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
 122  * @param $b
 123  * @return int
 124  */
 125 function wfArrayDiff2_cmp( $a, $b ) {
 126         if ( !is_array( $a ) ) {
 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  * @param string $msg message shown when dying.
1707  * @throws MWException
1708  */
1709 function wfDebugDieBacktrace( $msg = '' ) {
1710         throw new MWException( $msg );
1711 }
1712
1713 /**
1714  * Fetch server name for use in error reporting etc.
1715  * Use real server name if available, so we know which machine
1716  * in a server farm generated the current page.
1717  *
1718  * @return string
1719  */
1720 function wfHostname() {
1721         static $host;
1722         if ( is_null( $host ) ) {
1723
1724                 # Hostname overriding
1725                 global $wgOverrideHostname;
1726                 if ( $wgOverrideHostname !== false ) {
1727                         # Set static and skip any detection
1728                         $host = $wgOverrideHostname;
1729                         return $host;
1730                 }
1731
1732                 if ( function_exists( 'posix_uname' ) ) {
1733                         // This function not present on Windows
1734                         $uname = posix_uname();
1735                 } else {
1736                         $uname = false;
1737                 }
1738                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1739                         $host = $uname['nodename'];
1740                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1741                         # Windows computer name
1742                         $host = getenv( 'COMPUTERNAME' );
1743                 } else {
1744                         # This may be a virtual server.
1745                         $host = $_SERVER['SERVER_NAME'];
1746                 }
1747         }
1748         return $host;
1749 }
1750
1751 /**
1752  * Returns a HTML comment with the elapsed time since request.
1753  * This method has no side effects.
1754  *
1755  * @return string
1756  */
1757 function wfReportTime() {
1758         global $wgRequestTime, $wgShowHostnames;
1759
1760         $elapsed = microtime( true ) - $wgRequestTime;
1761
1762         return $wgShowHostnames
1763                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1764                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1765 }
1766
1767 /**
1768  * Safety wrapper for debug_backtrace().
1769  *
1770  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1771  * murky circumstances, which may be triggered in part by stub objects
1772  * or other fancy talking'.
1773  *
1774  * Will return an empty array if Zend Optimizer is detected or if
1775  * debug_backtrace is disabled, otherwise the output from
1776  * debug_backtrace() (trimmed).
1777  *
1778  * @param int $limit This parameter can be used to limit the number of stack frames returned
1779  *
1780  * @return array of backtrace information
1781  */
1782 function wfDebugBacktrace( $limit = 0 ) {
1783         static $disabled = null;
1784
1785         if ( extension_loaded( 'Zend Optimizer' ) ) {
1786                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1787                 return array();
1788         }
1789
1790         if ( is_null( $disabled ) ) {
1791                 $disabled = false;
1792                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1793                 $functions = array_map( 'trim', $functions );
1794                 $functions = array_map( 'strtolower', $functions );
1795                 if ( in_array( 'debug_backtrace', $functions ) ) {
1796                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1797                         $disabled = true;
1798                 }
1799         }
1800         if ( $disabled ) {
1801                 return array();
1802         }
1803
1804         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1805                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1806         } else {
1807                 return array_slice( debug_backtrace(), 1 );
1808         }
1809 }
1810
1811 /**
1812  * Get a debug backtrace as a string
1813  *
1814  * @return string
1815  */
1816 function wfBacktrace() {
1817         global $wgCommandLineMode;
1818
1819         if ( $wgCommandLineMode ) {
1820                 $msg = '';
1821         } else {
1822                 $msg = "<ul>\n";
1823         }
1824         $backtrace = wfDebugBacktrace();
1825         foreach ( $backtrace as $call ) {
1826                 if ( isset( $call['file'] ) ) {
1827                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1828                         $file = $f[count( $f ) - 1];
1829                 } else {
1830                         $file = '-';
1831                 }
1832                 if ( isset( $call['line'] ) ) {
1833                         $line = $call['line'];
1834                 } else {
1835                         $line = '-';
1836                 }
1837                 if ( $wgCommandLineMode ) {
1838                         $msg .= "$file line $line calls ";
1839                 } else {
1840                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1841                 }
1842                 if ( !empty( $call['class'] ) ) {
1843                         $msg .= $call['class'] . $call['type'];
1844                 }
1845                 $msg .= $call['function'] . '()';
1846
1847                 if ( $wgCommandLineMode ) {
1848                         $msg .= "\n";
1849                 } else {
1850                         $msg .= "</li>\n";
1851                 }
1852         }
1853         if ( $wgCommandLineMode ) {
1854                 $msg .= "\n";
1855         } else {
1856                 $msg .= "</ul>\n";
1857         }
1858
1859         return $msg;
1860 }
1861
1862 /**
1863  * Get the name of the function which called this function
1864  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1865  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1866  * wfGetCaller( 3 ) is the parent of that.
1867  *
1868  * @param $level Int
1869  * @return string
1870  */
1871 function wfGetCaller( $level = 2 ) {
1872         $backtrace = wfDebugBacktrace( $level + 1 );
1873         if ( isset( $backtrace[$level] ) ) {
1874                 return wfFormatStackFrame( $backtrace[$level] );
1875         } else {
1876                 return 'unknown';
1877         }
1878 }
1879
1880 /**
1881  * Return a string consisting of callers in the stack. Useful sometimes
1882  * for profiling specific points.
1883  *
1884  * @param int $limit The maximum depth of the stack frame to return, or false for
1885  *               the entire stack.
1886  * @return String
1887  */
1888 function wfGetAllCallers( $limit = 3 ) {
1889         $trace = array_reverse( wfDebugBacktrace() );
1890         if ( !$limit || $limit > count( $trace ) - 1 ) {
1891                 $limit = count( $trace ) - 1;
1892         }
1893         $trace = array_slice( $trace, -$limit - 1, $limit );
1894         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1895 }
1896
1897 /**
1898  * Return a string representation of frame
1899  *
1900  * @param $frame Array
1901  * @return string
1902  */
1903 function wfFormatStackFrame( $frame ) {
1904         return isset( $frame['class'] ) ?
1905                 $frame['class'] . '::' . $frame['function'] :
1906                 $frame['function'];
1907 }
1908
1909 /* Some generic result counters, pulled out of SearchEngine */
1910
1911 /**
1912  * @todo document
1913  *
1914  * @param $offset Int
1915  * @param $limit Int
1916  * @return String
1917  */
1918 function wfShowingResults( $offset, $limit ) {
1919         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1920 }
1921
1922 /**
1923  * Generate (prev x| next x) (20|50|100...) type links for paging
1924  *
1925  * @param $offset String
1926  * @param $limit Integer
1927  * @param $link String
1928  * @param string $query optional URL query parameter string
1929  * @param bool $atend optional param for specified if this is the last page
1930  * @return String
1931  * @deprecated in 1.19; use Language::viewPrevNext() instead
1932  */
1933 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1934         wfDeprecated( __METHOD__, '1.19' );
1935
1936         global $wgLang;
1937
1938         $query = wfCgiToArray( $query );
1939
1940         if ( is_object( $link ) ) {
1941                 $title = $link;
1942         } else {
1943                 $title = Title::newFromText( $link );
1944                 if ( is_null( $title ) ) {
1945                         return false;
1946                 }
1947         }
1948
1949         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1950 }
1951
1952 /**
1953  * Make a list item, used by various special pages
1954  *
1955  * @param string $page Page link
1956  * @param string $details Text between brackets
1957  * @param $oppositedm Boolean   Add the direction mark opposite to your
1958  *                                                              language, to display text properly
1959  * @return String
1960  * @deprecated since 1.19; use Language::specialList() instead
1961  */
1962 function wfSpecialList( $page, $details, $oppositedm = true ) {
1963         wfDeprecated( __METHOD__, '1.19' );
1964
1965         global $wgLang;
1966         return $wgLang->specialList( $page, $details, $oppositedm );
1967 }
1968
1969 /**
1970  * @todo document
1971  * @todo FIXME: We may want to blacklist some broken browsers
1972  *
1973  * @param $force Bool
1974  * @return bool Whereas client accept gzip compression
1975  */
1976 function wfClientAcceptsGzip( $force = false ) {
1977         static $result = null;
1978         if ( $result === null || $force ) {
1979                 $result = false;
1980                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1981                         # @todo FIXME: We may want to blacklist some broken browsers
1982                         $m = array();
1983                         if ( preg_match(
1984                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1985                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1986                                 $m )
1987                         )
1988                         {
1989                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1990                                         $result = false;
1991                                         return $result;
1992                                 }
1993                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1994                                 $result = true;
1995                         }
1996                 }
1997         }
1998         return $result;
1999 }
2000
2001 /**
2002  * Obtain the offset and limit values from the request string;
2003  * used in special pages
2004  *
2005  * @param int $deflimit default limit if none supplied
2006  * @param string $optionname Name of a user preference to check against
2007  * @return array
2008  *
2009  */
2010 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2011         global $wgRequest;
2012         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2013 }
2014
2015 /**
2016  * Escapes the given text so that it may be output using addWikiText()
2017  * without any linking, formatting, etc. making its way through. This
2018  * is achieved by substituting certain characters with HTML entities.
2019  * As required by the callers, "<nowiki>" is not used.
2020  *
2021  * @param string $text text to be escaped
2022  * @return String
2023  */
2024 function wfEscapeWikiText( $text ) {
2025         static $repl = null, $repl2 = null;
2026         if ( $repl === null ) {
2027                 $repl = array(
2028                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2029                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2030                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2031                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2032                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2033                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2034                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2035                         '__' => '_&#95;', '://' => '&#58;//',
2036                 );
2037
2038                 // We have to catch everything "\s" matches in PCRE
2039                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2040                         $repl["$magic "] = "$magic&#32;";
2041                         $repl["$magic\t"] = "$magic&#9;";
2042                         $repl["$magic\r"] = "$magic&#13;";
2043                         $repl["$magic\n"] = "$magic&#10;";
2044                         $repl["$magic\f"] = "$magic&#12;";
2045                 }
2046
2047                 // And handle protocols that don't use "://"
2048                 global $wgUrlProtocols;
2049                 $repl2 = array();
2050                 foreach ( $wgUrlProtocols as $prot ) {
2051                         if ( substr( $prot, -1 ) === ':' ) {
2052                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2053                         }
2054                 }
2055                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2056         }
2057         $text = substr( strtr( "\n$text", $repl ), 1 );
2058         $text = preg_replace( $repl2, '$1&#58;', $text );
2059         return $text;
2060 }
2061
2062 /**
2063  * Get the current unix timestamp with microseconds.  Useful for profiling
2064  * @deprecated since 1.22; call microtime() directly
2065  * @return Float
2066  */
2067 function wfTime() {
2068         wfDeprecated( __FUNCTION__, '1.22' );
2069         return microtime( true );
2070 }
2071
2072 /**
2073  * Sets dest to source and returns the original value of dest
2074  * If source is NULL, it just returns the value, it doesn't set the variable
2075  * If force is true, it will set the value even if source is NULL
2076  *
2077  * @param $dest Mixed
2078  * @param $source Mixed
2079  * @param $force Bool
2080  * @return Mixed
2081  */
2082 function wfSetVar( &$dest, $source, $force = false ) {
2083         $temp = $dest;
2084         if ( !is_null( $source ) || $force ) {
2085                 $dest = $source;
2086         }
2087         return $temp;
2088 }
2089
2090 /**
2091  * As for wfSetVar except setting a bit
2092  *
2093  * @param $dest Int
2094  * @param $bit Int
2095  * @param $state Bool
2096  *
2097  * @return bool
2098  */
2099 function wfSetBit( &$dest, $bit, $state = true ) {
2100         $temp = (bool)( $dest & $bit );
2101         if ( !is_null( $state ) ) {
2102                 if ( $state ) {
2103                         $dest |= $bit;
2104                 } else {
2105                         $dest &= ~$bit;
2106                 }
2107         }
2108         return $temp;
2109 }
2110
2111 /**
2112  * A wrapper around the PHP function var_export().
2113  * Either print it or add it to the regular output ($wgOut).
2114  *
2115  * @param $var mixed A PHP variable to dump.
2116  */
2117 function wfVarDump( $var ) {
2118         global $wgOut;
2119         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2120         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2121                 print $s;
2122         } else {
2123                 $wgOut->addHTML( $s );
2124         }
2125 }
2126
2127 /**
2128  * Provide a simple HTTP error.
2129  *
2130  * @param $code Int|String
2131  * @param $label String
2132  * @param $desc String
2133  */
2134 function wfHttpError( $code, $label, $desc ) {
2135         global $wgOut;
2136         $wgOut->disable();
2137         header( "HTTP/1.0 $code $label" );
2138         header( "Status: $code $label" );
2139         $wgOut->sendCacheControl();
2140
2141         header( 'Content-type: text/html; charset=utf-8' );
2142         print "<!doctype html>" .
2143                 '<html><head><title>' .
2144                 htmlspecialchars( $label ) .
2145                 '</title></head><body><h1>' .
2146                 htmlspecialchars( $label ) .
2147                 '</h1><p>' .
2148                 nl2br( htmlspecialchars( $desc ) ) .
2149                 "</p></body></html>\n";
2150 }
2151
2152 /**
2153  * Clear away any user-level output buffers, discarding contents.
2154  *
2155  * Suitable for 'starting afresh', for instance when streaming
2156  * relatively large amounts of data without buffering, or wanting to
2157  * output image files without ob_gzhandler's compression.
2158  *
2159  * The optional $resetGzipEncoding parameter controls suppression of
2160  * the Content-Encoding header sent by ob_gzhandler; by default it
2161  * is left. See comments for wfClearOutputBuffers() for why it would
2162  * be used.
2163  *
2164  * Note that some PHP configuration options may add output buffer
2165  * layers which cannot be removed; these are left in place.
2166  *
2167  * @param $resetGzipEncoding Bool
2168  */
2169 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2170         if ( $resetGzipEncoding ) {
2171                 // Suppress Content-Encoding and Content-Length
2172                 // headers from 1.10+s wfOutputHandler
2173                 global $wgDisableOutputCompression;
2174                 $wgDisableOutputCompression = true;
2175         }
2176         while ( $status = ob_get_status() ) {
2177                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2178                         // Probably from zlib.output_compression or other
2179                         // PHP-internal setting which can't be removed.
2180                         //
2181                         // Give up, and hope the result doesn't break
2182                         // output behavior.
2183                         break;
2184                 }
2185                 if ( !ob_end_clean() ) {
2186                         // Could not remove output buffer handler; abort now
2187                         // to avoid getting in some kind of infinite loop.
2188                         break;
2189                 }
2190                 if ( $resetGzipEncoding ) {
2191                         if ( $status['name'] == 'ob_gzhandler' ) {
2192                                 // Reset the 'Content-Encoding' field set by this handler
2193                                 // so we can start fresh.
2194                                 header_remove( 'Content-Encoding' );
2195                                 break;
2196                         }
2197                 }
2198         }
2199 }
2200
2201 /**
2202  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2203  *
2204  * Clear away output buffers, but keep the Content-Encoding header
2205  * produced by ob_gzhandler, if any.
2206  *
2207  * This should be used for HTTP 304 responses, where you need to
2208  * preserve the Content-Encoding header of the real result, but
2209  * also need to suppress the output of ob_gzhandler to keep to spec
2210  * and avoid breaking Firefox in rare cases where the headers and
2211  * body are broken over two packets.
2212  */
2213 function wfClearOutputBuffers() {
2214         wfResetOutputBuffers( false );
2215 }
2216
2217 /**
2218  * Converts an Accept-* header into an array mapping string values to quality
2219  * factors
2220  *
2221  * @param $accept String
2222  * @param string $def default
2223  * @return Array
2224  */
2225 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2226         # No arg means accept anything (per HTTP spec)
2227         if ( !$accept ) {
2228                 return array( $def => 1.0 );
2229         }
2230
2231         $prefs = array();
2232
2233         $parts = explode( ',', $accept );
2234
2235         foreach ( $parts as $part ) {
2236                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2237                 $values = explode( ';', trim( $part ) );
2238                 $match = array();
2239                 if ( count( $values ) == 1 ) {
2240                         $prefs[$values[0]] = 1.0;
2241                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2242                         $prefs[$values[0]] = floatval( $match[1] );
2243                 }
2244         }
2245
2246         return $prefs;
2247 }
2248
2249 /**
2250  * Checks if a given MIME type matches any of the keys in the given
2251  * array. Basic wildcards are accepted in the array keys.
2252  *
2253  * Returns the matching MIME type (or wildcard) if a match, otherwise
2254  * NULL if no match.
2255  *
2256  * @param $type String
2257  * @param $avail Array
2258  * @return string
2259  * @private
2260  */
2261 function mimeTypeMatch( $type, $avail ) {
2262         if ( array_key_exists( $type, $avail ) ) {
2263                 return $type;
2264         } else {
2265                 $parts = explode( '/', $type );
2266                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2267                         return $parts[0] . '/*';
2268                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2269                         return '*/*';
2270                 } else {
2271                         return null;
2272                 }
2273         }
2274 }
2275
2276 /**
2277  * Returns the 'best' match between a client's requested internet media types
2278  * and the server's list of available types. Each list should be an associative
2279  * array of type to preference (preference is a float between 0.0 and 1.0).
2280  * Wildcards in the types are acceptable.
2281  *
2282  * @param array $cprefs client's acceptable type list
2283  * @param array $sprefs server's offered types
2284  * @return string
2285  *
2286  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2287  * XXX: generalize to negotiate other stuff
2288  */
2289 function wfNegotiateType( $cprefs, $sprefs ) {
2290         $combine = array();
2291
2292         foreach ( array_keys( $sprefs ) as $type ) {
2293                 $parts = explode( '/', $type );
2294                 if ( $parts[1] != '*' ) {
2295                         $ckey = mimeTypeMatch( $type, $cprefs );
2296                         if ( $ckey ) {
2297                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2298                         }
2299                 }
2300         }
2301
2302         foreach ( array_keys( $cprefs ) as $type ) {
2303                 $parts = explode( '/', $type );
2304                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2305                         $skey = mimeTypeMatch( $type, $sprefs );
2306                         if ( $skey ) {
2307                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2308                         }
2309                 }
2310         }
2311
2312         $bestq = 0;
2313         $besttype = null;
2314
2315         foreach ( array_keys( $combine ) as $type ) {
2316                 if ( $combine[$type] > $bestq ) {
2317                         $besttype = $type;
2318                         $bestq = $combine[$type];
2319                 }
2320         }
2321
2322         return $besttype;
2323 }
2324
2325 /**
2326  * Reference-counted warning suppression
2327  *
2328  * @param $end Bool
2329  */
2330 function wfSuppressWarnings( $end = false ) {
2331         static $suppressCount = 0;
2332         static $originalLevel = false;
2333
2334         if ( $end ) {
2335                 if ( $suppressCount ) {
2336                         --$suppressCount;
2337                         if ( !$suppressCount ) {
2338                                 error_reporting( $originalLevel );
2339                         }
2340                 }
2341         } else {
2342                 if ( !$suppressCount ) {
2343                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT ) );
2344                 }
2345                 ++$suppressCount;
2346         }
2347 }
2348
2349 /**
2350  * Restore error level to previous value
2351  */
2352 function wfRestoreWarnings() {
2353         wfSuppressWarnings( true );
2354 }
2355
2356 # Autodetect, convert and provide timestamps of various types
2357
2358 /**
2359  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2360  */
2361 define( 'TS_UNIX', 0 );
2362
2363 /**
2364  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2365  */
2366 define( 'TS_MW', 1 );
2367
2368 /**
2369  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2370  */
2371 define( 'TS_DB', 2 );
2372
2373 /**
2374  * RFC 2822 format, for E-mail and HTTP headers
2375  */
2376 define( 'TS_RFC2822', 3 );
2377
2378 /**
2379  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2380  *
2381  * This is used by Special:Export
2382  */
2383 define( 'TS_ISO_8601', 4 );
2384
2385 /**
2386  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2387  *
2388  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2389  *       DateTime tag and page 36 for the DateTimeOriginal and
2390  *       DateTimeDigitized tags.
2391  */
2392 define( 'TS_EXIF', 5 );
2393
2394 /**
2395  * Oracle format time.
2396  */
2397 define( 'TS_ORACLE', 6 );
2398
2399 /**
2400  * Postgres format time.
2401  */
2402 define( 'TS_POSTGRES', 7 );
2403
2404 /**
2405  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2406  */
2407 define( 'TS_ISO_8601_BASIC', 9 );
2408
2409 /**
2410  * Get a timestamp string in one of various formats
2411  *
2412  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2413  *                    function will autodetect which format is supplied and act
2414  *                    accordingly.
2415  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2416  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2417  */
2418 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2419         try {
2420                 $timestamp = new MWTimestamp( $ts );
2421                 return $timestamp->getTimestamp( $outputtype );
2422         } catch ( TimestampException $e ) {
2423                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2424                 return false;
2425         }
2426 }
2427
2428 /**
2429  * Return a formatted timestamp, or null if input is null.
2430  * For dealing with nullable timestamp columns in the database.
2431  *
2432  * @param $outputtype Integer
2433  * @param $ts String
2434  * @return String
2435  */
2436 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2437         if ( is_null( $ts ) ) {
2438                 return null;
2439         } else {
2440                 return wfTimestamp( $outputtype, $ts );
2441         }
2442 }
2443
2444 /**
2445  * Convenience function; returns MediaWiki timestamp for the present time.
2446  *
2447  * @return string
2448  */
2449 function wfTimestampNow() {
2450         # return NOW
2451         return wfTimestamp( TS_MW, time() );
2452 }
2453
2454 /**
2455  * Check if the operating system is Windows
2456  *
2457  * @return Bool: true if it's Windows, False otherwise.
2458  */
2459 function wfIsWindows() {
2460         static $isWindows = null;
2461         if ( $isWindows === null ) {
2462                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2463         }
2464         return $isWindows;
2465 }
2466
2467 /**
2468  * Check if we are running under HipHop
2469  *
2470  * @return Bool
2471  */
2472 function wfIsHipHop() {
2473         return function_exists( 'hphp_thread_set_warmup_enabled' );
2474 }
2475
2476 /**
2477  * Swap two variables
2478  *
2479  * @param $x Mixed
2480  * @param $y Mixed
2481  */
2482 function swap( &$x, &$y ) {
2483         $z = $x;
2484         $x = $y;
2485         $y = $z;
2486 }
2487
2488 /**
2489  * Tries to get the system directory for temporary files. First
2490  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2491  * environment variables are then checked in sequence, and if none are
2492  * set try sys_get_temp_dir().
2493  *
2494  * NOTE: When possible, use instead the tmpfile() function to create
2495  * temporary files to avoid race conditions on file creation, etc.
2496  *
2497  * @return String
2498  */
2499 function wfTempDir() {
2500         global $wgTmpDirectory;
2501
2502         if ( $wgTmpDirectory !== false ) {
2503                 return $wgTmpDirectory;
2504         }
2505
2506         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2507
2508         foreach ( $tmpDir as $tmp ) {
2509                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2510                         return $tmp;
2511                 }
2512         }
2513         return sys_get_temp_dir();
2514 }
2515
2516 /**
2517  * Make directory, and make all parent directories if they don't exist
2518  *
2519  * @param string $dir full path to directory to create
2520  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2521  * @param string $caller optional caller param for debugging.
2522  * @throws MWException
2523  * @return bool
2524  */
2525 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2526         global $wgDirectoryMode;
2527
2528         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2529                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2530         }
2531
2532         if ( !is_null( $caller ) ) {
2533                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2534         }
2535
2536         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2537                 return true;
2538         }
2539
2540         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2541
2542         if ( is_null( $mode ) ) {
2543                 $mode = $wgDirectoryMode;
2544         }
2545
2546         // Turn off the normal warning, we're doing our own below
2547         wfSuppressWarnings();
2548         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2549         wfRestoreWarnings();
2550
2551         if ( !$ok ) {
2552                 //directory may have been created on another request since we last checked
2553                 if ( is_dir( $dir ) ) {
2554                         return true;
2555                 }
2556
2557                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2558                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2559         }
2560         return $ok;
2561 }
2562
2563 /**
2564  * Remove a directory and all its content.
2565  * Does not hide error.
2566  */
2567 function wfRecursiveRemoveDir( $dir ) {
2568         wfDebug( __FUNCTION__ . "( $dir )\n" );
2569         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2570         if ( is_dir( $dir ) ) {
2571                 $objects = scandir( $dir );
2572                 foreach ( $objects as $object ) {
2573                         if ( $object != "." && $object != ".." ) {
2574                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2575                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2576                                 } else {
2577                                         unlink( $dir . '/' . $object );
2578                                 }
2579                         }
2580                 }
2581                 reset( $objects );
2582                 rmdir( $dir );
2583         }
2584 }
2585
2586 /**
2587  * @param $nr Mixed: the number to format
2588  * @param $acc Integer: the number of digits after the decimal point, default 2
2589  * @param $round Boolean: whether or not to round the value, default true
2590  * @return float
2591  */
2592 function wfPercent( $nr, $acc = 2, $round = true ) {
2593         $ret = sprintf( "%.${acc}f", $nr );
2594         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2595 }
2596
2597 /**
2598  * Find out whether or not a mixed variable exists in a string
2599  *
2600  * @deprecated Just use str(i)pos
2601  * @param $needle String
2602  * @param $str String
2603  * @param $insensitive Boolean
2604  * @return Boolean
2605  */
2606 function in_string( $needle, $str, $insensitive = false ) {
2607         wfDeprecated( __METHOD__, '1.21' );
2608         $func = 'strpos';
2609         if ( $insensitive ) {
2610                 $func = 'stripos';
2611         }
2612
2613         return $func( $str, $needle ) !== false;
2614 }
2615
2616 /**
2617  * Safety wrapper around ini_get() for boolean settings.
2618  * The values returned from ini_get() are pre-normalized for settings
2619  * set via php.ini or php_flag/php_admin_flag... but *not*
2620  * for those set via php_value/php_admin_value.
2621  *
2622  * It's fairly common for people to use php_value instead of php_flag,
2623  * which can leave you with an 'off' setting giving a false positive
2624  * for code that just takes the ini_get() return value as a boolean.
2625  *
2626  * To make things extra interesting, setting via php_value accepts
2627  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2628  * Unrecognized values go false... again opposite PHP's own coercion
2629  * from string to bool.
2630  *
2631  * Luckily, 'properly' set settings will always come back as '0' or '1',
2632  * so we only have to worry about them and the 'improper' settings.
2633  *
2634  * I frickin' hate PHP... :P
2635  *
2636  * @param $setting String
2637  * @return Bool
2638  */
2639 function wfIniGetBool( $setting ) {
2640         $val = strtolower( ini_get( $setting ) );
2641         // 'on' and 'true' can't have whitespace around them, but '1' can.
2642         return $val == 'on'
2643                 || $val == 'true'
2644                 || $val == 'yes'
2645                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2646 }
2647
2648 /**
2649  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2650  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2651  *
2652  * @param string $extension A PHP extension. The file suffix (.so or .dll)
2653  *                          should be omitted
2654  * @param string $fileName Name of the library, if not $extension.suffix
2655  * @return Bool - Whether or not the extension is loaded
2656  */
2657 function wfDl( $extension, $fileName = null ) {
2658         if ( extension_loaded( $extension ) ) {
2659                 return true;
2660         }
2661
2662         $canDl = false;
2663         if ( PHP_SAPI == 'cli' || PHP_SAPI == 'cgi' || PHP_SAPI == 'embed' ) {
2664                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2665                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2666         }
2667
2668         if ( $canDl ) {
2669                 $fileName = $fileName ? $fileName : $extension;
2670                 if ( wfIsWindows() ) {
2671                         $fileName = 'php_' . $fileName;
2672                 }
2673                 wfSuppressWarnings();
2674                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2675                 wfRestoreWarnings();
2676         }
2677         return extension_loaded( $extension );
2678 }
2679
2680 /**
2681  * Windows-compatible version of escapeshellarg()
2682  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2683  * function puts single quotes in regardless of OS.
2684  *
2685  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2686  * earlier distro releases of PHP)
2687  *
2688  * @param varargs
2689  * @return String
2690  */
2691 function wfEscapeShellArg() {
2692         wfInitShellLocale();
2693
2694         $args = func_get_args();
2695         $first = true;
2696         $retVal = '';
2697         foreach ( $args as $arg ) {
2698                 if ( !$first ) {
2699                         $retVal .= ' ';
2700                 } else {
2701                         $first = false;
2702                 }
2703
2704                 if ( wfIsWindows() ) {
2705                         // Escaping for an MSVC-style command line parser and CMD.EXE
2706                         // Refs:
2707                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2708                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2709                         //  * Bug #13518
2710                         //  * CR r63214
2711                         // Double the backslashes before any double quotes. Escape the double quotes.
2712                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2713                         $arg = '';
2714                         $iteration = 0;
2715                         foreach ( $tokens as $token ) {
2716                                 if ( $iteration % 2 == 1 ) {
2717                                         // Delimiter, a double quote preceded by zero or more slashes
2718                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2719                                 } elseif ( $iteration % 4 == 2 ) {
2720                                         // ^ in $token will be outside quotes, need to be escaped
2721                                         $arg .= str_replace( '^', '^^', $token );
2722                                 } else { // $iteration % 4 == 0
2723                                         // ^ in $token will appear inside double quotes, so leave as is
2724                                         $arg .= $token;
2725                                 }
2726                                 $iteration++;
2727                         }
2728                         // Double the backslashes before the end of the string, because
2729                         // we will soon add a quote
2730                         $m = array();
2731                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2732                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2733                         }
2734
2735                         // Add surrounding quotes
2736                         $retVal .= '"' . $arg . '"';
2737                 } else {
2738                         $retVal .= escapeshellarg( $arg );
2739                 }
2740         }
2741         return $retVal;
2742 }
2743
2744 /**
2745  * Check if wfShellExec() is effectively disabled via php.ini config
2746  * @return bool|string False or one of (safemode,disabled)
2747  * @since 1.22
2748  */
2749 function wfShellExecDisabled() {
2750         static $disabled = null;
2751         if ( is_null( $disabled ) ) {
2752                 $disabled = false;
2753                 if ( wfIniGetBool( 'safe_mode' ) ) {
2754                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2755                         $disabled = 'safemode';
2756                 } else {
2757                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2758                         $functions = array_map( 'trim', $functions );
2759                         $functions = array_map( 'strtolower', $functions );
2760                         if ( in_array( 'passthru', $functions ) ) {
2761                                 wfDebug( "passthru is in disabled_functions\n" );
2762                                 $disabled = 'passthru';
2763                         }
2764                 }
2765         }
2766         return $disabled;
2767 }
2768
2769 /**
2770  * Execute a shell command, with time and memory limits mirrored from the PHP
2771  * configuration if supported.
2772  * @param string $cmd Command line, properly escaped for shell.
2773  * @param &$retval null|Mixed optional, will receive the program's exit code.
2774  *                 (non-zero is usually failure)
2775  * @param array $environ optional environment variables which should be
2776  *                 added to the executed command environment.
2777  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2778  *                 this overwrites the global wgShellMax* limits.
2779  * @return string collected stdout as a string (trailing newlines stripped)
2780  */
2781 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2782         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2783                 $wgMaxShellWallClockTime, $wgShellCgroup;
2784
2785         $disabled = wfShellExecDisabled();
2786         if ( $disabled ) {
2787                 $retval = 1;
2788                 return $disabled == 'safemode' ?
2789                         'Unable to run external programs in safe mode.' :
2790                         'Unable to run external programs, passthru() is disabled.';
2791         }
2792
2793         wfInitShellLocale();
2794
2795         $envcmd = '';
2796         foreach ( $environ as $k => $v ) {
2797                 if ( wfIsWindows() ) {
2798                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2799                          * appear in the environment variable, so we must use carat escaping as documented in
2800                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2801                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2802                          * are listed there but doesn't appear to need it.
2803                          */
2804                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2805                 } else {
2806                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2807                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2808                          */
2809                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2810                 }
2811         }
2812         $cmd = $envcmd . $cmd;
2813
2814         if ( php_uname( 's' ) == 'Linux' ) {
2815                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2816                 if ( isset( $limits['walltime'] ) ) {
2817                         $wallTime = intval( $limits['walltime'] );
2818                 } elseif ( isset( $limits['time'] ) ) {
2819                         $wallTime = $time;
2820                 } else {
2821                         $wallTime = intval( $wgMaxShellWallClockTime );
2822                 }
2823                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2824                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2825
2826                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2827                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2828                                 escapeshellarg( $cmd ) . ' ' .
2829                                 escapeshellarg(
2830                                         "MW_CPU_LIMIT=$time; " .
2831                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2832                                         "MW_MEM_LIMIT=$mem; " .
2833                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2834                                         "MW_WALL_CLOCK_LIMIT=$wallTime"
2835                                 );
2836                 }
2837         }
2838         wfDebug( "wfShellExec: $cmd\n" );
2839
2840         $retval = 1; // error by default?
2841         ob_start();
2842         passthru( $cmd, $retval );
2843         $output = ob_get_contents();
2844         ob_end_clean();
2845
2846         if ( $retval == 127 ) {
2847                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2848         }
2849         return $output;
2850 }
2851
2852 /**
2853  * Workaround for http://bugs.php.net/bug.php?id=45132
2854  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2855  */
2856 function wfInitShellLocale() {
2857         static $done = false;
2858         if ( $done ) {
2859                 return;
2860         }
2861         $done = true;
2862         global $wgShellLocale;
2863         if ( !wfIniGetBool( 'safe_mode' ) ) {
2864                 putenv( "LC_CTYPE=$wgShellLocale" );
2865                 setlocale( LC_CTYPE, $wgShellLocale );
2866         }
2867 }
2868
2869 /**
2870  * Alias to wfShellWikiCmd()
2871  * @see wfShellWikiCmd()
2872  */
2873 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2874         return wfShellWikiCmd( $script, $parameters, $options );
2875 }
2876
2877 /**
2878  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2879  * Note that $parameters should be a flat array and an option with an argument
2880  * should consist of two consecutive items in the array (do not use "--option value").
2881  * @param string $script MediaWiki cli script path
2882  * @param array $parameters Arguments and options to the script
2883  * @param array $options Associative array of options:
2884  *              'php': The path to the php executable
2885  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2886  * @return Array
2887  */
2888 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2889         global $wgPhpCli;
2890         // Give site config file a chance to run the script in a wrapper.
2891         // The caller may likely want to call wfBasename() on $script.
2892         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2893         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2894         if ( isset( $options['wrapper'] ) ) {
2895                 $cmd[] = $options['wrapper'];
2896         }
2897         $cmd[] = $script;
2898         // Escape each parameter for shell
2899         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2900 }
2901
2902 /**
2903  * wfMerge attempts to merge differences between three texts.
2904  * Returns true for a clean merge and false for failure or a conflict.
2905  *
2906  * @param $old String
2907  * @param $mine String
2908  * @param $yours String
2909  * @param $result String
2910  * @return Bool
2911  */
2912 function wfMerge( $old, $mine, $yours, &$result ) {
2913         global $wgDiff3;
2914
2915         # This check may also protect against code injection in
2916         # case of broken installations.
2917         wfSuppressWarnings();
2918         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2919         wfRestoreWarnings();
2920
2921         if ( !$haveDiff3 ) {
2922                 wfDebug( "diff3 not found\n" );
2923                 return false;
2924         }
2925
2926         # Make temporary files
2927         $td = wfTempDir();
2928         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2929         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2930         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2931
2932         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2933         #       a newline character. To avoid this, we normalize the trailing whitespace before
2934         #       creating the diff.
2935
2936         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2937         fclose( $oldtextFile );
2938         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2939         fclose( $mytextFile );
2940         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2941         fclose( $yourtextFile );
2942
2943         # Check for a conflict
2944         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
2945                 wfEscapeShellArg( $mytextName ) . ' ' .
2946                 wfEscapeShellArg( $oldtextName ) . ' ' .
2947                 wfEscapeShellArg( $yourtextName );
2948         $handle = popen( $cmd, 'r' );
2949
2950         if ( fgets( $handle, 1024 ) ) {
2951                 $conflict = true;
2952         } else {
2953                 $conflict = false;
2954         }
2955         pclose( $handle );
2956
2957         # Merge differences
2958         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
2959                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2960         $handle = popen( $cmd, 'r' );
2961         $result = '';
2962         do {
2963                 $data = fread( $handle, 8192 );
2964                 if ( strlen( $data ) == 0 ) {
2965                         break;
2966                 }
2967                 $result .= $data;
2968         } while ( true );
2969         pclose( $handle );
2970         unlink( $mytextName );
2971         unlink( $oldtextName );
2972         unlink( $yourtextName );
2973
2974         if ( $result === '' && $old !== '' && !$conflict ) {
2975                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2976                 $conflict = true;
2977         }
2978         return !$conflict;
2979 }
2980
2981 /**
2982  * Returns unified plain-text diff of two texts.
2983  * Useful for machine processing of diffs.
2984  *
2985  * @param string $before the text before the changes.
2986  * @param string $after the text after the changes.
2987  * @param string $params command-line options for the diff command.
2988  * @return String: unified diff of $before and $after
2989  */
2990 function wfDiff( $before, $after, $params = '-u' ) {
2991         if ( $before == $after ) {
2992                 return '';
2993         }
2994
2995         global $wgDiff;
2996         wfSuppressWarnings();
2997         $haveDiff = $wgDiff && file_exists( $wgDiff );
2998         wfRestoreWarnings();
2999
3000         # This check may also protect against code injection in
3001         # case of broken installations.
3002         if ( !$haveDiff ) {
3003                 wfDebug( "diff executable not found\n" );
3004                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3005                 $format = new UnifiedDiffFormatter();
3006                 return $format->format( $diffs );
3007         }
3008
3009         # Make temporary files
3010         $td = wfTempDir();
3011         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3012         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3013
3014         fwrite( $oldtextFile, $before );
3015         fclose( $oldtextFile );
3016         fwrite( $newtextFile, $after );
3017         fclose( $newtextFile );
3018
3019         // Get the diff of the two files
3020         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3021
3022         $h = popen( $cmd, 'r' );
3023
3024         $diff = '';
3025
3026         do {
3027                 $data = fread( $h, 8192 );
3028                 if ( strlen( $data ) == 0 ) {
3029                         break;
3030                 }
3031                 $diff .= $data;
3032         } while ( true );
3033
3034         // Clean up
3035         pclose( $h );
3036         unlink( $oldtextName );
3037         unlink( $newtextName );
3038
3039         // Kill the --- and +++ lines. They're not useful.
3040         $diff_lines = explode( "\n", $diff );
3041         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3042                 unset( $diff_lines[0] );
3043         }
3044         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3045                 unset( $diff_lines[1] );
3046         }
3047
3048         $diff = implode( "\n", $diff_lines );
3049
3050         return $diff;
3051 }
3052
3053 /**
3054  * This function works like "use VERSION" in Perl, the program will die with a
3055  * backtrace if the current version of PHP is less than the version provided
3056  *
3057  * This is useful for extensions which due to their nature are not kept in sync
3058  * with releases, and might depend on other versions of PHP than the main code
3059  *
3060  * Note: PHP might die due to parsing errors in some cases before it ever
3061  *       manages to call this function, such is life
3062  *
3063  * @see perldoc -f use
3064  *
3065  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3066  *                 a float
3067  * @throws MWException
3068  */
3069 function wfUsePHP( $req_ver ) {
3070         $php_ver = PHP_VERSION;
3071
3072         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3073                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3074         }
3075 }
3076
3077 /**
3078  * This function works like "use VERSION" in Perl except it checks the version
3079  * of MediaWiki, the program will die with a backtrace if the current version
3080  * of MediaWiki is less than the version provided.
3081  *
3082  * This is useful for extensions which due to their nature are not kept in sync
3083  * with releases
3084  *
3085  * @see perldoc -f use
3086  *
3087  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3088  *                 a float
3089  * @throws MWException
3090  */
3091 function wfUseMW( $req_ver ) {
3092         global $wgVersion;
3093
3094         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3095                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3096         }
3097 }
3098
3099 /**
3100  * Return the final portion of a pathname.
3101  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3102  * http://bugs.php.net/bug.php?id=33898
3103  *
3104  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3105  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3106  *
3107  * @param $path String
3108  * @param string $suffix to remove if present
3109  * @return String
3110  */
3111 function wfBaseName( $path, $suffix = '' ) {
3112         $encSuffix = ( $suffix == '' )
3113                 ? ''
3114                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3115         $matches = array();
3116         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3117                 return $matches[1];
3118         } else {
3119                 return '';
3120         }
3121 }
3122
3123 /**
3124  * Generate a relative path name to the given file.
3125  * May explode on non-matching case-insensitive paths,
3126  * funky symlinks, etc.
3127  *
3128  * @param string $path absolute destination path including target filename
3129  * @param string $from Absolute source path, directory only
3130  * @return String
3131  */
3132 function wfRelativePath( $path, $from ) {
3133         // Normalize mixed input on Windows...
3134         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3135         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3136
3137         // Trim trailing slashes -- fix for drive root
3138         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3139         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3140
3141         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3142         $against = explode( DIRECTORY_SEPARATOR, $from );
3143
3144         if ( $pieces[0] !== $against[0] ) {
3145                 // Non-matching Windows drive letters?
3146                 // Return a full path.
3147                 return $path;
3148         }
3149
3150         // Trim off common prefix
3151         while ( count( $pieces ) && count( $against )
3152                 && $pieces[0] == $against[0] ) {
3153                 array_shift( $pieces );
3154                 array_shift( $against );
3155         }
3156
3157         // relative dots to bump us to the parent
3158         while ( count( $against ) ) {
3159                 array_unshift( $pieces, '..' );
3160                 array_shift( $against );
3161         }
3162
3163         array_push( $pieces, wfBaseName( $path ) );
3164
3165         return implode( DIRECTORY_SEPARATOR, $pieces );
3166 }
3167
3168 /**
3169  * Do any deferred updates and clear the list
3170  *
3171  * @deprecated since 1.19
3172  * @see DeferredUpdates::doUpdate()
3173  * @param $commit string
3174  */
3175 function wfDoUpdates( $commit = '' ) {
3176         wfDeprecated( __METHOD__, '1.19' );
3177         DeferredUpdates::doUpdates( $commit );
3178 }
3179
3180 /**
3181  * Convert an arbitrarily-long digit string from one numeric base
3182  * to another, optionally zero-padding to a minimum column width.
3183  *
3184  * Supports base 2 through 36; digit values 10-36 are represented
3185  * as lowercase letters a-z. Input is case-insensitive.
3186  *
3187  * @param string $input Input number
3188  * @param int $sourceBase Base of the input number
3189  * @param int $destBase Desired base of the output
3190  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3191  * @param bool $lowercase Whether to output in lowercase or uppercase
3192  * @param string $engine Either "gmp", "bcmath", or "php"
3193  * @return string|bool The output number as a string, or false on error
3194  */
3195 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true, $engine = 'auto' ) {
3196         $input = (string)$input;
3197         if (
3198                 $sourceBase < 2 ||
3199                 $sourceBase > 36 ||
3200                 $destBase < 2 ||
3201                 $destBase > 36 ||
3202                 $sourceBase != (int)$sourceBase ||
3203                 $destBase != (int)$destBase ||
3204                 $pad != (int)$pad ||
3205                 !preg_match( "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i", $input )
3206         ) {
3207                 return false;
3208         }
3209
3210         static $baseChars = array(
3211                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3212                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3213                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3214                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3215                 34 => 'y', 35 => 'z',
3216
3217                 '0' => 0,  '1' => 1,  '2' => 2,  '3' => 3,  '4' => 4,  '5' => 5,
3218                 '6' => 6,  '7' => 7,  '8' => 8,  '9' => 9,  'a' => 10, 'b' => 11,
3219                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3220                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3221                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3222                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3223         );
3224
3225         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3226                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3227         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3228                 $decimal = '0';
3229                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3230                         $decimal = bcmul( $decimal, $sourceBase );
3231                         $decimal = bcadd( $decimal, $baseChars[$char] );
3232                 }
3233
3234                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3235                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3236                 }
3237
3238                 $result = strrev( $result );
3239         } else {
3240                 $inDigits = array();
3241                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3242                         $inDigits[] = $baseChars[$char];
3243                 }
3244
3245                 // Iterate over the input, modulo-ing out an output digit
3246                 // at a time until input is gone.
3247                 $result = '';
3248                 while ( $inDigits ) {
3249                         $work = 0;
3250                         $workDigits = array();
3251
3252                         // Long division...
3253                         foreach ( $inDigits as $digit ) {
3254                                 $work *= $sourceBase;
3255                                 $work += $digit;
3256
3257                                 if ( $workDigits || $work >= $destBase ) {
3258                                         $workDigits[] = (int)( $work / $destBase );
3259                                 }
3260                                 $work %= $destBase;
3261                         }
3262
3263                         // All that division leaves us with a remainder,
3264                         // which is conveniently our next output digit.
3265                         $result .= $baseChars[$work];
3266
3267                         // And we continue!
3268                         $inDigits = $workDigits;
3269                 }
3270
3271                 $result = strrev( $result );
3272         }
3273
3274         if ( !$lowercase ) {
3275                 $result = strtoupper( $result );
3276         }
3277
3278         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3279 }
3280
3281 /**
3282  * Create an object with a given name and an array of construct parameters
3283  *
3284  * @param $name String
3285  * @param array $p parameters
3286  * @return object
3287  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3288  */
3289 function wfCreateObject( $name, $p ) {
3290         wfDeprecated( __FUNCTION__, '1.18' );
3291         return MWFunction::newObj( $name, $p );
3292 }
3293
3294 /**
3295  * @return bool
3296  */
3297 function wfHttpOnlySafe() {
3298         global $wgHttpOnlyBlacklist;
3299
3300         if ( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3301                 foreach ( $wgHttpOnlyBlacklist as $regex ) {
3302                         if ( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3303                                 return false;
3304                         }
3305                 }
3306         }
3307
3308         return true;
3309 }
3310
3311 /**
3312  * Check if there is sufficient entropy in php's built-in session generation
3313  * @return bool true = there is sufficient entropy
3314  */
3315 function wfCheckEntropy() {
3316         return (
3317                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3318                         || ini_get( 'session.entropy_file' )
3319                 )
3320                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3321 }
3322
3323 /**
3324  * Override session_id before session startup if php's built-in
3325  * session generation code is not secure.
3326  */
3327 function wfFixSessionID() {
3328         // If the cookie or session id is already set we already have a session and should abort
3329         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3330                 return;
3331         }
3332
3333         // PHP's built-in session entropy is enabled if:
3334         // - entropy_file is set or you're on Windows with php 5.3.3+
3335         // - AND entropy_length is > 0
3336         // We treat it as disabled if it doesn't have an entropy length of at least 32
3337         $entropyEnabled = wfCheckEntropy();
3338
3339         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3340         if ( !$entropyEnabled ) {
3341                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3342                 session_id( MWCryptRand::generateHex( 32 ) );
3343         }
3344 }
3345
3346 /**
3347  * Reset the session_id
3348  * @since 1.22
3349  */
3350 function wfResetSessionID() {
3351         global $wgCookieSecure;
3352         $oldSessionId = session_id();
3353         $cookieParams = session_get_cookie_params();
3354         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3355                 session_regenerate_id( false );
3356         } else {
3357                 $tmp = $_SESSION;
3358                 session_destroy();
3359                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3360                 $_SESSION = $tmp;
3361         }
3362         $newSessionId = session_id();
3363         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3364 }
3365
3366
3367 /**
3368  * Initialise php session
3369  *
3370  * @param $sessionId Bool
3371  */
3372 function wfSetupSession( $sessionId = false ) {
3373         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3374                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3375         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3376                 ObjectCacheSessionHandler::install();
3377         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3378                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3379                 # hasn't already been set to the desired value (that causes errors)
3380                 ini_set( 'session.save_handler', $wgSessionHandler );
3381         }
3382         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3383         wfDebugLog( 'cookie',
3384                 'session_set_cookie_params: "' . implode( '", "',
3385                         array(
3386                                 0,
3387                                 $wgCookiePath,
3388                                 $wgCookieDomain,
3389                                 $wgCookieSecure,
3390                                 $httpOnlySafe ) ) . '"' );
3391         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3392         session_cache_limiter( 'private, must-revalidate' );
3393         if ( $sessionId ) {
3394                 session_id( $sessionId );
3395         } else {
3396                 wfFixSessionID();
3397         }
3398         wfSuppressWarnings();
3399         session_start();
3400         wfRestoreWarnings();
3401 }
3402
3403 /**
3404  * Get an object from the precompiled serialized directory
3405  *
3406  * @param $name String
3407  * @return Mixed: the variable on success, false on failure
3408  */
3409 function wfGetPrecompiledData( $name ) {
3410         global $IP;
3411
3412         $file = "$IP/serialized/$name";
3413         if ( file_exists( $file ) ) {
3414                 $blob = file_get_contents( $file );
3415                 if ( $blob ) {
3416                         return unserialize( $blob );
3417                 }
3418         }
3419         return false;
3420 }
3421
3422 /**
3423  * Get a cache key
3424  *
3425  * @param varargs
3426  * @return String
3427  */
3428 function wfMemcKey( /*... */ ) {
3429         global $wgCachePrefix;
3430         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3431         $args = func_get_args();
3432         $key = $prefix . ':' . implode( ':', $args );
3433         $key = str_replace( ' ', '_', $key );
3434         return $key;
3435 }
3436
3437 /**
3438  * Get a cache key for a foreign DB
3439  *
3440  * @param $db String
3441  * @param $prefix String
3442  * @param varargs String
3443  * @return String
3444  */
3445 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3446         $args = array_slice( func_get_args(), 2 );
3447         if ( $prefix ) {
3448                 $key = "$db-$prefix:" . implode( ':', $args );
3449         } else {
3450                 $key = $db . ':' . implode( ':', $args );
3451         }
3452         return str_replace( ' ', '_', $key );
3453 }
3454
3455 /**
3456  * Get an ASCII string identifying this wiki
3457  * This is used as a prefix in memcached keys
3458  *
3459  * @return String
3460  */
3461 function wfWikiID() {
3462         global $wgDBprefix, $wgDBname;
3463         if ( $wgDBprefix ) {
3464                 return "$wgDBname-$wgDBprefix";
3465         } else {
3466                 return $wgDBname;
3467         }
3468 }
3469
3470 /**
3471  * Split a wiki ID into DB name and table prefix
3472  *
3473  * @param $wiki String
3474  *
3475  * @return array
3476  */
3477 function wfSplitWikiID( $wiki ) {
3478         $bits = explode( '-', $wiki, 2 );
3479         if ( count( $bits ) < 2 ) {
3480                 $bits[] = '';
3481         }
3482         return $bits;
3483 }
3484
3485 /**
3486  * Get a Database object.
3487  *
3488  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3489  *            master (for write queries), DB_SLAVE for potentially lagged read
3490  *            queries, or an integer >= 0 for a particular server.
3491  *
3492  * @param $groups Mixed: query groups. An array of group names that this query
3493  *                belongs to. May contain a single string if the query is only
3494  *                in one group.
3495  *
3496  * @param string $wiki the wiki ID, or false for the current wiki
3497  *
3498  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3499  * will always return the same object, unless the underlying connection or load
3500  * balancer is manually destroyed.
3501  *
3502  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3503  * updater to ensure that a proper database is being updated.
3504  *
3505  * @return DatabaseBase
3506  */
3507 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3508         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3509 }
3510
3511 /**
3512  * Get a load balancer object.
3513  *
3514  * @param string $wiki wiki ID, or false for the current wiki
3515  * @return LoadBalancer
3516  */
3517 function wfGetLB( $wiki = false ) {
3518         return wfGetLBFactory()->getMainLB( $wiki );
3519 }
3520
3521 /**
3522  * Get the load balancer factory object
3523  *
3524  * @return LBFactory
3525  */
3526 function &wfGetLBFactory() {
3527         return LBFactory::singleton();
3528 }
3529
3530 /**
3531  * Find a file.
3532  * Shortcut for RepoGroup::singleton()->findFile()
3533  *
3534  * @param string $title or Title object
3535  * @param array $options Associative array of options:
3536  *     time:           requested time for an archived image, or false for the
3537  *                     current version. An image object will be returned which was
3538  *                     created at the specified time.
3539  *
3540  *     ignoreRedirect: If true, do not follow file redirects
3541  *
3542  *     private:        If true, return restricted (deleted) files if the current
3543  *                     user is allowed to view them. Otherwise, such files will not
3544  *                     be found.
3545  *
3546  *     bypassCache:    If true, do not use the process-local cache of File objects
3547  *
3548  * @return File, or false if the file does not exist
3549  */
3550 function wfFindFile( $title, $options = array() ) {
3551         return RepoGroup::singleton()->findFile( $title, $options );
3552 }
3553
3554 /**
3555  * Get an object referring to a locally registered file.
3556  * Returns a valid placeholder object if the file does not exist.
3557  *
3558  * @param $title Title|String
3559  * @return LocalFile|null A File, or null if passed an invalid Title
3560  */
3561 function wfLocalFile( $title ) {
3562         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3563 }
3564
3565 /**
3566  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3567  * @deprecated since 1.19
3568  */
3569 function wfStreamFile( $fname, $headers = array() ) {
3570         wfDeprecated( __FUNCTION__, '1.19' );
3571         StreamFile::stream( $fname, $headers );
3572 }
3573
3574 /**
3575  * Should low-performance queries be disabled?
3576  *
3577  * @return Boolean
3578  * @codeCoverageIgnore
3579  */
3580 function wfQueriesMustScale() {
3581         global $wgMiserMode;
3582         return $wgMiserMode
3583                 || ( SiteStats::pages() > 100000
3584                 && SiteStats::edits() > 1000000
3585                 && SiteStats::users() > 10000 );
3586 }
3587
3588 /**
3589  * Get the path to a specified script file, respecting file
3590  * extensions; this is a wrapper around $wgScriptExtension etc.
3591  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3592  *
3593  * @param string $script script filename, sans extension
3594  * @return String
3595  */
3596 function wfScript( $script = 'index' ) {
3597         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3598         if ( $script === 'index' ) {
3599                 return $wgScript;
3600         } elseif ( $script === 'load' ) {
3601                 return $wgLoadScript;
3602         } else {
3603                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3604         }
3605 }
3606
3607 /**
3608  * Get the script URL.
3609  *
3610  * @return string script URL
3611  */
3612 function wfGetScriptUrl() {
3613         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3614                 #
3615                 # as it was called, minus the query string.
3616                 #
3617                 # Some sites use Apache rewrite rules to handle subdomains,
3618                 # and have PHP set up in a weird way that causes PHP_SELF
3619                 # to contain the rewritten URL instead of the one that the
3620                 # outside world sees.
3621                 #
3622                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3623                 # provides containing the "before" URL.
3624                 return $_SERVER['SCRIPT_NAME'];
3625         } else {
3626                 return $_SERVER['URL'];
3627         }
3628 }
3629
3630 /**
3631  * Convenience function converts boolean values into "true"
3632  * or "false" (string) values
3633  *
3634  * @param $value Boolean
3635  * @return String
3636  */
3637 function wfBoolToStr( $value ) {
3638         return $value ? 'true' : 'false';
3639 }
3640
3641 /**
3642  * Get a platform-independent path to the null file, e.g. /dev/null
3643  *
3644  * @return string
3645  */
3646 function wfGetNull() {
3647         return wfIsWindows()
3648                 ? 'NUL'
3649                 : '/dev/null';
3650 }
3651
3652 /**
3653  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3654  * and waiting for it to go down, this waits for the slaves to catch up to the
3655  * master position. Use this when updating very large numbers of rows, as
3656  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3657  * a no-op if there are no slaves.
3658  *
3659  * @param $maxLag Integer (deprecated)
3660  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3661  * @param $cluster string cluster name accepted by LBFactory
3662  */
3663 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3664         $lb = ( $cluster !== false )
3665                 ? wfGetLBFactory()->getExternalLB( $cluster )
3666                 : wfGetLB( $wiki );
3667         // bug 27975 - Don't try to wait for slaves if there are none
3668         // Prevents permission error when getting master position
3669         if ( $lb->getServerCount() > 1 ) {
3670                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3671                 $pos = $dbw->getMasterPos();
3672                 // The DBMS may not support getMasterPos() or the whole
3673                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3674                 if ( $pos !== false ) {
3675                         $lb->waitForAll( $pos );
3676                 }
3677         }
3678 }
3679
3680 /**
3681  * Used to be used for outputting text in the installer/updater
3682  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3683  */
3684 function wfOut( $s ) {
3685         wfDeprecated( __FUNCTION__, '1.18' );
3686         global $wgCommandLineMode;
3687         if ( $wgCommandLineMode ) {
3688                 echo $s;
3689         } else {
3690                 echo htmlspecialchars( $s );
3691         }
3692         flush();
3693 }
3694
3695 /**
3696  * Count down from $n to zero on the terminal, with a one-second pause
3697  * between showing each number. For use in command-line scripts.
3698  * @codeCoverageIgnore
3699  * @param $n int
3700  */
3701 function wfCountDown( $n ) {
3702         for ( $i = $n; $i >= 0; $i-- ) {
3703                 if ( $i != $n ) {
3704                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3705                 }
3706                 echo $i;
3707                 flush();
3708                 if ( $i ) {
3709                         sleep( 1 );
3710                 }
3711         }
3712         echo "\n";
3713 }
3714
3715 /**
3716  * Generate a random 32-character hexadecimal token.
3717  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3718  *              characters before hashing.
3719  * @return string
3720  * @codeCoverageIgnore
3721  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pseudo-random strings
3722  * @warning This method is NOT secure. Additionally it has many callers that use it for pseudo-random purposes.
3723  */
3724 function wfGenerateToken( $salt = '' ) {
3725         wfDeprecated( __METHOD__, '1.20' );
3726         $salt = serialize( $salt );
3727         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3728 }
3729
3730 /**
3731  * Replace all invalid characters with -
3732  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3733  * By default, $wgIllegalFileChars = ':'
3734  *
3735  * @param $name Mixed: filename to process
3736  * @return String
3737  */
3738 function wfStripIllegalFilenameChars( $name ) {
3739         global $wgIllegalFileChars;
3740         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3741         $name = wfBaseName( $name );
3742         $name = preg_replace(
3743                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3744                 '-',
3745                 $name
3746         );
3747         return $name;
3748 }
3749
3750 /**
3751  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3752  *
3753  * @return Integer value memory was set to.
3754  */
3755 function wfMemoryLimit() {
3756         global $wgMemoryLimit;
3757         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3758         if ( $memlimit != -1 ) {
3759                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3760                 if ( $conflimit == -1 ) {
3761                         wfDebug( "Removing PHP's memory limit\n" );
3762                         wfSuppressWarnings();
3763                         ini_set( 'memory_limit', $conflimit );
3764                         wfRestoreWarnings();
3765                         return $conflimit;
3766                 } elseif ( $conflimit > $memlimit ) {
3767                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3768                         wfSuppressWarnings();
3769                         ini_set( 'memory_limit', $conflimit );
3770                         wfRestoreWarnings();
3771                         return $conflimit;
3772                 }
3773         }
3774         return $memlimit;
3775 }
3776
3777 /**
3778  * Converts shorthand byte notation to integer form
3779  *
3780  * @param $string String
3781  * @return Integer
3782  */
3783 function wfShorthandToInteger( $string = '' ) {
3784         $string = trim( $string );
3785         if ( $string === '' ) {
3786                 return -1;
3787         }
3788         $last = $string[strlen( $string ) - 1];
3789         $val = intval( $string );
3790         switch ( $last ) {
3791                 case 'g':
3792                 case 'G':
3793                         $val *= 1024;
3794                         // break intentionally missing
3795                 case 'm':
3796                 case 'M':
3797                         $val *= 1024;
3798                         // break intentionally missing
3799                 case 'k':
3800                 case 'K':
3801                         $val *= 1024;
3802         }
3803
3804         return $val;
3805 }
3806
3807 /**
3808  * Get the normalised IETF language tag
3809  * See unit test for examples.
3810  *
3811  * @param string $code The language code.
3812  * @return String: The language code which complying with BCP 47 standards.
3813  */
3814 function wfBCP47( $code ) {
3815         $codeSegment = explode( '-', $code );
3816         $codeBCP = array();
3817         foreach ( $codeSegment as $segNo => $seg ) {
3818                 // when previous segment is x, it is a private segment and should be lc
3819                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3820                         $codeBCP[$segNo] = strtolower( $seg );
3821                 // ISO 3166 country code
3822                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3823                         $codeBCP[$segNo] = strtoupper( $seg );
3824                 // ISO 15924 script code
3825                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3826                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3827                 // Use lowercase for other cases
3828                 } else {
3829                         $codeBCP[$segNo] = strtolower( $seg );
3830                 }
3831         }
3832         $langCode = implode( '-', $codeBCP );
3833         return $langCode;
3834 }
3835
3836 /**
3837  * Get a cache object.
3838  *
3839  * @param $inputType integer Cache type, one the the CACHE_* constants.
3840  * @return BagOStuff
3841  */
3842 function wfGetCache( $inputType ) {
3843         return ObjectCache::getInstance( $inputType );
3844 }
3845
3846 /**
3847  * Get the main cache object
3848  *
3849  * @return BagOStuff
3850  */
3851 function wfGetMainCache() {
3852         global $wgMainCacheType;
3853         return ObjectCache::getInstance( $wgMainCacheType );
3854 }
3855
3856 /**
3857  * Get the cache object used by the message cache
3858  *
3859  * @return BagOStuff
3860  */
3861 function wfGetMessageCacheStorage() {
3862         global $wgMessageCacheType;
3863         return ObjectCache::getInstance( $wgMessageCacheType );
3864 }
3865
3866 /**
3867  * Get the cache object used by the parser cache
3868  *
3869  * @return BagOStuff
3870  */
3871 function wfGetParserCacheStorage() {
3872         global $wgParserCacheType;
3873         return ObjectCache::getInstance( $wgParserCacheType );
3874 }
3875
3876 /**
3877  * Get the cache object used by the language converter
3878  *
3879  * @return BagOStuff
3880  */
3881 function wfGetLangConverterCacheStorage() {
3882         global $wgLanguageConverterCacheType;
3883         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3884 }
3885
3886 /**
3887  * Call hook functions defined in $wgHooks
3888  *
3889  * @param string $event event name
3890  * @param array $args parameters passed to hook functions
3891  * @return Boolean True if no handler aborted the hook
3892  */
3893 function wfRunHooks( $event, array $args = array() ) {
3894         return Hooks::run( $event, $args );
3895 }
3896
3897 /**
3898  * Wrapper around php's unpack.
3899  *
3900  * @param string $format The format string (See php's docs)
3901  * @param $data: A binary string of binary data
3902  * @param $length integer or false: The minimum length of $data. This is to
3903  *      prevent reading beyond the end of $data. false to disable the check.
3904  *
3905  * Also be careful when using this function to read unsigned 32 bit integer
3906  * because php might make it negative.
3907  *
3908  * @throws MWException if $data not long enough, or if unpack fails
3909  * @return array Associative array of the extracted data
3910  */
3911 function wfUnpack( $format, $data, $length = false ) {
3912         if ( $length !== false ) {
3913                 $realLen = strlen( $data );
3914                 if ( $realLen < $length ) {
3915                         throw new MWException( "Tried to use wfUnpack on a "
3916                                 . "string of length $realLen, but needed one "
3917                                 . "of at least length $length."
3918                         );
3919                 }
3920         }
3921
3922         wfSuppressWarnings();
3923         $result = unpack( $format, $data );
3924         wfRestoreWarnings();
3925
3926         if ( $result === false ) {
3927                 // If it cannot extract the packed data.
3928                 throw new MWException( "unpack could not unpack binary data" );
3929         }
3930         return $result;
3931 }
3932
3933 /**
3934  * Determine if an image exists on the 'bad image list'.
3935  *
3936  * The format of MediaWiki:Bad_image_list is as follows:
3937  *    * Only list items (lines starting with "*") are considered
3938  *    * The first link on a line must be a link to a bad image
3939  *    * Any subsequent links on the same line are considered to be exceptions,
3940  *      i.e. articles where the image may occur inline.
3941  *
3942  * @param string $name the image name to check
3943  * @param $contextTitle Title|bool the page on which the image occurs, if known
3944  * @param string $blacklist wikitext of a file blacklist
3945  * @return bool
3946  */
3947 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3948         static $badImageCache = null; // based on bad_image_list msg
3949         wfProfileIn( __METHOD__ );
3950
3951         # Handle redirects
3952         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3953         if ( $redirectTitle ) {
3954                 $name = $redirectTitle->getDBkey();
3955         }
3956
3957         # Run the extension hook
3958         $bad = false;
3959         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3960                 wfProfileOut( __METHOD__ );
3961                 return $bad;
3962         }
3963
3964         $cacheable = ( $blacklist === null );
3965         if ( $cacheable && $badImageCache !== null ) {
3966                 $badImages = $badImageCache;
3967         } else { // cache miss
3968                 if ( $blacklist === null ) {
3969                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3970                 }
3971                 # Build the list now
3972                 $badImages = array();
3973                 $lines = explode( "\n", $blacklist );
3974                 foreach ( $lines as $line ) {
3975                         # List items only
3976                         if ( substr( $line, 0, 1 ) !== '*' ) {
3977                                 continue;
3978                         }
3979
3980                         # Find all links
3981                         $m = array();
3982                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3983                                 continue;
3984                         }
3985
3986                         $exceptions = array();
3987                         $imageDBkey = false;
3988                         foreach ( $m[1] as $i => $titleText ) {
3989                                 $title = Title::newFromText( $titleText );
3990                                 if ( !is_null( $title ) ) {
3991                                         if ( $i == 0 ) {
3992                                                 $imageDBkey = $title->getDBkey();
3993                                         } else {
3994                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3995                                         }
3996                                 }
3997                         }
3998
3999                         if ( $imageDBkey !== false ) {
4000                                 $badImages[$imageDBkey] = $exceptions;
4001                         }
4002                 }
4003                 if ( $cacheable ) {
4004                         $badImageCache = $badImages;
4005                 }
4006         }
4007
4008         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4009         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4010         wfProfileOut( __METHOD__ );
4011         return $bad;
4012 }
4013
4014 /**
4015  * Determine whether the client at a given source IP is likely to be able to
4016  * access the wiki via HTTPS.
4017  *
4018  * @param string $ip The IPv4/6 address in the normal human-readable form
4019  * @return boolean
4020  */
4021 function wfCanIPUseHTTPS( $ip ) {
4022         $canDo = true;
4023         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4024         return !!$canDo;
4025 }