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         /** @codeCoverageIgnore */
  24         function iconv( $from, $to, $string ) {
  25                 return Fallback::iconv( $from, $to, $string );
  26         }
  27 }
  28
  29 if ( !function_exists( 'mb_substr' ) ) {
  30         /** @codeCoverageIgnore */
  31         function mb_substr( $str, $start, $count='end' ) {
  32                 return Fallback::mb_substr( $str, $start, $count );
  33         }
  34
  35         /** @codeCoverageIgnore */
  36         function mb_substr_split_unicode( $str, $splitPos ) {
  37                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  38         }
  39 }
  40
  41 if ( !function_exists( 'mb_strlen' ) ) {
  42         /** @codeCoverageIgnore */
  43         function mb_strlen( $str, $enc = '' ) {
  44                 return Fallback::mb_strlen( $str, $enc );
  45         }
  46 }
  47
  48 if( !function_exists( 'mb_strpos' ) ) {
  49         /** @codeCoverageIgnore */
  50         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  51                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  52         }
  53
  54 }
  55
  56 if( !function_exists( 'mb_strrpos' ) ) {
  57         /** @codeCoverageIgnore */
  58         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  59                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  60         }
  61 }
  62
  63
  64 // Support for Wietse Venema's taint feature
  65 if ( !function_exists( 'istainted' ) ) {
  66         /** @codeCoverageIgnore */
  67         function istainted( $var ) {
  68                 return 0;
  69         }
  70         /** @codeCoverageIgnore */
  71         function taint( $var, $level = 0 ) {}
  72         /** @codeCoverageIgnore */
  73         function untaint( $var, $level = 0 ) {}
  74         define( 'TC_HTML', 1 );
  75         define( 'TC_SHELL', 1 );
  76         define( 'TC_MYSQL', 1 );
  77         define( 'TC_PCRE', 1 );
  78         define( 'TC_SELF', 1 );
  79 }
  80 /// @endcond
  81
  82 /**
  83  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
  84  * @param $a array
  85  * @param $b array
  86  * @return array
  87  */
  88 function wfArrayDiff2( $a, $b ) {
  89         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
  90 }
  91
  92 /**
  93  * @param $a
  94  * @param $b
  95  * @return int
  96  */
  97 function wfArrayDiff2_cmp( $a, $b ) {
  98         if ( !is_array( $a ) ) {
  99                 return strcmp( $a, $b );
 100         } elseif ( count( $a ) !== count( $b ) ) {
 101                 return count( $a ) < count( $b ) ? -1 : 1;
 102         } else {
 103                 reset( $a );
 104                 reset( $b );
 105                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 106                         $cmp = strcmp( $valueA, $valueB );
 107                         if ( $cmp !== 0 ) {
 108                                 return $cmp;
 109                         }
 110                 }
 111                 return 0;
 112         }
 113 }
 114
 115 /**
 116  * Array lookup
 117  * Returns an array where the values in the first array are replaced by the
 118  * values in the second array with the corresponding keys
 119  *
 120  * @param $a Array
 121  * @param $b Array
 122  * @return array
 123  */
 124 function wfArrayLookup( $a, $b ) {
 125         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 126 }
 127
 128 /**
 129  * Appends to second array if $value differs from that in $default
 130  *
 131  * @param $key String|Int
 132  * @param $value Mixed
 133  * @param $default Mixed
 134  * @param $changed Array to alter
 135  */
 136 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 137         if ( is_null( $changed ) ) {
 138                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 139         }
 140         if ( $default[$key] !== $value ) {
 141                 $changed[$key] = $value;
 142         }
 143 }
 144
 145 /**
 146  * Backwards array plus for people who haven't bothered to read the PHP manual
 147  * XXX: will not darn your socks for you.
 148  *
 149  * @param $array1 Array
 150  * @param [$array2, [...]] Arrays
 151  * @return Array
 152  */
 153 function wfArrayMerge( $array1/* ... */ ) {
 154         $args = func_get_args();
 155         $args = array_reverse( $args, true );
 156         $out = array();
 157         foreach ( $args as $arg ) {
 158                 $out += $arg;
 159         }
 160         return $out;
 161 }
 162
 163 /**
 164  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 165  * e.g.
 166  *      wfMergeErrorArrays(
 167  *              array( array( 'x' ) ),
 168  *              array( array( 'x', '2' ) ),
 169  *              array( array( 'x' ) ),
 170  *              array( array( 'y' ) )
 171  *      );
 172  * returns:
 173  *              array(
 174  *              array( 'x', '2' ),
 175  *              array( 'x' ),
 176  *              array( 'y' )
 177  *      )
 178  * @param varargs
 179  * @return Array
 180  */
 181 function wfMergeErrorArrays( /*...*/ ) {
 182         $args = func_get_args();
 183         $out = array();
 184         foreach ( $args as $errors ) {
 185                 foreach ( $errors as $params ) {
 186                         # @todo FIXME: Sometimes get nested arrays for $params,
 187                         # which leads to E_NOTICEs
 188                         $spec = implode( "\t", $params );
 189                         $out[$spec] = $params;
 190                 }
 191         }
 192         return array_values( $out );
 193 }
 194
 195 /**
 196  * Insert array into another array after the specified *KEY*
 197  *
 198  * @param $array Array: The array.
 199  * @param $insert Array: The array to insert.
 200  * @param $after Mixed: The key to insert after
 201  * @return Array
 202  */
 203 function wfArrayInsertAfter( $array, $insert, $after ) {
 204         // Find the offset of the element to insert after.
 205         $keys = array_keys( $array );
 206         $offsetByKey = array_flip( $keys );
 207
 208         $offset = $offsetByKey[$after];
 209
 210         // Insert at the specified offset
 211         $before = array_slice( $array, 0, $offset + 1, true );
 212         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 213
 214         $output = $before + $insert + $after;
 215
 216         return $output;
 217 }
 218
 219 /**
 220  * Recursively converts the parameter (an object) to an array with the same data
 221  *
 222  * @param $objOrArray Object|Array
 223  * @param $recursive Bool
 224  * @return Array
 225  */
 226 function wfObjectToArray( $objOrArray, $recursive = true ) {
 227         $array = array();
 228         if( is_object( $objOrArray ) ) {
 229                 $objOrArray = get_object_vars( $objOrArray );
 230         }
 231         foreach ( $objOrArray as $key => $value ) {
 232                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 233                         $value = wfObjectToArray( $value );
 234                 }
 235
 236                 $array[$key] = $value;
 237         }
 238
 239         return $array;
 240 }
 241
 242 /**
 243  * Wrapper around array_map() which also taints variables
 244  *
 245  * @param  $function Callback
 246  * @param  $input Array
 247  * @return Array
 248  */
 249 function wfArrayMap( $function, $input ) {
 250         $ret = array_map( $function, $input );
 251         foreach ( $ret as $key => $value ) {
 252                 $taint = istainted( $input[$key] );
 253                 if ( $taint ) {
 254                         taint( $ret[$key], $taint );
 255                 }
 256         }
 257         return $ret;
 258 }
 259
 260 /**
 261  * Get a random decimal value between 0 and 1, in a way
 262  * not likely to give duplicate values for any realistic
 263  * number of articles.
 264  *
 265  * @return string
 266  */
 267 function wfRandom() {
 268         # The maximum random value is "only" 2^31-1, so get two random
 269         # values to reduce the chance of dupes
 270         $max = mt_getrandmax() + 1;
 271         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 272                 / $max / $max, 12, '.', '' );
 273         return $rand;
 274 }
 275
 276 /**
 277  * We want some things to be included as literal characters in our title URLs
 278  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 279  * all of the following should be safe:
 280  *
 281  * ;:@&=$-_.+!*'(),
 282  *
 283  * But + is not safe because it's used to indicate a space; &= are only safe in
 284  * paths and not in queries (and we don't distinguish here); ' seems kind of
 285  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 286  * is reserved, we don't care.  So the list we unescape is:
 287  *
 288  * ;:@$!*(),/
 289  *
 290  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 291  * so no fancy : for IIS7.
 292  *
 293  * %2F in the page titles seems to fatally break for some reason.
 294  *
 295  * @param $s String:
 296  * @return string
 297 */
 298 function wfUrlencode( $s ) {
 299         static $needle;
 300         if ( is_null( $s ) ) {
 301                 $needle = null;
 302                 return '';
 303         }
 304
 305         if ( is_null( $needle ) ) {
 306                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 307                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 308                         $needle[] = '%3A';
 309                 }
 310         }
 311
 312         $s = urlencode( $s );
 313         $s = str_ireplace(
 314                 $needle,
 315                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 316                 $s
 317         );
 318
 319         return $s;
 320 }
 321
 322 /**
 323  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 324  * "days=7&limit=100". Options in the first array override options in the second.
 325  * Options set to null or false will not be output.
 326  *
 327  * @param $array1 Array ( String|Array )
 328  * @param $array2 Array ( String|Array )
 329  * @param $prefix String
 330  * @return String
 331  */
 332 function wfArrayToCGI( $array1, $array2 = null, $prefix = '' ) {
 333         if ( !is_null( $array2 ) ) {
 334                 $array1 = $array1 + $array2;
 335         }
 336
 337         $cgi = '';
 338         foreach ( $array1 as $key => $value ) {
 339                 if ( !is_null($value) && $value !== false ) {
 340                         if ( $cgi != '' ) {
 341                                 $cgi .= '&';
 342                         }
 343                         if ( $prefix !== '' ) {
 344                                 $key = $prefix . "[$key]";
 345                         }
 346                         if ( is_array( $value ) ) {
 347                                 $firstTime = true;
 348                                 foreach ( $value as $k => $v ) {
 349                                         $cgi .= $firstTime ? '' : '&';
 350                                         if ( is_array( $v ) ) {
 351                                                 $cgi .= wfArrayToCGI( $v, null, $key . "[$k]" );
 352                                         } else {
 353                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 354                                         }
 355                                         $firstTime = false;
 356                                 }
 357                         } else {
 358                                 if ( is_object( $value ) ) {
 359                                         $value = $value->__toString();
 360                                 }
 361                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 362                         }
 363                 }
 364         }
 365         return $cgi;
 366 }
 367
 368 /**
 369  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
 370  * its argument and returns the same string in array form.  This allows compa-
 371  * tibility with legacy functions that accept raw query strings instead of nice
 372  * arrays.  Of course, keys and values are urldecode()d.
 373  *
 374  * @param $query String: query string
 375  * @return array Array version of input
 376  */
 377 function wfCgiToArray( $query ) {
 378         if ( isset( $query[0] ) && $query[0] == '?' ) {
 379                 $query = substr( $query, 1 );
 380         }
 381         $bits = explode( '&', $query );
 382         $ret = array();
 383         foreach ( $bits as $bit ) {
 384                 if ( $bit === '' ) {
 385                         continue;
 386                 }
 387                 if ( strpos( $bit, '=' ) === false ) {
 388                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 389                         $key = $bit;
 390                         $value = '';
 391                 } else {
 392                         list( $key, $value ) = explode( '=', $bit );
 393                 }
 394                 $key = urldecode( $key );
 395                 $value = urldecode( $value );
 396                 if ( strpos( $key, '[' ) !== false ) {
 397                         $keys = array_reverse( explode( '[', $key ) );
 398                         $key = array_pop( $keys );
 399                         $temp = $value;
 400                         foreach ( $keys as $k ) {
 401                                 $k = substr( $k, 0, -1 );
 402                                 $temp = array( $k => $temp );
 403                         }
 404                         if ( isset( $ret[$key] ) ) {
 405                                 $ret[$key] = array_merge( $ret[$key], $temp );
 406                         } else {
 407                                 $ret[$key] = $temp;
 408                         }
 409                 } else {
 410                         $ret[$key] = $value;
 411                 }
 412         }
 413         return $ret;
 414 }
 415
 416 /**
 417  * Append a query string to an existing URL, which may or may not already
 418  * have query string parameters already. If so, they will be combined.
 419  *
 420  * @param $url String
 421  * @param $query Mixed: string or associative array
 422  * @return string
 423  */
 424 function wfAppendQuery( $url, $query ) {
 425         if ( is_array( $query ) ) {
 426                 $query = wfArrayToCGI( $query );
 427         }
 428         if( $query != '' ) {
 429                 if( false === strpos( $url, '?' ) ) {
 430                         $url .= '?';
 431                 } else {
 432                         $url .= '&';
 433                 }
 434                 $url .= $query;
 435         }
 436         return $url;
 437 }
 438
 439 /**
 440  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 441  * is correct.
 442  *
 443  * The meaning of the PROTO_* constants is as follows:
 444  * PROTO_HTTP: Output a URL starting with http://
 445  * PROTO_HTTPS: Output a URL starting with https://
 446  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 447  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 448  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 449  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 450  *
 451  * @todo this won't work with current-path-relative URLs
 452  * like "subdir/foo.html", etc.
 453  *
 454  * @param $url String: either fully-qualified or a local path + query
 455  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 456  *                             protocol to use if $url or $wgServer is
 457  *                             protocol-relative
 458  * @return string Fully-qualified URL, current-path-relative URL or false if
 459  *                no valid URL can be constructed
 460  */
 461 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 462         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 463         $serverUrl = $wgServer;
 464         if ( $defaultProto === PROTO_CANONICAL ) {
 465                 $serverUrl = $wgCanonicalServer;
 466         }
 467         // Make $wgInternalServer fall back to $wgServer if not set
 468         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 469                 $serverUrl = $wgInternalServer;
 470         }
 471         if ( $defaultProto === PROTO_CURRENT ) {
 472                 $defaultProto = WebRequest::detectProtocol() . '://';
 473         }
 474
 475         // Analyze $serverUrl to obtain its protocol
 476         $bits = wfParseUrl( $serverUrl );
 477         $serverHasProto = $bits && $bits['scheme'] != '';
 478
 479         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 480                 if ( $serverHasProto ) {
 481                         $defaultProto = $bits['scheme'] . '://';
 482                 } else {
 483                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 484                         // Fall back to HTTP in this ridiculous case
 485                         $defaultProto = PROTO_HTTP;
 486                 }
 487         }
 488
 489         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 490
 491         if ( substr( $url, 0, 2 ) == '//' ) {
 492                 $url = $defaultProtoWithoutSlashes . $url;
 493         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 494                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 495                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 496         }
 497
 498         $bits = wfParseUrl( $url );
 499         if ( $bits && isset( $bits['path'] ) ) {
 500                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 501                 return wfAssembleUrl( $bits );
 502         } elseif ( $bits ) {
 503                 # No path to expand
 504                 return $url;
 505         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 506                 # URL is a relative path
 507                 return wfRemoveDotSegments( $url );
 508         }
 509
 510         # Expanded URL is not valid.
 511         return false;
 512 }
 513
 514 /**
 515  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 516  * if you need to edit part of a URL and put it back together.
 517  *
 518  * This is the basic structure used (brackets contain keys for $urlParts):
 519  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 520  *
 521  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 522  *
 523  * @param $urlParts Array URL parts, as output from wfParseUrl
 524  * @return string URL assembled from its component parts
 525  */
 526 function wfAssembleUrl( $urlParts ) {
 527         $result = '';
 528
 529         if ( isset( $urlParts['delimiter'] ) ) {
 530                 if ( isset( $urlParts['scheme'] ) ) {
 531                         $result .= $urlParts['scheme'];
 532                 }
 533
 534                 $result .= $urlParts['delimiter'];
 535         }
 536
 537         if ( isset( $urlParts['host'] ) ) {
 538                 if ( isset( $urlParts['user'] ) ) {
 539                         $result .= $urlParts['user'];
 540                         if ( isset( $urlParts['pass'] ) ) {
 541                                 $result .= ':' . $urlParts['pass'];
 542                         }
 543                         $result .= '@';
 544                 }
 545
 546                 $result .= $urlParts['host'];
 547
 548                 if ( isset( $urlParts['port'] ) ) {
 549                         $result .= ':' . $urlParts['port'];
 550                 }
 551         }
 552
 553         if ( isset( $urlParts['path'] ) ) {
 554                 $result .= $urlParts['path'];
 555         }
 556
 557         if ( isset( $urlParts['query'] ) ) {
 558                 $result .= '?' . $urlParts['query'];
 559         }
 560
 561         if ( isset( $urlParts['fragment'] ) ) {
 562                 $result .= '#' . $urlParts['fragment'];
 563         }
 564
 565         return $result;
 566 }
 567
 568 /**
 569  * Remove all dot-segments in the provided URL path.  For example,
 570  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 571  * RFC3986 section 5.2.4.
 572  *
 573  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 574  *
 575  * @param $urlPath String URL path, potentially containing dot-segments
 576  * @return string URL path with all dot-segments removed
 577  */
 578 function wfRemoveDotSegments( $urlPath ) {
 579         $output = '';
 580         $inputOffset = 0;
 581         $inputLength = strlen( $urlPath );
 582
 583         while ( $inputOffset < $inputLength ) {
 584                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 585                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 586                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 587                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 588                 $trimOutput = false;
 589
 590                 if ( $prefixLengthTwo == './' ) {
 591                         # Step A, remove leading "./"
 592                         $inputOffset += 2;
 593                 } elseif ( $prefixLengthThree == '../' ) {
 594                         # Step A, remove leading "../"
 595                         $inputOffset += 3;
 596                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 597                         # Step B, replace leading "/.$" with "/"
 598                         $inputOffset += 1;
 599                         $urlPath[$inputOffset] = '/';
 600                 } elseif ( $prefixLengthThree == '/./' ) {
 601                         # Step B, replace leading "/./" with "/"
 602                         $inputOffset += 2;
 603                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 604                         # Step C, replace leading "/..$" with "/" and
 605                         # remove last path component in output
 606                         $inputOffset += 2;
 607                         $urlPath[$inputOffset] = '/';
 608                         $trimOutput = true;
 609                 } elseif ( $prefixLengthFour == '/../' ) {
 610                         # Step C, replace leading "/../" with "/" and
 611                         # remove last path component in output
 612                         $inputOffset += 3;
 613                         $trimOutput = true;
 614                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 615                         # Step D, remove "^.$"
 616                         $inputOffset += 1;
 617                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 618                         # Step D, remove "^..$"
 619                         $inputOffset += 2;
 620                 } else {
 621                         # Step E, move leading path segment to output
 622                         if ( $prefixLengthOne == '/' ) {
 623                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 624                         } else {
 625                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 626                         }
 627                         if ( $slashPos === false ) {
 628                                 $output .= substr( $urlPath, $inputOffset );
 629                                 $inputOffset = $inputLength;
 630                         } else {
 631                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 632                                 $inputOffset += $slashPos - $inputOffset;
 633                         }
 634                 }
 635
 636                 if ( $trimOutput ) {
 637                         $slashPos = strrpos( $output, '/' );
 638                         if ( $slashPos === false ) {
 639                                 $output = '';
 640                         } else {
 641                                 $output = substr( $output, 0, $slashPos );
 642                         }
 643                 }
 644         }
 645
 646         return $output;
 647 }
 648
 649 /**
 650  * Returns a regular expression of url protocols
 651  *
 652  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 653  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 654  * @return String
 655  */
 656 function wfUrlProtocols( $includeProtocolRelative = true ) {
 657         global $wgUrlProtocols;
 658
 659         // Cache return values separately based on $includeProtocolRelative
 660         static $withProtRel = null, $withoutProtRel = null;
 661         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 662         if ( !is_null( $cachedValue ) ) {
 663                 return $cachedValue;
 664         }
 665
 666         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 667         // with LocalSettings files from 1.5
 668         if ( is_array( $wgUrlProtocols ) ) {
 669                 $protocols = array();
 670                 foreach ( $wgUrlProtocols as $protocol ) {
 671                         // Filter out '//' if !$includeProtocolRelative
 672                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 673                                 $protocols[] = preg_quote( $protocol, '/' );
 674                         }
 675                 }
 676
 677                 $retval = implode( '|', $protocols );
 678         } else {
 679                 // Ignore $includeProtocolRelative in this case
 680                 // This case exists for pre-1.6 compatibility, and we can safely assume
 681                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 682                 // URLs weren't supported until 1.18
 683                 $retval = $wgUrlProtocols;
 684         }
 685
 686         // Cache return value
 687         if ( $includeProtocolRelative ) {
 688                 $withProtRel = $retval;
 689         } else {
 690                 $withoutProtRel = $retval;
 691         }
 692         return $retval;
 693 }
 694
 695 /**
 696  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 697  * you need a regex that matches all URL protocols but does not match protocol-
 698  * relative URLs
 699  * @return String
 700  */
 701 function wfUrlProtocolsWithoutProtRel() {
 702         return wfUrlProtocols( false );
 703 }
 704
 705 /**
 706  * parse_url() work-alike, but non-broken.  Differences:
 707  *
 708  * 1) Does not raise warnings on bad URLs (just returns false)
 709  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 710  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 711  *
 712  * @param $url String: a URL to parse
 713  * @return Array: bits of the URL in an associative array, per PHP docs
 714  */
 715 function wfParseUrl( $url ) {
 716         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 717
 718         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 719         // way to handle them is to just prepend 'http:' and strip the protocol out later
 720         $wasRelative = substr( $url, 0, 2 ) == '//';
 721         if ( $wasRelative ) {
 722                 $url = "http:$url";
 723         }
 724         wfSuppressWarnings();
 725         $bits = parse_url( $url );
 726         wfRestoreWarnings();
 727         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 728         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 729         if ( !$bits || !isset( $bits['scheme'] ) ) {
 730                 return false;
 731         }
 732
 733         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 734         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 735                 $bits['delimiter'] = '://';
 736         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 737                 $bits['delimiter'] = ':';
 738                 // parse_url detects for news: and mailto: the host part of an url as path
 739                 // We have to correct this wrong detection
 740                 if ( isset( $bits['path'] ) ) {
 741                         $bits['host'] = $bits['path'];
 742                         $bits['path'] = '';
 743                 }
 744         } else {
 745                 return false;
 746         }
 747
 748         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 749         if ( !isset( $bits['host'] ) ) {
 750                 $bits['host'] = '';
 751
 752                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 753                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 754                         $bits['path'] = '/' . $bits['path'];
 755                 }
 756         }
 757
 758         // If the URL was protocol-relative, fix scheme and delimiter
 759         if ( $wasRelative ) {
 760                 $bits['scheme'] = '';
 761                 $bits['delimiter'] = '//';
 762         }
 763         return $bits;
 764 }
 765
 766 /**
 767  * Make URL indexes, appropriate for the el_index field of externallinks.
 768  *
 769  * @param $url String
 770  * @return array
 771  */
 772 function wfMakeUrlIndexes( $url ) {
 773         $bits = wfParseUrl( $url );
 774
 775         // Reverse the labels in the hostname, convert to lower case
 776         // For emails reverse domainpart only
 777         if ( $bits['scheme'] == 'mailto' ) {
 778                 $mailparts = explode( '@', $bits['host'], 2 );
 779                 if ( count( $mailparts ) === 2 ) {
 780                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 781                 } else {
 782                         // No domain specified, don't mangle it
 783                         $domainpart = '';
 784                 }
 785                 $reversedHost = $domainpart . '@' . $mailparts[0];
 786         } else {
 787                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 788         }
 789         // Add an extra dot to the end
 790         // Why? Is it in wrong place in mailto links?
 791         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 792                 $reversedHost .= '.';
 793         }
 794         // Reconstruct the pseudo-URL
 795         $prot = $bits['scheme'];
 796         $index = $prot . $bits['delimiter'] . $reversedHost;
 797         // Leave out user and password. Add the port, path, query and fragment
 798         if ( isset( $bits['port'] ) ) {
 799                 $index .= ':' . $bits['port'];
 800         }
 801         if ( isset( $bits['path'] ) ) {
 802                 $index .= $bits['path'];
 803         } else {
 804                 $index .= '/';
 805         }
 806         if ( isset( $bits['query'] ) ) {
 807                 $index .= '?' . $bits['query'];
 808         }
 809         if ( isset( $bits['fragment'] ) ) {
 810                 $index .= '#' . $bits['fragment'];
 811         }
 812
 813         if ( $prot == '' ) {
 814                 return array( "http:$index", "https:$index" );
 815         } else {
 816                 return array( $index );
 817         }
 818 }
 819
 820 /**
 821  * Check whether a given URL has a domain that occurs in a given set of domains
 822  * @param $url string URL
 823  * @param $domains array Array of domains (strings)
 824  * @return bool True if the host part of $url ends in one of the strings in $domains
 825  */
 826 function wfMatchesDomainList( $url, $domains ) {
 827         $bits = wfParseUrl( $url );
 828         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 829                 foreach ( (array)$domains as $domain ) {
 830                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 831                         // We should use something that interprets dots instead
 832                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 833                                 return true;
 834                         }
 835                 }
 836         }
 837         return false;
 838 }
 839
 840 /**
 841  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 842  * In normal operation this is a NOP.
 843  *
 844  * Controlling globals:
 845  * $wgDebugLogFile - points to the log file
 846  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 847  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 848  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 849  *
 850  * @param $text String
 851  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 852  */
 853 function wfDebug( $text, $logonly = false ) {
 854         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 855         global $wgDebugLogPrefix, $wgShowDebug;
 856
 857         static $cache = array(); // Cache of unoutputted messages
 858         $text = wfDebugTimer() . $text;
 859
 860         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 861                 return;
 862         }
 863
 864         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 865                 $cache[] = $text;
 866
 867                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 868                         // add the message and any cached messages to the output
 869                         array_map( array( $wgOut, 'debug' ), $cache );
 870                         $cache = array();
 871                 }
 872         }
 873         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 874                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 875                         # Strip unprintables; they can switch terminal modes when binary data
 876                         # gets dumped, which is pretty annoying.
 877                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 878                         $text = $wgDebugLogPrefix . $text;
 879                         wfErrorLog( $text, $wgDebugLogFile );
 880                 }
 881         }
 882
 883         MWDebug::debugMsg( $text );
 884 }
 885
 886 /**
 887  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 888  */
 889 function wfIsDebugRawPage() {
 890         static $cache;
 891         if ( $cache !== null ) {
 892                 return $cache;
 893         }
 894         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 895         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 896                 || (
 897                         isset( $_SERVER['SCRIPT_NAME'] )
 898                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 899                 ) )
 900         {
 901                 $cache = true;
 902         } else {
 903                 $cache = false;
 904         }
 905         return $cache;
 906 }
 907
 908 /**
 909  * Get microsecond timestamps for debug logs
 910  *
 911  * @return string
 912  */
 913 function wfDebugTimer() {
 914         global $wgDebugTimestamps;
 915         if ( !$wgDebugTimestamps ) {
 916                 return '';
 917         }
 918         static $start = null;
 919
 920         if ( $start === null ) {
 921                 $start = microtime( true );
 922                 $prefix = "\n$start";
 923         } else {
 924                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 925         }
 926         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / (1024*1024) ) );
 927         return "$prefix $mem  " ;
 928 }
 929
 930 /**
 931  * Send a line giving PHP memory usage.
 932  *
 933  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 934  */
 935 function wfDebugMem( $exact = false ) {
 936         $mem = memory_get_usage();
 937         if( !$exact ) {
 938                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 939         } else {
 940                 $mem .= ' bytes';
 941         }
 942         wfDebug( "Memory usage: $mem\n" );
 943 }
 944
 945 /**
 946  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 947  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 948  *
 949  * @param $logGroup String
 950  * @param $text String
 951  * @param $public Bool: whether to log the event in the public log if no private
 952  *                     log file is specified, (default true)
 953  */
 954 function wfDebugLog( $logGroup, $text, $public = true ) {
 955         global $wgDebugLogGroups, $wgShowHostnames;
 956         $text = trim( $text ) . "\n";
 957         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 958                 $time = wfTimestamp( TS_DB );
 959                 $wiki = wfWikiID();
 960                 if ( $wgShowHostnames ) {
 961                         $host = wfHostname();
 962                 } else {
 963                         $host = '';
 964                 }
 965                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 966                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 967                 }
 968         } elseif ( $public === true ) {
 969                 wfDebug( $text, true );
 970         }
 971 }
 972
 973 /**
 974  * Log for database errors
 975  *
 976  * @param $text String: database error message.
 977  */
 978 function wfLogDBError( $text ) {
 979         global $wgDBerrorLog, $wgDBname;
 980         if ( $wgDBerrorLog ) {
 981                 $host = trim(`hostname`);
 982                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 983                 wfErrorLog( $text, $wgDBerrorLog );
 984         }
 985 }
 986
 987 /**
 988  * Log to a file without getting "file size exceeded" signals.
 989  *
 990  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 991  * send lines to the specified port, prefixed by the specified prefix and a space.
 992  *
 993  * @param $text String
 994  * @param $file String filename
 995  */
 996 function wfErrorLog( $text, $file ) {
 997         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 998                 # Needs the sockets extension
 999                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1000                         // IPv6 bracketed host
1001                         $host = $m[2];
1002                         $port = intval( $m[3] );
1003                         $prefix = isset( $m[4] ) ? $m[4] : false;
1004                         $domain = AF_INET6;
1005                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1006                         $host = $m[2];
1007                         if ( !IP::isIPv4( $host ) ) {
1008                                 $host = gethostbyname( $host );
1009                         }
1010                         $port = intval( $m[3] );
1011                         $prefix = isset( $m[4] ) ? $m[4] : false;
1012                         $domain = AF_INET;
1013                 } else {
1014                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1015                 }
1016
1017                 // Clean it up for the multiplexer
1018                 if ( strval( $prefix ) !== '' ) {
1019                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1020
1021                         // Limit to 64KB
1022                         if ( strlen( $text ) > 65506 ) {
1023                                 $text = substr( $text, 0, 65506 );
1024                         }
1025
1026                         if ( substr( $text, -1 ) != "\n" ) {
1027                                 $text .= "\n";
1028                         }
1029                 } elseif ( strlen( $text ) > 65507 ) {
1030                         $text = substr( $text, 0, 65507 );
1031                 }
1032
1033                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1034                 if ( !$sock ) {
1035                         return;
1036                 }
1037
1038                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1039                 socket_close( $sock );
1040         } else {
1041                 wfSuppressWarnings();
1042                 $exists = file_exists( $file );
1043                 $size = $exists ? filesize( $file ) : false;
1044                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1045                         file_put_contents( $file, $text, FILE_APPEND );
1046                 }
1047                 wfRestoreWarnings();
1048         }
1049 }
1050
1051 /**
1052  * @todo document
1053  */
1054 function wfLogProfilingData() {
1055         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1056         global $wgProfileLimit, $wgUser;
1057
1058         $profiler = Profiler::instance();
1059
1060         # Profiling must actually be enabled...
1061         if ( $profiler->isStub() ) {
1062                 return;
1063         }
1064
1065         // Get total page request time and only show pages that longer than
1066         // $wgProfileLimit time (default is 0)
1067         $now = wfTime();
1068         $elapsed = $now - $wgRequestTime;
1069         if ( $elapsed <= $wgProfileLimit ) {
1070                 return;
1071         }
1072
1073         $profiler->logData();
1074
1075         // Check whether this should be logged in the debug file.
1076         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1077                 return;
1078         }
1079
1080         $forward = '';
1081         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1082                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1083         }
1084         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1085                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1086         }
1087         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1088                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1089         }
1090         if ( $forward ) {
1091                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1092         }
1093         // Don't load $wgUser at this late stage just for statistics purposes
1094         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1095         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1096                 $forward .= ' anon';
1097         }
1098         $log = sprintf( "%s\t%04.3f\t%s\n",
1099                 gmdate( 'YmdHis' ), $elapsed,
1100                 urldecode( $wgRequest->getRequestURL() . $forward ) );
1101
1102         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1103 }
1104
1105 /**
1106  * Check if the wiki read-only lock file is present. This can be used to lock
1107  * off editing functions, but doesn't guarantee that the database will not be
1108  * modified.
1109  *
1110  * @return bool
1111  */
1112 function wfReadOnly() {
1113         global $wgReadOnlyFile, $wgReadOnly;
1114
1115         if ( !is_null( $wgReadOnly ) ) {
1116                 return (bool)$wgReadOnly;
1117         }
1118         if ( $wgReadOnlyFile == '' ) {
1119                 return false;
1120         }
1121         // Set $wgReadOnly for faster access next time
1122         if ( is_file( $wgReadOnlyFile ) ) {
1123                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1124         } else {
1125                 $wgReadOnly = false;
1126         }
1127         return (bool)$wgReadOnly;
1128 }
1129
1130 /**
1131  * @return bool
1132  */
1133 function wfReadOnlyReason() {
1134         global $wgReadOnly;
1135         wfReadOnly();
1136         return $wgReadOnly;
1137 }
1138
1139 /**
1140  * Return a Language object from $langcode
1141  *
1142  * @param $langcode Mixed: either:
1143  *                  - a Language object
1144  *                  - code of the language to get the message for, if it is
1145  *                    a valid code create a language for that language, if
1146  *                    it is a string but not a valid code then make a basic
1147  *                    language object
1148  *                  - a boolean: if it's false then use the global object for
1149  *                    the current user's language (as a fallback for the old parameter
1150  *                    functionality), or if it is true then use global object
1151  *                    for the wiki's content language.
1152  * @return Language object
1153  */
1154 function wfGetLangObj( $langcode = false ) {
1155         # Identify which language to get or create a language object for.
1156         # Using is_object here due to Stub objects.
1157         if( is_object( $langcode ) ) {
1158                 # Great, we already have the object (hopefully)!
1159                 return $langcode;
1160         }
1161
1162         global $wgContLang, $wgLanguageCode;
1163         if( $langcode === true || $langcode === $wgLanguageCode ) {
1164                 # $langcode is the language code of the wikis content language object.
1165                 # or it is a boolean and value is true
1166                 return $wgContLang;
1167         }
1168
1169         global $wgLang;
1170         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1171                 # $langcode is the language code of user language object.
1172                 # or it was a boolean and value is false
1173                 return $wgLang;
1174         }
1175
1176         $validCodes = array_keys( Language::getLanguageNames() );
1177         if( in_array( $langcode, $validCodes ) ) {
1178                 # $langcode corresponds to a valid language.
1179                 return Language::factory( $langcode );
1180         }
1181
1182         # $langcode is a string, but not a valid language code; use content language.
1183         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1184         return $wgContLang;
1185 }
1186
1187 /**
1188  * Old function when $wgBetterDirectionality existed
1189  * Removed in core, kept in extensions for backwards compat.
1190  *
1191  * @deprecated since 1.18
1192  * @return Language
1193  */
1194 function wfUILang() {
1195         wfDeprecated( __METHOD__, '1.18' );
1196         global $wgLang;
1197         return $wgLang;
1198 }
1199
1200 /**
1201  * This is the new function for getting translated interface messages.
1202  * See the Message class for documentation how to use them.
1203  * The intention is that this function replaces all old wfMsg* functions.
1204  * @param $key \string Message key.
1205  * Varargs: normal message parameters.
1206  * @return Message
1207  * @since 1.17
1208  */
1209 function wfMessage( $key /*...*/) {
1210         $params = func_get_args();
1211         array_shift( $params );
1212         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1213                 $params = $params[0];
1214         }
1215         return new Message( $key, $params );
1216 }
1217
1218 /**
1219  * This function accepts multiple message keys and returns a message instance
1220  * for the first message which is non-empty. If all messages are empty then an
1221  * instance of the first message key is returned.
1222  * @param varargs: message keys
1223  * @return Message
1224  * @since 1.18
1225  */
1226 function wfMessageFallback( /*...*/ ) {
1227         $args = func_get_args();
1228         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1229 }
1230
1231 /**
1232  * Get a message from anywhere, for the current user language.
1233  *
1234  * Use wfMsgForContent() instead if the message should NOT
1235  * change depending on the user preferences.
1236  *
1237  * @param $key String: lookup key for the message, usually
1238  *    defined in languages/Language.php
1239  *
1240  * Parameters to the message, which can be used to insert variable text into
1241  * it, can be passed to this function in the following formats:
1242  * - One per argument, starting at the second parameter
1243  * - As an array in the second parameter
1244  * These are not shown in the function definition.
1245  *
1246  * @return String
1247  */
1248 function wfMsg( $key ) {
1249         $args = func_get_args();
1250         array_shift( $args );
1251         return wfMsgReal( $key, $args );
1252 }
1253
1254 /**
1255  * Same as above except doesn't transform the message
1256  *
1257  * @param $key String
1258  * @return String
1259  */
1260 function wfMsgNoTrans( $key ) {
1261         $args = func_get_args();
1262         array_shift( $args );
1263         return wfMsgReal( $key, $args, true, false, false );
1264 }
1265
1266 /**
1267  * Get a message from anywhere, for the current global language
1268  * set with $wgLanguageCode.
1269  *
1270  * Use this if the message should NOT change dependent on the
1271  * language set in the user's preferences. This is the case for
1272  * most text written into logs, as well as link targets (such as
1273  * the name of the copyright policy page). Link titles, on the
1274  * other hand, should be shown in the UI language.
1275  *
1276  * Note that MediaWiki allows users to change the user interface
1277  * language in their preferences, but a single installation
1278  * typically only contains content in one language.
1279  *
1280  * Be wary of this distinction: If you use wfMsg() where you should
1281  * use wfMsgForContent(), a user of the software may have to
1282  * customize potentially hundreds of messages in
1283  * order to, e.g., fix a link in every possible language.
1284  *
1285  * @param $key String: lookup key for the message, usually
1286  *     defined in languages/Language.php
1287  * @return String
1288  */
1289 function wfMsgForContent( $key ) {
1290         global $wgForceUIMsgAsContentMsg;
1291         $args = func_get_args();
1292         array_shift( $args );
1293         $forcontent = true;
1294         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1295                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1296         {
1297                 $forcontent = false;
1298         }
1299         return wfMsgReal( $key, $args, true, $forcontent );
1300 }
1301
1302 /**
1303  * Same as above except doesn't transform the message
1304  *
1305  * @param $key String
1306  * @return String
1307  */
1308 function wfMsgForContentNoTrans( $key ) {
1309         global $wgForceUIMsgAsContentMsg;
1310         $args = func_get_args();
1311         array_shift( $args );
1312         $forcontent = true;
1313         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1314                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1315         {
1316                 $forcontent = false;
1317         }
1318         return wfMsgReal( $key, $args, true, $forcontent, false );
1319 }
1320
1321 /**
1322  * Really get a message
1323  *
1324  * @param $key String: key to get.
1325  * @param $args
1326  * @param $useDB Boolean
1327  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1328  * @param $transform Boolean: Whether or not to transform the message.
1329  * @return String: the requested message.
1330  */
1331 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1332         wfProfileIn( __METHOD__ );
1333         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1334         $message = wfMsgReplaceArgs( $message, $args );
1335         wfProfileOut( __METHOD__ );
1336         return $message;
1337 }
1338
1339 /**
1340  * Fetch a message string value, but don't replace any keys yet.
1341  *
1342  * @param $key String
1343  * @param $useDB Bool
1344  * @param $langCode String: Code of the language to get the message for, or
1345  *                  behaves as a content language switch if it is a boolean.
1346  * @param $transform Boolean: whether to parse magic words, etc.
1347  * @return string
1348  */
1349 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1350         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1351
1352         $cache = MessageCache::singleton();
1353         $message = $cache->get( $key, $useDB, $langCode );
1354         if( $message === false ) {
1355                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1356         } elseif ( $transform ) {
1357                 $message = $cache->transform( $message );
1358         }
1359         return $message;
1360 }
1361
1362 /**
1363  * Replace message parameter keys on the given formatted output.
1364  *
1365  * @param $message String
1366  * @param $args Array
1367  * @return string
1368  * @private
1369  */
1370 function wfMsgReplaceArgs( $message, $args ) {
1371         # Fix windows line-endings
1372         # Some messages are split with explode("\n", $msg)
1373         $message = str_replace( "\r", '', $message );
1374
1375         // Replace arguments
1376         if ( count( $args ) ) {
1377                 if ( is_array( $args[0] ) ) {
1378                         $args = array_values( $args[0] );
1379                 }
1380                 $replacementKeys = array();
1381                 foreach( $args as $n => $param ) {
1382                         $replacementKeys['$' . ( $n + 1 )] = $param;
1383                 }
1384                 $message = strtr( $message, $replacementKeys );
1385         }
1386
1387         return $message;
1388 }
1389
1390 /**
1391  * Return an HTML-escaped version of a message.
1392  * Parameter replacements, if any, are done *after* the HTML-escaping,
1393  * so parameters may contain HTML (eg links or form controls). Be sure
1394  * to pre-escape them if you really do want plaintext, or just wrap
1395  * the whole thing in htmlspecialchars().
1396  *
1397  * @param $key String
1398  * @param string ... parameters
1399  * @return string
1400  */
1401 function wfMsgHtml( $key ) {
1402         $args = func_get_args();
1403         array_shift( $args );
1404         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1405 }
1406
1407 /**
1408  * Return an HTML version of message
1409  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1410  * so parameters may contain HTML (eg links or form controls). Be sure
1411  * to pre-escape them if you really do want plaintext, or just wrap
1412  * the whole thing in htmlspecialchars().
1413  *
1414  * @param $key String
1415  * @param string ... parameters
1416  * @return string
1417  */
1418 function wfMsgWikiHtml( $key ) {
1419         $args = func_get_args();
1420         array_shift( $args );
1421         return wfMsgReplaceArgs(
1422                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1423                 /* can't be set to false */ true, /* interface */ true )->getText(),
1424                 $args );
1425 }
1426
1427 /**
1428  * Returns message in the requested format
1429  * @param $key String: key of the message
1430  * @param $options Array: processing rules. Can take the following options:
1431  *   <i>parse</i>: parses wikitext to HTML
1432  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1433  *       p's added by parser or tidy
1434  *   <i>escape</i>: filters message through htmlspecialchars
1435  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1436  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1437  *   <i>parsemag</i>: transform the message using magic phrases
1438  *   <i>content</i>: fetch message for content language instead of interface
1439  * Also can accept a single associative argument, of the form 'language' => 'xx':
1440  *   <i>language</i>: Language object or language code to fetch message for
1441  *       (overriden by <i>content</i>).
1442  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1443  *
1444  * @return String
1445  */
1446 function wfMsgExt( $key, $options ) {
1447         $args = func_get_args();
1448         array_shift( $args );
1449         array_shift( $args );
1450         $options = (array)$options;
1451
1452         foreach( $options as $arrayKey => $option ) {
1453                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1454                         # An unknown index, neither numeric nor "language"
1455                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1456                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1457                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1458                 'replaceafter', 'parsemag', 'content' ) ) ) {
1459                         # A numeric index with unknown value
1460                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1461                 }
1462         }
1463
1464         if( in_array( 'content', $options, true ) ) {
1465                 $forContent = true;
1466                 $langCode = true;
1467                 $langCodeObj = null;
1468         } elseif( array_key_exists( 'language', $options ) ) {
1469                 $forContent = false;
1470                 $langCode = wfGetLangObj( $options['language'] );
1471                 $langCodeObj = $langCode;
1472         } else {
1473                 $forContent = false;
1474                 $langCode = false;
1475                 $langCodeObj = null;
1476         }
1477
1478         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1479
1480         if( !in_array( 'replaceafter', $options, true ) ) {
1481                 $string = wfMsgReplaceArgs( $string, $args );
1482         }
1483
1484         $messageCache = MessageCache::singleton();
1485         if( in_array( 'parse', $options, true ) ) {
1486                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1487         } elseif ( in_array( 'parseinline', $options, true ) ) {
1488                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1489                 $m = array();
1490                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1491                         $string = $m[1];
1492                 }
1493         } elseif ( in_array( 'parsemag', $options, true ) ) {
1494                 $string = $messageCache->transform( $string,
1495                                 !$forContent, $langCodeObj );
1496         }
1497
1498         if ( in_array( 'escape', $options, true ) ) {
1499                 $string = htmlspecialchars ( $string );
1500         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1501                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1502         }
1503
1504         if( in_array( 'replaceafter', $options, true ) ) {
1505                 $string = wfMsgReplaceArgs( $string, $args );
1506         }
1507
1508         return $string;
1509 }
1510
1511 /**
1512  * Since wfMsg() and co suck, they don't return false if the message key they
1513  * looked up didn't exist but a XHTML string, this function checks for the
1514  * nonexistance of messages by checking the MessageCache::get() result directly.
1515  *
1516  * @param $key      String: the message key looked up
1517  * @return Boolean True if the message *doesn't* exist.
1518  */
1519 function wfEmptyMsg( $key ) {
1520         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1521 }
1522
1523 /**
1524  * Throw a debugging exception. This function previously once exited the process,
1525  * but now throws an exception instead, with similar results.
1526  *
1527  * @param $msg String: message shown when dying.
1528  */
1529 function wfDebugDieBacktrace( $msg = '' ) {
1530         throw new MWException( $msg );
1531 }
1532
1533 /**
1534  * Fetch server name for use in error reporting etc.
1535  * Use real server name if available, so we know which machine
1536  * in a server farm generated the current page.
1537  *
1538  * @return string
1539  */
1540 function wfHostname() {
1541         static $host;
1542         if ( is_null( $host ) ) {
1543                 if ( function_exists( 'posix_uname' ) ) {
1544                         // This function not present on Windows
1545                         $uname = posix_uname();
1546                 } else {
1547                         $uname = false;
1548                 }
1549                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1550                         $host = $uname['nodename'];
1551                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1552                         # Windows computer name
1553                         $host = getenv( 'COMPUTERNAME' );
1554                 } else {
1555                         # This may be a virtual server.
1556                         $host = $_SERVER['SERVER_NAME'];
1557                 }
1558         }
1559         return $host;
1560 }
1561
1562 /**
1563  * Returns a HTML comment with the elapsed time since request.
1564  * This method has no side effects.
1565  *
1566  * @return string
1567  */
1568 function wfReportTime() {
1569         global $wgRequestTime, $wgShowHostnames;
1570
1571         $now = wfTime();
1572         $elapsed = $now - $wgRequestTime;
1573
1574         return $wgShowHostnames
1575                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1576                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1577 }
1578
1579 /**
1580  * Safety wrapper for debug_backtrace().
1581  *
1582  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1583  * murky circumstances, which may be triggered in part by stub objects
1584  * or other fancy talkin'.
1585  *
1586  * Will return an empty array if Zend Optimizer is detected or if
1587  * debug_backtrace is disabled, otherwise the output from
1588  * debug_backtrace() (trimmed).
1589  *
1590  * @param $limit int This parameter can be used to limit the number of stack frames returned
1591  *
1592  * @return array of backtrace information
1593  */
1594 function wfDebugBacktrace( $limit = 0 ) {
1595         static $disabled = null;
1596
1597         if( extension_loaded( 'Zend Optimizer' ) ) {
1598                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1599                 return array();
1600         }
1601
1602         if ( is_null( $disabled ) ) {
1603                 $disabled = false;
1604                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1605                 $functions = array_map( 'trim', $functions );
1606                 $functions = array_map( 'strtolower', $functions );
1607                 if ( in_array( 'debug_backtrace', $functions ) ) {
1608                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1609                         $disabled = true;
1610                 }
1611         }
1612         if ( $disabled ) {
1613                 return array();
1614         }
1615
1616         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1617                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit ), 1 );
1618         } else {
1619                 return array_slice( debug_backtrace(), 1 );
1620         }
1621 }
1622
1623 /**
1624  * Get a debug backtrace as a string
1625  *
1626  * @return string
1627  */
1628 function wfBacktrace() {
1629         global $wgCommandLineMode;
1630
1631         if ( $wgCommandLineMode ) {
1632                 $msg = '';
1633         } else {
1634                 $msg = "<ul>\n";
1635         }
1636         $backtrace = wfDebugBacktrace();
1637         foreach( $backtrace as $call ) {
1638                 if( isset( $call['file'] ) ) {
1639                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1640                         $file = $f[count( $f ) - 1];
1641                 } else {
1642                         $file = '-';
1643                 }
1644                 if( isset( $call['line'] ) ) {
1645                         $line = $call['line'];
1646                 } else {
1647                         $line = '-';
1648                 }
1649                 if ( $wgCommandLineMode ) {
1650                         $msg .= "$file line $line calls ";
1651                 } else {
1652                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1653                 }
1654                 if( !empty( $call['class'] ) ) {
1655                         $msg .= $call['class'] . $call['type'];
1656                 }
1657                 $msg .= $call['function'] . '()';
1658
1659                 if ( $wgCommandLineMode ) {
1660                         $msg .= "\n";
1661                 } else {
1662                         $msg .= "</li>\n";
1663                 }
1664         }
1665         if ( $wgCommandLineMode ) {
1666                 $msg .= "\n";
1667         } else {
1668                 $msg .= "</ul>\n";
1669         }
1670
1671         return $msg;
1672 }
1673
1674 /**
1675  * Get the name of the function which called this function
1676  *
1677  * @param $level Int
1678  * @return Bool|string
1679  */
1680 function wfGetCaller( $level = 2 ) {
1681         $backtrace = wfDebugBacktrace( $level );
1682         if ( isset( $backtrace[$level] ) ) {
1683                 return wfFormatStackFrame( $backtrace[$level] );
1684         } else {
1685                 $caller = 'unknown';
1686         }
1687         return $caller;
1688 }
1689
1690 /**
1691  * Return a string consisting of callers in the stack. Useful sometimes
1692  * for profiling specific points.
1693  *
1694  * @param $limit The maximum depth of the stack frame to return, or false for
1695  *               the entire stack.
1696  * @return String
1697  */
1698 function wfGetAllCallers( $limit = 3 ) {
1699         $trace = array_reverse( wfDebugBacktrace() );
1700         if ( !$limit || $limit > count( $trace ) - 1 ) {
1701                 $limit = count( $trace ) - 1;
1702         }
1703         $trace = array_slice( $trace, -$limit - 1, $limit );
1704         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1705 }
1706
1707 /**
1708  * Return a string representation of frame
1709  *
1710  * @param $frame Array
1711  * @return Bool
1712  */
1713 function wfFormatStackFrame( $frame ) {
1714         return isset( $frame['class'] ) ?
1715                 $frame['class'] . '::' . $frame['function'] :
1716                 $frame['function'];
1717 }
1718
1719
1720 /* Some generic result counters, pulled out of SearchEngine */
1721
1722
1723 /**
1724  * @todo document
1725  *
1726  * @param $offset Int
1727  * @param $limit Int
1728  * @return String
1729  */
1730 function wfShowingResults( $offset, $limit ) {
1731         global $wgLang;
1732         return wfMsgExt(
1733                 'showingresults',
1734                 array( 'parseinline' ),
1735                 $wgLang->formatNum( $limit ),
1736                 $wgLang->formatNum( $offset + 1 )
1737         );
1738 }
1739
1740 /**
1741  * Generate (prev x| next x) (20|50|100...) type links for paging
1742  *
1743  * @param $offset String
1744  * @param $limit Integer
1745  * @param $link String
1746  * @param $query String: optional URL query parameter string
1747  * @param $atend Bool: optional param for specified if this is the last page
1748  * @return String
1749  * @deprecated in 1.19; use Language::viewPrevNext() instead
1750  */
1751 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1752         wfDeprecated( __METHOD__, '1.19' );
1753
1754         global $wgLang;
1755
1756         $query = wfCgiToArray( $query );
1757
1758         if( is_object( $link ) ) {
1759                 $title = $link;
1760         } else {
1761                 $title = Title::newFromText( $link );
1762                 if( is_null( $title ) ) {
1763                         return false;
1764                 }
1765         }
1766
1767         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1768 }
1769
1770 /**
1771  * Make a list item, used by various special pages
1772  *
1773  * @param $page String Page link
1774  * @param $details String Text between brackets
1775  * @param $oppositedm Boolean   Add the direction mark opposite to your
1776  *                                                              language, to display text properly
1777  * @return String
1778  * @deprecated since 1.19; use Language::specialList() instead
1779  */
1780 function wfSpecialList( $page, $details, $oppositedm = true ) {
1781         global $wgLang;
1782         return $wgLang->specialList( $page, $details, $oppositedm );
1783 }
1784
1785 /**
1786  * @todo document
1787  * @todo FIXME: We may want to blacklist some broken browsers
1788  *
1789  * @param $force Bool
1790  * @return bool Whereas client accept gzip compression
1791  */
1792 function wfClientAcceptsGzip( $force = false ) {
1793         static $result = null;
1794         if ( $result === null || $force ) {
1795                 $result = false;
1796                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1797                         # @todo FIXME: We may want to blacklist some broken browsers
1798                         $m = array();
1799                         if( preg_match(
1800                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1801                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1802                                 $m )
1803                         )
1804                         {
1805                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1806                                         $result = false;
1807                                         return $result;
1808                                 }
1809                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1810                                 $result = true;
1811                         }
1812                 }
1813         }
1814         return $result;
1815 }
1816
1817 /**
1818  * Obtain the offset and limit values from the request string;
1819  * used in special pages
1820  *
1821  * @param $deflimit Int default limit if none supplied
1822  * @param $optionname String Name of a user preference to check against
1823  * @return array
1824  *
1825  */
1826 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1827         global $wgRequest;
1828         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1829 }
1830
1831 /**
1832  * Escapes the given text so that it may be output using addWikiText()
1833  * without any linking, formatting, etc. making its way through. This
1834  * is achieved by substituting certain characters with HTML entities.
1835  * As required by the callers, <nowiki> is not used.
1836  *
1837  * @param $text String: text to be escaped
1838  * @return String
1839  */
1840 function wfEscapeWikiText( $text ) {
1841         $text = strtr( "\n$text", array(
1842                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1843                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1844                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1845                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1846                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1847                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1848         ) );
1849         return substr( $text, 1 );
1850 }
1851
1852 /**
1853  * Get the current unix timetstamp with microseconds.  Useful for profiling
1854  * @return Float
1855  */
1856 function wfTime() {
1857         return microtime( true );
1858 }
1859
1860 /**
1861  * Sets dest to source and returns the original value of dest
1862  * If source is NULL, it just returns the value, it doesn't set the variable
1863  * If force is true, it will set the value even if source is NULL
1864  *
1865  * @param $dest Mixed
1866  * @param $source Mixed
1867  * @param $force Bool
1868  * @return Mixed
1869  */
1870 function wfSetVar( &$dest, $source, $force = false ) {
1871         $temp = $dest;
1872         if ( !is_null( $source ) || $force ) {
1873                 $dest = $source;
1874         }
1875         return $temp;
1876 }
1877
1878 /**
1879  * As for wfSetVar except setting a bit
1880  *
1881  * @param $dest Int
1882  * @param $bit Int
1883  * @param $state Bool
1884  *
1885  * @return bool
1886  */
1887 function wfSetBit( &$dest, $bit, $state = true ) {
1888         $temp = (bool)( $dest & $bit );
1889         if ( !is_null( $state ) ) {
1890                 if ( $state ) {
1891                         $dest |= $bit;
1892                 } else {
1893                         $dest &= ~$bit;
1894                 }
1895         }
1896         return $temp;
1897 }
1898
1899 /**
1900  * A wrapper around the PHP function var_export().
1901  * Either print it or add it to the regular output ($wgOut).
1902  *
1903  * @param $var A PHP variable to dump.
1904  */
1905 function wfVarDump( $var ) {
1906         global $wgOut;
1907         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1908         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1909                 print $s;
1910         } else {
1911                 $wgOut->addHTML( $s );
1912         }
1913 }
1914
1915 /**
1916  * Provide a simple HTTP error.
1917  *
1918  * @param $code Int|String
1919  * @param $label String
1920  * @param $desc String
1921  */
1922 function wfHttpError( $code, $label, $desc ) {
1923         global $wgOut;
1924         $wgOut->disable();
1925         header( "HTTP/1.0 $code $label" );
1926         header( "Status: $code $label" );
1927         $wgOut->sendCacheControl();
1928
1929         header( 'Content-type: text/html; charset=utf-8' );
1930         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1931                 '<html><head><title>' .
1932                 htmlspecialchars( $label ) .
1933                 '</title></head><body><h1>' .
1934                 htmlspecialchars( $label ) .
1935                 '</h1><p>' .
1936                 nl2br( htmlspecialchars( $desc ) ) .
1937                 "</p></body></html>\n";
1938 }
1939
1940 /**
1941  * Clear away any user-level output buffers, discarding contents.
1942  *
1943  * Suitable for 'starting afresh', for instance when streaming
1944  * relatively large amounts of data without buffering, or wanting to
1945  * output image files without ob_gzhandler's compression.
1946  *
1947  * The optional $resetGzipEncoding parameter controls suppression of
1948  * the Content-Encoding header sent by ob_gzhandler; by default it
1949  * is left. See comments for wfClearOutputBuffers() for why it would
1950  * be used.
1951  *
1952  * Note that some PHP configuration options may add output buffer
1953  * layers which cannot be removed; these are left in place.
1954  *
1955  * @param $resetGzipEncoding Bool
1956  */
1957 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1958         if( $resetGzipEncoding ) {
1959                 // Suppress Content-Encoding and Content-Length
1960                 // headers from 1.10+s wfOutputHandler
1961                 global $wgDisableOutputCompression;
1962                 $wgDisableOutputCompression = true;
1963         }
1964         while( $status = ob_get_status() ) {
1965                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1966                         // Probably from zlib.output_compression or other
1967                         // PHP-internal setting which can't be removed.
1968                         //
1969                         // Give up, and hope the result doesn't break
1970                         // output behavior.
1971                         break;
1972                 }
1973                 if( !ob_end_clean() ) {
1974                         // Could not remove output buffer handler; abort now
1975                         // to avoid getting in some kind of infinite loop.
1976                         break;
1977                 }
1978                 if( $resetGzipEncoding ) {
1979                         if( $status['name'] == 'ob_gzhandler' ) {
1980                                 // Reset the 'Content-Encoding' field set by this handler
1981                                 // so we can start fresh.
1982                                 if ( function_exists( 'header_remove' ) ) {
1983                                         // Available since PHP 5.3.0
1984                                         header_remove( 'Content-Encoding' );
1985                                 } else {
1986                                         // We need to provide a valid content-coding. See bug 28069
1987                                         header( 'Content-Encoding: identity' );
1988                                 }
1989                                 break;
1990                         }
1991                 }
1992         }
1993 }
1994
1995 /**
1996  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1997  *
1998  * Clear away output buffers, but keep the Content-Encoding header
1999  * produced by ob_gzhandler, if any.
2000  *
2001  * This should be used for HTTP 304 responses, where you need to
2002  * preserve the Content-Encoding header of the real result, but
2003  * also need to suppress the output of ob_gzhandler to keep to spec
2004  * and avoid breaking Firefox in rare cases where the headers and
2005  * body are broken over two packets.
2006  */
2007 function wfClearOutputBuffers() {
2008         wfResetOutputBuffers( false );
2009 }
2010
2011 /**
2012  * Converts an Accept-* header into an array mapping string values to quality
2013  * factors
2014  *
2015  * @param $accept String
2016  * @param $def String default
2017  * @return Array
2018  */
2019 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2020         # No arg means accept anything (per HTTP spec)
2021         if( !$accept ) {
2022                 return array( $def => 1.0 );
2023         }
2024
2025         $prefs = array();
2026
2027         $parts = explode( ',', $accept );
2028
2029         foreach( $parts as $part ) {
2030                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2031                 $values = explode( ';', trim( $part ) );
2032                 $match = array();
2033                 if ( count( $values ) == 1 ) {
2034                         $prefs[$values[0]] = 1.0;
2035                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2036                         $prefs[$values[0]] = floatval( $match[1] );
2037                 }
2038         }
2039
2040         return $prefs;
2041 }
2042
2043 /**
2044  * Checks if a given MIME type matches any of the keys in the given
2045  * array. Basic wildcards are accepted in the array keys.
2046  *
2047  * Returns the matching MIME type (or wildcard) if a match, otherwise
2048  * NULL if no match.
2049  *
2050  * @param $type String
2051  * @param $avail Array
2052  * @return string
2053  * @private
2054  */
2055 function mimeTypeMatch( $type, $avail ) {
2056         if( array_key_exists( $type, $avail ) ) {
2057                 return $type;
2058         } else {
2059                 $parts = explode( '/', $type );
2060                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2061                         return $parts[0] . '/*';
2062                 } elseif( array_key_exists( '*/*', $avail ) ) {
2063                         return '*/*';
2064                 } else {
2065                         return null;
2066                 }
2067         }
2068 }
2069
2070 /**
2071  * Returns the 'best' match between a client's requested internet media types
2072  * and the server's list of available types. Each list should be an associative
2073  * array of type to preference (preference is a float between 0.0 and 1.0).
2074  * Wildcards in the types are acceptable.
2075  *
2076  * @param $cprefs Array: client's acceptable type list
2077  * @param $sprefs Array: server's offered types
2078  * @return string
2079  *
2080  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2081  * XXX: generalize to negotiate other stuff
2082  */
2083 function wfNegotiateType( $cprefs, $sprefs ) {
2084         $combine = array();
2085
2086         foreach( array_keys( $sprefs ) as $type ) {
2087                 $parts = explode( '/', $type );
2088                 if( $parts[1] != '*' ) {
2089                         $ckey = mimeTypeMatch( $type, $cprefs );
2090                         if( $ckey ) {
2091                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2092                         }
2093                 }
2094         }
2095
2096         foreach( array_keys( $cprefs ) as $type ) {
2097                 $parts = explode( '/', $type );
2098                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2099                         $skey = mimeTypeMatch( $type, $sprefs );
2100                         if( $skey ) {
2101                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2102                         }
2103                 }
2104         }
2105
2106         $bestq = 0;
2107         $besttype = null;
2108
2109         foreach( array_keys( $combine ) as $type ) {
2110                 if( $combine[$type] > $bestq ) {
2111                         $besttype = $type;
2112                         $bestq = $combine[$type];
2113                 }
2114         }
2115
2116         return $besttype;
2117 }
2118
2119 /**
2120  * Reference-counted warning suppression
2121  *
2122  * @param $end Bool
2123  */
2124 function wfSuppressWarnings( $end = false ) {
2125         static $suppressCount = 0;
2126         static $originalLevel = false;
2127
2128         if ( $end ) {
2129                 if ( $suppressCount ) {
2130                         --$suppressCount;
2131                         if ( !$suppressCount ) {
2132                                 error_reporting( $originalLevel );
2133                         }
2134                 }
2135         } else {
2136                 if ( !$suppressCount ) {
2137                         // E_DEPRECATED is undefined in PHP 5.2
2138                         if( !defined( 'E_DEPRECATED' ) ) {
2139                                 define( 'E_DEPRECATED', 8192 );
2140                         }
2141                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2142                 }
2143                 ++$suppressCount;
2144         }
2145 }
2146
2147 /**
2148  * Restore error level to previous value
2149  */
2150 function wfRestoreWarnings() {
2151         wfSuppressWarnings( true );
2152 }
2153
2154 # Autodetect, convert and provide timestamps of various types
2155
2156 /**
2157  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2158  */
2159 define( 'TS_UNIX', 0 );
2160
2161 /**
2162  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2163  */
2164 define( 'TS_MW', 1 );
2165
2166 /**
2167  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2168  */
2169 define( 'TS_DB', 2 );
2170
2171 /**
2172  * RFC 2822 format, for E-mail and HTTP headers
2173  */
2174 define( 'TS_RFC2822', 3 );
2175
2176 /**
2177  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2178  *
2179  * This is used by Special:Export
2180  */
2181 define( 'TS_ISO_8601', 4 );
2182
2183 /**
2184  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2185  *
2186  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2187  *       DateTime tag and page 36 for the DateTimeOriginal and
2188  *       DateTimeDigitized tags.
2189  */
2190 define( 'TS_EXIF', 5 );
2191
2192 /**
2193  * Oracle format time.
2194  */
2195 define( 'TS_ORACLE', 6 );
2196
2197 /**
2198  * Postgres format time.
2199  */
2200 define( 'TS_POSTGRES', 7 );
2201
2202 /**
2203  * DB2 format time
2204  */
2205 define( 'TS_DB2', 8 );
2206
2207 /**
2208  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2209  */
2210 define( 'TS_ISO_8601_BASIC', 9 );
2211
2212 /**
2213  * Get a timestamp string in one of various formats
2214  *
2215  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2216  *                    function will autodetect which format is supplied and act
2217  *                    accordingly.
2218  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2219  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2220  */
2221 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2222         $uts = 0;
2223         $da = array();
2224         $strtime = '';
2225
2226         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2227                 $uts = time();
2228                 $strtime = "@$uts";
2229         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2230                 # TS_DB
2231         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2232                 # TS_EXIF
2233         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2234                 # TS_MW
2235         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2236                 # TS_UNIX
2237                 $uts = $ts;
2238                 $strtime = "@$ts"; // http://php.net/manual/en/datetime.formats.compound.php
2239         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2240                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2241                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2242                                 str_replace( '+00:00', 'UTC', $ts ) );
2243         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2244                 # TS_ISO_8601
2245         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2246                 #TS_ISO_8601_BASIC
2247         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2248                 # TS_POSTGRES
2249         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2250                 # TS_POSTGRES
2251         } elseif (preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/', $ts, $da ) ) {
2252                 # TS_DB2
2253         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2254                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2255                                                         '[ \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
2256                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2257                 # The regex is a superset of rfc2822 for readability
2258                 $strtime = strtok( $ts, ';' );
2259         } 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 ) ) {
2260                 # TS_RFC850
2261                 $strtime = $ts;
2262         } 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 ) ) {
2263                 # asctime
2264                 $strtime = $ts;
2265         } else {
2266                 # Bogus value...
2267                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2268
2269                 return false;
2270         }
2271
2272         static $formats = array(
2273                 TS_UNIX => 'U',
2274                 TS_MW => 'YmdHis',
2275                 TS_DB => 'Y-m-d H:i:s',
2276                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2277                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2278                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2279                 TS_RFC2822 => 'D, d M Y H:i:s',
2280                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2281                 TS_POSTGRES => 'Y-m-d H:i:s',
2282                 TS_DB2 => 'Y-m-d H:i:s',
2283         );
2284
2285         if ( !isset( $formats[$outputtype] ) ) {
2286                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2287         }
2288
2289         if ( function_exists( "date_create" ) ) {
2290                 if ( count( $da ) ) {
2291                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2292                                 (int)$da[1], (int)$da[2], (int)$da[3],
2293                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2294
2295                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2296                 } elseif ( $strtime ) {
2297                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2298                 } else {
2299                         return false;
2300                 }
2301
2302                 if ( !$d ) {
2303                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2304                         return false;
2305                 }
2306
2307                 $output = $d->format( $formats[$outputtype] );
2308         } else {
2309                 if ( count( $da ) ) {
2310                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2311                         // We may want to handle that explicitly at some point
2312                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2313                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2314                 } elseif ( $strtime ) {
2315                         $uts = strtotime( $strtime );
2316                 }
2317
2318                 if ( $uts === false ) {
2319                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2320                         return false;
2321                 }
2322
2323                 if ( TS_UNIX == $outputtype ) {
2324                         return $uts;
2325                 }
2326                 $output = gmdate( $formats[$outputtype], $uts );
2327         }
2328
2329         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2330                 $output .= ' GMT';
2331         }
2332
2333         return $output;
2334 }
2335
2336 /**
2337  * Return a formatted timestamp, or null if input is null.
2338  * For dealing with nullable timestamp columns in the database.
2339  *
2340  * @param $outputtype Integer
2341  * @param $ts String
2342  * @return String
2343  */
2344 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2345         if( is_null( $ts ) ) {
2346                 return null;
2347         } else {
2348                 return wfTimestamp( $outputtype, $ts );
2349         }
2350 }
2351
2352 /**
2353  * Convenience function; returns MediaWiki timestamp for the present time.
2354  *
2355  * @return string
2356  */
2357 function wfTimestampNow() {
2358         # return NOW
2359         return wfTimestamp( TS_MW, time() );
2360 }
2361
2362 /**
2363  * Check if the operating system is Windows
2364  *
2365  * @return Bool: true if it's Windows, False otherwise.
2366  */
2367 function wfIsWindows() {
2368         static $isWindows = null;
2369         if ( $isWindows === null ) {
2370                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2371         }
2372         return $isWindows;
2373 }
2374
2375 /**
2376  * Check if we are running under HipHop
2377  *
2378  * @return Bool
2379  */
2380 function wfIsHipHop() {
2381         return function_exists( 'hphp_thread_set_warmup_enabled' );
2382 }
2383
2384 /**
2385  * Swap two variables
2386  *
2387  * @param $x Mixed
2388  * @param $y Mixed
2389  */
2390 function swap( &$x, &$y ) {
2391         $z = $x;
2392         $x = $y;
2393         $y = $z;
2394 }
2395
2396 /**
2397  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2398  * TEMP environment variables are then checked in sequence, and if none are set
2399  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2400  * or C:\Windows\Temp for Windows and hope for the best.
2401  * It is common to call it with tempnam().
2402  *
2403  * NOTE: When possible, use instead the tmpfile() function to create
2404  * temporary files to avoid race conditions on file creation, etc.
2405  *
2406  * @return String
2407  */
2408 function wfTempDir() {
2409         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2410                 $tmp = getenv( $var );
2411                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2412                         return $tmp;
2413                 }
2414         }
2415         if( function_exists( 'sys_get_temp_dir' ) ) {
2416                 return sys_get_temp_dir();
2417         }
2418         # Usual defaults
2419         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2420 }
2421
2422 /**
2423  * Make directory, and make all parent directories if they don't exist
2424  *
2425  * @param $dir String: full path to directory to create
2426  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2427  * @param $caller String: optional caller param for debugging.
2428  * @return bool
2429  */
2430 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2431         global $wgDirectoryMode;
2432
2433         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2434                 throw new MWException( __FUNCTION__ . " given storage path `$dir`.");
2435         }
2436
2437         if ( !is_null( $caller ) ) {
2438                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2439         }
2440
2441         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2442                 return true;
2443         }
2444
2445         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2446
2447         if ( is_null( $mode ) ) {
2448                 $mode = $wgDirectoryMode;
2449         }
2450
2451         // Turn off the normal warning, we're doing our own below
2452         wfSuppressWarnings();
2453         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2454         wfRestoreWarnings();
2455
2456         if( !$ok ) {
2457                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2458                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2459         }
2460         return $ok;
2461 }
2462
2463 /**
2464  * Increment a statistics counter
2465  *
2466  * @param $key String
2467  * @param $count Int
2468  */
2469 function wfIncrStats( $key, $count = 1 ) {
2470         global $wgStatsMethod;
2471
2472         $count = intval( $count );
2473
2474         if( $wgStatsMethod == 'udp' ) {
2475                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2476                 static $socket;
2477
2478                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2479
2480                 if ( !$socket ) {
2481                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2482                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2483                         socket_sendto(
2484                                 $socket,
2485                                 $statline,
2486                                 strlen( $statline ),
2487                                 0,
2488                                 $wgUDPProfilerHost,
2489                                 $wgUDPProfilerPort
2490                         );
2491                 }
2492                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2493                 wfSuppressWarnings();
2494                 socket_sendto(
2495                         $socket,
2496                         $statline,
2497                         strlen( $statline ),
2498                         0,
2499                         $wgUDPProfilerHost,
2500                         $wgUDPProfilerPort
2501                 );
2502                 wfRestoreWarnings();
2503         } elseif( $wgStatsMethod == 'cache' ) {
2504                 global $wgMemc;
2505                 $key = wfMemcKey( 'stats', $key );
2506                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2507                         $wgMemc->add( $key, $count );
2508                 }
2509         } else {
2510                 // Disabled
2511         }
2512 }
2513
2514 /**
2515  * @param $nr Mixed: the number to format
2516  * @param $acc Integer: the number of digits after the decimal point, default 2
2517  * @param $round Boolean: whether or not to round the value, default true
2518  * @return float
2519  */
2520 function wfPercent( $nr, $acc = 2, $round = true ) {
2521         $ret = sprintf( "%.${acc}f", $nr );
2522         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2523 }
2524
2525 /**
2526  * Find out whether or not a mixed variable exists in a string
2527  *
2528  * @param $needle String
2529  * @param $str String
2530  * @param $insensitive Boolean
2531  * @return Boolean
2532  */
2533 function in_string( $needle, $str, $insensitive = false ) {
2534         $func = 'strpos';
2535         if( $insensitive ) $func = 'stripos';
2536
2537         return $func( $str, $needle ) !== false;
2538 }
2539
2540 /**
2541  * Safety wrapper around ini_get() for boolean settings.
2542  * The values returned from ini_get() are pre-normalized for settings
2543  * set via php.ini or php_flag/php_admin_flag... but *not*
2544  * for those set via php_value/php_admin_value.
2545  *
2546  * It's fairly common for people to use php_value instead of php_flag,
2547  * which can leave you with an 'off' setting giving a false positive
2548  * for code that just takes the ini_get() return value as a boolean.
2549  *
2550  * To make things extra interesting, setting via php_value accepts
2551  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2552  * Unrecognized values go false... again opposite PHP's own coercion
2553  * from string to bool.
2554  *
2555  * Luckily, 'properly' set settings will always come back as '0' or '1',
2556  * so we only have to worry about them and the 'improper' settings.
2557  *
2558  * I frickin' hate PHP... :P
2559  *
2560  * @param $setting String
2561  * @return Bool
2562  */
2563 function wfIniGetBool( $setting ) {
2564         $val = ini_get( $setting );
2565         // 'on' and 'true' can't have whitespace around them, but '1' can.
2566         return strtolower( $val ) == 'on'
2567                 || strtolower( $val ) == 'true'
2568                 || strtolower( $val ) == 'yes'
2569                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2570 }
2571
2572 /**
2573  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2574  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2575  *
2576  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2577  *                          should be omitted
2578  * @param $fileName String Name of the library, if not $extension.suffix
2579  * @return Bool - Whether or not the extension is loaded
2580  */
2581 function wfDl( $extension, $fileName = null ) {
2582         if( extension_loaded( $extension ) ) {
2583                 return true;
2584         }
2585
2586         $canDl = false;
2587         $sapi = php_sapi_name();
2588         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2589                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2590         {
2591                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2592                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2593         }
2594
2595         if( $canDl ) {
2596                 $fileName = $fileName ? $fileName : $extension;
2597                 if( wfIsWindows() ) {
2598                         $fileName = 'php_' . $fileName;
2599                 }
2600                 wfSuppressWarnings();
2601                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2602                 wfRestoreWarnings();
2603         }
2604         return extension_loaded( $extension );
2605 }
2606
2607 /**
2608  * Windows-compatible version of escapeshellarg()
2609  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2610  * function puts single quotes in regardless of OS.
2611  *
2612  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2613  * earlier distro releases of PHP)
2614  *
2615  * @param varargs
2616  * @return String
2617  */
2618 function wfEscapeShellArg( ) {
2619         wfInitShellLocale();
2620
2621         $args = func_get_args();
2622         $first = true;
2623         $retVal = '';
2624         foreach ( $args as $arg ) {
2625                 if ( !$first ) {
2626                         $retVal .= ' ';
2627                 } else {
2628                         $first = false;
2629                 }
2630
2631                 if ( wfIsWindows() ) {
2632                         // Escaping for an MSVC-style command line parser and CMD.EXE
2633                         // Refs:
2634                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2635                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2636                         //  * Bug #13518
2637                         //  * CR r63214
2638                         // Double the backslashes before any double quotes. Escape the double quotes.
2639                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2640                         $arg = '';
2641                         $iteration = 0;
2642                         foreach ( $tokens as $token ) {
2643                                 if ( $iteration % 2 == 1 ) {
2644                                         // Delimiter, a double quote preceded by zero or more slashes
2645                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2646                                 } elseif ( $iteration % 4 == 2 ) {
2647                                         // ^ in $token will be outside quotes, need to be escaped
2648                                         $arg .= str_replace( '^', '^^', $token );
2649                                 } else { // $iteration % 4 == 0
2650                                         // ^ in $token will appear inside double quotes, so leave as is
2651                                         $arg .= $token;
2652                                 }
2653                                 $iteration++;
2654                         }
2655                         // Double the backslashes before the end of the string, because
2656                         // we will soon add a quote
2657                         $m = array();
2658                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2659                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2660                         }
2661
2662                         // Add surrounding quotes
2663                         $retVal .= '"' . $arg . '"';
2664                 } else {
2665                         $retVal .= escapeshellarg( $arg );
2666                 }
2667         }
2668         return $retVal;
2669 }
2670
2671 /**
2672  * Execute a shell command, with time and memory limits mirrored from the PHP
2673  * configuration if supported.
2674  * @param $cmd String Command line, properly escaped for shell.
2675  * @param &$retval optional, will receive the program's exit code.
2676  *                 (non-zero is usually failure)
2677  * @param $environ Array optional environment variables which should be
2678  *                 added to the executed command environment.
2679  * @return collected stdout as a string (trailing newlines stripped)
2680  */
2681 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2682         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2683
2684         static $disabled;
2685         if ( is_null( $disabled ) ) {
2686                 $disabled = false;
2687                 if( wfIniGetBool( 'safe_mode' ) ) {
2688                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2689                         $disabled = 'safemode';
2690                 } else {
2691                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2692                         $functions = array_map( 'trim', $functions );
2693                         $functions = array_map( 'strtolower', $functions );
2694                         if ( in_array( 'passthru', $functions ) ) {
2695                                 wfDebug( "passthru is in disabled_functions\n" );
2696                                 $disabled = 'passthru';
2697                         }
2698                 }
2699         }
2700         if ( $disabled ) {
2701                 $retval = 1;
2702                 return $disabled == 'safemode' ?
2703                         'Unable to run external programs in safe mode.' :
2704                         'Unable to run external programs, passthru() is disabled.';
2705         }
2706
2707         wfInitShellLocale();
2708
2709         $envcmd = '';
2710         foreach( $environ as $k => $v ) {
2711                 if ( wfIsWindows() ) {
2712                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2713                          * appear in the environment variable, so we must use carat escaping as documented in
2714                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2715                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2716                          * are listed there but doesn't appear to need it.
2717                          */
2718                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2719                 } else {
2720                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2721                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2722                          */
2723                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2724                 }
2725         }
2726         $cmd = $envcmd . $cmd;
2727
2728         if ( wfIsWindows() ) {
2729                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2730                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2731                 {
2732                         # Hack to work around PHP's flawed invocation of cmd.exe
2733                         # http://news.php.net/php.internals/21796
2734                         # Windows 9x doesn't accept any kind of quotes
2735                         $cmd = '"' . $cmd . '"';
2736                 }
2737         } elseif ( php_uname( 's' ) == 'Linux' ) {
2738                 $time = intval( $wgMaxShellTime );
2739                 $mem = intval( $wgMaxShellMemory );
2740                 $filesize = intval( $wgMaxShellFileSize );
2741
2742                 if ( $time > 0 && $mem > 0 ) {
2743                         $script = "$IP/bin/ulimit4.sh";
2744                         if ( is_executable( $script ) ) {
2745                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2746                         }
2747                 }
2748         }
2749         wfDebug( "wfShellExec: $cmd\n" );
2750
2751         $retval = 1; // error by default?
2752         ob_start();
2753         passthru( $cmd, $retval );
2754         $output = ob_get_contents();
2755         ob_end_clean();
2756
2757         if ( $retval == 127 ) {
2758                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2759         }
2760         return $output;
2761 }
2762
2763 /**
2764  * Workaround for http://bugs.php.net/bug.php?id=45132
2765  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2766  */
2767 function wfInitShellLocale() {
2768         static $done = false;
2769         if ( $done ) {
2770                 return;
2771         }
2772         $done = true;
2773         global $wgShellLocale;
2774         if ( !wfIniGetBool( 'safe_mode' ) ) {
2775                 putenv( "LC_CTYPE=$wgShellLocale" );
2776                 setlocale( LC_CTYPE, $wgShellLocale );
2777         }
2778 }
2779
2780 /**
2781  * Generate a shell-escaped command line string to run a maintenance script.
2782  * Note that $parameters should be a flat array and an option with an argument
2783  * should consist of two consecutive items in the array (do not use "--option value").
2784  * @param $script string MediaWiki maintenance script path
2785  * @param $parameters Array Arguments and options to the script
2786  * @param $options Array Associative array of options:
2787  *              'php': The path to the php executable
2788  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2789  * @return Array
2790  */
2791 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2792         global $wgPhpCli;
2793         // Give site config file a chance to run the script in a wrapper.
2794         // The caller may likely want to call wfBasename() on $script.
2795         wfRunHooks( 'wfShellMaintenanceCmd', array( &$script, &$parameters, &$options ) );
2796         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2797         if ( isset( $options['wrapper'] ) ) {
2798                 $cmd[] = $options['wrapper'];
2799         }
2800         $cmd[] = $script;
2801         // Escape each parameter for shell
2802         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2803 }
2804
2805 /**
2806  * wfMerge attempts to merge differences between three texts.
2807  * Returns true for a clean merge and false for failure or a conflict.
2808  *
2809  * @param $old String
2810  * @param $mine String
2811  * @param $yours String
2812  * @param $result String
2813  * @return Bool
2814  */
2815 function wfMerge( $old, $mine, $yours, &$result ) {
2816         global $wgDiff3;
2817
2818         # This check may also protect against code injection in
2819         # case of broken installations.
2820         wfSuppressWarnings();
2821         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2822         wfRestoreWarnings();
2823
2824         if( !$haveDiff3 ) {
2825                 wfDebug( "diff3 not found\n" );
2826                 return false;
2827         }
2828
2829         # Make temporary files
2830         $td = wfTempDir();
2831         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2832         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2833         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2834
2835         fwrite( $oldtextFile, $old );
2836         fclose( $oldtextFile );
2837         fwrite( $mytextFile, $mine );
2838         fclose( $mytextFile );
2839         fwrite( $yourtextFile, $yours );
2840         fclose( $yourtextFile );
2841
2842         # Check for a conflict
2843         $cmd = $wgDiff3 . ' -a --overlap-only ' .
2844                 wfEscapeShellArg( $mytextName ) . ' ' .
2845                 wfEscapeShellArg( $oldtextName ) . ' ' .
2846                 wfEscapeShellArg( $yourtextName );
2847         $handle = popen( $cmd, 'r' );
2848
2849         if( fgets( $handle, 1024 ) ) {
2850                 $conflict = true;
2851         } else {
2852                 $conflict = false;
2853         }
2854         pclose( $handle );
2855
2856         # Merge differences
2857         $cmd = $wgDiff3 . ' -a -e --merge ' .
2858                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2859         $handle = popen( $cmd, 'r' );
2860         $result = '';
2861         do {
2862                 $data = fread( $handle, 8192 );
2863                 if ( strlen( $data ) == 0 ) {
2864                         break;
2865                 }
2866                 $result .= $data;
2867         } while ( true );
2868         pclose( $handle );
2869         unlink( $mytextName );
2870         unlink( $oldtextName );
2871         unlink( $yourtextName );
2872
2873         if ( $result === '' && $old !== '' && !$conflict ) {
2874                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2875                 $conflict = true;
2876         }
2877         return !$conflict;
2878 }
2879
2880 /**
2881  * Returns unified plain-text diff of two texts.
2882  * Useful for machine processing of diffs.
2883  *
2884  * @param $before String: the text before the changes.
2885  * @param $after String: the text after the changes.
2886  * @param $params String: command-line options for the diff command.
2887  * @return String: unified diff of $before and $after
2888  */
2889 function wfDiff( $before, $after, $params = '-u' ) {
2890         if ( $before == $after ) {
2891                 return '';
2892         }
2893
2894         global $wgDiff;
2895         wfSuppressWarnings();
2896         $haveDiff = $wgDiff && file_exists( $wgDiff );
2897         wfRestoreWarnings();
2898
2899         # This check may also protect against code injection in
2900         # case of broken installations.
2901         if( !$haveDiff ) {
2902                 wfDebug( "diff executable not found\n" );
2903                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2904                 $format = new UnifiedDiffFormatter();
2905                 return $format->format( $diffs );
2906         }
2907
2908         # Make temporary files
2909         $td = wfTempDir();
2910         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2911         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2912
2913         fwrite( $oldtextFile, $before );
2914         fclose( $oldtextFile );
2915         fwrite( $newtextFile, $after );
2916         fclose( $newtextFile );
2917
2918         // Get the diff of the two files
2919         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2920
2921         $h = popen( $cmd, 'r' );
2922
2923         $diff = '';
2924
2925         do {
2926                 $data = fread( $h, 8192 );
2927                 if ( strlen( $data ) == 0 ) {
2928                         break;
2929                 }
2930                 $diff .= $data;
2931         } while ( true );
2932
2933         // Clean up
2934         pclose( $h );
2935         unlink( $oldtextName );
2936         unlink( $newtextName );
2937
2938         // Kill the --- and +++ lines. They're not useful.
2939         $diff_lines = explode( "\n", $diff );
2940         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
2941                 unset( $diff_lines[0] );
2942         }
2943         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
2944                 unset( $diff_lines[1] );
2945         }
2946
2947         $diff = implode( "\n", $diff_lines );
2948
2949         return $diff;
2950 }
2951
2952 /**
2953  * This function works like "use VERSION" in Perl, the program will die with a
2954  * backtrace if the current version of PHP is less than the version provided
2955  *
2956  * This is useful for extensions which due to their nature are not kept in sync
2957  * with releases, and might depend on other versions of PHP than the main code
2958  *
2959  * Note: PHP might die due to parsing errors in some cases before it ever
2960  *       manages to call this function, such is life
2961  *
2962  * @see perldoc -f use
2963  *
2964  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2965  *                 a float
2966  */
2967 function wfUsePHP( $req_ver ) {
2968         $php_ver = PHP_VERSION;
2969
2970         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2971                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2972         }
2973 }
2974
2975 /**
2976  * This function works like "use VERSION" in Perl except it checks the version
2977  * of MediaWiki, the program will die with a backtrace if the current version
2978  * of MediaWiki is less than the version provided.
2979  *
2980  * This is useful for extensions which due to their nature are not kept in sync
2981  * with releases
2982  *
2983  * @see perldoc -f use
2984  *
2985  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2986  *                 a float
2987  */
2988 function wfUseMW( $req_ver ) {
2989         global $wgVersion;
2990
2991         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2992                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2993         }
2994 }
2995
2996 /**
2997  * Return the final portion of a pathname.
2998  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2999  * http://bugs.php.net/bug.php?id=33898
3000  *
3001  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3002  * We'll consider it so always, as we don't want \s in our Unix paths either.
3003  *
3004  * @param $path String
3005  * @param $suffix String: to remove if present
3006  * @return String
3007  */
3008 function wfBaseName( $path, $suffix = '' ) {
3009         $encSuffix = ( $suffix == '' )
3010                 ? ''
3011                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3012         $matches = array();
3013         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3014                 return $matches[1];
3015         } else {
3016                 return '';
3017         }
3018 }
3019
3020 /**
3021  * Generate a relative path name to the given file.
3022  * May explode on non-matching case-insensitive paths,
3023  * funky symlinks, etc.
3024  *
3025  * @param $path String: absolute destination path including target filename
3026  * @param $from String: Absolute source path, directory only
3027  * @return String
3028  */
3029 function wfRelativePath( $path, $from ) {
3030         // Normalize mixed input on Windows...
3031         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3032         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3033
3034         // Trim trailing slashes -- fix for drive root
3035         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3036         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3037
3038         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3039         $against = explode( DIRECTORY_SEPARATOR, $from );
3040
3041         if( $pieces[0] !== $against[0] ) {
3042                 // Non-matching Windows drive letters?
3043                 // Return a full path.
3044                 return $path;
3045         }
3046
3047         // Trim off common prefix
3048         while( count( $pieces ) && count( $against )
3049                 && $pieces[0] == $against[0] ) {
3050                 array_shift( $pieces );
3051                 array_shift( $against );
3052         }
3053
3054         // relative dots to bump us to the parent
3055         while( count( $against ) ) {
3056                 array_unshift( $pieces, '..' );
3057                 array_shift( $against );
3058         }
3059
3060         array_push( $pieces, wfBaseName( $path ) );
3061
3062         return implode( DIRECTORY_SEPARATOR, $pieces );
3063 }
3064
3065 /**
3066  * Do any deferred updates and clear the list
3067  *
3068  * @deprecated since 1.19
3069  * @see DeferredUpdates::doUpdate()
3070  * @param $commit string
3071  */
3072 function wfDoUpdates( $commit = '' ) {
3073         wfDeprecated( __METHOD__, '1.19' );
3074         DeferredUpdates::doUpdates( $commit );
3075 }
3076
3077 /**
3078  * Convert an arbitrarily-long digit string from one numeric base
3079  * to another, optionally zero-padding to a minimum column width.
3080  *
3081  * Supports base 2 through 36; digit values 10-36 are represented
3082  * as lowercase letters a-z. Input is case-insensitive.
3083  *
3084  * @param $input String: of digits
3085  * @param $sourceBase Integer: 2-36
3086  * @param $destBase Integer: 2-36
3087  * @param $pad Integer: 1 or greater
3088  * @param $lowercase Boolean
3089  * @return String or false on invalid input
3090  */
3091 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3092         $input = strval( $input );
3093         if( $sourceBase < 2 ||
3094                 $sourceBase > 36 ||
3095                 $destBase < 2 ||
3096                 $destBase > 36 ||
3097                 $pad < 1 ||
3098                 $sourceBase != intval( $sourceBase ) ||
3099                 $destBase != intval( $destBase ) ||
3100                 $pad != intval( $pad ) ||
3101                 !is_string( $input ) ||
3102                 $input == '' ) {
3103                 return false;
3104         }
3105         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3106         $inDigits = array();
3107         $outChars = '';
3108
3109         // Decode and validate input string
3110         $input = strtolower( $input );
3111         for( $i = 0; $i < strlen( $input ); $i++ ) {
3112                 $n = strpos( $digitChars, $input[$i] );
3113                 if( $n === false || $n > $sourceBase ) {
3114                         return false;
3115                 }
3116                 $inDigits[] = $n;
3117         }
3118
3119         // Iterate over the input, modulo-ing out an output digit
3120         // at a time until input is gone.
3121         while( count( $inDigits ) ) {
3122                 $work = 0;
3123                 $workDigits = array();
3124
3125                 // Long division...
3126                 foreach( $inDigits as $digit ) {
3127                         $work *= $sourceBase;
3128                         $work += $digit;
3129
3130                         if( $work < $destBase ) {
3131                                 // Gonna need to pull another digit.
3132                                 if( count( $workDigits ) ) {
3133                                         // Avoid zero-padding; this lets us find
3134                                         // the end of the input very easily when
3135                                         // length drops to zero.
3136                                         $workDigits[] = 0;
3137                                 }
3138                         } else {
3139                                 // Finally! Actual division!
3140                                 $workDigits[] = intval( $work / $destBase );
3141
3142                                 // Isn't it annoying that most programming languages
3143                                 // don't have a single divide-and-remainder operator,
3144                                 // even though the CPU implements it that way?
3145                                 $work = $work % $destBase;
3146                         }
3147                 }
3148
3149                 // All that division leaves us with a remainder,
3150                 // which is conveniently our next output digit.
3151                 $outChars .= $digitChars[$work];
3152
3153                 // And we continue!
3154                 $inDigits = $workDigits;
3155         }
3156
3157         while( strlen( $outChars ) < $pad ) {
3158                 $outChars .= '0';
3159         }
3160
3161         return strrev( $outChars );
3162 }
3163
3164 /**
3165  * Create an object with a given name and an array of construct parameters
3166  *
3167  * @param $name String
3168  * @param $p Array: parameters
3169  * @return object
3170  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3171  */
3172 function wfCreateObject( $name, $p ) {
3173         wfDeprecated( __FUNCTION__, '1.18' );
3174         return MWFunction::newObj( $name, $p );
3175 }
3176
3177 /**
3178  * @return bool
3179  */
3180 function wfHttpOnlySafe() {
3181         global $wgHttpOnlyBlacklist;
3182
3183         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3184                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3185                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3186                                 return false;
3187                         }
3188                 }
3189         }
3190
3191         return true;
3192 }
3193
3194 /**
3195  * Initialise php session
3196  *
3197  * @param $sessionId Bool
3198  */
3199 function wfSetupSession( $sessionId = false ) {
3200         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3201                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3202         if( $wgSessionsInMemcached ) {
3203                 if ( !defined( 'MW_COMPILED' ) ) {
3204                         global $IP;
3205                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
3206                 }
3207                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3208                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3209
3210                 // It's necessary to register a shutdown function to call session_write_close(),
3211                 // because by the time the request shutdown function for the session module is
3212                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3213                 // this way are called before object destruction.
3214                 register_shutdown_function( 'memsess_write_close' );
3215         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3216                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3217                 # hasn't already been set to the desired value (that causes errors)
3218                 ini_set( 'session.save_handler', $wgSessionHandler );
3219         }
3220         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3221         wfDebugLog( 'cookie',
3222                 'session_set_cookie_params: "' . implode( '", "',
3223                         array(
3224                                 0,
3225                                 $wgCookiePath,
3226                                 $wgCookieDomain,
3227                                 $wgCookieSecure,
3228                                 $httpOnlySafe ) ) . '"' );
3229         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3230         session_cache_limiter( 'private, must-revalidate' );
3231         if ( $sessionId ) {
3232                 session_id( $sessionId );
3233         }
3234         wfSuppressWarnings();
3235         session_start();
3236         wfRestoreWarnings();
3237 }
3238
3239 /**
3240  * Get an object from the precompiled serialized directory
3241  *
3242  * @param $name String
3243  * @return Mixed: the variable on success, false on failure
3244  */
3245 function wfGetPrecompiledData( $name ) {
3246         global $IP;
3247
3248         $file = "$IP/serialized/$name";
3249         if ( file_exists( $file ) ) {
3250                 $blob = file_get_contents( $file );
3251                 if ( $blob ) {
3252                         return unserialize( $blob );
3253                 }
3254         }
3255         return false;
3256 }
3257
3258 /**
3259  * Get a cache key
3260  *
3261  * @param varargs
3262  * @return String
3263  */
3264 function wfMemcKey( /*... */ ) {
3265         global $wgCachePrefix;
3266         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3267         $args = func_get_args();
3268         $key = $prefix . ':' . implode( ':', $args );
3269         $key = str_replace( ' ', '_', $key );
3270         return $key;
3271 }
3272
3273 /**
3274  * Get a cache key for a foreign DB
3275  *
3276  * @param $db String
3277  * @param $prefix String
3278  * @param varargs String
3279  * @return String
3280  */
3281 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3282         $args = array_slice( func_get_args(), 2 );
3283         if ( $prefix ) {
3284                 $key = "$db-$prefix:" . implode( ':', $args );
3285         } else {
3286                 $key = $db . ':' . implode( ':', $args );
3287         }
3288         return $key;
3289 }
3290
3291 /**
3292  * Get an ASCII string identifying this wiki
3293  * This is used as a prefix in memcached keys
3294  *
3295  * @return String
3296  */
3297 function wfWikiID() {
3298         global $wgDBprefix, $wgDBname;
3299         if ( $wgDBprefix ) {
3300                 return "$wgDBname-$wgDBprefix";
3301         } else {
3302                 return $wgDBname;
3303         }
3304 }
3305
3306 /**
3307  * Split a wiki ID into DB name and table prefix
3308  *
3309  * @param $wiki String
3310  *
3311  * @return array
3312  */
3313 function wfSplitWikiID( $wiki ) {
3314         $bits = explode( '-', $wiki, 2 );
3315         if ( count( $bits ) < 2 ) {
3316                 $bits[] = '';
3317         }
3318         return $bits;
3319 }
3320
3321 /**
3322  * Get a Database object.
3323  *
3324  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3325  *            master (for write queries), DB_SLAVE for potentially lagged read
3326  *            queries, or an integer >= 0 for a particular server.
3327  *
3328  * @param $groups Mixed: query groups. An array of group names that this query
3329  *                belongs to. May contain a single string if the query is only
3330  *                in one group.
3331  *
3332  * @param $wiki String: the wiki ID, or false for the current wiki
3333  *
3334  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3335  * will always return the same object, unless the underlying connection or load
3336  * balancer is manually destroyed.
3337  *
3338  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3339  * updater to ensure that a proper database is being updated.
3340  *
3341  * @return DatabaseBase
3342  */
3343 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3344         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3345 }
3346
3347 /**
3348  * Get a load balancer object.
3349  *
3350  * @param $wiki String: wiki ID, or false for the current wiki
3351  * @return LoadBalancer
3352  */
3353 function wfGetLB( $wiki = false ) {
3354         return wfGetLBFactory()->getMainLB( $wiki );
3355 }
3356
3357 /**
3358  * Get the load balancer factory object
3359  *
3360  * @return LBFactory
3361  */
3362 function &wfGetLBFactory() {
3363         return LBFactory::singleton();
3364 }
3365
3366 /**
3367  * Find a file.
3368  * Shortcut for RepoGroup::singleton()->findFile()
3369  *
3370  * @param $title String or Title object
3371  * @param $options Associative array of options:
3372  *     time:           requested time for an archived image, or false for the
3373  *                     current version. An image object will be returned which was
3374  *                     created at the specified time.
3375  *
3376  *     ignoreRedirect: If true, do not follow file redirects
3377  *
3378  *     private:        If true, return restricted (deleted) files if the current
3379  *                     user is allowed to view them. Otherwise, such files will not
3380  *                     be found.
3381  *
3382  *     bypassCache:    If true, do not use the process-local cache of File objects
3383  *
3384  * @return File, or false if the file does not exist
3385  */
3386 function wfFindFile( $title, $options = array() ) {
3387         return RepoGroup::singleton()->findFile( $title, $options );
3388 }
3389
3390 /**
3391  * Get an object referring to a locally registered file.
3392  * Returns a valid placeholder object if the file does not exist.
3393  *
3394  * @param $title Title|String
3395  * @return File|null A File, or null if passed an invalid Title
3396  */
3397 function wfLocalFile( $title ) {
3398         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3399 }
3400
3401 /**
3402  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3403  * @deprecated since 1.19
3404  */
3405 function wfStreamFile( $fname, $headers = array() ) {
3406         wfDeprecated( __FUNCTION__, '1.19' );
3407         StreamFile::stream( $fname, $headers );
3408 }
3409
3410 /**
3411  * Should low-performance queries be disabled?
3412  *
3413  * @return Boolean
3414  * @codeCoverageIgnore
3415  */
3416 function wfQueriesMustScale() {
3417         global $wgMiserMode;
3418         return $wgMiserMode
3419                 || ( SiteStats::pages() > 100000
3420                 && SiteStats::edits() > 1000000
3421                 && SiteStats::users() > 10000 );
3422 }
3423
3424 /**
3425  * Get the path to a specified script file, respecting file
3426  * extensions; this is a wrapper around $wgScriptExtension etc.
3427  *
3428  * @param $script String: script filename, sans extension
3429  * @return String
3430  */
3431 function wfScript( $script = 'index' ) {
3432         global $wgScriptPath, $wgScriptExtension;
3433         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3434 }
3435
3436 /**
3437  * Get the script URL.
3438  *
3439  * @return script URL
3440  */
3441 function wfGetScriptUrl() {
3442         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3443                 #
3444                 # as it was called, minus the query string.
3445                 #
3446                 # Some sites use Apache rewrite rules to handle subdomains,
3447                 # and have PHP set up in a weird way that causes PHP_SELF
3448                 # to contain the rewritten URL instead of the one that the
3449                 # outside world sees.
3450                 #
3451                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3452                 # provides containing the "before" URL.
3453                 return $_SERVER['SCRIPT_NAME'];
3454         } else {
3455                 return $_SERVER['URL'];
3456         }
3457 }
3458
3459 /**
3460  * Convenience function converts boolean values into "true"
3461  * or "false" (string) values
3462  *
3463  * @param $value Boolean
3464  * @return String
3465  */
3466 function wfBoolToStr( $value ) {
3467         return $value ? 'true' : 'false';
3468 }
3469
3470 /**
3471  * Load an extension messages file
3472  *
3473  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3474  * @codeCoverageIgnore
3475  */
3476 function wfLoadExtensionMessages() {
3477         wfDeprecated( __FUNCTION__, '1.16' );
3478 }
3479
3480 /**
3481  * Get a platform-independent path to the null file, e.g. /dev/null
3482  *
3483  * @return string
3484  */
3485 function wfGetNull() {
3486         return wfIsWindows()
3487                 ? 'NUL'
3488                 : '/dev/null';
3489 }
3490
3491 /**
3492  * Throws a warning that $function is deprecated
3493  *
3494  * @param $function String
3495  * @param $version String|false: Added in 1.19.
3496  * @param $component String|false: Added in 1.19.
3497  *
3498  * @return null
3499  */
3500 function wfDeprecated( $function, $version = false, $component = false ) {
3501         static $functionsWarned = array();
3502
3503         MWDebug::deprecated( $function, $version, $component );
3504
3505         if ( !isset( $functionsWarned[$function] ) ) {
3506                 $functionsWarned[$function] = true;
3507
3508                 if ( $version ) {
3509                         global $wgDeprecationReleaseLimit;
3510
3511                         if ( $wgDeprecationReleaseLimit && $component === false ) {
3512                                 # Strip -* off the end of $version so that branches can use the
3513                                 # format #.##-branchname to avoid issues if the branch is merged into
3514                                 # a version of MediaWiki later than what it was branched from
3515                                 $comparableVersion = preg_replace( '/-.*$/', '', $version );
3516
3517                                 # If the comparableVersion is larger than our release limit then
3518                                 # skip the warning message for the deprecation
3519                                 if ( version_compare( $wgDeprecationReleaseLimit, $comparableVersion, '<' ) ) {
3520                                         return;
3521                                 }
3522                         }
3523
3524                         $component = $component === false ? 'MediaWiki' : $component;
3525                         wfWarn( "Use of $function was deprecated in $component $version.", 2 );
3526                 } else {
3527                         wfWarn( "Use of $function is deprecated.", 2 );
3528                 }
3529         }
3530 }
3531
3532 /**
3533  * Send a warning either to the debug log or in a PHP error depending on
3534  * $wgDevelopmentWarnings
3535  *
3536  * @param $msg String: message to send
3537  * @param $callerOffset Integer: number of items to go back in the backtrace to
3538  *        find the correct caller (1 = function calling wfWarn, ...)
3539  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3540  *        is true
3541  */
3542 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3543         global $wgDevelopmentWarnings;
3544
3545         MWDebug::warning( $msg, $callerOffset + 2 );
3546
3547         $callers = wfDebugBacktrace();
3548         if ( isset( $callers[$callerOffset + 1] ) ) {
3549                 $callerfunc = $callers[$callerOffset + 1];
3550                 $callerfile = $callers[$callerOffset];
3551                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3552                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3553                 } else {
3554                         $file = '(internal function)';
3555                 }
3556                 $func = '';
3557                 if ( isset( $callerfunc['class'] ) ) {
3558                         $func .= $callerfunc['class'] . '::';
3559                 }
3560                 if ( isset( $callerfunc['function'] ) ) {
3561                         $func .= $callerfunc['function'];
3562                 }
3563                 $msg .= " [Called from $func in $file]";
3564         }
3565
3566         if ( $wgDevelopmentWarnings ) {
3567                 trigger_error( $msg, $level );
3568         } else {
3569                 wfDebug( "$msg\n" );
3570         }
3571 }
3572
3573 /**
3574  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3575  * and waiting for it to go down, this waits for the slaves to catch up to the
3576  * master position. Use this when updating very large numbers of rows, as
3577  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3578  * a no-op if there are no slaves.
3579  *
3580  * @param $maxLag Integer (deprecated)
3581  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3582  */
3583 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3584         $lb = wfGetLB( $wiki );
3585         // bug 27975 - Don't try to wait for slaves if there are none
3586         // Prevents permission error when getting master position
3587         if ( $lb->getServerCount() > 1 ) {
3588                 $dbw = $lb->getConnection( DB_MASTER );
3589                 $pos = $dbw->getMasterPos();
3590                 $lb->waitForAll( $pos );
3591         }
3592 }
3593
3594 /**
3595  * Used to be used for outputting text in the installer/updater
3596  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3597  */
3598 function wfOut( $s ) {
3599         wfDeprecated( __FUNCTION__, '1.18' );
3600         global $wgCommandLineMode;
3601         if ( $wgCommandLineMode ) {
3602                 echo $s;
3603         } else {
3604                 echo htmlspecialchars( $s );
3605         }
3606         flush();
3607 }
3608
3609 /**
3610  * Count down from $n to zero on the terminal, with a one-second pause
3611  * between showing each number. For use in command-line scripts.
3612  * @codeCoverageIgnore
3613  * @param $n int
3614  */
3615 function wfCountDown( $n ) {
3616         for ( $i = $n; $i >= 0; $i-- ) {
3617                 if ( $i != $n ) {
3618                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3619                 }
3620                 echo $i;
3621                 flush();
3622                 if ( $i ) {
3623                         sleep( 1 );
3624                 }
3625         }
3626         echo "\n";
3627 }
3628
3629 /**
3630  * Generate a random 32-character hexadecimal token.
3631  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3632  *              characters before hashing.
3633  * @return string
3634  * @codeCoverageIgnore
3635  */
3636 function wfGenerateToken( $salt = '' ) {
3637         $salt = serialize( $salt );
3638         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3639 }
3640
3641 /**
3642  * Replace all invalid characters with -
3643  *
3644  * @param $name Mixed: filename to process
3645  * @return String
3646  */
3647 function wfStripIllegalFilenameChars( $name ) {
3648         global $wgIllegalFileChars;
3649         $name = wfBaseName( $name );
3650         $name = preg_replace(
3651                 "/[^" . Title::legalChars() . "]" .
3652                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3653                         "/",
3654                 '-',
3655                 $name
3656         );
3657         return $name;
3658 }
3659
3660 /**
3661  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3662  *
3663  * @return Integer value memory was set to.
3664  */
3665 function wfMemoryLimit() {
3666         global $wgMemoryLimit;
3667         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3668         if( $memlimit != -1 ) {
3669                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3670                 if( $conflimit == -1 ) {
3671                         wfDebug( "Removing PHP's memory limit\n" );
3672                         wfSuppressWarnings();
3673                         ini_set( 'memory_limit', $conflimit );
3674                         wfRestoreWarnings();
3675                         return $conflimit;
3676                 } elseif ( $conflimit > $memlimit ) {
3677                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3678                         wfSuppressWarnings();
3679                         ini_set( 'memory_limit', $conflimit );
3680                         wfRestoreWarnings();
3681                         return $conflimit;
3682                 }
3683         }
3684         return $memlimit;
3685 }
3686
3687 /**
3688  * Converts shorthand byte notation to integer form
3689  *
3690  * @param $string String
3691  * @return Integer
3692  */
3693 function wfShorthandToInteger( $string = '' ) {
3694         $string = trim( $string );
3695         if( $string === '' ) {
3696                 return -1;
3697         }
3698         $last = $string[strlen( $string ) - 1];
3699         $val = intval( $string );
3700         switch( $last ) {
3701                 case 'g':
3702                 case 'G':
3703                         $val *= 1024;
3704                         // break intentionally missing
3705                 case 'm':
3706                 case 'M':
3707                         $val *= 1024;
3708                         // break intentionally missing
3709                 case 'k':
3710                 case 'K':
3711                         $val *= 1024;
3712         }
3713
3714         return $val;
3715 }
3716
3717 /**
3718  * Get the normalised IETF language tag
3719  * See unit test for examples.
3720  *
3721  * @param $code String: The language code.
3722  * @return String: The language code which complying with BCP 47 standards.
3723  */
3724 function wfBCP47( $code ) {
3725         $codeSegment = explode( '-', $code );
3726         $codeBCP = array();
3727         foreach ( $codeSegment as $segNo => $seg ) {
3728                 if ( count( $codeSegment ) > 0 ) {
3729                         // when previous segment is x, it is a private segment and should be lc
3730                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3731                                 $codeBCP[$segNo] = strtolower( $seg );
3732                         // ISO 3166 country code
3733                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3734                                 $codeBCP[$segNo] = strtoupper( $seg );
3735                         // ISO 15924 script code
3736                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3737                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3738                         // Use lowercase for other cases
3739                         } else {
3740                                 $codeBCP[$segNo] = strtolower( $seg );
3741                         }
3742                 } else {
3743                 // Use lowercase for single segment
3744                         $codeBCP[$segNo] = strtolower( $seg );
3745                 }
3746         }
3747         $langCode = implode( '-', $codeBCP );
3748         return $langCode;
3749 }
3750
3751 /**
3752  * Get a cache object.
3753  *
3754  * @param $inputType integer Cache type, one the the CACHE_* constants.
3755  * @return BagOStuff
3756  */
3757 function wfGetCache( $inputType ) {
3758         return ObjectCache::getInstance( $inputType );
3759 }
3760
3761 /**
3762  * Get the main cache object
3763  *
3764  * @return BagOStuff
3765  */
3766 function wfGetMainCache() {
3767         global $wgMainCacheType;
3768         return ObjectCache::getInstance( $wgMainCacheType );
3769 }
3770
3771 /**
3772  * Get the cache object used by the message cache
3773  *
3774  * @return BagOStuff
3775  */
3776 function wfGetMessageCacheStorage() {
3777         global $wgMessageCacheType;
3778         return ObjectCache::getInstance( $wgMessageCacheType );
3779 }
3780
3781 /**
3782  * Get the cache object used by the parser cache
3783  *
3784  * @return BagOStuff
3785  */
3786 function wfGetParserCacheStorage() {
3787         global $wgParserCacheType;
3788         return ObjectCache::getInstance( $wgParserCacheType );
3789 }
3790
3791 /**
3792  * Call hook functions defined in $wgHooks
3793  *
3794  * @param $event String: event name
3795  * @param $args Array: parameters passed to hook functions
3796  * @return Boolean True if no handler aborted the hook
3797  */
3798 function wfRunHooks( $event, $args = array() ) {
3799         return Hooks::run( $event, $args );
3800 }
3801
3802 /**
3803  * Wrapper around php's unpack.
3804  *
3805  * @param $format String: The format string (See php's docs)
3806  * @param $data: A binary string of binary data
3807  * @param $length integer or false: The minimun length of $data. This is to
3808  *      prevent reading beyond the end of $data. false to disable the check.
3809  *
3810  * Also be careful when using this function to read unsigned 32 bit integer
3811  * because php might make it negative.
3812  *
3813  * @throws MWException if $data not long enough, or if unpack fails
3814  * @return Associative array of the extracted data
3815  */
3816 function wfUnpack( $format, $data, $length=false ) {
3817         if ( $length !== false ) {
3818                 $realLen = strlen( $data );
3819                 if ( $realLen < $length ) {
3820                         throw new MWException( "Tried to use wfUnpack on a "
3821                                 . "string of length $realLen, but needed one "
3822                                 . "of at least length $length."
3823                         );
3824                 }
3825         }
3826
3827         wfSuppressWarnings();
3828         $result = unpack( $format, $data );
3829         wfRestoreWarnings();
3830
3831         if ( $result === false ) {
3832                 // If it cannot extract the packed data.
3833                 throw new MWException( "unpack could not unpack binary data" );
3834         }
3835         return $result;
3836 }