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 ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 935                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 936                         # Strip unprintables; they can switch terminal modes when binary data
 937                         # gets dumped, which is pretty annoying.
 938                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 939                         $text = $wgDebugLogPrefix . $text;
 940                         wfErrorLog( $text, $wgDebugLogFile );
 941                 }
 942         }
 943 }
 944
 945 /**
 946  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 947  * @return bool
 948  */
 949 function wfIsDebugRawPage() {
 950         static $cache;
 951         if ( $cache !== null ) {
 952                 return $cache;
 953         }
 954         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 955         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 956                 || (
 957                         isset( $_SERVER['SCRIPT_NAME'] )
 958                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 959                 ) )
 960         {
 961                 $cache = true;
 962         } else {
 963                 $cache = false;
 964         }
 965         return $cache;
 966 }
 967
 968 /**
 969  * Get microsecond timestamps for debug logs
 970  *
 971  * @return string
 972  */
 973 function wfDebugTimer() {
 974         global $wgDebugTimestamps, $wgRequestTime;
 975
 976         if ( !$wgDebugTimestamps ) {
 977                 return '';
 978         }
 979
 980         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 981         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 982         return "$prefix $mem  ";
 983 }
 984
 985 /**
 986  * Send a line giving PHP memory usage.
 987  *
 988  * @param bool $exact print exact values instead of kilobytes (default: false)
 989  */
 990 function wfDebugMem( $exact = false ) {
 991         $mem = memory_get_usage();
 992         if ( !$exact ) {
 993                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 994         } else {
 995                 $mem .= ' bytes';
 996         }
 997         wfDebug( "Memory usage: $mem\n" );
 998 }
 999
1000 /**
1001  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1002  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1003  *
1004  * @param $logGroup String
1005  * @param $text String
1006  * @param bool $public whether to log the event in the public log if no private
1007  *                     log file is specified, (default true)
1008  */
1009 function wfDebugLog( $logGroup, $text, $public = true ) {
1010         global $wgDebugLogGroups;
1011         $text = trim( $text ) . "\n";
1012         if ( isset( $wgDebugLogGroups[$logGroup] ) ) {
1013                 $time = wfTimestamp( TS_DB );
1014                 $wiki = wfWikiID();
1015                 $host = wfHostname();
1016                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1017                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1018                 }
1019         } elseif ( $public === true ) {
1020                 wfDebug( "[$logGroup] $text", false );
1021         }
1022 }
1023
1024 /**
1025  * Log for database errors
1026  *
1027  * @param string $text database error message.
1028  */
1029 function wfLogDBError( $text ) {
1030         global $wgDBerrorLog, $wgDBerrorLogTZ;
1031         static $logDBErrorTimeZoneObject = null;
1032
1033         if ( $wgDBerrorLog ) {
1034                 $host = wfHostname();
1035                 $wiki = wfWikiID();
1036
1037                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1038                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1039                 }
1040
1041                 // Workaround for https://bugs.php.net/bug.php?id=52063
1042                 // Can be removed when min PHP > 5.3.2
1043                 if ( $logDBErrorTimeZoneObject === null ) {
1044                         $d = date_create( "now" );
1045                 } else {
1046                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1047                 }
1048
1049                 $date = $d->format( 'D M j G:i:s T Y' );
1050
1051                 $text = "$date\t$host\t$wiki\t$text";
1052                 wfErrorLog( $text, $wgDBerrorLog );
1053         }
1054 }
1055
1056 /**
1057  * Throws a warning that $function is deprecated
1058  *
1059  * @param $function String
1060  * @param string|bool $version Version of MediaWiki that the function was deprecated in (Added in 1.19).
1061  * @param string|bool $component Added in 1.19.
1062  * @param $callerOffset integer: How far up the call stack is the original
1063  *    caller. 2 = function that called the function that called
1064  *    wfDeprecated (Added in 1.20)
1065  *
1066  * @return null
1067  */
1068 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1069         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1070 }
1071
1072 /**
1073  * Send a warning either to the debug log or in a PHP error depending on
1074  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1075  *
1076  * @param string $msg message to send
1077  * @param $callerOffset Integer: number of items to go back in the backtrace to
1078  *        find the correct caller (1 = function calling wfWarn, ...)
1079  * @param $level Integer: PHP error level; defaults to E_USER_NOTICE;
1080  *        only used when $wgDevelopmentWarnings is true
1081  */
1082 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1083         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1084 }
1085
1086 /**
1087  * Send a warning as a PHP error and the debug log. This is intended for logging
1088  * warnings in production. For logging development warnings, use WfWarn instead.
1089  *
1090  * @param $msg String: message to send
1091  * @param $callerOffset Integer: number of items to go back in the backtrace to
1092  *        find the correct caller (1 = function calling wfLogWarning, ...)
1093  * @param $level Integer: PHP error level; defaults to E_USER_WARNING
1094  */
1095 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1096         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1097 }
1098
1099 /**
1100  * Log to a file without getting "file size exceeded" signals.
1101  *
1102  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1103  * send lines to the specified port, prefixed by the specified prefix and a space.
1104  *
1105  * @param $text String
1106  * @param string $file filename
1107  * @throws MWException
1108  */
1109 function wfErrorLog( $text, $file ) {
1110         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1111                 # Needs the sockets extension
1112                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1113                         // IPv6 bracketed host
1114                         $host = $m[2];
1115                         $port = intval( $m[3] );
1116                         $prefix = isset( $m[4] ) ? $m[4] : false;
1117                         $domain = AF_INET6;
1118                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1119                         $host = $m[2];
1120                         if ( !IP::isIPv4( $host ) ) {
1121                                 $host = gethostbyname( $host );
1122                         }
1123                         $port = intval( $m[3] );
1124                         $prefix = isset( $m[4] ) ? $m[4] : false;
1125                         $domain = AF_INET;
1126                 } else {
1127                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1128                 }
1129
1130                 // Clean it up for the multiplexer
1131                 if ( strval( $prefix ) !== '' ) {
1132                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1133
1134                         // Limit to 64KB
1135                         if ( strlen( $text ) > 65506 ) {
1136                                 $text = substr( $text, 0, 65506 );
1137                         }
1138
1139                         if ( substr( $text, -1 ) != "\n" ) {
1140                                 $text .= "\n";
1141                         }
1142                 } elseif ( strlen( $text ) > 65507 ) {
1143                         $text = substr( $text, 0, 65507 );
1144                 }
1145
1146                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1147                 if ( !$sock ) {
1148                         return;
1149                 }
1150
1151                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1152                 socket_close( $sock );
1153         } else {
1154                 wfSuppressWarnings();
1155                 $exists = file_exists( $file );
1156                 $size = $exists ? filesize( $file ) : false;
1157                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1158                         file_put_contents( $file, $text, FILE_APPEND );
1159                 }
1160                 wfRestoreWarnings();
1161         }
1162 }
1163
1164 /**
1165  * @todo document
1166  */
1167 function wfLogProfilingData() {
1168         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1169         global $wgProfileLimit, $wgUser;
1170
1171         StatCounter::singleton()->flush();
1172
1173         $profiler = Profiler::instance();
1174
1175         # Profiling must actually be enabled...
1176         if ( $profiler->isStub() ) {
1177                 return;
1178         }
1179
1180         // Get total page request time and only show pages that longer than
1181         // $wgProfileLimit time (default is 0)
1182         $elapsed = microtime( true ) - $wgRequestTime;
1183         if ( $elapsed <= $wgProfileLimit ) {
1184                 return;
1185         }
1186
1187         $profiler->logData();
1188
1189         // Check whether this should be logged in the debug file.
1190         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1191                 return;
1192         }
1193
1194         $forward = '';
1195         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1196                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1197         }
1198         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1199                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1200         }
1201         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1202                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1203         }
1204         if ( $forward ) {
1205                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1206         }
1207         // Don't load $wgUser at this late stage just for statistics purposes
1208         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1209         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1210                 $forward .= ' anon';
1211         }
1212
1213         // Command line script uses a FauxRequest object which does not have
1214         // any knowledge about an URL and throw an exception instead.
1215         try {
1216                 $requestUrl = $wgRequest->getRequestURL();
1217         } catch ( MWException $e ) {
1218                 $requestUrl = 'n/a';
1219         }
1220
1221         $log = sprintf( "%s\t%04.3f\t%s\n",
1222                 gmdate( 'YmdHis' ), $elapsed,
1223                 urldecode( $requestUrl . $forward ) );
1224
1225         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1226 }
1227
1228 /**
1229  * Increment a statistics counter
1230  *
1231  * @param $key String
1232  * @param $count Int
1233  * @return void
1234  */
1235 function wfIncrStats( $key, $count = 1 ) {
1236         StatCounter::singleton()->incr( $key, $count );
1237 }
1238
1239 /**
1240  * Check whether the wiki is in read-only mode.
1241  *
1242  * @return bool
1243  */
1244 function wfReadOnly() {
1245         return wfReadOnlyReason() !== false;
1246 }
1247
1248 /**
1249  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1250  *
1251  * @return string|bool: String when in read-only mode; false otherwise
1252  */
1253 function wfReadOnlyReason() {
1254         global $wgReadOnly, $wgReadOnlyFile;
1255
1256         if ( $wgReadOnly === null ) {
1257                 // Set $wgReadOnly for faster access next time
1258                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1259                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1260                 } else {
1261                         $wgReadOnly = false;
1262                 }
1263         }
1264
1265         return $wgReadOnly;
1266 }
1267
1268 /**
1269  * Return a Language object from $langcode
1270  *
1271  * @param $langcode Mixed: either:
1272  *                  - a Language object
1273  *                  - code of the language to get the message for, if it is
1274  *                    a valid code create a language for that language, if
1275  *                    it is a string but not a valid code then make a basic
1276  *                    language object
1277  *                  - a boolean: if it's false then use the global object for
1278  *                    the current user's language (as a fallback for the old parameter
1279  *                    functionality), or if it is true then use global object
1280  *                    for the wiki's content language.
1281  * @return Language object
1282  */
1283 function wfGetLangObj( $langcode = false ) {
1284         # Identify which language to get or create a language object for.
1285         # Using is_object here due to Stub objects.
1286         if ( is_object( $langcode ) ) {
1287                 # Great, we already have the object (hopefully)!
1288                 return $langcode;
1289         }
1290
1291         global $wgContLang, $wgLanguageCode;
1292         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1293                 # $langcode is the language code of the wikis content language object.
1294                 # or it is a boolean and value is true
1295                 return $wgContLang;
1296         }
1297
1298         global $wgLang;
1299         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1300                 # $langcode is the language code of user language object.
1301                 # or it was a boolean and value is false
1302                 return $wgLang;
1303         }
1304
1305         $validCodes = array_keys( Language::fetchLanguageNames() );
1306         if ( in_array( $langcode, $validCodes ) ) {
1307                 # $langcode corresponds to a valid language.
1308                 return Language::factory( $langcode );
1309         }
1310
1311         # $langcode is a string, but not a valid language code; use content language.
1312         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1313         return $wgContLang;
1314 }
1315
1316 /**
1317  * Old function when $wgBetterDirectionality existed
1318  * All usage removed, wfUILang can be removed in near future
1319  *
1320  * @deprecated since 1.18
1321  * @return Language
1322  */
1323 function wfUILang() {
1324         wfDeprecated( __METHOD__, '1.18' );
1325         global $wgLang;
1326         return $wgLang;
1327 }
1328
1329 /**
1330  * This is the function for getting translated interface messages.
1331  *
1332  * @see Message class for documentation how to use them.
1333  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1334  *
1335  * This function replaces all old wfMsg* functions.
1336  *
1337  * @param $key \string Message key.
1338  * Varargs: normal message parameters.
1339  * @return Message
1340  * @since 1.17
1341  */
1342 function wfMessage( $key /*...*/) {
1343         $params = func_get_args();
1344         array_shift( $params );
1345         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1346                 $params = $params[0];
1347         }
1348         return new Message( $key, $params );
1349 }
1350
1351 /**
1352  * This function accepts multiple message keys and returns a message instance
1353  * for the first message which is non-empty. If all messages are empty then an
1354  * instance of the first message key is returned.
1355  * @param varargs: message keys
1356  * @return Message
1357  * @since 1.18
1358  */
1359 function wfMessageFallback( /*...*/ ) {
1360         $args = func_get_args();
1361         return call_user_func_array( 'Message::newFallbackSequence', $args );
1362 }
1363
1364 /**
1365  * Get a message from anywhere, for the current user language.
1366  *
1367  * Use wfMsgForContent() instead if the message should NOT
1368  * change depending on the user preferences.
1369  *
1370  * @deprecated since 1.18
1371  *
1372  * @param string $key lookup key for the message, usually
1373  *    defined in languages/Language.php
1374  *
1375  * Parameters to the message, which can be used to insert variable text into
1376  * it, can be passed to this function in the following formats:
1377  * - One per argument, starting at the second parameter
1378  * - As an array in the second parameter
1379  * These are not shown in the function definition.
1380  *
1381  * @return String
1382  */
1383 function wfMsg( $key ) {
1384         wfDeprecated( __METHOD__, '1.21' );
1385
1386         $args = func_get_args();
1387         array_shift( $args );
1388         return wfMsgReal( $key, $args );
1389 }
1390
1391 /**
1392  * Same as above except doesn't transform the message
1393  *
1394  * @deprecated since 1.18
1395  *
1396  * @param $key String
1397  * @return String
1398  */
1399 function wfMsgNoTrans( $key ) {
1400         wfDeprecated( __METHOD__, '1.21' );
1401
1402         $args = func_get_args();
1403         array_shift( $args );
1404         return wfMsgReal( $key, $args, true, false, false );
1405 }
1406
1407 /**
1408  * Get a message from anywhere, for the current global language
1409  * set with $wgLanguageCode.
1410  *
1411  * Use this if the message should NOT change dependent on the
1412  * language set in the user's preferences. This is the case for
1413  * most text written into logs, as well as link targets (such as
1414  * the name of the copyright policy page). Link titles, on the
1415  * other hand, should be shown in the UI language.
1416  *
1417  * Note that MediaWiki allows users to change the user interface
1418  * language in their preferences, but a single installation
1419  * typically only contains content in one language.
1420  *
1421  * Be wary of this distinction: If you use wfMsg() where you should
1422  * use wfMsgForContent(), a user of the software may have to
1423  * customize potentially hundreds of messages in
1424  * order to, e.g., fix a link in every possible language.
1425  *
1426  * @deprecated since 1.18
1427  *
1428  * @param string $key lookup key for the message, usually
1429  *     defined in languages/Language.php
1430  * @return String
1431  */
1432 function wfMsgForContent( $key ) {
1433         wfDeprecated( __METHOD__, '1.21' );
1434
1435         global $wgForceUIMsgAsContentMsg;
1436         $args = func_get_args();
1437         array_shift( $args );
1438         $forcontent = true;
1439         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1440                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1441         {
1442                 $forcontent = false;
1443         }
1444         return wfMsgReal( $key, $args, true, $forcontent );
1445 }
1446
1447 /**
1448  * Same as above except doesn't transform the message
1449  *
1450  * @deprecated since 1.18
1451  *
1452  * @param $key String
1453  * @return String
1454  */
1455 function wfMsgForContentNoTrans( $key ) {
1456         wfDeprecated( __METHOD__, '1.21' );
1457
1458         global $wgForceUIMsgAsContentMsg;
1459         $args = func_get_args();
1460         array_shift( $args );
1461         $forcontent = true;
1462         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1463                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1464         {
1465                 $forcontent = false;
1466         }
1467         return wfMsgReal( $key, $args, true, $forcontent, false );
1468 }
1469
1470 /**
1471  * Really get a message
1472  *
1473  * @deprecated since 1.18
1474  *
1475  * @param string $key key to get.
1476  * @param $args
1477  * @param $useDB Boolean
1478  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1479  * @param $transform Boolean: Whether or not to transform the message.
1480  * @return String: the requested message.
1481  */
1482 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1483         wfDeprecated( __METHOD__, '1.21' );
1484
1485         wfProfileIn( __METHOD__ );
1486         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1487         $message = wfMsgReplaceArgs( $message, $args );
1488         wfProfileOut( __METHOD__ );
1489         return $message;
1490 }
1491
1492 /**
1493  * Fetch a message string value, but don't replace any keys yet.
1494  *
1495  * @deprecated since 1.18
1496  *
1497  * @param $key String
1498  * @param $useDB Bool
1499  * @param string $langCode Code of the language to get the message for, or
1500  *                  behaves as a content language switch if it is a boolean.
1501  * @param $transform Boolean: whether to parse magic words, etc.
1502  * @return string
1503  */
1504 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1505         wfDeprecated( __METHOD__, '1.21' );
1506
1507         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1508
1509         $cache = MessageCache::singleton();
1510         $message = $cache->get( $key, $useDB, $langCode );
1511         if ( $message === false ) {
1512                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1513         } elseif ( $transform ) {
1514                 $message = $cache->transform( $message );
1515         }
1516         return $message;
1517 }
1518
1519 /**
1520  * Replace message parameter keys on the given formatted output.
1521  *
1522  * @param $message String
1523  * @param $args Array
1524  * @return string
1525  * @private
1526  */
1527 function wfMsgReplaceArgs( $message, $args ) {
1528         # Fix windows line-endings
1529         # Some messages are split with explode("\n", $msg)
1530         $message = str_replace( "\r", '', $message );
1531
1532         // Replace arguments
1533         if ( count( $args ) ) {
1534                 if ( is_array( $args[0] ) ) {
1535                         $args = array_values( $args[0] );
1536                 }
1537                 $replacementKeys = array();
1538                 foreach ( $args as $n => $param ) {
1539                         $replacementKeys['$' . ( $n + 1 )] = $param;
1540                 }
1541                 $message = strtr( $message, $replacementKeys );
1542         }
1543
1544         return $message;
1545 }
1546
1547 /**
1548  * Return an HTML-escaped version of a message.
1549  * Parameter replacements, if any, are done *after* the HTML-escaping,
1550  * so parameters may contain HTML (eg links or form controls). Be sure
1551  * to pre-escape them if you really do want plaintext, or just wrap
1552  * the whole thing in htmlspecialchars().
1553  *
1554  * @deprecated since 1.18
1555  *
1556  * @param $key String
1557  * @param string ... parameters
1558  * @return string
1559  */
1560 function wfMsgHtml( $key ) {
1561         wfDeprecated( __METHOD__, '1.21' );
1562
1563         $args = func_get_args();
1564         array_shift( $args );
1565         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1566 }
1567
1568 /**
1569  * Return an HTML version of message
1570  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1571  * so parameters may contain HTML (eg links or form controls). Be sure
1572  * to pre-escape them if you really do want plaintext, or just wrap
1573  * the whole thing in htmlspecialchars().
1574  *
1575  * @deprecated since 1.18
1576  *
1577  * @param $key String
1578  * @param string ... parameters
1579  * @return string
1580  */
1581 function wfMsgWikiHtml( $key ) {
1582         wfDeprecated( __METHOD__, '1.21' );
1583
1584         $args = func_get_args();
1585         array_shift( $args );
1586         return wfMsgReplaceArgs(
1587                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1588                 /* can't be set to false */ true, /* interface */ true )->getText(),
1589                 $args );
1590 }
1591
1592 /**
1593  * Returns message in the requested format
1594  *
1595  * @deprecated since 1.18
1596  *
1597  * @param string $key key of the message
1598  * @param array $options processing rules. Can take the following options:
1599  *   <i>parse</i>: parses wikitext to HTML
1600  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1601  *       p's added by parser or tidy
1602  *   <i>escape</i>: filters message through htmlspecialchars
1603  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1604  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1605  *   <i>parsemag</i>: transform the message using magic phrases
1606  *   <i>content</i>: fetch message for content language instead of interface
1607  * Also can accept a single associative argument, of the form 'language' => 'xx':
1608  *   <i>language</i>: Language object or language code to fetch message for
1609  *       (overridden by <i>content</i>).
1610  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1611  *
1612  * @return String
1613  */
1614 function wfMsgExt( $key, $options ) {
1615         wfDeprecated( __METHOD__, '1.21' );
1616
1617         $args = func_get_args();
1618         array_shift( $args );
1619         array_shift( $args );
1620         $options = (array)$options;
1621
1622         foreach ( $options as $arrayKey => $option ) {
1623                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1624                         # An unknown index, neither numeric nor "language"
1625                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1626                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1627                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1628                 'replaceafter', 'parsemag', 'content' ) ) ) {
1629                         # A numeric index with unknown value
1630                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1631                 }
1632         }
1633
1634         if ( in_array( 'content', $options, true ) ) {
1635                 $forContent = true;
1636                 $langCode = true;
1637                 $langCodeObj = null;
1638         } elseif ( array_key_exists( 'language', $options ) ) {
1639                 $forContent = false;
1640                 $langCode = wfGetLangObj( $options['language'] );
1641                 $langCodeObj = $langCode;
1642         } else {
1643                 $forContent = false;
1644                 $langCode = false;
1645                 $langCodeObj = null;
1646         }
1647
1648         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1649
1650         if ( !in_array( 'replaceafter', $options, true ) ) {
1651                 $string = wfMsgReplaceArgs( $string, $args );
1652         }
1653
1654         $messageCache = MessageCache::singleton();
1655         $parseInline = in_array( 'parseinline', $options, true );
1656         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1657                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1658                 if ( $string instanceof ParserOutput ) {
1659                         $string = $string->getText();
1660                 }
1661
1662                 if ( $parseInline ) {
1663                         $m = array();
1664                         if ( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1665                                 $string = $m[1];
1666                         }
1667                 }
1668         } elseif ( in_array( 'parsemag', $options, true ) ) {
1669                 $string = $messageCache->transform( $string,
1670                                 !$forContent, $langCodeObj );
1671         }
1672
1673         if ( in_array( 'escape', $options, true ) ) {
1674                 $string = htmlspecialchars ( $string );
1675         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1676                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1677         }
1678
1679         if ( in_array( 'replaceafter', $options, true ) ) {
1680                 $string = wfMsgReplaceArgs( $string, $args );
1681         }
1682
1683         return $string;
1684 }
1685
1686 /**
1687  * Since wfMsg() and co suck, they don't return false if the message key they
1688  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1689  * nonexistence of messages by checking the MessageCache::get() result directly.
1690  *
1691  * @deprecated since 1.18. Use Message::isDisabled().
1692  *
1693  * @param $key      String: the message key looked up
1694  * @return Boolean True if the message *doesn't* exist.
1695  */
1696 function wfEmptyMsg( $key ) {
1697         wfDeprecated( __METHOD__, '1.21' );
1698
1699         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1700 }
1701
1702 /**
1703  * Throw a debugging exception. This function previously once exited the process,
1704  * but now throws an exception instead, with similar results.
1705  *
1706  * @deprecated since 1.22; just throw an MWException yourself
1707  * @param string $msg message shown when dying.
1708  * @throws MWException
1709  */
1710 function wfDebugDieBacktrace( $msg = '' ) {
1711         wfDeprecated( __FUNCTION__, '1.22' );
1712         throw new MWException( $msg );
1713 }
1714
1715 /**
1716  * Fetch server name for use in error reporting etc.
1717  * Use real server name if available, so we know which machine
1718  * in a server farm generated the current page.
1719  *
1720  * @return string
1721  */
1722 function wfHostname() {
1723         static $host;
1724         if ( is_null( $host ) ) {
1725
1726                 # Hostname overriding
1727                 global $wgOverrideHostname;
1728                 if ( $wgOverrideHostname !== false ) {
1729                         # Set static and skip any detection
1730                         $host = $wgOverrideHostname;
1731                         return $host;
1732                 }
1733
1734                 if ( function_exists( 'posix_uname' ) ) {
1735                         // This function not present on Windows
1736                         $uname = posix_uname();
1737                 } else {
1738                         $uname = false;
1739                 }
1740                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1741                         $host = $uname['nodename'];
1742                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1743                         # Windows computer name
1744                         $host = getenv( 'COMPUTERNAME' );
1745                 } else {
1746                         # This may be a virtual server.
1747                         $host = $_SERVER['SERVER_NAME'];
1748                 }
1749         }
1750         return $host;
1751 }
1752
1753 /**
1754  * Returns a HTML comment with the elapsed time since request.
1755  * This method has no side effects.
1756  *
1757  * @return string
1758  */
1759 function wfReportTime() {
1760         global $wgRequestTime, $wgShowHostnames;
1761
1762         $elapsed = microtime( true ) - $wgRequestTime;
1763
1764         return $wgShowHostnames
1765                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1766                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1767 }
1768
1769 /**
1770  * Safety wrapper for debug_backtrace().
1771  *
1772  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1773  * murky circumstances, which may be triggered in part by stub objects
1774  * or other fancy talking'.
1775  *
1776  * Will return an empty array if Zend Optimizer is detected or if
1777  * debug_backtrace is disabled, otherwise the output from
1778  * debug_backtrace() (trimmed).
1779  *
1780  * @param int $limit This parameter can be used to limit the number of stack frames returned
1781  *
1782  * @return array of backtrace information
1783  */
1784 function wfDebugBacktrace( $limit = 0 ) {
1785         static $disabled = null;
1786
1787         if ( extension_loaded( 'Zend Optimizer' ) ) {
1788                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1789                 return array();
1790         }
1791
1792         if ( is_null( $disabled ) ) {
1793                 $disabled = false;
1794                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1795                 $functions = array_map( 'trim', $functions );
1796                 $functions = array_map( 'strtolower', $functions );
1797                 if ( in_array( 'debug_backtrace', $functions ) ) {
1798                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1799                         $disabled = true;
1800                 }
1801         }
1802         if ( $disabled ) {
1803                 return array();
1804         }
1805
1806         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1807                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1808         } else {
1809                 return array_slice( debug_backtrace(), 1 );
1810         }
1811 }
1812
1813 /**
1814  * Get a debug backtrace as a string
1815  *
1816  * @return string
1817  */
1818 function wfBacktrace() {
1819         global $wgCommandLineMode;
1820
1821         if ( $wgCommandLineMode ) {
1822                 $msg = '';
1823         } else {
1824                 $msg = "<ul>\n";
1825         }
1826         $backtrace = wfDebugBacktrace();
1827         foreach ( $backtrace as $call ) {
1828                 if ( isset( $call['file'] ) ) {
1829                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1830                         $file = $f[count( $f ) - 1];
1831                 } else {
1832                         $file = '-';
1833                 }
1834                 if ( isset( $call['line'] ) ) {
1835                         $line = $call['line'];
1836                 } else {
1837                         $line = '-';
1838                 }
1839                 if ( $wgCommandLineMode ) {
1840                         $msg .= "$file line $line calls ";
1841                 } else {
1842                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1843                 }
1844                 if ( !empty( $call['class'] ) ) {
1845                         $msg .= $call['class'] . $call['type'];
1846                 }
1847                 $msg .= $call['function'] . '()';
1848
1849                 if ( $wgCommandLineMode ) {
1850                         $msg .= "\n";
1851                 } else {
1852                         $msg .= "</li>\n";
1853                 }
1854         }
1855         if ( $wgCommandLineMode ) {
1856                 $msg .= "\n";
1857         } else {
1858                 $msg .= "</ul>\n";
1859         }
1860
1861         return $msg;
1862 }
1863
1864 /**
1865  * Get the name of the function which called this function
1866  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1867  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1868  * wfGetCaller( 3 ) is the parent of that.
1869  *
1870  * @param $level Int
1871  * @return string
1872  */
1873 function wfGetCaller( $level = 2 ) {
1874         $backtrace = wfDebugBacktrace( $level + 1 );
1875         if ( isset( $backtrace[$level] ) ) {
1876                 return wfFormatStackFrame( $backtrace[$level] );
1877         } else {
1878                 return 'unknown';
1879         }
1880 }
1881
1882 /**
1883  * Return a string consisting of callers in the stack. Useful sometimes
1884  * for profiling specific points.
1885  *
1886  * @param int $limit The maximum depth of the stack frame to return, or false for
1887  *               the entire stack.
1888  * @return String
1889  */
1890 function wfGetAllCallers( $limit = 3 ) {
1891         $trace = array_reverse( wfDebugBacktrace() );
1892         if ( !$limit || $limit > count( $trace ) - 1 ) {
1893                 $limit = count( $trace ) - 1;
1894         }
1895         $trace = array_slice( $trace, -$limit - 1, $limit );
1896         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1897 }
1898
1899 /**
1900  * Return a string representation of frame
1901  *
1902  * @param $frame Array
1903  * @return string
1904  */
1905 function wfFormatStackFrame( $frame ) {
1906         return isset( $frame['class'] ) ?
1907                 $frame['class'] . '::' . $frame['function'] :
1908                 $frame['function'];
1909 }
1910
1911 /* Some generic result counters, pulled out of SearchEngine */
1912
1913 /**
1914  * @todo document
1915  *
1916  * @param $offset Int
1917  * @param $limit Int
1918  * @return String
1919  */
1920 function wfShowingResults( $offset, $limit ) {
1921         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1922 }
1923
1924 /**
1925  * Generate (prev x| next x) (20|50|100...) type links for paging
1926  *
1927  * @param $offset String
1928  * @param $limit Integer
1929  * @param $link String
1930  * @param string $query optional URL query parameter string
1931  * @param bool $atend optional param for specified if this is the last page
1932  * @return String
1933  * @deprecated in 1.19; use Language::viewPrevNext() instead
1934  */
1935 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1936         wfDeprecated( __METHOD__, '1.19' );
1937
1938         global $wgLang;
1939
1940         $query = wfCgiToArray( $query );
1941
1942         if ( is_object( $link ) ) {
1943                 $title = $link;
1944         } else {
1945                 $title = Title::newFromText( $link );
1946                 if ( is_null( $title ) ) {
1947                         return false;
1948                 }
1949         }
1950
1951         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1952 }
1953
1954 /**
1955  * @todo document
1956  * @todo FIXME: We may want to blacklist some broken browsers
1957  *
1958  * @param $force Bool
1959  * @return bool Whereas client accept gzip compression
1960  */
1961 function wfClientAcceptsGzip( $force = false ) {
1962         static $result = null;
1963         if ( $result === null || $force ) {
1964                 $result = false;
1965                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1966                         # @todo FIXME: We may want to blacklist some broken browsers
1967                         $m = array();
1968                         if ( preg_match(
1969                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1970                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1971                                 $m )
1972                         )
1973                         {
1974                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1975                                         $result = false;
1976                                         return $result;
1977                                 }
1978                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1979                                 $result = true;
1980                         }
1981                 }
1982         }
1983         return $result;
1984 }
1985
1986 /**
1987  * Obtain the offset and limit values from the request string;
1988  * used in special pages
1989  *
1990  * @param int $deflimit default limit if none supplied
1991  * @param string $optionname Name of a user preference to check against
1992  * @return array
1993  *
1994  */
1995 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1996         global $wgRequest;
1997         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1998 }
1999
2000 /**
2001  * Escapes the given text so that it may be output using addWikiText()
2002  * without any linking, formatting, etc. making its way through. This
2003  * is achieved by substituting certain characters with HTML entities.
2004  * As required by the callers, "<nowiki>" is not used.
2005  *
2006  * @param string $text text to be escaped
2007  * @return String
2008  */
2009 function wfEscapeWikiText( $text ) {
2010         static $repl = null, $repl2 = null;
2011         if ( $repl === null ) {
2012                 $repl = array(
2013                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2014                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2015                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2016                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2017                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2018                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2019                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2020                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2021                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2022                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2023                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2024                         '__' => '_&#95;', '://' => '&#58;//',
2025                 );
2026
2027                 // We have to catch everything "\s" matches in PCRE
2028                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2029                         $repl["$magic "] = "$magic&#32;";
2030                         $repl["$magic\t"] = "$magic&#9;";
2031                         $repl["$magic\r"] = "$magic&#13;";
2032                         $repl["$magic\n"] = "$magic&#10;";
2033                         $repl["$magic\f"] = "$magic&#12;";
2034                 }
2035
2036                 // And handle protocols that don't use "://"
2037                 global $wgUrlProtocols;
2038                 $repl2 = array();
2039                 foreach ( $wgUrlProtocols as $prot ) {
2040                         if ( substr( $prot, -1 ) === ':' ) {
2041                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2042                         }
2043                 }
2044                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2045         }
2046         $text = substr( strtr( "\n$text", $repl ), 1 );
2047         $text = preg_replace( $repl2, '$1&#58;', $text );
2048         return $text;
2049 }
2050
2051 /**
2052  * Get the current unix timestamp with microseconds.  Useful for profiling
2053  * @deprecated since 1.22; call microtime() directly
2054  * @return Float
2055  */
2056 function wfTime() {
2057         wfDeprecated( __FUNCTION__, '1.22' );
2058         return microtime( true );
2059 }
2060
2061 /**
2062  * Sets dest to source and returns the original value of dest
2063  * If source is NULL, it just returns the value, it doesn't set the variable
2064  * If force is true, it will set the value even if source is NULL
2065  *
2066  * @param $dest Mixed
2067  * @param $source Mixed
2068  * @param $force Bool
2069  * @return Mixed
2070  */
2071 function wfSetVar( &$dest, $source, $force = false ) {
2072         $temp = $dest;
2073         if ( !is_null( $source ) || $force ) {
2074                 $dest = $source;
2075         }
2076         return $temp;
2077 }
2078
2079 /**
2080  * As for wfSetVar except setting a bit
2081  *
2082  * @param $dest Int
2083  * @param $bit Int
2084  * @param $state Bool
2085  *
2086  * @return bool
2087  */
2088 function wfSetBit( &$dest, $bit, $state = true ) {
2089         $temp = (bool)( $dest & $bit );
2090         if ( !is_null( $state ) ) {
2091                 if ( $state ) {
2092                         $dest |= $bit;
2093                 } else {
2094                         $dest &= ~$bit;
2095                 }
2096         }
2097         return $temp;
2098 }
2099
2100 /**
2101  * A wrapper around the PHP function var_export().
2102  * Either print it or add it to the regular output ($wgOut).
2103  *
2104  * @param $var mixed A PHP variable to dump.
2105  */
2106 function wfVarDump( $var ) {
2107         global $wgOut;
2108         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2109         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2110                 print $s;
2111         } else {
2112                 $wgOut->addHTML( $s );
2113         }
2114 }
2115
2116 /**
2117  * Provide a simple HTTP error.
2118  *
2119  * @param $code Int|String
2120  * @param $label String
2121  * @param $desc String
2122  */
2123 function wfHttpError( $code, $label, $desc ) {
2124         global $wgOut;
2125         $wgOut->disable();
2126         header( "HTTP/1.0 $code $label" );
2127         header( "Status: $code $label" );
2128         $wgOut->sendCacheControl();
2129
2130         header( 'Content-type: text/html; charset=utf-8' );
2131         print "<!doctype html>" .
2132                 '<html><head><title>' .
2133                 htmlspecialchars( $label ) .
2134                 '</title></head><body><h1>' .
2135                 htmlspecialchars( $label ) .
2136                 '</h1><p>' .
2137                 nl2br( htmlspecialchars( $desc ) ) .
2138                 "</p></body></html>\n";
2139 }
2140
2141 /**
2142  * Clear away any user-level output buffers, discarding contents.
2143  *
2144  * Suitable for 'starting afresh', for instance when streaming
2145  * relatively large amounts of data without buffering, or wanting to
2146  * output image files without ob_gzhandler's compression.
2147  *
2148  * The optional $resetGzipEncoding parameter controls suppression of
2149  * the Content-Encoding header sent by ob_gzhandler; by default it
2150  * is left. See comments for wfClearOutputBuffers() for why it would
2151  * be used.
2152  *
2153  * Note that some PHP configuration options may add output buffer
2154  * layers which cannot be removed; these are left in place.
2155  *
2156  * @param $resetGzipEncoding Bool
2157  */
2158 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2159         if ( $resetGzipEncoding ) {
2160                 // Suppress Content-Encoding and Content-Length
2161                 // headers from 1.10+s wfOutputHandler
2162                 global $wgDisableOutputCompression;
2163                 $wgDisableOutputCompression = true;
2164         }
2165         while ( $status = ob_get_status() ) {
2166                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2167                         // Probably from zlib.output_compression or other
2168                         // PHP-internal setting which can't be removed.
2169                         //
2170                         // Give up, and hope the result doesn't break
2171                         // output behavior.
2172                         break;
2173                 }
2174                 if ( !ob_end_clean() ) {
2175                         // Could not remove output buffer handler; abort now
2176                         // to avoid getting in some kind of infinite loop.
2177                         break;
2178                 }
2179                 if ( $resetGzipEncoding ) {
2180                         if ( $status['name'] == 'ob_gzhandler' ) {
2181                                 // Reset the 'Content-Encoding' field set by this handler
2182                                 // so we can start fresh.
2183                                 header_remove( 'Content-Encoding' );
2184                                 break;
2185                         }
2186                 }
2187         }
2188 }
2189
2190 /**
2191  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2192  *
2193  * Clear away output buffers, but keep the Content-Encoding header
2194  * produced by ob_gzhandler, if any.
2195  *
2196  * This should be used for HTTP 304 responses, where you need to
2197  * preserve the Content-Encoding header of the real result, but
2198  * also need to suppress the output of ob_gzhandler to keep to spec
2199  * and avoid breaking Firefox in rare cases where the headers and
2200  * body are broken over two packets.
2201  */
2202 function wfClearOutputBuffers() {
2203         wfResetOutputBuffers( false );
2204 }
2205
2206 /**
2207  * Converts an Accept-* header into an array mapping string values to quality
2208  * factors
2209  *
2210  * @param $accept String
2211  * @param string $def default
2212  * @return Array
2213  */
2214 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2215         # No arg means accept anything (per HTTP spec)
2216         if ( !$accept ) {
2217                 return array( $def => 1.0 );
2218         }
2219
2220         $prefs = array();
2221
2222         $parts = explode( ',', $accept );
2223
2224         foreach ( $parts as $part ) {
2225                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2226                 $values = explode( ';', trim( $part ) );
2227                 $match = array();
2228                 if ( count( $values ) == 1 ) {
2229                         $prefs[$values[0]] = 1.0;
2230                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2231                         $prefs[$values[0]] = floatval( $match[1] );
2232                 }
2233         }
2234
2235         return $prefs;
2236 }
2237
2238 /**
2239  * Checks if a given MIME type matches any of the keys in the given
2240  * array. Basic wildcards are accepted in the array keys.
2241  *
2242  * Returns the matching MIME type (or wildcard) if a match, otherwise
2243  * NULL if no match.
2244  *
2245  * @param $type String
2246  * @param $avail Array
2247  * @return string
2248  * @private
2249  */
2250 function mimeTypeMatch( $type, $avail ) {
2251         if ( array_key_exists( $type, $avail ) ) {
2252                 return $type;
2253         } else {
2254                 $parts = explode( '/', $type );
2255                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2256                         return $parts[0] . '/*';
2257                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2258                         return '*/*';
2259                 } else {
2260                         return null;
2261                 }
2262         }
2263 }
2264
2265 /**
2266  * Returns the 'best' match between a client's requested internet media types
2267  * and the server's list of available types. Each list should be an associative
2268  * array of type to preference (preference is a float between 0.0 and 1.0).
2269  * Wildcards in the types are acceptable.
2270  *
2271  * @param array $cprefs client's acceptable type list
2272  * @param array $sprefs server's offered types
2273  * @return string
2274  *
2275  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2276  * XXX: generalize to negotiate other stuff
2277  */
2278 function wfNegotiateType( $cprefs, $sprefs ) {
2279         $combine = array();
2280
2281         foreach ( array_keys( $sprefs ) as $type ) {
2282                 $parts = explode( '/', $type );
2283                 if ( $parts[1] != '*' ) {
2284                         $ckey = mimeTypeMatch( $type, $cprefs );
2285                         if ( $ckey ) {
2286                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2287                         }
2288                 }
2289         }
2290
2291         foreach ( array_keys( $cprefs ) as $type ) {
2292                 $parts = explode( '/', $type );
2293                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2294                         $skey = mimeTypeMatch( $type, $sprefs );
2295                         if ( $skey ) {
2296                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2297                         }
2298                 }
2299         }
2300
2301         $bestq = 0;
2302         $besttype = null;
2303
2304         foreach ( array_keys( $combine ) as $type ) {
2305                 if ( $combine[$type] > $bestq ) {
2306                         $besttype = $type;
2307                         $bestq = $combine[$type];
2308                 }
2309         }
2310
2311         return $besttype;
2312 }
2313
2314 /**
2315  * Reference-counted warning suppression
2316  *
2317  * @param $end Bool
2318  */
2319 function wfSuppressWarnings( $end = false ) {
2320         static $suppressCount = 0;
2321         static $originalLevel = false;
2322
2323         if ( $end ) {
2324                 if ( $suppressCount ) {
2325                         --$suppressCount;
2326                         if ( !$suppressCount ) {
2327                                 error_reporting( $originalLevel );
2328                         }
2329                 }
2330         } else {
2331                 if ( !$suppressCount ) {
2332                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT ) );
2333                 }
2334                 ++$suppressCount;
2335         }
2336 }
2337
2338 /**
2339  * Restore error level to previous value
2340  */
2341 function wfRestoreWarnings() {
2342         wfSuppressWarnings( true );
2343 }
2344
2345 # Autodetect, convert and provide timestamps of various types
2346
2347 /**
2348  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2349  */
2350 define( 'TS_UNIX', 0 );
2351
2352 /**
2353  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2354  */
2355 define( 'TS_MW', 1 );
2356
2357 /**
2358  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2359  */
2360 define( 'TS_DB', 2 );
2361
2362 /**
2363  * RFC 2822 format, for E-mail and HTTP headers
2364  */
2365 define( 'TS_RFC2822', 3 );
2366
2367 /**
2368  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2369  *
2370  * This is used by Special:Export
2371  */
2372 define( 'TS_ISO_8601', 4 );
2373
2374 /**
2375  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2376  *
2377  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2378  *       DateTime tag and page 36 for the DateTimeOriginal and
2379  *       DateTimeDigitized tags.
2380  */
2381 define( 'TS_EXIF', 5 );
2382
2383 /**
2384  * Oracle format time.
2385  */
2386 define( 'TS_ORACLE', 6 );
2387
2388 /**
2389  * Postgres format time.
2390  */
2391 define( 'TS_POSTGRES', 7 );
2392
2393 /**
2394  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2395  */
2396 define( 'TS_ISO_8601_BASIC', 9 );
2397
2398 /**
2399  * Get a timestamp string in one of various formats
2400  *
2401  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2402  *                    function will autodetect which format is supplied and act
2403  *                    accordingly.
2404  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2405  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2406  */
2407 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2408         try {
2409                 $timestamp = new MWTimestamp( $ts );
2410                 return $timestamp->getTimestamp( $outputtype );
2411         } catch ( TimestampException $e ) {
2412                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2413                 return false;
2414         }
2415 }
2416
2417 /**
2418  * Return a formatted timestamp, or null if input is null.
2419  * For dealing with nullable timestamp columns in the database.
2420  *
2421  * @param $outputtype Integer
2422  * @param $ts String
2423  * @return String
2424  */
2425 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2426         if ( is_null( $ts ) ) {
2427                 return null;
2428         } else {
2429                 return wfTimestamp( $outputtype, $ts );
2430         }
2431 }
2432
2433 /**
2434  * Convenience function; returns MediaWiki timestamp for the present time.
2435  *
2436  * @return string
2437  */
2438 function wfTimestampNow() {
2439         # return NOW
2440         return wfTimestamp( TS_MW, time() );
2441 }
2442
2443 /**
2444  * Check if the operating system is Windows
2445  *
2446  * @return Bool: true if it's Windows, False otherwise.
2447  */
2448 function wfIsWindows() {
2449         static $isWindows = null;
2450         if ( $isWindows === null ) {
2451                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2452         }
2453         return $isWindows;
2454 }
2455
2456 /**
2457  * Check if we are running under HipHop
2458  *
2459  * @return Bool
2460  */
2461 function wfIsHipHop() {
2462         return defined( 'HPHP_VERSION' );
2463 }
2464
2465 /**
2466  * Swap two variables
2467  *
2468  * @param $x Mixed
2469  * @param $y Mixed
2470  */
2471 function swap( &$x, &$y ) {
2472         $z = $x;
2473         $x = $y;
2474         $y = $z;
2475 }
2476
2477 /**
2478  * Tries to get the system directory for temporary files. First
2479  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2480  * environment variables are then checked in sequence, and if none are
2481  * set try sys_get_temp_dir().
2482  *
2483  * NOTE: When possible, use instead the tmpfile() function to create
2484  * temporary files to avoid race conditions on file creation, etc.
2485  *
2486  * @return String
2487  */
2488 function wfTempDir() {
2489         global $wgTmpDirectory;
2490
2491         if ( $wgTmpDirectory !== false ) {
2492                 return $wgTmpDirectory;
2493         }
2494
2495         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2496
2497         foreach ( $tmpDir as $tmp ) {
2498                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2499                         return $tmp;
2500                 }
2501         }
2502         return sys_get_temp_dir();
2503 }
2504
2505 /**
2506  * Make directory, and make all parent directories if they don't exist
2507  *
2508  * @param string $dir full path to directory to create
2509  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2510  * @param string $caller optional caller param for debugging.
2511  * @throws MWException
2512  * @return bool
2513  */
2514 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2515         global $wgDirectoryMode;
2516
2517         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2518                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2519         }
2520
2521         if ( !is_null( $caller ) ) {
2522                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2523         }
2524
2525         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2526                 return true;
2527         }
2528
2529         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2530
2531         if ( is_null( $mode ) ) {
2532                 $mode = $wgDirectoryMode;
2533         }
2534
2535         // Turn off the normal warning, we're doing our own below
2536         wfSuppressWarnings();
2537         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2538         wfRestoreWarnings();
2539
2540         if ( !$ok ) {
2541                 //directory may have been created on another request since we last checked
2542                 if ( is_dir( $dir ) ) {
2543                         return true;
2544                 }
2545
2546                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2547                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2548         }
2549         return $ok;
2550 }
2551
2552 /**
2553  * Remove a directory and all its content.
2554  * Does not hide error.
2555  */
2556 function wfRecursiveRemoveDir( $dir ) {
2557         wfDebug( __FUNCTION__ . "( $dir )\n" );
2558         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2559         if ( is_dir( $dir ) ) {
2560                 $objects = scandir( $dir );
2561                 foreach ( $objects as $object ) {
2562                         if ( $object != "." && $object != ".." ) {
2563                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2564                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2565                                 } else {
2566                                         unlink( $dir . '/' . $object );
2567                                 }
2568                         }
2569                 }
2570                 reset( $objects );
2571                 rmdir( $dir );
2572         }
2573 }
2574
2575 /**
2576  * @param $nr Mixed: the number to format
2577  * @param $acc Integer: the number of digits after the decimal point, default 2
2578  * @param $round Boolean: whether or not to round the value, default true
2579  * @return float
2580  */
2581 function wfPercent( $nr, $acc = 2, $round = true ) {
2582         $ret = sprintf( "%.${acc}f", $nr );
2583         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2584 }
2585
2586 /**
2587  * Find out whether or not a mixed variable exists in a string
2588  *
2589  * @deprecated Just use str(i)pos
2590  * @param $needle String
2591  * @param $str String
2592  * @param $insensitive Boolean
2593  * @return Boolean
2594  */
2595 function in_string( $needle, $str, $insensitive = false ) {
2596         wfDeprecated( __METHOD__, '1.21' );
2597         $func = 'strpos';
2598         if ( $insensitive ) {
2599                 $func = 'stripos';
2600         }
2601
2602         return $func( $str, $needle ) !== false;
2603 }
2604
2605 /**
2606  * Safety wrapper around ini_get() for boolean settings.
2607  * The values returned from ini_get() are pre-normalized for settings
2608  * set via php.ini or php_flag/php_admin_flag... but *not*
2609  * for those set via php_value/php_admin_value.
2610  *
2611  * It's fairly common for people to use php_value instead of php_flag,
2612  * which can leave you with an 'off' setting giving a false positive
2613  * for code that just takes the ini_get() return value as a boolean.
2614  *
2615  * To make things extra interesting, setting via php_value accepts
2616  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2617  * Unrecognized values go false... again opposite PHP's own coercion
2618  * from string to bool.
2619  *
2620  * Luckily, 'properly' set settings will always come back as '0' or '1',
2621  * so we only have to worry about them and the 'improper' settings.
2622  *
2623  * I frickin' hate PHP... :P
2624  *
2625  * @param $setting String
2626  * @return Bool
2627  */
2628 function wfIniGetBool( $setting ) {
2629         $val = strtolower( ini_get( $setting ) );
2630         // 'on' and 'true' can't have whitespace around them, but '1' can.
2631         return $val == 'on'
2632                 || $val == 'true'
2633                 || $val == 'yes'
2634                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2635 }
2636
2637 /**
2638  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2639  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2640  *
2641  * @param string $extension A PHP extension. The file suffix (.so or .dll)
2642  *                          should be omitted
2643  * @param string $fileName Name of the library, if not $extension.suffix
2644  * @return Bool - Whether or not the extension is loaded
2645  */
2646 function wfDl( $extension, $fileName = null ) {
2647         if ( extension_loaded( $extension ) ) {
2648                 return true;
2649         }
2650
2651         $canDl = false;
2652         if ( PHP_SAPI == 'cli' || PHP_SAPI == 'cgi' || PHP_SAPI == 'embed' ) {
2653                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2654                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2655         }
2656
2657         if ( $canDl ) {
2658                 $fileName = $fileName ? $fileName : $extension;
2659                 if ( wfIsWindows() ) {
2660                         $fileName = 'php_' . $fileName;
2661                 }
2662                 wfSuppressWarnings();
2663                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2664                 wfRestoreWarnings();
2665         }
2666         return extension_loaded( $extension );
2667 }
2668
2669 /**
2670  * Windows-compatible version of escapeshellarg()
2671  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2672  * function puts single quotes in regardless of OS.
2673  *
2674  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2675  * earlier distro releases of PHP)
2676  *
2677  * @param varargs
2678  * @return String
2679  */
2680 function wfEscapeShellArg() {
2681         wfInitShellLocale();
2682
2683         $args = func_get_args();
2684         $first = true;
2685         $retVal = '';
2686         foreach ( $args as $arg ) {
2687                 if ( !$first ) {
2688                         $retVal .= ' ';
2689                 } else {
2690                         $first = false;
2691                 }
2692
2693                 if ( wfIsWindows() ) {
2694                         // Escaping for an MSVC-style command line parser and CMD.EXE
2695                         // Refs:
2696                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2697                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2698                         //  * Bug #13518
2699                         //  * CR r63214
2700                         // Double the backslashes before any double quotes. Escape the double quotes.
2701                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2702                         $arg = '';
2703                         $iteration = 0;
2704                         foreach ( $tokens as $token ) {
2705                                 if ( $iteration % 2 == 1 ) {
2706                                         // Delimiter, a double quote preceded by zero or more slashes
2707                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2708                                 } elseif ( $iteration % 4 == 2 ) {
2709                                         // ^ in $token will be outside quotes, need to be escaped
2710                                         $arg .= str_replace( '^', '^^', $token );
2711                                 } else { // $iteration % 4 == 0
2712                                         // ^ in $token will appear inside double quotes, so leave as is
2713                                         $arg .= $token;
2714                                 }
2715                                 $iteration++;
2716                         }
2717                         // Double the backslashes before the end of the string, because
2718                         // we will soon add a quote
2719                         $m = array();
2720                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2721                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2722                         }
2723
2724                         // Add surrounding quotes
2725                         $retVal .= '"' . $arg . '"';
2726                 } else {
2727                         $retVal .= escapeshellarg( $arg );
2728                 }
2729         }
2730         return $retVal;
2731 }
2732
2733 /**
2734  * Check if wfShellExec() is effectively disabled via php.ini config
2735  * @return bool|string False or one of (safemode,disabled)
2736  * @since 1.22
2737  */
2738 function wfShellExecDisabled() {
2739         static $disabled = null;
2740         if ( is_null( $disabled ) ) {
2741                 $disabled = false;
2742                 if ( wfIniGetBool( 'safe_mode' ) ) {
2743                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2744                         $disabled = 'safemode';
2745                 } else {
2746                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2747                         $functions = array_map( 'trim', $functions );
2748                         $functions = array_map( 'strtolower', $functions );
2749                         if ( in_array( 'passthru', $functions ) ) {
2750                                 wfDebug( "passthru is in disabled_functions\n" );
2751                                 $disabled = 'passthru';
2752                         }
2753                 }
2754         }
2755         return $disabled;
2756 }
2757
2758 /**
2759  * Execute a shell command, with time and memory limits mirrored from the PHP
2760  * configuration if supported.
2761  * @param string $cmd Command line, properly escaped for shell.
2762  * @param &$retval null|Mixed optional, will receive the program's exit code.
2763  *                 (non-zero is usually failure)
2764  * @param array $environ optional environment variables which should be
2765  *                 added to the executed command environment.
2766  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2767  *                 this overwrites the global wgShellMax* limits.
2768  * @param array $options Array of options. Only one is "duplicateStderr" => true, which
2769  *                 Which duplicates stderr to stdout, including errors from limit.sh
2770  * @return string collected stdout as a string
2771  */
2772 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array(), $options = array() ) {
2773         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2774                 $wgMaxShellWallClockTime, $wgShellCgroup;
2775
2776         $disabled = wfShellExecDisabled();
2777         if ( $disabled ) {
2778                 $retval = 1;
2779                 return $disabled == 'safemode' ?
2780                         'Unable to run external programs in safe mode.' :
2781                         'Unable to run external programs, passthru() is disabled.';
2782         }
2783
2784         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2785
2786         wfInitShellLocale();
2787
2788         $envcmd = '';
2789         foreach ( $environ as $k => $v ) {
2790                 if ( wfIsWindows() ) {
2791                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2792                          * appear in the environment variable, so we must use carat escaping as documented in
2793                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2794                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2795                          * are listed there but doesn't appear to need it.
2796                          */
2797                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2798                 } else {
2799                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2800                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2801                          */
2802                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2803                 }
2804         }
2805         $cmd = $envcmd . $cmd;
2806
2807         if ( php_uname( 's' ) == 'Linux' ) {
2808                 $stderrDuplication = '';
2809                 if ( $includeStderr ) {
2810                         $stderrDuplication = 'exec 2>&1; ';
2811                 }
2812                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2813                 if ( isset( $limits['walltime'] ) ) {
2814                         $wallTime = intval( $limits['walltime'] );
2815                 } elseif ( isset( $limits['time'] ) ) {
2816                         $wallTime = $time;
2817                 } else {
2818                         $wallTime = intval( $wgMaxShellWallClockTime );
2819                 }
2820                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2821                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2822
2823                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2824                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2825                                 escapeshellarg( $cmd ) . ' ' .
2826                                 escapeshellarg(
2827                                         $stderrDuplication .
2828                                         "MW_CPU_LIMIT=$time; " .
2829                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2830                                         "MW_MEM_LIMIT=$mem; " .
2831                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2832                                         "MW_WALL_CLOCK_LIMIT=$wallTime"
2833                                 );
2834                 } else {
2835                         $cmd .= ' 2>&1';
2836                 }
2837         } elseif ( $includeStderr ) {
2838                 $cmd .= ' 2>&1';
2839         }
2840         wfDebug( "wfShellExec: $cmd\n" );
2841
2842         // Default to an unusual value that shouldn't happen naturally,
2843         // so in the unlikely event of a weird php bug, it would be
2844         // more obvious what happened.
2845         $retval = 200;
2846         ob_start();
2847         passthru( $cmd, $retval );
2848         $output = ob_get_contents();
2849         ob_end_clean();
2850
2851         if ( $retval == 127 ) {
2852                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2853         }
2854         return $output;
2855 }
2856
2857 /**
2858  * Execute a shell command, returning both stdout and stderr. Convenience
2859  * function, as all the arguments to wfShellExec can become unwieldy.
2860  *
2861  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2862  * @param string $cmd Command line, properly escaped for shell.
2863  * @param &$retval null|Mixed optional, will receive the program's exit code.
2864  *                 (non-zero is usually failure)
2865  * @param array $environ optional environment variables which should be
2866  *                 added to the executed command environment.
2867  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2868  *                 this overwrites the global wgShellMax* limits.
2869  * @return string collected stdout and stderr as a string
2870  */
2871 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2872         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
2873 }
2874
2875 /**
2876  * Workaround for http://bugs.php.net/bug.php?id=45132
2877  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2878  */
2879 function wfInitShellLocale() {
2880         static $done = false;
2881         if ( $done ) {
2882                 return;
2883         }
2884         $done = true;
2885         global $wgShellLocale;
2886         if ( !wfIniGetBool( 'safe_mode' ) ) {
2887                 putenv( "LC_CTYPE=$wgShellLocale" );
2888                 setlocale( LC_CTYPE, $wgShellLocale );
2889         }
2890 }
2891
2892 /**
2893  * Alias to wfShellWikiCmd()
2894  * @see wfShellWikiCmd()
2895  */
2896 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2897         return wfShellWikiCmd( $script, $parameters, $options );
2898 }
2899
2900 /**
2901  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2902  * Note that $parameters should be a flat array and an option with an argument
2903  * should consist of two consecutive items in the array (do not use "--option value").
2904  * @param string $script MediaWiki cli script path
2905  * @param array $parameters Arguments and options to the script
2906  * @param array $options Associative array of options:
2907  *              'php': The path to the php executable
2908  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2909  * @return Array
2910  */
2911 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2912         global $wgPhpCli;
2913         // Give site config file a chance to run the script in a wrapper.
2914         // The caller may likely want to call wfBasename() on $script.
2915         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2916         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2917         if ( isset( $options['wrapper'] ) ) {
2918                 $cmd[] = $options['wrapper'];
2919         }
2920         $cmd[] = $script;
2921         // Escape each parameter for shell
2922         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2923 }
2924
2925 /**
2926  * wfMerge attempts to merge differences between three texts.
2927  * Returns true for a clean merge and false for failure or a conflict.
2928  *
2929  * @param $old String
2930  * @param $mine String
2931  * @param $yours String
2932  * @param $result String
2933  * @return Bool
2934  */
2935 function wfMerge( $old, $mine, $yours, &$result ) {
2936         global $wgDiff3;
2937
2938         # This check may also protect against code injection in
2939         # case of broken installations.
2940         wfSuppressWarnings();
2941         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2942         wfRestoreWarnings();
2943
2944         if ( !$haveDiff3 ) {
2945                 wfDebug( "diff3 not found\n" );
2946                 return false;
2947         }
2948
2949         # Make temporary files
2950         $td = wfTempDir();
2951         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2952         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2953         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2954
2955         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2956         #       a newline character. To avoid this, we normalize the trailing whitespace before
2957         #       creating the diff.
2958
2959         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2960         fclose( $oldtextFile );
2961         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2962         fclose( $mytextFile );
2963         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2964         fclose( $yourtextFile );
2965
2966         # Check for a conflict
2967         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
2968                 wfEscapeShellArg( $mytextName ) . ' ' .
2969                 wfEscapeShellArg( $oldtextName ) . ' ' .
2970                 wfEscapeShellArg( $yourtextName );
2971         $handle = popen( $cmd, 'r' );
2972
2973         if ( fgets( $handle, 1024 ) ) {
2974                 $conflict = true;
2975         } else {
2976                 $conflict = false;
2977         }
2978         pclose( $handle );
2979
2980         # Merge differences
2981         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
2982                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2983         $handle = popen( $cmd, 'r' );
2984         $result = '';
2985         do {
2986                 $data = fread( $handle, 8192 );
2987                 if ( strlen( $data ) == 0 ) {
2988                         break;
2989                 }
2990                 $result .= $data;
2991         } while ( true );
2992         pclose( $handle );
2993         unlink( $mytextName );
2994         unlink( $oldtextName );
2995         unlink( $yourtextName );
2996
2997         if ( $result === '' && $old !== '' && !$conflict ) {
2998                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2999                 $conflict = true;
3000         }
3001         return !$conflict;
3002 }
3003
3004 /**
3005  * Returns unified plain-text diff of two texts.
3006  * Useful for machine processing of diffs.
3007  *
3008  * @param string $before the text before the changes.
3009  * @param string $after the text after the changes.
3010  * @param string $params command-line options for the diff command.
3011  * @return String: unified diff of $before and $after
3012  */
3013 function wfDiff( $before, $after, $params = '-u' ) {
3014         if ( $before == $after ) {
3015                 return '';
3016         }
3017
3018         global $wgDiff;
3019         wfSuppressWarnings();
3020         $haveDiff = $wgDiff && file_exists( $wgDiff );
3021         wfRestoreWarnings();
3022
3023         # This check may also protect against code injection in
3024         # case of broken installations.
3025         if ( !$haveDiff ) {
3026                 wfDebug( "diff executable not found\n" );
3027                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3028                 $format = new UnifiedDiffFormatter();
3029                 return $format->format( $diffs );
3030         }
3031
3032         # Make temporary files
3033         $td = wfTempDir();
3034         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3035         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3036
3037         fwrite( $oldtextFile, $before );
3038         fclose( $oldtextFile );
3039         fwrite( $newtextFile, $after );
3040         fclose( $newtextFile );
3041
3042         // Get the diff of the two files
3043         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3044
3045         $h = popen( $cmd, 'r' );
3046
3047         $diff = '';
3048
3049         do {
3050                 $data = fread( $h, 8192 );
3051                 if ( strlen( $data ) == 0 ) {
3052                         break;
3053                 }
3054                 $diff .= $data;
3055         } while ( true );
3056
3057         // Clean up
3058         pclose( $h );
3059         unlink( $oldtextName );
3060         unlink( $newtextName );
3061
3062         // Kill the --- and +++ lines. They're not useful.
3063         $diff_lines = explode( "\n", $diff );
3064         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3065                 unset( $diff_lines[0] );
3066         }
3067         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3068                 unset( $diff_lines[1] );
3069         }
3070
3071         $diff = implode( "\n", $diff_lines );
3072
3073         return $diff;
3074 }
3075
3076 /**
3077  * This function works like "use VERSION" in Perl, the program will die with a
3078  * backtrace if the current version of PHP is less than the version provided
3079  *
3080  * This is useful for extensions which due to their nature are not kept in sync
3081  * with releases, and might depend on other versions of PHP than the main code
3082  *
3083  * Note: PHP might die due to parsing errors in some cases before it ever
3084  *       manages to call this function, such is life
3085  *
3086  * @see perldoc -f use
3087  *
3088  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3089  *                 a float
3090  * @throws MWException
3091  */
3092 function wfUsePHP( $req_ver ) {
3093         $php_ver = PHP_VERSION;
3094
3095         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3096                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3097         }
3098 }
3099
3100 /**
3101  * This function works like "use VERSION" in Perl except it checks the version
3102  * of MediaWiki, the program will die with a backtrace if the current version
3103  * of MediaWiki is less than the version provided.
3104  *
3105  * This is useful for extensions which due to their nature are not kept in sync
3106  * with releases
3107  *
3108  * @see perldoc -f use
3109  *
3110  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3111  *                 a float
3112  * @throws MWException
3113  */
3114 function wfUseMW( $req_ver ) {
3115         global $wgVersion;
3116
3117         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3118                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3119         }
3120 }
3121
3122 /**
3123  * Return the final portion of a pathname.
3124  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3125  * http://bugs.php.net/bug.php?id=33898
3126  *
3127  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3128  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3129  *
3130  * @param $path String
3131  * @param string $suffix to remove if present
3132  * @return String
3133  */
3134 function wfBaseName( $path, $suffix = '' ) {
3135         $encSuffix = ( $suffix == '' )
3136                 ? ''
3137                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3138         $matches = array();
3139         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3140                 return $matches[1];
3141         } else {
3142                 return '';
3143         }
3144 }
3145
3146 /**
3147  * Generate a relative path name to the given file.
3148  * May explode on non-matching case-insensitive paths,
3149  * funky symlinks, etc.
3150  *
3151  * @param string $path absolute destination path including target filename
3152  * @param string $from Absolute source path, directory only
3153  * @return String
3154  */
3155 function wfRelativePath( $path, $from ) {
3156         // Normalize mixed input on Windows...
3157         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3158         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3159
3160         // Trim trailing slashes -- fix for drive root
3161         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3162         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3163
3164         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3165         $against = explode( DIRECTORY_SEPARATOR, $from );
3166
3167         if ( $pieces[0] !== $against[0] ) {
3168                 // Non-matching Windows drive letters?
3169                 // Return a full path.
3170                 return $path;
3171         }
3172
3173         // Trim off common prefix
3174         while ( count( $pieces ) && count( $against )
3175                 && $pieces[0] == $against[0] ) {
3176                 array_shift( $pieces );
3177                 array_shift( $against );
3178         }
3179
3180         // relative dots to bump us to the parent
3181         while ( count( $against ) ) {
3182                 array_unshift( $pieces, '..' );
3183                 array_shift( $against );
3184         }
3185
3186         array_push( $pieces, wfBaseName( $path ) );
3187
3188         return implode( DIRECTORY_SEPARATOR, $pieces );
3189 }
3190
3191 /**
3192  * Do any deferred updates and clear the list
3193  *
3194  * @deprecated since 1.19
3195  * @see DeferredUpdates::doUpdate()
3196  * @param $commit string
3197  */
3198 function wfDoUpdates( $commit = '' ) {
3199         wfDeprecated( __METHOD__, '1.19' );
3200         DeferredUpdates::doUpdates( $commit );
3201 }
3202
3203 /**
3204  * Convert an arbitrarily-long digit string from one numeric base
3205  * to another, optionally zero-padding to a minimum column width.
3206  *
3207  * Supports base 2 through 36; digit values 10-36 are represented
3208  * as lowercase letters a-z. Input is case-insensitive.
3209  *
3210  * @param string $input Input number
3211  * @param int $sourceBase Base of the input number
3212  * @param int $destBase Desired base of the output
3213  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3214  * @param bool $lowercase Whether to output in lowercase or uppercase
3215  * @param string $engine Either "gmp", "bcmath", or "php"
3216  * @return string|bool The output number as a string, or false on error
3217  */
3218 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true, $engine = 'auto' ) {
3219         $input = (string)$input;
3220         if (
3221                 $sourceBase < 2 ||
3222                 $sourceBase > 36 ||
3223                 $destBase < 2 ||
3224                 $destBase > 36 ||
3225                 $sourceBase != (int)$sourceBase ||
3226                 $destBase != (int)$destBase ||
3227                 $pad != (int)$pad ||
3228                 !preg_match( "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i", $input )
3229         ) {
3230                 return false;
3231         }
3232
3233         static $baseChars = array(
3234                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3235                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3236                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3237                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3238                 34 => 'y', 35 => 'z',
3239
3240                 '0' => 0,  '1' => 1,  '2' => 2,  '3' => 3,  '4' => 4,  '5' => 5,
3241                 '6' => 6,  '7' => 7,  '8' => 8,  '9' => 9,  'a' => 10, 'b' => 11,
3242                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3243                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3244                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3245                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3246         );
3247
3248         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3249                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3250         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3251                 $decimal = '0';
3252                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3253                         $decimal = bcmul( $decimal, $sourceBase );
3254                         $decimal = bcadd( $decimal, $baseChars[$char] );
3255                 }
3256
3257                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3258                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3259                 }
3260
3261                 $result = strrev( $result );
3262         } else {
3263                 $inDigits = array();
3264                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3265                         $inDigits[] = $baseChars[$char];
3266                 }
3267
3268                 // Iterate over the input, modulo-ing out an output digit
3269                 // at a time until input is gone.
3270                 $result = '';
3271                 while ( $inDigits ) {
3272                         $work = 0;
3273                         $workDigits = array();
3274
3275                         // Long division...
3276                         foreach ( $inDigits as $digit ) {
3277                                 $work *= $sourceBase;
3278                                 $work += $digit;
3279
3280                                 if ( $workDigits || $work >= $destBase ) {
3281                                         $workDigits[] = (int)( $work / $destBase );
3282                                 }
3283                                 $work %= $destBase;
3284                         }
3285
3286                         // All that division leaves us with a remainder,
3287                         // which is conveniently our next output digit.
3288                         $result .= $baseChars[$work];
3289
3290                         // And we continue!
3291                         $inDigits = $workDigits;
3292                 }
3293
3294                 $result = strrev( $result );
3295         }
3296
3297         if ( !$lowercase ) {
3298                 $result = strtoupper( $result );
3299         }
3300
3301         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3302 }
3303
3304 /**
3305  * Create an object with a given name and an array of construct parameters
3306  *
3307  * @param $name String
3308  * @param array $p parameters
3309  * @return object
3310  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3311  */
3312 function wfCreateObject( $name, $p ) {
3313         wfDeprecated( __FUNCTION__, '1.18' );
3314         return MWFunction::newObj( $name, $p );
3315 }
3316
3317 /**
3318  * @return bool
3319  */
3320 function wfHttpOnlySafe() {
3321         global $wgHttpOnlyBlacklist;
3322
3323         if ( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3324                 foreach ( $wgHttpOnlyBlacklist as $regex ) {
3325                         if ( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3326                                 return false;
3327                         }
3328                 }
3329         }
3330
3331         return true;
3332 }
3333
3334 /**
3335  * Check if there is sufficient entropy in php's built-in session generation
3336  * @return bool true = there is sufficient entropy
3337  */
3338 function wfCheckEntropy() {
3339         return (
3340                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3341                         || ini_get( 'session.entropy_file' )
3342                 )
3343                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3344 }
3345
3346 /**
3347  * Override session_id before session startup if php's built-in
3348  * session generation code is not secure.
3349  */
3350 function wfFixSessionID() {
3351         // If the cookie or session id is already set we already have a session and should abort
3352         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3353                 return;
3354         }
3355
3356         // PHP's built-in session entropy is enabled if:
3357         // - entropy_file is set or you're on Windows with php 5.3.3+
3358         // - AND entropy_length is > 0
3359         // We treat it as disabled if it doesn't have an entropy length of at least 32
3360         $entropyEnabled = wfCheckEntropy();
3361
3362         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3363         if ( !$entropyEnabled ) {
3364                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3365                 session_id( MWCryptRand::generateHex( 32 ) );
3366         }
3367 }
3368
3369 /**
3370  * Reset the session_id
3371  * @since 1.22
3372  */
3373 function wfResetSessionID() {
3374         global $wgCookieSecure;
3375         $oldSessionId = session_id();
3376         $cookieParams = session_get_cookie_params();
3377         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3378                 session_regenerate_id( false );
3379         } else {
3380                 $tmp = $_SESSION;
3381                 session_destroy();
3382                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3383                 $_SESSION = $tmp;
3384         }
3385         $newSessionId = session_id();
3386         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3387 }
3388
3389
3390 /**
3391  * Initialise php session
3392  *
3393  * @param $sessionId Bool
3394  */
3395 function wfSetupSession( $sessionId = false ) {
3396         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3397                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3398         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3399                 ObjectCacheSessionHandler::install();
3400         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3401                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3402                 # hasn't already been set to the desired value (that causes errors)
3403                 ini_set( 'session.save_handler', $wgSessionHandler );
3404         }
3405         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3406         wfDebugLog( 'cookie',
3407                 'session_set_cookie_params: "' . implode( '", "',
3408                         array(
3409                                 0,
3410                                 $wgCookiePath,
3411                                 $wgCookieDomain,
3412                                 $wgCookieSecure,
3413                                 $httpOnlySafe ) ) . '"' );
3414         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3415         session_cache_limiter( 'private, must-revalidate' );
3416         if ( $sessionId ) {
3417                 session_id( $sessionId );
3418         } else {
3419                 wfFixSessionID();
3420         }
3421         wfSuppressWarnings();
3422         session_start();
3423         wfRestoreWarnings();
3424 }
3425
3426 /**
3427  * Get an object from the precompiled serialized directory
3428  *
3429  * @param $name String
3430  * @return Mixed: the variable on success, false on failure
3431  */
3432 function wfGetPrecompiledData( $name ) {
3433         global $IP;
3434
3435         $file = "$IP/serialized/$name";
3436         if ( file_exists( $file ) ) {
3437                 $blob = file_get_contents( $file );
3438                 if ( $blob ) {
3439                         return unserialize( $blob );
3440                 }
3441         }
3442         return false;
3443 }
3444
3445 /**
3446  * Get a cache key
3447  *
3448  * @param varargs
3449  * @return String
3450  */
3451 function wfMemcKey( /*... */ ) {
3452         global $wgCachePrefix;
3453         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3454         $args = func_get_args();
3455         $key = $prefix . ':' . implode( ':', $args );
3456         $key = str_replace( ' ', '_', $key );
3457         return $key;
3458 }
3459
3460 /**
3461  * Get a cache key for a foreign DB
3462  *
3463  * @param $db String
3464  * @param $prefix String
3465  * @param varargs String
3466  * @return String
3467  */
3468 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3469         $args = array_slice( func_get_args(), 2 );
3470         if ( $prefix ) {
3471                 $key = "$db-$prefix:" . implode( ':', $args );
3472         } else {
3473                 $key = $db . ':' . implode( ':', $args );
3474         }
3475         return str_replace( ' ', '_', $key );
3476 }
3477
3478 /**
3479  * Get an ASCII string identifying this wiki
3480  * This is used as a prefix in memcached keys
3481  *
3482  * @return String
3483  */
3484 function wfWikiID() {
3485         global $wgDBprefix, $wgDBname;
3486         if ( $wgDBprefix ) {
3487                 return "$wgDBname-$wgDBprefix";
3488         } else {
3489                 return $wgDBname;
3490         }
3491 }
3492
3493 /**
3494  * Split a wiki ID into DB name and table prefix
3495  *
3496  * @param $wiki String
3497  *
3498  * @return array
3499  */
3500 function wfSplitWikiID( $wiki ) {
3501         $bits = explode( '-', $wiki, 2 );
3502         if ( count( $bits ) < 2 ) {
3503                 $bits[] = '';
3504         }
3505         return $bits;
3506 }
3507
3508 /**
3509  * Get a Database object.
3510  *
3511  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3512  *            master (for write queries), DB_SLAVE for potentially lagged read
3513  *            queries, or an integer >= 0 for a particular server.
3514  *
3515  * @param $groups Mixed: query groups. An array of group names that this query
3516  *                belongs to. May contain a single string if the query is only
3517  *                in one group.
3518  *
3519  * @param string $wiki the wiki ID, or false for the current wiki
3520  *
3521  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3522  * will always return the same object, unless the underlying connection or load
3523  * balancer is manually destroyed.
3524  *
3525  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3526  * updater to ensure that a proper database is being updated.
3527  *
3528  * @return DatabaseBase
3529  */
3530 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3531         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3532 }
3533
3534 /**
3535  * Get a load balancer object.
3536  *
3537  * @param string $wiki wiki ID, or false for the current wiki
3538  * @return LoadBalancer
3539  */
3540 function wfGetLB( $wiki = false ) {
3541         return wfGetLBFactory()->getMainLB( $wiki );
3542 }
3543
3544 /**
3545  * Get the load balancer factory object
3546  *
3547  * @return LBFactory
3548  */
3549 function &wfGetLBFactory() {
3550         return LBFactory::singleton();
3551 }
3552
3553 /**
3554  * Find a file.
3555  * Shortcut for RepoGroup::singleton()->findFile()
3556  *
3557  * @param string $title or Title object
3558  * @param array $options Associative array of options:
3559  *     time:           requested time for an archived image, or false for the
3560  *                     current version. An image object will be returned which was
3561  *                     created at the specified time.
3562  *
3563  *     ignoreRedirect: If true, do not follow file redirects
3564  *
3565  *     private:        If true, return restricted (deleted) files if the current
3566  *                     user is allowed to view them. Otherwise, such files will not
3567  *                     be found.
3568  *
3569  *     bypassCache:    If true, do not use the process-local cache of File objects
3570  *
3571  * @return File, or false if the file does not exist
3572  */
3573 function wfFindFile( $title, $options = array() ) {
3574         return RepoGroup::singleton()->findFile( $title, $options );
3575 }
3576
3577 /**
3578  * Get an object referring to a locally registered file.
3579  * Returns a valid placeholder object if the file does not exist.
3580  *
3581  * @param $title Title|String
3582  * @return LocalFile|null A File, or null if passed an invalid Title
3583  */
3584 function wfLocalFile( $title ) {
3585         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3586 }
3587
3588 /**
3589  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3590  * @deprecated since 1.19
3591  */
3592 function wfStreamFile( $fname, $headers = array() ) {
3593         wfDeprecated( __FUNCTION__, '1.19' );
3594         StreamFile::stream( $fname, $headers );
3595 }
3596
3597 /**
3598  * Should low-performance queries be disabled?
3599  *
3600  * @return Boolean
3601  * @codeCoverageIgnore
3602  */
3603 function wfQueriesMustScale() {
3604         global $wgMiserMode;
3605         return $wgMiserMode
3606                 || ( SiteStats::pages() > 100000
3607                 && SiteStats::edits() > 1000000
3608                 && SiteStats::users() > 10000 );
3609 }
3610
3611 /**
3612  * Get the path to a specified script file, respecting file
3613  * extensions; this is a wrapper around $wgScriptExtension etc.
3614  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3615  *
3616  * @param string $script script filename, sans extension
3617  * @return String
3618  */
3619 function wfScript( $script = 'index' ) {
3620         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3621         if ( $script === 'index' ) {
3622                 return $wgScript;
3623         } elseif ( $script === 'load' ) {
3624                 return $wgLoadScript;
3625         } else {
3626                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3627         }
3628 }
3629
3630 /**
3631  * Get the script URL.
3632  *
3633  * @return string script URL
3634  */
3635 function wfGetScriptUrl() {
3636         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3637                 #
3638                 # as it was called, minus the query string.
3639                 #
3640                 # Some sites use Apache rewrite rules to handle subdomains,
3641                 # and have PHP set up in a weird way that causes PHP_SELF
3642                 # to contain the rewritten URL instead of the one that the
3643                 # outside world sees.
3644                 #
3645                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3646                 # provides containing the "before" URL.
3647                 return $_SERVER['SCRIPT_NAME'];
3648         } else {
3649                 return $_SERVER['URL'];
3650         }
3651 }
3652
3653 /**
3654  * Convenience function converts boolean values into "true"
3655  * or "false" (string) values
3656  *
3657  * @param $value Boolean
3658  * @return String
3659  */
3660 function wfBoolToStr( $value ) {
3661         return $value ? 'true' : 'false';
3662 }
3663
3664 /**
3665  * Get a platform-independent path to the null file, e.g. /dev/null
3666  *
3667  * @return string
3668  */
3669 function wfGetNull() {
3670         return wfIsWindows()
3671                 ? 'NUL'
3672                 : '/dev/null';
3673 }
3674
3675 /**
3676  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3677  * and waiting for it to go down, this waits for the slaves to catch up to the
3678  * master position. Use this when updating very large numbers of rows, as
3679  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3680  * a no-op if there are no slaves.
3681  *
3682  * @param $maxLag Integer (deprecated)
3683  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3684  * @param $cluster string cluster name accepted by LBFactory
3685  */
3686 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3687         $lb = ( $cluster !== false )
3688                 ? wfGetLBFactory()->getExternalLB( $cluster )
3689                 : wfGetLB( $wiki );
3690         // bug 27975 - Don't try to wait for slaves if there are none
3691         // Prevents permission error when getting master position
3692         if ( $lb->getServerCount() > 1 ) {
3693                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3694                 $pos = $dbw->getMasterPos();
3695                 // The DBMS may not support getMasterPos() or the whole
3696                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3697                 if ( $pos !== false ) {
3698                         $lb->waitForAll( $pos );
3699                 }
3700         }
3701 }
3702
3703 /**
3704  * Used to be used for outputting text in the installer/updater
3705  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3706  */
3707 function wfOut( $s ) {
3708         wfDeprecated( __FUNCTION__, '1.18' );
3709         global $wgCommandLineMode;
3710         if ( $wgCommandLineMode ) {
3711                 echo $s;
3712         } else {
3713                 echo htmlspecialchars( $s );
3714         }
3715         flush();
3716 }
3717
3718 /**
3719  * Count down from $n to zero on the terminal, with a one-second pause
3720  * between showing each number. For use in command-line scripts.
3721  * @codeCoverageIgnore
3722  * @param $n int
3723  */
3724 function wfCountDown( $n ) {
3725         for ( $i = $n; $i >= 0; $i-- ) {
3726                 if ( $i != $n ) {
3727                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3728                 }
3729                 echo $i;
3730                 flush();
3731                 if ( $i ) {
3732                         sleep( 1 );
3733                 }
3734         }
3735         echo "\n";
3736 }
3737
3738 /**
3739  * Generate a random 32-character hexadecimal token.
3740  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3741  *              characters before hashing.
3742  * @return string
3743  * @codeCoverageIgnore
3744  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pseudo-random strings
3745  * @warning This method is NOT secure. Additionally it has many callers that use it for pseudo-random purposes.
3746  */
3747 function wfGenerateToken( $salt = '' ) {
3748         wfDeprecated( __METHOD__, '1.20' );
3749         $salt = serialize( $salt );
3750         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3751 }
3752
3753 /**
3754  * Replace all invalid characters with -
3755  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3756  * By default, $wgIllegalFileChars = ':'
3757  *
3758  * @param $name Mixed: filename to process
3759  * @return String
3760  */
3761 function wfStripIllegalFilenameChars( $name ) {
3762         global $wgIllegalFileChars;
3763         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3764         $name = wfBaseName( $name );
3765         $name = preg_replace(
3766                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3767                 '-',
3768                 $name
3769         );
3770         return $name;
3771 }
3772
3773 /**
3774  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3775  *
3776  * @return Integer value memory was set to.
3777  */
3778 function wfMemoryLimit() {
3779         global $wgMemoryLimit;
3780         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3781         if ( $memlimit != -1 ) {
3782                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3783                 if ( $conflimit == -1 ) {
3784                         wfDebug( "Removing PHP's memory limit\n" );
3785                         wfSuppressWarnings();
3786                         ini_set( 'memory_limit', $conflimit );
3787                         wfRestoreWarnings();
3788                         return $conflimit;
3789                 } elseif ( $conflimit > $memlimit ) {
3790                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3791                         wfSuppressWarnings();
3792                         ini_set( 'memory_limit', $conflimit );
3793                         wfRestoreWarnings();
3794                         return $conflimit;
3795                 }
3796         }
3797         return $memlimit;
3798 }
3799
3800 /**
3801  * Converts shorthand byte notation to integer form
3802  *
3803  * @param $string String
3804  * @return Integer
3805  */
3806 function wfShorthandToInteger( $string = '' ) {
3807         $string = trim( $string );
3808         if ( $string === '' ) {
3809                 return -1;
3810         }
3811         $last = $string[strlen( $string ) - 1];
3812         $val = intval( $string );
3813         switch ( $last ) {
3814                 case 'g':
3815                 case 'G':
3816                         $val *= 1024;
3817                         // break intentionally missing
3818                 case 'm':
3819                 case 'M':
3820                         $val *= 1024;
3821                         // break intentionally missing
3822                 case 'k':
3823                 case 'K':
3824                         $val *= 1024;
3825         }
3826
3827         return $val;
3828 }
3829
3830 /**
3831  * Get the normalised IETF language tag
3832  * See unit test for examples.
3833  *
3834  * @param string $code The language code.
3835  * @return String: The language code which complying with BCP 47 standards.
3836  */
3837 function wfBCP47( $code ) {
3838         $codeSegment = explode( '-', $code );
3839         $codeBCP = array();
3840         foreach ( $codeSegment as $segNo => $seg ) {
3841                 // when previous segment is x, it is a private segment and should be lc
3842                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3843                         $codeBCP[$segNo] = strtolower( $seg );
3844                 // ISO 3166 country code
3845                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3846                         $codeBCP[$segNo] = strtoupper( $seg );
3847                 // ISO 15924 script code
3848                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3849                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3850                 // Use lowercase for other cases
3851                 } else {
3852                         $codeBCP[$segNo] = strtolower( $seg );
3853                 }
3854         }
3855         $langCode = implode( '-', $codeBCP );
3856         return $langCode;
3857 }
3858
3859 /**
3860  * Get a cache object.
3861  *
3862  * @param $inputType integer Cache type, one the the CACHE_* constants.
3863  * @return BagOStuff
3864  */
3865 function wfGetCache( $inputType ) {
3866         return ObjectCache::getInstance( $inputType );
3867 }
3868
3869 /**
3870  * Get the main cache object
3871  *
3872  * @return BagOStuff
3873  */
3874 function wfGetMainCache() {
3875         global $wgMainCacheType;
3876         return ObjectCache::getInstance( $wgMainCacheType );
3877 }
3878
3879 /**
3880  * Get the cache object used by the message cache
3881  *
3882  * @return BagOStuff
3883  */
3884 function wfGetMessageCacheStorage() {
3885         global $wgMessageCacheType;
3886         return ObjectCache::getInstance( $wgMessageCacheType );
3887 }
3888
3889 /**
3890  * Get the cache object used by the parser cache
3891  *
3892  * @return BagOStuff
3893  */
3894 function wfGetParserCacheStorage() {
3895         global $wgParserCacheType;
3896         return ObjectCache::getInstance( $wgParserCacheType );
3897 }
3898
3899 /**
3900  * Get the cache object used by the language converter
3901  *
3902  * @return BagOStuff
3903  */
3904 function wfGetLangConverterCacheStorage() {
3905         global $wgLanguageConverterCacheType;
3906         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3907 }
3908
3909 /**
3910  * Call hook functions defined in $wgHooks
3911  *
3912  * @param string $event event name
3913  * @param array $args parameters passed to hook functions
3914  * @return Boolean True if no handler aborted the hook
3915  */
3916 function wfRunHooks( $event, array $args = array() ) {
3917         return Hooks::run( $event, $args );
3918 }
3919
3920 /**
3921  * Wrapper around php's unpack.
3922  *
3923  * @param string $format The format string (See php's docs)
3924  * @param $data: A binary string of binary data
3925  * @param $length integer or false: The minimum length of $data. This is to
3926  *      prevent reading beyond the end of $data. false to disable the check.
3927  *
3928  * Also be careful when using this function to read unsigned 32 bit integer
3929  * because php might make it negative.
3930  *
3931  * @throws MWException if $data not long enough, or if unpack fails
3932  * @return array Associative array of the extracted data
3933  */
3934 function wfUnpack( $format, $data, $length = false ) {
3935         if ( $length !== false ) {
3936                 $realLen = strlen( $data );
3937                 if ( $realLen < $length ) {
3938                         throw new MWException( "Tried to use wfUnpack on a "
3939                                 . "string of length $realLen, but needed one "
3940                                 . "of at least length $length."
3941                         );
3942                 }
3943         }
3944
3945         wfSuppressWarnings();
3946         $result = unpack( $format, $data );
3947         wfRestoreWarnings();
3948
3949         if ( $result === false ) {
3950                 // If it cannot extract the packed data.
3951                 throw new MWException( "unpack could not unpack binary data" );
3952         }
3953         return $result;
3954 }
3955
3956 /**
3957  * Determine if an image exists on the 'bad image list'.
3958  *
3959  * The format of MediaWiki:Bad_image_list is as follows:
3960  *    * Only list items (lines starting with "*") are considered
3961  *    * The first link on a line must be a link to a bad image
3962  *    * Any subsequent links on the same line are considered to be exceptions,
3963  *      i.e. articles where the image may occur inline.
3964  *
3965  * @param string $name the image name to check
3966  * @param $contextTitle Title|bool the page on which the image occurs, if known
3967  * @param string $blacklist wikitext of a file blacklist
3968  * @return bool
3969  */
3970 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3971         static $badImageCache = null; // based on bad_image_list msg
3972         wfProfileIn( __METHOD__ );
3973
3974         # Handle redirects
3975         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3976         if ( $redirectTitle ) {
3977                 $name = $redirectTitle->getDBkey();
3978         }
3979
3980         # Run the extension hook
3981         $bad = false;
3982         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3983                 wfProfileOut( __METHOD__ );
3984                 return $bad;
3985         }
3986
3987         $cacheable = ( $blacklist === null );
3988         if ( $cacheable && $badImageCache !== null ) {
3989                 $badImages = $badImageCache;
3990         } else { // cache miss
3991                 if ( $blacklist === null ) {
3992                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3993                 }
3994                 # Build the list now
3995                 $badImages = array();
3996                 $lines = explode( "\n", $blacklist );
3997                 foreach ( $lines as $line ) {
3998                         # List items only
3999                         if ( substr( $line, 0, 1 ) !== '*' ) {
4000                                 continue;
4001                         }
4002
4003                         # Find all links
4004                         $m = array();
4005                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4006                                 continue;
4007                         }
4008
4009                         $exceptions = array();
4010                         $imageDBkey = false;
4011                         foreach ( $m[1] as $i => $titleText ) {
4012                                 $title = Title::newFromText( $titleText );
4013                                 if ( !is_null( $title ) ) {
4014                                         if ( $i == 0 ) {
4015                                                 $imageDBkey = $title->getDBkey();
4016                                         } else {
4017                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4018                                         }
4019                                 }
4020                         }
4021
4022                         if ( $imageDBkey !== false ) {
4023                                 $badImages[$imageDBkey] = $exceptions;
4024                         }
4025                 }
4026                 if ( $cacheable ) {
4027                         $badImageCache = $badImages;
4028                 }
4029         }
4030
4031         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4032         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4033         wfProfileOut( __METHOD__ );
4034         return $bad;
4035 }
4036
4037 /**
4038  * Determine whether the client at a given source IP is likely to be able to
4039  * access the wiki via HTTPS.
4040  *
4041  * @param string $ip The IPv4/6 address in the normal human-readable form
4042  * @return boolean
4043  */
4044 function wfCanIPUseHTTPS( $ip ) {
4045         $canDo = true;
4046         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4047         return !!$canDo;
4048 }