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, $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 $rand;
 295 }
 296
 297 /**
 298  * We want some things to be included as literal characters in our title URLs
 299  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 300  * all of the following should be safe:
 301  *
 302  * ;:@&=$-_.+!*'(),
 303  *
 304  * But + is not safe because it's used to indicate a space; &= are only safe in
 305  * paths and not in queries (and we don't distinguish here); ' seems kind of
 306  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 307  * is reserved, we don't care.  So the list we unescape is:
 308  *
 309  * ;:@$!*(),/
 310  *
 311  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 312  * so no fancy : for IIS7.
 313  *
 314  * %2F in the page titles seems to fatally break for some reason.
 315  *
 316  * @param $s String:
 317  * @return string
 318 */
 319 function wfUrlencode( $s ) {
 320         static $needle;
 321         if ( is_null( $s ) ) {
 322                 $needle = null;
 323                 return '';
 324         }
 325
 326         if ( is_null( $needle ) ) {
 327                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 328                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 329                         $needle[] = '%3A';
 330                 }
 331         }
 332
 333         $s = urlencode( $s );
 334         $s = str_ireplace(
 335                 $needle,
 336                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 337                 $s
 338         );
 339
 340         return $s;
 341 }
 342
 343 /**
 344  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 345  * "days=7&limit=100". Options in the first array override options in the second.
 346  * Options set to null or false will not be output.
 347  *
 348  * @param $array1 Array ( String|Array )
 349  * @param $array2 Array ( String|Array )
 350  * @param $prefix String
 351  * @return String
 352  */
 353 function wfArrayToCGI( $array1, $array2 = null, $prefix = '' ) {
 354         if ( !is_null( $array2 ) ) {
 355                 $array1 = $array1 + $array2;
 356         }
 357
 358         $cgi = '';
 359         foreach ( $array1 as $key => $value ) {
 360                 if ( !is_null($value) && $value !== false ) {
 361                         if ( $cgi != '' ) {
 362                                 $cgi .= '&';
 363                         }
 364                         if ( $prefix !== '' ) {
 365                                 $key = $prefix . "[$key]";
 366                         }
 367                         if ( is_array( $value ) ) {
 368                                 $firstTime = true;
 369                                 foreach ( $value as $k => $v ) {
 370                                         $cgi .= $firstTime ? '' : '&';
 371                                         if ( is_array( $v ) ) {
 372                                                 $cgi .= wfArrayToCGI( $v, null, $key . "[$k]" );
 373                                         } else {
 374                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 375                                         }
 376                                         $firstTime = false;
 377                                 }
 378                         } else {
 379                                 if ( is_object( $value ) ) {
 380                                         $value = $value->__toString();
 381                                 }
 382                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 383                         }
 384                 }
 385         }
 386         return $cgi;
 387 }
 388
 389 /**
 390  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
 391  * its argument and returns the same string in array form.  This allows compa-
 392  * tibility with legacy functions that accept raw query strings instead of nice
 393  * arrays.  Of course, keys and values are urldecode()d.
 394  *
 395  * @param $query String: query string
 396  * @return array Array version of input
 397  */
 398 function wfCgiToArray( $query ) {
 399         if ( isset( $query[0] ) && $query[0] == '?' ) {
 400                 $query = substr( $query, 1 );
 401         }
 402         $bits = explode( '&', $query );
 403         $ret = array();
 404         foreach ( $bits as $bit ) {
 405                 if ( $bit === '' ) {
 406                         continue;
 407                 }
 408                 if ( strpos( $bit, '=' ) === false ) {
 409                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 410                         $key = $bit;
 411                         $value = '';
 412                 } else {
 413                         list( $key, $value ) = explode( '=', $bit );
 414                 }
 415                 $key = urldecode( $key );
 416                 $value = urldecode( $value );
 417                 if ( strpos( $key, '[' ) !== false ) {
 418                         $keys = array_reverse( explode( '[', $key ) );
 419                         $key = array_pop( $keys );
 420                         $temp = $value;
 421                         foreach ( $keys as $k ) {
 422                                 $k = substr( $k, 0, -1 );
 423                                 $temp = array( $k => $temp );
 424                         }
 425                         if ( isset( $ret[$key] ) ) {
 426                                 $ret[$key] = array_merge( $ret[$key], $temp );
 427                         } else {
 428                                 $ret[$key] = $temp;
 429                         }
 430                 } else {
 431                         $ret[$key] = $value;
 432                 }
 433         }
 434         return $ret;
 435 }
 436
 437 /**
 438  * Append a query string to an existing URL, which may or may not already
 439  * have query string parameters already. If so, they will be combined.
 440  *
 441  * @param $url String
 442  * @param $query Mixed: string or associative array
 443  * @return string
 444  */
 445 function wfAppendQuery( $url, $query ) {
 446         if ( is_array( $query ) ) {
 447                 $query = wfArrayToCGI( $query );
 448         }
 449         if( $query != '' ) {
 450                 if( false === strpos( $url, '?' ) ) {
 451                         $url .= '?';
 452                 } else {
 453                         $url .= '&';
 454                 }
 455                 $url .= $query;
 456         }
 457         return $url;
 458 }
 459
 460 /**
 461  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 462  * is correct.
 463  *
 464  * The meaning of the PROTO_* constants is as follows:
 465  * PROTO_HTTP: Output a URL starting with http://
 466  * PROTO_HTTPS: Output a URL starting with https://
 467  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 468  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 469  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 470  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 471  *
 472  * @todo this won't work with current-path-relative URLs
 473  * like "subdir/foo.html", etc.
 474  *
 475  * @param $url String: either fully-qualified or a local path + query
 476  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 477  *                             protocol to use if $url or $wgServer is
 478  *                             protocol-relative
 479  * @return string Fully-qualified URL, current-path-relative URL or false if
 480  *                no valid URL can be constructed
 481  */
 482 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 483         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 484         $serverUrl = $wgServer;
 485         if ( $defaultProto === PROTO_CANONICAL ) {
 486                 $serverUrl = $wgCanonicalServer;
 487         }
 488         // Make $wgInternalServer fall back to $wgServer if not set
 489         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 490                 $serverUrl = $wgInternalServer;
 491         }
 492         if ( $defaultProto === PROTO_CURRENT ) {
 493                 $defaultProto = WebRequest::detectProtocol() . '://';
 494         }
 495
 496         // Analyze $serverUrl to obtain its protocol
 497         $bits = wfParseUrl( $serverUrl );
 498         $serverHasProto = $bits && $bits['scheme'] != '';
 499
 500         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 501                 if ( $serverHasProto ) {
 502                         $defaultProto = $bits['scheme'] . '://';
 503                 } else {
 504                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 505                         // Fall back to HTTP in this ridiculous case
 506                         $defaultProto = PROTO_HTTP;
 507                 }
 508         }
 509
 510         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 511
 512         if ( substr( $url, 0, 2 ) == '//' ) {
 513                 $url = $defaultProtoWithoutSlashes . $url;
 514         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 515                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 516                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 517         }
 518
 519         $bits = wfParseUrl( $url );
 520         if ( $bits && isset( $bits['path'] ) ) {
 521                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 522                 return wfAssembleUrl( $bits );
 523         } elseif ( $bits ) {
 524                 # No path to expand
 525                 return $url;
 526         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 527                 # URL is a relative path
 528                 return wfRemoveDotSegments( $url );
 529         }
 530
 531         # Expanded URL is not valid.
 532         return false;
 533 }
 534
 535 /**
 536  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 537  * if you need to edit part of a URL and put it back together.
 538  *
 539  * This is the basic structure used (brackets contain keys for $urlParts):
 540  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 541  *
 542  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 543  *
 544  * @param $urlParts Array URL parts, as output from wfParseUrl
 545  * @return string URL assembled from its component parts
 546  */
 547 function wfAssembleUrl( $urlParts ) {
 548         $result = '';
 549
 550         if ( isset( $urlParts['delimiter'] ) ) {
 551                 if ( isset( $urlParts['scheme'] ) ) {
 552                         $result .= $urlParts['scheme'];
 553                 }
 554
 555                 $result .= $urlParts['delimiter'];
 556         }
 557
 558         if ( isset( $urlParts['host'] ) ) {
 559                 if ( isset( $urlParts['user'] ) ) {
 560                         $result .= $urlParts['user'];
 561                         if ( isset( $urlParts['pass'] ) ) {
 562                                 $result .= ':' . $urlParts['pass'];
 563                         }
 564                         $result .= '@';
 565                 }
 566
 567                 $result .= $urlParts['host'];
 568
 569                 if ( isset( $urlParts['port'] ) ) {
 570                         $result .= ':' . $urlParts['port'];
 571                 }
 572         }
 573
 574         if ( isset( $urlParts['path'] ) ) {
 575                 $result .= $urlParts['path'];
 576         }
 577
 578         if ( isset( $urlParts['query'] ) ) {
 579                 $result .= '?' . $urlParts['query'];
 580         }
 581
 582         if ( isset( $urlParts['fragment'] ) ) {
 583                 $result .= '#' . $urlParts['fragment'];
 584         }
 585
 586         return $result;
 587 }
 588
 589 /**
 590  * Remove all dot-segments in the provided URL path.  For example,
 591  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 592  * RFC3986 section 5.2.4.
 593  *
 594  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 595  *
 596  * @param $urlPath String URL path, potentially containing dot-segments
 597  * @return string URL path with all dot-segments removed
 598  */
 599 function wfRemoveDotSegments( $urlPath ) {
 600         $output = '';
 601         $inputOffset = 0;
 602         $inputLength = strlen( $urlPath );
 603
 604         while ( $inputOffset < $inputLength ) {
 605                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 606                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 607                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 608                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 609                 $trimOutput = false;
 610
 611                 if ( $prefixLengthTwo == './' ) {
 612                         # Step A, remove leading "./"
 613                         $inputOffset += 2;
 614                 } elseif ( $prefixLengthThree == '../' ) {
 615                         # Step A, remove leading "../"
 616                         $inputOffset += 3;
 617                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 618                         # Step B, replace leading "/.$" with "/"
 619                         $inputOffset += 1;
 620                         $urlPath[$inputOffset] = '/';
 621                 } elseif ( $prefixLengthThree == '/./' ) {
 622                         # Step B, replace leading "/./" with "/"
 623                         $inputOffset += 2;
 624                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 625                         # Step C, replace leading "/..$" with "/" and
 626                         # remove last path component in output
 627                         $inputOffset += 2;
 628                         $urlPath[$inputOffset] = '/';
 629                         $trimOutput = true;
 630                 } elseif ( $prefixLengthFour == '/../' ) {
 631                         # Step C, replace leading "/../" with "/" and
 632                         # remove last path component in output
 633                         $inputOffset += 3;
 634                         $trimOutput = true;
 635                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 636                         # Step D, remove "^.$"
 637                         $inputOffset += 1;
 638                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 639                         # Step D, remove "^..$"
 640                         $inputOffset += 2;
 641                 } else {
 642                         # Step E, move leading path segment to output
 643                         if ( $prefixLengthOne == '/' ) {
 644                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 645                         } else {
 646                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 647                         }
 648                         if ( $slashPos === false ) {
 649                                 $output .= substr( $urlPath, $inputOffset );
 650                                 $inputOffset = $inputLength;
 651                         } else {
 652                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 653                                 $inputOffset += $slashPos - $inputOffset;
 654                         }
 655                 }
 656
 657                 if ( $trimOutput ) {
 658                         $slashPos = strrpos( $output, '/' );
 659                         if ( $slashPos === false ) {
 660                                 $output = '';
 661                         } else {
 662                                 $output = substr( $output, 0, $slashPos );
 663                         }
 664                 }
 665         }
 666
 667         return $output;
 668 }
 669
 670 /**
 671  * Returns a regular expression of url protocols
 672  *
 673  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 674  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 675  * @return String
 676  */
 677 function wfUrlProtocols( $includeProtocolRelative = true ) {
 678         global $wgUrlProtocols;
 679
 680         // Cache return values separately based on $includeProtocolRelative
 681         static $withProtRel = null, $withoutProtRel = null;
 682         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 683         if ( !is_null( $cachedValue ) ) {
 684                 return $cachedValue;
 685         }
 686
 687         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 688         // with LocalSettings files from 1.5
 689         if ( is_array( $wgUrlProtocols ) ) {
 690                 $protocols = array();
 691                 foreach ( $wgUrlProtocols as $protocol ) {
 692                         // Filter out '//' if !$includeProtocolRelative
 693                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 694                                 $protocols[] = preg_quote( $protocol, '/' );
 695                         }
 696                 }
 697
 698                 $retval = implode( '|', $protocols );
 699         } else {
 700                 // Ignore $includeProtocolRelative in this case
 701                 // This case exists for pre-1.6 compatibility, and we can safely assume
 702                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 703                 // URLs weren't supported until 1.18
 704                 $retval = $wgUrlProtocols;
 705         }
 706
 707         // Cache return value
 708         if ( $includeProtocolRelative ) {
 709                 $withProtRel = $retval;
 710         } else {
 711                 $withoutProtRel = $retval;
 712         }
 713         return $retval;
 714 }
 715
 716 /**
 717  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 718  * you need a regex that matches all URL protocols but does not match protocol-
 719  * relative URLs
 720  * @return String
 721  */
 722 function wfUrlProtocolsWithoutProtRel() {
 723         return wfUrlProtocols( false );
 724 }
 725
 726 /**
 727  * parse_url() work-alike, but non-broken.  Differences:
 728  *
 729  * 1) Does not raise warnings on bad URLs (just returns false)
 730  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 731  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 732  *
 733  * @param $url String: a URL to parse
 734  * @return Array: bits of the URL in an associative array, per PHP docs
 735  */
 736 function wfParseUrl( $url ) {
 737         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 738
 739         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 740         // way to handle them is to just prepend 'http:' and strip the protocol out later
 741         $wasRelative = substr( $url, 0, 2 ) == '//';
 742         if ( $wasRelative ) {
 743                 $url = "http:$url";
 744         }
 745         wfSuppressWarnings();
 746         $bits = parse_url( $url );
 747         wfRestoreWarnings();
 748         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 749         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 750         if ( !$bits || !isset( $bits['scheme'] ) ) {
 751                 return false;
 752         }
 753
 754         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 755         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 756                 $bits['delimiter'] = '://';
 757         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 758                 $bits['delimiter'] = ':';
 759                 // parse_url detects for news: and mailto: the host part of an url as path
 760                 // We have to correct this wrong detection
 761                 if ( isset( $bits['path'] ) ) {
 762                         $bits['host'] = $bits['path'];
 763                         $bits['path'] = '';
 764                 }
 765         } else {
 766                 return false;
 767         }
 768
 769         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 770         if ( !isset( $bits['host'] ) ) {
 771                 $bits['host'] = '';
 772
 773                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 774                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 775                         $bits['path'] = '/' . $bits['path'];
 776                 }
 777         }
 778
 779         // If the URL was protocol-relative, fix scheme and delimiter
 780         if ( $wasRelative ) {
 781                 $bits['scheme'] = '';
 782                 $bits['delimiter'] = '//';
 783         }
 784         return $bits;
 785 }
 786
 787 /**
 788  * Make URL indexes, appropriate for the el_index field of externallinks.
 789  *
 790  * @param $url String
 791  * @return array
 792  */
 793 function wfMakeUrlIndexes( $url ) {
 794         $bits = wfParseUrl( $url );
 795
 796         // Reverse the labels in the hostname, convert to lower case
 797         // For emails reverse domainpart only
 798         if ( $bits['scheme'] == 'mailto' ) {
 799                 $mailparts = explode( '@', $bits['host'], 2 );
 800                 if ( count( $mailparts ) === 2 ) {
 801                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 802                 } else {
 803                         // No domain specified, don't mangle it
 804                         $domainpart = '';
 805                 }
 806                 $reversedHost = $domainpart . '@' . $mailparts[0];
 807         } else {
 808                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 809         }
 810         // Add an extra dot to the end
 811         // Why? Is it in wrong place in mailto links?
 812         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 813                 $reversedHost .= '.';
 814         }
 815         // Reconstruct the pseudo-URL
 816         $prot = $bits['scheme'];
 817         $index = $prot . $bits['delimiter'] . $reversedHost;
 818         // Leave out user and password. Add the port, path, query and fragment
 819         if ( isset( $bits['port'] ) ) {
 820                 $index .= ':' . $bits['port'];
 821         }
 822         if ( isset( $bits['path'] ) ) {
 823                 $index .= $bits['path'];
 824         } else {
 825                 $index .= '/';
 826         }
 827         if ( isset( $bits['query'] ) ) {
 828                 $index .= '?' . $bits['query'];
 829         }
 830         if ( isset( $bits['fragment'] ) ) {
 831                 $index .= '#' . $bits['fragment'];
 832         }
 833
 834         if ( $prot == '' ) {
 835                 return array( "http:$index", "https:$index" );
 836         } else {
 837                 return array( $index );
 838         }
 839 }
 840
 841 /**
 842  * Check whether a given URL has a domain that occurs in a given set of domains
 843  * @param $url string URL
 844  * @param $domains array Array of domains (strings)
 845  * @return bool True if the host part of $url ends in one of the strings in $domains
 846  */
 847 function wfMatchesDomainList( $url, $domains ) {
 848         $bits = wfParseUrl( $url );
 849         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 850                 foreach ( (array)$domains as $domain ) {
 851                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 852                         // We should use something that interprets dots instead
 853                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 854                                 return true;
 855                         }
 856                 }
 857         }
 858         return false;
 859 }
 860
 861 /**
 862  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 863  * In normal operation this is a NOP.
 864  *
 865  * Controlling globals:
 866  * $wgDebugLogFile - points to the log file
 867  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 868  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 869  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 870  *
 871  * @param $text String
 872  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 873  */
 874 function wfDebug( $text, $logonly = false ) {
 875         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 876         global $wgDebugLogPrefix, $wgShowDebug;
 877
 878         static $cache = array(); // Cache of unoutputted messages
 879         $text = wfDebugTimer() . $text;
 880
 881         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 882                 return;
 883         }
 884
 885         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 886                 $cache[] = $text;
 887
 888                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 889                         // add the message and any cached messages to the output
 890                         array_map( array( $wgOut, 'debug' ), $cache );
 891                         $cache = array();
 892                 }
 893         }
 894         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 895                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 896                         # Strip unprintables; they can switch terminal modes when binary data
 897                         # gets dumped, which is pretty annoying.
 898                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 899                         $text = $wgDebugLogPrefix . $text;
 900                         wfErrorLog( $text, $wgDebugLogFile );
 901                 }
 902         }
 903
 904         MWDebug::debugMsg( $text );
 905 }
 906
 907 /**
 908  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 909  * @return bool
 910  */
 911 function wfIsDebugRawPage() {
 912         static $cache;
 913         if ( $cache !== null ) {
 914                 return $cache;
 915         }
 916         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 917         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 918                 || (
 919                         isset( $_SERVER['SCRIPT_NAME'] )
 920                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 921                 ) )
 922         {
 923                 $cache = true;
 924         } else {
 925                 $cache = false;
 926         }
 927         return $cache;
 928 }
 929
 930 /**
 931  * Get microsecond timestamps for debug logs
 932  *
 933  * @return string
 934  */
 935 function wfDebugTimer() {
 936         global $wgDebugTimestamps, $wgRequestTime;
 937
 938         if ( !$wgDebugTimestamps ) {
 939                 return '';
 940         }
 941
 942         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 943         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 944         return "$prefix $mem  ";
 945 }
 946
 947 /**
 948  * Send a line giving PHP memory usage.
 949  *
 950  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 951  */
 952 function wfDebugMem( $exact = false ) {
 953         $mem = memory_get_usage();
 954         if( !$exact ) {
 955                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 956         } else {
 957                 $mem .= ' bytes';
 958         }
 959         wfDebug( "Memory usage: $mem\n" );
 960 }
 961
 962 /**
 963  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 964  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 965  *
 966  * @param $logGroup String
 967  * @param $text String
 968  * @param $public Bool: whether to log the event in the public log if no private
 969  *                     log file is specified, (default true)
 970  */
 971 function wfDebugLog( $logGroup, $text, $public = true ) {
 972         global $wgDebugLogGroups;
 973         $text = trim( $text ) . "\n";
 974         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 975                 $time = wfTimestamp( TS_DB );
 976                 $wiki = wfWikiID();
 977                 $host = wfHostname();
 978                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 979                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 980                 }
 981         } elseif ( $public === true ) {
 982                 wfDebug( $text, true );
 983         }
 984 }
 985
 986 /**
 987  * Log for database errors
 988  *
 989  * @param $text String: database error message.
 990  */
 991 function wfLogDBError( $text ) {
 992         global $wgDBerrorLog;
 993         if ( $wgDBerrorLog ) {
 994                 $host = wfHostname();
 995                 $wiki = wfWikiID();
 996                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wiki\t$text";
 997                 wfErrorLog( $text, $wgDBerrorLog );
 998         }
 999 }
1000
1001 /**
1002  * Throws a warning that $function is deprecated
1003  *
1004  * @param $function String
1005  * @param $version String|bool: Version of MediaWiki that the function was deprecated in (Added in 1.19).
1006  * @param $component String|bool: Added in 1.19.
1007  * @param $callerOffset integer: How far up the callstack is the original
1008  *    caller. 2 = function that called the function that called
1009  *    wfDeprecated (Added in 1.20)
1010  *
1011  * @return null
1012  */
1013 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1014         static $functionsWarned = array();
1015
1016         MWDebug::deprecated( $function, $version, $component );
1017
1018         if ( !isset( $functionsWarned[$function] ) ) {
1019                 $functionsWarned[$function] = true;
1020
1021                 if ( $version ) {
1022                         global $wgDeprecationReleaseLimit;
1023
1024                         if ( $wgDeprecationReleaseLimit && $component === false ) {
1025                                 # Strip -* off the end of $version so that branches can use the
1026                                 # format #.##-branchname to avoid issues if the branch is merged into
1027                                 # a version of MediaWiki later than what it was branched from
1028                                 $comparableVersion = preg_replace( '/-.*$/', '', $version );
1029
1030                                 # If the comparableVersion is larger than our release limit then
1031                                 # skip the warning message for the deprecation
1032                                 if ( version_compare( $wgDeprecationReleaseLimit, $comparableVersion, '<' ) ) {
1033                                         return;
1034                                 }
1035                         }
1036
1037                         $component = $component === false ? 'MediaWiki' : $component;
1038                         wfWarn( "Use of $function was deprecated in $component $version.", $callerOffset );
1039                 } else {
1040                         wfWarn( "Use of $function is deprecated.", $callerOffset );
1041                 }
1042         }
1043 }
1044
1045 /**
1046  * Send a warning either to the debug log or in a PHP error depending on
1047  * $wgDevelopmentWarnings
1048  *
1049  * @param $msg String: message to send
1050  * @param $callerOffset Integer: number of items to go back in the backtrace to
1051  *        find the correct caller (1 = function calling wfWarn, ...)
1052  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1053  *        is true
1054  */
1055 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1056         global $wgDevelopmentWarnings;
1057
1058         MWDebug::warning( $msg, $callerOffset + 2 );
1059
1060         $callers = wfDebugBacktrace();
1061         if ( isset( $callers[$callerOffset + 1] ) ) {
1062                 $callerfunc = $callers[$callerOffset + 1];
1063                 $callerfile = $callers[$callerOffset];
1064                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
1065                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
1066                 } else {
1067                         $file = '(internal function)';
1068                 }
1069                 $func = '';
1070                 if ( isset( $callerfunc['class'] ) ) {
1071                         $func .= $callerfunc['class'] . '::';
1072                 }
1073                 if ( isset( $callerfunc['function'] ) ) {
1074                         $func .= $callerfunc['function'];
1075                 }
1076                 $msg .= " [Called from $func in $file]";
1077         }
1078
1079         if ( $wgDevelopmentWarnings ) {
1080                 trigger_error( $msg, $level );
1081         } else {
1082                 wfDebug( "$msg\n" );
1083         }
1084 }
1085
1086 /**
1087  * Log to a file without getting "file size exceeded" signals.
1088  *
1089  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1090  * send lines to the specified port, prefixed by the specified prefix and a space.
1091  *
1092  * @param $text String
1093  * @param $file String filename
1094  */
1095 function wfErrorLog( $text, $file ) {
1096         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1097                 # Needs the sockets extension
1098                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1099                         // IPv6 bracketed host
1100                         $host = $m[2];
1101                         $port = intval( $m[3] );
1102                         $prefix = isset( $m[4] ) ? $m[4] : false;
1103                         $domain = AF_INET6;
1104                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1105                         $host = $m[2];
1106                         if ( !IP::isIPv4( $host ) ) {
1107                                 $host = gethostbyname( $host );
1108                         }
1109                         $port = intval( $m[3] );
1110                         $prefix = isset( $m[4] ) ? $m[4] : false;
1111                         $domain = AF_INET;
1112                 } else {
1113                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1114                 }
1115
1116                 // Clean it up for the multiplexer
1117                 if ( strval( $prefix ) !== '' ) {
1118                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1119
1120                         // Limit to 64KB
1121                         if ( strlen( $text ) > 65506 ) {
1122                                 $text = substr( $text, 0, 65506 );
1123                         }
1124
1125                         if ( substr( $text, -1 ) != "\n" ) {
1126                                 $text .= "\n";
1127                         }
1128                 } elseif ( strlen( $text ) > 65507 ) {
1129                         $text = substr( $text, 0, 65507 );
1130                 }
1131
1132                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1133                 if ( !$sock ) {
1134                         return;
1135                 }
1136
1137                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1138                 socket_close( $sock );
1139         } else {
1140                 wfSuppressWarnings();
1141                 $exists = file_exists( $file );
1142                 $size = $exists ? filesize( $file ) : false;
1143                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1144                         file_put_contents( $file, $text, FILE_APPEND );
1145                 }
1146                 wfRestoreWarnings();
1147         }
1148 }
1149
1150 /**
1151  * @todo document
1152  */
1153 function wfLogProfilingData() {
1154         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1155         global $wgProfileLimit, $wgUser;
1156
1157         $profiler = Profiler::instance();
1158
1159         # Profiling must actually be enabled...
1160         if ( $profiler->isStub() ) {
1161                 return;
1162         }
1163
1164         // Get total page request time and only show pages that longer than
1165         // $wgProfileLimit time (default is 0)
1166         $elapsed = microtime( true ) - $wgRequestTime;
1167         if ( $elapsed <= $wgProfileLimit ) {
1168                 return;
1169         }
1170
1171         $profiler->logData();
1172
1173         // Check whether this should be logged in the debug file.
1174         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1175                 return;
1176         }
1177
1178         $forward = '';
1179         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1180                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1181         }
1182         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1183                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1184         }
1185         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1186                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1187         }
1188         if ( $forward ) {
1189                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1190         }
1191         // Don't load $wgUser at this late stage just for statistics purposes
1192         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1193         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1194                 $forward .= ' anon';
1195         }
1196         $log = sprintf( "%s\t%04.3f\t%s\n",
1197                 gmdate( 'YmdHis' ), $elapsed,
1198                 urldecode( $wgRequest->getRequestURL() . $forward ) );
1199
1200         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1201 }
1202
1203 /**
1204  * Check if the wiki read-only lock file is present. This can be used to lock
1205  * off editing functions, but doesn't guarantee that the database will not be
1206  * modified.
1207  *
1208  * @return bool
1209  */
1210 function wfReadOnly() {
1211         global $wgReadOnlyFile, $wgReadOnly;
1212
1213         if ( !is_null( $wgReadOnly ) ) {
1214                 return (bool)$wgReadOnly;
1215         }
1216         if ( $wgReadOnlyFile == '' ) {
1217                 return false;
1218         }
1219         // Set $wgReadOnly for faster access next time
1220         if ( is_file( $wgReadOnlyFile ) ) {
1221                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1222         } else {
1223                 $wgReadOnly = false;
1224         }
1225         return (bool)$wgReadOnly;
1226 }
1227
1228 /**
1229  * @return bool
1230  */
1231 function wfReadOnlyReason() {
1232         global $wgReadOnly;
1233         wfReadOnly();
1234         return $wgReadOnly;
1235 }
1236
1237 /**
1238  * Return a Language object from $langcode
1239  *
1240  * @param $langcode Mixed: either:
1241  *                  - a Language object
1242  *                  - code of the language to get the message for, if it is
1243  *                    a valid code create a language for that language, if
1244  *                    it is a string but not a valid code then make a basic
1245  *                    language object
1246  *                  - a boolean: if it's false then use the global object for
1247  *                    the current user's language (as a fallback for the old parameter
1248  *                    functionality), or if it is true then use global object
1249  *                    for the wiki's content language.
1250  * @return Language object
1251  */
1252 function wfGetLangObj( $langcode = false ) {
1253         # Identify which language to get or create a language object for.
1254         # Using is_object here due to Stub objects.
1255         if( is_object( $langcode ) ) {
1256                 # Great, we already have the object (hopefully)!
1257                 return $langcode;
1258         }
1259
1260         global $wgContLang, $wgLanguageCode;
1261         if( $langcode === true || $langcode === $wgLanguageCode ) {
1262                 # $langcode is the language code of the wikis content language object.
1263                 # or it is a boolean and value is true
1264                 return $wgContLang;
1265         }
1266
1267         global $wgLang;
1268         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1269                 # $langcode is the language code of user language object.
1270                 # or it was a boolean and value is false
1271                 return $wgLang;
1272         }
1273
1274         $validCodes = array_keys( Language::getLanguageNames() );
1275         if( in_array( $langcode, $validCodes ) ) {
1276                 # $langcode corresponds to a valid language.
1277                 return Language::factory( $langcode );
1278         }
1279
1280         # $langcode is a string, but not a valid language code; use content language.
1281         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1282         return $wgContLang;
1283 }
1284
1285 /**
1286  * Old function when $wgBetterDirectionality existed
1287  * All usage removed, wfUILang can be removed in near future
1288  *
1289  * @deprecated since 1.18
1290  * @return Language
1291  */
1292 function wfUILang() {
1293         wfDeprecated( __METHOD__, '1.18' );
1294         global $wgLang;
1295         return $wgLang;
1296 }
1297
1298 /**
1299  * This is the new function for getting translated interface messages.
1300  * See the Message class for documentation how to use them.
1301  * The intention is that this function replaces all old wfMsg* functions.
1302  * @param $key \string Message key.
1303  * Varargs: normal message parameters.
1304  * @return Message
1305  * @since 1.17
1306  */
1307 function wfMessage( $key /*...*/) {
1308         $params = func_get_args();
1309         array_shift( $params );
1310         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1311                 $params = $params[0];
1312         }
1313         return new Message( $key, $params );
1314 }
1315
1316 /**
1317  * This function accepts multiple message keys and returns a message instance
1318  * for the first message which is non-empty. If all messages are empty then an
1319  * instance of the first message key is returned.
1320  * @param varargs: message keys
1321  * @return Message
1322  * @since 1.18
1323  */
1324 function wfMessageFallback( /*...*/ ) {
1325         $args = func_get_args();
1326         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1327 }
1328
1329 /**
1330  * Get a message from anywhere, for the current user language.
1331  *
1332  * Use wfMsgForContent() instead if the message should NOT
1333  * change depending on the user preferences.
1334  *
1335  * @param $key String: lookup key for the message, usually
1336  *    defined in languages/Language.php
1337  *
1338  * Parameters to the message, which can be used to insert variable text into
1339  * it, can be passed to this function in the following formats:
1340  * - One per argument, starting at the second parameter
1341  * - As an array in the second parameter
1342  * These are not shown in the function definition.
1343  *
1344  * @return String
1345  */
1346 function wfMsg( $key ) {
1347         $args = func_get_args();
1348         array_shift( $args );
1349         return wfMsgReal( $key, $args );
1350 }
1351
1352 /**
1353  * Same as above except doesn't transform the message
1354  *
1355  * @param $key String
1356  * @return String
1357  */
1358 function wfMsgNoTrans( $key ) {
1359         $args = func_get_args();
1360         array_shift( $args );
1361         return wfMsgReal( $key, $args, true, false, false );
1362 }
1363
1364 /**
1365  * Get a message from anywhere, for the current global language
1366  * set with $wgLanguageCode.
1367  *
1368  * Use this if the message should NOT change dependent on the
1369  * language set in the user's preferences. This is the case for
1370  * most text written into logs, as well as link targets (such as
1371  * the name of the copyright policy page). Link titles, on the
1372  * other hand, should be shown in the UI language.
1373  *
1374  * Note that MediaWiki allows users to change the user interface
1375  * language in their preferences, but a single installation
1376  * typically only contains content in one language.
1377  *
1378  * Be wary of this distinction: If you use wfMsg() where you should
1379  * use wfMsgForContent(), a user of the software may have to
1380  * customize potentially hundreds of messages in
1381  * order to, e.g., fix a link in every possible language.
1382  *
1383  * @param $key String: lookup key for the message, usually
1384  *     defined in languages/Language.php
1385  * @return String
1386  */
1387 function wfMsgForContent( $key ) {
1388         global $wgForceUIMsgAsContentMsg;
1389         $args = func_get_args();
1390         array_shift( $args );
1391         $forcontent = true;
1392         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1393                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1394         {
1395                 $forcontent = false;
1396         }
1397         return wfMsgReal( $key, $args, true, $forcontent );
1398 }
1399
1400 /**
1401  * Same as above except doesn't transform the message
1402  *
1403  * @param $key String
1404  * @return String
1405  */
1406 function wfMsgForContentNoTrans( $key ) {
1407         global $wgForceUIMsgAsContentMsg;
1408         $args = func_get_args();
1409         array_shift( $args );
1410         $forcontent = true;
1411         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1412                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1413         {
1414                 $forcontent = false;
1415         }
1416         return wfMsgReal( $key, $args, true, $forcontent, false );
1417 }
1418
1419 /**
1420  * Really get a message
1421  *
1422  * @param $key String: key to get.
1423  * @param $args
1424  * @param $useDB Boolean
1425  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1426  * @param $transform Boolean: Whether or not to transform the message.
1427  * @return String: the requested message.
1428  */
1429 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1430         wfProfileIn( __METHOD__ );
1431         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1432         $message = wfMsgReplaceArgs( $message, $args );
1433         wfProfileOut( __METHOD__ );
1434         return $message;
1435 }
1436
1437 /**
1438  * Fetch a message string value, but don't replace any keys yet.
1439  *
1440  * @param $key String
1441  * @param $useDB Bool
1442  * @param $langCode String: Code of the language to get the message for, or
1443  *                  behaves as a content language switch if it is a boolean.
1444  * @param $transform Boolean: whether to parse magic words, etc.
1445  * @return string
1446  */
1447 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1448         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1449
1450         $cache = MessageCache::singleton();
1451         $message = $cache->get( $key, $useDB, $langCode );
1452         if( $message === false ) {
1453                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1454         } elseif ( $transform ) {
1455                 $message = $cache->transform( $message );
1456         }
1457         return $message;
1458 }
1459
1460 /**
1461  * Replace message parameter keys on the given formatted output.
1462  *
1463  * @param $message String
1464  * @param $args Array
1465  * @return string
1466  * @private
1467  */
1468 function wfMsgReplaceArgs( $message, $args ) {
1469         # Fix windows line-endings
1470         # Some messages are split with explode("\n", $msg)
1471         $message = str_replace( "\r", '', $message );
1472
1473         // Replace arguments
1474         if ( count( $args ) ) {
1475                 if ( is_array( $args[0] ) ) {
1476                         $args = array_values( $args[0] );
1477                 }
1478                 $replacementKeys = array();
1479                 foreach( $args as $n => $param ) {
1480                         $replacementKeys['$' . ( $n + 1 )] = $param;
1481                 }
1482                 $message = strtr( $message, $replacementKeys );
1483         }
1484
1485         return $message;
1486 }
1487
1488 /**
1489  * Return an HTML-escaped version of a message.
1490  * Parameter replacements, if any, are done *after* the HTML-escaping,
1491  * so parameters may contain HTML (eg links or form controls). Be sure
1492  * to pre-escape them if you really do want plaintext, or just wrap
1493  * the whole thing in htmlspecialchars().
1494  *
1495  * @param $key String
1496  * @param string ... parameters
1497  * @return string
1498  */
1499 function wfMsgHtml( $key ) {
1500         $args = func_get_args();
1501         array_shift( $args );
1502         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1503 }
1504
1505 /**
1506  * Return an HTML version of message
1507  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1508  * so parameters may contain HTML (eg links or form controls). Be sure
1509  * to pre-escape them if you really do want plaintext, or just wrap
1510  * the whole thing in htmlspecialchars().
1511  *
1512  * @param $key String
1513  * @param string ... parameters
1514  * @return string
1515  */
1516 function wfMsgWikiHtml( $key ) {
1517         $args = func_get_args();
1518         array_shift( $args );
1519         return wfMsgReplaceArgs(
1520                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1521                 /* can't be set to false */ true, /* interface */ true )->getText(),
1522                 $args );
1523 }
1524
1525 /**
1526  * Returns message in the requested format
1527  * @param $key String: key of the message
1528  * @param $options Array: processing rules. Can take the following options:
1529  *   <i>parse</i>: parses wikitext to HTML
1530  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1531  *       p's added by parser or tidy
1532  *   <i>escape</i>: filters message through htmlspecialchars
1533  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1534  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1535  *   <i>parsemag</i>: transform the message using magic phrases
1536  *   <i>content</i>: fetch message for content language instead of interface
1537  * Also can accept a single associative argument, of the form 'language' => 'xx':
1538  *   <i>language</i>: Language object or language code to fetch message for
1539  *       (overriden by <i>content</i>).
1540  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1541  *
1542  * @return String
1543  */
1544 function wfMsgExt( $key, $options ) {
1545         $args = func_get_args();
1546         array_shift( $args );
1547         array_shift( $args );
1548         $options = (array)$options;
1549
1550         foreach( $options as $arrayKey => $option ) {
1551                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1552                         # An unknown index, neither numeric nor "language"
1553                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1554                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1555                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1556                 'replaceafter', 'parsemag', 'content' ) ) ) {
1557                         # A numeric index with unknown value
1558                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1559                 }
1560         }
1561
1562         if( in_array( 'content', $options, true ) ) {
1563                 $forContent = true;
1564                 $langCode = true;
1565                 $langCodeObj = null;
1566         } elseif( array_key_exists( 'language', $options ) ) {
1567                 $forContent = false;
1568                 $langCode = wfGetLangObj( $options['language'] );
1569                 $langCodeObj = $langCode;
1570         } else {
1571                 $forContent = false;
1572                 $langCode = false;
1573                 $langCodeObj = null;
1574         }
1575
1576         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1577
1578         if( !in_array( 'replaceafter', $options, true ) ) {
1579                 $string = wfMsgReplaceArgs( $string, $args );
1580         }
1581
1582         $messageCache = MessageCache::singleton();
1583         $parseInline = in_array( 'parseinline', $options, true );
1584         if( in_array( 'parse', $options, true ) || $parseInline ) {
1585                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1586                 if ( $string instanceof ParserOutput ) {
1587                         $string = $string->getText();
1588                 }
1589
1590                 if ( $parseInline ) {
1591                         $m = array();
1592                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1593                                 $string = $m[1];
1594                         }
1595                 }
1596         } elseif ( in_array( 'parsemag', $options, true ) ) {
1597                 $string = $messageCache->transform( $string,
1598                                 !$forContent, $langCodeObj );
1599         }
1600
1601         if ( in_array( 'escape', $options, true ) ) {
1602                 $string = htmlspecialchars ( $string );
1603         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1604                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1605         }
1606
1607         if( in_array( 'replaceafter', $options, true ) ) {
1608                 $string = wfMsgReplaceArgs( $string, $args );
1609         }
1610
1611         return $string;
1612 }
1613
1614 /**
1615  * Since wfMsg() and co suck, they don't return false if the message key they
1616  * looked up didn't exist but a XHTML string, this function checks for the
1617  * nonexistance of messages by checking the MessageCache::get() result directly.
1618  *
1619  * @param $key      String: the message key looked up
1620  * @return Boolean True if the message *doesn't* exist.
1621  */
1622 function wfEmptyMsg( $key ) {
1623         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1624 }
1625
1626 /**
1627  * Throw a debugging exception. This function previously once exited the process,
1628  * but now throws an exception instead, with similar results.
1629  *
1630  * @param $msg String: message shown when dying.
1631  */
1632 function wfDebugDieBacktrace( $msg = '' ) {
1633         throw new MWException( $msg );
1634 }
1635
1636 /**
1637  * Fetch server name for use in error reporting etc.
1638  * Use real server name if available, so we know which machine
1639  * in a server farm generated the current page.
1640  *
1641  * @return string
1642  */
1643 function wfHostname() {
1644         static $host;
1645         if ( is_null( $host ) ) {
1646                 if ( function_exists( 'posix_uname' ) ) {
1647                         // This function not present on Windows
1648                         $uname = posix_uname();
1649                 } else {
1650                         $uname = false;
1651                 }
1652                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1653                         $host = $uname['nodename'];
1654                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1655                         # Windows computer name
1656                         $host = getenv( 'COMPUTERNAME' );
1657                 } else {
1658                         # This may be a virtual server.
1659                         $host = $_SERVER['SERVER_NAME'];
1660                 }
1661         }
1662         return $host;
1663 }
1664
1665 /**
1666  * Returns a HTML comment with the elapsed time since request.
1667  * This method has no side effects.
1668  *
1669  * @return string
1670  */
1671 function wfReportTime() {
1672         global $wgRequestTime, $wgShowHostnames;
1673
1674         $elapsed = microtime( true ) - $wgRequestTime;
1675
1676         return $wgShowHostnames
1677                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1678                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1679 }
1680
1681 /**
1682  * Safety wrapper for debug_backtrace().
1683  *
1684  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1685  * murky circumstances, which may be triggered in part by stub objects
1686  * or other fancy talkin'.
1687  *
1688  * Will return an empty array if Zend Optimizer is detected or if
1689  * debug_backtrace is disabled, otherwise the output from
1690  * debug_backtrace() (trimmed).
1691  *
1692  * @param $limit int This parameter can be used to limit the number of stack frames returned
1693  *
1694  * @return array of backtrace information
1695  */
1696 function wfDebugBacktrace( $limit = 0 ) {
1697         static $disabled = null;
1698
1699         if( extension_loaded( 'Zend Optimizer' ) ) {
1700                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1701                 return array();
1702         }
1703
1704         if ( is_null( $disabled ) ) {
1705                 $disabled = false;
1706                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1707                 $functions = array_map( 'trim', $functions );
1708                 $functions = array_map( 'strtolower', $functions );
1709                 if ( in_array( 'debug_backtrace', $functions ) ) {
1710                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1711                         $disabled = true;
1712                 }
1713         }
1714         if ( $disabled ) {
1715                 return array();
1716         }
1717
1718         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1719                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit ), 1 );
1720         } else {
1721                 return array_slice( debug_backtrace(), 1 );
1722         }
1723 }
1724
1725 /**
1726  * Get a debug backtrace as a string
1727  *
1728  * @return string
1729  */
1730 function wfBacktrace() {
1731         global $wgCommandLineMode;
1732
1733         if ( $wgCommandLineMode ) {
1734                 $msg = '';
1735         } else {
1736                 $msg = "<ul>\n";
1737         }
1738         $backtrace = wfDebugBacktrace();
1739         foreach( $backtrace as $call ) {
1740                 if( isset( $call['file'] ) ) {
1741                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1742                         $file = $f[count( $f ) - 1];
1743                 } else {
1744                         $file = '-';
1745                 }
1746                 if( isset( $call['line'] ) ) {
1747                         $line = $call['line'];
1748                 } else {
1749                         $line = '-';
1750                 }
1751                 if ( $wgCommandLineMode ) {
1752                         $msg .= "$file line $line calls ";
1753                 } else {
1754                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1755                 }
1756                 if( !empty( $call['class'] ) ) {
1757                         $msg .= $call['class'] . $call['type'];
1758                 }
1759                 $msg .= $call['function'] . '()';
1760
1761                 if ( $wgCommandLineMode ) {
1762                         $msg .= "\n";
1763                 } else {
1764                         $msg .= "</li>\n";
1765                 }
1766         }
1767         if ( $wgCommandLineMode ) {
1768                 $msg .= "\n";
1769         } else {
1770                 $msg .= "</ul>\n";
1771         }
1772
1773         return $msg;
1774 }
1775
1776 /**
1777  * Get the name of the function which called this function
1778  *
1779  * @param $level Int
1780  * @return Bool|string
1781  */
1782 function wfGetCaller( $level = 2 ) {
1783         $backtrace = wfDebugBacktrace( $level );
1784         if ( isset( $backtrace[$level] ) ) {
1785                 return wfFormatStackFrame( $backtrace[$level] );
1786         } else {
1787                 $caller = 'unknown';
1788         }
1789         return $caller;
1790 }
1791
1792 /**
1793  * Return a string consisting of callers in the stack. Useful sometimes
1794  * for profiling specific points.
1795  *
1796  * @param $limit int The maximum depth of the stack frame to return, or false for
1797  *               the entire stack.
1798  * @return String
1799  */
1800 function wfGetAllCallers( $limit = 3 ) {
1801         $trace = array_reverse( wfDebugBacktrace() );
1802         if ( !$limit || $limit > count( $trace ) - 1 ) {
1803                 $limit = count( $trace ) - 1;
1804         }
1805         $trace = array_slice( $trace, -$limit - 1, $limit );
1806         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1807 }
1808
1809 /**
1810  * Return a string representation of frame
1811  *
1812  * @param $frame Array
1813  * @return Bool
1814  */
1815 function wfFormatStackFrame( $frame ) {
1816         return isset( $frame['class'] ) ?
1817                 $frame['class'] . '::' . $frame['function'] :
1818                 $frame['function'];
1819 }
1820
1821
1822 /* Some generic result counters, pulled out of SearchEngine */
1823
1824
1825 /**
1826  * @todo document
1827  *
1828  * @param $offset Int
1829  * @param $limit Int
1830  * @return String
1831  */
1832 function wfShowingResults( $offset, $limit ) {
1833         global $wgLang;
1834         return wfMsgExt(
1835                 'showingresults',
1836                 array( 'parseinline' ),
1837                 $wgLang->formatNum( $limit ),
1838                 $wgLang->formatNum( $offset + 1 )
1839         );
1840 }
1841
1842 /**
1843  * Generate (prev x| next x) (20|50|100...) type links for paging
1844  *
1845  * @param $offset String
1846  * @param $limit Integer
1847  * @param $link String
1848  * @param $query String: optional URL query parameter string
1849  * @param $atend Bool: optional param for specified if this is the last page
1850  * @return String
1851  * @deprecated in 1.19; use Language::viewPrevNext() instead
1852  */
1853 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1854         wfDeprecated( __METHOD__, '1.19' );
1855
1856         global $wgLang;
1857
1858         $query = wfCgiToArray( $query );
1859
1860         if( is_object( $link ) ) {
1861                 $title = $link;
1862         } else {
1863                 $title = Title::newFromText( $link );
1864                 if( is_null( $title ) ) {
1865                         return false;
1866                 }
1867         }
1868
1869         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1870 }
1871
1872 /**
1873  * Make a list item, used by various special pages
1874  *
1875  * @param $page String Page link
1876  * @param $details String Text between brackets
1877  * @param $oppositedm Boolean   Add the direction mark opposite to your
1878  *                                                              language, to display text properly
1879  * @return String
1880  * @deprecated since 1.19; use Language::specialList() instead
1881  */
1882 function wfSpecialList( $page, $details, $oppositedm = true ) {
1883         global $wgLang;
1884         return $wgLang->specialList( $page, $details, $oppositedm );
1885 }
1886
1887 /**
1888  * @todo document
1889  * @todo FIXME: We may want to blacklist some broken browsers
1890  *
1891  * @param $force Bool
1892  * @return bool Whereas client accept gzip compression
1893  */
1894 function wfClientAcceptsGzip( $force = false ) {
1895         static $result = null;
1896         if ( $result === null || $force ) {
1897                 $result = false;
1898                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1899                         # @todo FIXME: We may want to blacklist some broken browsers
1900                         $m = array();
1901                         if( preg_match(
1902                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1903                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1904                                 $m )
1905                         )
1906                         {
1907                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1908                                         $result = false;
1909                                         return $result;
1910                                 }
1911                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1912                                 $result = true;
1913                         }
1914                 }
1915         }
1916         return $result;
1917 }
1918
1919 /**
1920  * Obtain the offset and limit values from the request string;
1921  * used in special pages
1922  *
1923  * @param $deflimit Int default limit if none supplied
1924  * @param $optionname String Name of a user preference to check against
1925  * @return array
1926  *
1927  */
1928 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1929         global $wgRequest;
1930         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1931 }
1932
1933 /**
1934  * Escapes the given text so that it may be output using addWikiText()
1935  * without any linking, formatting, etc. making its way through. This
1936  * is achieved by substituting certain characters with HTML entities.
1937  * As required by the callers, <nowiki> is not used.
1938  *
1939  * @param $text String: text to be escaped
1940  * @return String
1941  */
1942 function wfEscapeWikiText( $text ) {
1943         $text = strtr( "\n$text", array(
1944                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1945                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1946                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1947                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1948                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1949                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1950         ) );
1951         return substr( $text, 1 );
1952 }
1953
1954 /**
1955  * Get the current unix timetstamp with microseconds.  Useful for profiling
1956  * @return Float
1957  */
1958 function wfTime() {
1959         return microtime( true );
1960 }
1961
1962 /**
1963  * Sets dest to source and returns the original value of dest
1964  * If source is NULL, it just returns the value, it doesn't set the variable
1965  * If force is true, it will set the value even if source is NULL
1966  *
1967  * @param $dest Mixed
1968  * @param $source Mixed
1969  * @param $force Bool
1970  * @return Mixed
1971  */
1972 function wfSetVar( &$dest, $source, $force = false ) {
1973         $temp = $dest;
1974         if ( !is_null( $source ) || $force ) {
1975                 $dest = $source;
1976         }
1977         return $temp;
1978 }
1979
1980 /**
1981  * As for wfSetVar except setting a bit
1982  *
1983  * @param $dest Int
1984  * @param $bit Int
1985  * @param $state Bool
1986  *
1987  * @return bool
1988  */
1989 function wfSetBit( &$dest, $bit, $state = true ) {
1990         $temp = (bool)( $dest & $bit );
1991         if ( !is_null( $state ) ) {
1992                 if ( $state ) {
1993                         $dest |= $bit;
1994                 } else {
1995                         $dest &= ~$bit;
1996                 }
1997         }
1998         return $temp;
1999 }
2000
2001 /**
2002  * A wrapper around the PHP function var_export().
2003  * Either print it or add it to the regular output ($wgOut).
2004  *
2005  * @param $var mixed A PHP variable to dump.
2006  */
2007 function wfVarDump( $var ) {
2008         global $wgOut;
2009         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2010         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2011                 print $s;
2012         } else {
2013                 $wgOut->addHTML( $s );
2014         }
2015 }
2016
2017 /**
2018  * Provide a simple HTTP error.
2019  *
2020  * @param $code Int|String
2021  * @param $label String
2022  * @param $desc String
2023  */
2024 function wfHttpError( $code, $label, $desc ) {
2025         global $wgOut;
2026         $wgOut->disable();
2027         header( "HTTP/1.0 $code $label" );
2028         header( "Status: $code $label" );
2029         $wgOut->sendCacheControl();
2030
2031         header( 'Content-type: text/html; charset=utf-8' );
2032         print "<!doctype html>" .
2033                 '<html><head><title>' .
2034                 htmlspecialchars( $label ) .
2035                 '</title></head><body><h1>' .
2036                 htmlspecialchars( $label ) .
2037                 '</h1><p>' .
2038                 nl2br( htmlspecialchars( $desc ) ) .
2039                 "</p></body></html>\n";
2040 }
2041
2042 /**
2043  * Clear away any user-level output buffers, discarding contents.
2044  *
2045  * Suitable for 'starting afresh', for instance when streaming
2046  * relatively large amounts of data without buffering, or wanting to
2047  * output image files without ob_gzhandler's compression.
2048  *
2049  * The optional $resetGzipEncoding parameter controls suppression of
2050  * the Content-Encoding header sent by ob_gzhandler; by default it
2051  * is left. See comments for wfClearOutputBuffers() for why it would
2052  * be used.
2053  *
2054  * Note that some PHP configuration options may add output buffer
2055  * layers which cannot be removed; these are left in place.
2056  *
2057  * @param $resetGzipEncoding Bool
2058  */
2059 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2060         if( $resetGzipEncoding ) {
2061                 // Suppress Content-Encoding and Content-Length
2062                 // headers from 1.10+s wfOutputHandler
2063                 global $wgDisableOutputCompression;
2064                 $wgDisableOutputCompression = true;
2065         }
2066         while( $status = ob_get_status() ) {
2067                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2068                         // Probably from zlib.output_compression or other
2069                         // PHP-internal setting which can't be removed.
2070                         //
2071                         // Give up, and hope the result doesn't break
2072                         // output behavior.
2073                         break;
2074                 }
2075                 if( !ob_end_clean() ) {
2076                         // Could not remove output buffer handler; abort now
2077                         // to avoid getting in some kind of infinite loop.
2078                         break;
2079                 }
2080                 if( $resetGzipEncoding ) {
2081                         if( $status['name'] == 'ob_gzhandler' ) {
2082                                 // Reset the 'Content-Encoding' field set by this handler
2083                                 // so we can start fresh.
2084                                 if ( function_exists( 'header_remove' ) ) {
2085                                         // Available since PHP 5.3.0
2086                                         header_remove( 'Content-Encoding' );
2087                                 } else {
2088                                         // We need to provide a valid content-coding. See bug 28069
2089                                         header( 'Content-Encoding: identity' );
2090                                 }
2091                                 break;
2092                         }
2093                 }
2094         }
2095 }
2096
2097 /**
2098  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2099  *
2100  * Clear away output buffers, but keep the Content-Encoding header
2101  * produced by ob_gzhandler, if any.
2102  *
2103  * This should be used for HTTP 304 responses, where you need to
2104  * preserve the Content-Encoding header of the real result, but
2105  * also need to suppress the output of ob_gzhandler to keep to spec
2106  * and avoid breaking Firefox in rare cases where the headers and
2107  * body are broken over two packets.
2108  */
2109 function wfClearOutputBuffers() {
2110         wfResetOutputBuffers( false );
2111 }
2112
2113 /**
2114  * Converts an Accept-* header into an array mapping string values to quality
2115  * factors
2116  *
2117  * @param $accept String
2118  * @param $def String default
2119  * @return Array
2120  */
2121 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2122         # No arg means accept anything (per HTTP spec)
2123         if( !$accept ) {
2124                 return array( $def => 1.0 );
2125         }
2126
2127         $prefs = array();
2128
2129         $parts = explode( ',', $accept );
2130
2131         foreach( $parts as $part ) {
2132                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2133                 $values = explode( ';', trim( $part ) );
2134                 $match = array();
2135                 if ( count( $values ) == 1 ) {
2136                         $prefs[$values[0]] = 1.0;
2137                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2138                         $prefs[$values[0]] = floatval( $match[1] );
2139                 }
2140         }
2141
2142         return $prefs;
2143 }
2144
2145 /**
2146  * Checks if a given MIME type matches any of the keys in the given
2147  * array. Basic wildcards are accepted in the array keys.
2148  *
2149  * Returns the matching MIME type (or wildcard) if a match, otherwise
2150  * NULL if no match.
2151  *
2152  * @param $type String
2153  * @param $avail Array
2154  * @return string
2155  * @private
2156  */
2157 function mimeTypeMatch( $type, $avail ) {
2158         if( array_key_exists( $type, $avail ) ) {
2159                 return $type;
2160         } else {
2161                 $parts = explode( '/', $type );
2162                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2163                         return $parts[0] . '/*';
2164                 } elseif( array_key_exists( '*/*', $avail ) ) {
2165                         return '*/*';
2166                 } else {
2167                         return null;
2168                 }
2169         }
2170 }
2171
2172 /**
2173  * Returns the 'best' match between a client's requested internet media types
2174  * and the server's list of available types. Each list should be an associative
2175  * array of type to preference (preference is a float between 0.0 and 1.0).
2176  * Wildcards in the types are acceptable.
2177  *
2178  * @param $cprefs Array: client's acceptable type list
2179  * @param $sprefs Array: server's offered types
2180  * @return string
2181  *
2182  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2183  * XXX: generalize to negotiate other stuff
2184  */
2185 function wfNegotiateType( $cprefs, $sprefs ) {
2186         $combine = array();
2187
2188         foreach( array_keys( $sprefs ) as $type ) {
2189                 $parts = explode( '/', $type );
2190                 if( $parts[1] != '*' ) {
2191                         $ckey = mimeTypeMatch( $type, $cprefs );
2192                         if( $ckey ) {
2193                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2194                         }
2195                 }
2196         }
2197
2198         foreach( array_keys( $cprefs ) as $type ) {
2199                 $parts = explode( '/', $type );
2200                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2201                         $skey = mimeTypeMatch( $type, $sprefs );
2202                         if( $skey ) {
2203                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2204                         }
2205                 }
2206         }
2207
2208         $bestq = 0;
2209         $besttype = null;
2210
2211         foreach( array_keys( $combine ) as $type ) {
2212                 if( $combine[$type] > $bestq ) {
2213                         $besttype = $type;
2214                         $bestq = $combine[$type];
2215                 }
2216         }
2217
2218         return $besttype;
2219 }
2220
2221 /**
2222  * Reference-counted warning suppression
2223  *
2224  * @param $end Bool
2225  */
2226 function wfSuppressWarnings( $end = false ) {
2227         static $suppressCount = 0;
2228         static $originalLevel = false;
2229
2230         if ( $end ) {
2231                 if ( $suppressCount ) {
2232                         --$suppressCount;
2233                         if ( !$suppressCount ) {
2234                                 error_reporting( $originalLevel );
2235                         }
2236                 }
2237         } else {
2238                 if ( !$suppressCount ) {
2239                         // E_DEPRECATED is undefined in PHP 5.2
2240                         if( !defined( 'E_DEPRECATED' ) ) {
2241                                 define( 'E_DEPRECATED', 8192 );
2242                         }
2243                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2244                 }
2245                 ++$suppressCount;
2246         }
2247 }
2248
2249 /**
2250  * Restore error level to previous value
2251  */
2252 function wfRestoreWarnings() {
2253         wfSuppressWarnings( true );
2254 }
2255
2256 # Autodetect, convert and provide timestamps of various types
2257
2258 /**
2259  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2260  */
2261 define( 'TS_UNIX', 0 );
2262
2263 /**
2264  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2265  */
2266 define( 'TS_MW', 1 );
2267
2268 /**
2269  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2270  */
2271 define( 'TS_DB', 2 );
2272
2273 /**
2274  * RFC 2822 format, for E-mail and HTTP headers
2275  */
2276 define( 'TS_RFC2822', 3 );
2277
2278 /**
2279  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2280  *
2281  * This is used by Special:Export
2282  */
2283 define( 'TS_ISO_8601', 4 );
2284
2285 /**
2286  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2287  *
2288  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2289  *       DateTime tag and page 36 for the DateTimeOriginal and
2290  *       DateTimeDigitized tags.
2291  */
2292 define( 'TS_EXIF', 5 );
2293
2294 /**
2295  * Oracle format time.
2296  */
2297 define( 'TS_ORACLE', 6 );
2298
2299 /**
2300  * Postgres format time.
2301  */
2302 define( 'TS_POSTGRES', 7 );
2303
2304 /**
2305  * DB2 format time
2306  */
2307 define( 'TS_DB2', 8 );
2308
2309 /**
2310  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2311  */
2312 define( 'TS_ISO_8601_BASIC', 9 );
2313
2314 /**
2315  * Get a timestamp string in one of various formats
2316  *
2317  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2318  *                    function will autodetect which format is supplied and act
2319  *                    accordingly.
2320  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2321  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2322  */
2323 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2324         $uts = 0;
2325         $da = array();
2326         $strtime = '';
2327
2328         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2329                 $uts = time();
2330                 $strtime = "@$uts";
2331         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2332                 # TS_DB
2333         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2334                 # TS_EXIF
2335         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2336                 # TS_MW
2337         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2338                 # TS_UNIX
2339                 $uts = $ts;
2340                 $strtime = "@$ts"; // http://php.net/manual/en/datetime.formats.compound.php
2341         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2342                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2343                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2344                                 str_replace( '+00:00', 'UTC', $ts ) );
2345         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2346                 # TS_ISO_8601
2347         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2348                 #TS_ISO_8601_BASIC
2349         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2350                 # TS_POSTGRES
2351         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2352                 # TS_POSTGRES
2353         } elseif (preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/', $ts, $da ) ) {
2354                 # TS_DB2
2355         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2356                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2357                                                         '[ \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
2358                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2359                 # The regex is a superset of rfc2822 for readability
2360                 $strtime = strtok( $ts, ';' );
2361         } 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 ) ) {
2362                 # TS_RFC850
2363                 $strtime = $ts;
2364         } 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 ) ) {
2365                 # asctime
2366                 $strtime = $ts;
2367         } else {
2368                 # Bogus value...
2369                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2370
2371                 return false;
2372         }
2373
2374         static $formats = array(
2375                 TS_UNIX => 'U',
2376                 TS_MW => 'YmdHis',
2377                 TS_DB => 'Y-m-d H:i:s',
2378                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2379                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2380                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2381                 TS_RFC2822 => 'D, d M Y H:i:s',
2382                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2383                 TS_POSTGRES => 'Y-m-d H:i:s',
2384                 TS_DB2 => 'Y-m-d H:i:s',
2385         );
2386
2387         if ( !isset( $formats[$outputtype] ) ) {
2388                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2389         }
2390
2391         if ( function_exists( "date_create" ) ) {
2392                 if ( count( $da ) ) {
2393                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2394                                 (int)$da[1], (int)$da[2], (int)$da[3],
2395                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2396
2397                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2398                 } elseif ( $strtime ) {
2399                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2400                 } else {
2401                         return false;
2402                 }
2403
2404                 if ( !$d ) {
2405                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2406                         return false;
2407                 }
2408
2409                 $output = $d->format( $formats[$outputtype] );
2410         } else {
2411                 if ( count( $da ) ) {
2412                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2413                         // We may want to handle that explicitly at some point
2414                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2415                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2416                 } elseif ( $strtime ) {
2417                         $uts = strtotime( $strtime );
2418                 }
2419
2420                 if ( $uts === false ) {
2421                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2422                         return false;
2423                 }
2424
2425                 if ( TS_UNIX == $outputtype ) {
2426                         return $uts;
2427                 }
2428                 $output = gmdate( $formats[$outputtype], $uts );
2429         }
2430
2431         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2432                 $output .= ' GMT';
2433         }
2434
2435         return $output;
2436 }
2437
2438 /**
2439  * Return a formatted timestamp, or null if input is null.
2440  * For dealing with nullable timestamp columns in the database.
2441  *
2442  * @param $outputtype Integer
2443  * @param $ts String
2444  * @return String
2445  */
2446 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2447         if( is_null( $ts ) ) {
2448                 return null;
2449         } else {
2450                 return wfTimestamp( $outputtype, $ts );
2451         }
2452 }
2453
2454 /**
2455  * Convenience function; returns MediaWiki timestamp for the present time.
2456  *
2457  * @return string
2458  */
2459 function wfTimestampNow() {
2460         # return NOW
2461         return wfTimestamp( TS_MW, time() );
2462 }
2463
2464 /**
2465  * Check if the operating system is Windows
2466  *
2467  * @return Bool: true if it's Windows, False otherwise.
2468  */
2469 function wfIsWindows() {
2470         static $isWindows = null;
2471         if ( $isWindows === null ) {
2472                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2473         }
2474         return $isWindows;
2475 }
2476
2477 /**
2478  * Check if we are running under HipHop
2479  *
2480  * @return Bool
2481  */
2482 function wfIsHipHop() {
2483         return function_exists( 'hphp_thread_set_warmup_enabled' );
2484 }
2485
2486 /**
2487  * Swap two variables
2488  *
2489  * @param $x Mixed
2490  * @param $y Mixed
2491  */
2492 function swap( &$x, &$y ) {
2493         $z = $x;
2494         $x = $y;
2495         $y = $z;
2496 }
2497
2498 /**
2499  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2500  * TEMP environment variables are then checked in sequence, and if none are set
2501  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2502  * or C:\Windows\Temp for Windows and hope for the best.
2503  * It is common to call it with tempnam().
2504  *
2505  * NOTE: When possible, use instead the tmpfile() function to create
2506  * temporary files to avoid race conditions on file creation, etc.
2507  *
2508  * @return String
2509  */
2510 function wfTempDir() {
2511         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2512                 $tmp = getenv( $var );
2513                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2514                         return $tmp;
2515                 }
2516         }
2517         if( function_exists( 'sys_get_temp_dir' ) ) {
2518                 return sys_get_temp_dir();
2519         }
2520         # Usual defaults
2521         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2522 }
2523
2524 /**
2525  * Make directory, and make all parent directories if they don't exist
2526  *
2527  * @param $dir String: full path to directory to create
2528  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2529  * @param $caller String: optional caller param for debugging.
2530  * @return bool
2531  */
2532 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2533         global $wgDirectoryMode;
2534
2535         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2536                 throw new MWException( __FUNCTION__ . " given storage path `$dir`.");
2537         }
2538
2539         if ( !is_null( $caller ) ) {
2540                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2541         }
2542
2543         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2544                 return true;
2545         }
2546
2547         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2548
2549         if ( is_null( $mode ) ) {
2550                 $mode = $wgDirectoryMode;
2551         }
2552
2553         // Turn off the normal warning, we're doing our own below
2554         wfSuppressWarnings();
2555         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2556         wfRestoreWarnings();
2557
2558         if( !$ok ) {
2559                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2560                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2561         }
2562         return $ok;
2563 }
2564
2565 /**
2566  * Increment a statistics counter
2567  *
2568  * @param $key String
2569  * @param $count Int
2570  */
2571 function wfIncrStats( $key, $count = 1 ) {
2572         global $wgStatsMethod;
2573
2574         $count = intval( $count );
2575
2576         if( $wgStatsMethod == 'udp' ) {
2577                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2578                 static $socket;
2579
2580                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2581
2582                 if ( !$socket ) {
2583                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2584                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
2585                         socket_sendto(
2586                                 $socket,
2587                                 $statline,
2588                                 strlen( $statline ),
2589                                 0,
2590                                 $wgUDPProfilerHost,
2591                                 $wgUDPProfilerPort
2592                         );
2593                 }
2594                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2595                 wfSuppressWarnings();
2596                 socket_sendto(
2597                         $socket,
2598                         $statline,
2599                         strlen( $statline ),
2600                         0,
2601                         $wgUDPProfilerHost,
2602                         $wgUDPProfilerPort
2603                 );
2604                 wfRestoreWarnings();
2605         } elseif( $wgStatsMethod == 'cache' ) {
2606                 global $wgMemc;
2607                 $key = wfMemcKey( 'stats', $key );
2608                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2609                         $wgMemc->add( $key, $count );
2610                 }
2611         } else {
2612                 // Disabled
2613         }
2614 }
2615
2616 /**
2617  * @param $nr Mixed: the number to format
2618  * @param $acc Integer: the number of digits after the decimal point, default 2
2619  * @param $round Boolean: whether or not to round the value, default true
2620  * @return float
2621  */
2622 function wfPercent( $nr, $acc = 2, $round = true ) {
2623         $ret = sprintf( "%.${acc}f", $nr );
2624         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2625 }
2626
2627 /**
2628  * Find out whether or not a mixed variable exists in a string
2629  *
2630  * @param $needle String
2631  * @param $str String
2632  * @param $insensitive Boolean
2633  * @return Boolean
2634  */
2635 function in_string( $needle, $str, $insensitive = false ) {
2636         $func = 'strpos';
2637         if( $insensitive ) $func = 'stripos';
2638
2639         return $func( $str, $needle ) !== false;
2640 }
2641
2642 /**
2643  * Safety wrapper around ini_get() for boolean settings.
2644  * The values returned from ini_get() are pre-normalized for settings
2645  * set via php.ini or php_flag/php_admin_flag... but *not*
2646  * for those set via php_value/php_admin_value.
2647  *
2648  * It's fairly common for people to use php_value instead of php_flag,
2649  * which can leave you with an 'off' setting giving a false positive
2650  * for code that just takes the ini_get() return value as a boolean.
2651  *
2652  * To make things extra interesting, setting via php_value accepts
2653  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2654  * Unrecognized values go false... again opposite PHP's own coercion
2655  * from string to bool.
2656  *
2657  * Luckily, 'properly' set settings will always come back as '0' or '1',
2658  * so we only have to worry about them and the 'improper' settings.
2659  *
2660  * I frickin' hate PHP... :P
2661  *
2662  * @param $setting String
2663  * @return Bool
2664  */
2665 function wfIniGetBool( $setting ) {
2666         $val = ini_get( $setting );
2667         // 'on' and 'true' can't have whitespace around them, but '1' can.
2668         return strtolower( $val ) == 'on'
2669                 || strtolower( $val ) == 'true'
2670                 || strtolower( $val ) == 'yes'
2671                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2672 }
2673
2674 /**
2675  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2676  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2677  *
2678  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2679  *                          should be omitted
2680  * @param $fileName String Name of the library, if not $extension.suffix
2681  * @return Bool - Whether or not the extension is loaded
2682  */
2683 function wfDl( $extension, $fileName = null ) {
2684         if( extension_loaded( $extension ) ) {
2685                 return true;
2686         }
2687
2688         $canDl = false;
2689         $sapi = php_sapi_name();
2690         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2691                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2692         {
2693                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2694                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2695         }
2696
2697         if( $canDl ) {
2698                 $fileName = $fileName ? $fileName : $extension;
2699                 if( wfIsWindows() ) {
2700                         $fileName = 'php_' . $fileName;
2701                 }
2702                 wfSuppressWarnings();
2703                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2704                 wfRestoreWarnings();
2705         }
2706         return extension_loaded( $extension );
2707 }
2708
2709 /**
2710  * Windows-compatible version of escapeshellarg()
2711  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2712  * function puts single quotes in regardless of OS.
2713  *
2714  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2715  * earlier distro releases of PHP)
2716  *
2717  * @param varargs
2718  * @return String
2719  */
2720 function wfEscapeShellArg( ) {
2721         wfInitShellLocale();
2722
2723         $args = func_get_args();
2724         $first = true;
2725         $retVal = '';
2726         foreach ( $args as $arg ) {
2727                 if ( !$first ) {
2728                         $retVal .= ' ';
2729                 } else {
2730                         $first = false;
2731                 }
2732
2733                 if ( wfIsWindows() ) {
2734                         // Escaping for an MSVC-style command line parser and CMD.EXE
2735                         // Refs:
2736                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2737                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2738                         //  * Bug #13518
2739                         //  * CR r63214
2740                         // Double the backslashes before any double quotes. Escape the double quotes.
2741                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2742                         $arg = '';
2743                         $iteration = 0;
2744                         foreach ( $tokens as $token ) {
2745                                 if ( $iteration % 2 == 1 ) {
2746                                         // Delimiter, a double quote preceded by zero or more slashes
2747                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2748                                 } elseif ( $iteration % 4 == 2 ) {
2749                                         // ^ in $token will be outside quotes, need to be escaped
2750                                         $arg .= str_replace( '^', '^^', $token );
2751                                 } else { // $iteration % 4 == 0
2752                                         // ^ in $token will appear inside double quotes, so leave as is
2753                                         $arg .= $token;
2754                                 }
2755                                 $iteration++;
2756                         }
2757                         // Double the backslashes before the end of the string, because
2758                         // we will soon add a quote
2759                         $m = array();
2760                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2761                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2762                         }
2763
2764                         // Add surrounding quotes
2765                         $retVal .= '"' . $arg . '"';
2766                 } else {
2767                         $retVal .= escapeshellarg( $arg );
2768                 }
2769         }
2770         return $retVal;
2771 }
2772
2773 /**
2774  * Execute a shell command, with time and memory limits mirrored from the PHP
2775  * configuration if supported.
2776  * @param $cmd String Command line, properly escaped for shell.
2777  * @param &$retval null|Mixed optional, will receive the program's exit code.
2778  *                 (non-zero is usually failure)
2779  * @param $environ Array optional environment variables which should be
2780  *                 added to the executed command environment.
2781  * @return string collected stdout as a string (trailing newlines stripped)
2782  */
2783 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2784         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2785
2786         static $disabled;
2787         if ( is_null( $disabled ) ) {
2788                 $disabled = false;
2789                 if( wfIniGetBool( 'safe_mode' ) ) {
2790                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2791                         $disabled = 'safemode';
2792                 } else {
2793                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2794                         $functions = array_map( 'trim', $functions );
2795                         $functions = array_map( 'strtolower', $functions );
2796                         if ( in_array( 'passthru', $functions ) ) {
2797                                 wfDebug( "passthru is in disabled_functions\n" );
2798                                 $disabled = 'passthru';
2799                         }
2800                 }
2801         }
2802         if ( $disabled ) {
2803                 $retval = 1;
2804                 return $disabled == 'safemode' ?
2805                         'Unable to run external programs in safe mode.' :
2806                         'Unable to run external programs, passthru() is disabled.';
2807         }
2808
2809         wfInitShellLocale();
2810
2811         $envcmd = '';
2812         foreach( $environ as $k => $v ) {
2813                 if ( wfIsWindows() ) {
2814                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2815                          * appear in the environment variable, so we must use carat escaping as documented in
2816                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2817                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2818                          * are listed there but doesn't appear to need it.
2819                          */
2820                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2821                 } else {
2822                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2823                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2824                          */
2825                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2826                 }
2827         }
2828         $cmd = $envcmd . $cmd;
2829
2830         if ( wfIsWindows() ) {
2831                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2832                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2833                 {
2834                         # Hack to work around PHP's flawed invocation of cmd.exe
2835                         # http://news.php.net/php.internals/21796
2836                         # Windows 9x doesn't accept any kind of quotes
2837                         $cmd = '"' . $cmd . '"';
2838                 }
2839         } elseif ( php_uname( 's' ) == 'Linux' ) {
2840                 $time = intval( $wgMaxShellTime );
2841                 $mem = intval( $wgMaxShellMemory );
2842                 $filesize = intval( $wgMaxShellFileSize );
2843
2844                 if ( $time > 0 && $mem > 0 ) {
2845                         $script = "$IP/bin/ulimit4.sh";
2846                         if ( is_executable( $script ) ) {
2847                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2848                         }
2849                 }
2850         }
2851         wfDebug( "wfShellExec: $cmd\n" );
2852
2853         $retval = 1; // error by default?
2854         ob_start();
2855         passthru( $cmd, $retval );
2856         $output = ob_get_contents();
2857         ob_end_clean();
2858
2859         if ( $retval == 127 ) {
2860                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2861         }
2862         return $output;
2863 }
2864
2865 /**
2866  * Workaround for http://bugs.php.net/bug.php?id=45132
2867  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2868  */
2869 function wfInitShellLocale() {
2870         static $done = false;
2871         if ( $done ) {
2872                 return;
2873         }
2874         $done = true;
2875         global $wgShellLocale;
2876         if ( !wfIniGetBool( 'safe_mode' ) ) {
2877                 putenv( "LC_CTYPE=$wgShellLocale" );
2878                 setlocale( LC_CTYPE, $wgShellLocale );
2879         }
2880 }
2881
2882 /**
2883  * Generate a shell-escaped command line string to run a maintenance script.
2884  * Note that $parameters should be a flat array and an option with an argument
2885  * should consist of two consecutive items in the array (do not use "--option value").
2886  * @param $script string MediaWiki maintenance script path
2887  * @param $parameters Array Arguments and options to the script
2888  * @param $options Array Associative array of options:
2889  *              'php': The path to the php executable
2890  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2891  * @return Array
2892  */
2893 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2894         global $wgPhpCli;
2895         // Give site config file a chance to run the script in a wrapper.
2896         // The caller may likely want to call wfBasename() on $script.
2897         wfRunHooks( 'wfShellMaintenanceCmd', array( &$script, &$parameters, &$options ) );
2898         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2899         if ( isset( $options['wrapper'] ) ) {
2900                 $cmd[] = $options['wrapper'];
2901         }
2902         $cmd[] = $script;
2903         // Escape each parameter for shell
2904         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2905 }
2906
2907 /**
2908  * wfMerge attempts to merge differences between three texts.
2909  * Returns true for a clean merge and false for failure or a conflict.
2910  *
2911  * @param $old String
2912  * @param $mine String
2913  * @param $yours String
2914  * @param $result String
2915  * @return Bool
2916  */
2917 function wfMerge( $old, $mine, $yours, &$result ) {
2918         global $wgDiff3;
2919
2920         # This check may also protect against code injection in
2921         # case of broken installations.
2922         wfSuppressWarnings();
2923         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2924         wfRestoreWarnings();
2925
2926         if( !$haveDiff3 ) {
2927                 wfDebug( "diff3 not found\n" );
2928                 return false;
2929         }
2930
2931         # Make temporary files
2932         $td = wfTempDir();
2933         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2934         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2935         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2936
2937         fwrite( $oldtextFile, $old );
2938         fclose( $oldtextFile );
2939         fwrite( $mytextFile, $mine );
2940         fclose( $mytextFile );
2941         fwrite( $yourtextFile, $yours );
2942         fclose( $yourtextFile );
2943
2944         # Check for a conflict
2945         $cmd = $wgDiff3 . ' -a --overlap-only ' .
2946                 wfEscapeShellArg( $mytextName ) . ' ' .
2947                 wfEscapeShellArg( $oldtextName ) . ' ' .
2948                 wfEscapeShellArg( $yourtextName );
2949         $handle = popen( $cmd, 'r' );
2950
2951         if( fgets( $handle, 1024 ) ) {
2952                 $conflict = true;
2953         } else {
2954                 $conflict = false;
2955         }
2956         pclose( $handle );
2957
2958         # Merge differences
2959         $cmd = $wgDiff3 . ' -a -e --merge ' .
2960                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2961         $handle = popen( $cmd, 'r' );
2962         $result = '';
2963         do {
2964                 $data = fread( $handle, 8192 );
2965                 if ( strlen( $data ) == 0 ) {
2966                         break;
2967                 }
2968                 $result .= $data;
2969         } while ( true );
2970         pclose( $handle );
2971         unlink( $mytextName );
2972         unlink( $oldtextName );
2973         unlink( $yourtextName );
2974
2975         if ( $result === '' && $old !== '' && !$conflict ) {
2976                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2977                 $conflict = true;
2978         }
2979         return !$conflict;
2980 }
2981
2982 /**
2983  * Returns unified plain-text diff of two texts.
2984  * Useful for machine processing of diffs.
2985  *
2986  * @param $before String: the text before the changes.
2987  * @param $after String: the text after the changes.
2988  * @param $params String: command-line options for the diff command.
2989  * @return String: unified diff of $before and $after
2990  */
2991 function wfDiff( $before, $after, $params = '-u' ) {
2992         if ( $before == $after ) {
2993                 return '';
2994         }
2995
2996         global $wgDiff;
2997         wfSuppressWarnings();
2998         $haveDiff = $wgDiff && file_exists( $wgDiff );
2999         wfRestoreWarnings();
3000
3001         # This check may also protect against code injection in
3002         # case of broken installations.
3003         if( !$haveDiff ) {
3004                 wfDebug( "diff executable not found\n" );
3005                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3006                 $format = new UnifiedDiffFormatter();
3007                 return $format->format( $diffs );
3008         }
3009
3010         # Make temporary files
3011         $td = wfTempDir();
3012         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3013         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3014
3015         fwrite( $oldtextFile, $before );
3016         fclose( $oldtextFile );
3017         fwrite( $newtextFile, $after );
3018         fclose( $newtextFile );
3019
3020         // Get the diff of the two files
3021         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3022
3023         $h = popen( $cmd, 'r' );
3024
3025         $diff = '';
3026
3027         do {
3028                 $data = fread( $h, 8192 );
3029                 if ( strlen( $data ) == 0 ) {
3030                         break;
3031                 }
3032                 $diff .= $data;
3033         } while ( true );
3034
3035         // Clean up
3036         pclose( $h );
3037         unlink( $oldtextName );
3038         unlink( $newtextName );
3039
3040         // Kill the --- and +++ lines. They're not useful.
3041         $diff_lines = explode( "\n", $diff );
3042         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3043                 unset( $diff_lines[0] );
3044         }
3045         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3046                 unset( $diff_lines[1] );
3047         }
3048
3049         $diff = implode( "\n", $diff_lines );
3050
3051         return $diff;
3052 }
3053
3054 /**
3055  * This function works like "use VERSION" in Perl, the program will die with a
3056  * backtrace if the current version of PHP is less than the version provided
3057  *
3058  * This is useful for extensions which due to their nature are not kept in sync
3059  * with releases, and might depend on other versions of PHP than the main code
3060  *
3061  * Note: PHP might die due to parsing errors in some cases before it ever
3062  *       manages to call this function, such is life
3063  *
3064  * @see perldoc -f use
3065  *
3066  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3067  *                 a float
3068  */
3069 function wfUsePHP( $req_ver ) {
3070         $php_ver = PHP_VERSION;
3071
3072         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3073                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3074         }
3075 }
3076
3077 /**
3078  * This function works like "use VERSION" in Perl except it checks the version
3079  * of MediaWiki, the program will die with a backtrace if the current version
3080  * of MediaWiki is less than the version provided.
3081  *
3082  * This is useful for extensions which due to their nature are not kept in sync
3083  * with releases
3084  *
3085  * @see perldoc -f use
3086  *
3087  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3088  *                 a float
3089  */
3090 function wfUseMW( $req_ver ) {
3091         global $wgVersion;
3092
3093         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3094                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3095         }
3096 }
3097
3098 /**
3099  * Return the final portion of a pathname.
3100  * Reimplemented because PHP5's basename() is buggy with multibyte text.
3101  * http://bugs.php.net/bug.php?id=33898
3102  *
3103  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3104  * We'll consider it so always, as we don't want \s in our Unix paths either.
3105  *
3106  * @param $path String
3107  * @param $suffix String: to remove if present
3108  * @return String
3109  */
3110 function wfBaseName( $path, $suffix = '' ) {
3111         $encSuffix = ( $suffix == '' )
3112                 ? ''
3113                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3114         $matches = array();
3115         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3116                 return $matches[1];
3117         } else {
3118                 return '';
3119         }
3120 }
3121
3122 /**
3123  * Generate a relative path name to the given file.
3124  * May explode on non-matching case-insensitive paths,
3125  * funky symlinks, etc.
3126  *
3127  * @param $path String: absolute destination path including target filename
3128  * @param $from String: Absolute source path, directory only
3129  * @return String
3130  */
3131 function wfRelativePath( $path, $from ) {
3132         // Normalize mixed input on Windows...
3133         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3134         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3135
3136         // Trim trailing slashes -- fix for drive root
3137         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3138         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3139
3140         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3141         $against = explode( DIRECTORY_SEPARATOR, $from );
3142
3143         if( $pieces[0] !== $against[0] ) {
3144                 // Non-matching Windows drive letters?
3145                 // Return a full path.
3146                 return $path;
3147         }
3148
3149         // Trim off common prefix
3150         while( count( $pieces ) && count( $against )
3151                 && $pieces[0] == $against[0] ) {
3152                 array_shift( $pieces );
3153                 array_shift( $against );
3154         }
3155
3156         // relative dots to bump us to the parent
3157         while( count( $against ) ) {
3158                 array_unshift( $pieces, '..' );
3159                 array_shift( $against );
3160         }
3161
3162         array_push( $pieces, wfBaseName( $path ) );
3163
3164         return implode( DIRECTORY_SEPARATOR, $pieces );
3165 }
3166
3167 /**
3168  * Do any deferred updates and clear the list
3169  *
3170  * @deprecated since 1.19
3171  * @see DeferredUpdates::doUpdate()
3172  * @param $commit string
3173  */
3174 function wfDoUpdates( $commit = '' ) {
3175         wfDeprecated( __METHOD__, '1.19' );
3176         DeferredUpdates::doUpdates( $commit );
3177 }
3178
3179 /**
3180  * Convert an arbitrarily-long digit string from one numeric base
3181  * to another, optionally zero-padding to a minimum column width.
3182  *
3183  * Supports base 2 through 36; digit values 10-36 are represented
3184  * as lowercase letters a-z. Input is case-insensitive.
3185  *
3186  * @param $input String: of digits
3187  * @param $sourceBase Integer: 2-36
3188  * @param $destBase Integer: 2-36
3189  * @param $pad Integer: 1 or greater
3190  * @param $lowercase Boolean
3191  * @return String or false on invalid input
3192  */
3193 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3194         $input = strval( $input );
3195         if( $sourceBase < 2 ||
3196                 $sourceBase > 36 ||
3197                 $destBase < 2 ||
3198                 $destBase > 36 ||
3199                 $pad < 1 ||
3200                 $sourceBase != intval( $sourceBase ) ||
3201                 $destBase != intval( $destBase ) ||
3202                 $pad != intval( $pad ) ||
3203                 !is_string( $input ) ||
3204                 $input == '' ) {
3205                 return false;
3206         }
3207         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3208         $inDigits = array();
3209         $outChars = '';
3210
3211         // Decode and validate input string
3212         $input = strtolower( $input );
3213         for( $i = 0; $i < strlen( $input ); $i++ ) {
3214                 $n = strpos( $digitChars, $input[$i] );
3215                 if( $n === false || $n > $sourceBase ) {
3216                         return false;
3217                 }
3218                 $inDigits[] = $n;
3219         }
3220
3221         // Iterate over the input, modulo-ing out an output digit
3222         // at a time until input is gone.
3223         while( count( $inDigits ) ) {
3224                 $work = 0;
3225                 $workDigits = array();
3226
3227                 // Long division...
3228                 foreach( $inDigits as $digit ) {
3229                         $work *= $sourceBase;
3230                         $work += $digit;
3231
3232                         if( $work < $destBase ) {
3233                                 // Gonna need to pull another digit.
3234                                 if( count( $workDigits ) ) {
3235                                         // Avoid zero-padding; this lets us find
3236                                         // the end of the input very easily when
3237                                         // length drops to zero.
3238                                         $workDigits[] = 0;
3239                                 }
3240                         } else {
3241                                 // Finally! Actual division!
3242                                 $workDigits[] = intval( $work / $destBase );
3243
3244                                 // Isn't it annoying that most programming languages
3245                                 // don't have a single divide-and-remainder operator,
3246                                 // even though the CPU implements it that way?
3247                                 $work = $work % $destBase;
3248                         }
3249                 }
3250
3251                 // All that division leaves us with a remainder,
3252                 // which is conveniently our next output digit.
3253                 $outChars .= $digitChars[$work];
3254
3255                 // And we continue!
3256                 $inDigits = $workDigits;
3257         }
3258
3259         while( strlen( $outChars ) < $pad ) {
3260                 $outChars .= '0';
3261         }
3262
3263         return strrev( $outChars );
3264 }
3265
3266 /**
3267  * Create an object with a given name and an array of construct parameters
3268  *
3269  * @param $name String
3270  * @param $p Array: parameters
3271  * @return object
3272  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3273  */
3274 function wfCreateObject( $name, $p ) {
3275         wfDeprecated( __FUNCTION__, '1.18' );
3276         return MWFunction::newObj( $name, $p );
3277 }
3278
3279 /**
3280  * @return bool
3281  */
3282 function wfHttpOnlySafe() {
3283         global $wgHttpOnlyBlacklist;
3284
3285         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3286                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3287                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3288                                 return false;
3289                         }
3290                 }
3291         }
3292
3293         return true;
3294 }
3295
3296 /**
3297  * Initialise php session
3298  *
3299  * @param $sessionId Bool
3300  */
3301 function wfSetupSession( $sessionId = false ) {
3302         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3303                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3304         if( $wgSessionsInMemcached ) {
3305                 if ( !defined( 'MW_COMPILED' ) ) {
3306                         global $IP;
3307                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
3308                 }
3309                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3310                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3311
3312                 // It's necessary to register a shutdown function to call session_write_close(),
3313                 // because by the time the request shutdown function for the session module is
3314                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3315                 // this way are called before object destruction.
3316                 register_shutdown_function( 'memsess_write_close' );
3317         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3318                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3319                 # hasn't already been set to the desired value (that causes errors)
3320                 ini_set( 'session.save_handler', $wgSessionHandler );
3321         }
3322         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3323         wfDebugLog( 'cookie',
3324                 'session_set_cookie_params: "' . implode( '", "',
3325                         array(
3326                                 0,
3327                                 $wgCookiePath,
3328                                 $wgCookieDomain,
3329                                 $wgCookieSecure,
3330                                 $httpOnlySafe ) ) . '"' );
3331         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3332         session_cache_limiter( 'private, must-revalidate' );
3333         if ( $sessionId ) {
3334                 session_id( $sessionId );
3335         }
3336         wfSuppressWarnings();
3337         session_start();
3338         wfRestoreWarnings();
3339 }
3340
3341 /**
3342  * Get an object from the precompiled serialized directory
3343  *
3344  * @param $name String
3345  * @return Mixed: the variable on success, false on failure
3346  */
3347 function wfGetPrecompiledData( $name ) {
3348         global $IP;
3349
3350         $file = "$IP/serialized/$name";
3351         if ( file_exists( $file ) ) {
3352                 $blob = file_get_contents( $file );
3353                 if ( $blob ) {
3354                         return unserialize( $blob );
3355                 }
3356         }
3357         return false;
3358 }
3359
3360 /**
3361  * Get a cache key
3362  *
3363  * @param varargs
3364  * @return String
3365  */
3366 function wfMemcKey( /*... */ ) {
3367         global $wgCachePrefix;
3368         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3369         $args = func_get_args();
3370         $key = $prefix . ':' . implode( ':', $args );
3371         $key = str_replace( ' ', '_', $key );
3372         return $key;
3373 }
3374
3375 /**
3376  * Get a cache key for a foreign DB
3377  *
3378  * @param $db String
3379  * @param $prefix String
3380  * @param varargs String
3381  * @return String
3382  */
3383 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3384         $args = array_slice( func_get_args(), 2 );
3385         if ( $prefix ) {
3386                 $key = "$db-$prefix:" . implode( ':', $args );
3387         } else {
3388                 $key = $db . ':' . implode( ':', $args );
3389         }
3390         return $key;
3391 }
3392
3393 /**
3394  * Get an ASCII string identifying this wiki
3395  * This is used as a prefix in memcached keys
3396  *
3397  * @return String
3398  */
3399 function wfWikiID() {
3400         global $wgDBprefix, $wgDBname;
3401         if ( $wgDBprefix ) {
3402                 return "$wgDBname-$wgDBprefix";
3403         } else {
3404                 return $wgDBname;
3405         }
3406 }
3407
3408 /**
3409  * Split a wiki ID into DB name and table prefix
3410  *
3411  * @param $wiki String
3412  *
3413  * @return array
3414  */
3415 function wfSplitWikiID( $wiki ) {
3416         $bits = explode( '-', $wiki, 2 );
3417         if ( count( $bits ) < 2 ) {
3418                 $bits[] = '';
3419         }
3420         return $bits;
3421 }
3422
3423 /**
3424  * Get a Database object.
3425  *
3426  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3427  *            master (for write queries), DB_SLAVE for potentially lagged read
3428  *            queries, or an integer >= 0 for a particular server.
3429  *
3430  * @param $groups Mixed: query groups. An array of group names that this query
3431  *                belongs to. May contain a single string if the query is only
3432  *                in one group.
3433  *
3434  * @param $wiki String: the wiki ID, or false for the current wiki
3435  *
3436  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3437  * will always return the same object, unless the underlying connection or load
3438  * balancer is manually destroyed.
3439  *
3440  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3441  * updater to ensure that a proper database is being updated.
3442  *
3443  * @return DatabaseBase
3444  */
3445 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3446         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3447 }
3448
3449 /**
3450  * Get a load balancer object.
3451  *
3452  * @param $wiki String: wiki ID, or false for the current wiki
3453  * @return LoadBalancer
3454  */
3455 function wfGetLB( $wiki = false ) {
3456         return wfGetLBFactory()->getMainLB( $wiki );
3457 }
3458
3459 /**
3460  * Get the load balancer factory object
3461  *
3462  * @return LBFactory
3463  */
3464 function &wfGetLBFactory() {
3465         return LBFactory::singleton();
3466 }
3467
3468 /**
3469  * Find a file.
3470  * Shortcut for RepoGroup::singleton()->findFile()
3471  *
3472  * @param $title String or Title object
3473  * @param $options array Associative array of options:
3474  *     time:           requested time for an archived image, or false for the
3475  *                     current version. An image object will be returned which was
3476  *                     created at the specified time.
3477  *
3478  *     ignoreRedirect: If true, do not follow file redirects
3479  *
3480  *     private:        If true, return restricted (deleted) files if the current
3481  *                     user is allowed to view them. Otherwise, such files will not
3482  *                     be found.
3483  *
3484  *     bypassCache:    If true, do not use the process-local cache of File objects
3485  *
3486  * @return File, or false if the file does not exist
3487  */
3488 function wfFindFile( $title, $options = array() ) {
3489         return RepoGroup::singleton()->findFile( $title, $options );
3490 }
3491
3492 /**
3493  * Get an object referring to a locally registered file.
3494  * Returns a valid placeholder object if the file does not exist.
3495  *
3496  * @param $title Title|String
3497  * @return File|null A File, or null if passed an invalid Title
3498  */
3499 function wfLocalFile( $title ) {
3500         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3501 }
3502
3503 /**
3504  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3505  * @deprecated since 1.19
3506  */
3507 function wfStreamFile( $fname, $headers = array() ) {
3508         wfDeprecated( __FUNCTION__, '1.19' );
3509         StreamFile::stream( $fname, $headers );
3510 }
3511
3512 /**
3513  * Should low-performance queries be disabled?
3514  *
3515  * @return Boolean
3516  * @codeCoverageIgnore
3517  */
3518 function wfQueriesMustScale() {
3519         global $wgMiserMode;
3520         return $wgMiserMode
3521                 || ( SiteStats::pages() > 100000
3522                 && SiteStats::edits() > 1000000
3523                 && SiteStats::users() > 10000 );
3524 }
3525
3526 /**
3527  * Get the path to a specified script file, respecting file
3528  * extensions; this is a wrapper around $wgScriptExtension etc.
3529  *
3530  * @param $script String: script filename, sans extension
3531  * @return String
3532  */
3533 function wfScript( $script = 'index' ) {
3534         global $wgScriptPath, $wgScriptExtension;
3535         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3536 }
3537
3538 /**
3539  * Get the script URL.
3540  *
3541  * @return string script URL
3542  */
3543 function wfGetScriptUrl() {
3544         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3545                 #
3546                 # as it was called, minus the query string.
3547                 #
3548                 # Some sites use Apache rewrite rules to handle subdomains,
3549                 # and have PHP set up in a weird way that causes PHP_SELF
3550                 # to contain the rewritten URL instead of the one that the
3551                 # outside world sees.
3552                 #
3553                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3554                 # provides containing the "before" URL.
3555                 return $_SERVER['SCRIPT_NAME'];
3556         } else {
3557                 return $_SERVER['URL'];
3558         }
3559 }
3560
3561 /**
3562  * Convenience function converts boolean values into "true"
3563  * or "false" (string) values
3564  *
3565  * @param $value Boolean
3566  * @return String
3567  */
3568 function wfBoolToStr( $value ) {
3569         return $value ? 'true' : 'false';
3570 }
3571
3572 /**
3573  * Load an extension messages file
3574  *
3575  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3576  * @codeCoverageIgnore
3577  */
3578 function wfLoadExtensionMessages() {
3579         wfDeprecated( __FUNCTION__, '1.16' );
3580 }
3581
3582 /**
3583  * Get a platform-independent path to the null file, e.g. /dev/null
3584  *
3585  * @return string
3586  */
3587 function wfGetNull() {
3588         return wfIsWindows()
3589                 ? 'NUL'
3590                 : '/dev/null';
3591 }
3592
3593 /**
3594  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3595  * and waiting for it to go down, this waits for the slaves to catch up to the
3596  * master position. Use this when updating very large numbers of rows, as
3597  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3598  * a no-op if there are no slaves.
3599  *
3600  * @param $maxLag Integer (deprecated)
3601  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3602  */
3603 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3604         $lb = wfGetLB( $wiki );
3605         // bug 27975 - Don't try to wait for slaves if there are none
3606         // Prevents permission error when getting master position
3607         if ( $lb->getServerCount() > 1 ) {
3608                 $dbw = $lb->getConnection( DB_MASTER );
3609                 $pos = $dbw->getMasterPos();
3610                 $lb->waitForAll( $pos );
3611         }
3612 }
3613
3614 /**
3615  * Used to be used for outputting text in the installer/updater
3616  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3617  */
3618 function wfOut( $s ) {
3619         wfDeprecated( __FUNCTION__, '1.18' );
3620         global $wgCommandLineMode;
3621         if ( $wgCommandLineMode ) {
3622                 echo $s;
3623         } else {
3624                 echo htmlspecialchars( $s );
3625         }
3626         flush();
3627 }
3628
3629 /**
3630  * Count down from $n to zero on the terminal, with a one-second pause
3631  * between showing each number. For use in command-line scripts.
3632  * @codeCoverageIgnore
3633  * @param $n int
3634  */
3635 function wfCountDown( $n ) {
3636         for ( $i = $n; $i >= 0; $i-- ) {
3637                 if ( $i != $n ) {
3638                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3639                 }
3640                 echo $i;
3641                 flush();
3642                 if ( $i ) {
3643                         sleep( 1 );
3644                 }
3645         }
3646         echo "\n";
3647 }
3648
3649 /**
3650  * Generate a random 32-character hexadecimal token.
3651  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3652  *              characters before hashing.
3653  * @return string
3654  * @codeCoverageIgnore
3655  */
3656 function wfGenerateToken( $salt = '' ) {
3657         $salt = serialize( $salt );
3658         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3659 }
3660
3661 /**
3662  * Replace all invalid characters with -
3663  *
3664  * @param $name Mixed: filename to process
3665  * @return String
3666  */
3667 function wfStripIllegalFilenameChars( $name ) {
3668         global $wgIllegalFileChars;
3669         $name = wfBaseName( $name );
3670         $name = preg_replace(
3671                 "/[^" . Title::legalChars() . "]" .
3672                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3673                         "/",
3674                 '-',
3675                 $name
3676         );
3677         return $name;
3678 }
3679
3680 /**
3681  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3682  *
3683  * @return Integer value memory was set to.
3684  */
3685 function wfMemoryLimit() {
3686         global $wgMemoryLimit;
3687         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3688         if( $memlimit != -1 ) {
3689                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3690                 if( $conflimit == -1 ) {
3691                         wfDebug( "Removing PHP's memory limit\n" );
3692                         wfSuppressWarnings();
3693                         ini_set( 'memory_limit', $conflimit );
3694                         wfRestoreWarnings();
3695                         return $conflimit;
3696                 } elseif ( $conflimit > $memlimit ) {
3697                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3698                         wfSuppressWarnings();
3699                         ini_set( 'memory_limit', $conflimit );
3700                         wfRestoreWarnings();
3701                         return $conflimit;
3702                 }
3703         }
3704         return $memlimit;
3705 }
3706
3707 /**
3708  * Converts shorthand byte notation to integer form
3709  *
3710  * @param $string String
3711  * @return Integer
3712  */
3713 function wfShorthandToInteger( $string = '' ) {
3714         $string = trim( $string );
3715         if( $string === '' ) {
3716                 return -1;
3717         }
3718         $last = $string[strlen( $string ) - 1];
3719         $val = intval( $string );
3720         switch( $last ) {
3721                 case 'g':
3722                 case 'G':
3723                         $val *= 1024;
3724                         // break intentionally missing
3725                 case 'm':
3726                 case 'M':
3727                         $val *= 1024;
3728                         // break intentionally missing
3729                 case 'k':
3730                 case 'K':
3731                         $val *= 1024;
3732         }
3733
3734         return $val;
3735 }
3736
3737 /**
3738  * Get the normalised IETF language tag
3739  * See unit test for examples.
3740  *
3741  * @param $code String: The language code.
3742  * @return String: The language code which complying with BCP 47 standards.
3743  */
3744 function wfBCP47( $code ) {
3745         $codeSegment = explode( '-', $code );
3746         $codeBCP = array();
3747         foreach ( $codeSegment as $segNo => $seg ) {
3748                 if ( count( $codeSegment ) > 0 ) {
3749                         // when previous segment is x, it is a private segment and should be lc
3750                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3751                                 $codeBCP[$segNo] = strtolower( $seg );
3752                         // ISO 3166 country code
3753                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3754                                 $codeBCP[$segNo] = strtoupper( $seg );
3755                         // ISO 15924 script code
3756                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3757                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3758                         // Use lowercase for other cases
3759                         } else {
3760                                 $codeBCP[$segNo] = strtolower( $seg );
3761                         }
3762                 } else {
3763                 // Use lowercase for single segment
3764                         $codeBCP[$segNo] = strtolower( $seg );
3765                 }
3766         }
3767         $langCode = implode( '-', $codeBCP );
3768         return $langCode;
3769 }
3770
3771 /**
3772  * Get a cache object.
3773  *
3774  * @param $inputType integer Cache type, one the the CACHE_* constants.
3775  * @return BagOStuff
3776  */
3777 function wfGetCache( $inputType ) {
3778         return ObjectCache::getInstance( $inputType );
3779 }
3780
3781 /**
3782  * Get the main cache object
3783  *
3784  * @return BagOStuff
3785  */
3786 function wfGetMainCache() {
3787         global $wgMainCacheType;
3788         return ObjectCache::getInstance( $wgMainCacheType );
3789 }
3790
3791 /**
3792  * Get the cache object used by the message cache
3793  *
3794  * @return BagOStuff
3795  */
3796 function wfGetMessageCacheStorage() {
3797         global $wgMessageCacheType;
3798         return ObjectCache::getInstance( $wgMessageCacheType );
3799 }
3800
3801 /**
3802  * Get the cache object used by the parser cache
3803  *
3804  * @return BagOStuff
3805  */
3806 function wfGetParserCacheStorage() {
3807         global $wgParserCacheType;
3808         return ObjectCache::getInstance( $wgParserCacheType );
3809 }
3810
3811 /**
3812  * Call hook functions defined in $wgHooks
3813  *
3814  * @param $event String: event name
3815  * @param $args Array: parameters passed to hook functions
3816  * @return Boolean True if no handler aborted the hook
3817  */
3818 function wfRunHooks( $event, $args = array() ) {
3819         return Hooks::run( $event, $args );
3820 }
3821
3822 /**
3823  * Wrapper around php's unpack.
3824  *
3825  * @param $format String: The format string (See php's docs)
3826  * @param $data: A binary string of binary data
3827  * @param $length integer or false: The minimun length of $data. This is to
3828  *      prevent reading beyond the end of $data. false to disable the check.
3829  *
3830  * Also be careful when using this function to read unsigned 32 bit integer
3831  * because php might make it negative.
3832  *
3833  * @throws MWException if $data not long enough, or if unpack fails
3834  * @return array Associative array of the extracted data
3835  */
3836 function wfUnpack( $format, $data, $length=false ) {
3837         if ( $length !== false ) {
3838                 $realLen = strlen( $data );
3839                 if ( $realLen < $length ) {
3840                         throw new MWException( "Tried to use wfUnpack on a "
3841                                 . "string of length $realLen, but needed one "
3842                                 . "of at least length $length."
3843                         );
3844                 }
3845         }
3846
3847         wfSuppressWarnings();
3848         $result = unpack( $format, $data );
3849         wfRestoreWarnings();
3850
3851         if ( $result === false ) {
3852                 // If it cannot extract the packed data.
3853                 throw new MWException( "unpack could not unpack binary data" );
3854         }
3855         return $result;
3856 }