includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 // Hide compatibility functions from Doxygen
  28 /// @cond
  29
  30 /**
  31  * Compatibility functions
  32  *
  33  * We support PHP 5.3.2 and up.
  34  * Re-implementations of newer functions or functions in non-standard
  35  * PHP extensions may be included here.
  36  */
  37
  38 if( !function_exists( 'iconv' ) ) {
  39         /**
  40          * @codeCoverageIgnore
  41          * @return string
  42          */
  43         function iconv( $from, $to, $string ) {
  44                 return Fallback::iconv( $from, $to, $string );
  45         }
  46 }
  47
  48 if ( !function_exists( 'mb_substr' ) ) {
  49         /**
  50          * @codeCoverageIgnore
  51          * @return string
  52          */
  53         function mb_substr( $str, $start, $count='end' ) {
  54                 return Fallback::mb_substr( $str, $start, $count );
  55         }
  56
  57         /**
  58          * @codeCoverageIgnore
  59          * @return int
  60          */
  61         function mb_substr_split_unicode( $str, $splitPos ) {
  62                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  63         }
  64 }
  65
  66 if ( !function_exists( 'mb_strlen' ) ) {
  67         /**
  68          * @codeCoverageIgnore
  69          * @return int
  70          */
  71         function mb_strlen( $str, $enc = '' ) {
  72                 return Fallback::mb_strlen( $str, $enc );
  73         }
  74 }
  75
  76 if( !function_exists( 'mb_strpos' ) ) {
  77         /**
  78          * @codeCoverageIgnore
  79          * @return int
  80          */
  81         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  82                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  83         }
  84
  85 }
  86
  87 if( !function_exists( 'mb_strrpos' ) ) {
  88         /**
  89          * @codeCoverageIgnore
  90          * @return int
  91          */
  92         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  93                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  94         }
  95 }
  96
  97
  98 // Support for Wietse Venema's taint feature
  99 if ( !function_exists( 'istainted' ) ) {
 100         /**
 101          * @codeCoverageIgnore
 102          * @return int
 103          */
 104         function istainted( $var ) {
 105                 return 0;
 106         }
 107         /** @codeCoverageIgnore */
 108         function taint( $var, $level = 0 ) {}
 109         /** @codeCoverageIgnore */
 110         function untaint( $var, $level = 0 ) {}
 111         define( 'TC_HTML', 1 );
 112         define( 'TC_SHELL', 1 );
 113         define( 'TC_MYSQL', 1 );
 114         define( 'TC_PCRE', 1 );
 115         define( 'TC_SELF', 1 );
 116 }
 117 /// @endcond
 118
 119 /**
 120  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 121  * @param $a array
 122  * @param $b array
 123  * @return array
 124  */
 125 function wfArrayDiff2( $a, $b ) {
 126         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 127 }
 128
 129 /**
 130  * @param $a
 131  * @param $b
 132  * @return int
 133  */
 134 function wfArrayDiff2_cmp( $a, $b ) {
 135         if ( !is_array( $a ) ) {
 136                 return strcmp( $a, $b );
 137         } elseif ( count( $a ) !== count( $b ) ) {
 138                 return count( $a ) < count( $b ) ? -1 : 1;
 139         } else {
 140                 reset( $a );
 141                 reset( $b );
 142                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 143                         $cmp = strcmp( $valueA, $valueB );
 144                         if ( $cmp !== 0 ) {
 145                                 return $cmp;
 146                         }
 147                 }
 148                 return 0;
 149         }
 150 }
 151
 152 /**
 153  * Array lookup
 154  * Returns an array where the values in the first array are replaced by the
 155  * values in the second array with the corresponding keys
 156  *
 157  * @param $a Array
 158  * @param $b Array
 159  * @return array
 160  */
 161 function wfArrayLookup( $a, $b ) {
 162         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 163 }
 164
 165 /**
 166  * Appends to second array if $value differs from that in $default
 167  *
 168  * @param $key String|Int
 169  * @param $value Mixed
 170  * @param $default Mixed
 171  * @param $changed Array to alter
 172  */
 173 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 174         if ( is_null( $changed ) ) {
 175                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 176         }
 177         if ( $default[$key] !== $value ) {
 178                 $changed[$key] = $value;
 179         }
 180 }
 181
 182 /**
 183  * Backwards array plus for people who haven't bothered to read the PHP manual
 184  * XXX: will not darn your socks for you.
 185  *
 186  * @param $array1 Array
 187  * @param [$array2, [...]] Arrays
 188  * @return Array
 189  */
 190 function wfArrayMerge( $array1/* ... */ ) {
 191         $args = func_get_args();
 192         $args = array_reverse( $args, true );
 193         $out = array();
 194         foreach ( $args as $arg ) {
 195                 $out += $arg;
 196         }
 197         return $out;
 198 }
 199
 200 /**
 201  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 202  * e.g.
 203  *      wfMergeErrorArrays(
 204  *              array( array( 'x' ) ),
 205  *              array( array( 'x', '2' ) ),
 206  *              array( array( 'x' ) ),
 207  *              array( array( 'y' ) )
 208  *      );
 209  * returns:
 210  *              array(
 211  *              array( 'x', '2' ),
 212  *              array( 'x' ),
 213  *              array( 'y' )
 214  *      )
 215  * @param varargs
 216  * @return Array
 217  */
 218 function wfMergeErrorArrays( /*...*/ ) {
 219         $args = func_get_args();
 220         $out = array();
 221         foreach ( $args as $errors ) {
 222                 foreach ( $errors as $params ) {
 223                         # @todo FIXME: Sometimes get nested arrays for $params,
 224                         # which leads to E_NOTICEs
 225                         $spec = implode( "\t", $params );
 226                         $out[$spec] = $params;
 227                 }
 228         }
 229         return array_values( $out );
 230 }
 231
 232 /**
 233  * Insert array into another array after the specified *KEY*
 234  *
 235  * @param $array Array: The array.
 236  * @param $insert Array: The array to insert.
 237  * @param $after Mixed: The key to insert after
 238  * @return Array
 239  */
 240 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 241         // Find the offset of the element to insert after.
 242         $keys = array_keys( $array );
 243         $offsetByKey = array_flip( $keys );
 244
 245         $offset = $offsetByKey[$after];
 246
 247         // Insert at the specified offset
 248         $before = array_slice( $array, 0, $offset + 1, true );
 249         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 250
 251         $output = $before + $insert + $after;
 252
 253         return $output;
 254 }
 255
 256 /**
 257  * Recursively converts the parameter (an object) to an array with the same data
 258  *
 259  * @param $objOrArray Object|Array
 260  * @param $recursive Bool
 261  * @return Array
 262  */
 263 function wfObjectToArray( $objOrArray, $recursive = true ) {
 264         $array = array();
 265         if( is_object( $objOrArray ) ) {
 266                 $objOrArray = get_object_vars( $objOrArray );
 267         }
 268         foreach ( $objOrArray as $key => $value ) {
 269                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 270                         $value = wfObjectToArray( $value );
 271                 }
 272
 273                 $array[$key] = $value;
 274         }
 275
 276         return $array;
 277 }
 278
 279 /**
 280  * Wrapper around array_map() which also taints variables
 281  *
 282  * @param  $function Callback
 283  * @param  $input Array
 284  * @return Array
 285  */
 286 function wfArrayMap( $function, $input ) {
 287         $ret = array_map( $function, $input );
 288         foreach ( $ret as $key => $value ) {
 289                 $taint = istainted( $input[$key] );
 290                 if ( $taint ) {
 291                         taint( $ret[$key], $taint );
 292                 }
 293         }
 294         return $ret;
 295 }
 296
 297 /**
 298  * Get a random decimal value between 0 and 1, in a way
 299  * not likely to give duplicate values for any realistic
 300  * number of articles.
 301  *
 302  * @return string
 303  */
 304 function wfRandom() {
 305         # The maximum random value is "only" 2^31-1, so get two random
 306         # values to reduce the chance of dupes
 307         $max = mt_getrandmax() + 1;
 308         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 309                 / $max / $max, 12, '.', '' );
 310         return $rand;
 311 }
 312
 313 /**
 314  * Get a random string containing a number of pesudo-random hex
 315  * characters.
 316  * @note This is not secure, if you are trying to generate some sort
 317  *       of token please use MWCryptRand instead.
 318  *
 319  * @param $length int The length of the string to generate
 320  * @return String
 321  * @since 1.20
 322  */
 323 function wfRandomString( $length = 32 ) {
 324         $str = '';
 325         while ( strlen( $str ) < $length ) {
 326                 $str .= dechex( mt_rand() );
 327         }
 328         return substr( $str, 0, $length );
 329 }
 330
 331 /**
 332  * We want some things to be included as literal characters in our title URLs
 333  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 334  * all of the following should be safe:
 335  *
 336  * ;:@&=$-_.+!*'(),
 337  *
 338  * But + is not safe because it's used to indicate a space; &= are only safe in
 339  * paths and not in queries (and we don't distinguish here); ' seems kind of
 340  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 341  * is reserved, we don't care.  So the list we unescape is:
 342  *
 343  * ;:@$!*(),/
 344  *
 345  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 346  * so no fancy : for IIS7.
 347  *
 348  * %2F in the page titles seems to fatally break for some reason.
 349  *
 350  * @param $s String:
 351  * @return string
 352 */
 353 function wfUrlencode( $s ) {
 354         static $needle;
 355         if ( is_null( $s ) ) {
 356                 $needle = null;
 357                 return '';
 358         }
 359
 360         if ( is_null( $needle ) ) {
 361                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 362                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 363                         $needle[] = '%3A';
 364                 }
 365         }
 366
 367         $s = urlencode( $s );
 368         $s = str_ireplace(
 369                 $needle,
 370                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 371                 $s
 372         );
 373
 374         return $s;
 375 }
 376
 377 /**
 378  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 379  * "days=7&limit=100". Options in the first array override options in the second.
 380  * Options set to null or false will not be output.
 381  *
 382  * @param $array1 Array ( String|Array )
 383  * @param $array2 Array ( String|Array )
 384  * @param $prefix String
 385  * @return String
 386  */
 387 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 388         if ( !is_null( $array2 ) ) {
 389                 $array1 = $array1 + $array2;
 390         }
 391
 392         $cgi = '';
 393         foreach ( $array1 as $key => $value ) {
 394                 if ( $value !== false ) {
 395                         if ( $cgi != '' ) {
 396                                 $cgi .= '&';
 397                         }
 398                         if ( $prefix !== '' ) {
 399                                 $key = $prefix . "[$key]";
 400                         }
 401                         if ( is_array( $value ) ) {
 402                                 $firstTime = true;
 403                                 foreach ( $value as $k => $v ) {
 404                                         $cgi .= $firstTime ? '' : '&';
 405                                         if ( is_array( $v ) ) {
 406                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 407                                         } else {
 408                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 409                                         }
 410                                         $firstTime = false;
 411                                 }
 412                         } else {
 413                                 if ( is_object( $value ) ) {
 414                                         $value = $value->__toString();
 415                                 } elseif( !is_null( $value ) ) {
 416                                         $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 417                                 } else {
 418                                         $cgi .= urlencode( $key );
 419                                 }
 420                         }
 421                 }
 422         }
 423         return $cgi;
 424 }
 425
 426 /**
 427  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 428  * its argument and returns the same string in array form.  This allows compa-
 429  * tibility with legacy functions that accept raw query strings instead of nice
 430  * arrays.  Of course, keys and values are urldecode()d.
 431  *
 432  * @param $query String: query string
 433  * @return array Array version of input
 434  */
 435 function wfCgiToArray( $query ) {
 436         if ( isset( $query[0] ) && $query[0] == '?' ) {
 437                 $query = substr( $query, 1 );
 438         }
 439         $bits = explode( '&', $query );
 440         $ret = array();
 441         foreach ( $bits as $bit ) {
 442                 if ( $bit === '' ) {
 443                         continue;
 444                 }
 445                 if ( strpos( $bit, '=' ) === false ) {
 446                         // Pieces like &qwerty become 'qwerty' => null
 447                         $key = urldecode( $bit );
 448                         $value = null;
 449                 } else {
 450                         list( $key, $value ) = explode( '=', $bit );
 451                         $key = urldecode( $key );
 452                         $value = urldecode( $value );
 453                 }
 454
 455                 if ( strpos( $key, '[' ) !== false ) {
 456                         $keys = array_reverse( explode( '[', $key ) );
 457                         $key = array_pop( $keys );
 458                         $temp = $value;
 459                         foreach ( $keys as $k ) {
 460                                 $k = substr( $k, 0, -1 );
 461                                 $temp = array( $k => $temp );
 462                         }
 463                         if ( isset( $ret[$key] ) ) {
 464                                 $ret[$key] = array_merge( $ret[$key], $temp );
 465                         } else {
 466                                 $ret[$key] = $temp;
 467                         }
 468                 } else {
 469                         $ret[$key] = $value;
 470                 }
 471         }
 472         return $ret;
 473 }
 474
 475 /**
 476  * Append a query string to an existing URL, which may or may not already
 477  * have query string parameters already. If so, they will be combined.
 478  *
 479  * @deprecated in 1.20. Use Uri class.
 480  * @param $url String
 481  * @param $query Mixed: string or associative array
 482  * @return string
 483  */
 484 function wfAppendQuery( $url, $query ) {
 485         $obj = new Uri( $url );
 486         $obj->extendQuery( $query );
 487         return $obj->toString();
 488 }
 489
 490 /**
 491  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 492  * is correct.
 493  *
 494  * The meaning of the PROTO_* constants is as follows:
 495  * PROTO_HTTP: Output a URL starting with http://
 496  * PROTO_HTTPS: Output a URL starting with https://
 497  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 498  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 499  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 500  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 501  *
 502  * @todo this won't work with current-path-relative URLs
 503  * like "subdir/foo.html", etc.
 504  *
 505  * @param $url String: either fully-qualified or a local path + query
 506  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 507  *                             protocol to use if $url or $wgServer is
 508  *                             protocol-relative
 509  * @return string Fully-qualified URL, current-path-relative URL or false if
 510  *                no valid URL can be constructed
 511  */
 512 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 513         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 514         $serverUrl = $wgServer;
 515         if ( $defaultProto === PROTO_CANONICAL ) {
 516                 $serverUrl = $wgCanonicalServer;
 517         }
 518         // Make $wgInternalServer fall back to $wgServer if not set
 519         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 520                 $serverUrl = $wgInternalServer;
 521         }
 522         if ( $defaultProto === PROTO_CURRENT ) {
 523                 $defaultProto = WebRequest::detectProtocol() . '://';
 524         }
 525
 526         // Analyze $serverUrl to obtain its protocol
 527         $bits = wfParseUrl( $serverUrl );
 528         $serverHasProto = $bits && $bits['scheme'] != '';
 529
 530         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 531                 if ( $serverHasProto ) {
 532                         $defaultProto = $bits['scheme'] . '://';
 533                 } else {
 534                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 535                         // Fall back to HTTP in this ridiculous case
 536                         $defaultProto = PROTO_HTTP;
 537                 }
 538         }
 539
 540         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 541
 542         if ( substr( $url, 0, 2 ) == '//' ) {
 543                 $url = $defaultProtoWithoutSlashes . $url;
 544         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 545                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 546                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 547         }
 548
 549         $bits = wfParseUrl( $url );
 550         if ( $bits && isset( $bits['path'] ) ) {
 551                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 552                 return wfAssembleUrl( $bits );
 553         } elseif ( $bits ) {
 554                 # No path to expand
 555                 return $url;
 556         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 557                 # URL is a relative path
 558                 return wfRemoveDotSegments( $url );
 559         }
 560
 561         # Expanded URL is not valid.
 562         return false;
 563 }
 564
 565 /**
 566  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 567  * if you need to edit part of a URL and put it back together.
 568  *
 569  * This is the basic structure used (brackets contain keys for $urlParts):
 570  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 571  *
 572  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 573  *
 574  * @since 1.19
 575  * @deprecated
 576  * @param $urlParts Array URL parts, as output from wfParseUrl
 577  * @return string URL assembled from its component parts
 578  */
 579 function wfAssembleUrl( $urlParts ) {
 580         $obj = new Uri( $urlParts );
 581         return $obj->toString();
 582 }
 583
 584 /**
 585  * Remove all dot-segments in the provided URL path.  For example,
 586  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 587  * RFC3986 section 5.2.4.
 588  *
 589  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 590  *
 591  * @param $urlPath String URL path, potentially containing dot-segments
 592  * @return string URL path with all dot-segments removed
 593  */
 594 function wfRemoveDotSegments( $urlPath ) {
 595         $output = '';
 596         $inputOffset = 0;
 597         $inputLength = strlen( $urlPath );
 598
 599         while ( $inputOffset < $inputLength ) {
 600                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 601                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 602                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 603                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 604                 $trimOutput = false;
 605
 606                 if ( $prefixLengthTwo == './' ) {
 607                         # Step A, remove leading "./"
 608                         $inputOffset += 2;
 609                 } elseif ( $prefixLengthThree == '../' ) {
 610                         # Step A, remove leading "../"
 611                         $inputOffset += 3;
 612                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 613                         # Step B, replace leading "/.$" with "/"
 614                         $inputOffset += 1;
 615                         $urlPath[$inputOffset] = '/';
 616                 } elseif ( $prefixLengthThree == '/./' ) {
 617                         # Step B, replace leading "/./" with "/"
 618                         $inputOffset += 2;
 619                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 620                         # Step C, replace leading "/..$" with "/" and
 621                         # remove last path component in output
 622                         $inputOffset += 2;
 623                         $urlPath[$inputOffset] = '/';
 624                         $trimOutput = true;
 625                 } elseif ( $prefixLengthFour == '/../' ) {
 626                         # Step C, replace leading "/../" with "/" and
 627                         # remove last path component in output
 628                         $inputOffset += 3;
 629                         $trimOutput = true;
 630                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 631                         # Step D, remove "^.$"
 632                         $inputOffset += 1;
 633                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 634                         # Step D, remove "^..$"
 635                         $inputOffset += 2;
 636                 } else {
 637                         # Step E, move leading path segment to output
 638                         if ( $prefixLengthOne == '/' ) {
 639                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 640                         } else {
 641                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 642                         }
 643                         if ( $slashPos === false ) {
 644                                 $output .= substr( $urlPath, $inputOffset );
 645                                 $inputOffset = $inputLength;
 646                         } else {
 647                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 648                                 $inputOffset += $slashPos - $inputOffset;
 649                         }
 650                 }
 651
 652                 if ( $trimOutput ) {
 653                         $slashPos = strrpos( $output, '/' );
 654                         if ( $slashPos === false ) {
 655                                 $output = '';
 656                         } else {
 657                                 $output = substr( $output, 0, $slashPos );
 658                         }
 659                 }
 660         }
 661
 662         return $output;
 663 }
 664
 665 /**
 666  * Returns a regular expression of url protocols
 667  *
 668  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 669  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 670  * @return String
 671  */
 672 function wfUrlProtocols( $includeProtocolRelative = true ) {
 673         global $wgUrlProtocols;
 674
 675         // Cache return values separately based on $includeProtocolRelative
 676         static $withProtRel = null, $withoutProtRel = null;
 677         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 678         if ( !is_null( $cachedValue ) ) {
 679                 return $cachedValue;
 680         }
 681
 682         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 683         // with LocalSettings files from 1.5
 684         if ( is_array( $wgUrlProtocols ) ) {
 685                 $protocols = array();
 686                 foreach ( $wgUrlProtocols as $protocol ) {
 687                         // Filter out '//' if !$includeProtocolRelative
 688                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 689                                 $protocols[] = preg_quote( $protocol, '/' );
 690                         }
 691                 }
 692
 693                 $retval = implode( '|', $protocols );
 694         } else {
 695                 // Ignore $includeProtocolRelative in this case
 696                 // This case exists for pre-1.6 compatibility, and we can safely assume
 697                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 698                 // URLs weren't supported until 1.18
 699                 $retval = $wgUrlProtocols;
 700         }
 701
 702         // Cache return value
 703         if ( $includeProtocolRelative ) {
 704                 $withProtRel = $retval;
 705         } else {
 706                 $withoutProtRel = $retval;
 707         }
 708         return $retval;
 709 }
 710
 711 /**
 712  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 713  * you need a regex that matches all URL protocols but does not match protocol-
 714  * relative URLs
 715  * @return String
 716  */
 717 function wfUrlProtocolsWithoutProtRel() {
 718         return wfUrlProtocols( false );
 719 }
 720
 721 /**
 722  * parse_url() work-alike, but non-broken.  Differences:
 723  *
 724  * 1) Does not raise warnings on bad URLs (just returns false)
 725  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 726  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 727  *
 728  * @deprecated
 729  * @param $url String: a URL to parse
 730  * @return Array: bits of the URL in an associative array, per PHP docs
 731  */
 732 function wfParseUrl( $url ) {
 733         $obj = new Uri( $url );
 734         return $obj->getComponents();
 735 }
 736
 737 /**
 738  * Take a URL, make sure it's expanded to fully qualified, and replace any
 739  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 740  * for more compact display and legibility for local audiences.
 741  *
 742  * @todo handle punycode domains too
 743  *
 744  * @param $url string
 745  * @return string
 746  */
 747 function wfExpandIRI( $url ) {
 748         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 749 }
 750
 751 /**
 752  * Private callback for wfExpandIRI
 753  * @param array $matches
 754  * @return string
 755  */
 756 function wfExpandIRI_callback( $matches ) {
 757         return urldecode( $matches[1] );
 758 }
 759
 760
 761
 762 /**
 763  * Make URL indexes, appropriate for the el_index field of externallinks.
 764  *
 765  * @param $url String
 766  * @return array
 767  */
 768 function wfMakeUrlIndexes( $url ) {
 769         $bits = wfParseUrl( $url );
 770
 771         // Reverse the labels in the hostname, convert to lower case
 772         // For emails reverse domainpart only
 773         if ( $bits['scheme'] == 'mailto' ) {
 774                 $mailparts = explode( '@', $bits['host'], 2 );
 775                 if ( count( $mailparts ) === 2 ) {
 776                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 777                 } else {
 778                         // No domain specified, don't mangle it
 779                         $domainpart = '';
 780                 }
 781                 $reversedHost = $domainpart . '@' . $mailparts[0];
 782         } else {
 783                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 784         }
 785         // Add an extra dot to the end
 786         // Why? Is it in wrong place in mailto links?
 787         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 788                 $reversedHost .= '.';
 789         }
 790         // Reconstruct the pseudo-URL
 791         $prot = $bits['scheme'];
 792         $index = $prot . $bits['delimiter'] . $reversedHost;
 793         // Leave out user and password. Add the port, path, query and fragment
 794         if ( isset( $bits['port'] ) ) {
 795                 $index .= ':' . $bits['port'];
 796         }
 797         if ( isset( $bits['path'] ) ) {
 798                 $index .= $bits['path'];
 799         } else {
 800                 $index .= '/';
 801         }
 802         if ( isset( $bits['query'] ) ) {
 803                 $index .= '?' . $bits['query'];
 804         }
 805         if ( isset( $bits['fragment'] ) ) {
 806                 $index .= '#' . $bits['fragment'];
 807         }
 808
 809         if ( $prot == '' ) {
 810                 return array( "http:$index", "https:$index" );
 811         } else {
 812                 return array( $index );
 813         }
 814 }
 815
 816 /**
 817  * Check whether a given URL has a domain that occurs in a given set of domains
 818  * @param $url string URL
 819  * @param $domains array Array of domains (strings)
 820  * @return bool True if the host part of $url ends in one of the strings in $domains
 821  */
 822 function wfMatchesDomainList( $url, $domains ) {
 823         $bits = wfParseUrl( $url );
 824         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 825                 foreach ( (array)$domains as $domain ) {
 826                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 827                         // We should use something that interprets dots instead
 828                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 829                                 return true;
 830                         }
 831                 }
 832         }
 833         return false;
 834 }
 835
 836 /**
 837  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 838  * In normal operation this is a NOP.
 839  *
 840  * Controlling globals:
 841  * $wgDebugLogFile - points to the log file
 842  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 843  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 844  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 845  *
 846  * @param $text String
 847  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 848  */
 849 function wfDebug( $text, $logonly = false ) {
 850         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 851
 852         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 853                 return;
 854         }
 855
 856         $timer = wfDebugTimer();
 857         if ( $timer !== '' ) {
 858                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 859         }
 860
 861         if ( !$logonly ) {
 862                 MWDebug::debugMsg( $text );
 863         }
 864
 865         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 866                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 867                         # Strip unprintables; they can switch terminal modes when binary data
 868                         # gets dumped, which is pretty annoying.
 869                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 870                         $text = $wgDebugLogPrefix . $text;
 871                         wfErrorLog( $text, $wgDebugLogFile );
 872                 }
 873         }
 874 }
 875
 876 /**
 877  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 878  * @return bool
 879  */
 880 function wfIsDebugRawPage() {
 881         static $cache;
 882         if ( $cache !== null ) {
 883                 return $cache;
 884         }
 885         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 886         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 887                 || (
 888                         isset( $_SERVER['SCRIPT_NAME'] )
 889                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 890                 ) )
 891         {
 892                 $cache = true;
 893         } else {
 894                 $cache = false;
 895         }
 896         return $cache;
 897 }
 898
 899 /**
 900  * Get microsecond timestamps for debug logs
 901  *
 902  * @return string
 903  */
 904 function wfDebugTimer() {
 905         global $wgDebugTimestamps, $wgRequestTime;
 906
 907         if ( !$wgDebugTimestamps ) {
 908                 return '';
 909         }
 910
 911         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 912         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 913         return "$prefix $mem  ";
 914 }
 915
 916 /**
 917  * Send a line giving PHP memory usage.
 918  *
 919  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 920  */
 921 function wfDebugMem( $exact = false ) {
 922         $mem = memory_get_usage();
 923         if( !$exact ) {
 924                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 925         } else {
 926                 $mem .= ' bytes';
 927         }
 928         wfDebug( "Memory usage: $mem\n" );
 929 }
 930
 931 /**
 932  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 933  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 934  *
 935  * @param $logGroup String
 936  * @param $text String
 937  * @param $public Bool: whether to log the event in the public log if no private
 938  *                     log file is specified, (default true)
 939  */
 940 function wfDebugLog( $logGroup, $text, $public = true ) {
 941         global $wgDebugLogGroups;
 942         $text = trim( $text ) . "\n";
 943         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 944                 $time = wfTimestamp( TS_DB );
 945                 $wiki = wfWikiID();
 946                 $host = wfHostname();
 947                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 948                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 949                 }
 950         } elseif ( $public === true ) {
 951                 wfDebug( $text, true );
 952         }
 953 }
 954
 955 /**
 956  * Log for database errors
 957  *
 958  * @param $text String: database error message.
 959  */
 960 function wfLogDBError( $text ) {
 961         global $wgDBerrorLog, $wgDBerrorLogTZ;
 962         static $logDBErrorTimeZoneObject = null;
 963
 964         if ( $wgDBerrorLog ) {
 965                 $host = wfHostname();
 966                 $wiki = wfWikiID();
 967
 968                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
 969                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
 970                 }
 971
 972                 // Workaround for https://bugs.php.net/bug.php?id=52063
 973                 // Can be removed when min PHP > 5.3.2
 974                 if ( $logDBErrorTimeZoneObject === null ) {
 975                         $d = date_create( "now" );
 976                 } else {
 977                         $d = date_create( "now", $logDBErrorTimeZoneObject );
 978                 }
 979                 $date = $d->format( 'D M j G:i:s T Y' );
 980
 981                 $text = "$date\t$host\t$wiki\t$text";
 982                 wfErrorLog( $text, $wgDBerrorLog );
 983         }
 984 }
 985
 986 /**
 987  * Throws a warning that $function is deprecated
 988  *
 989  * @param $function String
 990  * @param $version String|bool: Version of MediaWiki that the function was deprecated in (Added in 1.19).
 991  * @param $component String|bool: Added in 1.19.
 992  * @param $callerOffset integer: How far up the callstack is the original
 993  *    caller. 2 = function that called the function that called
 994  *    wfDeprecated (Added in 1.20)
 995  *
 996  * @return null
 997  */
 998 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
 999         static $functionsWarned = array();
1000
1001         MWDebug::deprecated( $function, $version, $component );
1002
1003         if ( !isset( $functionsWarned[$function] ) ) {
1004                 $functionsWarned[$function] = true;
1005
1006                 if ( $version ) {
1007                         global $wgDeprecationReleaseLimit;
1008
1009                         if ( $wgDeprecationReleaseLimit && $component === false ) {
1010                                 # Strip -* off the end of $version so that branches can use the
1011                                 # format #.##-branchname to avoid issues if the branch is merged into
1012                                 # a version of MediaWiki later than what it was branched from
1013                                 $comparableVersion = preg_replace( '/-.*$/', '', $version );
1014
1015                                 # If the comparableVersion is larger than our release limit then
1016                                 # skip the warning message for the deprecation
1017                                 if ( version_compare( $wgDeprecationReleaseLimit, $comparableVersion, '<' ) ) {
1018                                         return;
1019                                 }
1020                         }
1021
1022                         $component = $component === false ? 'MediaWiki' : $component;
1023                         wfWarn( "Use of $function was deprecated in $component $version.", $callerOffset );
1024                 } else {
1025                         wfWarn( "Use of $function is deprecated.", $callerOffset );
1026                 }
1027         }
1028 }
1029
1030 /**
1031  * Send a warning either to the debug log or in a PHP error depending on
1032  * $wgDevelopmentWarnings
1033  *
1034  * @param $msg String: message to send
1035  * @param $callerOffset Integer: number of items to go back in the backtrace to
1036  *        find the correct caller (1 = function calling wfWarn, ...)
1037  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1038  *        is true
1039  */
1040 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1041         global $wgDevelopmentWarnings;
1042
1043         MWDebug::warning( $msg, $callerOffset + 2 );
1044
1045         $callers = wfDebugBacktrace();
1046         if ( isset( $callers[$callerOffset + 1] ) ) {
1047                 $callerfunc = $callers[$callerOffset + 1];
1048                 $callerfile = $callers[$callerOffset];
1049                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
1050                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
1051                 } else {
1052                         $file = '(internal function)';
1053                 }
1054                 $func = '';
1055                 if ( isset( $callerfunc['class'] ) ) {
1056                         $func .= $callerfunc['class'] . '::';
1057                 }
1058                 if ( isset( $callerfunc['function'] ) ) {
1059                         $func .= $callerfunc['function'];
1060                 }
1061                 $msg .= " [Called from $func in $file]";
1062         }
1063
1064         if ( $wgDevelopmentWarnings ) {
1065                 trigger_error( $msg, $level );
1066         } else {
1067                 wfDebug( "$msg\n" );
1068         }
1069 }
1070
1071 /**
1072  * Log to a file without getting "file size exceeded" signals.
1073  *
1074  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1075  * send lines to the specified port, prefixed by the specified prefix and a space.
1076  *
1077  * @param $text String
1078  * @param $file String filename
1079  */
1080 function wfErrorLog( $text, $file ) {
1081         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1082                 # Needs the sockets extension
1083                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1084                         // IPv6 bracketed host
1085                         $host = $m[2];
1086                         $port = intval( $m[3] );
1087                         $prefix = isset( $m[4] ) ? $m[4] : false;
1088                         $domain = AF_INET6;
1089                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1090                         $host = $m[2];
1091                         if ( !IP::isIPv4( $host ) ) {
1092                                 $host = gethostbyname( $host );
1093                         }
1094                         $port = intval( $m[3] );
1095                         $prefix = isset( $m[4] ) ? $m[4] : false;
1096                         $domain = AF_INET;
1097                 } else {
1098                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1099                 }
1100
1101                 // Clean it up for the multiplexer
1102                 if ( strval( $prefix ) !== '' ) {
1103                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1104
1105                         // Limit to 64KB
1106                         if ( strlen( $text ) > 65506 ) {
1107                                 $text = substr( $text, 0, 65506 );
1108                         }
1109
1110                         if ( substr( $text, -1 ) != "\n" ) {
1111                                 $text .= "\n";
1112                         }
1113                 } elseif ( strlen( $text ) > 65507 ) {
1114                         $text = substr( $text, 0, 65507 );
1115                 }
1116
1117                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1118                 if ( !$sock ) {
1119                         return;
1120                 }
1121
1122                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1123                 socket_close( $sock );
1124         } else {
1125                 wfSuppressWarnings();
1126                 $exists = file_exists( $file );
1127                 $size = $exists ? filesize( $file ) : false;
1128                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1129                         file_put_contents( $file, $text, FILE_APPEND );
1130                 }
1131                 wfRestoreWarnings();
1132         }
1133 }
1134
1135 /**
1136  * @todo document
1137  */
1138 function wfLogProfilingData() {
1139         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1140         global $wgProfileLimit, $wgUser;
1141
1142         $profiler = Profiler::instance();
1143
1144         # Profiling must actually be enabled...
1145         if ( $profiler->isStub() ) {
1146                 return;
1147         }
1148
1149         // Get total page request time and only show pages that longer than
1150         // $wgProfileLimit time (default is 0)
1151         $elapsed = microtime( true ) - $wgRequestTime;
1152         if ( $elapsed <= $wgProfileLimit ) {
1153                 return;
1154         }
1155
1156         $profiler->logData();
1157
1158         // Check whether this should be logged in the debug file.
1159         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1160                 return;
1161         }
1162
1163         $forward = '';
1164         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1165                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1166         }
1167         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1168                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1169         }
1170         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1171                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1172         }
1173         if ( $forward ) {
1174                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1175         }
1176         // Don't load $wgUser at this late stage just for statistics purposes
1177         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1178         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1179                 $forward .= ' anon';
1180         }
1181         $log = sprintf( "%s\t%04.3f\t%s\n",
1182                 gmdate( 'YmdHis' ), $elapsed,
1183                 urldecode( $wgRequest->getRequestURL() . $forward ) );
1184
1185         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1186 }
1187
1188 /**
1189  * Increment a statistics counter
1190  *
1191  * @param $key String
1192  * @param $count Int
1193  */
1194 function wfIncrStats( $key, $count = 1 ) {
1195         global $wgStatsMethod;
1196
1197         $count = intval( $count );
1198
1199         if( $wgStatsMethod == 'udp' ) {
1200                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
1201                 static $socket;
1202
1203                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
1204
1205                 if ( !$socket ) {
1206                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1207                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1208                         socket_sendto(
1209                                 $socket,
1210                                 $statline,
1211                                 strlen( $statline ),
1212                                 0,
1213                                 $wgUDPProfilerHost,
1214                                 $wgUDPProfilerPort
1215                         );
1216                 }
1217                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1218                 wfSuppressWarnings();
1219                 socket_sendto(
1220                         $socket,
1221                         $statline,
1222                         strlen( $statline ),
1223                         0,
1224                         $wgUDPProfilerHost,
1225                         $wgUDPProfilerPort
1226                 );
1227                 wfRestoreWarnings();
1228         } elseif( $wgStatsMethod == 'cache' ) {
1229                 global $wgMemc;
1230                 $key = wfMemcKey( 'stats', $key );
1231                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1232                         $wgMemc->add( $key, $count );
1233                 }
1234         } else {
1235                 // Disabled
1236         }
1237 }
1238
1239 /**
1240  * Check if the wiki read-only lock file is present. This can be used to lock
1241  * off editing functions, but doesn't guarantee that the database will not be
1242  * modified.
1243  *
1244  * @return bool
1245  */
1246 function wfReadOnly() {
1247         global $wgReadOnlyFile, $wgReadOnly;
1248
1249         if ( !is_null( $wgReadOnly ) ) {
1250                 return (bool)$wgReadOnly;
1251         }
1252         if ( $wgReadOnlyFile == '' ) {
1253                 return false;
1254         }
1255         // Set $wgReadOnly for faster access next time
1256         if ( is_file( $wgReadOnlyFile ) ) {
1257                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1258         } else {
1259                 $wgReadOnly = false;
1260         }
1261         return (bool)$wgReadOnly;
1262 }
1263
1264 /**
1265  * @return bool
1266  */
1267 function wfReadOnlyReason() {
1268         global $wgReadOnly;
1269         wfReadOnly();
1270         return $wgReadOnly;
1271 }
1272
1273 /**
1274  * Return a Language object from $langcode
1275  *
1276  * @param $langcode Mixed: either:
1277  *                  - a Language object
1278  *                  - code of the language to get the message for, if it is
1279  *                    a valid code create a language for that language, if
1280  *                    it is a string but not a valid code then make a basic
1281  *                    language object
1282  *                  - a boolean: if it's false then use the global object for
1283  *                    the current user's language (as a fallback for the old parameter
1284  *                    functionality), or if it is true then use global object
1285  *                    for the wiki's content language.
1286  * @return Language object
1287  */
1288 function wfGetLangObj( $langcode = false ) {
1289         # Identify which language to get or create a language object for.
1290         # Using is_object here due to Stub objects.
1291         if( is_object( $langcode ) ) {
1292                 # Great, we already have the object (hopefully)!
1293                 return $langcode;
1294         }
1295
1296         global $wgContLang, $wgLanguageCode;
1297         if( $langcode === true || $langcode === $wgLanguageCode ) {
1298                 # $langcode is the language code of the wikis content language object.
1299                 # or it is a boolean and value is true
1300                 return $wgContLang;
1301         }
1302
1303         global $wgLang;
1304         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1305                 # $langcode is the language code of user language object.
1306                 # or it was a boolean and value is false
1307                 return $wgLang;
1308         }
1309
1310         $validCodes = array_keys( Language::fetchLanguageNames() );
1311         if( in_array( $langcode, $validCodes ) ) {
1312                 # $langcode corresponds to a valid language.
1313                 return Language::factory( $langcode );
1314         }
1315
1316         # $langcode is a string, but not a valid language code; use content language.
1317         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1318         return $wgContLang;
1319 }
1320
1321 /**
1322  * Old function when $wgBetterDirectionality existed
1323  * All usage removed, wfUILang can be removed in near future
1324  *
1325  * @deprecated since 1.18
1326  * @return Language
1327  */
1328 function wfUILang() {
1329         wfDeprecated( __METHOD__, '1.18' );
1330         global $wgLang;
1331         return $wgLang;
1332 }
1333
1334 /**
1335  * This is the new function for getting translated interface messages.
1336  * See the Message class for documentation how to use them.
1337  * The intention is that this function replaces all old wfMsg* functions.
1338  * @param $key \string Message key.
1339  * Varargs: normal message parameters.
1340  * @return Message
1341  * @since 1.17
1342  */
1343 function wfMessage( $key /*...*/) {
1344         $params = func_get_args();
1345         array_shift( $params );
1346         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1347                 $params = $params[0];
1348         }
1349         return new Message( $key, $params );
1350 }
1351
1352 /**
1353  * This function accepts multiple message keys and returns a message instance
1354  * for the first message which is non-empty. If all messages are empty then an
1355  * instance of the first message key is returned.
1356  * @param varargs: message keys
1357  * @return Message
1358  * @since 1.18
1359  */
1360 function wfMessageFallback( /*...*/ ) {
1361         $args = func_get_args();
1362         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1363 }
1364
1365 /**
1366  * Get a message from anywhere, for the current user language.
1367  *
1368  * Use wfMsgForContent() instead if the message should NOT
1369  * change depending on the user preferences.
1370  *
1371  * @deprecated since 1.18
1372  *
1373  * @param $key String: lookup key for the message, usually
1374  *    defined in languages/Language.php
1375  *
1376  * Parameters to the message, which can be used to insert variable text into
1377  * it, can be passed to this function in the following formats:
1378  * - One per argument, starting at the second parameter
1379  * - As an array in the second parameter
1380  * These are not shown in the function definition.
1381  *
1382  * @return String
1383  */
1384 function wfMsg( $key ) {
1385         $args = func_get_args();
1386         array_shift( $args );
1387         return wfMsgReal( $key, $args );
1388 }
1389
1390 /**
1391  * Same as above except doesn't transform the message
1392  *
1393  * @deprecated since 1.18
1394  *
1395  * @param $key String
1396  * @return String
1397  */
1398 function wfMsgNoTrans( $key ) {
1399         $args = func_get_args();
1400         array_shift( $args );
1401         return wfMsgReal( $key, $args, true, false, false );
1402 }
1403
1404 /**
1405  * Get a message from anywhere, for the current global language
1406  * set with $wgLanguageCode.
1407  *
1408  * Use this if the message should NOT change dependent on the
1409  * language set in the user's preferences. This is the case for
1410  * most text written into logs, as well as link targets (such as
1411  * the name of the copyright policy page). Link titles, on the
1412  * other hand, should be shown in the UI language.
1413  *
1414  * Note that MediaWiki allows users to change the user interface
1415  * language in their preferences, but a single installation
1416  * typically only contains content in one language.
1417  *
1418  * Be wary of this distinction: If you use wfMsg() where you should
1419  * use wfMsgForContent(), a user of the software may have to
1420  * customize potentially hundreds of messages in
1421  * order to, e.g., fix a link in every possible language.
1422  *
1423  * @deprecated since 1.18
1424  *
1425  * @param $key String: lookup key for the message, usually
1426  *     defined in languages/Language.php
1427  * @return String
1428  */
1429 function wfMsgForContent( $key ) {
1430         global $wgForceUIMsgAsContentMsg;
1431         $args = func_get_args();
1432         array_shift( $args );
1433         $forcontent = true;
1434         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1435                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1436         {
1437                 $forcontent = false;
1438         }
1439         return wfMsgReal( $key, $args, true, $forcontent );
1440 }
1441
1442 /**
1443  * Same as above except doesn't transform the message
1444  *
1445  * @deprecated since 1.18
1446  *
1447  * @param $key String
1448  * @return String
1449  */
1450 function wfMsgForContentNoTrans( $key ) {
1451         global $wgForceUIMsgAsContentMsg;
1452         $args = func_get_args();
1453         array_shift( $args );
1454         $forcontent = true;
1455         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1456                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1457         {
1458                 $forcontent = false;
1459         }
1460         return wfMsgReal( $key, $args, true, $forcontent, false );
1461 }
1462
1463 /**
1464  * Really get a message
1465  *
1466  * @deprecated since 1.18
1467  *
1468  * @param $key String: key to get.
1469  * @param $args
1470  * @param $useDB Boolean
1471  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1472  * @param $transform Boolean: Whether or not to transform the message.
1473  * @return String: the requested message.
1474  */
1475 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1476         wfProfileIn( __METHOD__ );
1477         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1478         $message = wfMsgReplaceArgs( $message, $args );
1479         wfProfileOut( __METHOD__ );
1480         return $message;
1481 }
1482
1483 /**
1484  * Fetch a message string value, but don't replace any keys yet.
1485  *
1486  * @deprecated since 1.18
1487  *
1488  * @param $key String
1489  * @param $useDB Bool
1490  * @param $langCode String: Code of the language to get the message for, or
1491  *                  behaves as a content language switch if it is a boolean.
1492  * @param $transform Boolean: whether to parse magic words, etc.
1493  * @return string
1494  */
1495 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1496         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1497
1498         $cache = MessageCache::singleton();
1499         $message = $cache->get( $key, $useDB, $langCode );
1500         if( $message === false ) {
1501                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1502         } elseif ( $transform ) {
1503                 $message = $cache->transform( $message );
1504         }
1505         return $message;
1506 }
1507
1508 /**
1509  * Replace message parameter keys on the given formatted output.
1510  *
1511  * @deprecated since 1.18
1512  *
1513  * @param $message String
1514  * @param $args Array
1515  * @return string
1516  * @private
1517  */
1518 function wfMsgReplaceArgs( $message, $args ) {
1519         # Fix windows line-endings
1520         # Some messages are split with explode("\n", $msg)
1521         $message = str_replace( "\r", '', $message );
1522
1523         // Replace arguments
1524         if ( count( $args ) ) {
1525                 if ( is_array( $args[0] ) ) {
1526                         $args = array_values( $args[0] );
1527                 }
1528                 $replacementKeys = array();
1529                 foreach( $args as $n => $param ) {
1530                         $replacementKeys['$' . ( $n + 1 )] = $param;
1531                 }
1532                 $message = strtr( $message, $replacementKeys );
1533         }
1534
1535         return $message;
1536 }
1537
1538 /**
1539  * Return an HTML-escaped version of a message.
1540  * Parameter replacements, if any, are done *after* the HTML-escaping,
1541  * so parameters may contain HTML (eg links or form controls). Be sure
1542  * to pre-escape them if you really do want plaintext, or just wrap
1543  * the whole thing in htmlspecialchars().
1544  *
1545  * @deprecated since 1.18
1546  *
1547  * @param $key String
1548  * @param string ... parameters
1549  * @return string
1550  */
1551 function wfMsgHtml( $key ) {
1552         $args = func_get_args();
1553         array_shift( $args );
1554         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1555 }
1556
1557 /**
1558  * Return an HTML version of message
1559  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1560  * so parameters may contain HTML (eg links or form controls). Be sure
1561  * to pre-escape them if you really do want plaintext, or just wrap
1562  * the whole thing in htmlspecialchars().
1563  *
1564  * @deprecated since 1.18
1565  *
1566  * @param $key String
1567  * @param string ... parameters
1568  * @return string
1569  */
1570 function wfMsgWikiHtml( $key ) {
1571         $args = func_get_args();
1572         array_shift( $args );
1573         return wfMsgReplaceArgs(
1574                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1575                 /* can't be set to false */ true, /* interface */ true )->getText(),
1576                 $args );
1577 }
1578
1579 /**
1580  * Returns message in the requested format
1581  *
1582  * @deprecated since 1.18
1583  *
1584  * @param $key String: key of the message
1585  * @param $options Array: processing rules. Can take the following options:
1586  *   <i>parse</i>: parses wikitext to HTML
1587  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1588  *       p's added by parser or tidy
1589  *   <i>escape</i>: filters message through htmlspecialchars
1590  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1591  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1592  *   <i>parsemag</i>: transform the message using magic phrases
1593  *   <i>content</i>: fetch message for content language instead of interface
1594  * Also can accept a single associative argument, of the form 'language' => 'xx':
1595  *   <i>language</i>: Language object or language code to fetch message for
1596  *       (overriden by <i>content</i>).
1597  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1598  *
1599  * @return String
1600  */
1601 function wfMsgExt( $key, $options ) {
1602         $args = func_get_args();
1603         array_shift( $args );
1604         array_shift( $args );
1605         $options = (array)$options;
1606
1607         foreach( $options as $arrayKey => $option ) {
1608                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1609                         # An unknown index, neither numeric nor "language"
1610                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1611                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1612                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1613                 'replaceafter', 'parsemag', 'content' ) ) ) {
1614                         # A numeric index with unknown value
1615                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1616                 }
1617         }
1618
1619         if( in_array( 'content', $options, true ) ) {
1620                 $forContent = true;
1621                 $langCode = true;
1622                 $langCodeObj = null;
1623         } elseif( array_key_exists( 'language', $options ) ) {
1624                 $forContent = false;
1625                 $langCode = wfGetLangObj( $options['language'] );
1626                 $langCodeObj = $langCode;
1627         } else {
1628                 $forContent = false;
1629                 $langCode = false;
1630                 $langCodeObj = null;
1631         }
1632
1633         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1634
1635         if( !in_array( 'replaceafter', $options, true ) ) {
1636                 $string = wfMsgReplaceArgs( $string, $args );
1637         }
1638
1639         $messageCache = MessageCache::singleton();
1640         $parseInline = in_array( 'parseinline', $options, true );
1641         if( in_array( 'parse', $options, true ) || $parseInline ) {
1642                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1643                 if ( $string instanceof ParserOutput ) {
1644                         $string = $string->getText();
1645                 }
1646
1647                 if ( $parseInline ) {
1648                         $m = array();
1649                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1650                                 $string = $m[1];
1651                         }
1652                 }
1653         } elseif ( in_array( 'parsemag', $options, true ) ) {
1654                 $string = $messageCache->transform( $string,
1655                                 !$forContent, $langCodeObj );
1656         }
1657
1658         if ( in_array( 'escape', $options, true ) ) {
1659                 $string = htmlspecialchars ( $string );
1660         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1661                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1662         }
1663
1664         if( in_array( 'replaceafter', $options, true ) ) {
1665                 $string = wfMsgReplaceArgs( $string, $args );
1666         }
1667
1668         return $string;
1669 }
1670
1671 /**
1672  * Since wfMsg() and co suck, they don't return false if the message key they
1673  * looked up didn't exist but a XHTML string, this function checks for the
1674  * nonexistance of messages by checking the MessageCache::get() result directly.
1675  *
1676  * @deprecated since 1.18. Use Message::isDisabled().
1677  *
1678  * @param $key      String: the message key looked up
1679  * @return Boolean True if the message *doesn't* exist.
1680  */
1681 function wfEmptyMsg( $key ) {
1682         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1683 }
1684
1685 /**
1686  * Throw a debugging exception. This function previously once exited the process,
1687  * but now throws an exception instead, with similar results.
1688  *
1689  * @param $msg String: message shown when dying.
1690  */
1691 function wfDebugDieBacktrace( $msg = '' ) {
1692         throw new MWException( $msg );
1693 }
1694
1695 /**
1696  * Fetch server name for use in error reporting etc.
1697  * Use real server name if available, so we know which machine
1698  * in a server farm generated the current page.
1699  *
1700  * @return string
1701  */
1702 function wfHostname() {
1703         static $host;
1704         if ( is_null( $host ) ) {
1705
1706                 # Hostname overriding
1707                 global $wgOverrideHostname;
1708                 if( $wgOverrideHostname !== false ) {
1709                         # Set static and skip any detection
1710                         $host = $wgOverrideHostname;
1711                         return $host;
1712                 }
1713
1714                 if ( function_exists( 'posix_uname' ) ) {
1715                         // This function not present on Windows
1716                         $uname = posix_uname();
1717                 } else {
1718                         $uname = false;
1719                 }
1720                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1721                         $host = $uname['nodename'];
1722                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1723                         # Windows computer name
1724                         $host = getenv( 'COMPUTERNAME' );
1725                 } else {
1726                         # This may be a virtual server.
1727                         $host = $_SERVER['SERVER_NAME'];
1728                 }
1729         }
1730         return $host;
1731 }
1732
1733 /**
1734  * Returns a HTML comment with the elapsed time since request.
1735  * This method has no side effects.
1736  *
1737  * @return string
1738  */
1739 function wfReportTime() {
1740         global $wgRequestTime, $wgShowHostnames;
1741
1742         $elapsed = microtime( true ) - $wgRequestTime;
1743
1744         return $wgShowHostnames
1745                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1746                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1747 }
1748
1749 /**
1750  * Safety wrapper for debug_backtrace().
1751  *
1752  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1753  * murky circumstances, which may be triggered in part by stub objects
1754  * or other fancy talkin'.
1755  *
1756  * Will return an empty array if Zend Optimizer is detected or if
1757  * debug_backtrace is disabled, otherwise the output from
1758  * debug_backtrace() (trimmed).
1759  *
1760  * @param $limit int This parameter can be used to limit the number of stack frames returned
1761  *
1762  * @return array of backtrace information
1763  */
1764 function wfDebugBacktrace( $limit = 0 ) {
1765         static $disabled = null;
1766
1767         if( extension_loaded( 'Zend Optimizer' ) ) {
1768                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1769                 return array();
1770         }
1771
1772         if ( is_null( $disabled ) ) {
1773                 $disabled = false;
1774                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1775                 $functions = array_map( 'trim', $functions );
1776                 $functions = array_map( 'strtolower', $functions );
1777                 if ( in_array( 'debug_backtrace', $functions ) ) {
1778                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1779                         $disabled = true;
1780                 }
1781         }
1782         if ( $disabled ) {
1783                 return array();
1784         }
1785
1786         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1787                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1788         } else {
1789                 return array_slice( debug_backtrace(), 1 );
1790         }
1791 }
1792
1793 /**
1794  * Get a debug backtrace as a string
1795  *
1796  * @return string
1797  */
1798 function wfBacktrace() {
1799         global $wgCommandLineMode;
1800
1801         if ( $wgCommandLineMode ) {
1802                 $msg = '';
1803         } else {
1804                 $msg = "<ul>\n";
1805         }
1806         $backtrace = wfDebugBacktrace();
1807         foreach( $backtrace as $call ) {
1808                 if( isset( $call['file'] ) ) {
1809                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1810                         $file = $f[count( $f ) - 1];
1811                 } else {
1812                         $file = '-';
1813                 }
1814                 if( isset( $call['line'] ) ) {
1815                         $line = $call['line'];
1816                 } else {
1817                         $line = '-';
1818                 }
1819                 if ( $wgCommandLineMode ) {
1820                         $msg .= "$file line $line calls ";
1821                 } else {
1822                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1823                 }
1824                 if( !empty( $call['class'] ) ) {
1825                         $msg .= $call['class'] . $call['type'];
1826                 }
1827                 $msg .= $call['function'] . '()';
1828
1829                 if ( $wgCommandLineMode ) {
1830                         $msg .= "\n";
1831                 } else {
1832                         $msg .= "</li>\n";
1833                 }
1834         }
1835         if ( $wgCommandLineMode ) {
1836                 $msg .= "\n";
1837         } else {
1838                 $msg .= "</ul>\n";
1839         }
1840
1841         return $msg;
1842 }
1843
1844 /**
1845  * Get the name of the function which called this function
1846  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1847  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1848  * wfGetCaller( 3 ) is the parent of that.
1849  *
1850  * @param $level Int
1851  * @return Bool|string
1852  */
1853 function wfGetCaller( $level = 2 ) {
1854         $backtrace = wfDebugBacktrace( $level + 1 );
1855         if ( isset( $backtrace[$level] ) ) {
1856                 return wfFormatStackFrame( $backtrace[$level] );
1857         } else {
1858                 $caller = 'unknown';
1859         }
1860         return $caller;
1861 }
1862
1863 /**
1864  * Return a string consisting of callers in the stack. Useful sometimes
1865  * for profiling specific points.
1866  *
1867  * @param $limit int The maximum depth of the stack frame to return, or false for
1868  *               the entire stack.
1869  * @return String
1870  */
1871 function wfGetAllCallers( $limit = 3 ) {
1872         $trace = array_reverse( wfDebugBacktrace() );
1873         if ( !$limit || $limit > count( $trace ) - 1 ) {
1874                 $limit = count( $trace ) - 1;
1875         }
1876         $trace = array_slice( $trace, -$limit - 1, $limit );
1877         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1878 }
1879
1880 /**
1881  * Return a string representation of frame
1882  *
1883  * @param $frame Array
1884  * @return Bool
1885  */
1886 function wfFormatStackFrame( $frame ) {
1887         return isset( $frame['class'] ) ?
1888                 $frame['class'] . '::' . $frame['function'] :
1889                 $frame['function'];
1890 }
1891
1892
1893 /* Some generic result counters, pulled out of SearchEngine */
1894
1895
1896 /**
1897  * @todo document
1898  *
1899  * @param $offset Int
1900  * @param $limit Int
1901  * @return String
1902  */
1903 function wfShowingResults( $offset, $limit ) {
1904         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1905 }
1906
1907 /**
1908  * Generate (prev x| next x) (20|50|100...) type links for paging
1909  *
1910  * @param $offset String
1911  * @param $limit Integer
1912  * @param $link String
1913  * @param $query String: optional URL query parameter string
1914  * @param $atend Bool: optional param for specified if this is the last page
1915  * @return String
1916  * @deprecated in 1.19; use Language::viewPrevNext() instead
1917  */
1918 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1919         wfDeprecated( __METHOD__, '1.19' );
1920
1921         global $wgLang;
1922
1923         $query = wfCgiToArray( $query );
1924
1925         if( is_object( $link ) ) {
1926                 $title = $link;
1927         } else {
1928                 $title = Title::newFromText( $link );
1929                 if( is_null( $title ) ) {
1930                         return false;
1931                 }
1932         }
1933
1934         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1935 }
1936
1937 /**
1938  * Make a list item, used by various special pages
1939  *
1940  * @param $page String Page link
1941  * @param $details String Text between brackets
1942  * @param $oppositedm Boolean   Add the direction mark opposite to your
1943  *                                                              language, to display text properly
1944  * @return String
1945  * @deprecated since 1.19; use Language::specialList() instead
1946  */
1947 function wfSpecialList( $page, $details, $oppositedm = true ) {
1948         wfDeprecated( __METHOD__, '1.19' );
1949
1950         global $wgLang;
1951         return $wgLang->specialList( $page, $details, $oppositedm );
1952 }
1953
1954 /**
1955  * @todo document
1956  * @todo FIXME: We may want to blacklist some broken browsers
1957  *
1958  * @param $force Bool
1959  * @return bool Whereas client accept gzip compression
1960  */
1961 function wfClientAcceptsGzip( $force = false ) {
1962         static $result = null;
1963         if ( $result === null || $force ) {
1964                 $result = false;
1965                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1966                         # @todo FIXME: We may want to blacklist some broken browsers
1967                         $m = array();
1968                         if( preg_match(
1969                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1970                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1971                                 $m )
1972                         )
1973                         {
1974                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1975                                         $result = false;
1976                                         return $result;
1977                                 }
1978                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1979                                 $result = true;
1980                         }
1981                 }
1982         }
1983         return $result;
1984 }
1985
1986 /**
1987  * Obtain the offset and limit values from the request string;
1988  * used in special pages
1989  *
1990  * @param $deflimit Int default limit if none supplied
1991  * @param $optionname String Name of a user preference to check against
1992  * @return array
1993  *
1994  */
1995 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1996         global $wgRequest;
1997         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1998 }
1999
2000 /**
2001  * Escapes the given text so that it may be output using addWikiText()
2002  * without any linking, formatting, etc. making its way through. This
2003  * is achieved by substituting certain characters with HTML entities.
2004  * As required by the callers, "<nowiki>" is not used.
2005  *
2006  * @param $text String: text to be escaped
2007  * @return String
2008  */
2009 function wfEscapeWikiText( $text ) {
2010         $text = strtr( "\n$text", array(
2011                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2012                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2013                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2014                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2015                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2016                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2017         ) );
2018         return substr( $text, 1 );
2019 }
2020
2021 /**
2022  * Get the current unix timetstamp with microseconds.  Useful for profiling
2023  * @return Float
2024  */
2025 function wfTime() {
2026         return microtime( true );
2027 }
2028
2029 /**
2030  * Sets dest to source and returns the original value of dest
2031  * If source is NULL, it just returns the value, it doesn't set the variable
2032  * If force is true, it will set the value even if source is NULL
2033  *
2034  * @param $dest Mixed
2035  * @param $source Mixed
2036  * @param $force Bool
2037  * @return Mixed
2038  */
2039 function wfSetVar( &$dest, $source, $force = false ) {
2040         $temp = $dest;
2041         if ( !is_null( $source ) || $force ) {
2042                 $dest = $source;
2043         }
2044         return $temp;
2045 }
2046
2047 /**
2048  * As for wfSetVar except setting a bit
2049  *
2050  * @param $dest Int
2051  * @param $bit Int
2052  * @param $state Bool
2053  *
2054  * @return bool
2055  */
2056 function wfSetBit( &$dest, $bit, $state = true ) {
2057         $temp = (bool)( $dest & $bit );
2058         if ( !is_null( $state ) ) {
2059                 if ( $state ) {
2060                         $dest |= $bit;
2061                 } else {
2062                         $dest &= ~$bit;
2063                 }
2064         }
2065         return $temp;
2066 }
2067
2068 /**
2069  * A wrapper around the PHP function var_export().
2070  * Either print it or add it to the regular output ($wgOut).
2071  *
2072  * @param $var mixed A PHP variable to dump.
2073  */
2074 function wfVarDump( $var ) {
2075         global $wgOut;
2076         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2077         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2078                 print $s;
2079         } else {
2080                 $wgOut->addHTML( $s );
2081         }
2082 }
2083
2084 /**
2085  * Provide a simple HTTP error.
2086  *
2087  * @param $code Int|String
2088  * @param $label String
2089  * @param $desc String
2090  */
2091 function wfHttpError( $code, $label, $desc ) {
2092         global $wgOut;
2093         $wgOut->disable();
2094         header( "HTTP/1.0 $code $label" );
2095         header( "Status: $code $label" );
2096         $wgOut->sendCacheControl();
2097
2098         header( 'Content-type: text/html; charset=utf-8' );
2099         print "<!doctype html>" .
2100                 '<html><head><title>' .
2101                 htmlspecialchars( $label ) .
2102                 '</title></head><body><h1>' .
2103                 htmlspecialchars( $label ) .
2104                 '</h1><p>' .
2105                 nl2br( htmlspecialchars( $desc ) ) .
2106                 "</p></body></html>\n";
2107 }
2108
2109 /**
2110  * Clear away any user-level output buffers, discarding contents.
2111  *
2112  * Suitable for 'starting afresh', for instance when streaming
2113  * relatively large amounts of data without buffering, or wanting to
2114  * output image files without ob_gzhandler's compression.
2115  *
2116  * The optional $resetGzipEncoding parameter controls suppression of
2117  * the Content-Encoding header sent by ob_gzhandler; by default it
2118  * is left. See comments for wfClearOutputBuffers() for why it would
2119  * be used.
2120  *
2121  * Note that some PHP configuration options may add output buffer
2122  * layers which cannot be removed; these are left in place.
2123  *
2124  * @param $resetGzipEncoding Bool
2125  */
2126 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2127         if( $resetGzipEncoding ) {
2128                 // Suppress Content-Encoding and Content-Length
2129                 // headers from 1.10+s wfOutputHandler
2130                 global $wgDisableOutputCompression;
2131                 $wgDisableOutputCompression = true;
2132         }
2133         while( $status = ob_get_status() ) {
2134                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2135                         // Probably from zlib.output_compression or other
2136                         // PHP-internal setting which can't be removed.
2137                         //
2138                         // Give up, and hope the result doesn't break
2139                         // output behavior.
2140                         break;
2141                 }
2142                 if( !ob_end_clean() ) {
2143                         // Could not remove output buffer handler; abort now
2144                         // to avoid getting in some kind of infinite loop.
2145                         break;
2146                 }
2147                 if( $resetGzipEncoding ) {
2148                         if( $status['name'] == 'ob_gzhandler' ) {
2149                                 // Reset the 'Content-Encoding' field set by this handler
2150                                 // so we can start fresh.
2151                                 header_remove( 'Content-Encoding' );
2152                                 break;
2153                         }
2154                 }
2155         }
2156 }
2157
2158 /**
2159  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2160  *
2161  * Clear away output buffers, but keep the Content-Encoding header
2162  * produced by ob_gzhandler, if any.
2163  *
2164  * This should be used for HTTP 304 responses, where you need to
2165  * preserve the Content-Encoding header of the real result, but
2166  * also need to suppress the output of ob_gzhandler to keep to spec
2167  * and avoid breaking Firefox in rare cases where the headers and
2168  * body are broken over two packets.
2169  */
2170 function wfClearOutputBuffers() {
2171         wfResetOutputBuffers( false );
2172 }
2173
2174 /**
2175  * Converts an Accept-* header into an array mapping string values to quality
2176  * factors
2177  *
2178  * @param $accept String
2179  * @param $def String default
2180  * @return Array
2181  */
2182 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2183         # No arg means accept anything (per HTTP spec)
2184         if( !$accept ) {
2185                 return array( $def => 1.0 );
2186         }
2187
2188         $prefs = array();
2189
2190         $parts = explode( ',', $accept );
2191
2192         foreach( $parts as $part ) {
2193                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2194                 $values = explode( ';', trim( $part ) );
2195                 $match = array();
2196                 if ( count( $values ) == 1 ) {
2197                         $prefs[$values[0]] = 1.0;
2198                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2199                         $prefs[$values[0]] = floatval( $match[1] );
2200                 }
2201         }
2202
2203         return $prefs;
2204 }
2205
2206 /**
2207  * Checks if a given MIME type matches any of the keys in the given
2208  * array. Basic wildcards are accepted in the array keys.
2209  *
2210  * Returns the matching MIME type (or wildcard) if a match, otherwise
2211  * NULL if no match.
2212  *
2213  * @param $type String
2214  * @param $avail Array
2215  * @return string
2216  * @private
2217  */
2218 function mimeTypeMatch( $type, $avail ) {
2219         if( array_key_exists( $type, $avail ) ) {
2220                 return $type;
2221         } else {
2222                 $parts = explode( '/', $type );
2223                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2224                         return $parts[0] . '/*';
2225                 } elseif( array_key_exists( '*/*', $avail ) ) {
2226                         return '*/*';
2227                 } else {
2228                         return null;
2229                 }
2230         }
2231 }
2232
2233 /**
2234  * Returns the 'best' match between a client's requested internet media types
2235  * and the server's list of available types. Each list should be an associative
2236  * array of type to preference (preference is a float between 0.0 and 1.0).
2237  * Wildcards in the types are acceptable.
2238  *
2239  * @param $cprefs Array: client's acceptable type list
2240  * @param $sprefs Array: server's offered types
2241  * @return string
2242  *
2243  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2244  * XXX: generalize to negotiate other stuff
2245  */
2246 function wfNegotiateType( $cprefs, $sprefs ) {
2247         $combine = array();
2248
2249         foreach( array_keys( $sprefs ) as $type ) {
2250                 $parts = explode( '/', $type );
2251                 if( $parts[1] != '*' ) {
2252                         $ckey = mimeTypeMatch( $type, $cprefs );
2253                         if( $ckey ) {
2254                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2255                         }
2256                 }
2257         }
2258
2259         foreach( array_keys( $cprefs ) as $type ) {
2260                 $parts = explode( '/', $type );
2261                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2262                         $skey = mimeTypeMatch( $type, $sprefs );
2263                         if( $skey ) {
2264                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2265                         }
2266                 }
2267         }
2268
2269         $bestq = 0;
2270         $besttype = null;
2271
2272         foreach( array_keys( $combine ) as $type ) {
2273                 if( $combine[$type] > $bestq ) {
2274                         $besttype = $type;
2275                         $bestq = $combine[$type];
2276                 }
2277         }
2278
2279         return $besttype;
2280 }
2281
2282 /**
2283  * Reference-counted warning suppression
2284  *
2285  * @param $end Bool
2286  */
2287 function wfSuppressWarnings( $end = false ) {
2288         static $suppressCount = 0;
2289         static $originalLevel = false;
2290
2291         if ( $end ) {
2292                 if ( $suppressCount ) {
2293                         --$suppressCount;
2294                         if ( !$suppressCount ) {
2295                                 error_reporting( $originalLevel );
2296                         }
2297                 }
2298         } else {
2299                 if ( !$suppressCount ) {
2300                         // E_DEPRECATED is undefined in PHP 5.2
2301                         if( !defined( 'E_DEPRECATED' ) ) {
2302                                 define( 'E_DEPRECATED', 8192 );
2303                         }
2304                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2305                 }
2306                 ++$suppressCount;
2307         }
2308 }
2309
2310 /**
2311  * Restore error level to previous value
2312  */
2313 function wfRestoreWarnings() {
2314         wfSuppressWarnings( true );
2315 }
2316
2317 # Autodetect, convert and provide timestamps of various types
2318
2319 /**
2320  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2321  */
2322 define( 'TS_UNIX', 0 );
2323
2324 /**
2325  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2326  */
2327 define( 'TS_MW', 1 );
2328
2329 /**
2330  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2331  */
2332 define( 'TS_DB', 2 );
2333
2334 /**
2335  * RFC 2822 format, for E-mail and HTTP headers
2336  */
2337 define( 'TS_RFC2822', 3 );
2338
2339 /**
2340  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2341  *
2342  * This is used by Special:Export
2343  */
2344 define( 'TS_ISO_8601', 4 );
2345
2346 /**
2347  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2348  *
2349  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2350  *       DateTime tag and page 36 for the DateTimeOriginal and
2351  *       DateTimeDigitized tags.
2352  */
2353 define( 'TS_EXIF', 5 );
2354
2355 /**
2356  * Oracle format time.
2357  */
2358 define( 'TS_ORACLE', 6 );
2359
2360 /**
2361  * Postgres format time.
2362  */
2363 define( 'TS_POSTGRES', 7 );
2364
2365 /**
2366  * DB2 format time
2367  */
2368 define( 'TS_DB2', 8 );
2369
2370 /**
2371  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2372  */
2373 define( 'TS_ISO_8601_BASIC', 9 );
2374
2375 /**
2376  * Get a timestamp string in one of various formats
2377  *
2378  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2379  *                    function will autodetect which format is supplied and act
2380  *                    accordingly.
2381  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2382  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2383  */
2384 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2385         $uts = 0;
2386         $da = array();
2387         $strtime = '';
2388
2389         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2390                 $uts = time();
2391                 $strtime = "@$uts";
2392         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2393                 # TS_DB
2394         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2395                 # TS_EXIF
2396         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2397                 # TS_MW
2398         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2399                 # TS_UNIX
2400                 $uts = $ts;
2401                 $strtime = "@$ts"; // http://php.net/manual/en/datetime.formats.compound.php
2402         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2403                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2404                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2405                                 str_replace( '+00:00', 'UTC', $ts ) );
2406         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2407                 # TS_ISO_8601
2408         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2409                 #TS_ISO_8601_BASIC
2410         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2411                 # TS_POSTGRES
2412         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2413                 # TS_POSTGRES
2414         } elseif (preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/', $ts, $da ) ) {
2415                 # TS_DB2
2416         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2417                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2418                                                         '[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d/S', $ts ) ) { # hh:mm:ss
2419                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2420                 # The regex is a superset of rfc2822 for readability
2421                 $strtime = strtok( $ts, ';' );
2422         } elseif ( preg_match( '/^[A-Z][a-z]{5,8}, \d\d-[A-Z][a-z]{2}-\d{2} \d\d:\d\d:\d\d/', $ts ) ) {
2423                 # TS_RFC850
2424                 $strtime = $ts;
2425         } elseif ( preg_match( '/^[A-Z][a-z]{2} [A-Z][a-z]{2} +\d{1,2} \d\d:\d\d:\d\d \d{4}/', $ts ) ) {
2426                 # asctime
2427                 $strtime = $ts;
2428         } else {
2429                 # Bogus value...
2430                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2431
2432                 return false;
2433         }
2434
2435         static $formats = array(
2436                 TS_UNIX => 'U',
2437                 TS_MW => 'YmdHis',
2438                 TS_DB => 'Y-m-d H:i:s',
2439                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2440                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2441                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2442                 TS_RFC2822 => 'D, d M Y H:i:s',
2443                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2444                 TS_POSTGRES => 'Y-m-d H:i:s',
2445                 TS_DB2 => 'Y-m-d H:i:s',
2446         );
2447
2448         if ( !isset( $formats[$outputtype] ) ) {
2449                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2450         }
2451
2452         if ( function_exists( "date_create" ) ) {
2453                 if ( count( $da ) ) {
2454                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2455                                 (int)$da[1], (int)$da[2], (int)$da[3],
2456                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2457
2458                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2459                 } elseif ( $strtime ) {
2460                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2461                 } else {
2462                         return false;
2463                 }
2464
2465                 if ( !$d ) {
2466                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2467                         return false;
2468                 }
2469
2470                 $output = $d->format( $formats[$outputtype] );
2471         } else {
2472                 if ( count( $da ) ) {
2473                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2474                         // We may want to handle that explicitly at some point
2475                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2476                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2477                 } elseif ( $strtime ) {
2478                         $uts = strtotime( $strtime );
2479                 }
2480
2481                 if ( $uts === false ) {
2482                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2483                         return false;
2484                 }
2485
2486                 if ( TS_UNIX == $outputtype ) {
2487                         return $uts;
2488                 }
2489                 $output = gmdate( $formats[$outputtype], $uts );
2490         }
2491
2492         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2493                 $output .= ' GMT';
2494         }
2495
2496         return $output;
2497 }
2498
2499 /**
2500  * Return a formatted timestamp, or null if input is null.
2501  * For dealing with nullable timestamp columns in the database.
2502  *
2503  * @param $outputtype Integer
2504  * @param $ts String
2505  * @return String
2506  */
2507 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2508         if( is_null( $ts ) ) {
2509                 return null;
2510         } else {
2511                 return wfTimestamp( $outputtype, $ts );
2512         }
2513 }
2514
2515 /**
2516  * Convenience function; returns MediaWiki timestamp for the present time.
2517  *
2518  * @return string
2519  */
2520 function wfTimestampNow() {
2521         # return NOW
2522         return wfTimestamp( TS_MW, time() );
2523 }
2524
2525 /**
2526  * Check if the operating system is Windows
2527  *
2528  * @return Bool: true if it's Windows, False otherwise.
2529  */
2530 function wfIsWindows() {
2531         static $isWindows = null;
2532         if ( $isWindows === null ) {
2533                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2534         }
2535         return $isWindows;
2536 }
2537
2538 /**
2539  * Check if we are running under HipHop
2540  *
2541  * @return Bool
2542  */
2543 function wfIsHipHop() {
2544         return function_exists( 'hphp_thread_set_warmup_enabled' );
2545 }
2546
2547 /**
2548  * Swap two variables
2549  *
2550  * @param $x Mixed
2551  * @param $y Mixed
2552  */
2553 function swap( &$x, &$y ) {
2554         $z = $x;
2555         $x = $y;
2556         $y = $z;
2557 }
2558
2559 /**
2560  * Tries to get the system directory for temporary files. First
2561  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2562  * environment variables are then checked in sequence, and if none are
2563  * set try sys_get_temp_dir().
2564  *
2565  * NOTE: When possible, use instead the tmpfile() function to create
2566  * temporary files to avoid race conditions on file creation, etc.
2567  *
2568  * @return String
2569  */
2570 function wfTempDir() {
2571         global $wgTmpDirectory;
2572
2573         if ( $wgTmpDirectory !== false ) {
2574                 return $wgTmpDirectory;
2575         }
2576
2577         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2578
2579         foreach( $tmpDir as $tmp ) {
2580                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2581                         return $tmp;
2582                 }
2583         }
2584         return sys_get_temp_dir();
2585 }
2586
2587 /**
2588  * Make directory, and make all parent directories if they don't exist
2589  *
2590  * @param $dir String: full path to directory to create
2591  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2592  * @param $caller String: optional caller param for debugging.
2593  * @return bool
2594  */
2595 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2596         global $wgDirectoryMode;
2597
2598         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2599                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2600         }
2601
2602         if ( !is_null( $caller ) ) {
2603                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2604         }
2605
2606         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2607                 return true;
2608         }
2609
2610         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2611
2612         if ( is_null( $mode ) ) {
2613                 $mode = $wgDirectoryMode;
2614         }
2615
2616         // Turn off the normal warning, we're doing our own below
2617         wfSuppressWarnings();
2618         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2619         wfRestoreWarnings();
2620
2621         if( !$ok ) {
2622                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2623                 trigger_error( sprintf( "%s: failed to mkdir \"%s\" mode 0%o", __FUNCTION__, $dir, $mode ),
2624                         E_USER_WARNING );
2625         }
2626         return $ok;
2627 }
2628
2629 /**
2630  * Remove a directory and all its content.
2631  * Does not hide error.
2632  */
2633 function wfRecursiveRemoveDir( $dir ) {
2634         wfDebug( __FUNCTION__ . "( $dir )\n" );
2635         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2636         if ( is_dir( $dir ) ) {
2637                 $objects = scandir( $dir );
2638                 foreach ( $objects as $object ) {
2639                         if ( $object != "." && $object != ".." ) {
2640                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2641                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2642                                 } else {
2643                                         unlink( $dir . '/' . $object );
2644                                 }
2645                         }
2646                 }
2647                 reset( $objects );
2648                 rmdir( $dir );
2649         }
2650 }
2651
2652 /**
2653  * @param $nr Mixed: the number to format
2654  * @param $acc Integer: the number of digits after the decimal point, default 2
2655  * @param $round Boolean: whether or not to round the value, default true
2656  * @return float
2657  */
2658 function wfPercent( $nr, $acc = 2, $round = true ) {
2659         $ret = sprintf( "%.${acc}f", $nr );
2660         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2661 }
2662
2663 /**
2664  * Find out whether or not a mixed variable exists in a string
2665  *
2666  * @param $needle String
2667  * @param $str String
2668  * @param $insensitive Boolean
2669  * @return Boolean
2670  */
2671 function in_string( $needle, $str, $insensitive = false ) {
2672         $func = 'strpos';
2673         if( $insensitive ) $func = 'stripos';
2674
2675         return $func( $str, $needle ) !== false;
2676 }
2677
2678 /**
2679  * Safety wrapper around ini_get() for boolean settings.
2680  * The values returned from ini_get() are pre-normalized for settings
2681  * set via php.ini or php_flag/php_admin_flag... but *not*
2682  * for those set via php_value/php_admin_value.
2683  *
2684  * It's fairly common for people to use php_value instead of php_flag,
2685  * which can leave you with an 'off' setting giving a false positive
2686  * for code that just takes the ini_get() return value as a boolean.
2687  *
2688  * To make things extra interesting, setting via php_value accepts
2689  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2690  * Unrecognized values go false... again opposite PHP's own coercion
2691  * from string to bool.
2692  *
2693  * Luckily, 'properly' set settings will always come back as '0' or '1',
2694  * so we only have to worry about them and the 'improper' settings.
2695  *
2696  * I frickin' hate PHP... :P
2697  *
2698  * @param $setting String
2699  * @return Bool
2700  */
2701 function wfIniGetBool( $setting ) {
2702         $val = ini_get( $setting );
2703         // 'on' and 'true' can't have whitespace around them, but '1' can.
2704         return strtolower( $val ) == 'on'
2705                 || strtolower( $val ) == 'true'
2706                 || strtolower( $val ) == 'yes'
2707                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2708 }
2709
2710 /**
2711  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2712  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2713  *
2714  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2715  *                          should be omitted
2716  * @param $fileName String Name of the library, if not $extension.suffix
2717  * @return Bool - Whether or not the extension is loaded
2718  */
2719 function wfDl( $extension, $fileName = null ) {
2720         if( extension_loaded( $extension ) ) {
2721                 return true;
2722         }
2723
2724         $canDl = false;
2725         $sapi = php_sapi_name();
2726         if( $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' ) {
2727                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2728                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2729         }
2730
2731         if( $canDl ) {
2732                 $fileName = $fileName ? $fileName : $extension;
2733                 if( wfIsWindows() ) {
2734                         $fileName = 'php_' . $fileName;
2735                 }
2736                 wfSuppressWarnings();
2737                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2738                 wfRestoreWarnings();
2739         }
2740         return extension_loaded( $extension );
2741 }
2742
2743 /**
2744  * Windows-compatible version of escapeshellarg()
2745  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2746  * function puts single quotes in regardless of OS.
2747  *
2748  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2749  * earlier distro releases of PHP)
2750  *
2751  * @param varargs
2752  * @return String
2753  */
2754 function wfEscapeShellArg( ) {
2755         wfInitShellLocale();
2756
2757         $args = func_get_args();
2758         $first = true;
2759         $retVal = '';
2760         foreach ( $args as $arg ) {
2761                 if ( !$first ) {
2762                         $retVal .= ' ';
2763                 } else {
2764                         $first = false;
2765                 }
2766
2767                 if ( wfIsWindows() ) {
2768                         // Escaping for an MSVC-style command line parser and CMD.EXE
2769                         // Refs:
2770                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2771                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2772                         //  * Bug #13518
2773                         //  * CR r63214
2774                         // Double the backslashes before any double quotes. Escape the double quotes.
2775                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2776                         $arg = '';
2777                         $iteration = 0;
2778                         foreach ( $tokens as $token ) {
2779                                 if ( $iteration % 2 == 1 ) {
2780                                         // Delimiter, a double quote preceded by zero or more slashes
2781                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2782                                 } elseif ( $iteration % 4 == 2 ) {
2783                                         // ^ in $token will be outside quotes, need to be escaped
2784                                         $arg .= str_replace( '^', '^^', $token );
2785                                 } else { // $iteration % 4 == 0
2786                                         // ^ in $token will appear inside double quotes, so leave as is
2787                                         $arg .= $token;
2788                                 }
2789                                 $iteration++;
2790                         }
2791                         // Double the backslashes before the end of the string, because
2792                         // we will soon add a quote
2793                         $m = array();
2794                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2795                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2796                         }
2797
2798                         // Add surrounding quotes
2799                         $retVal .= '"' . $arg . '"';
2800                 } else {
2801                         $retVal .= escapeshellarg( $arg );
2802                 }
2803         }
2804         return $retVal;
2805 }
2806
2807 /**
2808  * Execute a shell command, with time and memory limits mirrored from the PHP
2809  * configuration if supported.
2810  * @param $cmd String Command line, properly escaped for shell.
2811  * @param &$retval null|Mixed optional, will receive the program's exit code.
2812  *                 (non-zero is usually failure)
2813  * @param $environ Array optional environment variables which should be
2814  *                 added to the executed command environment.
2815  * @param $limits Array optional array with limits(filesize, memory, time)
2816  *                 this overwrites the global wgShellMax* limits.
2817  * @return string collected stdout as a string (trailing newlines stripped)
2818  */
2819 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2820         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2821
2822         static $disabled;
2823         if ( is_null( $disabled ) ) {
2824                 $disabled = false;
2825                 if( wfIniGetBool( 'safe_mode' ) ) {
2826                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2827                         $disabled = 'safemode';
2828                 } else {
2829                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2830                         $functions = array_map( 'trim', $functions );
2831                         $functions = array_map( 'strtolower', $functions );
2832                         if ( in_array( 'passthru', $functions ) ) {
2833                                 wfDebug( "passthru is in disabled_functions\n" );
2834                                 $disabled = 'passthru';
2835                         }
2836                 }
2837         }
2838         if ( $disabled ) {
2839                 $retval = 1;
2840                 return $disabled == 'safemode' ?
2841                         'Unable to run external programs in safe mode.' :
2842                         'Unable to run external programs, passthru() is disabled.';
2843         }
2844
2845         wfInitShellLocale();
2846
2847         $envcmd = '';
2848         foreach( $environ as $k => $v ) {
2849                 if ( wfIsWindows() ) {
2850                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2851                          * appear in the environment variable, so we must use carat escaping as documented in
2852                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2853                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2854                          * are listed there but doesn't appear to need it.
2855                          */
2856                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2857                 } else {
2858                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2859                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2860                          */
2861                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2862                 }
2863         }
2864         $cmd = $envcmd . $cmd;
2865
2866         if ( php_uname( 's' ) == 'Linux' ) {
2867                 $time = intval ( isset($limits['time']) ? $limits['time'] : $wgMaxShellTime );
2868                 $mem = intval ( isset($limits['memory']) ? $limits['memory'] : $wgMaxShellMemory );
2869                 $filesize = intval ( isset($limits['filesize']) ? $limits['filesize'] : $wgMaxShellFileSize );
2870
2871                 if ( $time > 0 && $mem > 0 ) {
2872                         $script = "$IP/bin/ulimit4.sh";
2873                         if ( is_executable( $script ) ) {
2874                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2875                         }
2876                 }
2877         }
2878         wfDebug( "wfShellExec: $cmd\n" );
2879
2880         $retval = 1; // error by default?
2881         ob_start();
2882         passthru( $cmd, $retval );
2883         $output = ob_get_contents();
2884         ob_end_clean();
2885
2886         if ( $retval == 127 ) {
2887                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2888         }
2889         return $output;
2890 }
2891
2892 /**
2893  * Workaround for http://bugs.php.net/bug.php?id=45132
2894  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2895  */
2896 function wfInitShellLocale() {
2897         static $done = false;
2898         if ( $done ) {
2899                 return;
2900         }
2901         $done = true;
2902         global $wgShellLocale;
2903         if ( !wfIniGetBool( 'safe_mode' ) ) {
2904                 putenv( "LC_CTYPE=$wgShellLocale" );
2905                 setlocale( LC_CTYPE, $wgShellLocale );
2906         }
2907 }
2908
2909 /**
2910  * Alias to wfShellWikiCmd()
2911  * @see wfShellWikiCmd()
2912  */
2913 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2914         return wfShellWikiCmd( $script, $parameters, $options );
2915 }
2916
2917 /**
2918  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2919  * Note that $parameters should be a flat array and an option with an argument
2920  * should consist of two consecutive items in the array (do not use "--option value").
2921  * @param $script string MediaWiki cli script path
2922  * @param $parameters Array Arguments and options to the script
2923  * @param $options Array Associative array of options:
2924  *              'php': The path to the php executable
2925  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2926  * @return Array
2927  */
2928 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2929         global $wgPhpCli;
2930         // Give site config file a chance to run the script in a wrapper.
2931         // The caller may likely want to call wfBasename() on $script.
2932         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2933         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2934         if ( isset( $options['wrapper'] ) ) {
2935                 $cmd[] = $options['wrapper'];
2936         }
2937         $cmd[] = $script;
2938         // Escape each parameter for shell
2939         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2940 }
2941
2942 /**
2943  * wfMerge attempts to merge differences between three texts.
2944  * Returns true for a clean merge and false for failure or a conflict.
2945  *
2946  * @param $old String
2947  * @param $mine String
2948  * @param $yours String
2949  * @param $result String
2950  * @return Bool
2951  */
2952 function wfMerge( $old, $mine, $yours, &$result ) {
2953         global $wgDiff3;
2954
2955         # This check may also protect against code injection in
2956         # case of broken installations.
2957         wfSuppressWarnings();
2958         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2959         wfRestoreWarnings();
2960
2961         if( !$haveDiff3 ) {
2962                 wfDebug( "diff3 not found\n" );
2963                 return false;
2964         }
2965
2966         # Make temporary files
2967         $td = wfTempDir();
2968         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2969         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2970         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2971
2972         fwrite( $oldtextFile, $old );
2973         fclose( $oldtextFile );
2974         fwrite( $mytextFile, $mine );
2975         fclose( $mytextFile );
2976         fwrite( $yourtextFile, $yours );
2977         fclose( $yourtextFile );
2978
2979         # Check for a conflict
2980         $cmd = $wgDiff3 . ' -a --overlap-only ' .
2981                 wfEscapeShellArg( $mytextName ) . ' ' .
2982                 wfEscapeShellArg( $oldtextName ) . ' ' .
2983                 wfEscapeShellArg( $yourtextName );
2984         $handle = popen( $cmd, 'r' );
2985
2986         if( fgets( $handle, 1024 ) ) {
2987                 $conflict = true;
2988         } else {
2989                 $conflict = false;
2990         }
2991         pclose( $handle );
2992
2993         # Merge differences
2994         $cmd = $wgDiff3 . ' -a -e --merge ' .
2995                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2996         $handle = popen( $cmd, 'r' );
2997         $result = '';
2998         do {
2999                 $data = fread( $handle, 8192 );
3000                 if ( strlen( $data ) == 0 ) {
3001                         break;
3002                 }
3003                 $result .= $data;
3004         } while ( true );
3005         pclose( $handle );
3006         unlink( $mytextName );
3007         unlink( $oldtextName );
3008         unlink( $yourtextName );
3009
3010         if ( $result === '' && $old !== '' && !$conflict ) {
3011                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3012                 $conflict = true;
3013         }
3014         return !$conflict;
3015 }
3016
3017 /**
3018  * Returns unified plain-text diff of two texts.
3019  * Useful for machine processing of diffs.
3020  *
3021  * @param $before String: the text before the changes.
3022  * @param $after String: the text after the changes.
3023  * @param $params String: command-line options for the diff command.
3024  * @return String: unified diff of $before and $after
3025  */
3026 function wfDiff( $before, $after, $params = '-u' ) {
3027         if ( $before == $after ) {
3028                 return '';
3029         }
3030
3031         global $wgDiff;
3032         wfSuppressWarnings();
3033         $haveDiff = $wgDiff && file_exists( $wgDiff );
3034         wfRestoreWarnings();
3035
3036         # This check may also protect against code injection in
3037         # case of broken installations.
3038         if( !$haveDiff ) {
3039                 wfDebug( "diff executable not found\n" );
3040                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3041                 $format = new UnifiedDiffFormatter();
3042                 return $format->format( $diffs );
3043         }
3044
3045         # Make temporary files
3046         $td = wfTempDir();
3047         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3048         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3049
3050         fwrite( $oldtextFile, $before );
3051         fclose( $oldtextFile );
3052         fwrite( $newtextFile, $after );
3053         fclose( $newtextFile );
3054
3055         // Get the diff of the two files
3056         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3057
3058         $h = popen( $cmd, 'r' );
3059
3060         $diff = '';
3061
3062         do {
3063                 $data = fread( $h, 8192 );
3064                 if ( strlen( $data ) == 0 ) {
3065                         break;
3066                 }
3067                 $diff .= $data;
3068         } while ( true );
3069
3070         // Clean up
3071         pclose( $h );
3072         unlink( $oldtextName );
3073         unlink( $newtextName );
3074
3075         // Kill the --- and +++ lines. They're not useful.
3076         $diff_lines = explode( "\n", $diff );
3077         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3078                 unset( $diff_lines[0] );
3079         }
3080         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3081                 unset( $diff_lines[1] );
3082         }
3083
3084         $diff = implode( "\n", $diff_lines );
3085
3086         return $diff;
3087 }
3088
3089 /**
3090  * This function works like "use VERSION" in Perl, the program will die with a
3091  * backtrace if the current version of PHP is less than the version provided
3092  *
3093  * This is useful for extensions which due to their nature are not kept in sync
3094  * with releases, and might depend on other versions of PHP than the main code
3095  *
3096  * Note: PHP might die due to parsing errors in some cases before it ever
3097  *       manages to call this function, such is life
3098  *
3099  * @see perldoc -f use
3100  *
3101  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3102  *                 a float
3103  */
3104 function wfUsePHP( $req_ver ) {
3105         $php_ver = PHP_VERSION;
3106
3107         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3108                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3109         }
3110 }
3111
3112 /**
3113  * This function works like "use VERSION" in Perl except it checks the version
3114  * of MediaWiki, the program will die with a backtrace if the current version
3115  * of MediaWiki is less than the version provided.
3116  *
3117  * This is useful for extensions which due to their nature are not kept in sync
3118  * with releases
3119  *
3120  * @see perldoc -f use
3121  *
3122  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3123  *                 a float
3124  */
3125 function wfUseMW( $req_ver ) {
3126         global $wgVersion;
3127
3128         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3129                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3130         }
3131 }
3132
3133 /**
3134  * Return the final portion of a pathname.
3135  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3136  * http://bugs.php.net/bug.php?id=33898
3137  *
3138  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3139  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3140  *
3141  * @param $path String
3142  * @param $suffix String: to remove if present
3143  * @return String
3144  */
3145 function wfBaseName( $path, $suffix = '' ) {
3146         $encSuffix = ( $suffix == '' )
3147                 ? ''
3148                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3149         $matches = array();
3150         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3151                 return $matches[1];
3152         } else {
3153                 return '';
3154         }
3155 }
3156
3157 /**
3158  * Generate a relative path name to the given file.
3159  * May explode on non-matching case-insensitive paths,
3160  * funky symlinks, etc.
3161  *
3162  * @param $path String: absolute destination path including target filename
3163  * @param $from String: Absolute source path, directory only
3164  * @return String
3165  */
3166 function wfRelativePath( $path, $from ) {
3167         // Normalize mixed input on Windows...
3168         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3169         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3170
3171         // Trim trailing slashes -- fix for drive root
3172         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3173         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3174
3175         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3176         $against = explode( DIRECTORY_SEPARATOR, $from );
3177
3178         if( $pieces[0] !== $against[0] ) {
3179                 // Non-matching Windows drive letters?
3180                 // Return a full path.
3181                 return $path;
3182         }
3183
3184         // Trim off common prefix
3185         while( count( $pieces ) && count( $against )
3186                 && $pieces[0] == $against[0] ) {
3187                 array_shift( $pieces );
3188                 array_shift( $against );
3189         }
3190
3191         // relative dots to bump us to the parent
3192         while( count( $against ) ) {
3193                 array_unshift( $pieces, '..' );
3194                 array_shift( $against );
3195         }
3196
3197         array_push( $pieces, wfBaseName( $path ) );
3198
3199         return implode( DIRECTORY_SEPARATOR, $pieces );
3200 }
3201
3202 /**
3203  * Do any deferred updates and clear the list
3204  *
3205  * @deprecated since 1.19
3206  * @see DeferredUpdates::doUpdate()
3207  * @param $commit string
3208  */
3209 function wfDoUpdates( $commit = '' ) {
3210         wfDeprecated( __METHOD__, '1.19' );
3211         DeferredUpdates::doUpdates( $commit );
3212 }
3213
3214 /**
3215  * Convert an arbitrarily-long digit string from one numeric base
3216  * to another, optionally zero-padding to a minimum column width.
3217  *
3218  * Supports base 2 through 36; digit values 10-36 are represented
3219  * as lowercase letters a-z. Input is case-insensitive.
3220  *
3221  * @param $input String: of digits
3222  * @param $sourceBase Integer: 2-36
3223  * @param $destBase Integer: 2-36
3224  * @param $pad Integer: 1 or greater
3225  * @param $lowercase Boolean
3226  * @return String or false on invalid input
3227  */
3228 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3229         $input = strval( $input );
3230         if( $sourceBase < 2 ||
3231                 $sourceBase > 36 ||
3232                 $destBase < 2 ||
3233                 $destBase > 36 ||
3234                 $pad < 1 ||
3235                 $sourceBase != intval( $sourceBase ) ||
3236                 $destBase != intval( $destBase ) ||
3237                 $pad != intval( $pad ) ||
3238                 !is_string( $input ) ||
3239                 $input == '' ) {
3240                 return false;
3241         }
3242         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3243         $inDigits = array();
3244         $outChars = '';
3245
3246         // Decode and validate input string
3247         $input = strtolower( $input );
3248         for( $i = 0; $i < strlen( $input ); $i++ ) {
3249                 $n = strpos( $digitChars, $input[$i] );
3250                 if( $n === false || $n > $sourceBase ) {
3251                         return false;
3252                 }
3253                 $inDigits[] = $n;
3254         }
3255
3256         // Iterate over the input, modulo-ing out an output digit
3257         // at a time until input is gone.
3258         while( count( $inDigits ) ) {
3259                 $work = 0;
3260                 $workDigits = array();
3261
3262                 // Long division...
3263                 foreach( $inDigits as $digit ) {
3264                         $work *= $sourceBase;
3265                         $work += $digit;
3266
3267                         if( $work < $destBase ) {
3268                                 // Gonna need to pull another digit.
3269                                 if( count( $workDigits ) ) {
3270                                         // Avoid zero-padding; this lets us find
3271                                         // the end of the input very easily when
3272                                         // length drops to zero.
3273                                         $workDigits[] = 0;
3274                                 }
3275                         } else {
3276                                 // Finally! Actual division!
3277                                 $workDigits[] = intval( $work / $destBase );
3278
3279                                 // Isn't it annoying that most programming languages
3280                                 // don't have a single divide-and-remainder operator,
3281                                 // even though the CPU implements it that way?
3282                                 $work = $work % $destBase;
3283                         }
3284                 }
3285
3286                 // All that division leaves us with a remainder,
3287                 // which is conveniently our next output digit.
3288                 $outChars .= $digitChars[$work];
3289
3290                 // And we continue!
3291                 $inDigits = $workDigits;
3292         }
3293
3294         while( strlen( $outChars ) < $pad ) {
3295                 $outChars .= '0';
3296         }
3297
3298         return strrev( $outChars );
3299 }
3300
3301 /**
3302  * Create an object with a given name and an array of construct parameters
3303  *
3304  * @param $name String
3305  * @param $p Array: parameters
3306  * @return object
3307  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3308  */
3309 function wfCreateObject( $name, $p ) {
3310         wfDeprecated( __FUNCTION__, '1.18' );
3311         return MWFunction::newObj( $name, $p );
3312 }
3313
3314 /**
3315  * @return bool
3316  */
3317 function wfHttpOnlySafe() {
3318         global $wgHttpOnlyBlacklist;
3319
3320         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3321                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3322                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3323                                 return false;
3324                         }
3325                 }
3326         }
3327
3328         return true;
3329 }
3330
3331 /**
3332  * Override session_id before session startup if php's built-in
3333  * session generation code is not secure.
3334  */
3335 function wfFixSessionID() {
3336         // If the cookie or session id is already set we already have a session and should abort
3337         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3338                 return;
3339         }
3340
3341         // PHP's built-in session entropy is enabled if:
3342         // - entropy_file is set or you're on Windows with php 5.3.3+
3343         // - AND entropy_length is > 0
3344         // We treat it as disabled if it doesn't have an entropy length of at least 32
3345         $entropyEnabled = (
3346                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3347                         || ini_get( 'session.entropy_file' )
3348                 )
3349                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3350
3351         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3352         if ( !$entropyEnabled ) {
3353                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3354                 session_id( MWCryptRand::generateHex( 32 ) );
3355         }
3356 }
3357
3358 /**
3359  * Initialise php session
3360  *
3361  * @param $sessionId Bool
3362  */
3363 function wfSetupSession( $sessionId = false ) {
3364         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3365                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3366         if( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3367                 ObjectCacheSessionHandler::install();
3368         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3369                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3370                 # hasn't already been set to the desired value (that causes errors)
3371                 ini_set( 'session.save_handler', $wgSessionHandler );
3372         }
3373         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3374         wfDebugLog( 'cookie',
3375                 'session_set_cookie_params: "' . implode( '", "',
3376                         array(
3377                                 0,
3378                                 $wgCookiePath,
3379                                 $wgCookieDomain,
3380                                 $wgCookieSecure,
3381                                 $httpOnlySafe ) ) . '"' );
3382         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3383         session_cache_limiter( 'private, must-revalidate' );
3384         if ( $sessionId ) {
3385                 session_id( $sessionId );
3386         } else {
3387                 wfFixSessionID();
3388         }
3389         wfSuppressWarnings();
3390         session_start();
3391         wfRestoreWarnings();
3392 }
3393
3394 /**
3395  * Get an object from the precompiled serialized directory
3396  *
3397  * @param $name String
3398  * @return Mixed: the variable on success, false on failure
3399  */
3400 function wfGetPrecompiledData( $name ) {
3401         global $IP;
3402
3403         $file = "$IP/serialized/$name";
3404         if ( file_exists( $file ) ) {
3405                 $blob = file_get_contents( $file );
3406                 if ( $blob ) {
3407                         return unserialize( $blob );
3408                 }
3409         }
3410         return false;
3411 }
3412
3413 /**
3414  * Get a cache key
3415  *
3416  * @param varargs
3417  * @return String
3418  */
3419 function wfMemcKey( /*... */ ) {
3420         global $wgCachePrefix;
3421         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3422         $args = func_get_args();
3423         $key = $prefix . ':' . implode( ':', $args );
3424         $key = str_replace( ' ', '_', $key );
3425         return $key;
3426 }
3427
3428 /**
3429  * Get a cache key for a foreign DB
3430  *
3431  * @param $db String
3432  * @param $prefix String
3433  * @param varargs String
3434  * @return String
3435  */
3436 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3437         $args = array_slice( func_get_args(), 2 );
3438         if ( $prefix ) {
3439                 $key = "$db-$prefix:" . implode( ':', $args );
3440         } else {
3441                 $key = $db . ':' . implode( ':', $args );
3442         }
3443         return $key;
3444 }
3445
3446 /**
3447  * Get an ASCII string identifying this wiki
3448  * This is used as a prefix in memcached keys
3449  *
3450  * @return String
3451  */
3452 function wfWikiID() {
3453         global $wgDBprefix, $wgDBname;
3454         if ( $wgDBprefix ) {
3455                 return "$wgDBname-$wgDBprefix";
3456         } else {
3457                 return $wgDBname;
3458         }
3459 }
3460
3461 /**
3462  * Split a wiki ID into DB name and table prefix
3463  *
3464  * @param $wiki String
3465  *
3466  * @return array
3467  */
3468 function wfSplitWikiID( $wiki ) {
3469         $bits = explode( '-', $wiki, 2 );
3470         if ( count( $bits ) < 2 ) {
3471                 $bits[] = '';
3472         }
3473         return $bits;
3474 }
3475
3476 /**
3477  * Get a Database object.
3478  *
3479  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3480  *            master (for write queries), DB_SLAVE for potentially lagged read
3481  *            queries, or an integer >= 0 for a particular server.
3482  *
3483  * @param $groups Mixed: query groups. An array of group names that this query
3484  *                belongs to. May contain a single string if the query is only
3485  *                in one group.
3486  *
3487  * @param $wiki String: the wiki ID, or false for the current wiki
3488  *
3489  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3490  * will always return the same object, unless the underlying connection or load
3491  * balancer is manually destroyed.
3492  *
3493  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3494  * updater to ensure that a proper database is being updated.
3495  *
3496  * @return DatabaseBase
3497  */
3498 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3499         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3500 }
3501
3502 /**
3503  * Get a load balancer object.
3504  *
3505  * @param $wiki String: wiki ID, or false for the current wiki
3506  * @return LoadBalancer
3507  */
3508 function wfGetLB( $wiki = false ) {
3509         return wfGetLBFactory()->getMainLB( $wiki );
3510 }
3511
3512 /**
3513  * Get the load balancer factory object
3514  *
3515  * @return LBFactory
3516  */
3517 function &wfGetLBFactory() {
3518         return LBFactory::singleton();
3519 }
3520
3521 /**
3522  * Find a file.
3523  * Shortcut for RepoGroup::singleton()->findFile()
3524  *
3525  * @param $title String or Title object
3526  * @param $options array Associative array of options:
3527  *     time:           requested time for an archived image, or false for the
3528  *                     current version. An image object will be returned which was
3529  *                     created at the specified time.
3530  *
3531  *     ignoreRedirect: If true, do not follow file redirects
3532  *
3533  *     private:        If true, return restricted (deleted) files if the current
3534  *                     user is allowed to view them. Otherwise, such files will not
3535  *                     be found.
3536  *
3537  *     bypassCache:    If true, do not use the process-local cache of File objects
3538  *
3539  * @return File, or false if the file does not exist
3540  */
3541 function wfFindFile( $title, $options = array() ) {
3542         return RepoGroup::singleton()->findFile( $title, $options );
3543 }
3544
3545 /**
3546  * Get an object referring to a locally registered file.
3547  * Returns a valid placeholder object if the file does not exist.
3548  *
3549  * @param $title Title|String
3550  * @return LocalFile|null A File, or null if passed an invalid Title
3551  */
3552 function wfLocalFile( $title ) {
3553         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3554 }
3555
3556 /**
3557  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3558  * @deprecated since 1.19
3559  */
3560 function wfStreamFile( $fname, $headers = array() ) {
3561         wfDeprecated( __FUNCTION__, '1.19' );
3562         StreamFile::stream( $fname, $headers );
3563 }
3564
3565 /**
3566  * Should low-performance queries be disabled?
3567  *
3568  * @return Boolean
3569  * @codeCoverageIgnore
3570  */
3571 function wfQueriesMustScale() {
3572         global $wgMiserMode;
3573         return $wgMiserMode
3574                 || ( SiteStats::pages() > 100000
3575                 && SiteStats::edits() > 1000000
3576                 && SiteStats::users() > 10000 );
3577 }
3578
3579 /**
3580  * Get the path to a specified script file, respecting file
3581  * extensions; this is a wrapper around $wgScriptExtension etc.
3582  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3583  *
3584  * @param $script String: script filename, sans extension
3585  * @return String
3586  */
3587 function wfScript( $script = 'index' ) {
3588         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3589         if ( $script === 'index' ) {
3590                 return $wgScript;
3591         } else if ( $script === 'load' ) {
3592                 return $wgLoadScript;
3593         } else {
3594                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3595         }
3596 }
3597
3598 /**
3599  * Get the script URL.
3600  *
3601  * @return string script URL
3602  */
3603 function wfGetScriptUrl() {
3604         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3605                 #
3606                 # as it was called, minus the query string.
3607                 #
3608                 # Some sites use Apache rewrite rules to handle subdomains,
3609                 # and have PHP set up in a weird way that causes PHP_SELF
3610                 # to contain the rewritten URL instead of the one that the
3611                 # outside world sees.
3612                 #
3613                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3614                 # provides containing the "before" URL.
3615                 return $_SERVER['SCRIPT_NAME'];
3616         } else {
3617                 return $_SERVER['URL'];
3618         }
3619 }
3620
3621 /**
3622  * Convenience function converts boolean values into "true"
3623  * or "false" (string) values
3624  *
3625  * @param $value Boolean
3626  * @return String
3627  */
3628 function wfBoolToStr( $value ) {
3629         return $value ? 'true' : 'false';
3630 }
3631
3632 /**
3633  * Load an extension messages file
3634  *
3635  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3636  * @codeCoverageIgnore
3637  */
3638 function wfLoadExtensionMessages() {
3639         wfDeprecated( __FUNCTION__, '1.16' );
3640 }
3641
3642 /**
3643  * Get a platform-independent path to the null file, e.g. /dev/null
3644  *
3645  * @return string
3646  */
3647 function wfGetNull() {
3648         return wfIsWindows()
3649                 ? 'NUL'
3650                 : '/dev/null';
3651 }
3652
3653 /**
3654  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3655  * and waiting for it to go down, this waits for the slaves to catch up to the
3656  * master position. Use this when updating very large numbers of rows, as
3657  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3658  * a no-op if there are no slaves.
3659  *
3660  * @param $maxLag Integer (deprecated)
3661  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3662  */
3663 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3664         $lb = wfGetLB( $wiki );
3665         // bug 27975 - Don't try to wait for slaves if there are none
3666         // Prevents permission error when getting master position
3667         if ( $lb->getServerCount() > 1 ) {
3668                 $dbw = $lb->getConnection( DB_MASTER );
3669                 $pos = $dbw->getMasterPos();
3670                 $lb->waitForAll( $pos );
3671         }
3672 }
3673
3674 /**
3675  * Used to be used for outputting text in the installer/updater
3676  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3677  */
3678 function wfOut( $s ) {
3679         wfDeprecated( __FUNCTION__, '1.18' );
3680         global $wgCommandLineMode;
3681         if ( $wgCommandLineMode ) {
3682                 echo $s;
3683         } else {
3684                 echo htmlspecialchars( $s );
3685         }
3686         flush();
3687 }
3688
3689 /**
3690  * Count down from $n to zero on the terminal, with a one-second pause
3691  * between showing each number. For use in command-line scripts.
3692  * @codeCoverageIgnore
3693  * @param $n int
3694  */
3695 function wfCountDown( $n ) {
3696         for ( $i = $n; $i >= 0; $i-- ) {
3697                 if ( $i != $n ) {
3698                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3699                 }
3700                 echo $i;
3701                 flush();
3702                 if ( $i ) {
3703                         sleep( 1 );
3704                 }
3705         }
3706         echo "\n";
3707 }
3708
3709 /**
3710  * Generate a random 32-character hexadecimal token.
3711  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3712  *              characters before hashing.
3713  * @return string
3714  * @codeCoverageIgnore
3715  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pesudo-random strings
3716  * @warning This method is NOT secure. Additionally it has many callers that use it for pesudo-random purposes.
3717  */
3718 function wfGenerateToken( $salt = '' ) {
3719         wfDeprecated( __METHOD__, '1.20' );
3720         $salt = serialize( $salt );
3721         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3722 }
3723
3724 /**
3725  * Replace all invalid characters with -
3726  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3727  * By default, $wgIllegalFileChars = ':'
3728  *
3729  * @param $name Mixed: filename to process
3730  * @return String
3731  */
3732 function wfStripIllegalFilenameChars( $name ) {
3733         global $wgIllegalFileChars;
3734         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3735         $name = wfBaseName( $name );
3736         $name = preg_replace(
3737                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3738                 '-',
3739                 $name
3740         );
3741         return $name;
3742 }
3743
3744 /**
3745  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3746  *
3747  * @return Integer value memory was set to.
3748  */
3749 function wfMemoryLimit() {
3750         global $wgMemoryLimit;
3751         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3752         if( $memlimit != -1 ) {
3753                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3754                 if( $conflimit == -1 ) {
3755                         wfDebug( "Removing PHP's memory limit\n" );
3756                         wfSuppressWarnings();
3757                         ini_set( 'memory_limit', $conflimit );
3758                         wfRestoreWarnings();
3759                         return $conflimit;
3760                 } elseif ( $conflimit > $memlimit ) {
3761                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3762                         wfSuppressWarnings();
3763                         ini_set( 'memory_limit', $conflimit );
3764                         wfRestoreWarnings();
3765                         return $conflimit;
3766                 }
3767         }
3768         return $memlimit;
3769 }
3770
3771 /**
3772  * Converts shorthand byte notation to integer form
3773  *
3774  * @param $string String
3775  * @return Integer
3776  */
3777 function wfShorthandToInteger( $string = '' ) {
3778         $string = trim( $string );
3779         if( $string === '' ) {
3780                 return -1;
3781         }
3782         $last = $string[strlen( $string ) - 1];
3783         $val = intval( $string );
3784         switch( $last ) {
3785                 case 'g':
3786                 case 'G':
3787                         $val *= 1024;
3788                         // break intentionally missing
3789                 case 'm':
3790                 case 'M':
3791                         $val *= 1024;
3792                         // break intentionally missing
3793                 case 'k':
3794                 case 'K':
3795                         $val *= 1024;
3796         }
3797
3798         return $val;
3799 }
3800
3801 /**
3802  * Get the normalised IETF language tag
3803  * See unit test for examples.
3804  *
3805  * @param $code String: The language code.
3806  * @return String: The language code which complying with BCP 47 standards.
3807  */
3808 function wfBCP47( $code ) {
3809         $codeSegment = explode( '-', $code );
3810         $codeBCP = array();
3811         foreach ( $codeSegment as $segNo => $seg ) {
3812                 if ( count( $codeSegment ) > 0 ) {
3813                         // when previous segment is x, it is a private segment and should be lc
3814                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3815                                 $codeBCP[$segNo] = strtolower( $seg );
3816                         // ISO 3166 country code
3817                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3818                                 $codeBCP[$segNo] = strtoupper( $seg );
3819                         // ISO 15924 script code
3820                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3821                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3822                         // Use lowercase for other cases
3823                         } else {
3824                                 $codeBCP[$segNo] = strtolower( $seg );
3825                         }
3826                 } else {
3827                 // Use lowercase for single segment
3828                         $codeBCP[$segNo] = strtolower( $seg );
3829                 }
3830         }
3831         $langCode = implode( '-', $codeBCP );
3832         return $langCode;
3833 }
3834
3835 /**
3836  * Get a cache object.
3837  *
3838  * @param $inputType integer Cache type, one the the CACHE_* constants.
3839  * @return BagOStuff
3840  */
3841 function wfGetCache( $inputType ) {
3842         return ObjectCache::getInstance( $inputType );
3843 }
3844
3845 /**
3846  * Get the main cache object
3847  *
3848  * @return BagOStuff
3849  */
3850 function wfGetMainCache() {
3851         global $wgMainCacheType;
3852         return ObjectCache::getInstance( $wgMainCacheType );
3853 }
3854
3855 /**
3856  * Get the cache object used by the message cache
3857  *
3858  * @return BagOStuff
3859  */
3860 function wfGetMessageCacheStorage() {
3861         global $wgMessageCacheType;
3862         return ObjectCache::getInstance( $wgMessageCacheType );
3863 }
3864
3865 /**
3866  * Get the cache object used by the parser cache
3867  *
3868  * @return BagOStuff
3869  */
3870 function wfGetParserCacheStorage() {
3871         global $wgParserCacheType;
3872         return ObjectCache::getInstance( $wgParserCacheType );
3873 }
3874
3875 /**
3876  * Get the cache object used by the language converter
3877  *
3878  * @return BagOStuff
3879  */
3880 function wfGetLangConverterCacheStorage() {
3881         global $wgLanguageConverterCacheType;
3882         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3883 }
3884
3885 /**
3886  * Call hook functions defined in $wgHooks
3887  *
3888  * @param $event String: event name
3889  * @param $args Array: parameters passed to hook functions
3890  * @return Boolean True if no handler aborted the hook
3891  */
3892 function wfRunHooks( $event, $args = array() ) {
3893         return Hooks::run( $event, $args );
3894 }
3895
3896 /**
3897  * Wrapper around php's unpack.
3898  *
3899  * @param $format String: The format string (See php's docs)
3900  * @param $data: A binary string of binary data
3901  * @param $length integer or false: The minimun length of $data. This is to
3902  *      prevent reading beyond the end of $data. false to disable the check.
3903  *
3904  * Also be careful when using this function to read unsigned 32 bit integer
3905  * because php might make it negative.
3906  *
3907  * @throws MWException if $data not long enough, or if unpack fails
3908  * @return array Associative array of the extracted data
3909  */
3910 function wfUnpack( $format, $data, $length=false ) {
3911         if ( $length !== false ) {
3912                 $realLen = strlen( $data );
3913                 if ( $realLen < $length ) {
3914                         throw new MWException( "Tried to use wfUnpack on a "
3915                                 . "string of length $realLen, but needed one "
3916                                 . "of at least length $length."
3917                         );
3918                 }
3919         }
3920
3921         wfSuppressWarnings();
3922         $result = unpack( $format, $data );
3923         wfRestoreWarnings();
3924
3925         if ( $result === false ) {
3926                 // If it cannot extract the packed data.
3927                 throw new MWException( "unpack could not unpack binary data" );
3928         }
3929         return $result;
3930 }
3931
3932 /**
3933  * Determine if an image exists on the 'bad image list'.
3934  *
3935  * The format of MediaWiki:Bad_image_list is as follows:
3936  *    * Only list items (lines starting with "*") are considered
3937  *    * The first link on a line must be a link to a bad image
3938  *    * Any subsequent links on the same line are considered to be exceptions,
3939  *      i.e. articles where the image may occur inline.
3940  *
3941  * @param $name string the image name to check
3942  * @param $contextTitle Title|bool the page on which the image occurs, if known
3943  * @param $blacklist string wikitext of a file blacklist
3944  * @return bool
3945  */
3946 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3947         static $badImageCache = null; // based on bad_image_list msg
3948         wfProfileIn( __METHOD__ );
3949
3950         # Handle redirects
3951         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3952         if( $redirectTitle ) {
3953                 $name = $redirectTitle->getDbKey();
3954         }
3955
3956         # Run the extension hook
3957         $bad = false;
3958         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3959                 wfProfileOut( __METHOD__ );
3960                 return $bad;
3961         }
3962
3963         $cacheable = ( $blacklist === null );
3964         if( $cacheable && $badImageCache !== null ) {
3965                 $badImages = $badImageCache;
3966         } else { // cache miss
3967                 if ( $blacklist === null ) {
3968                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3969                 }
3970                 # Build the list now
3971                 $badImages = array();
3972                 $lines = explode( "\n", $blacklist );
3973                 foreach( $lines as $line ) {
3974                         # List items only
3975                         if ( substr( $line, 0, 1 ) !== '*' ) {
3976                                 continue;
3977                         }
3978
3979                         # Find all links
3980                         $m = array();
3981                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3982                                 continue;
3983                         }
3984
3985                         $exceptions = array();
3986                         $imageDBkey = false;
3987                         foreach ( $m[1] as $i => $titleText ) {
3988                                 $title = Title::newFromText( $titleText );
3989                                 if ( !is_null( $title ) ) {
3990                                         if ( $i == 0 ) {
3991                                                 $imageDBkey = $title->getDBkey();
3992                                         } else {
3993                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3994                                         }
3995                                 }
3996                         }
3997
3998                         if ( $imageDBkey !== false ) {
3999                                 $badImages[$imageDBkey] = $exceptions;
4000                         }
4001                 }
4002                 if ( $cacheable ) {
4003                         $badImageCache = $badImages;
4004                 }
4005         }
4006
4007         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4008         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4009         wfProfileOut( __METHOD__ );
4010         return $bad;
4011 }