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  * @throws MWException
 173  */
 174 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 175         if ( is_null( $changed ) ) {
 176                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 177         }
 178         if ( $default[$key] !== $value ) {
 179                 $changed[$key] = $value;
 180         }
 181 }
 182
 183 /**
 184  * Backwards array plus for people who haven't bothered to read the PHP manual
 185  * XXX: will not darn your socks for you.
 186  *
 187  * @param $array1 Array
 188  * @param [$array2, [...]] Arrays
 189  * @return Array
 190  */
 191 function wfArrayMerge( $array1/* ... */ ) {
 192         $args = func_get_args();
 193         $args = array_reverse( $args, true );
 194         $out = array();
 195         foreach ( $args as $arg ) {
 196                 $out += $arg;
 197         }
 198         return $out;
 199 }
 200
 201 /**
 202  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 203  * e.g.
 204  *      wfMergeErrorArrays(
 205  *              array( array( 'x' ) ),
 206  *              array( array( 'x', '2' ) ),
 207  *              array( array( 'x' ) ),
 208  *              array( array( 'y' ) )
 209  *      );
 210  * returns:
 211  *              array(
 212  *              array( 'x', '2' ),
 213  *              array( 'x' ),
 214  *              array( 'y' )
 215  *      )
 216  * @param varargs
 217  * @return Array
 218  */
 219 function wfMergeErrorArrays( /*...*/ ) {
 220         $args = func_get_args();
 221         $out = array();
 222         foreach ( $args as $errors ) {
 223                 foreach ( $errors as $params ) {
 224                         # @todo FIXME: Sometimes get nested arrays for $params,
 225                         # which leads to E_NOTICEs
 226                         $spec = implode( "\t", $params );
 227                         $out[$spec] = $params;
 228                 }
 229         }
 230         return array_values( $out );
 231 }
 232
 233 /**
 234  * Insert array into another array after the specified *KEY*
 235  *
 236  * @param $array Array: The array.
 237  * @param $insert Array: The array to insert.
 238  * @param $after Mixed: The key to insert after
 239  * @return Array
 240  */
 241 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 242         // Find the offset of the element to insert after.
 243         $keys = array_keys( $array );
 244         $offsetByKey = array_flip( $keys );
 245
 246         $offset = $offsetByKey[$after];
 247
 248         // Insert at the specified offset
 249         $before = array_slice( $array, 0, $offset + 1, true );
 250         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 251
 252         $output = $before + $insert + $after;
 253
 254         return $output;
 255 }
 256
 257 /**
 258  * Recursively converts the parameter (an object) to an array with the same data
 259  *
 260  * @param $objOrArray Object|Array
 261  * @param $recursive Bool
 262  * @return Array
 263  */
 264 function wfObjectToArray( $objOrArray, $recursive = true ) {
 265         $array = array();
 266         if( is_object( $objOrArray ) ) {
 267                 $objOrArray = get_object_vars( $objOrArray );
 268         }
 269         foreach ( $objOrArray as $key => $value ) {
 270                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 271                         $value = wfObjectToArray( $value );
 272                 }
 273
 274                 $array[$key] = $value;
 275         }
 276
 277         return $array;
 278 }
 279
 280 /**
 281  * Wrapper around array_map() which also taints variables
 282  *
 283  * @param  $function Callback
 284  * @param  $input Array
 285  * @return Array
 286  */
 287 function wfArrayMap( $function, $input ) {
 288         $ret = array_map( $function, $input );
 289         foreach ( $ret as $key => $value ) {
 290                 $taint = istainted( $input[$key] );
 291                 if ( $taint ) {
 292                         taint( $ret[$key], $taint );
 293                 }
 294         }
 295         return $ret;
 296 }
 297
 298 /**
 299  * Get a random decimal value between 0 and 1, in a way
 300  * not likely to give duplicate values for any realistic
 301  * number of articles.
 302  *
 303  * @return string
 304  */
 305 function wfRandom() {
 306         # The maximum random value is "only" 2^31-1, so get two random
 307         # values to reduce the chance of dupes
 308         $max = mt_getrandmax() + 1;
 309         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 310                 / $max / $max, 12, '.', '' );
 311         return $rand;
 312 }
 313
 314 /**
 315  * Get a random string containing a number of pesudo-random hex
 316  * characters.
 317  * @note This is not secure, if you are trying to generate some sort
 318  *       of token please use MWCryptRand instead.
 319  *
 320  * @param $length int The length of the string to generate
 321  * @return String
 322  * @since 1.20
 323  */
 324 function wfRandomString( $length = 32 ) {
 325         $str = '';
 326         while ( strlen( $str ) < $length ) {
 327                 $str .= dechex( mt_rand() );
 328         }
 329         return substr( $str, 0, $length );
 330 }
 331
 332 /**
 333  * We want some things to be included as literal characters in our title URLs
 334  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 335  * all of the following should be safe:
 336  *
 337  * ;:@&=$-_.+!*'(),
 338  *
 339  * But + is not safe because it's used to indicate a space; &= are only safe in
 340  * paths and not in queries (and we don't distinguish here); ' seems kind of
 341  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 342  * is reserved, we don't care.  So the list we unescape is:
 343  *
 344  * ;:@$!*(),/
 345  *
 346  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 347  * so no fancy : for IIS7.
 348  *
 349  * %2F in the page titles seems to fatally break for some reason.
 350  *
 351  * @param $s String:
 352  * @return string
 353 */
 354 function wfUrlencode( $s ) {
 355         static $needle;
 356         if ( is_null( $s ) ) {
 357                 $needle = null;
 358                 return '';
 359         }
 360
 361         if ( is_null( $needle ) ) {
 362                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 363                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 364                         $needle[] = '%3A';
 365                 }
 366         }
 367
 368         $s = urlencode( $s );
 369         $s = str_ireplace(
 370                 $needle,
 371                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 372                 $s
 373         );
 374
 375         return $s;
 376 }
 377
 378 /**
 379  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 380  * "days=7&limit=100". Options in the first array override options in the second.
 381  * Options set to null or false will not be output.
 382  *
 383  * @param $array1 Array ( String|Array )
 384  * @param $array2 Array ( String|Array )
 385  * @param $prefix String
 386  * @return String
 387  */
 388 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 389         if ( !is_null( $array2 ) ) {
 390                 $array1 = $array1 + $array2;
 391         }
 392
 393         $cgi = '';
 394         foreach ( $array1 as $key => $value ) {
 395                 if ( !is_null($value) && $value !== false ) {
 396                         if ( $cgi != '' ) {
 397                                 $cgi .= '&';
 398                         }
 399                         if ( $prefix !== '' ) {
 400                                 $key = $prefix . "[$key]";
 401                         }
 402                         if ( is_array( $value ) ) {
 403                                 $firstTime = true;
 404                                 foreach ( $value as $k => $v ) {
 405                                         $cgi .= $firstTime ? '' : '&';
 406                                         if ( is_array( $v ) ) {
 407                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 408                                         } else {
 409                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 410                                         }
 411                                         $firstTime = false;
 412                                 }
 413                         } else {
 414                                 if ( is_object( $value ) ) {
 415                                         $value = $value->__toString();
 416                                 }
 417                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 418                         }
 419                 }
 420         }
 421         return $cgi;
 422 }
 423
 424 /**
 425  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 426  * its argument and returns the same string in array form.  This allows compa-
 427  * tibility with legacy functions that accept raw query strings instead of nice
 428  * arrays.  Of course, keys and values are urldecode()d.
 429  *
 430  * @param $query String: query string
 431  * @return array Array version of input
 432  */
 433 function wfCgiToArray( $query ) {
 434         if ( isset( $query[0] ) && $query[0] == '?' ) {
 435                 $query = substr( $query, 1 );
 436         }
 437         $bits = explode( '&', $query );
 438         $ret = array();
 439         foreach ( $bits as $bit ) {
 440                 if ( $bit === '' ) {
 441                         continue;
 442                 }
 443                 if ( strpos( $bit, '=' ) === false ) {
 444                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 445                         $key = $bit;
 446                         $value = '';
 447                 } else {
 448                         list( $key, $value ) = explode( '=', $bit );
 449                 }
 450                 $key = urldecode( $key );
 451                 $value = urldecode( $value );
 452                 if ( strpos( $key, '[' ) !== false ) {
 453                         $keys = array_reverse( explode( '[', $key ) );
 454                         $key = array_pop( $keys );
 455                         $temp = $value;
 456                         foreach ( $keys as $k ) {
 457                                 $k = substr( $k, 0, -1 );
 458                                 $temp = array( $k => $temp );
 459                         }
 460                         if ( isset( $ret[$key] ) ) {
 461                                 $ret[$key] = array_merge( $ret[$key], $temp );
 462                         } else {
 463                                 $ret[$key] = $temp;
 464                         }
 465                 } else {
 466                         $ret[$key] = $value;
 467                 }
 468         }
 469         return $ret;
 470 }
 471
 472 /**
 473  * Append a query string to an existing URL, which may or may not already
 474  * have query string parameters already. If so, they will be combined.
 475  *
 476  * @param $url String
 477  * @param $query Mixed: string or associative array
 478  * @return string
 479  */
 480 function wfAppendQuery( $url, $query ) {
 481         if ( is_array( $query ) ) {
 482                 $query = wfArrayToCgi( $query );
 483         }
 484         if( $query != '' ) {
 485                 if( false === strpos( $url, '?' ) ) {
 486                         $url .= '?';
 487                 } else {
 488                         $url .= '&';
 489                 }
 490                 $url .= $query;
 491         }
 492         return $url;
 493 }
 494
 495 /**
 496  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 497  * is correct.
 498  *
 499  * The meaning of the PROTO_* constants is as follows:
 500  * PROTO_HTTP: Output a URL starting with http://
 501  * PROTO_HTTPS: Output a URL starting with https://
 502  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 503  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 504  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 505  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 506  *
 507  * @todo this won't work with current-path-relative URLs
 508  * like "subdir/foo.html", etc.
 509  *
 510  * @param $url String: either fully-qualified or a local path + query
 511  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 512  *                             protocol to use if $url or $wgServer is
 513  *                             protocol-relative
 514  * @return string Fully-qualified URL, current-path-relative URL or false if
 515  *                no valid URL can be constructed
 516  */
 517 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 518         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 519         $serverUrl = $wgServer;
 520         if ( $defaultProto === PROTO_CANONICAL ) {
 521                 $serverUrl = $wgCanonicalServer;
 522         }
 523         // Make $wgInternalServer fall back to $wgServer if not set
 524         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 525                 $serverUrl = $wgInternalServer;
 526         }
 527         if ( $defaultProto === PROTO_CURRENT ) {
 528                 $defaultProto = WebRequest::detectProtocol() . '://';
 529         }
 530
 531         // Analyze $serverUrl to obtain its protocol
 532         $bits = wfParseUrl( $serverUrl );
 533         $serverHasProto = $bits && $bits['scheme'] != '';
 534
 535         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 536                 if ( $serverHasProto ) {
 537                         $defaultProto = $bits['scheme'] . '://';
 538                 } else {
 539                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 540                         // Fall back to HTTP in this ridiculous case
 541                         $defaultProto = PROTO_HTTP;
 542                 }
 543         }
 544
 545         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 546
 547         if ( substr( $url, 0, 2 ) == '//' ) {
 548                 $url = $defaultProtoWithoutSlashes . $url;
 549         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 550                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 551                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 552         }
 553
 554         $bits = wfParseUrl( $url );
 555         if ( $bits && isset( $bits['path'] ) ) {
 556                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 557                 return wfAssembleUrl( $bits );
 558         } elseif ( $bits ) {
 559                 # No path to expand
 560                 return $url;
 561         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 562                 # URL is a relative path
 563                 return wfRemoveDotSegments( $url );
 564         }
 565
 566         # Expanded URL is not valid.
 567         return false;
 568 }
 569
 570 /**
 571  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 572  * if you need to edit part of a URL and put it back together.
 573  *
 574  * This is the basic structure used (brackets contain keys for $urlParts):
 575  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 576  *
 577  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 578  *
 579  * @since 1.19
 580  * @param $urlParts Array URL parts, as output from wfParseUrl
 581  * @return string URL assembled from its component parts
 582  */
 583 function wfAssembleUrl( $urlParts ) {
 584         $result = '';
 585
 586         if ( isset( $urlParts['delimiter'] ) ) {
 587                 if ( isset( $urlParts['scheme'] ) ) {
 588                         $result .= $urlParts['scheme'];
 589                 }
 590
 591                 $result .= $urlParts['delimiter'];
 592         }
 593
 594         if ( isset( $urlParts['host'] ) ) {
 595                 if ( isset( $urlParts['user'] ) ) {
 596                         $result .= $urlParts['user'];
 597                         if ( isset( $urlParts['pass'] ) ) {
 598                                 $result .= ':' . $urlParts['pass'];
 599                         }
 600                         $result .= '@';
 601                 }
 602
 603                 $result .= $urlParts['host'];
 604
 605                 if ( isset( $urlParts['port'] ) ) {
 606                         $result .= ':' . $urlParts['port'];
 607                 }
 608         }
 609
 610         if ( isset( $urlParts['path'] ) ) {
 611                 $result .= $urlParts['path'];
 612         }
 613
 614         if ( isset( $urlParts['query'] ) ) {
 615                 $result .= '?' . $urlParts['query'];
 616         }
 617
 618         if ( isset( $urlParts['fragment'] ) ) {
 619                 $result .= '#' . $urlParts['fragment'];
 620         }
 621
 622         return $result;
 623 }
 624
 625 /**
 626  * Remove all dot-segments in the provided URL path.  For example,
 627  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 628  * RFC3986 section 5.2.4.
 629  *
 630  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 631  *
 632  * @param $urlPath String URL path, potentially containing dot-segments
 633  * @return string URL path with all dot-segments removed
 634  */
 635 function wfRemoveDotSegments( $urlPath ) {
 636         $output = '';
 637         $inputOffset = 0;
 638         $inputLength = strlen( $urlPath );
 639
 640         while ( $inputOffset < $inputLength ) {
 641                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 642                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 643                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 644                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 645                 $trimOutput = false;
 646
 647                 if ( $prefixLengthTwo == './' ) {
 648                         # Step A, remove leading "./"
 649                         $inputOffset += 2;
 650                 } elseif ( $prefixLengthThree == '../' ) {
 651                         # Step A, remove leading "../"
 652                         $inputOffset += 3;
 653                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 654                         # Step B, replace leading "/.$" with "/"
 655                         $inputOffset += 1;
 656                         $urlPath[$inputOffset] = '/';
 657                 } elseif ( $prefixLengthThree == '/./' ) {
 658                         # Step B, replace leading "/./" with "/"
 659                         $inputOffset += 2;
 660                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 661                         # Step C, replace leading "/..$" with "/" and
 662                         # remove last path component in output
 663                         $inputOffset += 2;
 664                         $urlPath[$inputOffset] = '/';
 665                         $trimOutput = true;
 666                 } elseif ( $prefixLengthFour == '/../' ) {
 667                         # Step C, replace leading "/../" with "/" and
 668                         # remove last path component in output
 669                         $inputOffset += 3;
 670                         $trimOutput = true;
 671                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 672                         # Step D, remove "^.$"
 673                         $inputOffset += 1;
 674                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 675                         # Step D, remove "^..$"
 676                         $inputOffset += 2;
 677                 } else {
 678                         # Step E, move leading path segment to output
 679                         if ( $prefixLengthOne == '/' ) {
 680                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 681                         } else {
 682                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 683                         }
 684                         if ( $slashPos === false ) {
 685                                 $output .= substr( $urlPath, $inputOffset );
 686                                 $inputOffset = $inputLength;
 687                         } else {
 688                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 689                                 $inputOffset += $slashPos - $inputOffset;
 690                         }
 691                 }
 692
 693                 if ( $trimOutput ) {
 694                         $slashPos = strrpos( $output, '/' );
 695                         if ( $slashPos === false ) {
 696                                 $output = '';
 697                         } else {
 698                                 $output = substr( $output, 0, $slashPos );
 699                         }
 700                 }
 701         }
 702
 703         return $output;
 704 }
 705
 706 /**
 707  * Returns a regular expression of url protocols
 708  *
 709  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 710  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 711  * @return String
 712  */
 713 function wfUrlProtocols( $includeProtocolRelative = true ) {
 714         global $wgUrlProtocols;
 715
 716         // Cache return values separately based on $includeProtocolRelative
 717         static $withProtRel = null, $withoutProtRel = null;
 718         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 719         if ( !is_null( $cachedValue ) ) {
 720                 return $cachedValue;
 721         }
 722
 723         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 724         // with LocalSettings files from 1.5
 725         if ( is_array( $wgUrlProtocols ) ) {
 726                 $protocols = array();
 727                 foreach ( $wgUrlProtocols as $protocol ) {
 728                         // Filter out '//' if !$includeProtocolRelative
 729                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 730                                 $protocols[] = preg_quote( $protocol, '/' );
 731                         }
 732                 }
 733
 734                 $retval = implode( '|', $protocols );
 735         } else {
 736                 // Ignore $includeProtocolRelative in this case
 737                 // This case exists for pre-1.6 compatibility, and we can safely assume
 738                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 739                 // URLs weren't supported until 1.18
 740                 $retval = $wgUrlProtocols;
 741         }
 742
 743         // Cache return value
 744         if ( $includeProtocolRelative ) {
 745                 $withProtRel = $retval;
 746         } else {
 747                 $withoutProtRel = $retval;
 748         }
 749         return $retval;
 750 }
 751
 752 /**
 753  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 754  * you need a regex that matches all URL protocols but does not match protocol-
 755  * relative URLs
 756  * @return String
 757  */
 758 function wfUrlProtocolsWithoutProtRel() {
 759         return wfUrlProtocols( false );
 760 }
 761
 762 /**
 763  * parse_url() work-alike, but non-broken.  Differences:
 764  *
 765  * 1) Does not raise warnings on bad URLs (just returns false)
 766  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 767  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 768  *
 769  * @param $url String: a URL to parse
 770  * @return Array: bits of the URL in an associative array, per PHP docs
 771  */
 772 function wfParseUrl( $url ) {
 773         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 774
 775         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 776         // way to handle them is to just prepend 'http:' and strip the protocol out later
 777         $wasRelative = substr( $url, 0, 2 ) == '//';
 778         if ( $wasRelative ) {
 779                 $url = "http:$url";
 780         }
 781         wfSuppressWarnings();
 782         $bits = parse_url( $url );
 783         wfRestoreWarnings();
 784         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 785         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 786         if ( !$bits || !isset( $bits['scheme'] ) ) {
 787                 return false;
 788         }
 789
 790         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 791         $bits['scheme'] = strtolower( $bits['scheme'] );
 792
 793         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 794         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 795                 $bits['delimiter'] = '://';
 796         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 797                 $bits['delimiter'] = ':';
 798                 // parse_url detects for news: and mailto: the host part of an url as path
 799                 // We have to correct this wrong detection
 800                 if ( isset( $bits['path'] ) ) {
 801                         $bits['host'] = $bits['path'];
 802                         $bits['path'] = '';
 803                 }
 804         } else {
 805                 return false;
 806         }
 807
 808         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 809         if ( !isset( $bits['host'] ) ) {
 810                 $bits['host'] = '';
 811
 812                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 813                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 814                         $bits['path'] = '/' . $bits['path'];
 815                 }
 816         }
 817
 818         // If the URL was protocol-relative, fix scheme and delimiter
 819         if ( $wasRelative ) {
 820                 $bits['scheme'] = '';
 821                 $bits['delimiter'] = '//';
 822         }
 823         return $bits;
 824 }
 825
 826 /**
 827  * Take a URL, make sure it's expanded to fully qualified, and replace any
 828  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 829  * for more compact display and legibility for local audiences.
 830  *
 831  * @todo handle punycode domains too
 832  *
 833  * @param $url string
 834  * @return string
 835  */
 836 function wfExpandIRI( $url ) {
 837         return preg_replace_callback( '/((?:%[89A-F][0-9A-F])+)/i', 'wfExpandIRI_callback', wfExpandUrl( $url ) );
 838 }
 839
 840 /**
 841  * Private callback for wfExpandIRI
 842  * @param array $matches
 843  * @return string
 844  */
 845 function wfExpandIRI_callback( $matches ) {
 846         return urldecode( $matches[1] );
 847 }
 848
 849
 850
 851 /**
 852  * Make URL indexes, appropriate for the el_index field of externallinks.
 853  *
 854  * @param $url String
 855  * @return array
 856  */
 857 function wfMakeUrlIndexes( $url ) {
 858         $bits = wfParseUrl( $url );
 859
 860         // Reverse the labels in the hostname, convert to lower case
 861         // For emails reverse domainpart only
 862         if ( $bits['scheme'] == 'mailto' ) {
 863                 $mailparts = explode( '@', $bits['host'], 2 );
 864                 if ( count( $mailparts ) === 2 ) {
 865                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 866                 } else {
 867                         // No domain specified, don't mangle it
 868                         $domainpart = '';
 869                 }
 870                 $reversedHost = $domainpart . '@' . $mailparts[0];
 871         } else {
 872                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 873         }
 874         // Add an extra dot to the end
 875         // Why? Is it in wrong place in mailto links?
 876         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 877                 $reversedHost .= '.';
 878         }
 879         // Reconstruct the pseudo-URL
 880         $prot = $bits['scheme'];
 881         $index = $prot . $bits['delimiter'] . $reversedHost;
 882         // Leave out user and password. Add the port, path, query and fragment
 883         if ( isset( $bits['port'] ) ) {
 884                 $index .= ':' . $bits['port'];
 885         }
 886         if ( isset( $bits['path'] ) ) {
 887                 $index .= $bits['path'];
 888         } else {
 889                 $index .= '/';
 890         }
 891         if ( isset( $bits['query'] ) ) {
 892                 $index .= '?' . $bits['query'];
 893         }
 894         if ( isset( $bits['fragment'] ) ) {
 895                 $index .= '#' . $bits['fragment'];
 896         }
 897
 898         if ( $prot == '' ) {
 899                 return array( "http:$index", "https:$index" );
 900         } else {
 901                 return array( $index );
 902         }
 903 }
 904
 905 /**
 906  * Check whether a given URL has a domain that occurs in a given set of domains
 907  * @param $url string URL
 908  * @param $domains array Array of domains (strings)
 909  * @return bool True if the host part of $url ends in one of the strings in $domains
 910  */
 911 function wfMatchesDomainList( $url, $domains ) {
 912         $bits = wfParseUrl( $url );
 913         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 914                 foreach ( (array)$domains as $domain ) {
 915                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 916                         // We should use something that interprets dots instead
 917                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 918                                 return true;
 919                         }
 920                 }
 921         }
 922         return false;
 923 }
 924
 925 /**
 926  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 927  * In normal operation this is a NOP.
 928  *
 929  * Controlling globals:
 930  * $wgDebugLogFile - points to the log file
 931  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 932  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 933  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 934  *
 935  * @param $text String
 936  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 937  */
 938 function wfDebug( $text, $logonly = false ) {
 939         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 940
 941         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 942                 return;
 943         }
 944
 945         $timer = wfDebugTimer();
 946         if ( $timer !== '' ) {
 947                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 948         }
 949
 950         if ( !$logonly ) {
 951                 MWDebug::debugMsg( $text );
 952         }
 953
 954         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 955                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 956                         # Strip unprintables; they can switch terminal modes when binary data
 957                         # gets dumped, which is pretty annoying.
 958                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 959                         $text = $wgDebugLogPrefix . $text;
 960                         wfErrorLog( $text, $wgDebugLogFile );
 961                 }
 962         }
 963 }
 964
 965 /**
 966  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 967  * @return bool
 968  */
 969 function wfIsDebugRawPage() {
 970         static $cache;
 971         if ( $cache !== null ) {
 972                 return $cache;
 973         }
 974         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 975         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 976                 || (
 977                         isset( $_SERVER['SCRIPT_NAME'] )
 978                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 979                 ) )
 980         {
 981                 $cache = true;
 982         } else {
 983                 $cache = false;
 984         }
 985         return $cache;
 986 }
 987
 988 /**
 989  * Get microsecond timestamps for debug logs
 990  *
 991  * @return string
 992  */
 993 function wfDebugTimer() {
 994         global $wgDebugTimestamps, $wgRequestTime;
 995
 996         if ( !$wgDebugTimestamps ) {
 997                 return '';
 998         }
 999
1000         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1001         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1002         return "$prefix $mem  ";
1003 }
1004
1005 /**
1006  * Send a line giving PHP memory usage.
1007  *
1008  * @param $exact Bool: print exact values instead of kilobytes (default: false)
1009  */
1010 function wfDebugMem( $exact = false ) {
1011         $mem = memory_get_usage();
1012         if( !$exact ) {
1013                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1014         } else {
1015                 $mem .= ' bytes';
1016         }
1017         wfDebug( "Memory usage: $mem\n" );
1018 }
1019
1020 /**
1021  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1022  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1023  *
1024  * @param $logGroup String
1025  * @param $text String
1026  * @param $public Bool: whether to log the event in the public log if no private
1027  *                     log file is specified, (default true)
1028  */
1029 function wfDebugLog( $logGroup, $text, $public = true ) {
1030         global $wgDebugLogGroups;
1031         $text = trim( $text ) . "\n";
1032         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
1033                 $time = wfTimestamp( TS_DB );
1034                 $wiki = wfWikiID();
1035                 $host = wfHostname();
1036                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
1037                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1038                 }
1039         } elseif ( $public === true ) {
1040                 wfDebug( $text, true );
1041         }
1042 }
1043
1044 /**
1045  * Log for database errors
1046  *
1047  * @param $text String: database error message.
1048  */
1049 function wfLogDBError( $text ) {
1050         global $wgDBerrorLog, $wgDBerrorLogTZ;
1051         static $logDBErrorTimeZoneObject = null;
1052
1053         if ( $wgDBerrorLog ) {
1054                 $host = wfHostname();
1055                 $wiki = wfWikiID();
1056
1057                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1058                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1059                 }
1060
1061                 // Workaround for https://bugs.php.net/bug.php?id=52063
1062                 // Can be removed when min PHP > 5.3.2
1063                 if ( $logDBErrorTimeZoneObject === null ) {
1064                         $d = date_create( "now" );
1065                 } else {
1066                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1067                 }
1068
1069                 $date = $d->format( 'D M j G:i:s T Y' );
1070
1071                 $text = "$date\t$host\t$wiki\t$text";
1072                 wfErrorLog( $text, $wgDBerrorLog );
1073         }
1074 }
1075
1076 /**
1077  * Throws a warning that $function is deprecated
1078  *
1079  * @param $function String
1080  * @param $version String|bool: Version of MediaWiki that the function was deprecated in (Added in 1.19).
1081  * @param $component String|bool: Added in 1.19.
1082  * @param $callerOffset integer: How far up the callstack is the original
1083  *    caller. 2 = function that called the function that called
1084  *    wfDeprecated (Added in 1.20)
1085  *
1086  * @return null
1087  */
1088 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1089         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1090 }
1091
1092 /**
1093  * Send a warning either to the debug log or in a PHP error depending on
1094  * $wgDevelopmentWarnings
1095  *
1096  * @param $msg String: message to send
1097  * @param $callerOffset Integer: number of items to go back in the backtrace to
1098  *        find the correct caller (1 = function calling wfWarn, ...)
1099  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
1100  *        is true
1101  */
1102 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1103         MWDebug::warning( $msg, $callerOffset + 1, $level );
1104 }
1105
1106 /**
1107  * Log to a file without getting "file size exceeded" signals.
1108  *
1109  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1110  * send lines to the specified port, prefixed by the specified prefix and a space.
1111  *
1112  * @param $text String
1113  * @param $file String filename
1114  * @throws MWException
1115  */
1116 function wfErrorLog( $text, $file ) {
1117         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1118                 # Needs the sockets extension
1119                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1120                         // IPv6 bracketed host
1121                         $host = $m[2];
1122                         $port = intval( $m[3] );
1123                         $prefix = isset( $m[4] ) ? $m[4] : false;
1124                         $domain = AF_INET6;
1125                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1126                         $host = $m[2];
1127                         if ( !IP::isIPv4( $host ) ) {
1128                                 $host = gethostbyname( $host );
1129                         }
1130                         $port = intval( $m[3] );
1131                         $prefix = isset( $m[4] ) ? $m[4] : false;
1132                         $domain = AF_INET;
1133                 } else {
1134                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1135                 }
1136
1137                 // Clean it up for the multiplexer
1138                 if ( strval( $prefix ) !== '' ) {
1139                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1140
1141                         // Limit to 64KB
1142                         if ( strlen( $text ) > 65506 ) {
1143                                 $text = substr( $text, 0, 65506 );
1144                         }
1145
1146                         if ( substr( $text, -1 ) != "\n" ) {
1147                                 $text .= "\n";
1148                         }
1149                 } elseif ( strlen( $text ) > 65507 ) {
1150                         $text = substr( $text, 0, 65507 );
1151                 }
1152
1153                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1154                 if ( !$sock ) {
1155                         return;
1156                 }
1157
1158                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1159                 socket_close( $sock );
1160         } else {
1161                 wfSuppressWarnings();
1162                 $exists = file_exists( $file );
1163                 $size = $exists ? filesize( $file ) : false;
1164                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1165                         file_put_contents( $file, $text, FILE_APPEND );
1166                 }
1167                 wfRestoreWarnings();
1168         }
1169 }
1170
1171 /**
1172  * @todo document
1173  */
1174 function wfLogProfilingData() {
1175         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1176         global $wgProfileLimit, $wgUser;
1177
1178         $profiler = Profiler::instance();
1179
1180         # Profiling must actually be enabled...
1181         if ( $profiler->isStub() ) {
1182                 return;
1183         }
1184
1185         // Get total page request time and only show pages that longer than
1186         // $wgProfileLimit time (default is 0)
1187         $elapsed = microtime( true ) - $wgRequestTime;
1188         if ( $elapsed <= $wgProfileLimit ) {
1189                 return;
1190         }
1191
1192         $profiler->logData();
1193
1194         // Check whether this should be logged in the debug file.
1195         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1196                 return;
1197         }
1198
1199         $forward = '';
1200         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1201                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1202         }
1203         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1204                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1205         }
1206         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1207                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1208         }
1209         if ( $forward ) {
1210                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1211         }
1212         // Don't load $wgUser at this late stage just for statistics purposes
1213         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1214         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1215                 $forward .= ' anon';
1216         }
1217         $log = sprintf( "%s\t%04.3f\t%s\n",
1218                 gmdate( 'YmdHis' ), $elapsed,
1219                 urldecode( $wgRequest->getRequestURL() . $forward ) );
1220
1221         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1222 }
1223
1224 /**
1225  * Increment a statistics counter
1226  *
1227  * @param $key String
1228  * @param $count Int
1229  */
1230 function wfIncrStats( $key, $count = 1 ) {
1231         global $wgStatsMethod;
1232
1233         $count = intval( $count );
1234
1235         if( $wgStatsMethod == 'udp' ) {
1236                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
1237                 static $socket;
1238
1239                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
1240
1241                 if ( !$socket ) {
1242                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1243                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1244                         socket_sendto(
1245                                 $socket,
1246                                 $statline,
1247                                 strlen( $statline ),
1248                                 0,
1249                                 $wgUDPProfilerHost,
1250                                 $wgUDPProfilerPort
1251                         );
1252                 }
1253                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1254                 wfSuppressWarnings();
1255                 socket_sendto(
1256                         $socket,
1257                         $statline,
1258                         strlen( $statline ),
1259                         0,
1260                         $wgUDPProfilerHost,
1261                         $wgUDPProfilerPort
1262                 );
1263                 wfRestoreWarnings();
1264         } elseif( $wgStatsMethod == 'cache' ) {
1265                 global $wgMemc;
1266                 $key = wfMemcKey( 'stats', $key );
1267                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1268                         $wgMemc->add( $key, $count );
1269                 }
1270         } else {
1271                 // Disabled
1272         }
1273 }
1274
1275 /**
1276  * Check if the wiki read-only lock file is present. This can be used to lock
1277  * off editing functions, but doesn't guarantee that the database will not be
1278  * modified.
1279  *
1280  * @return bool
1281  */
1282 function wfReadOnly() {
1283         global $wgReadOnlyFile, $wgReadOnly;
1284
1285         if ( !is_null( $wgReadOnly ) ) {
1286                 return (bool)$wgReadOnly;
1287         }
1288         if ( $wgReadOnlyFile == '' ) {
1289                 return false;
1290         }
1291         // Set $wgReadOnly for faster access next time
1292         if ( is_file( $wgReadOnlyFile ) ) {
1293                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1294         } else {
1295                 $wgReadOnly = false;
1296         }
1297         return (bool)$wgReadOnly;
1298 }
1299
1300 /**
1301  * @return bool
1302  */
1303 function wfReadOnlyReason() {
1304         global $wgReadOnly;
1305         wfReadOnly();
1306         return $wgReadOnly;
1307 }
1308
1309 /**
1310  * Return a Language object from $langcode
1311  *
1312  * @param $langcode Mixed: either:
1313  *                  - a Language object
1314  *                  - code of the language to get the message for, if it is
1315  *                    a valid code create a language for that language, if
1316  *                    it is a string but not a valid code then make a basic
1317  *                    language object
1318  *                  - a boolean: if it's false then use the global object for
1319  *                    the current user's language (as a fallback for the old parameter
1320  *                    functionality), or if it is true then use global object
1321  *                    for the wiki's content language.
1322  * @return Language object
1323  */
1324 function wfGetLangObj( $langcode = false ) {
1325         # Identify which language to get or create a language object for.
1326         # Using is_object here due to Stub objects.
1327         if( is_object( $langcode ) ) {
1328                 # Great, we already have the object (hopefully)!
1329                 return $langcode;
1330         }
1331
1332         global $wgContLang, $wgLanguageCode;
1333         if( $langcode === true || $langcode === $wgLanguageCode ) {
1334                 # $langcode is the language code of the wikis content language object.
1335                 # or it is a boolean and value is true
1336                 return $wgContLang;
1337         }
1338
1339         global $wgLang;
1340         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1341                 # $langcode is the language code of user language object.
1342                 # or it was a boolean and value is false
1343                 return $wgLang;
1344         }
1345
1346         $validCodes = array_keys( Language::fetchLanguageNames() );
1347         if( in_array( $langcode, $validCodes ) ) {
1348                 # $langcode corresponds to a valid language.
1349                 return Language::factory( $langcode );
1350         }
1351
1352         # $langcode is a string, but not a valid language code; use content language.
1353         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1354         return $wgContLang;
1355 }
1356
1357 /**
1358  * Old function when $wgBetterDirectionality existed
1359  * All usage removed, wfUILang can be removed in near future
1360  *
1361  * @deprecated since 1.18
1362  * @return Language
1363  */
1364 function wfUILang() {
1365         wfDeprecated( __METHOD__, '1.18' );
1366         global $wgLang;
1367         return $wgLang;
1368 }
1369
1370 /**
1371  * This is the new function for getting translated interface messages.
1372  * See the Message class for documentation how to use them.
1373  * The intention is that this function replaces all old wfMsg* functions.
1374  * @param $key \string Message key.
1375  * Varargs: normal message parameters.
1376  * @return Message
1377  * @since 1.17
1378  */
1379 function wfMessage( $key /*...*/) {
1380         $params = func_get_args();
1381         array_shift( $params );
1382         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1383                 $params = $params[0];
1384         }
1385         return new Message( $key, $params );
1386 }
1387
1388 /**
1389  * This function accepts multiple message keys and returns a message instance
1390  * for the first message which is non-empty. If all messages are empty then an
1391  * instance of the first message key is returned.
1392  * @param varargs: message keys
1393  * @return Message
1394  * @since 1.18
1395  */
1396 function wfMessageFallback( /*...*/ ) {
1397         $args = func_get_args();
1398         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1399 }
1400
1401 /**
1402  * Get a message from anywhere, for the current user language.
1403  *
1404  * Use wfMsgForContent() instead if the message should NOT
1405  * change depending on the user preferences.
1406  *
1407  * @deprecated since 1.18
1408  *
1409  * @param $key String: lookup key for the message, usually
1410  *    defined in languages/Language.php
1411  *
1412  * Parameters to the message, which can be used to insert variable text into
1413  * it, can be passed to this function in the following formats:
1414  * - One per argument, starting at the second parameter
1415  * - As an array in the second parameter
1416  * These are not shown in the function definition.
1417  *
1418  * @return String
1419  */
1420 function wfMsg( $key ) {
1421         $args = func_get_args();
1422         array_shift( $args );
1423         return wfMsgReal( $key, $args );
1424 }
1425
1426 /**
1427  * Same as above except doesn't transform the message
1428  *
1429  * @deprecated since 1.18
1430  *
1431  * @param $key String
1432  * @return String
1433  */
1434 function wfMsgNoTrans( $key ) {
1435         $args = func_get_args();
1436         array_shift( $args );
1437         return wfMsgReal( $key, $args, true, false, false );
1438 }
1439
1440 /**
1441  * Get a message from anywhere, for the current global language
1442  * set with $wgLanguageCode.
1443  *
1444  * Use this if the message should NOT change dependent on the
1445  * language set in the user's preferences. This is the case for
1446  * most text written into logs, as well as link targets (such as
1447  * the name of the copyright policy page). Link titles, on the
1448  * other hand, should be shown in the UI language.
1449  *
1450  * Note that MediaWiki allows users to change the user interface
1451  * language in their preferences, but a single installation
1452  * typically only contains content in one language.
1453  *
1454  * Be wary of this distinction: If you use wfMsg() where you should
1455  * use wfMsgForContent(), a user of the software may have to
1456  * customize potentially hundreds of messages in
1457  * order to, e.g., fix a link in every possible language.
1458  *
1459  * @deprecated since 1.18
1460  *
1461  * @param $key String: lookup key for the message, usually
1462  *     defined in languages/Language.php
1463  * @return String
1464  */
1465 function wfMsgForContent( $key ) {
1466         global $wgForceUIMsgAsContentMsg;
1467         $args = func_get_args();
1468         array_shift( $args );
1469         $forcontent = true;
1470         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1471                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1472         {
1473                 $forcontent = false;
1474         }
1475         return wfMsgReal( $key, $args, true, $forcontent );
1476 }
1477
1478 /**
1479  * Same as above except doesn't transform the message
1480  *
1481  * @deprecated since 1.18
1482  *
1483  * @param $key String
1484  * @return String
1485  */
1486 function wfMsgForContentNoTrans( $key ) {
1487         global $wgForceUIMsgAsContentMsg;
1488         $args = func_get_args();
1489         array_shift( $args );
1490         $forcontent = true;
1491         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1492                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1493         {
1494                 $forcontent = false;
1495         }
1496         return wfMsgReal( $key, $args, true, $forcontent, false );
1497 }
1498
1499 /**
1500  * Really get a message
1501  *
1502  * @deprecated since 1.18
1503  *
1504  * @param $key String: key to get.
1505  * @param $args
1506  * @param $useDB Boolean
1507  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1508  * @param $transform Boolean: Whether or not to transform the message.
1509  * @return String: the requested message.
1510  */
1511 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1512         wfProfileIn( __METHOD__ );
1513         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1514         $message = wfMsgReplaceArgs( $message, $args );
1515         wfProfileOut( __METHOD__ );
1516         return $message;
1517 }
1518
1519 /**
1520  * Fetch a message string value, but don't replace any keys yet.
1521  *
1522  * @deprecated since 1.18
1523  *
1524  * @param $key String
1525  * @param $useDB Bool
1526  * @param $langCode String: Code of the language to get the message for, or
1527  *                  behaves as a content language switch if it is a boolean.
1528  * @param $transform Boolean: whether to parse magic words, etc.
1529  * @return string
1530  */
1531 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1532         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1533
1534         $cache = MessageCache::singleton();
1535         $message = $cache->get( $key, $useDB, $langCode );
1536         if( $message === false ) {
1537                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1538         } elseif ( $transform ) {
1539                 $message = $cache->transform( $message );
1540         }
1541         return $message;
1542 }
1543
1544 /**
1545  * Replace message parameter keys on the given formatted output.
1546  *
1547  * @param $message String
1548  * @param $args Array
1549  * @return string
1550  * @private
1551  */
1552 function wfMsgReplaceArgs( $message, $args ) {
1553         # Fix windows line-endings
1554         # Some messages are split with explode("\n", $msg)
1555         $message = str_replace( "\r", '', $message );
1556
1557         // Replace arguments
1558         if ( count( $args ) ) {
1559                 if ( is_array( $args[0] ) ) {
1560                         $args = array_values( $args[0] );
1561                 }
1562                 $replacementKeys = array();
1563                 foreach( $args as $n => $param ) {
1564                         $replacementKeys['$' . ( $n + 1 )] = $param;
1565                 }
1566                 $message = strtr( $message, $replacementKeys );
1567         }
1568
1569         return $message;
1570 }
1571
1572 /**
1573  * Return an HTML-escaped version of a message.
1574  * Parameter replacements, if any, are done *after* the HTML-escaping,
1575  * so parameters may contain HTML (eg links or form controls). Be sure
1576  * to pre-escape them if you really do want plaintext, or just wrap
1577  * the whole thing in htmlspecialchars().
1578  *
1579  * @deprecated since 1.18
1580  *
1581  * @param $key String
1582  * @param string ... parameters
1583  * @return string
1584  */
1585 function wfMsgHtml( $key ) {
1586         $args = func_get_args();
1587         array_shift( $args );
1588         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1589 }
1590
1591 /**
1592  * Return an HTML version of message
1593  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1594  * so parameters may contain HTML (eg links or form controls). Be sure
1595  * to pre-escape them if you really do want plaintext, or just wrap
1596  * the whole thing in htmlspecialchars().
1597  *
1598  * @deprecated since 1.18
1599  *
1600  * @param $key String
1601  * @param string ... parameters
1602  * @return string
1603  */
1604 function wfMsgWikiHtml( $key ) {
1605         $args = func_get_args();
1606         array_shift( $args );
1607         return wfMsgReplaceArgs(
1608                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1609                 /* can't be set to false */ true, /* interface */ true )->getText(),
1610                 $args );
1611 }
1612
1613 /**
1614  * Returns message in the requested format
1615  *
1616  * @deprecated since 1.18
1617  *
1618  * @param $key String: key of the message
1619  * @param $options Array: processing rules. Can take the following options:
1620  *   <i>parse</i>: parses wikitext to HTML
1621  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1622  *       p's added by parser or tidy
1623  *   <i>escape</i>: filters message through htmlspecialchars
1624  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1625  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1626  *   <i>parsemag</i>: transform the message using magic phrases
1627  *   <i>content</i>: fetch message for content language instead of interface
1628  * Also can accept a single associative argument, of the form 'language' => 'xx':
1629  *   <i>language</i>: Language object or language code to fetch message for
1630  *       (overriden by <i>content</i>).
1631  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1632  *
1633  * @return String
1634  */
1635 function wfMsgExt( $key, $options ) {
1636         $args = func_get_args();
1637         array_shift( $args );
1638         array_shift( $args );
1639         $options = (array)$options;
1640
1641         foreach( $options as $arrayKey => $option ) {
1642                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1643                         # An unknown index, neither numeric nor "language"
1644                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1645                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1646                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1647                 'replaceafter', 'parsemag', 'content' ) ) ) {
1648                         # A numeric index with unknown value
1649                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1650                 }
1651         }
1652
1653         if( in_array( 'content', $options, true ) ) {
1654                 $forContent = true;
1655                 $langCode = true;
1656                 $langCodeObj = null;
1657         } elseif( array_key_exists( 'language', $options ) ) {
1658                 $forContent = false;
1659                 $langCode = wfGetLangObj( $options['language'] );
1660                 $langCodeObj = $langCode;
1661         } else {
1662                 $forContent = false;
1663                 $langCode = false;
1664                 $langCodeObj = null;
1665         }
1666
1667         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1668
1669         if( !in_array( 'replaceafter', $options, true ) ) {
1670                 $string = wfMsgReplaceArgs( $string, $args );
1671         }
1672
1673         $messageCache = MessageCache::singleton();
1674         $parseInline = in_array( 'parseinline', $options, true );
1675         if( in_array( 'parse', $options, true ) || $parseInline ) {
1676                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1677                 if ( $string instanceof ParserOutput ) {
1678                         $string = $string->getText();
1679                 }
1680
1681                 if ( $parseInline ) {
1682                         $m = array();
1683                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1684                                 $string = $m[1];
1685                         }
1686                 }
1687         } elseif ( in_array( 'parsemag', $options, true ) ) {
1688                 $string = $messageCache->transform( $string,
1689                                 !$forContent, $langCodeObj );
1690         }
1691
1692         if ( in_array( 'escape', $options, true ) ) {
1693                 $string = htmlspecialchars ( $string );
1694         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1695                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1696         }
1697
1698         if( in_array( 'replaceafter', $options, true ) ) {
1699                 $string = wfMsgReplaceArgs( $string, $args );
1700         }
1701
1702         return $string;
1703 }
1704
1705 /**
1706  * Since wfMsg() and co suck, they don't return false if the message key they
1707  * looked up didn't exist but a XHTML string, this function checks for the
1708  * nonexistance of messages by checking the MessageCache::get() result directly.
1709  *
1710  * @deprecated since 1.18. Use Message::isDisabled().
1711  *
1712  * @param $key      String: the message key looked up
1713  * @return Boolean True if the message *doesn't* exist.
1714  */
1715 function wfEmptyMsg( $key ) {
1716         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1717 }
1718
1719 /**
1720  * Throw a debugging exception. This function previously once exited the process,
1721  * but now throws an exception instead, with similar results.
1722  *
1723  * @param $msg String: message shown when dying.
1724  * @throws MWException
1725  */
1726 function wfDebugDieBacktrace( $msg = '' ) {
1727         throw new MWException( $msg );
1728 }
1729
1730 /**
1731  * Fetch server name for use in error reporting etc.
1732  * Use real server name if available, so we know which machine
1733  * in a server farm generated the current page.
1734  *
1735  * @return string
1736  */
1737 function wfHostname() {
1738         static $host;
1739         if ( is_null( $host ) ) {
1740
1741                 # Hostname overriding
1742                 global $wgOverrideHostname;
1743                 if( $wgOverrideHostname !== false ) {
1744                         # Set static and skip any detection
1745                         $host = $wgOverrideHostname;
1746                         return $host;
1747                 }
1748
1749                 if ( function_exists( 'posix_uname' ) ) {
1750                         // This function not present on Windows
1751                         $uname = posix_uname();
1752                 } else {
1753                         $uname = false;
1754                 }
1755                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1756                         $host = $uname['nodename'];
1757                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1758                         # Windows computer name
1759                         $host = getenv( 'COMPUTERNAME' );
1760                 } else {
1761                         # This may be a virtual server.
1762                         $host = $_SERVER['SERVER_NAME'];
1763                 }
1764         }
1765         return $host;
1766 }
1767
1768 /**
1769  * Returns a HTML comment with the elapsed time since request.
1770  * This method has no side effects.
1771  *
1772  * @return string
1773  */
1774 function wfReportTime() {
1775         global $wgRequestTime, $wgShowHostnames;
1776
1777         $elapsed = microtime( true ) - $wgRequestTime;
1778
1779         return $wgShowHostnames
1780                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1781                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1782 }
1783
1784 /**
1785  * Safety wrapper for debug_backtrace().
1786  *
1787  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1788  * murky circumstances, which may be triggered in part by stub objects
1789  * or other fancy talkin'.
1790  *
1791  * Will return an empty array if Zend Optimizer is detected or if
1792  * debug_backtrace is disabled, otherwise the output from
1793  * debug_backtrace() (trimmed).
1794  *
1795  * @param $limit int This parameter can be used to limit the number of stack frames returned
1796  *
1797  * @return array of backtrace information
1798  */
1799 function wfDebugBacktrace( $limit = 0 ) {
1800         static $disabled = null;
1801
1802         if( extension_loaded( 'Zend Optimizer' ) ) {
1803                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1804                 return array();
1805         }
1806
1807         if ( is_null( $disabled ) ) {
1808                 $disabled = false;
1809                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1810                 $functions = array_map( 'trim', $functions );
1811                 $functions = array_map( 'strtolower', $functions );
1812                 if ( in_array( 'debug_backtrace', $functions ) ) {
1813                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1814                         $disabled = true;
1815                 }
1816         }
1817         if ( $disabled ) {
1818                 return array();
1819         }
1820
1821         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1822                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1823         } else {
1824                 return array_slice( debug_backtrace(), 1 );
1825         }
1826 }
1827
1828 /**
1829  * Get a debug backtrace as a string
1830  *
1831  * @return string
1832  */
1833 function wfBacktrace() {
1834         global $wgCommandLineMode;
1835
1836         if ( $wgCommandLineMode ) {
1837                 $msg = '';
1838         } else {
1839                 $msg = "<ul>\n";
1840         }
1841         $backtrace = wfDebugBacktrace();
1842         foreach( $backtrace as $call ) {
1843                 if( isset( $call['file'] ) ) {
1844                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1845                         $file = $f[count( $f ) - 1];
1846                 } else {
1847                         $file = '-';
1848                 }
1849                 if( isset( $call['line'] ) ) {
1850                         $line = $call['line'];
1851                 } else {
1852                         $line = '-';
1853                 }
1854                 if ( $wgCommandLineMode ) {
1855                         $msg .= "$file line $line calls ";
1856                 } else {
1857                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1858                 }
1859                 if( !empty( $call['class'] ) ) {
1860                         $msg .= $call['class'] . $call['type'];
1861                 }
1862                 $msg .= $call['function'] . '()';
1863
1864                 if ( $wgCommandLineMode ) {
1865                         $msg .= "\n";
1866                 } else {
1867                         $msg .= "</li>\n";
1868                 }
1869         }
1870         if ( $wgCommandLineMode ) {
1871                 $msg .= "\n";
1872         } else {
1873                 $msg .= "</ul>\n";
1874         }
1875
1876         return $msg;
1877 }
1878
1879 /**
1880  * Get the name of the function which called this function
1881  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1882  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1883  * wfGetCaller( 3 ) is the parent of that.
1884  *
1885  * @param $level Int
1886  * @return string
1887  */
1888 function wfGetCaller( $level = 2 ) {
1889         $backtrace = wfDebugBacktrace( $level + 1 );
1890         if ( isset( $backtrace[$level] ) ) {
1891                 return wfFormatStackFrame( $backtrace[$level] );
1892         } else {
1893                 return 'unknown';
1894         }
1895 }
1896
1897 /**
1898  * Return a string consisting of callers in the stack. Useful sometimes
1899  * for profiling specific points.
1900  *
1901  * @param $limit int The maximum depth of the stack frame to return, or false for
1902  *               the entire stack.
1903  * @return String
1904  */
1905 function wfGetAllCallers( $limit = 3 ) {
1906         $trace = array_reverse( wfDebugBacktrace() );
1907         if ( !$limit || $limit > count( $trace ) - 1 ) {
1908                 $limit = count( $trace ) - 1;
1909         }
1910         $trace = array_slice( $trace, -$limit - 1, $limit );
1911         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1912 }
1913
1914 /**
1915  * Return a string representation of frame
1916  *
1917  * @param $frame Array
1918  * @return string
1919  */
1920 function wfFormatStackFrame( $frame ) {
1921         return isset( $frame['class'] ) ?
1922                 $frame['class'] . '::' . $frame['function'] :
1923                 $frame['function'];
1924 }
1925
1926
1927 /* Some generic result counters, pulled out of SearchEngine */
1928
1929
1930 /**
1931  * @todo document
1932  *
1933  * @param $offset Int
1934  * @param $limit Int
1935  * @return String
1936  */
1937 function wfShowingResults( $offset, $limit ) {
1938         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1939 }
1940
1941 /**
1942  * Generate (prev x| next x) (20|50|100...) type links for paging
1943  *
1944  * @param $offset String
1945  * @param $limit Integer
1946  * @param $link String
1947  * @param $query String: optional URL query parameter string
1948  * @param $atend Bool: optional param for specified if this is the last page
1949  * @return String
1950  * @deprecated in 1.19; use Language::viewPrevNext() instead
1951  */
1952 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1953         wfDeprecated( __METHOD__, '1.19' );
1954
1955         global $wgLang;
1956
1957         $query = wfCgiToArray( $query );
1958
1959         if( is_object( $link ) ) {
1960                 $title = $link;
1961         } else {
1962                 $title = Title::newFromText( $link );
1963                 if( is_null( $title ) ) {
1964                         return false;
1965                 }
1966         }
1967
1968         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1969 }
1970
1971 /**
1972  * Make a list item, used by various special pages
1973  *
1974  * @param $page String Page link
1975  * @param $details String Text between brackets
1976  * @param $oppositedm Boolean   Add the direction mark opposite to your
1977  *                                                              language, to display text properly
1978  * @return String
1979  * @deprecated since 1.19; use Language::specialList() instead
1980  */
1981 function wfSpecialList( $page, $details, $oppositedm = true ) {
1982         wfDeprecated( __METHOD__, '1.19' );
1983
1984         global $wgLang;
1985         return $wgLang->specialList( $page, $details, $oppositedm );
1986 }
1987
1988 /**
1989  * @todo document
1990  * @todo FIXME: We may want to blacklist some broken browsers
1991  *
1992  * @param $force Bool
1993  * @return bool Whereas client accept gzip compression
1994  */
1995 function wfClientAcceptsGzip( $force = false ) {
1996         static $result = null;
1997         if ( $result === null || $force ) {
1998                 $result = false;
1999                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2000                         # @todo FIXME: We may want to blacklist some broken browsers
2001                         $m = array();
2002                         if( preg_match(
2003                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2004                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
2005                                 $m )
2006                         )
2007                         {
2008                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2009                                         $result = false;
2010                                         return $result;
2011                                 }
2012                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2013                                 $result = true;
2014                         }
2015                 }
2016         }
2017         return $result;
2018 }
2019
2020 /**
2021  * Obtain the offset and limit values from the request string;
2022  * used in special pages
2023  *
2024  * @param $deflimit Int default limit if none supplied
2025  * @param $optionname String Name of a user preference to check against
2026  * @return array
2027  *
2028  */
2029 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2030         global $wgRequest;
2031         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2032 }
2033
2034 /**
2035  * Escapes the given text so that it may be output using addWikiText()
2036  * without any linking, formatting, etc. making its way through. This
2037  * is achieved by substituting certain characters with HTML entities.
2038  * As required by the callers, "<nowiki>" is not used.
2039  *
2040  * @param $text String: text to be escaped
2041  * @return String
2042  */
2043 function wfEscapeWikiText( $text ) {
2044         $text = strtr( "\n$text", array(
2045                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2046                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2047                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2048                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2049                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2050                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2051         ) );
2052         return substr( $text, 1 );
2053 }
2054
2055 /**
2056  * Get the current unix timetstamp with microseconds.  Useful for profiling
2057  * @return Float
2058  */
2059 function wfTime() {
2060         return microtime( true );
2061 }
2062
2063 /**
2064  * Sets dest to source and returns the original value of dest
2065  * If source is NULL, it just returns the value, it doesn't set the variable
2066  * If force is true, it will set the value even if source is NULL
2067  *
2068  * @param $dest Mixed
2069  * @param $source Mixed
2070  * @param $force Bool
2071  * @return Mixed
2072  */
2073 function wfSetVar( &$dest, $source, $force = false ) {
2074         $temp = $dest;
2075         if ( !is_null( $source ) || $force ) {
2076                 $dest = $source;
2077         }
2078         return $temp;
2079 }
2080
2081 /**
2082  * As for wfSetVar except setting a bit
2083  *
2084  * @param $dest Int
2085  * @param $bit Int
2086  * @param $state Bool
2087  *
2088  * @return bool
2089  */
2090 function wfSetBit( &$dest, $bit, $state = true ) {
2091         $temp = (bool)( $dest & $bit );
2092         if ( !is_null( $state ) ) {
2093                 if ( $state ) {
2094                         $dest |= $bit;
2095                 } else {
2096                         $dest &= ~$bit;
2097                 }
2098         }
2099         return $temp;
2100 }
2101
2102 /**
2103  * A wrapper around the PHP function var_export().
2104  * Either print it or add it to the regular output ($wgOut).
2105  *
2106  * @param $var mixed A PHP variable to dump.
2107  */
2108 function wfVarDump( $var ) {
2109         global $wgOut;
2110         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2111         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2112                 print $s;
2113         } else {
2114                 $wgOut->addHTML( $s );
2115         }
2116 }
2117
2118 /**
2119  * Provide a simple HTTP error.
2120  *
2121  * @param $code Int|String
2122  * @param $label String
2123  * @param $desc String
2124  */
2125 function wfHttpError( $code, $label, $desc ) {
2126         global $wgOut;
2127         $wgOut->disable();
2128         header( "HTTP/1.0 $code $label" );
2129         header( "Status: $code $label" );
2130         $wgOut->sendCacheControl();
2131
2132         header( 'Content-type: text/html; charset=utf-8' );
2133         print "<!doctype html>" .
2134                 '<html><head><title>' .
2135                 htmlspecialchars( $label ) .
2136                 '</title></head><body><h1>' .
2137                 htmlspecialchars( $label ) .
2138                 '</h1><p>' .
2139                 nl2br( htmlspecialchars( $desc ) ) .
2140                 "</p></body></html>\n";
2141 }
2142
2143 /**
2144  * Clear away any user-level output buffers, discarding contents.
2145  *
2146  * Suitable for 'starting afresh', for instance when streaming
2147  * relatively large amounts of data without buffering, or wanting to
2148  * output image files without ob_gzhandler's compression.
2149  *
2150  * The optional $resetGzipEncoding parameter controls suppression of
2151  * the Content-Encoding header sent by ob_gzhandler; by default it
2152  * is left. See comments for wfClearOutputBuffers() for why it would
2153  * be used.
2154  *
2155  * Note that some PHP configuration options may add output buffer
2156  * layers which cannot be removed; these are left in place.
2157  *
2158  * @param $resetGzipEncoding Bool
2159  */
2160 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2161         if( $resetGzipEncoding ) {
2162                 // Suppress Content-Encoding and Content-Length
2163                 // headers from 1.10+s wfOutputHandler
2164                 global $wgDisableOutputCompression;
2165                 $wgDisableOutputCompression = true;
2166         }
2167         while( $status = ob_get_status() ) {
2168                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2169                         // Probably from zlib.output_compression or other
2170                         // PHP-internal setting which can't be removed.
2171                         //
2172                         // Give up, and hope the result doesn't break
2173                         // output behavior.
2174                         break;
2175                 }
2176                 if( !ob_end_clean() ) {
2177                         // Could not remove output buffer handler; abort now
2178                         // to avoid getting in some kind of infinite loop.
2179                         break;
2180                 }
2181                 if( $resetGzipEncoding ) {
2182                         if( $status['name'] == 'ob_gzhandler' ) {
2183                                 // Reset the 'Content-Encoding' field set by this handler
2184                                 // so we can start fresh.
2185                                 header_remove( 'Content-Encoding' );
2186                                 break;
2187                         }
2188                 }
2189         }
2190 }
2191
2192 /**
2193  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2194  *
2195  * Clear away output buffers, but keep the Content-Encoding header
2196  * produced by ob_gzhandler, if any.
2197  *
2198  * This should be used for HTTP 304 responses, where you need to
2199  * preserve the Content-Encoding header of the real result, but
2200  * also need to suppress the output of ob_gzhandler to keep to spec
2201  * and avoid breaking Firefox in rare cases where the headers and
2202  * body are broken over two packets.
2203  */
2204 function wfClearOutputBuffers() {
2205         wfResetOutputBuffers( false );
2206 }
2207
2208 /**
2209  * Converts an Accept-* header into an array mapping string values to quality
2210  * factors
2211  *
2212  * @param $accept String
2213  * @param $def String default
2214  * @return Array
2215  */
2216 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2217         # No arg means accept anything (per HTTP spec)
2218         if( !$accept ) {
2219                 return array( $def => 1.0 );
2220         }
2221
2222         $prefs = array();
2223
2224         $parts = explode( ',', $accept );
2225
2226         foreach( $parts as $part ) {
2227                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2228                 $values = explode( ';', trim( $part ) );
2229                 $match = array();
2230                 if ( count( $values ) == 1 ) {
2231                         $prefs[$values[0]] = 1.0;
2232                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2233                         $prefs[$values[0]] = floatval( $match[1] );
2234                 }
2235         }
2236
2237         return $prefs;
2238 }
2239
2240 /**
2241  * Checks if a given MIME type matches any of the keys in the given
2242  * array. Basic wildcards are accepted in the array keys.
2243  *
2244  * Returns the matching MIME type (or wildcard) if a match, otherwise
2245  * NULL if no match.
2246  *
2247  * @param $type String
2248  * @param $avail Array
2249  * @return string
2250  * @private
2251  */
2252 function mimeTypeMatch( $type, $avail ) {
2253         if( array_key_exists( $type, $avail ) ) {
2254                 return $type;
2255         } else {
2256                 $parts = explode( '/', $type );
2257                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2258                         return $parts[0] . '/*';
2259                 } elseif( array_key_exists( '*/*', $avail ) ) {
2260                         return '*/*';
2261                 } else {
2262                         return null;
2263                 }
2264         }
2265 }
2266
2267 /**
2268  * Returns the 'best' match between a client's requested internet media types
2269  * and the server's list of available types. Each list should be an associative
2270  * array of type to preference (preference is a float between 0.0 and 1.0).
2271  * Wildcards in the types are acceptable.
2272  *
2273  * @param $cprefs Array: client's acceptable type list
2274  * @param $sprefs Array: server's offered types
2275  * @return string
2276  *
2277  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2278  * XXX: generalize to negotiate other stuff
2279  */
2280 function wfNegotiateType( $cprefs, $sprefs ) {
2281         $combine = array();
2282
2283         foreach( array_keys( $sprefs ) as $type ) {
2284                 $parts = explode( '/', $type );
2285                 if( $parts[1] != '*' ) {
2286                         $ckey = mimeTypeMatch( $type, $cprefs );
2287                         if( $ckey ) {
2288                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2289                         }
2290                 }
2291         }
2292
2293         foreach( array_keys( $cprefs ) as $type ) {
2294                 $parts = explode( '/', $type );
2295                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2296                         $skey = mimeTypeMatch( $type, $sprefs );
2297                         if( $skey ) {
2298                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2299                         }
2300                 }
2301         }
2302
2303         $bestq = 0;
2304         $besttype = null;
2305
2306         foreach( array_keys( $combine ) as $type ) {
2307                 if( $combine[$type] > $bestq ) {
2308                         $besttype = $type;
2309                         $bestq = $combine[$type];
2310                 }
2311         }
2312
2313         return $besttype;
2314 }
2315
2316 /**
2317  * Reference-counted warning suppression
2318  *
2319  * @param $end Bool
2320  */
2321 function wfSuppressWarnings( $end = false ) {
2322         static $suppressCount = 0;
2323         static $originalLevel = false;
2324
2325         if ( $end ) {
2326                 if ( $suppressCount ) {
2327                         --$suppressCount;
2328                         if ( !$suppressCount ) {
2329                                 error_reporting( $originalLevel );
2330                         }
2331                 }
2332         } else {
2333                 if ( !$suppressCount ) {
2334                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED ) );
2335                 }
2336                 ++$suppressCount;
2337         }
2338 }
2339
2340 /**
2341  * Restore error level to previous value
2342  */
2343 function wfRestoreWarnings() {
2344         wfSuppressWarnings( true );
2345 }
2346
2347 # Autodetect, convert and provide timestamps of various types
2348
2349 /**
2350  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2351  */
2352 define( 'TS_UNIX', 0 );
2353
2354 /**
2355  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2356  */
2357 define( 'TS_MW', 1 );
2358
2359 /**
2360  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2361  */
2362 define( 'TS_DB', 2 );
2363
2364 /**
2365  * RFC 2822 format, for E-mail and HTTP headers
2366  */
2367 define( 'TS_RFC2822', 3 );
2368
2369 /**
2370  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2371  *
2372  * This is used by Special:Export
2373  */
2374 define( 'TS_ISO_8601', 4 );
2375
2376 /**
2377  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2378  *
2379  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2380  *       DateTime tag and page 36 for the DateTimeOriginal and
2381  *       DateTimeDigitized tags.
2382  */
2383 define( 'TS_EXIF', 5 );
2384
2385 /**
2386  * Oracle format time.
2387  */
2388 define( 'TS_ORACLE', 6 );
2389
2390 /**
2391  * Postgres format time.
2392  */
2393 define( 'TS_POSTGRES', 7 );
2394
2395 /**
2396  * DB2 format time
2397  */
2398 define( 'TS_DB2', 8 );
2399
2400 /**
2401  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2402  */
2403 define( 'TS_ISO_8601_BASIC', 9 );
2404
2405 /**
2406  * Get a timestamp string in one of various formats
2407  *
2408  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2409  *                    function will autodetect which format is supplied and act
2410  *                    accordingly.
2411  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2412  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2413  */
2414 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2415         try {
2416                 $timestamp = new MWTimestamp( $ts );
2417                 return $timestamp->getTimestamp( $outputtype );
2418         } catch( TimestampException $e ) {
2419                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2420                 return false;
2421         }
2422 }
2423
2424 /**
2425  * Return a formatted timestamp, or null if input is null.
2426  * For dealing with nullable timestamp columns in the database.
2427  *
2428  * @param $outputtype Integer
2429  * @param $ts String
2430  * @return String
2431  */
2432 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2433         if( is_null( $ts ) ) {
2434                 return null;
2435         } else {
2436                 return wfTimestamp( $outputtype, $ts );
2437         }
2438 }
2439
2440 /**
2441  * Convenience function; returns MediaWiki timestamp for the present time.
2442  *
2443  * @return string
2444  */
2445 function wfTimestampNow() {
2446         # return NOW
2447         return wfTimestamp( TS_MW, time() );
2448 }
2449
2450 /**
2451  * Check if the operating system is Windows
2452  *
2453  * @return Bool: true if it's Windows, False otherwise.
2454  */
2455 function wfIsWindows() {
2456         static $isWindows = null;
2457         if ( $isWindows === null ) {
2458                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2459         }
2460         return $isWindows;
2461 }
2462
2463 /**
2464  * Check if we are running under HipHop
2465  *
2466  * @return Bool
2467  */
2468 function wfIsHipHop() {
2469         return function_exists( 'hphp_thread_set_warmup_enabled' );
2470 }
2471
2472 /**
2473  * Swap two variables
2474  *
2475  * @param $x Mixed
2476  * @param $y Mixed
2477  */
2478 function swap( &$x, &$y ) {
2479         $z = $x;
2480         $x = $y;
2481         $y = $z;
2482 }
2483
2484 /**
2485  * Tries to get the system directory for temporary files. First
2486  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2487  * environment variables are then checked in sequence, and if none are
2488  * set try sys_get_temp_dir().
2489  *
2490  * NOTE: When possible, use instead the tmpfile() function to create
2491  * temporary files to avoid race conditions on file creation, etc.
2492  *
2493  * @return String
2494  */
2495 function wfTempDir() {
2496         global $wgTmpDirectory;
2497
2498         if ( $wgTmpDirectory !== false ) {
2499                 return $wgTmpDirectory;
2500         }
2501
2502         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2503
2504         foreach( $tmpDir as $tmp ) {
2505                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2506                         return $tmp;
2507                 }
2508         }
2509         return sys_get_temp_dir();
2510 }
2511
2512 /**
2513  * Make directory, and make all parent directories if they don't exist
2514  *
2515  * @param $dir String: full path to directory to create
2516  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2517  * @param $caller String: optional caller param for debugging.
2518  * @throws MWException
2519  * @return bool
2520  */
2521 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2522         global $wgDirectoryMode;
2523
2524         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2525                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2526         }
2527
2528         if ( !is_null( $caller ) ) {
2529                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2530         }
2531
2532         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2533                 return true;
2534         }
2535
2536         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2537
2538         if ( is_null( $mode ) ) {
2539                 $mode = $wgDirectoryMode;
2540         }
2541
2542         // Turn off the normal warning, we're doing our own below
2543         wfSuppressWarnings();
2544         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2545         wfRestoreWarnings();
2546
2547         if( !$ok ) {
2548                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2549                 trigger_error( sprintf( "%s: failed to mkdir \"%s\" mode 0%o", __FUNCTION__, $dir, $mode ),
2550                         E_USER_WARNING );
2551         }
2552         return $ok;
2553 }
2554
2555 /**
2556  * Remove a directory and all its content.
2557  * Does not hide error.
2558  */
2559 function wfRecursiveRemoveDir( $dir ) {
2560         wfDebug( __FUNCTION__ . "( $dir )\n" );
2561         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2562         if ( is_dir( $dir ) ) {
2563                 $objects = scandir( $dir );
2564                 foreach ( $objects as $object ) {
2565                         if ( $object != "." && $object != ".." ) {
2566                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2567                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2568                                 } else {
2569                                         unlink( $dir . '/' . $object );
2570                                 }
2571                         }
2572                 }
2573                 reset( $objects );
2574                 rmdir( $dir );
2575         }
2576 }
2577
2578 /**
2579  * @param $nr Mixed: the number to format
2580  * @param $acc Integer: the number of digits after the decimal point, default 2
2581  * @param $round Boolean: whether or not to round the value, default true
2582  * @return float
2583  */
2584 function wfPercent( $nr, $acc = 2, $round = true ) {
2585         $ret = sprintf( "%.${acc}f", $nr );
2586         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2587 }
2588
2589 /**
2590  * Find out whether or not a mixed variable exists in a string
2591  *
2592  * @param $needle String
2593  * @param $str String
2594  * @param $insensitive Boolean
2595  * @return Boolean
2596  */
2597 function in_string( $needle, $str, $insensitive = false ) {
2598         $func = 'strpos';
2599         if( $insensitive ) $func = 'stripos';
2600
2601         return $func( $str, $needle ) !== false;
2602 }
2603
2604 /**
2605  * Safety wrapper around ini_get() for boolean settings.
2606  * The values returned from ini_get() are pre-normalized for settings
2607  * set via php.ini or php_flag/php_admin_flag... but *not*
2608  * for those set via php_value/php_admin_value.
2609  *
2610  * It's fairly common for people to use php_value instead of php_flag,
2611  * which can leave you with an 'off' setting giving a false positive
2612  * for code that just takes the ini_get() return value as a boolean.
2613  *
2614  * To make things extra interesting, setting via php_value accepts
2615  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2616  * Unrecognized values go false... again opposite PHP's own coercion
2617  * from string to bool.
2618  *
2619  * Luckily, 'properly' set settings will always come back as '0' or '1',
2620  * so we only have to worry about them and the 'improper' settings.
2621  *
2622  * I frickin' hate PHP... :P
2623  *
2624  * @param $setting String
2625  * @return Bool
2626  */
2627 function wfIniGetBool( $setting ) {
2628         $val = ini_get( $setting );
2629         // 'on' and 'true' can't have whitespace around them, but '1' can.
2630         return strtolower( $val ) == 'on'
2631                 || strtolower( $val ) == 'true'
2632                 || strtolower( $val ) == 'yes'
2633                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2634 }
2635
2636 /**
2637  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2638  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2639  *
2640  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2641  *                          should be omitted
2642  * @param $fileName String Name of the library, if not $extension.suffix
2643  * @return Bool - Whether or not the extension is loaded
2644  */
2645 function wfDl( $extension, $fileName = null ) {
2646         if( extension_loaded( $extension ) ) {
2647                 return true;
2648         }
2649
2650         $canDl = false;
2651         $sapi = php_sapi_name();
2652         if( $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' ) {
2653                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2654                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2655         }
2656
2657         if( $canDl ) {
2658                 $fileName = $fileName ? $fileName : $extension;
2659                 if( wfIsWindows() ) {
2660                         $fileName = 'php_' . $fileName;
2661                 }
2662                 wfSuppressWarnings();
2663                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2664                 wfRestoreWarnings();
2665         }
2666         return extension_loaded( $extension );
2667 }
2668
2669 /**
2670  * Windows-compatible version of escapeshellarg()
2671  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2672  * function puts single quotes in regardless of OS.
2673  *
2674  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2675  * earlier distro releases of PHP)
2676  *
2677  * @param varargs
2678  * @return String
2679  */
2680 function wfEscapeShellArg( ) {
2681         wfInitShellLocale();
2682
2683         $args = func_get_args();
2684         $first = true;
2685         $retVal = '';
2686         foreach ( $args as $arg ) {
2687                 if ( !$first ) {
2688                         $retVal .= ' ';
2689                 } else {
2690                         $first = false;
2691                 }
2692
2693                 if ( wfIsWindows() ) {
2694                         // Escaping for an MSVC-style command line parser and CMD.EXE
2695                         // Refs:
2696                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2697                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2698                         //  * Bug #13518
2699                         //  * CR r63214
2700                         // Double the backslashes before any double quotes. Escape the double quotes.
2701                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2702                         $arg = '';
2703                         $iteration = 0;
2704                         foreach ( $tokens as $token ) {
2705                                 if ( $iteration % 2 == 1 ) {
2706                                         // Delimiter, a double quote preceded by zero or more slashes
2707                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2708                                 } elseif ( $iteration % 4 == 2 ) {
2709                                         // ^ in $token will be outside quotes, need to be escaped
2710                                         $arg .= str_replace( '^', '^^', $token );
2711                                 } else { // $iteration % 4 == 0
2712                                         // ^ in $token will appear inside double quotes, so leave as is
2713                                         $arg .= $token;
2714                                 }
2715                                 $iteration++;
2716                         }
2717                         // Double the backslashes before the end of the string, because
2718                         // we will soon add a quote
2719                         $m = array();
2720                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2721                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2722                         }
2723
2724                         // Add surrounding quotes
2725                         $retVal .= '"' . $arg . '"';
2726                 } else {
2727                         $retVal .= escapeshellarg( $arg );
2728                 }
2729         }
2730         return $retVal;
2731 }
2732
2733 /**
2734  * Execute a shell command, with time and memory limits mirrored from the PHP
2735  * configuration if supported.
2736  * @param $cmd String Command line, properly escaped for shell.
2737  * @param &$retval null|Mixed optional, will receive the program's exit code.
2738  *                 (non-zero is usually failure)
2739  * @param $environ Array optional environment variables which should be
2740  *                 added to the executed command environment.
2741  * @param $limits Array optional array with limits(filesize, memory, time)
2742  *                 this overwrites the global wgShellMax* limits.
2743  * @return string collected stdout as a string (trailing newlines stripped)
2744  */
2745 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2746         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2747
2748         static $disabled;
2749         if ( is_null( $disabled ) ) {
2750                 $disabled = false;
2751                 if( wfIniGetBool( 'safe_mode' ) ) {
2752                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2753                         $disabled = 'safemode';
2754                 } else {
2755                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2756                         $functions = array_map( 'trim', $functions );
2757                         $functions = array_map( 'strtolower', $functions );
2758                         if ( in_array( 'passthru', $functions ) ) {
2759                                 wfDebug( "passthru is in disabled_functions\n" );
2760                                 $disabled = 'passthru';
2761                         }
2762                 }
2763         }
2764         if ( $disabled ) {
2765                 $retval = 1;
2766                 return $disabled == 'safemode' ?
2767                         'Unable to run external programs in safe mode.' :
2768                         'Unable to run external programs, passthru() is disabled.';
2769         }
2770
2771         wfInitShellLocale();
2772
2773         $envcmd = '';
2774         foreach( $environ as $k => $v ) {
2775                 if ( wfIsWindows() ) {
2776                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2777                          * appear in the environment variable, so we must use carat escaping as documented in
2778                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2779                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2780                          * are listed there but doesn't appear to need it.
2781                          */
2782                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2783                 } else {
2784                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2785                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2786                          */
2787                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2788                 }
2789         }
2790         $cmd = $envcmd . $cmd;
2791
2792         if ( php_uname( 's' ) == 'Linux' ) {
2793                 $time = intval ( isset($limits['time']) ? $limits['time'] : $wgMaxShellTime );
2794                 $mem = intval ( isset($limits['memory']) ? $limits['memory'] : $wgMaxShellMemory );
2795                 $filesize = intval ( isset($limits['filesize']) ? $limits['filesize'] : $wgMaxShellFileSize );
2796
2797                 if ( $time > 0 && $mem > 0 ) {
2798                         $script = "$IP/bin/ulimit4.sh";
2799                         if ( is_executable( $script ) ) {
2800                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2801                         }
2802                 }
2803         }
2804         wfDebug( "wfShellExec: $cmd\n" );
2805
2806         $retval = 1; // error by default?
2807         ob_start();
2808         passthru( $cmd, $retval );
2809         $output = ob_get_contents();
2810         ob_end_clean();
2811
2812         if ( $retval == 127 ) {
2813                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2814         }
2815         return $output;
2816 }
2817
2818 /**
2819  * Workaround for http://bugs.php.net/bug.php?id=45132
2820  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2821  */
2822 function wfInitShellLocale() {
2823         static $done = false;
2824         if ( $done ) {
2825                 return;
2826         }
2827         $done = true;
2828         global $wgShellLocale;
2829         if ( !wfIniGetBool( 'safe_mode' ) ) {
2830                 putenv( "LC_CTYPE=$wgShellLocale" );
2831                 setlocale( LC_CTYPE, $wgShellLocale );
2832         }
2833 }
2834
2835 /**
2836  * Alias to wfShellWikiCmd()
2837  * @see wfShellWikiCmd()
2838  */
2839 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2840         return wfShellWikiCmd( $script, $parameters, $options );
2841 }
2842
2843 /**
2844  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2845  * Note that $parameters should be a flat array and an option with an argument
2846  * should consist of two consecutive items in the array (do not use "--option value").
2847  * @param $script string MediaWiki cli script path
2848  * @param $parameters Array Arguments and options to the script
2849  * @param $options Array Associative array of options:
2850  *              'php': The path to the php executable
2851  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2852  * @return Array
2853  */
2854 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2855         global $wgPhpCli;
2856         // Give site config file a chance to run the script in a wrapper.
2857         // The caller may likely want to call wfBasename() on $script.
2858         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2859         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2860         if ( isset( $options['wrapper'] ) ) {
2861                 $cmd[] = $options['wrapper'];
2862         }
2863         $cmd[] = $script;
2864         // Escape each parameter for shell
2865         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2866 }
2867
2868 /**
2869  * wfMerge attempts to merge differences between three texts.
2870  * Returns true for a clean merge and false for failure or a conflict.
2871  *
2872  * @param $old String
2873  * @param $mine String
2874  * @param $yours String
2875  * @param $result String
2876  * @return Bool
2877  */
2878 function wfMerge( $old, $mine, $yours, &$result ) {
2879         global $wgDiff3;
2880
2881         # This check may also protect against code injection in
2882         # case of broken installations.
2883         wfSuppressWarnings();
2884         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2885         wfRestoreWarnings();
2886
2887         if( !$haveDiff3 ) {
2888                 wfDebug( "diff3 not found\n" );
2889                 return false;
2890         }
2891
2892         # Make temporary files
2893         $td = wfTempDir();
2894         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2895         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2896         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2897
2898         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2899         #       a newline character. To avoid this, we normalize the trailing whitespace before
2900         #       creating the diff.
2901
2902         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2903         fclose( $oldtextFile );
2904         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2905         fclose( $mytextFile );
2906         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2907         fclose( $yourtextFile );
2908
2909         # Check for a conflict
2910         $cmd = $wgDiff3 . ' -a --overlap-only ' .
2911                 wfEscapeShellArg( $mytextName ) . ' ' .
2912                 wfEscapeShellArg( $oldtextName ) . ' ' .
2913                 wfEscapeShellArg( $yourtextName );
2914         $handle = popen( $cmd, 'r' );
2915
2916         if( fgets( $handle, 1024 ) ) {
2917                 $conflict = true;
2918         } else {
2919                 $conflict = false;
2920         }
2921         pclose( $handle );
2922
2923         # Merge differences
2924         $cmd = $wgDiff3 . ' -a -e --merge ' .
2925                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2926         $handle = popen( $cmd, 'r' );
2927         $result = '';
2928         do {
2929                 $data = fread( $handle, 8192 );
2930                 if ( strlen( $data ) == 0 ) {
2931                         break;
2932                 }
2933                 $result .= $data;
2934         } while ( true );
2935         pclose( $handle );
2936         unlink( $mytextName );
2937         unlink( $oldtextName );
2938         unlink( $yourtextName );
2939
2940         if ( $result === '' && $old !== '' && !$conflict ) {
2941                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2942                 $conflict = true;
2943         }
2944         return !$conflict;
2945 }
2946
2947 /**
2948  * Returns unified plain-text diff of two texts.
2949  * Useful for machine processing of diffs.
2950  *
2951  * @param $before String: the text before the changes.
2952  * @param $after String: the text after the changes.
2953  * @param $params String: command-line options for the diff command.
2954  * @return String: unified diff of $before and $after
2955  */
2956 function wfDiff( $before, $after, $params = '-u' ) {
2957         if ( $before == $after ) {
2958                 return '';
2959         }
2960
2961         global $wgDiff;
2962         wfSuppressWarnings();
2963         $haveDiff = $wgDiff && file_exists( $wgDiff );
2964         wfRestoreWarnings();
2965
2966         # This check may also protect against code injection in
2967         # case of broken installations.
2968         if( !$haveDiff ) {
2969                 wfDebug( "diff executable not found\n" );
2970                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2971                 $format = new UnifiedDiffFormatter();
2972                 return $format->format( $diffs );
2973         }
2974
2975         # Make temporary files
2976         $td = wfTempDir();
2977         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2978         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2979
2980         fwrite( $oldtextFile, $before );
2981         fclose( $oldtextFile );
2982         fwrite( $newtextFile, $after );
2983         fclose( $newtextFile );
2984
2985         // Get the diff of the two files
2986         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2987
2988         $h = popen( $cmd, 'r' );
2989
2990         $diff = '';
2991
2992         do {
2993                 $data = fread( $h, 8192 );
2994                 if ( strlen( $data ) == 0 ) {
2995                         break;
2996                 }
2997                 $diff .= $data;
2998         } while ( true );
2999
3000         // Clean up
3001         pclose( $h );
3002         unlink( $oldtextName );
3003         unlink( $newtextName );
3004
3005         // Kill the --- and +++ lines. They're not useful.
3006         $diff_lines = explode( "\n", $diff );
3007         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3008                 unset( $diff_lines[0] );
3009         }
3010         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3011                 unset( $diff_lines[1] );
3012         }
3013
3014         $diff = implode( "\n", $diff_lines );
3015
3016         return $diff;
3017 }
3018
3019 /**
3020  * This function works like "use VERSION" in Perl, the program will die with a
3021  * backtrace if the current version of PHP is less than the version provided
3022  *
3023  * This is useful for extensions which due to their nature are not kept in sync
3024  * with releases, and might depend on other versions of PHP than the main code
3025  *
3026  * Note: PHP might die due to parsing errors in some cases before it ever
3027  *       manages to call this function, such is life
3028  *
3029  * @see perldoc -f use
3030  *
3031  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3032  *                 a float
3033  * @throws MWException
3034  */
3035 function wfUsePHP( $req_ver ) {
3036         $php_ver = PHP_VERSION;
3037
3038         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3039                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3040         }
3041 }
3042
3043 /**
3044  * This function works like "use VERSION" in Perl except it checks the version
3045  * of MediaWiki, the program will die with a backtrace if the current version
3046  * of MediaWiki is less than the version provided.
3047  *
3048  * This is useful for extensions which due to their nature are not kept in sync
3049  * with releases
3050  *
3051  * @see perldoc -f use
3052  *
3053  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3054  *                 a float
3055  * @throws MWException
3056  */
3057 function wfUseMW( $req_ver ) {
3058         global $wgVersion;
3059
3060         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3061                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3062         }
3063 }
3064
3065 /**
3066  * Return the final portion of a pathname.
3067  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3068  * http://bugs.php.net/bug.php?id=33898
3069  *
3070  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3071  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3072  *
3073  * @param $path String
3074  * @param $suffix String: to remove if present
3075  * @return String
3076  */
3077 function wfBaseName( $path, $suffix = '' ) {
3078         $encSuffix = ( $suffix == '' )
3079                 ? ''
3080                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3081         $matches = array();
3082         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3083                 return $matches[1];
3084         } else {
3085                 return '';
3086         }
3087 }
3088
3089 /**
3090  * Generate a relative path name to the given file.
3091  * May explode on non-matching case-insensitive paths,
3092  * funky symlinks, etc.
3093  *
3094  * @param $path String: absolute destination path including target filename
3095  * @param $from String: Absolute source path, directory only
3096  * @return String
3097  */
3098 function wfRelativePath( $path, $from ) {
3099         // Normalize mixed input on Windows...
3100         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3101         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3102
3103         // Trim trailing slashes -- fix for drive root
3104         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3105         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3106
3107         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3108         $against = explode( DIRECTORY_SEPARATOR, $from );
3109
3110         if( $pieces[0] !== $against[0] ) {
3111                 // Non-matching Windows drive letters?
3112                 // Return a full path.
3113                 return $path;
3114         }
3115
3116         // Trim off common prefix
3117         while( count( $pieces ) && count( $against )
3118                 && $pieces[0] == $against[0] ) {
3119                 array_shift( $pieces );
3120                 array_shift( $against );
3121         }
3122
3123         // relative dots to bump us to the parent
3124         while( count( $against ) ) {
3125                 array_unshift( $pieces, '..' );
3126                 array_shift( $against );
3127         }
3128
3129         array_push( $pieces, wfBaseName( $path ) );
3130
3131         return implode( DIRECTORY_SEPARATOR, $pieces );
3132 }
3133
3134 /**
3135  * Do any deferred updates and clear the list
3136  *
3137  * @deprecated since 1.19
3138  * @see DeferredUpdates::doUpdate()
3139  * @param $commit string
3140  */
3141 function wfDoUpdates( $commit = '' ) {
3142         wfDeprecated( __METHOD__, '1.19' );
3143         DeferredUpdates::doUpdates( $commit );
3144 }
3145
3146 /**
3147  * Convert an arbitrarily-long digit string from one numeric base
3148  * to another, optionally zero-padding to a minimum column width.
3149  *
3150  * Supports base 2 through 36; digit values 10-36 are represented
3151  * as lowercase letters a-z. Input is case-insensitive.
3152  *
3153  * @param $input String: of digits
3154  * @param $sourceBase Integer: 2-36
3155  * @param $destBase Integer: 2-36
3156  * @param $pad Integer: 1 or greater
3157  * @param $lowercase Boolean
3158  * @return String or false on invalid input
3159  */
3160 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3161         $input = strval( $input );
3162         if( $sourceBase < 2 ||
3163                 $sourceBase > 36 ||
3164                 $destBase < 2 ||
3165                 $destBase > 36 ||
3166                 $pad < 1 ||
3167                 $sourceBase != intval( $sourceBase ) ||
3168                 $destBase != intval( $destBase ) ||
3169                 $pad != intval( $pad ) ||
3170                 !is_string( $input ) ||
3171                 $input == '' ) {
3172                 return false;
3173         }
3174         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3175         $inDigits = array();
3176         $outChars = '';
3177
3178         // Decode and validate input string
3179         $input = strtolower( $input );
3180         for( $i = 0; $i < strlen( $input ); $i++ ) {
3181                 $n = strpos( $digitChars, $input[$i] );
3182                 if( $n === false || $n > $sourceBase ) {
3183                         return false;
3184                 }
3185                 $inDigits[] = $n;
3186         }
3187
3188         // Iterate over the input, modulo-ing out an output digit
3189         // at a time until input is gone.
3190         while( count( $inDigits ) ) {
3191                 $work = 0;
3192                 $workDigits = array();
3193
3194                 // Long division...
3195                 foreach( $inDigits as $digit ) {
3196                         $work *= $sourceBase;
3197                         $work += $digit;
3198
3199                         if( $work < $destBase ) {
3200                                 // Gonna need to pull another digit.
3201                                 if( count( $workDigits ) ) {
3202                                         // Avoid zero-padding; this lets us find
3203                                         // the end of the input very easily when
3204                                         // length drops to zero.
3205                                         $workDigits[] = 0;
3206                                 }
3207                         } else {
3208                                 // Finally! Actual division!
3209                                 $workDigits[] = intval( $work / $destBase );
3210
3211                                 // Isn't it annoying that most programming languages
3212                                 // don't have a single divide-and-remainder operator,
3213                                 // even though the CPU implements it that way?
3214                                 $work = $work % $destBase;
3215                         }
3216                 }
3217
3218                 // All that division leaves us with a remainder,
3219                 // which is conveniently our next output digit.
3220                 $outChars .= $digitChars[$work];
3221
3222                 // And we continue!
3223                 $inDigits = $workDigits;
3224         }
3225
3226         while( strlen( $outChars ) < $pad ) {
3227                 $outChars .= '0';
3228         }
3229
3230         return strrev( $outChars );
3231 }
3232
3233 /**
3234  * Create an object with a given name and an array of construct parameters
3235  *
3236  * @param $name String
3237  * @param $p Array: parameters
3238  * @return object
3239  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3240  */
3241 function wfCreateObject( $name, $p ) {
3242         wfDeprecated( __FUNCTION__, '1.18' );
3243         return MWFunction::newObj( $name, $p );
3244 }
3245
3246 /**
3247  * @return bool
3248  */
3249 function wfHttpOnlySafe() {
3250         global $wgHttpOnlyBlacklist;
3251
3252         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3253                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3254                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3255                                 return false;
3256                         }
3257                 }
3258         }
3259
3260         return true;
3261 }
3262
3263 /**
3264  * Override session_id before session startup if php's built-in
3265  * session generation code is not secure.
3266  */
3267 function wfFixSessionID() {
3268         // If the cookie or session id is already set we already have a session and should abort
3269         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3270                 return;
3271         }
3272
3273         // PHP's built-in session entropy is enabled if:
3274         // - entropy_file is set or you're on Windows with php 5.3.3+
3275         // - AND entropy_length is > 0
3276         // We treat it as disabled if it doesn't have an entropy length of at least 32
3277         $entropyEnabled = (
3278                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3279                         || ini_get( 'session.entropy_file' )
3280                 )
3281                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3282
3283         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3284         if ( !$entropyEnabled ) {
3285                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3286                 session_id( MWCryptRand::generateHex( 32 ) );
3287         }
3288 }
3289
3290 /**
3291  * Initialise php session
3292  *
3293  * @param $sessionId Bool
3294  */
3295 function wfSetupSession( $sessionId = false ) {
3296         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3297                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3298         if( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3299                 ObjectCacheSessionHandler::install();
3300         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3301                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3302                 # hasn't already been set to the desired value (that causes errors)
3303                 ini_set( 'session.save_handler', $wgSessionHandler );
3304         }
3305         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3306         wfDebugLog( 'cookie',
3307                 'session_set_cookie_params: "' . implode( '", "',
3308                         array(
3309                                 0,
3310                                 $wgCookiePath,
3311                                 $wgCookieDomain,
3312                                 $wgCookieSecure,
3313                                 $httpOnlySafe ) ) . '"' );
3314         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3315         session_cache_limiter( 'private, must-revalidate' );
3316         if ( $sessionId ) {
3317                 session_id( $sessionId );
3318         } else {
3319                 wfFixSessionID();
3320         }
3321         wfSuppressWarnings();
3322         session_start();
3323         wfRestoreWarnings();
3324 }
3325
3326 /**
3327  * Get an object from the precompiled serialized directory
3328  *
3329  * @param $name String
3330  * @return Mixed: the variable on success, false on failure
3331  */
3332 function wfGetPrecompiledData( $name ) {
3333         global $IP;
3334
3335         $file = "$IP/serialized/$name";
3336         if ( file_exists( $file ) ) {
3337                 $blob = file_get_contents( $file );
3338                 if ( $blob ) {
3339                         return unserialize( $blob );
3340                 }
3341         }
3342         return false;
3343 }
3344
3345 /**
3346  * Get a cache key
3347  *
3348  * @param varargs
3349  * @return String
3350  */
3351 function wfMemcKey( /*... */ ) {
3352         global $wgCachePrefix;
3353         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3354         $args = func_get_args();
3355         $key = $prefix . ':' . implode( ':', $args );
3356         $key = str_replace( ' ', '_', $key );
3357         return $key;
3358 }
3359
3360 /**
3361  * Get a cache key for a foreign DB
3362  *
3363  * @param $db String
3364  * @param $prefix String
3365  * @param varargs String
3366  * @return String
3367  */
3368 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3369         $args = array_slice( func_get_args(), 2 );
3370         if ( $prefix ) {
3371                 $key = "$db-$prefix:" . implode( ':', $args );
3372         } else {
3373                 $key = $db . ':' . implode( ':', $args );
3374         }
3375         return $key;
3376 }
3377
3378 /**
3379  * Get an ASCII string identifying this wiki
3380  * This is used as a prefix in memcached keys
3381  *
3382  * @return String
3383  */
3384 function wfWikiID() {
3385         global $wgDBprefix, $wgDBname;
3386         if ( $wgDBprefix ) {
3387                 return "$wgDBname-$wgDBprefix";
3388         } else {
3389                 return $wgDBname;
3390         }
3391 }
3392
3393 /**
3394  * Split a wiki ID into DB name and table prefix
3395  *
3396  * @param $wiki String
3397  *
3398  * @return array
3399  */
3400 function wfSplitWikiID( $wiki ) {
3401         $bits = explode( '-', $wiki, 2 );
3402         if ( count( $bits ) < 2 ) {
3403                 $bits[] = '';
3404         }
3405         return $bits;
3406 }
3407
3408 /**
3409  * Get a Database object.
3410  *
3411  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3412  *            master (for write queries), DB_SLAVE for potentially lagged read
3413  *            queries, or an integer >= 0 for a particular server.
3414  *
3415  * @param $groups Mixed: query groups. An array of group names that this query
3416  *                belongs to. May contain a single string if the query is only
3417  *                in one group.
3418  *
3419  * @param $wiki String: the wiki ID, or false for the current wiki
3420  *
3421  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3422  * will always return the same object, unless the underlying connection or load
3423  * balancer is manually destroyed.
3424  *
3425  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3426  * updater to ensure that a proper database is being updated.
3427  *
3428  * @return DatabaseBase
3429  */
3430 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3431         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3432 }
3433
3434 /**
3435  * Get a load balancer object.
3436  *
3437  * @param $wiki String: wiki ID, or false for the current wiki
3438  * @return LoadBalancer
3439  */
3440 function wfGetLB( $wiki = false ) {
3441         return wfGetLBFactory()->getMainLB( $wiki );
3442 }
3443
3444 /**
3445  * Get the load balancer factory object
3446  *
3447  * @return LBFactory
3448  */
3449 function &wfGetLBFactory() {
3450         return LBFactory::singleton();
3451 }
3452
3453 /**
3454  * Find a file.
3455  * Shortcut for RepoGroup::singleton()->findFile()
3456  *
3457  * @param $title String or Title object
3458  * @param $options array Associative array of options:
3459  *     time:           requested time for an archived image, or false for the
3460  *                     current version. An image object will be returned which was
3461  *                     created at the specified time.
3462  *
3463  *     ignoreRedirect: If true, do not follow file redirects
3464  *
3465  *     private:        If true, return restricted (deleted) files if the current
3466  *                     user is allowed to view them. Otherwise, such files will not
3467  *                     be found.
3468  *
3469  *     bypassCache:    If true, do not use the process-local cache of File objects
3470  *
3471  * @return File, or false if the file does not exist
3472  */
3473 function wfFindFile( $title, $options = array() ) {
3474         return RepoGroup::singleton()->findFile( $title, $options );
3475 }
3476
3477 /**
3478  * Get an object referring to a locally registered file.
3479  * Returns a valid placeholder object if the file does not exist.
3480  *
3481  * @param $title Title|String
3482  * @return LocalFile|null A File, or null if passed an invalid Title
3483  */
3484 function wfLocalFile( $title ) {
3485         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3486 }
3487
3488 /**
3489  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3490  * @deprecated since 1.19
3491  */
3492 function wfStreamFile( $fname, $headers = array() ) {
3493         wfDeprecated( __FUNCTION__, '1.19' );
3494         StreamFile::stream( $fname, $headers );
3495 }
3496
3497 /**
3498  * Should low-performance queries be disabled?
3499  *
3500  * @return Boolean
3501  * @codeCoverageIgnore
3502  */
3503 function wfQueriesMustScale() {
3504         global $wgMiserMode;
3505         return $wgMiserMode
3506                 || ( SiteStats::pages() > 100000
3507                 && SiteStats::edits() > 1000000
3508                 && SiteStats::users() > 10000 );
3509 }
3510
3511 /**
3512  * Get the path to a specified script file, respecting file
3513  * extensions; this is a wrapper around $wgScriptExtension etc.
3514  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3515  *
3516  * @param $script String: script filename, sans extension
3517  * @return String
3518  */
3519 function wfScript( $script = 'index' ) {
3520         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3521         if ( $script === 'index' ) {
3522                 return $wgScript;
3523         } else if ( $script === 'load' ) {
3524                 return $wgLoadScript;
3525         } else {
3526                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3527         }
3528 }
3529
3530 /**
3531  * Get the script URL.
3532  *
3533  * @return string script URL
3534  */
3535 function wfGetScriptUrl() {
3536         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3537                 #
3538                 # as it was called, minus the query string.
3539                 #
3540                 # Some sites use Apache rewrite rules to handle subdomains,
3541                 # and have PHP set up in a weird way that causes PHP_SELF
3542                 # to contain the rewritten URL instead of the one that the
3543                 # outside world sees.
3544                 #
3545                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3546                 # provides containing the "before" URL.
3547                 return $_SERVER['SCRIPT_NAME'];
3548         } else {
3549                 return $_SERVER['URL'];
3550         }
3551 }
3552
3553 /**
3554  * Convenience function converts boolean values into "true"
3555  * or "false" (string) values
3556  *
3557  * @param $value Boolean
3558  * @return String
3559  */
3560 function wfBoolToStr( $value ) {
3561         return $value ? 'true' : 'false';
3562 }
3563
3564 /**
3565  * Get a platform-independent path to the null file, e.g. /dev/null
3566  *
3567  * @return string
3568  */
3569 function wfGetNull() {
3570         return wfIsWindows()
3571                 ? 'NUL'
3572                 : '/dev/null';
3573 }
3574
3575 /**
3576  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3577  * and waiting for it to go down, this waits for the slaves to catch up to the
3578  * master position. Use this when updating very large numbers of rows, as
3579  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3580  * a no-op if there are no slaves.
3581  *
3582  * @param $maxLag Integer (deprecated)
3583  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3584  */
3585 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3586         $lb = wfGetLB( $wiki );
3587         // bug 27975 - Don't try to wait for slaves if there are none
3588         // Prevents permission error when getting master position
3589         if ( $lb->getServerCount() > 1 ) {
3590                 $dbw = $lb->getConnection( DB_MASTER );
3591                 $pos = $dbw->getMasterPos();
3592                 $lb->waitForAll( $pos );
3593         }
3594 }
3595
3596 /**
3597  * Used to be used for outputting text in the installer/updater
3598  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3599  */
3600 function wfOut( $s ) {
3601         wfDeprecated( __FUNCTION__, '1.18' );
3602         global $wgCommandLineMode;
3603         if ( $wgCommandLineMode ) {
3604                 echo $s;
3605         } else {
3606                 echo htmlspecialchars( $s );
3607         }
3608         flush();
3609 }
3610
3611 /**
3612  * Count down from $n to zero on the terminal, with a one-second pause
3613  * between showing each number. For use in command-line scripts.
3614  * @codeCoverageIgnore
3615  * @param $n int
3616  */
3617 function wfCountDown( $n ) {
3618         for ( $i = $n; $i >= 0; $i-- ) {
3619                 if ( $i != $n ) {
3620                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3621                 }
3622                 echo $i;
3623                 flush();
3624                 if ( $i ) {
3625                         sleep( 1 );
3626                 }
3627         }
3628         echo "\n";
3629 }
3630
3631 /**
3632  * Generate a random 32-character hexadecimal token.
3633  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3634  *              characters before hashing.
3635  * @return string
3636  * @codeCoverageIgnore
3637  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pesudo-random strings
3638  * @warning This method is NOT secure. Additionally it has many callers that use it for pesudo-random purposes.
3639  */
3640 function wfGenerateToken( $salt = '' ) {
3641         wfDeprecated( __METHOD__, '1.20' );
3642         $salt = serialize( $salt );
3643         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3644 }
3645
3646 /**
3647  * Replace all invalid characters with -
3648  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3649  * By default, $wgIllegalFileChars = ':'
3650  *
3651  * @param $name Mixed: filename to process
3652  * @return String
3653  */
3654 function wfStripIllegalFilenameChars( $name ) {
3655         global $wgIllegalFileChars;
3656         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3657         $name = wfBaseName( $name );
3658         $name = preg_replace(
3659                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3660                 '-',
3661                 $name
3662         );
3663         return $name;
3664 }
3665
3666 /**
3667  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3668  *
3669  * @return Integer value memory was set to.
3670  */
3671 function wfMemoryLimit() {
3672         global $wgMemoryLimit;
3673         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3674         if( $memlimit != -1 ) {
3675                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3676                 if( $conflimit == -1 ) {
3677                         wfDebug( "Removing PHP's memory limit\n" );
3678                         wfSuppressWarnings();
3679                         ini_set( 'memory_limit', $conflimit );
3680                         wfRestoreWarnings();
3681                         return $conflimit;
3682                 } elseif ( $conflimit > $memlimit ) {
3683                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3684                         wfSuppressWarnings();
3685                         ini_set( 'memory_limit', $conflimit );
3686                         wfRestoreWarnings();
3687                         return $conflimit;
3688                 }
3689         }
3690         return $memlimit;
3691 }
3692
3693 /**
3694  * Converts shorthand byte notation to integer form
3695  *
3696  * @param $string String
3697  * @return Integer
3698  */
3699 function wfShorthandToInteger( $string = '' ) {
3700         $string = trim( $string );
3701         if( $string === '' ) {
3702                 return -1;
3703         }
3704         $last = $string[strlen( $string ) - 1];
3705         $val = intval( $string );
3706         switch( $last ) {
3707                 case 'g':
3708                 case 'G':
3709                         $val *= 1024;
3710                         // break intentionally missing
3711                 case 'm':
3712                 case 'M':
3713                         $val *= 1024;
3714                         // break intentionally missing
3715                 case 'k':
3716                 case 'K':
3717                         $val *= 1024;
3718         }
3719
3720         return $val;
3721 }
3722
3723 /**
3724  * Get the normalised IETF language tag
3725  * See unit test for examples.
3726  *
3727  * @param $code String: The language code.
3728  * @return String: The language code which complying with BCP 47 standards.
3729  */
3730 function wfBCP47( $code ) {
3731         $codeSegment = explode( '-', $code );
3732         $codeBCP = array();
3733         foreach ( $codeSegment as $segNo => $seg ) {
3734                 if ( count( $codeSegment ) > 0 ) {
3735                         // when previous segment is x, it is a private segment and should be lc
3736                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3737                                 $codeBCP[$segNo] = strtolower( $seg );
3738                         // ISO 3166 country code
3739                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3740                                 $codeBCP[$segNo] = strtoupper( $seg );
3741                         // ISO 15924 script code
3742                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3743                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3744                         // Use lowercase for other cases
3745                         } else {
3746                                 $codeBCP[$segNo] = strtolower( $seg );
3747                         }
3748                 } else {
3749                 // Use lowercase for single segment
3750                         $codeBCP[$segNo] = strtolower( $seg );
3751                 }
3752         }
3753         $langCode = implode( '-', $codeBCP );
3754         return $langCode;
3755 }
3756
3757 /**
3758  * Get a cache object.
3759  *
3760  * @param $inputType integer Cache type, one the the CACHE_* constants.
3761  * @return BagOStuff
3762  */
3763 function wfGetCache( $inputType ) {
3764         return ObjectCache::getInstance( $inputType );
3765 }
3766
3767 /**
3768  * Get the main cache object
3769  *
3770  * @return BagOStuff
3771  */
3772 function wfGetMainCache() {
3773         global $wgMainCacheType;
3774         return ObjectCache::getInstance( $wgMainCacheType );
3775 }
3776
3777 /**
3778  * Get the cache object used by the message cache
3779  *
3780  * @return BagOStuff
3781  */
3782 function wfGetMessageCacheStorage() {
3783         global $wgMessageCacheType;
3784         return ObjectCache::getInstance( $wgMessageCacheType );
3785 }
3786
3787 /**
3788  * Get the cache object used by the parser cache
3789  *
3790  * @return BagOStuff
3791  */
3792 function wfGetParserCacheStorage() {
3793         global $wgParserCacheType;
3794         return ObjectCache::getInstance( $wgParserCacheType );
3795 }
3796
3797 /**
3798  * Get the cache object used by the language converter
3799  *
3800  * @return BagOStuff
3801  */
3802 function wfGetLangConverterCacheStorage() {
3803         global $wgLanguageConverterCacheType;
3804         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3805 }
3806
3807 /**
3808  * Call hook functions defined in $wgHooks
3809  *
3810  * @param $event String: event name
3811  * @param $args Array: parameters passed to hook functions
3812  * @return Boolean True if no handler aborted the hook
3813  */
3814 function wfRunHooks( $event, $args = array() ) {
3815         return Hooks::run( $event, $args );
3816 }
3817
3818 /**
3819  * Wrapper around php's unpack.
3820  *
3821  * @param $format String: The format string (See php's docs)
3822  * @param $data: A binary string of binary data
3823  * @param $length integer or false: The minimun length of $data. This is to
3824  *      prevent reading beyond the end of $data. false to disable the check.
3825  *
3826  * Also be careful when using this function to read unsigned 32 bit integer
3827  * because php might make it negative.
3828  *
3829  * @throws MWException if $data not long enough, or if unpack fails
3830  * @return array Associative array of the extracted data
3831  */
3832 function wfUnpack( $format, $data, $length=false ) {
3833         if ( $length !== false ) {
3834                 $realLen = strlen( $data );
3835                 if ( $realLen < $length ) {
3836                         throw new MWException( "Tried to use wfUnpack on a "
3837                                 . "string of length $realLen, but needed one "
3838                                 . "of at least length $length."
3839                         );
3840                 }
3841         }
3842
3843         wfSuppressWarnings();
3844         $result = unpack( $format, $data );
3845         wfRestoreWarnings();
3846
3847         if ( $result === false ) {
3848                 // If it cannot extract the packed data.
3849                 throw new MWException( "unpack could not unpack binary data" );
3850         }
3851         return $result;
3852 }
3853
3854 /**
3855  * Determine if an image exists on the 'bad image list'.
3856  *
3857  * The format of MediaWiki:Bad_image_list is as follows:
3858  *    * Only list items (lines starting with "*") are considered
3859  *    * The first link on a line must be a link to a bad image
3860  *    * Any subsequent links on the same line are considered to be exceptions,
3861  *      i.e. articles where the image may occur inline.
3862  *
3863  * @param $name string the image name to check
3864  * @param $contextTitle Title|bool the page on which the image occurs, if known
3865  * @param $blacklist string wikitext of a file blacklist
3866  * @return bool
3867  */
3868 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3869         static $badImageCache = null; // based on bad_image_list msg
3870         wfProfileIn( __METHOD__ );
3871
3872         # Handle redirects
3873         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3874         if( $redirectTitle ) {
3875                 $name = $redirectTitle->getDbKey();
3876         }
3877
3878         # Run the extension hook
3879         $bad = false;
3880         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3881                 wfProfileOut( __METHOD__ );
3882                 return $bad;
3883         }
3884
3885         $cacheable = ( $blacklist === null );
3886         if( $cacheable && $badImageCache !== null ) {
3887                 $badImages = $badImageCache;
3888         } else { // cache miss
3889                 if ( $blacklist === null ) {
3890                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3891                 }
3892                 # Build the list now
3893                 $badImages = array();
3894                 $lines = explode( "\n", $blacklist );
3895                 foreach( $lines as $line ) {
3896                         # List items only
3897                         if ( substr( $line, 0, 1 ) !== '*' ) {
3898                                 continue;
3899                         }
3900
3901                         # Find all links
3902                         $m = array();
3903                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3904                                 continue;
3905                         }
3906
3907                         $exceptions = array();
3908                         $imageDBkey = false;
3909                         foreach ( $m[1] as $i => $titleText ) {
3910                                 $title = Title::newFromText( $titleText );
3911                                 if ( !is_null( $title ) ) {
3912                                         if ( $i == 0 ) {
3913                                                 $imageDBkey = $title->getDBkey();
3914                                         } else {
3915                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3916                                         }
3917                                 }
3918                         }
3919
3920                         if ( $imageDBkey !== false ) {
3921                                 $badImages[$imageDBkey] = $exceptions;
3922                         }
3923                 }
3924                 if ( $cacheable ) {
3925                         $badImageCache = $badImages;
3926                 }
3927         }
3928
3929         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3930         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3931         wfProfileOut( __METHOD__ );
3932         return $bad;
3933 }