includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 // Hide compatibility functions from Doxygen
  28 /// @cond
  29
  30 /**
  31  * Compatibility functions
  32  *
  33  * We support PHP 5.3.2 and up.
  34  * Re-implementations of newer functions or functions in non-standard
  35  * PHP extensions may be included here.
  36  */
  37
  38 if( !function_exists( 'iconv' ) ) {
  39         /**
  40          * @codeCoverageIgnore
  41          * @return string
  42          */
  43         function iconv( $from, $to, $string ) {
  44                 return Fallback::iconv( $from, $to, $string );
  45         }
  46 }
  47
  48 if ( !function_exists( 'mb_substr' ) ) {
  49         /**
  50          * @codeCoverageIgnore
  51          * @return string
  52          */
  53         function mb_substr( $str, $start, $count='end' ) {
  54                 return Fallback::mb_substr( $str, $start, $count );
  55         }
  56
  57         /**
  58          * @codeCoverageIgnore
  59          * @return int
  60          */
  61         function mb_substr_split_unicode( $str, $splitPos ) {
  62                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  63         }
  64 }
  65
  66 if ( !function_exists( 'mb_strlen' ) ) {
  67         /**
  68          * @codeCoverageIgnore
  69          * @return int
  70          */
  71         function mb_strlen( $str, $enc = '' ) {
  72                 return Fallback::mb_strlen( $str, $enc );
  73         }
  74 }
  75
  76 if( !function_exists( 'mb_strpos' ) ) {
  77         /**
  78          * @codeCoverageIgnore
  79          * @return int
  80          */
  81         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  82                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  83         }
  84
  85 }
  86
  87 if( !function_exists( 'mb_strrpos' ) ) {
  88         /**
  89          * @codeCoverageIgnore
  90          * @return int
  91          */
  92         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  93                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  94         }
  95 }
  96
  97
  98 // Support for Wietse Venema's taint feature
  99 if ( !function_exists( 'istainted' ) ) {
 100         /**
 101          * @codeCoverageIgnore
 102          * @return int
 103          */
 104         function istainted( $var ) {
 105                 return 0;
 106         }
 107         /** @codeCoverageIgnore */
 108         function taint( $var, $level = 0 ) {}
 109         /** @codeCoverageIgnore */
 110         function untaint( $var, $level = 0 ) {}
 111         define( 'TC_HTML', 1 );
 112         define( 'TC_SHELL', 1 );
 113         define( 'TC_MYSQL', 1 );
 114         define( 'TC_PCRE', 1 );
 115         define( 'TC_SELF', 1 );
 116 }
 117 /// @endcond
 118
 119 /**
 120  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 121  * @param $a array
 122  * @param $b array
 123  * @return array
 124  */
 125 function wfArrayDiff2( $a, $b ) {
 126         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 127 }
 128
 129 /**
 130  * @param $a
 131  * @param $b
 132  * @return int
 133  */
 134 function wfArrayDiff2_cmp( $a, $b ) {
 135         if ( !is_array( $a ) ) {
 136                 return strcmp( $a, $b );
 137         } elseif ( count( $a ) !== count( $b ) ) {
 138                 return count( $a ) < count( $b ) ? -1 : 1;
 139         } else {
 140                 reset( $a );
 141                 reset( $b );
 142                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 143                         $cmp = strcmp( $valueA, $valueB );
 144                         if ( $cmp !== 0 ) {
 145                                 return $cmp;
 146                         }
 147                 }
 148                 return 0;
 149         }
 150 }
 151
 152 /**
 153  * Array lookup
 154  * Returns an array where the values in the first array are replaced by the
 155  * values in the second array with the corresponding keys
 156  *
 157  * @param $a Array
 158  * @param $b Array
 159  * @return array
 160  */
 161 function wfArrayLookup( $a, $b ) {
 162         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 163 }
 164
 165 /**
 166  * Appends to second array if $value differs from that in $default
 167  *
 168  * @param $key String|Int
 169  * @param $value Mixed
 170  * @param $default Mixed
 171  * @param $changed Array to alter
 172  */
 173 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 174         if ( is_null( $changed ) ) {
 175                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 176         }
 177         if ( $default[$key] !== $value ) {
 178                 $changed[$key] = $value;
 179         }
 180 }
 181
 182 /**
 183  * Backwards array plus for people who haven't bothered to read the PHP manual
 184  * XXX: will not darn your socks for you.
 185  *
 186  * @param $array1 Array
 187  * @param [$array2, [...]] Arrays
 188  * @return Array
 189  */
 190 function wfArrayMerge( $array1/* ... */ ) {
 191         $args = func_get_args();
 192         $args = array_reverse( $args, true );
 193         $out = array();
 194         foreach ( $args as $arg ) {
 195                 $out += $arg;
 196         }
 197         return $out;
 198 }
 199
 200 /**
 201  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 202  * e.g.
 203  *      wfMergeErrorArrays(
 204  *              array( array( 'x' ) ),
 205  *              array( array( 'x', '2' ) ),
 206  *              array( array( 'x' ) ),
 207  *              array( array( 'y' ) )
 208  *      );
 209  * returns:
 210  *              array(
 211  *              array( 'x', '2' ),
 212  *              array( 'x' ),
 213  *              array( 'y' )
 214  *      )
 215  * @param varargs
 216  * @return Array
 217  */
 218 function wfMergeErrorArrays( /*...*/ ) {
 219         $args = func_get_args();
 220         $out = array();
 221         foreach ( $args as $errors ) {
 222                 foreach ( $errors as $params ) {
 223                         # @todo FIXME: Sometimes get nested arrays for $params,
 224                         # which leads to E_NOTICEs
 225                         $spec = implode( "\t", $params );
 226                         $out[$spec] = $params;
 227                 }
 228         }
 229         return array_values( $out );
 230 }
 231
 232 /**
 233  * Insert array into another array after the specified *KEY*
 234  *
 235  * @param $array Array: The array.
 236  * @param $insert Array: The array to insert.
 237  * @param $after Mixed: The key to insert after
 238  * @return Array
 239  */
 240 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 241         // Find the offset of the element to insert after.
 242         $keys = array_keys( $array );
 243         $offsetByKey = array_flip( $keys );
 244
 245         $offset = $offsetByKey[$after];
 246
 247         // Insert at the specified offset
 248         $before = array_slice( $array, 0, $offset + 1, true );
 249         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 250
 251         $output = $before + $insert + $after;
 252
 253         return $output;
 254 }
 255
 256 /**
 257  * Recursively converts the parameter (an object) to an array with the same data
 258  *
 259  * @param $objOrArray Object|Array
 260  * @param $recursive Bool
 261  * @return Array
 262  */
 263 function wfObjectToArray( $objOrArray, $recursive = true ) {
 264         $array = array();
 265         if( is_object( $objOrArray ) ) {
 266                 $objOrArray = get_object_vars( $objOrArray );
 267         }
 268         foreach ( $objOrArray as $key => $value ) {
 269                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 270                         $value = wfObjectToArray( $value );
 271                 }
 272
 273                 $array[$key] = $value;
 274         }
 275
 276         return $array;
 277 }
 278
 279 /**
 280  * Wrapper around array_map() which also taints variables
 281  *
 282  * @param  $function Callback
 283  * @param  $input Array
 284  * @return Array
 285  */
 286 function wfArrayMap( $function, $input ) {
 287         $ret = array_map( $function, $input );
 288         foreach ( $ret as $key => $value ) {
 289                 $taint = istainted( $input[$key] );
 290                 if ( $taint ) {
 291                         taint( $ret[$key], $taint );
 292                 }
 293         }
 294         return $ret;
 295 }
 296
 297 /**
 298  * Get a random decimal value between 0 and 1, in a way
 299  * not likely to give duplicate values for any realistic
 300  * number of articles.
 301  *
 302  * @return string
 303  */
 304 function wfRandom() {
 305         # The maximum random value is "only" 2^31-1, so get two random
 306         # values to reduce the chance of dupes
 307         $max = mt_getrandmax() + 1;
 308         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 309                 / $max / $max, 12, '.', '' );
 310         return $rand;
 311 }
 312
 313 /**
 314  * Get a random string containing a number of pesudo-random hex
 315  * characters.
 316  * @note This is not secure, if you are trying to generate some sort
 317  *       of token please use MWCryptRand instead.
 318  *
 319  * @param $length int The length of the string to generate
 320  * @return String
 321  * @since 1.20
 322  */
 323 function wfRandomString( $length = 32 ) {
 324         $str = '';
 325         while ( strlen( $str ) < $length ) {
 326                 $str .= dechex( mt_rand() );
 327         }
 328         return substr( $str, 0, $length );
 329 }
 330
 331 /**
 332  * We want some things to be included as literal characters in our title URLs
 333  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 334  * all of the following should be safe:
 335  *
 336  * ;:@&=$-_.+!*'(),
 337  *
 338  * But + is not safe because it's used to indicate a space; &= are only safe in
 339  * paths and not in queries (and we don't distinguish here); ' seems kind of
 340  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 341  * is reserved, we don't care.  So the list we unescape is:
 342  *
 343  * ;:@$!*(),/
 344  *
 345  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 346  * so no fancy : for IIS7.
 347  *
 348  * %2F in the page titles seems to fatally break for some reason.
 349  *
 350  * @param $s String:
 351  * @return string
 352 */
 353 function wfUrlencode( $s ) {
 354         static $needle;
 355         if ( is_null( $s ) ) {
 356                 $needle = null;
 357                 return '';
 358         }
 359
 360         if ( is_null( $needle ) ) {
 361                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 362                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 363                         $needle[] = '%3A';
 364                 }
 365         }
 366
 367         $s = urlencode( $s );
 368         $s = str_ireplace(
 369                 $needle,
 370                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 371                 $s
 372         );
 373
 374         return $s;
 375 }
 376
 377 /**
 378  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 379  * "days=7&limit=100". Options in the first array override options in the second.
 380  * Options set to null or false will not be output.
 381  *
 382  * @param $array1 Array ( String|Array )
 383  * @param $array2 Array ( String|Array )
 384  * @param $prefix String
 385  * @return String
 386  */
 387 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 388         if ( !is_null( $array2 ) ) {
 389                 $array1 = $array1 + $array2;
 390         }
 391
 392         $cgi = '';
 393         foreach ( $array1 as $key => $value ) {
 394                 if ( !is_null($value) && $value !== false ) {
 395                         if ( $cgi != '' ) {
 396                                 $cgi .= '&';
 397                         }
 398                         if ( $prefix !== '' ) {
 399                                 $key = $prefix . "[$key]";
 400                         }
 401                         if ( is_array( $value ) ) {
 402                                 $firstTime = true;
 403                                 foreach ( $value as $k => $v ) {
 404                                         $cgi .= $firstTime ? '' : '&';
 405                                         if ( is_array( $v ) ) {
 406                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 407                                         } else {
 408                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 409                                         }
 410                                         $firstTime = false;
 411                                 }
 412                         } else {
 413                                 if ( is_object( $value ) ) {
 414                                         $value = $value->__toString();
 415                                 }
 416                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 417                         }
 418                 }
 419         }
 420         return $cgi;
 421 }
 422
 423 /**
 424  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 425  * its argument and returns the same string in array form.  This allows compa-
 426  * tibility with legacy functions that accept raw query strings instead of nice
 427  * arrays.  Of course, keys and values are urldecode()d.
 428  *
 429  * @param $query String: query string
 430  * @return array Array version of input
 431  */
 432 function wfCgiToArray( $query ) {
 433         if ( isset( $query[0] ) && $query[0] == '?' ) {
 434                 $query = substr( $query, 1 );
 435         }
 436         $bits = explode( '&', $query );
 437         $ret = array();
 438         foreach ( $bits as $bit ) {
 439                 if ( $bit === '' ) {
 440                         continue;
 441                 }
 442                 if ( strpos( $bit, '=' ) === false ) {
 443                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 444                         $key = $bit;
 445                         $value = '';
 446                 } else {
 447                         list( $key, $value ) = explode( '=', $bit );
 448                 }
 449                 $key = urldecode( $key );
 450                 $value = urldecode( $value );
 451                 if ( strpos( $key, '[' ) !== false ) {
 452                         $keys = array_reverse( explode( '[', $key ) );
 453                         $key = array_pop( $keys );
 454                         $temp = $value;
 455                         foreach ( $keys as $k ) {
 456                                 $k = substr( $k, 0, -1 );
 457                                 $temp = array( $k => $temp );
 458                         }
 459                         if ( isset( $ret[$key] ) ) {
 460                                 $ret[$key] = array_merge( $ret[$key], $temp );
 461                         } else {
 462                                 $ret[$key] = $temp;
 463                         }
 464                 } else {
 465                         $ret[$key] = $value;
 466                 }
 467         }
 468         return $ret;
 469 }
 470
 471 /**
 472  * Append a query string to an existing URL, which may or may not already
 473  * have query string parameters already. If so, they will be combined.
 474  *
 475  * @param $url String
 476  * @param $query Mixed: string or associative array
 477  * @return string
 478  */
 479 function wfAppendQuery( $url, $query ) {
 480         if ( is_array( $query ) ) {
 481                 $query = wfArrayToCgi( $query );
 482         }
 483         if( $query != '' ) {
 484                 if( false === strpos( $url, '?' ) ) {
 485                         $url .= '?';
 486                 } else {
 487                         $url .= '&';
 488                 }
 489                 $url .= $query;
 490         }
 491         return $url;
 492 }
 493
 494 /**
 495  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 496  * is correct.
 497  *
 498  * The meaning of the PROTO_* constants is as follows:
 499  * PROTO_HTTP: Output a URL starting with http://
 500  * PROTO_HTTPS: Output a URL starting with https://
 501  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 502  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 503  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 504  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 505  *
 506  * @todo this won't work with current-path-relative URLs
 507  * like "subdir/foo.html", etc.
 508  *
 509  * @param $url String: either fully-qualified or a local path + query
 510  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 511  *                             protocol to use if $url or $wgServer is
 512  *                             protocol-relative
 513  * @return string Fully-qualified URL, current-path-relative URL or false if
 514  *                no valid URL can be constructed
 515  */
 516 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 517         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 518         $serverUrl = $wgServer;
 519         if ( $defaultProto === PROTO_CANONICAL ) {
 520                 $serverUrl = $wgCanonicalServer;
 521         }
 522         // Make $wgInternalServer fall back to $wgServer if not set
 523         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 524                 $serverUrl = $wgInternalServer;
 525         }
 526         if ( $defaultProto === PROTO_CURRENT ) {
 527                 $defaultProto = WebRequest::detectProtocol() . '://';
 528         }
 529
 530         // Analyze $serverUrl to obtain its protocol
 531         $bits = wfParseUrl( $serverUrl );
 532         $serverHasProto = $bits && $bits['scheme'] != '';
 533
 534         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 535                 if ( $serverHasProto ) {
 536                         $defaultProto = $bits['scheme'] . '://';
 537                 } else {
 538                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 539                         // Fall back to HTTP in this ridiculous case
 540                         $defaultProto = PROTO_HTTP;
 541                 }
 542         }
 543
 544         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 545
 546         if ( substr( $url, 0, 2 ) == '//' ) {
 547                 $url = $defaultProtoWithoutSlashes . $url;
 548         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 549                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 550                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 551         }
 552
 553         $bits = wfParseUrl( $url );
 554         if ( $bits && isset( $bits['path'] ) ) {
 555                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 556                 return wfAssembleUrl( $bits );
 557         } elseif ( $bits ) {
 558                 # No path to expand
 559                 return $url;
 560         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 561                 # URL is a relative path
 562                 return wfRemoveDotSegments( $url );
 563         }
 564
 565         # Expanded URL is not valid.
 566         return false;
 567 }
 568
 569 /**
 570  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 571  * if you need to edit part of a URL and put it back together.
 572  *
 573  * This is the basic structure used (brackets contain keys for $urlParts):
 574  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 575  *
 576  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 577  *
 578  * @since 1.19
 579  * @param $urlParts Array URL parts, as output from wfParseUrl
 580  * @return string URL assembled from its component parts
 581  */
 582 function wfAssembleUrl( $urlParts ) {
 583         $result = '';
 584
 585         if ( isset( $urlParts['delimiter'] ) ) {
 586                 if ( isset( $urlParts['scheme'] ) ) {
 587                         $result .= $urlParts['scheme'];
 588                 }
 589
 590                 $result .= $urlParts['delimiter'];
 591         }
 592
 593         if ( isset( $urlParts['host'] ) ) {
 594                 if ( isset( $urlParts['user'] ) ) {
 595                         $result .= $urlParts['user'];
 596                         if ( isset( $urlParts['pass'] ) ) {
 597                                 $result .= ':' . $urlParts['pass'];
 598                         }
 599                         $result .= '@';
 600                 }
 601
 602                 $result .= $urlParts['host'];
 603
 604                 if ( isset( $urlParts['port'] ) ) {
 605                         $result .= ':' . $urlParts['port'];
 606                 }
 607         }
 608
 609         if ( isset( $urlParts['path'] ) ) {
 610                 $result .= $urlParts['path'];
 611         }
 612
 613         if ( isset( $urlParts['query'] ) ) {
 614                 $result .= '?' . $urlParts['query'];
 615         }
 616
 617         if ( isset( $urlParts['fragment'] ) ) {
 618                 $result .= '#' . $urlParts['fragment'];
 619         }
 620
 621         return $result;
 622 }
 623
 624 /**
 625  * Remove all dot-segments in the provided URL path.  For example,
 626  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 627  * RFC3986 section 5.2.4.
 628  *
 629  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 630  *
 631  * @param $urlPath String URL path, potentially containing dot-segments
 632  * @return string URL path with all dot-segments removed
 633  */
 634 function wfRemoveDotSegments( $urlPath ) {
 635         $output = '';
 636         $inputOffset = 0;
 637         $inputLength = strlen( $urlPath );
 638
 639         while ( $inputOffset < $inputLength ) {
 640                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 641                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 642                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 643                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 644                 $trimOutput = false;
 645
 646                 if ( $prefixLengthTwo == './' ) {
 647                         # Step A, remove leading "./"
 648                         $inputOffset += 2;
 649                 } elseif ( $prefixLengthThree == '../' ) {
 650                         # Step A, remove leading "../"
 651                         $inputOffset += 3;
 652                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 653                         # Step B, replace leading "/.$" with "/"
 654                         $inputOffset += 1;
 655                         $urlPath[$inputOffset] = '/';
 656                 } elseif ( $prefixLengthThree == '/./' ) {
 657                         # Step B, replace leading "/./" with "/"
 658                         $inputOffset += 2;
 659                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 660                         # Step C, replace leading "/..$" with "/" and
 661                         # remove last path component in output
 662                         $inputOffset += 2;
 663                         $urlPath[$inputOffset] = '/';
 664                         $trimOutput = true;
 665                 } elseif ( $prefixLengthFour == '/../' ) {
 666                         # Step C, replace leading "/../" with "/" and
 667                         # remove last path component in output
 668                         $inputOffset += 3;
 669                         $trimOutput = true;
 670                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 671                         # Step D, remove "^.$"
 672                         $inputOffset += 1;
 673                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 674                         # Step D, remove "^..$"
 675                         $inputOffset += 2;
 676                 } else {
 677                         # Step E, move leading path segment to output
 678                         if ( $prefixLengthOne == '/' ) {
 679                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 680                         } else {
 681                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 682                         }
 683                         if ( $slashPos === false ) {
 684                                 $output .= substr( $urlPath, $inputOffset );
 685                                 $inputOffset = $inputLength;
 686                         } else {
 687                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 688                                 $inputOffset += $slashPos - $inputOffset;
 689                         }
 690                 }
 691
 692                 if ( $trimOutput ) {
 693                         $slashPos = strrpos( $output, '/' );
 694                         if ( $slashPos === false ) {
 695                                 $output = '';
 696                         } else {
 697                                 $output = substr( $output, 0, $slashPos );
 698                         }
 699                 }
 700         }
 701
 702         return $output;
 703 }
 704
 705 /**
 706  * Returns a regular expression of url protocols
 707  *
 708  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 709  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 710  * @return String
 711  */
 712 function wfUrlProtocols( $includeProtocolRelative = true ) {
 713         global $wgUrlProtocols;
 714
 715         // Cache return values separately based on $includeProtocolRelative
 716         static $withProtRel = null, $withoutProtRel = null;
 717         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 718         if ( !is_null( $cachedValue ) ) {
 719                 return $cachedValue;
 720         }
 721
 722         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 723         // with LocalSettings files from 1.5
 724         if ( is_array( $wgUrlProtocols ) ) {
 725                 $protocols = array();
 726                 foreach ( $wgUrlProtocols as $protocol ) {
 727                         // Filter out '//' if !$includeProtocolRelative
 728                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 729                                 $protocols[] = preg_quote( $protocol, '/' );
 730                         }
 731                 }
 732
 733                 $retval = implode( '|', $protocols );
 734         } else {
 735                 // Ignore $includeProtocolRelative in this case
 736                 // This case exists for pre-1.6 compatibility, and we can safely assume
 737                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 738                 // URLs weren't supported until 1.18
 739                 $retval = $wgUrlProtocols;
 740         }
 741
 742         // Cache return value
 743         if ( $includeProtocolRelative ) {
 744                 $withProtRel = $retval;
 745         } else {
 746                 $withoutProtRel = $retval;
 747         }
 748         return $retval;
 749 }
 750
 751 /**
 752  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 753  * you need a regex that matches all URL protocols but does not match protocol-
 754  * relative URLs
 755  * @return String
 756  */
 757 function wfUrlProtocolsWithoutProtRel() {
 758         return wfUrlProtocols( false );
 759 }
 760
 761 /**
 762  * parse_url() work-alike, but non-broken.  Differences:
 763  *
 764  * 1) Does not raise warnings on bad URLs (just returns false)
 765  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 766  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 767  *
 768  * @param $url String: a URL to parse
 769  * @return Array: bits of the URL in an associative array, per PHP docs
 770  */
 771 function wfParseUrl( $url ) {
 772         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 773
 774         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 775         // way to handle them is to just prepend 'http:' and strip the protocol out later
 776         $wasRelative = substr( $url, 0, 2 ) == '//';
 777         if ( $wasRelative ) {
 778                 $url = "http:$url";
 779         }
 780         wfSuppressWarnings();
 781         $bits = parse_url( $url );
 782         wfRestoreWarnings();
 783         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 784         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 785         if ( !$bits || !isset( $bits['scheme'] ) ) {
 786                 return false;
 787         }
 788
 789         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 790         $bits['scheme'] = strtolower( $bits['scheme'] );
 791
 792         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 793         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 794                 $bits['delimiter'] = '://';
 795         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 796                 $bits['delimiter'] = ':';
 797                 // parse_url detects for news: and mailto: the host part of an url as path
 798                 // We have to correct this wrong detection
 799                 if ( isset( $bits['path'] ) ) {
 800                         $bits['host'] = $bits['path'];
 801                         $bits['path'] = '';
 802                 }
 803         } else {
 804                 return false;
 805         }
 806
 807         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 808         if ( !isset( $bits['host'] ) ) {
 809                 $bits['host'] = '';
 810
 811                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 812                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 813                         $bits['path'] = '/' . $bits['path'];
 814                 }
 815         }
 816
 817         // If the URL was protocol-relative, fix scheme and delimiter
 818         if ( $wasRelative ) {
 819                 $bits['scheme'] = '';
 820                 $bits['delimiter'] = '//';
 821         }
 822         return $bits;
 823 }
 824
 825 /**
 826  * Take a URL, make sure it's expanded to fully qualified, and replace any
 827  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 828  * for more compact display and legibility for local audiences.
 829  *
 830  * @todo handle punycode domains too
 831  *
 832  * @param $url string
 833  * @return string
 834  */
 835 function wfExpandIRI( $url ) {
 836         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 837 }
 838
 839 /**
 840  * Private callback for wfExpandIRI
 841  * @param array $matches
 842  * @return string
 843  */
 844 function wfExpandIRI_callback( $matches ) {
 845         return urldecode( $matches[1] );
 846 }
 847
 848
 849
 850 /**
 851  * Make URL indexes, appropriate for the el_index field of externallinks.
 852  *
 853  * @param $url String
 854  * @return array
 855  */
 856 function wfMakeUrlIndexes( $url ) {
 857         $bits = wfParseUrl( $url );
 858
 859         // Reverse the labels in the hostname, convert to lower case
 860         // For emails reverse domainpart only
 861         if ( $bits['scheme'] == 'mailto' ) {
 862                 $mailparts = explode( '@', $bits['host'], 2 );
 863                 if ( count( $mailparts ) === 2 ) {
 864                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 865                 } else {
 866                         // No domain specified, don't mangle it
 867                         $domainpart = '';
 868                 }
 869                 $reversedHost = $domainpart . '@' . $mailparts[0];
 870         } else {
 871                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 872         }
 873         // Add an extra dot to the end
 874         // Why? Is it in wrong place in mailto links?
 875         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 876                 $reversedHost .= '.';
 877         }
 878         // Reconstruct the pseudo-URL
 879         $prot = $bits['scheme'];
 880         $index = $prot . $bits['delimiter'] . $reversedHost;
 881         // Leave out user and password. Add the port, path, query and fragment
 882         if ( isset( $bits['port'] ) ) {
 883                 $index .= ':' . $bits['port'];
 884         }
 885         if ( isset( $bits['path'] ) ) {
 886                 $index .= $bits['path'];
 887         } else {
 888                 $index .= '/';
 889         }
 890         if ( isset( $bits['query'] ) ) {
 891                 $index .= '?' . $bits['query'];
 892         }
 893         if ( isset( $bits['fragment'] ) ) {
 894                 $index .= '#' . $bits['fragment'];
 895         }
 896
 897         if ( $prot == '' ) {
 898                 return array( "http:$index", "https:$index" );
 899         } else {
 900                 return array( $index );
 901         }
 902 }
 903
 904 /**
 905  * Check whether a given URL has a domain that occurs in a given set of domains
 906  * @param $url string URL
 907  * @param $domains array Array of domains (strings)
 908  * @return bool True if the host part of $url ends in one of the strings in $domains
 909  */
 910 function wfMatchesDomainList( $url, $domains ) {
 911         $bits = wfParseUrl( $url );
 912         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 913                 foreach ( (array)$domains as $domain ) {
 914                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 915                         // We should use something that interprets dots instead
 916                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 917                                 return true;
 918                         }
 919                 }
 920         }
 921         return false;
 922 }
 923
 924 /**
 925  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 926  * In normal operation this is a NOP.
 927  *
 928  * Controlling globals:
 929  * $wgDebugLogFile - points to the log file
 930  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 931  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 932  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 933  *
 934  * @param $text String
 935  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 936  */
 937 function wfDebug( $text, $logonly = false ) {
 938         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 939
 940         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 941                 return;
 942         }
 943
 944         $timer = wfDebugTimer();
 945         if ( $timer !== '' ) {
 946                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 947         }
 948
 949         if ( !$logonly ) {
 950                 MWDebug::debugMsg( $text );
 951         }
 952
 953         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 954                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 955                         # Strip unprintables; they can switch terminal modes when binary data
 956                         # gets dumped, which is pretty annoying.
 957                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 958                         $text = $wgDebugLogPrefix . $text;
 959                         wfErrorLog( $text, $wgDebugLogFile );
 960                 }
 961         }
 962 }
 963
 964 /**
 965  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 966  * @return bool
 967  */
 968 function wfIsDebugRawPage() {
 969         static $cache;
 970         if ( $cache !== null ) {
 971                 return $cache;
 972         }
 973         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 974         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 975                 || (
 976                         isset( $_SERVER['SCRIPT_NAME'] )
 977                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 978                 ) )
 979         {
 980                 $cache = true;
 981         } else {
 982                 $cache = false;
 983         }
 984         return $cache;
 985 }
 986
 987 /**
 988  * Get microsecond timestamps for debug logs
 989  *
 990  * @return string
 991  */
 992 function wfDebugTimer() {
 993         global $wgDebugTimestamps, $wgRequestTime;
 994
 995         if ( !$wgDebugTimestamps ) {
 996                 return '';
 997         }
 998
 999         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1000         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1001         return "$prefix $mem  ";
1002 }
1003
1004 /**
1005  * Send a line giving PHP memory usage.
1006  *
1007  * @param $exact Bool: print exact values instead of kilobytes (default: false)
1008  */
1009 function wfDebugMem( $exact = false ) {
1010         $mem = memory_get_usage();
1011         if( !$exact ) {
1012                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1013         } else {
1014                 $mem .= ' bytes';
1015         }
1016         wfDebug( "Memory usage: $mem\n" );
1017 }
1018
1019 /**
1020  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1021  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1022  *
1023  * @param $logGroup String
1024  * @param $text String
1025  * @param $public Bool: whether to log the event in the public log if no private
1026  *                     log file is specified, (default true)
1027  */
1028 function wfDebugLog( $logGroup, $text, $public = true ) {
1029         global $wgDebugLogGroups;
1030         $text = trim( $text ) . "\n";
1031         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
1032                 $time = wfTimestamp( TS_DB );
1033                 $wiki = wfWikiID();
1034                 $host = wfHostname();
1035                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1036                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1037                 }
1038         } elseif ( $public === true ) {
1039                 wfDebug( $text, true );
1040         }
1041 }
1042
1043 /**
1044  * Log for database errors
1045  *
1046  * @param $text String: database error message.
1047  */
1048 function wfLogDBError( $text ) {
1049         global $wgDBerrorLog, $wgDBerrorLogTZ;
1050         static $logDBErrorTimeZoneObject = null;
1051
1052         if ( $wgDBerrorLog ) {
1053                 $host = wfHostname();
1054                 $wiki = wfWikiID();
1055
1056                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1057                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1058                 }
1059
1060                 // Workaround for https://bugs.php.net/bug.php?id=52063
1061                 // Can be removed when min PHP > 5.3.2
1062                 if ( $logDBErrorTimeZoneObject === null ) {
1063                         $d = date_create( "now" );
1064                 } else {
1065                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1066                 }
1067
1068                 $date = $d->format( 'D M j G:i:s T Y' );
1069
1070                 $text = "$date\t$host\t$wiki\t$text";
1071                 wfErrorLog( $text, $wgDBerrorLog );
1072         }
1073 }
1074
1075 /**
1076  * Throws a warning that $function is deprecated
1077  *
1078  * @param $function String
1079  * @param $version String|bool: Version of MediaWiki that the function was deprecated in (Added in 1.19).
1080  * @param $component String|bool: Added in 1.19.
1081  * @param $callerOffset integer: How far up the callstack is the original
1082  *    caller. 2 = function that called the function that called
1083  *    wfDeprecated (Added in 1.20)
1084  *
1085  * @return null
1086  */
1087 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1088         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1089 }
1090
1091 /**
1092  * Send a warning either to the debug log or in a PHP error depending on
1093  * $wgDevelopmentWarnings
1094  *
1095  * @param $msg String: message to send
1096  * @param $callerOffset Integer: number of items to go back in the backtrace to
1097  *        find the correct caller (1 = function calling wfWarn, ...)
1098  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1099  *        is true
1100  */
1101 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1102         MWDebug::warning( $msg, $callerOffset + 1, $level );
1103 }
1104
1105 /**
1106  * Log to a file without getting "file size exceeded" signals.
1107  *
1108  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1109  * send lines to the specified port, prefixed by the specified prefix and a space.
1110  *
1111  * @param $text String
1112  * @param $file String filename
1113  */
1114 function wfErrorLog( $text, $file ) {
1115         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1116                 # Needs the sockets extension
1117                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1118                         // IPv6 bracketed host
1119                         $host = $m[2];
1120                         $port = intval( $m[3] );
1121                         $prefix = isset( $m[4] ) ? $m[4] : false;
1122                         $domain = AF_INET6;
1123                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1124                         $host = $m[2];
1125                         if ( !IP::isIPv4( $host ) ) {
1126                                 $host = gethostbyname( $host );
1127                         }
1128                         $port = intval( $m[3] );
1129                         $prefix = isset( $m[4] ) ? $m[4] : false;
1130                         $domain = AF_INET;
1131                 } else {
1132                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1133                 }
1134
1135                 // Clean it up for the multiplexer
1136                 if ( strval( $prefix ) !== '' ) {
1137                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1138
1139                         // Limit to 64KB
1140                         if ( strlen( $text ) > 65506 ) {
1141                                 $text = substr( $text, 0, 65506 );
1142                         }
1143
1144                         if ( substr( $text, -1 ) != "\n" ) {
1145                                 $text .= "\n";
1146                         }
1147                 } elseif ( strlen( $text ) > 65507 ) {
1148                         $text = substr( $text, 0, 65507 );
1149                 }
1150
1151                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1152                 if ( !$sock ) {
1153                         return;
1154                 }
1155
1156                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1157                 socket_close( $sock );
1158         } else {
1159                 wfSuppressWarnings();
1160                 $exists = file_exists( $file );
1161                 $size = $exists ? filesize( $file ) : false;
1162                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1163                         file_put_contents( $file, $text, FILE_APPEND );
1164                 }
1165                 wfRestoreWarnings();
1166         }
1167 }
1168
1169 /**
1170  * @todo document
1171  */
1172 function wfLogProfilingData() {
1173         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1174         global $wgProfileLimit, $wgUser;
1175
1176         $profiler = Profiler::instance();
1177
1178         # Profiling must actually be enabled...
1179         if ( $profiler->isStub() ) {
1180                 return;
1181         }
1182
1183         // Get total page request time and only show pages that longer than
1184         // $wgProfileLimit time (default is 0)
1185         $elapsed = microtime( true ) - $wgRequestTime;
1186         if ( $elapsed <= $wgProfileLimit ) {
1187                 return;
1188         }
1189
1190         $profiler->logData();
1191
1192         // Check whether this should be logged in the debug file.
1193         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1194                 return;
1195         }
1196
1197         $forward = '';
1198         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1199                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1200         }
1201         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1202                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1203         }
1204         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1205                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1206         }
1207         if ( $forward ) {
1208                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1209         }
1210         // Don't load $wgUser at this late stage just for statistics purposes
1211         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1212         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1213                 $forward .= ' anon';
1214         }
1215         $log = sprintf( "%s\t%04.3f\t%s\n",
1216                 gmdate( 'YmdHis' ), $elapsed,
1217                 urldecode( $wgRequest->getRequestURL() . $forward ) );
1218
1219         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1220 }
1221
1222 /**
1223  * Increment a statistics counter
1224  *
1225  * @param $key String
1226  * @param $count Int
1227  */
1228 function wfIncrStats( $key, $count = 1 ) {
1229         global $wgStatsMethod;
1230
1231         $count = intval( $count );
1232
1233         if( $wgStatsMethod == 'udp' ) {
1234                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
1235                 static $socket;
1236
1237                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
1238
1239                 if ( !$socket ) {
1240                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1241                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1242                         socket_sendto(
1243                                 $socket,
1244                                 $statline,
1245                                 strlen( $statline ),
1246                                 0,
1247                                 $wgUDPProfilerHost,
1248                                 $wgUDPProfilerPort
1249                         );
1250                 }
1251                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1252                 wfSuppressWarnings();
1253                 socket_sendto(
1254                         $socket,
1255                         $statline,
1256                         strlen( $statline ),
1257                         0,
1258                         $wgUDPProfilerHost,
1259                         $wgUDPProfilerPort
1260                 );
1261                 wfRestoreWarnings();
1262         } elseif( $wgStatsMethod == 'cache' ) {
1263                 global $wgMemc;
1264                 $key = wfMemcKey( 'stats', $key );
1265                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1266                         $wgMemc->add( $key, $count );
1267                 }
1268         } else {
1269                 // Disabled
1270         }
1271 }
1272
1273 /**
1274  * Check if the wiki read-only lock file is present. This can be used to lock
1275  * off editing functions, but doesn't guarantee that the database will not be
1276  * modified.
1277  *
1278  * @return bool
1279  */
1280 function wfReadOnly() {
1281         global $wgReadOnlyFile, $wgReadOnly;
1282
1283         if ( !is_null( $wgReadOnly ) ) {
1284                 return (bool)$wgReadOnly;
1285         }
1286         if ( $wgReadOnlyFile == '' ) {
1287                 return false;
1288         }
1289         // Set $wgReadOnly for faster access next time
1290         if ( is_file( $wgReadOnlyFile ) ) {
1291                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1292         } else {
1293                 $wgReadOnly = false;
1294         }
1295         return (bool)$wgReadOnly;
1296 }
1297
1298 /**
1299  * @return bool
1300  */
1301 function wfReadOnlyReason() {
1302         global $wgReadOnly;
1303         wfReadOnly();
1304         return $wgReadOnly;
1305 }
1306
1307 /**
1308  * Return a Language object from $langcode
1309  *
1310  * @param $langcode Mixed: either:
1311  *                  - a Language object
1312  *                  - code of the language to get the message for, if it is
1313  *                    a valid code create a language for that language, if
1314  *                    it is a string but not a valid code then make a basic
1315  *                    language object
1316  *                  - a boolean: if it's false then use the global object for
1317  *                    the current user's language (as a fallback for the old parameter
1318  *                    functionality), or if it is true then use global object
1319  *                    for the wiki's content language.
1320  * @return Language object
1321  */
1322 function wfGetLangObj( $langcode = false ) {
1323         # Identify which language to get or create a language object for.
1324         # Using is_object here due to Stub objects.
1325         if( is_object( $langcode ) ) {
1326                 # Great, we already have the object (hopefully)!
1327                 return $langcode;
1328         }
1329
1330         global $wgContLang, $wgLanguageCode;
1331         if( $langcode === true || $langcode === $wgLanguageCode ) {
1332                 # $langcode is the language code of the wikis content language object.
1333                 # or it is a boolean and value is true
1334                 return $wgContLang;
1335         }
1336
1337         global $wgLang;
1338         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1339                 # $langcode is the language code of user language object.
1340                 # or it was a boolean and value is false
1341                 return $wgLang;
1342         }
1343
1344         $validCodes = array_keys( Language::fetchLanguageNames() );
1345         if( in_array( $langcode, $validCodes ) ) {
1346                 # $langcode corresponds to a valid language.
1347                 return Language::factory( $langcode );
1348         }
1349
1350         # $langcode is a string, but not a valid language code; use content language.
1351         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1352         return $wgContLang;
1353 }
1354
1355 /**
1356  * Old function when $wgBetterDirectionality existed
1357  * All usage removed, wfUILang can be removed in near future
1358  *
1359  * @deprecated since 1.18
1360  * @return Language
1361  */
1362 function wfUILang() {
1363         wfDeprecated( __METHOD__, '1.18' );
1364         global $wgLang;
1365         return $wgLang;
1366 }
1367
1368 /**
1369  * This is the new function for getting translated interface messages.
1370  * See the Message class for documentation how to use them.
1371  * The intention is that this function replaces all old wfMsg* functions.
1372  * @param $key \string Message key.
1373  * Varargs: normal message parameters.
1374  * @return Message
1375  * @since 1.17
1376  */
1377 function wfMessage( $key /*...*/) {
1378         $params = func_get_args();
1379         array_shift( $params );
1380         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1381                 $params = $params[0];
1382         }
1383         return new Message( $key, $params );
1384 }
1385
1386 /**
1387  * This function accepts multiple message keys and returns a message instance
1388  * for the first message which is non-empty. If all messages are empty then an
1389  * instance of the first message key is returned.
1390  * @param varargs: message keys
1391  * @return Message
1392  * @since 1.18
1393  */
1394 function wfMessageFallback( /*...*/ ) {
1395         $args = func_get_args();
1396         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1397 }
1398
1399 /**
1400  * Get a message from anywhere, for the current user language.
1401  *
1402  * Use wfMsgForContent() instead if the message should NOT
1403  * change depending on the user preferences.
1404  *
1405  * @deprecated since 1.18
1406  *
1407  * @param $key String: lookup key for the message, usually
1408  *    defined in languages/Language.php
1409  *
1410  * Parameters to the message, which can be used to insert variable text into
1411  * it, can be passed to this function in the following formats:
1412  * - One per argument, starting at the second parameter
1413  * - As an array in the second parameter
1414  * These are not shown in the function definition.
1415  *
1416  * @return String
1417  */
1418 function wfMsg( $key ) {
1419         $args = func_get_args();
1420         array_shift( $args );
1421         return wfMsgReal( $key, $args );
1422 }
1423
1424 /**
1425  * Same as above except doesn't transform the message
1426  *
1427  * @deprecated since 1.18
1428  *
1429  * @param $key String
1430  * @return String
1431  */
1432 function wfMsgNoTrans( $key ) {
1433         $args = func_get_args();
1434         array_shift( $args );
1435         return wfMsgReal( $key, $args, true, false, false );
1436 }
1437
1438 /**
1439  * Get a message from anywhere, for the current global language
1440  * set with $wgLanguageCode.
1441  *
1442  * Use this if the message should NOT change dependent on the
1443  * language set in the user's preferences. This is the case for
1444  * most text written into logs, as well as link targets (such as
1445  * the name of the copyright policy page). Link titles, on the
1446  * other hand, should be shown in the UI language.
1447  *
1448  * Note that MediaWiki allows users to change the user interface
1449  * language in their preferences, but a single installation
1450  * typically only contains content in one language.
1451  *
1452  * Be wary of this distinction: If you use wfMsg() where you should
1453  * use wfMsgForContent(), a user of the software may have to
1454  * customize potentially hundreds of messages in
1455  * order to, e.g., fix a link in every possible language.
1456  *
1457  * @deprecated since 1.18
1458  *
1459  * @param $key String: lookup key for the message, usually
1460  *     defined in languages/Language.php
1461  * @return String
1462  */
1463 function wfMsgForContent( $key ) {
1464         global $wgForceUIMsgAsContentMsg;
1465         $args = func_get_args();
1466         array_shift( $args );
1467         $forcontent = true;
1468         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1469                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1470         {
1471                 $forcontent = false;
1472         }
1473         return wfMsgReal( $key, $args, true, $forcontent );
1474 }
1475
1476 /**
1477  * Same as above except doesn't transform the message
1478  *
1479  * @deprecated since 1.18
1480  *
1481  * @param $key String
1482  * @return String
1483  */
1484 function wfMsgForContentNoTrans( $key ) {
1485         global $wgForceUIMsgAsContentMsg;
1486         $args = func_get_args();
1487         array_shift( $args );
1488         $forcontent = true;
1489         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1490                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1491         {
1492                 $forcontent = false;
1493         }
1494         return wfMsgReal( $key, $args, true, $forcontent, false );
1495 }
1496
1497 /**
1498  * Really get a message
1499  *
1500  * @deprecated since 1.18
1501  *
1502  * @param $key String: key to get.
1503  * @param $args
1504  * @param $useDB Boolean
1505  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1506  * @param $transform Boolean: Whether or not to transform the message.
1507  * @return String: the requested message.
1508  */
1509 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1510         wfProfileIn( __METHOD__ );
1511         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1512         $message = wfMsgReplaceArgs( $message, $args );
1513         wfProfileOut( __METHOD__ );
1514         return $message;
1515 }
1516
1517 /**
1518  * Fetch a message string value, but don't replace any keys yet.
1519  *
1520  * @deprecated since 1.18
1521  *
1522  * @param $key String
1523  * @param $useDB Bool
1524  * @param $langCode String: Code of the language to get the message for, or
1525  *                  behaves as a content language switch if it is a boolean.
1526  * @param $transform Boolean: whether to parse magic words, etc.
1527  * @return string
1528  */
1529 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1530         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1531
1532         $cache = MessageCache::singleton();
1533         $message = $cache->get( $key, $useDB, $langCode );
1534         if( $message === false ) {
1535                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1536         } elseif ( $transform ) {
1537                 $message = $cache->transform( $message );
1538         }
1539         return $message;
1540 }
1541
1542 /**
1543  * Replace message parameter keys on the given formatted output.
1544  *
1545  * @param $message String
1546  * @param $args Array
1547  * @return string
1548  * @private
1549  */
1550 function wfMsgReplaceArgs( $message, $args ) {
1551         # Fix windows line-endings
1552         # Some messages are split with explode("\n", $msg)
1553         $message = str_replace( "\r", '', $message );
1554
1555         // Replace arguments
1556         if ( count( $args ) ) {
1557                 if ( is_array( $args[0] ) ) {
1558                         $args = array_values( $args[0] );
1559                 }
1560                 $replacementKeys = array();
1561                 foreach( $args as $n => $param ) {
1562                         $replacementKeys['$' . ( $n + 1 )] = $param;
1563                 }
1564                 $message = strtr( $message, $replacementKeys );
1565         }
1566
1567         return $message;
1568 }
1569
1570 /**
1571  * Return an HTML-escaped version of a message.
1572  * Parameter replacements, if any, are done *after* the HTML-escaping,
1573  * so parameters may contain HTML (eg links or form controls). Be sure
1574  * to pre-escape them if you really do want plaintext, or just wrap
1575  * the whole thing in htmlspecialchars().
1576  *
1577  * @deprecated since 1.18
1578  *
1579  * @param $key String
1580  * @param string ... parameters
1581  * @return string
1582  */
1583 function wfMsgHtml( $key ) {
1584         $args = func_get_args();
1585         array_shift( $args );
1586         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1587 }
1588
1589 /**
1590  * Return an HTML version of message
1591  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1592  * so parameters may contain HTML (eg links or form controls). Be sure
1593  * to pre-escape them if you really do want plaintext, or just wrap
1594  * the whole thing in htmlspecialchars().
1595  *
1596  * @deprecated since 1.18
1597  *
1598  * @param $key String
1599  * @param string ... parameters
1600  * @return string
1601  */
1602 function wfMsgWikiHtml( $key ) {
1603         $args = func_get_args();
1604         array_shift( $args );
1605         return wfMsgReplaceArgs(
1606                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1607                 /* can't be set to false */ true, /* interface */ true )->getText(),
1608                 $args );
1609 }
1610
1611 /**
1612  * Returns message in the requested format
1613  *
1614  * @deprecated since 1.18
1615  *
1616  * @param $key String: key of the message
1617  * @param $options Array: processing rules. Can take the following options:
1618  *   <i>parse</i>: parses wikitext to HTML
1619  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1620  *       p's added by parser or tidy
1621  *   <i>escape</i>: filters message through htmlspecialchars
1622  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1623  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1624  *   <i>parsemag</i>: transform the message using magic phrases
1625  *   <i>content</i>: fetch message for content language instead of interface
1626  * Also can accept a single associative argument, of the form 'language' => 'xx':
1627  *   <i>language</i>: Language object or language code to fetch message for
1628  *       (overriden by <i>content</i>).
1629  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1630  *
1631  * @return String
1632  */
1633 function wfMsgExt( $key, $options ) {
1634         $args = func_get_args();
1635         array_shift( $args );
1636         array_shift( $args );
1637         $options = (array)$options;
1638
1639         foreach( $options as $arrayKey => $option ) {
1640                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1641                         # An unknown index, neither numeric nor "language"
1642                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1643                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1644                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1645                 'replaceafter', 'parsemag', 'content' ) ) ) {
1646                         # A numeric index with unknown value
1647                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1648                 }
1649         }
1650
1651         if( in_array( 'content', $options, true ) ) {
1652                 $forContent = true;
1653                 $langCode = true;
1654                 $langCodeObj = null;
1655         } elseif( array_key_exists( 'language', $options ) ) {
1656                 $forContent = false;
1657                 $langCode = wfGetLangObj( $options['language'] );
1658                 $langCodeObj = $langCode;
1659         } else {
1660                 $forContent = false;
1661                 $langCode = false;
1662                 $langCodeObj = null;
1663         }
1664
1665         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1666
1667         if( !in_array( 'replaceafter', $options, true ) ) {
1668                 $string = wfMsgReplaceArgs( $string, $args );
1669         }
1670
1671         $messageCache = MessageCache::singleton();
1672         $parseInline = in_array( 'parseinline', $options, true );
1673         if( in_array( 'parse', $options, true ) || $parseInline ) {
1674                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1675                 if ( $string instanceof ParserOutput ) {
1676                         $string = $string->getText();
1677                 }
1678
1679                 if ( $parseInline ) {
1680                         $m = array();
1681                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1682                                 $string = $m[1];
1683                         }
1684                 }
1685         } elseif ( in_array( 'parsemag', $options, true ) ) {
1686                 $string = $messageCache->transform( $string,
1687                                 !$forContent, $langCodeObj );
1688         }
1689
1690         if ( in_array( 'escape', $options, true ) ) {
1691                 $string = htmlspecialchars ( $string );
1692         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1693                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1694         }
1695
1696         if( in_array( 'replaceafter', $options, true ) ) {
1697                 $string = wfMsgReplaceArgs( $string, $args );
1698         }
1699
1700         return $string;
1701 }
1702
1703 /**
1704  * Since wfMsg() and co suck, they don't return false if the message key they
1705  * looked up didn't exist but a XHTML string, this function checks for the
1706  * nonexistance of messages by checking the MessageCache::get() result directly.
1707  *
1708  * @deprecated since 1.18. Use Message::isDisabled().
1709  *
1710  * @param $key      String: the message key looked up
1711  * @return Boolean True if the message *doesn't* exist.
1712  */
1713 function wfEmptyMsg( $key ) {
1714         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1715 }
1716
1717 /**
1718  * Throw a debugging exception. This function previously once exited the process,
1719  * but now throws an exception instead, with similar results.
1720  *
1721  * @param $msg String: message shown when dying.
1722  */
1723 function wfDebugDieBacktrace( $msg = '' ) {
1724         throw new MWException( $msg );
1725 }
1726
1727 /**
1728  * Fetch server name for use in error reporting etc.
1729  * Use real server name if available, so we know which machine
1730  * in a server farm generated the current page.
1731  *
1732  * @return string
1733  */
1734 function wfHostname() {
1735         static $host;
1736         if ( is_null( $host ) ) {
1737
1738                 # Hostname overriding
1739                 global $wgOverrideHostname;
1740                 if( $wgOverrideHostname !== false ) {
1741                         # Set static and skip any detection
1742                         $host = $wgOverrideHostname;
1743                         return $host;
1744                 }
1745
1746                 if ( function_exists( 'posix_uname' ) ) {
1747                         // This function not present on Windows
1748                         $uname = posix_uname();
1749                 } else {
1750                         $uname = false;
1751                 }
1752                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1753                         $host = $uname['nodename'];
1754                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1755                         # Windows computer name
1756                         $host = getenv( 'COMPUTERNAME' );
1757                 } else {
1758                         # This may be a virtual server.
1759                         $host = $_SERVER['SERVER_NAME'];
1760                 }
1761         }
1762         return $host;
1763 }
1764
1765 /**
1766  * Returns a HTML comment with the elapsed time since request.
1767  * This method has no side effects.
1768  *
1769  * @return string
1770  */
1771 function wfReportTime() {
1772         global $wgRequestTime, $wgShowHostnames;
1773
1774         $elapsed = microtime( true ) - $wgRequestTime;
1775
1776         return $wgShowHostnames
1777                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1778                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1779 }
1780
1781 /**
1782  * Safety wrapper for debug_backtrace().
1783  *
1784  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1785  * murky circumstances, which may be triggered in part by stub objects
1786  * or other fancy talkin'.
1787  *
1788  * Will return an empty array if Zend Optimizer is detected or if
1789  * debug_backtrace is disabled, otherwise the output from
1790  * debug_backtrace() (trimmed).
1791  *
1792  * @param $limit int This parameter can be used to limit the number of stack frames returned
1793  *
1794  * @return array of backtrace information
1795  */
1796 function wfDebugBacktrace( $limit = 0 ) {
1797         static $disabled = null;
1798
1799         if( extension_loaded( 'Zend Optimizer' ) ) {
1800                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1801                 return array();
1802         }
1803
1804         if ( is_null( $disabled ) ) {
1805                 $disabled = false;
1806                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1807                 $functions = array_map( 'trim', $functions );
1808                 $functions = array_map( 'strtolower', $functions );
1809                 if ( in_array( 'debug_backtrace', $functions ) ) {
1810                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1811                         $disabled = true;
1812                 }
1813         }
1814         if ( $disabled ) {
1815                 return array();
1816         }
1817
1818         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1819                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1820         } else {
1821                 return array_slice( debug_backtrace(), 1 );
1822         }
1823 }
1824
1825 /**
1826  * Get a debug backtrace as a string
1827  *
1828  * @return string
1829  */
1830 function wfBacktrace() {
1831         global $wgCommandLineMode;
1832
1833         if ( $wgCommandLineMode ) {
1834                 $msg = '';
1835         } else {
1836                 $msg = "<ul>\n";
1837         }
1838         $backtrace = wfDebugBacktrace();
1839         foreach( $backtrace as $call ) {
1840                 if( isset( $call['file'] ) ) {
1841                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1842                         $file = $f[count( $f ) - 1];
1843                 } else {
1844                         $file = '-';
1845                 }
1846                 if( isset( $call['line'] ) ) {
1847                         $line = $call['line'];
1848                 } else {
1849                         $line = '-';
1850                 }
1851                 if ( $wgCommandLineMode ) {
1852                         $msg .= "$file line $line calls ";
1853                 } else {
1854                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1855                 }
1856                 if( !empty( $call['class'] ) ) {
1857                         $msg .= $call['class'] . $call['type'];
1858                 }
1859                 $msg .= $call['function'] . '()';
1860
1861                 if ( $wgCommandLineMode ) {
1862                         $msg .= "\n";
1863                 } else {
1864                         $msg .= "</li>\n";
1865                 }
1866         }
1867         if ( $wgCommandLineMode ) {
1868                 $msg .= "\n";
1869         } else {
1870                 $msg .= "</ul>\n";
1871         }
1872
1873         return $msg;
1874 }
1875
1876 /**
1877  * Get the name of the function which called this function
1878  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1879  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1880  * wfGetCaller( 3 ) is the parent of that.
1881  *
1882  * @param $level Int
1883  * @return string
1884  */
1885 function wfGetCaller( $level = 2 ) {
1886         $backtrace = wfDebugBacktrace( $level + 1 );
1887         if ( isset( $backtrace[$level] ) ) {
1888                 return wfFormatStackFrame( $backtrace[$level] );
1889         } else {
1890                 return 'unknown';
1891         }
1892 }
1893
1894 /**
1895  * Return a string consisting of callers in the stack. Useful sometimes
1896  * for profiling specific points.
1897  *
1898  * @param $limit int The maximum depth of the stack frame to return, or false for
1899  *               the entire stack.
1900  * @return String
1901  */
1902 function wfGetAllCallers( $limit = 3 ) {
1903         $trace = array_reverse( wfDebugBacktrace() );
1904         if ( !$limit || $limit > count( $trace ) - 1 ) {
1905                 $limit = count( $trace ) - 1;
1906         }
1907         $trace = array_slice( $trace, -$limit - 1, $limit );
1908         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1909 }
1910
1911 /**
1912  * Return a string representation of frame
1913  *
1914  * @param $frame Array
1915  * @return string
1916  */
1917 function wfFormatStackFrame( $frame ) {
1918         return isset( $frame['class'] ) ?
1919                 $frame['class'] . '::' . $frame['function'] :
1920                 $frame['function'];
1921 }
1922
1923
1924 /* Some generic result counters, pulled out of SearchEngine */
1925
1926
1927 /**
1928  * @todo document
1929  *
1930  * @param $offset Int
1931  * @param $limit Int
1932  * @return String
1933  */
1934 function wfShowingResults( $offset, $limit ) {
1935         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1936 }
1937
1938 /**
1939  * Generate (prev x| next x) (20|50|100...) type links for paging
1940  *
1941  * @param $offset String
1942  * @param $limit Integer
1943  * @param $link String
1944  * @param $query String: optional URL query parameter string
1945  * @param $atend Bool: optional param for specified if this is the last page
1946  * @return String
1947  * @deprecated in 1.19; use Language::viewPrevNext() instead
1948  */
1949 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1950         wfDeprecated( __METHOD__, '1.19' );
1951
1952         global $wgLang;
1953
1954         $query = wfCgiToArray( $query );
1955
1956         if( is_object( $link ) ) {
1957                 $title = $link;
1958         } else {
1959                 $title = Title::newFromText( $link );
1960                 if( is_null( $title ) ) {
1961                         return false;
1962                 }
1963         }
1964
1965         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1966 }
1967
1968 /**
1969  * Make a list item, used by various special pages
1970  *
1971  * @param $page String Page link
1972  * @param $details String Text between brackets
1973  * @param $oppositedm Boolean   Add the direction mark opposite to your
1974  *                                                              language, to display text properly
1975  * @return String
1976  * @deprecated since 1.19; use Language::specialList() instead
1977  */
1978 function wfSpecialList( $page, $details, $oppositedm = true ) {
1979         wfDeprecated( __METHOD__, '1.19' );
1980
1981         global $wgLang;
1982         return $wgLang->specialList( $page, $details, $oppositedm );
1983 }
1984
1985 /**
1986  * @todo document
1987  * @todo FIXME: We may want to blacklist some broken browsers
1988  *
1989  * @param $force Bool
1990  * @return bool Whereas client accept gzip compression
1991  */
1992 function wfClientAcceptsGzip( $force = false ) {
1993         static $result = null;
1994         if ( $result === null || $force ) {
1995                 $result = false;
1996                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1997                         # @todo FIXME: We may want to blacklist some broken browsers
1998                         $m = array();
1999                         if( preg_match(
2000                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2001                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
2002                                 $m )
2003                         )
2004                         {
2005                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2006                                         $result = false;
2007                                         return $result;
2008                                 }
2009                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2010                                 $result = true;
2011                         }
2012                 }
2013         }
2014         return $result;
2015 }
2016
2017 /**
2018  * Obtain the offset and limit values from the request string;
2019  * used in special pages
2020  *
2021  * @param $deflimit Int default limit if none supplied
2022  * @param $optionname String Name of a user preference to check against
2023  * @return array
2024  *
2025  */
2026 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2027         global $wgRequest;
2028         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2029 }
2030
2031 /**
2032  * Escapes the given text so that it may be output using addWikiText()
2033  * without any linking, formatting, etc. making its way through. This
2034  * is achieved by substituting certain characters with HTML entities.
2035  * As required by the callers, "<nowiki>" is not used.
2036  *
2037  * @param $text String: text to be escaped
2038  * @return String
2039  */
2040 function wfEscapeWikiText( $text ) {
2041         $text = strtr( "\n$text", array(
2042                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2043                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2044                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2045                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2046                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2047                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2048         ) );
2049         return substr( $text, 1 );
2050 }
2051
2052 /**
2053  * Get the current unix timetstamp with microseconds.  Useful for profiling
2054  * @return Float
2055  */
2056 function wfTime() {
2057         return microtime( true );
2058 }
2059
2060 /**
2061  * Sets dest to source and returns the original value of dest
2062  * If source is NULL, it just returns the value, it doesn't set the variable
2063  * If force is true, it will set the value even if source is NULL
2064  *
2065  * @param $dest Mixed
2066  * @param $source Mixed
2067  * @param $force Bool
2068  * @return Mixed
2069  */
2070 function wfSetVar( &$dest, $source, $force = false ) {
2071         $temp = $dest;
2072         if ( !is_null( $source ) || $force ) {
2073                 $dest = $source;
2074         }
2075         return $temp;
2076 }
2077
2078 /**
2079  * As for wfSetVar except setting a bit
2080  *
2081  * @param $dest Int
2082  * @param $bit Int
2083  * @param $state Bool
2084  *
2085  * @return bool
2086  */
2087 function wfSetBit( &$dest, $bit, $state = true ) {
2088         $temp = (bool)( $dest & $bit );
2089         if ( !is_null( $state ) ) {
2090                 if ( $state ) {
2091                         $dest |= $bit;
2092                 } else {
2093                         $dest &= ~$bit;
2094                 }
2095         }
2096         return $temp;
2097 }
2098
2099 /**
2100  * A wrapper around the PHP function var_export().
2101  * Either print it or add it to the regular output ($wgOut).
2102  *
2103  * @param $var mixed A PHP variable to dump.
2104  */
2105 function wfVarDump( $var ) {
2106         global $wgOut;
2107         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2108         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2109                 print $s;
2110         } else {
2111                 $wgOut->addHTML( $s );
2112         }
2113 }
2114
2115 /**
2116  * Provide a simple HTTP error.
2117  *
2118  * @param $code Int|String
2119  * @param $label String
2120  * @param $desc String
2121  */
2122 function wfHttpError( $code, $label, $desc ) {
2123         global $wgOut;
2124         $wgOut->disable();
2125         header( "HTTP/1.0 $code $label" );
2126         header( "Status: $code $label" );
2127         $wgOut->sendCacheControl();
2128
2129         header( 'Content-type: text/html; charset=utf-8' );
2130         print "<!doctype html>" .
2131                 '<html><head><title>' .
2132                 htmlspecialchars( $label ) .
2133                 '</title></head><body><h1>' .
2134                 htmlspecialchars( $label ) .
2135                 '</h1><p>' .
2136                 nl2br( htmlspecialchars( $desc ) ) .
2137                 "</p></body></html>\n";
2138 }
2139
2140 /**
2141  * Clear away any user-level output buffers, discarding contents.
2142  *
2143  * Suitable for 'starting afresh', for instance when streaming
2144  * relatively large amounts of data without buffering, or wanting to
2145  * output image files without ob_gzhandler's compression.
2146  *
2147  * The optional $resetGzipEncoding parameter controls suppression of
2148  * the Content-Encoding header sent by ob_gzhandler; by default it
2149  * is left. See comments for wfClearOutputBuffers() for why it would
2150  * be used.
2151  *
2152  * Note that some PHP configuration options may add output buffer
2153  * layers which cannot be removed; these are left in place.
2154  *
2155  * @param $resetGzipEncoding Bool
2156  */
2157 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2158         if( $resetGzipEncoding ) {
2159                 // Suppress Content-Encoding and Content-Length
2160                 // headers from 1.10+s wfOutputHandler
2161                 global $wgDisableOutputCompression;
2162                 $wgDisableOutputCompression = true;
2163         }
2164         while( $status = ob_get_status() ) {
2165                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2166                         // Probably from zlib.output_compression or other
2167                         // PHP-internal setting which can't be removed.
2168                         //
2169                         // Give up, and hope the result doesn't break
2170                         // output behavior.
2171                         break;
2172                 }
2173                 if( !ob_end_clean() ) {
2174                         // Could not remove output buffer handler; abort now
2175                         // to avoid getting in some kind of infinite loop.
2176                         break;
2177                 }
2178                 if( $resetGzipEncoding ) {
2179                         if( $status['name'] == 'ob_gzhandler' ) {
2180                                 // Reset the 'Content-Encoding' field set by this handler
2181                                 // so we can start fresh.
2182                                 header_remove( 'Content-Encoding' );
2183                                 break;
2184                         }
2185                 }
2186         }
2187 }
2188
2189 /**
2190  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2191  *
2192  * Clear away output buffers, but keep the Content-Encoding header
2193  * produced by ob_gzhandler, if any.
2194  *
2195  * This should be used for HTTP 304 responses, where you need to
2196  * preserve the Content-Encoding header of the real result, but
2197  * also need to suppress the output of ob_gzhandler to keep to spec
2198  * and avoid breaking Firefox in rare cases where the headers and
2199  * body are broken over two packets.
2200  */
2201 function wfClearOutputBuffers() {
2202         wfResetOutputBuffers( false );
2203 }
2204
2205 /**
2206  * Converts an Accept-* header into an array mapping string values to quality
2207  * factors
2208  *
2209  * @param $accept String
2210  * @param $def String default
2211  * @return Array
2212  */
2213 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2214         # No arg means accept anything (per HTTP spec)
2215         if( !$accept ) {
2216                 return array( $def => 1.0 );
2217         }
2218
2219         $prefs = array();
2220
2221         $parts = explode( ',', $accept );
2222
2223         foreach( $parts as $part ) {
2224                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2225                 $values = explode( ';', trim( $part ) );
2226                 $match = array();
2227                 if ( count( $values ) == 1 ) {
2228                         $prefs[$values[0]] = 1.0;
2229                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2230                         $prefs[$values[0]] = floatval( $match[1] );
2231                 }
2232         }
2233
2234         return $prefs;
2235 }
2236
2237 /**
2238  * Checks if a given MIME type matches any of the keys in the given
2239  * array. Basic wildcards are accepted in the array keys.
2240  *
2241  * Returns the matching MIME type (or wildcard) if a match, otherwise
2242  * NULL if no match.
2243  *
2244  * @param $type String
2245  * @param $avail Array
2246  * @return string
2247  * @private
2248  */
2249 function mimeTypeMatch( $type, $avail ) {
2250         if( array_key_exists( $type, $avail ) ) {
2251                 return $type;
2252         } else {
2253                 $parts = explode( '/', $type );
2254                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2255                         return $parts[0] . '/*';
2256                 } elseif( array_key_exists( '*/*', $avail ) ) {
2257                         return '*/*';
2258                 } else {
2259                         return null;
2260                 }
2261         }
2262 }
2263
2264 /**
2265  * Returns the 'best' match between a client's requested internet media types
2266  * and the server's list of available types. Each list should be an associative
2267  * array of type to preference (preference is a float between 0.0 and 1.0).
2268  * Wildcards in the types are acceptable.
2269  *
2270  * @param $cprefs Array: client's acceptable type list
2271  * @param $sprefs Array: server's offered types
2272  * @return string
2273  *
2274  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2275  * XXX: generalize to negotiate other stuff
2276  */
2277 function wfNegotiateType( $cprefs, $sprefs ) {
2278         $combine = array();
2279
2280         foreach( array_keys( $sprefs ) as $type ) {
2281                 $parts = explode( '/', $type );
2282                 if( $parts[1] != '*' ) {
2283                         $ckey = mimeTypeMatch( $type, $cprefs );
2284                         if( $ckey ) {
2285                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2286                         }
2287                 }
2288         }
2289
2290         foreach( array_keys( $cprefs ) as $type ) {
2291                 $parts = explode( '/', $type );
2292                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2293                         $skey = mimeTypeMatch( $type, $sprefs );
2294                         if( $skey ) {
2295                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2296                         }
2297                 }
2298         }
2299
2300         $bestq = 0;
2301         $besttype = null;
2302
2303         foreach( array_keys( $combine ) as $type ) {
2304                 if( $combine[$type] > $bestq ) {
2305                         $besttype = $type;
2306                         $bestq = $combine[$type];
2307                 }
2308         }
2309
2310         return $besttype;
2311 }
2312
2313 /**
2314  * Reference-counted warning suppression
2315  *
2316  * @param $end Bool
2317  */
2318 function wfSuppressWarnings( $end = false ) {
2319         static $suppressCount = 0;
2320         static $originalLevel = false;
2321
2322         if ( $end ) {
2323                 if ( $suppressCount ) {
2324                         --$suppressCount;
2325                         if ( !$suppressCount ) {
2326                                 error_reporting( $originalLevel );
2327                         }
2328                 }
2329         } else {
2330                 if ( !$suppressCount ) {
2331                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED ) );
2332                 }
2333                 ++$suppressCount;
2334         }
2335 }
2336
2337 /**
2338  * Restore error level to previous value
2339  */
2340 function wfRestoreWarnings() {
2341         wfSuppressWarnings( true );
2342 }
2343
2344 # Autodetect, convert and provide timestamps of various types
2345
2346 /**
2347  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2348  */
2349 define( 'TS_UNIX', 0 );
2350
2351 /**
2352  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2353  */
2354 define( 'TS_MW', 1 );
2355
2356 /**
2357  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2358  */
2359 define( 'TS_DB', 2 );
2360
2361 /**
2362  * RFC 2822 format, for E-mail and HTTP headers
2363  */
2364 define( 'TS_RFC2822', 3 );
2365
2366 /**
2367  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2368  *
2369  * This is used by Special:Export
2370  */
2371 define( 'TS_ISO_8601', 4 );
2372
2373 /**
2374  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2375  *
2376  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2377  *       DateTime tag and page 36 for the DateTimeOriginal and
2378  *       DateTimeDigitized tags.
2379  */
2380 define( 'TS_EXIF', 5 );
2381
2382 /**
2383  * Oracle format time.
2384  */
2385 define( 'TS_ORACLE', 6 );
2386
2387 /**
2388  * Postgres format time.
2389  */
2390 define( 'TS_POSTGRES', 7 );
2391
2392 /**
2393  * DB2 format time
2394  */
2395 define( 'TS_DB2', 8 );
2396
2397 /**
2398  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2399  */
2400 define( 'TS_ISO_8601_BASIC', 9 );
2401
2402 /**
2403  * Get a timestamp string in one of various formats
2404  *
2405  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2406  *                    function will autodetect which format is supplied and act
2407  *                    accordingly.
2408  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2409  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2410  */
2411 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2412         try {
2413                 $timestamp = new MWTimestamp( $ts );
2414                 return $timestamp->getTimestamp( $outputtype );
2415         } catch( TimestampException $e ) {
2416                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2417                 return false;
2418         }
2419 }
2420
2421 /**
2422  * Return a formatted timestamp, or null if input is null.
2423  * For dealing with nullable timestamp columns in the database.
2424  *
2425  * @param $outputtype Integer
2426  * @param $ts String
2427  * @return String
2428  */
2429 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2430         if( is_null( $ts ) ) {
2431                 return null;
2432         } else {
2433                 return wfTimestamp( $outputtype, $ts );
2434         }
2435 }
2436
2437 /**
2438  * Convenience function; returns MediaWiki timestamp for the present time.
2439  *
2440  * @return string
2441  */
2442 function wfTimestampNow() {
2443         # return NOW
2444         return wfTimestamp( TS_MW, time() );
2445 }
2446
2447 /**
2448  * Check if the operating system is Windows
2449  *
2450  * @return Bool: true if it's Windows, False otherwise.
2451  */
2452 function wfIsWindows() {
2453         static $isWindows = null;
2454         if ( $isWindows === null ) {
2455                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2456         }
2457         return $isWindows;
2458 }
2459
2460 /**
2461  * Check if we are running under HipHop
2462  *
2463  * @return Bool
2464  */
2465 function wfIsHipHop() {
2466         return function_exists( 'hphp_thread_set_warmup_enabled' );
2467 }
2468
2469 /**
2470  * Swap two variables
2471  *
2472  * @param $x Mixed
2473  * @param $y Mixed
2474  */
2475 function swap( &$x, &$y ) {
2476         $z = $x;
2477         $x = $y;
2478         $y = $z;
2479 }
2480
2481 /**
2482  * Tries to get the system directory for temporary files. First
2483  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2484  * environment variables are then checked in sequence, and if none are
2485  * set try sys_get_temp_dir().
2486  *
2487  * NOTE: When possible, use instead the tmpfile() function to create
2488  * temporary files to avoid race conditions on file creation, etc.
2489  *
2490  * @return String
2491  */
2492 function wfTempDir() {
2493         global $wgTmpDirectory;
2494
2495         if ( $wgTmpDirectory !== false ) {
2496                 return $wgTmpDirectory;
2497         }
2498
2499         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2500
2501         foreach( $tmpDir as $tmp ) {
2502                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2503                         return $tmp;
2504                 }
2505         }
2506         return sys_get_temp_dir();
2507 }
2508
2509 /**
2510  * Make directory, and make all parent directories if they don't exist
2511  *
2512  * @param $dir String: full path to directory to create
2513  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2514  * @param $caller String: optional caller param for debugging.
2515  * @return bool
2516  */
2517 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2518         global $wgDirectoryMode;
2519
2520         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2521                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2522         }
2523
2524         if ( !is_null( $caller ) ) {
2525                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2526         }
2527
2528         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2529                 return true;
2530         }
2531
2532         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2533
2534         if ( is_null( $mode ) ) {
2535                 $mode = $wgDirectoryMode;
2536         }
2537
2538         // Turn off the normal warning, we're doing our own below
2539         wfSuppressWarnings();
2540         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2541         wfRestoreWarnings();
2542
2543         if( !$ok ) {
2544                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2545                 trigger_error( sprintf( "%s: failed to mkdir \"%s\" mode 0%o", __FUNCTION__, $dir, $mode ),
2546                         E_USER_WARNING );
2547         }
2548         return $ok;
2549 }
2550
2551 /**
2552  * Remove a directory and all its content.
2553  * Does not hide error.
2554  */
2555 function wfRecursiveRemoveDir( $dir ) {
2556         wfDebug( __FUNCTION__ . "( $dir )\n" );
2557         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2558         if ( is_dir( $dir ) ) {
2559                 $objects = scandir( $dir );
2560                 foreach ( $objects as $object ) {
2561                         if ( $object != "." && $object != ".." ) {
2562                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2563                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2564                                 } else {
2565                                         unlink( $dir . '/' . $object );
2566                                 }
2567                         }
2568                 }
2569                 reset( $objects );
2570                 rmdir( $dir );
2571         }
2572 }
2573
2574 /**
2575  * @param $nr Mixed: the number to format
2576  * @param $acc Integer: the number of digits after the decimal point, default 2
2577  * @param $round Boolean: whether or not to round the value, default true
2578  * @return float
2579  */
2580 function wfPercent( $nr, $acc = 2, $round = true ) {
2581         $ret = sprintf( "%.${acc}f", $nr );
2582         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2583 }
2584
2585 /**
2586  * Find out whether or not a mixed variable exists in a string
2587  *
2588  * @param $needle String
2589  * @param $str String
2590  * @param $insensitive Boolean
2591  * @return Boolean
2592  */
2593 function in_string( $needle, $str, $insensitive = false ) {
2594         $func = 'strpos';
2595         if( $insensitive ) $func = 'stripos';
2596
2597         return $func( $str, $needle ) !== false;
2598 }
2599
2600 /**
2601  * Safety wrapper around ini_get() for boolean settings.
2602  * The values returned from ini_get() are pre-normalized for settings
2603  * set via php.ini or php_flag/php_admin_flag... but *not*
2604  * for those set via php_value/php_admin_value.
2605  *
2606  * It's fairly common for people to use php_value instead of php_flag,
2607  * which can leave you with an 'off' setting giving a false positive
2608  * for code that just takes the ini_get() return value as a boolean.
2609  *
2610  * To make things extra interesting, setting via php_value accepts
2611  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2612  * Unrecognized values go false... again opposite PHP's own coercion
2613  * from string to bool.
2614  *
2615  * Luckily, 'properly' set settings will always come back as '0' or '1',
2616  * so we only have to worry about them and the 'improper' settings.
2617  *
2618  * I frickin' hate PHP... :P
2619  *
2620  * @param $setting String
2621  * @return Bool
2622  */
2623 function wfIniGetBool( $setting ) {
2624         $val = ini_get( $setting );
2625         // 'on' and 'true' can't have whitespace around them, but '1' can.
2626         return strtolower( $val ) == 'on'
2627                 || strtolower( $val ) == 'true'
2628                 || strtolower( $val ) == 'yes'
2629                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2630 }
2631
2632 /**
2633  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2634  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2635  *
2636  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2637  *                          should be omitted
2638  * @param $fileName String Name of the library, if not $extension.suffix
2639  * @return Bool - Whether or not the extension is loaded
2640  */
2641 function wfDl( $extension, $fileName = null ) {
2642         if( extension_loaded( $extension ) ) {
2643                 return true;
2644         }
2645
2646         $canDl = false;
2647         $sapi = php_sapi_name();
2648         if( $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' ) {
2649                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2650                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2651         }
2652
2653         if( $canDl ) {
2654                 $fileName = $fileName ? $fileName : $extension;
2655                 if( wfIsWindows() ) {
2656                         $fileName = 'php_' . $fileName;
2657                 }
2658                 wfSuppressWarnings();
2659                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2660                 wfRestoreWarnings();
2661         }
2662         return extension_loaded( $extension );
2663 }
2664
2665 /**
2666  * Windows-compatible version of escapeshellarg()
2667  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2668  * function puts single quotes in regardless of OS.
2669  *
2670  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2671  * earlier distro releases of PHP)
2672  *
2673  * @param varargs
2674  * @return String
2675  */
2676 function wfEscapeShellArg( ) {
2677         wfInitShellLocale();
2678
2679         $args = func_get_args();
2680         $first = true;
2681         $retVal = '';
2682         foreach ( $args as $arg ) {
2683                 if ( !$first ) {
2684                         $retVal .= ' ';
2685                 } else {
2686                         $first = false;
2687                 }
2688
2689                 if ( wfIsWindows() ) {
2690                         // Escaping for an MSVC-style command line parser and CMD.EXE
2691                         // Refs:
2692                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2693                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2694                         //  * Bug #13518
2695                         //  * CR r63214
2696                         // Double the backslashes before any double quotes. Escape the double quotes.
2697                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2698                         $arg = '';
2699                         $iteration = 0;
2700                         foreach ( $tokens as $token ) {
2701                                 if ( $iteration % 2 == 1 ) {
2702                                         // Delimiter, a double quote preceded by zero or more slashes
2703                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2704                                 } elseif ( $iteration % 4 == 2 ) {
2705                                         // ^ in $token will be outside quotes, need to be escaped
2706                                         $arg .= str_replace( '^', '^^', $token );
2707                                 } else { // $iteration % 4 == 0
2708                                         // ^ in $token will appear inside double quotes, so leave as is
2709                                         $arg .= $token;
2710                                 }
2711                                 $iteration++;
2712                         }
2713                         // Double the backslashes before the end of the string, because
2714                         // we will soon add a quote
2715                         $m = array();
2716                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2717                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2718                         }
2719
2720                         // Add surrounding quotes
2721                         $retVal .= '"' . $arg . '"';
2722                 } else {
2723                         $retVal .= escapeshellarg( $arg );
2724                 }
2725         }
2726         return $retVal;
2727 }
2728
2729 /**
2730  * Execute a shell command, with time and memory limits mirrored from the PHP
2731  * configuration if supported.
2732  * @param $cmd String Command line, properly escaped for shell.
2733  * @param &$retval null|Mixed optional, will receive the program's exit code.
2734  *                 (non-zero is usually failure)
2735  * @param $environ Array optional environment variables which should be
2736  *                 added to the executed command environment.
2737  * @param $limits Array optional array with limits(filesize, memory, time)
2738  *                 this overwrites the global wgShellMax* limits.
2739  * @return string collected stdout as a string (trailing newlines stripped)
2740  */
2741 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2742         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2743
2744         static $disabled;
2745         if ( is_null( $disabled ) ) {
2746                 $disabled = false;
2747                 if( wfIniGetBool( 'safe_mode' ) ) {
2748                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2749                         $disabled = 'safemode';
2750                 } else {
2751                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2752                         $functions = array_map( 'trim', $functions );
2753                         $functions = array_map( 'strtolower', $functions );
2754                         if ( in_array( 'passthru', $functions ) ) {
2755                                 wfDebug( "passthru is in disabled_functions\n" );
2756                                 $disabled = 'passthru';
2757                         }
2758                 }
2759         }
2760         if ( $disabled ) {
2761                 $retval = 1;
2762                 return $disabled == 'safemode' ?
2763                         'Unable to run external programs in safe mode.' :
2764                         'Unable to run external programs, passthru() is disabled.';
2765         }
2766
2767         wfInitShellLocale();
2768
2769         $envcmd = '';
2770         foreach( $environ as $k => $v ) {
2771                 if ( wfIsWindows() ) {
2772                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2773                          * appear in the environment variable, so we must use carat escaping as documented in
2774                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2775                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2776                          * are listed there but doesn't appear to need it.
2777                          */
2778                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2779                 } else {
2780                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2781                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2782                          */
2783                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2784                 }
2785         }
2786         $cmd = $envcmd . $cmd;
2787
2788         if ( php_uname( 's' ) == 'Linux' ) {
2789                 $time = intval ( isset($limits['time']) ? $limits['time'] : $wgMaxShellTime );
2790                 $mem = intval ( isset($limits['memory']) ? $limits['memory'] : $wgMaxShellMemory );
2791                 $filesize = intval ( isset($limits['filesize']) ? $limits['filesize'] : $wgMaxShellFileSize );
2792
2793                 if ( $time > 0 && $mem > 0 ) {
2794                         $script = "$IP/bin/ulimit4.sh";
2795                         if ( is_executable( $script ) ) {
2796                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2797                         }
2798                 }
2799         }
2800         wfDebug( "wfShellExec: $cmd\n" );
2801
2802         $retval = 1; // error by default?
2803         ob_start();
2804         passthru( $cmd, $retval );
2805         $output = ob_get_contents();
2806         ob_end_clean();
2807
2808         if ( $retval == 127 ) {
2809                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2810         }
2811         return $output;
2812 }
2813
2814 /**
2815  * Workaround for http://bugs.php.net/bug.php?id=45132
2816  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2817  */
2818 function wfInitShellLocale() {
2819         static $done = false;
2820         if ( $done ) {
2821                 return;
2822         }
2823         $done = true;
2824         global $wgShellLocale;
2825         if ( !wfIniGetBool( 'safe_mode' ) ) {
2826                 putenv( "LC_CTYPE=$wgShellLocale" );
2827                 setlocale( LC_CTYPE, $wgShellLocale );
2828         }
2829 }
2830
2831 /**
2832  * Alias to wfShellWikiCmd()
2833  * @see wfShellWikiCmd()
2834  */
2835 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2836         return wfShellWikiCmd( $script, $parameters, $options );
2837 }
2838
2839 /**
2840  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2841  * Note that $parameters should be a flat array and an option with an argument
2842  * should consist of two consecutive items in the array (do not use "--option value").
2843  * @param $script string MediaWiki cli script path
2844  * @param $parameters Array Arguments and options to the script
2845  * @param $options Array Associative array of options:
2846  *              'php': The path to the php executable
2847  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2848  * @return Array
2849  */
2850 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2851         global $wgPhpCli;
2852         // Give site config file a chance to run the script in a wrapper.
2853         // The caller may likely want to call wfBasename() on $script.
2854         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2855         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2856         if ( isset( $options['wrapper'] ) ) {
2857                 $cmd[] = $options['wrapper'];
2858         }
2859         $cmd[] = $script;
2860         // Escape each parameter for shell
2861         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2862 }
2863
2864 /**
2865  * wfMerge attempts to merge differences between three texts.
2866  * Returns true for a clean merge and false for failure or a conflict.
2867  *
2868  * @param $old String
2869  * @param $mine String
2870  * @param $yours String
2871  * @param $result String
2872  * @return Bool
2873  */
2874 function wfMerge( $old, $mine, $yours, &$result ) {
2875         global $wgDiff3;
2876
2877         # This check may also protect against code injection in
2878         # case of broken installations.
2879         wfSuppressWarnings();
2880         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2881         wfRestoreWarnings();
2882
2883         if( !$haveDiff3 ) {
2884                 wfDebug( "diff3 not found\n" );
2885                 return false;
2886         }
2887
2888         # Make temporary files
2889         $td = wfTempDir();
2890         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2891         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2892         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2893
2894         fwrite( $oldtextFile, $old );
2895         fclose( $oldtextFile );
2896         fwrite( $mytextFile, $mine );
2897         fclose( $mytextFile );
2898         fwrite( $yourtextFile, $yours );
2899         fclose( $yourtextFile );
2900
2901         # Check for a conflict
2902         $cmd = $wgDiff3 . ' -a --overlap-only ' .
2903                 wfEscapeShellArg( $mytextName ) . ' ' .
2904                 wfEscapeShellArg( $oldtextName ) . ' ' .
2905                 wfEscapeShellArg( $yourtextName );
2906         $handle = popen( $cmd, 'r' );
2907
2908         if( fgets( $handle, 1024 ) ) {
2909                 $conflict = true;
2910         } else {
2911                 $conflict = false;
2912         }
2913         pclose( $handle );
2914
2915         # Merge differences
2916         $cmd = $wgDiff3 . ' -a -e --merge ' .
2917                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2918         $handle = popen( $cmd, 'r' );
2919         $result = '';
2920         do {
2921                 $data = fread( $handle, 8192 );
2922                 if ( strlen( $data ) == 0 ) {
2923                         break;
2924                 }
2925                 $result .= $data;
2926         } while ( true );
2927         pclose( $handle );
2928         unlink( $mytextName );
2929         unlink( $oldtextName );
2930         unlink( $yourtextName );
2931
2932         if ( $result === '' && $old !== '' && !$conflict ) {
2933                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2934                 $conflict = true;
2935         }
2936         return !$conflict;
2937 }
2938
2939 /**
2940  * Returns unified plain-text diff of two texts.
2941  * Useful for machine processing of diffs.
2942  *
2943  * @param $before String: the text before the changes.
2944  * @param $after String: the text after the changes.
2945  * @param $params String: command-line options for the diff command.
2946  * @return String: unified diff of $before and $after
2947  */
2948 function wfDiff( $before, $after, $params = '-u' ) {
2949         if ( $before == $after ) {
2950                 return '';
2951         }
2952
2953         global $wgDiff;
2954         wfSuppressWarnings();
2955         $haveDiff = $wgDiff && file_exists( $wgDiff );
2956         wfRestoreWarnings();
2957
2958         # This check may also protect against code injection in
2959         # case of broken installations.
2960         if( !$haveDiff ) {
2961                 wfDebug( "diff executable not found\n" );
2962                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2963                 $format = new UnifiedDiffFormatter();
2964                 return $format->format( $diffs );
2965         }
2966
2967         # Make temporary files
2968         $td = wfTempDir();
2969         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2970         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2971
2972         fwrite( $oldtextFile, $before );
2973         fclose( $oldtextFile );
2974         fwrite( $newtextFile, $after );
2975         fclose( $newtextFile );
2976
2977         // Get the diff of the two files
2978         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2979
2980         $h = popen( $cmd, 'r' );
2981
2982         $diff = '';
2983
2984         do {
2985                 $data = fread( $h, 8192 );
2986                 if ( strlen( $data ) == 0 ) {
2987                         break;
2988                 }
2989                 $diff .= $data;
2990         } while ( true );
2991
2992         // Clean up
2993         pclose( $h );
2994         unlink( $oldtextName );
2995         unlink( $newtextName );
2996
2997         // Kill the --- and +++ lines. They're not useful.
2998         $diff_lines = explode( "\n", $diff );
2999         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3000                 unset( $diff_lines[0] );
3001         }
3002         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3003                 unset( $diff_lines[1] );
3004         }
3005
3006         $diff = implode( "\n", $diff_lines );
3007
3008         return $diff;
3009 }
3010
3011 /**
3012  * This function works like "use VERSION" in Perl, the program will die with a
3013  * backtrace if the current version of PHP is less than the version provided
3014  *
3015  * This is useful for extensions which due to their nature are not kept in sync
3016  * with releases, and might depend on other versions of PHP than the main code
3017  *
3018  * Note: PHP might die due to parsing errors in some cases before it ever
3019  *       manages to call this function, such is life
3020  *
3021  * @see perldoc -f use
3022  *
3023  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3024  *                 a float
3025  */
3026 function wfUsePHP( $req_ver ) {
3027         $php_ver = PHP_VERSION;
3028
3029         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3030                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3031         }
3032 }
3033
3034 /**
3035  * This function works like "use VERSION" in Perl except it checks the version
3036  * of MediaWiki, the program will die with a backtrace if the current version
3037  * of MediaWiki is less than the version provided.
3038  *
3039  * This is useful for extensions which due to their nature are not kept in sync
3040  * with releases
3041  *
3042  * @see perldoc -f use
3043  *
3044  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3045  *                 a float
3046  */
3047 function wfUseMW( $req_ver ) {
3048         global $wgVersion;
3049
3050         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3051                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3052         }
3053 }
3054
3055 /**
3056  * Return the final portion of a pathname.
3057  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3058  * http://bugs.php.net/bug.php?id=33898
3059  *
3060  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3061  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3062  *
3063  * @param $path String
3064  * @param $suffix String: to remove if present
3065  * @return String
3066  */
3067 function wfBaseName( $path, $suffix = '' ) {
3068         $encSuffix = ( $suffix == '' )
3069                 ? ''
3070                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3071         $matches = array();
3072         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3073                 return $matches[1];
3074         } else {
3075                 return '';
3076         }
3077 }
3078
3079 /**
3080  * Generate a relative path name to the given file.
3081  * May explode on non-matching case-insensitive paths,
3082  * funky symlinks, etc.
3083  *
3084  * @param $path String: absolute destination path including target filename
3085  * @param $from String: Absolute source path, directory only
3086  * @return String
3087  */
3088 function wfRelativePath( $path, $from ) {
3089         // Normalize mixed input on Windows...
3090         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3091         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3092
3093         // Trim trailing slashes -- fix for drive root
3094         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3095         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3096
3097         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3098         $against = explode( DIRECTORY_SEPARATOR, $from );
3099
3100         if( $pieces[0] !== $against[0] ) {
3101                 // Non-matching Windows drive letters?
3102                 // Return a full path.
3103                 return $path;
3104         }
3105
3106         // Trim off common prefix
3107         while( count( $pieces ) && count( $against )
3108                 && $pieces[0] == $against[0] ) {
3109                 array_shift( $pieces );
3110                 array_shift( $against );
3111         }
3112
3113         // relative dots to bump us to the parent
3114         while( count( $against ) ) {
3115                 array_unshift( $pieces, '..' );
3116                 array_shift( $against );
3117         }
3118
3119         array_push( $pieces, wfBaseName( $path ) );
3120
3121         return implode( DIRECTORY_SEPARATOR, $pieces );
3122 }
3123
3124 /**
3125  * Do any deferred updates and clear the list
3126  *
3127  * @deprecated since 1.19
3128  * @see DeferredUpdates::doUpdate()
3129  * @param $commit string
3130  */
3131 function wfDoUpdates( $commit = '' ) {
3132         wfDeprecated( __METHOD__, '1.19' );
3133         DeferredUpdates::doUpdates( $commit );
3134 }
3135
3136 /**
3137  * Convert an arbitrarily-long digit string from one numeric base
3138  * to another, optionally zero-padding to a minimum column width.
3139  *
3140  * Supports base 2 through 36; digit values 10-36 are represented
3141  * as lowercase letters a-z. Input is case-insensitive.
3142  *
3143  * @param $input String: of digits
3144  * @param $sourceBase Integer: 2-36
3145  * @param $destBase Integer: 2-36
3146  * @param $pad Integer: 1 or greater
3147  * @param $lowercase Boolean
3148  * @return String or false on invalid input
3149  */
3150 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3151         $input = strval( $input );
3152         if( $sourceBase < 2 ||
3153                 $sourceBase > 36 ||
3154                 $destBase < 2 ||
3155                 $destBase > 36 ||
3156                 $pad < 1 ||
3157                 $sourceBase != intval( $sourceBase ) ||
3158                 $destBase != intval( $destBase ) ||
3159                 $pad != intval( $pad ) ||
3160                 !is_string( $input ) ||
3161                 $input == '' ) {
3162                 return false;
3163         }
3164         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3165         $inDigits = array();
3166         $outChars = '';
3167
3168         // Decode and validate input string
3169         $input = strtolower( $input );
3170         for( $i = 0; $i < strlen( $input ); $i++ ) {
3171                 $n = strpos( $digitChars, $input[$i] );
3172                 if( $n === false || $n > $sourceBase ) {
3173                         return false;
3174                 }
3175                 $inDigits[] = $n;
3176         }
3177
3178         // Iterate over the input, modulo-ing out an output digit
3179         // at a time until input is gone.
3180         while( count( $inDigits ) ) {
3181                 $work = 0;
3182                 $workDigits = array();
3183
3184                 // Long division...
3185                 foreach( $inDigits as $digit ) {
3186                         $work *= $sourceBase;
3187                         $work += $digit;
3188
3189                         if( $work < $destBase ) {
3190                                 // Gonna need to pull another digit.
3191                                 if( count( $workDigits ) ) {
3192                                         // Avoid zero-padding; this lets us find
3193                                         // the end of the input very easily when
3194                                         // length drops to zero.
3195                                         $workDigits[] = 0;
3196                                 }
3197                         } else {
3198                                 // Finally! Actual division!
3199                                 $workDigits[] = intval( $work / $destBase );
3200
3201                                 // Isn't it annoying that most programming languages
3202                                 // don't have a single divide-and-remainder operator,
3203                                 // even though the CPU implements it that way?
3204                                 $work = $work % $destBase;
3205                         }
3206                 }
3207
3208                 // All that division leaves us with a remainder,
3209                 // which is conveniently our next output digit.
3210                 $outChars .= $digitChars[$work];
3211
3212                 // And we continue!
3213                 $inDigits = $workDigits;
3214         }
3215
3216         while( strlen( $outChars ) < $pad ) {
3217                 $outChars .= '0';
3218         }
3219
3220         return strrev( $outChars );
3221 }
3222
3223 /**
3224  * Create an object with a given name and an array of construct parameters
3225  *
3226  * @param $name String
3227  * @param $p Array: parameters
3228  * @return object
3229  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3230  */
3231 function wfCreateObject( $name, $p ) {
3232         wfDeprecated( __FUNCTION__, '1.18' );
3233         return MWFunction::newObj( $name, $p );
3234 }
3235
3236 /**
3237  * @return bool
3238  */
3239 function wfHttpOnlySafe() {
3240         global $wgHttpOnlyBlacklist;
3241
3242         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3243                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3244                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3245                                 return false;
3246                         }
3247                 }
3248         }
3249
3250         return true;
3251 }
3252
3253 /**
3254  * Override session_id before session startup if php's built-in
3255  * session generation code is not secure.
3256  */
3257 function wfFixSessionID() {
3258         // If the cookie or session id is already set we already have a session and should abort
3259         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3260                 return;
3261         }
3262
3263         // PHP's built-in session entropy is enabled if:
3264         // - entropy_file is set or you're on Windows with php 5.3.3+
3265         // - AND entropy_length is > 0
3266         // We treat it as disabled if it doesn't have an entropy length of at least 32
3267         $entropyEnabled = (
3268                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3269                         || ini_get( 'session.entropy_file' )
3270                 )
3271                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3272
3273         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3274         if ( !$entropyEnabled ) {
3275                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3276                 session_id( MWCryptRand::generateHex( 32 ) );
3277         }
3278 }
3279
3280 /**
3281  * Initialise php session
3282  *
3283  * @param $sessionId Bool
3284  */
3285 function wfSetupSession( $sessionId = false ) {
3286         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3287                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3288         if( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3289                 ObjectCacheSessionHandler::install();
3290         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3291                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3292                 # hasn't already been set to the desired value (that causes errors)
3293                 ini_set( 'session.save_handler', $wgSessionHandler );
3294         }
3295         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3296         wfDebugLog( 'cookie',
3297                 'session_set_cookie_params: "' . implode( '", "',
3298                         array(
3299                                 0,
3300                                 $wgCookiePath,
3301                                 $wgCookieDomain,
3302                                 $wgCookieSecure,
3303                                 $httpOnlySafe ) ) . '"' );
3304         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3305         session_cache_limiter( 'private, must-revalidate' );
3306         if ( $sessionId ) {
3307                 session_id( $sessionId );
3308         } else {
3309                 wfFixSessionID();
3310         }
3311         wfSuppressWarnings();
3312         session_start();
3313         wfRestoreWarnings();
3314 }
3315
3316 /**
3317  * Get an object from the precompiled serialized directory
3318  *
3319  * @param $name String
3320  * @return Mixed: the variable on success, false on failure
3321  */
3322 function wfGetPrecompiledData( $name ) {
3323         global $IP;
3324
3325         $file = "$IP/serialized/$name";
3326         if ( file_exists( $file ) ) {
3327                 $blob = file_get_contents( $file );
3328                 if ( $blob ) {
3329                         return unserialize( $blob );
3330                 }
3331         }
3332         return false;
3333 }
3334
3335 /**
3336  * Get a cache key
3337  *
3338  * @param varargs
3339  * @return String
3340  */
3341 function wfMemcKey( /*... */ ) {
3342         global $wgCachePrefix;
3343         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3344         $args = func_get_args();
3345         $key = $prefix . ':' . implode( ':', $args );
3346         $key = str_replace( ' ', '_', $key );
3347         return $key;
3348 }
3349
3350 /**
3351  * Get a cache key for a foreign DB
3352  *
3353  * @param $db String
3354  * @param $prefix String
3355  * @param varargs String
3356  * @return String
3357  */
3358 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3359         $args = array_slice( func_get_args(), 2 );
3360         if ( $prefix ) {
3361                 $key = "$db-$prefix:" . implode( ':', $args );
3362         } else {
3363                 $key = $db . ':' . implode( ':', $args );
3364         }
3365         return $key;
3366 }
3367
3368 /**
3369  * Get an ASCII string identifying this wiki
3370  * This is used as a prefix in memcached keys
3371  *
3372  * @return String
3373  */
3374 function wfWikiID() {
3375         global $wgDBprefix, $wgDBname;
3376         if ( $wgDBprefix ) {
3377                 return "$wgDBname-$wgDBprefix";
3378         } else {
3379                 return $wgDBname;
3380         }
3381 }
3382
3383 /**
3384  * Split a wiki ID into DB name and table prefix
3385  *
3386  * @param $wiki String
3387  *
3388  * @return array
3389  */
3390 function wfSplitWikiID( $wiki ) {
3391         $bits = explode( '-', $wiki, 2 );
3392         if ( count( $bits ) < 2 ) {
3393                 $bits[] = '';
3394         }
3395         return $bits;
3396 }
3397
3398 /**
3399  * Get a Database object.
3400  *
3401  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3402  *            master (for write queries), DB_SLAVE for potentially lagged read
3403  *            queries, or an integer >= 0 for a particular server.
3404  *
3405  * @param $groups Mixed: query groups. An array of group names that this query
3406  *                belongs to. May contain a single string if the query is only
3407  *                in one group.
3408  *
3409  * @param $wiki String: the wiki ID, or false for the current wiki
3410  *
3411  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3412  * will always return the same object, unless the underlying connection or load
3413  * balancer is manually destroyed.
3414  *
3415  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3416  * updater to ensure that a proper database is being updated.
3417  *
3418  * @return DatabaseBase
3419  */
3420 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3421         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3422 }
3423
3424 /**
3425  * Get a load balancer object.
3426  *
3427  * @param $wiki String: wiki ID, or false for the current wiki
3428  * @return LoadBalancer
3429  */
3430 function wfGetLB( $wiki = false ) {
3431         return wfGetLBFactory()->getMainLB( $wiki );
3432 }
3433
3434 /**
3435  * Get the load balancer factory object
3436  *
3437  * @return LBFactory
3438  */
3439 function &wfGetLBFactory() {
3440         return LBFactory::singleton();
3441 }
3442
3443 /**
3444  * Find a file.
3445  * Shortcut for RepoGroup::singleton()->findFile()
3446  *
3447  * @param $title String or Title object
3448  * @param $options array Associative array of options:
3449  *     time:           requested time for an archived image, or false for the
3450  *                     current version. An image object will be returned which was
3451  *                     created at the specified time.
3452  *
3453  *     ignoreRedirect: If true, do not follow file redirects
3454  *
3455  *     private:        If true, return restricted (deleted) files if the current
3456  *                     user is allowed to view them. Otherwise, such files will not
3457  *                     be found.
3458  *
3459  *     bypassCache:    If true, do not use the process-local cache of File objects
3460  *
3461  * @return File, or false if the file does not exist
3462  */
3463 function wfFindFile( $title, $options = array() ) {
3464         return RepoGroup::singleton()->findFile( $title, $options );
3465 }
3466
3467 /**
3468  * Get an object referring to a locally registered file.
3469  * Returns a valid placeholder object if the file does not exist.
3470  *
3471  * @param $title Title|String
3472  * @return LocalFile|null A File, or null if passed an invalid Title
3473  */
3474 function wfLocalFile( $title ) {
3475         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3476 }
3477
3478 /**
3479  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3480  * @deprecated since 1.19
3481  */
3482 function wfStreamFile( $fname, $headers = array() ) {
3483         wfDeprecated( __FUNCTION__, '1.19' );
3484         StreamFile::stream( $fname, $headers );
3485 }
3486
3487 /**
3488  * Should low-performance queries be disabled?
3489  *
3490  * @return Boolean
3491  * @codeCoverageIgnore
3492  */
3493 function wfQueriesMustScale() {
3494         global $wgMiserMode;
3495         return $wgMiserMode
3496                 || ( SiteStats::pages() > 100000
3497                 && SiteStats::edits() > 1000000
3498                 && SiteStats::users() > 10000 );
3499 }
3500
3501 /**
3502  * Get the path to a specified script file, respecting file
3503  * extensions; this is a wrapper around $wgScriptExtension etc.
3504  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3505  *
3506  * @param $script String: script filename, sans extension
3507  * @return String
3508  */
3509 function wfScript( $script = 'index' ) {
3510         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3511         if ( $script === 'index' ) {
3512                 return $wgScript;
3513         } else if ( $script === 'load' ) {
3514                 return $wgLoadScript;
3515         } else {
3516                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3517         }
3518 }
3519
3520 /**
3521  * Get the script URL.
3522  *
3523  * @return string script URL
3524  */
3525 function wfGetScriptUrl() {
3526         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3527                 #
3528                 # as it was called, minus the query string.
3529                 #
3530                 # Some sites use Apache rewrite rules to handle subdomains,
3531                 # and have PHP set up in a weird way that causes PHP_SELF
3532                 # to contain the rewritten URL instead of the one that the
3533                 # outside world sees.
3534                 #
3535                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3536                 # provides containing the "before" URL.
3537                 return $_SERVER['SCRIPT_NAME'];
3538         } else {
3539                 return $_SERVER['URL'];
3540         }
3541 }
3542
3543 /**
3544  * Convenience function converts boolean values into "true"
3545  * or "false" (string) values
3546  *
3547  * @param $value Boolean
3548  * @return String
3549  */
3550 function wfBoolToStr( $value ) {
3551         return $value ? 'true' : 'false';
3552 }
3553
3554 /**
3555  * Load an extension messages file
3556  *
3557  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3558  * @codeCoverageIgnore
3559  */
3560 function wfLoadExtensionMessages() {
3561         wfDeprecated( __FUNCTION__, '1.16' );
3562 }
3563
3564 /**
3565  * Get a platform-independent path to the null file, e.g. /dev/null
3566  *
3567  * @return string
3568  */
3569 function wfGetNull() {
3570         return wfIsWindows()
3571                 ? 'NUL'
3572                 : '/dev/null';
3573 }
3574
3575 /**
3576  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3577  * and waiting for it to go down, this waits for the slaves to catch up to the
3578  * master position. Use this when updating very large numbers of rows, as
3579  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3580  * a no-op if there are no slaves.
3581  *
3582  * @param $maxLag Integer (deprecated)
3583  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3584  */
3585 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3586         $lb = wfGetLB( $wiki );
3587         // bug 27975 - Don't try to wait for slaves if there are none
3588         // Prevents permission error when getting master position
3589         if ( $lb->getServerCount() > 1 ) {
3590                 $dbw = $lb->getConnection( DB_MASTER );
3591                 $pos = $dbw->getMasterPos();
3592                 $lb->waitForAll( $pos );
3593         }
3594 }
3595
3596 /**
3597  * Used to be used for outputting text in the installer/updater
3598  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3599  */
3600 function wfOut( $s ) {
3601         wfDeprecated( __FUNCTION__, '1.18' );
3602         global $wgCommandLineMode;
3603         if ( $wgCommandLineMode ) {
3604                 echo $s;
3605         } else {
3606                 echo htmlspecialchars( $s );
3607         }
3608         flush();
3609 }
3610
3611 /**
3612  * Count down from $n to zero on the terminal, with a one-second pause
3613  * between showing each number. For use in command-line scripts.
3614  * @codeCoverageIgnore
3615  * @param $n int
3616  */
3617 function wfCountDown( $n ) {
3618         for ( $i = $n; $i >= 0; $i-- ) {
3619                 if ( $i != $n ) {
3620                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3621                 }
3622                 echo $i;
3623                 flush();
3624                 if ( $i ) {
3625                         sleep( 1 );
3626                 }
3627         }
3628         echo "\n";
3629 }
3630
3631 /**
3632  * Generate a random 32-character hexadecimal token.
3633  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3634  *              characters before hashing.
3635  * @return string
3636  * @codeCoverageIgnore
3637  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pesudo-random strings
3638  * @warning This method is NOT secure. Additionally it has many callers that use it for pesudo-random purposes.
3639  */
3640 function wfGenerateToken( $salt = '' ) {
3641         wfDeprecated( __METHOD__, '1.20' );
3642         $salt = serialize( $salt );
3643         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3644 }
3645
3646 /**
3647  * Replace all invalid characters with -
3648  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3649  * By default, $wgIllegalFileChars = ':'
3650  *
3651  * @param $name Mixed: filename to process
3652  * @return String
3653  */
3654 function wfStripIllegalFilenameChars( $name ) {
3655         global $wgIllegalFileChars;
3656         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3657         $name = wfBaseName( $name );
3658         $name = preg_replace(
3659                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3660                 '-',
3661                 $name
3662         );
3663         return $name;
3664 }
3665
3666 /**
3667  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3668  *
3669  * @return Integer value memory was set to.
3670  */
3671 function wfMemoryLimit() {
3672         global $wgMemoryLimit;
3673         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3674         if( $memlimit != -1 ) {
3675                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3676                 if( $conflimit == -1 ) {
3677                         wfDebug( "Removing PHP's memory limit\n" );
3678                         wfSuppressWarnings();
3679                         ini_set( 'memory_limit', $conflimit );
3680                         wfRestoreWarnings();
3681                         return $conflimit;
3682                 } elseif ( $conflimit > $memlimit ) {
3683                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3684                         wfSuppressWarnings();
3685                         ini_set( 'memory_limit', $conflimit );
3686                         wfRestoreWarnings();
3687                         return $conflimit;
3688                 }
3689         }
3690         return $memlimit;
3691 }
3692
3693 /**
3694  * Converts shorthand byte notation to integer form
3695  *
3696  * @param $string String
3697  * @return Integer
3698  */
3699 function wfShorthandToInteger( $string = '' ) {
3700         $string = trim( $string );
3701         if( $string === '' ) {
3702                 return -1;
3703         }
3704         $last = $string[strlen( $string ) - 1];
3705         $val = intval( $string );
3706         switch( $last ) {
3707                 case 'g':
3708                 case 'G':
3709                         $val *= 1024;
3710                         // break intentionally missing
3711                 case 'm':
3712                 case 'M':
3713                         $val *= 1024;
3714                         // break intentionally missing
3715                 case 'k':
3716                 case 'K':
3717                         $val *= 1024;
3718         }
3719
3720         return $val;
3721 }
3722
3723 /**
3724  * Get the normalised IETF language tag
3725  * See unit test for examples.
3726  *
3727  * @param $code String: The language code.
3728  * @return String: The language code which complying with BCP 47 standards.
3729  */
3730 function wfBCP47( $code ) {
3731         $codeSegment = explode( '-', $code );
3732         $codeBCP = array();
3733         foreach ( $codeSegment as $segNo => $seg ) {
3734                 if ( count( $codeSegment ) > 0 ) {
3735                         // when previous segment is x, it is a private segment and should be lc
3736                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3737                                 $codeBCP[$segNo] = strtolower( $seg );
3738                         // ISO 3166 country code
3739                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3740                                 $codeBCP[$segNo] = strtoupper( $seg );
3741                         // ISO 15924 script code
3742                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3743                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3744                         // Use lowercase for other cases
3745                         } else {
3746                                 $codeBCP[$segNo] = strtolower( $seg );
3747                         }
3748                 } else {
3749                 // Use lowercase for single segment
3750                         $codeBCP[$segNo] = strtolower( $seg );
3751                 }
3752         }
3753         $langCode = implode( '-', $codeBCP );
3754         return $langCode;
3755 }
3756
3757 /**
3758  * Get a cache object.
3759  *
3760  * @param $inputType integer Cache type, one the the CACHE_* constants.
3761  * @return BagOStuff
3762  */
3763 function wfGetCache( $inputType ) {
3764         return ObjectCache::getInstance( $inputType );
3765 }
3766
3767 /**
3768  * Get the main cache object
3769  *
3770  * @return BagOStuff
3771  */
3772 function wfGetMainCache() {
3773         global $wgMainCacheType;
3774         return ObjectCache::getInstance( $wgMainCacheType );
3775 }
3776
3777 /**
3778  * Get the cache object used by the message cache
3779  *
3780  * @return BagOStuff
3781  */
3782 function wfGetMessageCacheStorage() {
3783         global $wgMessageCacheType;
3784         return ObjectCache::getInstance( $wgMessageCacheType );
3785 }
3786
3787 /**
3788  * Get the cache object used by the parser cache
3789  *
3790  * @return BagOStuff
3791  */
3792 function wfGetParserCacheStorage() {
3793         global $wgParserCacheType;
3794         return ObjectCache::getInstance( $wgParserCacheType );
3795 }
3796
3797 /**
3798  * Get the cache object used by the language converter
3799  *
3800  * @return BagOStuff
3801  */
3802 function wfGetLangConverterCacheStorage() {
3803         global $wgLanguageConverterCacheType;
3804         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3805 }
3806
3807 /**
3808  * Call hook functions defined in $wgHooks
3809  *
3810  * @param $event String: event name
3811  * @param $args Array: parameters passed to hook functions
3812  * @return Boolean True if no handler aborted the hook
3813  */
3814 function wfRunHooks( $event, $args = array() ) {
3815         return Hooks::run( $event, $args );
3816 }
3817
3818 /**
3819  * Wrapper around php's unpack.
3820  *
3821  * @param $format String: The format string (See php's docs)
3822  * @param $data: A binary string of binary data
3823  * @param $length integer or false: The minimun length of $data. This is to
3824  *      prevent reading beyond the end of $data. false to disable the check.
3825  *
3826  * Also be careful when using this function to read unsigned 32 bit integer
3827  * because php might make it negative.
3828  *
3829  * @throws MWException if $data not long enough, or if unpack fails
3830  * @return array Associative array of the extracted data
3831  */
3832 function wfUnpack( $format, $data, $length=false ) {
3833         if ( $length !== false ) {
3834                 $realLen = strlen( $data );
3835                 if ( $realLen < $length ) {
3836                         throw new MWException( "Tried to use wfUnpack on a "
3837                                 . "string of length $realLen, but needed one "
3838                                 . "of at least length $length."
3839                         );
3840                 }
3841         }
3842
3843         wfSuppressWarnings();
3844         $result = unpack( $format, $data );
3845         wfRestoreWarnings();
3846
3847         if ( $result === false ) {
3848                 // If it cannot extract the packed data.
3849                 throw new MWException( "unpack could not unpack binary data" );
3850         }
3851         return $result;
3852 }
3853
3854 /**
3855  * Determine if an image exists on the 'bad image list'.
3856  *
3857  * The format of MediaWiki:Bad_image_list is as follows:
3858  *    * Only list items (lines starting with "*") are considered
3859  *    * The first link on a line must be a link to a bad image
3860  *    * Any subsequent links on the same line are considered to be exceptions,
3861  *      i.e. articles where the image may occur inline.
3862  *
3863  * @param $name string the image name to check
3864  * @param $contextTitle Title|bool the page on which the image occurs, if known
3865  * @param $blacklist string wikitext of a file blacklist
3866  * @return bool
3867  */
3868 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3869         static $badImageCache = null; // based on bad_image_list msg
3870         wfProfileIn( __METHOD__ );
3871
3872         # Handle redirects
3873         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3874         if( $redirectTitle ) {
3875                 $name = $redirectTitle->getDbKey();
3876         }
3877
3878         # Run the extension hook
3879         $bad = false;
3880         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3881                 wfProfileOut( __METHOD__ );
3882                 return $bad;
3883         }
3884
3885         $cacheable = ( $blacklist === null );
3886         if( $cacheable && $badImageCache !== null ) {
3887                 $badImages = $badImageCache;
3888         } else { // cache miss
3889                 if ( $blacklist === null ) {
3890                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3891                 }
3892                 # Build the list now
3893                 $badImages = array();
3894                 $lines = explode( "\n", $blacklist );
3895                 foreach( $lines as $line ) {
3896                         # List items only
3897                         if ( substr( $line, 0, 1 ) !== '*' ) {
3898                                 continue;
3899                         }
3900
3901                         # Find all links
3902                         $m = array();
3903                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3904                                 continue;
3905                         }
3906
3907                         $exceptions = array();
3908                         $imageDBkey = false;
3909                         foreach ( $m[1] as $i => $titleText ) {
3910                                 $title = Title::newFromText( $titleText );
3911                                 if ( !is_null( $title ) ) {
3912                                         if ( $i == 0 ) {
3913                                                 $imageDBkey = $title->getDBkey();
3914                                         } else {
3915                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3916                                         }
3917                                 }
3918                         }
3919
3920                         if ( $imageDBkey !== false ) {
3921                                 $badImages[$imageDBkey] = $exceptions;
3922                         }
3923                 }
3924                 if ( $cacheable ) {
3925                         $badImageCache = $badImages;
3926                 }
3927         }
3928
3929         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3930         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3931         wfProfileOut( __METHOD__ );
3932         return $bad;
3933 }