" );
3052                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3053                 $format = new UnifiedDiffFormatter();
3054                 return $format->format( $diffs );
3055         }
3056
3057         # Make temporary files
3058         $td = wfTempDir();
3059         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3060         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3061
3062         fwrite( $oldtextFile, $before );
3063         fclose( $oldtextFile );
3064         fwrite( $newtextFile, $after );
3065         fclose( $newtextFile );
3066
3067         // Get the diff of the two files
3068         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3069
3070         $h = popen( $cmd, 'r' );
3071
3072         $diff = '';
3073
3074         do {
3075                 $data = fread( $h, 8192 );
3076                 if ( strlen( $data ) == 0 ) {
3077                         break;
3078                 }
3079                 $diff .= $data;
3080         } while ( true );
3081
3082         // Clean up
3083         pclose( $h );
3084         unlink( $oldtextName );
3085         unlink( $newtextName );
3086
3087         // Kill the --- and +++ lines. They're not useful.
3088         $diff_lines = explode( "\n", $diff );
3089         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3090                 unset( $diff_lines[0] );
3091         }
3092         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3093                 unset( $diff_lines[1] );
3094         }
3095
3096         $diff = implode( "\n", $diff_lines );
3097
3098         return $diff;
3099 }
3100
3101 /**
3102  * This function works like "use VERSION" in Perl, the program will die with a
3103  * backtrace if the current version of PHP is less than the version provided
3104  *
3105  * This is useful for extensions which due to their nature are not kept in sync
3106  * with releases, and might depend on other versions of PHP than the main code
3107  *
3108  * Note: PHP might die due to parsing errors in some cases before it ever
3109  *       manages to call this function, such is life
3110  *
3111  * @see perldoc -f use
3112  *
3113  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3114  *                 a float
3115  */
3116 function wfUsePHP( $req_ver ) {
3117         $php_ver = PHP_VERSION;
3118
3119         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3120                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3121         }
3122 }
3123
3124 /**
3125  * This function works like "use VERSION" in Perl except it checks the version
3126  * of MediaWiki, the program will die with a backtrace if the current version
3127  * of MediaWiki 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
3131  *
3132  * @see perldoc -f use
3133  *
3134  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3135  *                 a float
3136  */
3137 function wfUseMW( $req_ver ) {
3138         global $wgVersion;
3139
3140         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3141                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3142         }
3143 }
3144
3145 /**
3146  * Return the final portion of a pathname.
3147  * Reimplemented because PHP5's basename() is buggy with multibyte text.
3148  * http://bugs.php.net/bug.php?id=33898
3149  *
3150  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3151  * We'll consider it so always, as we don't want \s in our Unix paths either.
3152  *
3153  * @param $path String
3154  * @param $suffix String: to remove if present
3155  * @return String
3156  */
3157 function wfBaseName( $path, $suffix = '' ) {
3158         $encSuffix = ( $suffix == '' )
3159                 ? ''
3160                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3161         $matches = array();
3162         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3163                 return $matches[1];
3164         } else {
3165                 return '';
3166         }
3167 }
3168
3169 /**
3170  * Generate a relative path name to the given file.
3171  * May explode on non-matching case-insensitive paths,
3172  * funky symlinks, etc.
3173  *
3174  * @param $path String: absolute destination path including target filename
3175  * @param $from String: Absolute source path, directory only
3176  * @return String
3177  */
3178 function wfRelativePath( $path, $from ) {
3179         // Normalize mixed input on Windows...
3180         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3181         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3182
3183         // Trim trailing slashes -- fix for drive root
3184         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3185         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3186
3187         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3188         $against = explode( DIRECTORY_SEPARATOR, $from );
3189
3190         if( $pieces[0] !== $against[0] ) {
3191                 // Non-matching Windows drive letters?
3192                 // Return a full path.
3193                 return $path;
3194         }
3195
3196         // Trim off common prefix
3197         while( count( $pieces ) && count( $against )
3198                 && $pieces[0] == $against[0] ) {
3199                 array_shift( $pieces );
3200                 array_shift( $against );
3201         }
3202
3203         // relative dots to bump us to the parent
3204         while( count( $against ) ) {
3205                 array_unshift( $pieces, '..' );
3206                 array_shift( $against );
3207         }
3208
3209         array_push( $pieces, wfBaseName( $path ) );
3210
3211         return implode( DIRECTORY_SEPARATOR, $pieces );
3212 }
3213
3214 /**
3215  * Do any deferred updates and clear the list
3216  *
3217  * @deprecated since 1.19
3218  * @see DeferredUpdates::doUpdate()
3219  * @param $commit string
3220  */
3221 function wfDoUpdates( $commit = '' ) {
3222         wfDeprecated( __METHOD__, '1.19' );
3223         DeferredUpdates::doUpdates( $commit );
3224 }
3225
3226 /**
3227  * Convert an arbitrarily-long digit string from one numeric base
3228  * to another, optionally zero-padding to a minimum column width.
3229  *
3230  * Supports base 2 through 36; digit values 10-36 are represented
3231  * as lowercase letters a-z. Input is case-insensitive.
3232  *
3233  * @param $input String: of digits
3234  * @param $sourceBase Integer: 2-36
3235  * @param $destBase Integer: 2-36
3236  * @param $pad Integer: 1 or greater
3237  * @param $lowercase Boolean
3238  * @return String or false on invalid input
3239  */
3240 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3241         $input = strval( $input );
3242         if( $sourceBase < 2 ||
3243                 $sourceBase > 36 ||
3244                 $destBase < 2 ||
3245                 $destBase > 36 ||
3246                 $pad < 1 ||
3247                 $sourceBase != intval( $sourceBase ) ||
3248                 $destBase != intval( $destBase ) ||
3249                 $pad != intval( $pad ) ||
3250                 !is_string( $input ) ||
3251                 $input == '' ) {
3252                 return false;
3253         }
3254         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3255         $inDigits = array();
3256         $outChars = '';
3257
3258         // Decode and validate input string
3259         $input = strtolower( $input );
3260         for( $i = 0; $i < strlen( $input ); $i++ ) {
3261                 $n = strpos( $digitChars, $input[$i] );
3262                 if( $n === false || $n > $sourceBase ) {
3263                         return false;
3264                 }
3265                 $inDigits[] = $n;
3266         }
3267
3268         // Iterate over the input, modulo-ing out an output digit
3269         // at a time until input is gone.
3270         while( count( $inDigits ) ) {
3271                 $work = 0;
3272                 $workDigits = array();
3273
3274                 // Long division...
3275                 foreach( $inDigits as $digit ) {
3276                         $work *= $sourceBase;
3277                         $work += $digit;
3278
3279                         if( $work < $destBase ) {
3280                                 // Gonna need to pull another digit.
3281                                 if( count( $workDigits ) ) {
3282                                         // Avoid zero-padding; this lets us find
3283                                         // the end of the input very easily when
3284                                         // length drops to zero.
3285                                         $workDigits[] = 0;
3286                                 }
3287                         } else {
3288                                 // Finally! Actual division!
3289                                 $workDigits[] = intval( $work / $destBase );
3290
3291                                 // Isn't it annoying that most programming languages
3292                                 // don't have a single divide-and-remainder operator,
3293                                 // even though the CPU implements it that way?
3294                                 $work = $work % $destBase;
3295                         }
3296                 }
3297
3298                 // All that division leaves us with a remainder,
3299                 // which is conveniently our next output digit.
3300                 $outChars .= $digitChars[$work];
3301
3302                 // And we continue!
3303                 $inDigits = $workDigits;
3304         }
3305
3306         while( strlen( $outChars ) < $pad ) {
3307                 $outChars .= '0';
3308         }
3309
3310         return strrev( $outChars );
3311 }
3312
3313 /**
3314  * Create an object with a given name and an array of construct parameters
3315  *
3316  * @param $name String
3317  * @param $p Array: parameters
3318  * @return object
3319  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3320  */
3321 function wfCreateObject( $name, $p ) {
3322         wfDeprecated( __FUNCTION__, '1.18' );
3323         return MWFunction::newObj( $name, $p );
3324 }
3325
3326 /**
3327  * @return bool
3328  */
3329 function wfHttpOnlySafe() {
3330         global $wgHttpOnlyBlacklist;
3331
3332         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3333                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3334                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3335                                 return false;
3336                         }
3337                 }
3338         }
3339
3340         return true;
3341 }
3342
3343 /**
3344  * Override session_id before session startup if php's built-in
3345  * session generation code is not secure.
3346  */
3347 function wfFixSessionID() {
3348         // If the cookie or session id is already set we already have a session and should abort
3349         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3350                 return;
3351         }
3352
3353         // PHP's built-in session entropy is enabled if:
3354         // - entropy_file is set or you're on Windows with php 5.3.3+
3355         // - AND entropy_length is > 0
3356         // We treat it as disabled if it doesn't have an entropy length of at least 32
3357         $entropyEnabled = (
3358                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3359                         || ini_get( 'session.entropy_file' )
3360                 )
3361                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3362
3363         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3364         if ( !$entropyEnabled ) {
3365                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3366                 session_id( MWCryptRand::generateHex( 32, __METHOD__ ) );
3367         }
3368 }
3369
3370 /**
3371  * Initialise php session
3372  *
3373  * @param $sessionId Bool
3374  */
3375 function wfSetupSession( $sessionId = false ) {
3376         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3377                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3378         if( $wgSessionsInMemcached ) {
3379                 if ( !defined( 'MW_COMPILED' ) ) {
3380                         global $IP;
3381                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
3382                 }
3383                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3384                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3385
3386                 // It's necessary to register a shutdown function to call session_write_close(),
3387                 // because by the time the request shutdown function for the session module is
3388                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3389                 // this way are called before object destruction.
3390                 register_shutdown_function( 'memsess_write_close' );
3391         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3392                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3393                 # hasn't already been set to the desired value (that causes errors)
3394                 ini_set( 'session.save_handler', $wgSessionHandler );
3395         }
3396         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3397         wfDebugLog( 'cookie',
3398                 'session_set_cookie_params: "' . implode( '", "',
3399                         array(
3400                                 0,
3401                                 $wgCookiePath,
3402                                 $wgCookieDomain,
3403                                 $wgCookieSecure,
3404                                 $httpOnlySafe ) ) . '"' );
3405         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3406         session_cache_limiter( 'private, must-revalidate' );
3407         if ( $sessionId ) {
3408                 session_id( $sessionId );
3409         } else {
3410                 wfFixSessionID();
3411         }
3412         wfSuppressWarnings();
3413         session_start();
3414         wfRestoreWarnings();
3415 }
3416
3417 /**
3418  * Get an object from the precompiled serialized directory
3419  *
3420  * @param $name String
3421  * @return Mixed: the variable on success, false on failure
3422  */
3423 function wfGetPrecompiledData( $name ) {
3424         global $IP;
3425
3426         $file = "$IP/serialized/$name";
3427         if ( file_exists( $file ) ) {
3428                 $blob = file_get_contents( $file );
3429                 if ( $blob ) {
3430                         return unserialize( $blob );
3431                 }
3432         }
3433         return false;
3434 }
3435
3436 /**
3437  * Get a cache key
3438  *
3439  * @param varargs
3440  * @return String
3441  */
3442 function wfMemcKey( /*... */ ) {
3443         global $wgCachePrefix;
3444         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3445         $args = func_get_args();
3446         $key = $prefix . ':' . implode( ':', $args );
3447         $key = str_replace( ' ', '_', $key );
3448         return $key;
3449 }
3450
3451 /**
3452  * Get a cache key for a foreign DB
3453  *
3454  * @param $db String
3455  * @param $prefix String
3456  * @param varargs String
3457  * @return String
3458  */
3459 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3460         $args = array_slice( func_get_args(), 2 );
3461         if ( $prefix ) {
3462                 $key = "$db-$prefix:" . implode( ':', $args );
3463         } else {
3464                 $key = $db . ':' . implode( ':', $args );
3465         }
3466         return $key;
3467 }
3468
3469 /**
3470  * Get an ASCII string identifying this wiki
3471  * This is used as a prefix in memcached keys
3472  *
3473  * @return String
3474  */
3475 function wfWikiID() {
3476         global $wgDBprefix, $wgDBname;
3477         if ( $wgDBprefix ) {
3478                 return "$wgDBname-$wgDBprefix";
3479         } else {
3480                 return $wgDBname;
3481         }
3482 }
3483
3484 /**
3485  * Split a wiki ID into DB name and table prefix
3486  *
3487  * @param $wiki String
3488  *
3489  * @return array
3490  */
3491 function wfSplitWikiID( $wiki ) {
3492         $bits = explode( '-', $wiki, 2 );
3493         if ( count( $bits ) < 2 ) {
3494                 $bits[] = '';
3495         }
3496         return $bits;
3497 }
3498
3499 /**
3500  * Get a Database object.
3501  *
3502  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3503  *            master (for write queries), DB_SLAVE for potentially lagged read
3504  *            queries, or an integer >= 0 for a particular server.
3505  *
3506  * @param $groups Mixed: query groups. An array of group names that this query
3507  *                belongs to. May contain a single string if the query is only
3508  *                in one group.
3509  *
3510  * @param $wiki String: the wiki ID, or false for the current wiki
3511  *
3512  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3513  * will always return the same object, unless the underlying connection or load
3514  * balancer is manually destroyed.
3515  *
3516  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3517  * updater to ensure that a proper database is being updated.
3518  *
3519  * @return DatabaseBase
3520  */
3521 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3522         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3523 }
3524
3525 /**
3526  * Get a load balancer object.
3527  *
3528  * @param $wiki String: wiki ID, or false for the current wiki
3529  * @return LoadBalancer
3530  */
3531 function wfGetLB( $wiki = false ) {
3532         return wfGetLBFactory()->getMainLB( $wiki );
3533 }
3534
3535 /**
3536  * Get the load balancer factory object
3537  *
3538  * @return LBFactory
3539  */
3540 function &wfGetLBFactory() {
3541         return LBFactory::singleton();
3542 }
3543
3544 /**
3545  * Find a file.
3546  * Shortcut for RepoGroup::singleton()->findFile()
3547  *
3548  * @param $title String or Title object
3549  * @param $options array Associative array of options:
3550  *     time:           requested time for an archived image, or false for the
3551  *                     current version. An image object will be returned which was
3552  *                     created at the specified time.
3553  *
3554  *     ignoreRedirect: If true, do not follow file redirects
3555  *
3556  *     private:        If true, return restricted (deleted) files if the current
3557  *                     user is allowed to view them. Otherwise, such files will not
3558  *                     be found.
3559  *
3560  *     bypassCache:    If true, do not use the process-local cache of File objects
3561  *
3562  * @return File, or false if the file does not exist
3563  */
3564 function wfFindFile( $title, $options = array() ) {
3565         return RepoGroup::singleton()->findFile( $title, $options );
3566 }
3567
3568 /**
3569  * Get an object referring to a locally registered file.
3570  * Returns a valid placeholder object if the file does not exist.
3571  *
3572  * @param $title Title|String
3573  * @return File|null A File, or null if passed an invalid Title
3574  */
3575 function wfLocalFile( $title ) {
3576         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3577 }
3578
3579 /**
3580  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3581  * @deprecated since 1.19
3582  */
3583 function wfStreamFile( $fname, $headers = array() ) {
3584         wfDeprecated( __FUNCTION__, '1.19' );
3585         StreamFile::stream( $fname, $headers );
3586 }
3587
3588 /**
3589  * Should low-performance queries be disabled?
3590  *
3591  * @return Boolean
3592  * @codeCoverageIgnore
3593  */
3594 function wfQueriesMustScale() {
3595         global $wgMiserMode;
3596         return $wgMiserMode
3597                 || ( SiteStats::pages() > 100000
3598                 && SiteStats::edits() > 1000000
3599                 && SiteStats::users() > 10000 );
3600 }
3601
3602 /**
3603  * Get the path to a specified script file, respecting file
3604  * extensions; this is a wrapper around $wgScriptExtension etc.
3605  *
3606  * @param $script String: script filename, sans extension
3607  * @return String
3608  */
3609 function wfScript( $script = 'index' ) {
3610         global $wgScriptPath, $wgScriptExtension;
3611         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3612 }
3613
3614 /**
3615  * Get the script URL.
3616  *
3617  * @return string script URL
3618  */
3619 function wfGetScriptUrl() {
3620         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3621                 #
3622                 # as it was called, minus the query string.
3623                 #
3624                 # Some sites use Apache rewrite rules to handle subdomains,
3625                 # and have PHP set up in a weird way that causes PHP_SELF
3626                 # to contain the rewritten URL instead of the one that the
3627                 # outside world sees.
3628                 #
3629                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3630                 # provides containing the "before" URL.
3631                 return $_SERVER['SCRIPT_NAME'];
3632         } else {
3633                 return $_SERVER['URL'];
3634         }
3635 }
3636
3637 /**
3638  * Convenience function converts boolean values into "true"
3639  * or "false" (string) values
3640  *
3641  * @param $value Boolean
3642  * @return String
3643  */
3644 function wfBoolToStr( $value ) {
3645         return $value ? 'true' : 'false';
3646 }
3647
3648 /**
3649  * Load an extension messages file
3650  *
3651  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3652  * @codeCoverageIgnore
3653  */
3654 function wfLoadExtensionMessages() {
3655         wfDeprecated( __FUNCTION__, '1.16' );
3656 }
3657
3658 /**
3659  * Get a platform-independent path to the null file, e.g. /dev/null
3660  *
3661  * @return string
3662  */
3663 function wfGetNull() {
3664         return wfIsWindows()
3665                 ? 'NUL'
3666                 : '/dev/null';
3667 }
3668
3669 /**
3670  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3671  * and waiting for it to go down, this waits for the slaves to catch up to the
3672  * master position. Use this when updating very large numbers of rows, as
3673  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3674  * a no-op if there are no slaves.
3675  *
3676  * @param $maxLag Integer (deprecated)
3677  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3678  */
3679 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3680         $lb = wfGetLB( $wiki );
3681         // bug 27975 - Don't try to wait for slaves if there are none
3682         // Prevents permission error when getting master position
3683         if ( $lb->getServerCount() > 1 ) {
3684                 $dbw = $lb->getConnection( DB_MASTER );
3685                 $pos = $dbw->getMasterPos();
3686                 $lb->waitForAll( $pos );
3687         }
3688 }
3689
3690 /**
3691  * Used to be used for outputting text in the installer/updater
3692  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3693  */
3694 function wfOut( $s ) {
3695         wfDeprecated( __FUNCTION__, '1.18' );
3696         global $wgCommandLineMode;
3697         if ( $wgCommandLineMode ) {
3698                 echo $s;
3699         } else {
3700                 echo htmlspecialchars( $s );
3701         }
3702         flush();
3703 }
3704
3705 /**
3706  * Count down from $n to zero on the terminal, with a one-second pause
3707  * between showing each number. For use in command-line scripts.
3708  * @codeCoverageIgnore
3709  * @param $n int
3710  */
3711 function wfCountDown( $n ) {
3712         for ( $i = $n; $i >= 0; $i-- ) {
3713                 if ( $i != $n ) {
3714                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3715                 }
3716                 echo $i;
3717                 flush();
3718                 if ( $i ) {
3719                         sleep( 1 );
3720                 }
3721         }
3722         echo "\n";
3723 }
3724
3725 /**
3726  * Generate a random 32-character hexadecimal token.
3727  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3728  *              characters before hashing.
3729  * @return string
3730  * @codeCoverageIgnore
3731  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pesudo-random strings
3732  * @warning This method is NOT secure. Additionally it has many callers that use it for pesudo-random purposes.
3733  */
3734 function wfGenerateToken( $salt = '' ) {
3735         wfDeprecated( __METHOD__, '1.20' );
3736         $salt = serialize( $salt );
3737         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3738 }
3739
3740 /**
3741  * Replace all invalid characters with -
3742  *
3743  * @param $name Mixed: filename to process
3744  * @return String
3745  */
3746 function wfStripIllegalFilenameChars( $name ) {
3747         global $wgIllegalFileChars;
3748         $name = wfBaseName( $name );
3749         $name = preg_replace(
3750                 "/[^" . Title::legalChars() . "]" .
3751                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3752                         "/",
3753                 '-',
3754                 $name
3755         );
3756         return $name;
3757 }
3758
3759 /**
3760  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3761  *
3762  * @return Integer value memory was set to.
3763  */
3764 function wfMemoryLimit() {
3765         global $wgMemoryLimit;
3766         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3767         if( $memlimit != -1 ) {
3768                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3769                 if( $conflimit == -1 ) {
3770                         wfDebug( "Removing PHP's memory limit\n" );
3771                         wfSuppressWarnings();
3772                         ini_set( 'memory_limit', $conflimit );
3773                         wfRestoreWarnings();
3774                         return $conflimit;
3775                 } elseif ( $conflimit > $memlimit ) {
3776                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3777                         wfSuppressWarnings();
3778                         ini_set( 'memory_limit', $conflimit );
3779                         wfRestoreWarnings();
3780                         return $conflimit;
3781                 }
3782         }
3783         return $memlimit;
3784 }
3785
3786 /**
3787  * Converts shorthand byte notation to integer form
3788  *
3789  * @param $string String
3790  * @return Integer
3791  */
3792 function wfShorthandToInteger( $string = '' ) {
3793         $string = trim( $string );
3794         if( $string === '' ) {
3795                 return -1;
3796         }
3797         $last = $string[strlen( $string ) - 1];
3798         $val = intval( $string );
3799         switch( $last ) {
3800                 case 'g':
3801                 case 'G':
3802                         $val *= 1024;
3803                         // break intentionally missing
3804                 case 'm':
3805                 case 'M':
3806                         $val *= 1024;
3807                         // break intentionally missing
3808                 case 'k':
3809                 case 'K':
3810                         $val *= 1024;
3811         }
3812
3813         return $val;
3814 }
3815
3816 /**
3817  * Get the normalised IETF language tag
3818  * See unit test for examples.
3819  *
3820  * @param $code String: The language code.
3821  * @return String: The language code which complying with BCP 47 standards.
3822  */
3823 function wfBCP47( $code ) {
3824         $codeSegment = explode( '-', $code );
3825         $codeBCP = array();
3826         foreach ( $codeSegment as $segNo => $seg ) {
3827                 if ( count( $codeSegment ) > 0 ) {
3828                         // when previous segment is x, it is a private segment and should be lc
3829                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3830                                 $codeBCP[$segNo] = strtolower( $seg );
3831                         // ISO 3166 country code
3832                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3833                                 $codeBCP[$segNo] = strtoupper( $seg );
3834                         // ISO 15924 script code
3835                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3836                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3837                         // Use lowercase for other cases
3838                         } else {
3839                                 $codeBCP[$segNo] = strtolower( $seg );
3840                         }
3841                 } else {
3842                 // Use lowercase for single segment
3843                         $codeBCP[$segNo] = strtolower( $seg );
3844                 }
3845         }
3846         $langCode = implode( '-', $codeBCP );
3847         return $langCode;
3848 }
3849
3850 /**
3851  * Get a cache object.
3852  *
3853  * @param $inputType integer Cache type, one the the CACHE_* constants.
3854  * @return BagOStuff
3855  */
3856 function wfGetCache( $inputType ) {
3857         return ObjectCache::getInstance( $inputType );
3858 }
3859
3860 /**
3861  * Get the main cache object
3862  *
3863  * @return BagOStuff
3864  */
3865 function wfGetMainCache() {
3866         global $wgMainCacheType;
3867         return ObjectCache::getInstance( $wgMainCacheType );
3868 }
3869
3870 /**
3871  * Get the cache object used by the message cache
3872  *
3873  * @return BagOStuff
3874  */
3875 function wfGetMessageCacheStorage() {
3876         global $wgMessageCacheType;
3877         return ObjectCache::getInstance( $wgMessageCacheType );
3878 }
3879
3880 /**
3881  * Get the cache object used by the parser cache
3882  *
3883  * @return BagOStuff
3884  */
3885 function wfGetParserCacheStorage() {
3886         global $wgParserCacheType;
3887         return ObjectCache::getInstance( $wgParserCacheType );
3888 }
3889
3890 /**
3891  * Call hook functions defined in $wgHooks
3892  *
3893  * @param $event String: event name
3894  * @param $args Array: parameters passed to hook functions
3895  * @return Boolean True if no handler aborted the hook
3896  */
3897 function wfRunHooks( $event, $args = array() ) {
3898         return Hooks::run( $event, $args );
3899 }
3900
3901 /**
3902  * Wrapper around php's unpack.
3903  *
3904  * @param $format String: The format string (See php's docs)
3905  * @param $data: A binary string of binary data
3906  * @param $length integer or false: The minimun length of $data. This is to
3907  *      prevent reading beyond the end of $data. false to disable the check.
3908  *
3909  * Also be careful when using this function to read unsigned 32 bit integer
3910  * because php might make it negative.
3911  *
3912  * @throws MWException if $data not long enough, or if unpack fails
3913  * @return array Associative array of the extracted data
3914  */
3915 function wfUnpack( $format, $data, $length=false ) {
3916         if ( $length !== false ) {
3917                 $realLen = strlen( $data );
3918                 if ( $realLen < $length ) {
3919                         throw new MWException( "Tried to use wfUnpack on a "
3920                                 . "string of length $realLen, but needed one "
3921                                 . "of at least length $length."
3922                         );
3923                 }
3924         }
3925
3926         wfSuppressWarnings();
3927         $result = unpack( $format, $data );
3928         wfRestoreWarnings();
3929
3930         if ( $result === false ) {
3931                 // If it cannot extract the packed data.
3932                 throw new MWException( "unpack could not unpack binary data" );
3933         }
3934         return $result;
3935 }