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