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 // gzdecode function only exists in PHP >= 5.4.0
  98 // http://php.net/gzdecode
  99 if ( !function_exists( 'gzdecode' ) ) {
 100         /**
 101          * @codeCoverageIgnore
 102          * @return string
 103          */
 104         function gzdecode( $data ) {
 105                 return gzinflate( substr( $data, 10, -8 ) );
 106         }
 107 }
 108 /// @endcond
 109
 110 /**
 111  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 112  * @param $a array
 113  * @param $b array
 114  * @return array
 115  */
 116 function wfArrayDiff2( $a, $b ) {
 117         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 118 }
 119
 120 /**
 121  * @param $a array|string
 122  * @param $b array|string
 123  * @return int
 124  */
 125 function wfArrayDiff2_cmp( $a, $b ) {
 126         if ( is_string( $a ) && is_string( $b ) ) {
 127                 return strcmp( $a, $b );
 128         } elseif ( count( $a ) !== count( $b ) ) {
 129                 return count( $a ) < count( $b ) ? -1 : 1;
 130         } else {
 131                 reset( $a );
 132                 reset( $b );
 133                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 134                         $cmp = strcmp( $valueA, $valueB );
 135                         if ( $cmp !== 0 ) {
 136                                 return $cmp;
 137                         }
 138                 }
 139                 return 0;
 140         }
 141 }
 142
 143 /**
 144  * Array lookup
 145  * Returns an array where the values in array $b are replaced by the
 146  * values in array $a with the corresponding keys
 147  *
 148  * @deprecated since 1.22; use array_intersect_key()
 149  * @param $a Array
 150  * @param $b Array
 151  * @return array
 152  */
 153 function wfArrayLookup( $a, $b ) {
 154         wfDeprecated( __FUNCTION__, '1.22' );
 155         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 156 }
 157
 158 /**
 159  * Appends to second array if $value differs from that in $default
 160  *
 161  * @param $key String|Int
 162  * @param $value Mixed
 163  * @param $default Mixed
 164  * @param array $changed to alter
 165  * @throws MWException
 166  */
 167 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 168         if ( is_null( $changed ) ) {
 169                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 170         }
 171         if ( $default[$key] !== $value ) {
 172                 $changed[$key] = $value;
 173         }
 174 }
 175
 176 /**
 177  * Backwards array plus for people who haven't bothered to read the PHP manual
 178  * XXX: will not darn your socks for you.
 179  *
 180  * @deprecated since 1.22; use array_replace()
 181  * @param $array1 Array
 182  * @param [$array2, [...]] Arrays
 183  * @return Array
 184  */
 185 function wfArrayMerge( $array1/* ... */ ) {
 186         wfDeprecated( __FUNCTION__, '1.22' );
 187         $args = func_get_args();
 188         $args = array_reverse( $args, true );
 189         $out = array();
 190         foreach ( $args as $arg ) {
 191                 $out += $arg;
 192         }
 193         return $out;
 194 }
 195
 196 /**
 197  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 198  * e.g.
 199  *      wfMergeErrorArrays(
 200  *              array( array( 'x' ) ),
 201  *              array( array( 'x', '2' ) ),
 202  *              array( array( 'x' ) ),
 203  *              array( array( 'y' ) )
 204  *      );
 205  * returns:
 206  *              array(
 207  *              array( 'x', '2' ),
 208  *              array( 'x' ),
 209  *              array( 'y' )
 210  *      )
 211  * @param varargs
 212  * @return Array
 213  */
 214 function wfMergeErrorArrays( /*...*/ ) {
 215         $args = func_get_args();
 216         $out = array();
 217         foreach ( $args as $errors ) {
 218                 foreach ( $errors as $params ) {
 219                         # @todo FIXME: Sometimes get nested arrays for $params,
 220                         # which leads to E_NOTICEs
 221                         $spec = implode( "\t", $params );
 222                         $out[$spec] = $params;
 223                 }
 224         }
 225         return array_values( $out );
 226 }
 227
 228 /**
 229  * Insert array into another array after the specified *KEY*
 230  *
 231  * @param array $array The array.
 232  * @param array $insert The array to insert.
 233  * @param $after Mixed: The key to insert after
 234  * @return Array
 235  */
 236 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 237         // Find the offset of the element to insert after.
 238         $keys = array_keys( $array );
 239         $offsetByKey = array_flip( $keys );
 240
 241         $offset = $offsetByKey[$after];
 242
 243         // Insert at the specified offset
 244         $before = array_slice( $array, 0, $offset + 1, true );
 245         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 246
 247         $output = $before + $insert + $after;
 248
 249         return $output;
 250 }
 251
 252 /**
 253  * Recursively converts the parameter (an object) to an array with the same data
 254  *
 255  * @param $objOrArray Object|Array
 256  * @param $recursive Bool
 257  * @return Array
 258  */
 259 function wfObjectToArray( $objOrArray, $recursive = true ) {
 260         $array = array();
 261         if ( is_object( $objOrArray ) ) {
 262                 $objOrArray = get_object_vars( $objOrArray );
 263         }
 264         foreach ( $objOrArray as $key => $value ) {
 265                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 266                         $value = wfObjectToArray( $value );
 267                 }
 268
 269                 $array[$key] = $value;
 270         }
 271
 272         return $array;
 273 }
 274
 275 /**
 276  * Get a random decimal value between 0 and 1, in a way
 277  * not likely to give duplicate values for any realistic
 278  * number of articles.
 279  *
 280  * @return string
 281  */
 282 function wfRandom() {
 283         # The maximum random value is "only" 2^31-1, so get two random
 284         # values to reduce the chance of dupes
 285         $max = mt_getrandmax() + 1;
 286         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 287                 / $max / $max, 12, '.', '' );
 288         return $rand;
 289 }
 290
 291 /**
 292  * Get a random string containing a number of pseudo-random hex
 293  * characters.
 294  * @note This is not secure, if you are trying to generate some sort
 295  *       of token please use MWCryptRand instead.
 296  *
 297  * @param int $length The length of the string to generate
 298  * @return String
 299  * @since 1.20
 300  */
 301 function wfRandomString( $length = 32 ) {
 302         $str = '';
 303         for ( $n = 0; $n < $length; $n += 7 ) {
 304                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 305         }
 306         return substr( $str, 0, $length );
 307 }
 308
 309 /**
 310  * We want some things to be included as literal characters in our title URLs
 311  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 312  * all of the following should be safe:
 313  *
 314  * ;:@&=$-_.+!*'(),
 315  *
 316  * But + is not safe because it's used to indicate a space; &= are only safe in
 317  * paths and not in queries (and we don't distinguish here); ' seems kind of
 318  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 319  * is reserved, we don't care.  So the list we unescape is:
 320  *
 321  * ;:@$!*(),/
 322  *
 323  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 324  * so no fancy : for IIS7.
 325  *
 326  * %2F in the page titles seems to fatally break for some reason.
 327  *
 328  * @param $s String:
 329  * @return string
 330  */
 331 function wfUrlencode( $s ) {
 332         static $needle;
 333         if ( is_null( $s ) ) {
 334                 $needle = null;
 335                 return '';
 336         }
 337
 338         if ( is_null( $needle ) ) {
 339                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 340                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 341                         $needle[] = '%3A';
 342                 }
 343         }
 344
 345         $s = urlencode( $s );
 346         $s = str_ireplace(
 347                 $needle,
 348                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 349                 $s
 350         );
 351
 352         return $s;
 353 }
 354
 355 /**
 356  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 357  * "days=7&limit=100". Options in the first array override options in the second.
 358  * Options set to null or false will not be output.
 359  *
 360  * @param array $array1 ( String|Array )
 361  * @param array $array2 ( String|Array )
 362  * @param $prefix String
 363  * @return String
 364  */
 365 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 366         if ( !is_null( $array2 ) ) {
 367                 $array1 = $array1 + $array2;
 368         }
 369
 370         $cgi = '';
 371         foreach ( $array1 as $key => $value ) {
 372                 if ( !is_null( $value ) && $value !== false ) {
 373                         if ( $cgi != '' ) {
 374                                 $cgi .= '&';
 375                         }
 376                         if ( $prefix !== '' ) {
 377                                 $key = $prefix . "[$key]";
 378                         }
 379                         if ( is_array( $value ) ) {
 380                                 $firstTime = true;
 381                                 foreach ( $value as $k => $v ) {
 382                                         $cgi .= $firstTime ? '' : '&';
 383                                         if ( is_array( $v ) ) {
 384                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 385                                         } else {
 386                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 387                                         }
 388                                         $firstTime = false;
 389                                 }
 390                         } else {
 391                                 if ( is_object( $value ) ) {
 392                                         $value = $value->__toString();
 393                                 }
 394                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 395                         }
 396                 }
 397         }
 398         return $cgi;
 399 }
 400
 401 /**
 402  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 403  * its argument and returns the same string in array form.  This allows compatibility
 404  * with legacy functions that accept raw query strings instead of nice
 405  * arrays.  Of course, keys and values are urldecode()d.
 406  *
 407  * @param string $query query string
 408  * @return array Array version of input
 409  */
 410 function wfCgiToArray( $query ) {
 411         if ( isset( $query[0] ) && $query[0] == '?' ) {
 412                 $query = substr( $query, 1 );
 413         }
 414         $bits = explode( '&', $query );
 415         $ret = array();
 416         foreach ( $bits as $bit ) {
 417                 if ( $bit === '' ) {
 418                         continue;
 419                 }
 420                 if ( strpos( $bit, '=' ) === false ) {
 421                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 422                         $key = $bit;
 423                         $value = '';
 424                 } else {
 425                         list( $key, $value ) = explode( '=', $bit );
 426                 }
 427                 $key = urldecode( $key );
 428                 $value = urldecode( $value );
 429                 if ( strpos( $key, '[' ) !== false ) {
 430                         $keys = array_reverse( explode( '[', $key ) );
 431                         $key = array_pop( $keys );
 432                         $temp = $value;
 433                         foreach ( $keys as $k ) {
 434                                 $k = substr( $k, 0, -1 );
 435                                 $temp = array( $k => $temp );
 436                         }
 437                         if ( isset( $ret[$key] ) ) {
 438                                 $ret[$key] = array_merge( $ret[$key], $temp );
 439                         } else {
 440                                 $ret[$key] = $temp;
 441                         }
 442                 } else {
 443                         $ret[$key] = $value;
 444                 }
 445         }
 446         return $ret;
 447 }
 448
 449 /**
 450  * Append a query string to an existing URL, which may or may not already
 451  * have query string parameters already. If so, they will be combined.
 452  *
 453  * @param $url String
 454  * @param $query Mixed: string or associative array
 455  * @return string
 456  */
 457 function wfAppendQuery( $url, $query ) {
 458         if ( is_array( $query ) ) {
 459                 $query = wfArrayToCgi( $query );
 460         }
 461         if ( $query != '' ) {
 462                 if ( false === strpos( $url, '?' ) ) {
 463                         $url .= '?';
 464                 } else {
 465                         $url .= '&';
 466                 }
 467                 $url .= $query;
 468         }
 469         return $url;
 470 }
 471
 472 /**
 473  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 474  * is correct.
 475  *
 476  * The meaning of the PROTO_* constants is as follows:
 477  * PROTO_HTTP: Output a URL starting with http://
 478  * PROTO_HTTPS: Output a URL starting with https://
 479  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 480  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 481  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 482  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 483  *
 484  * @todo this won't work with current-path-relative URLs
 485  * like "subdir/foo.html", etc.
 486  *
 487  * @param string $url either fully-qualified or a local path + query
 488  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 489  *                             protocol to use if $url or $wgServer is
 490  *                             protocol-relative
 491  * @return string Fully-qualified URL, current-path-relative URL or false if
 492  *                no valid URL can be constructed
 493  */
 494 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 495         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 496         $serverUrl = $wgServer;
 497         if ( $defaultProto === PROTO_CANONICAL ) {
 498                 $serverUrl = $wgCanonicalServer;
 499         }
 500         // Make $wgInternalServer fall back to $wgServer if not set
 501         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 502                 $serverUrl = $wgInternalServer;
 503         }
 504         if ( $defaultProto === PROTO_CURRENT ) {
 505                 $defaultProto = WebRequest::detectProtocol() . '://';
 506         }
 507
 508         // Analyze $serverUrl to obtain its protocol
 509         $bits = wfParseUrl( $serverUrl );
 510         $serverHasProto = $bits && $bits['scheme'] != '';
 511
 512         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 513                 if ( $serverHasProto ) {
 514                         $defaultProto = $bits['scheme'] . '://';
 515                 } else {
 516                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 517                         // Fall back to HTTP in this ridiculous case
 518                         $defaultProto = PROTO_HTTP;
 519                 }
 520         }
 521
 522         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 523
 524         if ( substr( $url, 0, 2 ) == '//' ) {
 525                 $url = $defaultProtoWithoutSlashes . $url;
 526         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 527                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 528                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 529         }
 530
 531         $bits = wfParseUrl( $url );
 532         if ( $bits && isset( $bits['path'] ) ) {
 533                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 534                 return wfAssembleUrl( $bits );
 535         } elseif ( $bits ) {
 536                 # No path to expand
 537                 return $url;
 538         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 539                 # URL is a relative path
 540                 return wfRemoveDotSegments( $url );
 541         }
 542
 543         # Expanded URL is not valid.
 544         return false;
 545 }
 546
 547 /**
 548  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 549  * if you need to edit part of a URL and put it back together.
 550  *
 551  * This is the basic structure used (brackets contain keys for $urlParts):
 552  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 553  *
 554  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 555  *
 556  * @since 1.19
 557  * @param array $urlParts URL parts, as output from wfParseUrl
 558  * @return string URL assembled from its component parts
 559  */
 560 function wfAssembleUrl( $urlParts ) {
 561         $result = '';
 562
 563         if ( isset( $urlParts['delimiter'] ) ) {
 564                 if ( isset( $urlParts['scheme'] ) ) {
 565                         $result .= $urlParts['scheme'];
 566                 }
 567
 568                 $result .= $urlParts['delimiter'];
 569         }
 570
 571         if ( isset( $urlParts['host'] ) ) {
 572                 if ( isset( $urlParts['user'] ) ) {
 573                         $result .= $urlParts['user'];
 574                         if ( isset( $urlParts['pass'] ) ) {
 575                                 $result .= ':' . $urlParts['pass'];
 576                         }
 577                         $result .= '@';
 578                 }
 579
 580                 $result .= $urlParts['host'];
 581
 582                 if ( isset( $urlParts['port'] ) ) {
 583                         $result .= ':' . $urlParts['port'];
 584                 }
 585         }
 586
 587         if ( isset( $urlParts['path'] ) ) {
 588                 $result .= $urlParts['path'];
 589         }
 590
 591         if ( isset( $urlParts['query'] ) ) {
 592                 $result .= '?' . $urlParts['query'];
 593         }
 594
 595         if ( isset( $urlParts['fragment'] ) ) {
 596                 $result .= '#' . $urlParts['fragment'];
 597         }
 598
 599         return $result;
 600 }
 601
 602 /**
 603  * Remove all dot-segments in the provided URL path.  For example,
 604  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 605  * RFC3986 section 5.2.4.
 606  *
 607  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 608  *
 609  * @param string $urlPath URL path, potentially containing dot-segments
 610  * @return string URL path with all dot-segments removed
 611  */
 612 function wfRemoveDotSegments( $urlPath ) {
 613         $output = '';
 614         $inputOffset = 0;
 615         $inputLength = strlen( $urlPath );
 616
 617         while ( $inputOffset < $inputLength ) {
 618                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 619                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 620                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 621                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 622                 $trimOutput = false;
 623
 624                 if ( $prefixLengthTwo == './' ) {
 625                         # Step A, remove leading "./"
 626                         $inputOffset += 2;
 627                 } elseif ( $prefixLengthThree == '../' ) {
 628                         # Step A, remove leading "../"
 629                         $inputOffset += 3;
 630                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 631                         # Step B, replace leading "/.$" with "/"
 632                         $inputOffset += 1;
 633                         $urlPath[$inputOffset] = '/';
 634                 } elseif ( $prefixLengthThree == '/./' ) {
 635                         # Step B, replace leading "/./" with "/"
 636                         $inputOffset += 2;
 637                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 638                         # Step C, replace leading "/..$" with "/" and
 639                         # remove last path component in output
 640                         $inputOffset += 2;
 641                         $urlPath[$inputOffset] = '/';
 642                         $trimOutput = true;
 643                 } elseif ( $prefixLengthFour == '/../' ) {
 644                         # Step C, replace leading "/../" with "/" and
 645                         # remove last path component in output
 646                         $inputOffset += 3;
 647                         $trimOutput = true;
 648                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 649                         # Step D, remove "^.$"
 650                         $inputOffset += 1;
 651                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 652                         # Step D, remove "^..$"
 653                         $inputOffset += 2;
 654                 } else {
 655                         # Step E, move leading path segment to output
 656                         if ( $prefixLengthOne == '/' ) {
 657                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 658                         } else {
 659                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 660                         }
 661                         if ( $slashPos === false ) {
 662                                 $output .= substr( $urlPath, $inputOffset );
 663                                 $inputOffset = $inputLength;
 664                         } else {
 665                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 666                                 $inputOffset += $slashPos - $inputOffset;
 667                         }
 668                 }
 669
 670                 if ( $trimOutput ) {
 671                         $slashPos = strrpos( $output, '/' );
 672                         if ( $slashPos === false ) {
 673                                 $output = '';
 674                         } else {
 675                                 $output = substr( $output, 0, $slashPos );
 676                         }
 677                 }
 678         }
 679
 680         return $output;
 681 }
 682
 683 /**
 684  * Returns a regular expression of url protocols
 685  *
 686  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 687  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 688  * @return String
 689  */
 690 function wfUrlProtocols( $includeProtocolRelative = true ) {
 691         global $wgUrlProtocols;
 692
 693         // Cache return values separately based on $includeProtocolRelative
 694         static $withProtRel = null, $withoutProtRel = null;
 695         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 696         if ( !is_null( $cachedValue ) ) {
 697                 return $cachedValue;
 698         }
 699
 700         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 701         // with LocalSettings files from 1.5
 702         if ( is_array( $wgUrlProtocols ) ) {
 703                 $protocols = array();
 704                 foreach ( $wgUrlProtocols as $protocol ) {
 705                         // Filter out '//' if !$includeProtocolRelative
 706                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 707                                 $protocols[] = preg_quote( $protocol, '/' );
 708                         }
 709                 }
 710
 711                 $retval = implode( '|', $protocols );
 712         } else {
 713                 // Ignore $includeProtocolRelative in this case
 714                 // This case exists for pre-1.6 compatibility, and we can safely assume
 715                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 716                 // URLs weren't supported until 1.18
 717                 $retval = $wgUrlProtocols;
 718         }
 719
 720         // Cache return value
 721         if ( $includeProtocolRelative ) {
 722                 $withProtRel = $retval;
 723         } else {
 724                 $withoutProtRel = $retval;
 725         }
 726         return $retval;
 727 }
 728
 729 /**
 730  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 731  * you need a regex that matches all URL protocols but does not match protocol-
 732  * relative URLs
 733  * @return String
 734  */
 735 function wfUrlProtocolsWithoutProtRel() {
 736         return wfUrlProtocols( false );
 737 }
 738
 739 /**
 740  * parse_url() work-alike, but non-broken.  Differences:
 741  *
 742  * 1) Does not raise warnings on bad URLs (just returns false)
 743  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 744  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 745  *
 746  * @param string $url a URL to parse
 747  * @return Array: bits of the URL in an associative array, per PHP docs
 748  */
 749 function wfParseUrl( $url ) {
 750         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 751
 752         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 753         // way to handle them is to just prepend 'http:' and strip the protocol out later
 754         $wasRelative = substr( $url, 0, 2 ) == '//';
 755         if ( $wasRelative ) {
 756                 $url = "http:$url";
 757         }
 758         wfSuppressWarnings();
 759         $bits = parse_url( $url );
 760         wfRestoreWarnings();
 761         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 762         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 763         if ( !$bits || !isset( $bits['scheme'] ) ) {
 764                 return false;
 765         }
 766
 767         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 768         $bits['scheme'] = strtolower( $bits['scheme'] );
 769
 770         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 771         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 772                 $bits['delimiter'] = '://';
 773         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 774                 $bits['delimiter'] = ':';
 775                 // parse_url detects for news: and mailto: the host part of an url as path
 776                 // We have to correct this wrong detection
 777                 if ( isset( $bits['path'] ) ) {
 778                         $bits['host'] = $bits['path'];
 779                         $bits['path'] = '';
 780                 }
 781         } else {
 782                 return false;
 783         }
 784
 785         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 786         if ( !isset( $bits['host'] ) ) {
 787                 $bits['host'] = '';
 788
 789                 // bug 45069
 790                 if ( isset( $bits['path'] ) ) {
 791                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 792                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 793                                 $bits['path'] = '/' . $bits['path'];
 794                         }
 795                 } else {
 796                         $bits['path'] = '';
 797                 }
 798         }
 799
 800         // If the URL was protocol-relative, fix scheme and delimiter
 801         if ( $wasRelative ) {
 802                 $bits['scheme'] = '';
 803                 $bits['delimiter'] = '//';
 804         }
 805         return $bits;
 806 }
 807
 808 /**
 809  * Take a URL, make sure it's expanded to fully qualified, and replace any
 810  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 811  * for more compact display and legibility for local audiences.
 812  *
 813  * @todo handle punycode domains too
 814  *
 815  * @param $url string
 816  * @return string
 817  */
 818 function wfExpandIRI( $url ) {
 819         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 820 }
 821
 822 /**
 823  * Private callback for wfExpandIRI
 824  * @param array $matches
 825  * @return string
 826  */
 827 function wfExpandIRI_callback( $matches ) {
 828         return urldecode( $matches[1] );
 829 }
 830
 831 /**
 832  * Make URL indexes, appropriate for the el_index field of externallinks.
 833  *
 834  * @param $url String
 835  * @return array
 836  */
 837 function wfMakeUrlIndexes( $url ) {
 838         $bits = wfParseUrl( $url );
 839
 840         // Reverse the labels in the hostname, convert to lower case
 841         // For emails reverse domainpart only
 842         if ( $bits['scheme'] == 'mailto' ) {
 843                 $mailparts = explode( '@', $bits['host'], 2 );
 844                 if ( count( $mailparts ) === 2 ) {
 845                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 846                 } else {
 847                         // No domain specified, don't mangle it
 848                         $domainpart = '';
 849                 }
 850                 $reversedHost = $domainpart . '@' . $mailparts[0];
 851         } else {
 852                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 853         }
 854         // Add an extra dot to the end
 855         // Why? Is it in wrong place in mailto links?
 856         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 857                 $reversedHost .= '.';
 858         }
 859         // Reconstruct the pseudo-URL
 860         $prot = $bits['scheme'];
 861         $index = $prot . $bits['delimiter'] . $reversedHost;
 862         // Leave out user and password. Add the port, path, query and fragment
 863         if ( isset( $bits['port'] ) ) {
 864                 $index .= ':' . $bits['port'];
 865         }
 866         if ( isset( $bits['path'] ) ) {
 867                 $index .= $bits['path'];
 868         } else {
 869                 $index .= '/';
 870         }
 871         if ( isset( $bits['query'] ) ) {
 872                 $index .= '?' . $bits['query'];
 873         }
 874         if ( isset( $bits['fragment'] ) ) {
 875                 $index .= '#' . $bits['fragment'];
 876         }
 877
 878         if ( $prot == '' ) {
 879                 return array( "http:$index", "https:$index" );
 880         } else {
 881                 return array( $index );
 882         }
 883 }
 884
 885 /**
 886  * Check whether a given URL has a domain that occurs in a given set of domains
 887  * @param string $url URL
 888  * @param array $domains Array of domains (strings)
 889  * @return bool True if the host part of $url ends in one of the strings in $domains
 890  */
 891 function wfMatchesDomainList( $url, $domains ) {
 892         $bits = wfParseUrl( $url );
 893         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 894                 $host = '.' . $bits['host'];
 895                 foreach ( (array)$domains as $domain ) {
 896                         $domain = '.' . $domain;
 897                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 898                                 return true;
 899                         }
 900                 }
 901         }
 902         return false;
 903 }
 904
 905 /**
 906  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 907  * In normal operation this is a NOP.
 908  *
 909  * Controlling globals:
 910  * $wgDebugLogFile - points to the log file
 911  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 912  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 913  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 914  *
 915  * @param $text String
 916  * @param bool $logonly set true to avoid appearing in HTML when $wgDebugComments is set
 917  */
 918 function wfDebug( $text, $logonly = false ) {
 919         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 920
 921         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 922                 return;
 923         }
 924
 925         $timer = wfDebugTimer();
 926         if ( $timer !== '' ) {
 927                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 928         }
 929
 930         if ( !$logonly ) {
 931                 MWDebug::debugMsg( $text );
 932         }
 933
 934         if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 935                 # Strip unprintables; they can switch terminal modes when binary data
 936                 # gets dumped, which is pretty annoying.
 937                 $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 938                 $text = $wgDebugLogPrefix . $text;
 939                 wfErrorLog( $text, $wgDebugLogFile );
 940         }
 941 }
 942
 943 /**
 944  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 945  * @return bool
 946  */
 947 function wfIsDebugRawPage() {
 948         static $cache;
 949         if ( $cache !== null ) {
 950                 return $cache;
 951         }
 952         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 953         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 954                 || (
 955                         isset( $_SERVER['SCRIPT_NAME'] )
 956                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 957                 ) )
 958         {
 959                 $cache = true;
 960         } else {
 961                 $cache = false;
 962         }
 963         return $cache;
 964 }
 965
 966 /**
 967  * Get microsecond timestamps for debug logs
 968  *
 969  * @return string
 970  */
 971 function wfDebugTimer() {
 972         global $wgDebugTimestamps, $wgRequestTime;
 973
 974         if ( !$wgDebugTimestamps ) {
 975                 return '';
 976         }
 977
 978         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 979         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 980         return "$prefix $mem  ";
 981 }
 982
 983 /**
 984  * Send a line giving PHP memory usage.
 985  *
 986  * @param bool $exact print exact values instead of kilobytes (default: false)
 987  */
 988 function wfDebugMem( $exact = false ) {
 989         $mem = memory_get_usage();
 990         if ( !$exact ) {
 991                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 992         } else {
 993                 $mem .= ' bytes';
 994         }
 995         wfDebug( "Memory usage: $mem\n" );
 996 }
 997
 998 /**
 999  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1000  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1001  *
1002  * @param $logGroup String
1003  * @param $text String
1004  * @param bool $public whether to log the event in the public log if no private
1005  *                     log file is specified, (default true)
1006  */
1007 function wfDebugLog( $logGroup, $text, $public = true ) {
1008         global $wgDebugLogGroups;
1009         $text = trim( $text ) . "\n";
1010         if ( isset( $wgDebugLogGroups[$logGroup] ) ) {
1011                 $time = wfTimestamp( TS_DB );
1012                 $wiki = wfWikiID();
1013                 $host = wfHostname();
1014                 wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1015         } elseif ( $public === true ) {
1016                 wfDebug( "[$logGroup] $text", false );
1017         }
1018 }
1019
1020 /**
1021  * Log for database errors
1022  *
1023  * @param string $text database error message.
1024  */
1025 function wfLogDBError( $text ) {
1026         global $wgDBerrorLog, $wgDBerrorLogTZ;
1027         static $logDBErrorTimeZoneObject = null;
1028
1029         if ( $wgDBerrorLog ) {
1030                 $host = wfHostname();
1031                 $wiki = wfWikiID();
1032
1033                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1034                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1035                 }
1036
1037                 // Workaround for https://bugs.php.net/bug.php?id=52063
1038                 // Can be removed when min PHP > 5.3.2
1039                 if ( $logDBErrorTimeZoneObject === null ) {
1040                         $d = date_create( "now" );
1041                 } else {
1042                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1043                 }
1044
1045                 $date = $d->format( 'D M j G:i:s T Y' );
1046
1047                 $text = "$date\t$host\t$wiki\t$text";
1048                 wfErrorLog( $text, $wgDBerrorLog );
1049         }
1050 }
1051
1052 /**
1053  * Throws a warning that $function is deprecated
1054  *
1055  * @param $function String
1056  * @param string|bool $version Version of MediaWiki that the function was deprecated in (Added in 1.19).
1057  * @param string|bool $component Added in 1.19.
1058  * @param $callerOffset integer: How far up the call stack is the original
1059  *    caller. 2 = function that called the function that called
1060  *    wfDeprecated (Added in 1.20)
1061  *
1062  * @return null
1063  */
1064 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1065         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1066 }
1067
1068 /**
1069  * Send a warning either to the debug log or in a PHP error depending on
1070  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1071  *
1072  * @param string $msg message to send
1073  * @param $callerOffset Integer: number of items to go back in the backtrace to
1074  *        find the correct caller (1 = function calling wfWarn, ...)
1075  * @param $level Integer: PHP error level; defaults to E_USER_NOTICE;
1076  *        only used when $wgDevelopmentWarnings is true
1077  */
1078 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1079         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1080 }
1081
1082 /**
1083  * Send a warning as a PHP error and the debug log. This is intended for logging
1084  * warnings in production. For logging development warnings, use WfWarn instead.
1085  *
1086  * @param $msg String: message to send
1087  * @param $callerOffset Integer: number of items to go back in the backtrace to
1088  *        find the correct caller (1 = function calling wfLogWarning, ...)
1089  * @param $level Integer: PHP error level; defaults to E_USER_WARNING
1090  */
1091 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1092         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1093 }
1094
1095 /**
1096  * Log to a file without getting "file size exceeded" signals.
1097  *
1098  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1099  * send lines to the specified port, prefixed by the specified prefix and a space.
1100  *
1101  * @param $text String
1102  * @param string $file filename
1103  * @throws MWException
1104  */
1105 function wfErrorLog( $text, $file ) {
1106         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1107                 # Needs the sockets extension
1108                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1109                         // IPv6 bracketed host
1110                         $host = $m[2];
1111                         $port = intval( $m[3] );
1112                         $prefix = isset( $m[4] ) ? $m[4] : false;
1113                         $domain = AF_INET6;
1114                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1115                         $host = $m[2];
1116                         if ( !IP::isIPv4( $host ) ) {
1117                                 $host = gethostbyname( $host );
1118                         }
1119                         $port = intval( $m[3] );
1120                         $prefix = isset( $m[4] ) ? $m[4] : false;
1121                         $domain = AF_INET;
1122                 } else {
1123                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1124                 }
1125
1126                 // Clean it up for the multiplexer
1127                 if ( strval( $prefix ) !== '' ) {
1128                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1129
1130                         // Limit to 64KB
1131                         if ( strlen( $text ) > 65506 ) {
1132                                 $text = substr( $text, 0, 65506 );
1133                         }
1134
1135                         if ( substr( $text, -1 ) != "\n" ) {
1136                                 $text .= "\n";
1137                         }
1138                 } elseif ( strlen( $text ) > 65507 ) {
1139                         $text = substr( $text, 0, 65507 );
1140                 }
1141
1142                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1143                 if ( !$sock ) {
1144                         return;
1145                 }
1146
1147                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1148                 socket_close( $sock );
1149         } else {
1150                 wfSuppressWarnings();
1151                 $exists = file_exists( $file );
1152                 $size = $exists ? filesize( $file ) : false;
1153                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1154                         file_put_contents( $file, $text, FILE_APPEND );
1155                 }
1156                 wfRestoreWarnings();
1157         }
1158 }
1159
1160 /**
1161  * @todo document
1162  */
1163 function wfLogProfilingData() {
1164         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1165         global $wgProfileLimit, $wgUser;
1166
1167         StatCounter::singleton()->flush();
1168
1169         $profiler = Profiler::instance();
1170
1171         # Profiling must actually be enabled...
1172         if ( $profiler->isStub() ) {
1173                 return;
1174         }
1175
1176         // Get total page request time and only show pages that longer than
1177         // $wgProfileLimit time (default is 0)
1178         $elapsed = microtime( true ) - $wgRequestTime;
1179         if ( $elapsed <= $wgProfileLimit ) {
1180                 return;
1181         }
1182
1183         $profiler->logData();
1184
1185         // Check whether this should be logged in the debug file.
1186         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1187                 return;
1188         }
1189
1190         $forward = '';
1191         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1192                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1193         }
1194         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1195                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1196         }
1197         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1198                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1199         }
1200         if ( $forward ) {
1201                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1202         }
1203         // Don't load $wgUser at this late stage just for statistics purposes
1204         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1205         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1206                 $forward .= ' anon';
1207         }
1208
1209         // Command line script uses a FauxRequest object which does not have
1210         // any knowledge about an URL and throw an exception instead.
1211         try {
1212                 $requestUrl = $wgRequest->getRequestURL();
1213         } catch ( MWException $e ) {
1214                 $requestUrl = 'n/a';
1215         }
1216
1217         $log = sprintf( "%s\t%04.3f\t%s\n",
1218                 gmdate( 'YmdHis' ), $elapsed,
1219                 urldecode( $requestUrl . $forward ) );
1220
1221         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1222 }
1223
1224 /**
1225  * Increment a statistics counter
1226  *
1227  * @param $key String
1228  * @param $count Int
1229  * @return void
1230  */
1231 function wfIncrStats( $key, $count = 1 ) {
1232         StatCounter::singleton()->incr( $key, $count );
1233 }
1234
1235 /**
1236  * Check whether the wiki is in read-only mode.
1237  *
1238  * @return bool
1239  */
1240 function wfReadOnly() {
1241         return wfReadOnlyReason() !== false;
1242 }
1243
1244 /**
1245  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1246  *
1247  * @return string|bool: String when in read-only mode; false otherwise
1248  */
1249 function wfReadOnlyReason() {
1250         global $wgReadOnly, $wgReadOnlyFile;
1251
1252         if ( $wgReadOnly === null ) {
1253                 // Set $wgReadOnly for faster access next time
1254                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1255                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1256                 } else {
1257                         $wgReadOnly = false;
1258                 }
1259         }
1260
1261         return $wgReadOnly;
1262 }
1263
1264 /**
1265  * Return a Language object from $langcode
1266  *
1267  * @param $langcode Mixed: either:
1268  *                  - a Language object
1269  *                  - code of the language to get the message for, if it is
1270  *                    a valid code create a language for that language, if
1271  *                    it is a string but not a valid code then make a basic
1272  *                    language object
1273  *                  - a boolean: if it's false then use the global object for
1274  *                    the current user's language (as a fallback for the old parameter
1275  *                    functionality), or if it is true then use global object
1276  *                    for the wiki's content language.
1277  * @return Language object
1278  */
1279 function wfGetLangObj( $langcode = false ) {
1280         # Identify which language to get or create a language object for.
1281         # Using is_object here due to Stub objects.
1282         if ( is_object( $langcode ) ) {
1283                 # Great, we already have the object (hopefully)!
1284                 return $langcode;
1285         }
1286
1287         global $wgContLang, $wgLanguageCode;
1288         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1289                 # $langcode is the language code of the wikis content language object.
1290                 # or it is a boolean and value is true
1291                 return $wgContLang;
1292         }
1293
1294         global $wgLang;
1295         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1296                 # $langcode is the language code of user language object.
1297                 # or it was a boolean and value is false
1298                 return $wgLang;
1299         }
1300
1301         $validCodes = array_keys( Language::fetchLanguageNames() );
1302         if ( in_array( $langcode, $validCodes ) ) {
1303                 # $langcode corresponds to a valid language.
1304                 return Language::factory( $langcode );
1305         }
1306
1307         # $langcode is a string, but not a valid language code; use content language.
1308         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1309         return $wgContLang;
1310 }
1311
1312 /**
1313  * Old function when $wgBetterDirectionality existed
1314  * All usage removed, wfUILang can be removed in near future
1315  *
1316  * @deprecated since 1.18
1317  * @return Language
1318  */
1319 function wfUILang() {
1320         wfDeprecated( __METHOD__, '1.18' );
1321         global $wgLang;
1322         return $wgLang;
1323 }
1324
1325 /**
1326  * This is the function for getting translated interface messages.
1327  *
1328  * @see Message class for documentation how to use them.
1329  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1330  *
1331  * This function replaces all old wfMsg* functions.
1332  *
1333  * @param $key \string Message key.
1334  * Varargs: normal message parameters.
1335  * @return Message
1336  * @since 1.17
1337  */
1338 function wfMessage( $key /*...*/) {
1339         $params = func_get_args();
1340         array_shift( $params );
1341         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1342                 $params = $params[0];
1343         }
1344         return new Message( $key, $params );
1345 }
1346
1347 /**
1348  * This function accepts multiple message keys and returns a message instance
1349  * for the first message which is non-empty. If all messages are empty then an
1350  * instance of the first message key is returned.
1351  * @param varargs: message keys
1352  * @return Message
1353  * @since 1.18
1354  */
1355 function wfMessageFallback( /*...*/ ) {
1356         $args = func_get_args();
1357         return call_user_func_array( 'Message::newFallbackSequence', $args );
1358 }
1359
1360 /**
1361  * Get a message from anywhere, for the current user language.
1362  *
1363  * Use wfMsgForContent() instead if the message should NOT
1364  * change depending on the user preferences.
1365  *
1366  * @deprecated since 1.18
1367  *
1368  * @param string $key lookup key for the message, usually
1369  *    defined in languages/Language.php
1370  *
1371  * Parameters to the message, which can be used to insert variable text into
1372  * it, can be passed to this function in the following formats:
1373  * - One per argument, starting at the second parameter
1374  * - As an array in the second parameter
1375  * These are not shown in the function definition.
1376  *
1377  * @return String
1378  */
1379 function wfMsg( $key ) {
1380         wfDeprecated( __METHOD__, '1.21' );
1381
1382         $args = func_get_args();
1383         array_shift( $args );
1384         return wfMsgReal( $key, $args );
1385 }
1386
1387 /**
1388  * Same as above except doesn't transform the message
1389  *
1390  * @deprecated since 1.18
1391  *
1392  * @param $key String
1393  * @return String
1394  */
1395 function wfMsgNoTrans( $key ) {
1396         wfDeprecated( __METHOD__, '1.21' );
1397
1398         $args = func_get_args();
1399         array_shift( $args );
1400         return wfMsgReal( $key, $args, true, false, false );
1401 }
1402
1403 /**
1404  * Get a message from anywhere, for the current global language
1405  * set with $wgLanguageCode.
1406  *
1407  * Use this if the message should NOT change dependent on the
1408  * language set in the user's preferences. This is the case for
1409  * most text written into logs, as well as link targets (such as
1410  * the name of the copyright policy page). Link titles, on the
1411  * other hand, should be shown in the UI language.
1412  *
1413  * Note that MediaWiki allows users to change the user interface
1414  * language in their preferences, but a single installation
1415  * typically only contains content in one language.
1416  *
1417  * Be wary of this distinction: If you use wfMsg() where you should
1418  * use wfMsgForContent(), a user of the software may have to
1419  * customize potentially hundreds of messages in
1420  * order to, e.g., fix a link in every possible language.
1421  *
1422  * @deprecated since 1.18
1423  *
1424  * @param string $key lookup key for the message, usually
1425  *     defined in languages/Language.php
1426  * @return String
1427  */
1428 function wfMsgForContent( $key ) {
1429         wfDeprecated( __METHOD__, '1.21' );
1430
1431         global $wgForceUIMsgAsContentMsg;
1432         $args = func_get_args();
1433         array_shift( $args );
1434         $forcontent = true;
1435         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1436                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1437         {
1438                 $forcontent = false;
1439         }
1440         return wfMsgReal( $key, $args, true, $forcontent );
1441 }
1442
1443 /**
1444  * Same as above except doesn't transform the message
1445  *
1446  * @deprecated since 1.18
1447  *
1448  * @param $key String
1449  * @return String
1450  */
1451 function wfMsgForContentNoTrans( $key ) {
1452         wfDeprecated( __METHOD__, '1.21' );
1453
1454         global $wgForceUIMsgAsContentMsg;
1455         $args = func_get_args();
1456         array_shift( $args );
1457         $forcontent = true;
1458         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1459                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1460         {
1461                 $forcontent = false;
1462         }
1463         return wfMsgReal( $key, $args, true, $forcontent, false );
1464 }
1465
1466 /**
1467  * Really get a message
1468  *
1469  * @deprecated since 1.18
1470  *
1471  * @param string $key key to get.
1472  * @param $args
1473  * @param $useDB Boolean
1474  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1475  * @param $transform Boolean: Whether or not to transform the message.
1476  * @return String: the requested message.
1477  */
1478 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1479         wfDeprecated( __METHOD__, '1.21' );
1480
1481         wfProfileIn( __METHOD__ );
1482         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1483         $message = wfMsgReplaceArgs( $message, $args );
1484         wfProfileOut( __METHOD__ );
1485         return $message;
1486 }
1487
1488 /**
1489  * Fetch a message string value, but don't replace any keys yet.
1490  *
1491  * @deprecated since 1.18
1492  *
1493  * @param $key String
1494  * @param $useDB Bool
1495  * @param string $langCode Code of the language to get the message for, or
1496  *                  behaves as a content language switch if it is a boolean.
1497  * @param $transform Boolean: whether to parse magic words, etc.
1498  * @return string
1499  */
1500 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1501         wfDeprecated( __METHOD__, '1.21' );
1502
1503         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1504
1505         $cache = MessageCache::singleton();
1506         $message = $cache->get( $key, $useDB, $langCode );
1507         if ( $message === false ) {
1508                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1509         } elseif ( $transform ) {
1510                 $message = $cache->transform( $message );
1511         }
1512         return $message;
1513 }
1514
1515 /**
1516  * Replace message parameter keys on the given formatted output.
1517  *
1518  * @param $message String
1519  * @param $args Array
1520  * @return string
1521  * @private
1522  */
1523 function wfMsgReplaceArgs( $message, $args ) {
1524         # Fix windows line-endings
1525         # Some messages are split with explode("\n", $msg)
1526         $message = str_replace( "\r", '', $message );
1527
1528         // Replace arguments
1529         if ( count( $args ) ) {
1530                 if ( is_array( $args[0] ) ) {
1531                         $args = array_values( $args[0] );
1532                 }
1533                 $replacementKeys = array();
1534                 foreach ( $args as $n => $param ) {
1535                         $replacementKeys['$' . ( $n + 1 )] = $param;
1536                 }
1537                 $message = strtr( $message, $replacementKeys );
1538         }
1539
1540         return $message;
1541 }
1542
1543 /**
1544  * Return an HTML-escaped version of a message.
1545  * Parameter replacements, if any, are done *after* the HTML-escaping,
1546  * so parameters may contain HTML (eg links or form controls). Be sure
1547  * to pre-escape them if you really do want plaintext, or just wrap
1548  * the whole thing in htmlspecialchars().
1549  *
1550  * @deprecated since 1.18
1551  *
1552  * @param $key String
1553  * @param string ... parameters
1554  * @return string
1555  */
1556 function wfMsgHtml( $key ) {
1557         wfDeprecated( __METHOD__, '1.21' );
1558
1559         $args = func_get_args();
1560         array_shift( $args );
1561         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1562 }
1563
1564 /**
1565  * Return an HTML version of message
1566  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1567  * so parameters may contain HTML (eg links or form controls). Be sure
1568  * to pre-escape them if you really do want plaintext, or just wrap
1569  * the whole thing in htmlspecialchars().
1570  *
1571  * @deprecated since 1.18
1572  *
1573  * @param $key String
1574  * @param string ... parameters
1575  * @return string
1576  */
1577 function wfMsgWikiHtml( $key ) {
1578         wfDeprecated( __METHOD__, '1.21' );
1579
1580         $args = func_get_args();
1581         array_shift( $args );
1582         return wfMsgReplaceArgs(
1583                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1584                 /* can't be set to false */ true, /* interface */ true )->getText(),
1585                 $args );
1586 }
1587
1588 /**
1589  * Returns message in the requested format
1590  *
1591  * @deprecated since 1.18
1592  *
1593  * @param string $key key of the message
1594  * @param array $options processing rules. Can take the following options:
1595  *   <i>parse</i>: parses wikitext to HTML
1596  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1597  *       p's added by parser or tidy
1598  *   <i>escape</i>: filters message through htmlspecialchars
1599  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1600  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1601  *   <i>parsemag</i>: transform the message using magic phrases
1602  *   <i>content</i>: fetch message for content language instead of interface
1603  * Also can accept a single associative argument, of the form 'language' => 'xx':
1604  *   <i>language</i>: Language object or language code to fetch message for
1605  *       (overridden by <i>content</i>).
1606  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1607  *
1608  * @return String
1609  */
1610 function wfMsgExt( $key, $options ) {
1611         wfDeprecated( __METHOD__, '1.21' );
1612
1613         $args = func_get_args();
1614         array_shift( $args );
1615         array_shift( $args );
1616         $options = (array)$options;
1617
1618         foreach ( $options as $arrayKey => $option ) {
1619                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1620                         # An unknown index, neither numeric nor "language"
1621                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1622                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1623                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1624                 'replaceafter', 'parsemag', 'content' ) ) ) {
1625                         # A numeric index with unknown value
1626                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1627                 }
1628         }
1629
1630         if ( in_array( 'content', $options, true ) ) {
1631                 $forContent = true;
1632                 $langCode = true;
1633                 $langCodeObj = null;
1634         } elseif ( array_key_exists( 'language', $options ) ) {
1635                 $forContent = false;
1636                 $langCode = wfGetLangObj( $options['language'] );
1637                 $langCodeObj = $langCode;
1638         } else {
1639                 $forContent = false;
1640                 $langCode = false;
1641                 $langCodeObj = null;
1642         }
1643
1644         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1645
1646         if ( !in_array( 'replaceafter', $options, true ) ) {
1647                 $string = wfMsgReplaceArgs( $string, $args );
1648         }
1649
1650         $messageCache = MessageCache::singleton();
1651         $parseInline = in_array( 'parseinline', $options, true );
1652         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1653                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1654                 if ( $string instanceof ParserOutput ) {
1655                         $string = $string->getText();
1656                 }
1657
1658                 if ( $parseInline ) {
1659                         $m = array();
1660                         if ( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1661                                 $string = $m[1];
1662                         }
1663                 }
1664         } elseif ( in_array( 'parsemag', $options, true ) ) {
1665                 $string = $messageCache->transform( $string,
1666                                 !$forContent, $langCodeObj );
1667         }
1668
1669         if ( in_array( 'escape', $options, true ) ) {
1670                 $string = htmlspecialchars ( $string );
1671         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1672                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1673         }
1674
1675         if ( in_array( 'replaceafter', $options, true ) ) {
1676                 $string = wfMsgReplaceArgs( $string, $args );
1677         }
1678
1679         return $string;
1680 }
1681
1682 /**
1683  * Since wfMsg() and co suck, they don't return false if the message key they
1684  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1685  * nonexistence of messages by checking the MessageCache::get() result directly.
1686  *
1687  * @deprecated since 1.18. Use Message::isDisabled().
1688  *
1689  * @param $key      String: the message key looked up
1690  * @return Boolean True if the message *doesn't* exist.
1691  */
1692 function wfEmptyMsg( $key ) {
1693         wfDeprecated( __METHOD__, '1.21' );
1694
1695         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1696 }
1697
1698 /**
1699  * Throw a debugging exception. This function previously once exited the process,
1700  * but now throws an exception instead, with similar results.
1701  *
1702  * @deprecated since 1.22; just throw an MWException yourself
1703  * @param string $msg message shown when dying.
1704  * @throws MWException
1705  */
1706 function wfDebugDieBacktrace( $msg = '' ) {
1707         wfDeprecated( __FUNCTION__, '1.22' );
1708         throw new MWException( $msg );
1709 }
1710
1711 /**
1712  * Fetch server name for use in error reporting etc.
1713  * Use real server name if available, so we know which machine
1714  * in a server farm generated the current page.
1715  *
1716  * @return string
1717  */
1718 function wfHostname() {
1719         static $host;
1720         if ( is_null( $host ) ) {
1721
1722                 # Hostname overriding
1723                 global $wgOverrideHostname;
1724                 if ( $wgOverrideHostname !== false ) {
1725                         # Set static and skip any detection
1726                         $host = $wgOverrideHostname;
1727                         return $host;
1728                 }
1729
1730                 if ( function_exists( 'posix_uname' ) ) {
1731                         // This function not present on Windows
1732                         $uname = posix_uname();
1733                 } else {
1734                         $uname = false;
1735                 }
1736                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1737                         $host = $uname['nodename'];
1738                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1739                         # Windows computer name
1740                         $host = getenv( 'COMPUTERNAME' );
1741                 } else {
1742                         # This may be a virtual server.
1743                         $host = $_SERVER['SERVER_NAME'];
1744                 }
1745         }
1746         return $host;
1747 }
1748
1749 /**
1750  * Returns a HTML comment with the elapsed time since request.
1751  * This method has no side effects.
1752  *
1753  * @return string
1754  */
1755 function wfReportTime() {
1756         global $wgRequestTime, $wgShowHostnames;
1757
1758         $elapsed = microtime( true ) - $wgRequestTime;
1759
1760         return $wgShowHostnames
1761                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1762                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1763 }
1764
1765 /**
1766  * Safety wrapper for debug_backtrace().
1767  *
1768  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1769  * murky circumstances, which may be triggered in part by stub objects
1770  * or other fancy talking'.
1771  *
1772  * Will return an empty array if Zend Optimizer is detected or if
1773  * debug_backtrace is disabled, otherwise the output from
1774  * debug_backtrace() (trimmed).
1775  *
1776  * @param int $limit This parameter can be used to limit the number of stack frames returned
1777  *
1778  * @return array of backtrace information
1779  */
1780 function wfDebugBacktrace( $limit = 0 ) {
1781         static $disabled = null;
1782
1783         if ( extension_loaded( 'Zend Optimizer' ) ) {
1784                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1785                 return array();
1786         }
1787
1788         if ( is_null( $disabled ) ) {
1789                 $disabled = false;
1790                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1791                 $functions = array_map( 'trim', $functions );
1792                 $functions = array_map( 'strtolower', $functions );
1793                 if ( in_array( 'debug_backtrace', $functions ) ) {
1794                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1795                         $disabled = true;
1796                 }
1797         }
1798         if ( $disabled ) {
1799                 return array();
1800         }
1801
1802         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1803                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1804         } else {
1805                 return array_slice( debug_backtrace(), 1 );
1806         }
1807 }
1808
1809 /**
1810  * Get a debug backtrace as a string
1811  *
1812  * @return string
1813  */
1814 function wfBacktrace() {
1815         global $wgCommandLineMode;
1816
1817         if ( $wgCommandLineMode ) {
1818                 $msg = '';
1819         } else {
1820                 $msg = "<ul>\n";
1821         }
1822         $backtrace = wfDebugBacktrace();
1823         foreach ( $backtrace as $call ) {
1824                 if ( isset( $call['file'] ) ) {
1825                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1826                         $file = $f[count( $f ) - 1];
1827                 } else {
1828                         $file = '-';
1829                 }
1830                 if ( isset( $call['line'] ) ) {
1831                         $line = $call['line'];
1832                 } else {
1833                         $line = '-';
1834                 }
1835                 if ( $wgCommandLineMode ) {
1836                         $msg .= "$file line $line calls ";
1837                 } else {
1838                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1839                 }
1840                 if ( !empty( $call['class'] ) ) {
1841                         $msg .= $call['class'] . $call['type'];
1842                 }
1843                 $msg .= $call['function'] . '()';
1844
1845                 if ( $wgCommandLineMode ) {
1846                         $msg .= "\n";
1847                 } else {
1848                         $msg .= "</li>\n";
1849                 }
1850         }
1851         if ( $wgCommandLineMode ) {
1852                 $msg .= "\n";
1853         } else {
1854                 $msg .= "</ul>\n";
1855         }
1856
1857         return $msg;
1858 }
1859
1860 /**
1861  * Get the name of the function which called this function
1862  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1863  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1864  * wfGetCaller( 3 ) is the parent of that.
1865  *
1866  * @param $level Int
1867  * @return string
1868  */
1869 function wfGetCaller( $level = 2 ) {
1870         $backtrace = wfDebugBacktrace( $level + 1 );
1871         if ( isset( $backtrace[$level] ) ) {
1872                 return wfFormatStackFrame( $backtrace[$level] );
1873         } else {
1874                 return 'unknown';
1875         }
1876 }
1877
1878 /**
1879  * Return a string consisting of callers in the stack. Useful sometimes
1880  * for profiling specific points.
1881  *
1882  * @param int $limit The maximum depth of the stack frame to return, or false for
1883  *               the entire stack.
1884  * @return String
1885  */
1886 function wfGetAllCallers( $limit = 3 ) {
1887         $trace = array_reverse( wfDebugBacktrace() );
1888         if ( !$limit || $limit > count( $trace ) - 1 ) {
1889                 $limit = count( $trace ) - 1;
1890         }
1891         $trace = array_slice( $trace, -$limit - 1, $limit );
1892         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1893 }
1894
1895 /**
1896  * Return a string representation of frame
1897  *
1898  * @param $frame Array
1899  * @return string
1900  */
1901 function wfFormatStackFrame( $frame ) {
1902         return isset( $frame['class'] ) ?
1903                 $frame['class'] . '::' . $frame['function'] :
1904                 $frame['function'];
1905 }
1906
1907 /* Some generic result counters, pulled out of SearchEngine */
1908
1909 /**
1910  * @todo document
1911  *
1912  * @param $offset Int
1913  * @param $limit Int
1914  * @return String
1915  */
1916 function wfShowingResults( $offset, $limit ) {
1917         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1918 }
1919
1920 /**
1921  * Generate (prev x| next x) (20|50|100...) type links for paging
1922  *
1923  * @param $offset String
1924  * @param $limit Integer
1925  * @param $link String
1926  * @param string $query optional URL query parameter string
1927  * @param bool $atend optional param for specified if this is the last page
1928  * @return String
1929  * @deprecated in 1.19; use Language::viewPrevNext() instead
1930  */
1931 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1932         wfDeprecated( __METHOD__, '1.19' );
1933
1934         global $wgLang;
1935
1936         $query = wfCgiToArray( $query );
1937
1938         if ( is_object( $link ) ) {
1939                 $title = $link;
1940         } else {
1941                 $title = Title::newFromText( $link );
1942                 if ( is_null( $title ) ) {
1943                         return false;
1944                 }
1945         }
1946
1947         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1948 }
1949
1950 /**
1951  * @todo document
1952  * @todo FIXME: We may want to blacklist some broken browsers
1953  *
1954  * @param $force Bool
1955  * @return bool Whereas client accept gzip compression
1956  */
1957 function wfClientAcceptsGzip( $force = false ) {
1958         static $result = null;
1959         if ( $result === null || $force ) {
1960                 $result = false;
1961                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1962                         # @todo FIXME: We may want to blacklist some broken browsers
1963                         $m = array();
1964                         if ( preg_match(
1965                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1966                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1967                                 $m )
1968                         )
1969                         {
1970                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1971                                         $result = false;
1972                                         return $result;
1973                                 }
1974                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1975                                 $result = true;
1976                         }
1977                 }
1978         }
1979         return $result;
1980 }
1981
1982 /**
1983  * Obtain the offset and limit values from the request string;
1984  * used in special pages
1985  *
1986  * @param int $deflimit default limit if none supplied
1987  * @param string $optionname Name of a user preference to check against
1988  * @return array
1989  *
1990  */
1991 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1992         global $wgRequest;
1993         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1994 }
1995
1996 /**
1997  * Escapes the given text so that it may be output using addWikiText()
1998  * without any linking, formatting, etc. making its way through. This
1999  * is achieved by substituting certain characters with HTML entities.
2000  * As required by the callers, "<nowiki>" is not used.
2001  *
2002  * @param string $text text to be escaped
2003  * @return String
2004  */
2005 function wfEscapeWikiText( $text ) {
2006         static $repl = null, $repl2 = null;
2007         if ( $repl === null ) {
2008                 $repl = array(
2009                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2010                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2011                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2012                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2013                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2014                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2015                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2016                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2017                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2018                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2019                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2020                         '__' => '_&#95;', '://' => '&#58;//',
2021                 );
2022
2023                 // We have to catch everything "\s" matches in PCRE
2024                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2025                         $repl["$magic "] = "$magic&#32;";
2026                         $repl["$magic\t"] = "$magic&#9;";
2027                         $repl["$magic\r"] = "$magic&#13;";
2028                         $repl["$magic\n"] = "$magic&#10;";
2029                         $repl["$magic\f"] = "$magic&#12;";
2030                 }
2031
2032                 // And handle protocols that don't use "://"
2033                 global $wgUrlProtocols;
2034                 $repl2 = array();
2035                 foreach ( $wgUrlProtocols as $prot ) {
2036                         if ( substr( $prot, -1 ) === ':' ) {
2037                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2038                         }
2039                 }
2040                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2041         }
2042         $text = substr( strtr( "\n$text", $repl ), 1 );
2043         $text = preg_replace( $repl2, '$1&#58;', $text );
2044         return $text;
2045 }
2046
2047 /**
2048  * Get the current unix timestamp with microseconds.  Useful for profiling
2049  * @deprecated since 1.22; call microtime() directly
2050  * @return Float
2051  */
2052 function wfTime() {
2053         wfDeprecated( __FUNCTION__, '1.22' );
2054         return microtime( true );
2055 }
2056
2057 /**
2058  * Sets dest to source and returns the original value of dest
2059  * If source is NULL, it just returns the value, it doesn't set the variable
2060  * If force is true, it will set the value even if source is NULL
2061  *
2062  * @param $dest Mixed
2063  * @param $source Mixed
2064  * @param $force Bool
2065  * @return Mixed
2066  */
2067 function wfSetVar( &$dest, $source, $force = false ) {
2068         $temp = $dest;
2069         if ( !is_null( $source ) || $force ) {
2070                 $dest = $source;
2071         }
2072         return $temp;
2073 }
2074
2075 /**
2076  * As for wfSetVar except setting a bit
2077  *
2078  * @param $dest Int
2079  * @param $bit Int
2080  * @param $state Bool
2081  *
2082  * @return bool
2083  */
2084 function wfSetBit( &$dest, $bit, $state = true ) {
2085         $temp = (bool)( $dest & $bit );
2086         if ( !is_null( $state ) ) {
2087                 if ( $state ) {
2088                         $dest |= $bit;
2089                 } else {
2090                         $dest &= ~$bit;
2091                 }
2092         }
2093         return $temp;
2094 }
2095
2096 /**
2097  * A wrapper around the PHP function var_export().
2098  * Either print it or add it to the regular output ($wgOut).
2099  *
2100  * @param $var mixed A PHP variable to dump.
2101  */
2102 function wfVarDump( $var ) {
2103         global $wgOut;
2104         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2105         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2106                 print $s;
2107         } else {
2108                 $wgOut->addHTML( $s );
2109         }
2110 }
2111
2112 /**
2113  * Provide a simple HTTP error.
2114  *
2115  * @param $code Int|String
2116  * @param $label String
2117  * @param $desc String
2118  */
2119 function wfHttpError( $code, $label, $desc ) {
2120         global $wgOut;
2121         $wgOut->disable();
2122         header( "HTTP/1.0 $code $label" );
2123         header( "Status: $code $label" );
2124         $wgOut->sendCacheControl();
2125
2126         header( 'Content-type: text/html; charset=utf-8' );
2127         print "<!doctype html>" .
2128                 '<html><head><title>' .
2129                 htmlspecialchars( $label ) .
2130                 '</title></head><body><h1>' .
2131                 htmlspecialchars( $label ) .
2132                 '</h1><p>' .
2133                 nl2br( htmlspecialchars( $desc ) ) .
2134                 "</p></body></html>\n";
2135 }
2136
2137 /**
2138  * Clear away any user-level output buffers, discarding contents.
2139  *
2140  * Suitable for 'starting afresh', for instance when streaming
2141  * relatively large amounts of data without buffering, or wanting to
2142  * output image files without ob_gzhandler's compression.
2143  *
2144  * The optional $resetGzipEncoding parameter controls suppression of
2145  * the Content-Encoding header sent by ob_gzhandler; by default it
2146  * is left. See comments for wfClearOutputBuffers() for why it would
2147  * be used.
2148  *
2149  * Note that some PHP configuration options may add output buffer
2150  * layers which cannot be removed; these are left in place.
2151  *
2152  * @param $resetGzipEncoding Bool
2153  */
2154 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2155         if ( $resetGzipEncoding ) {
2156                 // Suppress Content-Encoding and Content-Length
2157                 // headers from 1.10+s wfOutputHandler
2158                 global $wgDisableOutputCompression;
2159                 $wgDisableOutputCompression = true;
2160         }
2161         while ( $status = ob_get_status() ) {
2162                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2163                         // Probably from zlib.output_compression or other
2164                         // PHP-internal setting which can't be removed.
2165                         //
2166                         // Give up, and hope the result doesn't break
2167                         // output behavior.
2168                         break;
2169                 }
2170                 if ( !ob_end_clean() ) {
2171                         // Could not remove output buffer handler; abort now
2172                         // to avoid getting in some kind of infinite loop.
2173                         break;
2174                 }
2175                 if ( $resetGzipEncoding ) {
2176                         if ( $status['name'] == 'ob_gzhandler' ) {
2177                                 // Reset the 'Content-Encoding' field set by this handler
2178                                 // so we can start fresh.
2179                                 header_remove( 'Content-Encoding' );
2180                                 break;
2181                         }
2182                 }
2183         }
2184 }
2185
2186 /**
2187  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2188  *
2189  * Clear away output buffers, but keep the Content-Encoding header
2190  * produced by ob_gzhandler, if any.
2191  *
2192  * This should be used for HTTP 304 responses, where you need to
2193  * preserve the Content-Encoding header of the real result, but
2194  * also need to suppress the output of ob_gzhandler to keep to spec
2195  * and avoid breaking Firefox in rare cases where the headers and
2196  * body are broken over two packets.
2197  */
2198 function wfClearOutputBuffers() {
2199         wfResetOutputBuffers( false );
2200 }
2201
2202 /**
2203  * Converts an Accept-* header into an array mapping string values to quality
2204  * factors
2205  *
2206  * @param $accept String
2207  * @param string $def default
2208  * @return Array
2209  */
2210 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2211         # No arg means accept anything (per HTTP spec)
2212         if ( !$accept ) {
2213                 return array( $def => 1.0 );
2214         }
2215
2216         $prefs = array();
2217
2218         $parts = explode( ',', $accept );
2219
2220         foreach ( $parts as $part ) {
2221                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2222                 $values = explode( ';', trim( $part ) );
2223                 $match = array();
2224                 if ( count( $values ) == 1 ) {
2225                         $prefs[$values[0]] = 1.0;
2226                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2227                         $prefs[$values[0]] = floatval( $match[1] );
2228                 }
2229         }
2230
2231         return $prefs;
2232 }
2233
2234 /**
2235  * Checks if a given MIME type matches any of the keys in the given
2236  * array. Basic wildcards are accepted in the array keys.
2237  *
2238  * Returns the matching MIME type (or wildcard) if a match, otherwise
2239  * NULL if no match.
2240  *
2241  * @param $type String
2242  * @param $avail Array
2243  * @return string
2244  * @private
2245  */
2246 function mimeTypeMatch( $type, $avail ) {
2247         if ( array_key_exists( $type, $avail ) ) {
2248                 return $type;
2249         } else {
2250                 $parts = explode( '/', $type );
2251                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2252                         return $parts[0] . '/*';
2253                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2254                         return '*/*';
2255                 } else {
2256                         return null;
2257                 }
2258         }
2259 }
2260
2261 /**
2262  * Returns the 'best' match between a client's requested internet media types
2263  * and the server's list of available types. Each list should be an associative
2264  * array of type to preference (preference is a float between 0.0 and 1.0).
2265  * Wildcards in the types are acceptable.
2266  *
2267  * @param array $cprefs client's acceptable type list
2268  * @param array $sprefs server's offered types
2269  * @return string
2270  *
2271  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2272  * XXX: generalize to negotiate other stuff
2273  */
2274 function wfNegotiateType( $cprefs, $sprefs ) {
2275         $combine = array();
2276
2277         foreach ( array_keys( $sprefs ) as $type ) {
2278                 $parts = explode( '/', $type );
2279                 if ( $parts[1] != '*' ) {
2280                         $ckey = mimeTypeMatch( $type, $cprefs );
2281                         if ( $ckey ) {
2282                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2283                         }
2284                 }
2285         }
2286
2287         foreach ( array_keys( $cprefs ) as $type ) {
2288                 $parts = explode( '/', $type );
2289                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2290                         $skey = mimeTypeMatch( $type, $sprefs );
2291                         if ( $skey ) {
2292                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2293                         }
2294                 }
2295         }
2296
2297         $bestq = 0;
2298         $besttype = null;
2299
2300         foreach ( array_keys( $combine ) as $type ) {
2301                 if ( $combine[$type] > $bestq ) {
2302                         $besttype = $type;
2303                         $bestq = $combine[$type];
2304                 }
2305         }
2306
2307         return $besttype;
2308 }
2309
2310 /**
2311  * Reference-counted warning suppression
2312  *
2313  * @param $end Bool
2314  */
2315 function wfSuppressWarnings( $end = false ) {
2316         static $suppressCount = 0;
2317         static $originalLevel = false;
2318
2319         if ( $end ) {
2320                 if ( $suppressCount ) {
2321                         --$suppressCount;
2322                         if ( !$suppressCount ) {
2323                                 error_reporting( $originalLevel );
2324                         }
2325                 }
2326         } else {
2327                 if ( !$suppressCount ) {
2328                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT ) );
2329                 }
2330                 ++$suppressCount;
2331         }
2332 }
2333
2334 /**
2335  * Restore error level to previous value
2336  */
2337 function wfRestoreWarnings() {
2338         wfSuppressWarnings( true );
2339 }
2340
2341 # Autodetect, convert and provide timestamps of various types
2342
2343 /**
2344  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2345  */
2346 define( 'TS_UNIX', 0 );
2347
2348 /**
2349  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2350  */
2351 define( 'TS_MW', 1 );
2352
2353 /**
2354  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2355  */
2356 define( 'TS_DB', 2 );
2357
2358 /**
2359  * RFC 2822 format, for E-mail and HTTP headers
2360  */
2361 define( 'TS_RFC2822', 3 );
2362
2363 /**
2364  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2365  *
2366  * This is used by Special:Export
2367  */
2368 define( 'TS_ISO_8601', 4 );
2369
2370 /**
2371  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2372  *
2373  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2374  *       DateTime tag and page 36 for the DateTimeOriginal and
2375  *       DateTimeDigitized tags.
2376  */
2377 define( 'TS_EXIF', 5 );
2378
2379 /**
2380  * Oracle format time.
2381  */
2382 define( 'TS_ORACLE', 6 );
2383
2384 /**
2385  * Postgres format time.
2386  */
2387 define( 'TS_POSTGRES', 7 );
2388
2389 /**
2390  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2391  */
2392 define( 'TS_ISO_8601_BASIC', 9 );
2393
2394 /**
2395  * Get a timestamp string in one of various formats
2396  *
2397  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2398  *                    function will autodetect which format is supplied and act
2399  *                    accordingly.
2400  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2401  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2402  */
2403 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2404         try {
2405                 $timestamp = new MWTimestamp( $ts );
2406                 return $timestamp->getTimestamp( $outputtype );
2407         } catch ( TimestampException $e ) {
2408                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2409                 return false;
2410         }
2411 }
2412
2413 /**
2414  * Return a formatted timestamp, or null if input is null.
2415  * For dealing with nullable timestamp columns in the database.
2416  *
2417  * @param $outputtype Integer
2418  * @param $ts String
2419  * @return String
2420  */
2421 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2422         if ( is_null( $ts ) ) {
2423                 return null;
2424         } else {
2425                 return wfTimestamp( $outputtype, $ts );
2426         }
2427 }
2428
2429 /**
2430  * Convenience function; returns MediaWiki timestamp for the present time.
2431  *
2432  * @return string
2433  */
2434 function wfTimestampNow() {
2435         # return NOW
2436         return wfTimestamp( TS_MW, time() );
2437 }
2438
2439 /**
2440  * Check if the operating system is Windows
2441  *
2442  * @return Bool: true if it's Windows, False otherwise.
2443  */
2444 function wfIsWindows() {
2445         static $isWindows = null;
2446         if ( $isWindows === null ) {
2447                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2448         }
2449         return $isWindows;
2450 }
2451
2452 /**
2453  * Check if we are running under HipHop
2454  *
2455  * @return Bool
2456  */
2457 function wfIsHipHop() {
2458         return defined( 'HPHP_VERSION' );
2459 }
2460
2461 /**
2462  * Swap two variables
2463  *
2464  * @param $x Mixed
2465  * @param $y Mixed
2466  */
2467 function swap( &$x, &$y ) {
2468         $z = $x;
2469         $x = $y;
2470         $y = $z;
2471 }
2472
2473 /**
2474  * Tries to get the system directory for temporary files. First
2475  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2476  * environment variables are then checked in sequence, and if none are
2477  * set try sys_get_temp_dir().
2478  *
2479  * NOTE: When possible, use instead the tmpfile() function to create
2480  * temporary files to avoid race conditions on file creation, etc.
2481  *
2482  * @return String
2483  */
2484 function wfTempDir() {
2485         global $wgTmpDirectory;
2486
2487         if ( $wgTmpDirectory !== false ) {
2488                 return $wgTmpDirectory;
2489         }
2490
2491         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2492
2493         foreach ( $tmpDir as $tmp ) {
2494                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2495                         return $tmp;
2496                 }
2497         }
2498         return sys_get_temp_dir();
2499 }
2500
2501 /**
2502  * Make directory, and make all parent directories if they don't exist
2503  *
2504  * @param string $dir full path to directory to create
2505  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2506  * @param string $caller optional caller param for debugging.
2507  * @throws MWException
2508  * @return bool
2509  */
2510 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2511         global $wgDirectoryMode;
2512
2513         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2514                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2515         }
2516
2517         if ( !is_null( $caller ) ) {
2518                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2519         }
2520
2521         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2522                 return true;
2523         }
2524
2525         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2526
2527         if ( is_null( $mode ) ) {
2528                 $mode = $wgDirectoryMode;
2529         }
2530
2531         // Turn off the normal warning, we're doing our own below
2532         wfSuppressWarnings();
2533         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2534         wfRestoreWarnings();
2535
2536         if ( !$ok ) {
2537                 //directory may have been created on another request since we last checked
2538                 if ( is_dir( $dir ) ) {
2539                         return true;
2540                 }
2541
2542                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2543                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2544         }
2545         return $ok;
2546 }
2547
2548 /**
2549  * Remove a directory and all its content.
2550  * Does not hide error.
2551  */
2552 function wfRecursiveRemoveDir( $dir ) {
2553         wfDebug( __FUNCTION__ . "( $dir )\n" );
2554         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2555         if ( is_dir( $dir ) ) {
2556                 $objects = scandir( $dir );
2557                 foreach ( $objects as $object ) {
2558                         if ( $object != "." && $object != ".." ) {
2559                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2560                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2561                                 } else {
2562                                         unlink( $dir . '/' . $object );
2563                                 }
2564                         }
2565                 }
2566                 reset( $objects );
2567                 rmdir( $dir );
2568         }
2569 }
2570
2571 /**
2572  * @param $nr Mixed: the number to format
2573  * @param $acc Integer: the number of digits after the decimal point, default 2
2574  * @param $round Boolean: whether or not to round the value, default true
2575  * @return float
2576  */
2577 function wfPercent( $nr, $acc = 2, $round = true ) {
2578         $ret = sprintf( "%.${acc}f", $nr );
2579         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2580 }
2581
2582 /**
2583  * Find out whether or not a mixed variable exists in a string
2584  *
2585  * @deprecated Just use str(i)pos
2586  * @param $needle String
2587  * @param $str String
2588  * @param $insensitive Boolean
2589  * @return Boolean
2590  */
2591 function in_string( $needle, $str, $insensitive = false ) {
2592         wfDeprecated( __METHOD__, '1.21' );
2593         $func = 'strpos';
2594         if ( $insensitive ) {
2595                 $func = 'stripos';
2596         }
2597
2598         return $func( $str, $needle ) !== false;
2599 }
2600
2601 /**
2602  * Safety wrapper around ini_get() for boolean settings.
2603  * The values returned from ini_get() are pre-normalized for settings
2604  * set via php.ini or php_flag/php_admin_flag... but *not*
2605  * for those set via php_value/php_admin_value.
2606  *
2607  * It's fairly common for people to use php_value instead of php_flag,
2608  * which can leave you with an 'off' setting giving a false positive
2609  * for code that just takes the ini_get() return value as a boolean.
2610  *
2611  * To make things extra interesting, setting via php_value accepts
2612  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2613  * Unrecognized values go false... again opposite PHP's own coercion
2614  * from string to bool.
2615  *
2616  * Luckily, 'properly' set settings will always come back as '0' or '1',
2617  * so we only have to worry about them and the 'improper' settings.
2618  *
2619  * I frickin' hate PHP... :P
2620  *
2621  * @param $setting String
2622  * @return Bool
2623  */
2624 function wfIniGetBool( $setting ) {
2625         $val = strtolower( ini_get( $setting ) );
2626         // 'on' and 'true' can't have whitespace around them, but '1' can.
2627         return $val == 'on'
2628                 || $val == 'true'
2629                 || $val == 'yes'
2630                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2631 }
2632
2633 /**
2634  * Windows-compatible version of escapeshellarg()
2635  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2636  * function puts single quotes in regardless of OS.
2637  *
2638  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2639  * earlier distro releases of PHP)
2640  *
2641  * @param varargs
2642  * @return String
2643  */
2644 function wfEscapeShellArg() {
2645         wfInitShellLocale();
2646
2647         $args = func_get_args();
2648         $first = true;
2649         $retVal = '';
2650         foreach ( $args as $arg ) {
2651                 if ( !$first ) {
2652                         $retVal .= ' ';
2653                 } else {
2654                         $first = false;
2655                 }
2656
2657                 if ( wfIsWindows() ) {
2658                         // Escaping for an MSVC-style command line parser and CMD.EXE
2659                         // Refs:
2660                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2661                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2662                         //  * Bug #13518
2663                         //  * CR r63214
2664                         // Double the backslashes before any double quotes. Escape the double quotes.
2665                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2666                         $arg = '';
2667                         $iteration = 0;
2668                         foreach ( $tokens as $token ) {
2669                                 if ( $iteration % 2 == 1 ) {
2670                                         // Delimiter, a double quote preceded by zero or more slashes
2671                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2672                                 } elseif ( $iteration % 4 == 2 ) {
2673                                         // ^ in $token will be outside quotes, need to be escaped
2674                                         $arg .= str_replace( '^', '^^', $token );
2675                                 } else { // $iteration % 4 == 0
2676                                         // ^ in $token will appear inside double quotes, so leave as is
2677                                         $arg .= $token;
2678                                 }
2679                                 $iteration++;
2680                         }
2681                         // Double the backslashes before the end of the string, because
2682                         // we will soon add a quote
2683                         $m = array();
2684                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2685                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2686                         }
2687
2688                         // Add surrounding quotes
2689                         $retVal .= '"' . $arg . '"';
2690                 } else {
2691                         $retVal .= escapeshellarg( $arg );
2692                 }
2693         }
2694         return $retVal;
2695 }
2696
2697 /**
2698  * Check if wfShellExec() is effectively disabled via php.ini config
2699  * @return bool|string False or one of (safemode,disabled)
2700  * @since 1.22
2701  */
2702 function wfShellExecDisabled() {
2703         static $disabled = null;
2704         if ( is_null( $disabled ) ) {
2705                 $disabled = false;
2706                 if ( wfIniGetBool( 'safe_mode' ) ) {
2707                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2708                         $disabled = 'safemode';
2709                 } else {
2710                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2711                         $functions = array_map( 'trim', $functions );
2712                         $functions = array_map( 'strtolower', $functions );
2713                         if ( in_array( 'passthru', $functions ) ) {
2714                                 wfDebug( "passthru is in disabled_functions\n" );
2715                                 $disabled = 'passthru';
2716                         }
2717                 }
2718         }
2719         return $disabled;
2720 }
2721
2722 /**
2723  * Execute a shell command, with time and memory limits mirrored from the PHP
2724  * configuration if supported.
2725  * @param string $cmd Command line, properly escaped for shell.
2726  * @param &$retval null|Mixed optional, will receive the program's exit code.
2727  *                 (non-zero is usually failure)
2728  * @param array $environ optional environment variables which should be
2729  *                 added to the executed command environment.
2730  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2731  *                 this overwrites the global wgShellMax* limits.
2732  * @param array $options Array of options. Only one is "duplicateStderr" => true, which
2733  *                 Which duplicates stderr to stdout, including errors from limit.sh
2734  * @return string collected stdout as a string
2735  */
2736 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array(), $options = array() ) {
2737         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2738                 $wgMaxShellWallClockTime, $wgShellCgroup;
2739
2740         $disabled = wfShellExecDisabled();
2741         if ( $disabled ) {
2742                 $retval = 1;
2743                 return $disabled == 'safemode' ?
2744                         'Unable to run external programs in safe mode.' :
2745                         'Unable to run external programs, passthru() is disabled.';
2746         }
2747
2748         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2749
2750         wfInitShellLocale();
2751
2752         $envcmd = '';
2753         foreach ( $environ as $k => $v ) {
2754                 if ( wfIsWindows() ) {
2755                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2756                          * appear in the environment variable, so we must use carat escaping as documented in
2757                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2758                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2759                          * are listed there but doesn't appear to need it.
2760                          */
2761                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2762                 } else {
2763                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2764                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2765                          */
2766                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2767                 }
2768         }
2769         $cmd = $envcmd . $cmd;
2770
2771         if ( php_uname( 's' ) == 'Linux' ) {
2772                 $stderrDuplication = '';
2773                 if ( $includeStderr ) {
2774                         $stderrDuplication = 'exec 2>&1; ';
2775                 }
2776                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2777                 if ( isset( $limits['walltime'] ) ) {
2778                         $wallTime = intval( $limits['walltime'] );
2779                 } elseif ( isset( $limits['time'] ) ) {
2780                         $wallTime = $time;
2781                 } else {
2782                         $wallTime = intval( $wgMaxShellWallClockTime );
2783                 }
2784                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2785                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2786
2787                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2788                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2789                                 escapeshellarg( $cmd ) . ' ' .
2790                                 escapeshellarg(
2791                                         $stderrDuplication .
2792                                         "MW_CPU_LIMIT=$time; " .
2793                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2794                                         "MW_MEM_LIMIT=$mem; " .
2795                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2796                                         "MW_WALL_CLOCK_LIMIT=$wallTime"
2797                                 );
2798                 } else {
2799                         $cmd .= ' 2>&1';
2800                 }
2801         } elseif ( $includeStderr ) {
2802                 $cmd .= ' 2>&1';
2803         }
2804         wfDebug( "wfShellExec: $cmd\n" );
2805
2806         // Default to an unusual value that shouldn't happen naturally,
2807         // so in the unlikely event of a weird php bug, it would be
2808         // more obvious what happened.
2809         $retval = 200;
2810         ob_start();
2811         passthru( $cmd, $retval );
2812         $output = ob_get_contents();
2813         ob_end_clean();
2814
2815         if ( $retval == 127 ) {
2816                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2817         }
2818         return $output;
2819 }
2820
2821 /**
2822  * Execute a shell command, returning both stdout and stderr. Convenience
2823  * function, as all the arguments to wfShellExec can become unwieldy.
2824  *
2825  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2826  * @param string $cmd Command line, properly escaped for shell.
2827  * @param &$retval null|Mixed optional, will receive the program's exit code.
2828  *                 (non-zero is usually failure)
2829  * @param array $environ optional environment variables which should be
2830  *                 added to the executed command environment.
2831  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2832  *                 this overwrites the global wgShellMax* limits.
2833  * @return string collected stdout and stderr as a string
2834  */
2835 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2836         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
2837 }
2838
2839 /**
2840  * Workaround for http://bugs.php.net/bug.php?id=45132
2841  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2842  */
2843 function wfInitShellLocale() {
2844         static $done = false;
2845         if ( $done ) {
2846                 return;
2847         }
2848         $done = true;
2849         global $wgShellLocale;
2850         if ( !wfIniGetBool( 'safe_mode' ) ) {
2851                 putenv( "LC_CTYPE=$wgShellLocale" );
2852                 setlocale( LC_CTYPE, $wgShellLocale );
2853         }
2854 }
2855
2856 /**
2857  * Alias to wfShellWikiCmd()
2858  * @see wfShellWikiCmd()
2859  */
2860 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2861         return wfShellWikiCmd( $script, $parameters, $options );
2862 }
2863
2864 /**
2865  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2866  * Note that $parameters should be a flat array and an option with an argument
2867  * should consist of two consecutive items in the array (do not use "--option value").
2868  * @param string $script MediaWiki cli script path
2869  * @param array $parameters Arguments and options to the script
2870  * @param array $options Associative array of options:
2871  *              'php': The path to the php executable
2872  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2873  * @return Array
2874  */
2875 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2876         global $wgPhpCli;
2877         // Give site config file a chance to run the script in a wrapper.
2878         // The caller may likely want to call wfBasename() on $script.
2879         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2880         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2881         if ( isset( $options['wrapper'] ) ) {
2882                 $cmd[] = $options['wrapper'];
2883         }
2884         $cmd[] = $script;
2885         // Escape each parameter for shell
2886         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2887 }
2888
2889 /**
2890  * wfMerge attempts to merge differences between three texts.
2891  * Returns true for a clean merge and false for failure or a conflict.
2892  *
2893  * @param $old String
2894  * @param $mine String
2895  * @param $yours String
2896  * @param $result String
2897  * @return Bool
2898  */
2899 function wfMerge( $old, $mine, $yours, &$result ) {
2900         global $wgDiff3;
2901
2902         # This check may also protect against code injection in
2903         # case of broken installations.
2904         wfSuppressWarnings();
2905         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2906         wfRestoreWarnings();
2907
2908         if ( !$haveDiff3 ) {
2909                 wfDebug( "diff3 not found\n" );
2910                 return false;
2911         }
2912
2913         # Make temporary files
2914         $td = wfTempDir();
2915         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2916         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2917         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2918
2919         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2920         #       a newline character. To avoid this, we normalize the trailing whitespace before
2921         #       creating the diff.
2922
2923         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2924         fclose( $oldtextFile );
2925         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2926         fclose( $mytextFile );
2927         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2928         fclose( $yourtextFile );
2929
2930         # Check for a conflict
2931         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
2932                 wfEscapeShellArg( $mytextName ) . ' ' .
2933                 wfEscapeShellArg( $oldtextName ) . ' ' .
2934                 wfEscapeShellArg( $yourtextName );
2935         $handle = popen( $cmd, 'r' );
2936
2937         if ( fgets( $handle, 1024 ) ) {
2938                 $conflict = true;
2939         } else {
2940                 $conflict = false;
2941         }
2942         pclose( $handle );
2943
2944         # Merge differences
2945         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
2946                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2947         $handle = popen( $cmd, 'r' );
2948         $result = '';
2949         do {
2950                 $data = fread( $handle, 8192 );
2951                 if ( strlen( $data ) == 0 ) {
2952                         break;
2953                 }
2954                 $result .= $data;
2955         } while ( true );
2956         pclose( $handle );
2957         unlink( $mytextName );
2958         unlink( $oldtextName );
2959         unlink( $yourtextName );
2960
2961         if ( $result === '' && $old !== '' && !$conflict ) {
2962                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2963                 $conflict = true;
2964         }
2965         return !$conflict;
2966 }
2967
2968 /**
2969  * Returns unified plain-text diff of two texts.
2970  * Useful for machine processing of diffs.
2971  *
2972  * @param string $before the text before the changes.
2973  * @param string $after the text after the changes.
2974  * @param string $params command-line options for the diff command.
2975  * @return String: unified diff of $before and $after
2976  */
2977 function wfDiff( $before, $after, $params = '-u' ) {
2978         if ( $before == $after ) {
2979                 return '';
2980         }
2981
2982         global $wgDiff;
2983         wfSuppressWarnings();
2984         $haveDiff = $wgDiff && file_exists( $wgDiff );
2985         wfRestoreWarnings();
2986
2987         # This check may also protect against code injection in
2988         # case of broken installations.
2989         if ( !$haveDiff ) {
2990                 wfDebug( "diff executable not found\n" );
2991                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2992                 $format = new UnifiedDiffFormatter();
2993                 return $format->format( $diffs );
2994         }
2995
2996         # Make temporary files
2997         $td = wfTempDir();
2998         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2999         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3000
3001         fwrite( $oldtextFile, $before );
3002         fclose( $oldtextFile );
3003         fwrite( $newtextFile, $after );
3004         fclose( $newtextFile );
3005
3006         // Get the diff of the two files
3007         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3008
3009         $h = popen( $cmd, 'r' );
3010
3011         $diff = '';
3012
3013         do {
3014                 $data = fread( $h, 8192 );
3015                 if ( strlen( $data ) == 0 ) {
3016                         break;
3017                 }
3018                 $diff .= $data;
3019         } while ( true );
3020
3021         // Clean up
3022         pclose( $h );
3023         unlink( $oldtextName );
3024         unlink( $newtextName );
3025
3026         // Kill the --- and +++ lines. They're not useful.
3027         $diff_lines = explode( "\n", $diff );
3028         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3029                 unset( $diff_lines[0] );
3030         }
3031         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3032                 unset( $diff_lines[1] );
3033         }
3034
3035         $diff = implode( "\n", $diff_lines );
3036
3037         return $diff;
3038 }
3039
3040 /**
3041  * This function works like "use VERSION" in Perl, the program will die with a
3042  * backtrace if the current version of PHP is less than the version provided
3043  *
3044  * This is useful for extensions which due to their nature are not kept in sync
3045  * with releases, and might depend on other versions of PHP than the main code
3046  *
3047  * Note: PHP might die due to parsing errors in some cases before it ever
3048  *       manages to call this function, such is life
3049  *
3050  * @see perldoc -f use
3051  *
3052  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3053  *                 a float
3054  * @throws MWException
3055  */
3056 function wfUsePHP( $req_ver ) {
3057         $php_ver = PHP_VERSION;
3058
3059         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3060                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3061         }
3062 }
3063
3064 /**
3065  * This function works like "use VERSION" in Perl except it checks the version
3066  * of MediaWiki, the program will die with a backtrace if the current version
3067  * of MediaWiki is less than the version provided.
3068  *
3069  * This is useful for extensions which due to their nature are not kept in sync
3070  * with releases
3071  *
3072  * @see perldoc -f use
3073  *
3074  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3075  *                 a float
3076  * @throws MWException
3077  */
3078 function wfUseMW( $req_ver ) {
3079         global $wgVersion;
3080
3081         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3082                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3083         }
3084 }
3085
3086 /**
3087  * Return the final portion of a pathname.
3088  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3089  * http://bugs.php.net/bug.php?id=33898
3090  *
3091  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3092  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3093  *
3094  * @param $path String
3095  * @param string $suffix to remove if present
3096  * @return String
3097  */
3098 function wfBaseName( $path, $suffix = '' ) {
3099         $encSuffix = ( $suffix == '' )
3100                 ? ''
3101                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3102         $matches = array();
3103         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3104                 return $matches[1];
3105         } else {
3106                 return '';
3107         }
3108 }
3109
3110 /**
3111  * Generate a relative path name to the given file.
3112  * May explode on non-matching case-insensitive paths,
3113  * funky symlinks, etc.
3114  *
3115  * @param string $path absolute destination path including target filename
3116  * @param string $from Absolute source path, directory only
3117  * @return String
3118  */
3119 function wfRelativePath( $path, $from ) {
3120         // Normalize mixed input on Windows...
3121         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3122         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3123
3124         // Trim trailing slashes -- fix for drive root
3125         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3126         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3127
3128         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3129         $against = explode( DIRECTORY_SEPARATOR, $from );
3130
3131         if ( $pieces[0] !== $against[0] ) {
3132                 // Non-matching Windows drive letters?
3133                 // Return a full path.
3134                 return $path;
3135         }
3136
3137         // Trim off common prefix
3138         while ( count( $pieces ) && count( $against )
3139                 && $pieces[0] == $against[0] ) {
3140                 array_shift( $pieces );
3141                 array_shift( $against );
3142         }
3143
3144         // relative dots to bump us to the parent
3145         while ( count( $against ) ) {
3146                 array_unshift( $pieces, '..' );
3147                 array_shift( $against );
3148         }
3149
3150         array_push( $pieces, wfBaseName( $path ) );
3151
3152         return implode( DIRECTORY_SEPARATOR, $pieces );
3153 }
3154
3155 /**
3156  * Do any deferred updates and clear the list
3157  *
3158  * @deprecated since 1.19
3159  * @see DeferredUpdates::doUpdate()
3160  * @param $commit string
3161  */
3162 function wfDoUpdates( $commit = '' ) {
3163         wfDeprecated( __METHOD__, '1.19' );
3164         DeferredUpdates::doUpdates( $commit );
3165 }
3166
3167 /**
3168  * Convert an arbitrarily-long digit string from one numeric base
3169  * to another, optionally zero-padding to a minimum column width.
3170  *
3171  * Supports base 2 through 36; digit values 10-36 are represented
3172  * as lowercase letters a-z. Input is case-insensitive.
3173  *
3174  * @param string $input Input number
3175  * @param int $sourceBase Base of the input number
3176  * @param int $destBase Desired base of the output
3177  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3178  * @param bool $lowercase Whether to output in lowercase or uppercase
3179  * @param string $engine Either "gmp", "bcmath", or "php"
3180  * @return string|bool The output number as a string, or false on error
3181  */
3182 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true, $engine = 'auto' ) {
3183         $input = (string)$input;
3184         if (
3185                 $sourceBase < 2 ||
3186                 $sourceBase > 36 ||
3187                 $destBase < 2 ||
3188                 $destBase > 36 ||
3189                 $sourceBase != (int)$sourceBase ||
3190                 $destBase != (int)$destBase ||
3191                 $pad != (int)$pad ||
3192                 !preg_match( "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i", $input )
3193         ) {
3194                 return false;
3195         }
3196
3197         static $baseChars = array(
3198                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3199                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3200                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3201                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3202                 34 => 'y', 35 => 'z',
3203
3204                 '0' => 0,  '1' => 1,  '2' => 2,  '3' => 3,  '4' => 4,  '5' => 5,
3205                 '6' => 6,  '7' => 7,  '8' => 8,  '9' => 9,  'a' => 10, 'b' => 11,
3206                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3207                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3208                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3209                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3210         );
3211
3212         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3213                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3214         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3215                 $decimal = '0';
3216                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3217                         $decimal = bcmul( $decimal, $sourceBase );
3218                         $decimal = bcadd( $decimal, $baseChars[$char] );
3219                 }
3220
3221                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3222                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3223                 }
3224
3225                 $result = strrev( $result );
3226         } else {
3227                 $inDigits = array();
3228                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3229                         $inDigits[] = $baseChars[$char];
3230                 }
3231
3232                 // Iterate over the input, modulo-ing out an output digit
3233                 // at a time until input is gone.
3234                 $result = '';
3235                 while ( $inDigits ) {
3236                         $work = 0;
3237                         $workDigits = array();
3238
3239                         // Long division...
3240                         foreach ( $inDigits as $digit ) {
3241                                 $work *= $sourceBase;
3242                                 $work += $digit;
3243
3244                                 if ( $workDigits || $work >= $destBase ) {
3245                                         $workDigits[] = (int)( $work / $destBase );
3246                                 }
3247                                 $work %= $destBase;
3248                         }
3249
3250                         // All that division leaves us with a remainder,
3251                         // which is conveniently our next output digit.
3252                         $result .= $baseChars[$work];
3253
3254                         // And we continue!
3255                         $inDigits = $workDigits;
3256                 }
3257
3258                 $result = strrev( $result );
3259         }
3260
3261         if ( !$lowercase ) {
3262                 $result = strtoupper( $result );
3263         }
3264
3265         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3266 }
3267
3268 /**
3269  * Create an object with a given name and an array of construct parameters
3270  *
3271  * @param $name String
3272  * @param array $p parameters
3273  * @return object
3274  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3275  */
3276 function wfCreateObject( $name, $p ) {
3277         wfDeprecated( __FUNCTION__, '1.18' );
3278         return MWFunction::newObj( $name, $p );
3279 }
3280
3281 /**
3282  * @return bool
3283  */
3284 function wfHttpOnlySafe() {
3285         global $wgHttpOnlyBlacklist;
3286
3287         if ( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3288                 foreach ( $wgHttpOnlyBlacklist as $regex ) {
3289                         if ( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3290                                 return false;
3291                         }
3292                 }
3293         }
3294
3295         return true;
3296 }
3297
3298 /**
3299  * Check if there is sufficient entropy in php's built-in session generation
3300  * @return bool true = there is sufficient entropy
3301  */
3302 function wfCheckEntropy() {
3303         return (
3304                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3305                         || ini_get( 'session.entropy_file' )
3306                 )
3307                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3308 }
3309
3310 /**
3311  * Override session_id before session startup if php's built-in
3312  * session generation code is not secure.
3313  */
3314 function wfFixSessionID() {
3315         // If the cookie or session id is already set we already have a session and should abort
3316         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3317                 return;
3318         }
3319
3320         // PHP's built-in session entropy is enabled if:
3321         // - entropy_file is set or you're on Windows with php 5.3.3+
3322         // - AND entropy_length is > 0
3323         // We treat it as disabled if it doesn't have an entropy length of at least 32
3324         $entropyEnabled = wfCheckEntropy();
3325
3326         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3327         if ( !$entropyEnabled ) {
3328                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3329                 session_id( MWCryptRand::generateHex( 32 ) );
3330         }
3331 }
3332
3333 /**
3334  * Reset the session_id
3335  * @since 1.22
3336  */
3337 function wfResetSessionID() {
3338         global $wgCookieSecure;
3339         $oldSessionId = session_id();
3340         $cookieParams = session_get_cookie_params();
3341         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3342                 session_regenerate_id( false );
3343         } else {
3344                 $tmp = $_SESSION;
3345                 session_destroy();
3346                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3347                 $_SESSION = $tmp;
3348         }
3349         $newSessionId = session_id();
3350         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3351 }
3352
3353
3354 /**
3355  * Initialise php session
3356  *
3357  * @param $sessionId Bool
3358  */
3359 function wfSetupSession( $sessionId = false ) {
3360         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3361                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3362         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3363                 ObjectCacheSessionHandler::install();
3364         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3365                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3366                 # hasn't already been set to the desired value (that causes errors)
3367                 ini_set( 'session.save_handler', $wgSessionHandler );
3368         }
3369         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3370         wfDebugLog( 'cookie',
3371                 'session_set_cookie_params: "' . implode( '", "',
3372                         array(
3373                                 0,
3374                                 $wgCookiePath,
3375                                 $wgCookieDomain,
3376                                 $wgCookieSecure,
3377                                 $httpOnlySafe ) ) . '"' );
3378         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3379         session_cache_limiter( 'private, must-revalidate' );
3380         if ( $sessionId ) {
3381                 session_id( $sessionId );
3382         } else {
3383                 wfFixSessionID();
3384         }
3385         wfSuppressWarnings();
3386         session_start();
3387         wfRestoreWarnings();
3388 }
3389
3390 /**
3391  * Get an object from the precompiled serialized directory
3392  *
3393  * @param $name String
3394  * @return Mixed: the variable on success, false on failure
3395  */
3396 function wfGetPrecompiledData( $name ) {
3397         global $IP;
3398
3399         $file = "$IP/serialized/$name";
3400         if ( file_exists( $file ) ) {
3401                 $blob = file_get_contents( $file );
3402                 if ( $blob ) {
3403                         return unserialize( $blob );
3404                 }
3405         }
3406         return false;
3407 }
3408
3409 /**
3410  * Get a cache key
3411  *
3412  * @param varargs
3413  * @return String
3414  */
3415 function wfMemcKey( /*... */ ) {
3416         global $wgCachePrefix;
3417         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3418         $args = func_get_args();
3419         $key = $prefix . ':' . implode( ':', $args );
3420         $key = str_replace( ' ', '_', $key );
3421         return $key;
3422 }
3423
3424 /**
3425  * Get a cache key for a foreign DB
3426  *
3427  * @param $db String
3428  * @param $prefix String
3429  * @param varargs String
3430  * @return String
3431  */
3432 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3433         $args = array_slice( func_get_args(), 2 );
3434         if ( $prefix ) {
3435                 $key = "$db-$prefix:" . implode( ':', $args );
3436         } else {
3437                 $key = $db . ':' . implode( ':', $args );
3438         }
3439         return str_replace( ' ', '_', $key );
3440 }
3441
3442 /**
3443  * Get an ASCII string identifying this wiki
3444  * This is used as a prefix in memcached keys
3445  *
3446  * @return String
3447  */
3448 function wfWikiID() {
3449         global $wgDBprefix, $wgDBname;
3450         if ( $wgDBprefix ) {
3451                 return "$wgDBname-$wgDBprefix";
3452         } else {
3453                 return $wgDBname;
3454         }
3455 }
3456
3457 /**
3458  * Split a wiki ID into DB name and table prefix
3459  *
3460  * @param $wiki String
3461  *
3462  * @return array
3463  */
3464 function wfSplitWikiID( $wiki ) {
3465         $bits = explode( '-', $wiki, 2 );
3466         if ( count( $bits ) < 2 ) {
3467                 $bits[] = '';
3468         }
3469         return $bits;
3470 }
3471
3472 /**
3473  * Get a Database object.
3474  *
3475  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3476  *            master (for write queries), DB_SLAVE for potentially lagged read
3477  *            queries, or an integer >= 0 for a particular server.
3478  *
3479  * @param $groups Mixed: query groups. An array of group names that this query
3480  *                belongs to. May contain a single string if the query is only
3481  *                in one group.
3482  *
3483  * @param string $wiki the wiki ID, or false for the current wiki
3484  *
3485  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3486  * will always return the same object, unless the underlying connection or load
3487  * balancer is manually destroyed.
3488  *
3489  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3490  * updater to ensure that a proper database is being updated.
3491  *
3492  * @return DatabaseBase
3493  */
3494 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3495         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3496 }
3497
3498 /**
3499  * Get a load balancer object.
3500  *
3501  * @param string $wiki wiki ID, or false for the current wiki
3502  * @return LoadBalancer
3503  */
3504 function wfGetLB( $wiki = false ) {
3505         return wfGetLBFactory()->getMainLB( $wiki );
3506 }
3507
3508 /**
3509  * Get the load balancer factory object
3510  *
3511  * @return LBFactory
3512  */
3513 function &wfGetLBFactory() {
3514         return LBFactory::singleton();
3515 }
3516
3517 /**
3518  * Find a file.
3519  * Shortcut for RepoGroup::singleton()->findFile()
3520  *
3521  * @param string $title or Title object
3522  * @param array $options Associative array of options:
3523  *     time:           requested time for an archived image, or false for the
3524  *                     current version. An image object will be returned which was
3525  *                     created at the specified time.
3526  *
3527  *     ignoreRedirect: If true, do not follow file redirects
3528  *
3529  *     private:        If true, return restricted (deleted) files if the current
3530  *                     user is allowed to view them. Otherwise, such files will not
3531  *                     be found.
3532  *
3533  *     bypassCache:    If true, do not use the process-local cache of File objects
3534  *
3535  * @return File, or false if the file does not exist
3536  */
3537 function wfFindFile( $title, $options = array() ) {
3538         return RepoGroup::singleton()->findFile( $title, $options );
3539 }
3540
3541 /**
3542  * Get an object referring to a locally registered file.
3543  * Returns a valid placeholder object if the file does not exist.
3544  *
3545  * @param $title Title|String
3546  * @return LocalFile|null A File, or null if passed an invalid Title
3547  */
3548 function wfLocalFile( $title ) {
3549         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3550 }
3551
3552 /**
3553  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3554  * @deprecated since 1.19
3555  */
3556 function wfStreamFile( $fname, $headers = array() ) {
3557         wfDeprecated( __FUNCTION__, '1.19' );
3558         StreamFile::stream( $fname, $headers );
3559 }
3560
3561 /**
3562  * Should low-performance queries be disabled?
3563  *
3564  * @return Boolean
3565  * @codeCoverageIgnore
3566  */
3567 function wfQueriesMustScale() {
3568         global $wgMiserMode;
3569         return $wgMiserMode
3570                 || ( SiteStats::pages() > 100000
3571                 && SiteStats::edits() > 1000000
3572                 && SiteStats::users() > 10000 );
3573 }
3574
3575 /**
3576  * Get the path to a specified script file, respecting file
3577  * extensions; this is a wrapper around $wgScriptExtension etc.
3578  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3579  *
3580  * @param string $script script filename, sans extension
3581  * @return String
3582  */
3583 function wfScript( $script = 'index' ) {
3584         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3585         if ( $script === 'index' ) {
3586                 return $wgScript;
3587         } elseif ( $script === 'load' ) {
3588                 return $wgLoadScript;
3589         } else {
3590                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3591         }
3592 }
3593
3594 /**
3595  * Get the script URL.
3596  *
3597  * @return string script URL
3598  */
3599 function wfGetScriptUrl() {
3600         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3601                 #
3602                 # as it was called, minus the query string.
3603                 #
3604                 # Some sites use Apache rewrite rules to handle subdomains,
3605                 # and have PHP set up in a weird way that causes PHP_SELF
3606                 # to contain the rewritten URL instead of the one that the
3607                 # outside world sees.
3608                 #
3609                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3610                 # provides containing the "before" URL.
3611                 return $_SERVER['SCRIPT_NAME'];
3612         } else {
3613                 return $_SERVER['URL'];
3614         }
3615 }
3616
3617 /**
3618  * Convenience function converts boolean values into "true"
3619  * or "false" (string) values
3620  *
3621  * @param $value Boolean
3622  * @return String
3623  */
3624 function wfBoolToStr( $value ) {
3625         return $value ? 'true' : 'false';
3626 }
3627
3628 /**
3629  * Get a platform-independent path to the null file, e.g. /dev/null
3630  *
3631  * @return string
3632  */
3633 function wfGetNull() {
3634         return wfIsWindows()
3635                 ? 'NUL'
3636                 : '/dev/null';
3637 }
3638
3639 /**
3640  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3641  * and waiting for it to go down, this waits for the slaves to catch up to the
3642  * master position. Use this when updating very large numbers of rows, as
3643  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3644  * a no-op if there are no slaves.
3645  *
3646  * @param $maxLag Integer (deprecated)
3647  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3648  * @param $cluster string cluster name accepted by LBFactory
3649  */
3650 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3651         $lb = ( $cluster !== false )
3652                 ? wfGetLBFactory()->getExternalLB( $cluster )
3653                 : wfGetLB( $wiki );
3654         // bug 27975 - Don't try to wait for slaves if there are none
3655         // Prevents permission error when getting master position
3656         if ( $lb->getServerCount() > 1 ) {
3657                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3658                 $pos = $dbw->getMasterPos();
3659                 // The DBMS may not support getMasterPos() or the whole
3660                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3661                 if ( $pos !== false ) {
3662                         $lb->waitForAll( $pos );
3663                 }
3664         }
3665 }
3666
3667 /**
3668  * Used to be used for outputting text in the installer/updater
3669  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3670  */
3671 function wfOut( $s ) {
3672         wfDeprecated( __FUNCTION__, '1.18' );
3673         global $wgCommandLineMode;
3674         if ( $wgCommandLineMode ) {
3675                 echo $s;
3676         } else {
3677                 echo htmlspecialchars( $s );
3678         }
3679         flush();
3680 }
3681
3682 /**
3683  * Count down from $n to zero on the terminal, with a one-second pause
3684  * between showing each number. For use in command-line scripts.
3685  * @codeCoverageIgnore
3686  * @param $n int
3687  */
3688 function wfCountDown( $n ) {
3689         for ( $i = $n; $i >= 0; $i-- ) {
3690                 if ( $i != $n ) {
3691                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3692                 }
3693                 echo $i;
3694                 flush();
3695                 if ( $i ) {
3696                         sleep( 1 );
3697                 }
3698         }
3699         echo "\n";
3700 }
3701
3702 /**
3703  * Generate a random 32-character hexadecimal token.
3704  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3705  *              characters before hashing.
3706  * @return string
3707  * @codeCoverageIgnore
3708  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pseudo-random strings
3709  * @warning This method is NOT secure. Additionally it has many callers that use it for pseudo-random purposes.
3710  */
3711 function wfGenerateToken( $salt = '' ) {
3712         wfDeprecated( __METHOD__, '1.20' );
3713         $salt = serialize( $salt );
3714         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3715 }
3716
3717 /**
3718  * Replace all invalid characters with -
3719  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3720  * By default, $wgIllegalFileChars = ':'
3721  *
3722  * @param $name Mixed: filename to process
3723  * @return String
3724  */
3725 function wfStripIllegalFilenameChars( $name ) {
3726         global $wgIllegalFileChars;
3727         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3728         $name = wfBaseName( $name );
3729         $name = preg_replace(
3730                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3731                 '-',
3732                 $name
3733         );
3734         return $name;
3735 }
3736
3737 /**
3738  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3739  *
3740  * @return Integer value memory was set to.
3741  */
3742 function wfMemoryLimit() {
3743         global $wgMemoryLimit;
3744         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3745         if ( $memlimit != -1 ) {
3746                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3747                 if ( $conflimit == -1 ) {
3748                         wfDebug( "Removing PHP's memory limit\n" );
3749                         wfSuppressWarnings();
3750                         ini_set( 'memory_limit', $conflimit );
3751                         wfRestoreWarnings();
3752                         return $conflimit;
3753                 } elseif ( $conflimit > $memlimit ) {
3754                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3755                         wfSuppressWarnings();
3756                         ini_set( 'memory_limit', $conflimit );
3757                         wfRestoreWarnings();
3758                         return $conflimit;
3759                 }
3760         }
3761         return $memlimit;
3762 }
3763
3764 /**
3765  * Converts shorthand byte notation to integer form
3766  *
3767  * @param $string String
3768  * @return Integer
3769  */
3770 function wfShorthandToInteger( $string = '' ) {
3771         $string = trim( $string );
3772         if ( $string === '' ) {
3773                 return -1;
3774         }
3775         $last = $string[strlen( $string ) - 1];
3776         $val = intval( $string );
3777         switch ( $last ) {
3778                 case 'g':
3779                 case 'G':
3780                         $val *= 1024;
3781                         // break intentionally missing
3782                 case 'm':
3783                 case 'M':
3784                         $val *= 1024;
3785                         // break intentionally missing
3786                 case 'k':
3787                 case 'K':
3788                         $val *= 1024;
3789         }
3790
3791         return $val;
3792 }
3793
3794 /**
3795  * Get the normalised IETF language tag
3796  * See unit test for examples.
3797  *
3798  * @param string $code The language code.
3799  * @return String: The language code which complying with BCP 47 standards.
3800  */
3801 function wfBCP47( $code ) {
3802         $codeSegment = explode( '-', $code );
3803         $codeBCP = array();
3804         foreach ( $codeSegment as $segNo => $seg ) {
3805                 // when previous segment is x, it is a private segment and should be lc
3806                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3807                         $codeBCP[$segNo] = strtolower( $seg );
3808                 // ISO 3166 country code
3809                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3810                         $codeBCP[$segNo] = strtoupper( $seg );
3811                 // ISO 15924 script code
3812                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3813                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3814                 // Use lowercase for other cases
3815                 } else {
3816                         $codeBCP[$segNo] = strtolower( $seg );
3817                 }
3818         }
3819         $langCode = implode( '-', $codeBCP );
3820         return $langCode;
3821 }
3822
3823 /**
3824  * Get a cache object.
3825  *
3826  * @param $inputType integer Cache type, one the the CACHE_* constants.
3827  * @return BagOStuff
3828  */
3829 function wfGetCache( $inputType ) {
3830         return ObjectCache::getInstance( $inputType );
3831 }
3832
3833 /**
3834  * Get the main cache object
3835  *
3836  * @return BagOStuff
3837  */
3838 function wfGetMainCache() {
3839         global $wgMainCacheType;
3840         return ObjectCache::getInstance( $wgMainCacheType );
3841 }
3842
3843 /**
3844  * Get the cache object used by the message cache
3845  *
3846  * @return BagOStuff
3847  */
3848 function wfGetMessageCacheStorage() {
3849         global $wgMessageCacheType;
3850         return ObjectCache::getInstance( $wgMessageCacheType );
3851 }
3852
3853 /**
3854  * Get the cache object used by the parser cache
3855  *
3856  * @return BagOStuff
3857  */
3858 function wfGetParserCacheStorage() {
3859         global $wgParserCacheType;
3860         return ObjectCache::getInstance( $wgParserCacheType );
3861 }
3862
3863 /**
3864  * Get the cache object used by the language converter
3865  *
3866  * @return BagOStuff
3867  */
3868 function wfGetLangConverterCacheStorage() {
3869         global $wgLanguageConverterCacheType;
3870         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3871 }
3872
3873 /**
3874  * Call hook functions defined in $wgHooks
3875  *
3876  * @param string $event event name
3877  * @param array $args parameters passed to hook functions
3878  * @return Boolean True if no handler aborted the hook
3879  */
3880 function wfRunHooks( $event, array $args = array() ) {
3881         return Hooks::run( $event, $args );
3882 }
3883
3884 /**
3885  * Wrapper around php's unpack.
3886  *
3887  * @param string $format The format string (See php's docs)
3888  * @param $data: A binary string of binary data
3889  * @param $length integer or false: The minimum length of $data. This is to
3890  *      prevent reading beyond the end of $data. false to disable the check.
3891  *
3892  * Also be careful when using this function to read unsigned 32 bit integer
3893  * because php might make it negative.
3894  *
3895  * @throws MWException if $data not long enough, or if unpack fails
3896  * @return array Associative array of the extracted data
3897  */
3898 function wfUnpack( $format, $data, $length = false ) {
3899         if ( $length !== false ) {
3900                 $realLen = strlen( $data );
3901                 if ( $realLen < $length ) {
3902                         throw new MWException( "Tried to use wfUnpack on a "
3903                                 . "string of length $realLen, but needed one "
3904                                 . "of at least length $length."
3905                         );
3906                 }
3907         }
3908
3909         wfSuppressWarnings();
3910         $result = unpack( $format, $data );
3911         wfRestoreWarnings();
3912
3913         if ( $result === false ) {
3914                 // If it cannot extract the packed data.
3915                 throw new MWException( "unpack could not unpack binary data" );
3916         }
3917         return $result;
3918 }
3919
3920 /**
3921  * Determine if an image exists on the 'bad image list'.
3922  *
3923  * The format of MediaWiki:Bad_image_list is as follows:
3924  *    * Only list items (lines starting with "*") are considered
3925  *    * The first link on a line must be a link to a bad image
3926  *    * Any subsequent links on the same line are considered to be exceptions,
3927  *      i.e. articles where the image may occur inline.
3928  *
3929  * @param string $name the image name to check
3930  * @param $contextTitle Title|bool the page on which the image occurs, if known
3931  * @param string $blacklist wikitext of a file blacklist
3932  * @return bool
3933  */
3934 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3935         static $badImageCache = null; // based on bad_image_list msg
3936         wfProfileIn( __METHOD__ );
3937
3938         # Handle redirects
3939         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3940         if ( $redirectTitle ) {
3941                 $name = $redirectTitle->getDBkey();
3942         }
3943
3944         # Run the extension hook
3945         $bad = false;
3946         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3947                 wfProfileOut( __METHOD__ );
3948                 return $bad;
3949         }
3950
3951         $cacheable = ( $blacklist === null );
3952         if ( $cacheable && $badImageCache !== null ) {
3953                 $badImages = $badImageCache;
3954         } else { // cache miss
3955                 if ( $blacklist === null ) {
3956                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3957                 }
3958                 # Build the list now
3959                 $badImages = array();
3960                 $lines = explode( "\n", $blacklist );
3961                 foreach ( $lines as $line ) {
3962                         # List items only
3963                         if ( substr( $line, 0, 1 ) !== '*' ) {
3964                                 continue;
3965                         }
3966
3967                         # Find all links
3968                         $m = array();
3969                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3970                                 continue;
3971                         }
3972
3973                         $exceptions = array();
3974                         $imageDBkey = false;
3975                         foreach ( $m[1] as $i => $titleText ) {
3976                                 $title = Title::newFromText( $titleText );
3977                                 if ( !is_null( $title ) ) {
3978                                         if ( $i == 0 ) {
3979                                                 $imageDBkey = $title->getDBkey();
3980                                         } else {
3981                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3982                                         }
3983                                 }
3984                         }
3985
3986                         if ( $imageDBkey !== false ) {
3987                                 $badImages[$imageDBkey] = $exceptions;
3988                         }
3989                 }
3990                 if ( $cacheable ) {
3991                         $badImageCache = $badImages;
3992                 }
3993         }
3994
3995         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3996         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3997         wfProfileOut( __METHOD__ );
3998         return $bad;
3999 }
4000
4001 /**
4002  * Determine whether the client at a given source IP is likely to be able to
4003  * access the wiki via HTTPS.
4004  *
4005  * @param string $ip The IPv4/6 address in the normal human-readable form
4006  * @return boolean
4007  */
4008 function wfCanIPUseHTTPS( $ip ) {
4009         $canDo = true;
4010         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4011         return !!$canDo;
4012 }