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 ( $public === true ) {
1040                 wfDebug( "[$logGroup] $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
1218         // Command line script uses a FauxRequest object which does not have
1219         // any knowledge about an URL and throw an exception instead.
1220         try {
1221                 $requestUrl = $wgRequest->getRequestURL();
1222         } catch ( MWException $e ) {
1223                 $requestUrl = 'n/a';
1224         }
1225
1226         $log = sprintf( "%s\t%04.3f\t%s\n",
1227                 gmdate( 'YmdHis' ), $elapsed,
1228                 urldecode( $requestUrl . $forward ) );
1229
1230         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1231 }
1232
1233 /**
1234  * Increment a statistics counter
1235  *
1236  * @param $key String
1237  * @param $count Int
1238  */
1239 function wfIncrStats( $key, $count = 1 ) {
1240         global $wgStatsMethod;
1241
1242         $count = intval( $count );
1243
1244         if( $wgStatsMethod == 'udp' ) {
1245                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
1246                 static $socket;
1247
1248                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
1249
1250                 if ( !$socket ) {
1251                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
1252                         $statline = "stats/{$id} - 1 1 1 1 1 -total\n";
1253                         socket_sendto(
1254                                 $socket,
1255                                 $statline,
1256                                 strlen( $statline ),
1257                                 0,
1258                                 $wgUDPProfilerHost,
1259                                 $wgUDPProfilerPort
1260                         );
1261                 }
1262                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
1263                 wfSuppressWarnings();
1264                 socket_sendto(
1265                         $socket,
1266                         $statline,
1267                         strlen( $statline ),
1268                         0,
1269                         $wgUDPProfilerHost,
1270                         $wgUDPProfilerPort
1271                 );
1272                 wfRestoreWarnings();
1273         } elseif( $wgStatsMethod == 'cache' ) {
1274                 global $wgMemc;
1275                 $key = wfMemcKey( 'stats', $key );
1276                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
1277                         $wgMemc->add( $key, $count );
1278                 }
1279         } else {
1280                 // Disabled
1281         }
1282 }
1283
1284 /**
1285  * Check if the wiki read-only lock file is present. This can be used to lock
1286  * off editing functions, but doesn't guarantee that the database will not be
1287  * modified.
1288  *
1289  * @return bool
1290  */
1291 function wfReadOnly() {
1292         global $wgReadOnlyFile, $wgReadOnly;
1293
1294         if ( !is_null( $wgReadOnly ) ) {
1295                 return (bool)$wgReadOnly;
1296         }
1297         if ( $wgReadOnlyFile == '' ) {
1298                 return false;
1299         }
1300         // Set $wgReadOnly for faster access next time
1301         if ( is_file( $wgReadOnlyFile ) ) {
1302                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1303         } else {
1304                 $wgReadOnly = false;
1305         }
1306         return (bool)$wgReadOnly;
1307 }
1308
1309 /**
1310  * @return bool
1311  */
1312 function wfReadOnlyReason() {
1313         global $wgReadOnly;
1314         wfReadOnly();
1315         return $wgReadOnly;
1316 }
1317
1318 /**
1319  * Return a Language object from $langcode
1320  *
1321  * @param $langcode Mixed: either:
1322  *                  - a Language object
1323  *                  - code of the language to get the message for, if it is
1324  *                    a valid code create a language for that language, if
1325  *                    it is a string but not a valid code then make a basic
1326  *                    language object
1327  *                  - a boolean: if it's false then use the global object for
1328  *                    the current user's language (as a fallback for the old parameter
1329  *                    functionality), or if it is true then use global object
1330  *                    for the wiki's content language.
1331  * @return Language object
1332  */
1333 function wfGetLangObj( $langcode = false ) {
1334         # Identify which language to get or create a language object for.
1335         # Using is_object here due to Stub objects.
1336         if( is_object( $langcode ) ) {
1337                 # Great, we already have the object (hopefully)!
1338                 return $langcode;
1339         }
1340
1341         global $wgContLang, $wgLanguageCode;
1342         if( $langcode === true || $langcode === $wgLanguageCode ) {
1343                 # $langcode is the language code of the wikis content language object.
1344                 # or it is a boolean and value is true
1345                 return $wgContLang;
1346         }
1347
1348         global $wgLang;
1349         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1350                 # $langcode is the language code of user language object.
1351                 # or it was a boolean and value is false
1352                 return $wgLang;
1353         }
1354
1355         $validCodes = array_keys( Language::fetchLanguageNames() );
1356         if( in_array( $langcode, $validCodes ) ) {
1357                 # $langcode corresponds to a valid language.
1358                 return Language::factory( $langcode );
1359         }
1360
1361         # $langcode is a string, but not a valid language code; use content language.
1362         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1363         return $wgContLang;
1364 }
1365
1366 /**
1367  * Old function when $wgBetterDirectionality existed
1368  * All usage removed, wfUILang can be removed in near future
1369  *
1370  * @deprecated since 1.18
1371  * @return Language
1372  */
1373 function wfUILang() {
1374         wfDeprecated( __METHOD__, '1.18' );
1375         global $wgLang;
1376         return $wgLang;
1377 }
1378
1379 /**
1380  * This is the new function for getting translated interface messages.
1381  * See the Message class for documentation how to use them.
1382  * The intention is that this function replaces all old wfMsg* functions.
1383  * @param $key \string Message key.
1384  * Varargs: normal message parameters.
1385  * @return Message
1386  * @since 1.17
1387  */
1388 function wfMessage( $key /*...*/) {
1389         $params = func_get_args();
1390         array_shift( $params );
1391         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1392                 $params = $params[0];
1393         }
1394         return new Message( $key, $params );
1395 }
1396
1397 /**
1398  * This function accepts multiple message keys and returns a message instance
1399  * for the first message which is non-empty. If all messages are empty then an
1400  * instance of the first message key is returned.
1401  * @param varargs: message keys
1402  * @return Message
1403  * @since 1.18
1404  */
1405 function wfMessageFallback( /*...*/ ) {
1406         $args = func_get_args();
1407         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1408 }
1409
1410 /**
1411  * Get a message from anywhere, for the current user language.
1412  *
1413  * Use wfMsgForContent() instead if the message should NOT
1414  * change depending on the user preferences.
1415  *
1416  * @deprecated since 1.18
1417  *
1418  * @param $key String: lookup key for the message, usually
1419  *    defined in languages/Language.php
1420  *
1421  * Parameters to the message, which can be used to insert variable text into
1422  * it, can be passed to this function in the following formats:
1423  * - One per argument, starting at the second parameter
1424  * - As an array in the second parameter
1425  * These are not shown in the function definition.
1426  *
1427  * @return String
1428  */
1429 function wfMsg( $key ) {
1430         wfDeprecated( __METHOD__, '1.21' );
1431
1432         $args = func_get_args();
1433         array_shift( $args );
1434         return wfMsgReal( $key, $args );
1435 }
1436
1437 /**
1438  * Same as above except doesn't transform the message
1439  *
1440  * @deprecated since 1.18
1441  *
1442  * @param $key String
1443  * @return String
1444  */
1445 function wfMsgNoTrans( $key ) {
1446         wfDeprecated( __METHOD__, '1.21' );
1447
1448         $args = func_get_args();
1449         array_shift( $args );
1450         return wfMsgReal( $key, $args, true, false, false );
1451 }
1452
1453 /**
1454  * Get a message from anywhere, for the current global language
1455  * set with $wgLanguageCode.
1456  *
1457  * Use this if the message should NOT change dependent on the
1458  * language set in the user's preferences. This is the case for
1459  * most text written into logs, as well as link targets (such as
1460  * the name of the copyright policy page). Link titles, on the
1461  * other hand, should be shown in the UI language.
1462  *
1463  * Note that MediaWiki allows users to change the user interface
1464  * language in their preferences, but a single installation
1465  * typically only contains content in one language.
1466  *
1467  * Be wary of this distinction: If you use wfMsg() where you should
1468  * use wfMsgForContent(), a user of the software may have to
1469  * customize potentially hundreds of messages in
1470  * order to, e.g., fix a link in every possible language.
1471  *
1472  * @deprecated since 1.18
1473  *
1474  * @param $key String: lookup key for the message, usually
1475  *     defined in languages/Language.php
1476  * @return String
1477  */
1478 function wfMsgForContent( $key ) {
1479         wfDeprecated( __METHOD__, '1.21' );
1480
1481         global $wgForceUIMsgAsContentMsg;
1482         $args = func_get_args();
1483         array_shift( $args );
1484         $forcontent = true;
1485         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1486                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1487         {
1488                 $forcontent = false;
1489         }
1490         return wfMsgReal( $key, $args, true, $forcontent );
1491 }
1492
1493 /**
1494  * Same as above except doesn't transform the message
1495  *
1496  * @deprecated since 1.18
1497  *
1498  * @param $key String
1499  * @return String
1500  */
1501 function wfMsgForContentNoTrans( $key ) {
1502         wfDeprecated( __METHOD__, '1.21' );
1503
1504         global $wgForceUIMsgAsContentMsg;
1505         $args = func_get_args();
1506         array_shift( $args );
1507         $forcontent = true;
1508         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1509                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1510         {
1511                 $forcontent = false;
1512         }
1513         return wfMsgReal( $key, $args, true, $forcontent, false );
1514 }
1515
1516 /**
1517  * Really get a message
1518  *
1519  * @deprecated since 1.18
1520  *
1521  * @param $key String: key to get.
1522  * @param $args
1523  * @param $useDB Boolean
1524  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1525  * @param $transform Boolean: Whether or not to transform the message.
1526  * @return String: the requested message.
1527  */
1528 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1529         wfDeprecated( __METHOD__, '1.21' );
1530
1531         wfProfileIn( __METHOD__ );
1532         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1533         $message = wfMsgReplaceArgs( $message, $args );
1534         wfProfileOut( __METHOD__ );
1535         return $message;
1536 }
1537
1538 /**
1539  * Fetch a message string value, but don't replace any keys yet.
1540  *
1541  * @deprecated since 1.18
1542  *
1543  * @param $key String
1544  * @param $useDB Bool
1545  * @param $langCode String: Code of the language to get the message for, or
1546  *                  behaves as a content language switch if it is a boolean.
1547  * @param $transform Boolean: whether to parse magic words, etc.
1548  * @return string
1549  */
1550 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1551         wfDeprecated( __METHOD__, '1.21' );
1552
1553         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1554
1555         $cache = MessageCache::singleton();
1556         $message = $cache->get( $key, $useDB, $langCode );
1557         if( $message === false ) {
1558                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1559         } elseif ( $transform ) {
1560                 $message = $cache->transform( $message );
1561         }
1562         return $message;
1563 }
1564
1565 /**
1566  * Replace message parameter keys on the given formatted output.
1567  *
1568  * @param $message String
1569  * @param $args Array
1570  * @return string
1571  * @private
1572  */
1573 function wfMsgReplaceArgs( $message, $args ) {
1574         # Fix windows line-endings
1575         # Some messages are split with explode("\n", $msg)
1576         $message = str_replace( "\r", '', $message );
1577
1578         // Replace arguments
1579         if ( count( $args ) ) {
1580                 if ( is_array( $args[0] ) ) {
1581                         $args = array_values( $args[0] );
1582                 }
1583                 $replacementKeys = array();
1584                 foreach( $args as $n => $param ) {
1585                         $replacementKeys['$' . ( $n + 1 )] = $param;
1586                 }
1587                 $message = strtr( $message, $replacementKeys );
1588         }
1589
1590         return $message;
1591 }
1592
1593 /**
1594  * Return an HTML-escaped version of a message.
1595  * Parameter replacements, if any, are done *after* the HTML-escaping,
1596  * so parameters may contain HTML (eg links or form controls). Be sure
1597  * to pre-escape them if you really do want plaintext, or just wrap
1598  * the whole thing in htmlspecialchars().
1599  *
1600  * @deprecated since 1.18
1601  *
1602  * @param $key String
1603  * @param string ... parameters
1604  * @return string
1605  */
1606 function wfMsgHtml( $key ) {
1607         wfDeprecated( __METHOD__, '1.21' );
1608
1609         $args = func_get_args();
1610         array_shift( $args );
1611         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1612 }
1613
1614 /**
1615  * Return an HTML version of message
1616  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1617  * so parameters may contain HTML (eg links or form controls). Be sure
1618  * to pre-escape them if you really do want plaintext, or just wrap
1619  * the whole thing in htmlspecialchars().
1620  *
1621  * @deprecated since 1.18
1622  *
1623  * @param $key String
1624  * @param string ... parameters
1625  * @return string
1626  */
1627 function wfMsgWikiHtml( $key ) {
1628         wfDeprecated( __METHOD__, '1.21' );
1629
1630         $args = func_get_args();
1631         array_shift( $args );
1632         return wfMsgReplaceArgs(
1633                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1634                 /* can't be set to false */ true, /* interface */ true )->getText(),
1635                 $args );
1636 }
1637
1638 /**
1639  * Returns message in the requested format
1640  *
1641  * @deprecated since 1.18
1642  *
1643  * @param $key String: key of the message
1644  * @param $options Array: processing rules. Can take the following options:
1645  *   <i>parse</i>: parses wikitext to HTML
1646  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1647  *       p's added by parser or tidy
1648  *   <i>escape</i>: filters message through htmlspecialchars
1649  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1650  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1651  *   <i>parsemag</i>: transform the message using magic phrases
1652  *   <i>content</i>: fetch message for content language instead of interface
1653  * Also can accept a single associative argument, of the form 'language' => 'xx':
1654  *   <i>language</i>: Language object or language code to fetch message for
1655  *       (overriden by <i>content</i>).
1656  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1657  *
1658  * @return String
1659  */
1660 function wfMsgExt( $key, $options ) {
1661         wfDeprecated( __METHOD__, '1.21' );
1662
1663         $args = func_get_args();
1664         array_shift( $args );
1665         array_shift( $args );
1666         $options = (array)$options;
1667
1668         foreach( $options as $arrayKey => $option ) {
1669                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1670                         # An unknown index, neither numeric nor "language"
1671                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1672                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1673                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1674                 'replaceafter', 'parsemag', 'content' ) ) ) {
1675                         # A numeric index with unknown value
1676                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1677                 }
1678         }
1679
1680         if( in_array( 'content', $options, true ) ) {
1681                 $forContent = true;
1682                 $langCode = true;
1683                 $langCodeObj = null;
1684         } elseif( array_key_exists( 'language', $options ) ) {
1685                 $forContent = false;
1686                 $langCode = wfGetLangObj( $options['language'] );
1687                 $langCodeObj = $langCode;
1688         } else {
1689                 $forContent = false;
1690                 $langCode = false;
1691                 $langCodeObj = null;
1692         }
1693
1694         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1695
1696         if( !in_array( 'replaceafter', $options, true ) ) {
1697                 $string = wfMsgReplaceArgs( $string, $args );
1698         }
1699
1700         $messageCache = MessageCache::singleton();
1701         $parseInline = in_array( 'parseinline', $options, true );
1702         if( in_array( 'parse', $options, true ) || $parseInline ) {
1703                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1704                 if ( $string instanceof ParserOutput ) {
1705                         $string = $string->getText();
1706                 }
1707
1708                 if ( $parseInline ) {
1709                         $m = array();
1710                         if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1711                                 $string = $m[1];
1712                         }
1713                 }
1714         } elseif ( in_array( 'parsemag', $options, true ) ) {
1715                 $string = $messageCache->transform( $string,
1716                                 !$forContent, $langCodeObj );
1717         }
1718
1719         if ( in_array( 'escape', $options, true ) ) {
1720                 $string = htmlspecialchars ( $string );
1721         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1722                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1723         }
1724
1725         if( in_array( 'replaceafter', $options, true ) ) {
1726                 $string = wfMsgReplaceArgs( $string, $args );
1727         }
1728
1729         return $string;
1730 }
1731
1732 /**
1733  * Since wfMsg() and co suck, they don't return false if the message key they
1734  * looked up didn't exist but a XHTML string, this function checks for the
1735  * nonexistance of messages by checking the MessageCache::get() result directly.
1736  *
1737  * @deprecated since 1.18. Use Message::isDisabled().
1738  *
1739  * @param $key      String: the message key looked up
1740  * @return Boolean True if the message *doesn't* exist.
1741  */
1742 function wfEmptyMsg( $key ) {
1743         wfDeprecated( __METHOD__, '1.21' );
1744
1745         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1746 }
1747
1748 /**
1749  * Throw a debugging exception. This function previously once exited the process,
1750  * but now throws an exception instead, with similar results.
1751  *
1752  * @param $msg String: message shown when dying.
1753  * @throws MWException
1754  */
1755 function wfDebugDieBacktrace( $msg = '' ) {
1756         throw new MWException( $msg );
1757 }
1758
1759 /**
1760  * Fetch server name for use in error reporting etc.
1761  * Use real server name if available, so we know which machine
1762  * in a server farm generated the current page.
1763  *
1764  * @return string
1765  */
1766 function wfHostname() {
1767         static $host;
1768         if ( is_null( $host ) ) {
1769
1770                 # Hostname overriding
1771                 global $wgOverrideHostname;
1772                 if( $wgOverrideHostname !== false ) {
1773                         # Set static and skip any detection
1774                         $host = $wgOverrideHostname;
1775                         return $host;
1776                 }
1777
1778                 if ( function_exists( 'posix_uname' ) ) {
1779                         // This function not present on Windows
1780                         $uname = posix_uname();
1781                 } else {
1782                         $uname = false;
1783                 }
1784                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1785                         $host = $uname['nodename'];
1786                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1787                         # Windows computer name
1788                         $host = getenv( 'COMPUTERNAME' );
1789                 } else {
1790                         # This may be a virtual server.
1791                         $host = $_SERVER['SERVER_NAME'];
1792                 }
1793         }
1794         return $host;
1795 }
1796
1797 /**
1798  * Returns a HTML comment with the elapsed time since request.
1799  * This method has no side effects.
1800  *
1801  * @return string
1802  */
1803 function wfReportTime() {
1804         global $wgRequestTime, $wgShowHostnames;
1805
1806         $elapsed = microtime( true ) - $wgRequestTime;
1807
1808         return $wgShowHostnames
1809                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1810                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1811 }
1812
1813 /**
1814  * Safety wrapper for debug_backtrace().
1815  *
1816  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1817  * murky circumstances, which may be triggered in part by stub objects
1818  * or other fancy talkin'.
1819  *
1820  * Will return an empty array if Zend Optimizer is detected or if
1821  * debug_backtrace is disabled, otherwise the output from
1822  * debug_backtrace() (trimmed).
1823  *
1824  * @param $limit int This parameter can be used to limit the number of stack frames returned
1825  *
1826  * @return array of backtrace information
1827  */
1828 function wfDebugBacktrace( $limit = 0 ) {
1829         static $disabled = null;
1830
1831         if( extension_loaded( 'Zend Optimizer' ) ) {
1832                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1833                 return array();
1834         }
1835
1836         if ( is_null( $disabled ) ) {
1837                 $disabled = false;
1838                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1839                 $functions = array_map( 'trim', $functions );
1840                 $functions = array_map( 'strtolower', $functions );
1841                 if ( in_array( 'debug_backtrace', $functions ) ) {
1842                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1843                         $disabled = true;
1844                 }
1845         }
1846         if ( $disabled ) {
1847                 return array();
1848         }
1849
1850         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1851                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1852         } else {
1853                 return array_slice( debug_backtrace(), 1 );
1854         }
1855 }
1856
1857 /**
1858  * Get a debug backtrace as a string
1859  *
1860  * @return string
1861  */
1862 function wfBacktrace() {
1863         global $wgCommandLineMode;
1864
1865         if ( $wgCommandLineMode ) {
1866                 $msg = '';
1867         } else {
1868                 $msg = "<ul>\n";
1869         }
1870         $backtrace = wfDebugBacktrace();
1871         foreach( $backtrace as $call ) {
1872                 if( isset( $call['file'] ) ) {
1873                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1874                         $file = $f[count( $f ) - 1];
1875                 } else {
1876                         $file = '-';
1877                 }
1878                 if( isset( $call['line'] ) ) {
1879                         $line = $call['line'];
1880                 } else {
1881                         $line = '-';
1882                 }
1883                 if ( $wgCommandLineMode ) {
1884                         $msg .= "$file line $line calls ";
1885                 } else {
1886                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1887                 }
1888                 if( !empty( $call['class'] ) ) {
1889                         $msg .= $call['class'] . $call['type'];
1890                 }
1891                 $msg .= $call['function'] . '()';
1892
1893                 if ( $wgCommandLineMode ) {
1894                         $msg .= "\n";
1895                 } else {
1896                         $msg .= "</li>\n";
1897                 }
1898         }
1899         if ( $wgCommandLineMode ) {
1900                 $msg .= "\n";
1901         } else {
1902                 $msg .= "</ul>\n";
1903         }
1904
1905         return $msg;
1906 }
1907
1908 /**
1909  * Get the name of the function which called this function
1910  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1911  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1912  * wfGetCaller( 3 ) is the parent of that.
1913  *
1914  * @param $level Int
1915  * @return string
1916  */
1917 function wfGetCaller( $level = 2 ) {
1918         $backtrace = wfDebugBacktrace( $level + 1 );
1919         if ( isset( $backtrace[$level] ) ) {
1920                 return wfFormatStackFrame( $backtrace[$level] );
1921         } else {
1922                 return 'unknown';
1923         }
1924 }
1925
1926 /**
1927  * Return a string consisting of callers in the stack. Useful sometimes
1928  * for profiling specific points.
1929  *
1930  * @param $limit int The maximum depth of the stack frame to return, or false for
1931  *               the entire stack.
1932  * @return String
1933  */
1934 function wfGetAllCallers( $limit = 3 ) {
1935         $trace = array_reverse( wfDebugBacktrace() );
1936         if ( !$limit || $limit > count( $trace ) - 1 ) {
1937                 $limit = count( $trace ) - 1;
1938         }
1939         $trace = array_slice( $trace, -$limit - 1, $limit );
1940         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1941 }
1942
1943 /**
1944  * Return a string representation of frame
1945  *
1946  * @param $frame Array
1947  * @return string
1948  */
1949 function wfFormatStackFrame( $frame ) {
1950         return isset( $frame['class'] ) ?
1951                 $frame['class'] . '::' . $frame['function'] :
1952                 $frame['function'];
1953 }
1954
1955
1956 /* Some generic result counters, pulled out of SearchEngine */
1957
1958
1959 /**
1960  * @todo document
1961  *
1962  * @param $offset Int
1963  * @param $limit Int
1964  * @return String
1965  */
1966 function wfShowingResults( $offset, $limit ) {
1967         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1968 }
1969
1970 /**
1971  * Generate (prev x| next x) (20|50|100...) type links for paging
1972  *
1973  * @param $offset String
1974  * @param $limit Integer
1975  * @param $link String
1976  * @param $query String: optional URL query parameter string
1977  * @param $atend Bool: optional param for specified if this is the last page
1978  * @return String
1979  * @deprecated in 1.19; use Language::viewPrevNext() instead
1980  */
1981 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1982         wfDeprecated( __METHOD__, '1.19' );
1983
1984         global $wgLang;
1985
1986         $query = wfCgiToArray( $query );
1987
1988         if( is_object( $link ) ) {
1989                 $title = $link;
1990         } else {
1991                 $title = Title::newFromText( $link );
1992                 if( is_null( $title ) ) {
1993                         return false;
1994                 }
1995         }
1996
1997         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1998 }
1999
2000 /**
2001  * Make a list item, used by various special pages
2002  *
2003  * @param $page String Page link
2004  * @param $details String Text between brackets
2005  * @param $oppositedm Boolean   Add the direction mark opposite to your
2006  *                                                              language, to display text properly
2007  * @return String
2008  * @deprecated since 1.19; use Language::specialList() instead
2009  */
2010 function wfSpecialList( $page, $details, $oppositedm = true ) {
2011         wfDeprecated( __METHOD__, '1.19' );
2012
2013         global $wgLang;
2014         return $wgLang->specialList( $page, $details, $oppositedm );
2015 }
2016
2017 /**
2018  * @todo document
2019  * @todo FIXME: We may want to blacklist some broken browsers
2020  *
2021  * @param $force Bool
2022  * @return bool Whereas client accept gzip compression
2023  */
2024 function wfClientAcceptsGzip( $force = false ) {
2025         static $result = null;
2026         if ( $result === null || $force ) {
2027                 $result = false;
2028                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2029                         # @todo FIXME: We may want to blacklist some broken browsers
2030                         $m = array();
2031                         if( preg_match(
2032                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2033                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
2034                                 $m )
2035                         )
2036                         {
2037                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2038                                         $result = false;
2039                                         return $result;
2040                                 }
2041                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2042                                 $result = true;
2043                         }
2044                 }
2045         }
2046         return $result;
2047 }
2048
2049 /**
2050  * Obtain the offset and limit values from the request string;
2051  * used in special pages
2052  *
2053  * @param $deflimit Int default limit if none supplied
2054  * @param $optionname String Name of a user preference to check against
2055  * @return array
2056  *
2057  */
2058 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2059         global $wgRequest;
2060         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2061 }
2062
2063 /**
2064  * Escapes the given text so that it may be output using addWikiText()
2065  * without any linking, formatting, etc. making its way through. This
2066  * is achieved by substituting certain characters with HTML entities.
2067  * As required by the callers, "<nowiki>" is not used.
2068  *
2069  * @param $text String: text to be escaped
2070  * @return String
2071  */
2072 function wfEscapeWikiText( $text ) {
2073         $text = strtr( "\n$text", array(
2074                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2075                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2076                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
2077                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
2078                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
2079                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
2080         ) );
2081         return substr( $text, 1 );
2082 }
2083
2084 /**
2085  * Get the current unix timetstamp with microseconds.  Useful for profiling
2086  * @return Float
2087  */
2088 function wfTime() {
2089         return microtime( true );
2090 }
2091
2092 /**
2093  * Sets dest to source and returns the original value of dest
2094  * If source is NULL, it just returns the value, it doesn't set the variable
2095  * If force is true, it will set the value even if source is NULL
2096  *
2097  * @param $dest Mixed
2098  * @param $source Mixed
2099  * @param $force Bool
2100  * @return Mixed
2101  */
2102 function wfSetVar( &$dest, $source, $force = false ) {
2103         $temp = $dest;
2104         if ( !is_null( $source ) || $force ) {
2105                 $dest = $source;
2106         }
2107         return $temp;
2108 }
2109
2110 /**
2111  * As for wfSetVar except setting a bit
2112  *
2113  * @param $dest Int
2114  * @param $bit Int
2115  * @param $state Bool
2116  *
2117  * @return bool
2118  */
2119 function wfSetBit( &$dest, $bit, $state = true ) {
2120         $temp = (bool)( $dest & $bit );
2121         if ( !is_null( $state ) ) {
2122                 if ( $state ) {
2123                         $dest |= $bit;
2124                 } else {
2125                         $dest &= ~$bit;
2126                 }
2127         }
2128         return $temp;
2129 }
2130
2131 /**
2132  * A wrapper around the PHP function var_export().
2133  * Either print it or add it to the regular output ($wgOut).
2134  *
2135  * @param $var mixed A PHP variable to dump.
2136  */
2137 function wfVarDump( $var ) {
2138         global $wgOut;
2139         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2140         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2141                 print $s;
2142         } else {
2143                 $wgOut->addHTML( $s );
2144         }
2145 }
2146
2147 /**
2148  * Provide a simple HTTP error.
2149  *
2150  * @param $code Int|String
2151  * @param $label String
2152  * @param $desc String
2153  */
2154 function wfHttpError( $code, $label, $desc ) {
2155         global $wgOut;
2156         $wgOut->disable();
2157         header( "HTTP/1.0 $code $label" );
2158         header( "Status: $code $label" );
2159         $wgOut->sendCacheControl();
2160
2161         header( 'Content-type: text/html; charset=utf-8' );
2162         print "<!doctype html>" .
2163                 '<html><head><title>' .
2164                 htmlspecialchars( $label ) .
2165                 '</title></head><body><h1>' .
2166                 htmlspecialchars( $label ) .
2167                 '</h1><p>' .
2168                 nl2br( htmlspecialchars( $desc ) ) .
2169                 "</p></body></html>\n";
2170 }
2171
2172 /**
2173  * Clear away any user-level output buffers, discarding contents.
2174  *
2175  * Suitable for 'starting afresh', for instance when streaming
2176  * relatively large amounts of data without buffering, or wanting to
2177  * output image files without ob_gzhandler's compression.
2178  *
2179  * The optional $resetGzipEncoding parameter controls suppression of
2180  * the Content-Encoding header sent by ob_gzhandler; by default it
2181  * is left. See comments for wfClearOutputBuffers() for why it would
2182  * be used.
2183  *
2184  * Note that some PHP configuration options may add output buffer
2185  * layers which cannot be removed; these are left in place.
2186  *
2187  * @param $resetGzipEncoding Bool
2188  */
2189 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2190         if( $resetGzipEncoding ) {
2191                 // Suppress Content-Encoding and Content-Length
2192                 // headers from 1.10+s wfOutputHandler
2193                 global $wgDisableOutputCompression;
2194                 $wgDisableOutputCompression = true;
2195         }
2196         while( $status = ob_get_status() ) {
2197                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2198                         // Probably from zlib.output_compression or other
2199                         // PHP-internal setting which can't be removed.
2200                         //
2201                         // Give up, and hope the result doesn't break
2202                         // output behavior.
2203                         break;
2204                 }
2205                 if( !ob_end_clean() ) {
2206                         // Could not remove output buffer handler; abort now
2207                         // to avoid getting in some kind of infinite loop.
2208                         break;
2209                 }
2210                 if( $resetGzipEncoding ) {
2211                         if( $status['name'] == 'ob_gzhandler' ) {
2212                                 // Reset the 'Content-Encoding' field set by this handler
2213                                 // so we can start fresh.
2214                                 header_remove( 'Content-Encoding' );
2215                                 break;
2216                         }
2217                 }
2218         }
2219 }
2220
2221 /**
2222  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2223  *
2224  * Clear away output buffers, but keep the Content-Encoding header
2225  * produced by ob_gzhandler, if any.
2226  *
2227  * This should be used for HTTP 304 responses, where you need to
2228  * preserve the Content-Encoding header of the real result, but
2229  * also need to suppress the output of ob_gzhandler to keep to spec
2230  * and avoid breaking Firefox in rare cases where the headers and
2231  * body are broken over two packets.
2232  */
2233 function wfClearOutputBuffers() {
2234         wfResetOutputBuffers( false );
2235 }
2236
2237 /**
2238  * Converts an Accept-* header into an array mapping string values to quality
2239  * factors
2240  *
2241  * @param $accept String
2242  * @param $def String default
2243  * @return Array
2244  */
2245 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2246         # No arg means accept anything (per HTTP spec)
2247         if( !$accept ) {
2248                 return array( $def => 1.0 );
2249         }
2250
2251         $prefs = array();
2252
2253         $parts = explode( ',', $accept );
2254
2255         foreach( $parts as $part ) {
2256                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2257                 $values = explode( ';', trim( $part ) );
2258                 $match = array();
2259                 if ( count( $values ) == 1 ) {
2260                         $prefs[$values[0]] = 1.0;
2261                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2262                         $prefs[$values[0]] = floatval( $match[1] );
2263                 }
2264         }
2265
2266         return $prefs;
2267 }
2268
2269 /**
2270  * Checks if a given MIME type matches any of the keys in the given
2271  * array. Basic wildcards are accepted in the array keys.
2272  *
2273  * Returns the matching MIME type (or wildcard) if a match, otherwise
2274  * NULL if no match.
2275  *
2276  * @param $type String
2277  * @param $avail Array
2278  * @return string
2279  * @private
2280  */
2281 function mimeTypeMatch( $type, $avail ) {
2282         if( array_key_exists( $type, $avail ) ) {
2283                 return $type;
2284         } else {
2285                 $parts = explode( '/', $type );
2286                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2287                         return $parts[0] . '/*';
2288                 } elseif( array_key_exists( '*/*', $avail ) ) {
2289                         return '*/*';
2290                 } else {
2291                         return null;
2292                 }
2293         }
2294 }
2295
2296 /**
2297  * Returns the 'best' match between a client's requested internet media types
2298  * and the server's list of available types. Each list should be an associative
2299  * array of type to preference (preference is a float between 0.0 and 1.0).
2300  * Wildcards in the types are acceptable.
2301  *
2302  * @param $cprefs Array: client's acceptable type list
2303  * @param $sprefs Array: server's offered types
2304  * @return string
2305  *
2306  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2307  * XXX: generalize to negotiate other stuff
2308  */
2309 function wfNegotiateType( $cprefs, $sprefs ) {
2310         $combine = array();
2311
2312         foreach( array_keys( $sprefs ) as $type ) {
2313                 $parts = explode( '/', $type );
2314                 if( $parts[1] != '*' ) {
2315                         $ckey = mimeTypeMatch( $type, $cprefs );
2316                         if( $ckey ) {
2317                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2318                         }
2319                 }
2320         }
2321
2322         foreach( array_keys( $cprefs ) as $type ) {
2323                 $parts = explode( '/', $type );
2324                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2325                         $skey = mimeTypeMatch( $type, $sprefs );
2326                         if( $skey ) {
2327                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2328                         }
2329                 }
2330         }
2331
2332         $bestq = 0;
2333         $besttype = null;
2334
2335         foreach( array_keys( $combine ) as $type ) {
2336                 if( $combine[$type] > $bestq ) {
2337                         $besttype = $type;
2338                         $bestq = $combine[$type];
2339                 }
2340         }
2341
2342         return $besttype;
2343 }
2344
2345 /**
2346  * Reference-counted warning suppression
2347  *
2348  * @param $end Bool
2349  */
2350 function wfSuppressWarnings( $end = false ) {
2351         static $suppressCount = 0;
2352         static $originalLevel = false;
2353
2354         if ( $end ) {
2355                 if ( $suppressCount ) {
2356                         --$suppressCount;
2357                         if ( !$suppressCount ) {
2358                                 error_reporting( $originalLevel );
2359                         }
2360                 }
2361         } else {
2362                 if ( !$suppressCount ) {
2363                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED | E_USER_DEPRECATED | E_STRICT ) );
2364                 }
2365                 ++$suppressCount;
2366         }
2367 }
2368
2369 /**
2370  * Restore error level to previous value
2371  */
2372 function wfRestoreWarnings() {
2373         wfSuppressWarnings( true );
2374 }
2375
2376 # Autodetect, convert and provide timestamps of various types
2377
2378 /**
2379  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2380  */
2381 define( 'TS_UNIX', 0 );
2382
2383 /**
2384  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2385  */
2386 define( 'TS_MW', 1 );
2387
2388 /**
2389  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2390  */
2391 define( 'TS_DB', 2 );
2392
2393 /**
2394  * RFC 2822 format, for E-mail and HTTP headers
2395  */
2396 define( 'TS_RFC2822', 3 );
2397
2398 /**
2399  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2400  *
2401  * This is used by Special:Export
2402  */
2403 define( 'TS_ISO_8601', 4 );
2404
2405 /**
2406  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2407  *
2408  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2409  *       DateTime tag and page 36 for the DateTimeOriginal and
2410  *       DateTimeDigitized tags.
2411  */
2412 define( 'TS_EXIF', 5 );
2413
2414 /**
2415  * Oracle format time.
2416  */
2417 define( 'TS_ORACLE', 6 );
2418
2419 /**
2420  * Postgres format time.
2421  */
2422 define( 'TS_POSTGRES', 7 );
2423
2424 /**
2425  * DB2 format time
2426  */
2427 define( 'TS_DB2', 8 );
2428
2429 /**
2430  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2431  */
2432 define( 'TS_ISO_8601_BASIC', 9 );
2433
2434 /**
2435  * Get a timestamp string in one of various formats
2436  *
2437  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2438  *                    function will autodetect which format is supplied and act
2439  *                    accordingly.
2440  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2441  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2442  */
2443 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2444         try {
2445                 $timestamp = new MWTimestamp( $ts );
2446                 return $timestamp->getTimestamp( $outputtype );
2447         } catch( TimestampException $e ) {
2448                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2449                 return false;
2450         }
2451 }
2452
2453 /**
2454  * Return a formatted timestamp, or null if input is null.
2455  * For dealing with nullable timestamp columns in the database.
2456  *
2457  * @param $outputtype Integer
2458  * @param $ts String
2459  * @return String
2460  */
2461 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2462         if( is_null( $ts ) ) {
2463                 return null;
2464         } else {
2465                 return wfTimestamp( $outputtype, $ts );
2466         }
2467 }
2468
2469 /**
2470  * Convenience function; returns MediaWiki timestamp for the present time.
2471  *
2472  * @return string
2473  */
2474 function wfTimestampNow() {
2475         # return NOW
2476         return wfTimestamp( TS_MW, time() );
2477 }
2478
2479 /**
2480  * Check if the operating system is Windows
2481  *
2482  * @return Bool: true if it's Windows, False otherwise.
2483  */
2484 function wfIsWindows() {
2485         static $isWindows = null;
2486         if ( $isWindows === null ) {
2487                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2488         }
2489         return $isWindows;
2490 }
2491
2492 /**
2493  * Check if we are running under HipHop
2494  *
2495  * @return Bool
2496  */
2497 function wfIsHipHop() {
2498         return function_exists( 'hphp_thread_set_warmup_enabled' );
2499 }
2500
2501 /**
2502  * Swap two variables
2503  *
2504  * @param $x Mixed
2505  * @param $y Mixed
2506  */
2507 function swap( &$x, &$y ) {
2508         $z = $x;
2509         $x = $y;
2510         $y = $z;
2511 }
2512
2513 /**
2514  * Tries to get the system directory for temporary files. First
2515  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2516  * environment variables are then checked in sequence, and if none are
2517  * set try sys_get_temp_dir().
2518  *
2519  * NOTE: When possible, use instead the tmpfile() function to create
2520  * temporary files to avoid race conditions on file creation, etc.
2521  *
2522  * @return String
2523  */
2524 function wfTempDir() {
2525         global $wgTmpDirectory;
2526
2527         if ( $wgTmpDirectory !== false ) {
2528                 return $wgTmpDirectory;
2529         }
2530
2531         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2532
2533         foreach( $tmpDir as $tmp ) {
2534                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2535                         return $tmp;
2536                 }
2537         }
2538         return sys_get_temp_dir();
2539 }
2540
2541 /**
2542  * Make directory, and make all parent directories if they don't exist
2543  *
2544  * @param $dir String: full path to directory to create
2545  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2546  * @param $caller String: optional caller param for debugging.
2547  * @throws MWException
2548  * @return bool
2549  */
2550 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2551         global $wgDirectoryMode;
2552
2553         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2554                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2555         }
2556
2557         if ( !is_null( $caller ) ) {
2558                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2559         }
2560
2561         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2562                 return true;
2563         }
2564
2565         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2566
2567         if ( is_null( $mode ) ) {
2568                 $mode = $wgDirectoryMode;
2569         }
2570
2571         // Turn off the normal warning, we're doing our own below
2572         wfSuppressWarnings();
2573         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2574         wfRestoreWarnings();
2575
2576         if( !$ok ) {
2577                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2578                 trigger_error( sprintf( "%s: failed to mkdir \"%s\" mode 0%o", __FUNCTION__, $dir, $mode ),
2579                         E_USER_WARNING );
2580         }
2581         return $ok;
2582 }
2583
2584 /**
2585  * Remove a directory and all its content.
2586  * Does not hide error.
2587  */
2588 function wfRecursiveRemoveDir( $dir ) {
2589         wfDebug( __FUNCTION__ . "( $dir )\n" );
2590         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2591         if ( is_dir( $dir ) ) {
2592                 $objects = scandir( $dir );
2593                 foreach ( $objects as $object ) {
2594                         if ( $object != "." && $object != ".." ) {
2595                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2596                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2597                                 } else {
2598                                         unlink( $dir . '/' . $object );
2599                                 }
2600                         }
2601                 }
2602                 reset( $objects );
2603                 rmdir( $dir );
2604         }
2605 }
2606
2607 /**
2608  * @param $nr Mixed: the number to format
2609  * @param $acc Integer: the number of digits after the decimal point, default 2
2610  * @param $round Boolean: whether or not to round the value, default true
2611  * @return float
2612  */
2613 function wfPercent( $nr, $acc = 2, $round = true ) {
2614         $ret = sprintf( "%.${acc}f", $nr );
2615         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2616 }
2617
2618 /**
2619  * Find out whether or not a mixed variable exists in a string
2620  *
2621  * @param $needle String
2622  * @param $str String
2623  * @param $insensitive Boolean
2624  * @return Boolean
2625  */
2626 function in_string( $needle, $str, $insensitive = false ) {
2627         $func = 'strpos';
2628         if( $insensitive ) $func = 'stripos';
2629
2630         return $func( $str, $needle ) !== false;
2631 }
2632
2633 /**
2634  * Safety wrapper around ini_get() for boolean settings.
2635  * The values returned from ini_get() are pre-normalized for settings
2636  * set via php.ini or php_flag/php_admin_flag... but *not*
2637  * for those set via php_value/php_admin_value.
2638  *
2639  * It's fairly common for people to use php_value instead of php_flag,
2640  * which can leave you with an 'off' setting giving a false positive
2641  * for code that just takes the ini_get() return value as a boolean.
2642  *
2643  * To make things extra interesting, setting via php_value accepts
2644  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2645  * Unrecognized values go false... again opposite PHP's own coercion
2646  * from string to bool.
2647  *
2648  * Luckily, 'properly' set settings will always come back as '0' or '1',
2649  * so we only have to worry about them and the 'improper' settings.
2650  *
2651  * I frickin' hate PHP... :P
2652  *
2653  * @param $setting String
2654  * @return Bool
2655  */
2656 function wfIniGetBool( $setting ) {
2657         $val = ini_get( $setting );
2658         // 'on' and 'true' can't have whitespace around them, but '1' can.
2659         return strtolower( $val ) == 'on'
2660                 || strtolower( $val ) == 'true'
2661                 || strtolower( $val ) == 'yes'
2662                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2663 }
2664
2665 /**
2666  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2667  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2668  *
2669  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2670  *                          should be omitted
2671  * @param $fileName String Name of the library, if not $extension.suffix
2672  * @return Bool - Whether or not the extension is loaded
2673  */
2674 function wfDl( $extension, $fileName = null ) {
2675         if( extension_loaded( $extension ) ) {
2676                 return true;
2677         }
2678
2679         $canDl = false;
2680         $sapi = php_sapi_name();
2681         if( $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' ) {
2682                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2683                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2684         }
2685
2686         if( $canDl ) {
2687                 $fileName = $fileName ? $fileName : $extension;
2688                 if( wfIsWindows() ) {
2689                         $fileName = 'php_' . $fileName;
2690                 }
2691                 wfSuppressWarnings();
2692                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2693                 wfRestoreWarnings();
2694         }
2695         return extension_loaded( $extension );
2696 }
2697
2698 /**
2699  * Windows-compatible version of escapeshellarg()
2700  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2701  * function puts single quotes in regardless of OS.
2702  *
2703  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2704  * earlier distro releases of PHP)
2705  *
2706  * @param varargs
2707  * @return String
2708  */
2709 function wfEscapeShellArg( ) {
2710         wfInitShellLocale();
2711
2712         $args = func_get_args();
2713         $first = true;
2714         $retVal = '';
2715         foreach ( $args as $arg ) {
2716                 if ( !$first ) {
2717                         $retVal .= ' ';
2718                 } else {
2719                         $first = false;
2720                 }
2721
2722                 if ( wfIsWindows() ) {
2723                         // Escaping for an MSVC-style command line parser and CMD.EXE
2724                         // Refs:
2725                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2726                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2727                         //  * Bug #13518
2728                         //  * CR r63214
2729                         // Double the backslashes before any double quotes. Escape the double quotes.
2730                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2731                         $arg = '';
2732                         $iteration = 0;
2733                         foreach ( $tokens as $token ) {
2734                                 if ( $iteration % 2 == 1 ) {
2735                                         // Delimiter, a double quote preceded by zero or more slashes
2736                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2737                                 } elseif ( $iteration % 4 == 2 ) {
2738                                         // ^ in $token will be outside quotes, need to be escaped
2739                                         $arg .= str_replace( '^', '^^', $token );
2740                                 } else { // $iteration % 4 == 0
2741                                         // ^ in $token will appear inside double quotes, so leave as is
2742                                         $arg .= $token;
2743                                 }
2744                                 $iteration++;
2745                         }
2746                         // Double the backslashes before the end of the string, because
2747                         // we will soon add a quote
2748                         $m = array();
2749                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2750                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2751                         }
2752
2753                         // Add surrounding quotes
2754                         $retVal .= '"' . $arg . '"';
2755                 } else {
2756                         $retVal .= escapeshellarg( $arg );
2757                 }
2758         }
2759         return $retVal;
2760 }
2761
2762 /**
2763  * Execute a shell command, with time and memory limits mirrored from the PHP
2764  * configuration if supported.
2765  * @param $cmd String Command line, properly escaped for shell.
2766  * @param &$retval null|Mixed optional, will receive the program's exit code.
2767  *                 (non-zero is usually failure)
2768  * @param $environ Array optional environment variables which should be
2769  *                 added to the executed command environment.
2770  * @param $limits Array optional array with limits(filesize, memory, time)
2771  *                 this overwrites the global wgShellMax* limits.
2772  * @return string collected stdout as a string (trailing newlines stripped)
2773  */
2774 function wfShellExec( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2775         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2776
2777         static $disabled;
2778         if ( is_null( $disabled ) ) {
2779                 $disabled = false;
2780                 if( wfIniGetBool( 'safe_mode' ) ) {
2781                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2782                         $disabled = 'safemode';
2783                 } else {
2784                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2785                         $functions = array_map( 'trim', $functions );
2786                         $functions = array_map( 'strtolower', $functions );
2787                         if ( in_array( 'passthru', $functions ) ) {
2788                                 wfDebug( "passthru is in disabled_functions\n" );
2789                                 $disabled = 'passthru';
2790                         }
2791                 }
2792         }
2793         if ( $disabled ) {
2794                 $retval = 1;
2795                 return $disabled == 'safemode' ?
2796                         'Unable to run external programs in safe mode.' :
2797                         'Unable to run external programs, passthru() is disabled.';
2798         }
2799
2800         wfInitShellLocale();
2801
2802         $envcmd = '';
2803         foreach( $environ as $k => $v ) {
2804                 if ( wfIsWindows() ) {
2805                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2806                          * appear in the environment variable, so we must use carat escaping as documented in
2807                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2808                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2809                          * are listed there but doesn't appear to need it.
2810                          */
2811                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2812                 } else {
2813                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2814                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2815                          */
2816                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2817                 }
2818         }
2819         $cmd = $envcmd . $cmd;
2820
2821         if ( php_uname( 's' ) == 'Linux' ) {
2822                 $time = intval ( isset($limits['time']) ? $limits['time'] : $wgMaxShellTime );
2823                 $mem = intval ( isset($limits['memory']) ? $limits['memory'] : $wgMaxShellMemory );
2824                 $filesize = intval ( isset($limits['filesize']) ? $limits['filesize'] : $wgMaxShellFileSize );
2825
2826                 if ( $time > 0 && $mem > 0 ) {
2827                         $script = "$IP/bin/ulimit4.sh";
2828                         if ( is_executable( $script ) ) {
2829                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2830                         }
2831                 }
2832         }
2833         wfDebug( "wfShellExec: $cmd\n" );
2834
2835         $retval = 1; // error by default?
2836         ob_start();
2837         passthru( $cmd, $retval );
2838         $output = ob_get_contents();
2839         ob_end_clean();
2840
2841         if ( $retval == 127 ) {
2842                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2843         }
2844         return $output;
2845 }
2846
2847 /**
2848  * Workaround for http://bugs.php.net/bug.php?id=45132
2849  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2850  */
2851 function wfInitShellLocale() {
2852         static $done = false;
2853         if ( $done ) {
2854                 return;
2855         }
2856         $done = true;
2857         global $wgShellLocale;
2858         if ( !wfIniGetBool( 'safe_mode' ) ) {
2859                 putenv( "LC_CTYPE=$wgShellLocale" );
2860                 setlocale( LC_CTYPE, $wgShellLocale );
2861         }
2862 }
2863
2864 /**
2865  * Alias to wfShellWikiCmd()
2866  * @see wfShellWikiCmd()
2867  */
2868 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2869         return wfShellWikiCmd( $script, $parameters, $options );
2870 }
2871
2872 /**
2873  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2874  * Note that $parameters should be a flat array and an option with an argument
2875  * should consist of two consecutive items in the array (do not use "--option value").
2876  * @param $script string MediaWiki cli script path
2877  * @param $parameters Array Arguments and options to the script
2878  * @param $options Array Associative array of options:
2879  *              'php': The path to the php executable
2880  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2881  * @return Array
2882  */
2883 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2884         global $wgPhpCli;
2885         // Give site config file a chance to run the script in a wrapper.
2886         // The caller may likely want to call wfBasename() on $script.
2887         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2888         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2889         if ( isset( $options['wrapper'] ) ) {
2890                 $cmd[] = $options['wrapper'];
2891         }
2892         $cmd[] = $script;
2893         // Escape each parameter for shell
2894         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2895 }
2896
2897 /**
2898  * wfMerge attempts to merge differences between three texts.
2899  * Returns true for a clean merge and false for failure or a conflict.
2900  *
2901  * @param $old String
2902  * @param $mine String
2903  * @param $yours String
2904  * @param $result String
2905  * @return Bool
2906  */
2907 function wfMerge( $old, $mine, $yours, &$result ) {
2908         global $wgDiff3;
2909
2910         # This check may also protect against code injection in
2911         # case of broken installations.
2912         wfSuppressWarnings();
2913         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2914         wfRestoreWarnings();
2915
2916         if( !$haveDiff3 ) {
2917                 wfDebug( "diff3 not found\n" );
2918                 return false;
2919         }
2920
2921         # Make temporary files
2922         $td = wfTempDir();
2923         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2924         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2925         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2926
2927         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2928         #       a newline character. To avoid this, we normalize the trailing whitespace before
2929         #       creating the diff.
2930
2931         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2932         fclose( $oldtextFile );
2933         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2934         fclose( $mytextFile );
2935         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2936         fclose( $yourtextFile );
2937
2938         # Check for a conflict
2939         $cmd = $wgDiff3 . ' -a --overlap-only ' .
2940                 wfEscapeShellArg( $mytextName ) . ' ' .
2941                 wfEscapeShellArg( $oldtextName ) . ' ' .
2942                 wfEscapeShellArg( $yourtextName );
2943         $handle = popen( $cmd, 'r' );
2944
2945         if( fgets( $handle, 1024 ) ) {
2946                 $conflict = true;
2947         } else {
2948                 $conflict = false;
2949         }
2950         pclose( $handle );
2951
2952         # Merge differences
2953         $cmd = $wgDiff3 . ' -a -e --merge ' .
2954                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2955         $handle = popen( $cmd, 'r' );
2956         $result = '';
2957         do {
2958                 $data = fread( $handle, 8192 );
2959                 if ( strlen( $data ) == 0 ) {
2960                         break;
2961                 }
2962                 $result .= $data;
2963         } while ( true );
2964         pclose( $handle );
2965         unlink( $mytextName );
2966         unlink( $oldtextName );
2967         unlink( $yourtextName );
2968
2969         if ( $result === '' && $old !== '' && !$conflict ) {
2970                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2971                 $conflict = true;
2972         }
2973         return !$conflict;
2974 }
2975
2976 /**
2977  * Returns unified plain-text diff of two texts.
2978  * Useful for machine processing of diffs.
2979  *
2980  * @param $before String: the text before the changes.
2981  * @param $after String: the text after the changes.
2982  * @param $params String: command-line options for the diff command.
2983  * @return String: unified diff of $before and $after
2984  */
2985 function wfDiff( $before, $after, $params = '-u' ) {
2986         if ( $before == $after ) {
2987                 return '';
2988         }
2989
2990         global $wgDiff;
2991         wfSuppressWarnings();
2992         $haveDiff = $wgDiff && file_exists( $wgDiff );
2993         wfRestoreWarnings();
2994
2995         # This check may also protect against code injection in
2996         # case of broken installations.
2997         if( !$haveDiff ) {
2998                 wfDebug( "diff executable not found\n" );
2999                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3000                 $format = new UnifiedDiffFormatter();
3001                 return $format->format( $diffs );
3002         }
3003
3004         # Make temporary files
3005         $td = wfTempDir();
3006         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3007         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3008
3009         fwrite( $oldtextFile, $before );
3010         fclose( $oldtextFile );
3011         fwrite( $newtextFile, $after );
3012         fclose( $newtextFile );
3013
3014         // Get the diff of the two files
3015         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3016
3017         $h = popen( $cmd, 'r' );
3018
3019         $diff = '';
3020
3021         do {
3022                 $data = fread( $h, 8192 );
3023                 if ( strlen( $data ) == 0 ) {
3024                         break;
3025                 }
3026                 $diff .= $data;
3027         } while ( true );
3028
3029         // Clean up
3030         pclose( $h );
3031         unlink( $oldtextName );
3032         unlink( $newtextName );
3033
3034         // Kill the --- and +++ lines. They're not useful.
3035         $diff_lines = explode( "\n", $diff );
3036         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3037                 unset( $diff_lines[0] );
3038         }
3039         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3040                 unset( $diff_lines[1] );
3041         }
3042
3043         $diff = implode( "\n", $diff_lines );
3044
3045         return $diff;
3046 }
3047
3048 /**
3049  * This function works like "use VERSION" in Perl, the program will die with a
3050  * backtrace if the current version of PHP is less than the version provided
3051  *
3052  * This is useful for extensions which due to their nature are not kept in sync
3053  * with releases, and might depend on other versions of PHP than the main code
3054  *
3055  * Note: PHP might die due to parsing errors in some cases before it ever
3056  *       manages to call this function, such is life
3057  *
3058  * @see perldoc -f use
3059  *
3060  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3061  *                 a float
3062  * @throws MWException
3063  */
3064 function wfUsePHP( $req_ver ) {
3065         $php_ver = PHP_VERSION;
3066
3067         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3068                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3069         }
3070 }
3071
3072 /**
3073  * This function works like "use VERSION" in Perl except it checks the version
3074  * of MediaWiki, the program will die with a backtrace if the current version
3075  * of MediaWiki is less than the version provided.
3076  *
3077  * This is useful for extensions which due to their nature are not kept in sync
3078  * with releases
3079  *
3080  * @see perldoc -f use
3081  *
3082  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3083  *                 a float
3084  * @throws MWException
3085  */
3086 function wfUseMW( $req_ver ) {
3087         global $wgVersion;
3088
3089         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3090                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3091         }
3092 }
3093
3094 /**
3095  * Return the final portion of a pathname.
3096  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3097  * http://bugs.php.net/bug.php?id=33898
3098  *
3099  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3100  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3101  *
3102  * @param $path String
3103  * @param $suffix String: to remove if present
3104  * @return String
3105  */
3106 function wfBaseName( $path, $suffix = '' ) {
3107         $encSuffix = ( $suffix == '' )
3108                 ? ''
3109                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
3110         $matches = array();
3111         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3112                 return $matches[1];
3113         } else {
3114                 return '';
3115         }
3116 }
3117
3118 /**
3119  * Generate a relative path name to the given file.
3120  * May explode on non-matching case-insensitive paths,
3121  * funky symlinks, etc.
3122  *
3123  * @param $path String: absolute destination path including target filename
3124  * @param $from String: Absolute source path, directory only
3125  * @return String
3126  */
3127 function wfRelativePath( $path, $from ) {
3128         // Normalize mixed input on Windows...
3129         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3130         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3131
3132         // Trim trailing slashes -- fix for drive root
3133         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3134         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3135
3136         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3137         $against = explode( DIRECTORY_SEPARATOR, $from );
3138
3139         if( $pieces[0] !== $against[0] ) {
3140                 // Non-matching Windows drive letters?
3141                 // Return a full path.
3142                 return $path;
3143         }
3144
3145         // Trim off common prefix
3146         while( count( $pieces ) && count( $against )
3147                 && $pieces[0] == $against[0] ) {
3148                 array_shift( $pieces );
3149                 array_shift( $against );
3150         }
3151
3152         // relative dots to bump us to the parent
3153         while( count( $against ) ) {
3154                 array_unshift( $pieces, '..' );
3155                 array_shift( $against );
3156         }
3157
3158         array_push( $pieces, wfBaseName( $path ) );
3159
3160         return implode( DIRECTORY_SEPARATOR, $pieces );
3161 }
3162
3163 /**
3164  * Do any deferred updates and clear the list
3165  *
3166  * @deprecated since 1.19
3167  * @see DeferredUpdates::doUpdate()
3168  * @param $commit string
3169  */
3170 function wfDoUpdates( $commit = '' ) {
3171         wfDeprecated( __METHOD__, '1.19' );
3172         DeferredUpdates::doUpdates( $commit );
3173 }
3174
3175 /**
3176  * Convert an arbitrarily-long digit string from one numeric base
3177  * to another, optionally zero-padding to a minimum column width.
3178  *
3179  * Supports base 2 through 36; digit values 10-36 are represented
3180  * as lowercase letters a-z. Input is case-insensitive.
3181  *
3182  * @param $input String: of digits
3183  * @param $sourceBase Integer: 2-36
3184  * @param $destBase Integer: 2-36
3185  * @param $pad Integer: 1 or greater
3186  * @param $lowercase Boolean
3187  * @return String or false on invalid input
3188  */
3189 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3190         $input = strval( $input );
3191         if( $sourceBase < 2 ||
3192                 $sourceBase > 36 ||
3193                 $destBase < 2 ||
3194                 $destBase > 36 ||
3195                 $pad < 1 ||
3196                 $sourceBase != intval( $sourceBase ) ||
3197                 $destBase != intval( $destBase ) ||
3198                 $pad != intval( $pad ) ||
3199                 !is_string( $input ) ||
3200                 $input == '' ) {
3201                 return false;
3202         }
3203         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3204         $inDigits = array();
3205         $outChars = '';
3206
3207         // Decode and validate input string
3208         $input = strtolower( $input );
3209         for( $i = 0; $i < strlen( $input ); $i++ ) {
3210                 $n = strpos( $digitChars, $input[$i] );
3211                 if( $n === false || $n > $sourceBase ) {
3212                         return false;
3213                 }
3214                 $inDigits[] = $n;
3215         }
3216
3217         // Iterate over the input, modulo-ing out an output digit
3218         // at a time until input is gone.
3219         while( count( $inDigits ) ) {
3220                 $work = 0;
3221                 $workDigits = array();
3222
3223                 // Long division...
3224                 foreach( $inDigits as $digit ) {
3225                         $work *= $sourceBase;
3226                         $work += $digit;
3227
3228                         if( $work < $destBase ) {
3229                                 // Gonna need to pull another digit.
3230                                 if( count( $workDigits ) ) {
3231                                         // Avoid zero-padding; this lets us find
3232                                         // the end of the input very easily when
3233                                         // length drops to zero.
3234                                         $workDigits[] = 0;
3235                                 }
3236                         } else {
3237                                 // Finally! Actual division!
3238                                 $workDigits[] = intval( $work / $destBase );
3239
3240                                 // Isn't it annoying that most programming languages
3241                                 // don't have a single divide-and-remainder operator,
3242                                 // even though the CPU implements it that way?
3243                                 $work = $work % $destBase;
3244                         }
3245                 }
3246
3247                 // All that division leaves us with a remainder,
3248                 // which is conveniently our next output digit.
3249                 $outChars .= $digitChars[$work];
3250
3251                 // And we continue!
3252                 $inDigits = $workDigits;
3253         }
3254
3255         while( strlen( $outChars ) < $pad ) {
3256                 $outChars .= '0';
3257         }
3258
3259         return strrev( $outChars );
3260 }
3261
3262 /**
3263  * Create an object with a given name and an array of construct parameters
3264  *
3265  * @param $name String
3266  * @param $p Array: parameters
3267  * @return object
3268  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3269  */
3270 function wfCreateObject( $name, $p ) {
3271         wfDeprecated( __FUNCTION__, '1.18' );
3272         return MWFunction::newObj( $name, $p );
3273 }
3274
3275 /**
3276  * @return bool
3277  */
3278 function wfHttpOnlySafe() {
3279         global $wgHttpOnlyBlacklist;
3280
3281         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3282                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3283                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3284                                 return false;
3285                         }
3286                 }
3287         }
3288
3289         return true;
3290 }
3291
3292 /**
3293  * Check if there is sufficent entropy in php's built-in session generation
3294  * @return bool true = there is sufficient entropy
3295  */
3296 function wfCheckEntropy() {
3297         return (
3298                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3299                         || ini_get( 'session.entropy_file' )
3300                 )
3301                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3302 }
3303
3304 /**
3305  * Override session_id before session startup if php's built-in
3306  * session generation code is not secure.
3307  */
3308 function wfFixSessionID() {
3309         // If the cookie or session id is already set we already have a session and should abort
3310         if ( isset( $_COOKIE[ session_name() ] ) || session_id() ) {
3311                 return;
3312         }
3313
3314         // PHP's built-in session entropy is enabled if:
3315         // - entropy_file is set or you're on Windows with php 5.3.3+
3316         // - AND entropy_length is > 0
3317         // We treat it as disabled if it doesn't have an entropy length of at least 32
3318         $entropyEnabled = wfCheckEntropy();
3319
3320         // If built-in entropy is not enabled or not sufficient override php's built in session id generation code
3321         if ( !$entropyEnabled ) {
3322                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, overriding session id generation using our cryptrand source.\n" );
3323                 session_id( MWCryptRand::generateHex( 32 ) );
3324         }
3325 }
3326
3327 /**
3328  * Initialise php session
3329  *
3330  * @param $sessionId Bool
3331  */
3332 function wfSetupSession( $sessionId = false ) {
3333         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3334                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3335         if( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3336                 ObjectCacheSessionHandler::install();
3337         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3338                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3339                 # hasn't already been set to the desired value (that causes errors)
3340                 ini_set( 'session.save_handler', $wgSessionHandler );
3341         }
3342         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3343         wfDebugLog( 'cookie',
3344                 'session_set_cookie_params: "' . implode( '", "',
3345                         array(
3346                                 0,
3347                                 $wgCookiePath,
3348                                 $wgCookieDomain,
3349                                 $wgCookieSecure,
3350                                 $httpOnlySafe ) ) . '"' );
3351         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3352         session_cache_limiter( 'private, must-revalidate' );
3353         if ( $sessionId ) {
3354                 session_id( $sessionId );
3355         } else {
3356                 wfFixSessionID();
3357         }
3358         wfSuppressWarnings();
3359         session_start();
3360         wfRestoreWarnings();
3361 }
3362
3363 /**
3364  * Get an object from the precompiled serialized directory
3365  *
3366  * @param $name String
3367  * @return Mixed: the variable on success, false on failure
3368  */
3369 function wfGetPrecompiledData( $name ) {
3370         global $IP;
3371
3372         $file = "$IP/serialized/$name";
3373         if ( file_exists( $file ) ) {
3374                 $blob = file_get_contents( $file );
3375                 if ( $blob ) {
3376                         return unserialize( $blob );
3377                 }
3378         }
3379         return false;
3380 }
3381
3382 /**
3383  * Get a cache key
3384  *
3385  * @param varargs
3386  * @return String
3387  */
3388 function wfMemcKey( /*... */ ) {
3389         global $wgCachePrefix;
3390         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3391         $args = func_get_args();
3392         $key = $prefix . ':' . implode( ':', $args );
3393         $key = str_replace( ' ', '_', $key );
3394         return $key;
3395 }
3396
3397 /**
3398  * Get a cache key for a foreign DB
3399  *
3400  * @param $db String
3401  * @param $prefix String
3402  * @param varargs String
3403  * @return String
3404  */
3405 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3406         $args = array_slice( func_get_args(), 2 );
3407         if ( $prefix ) {
3408                 $key = "$db-$prefix:" . implode( ':', $args );
3409         } else {
3410                 $key = $db . ':' . implode( ':', $args );
3411         }
3412         return $key;
3413 }
3414
3415 /**
3416  * Get an ASCII string identifying this wiki
3417  * This is used as a prefix in memcached keys
3418  *
3419  * @return String
3420  */
3421 function wfWikiID() {
3422         global $wgDBprefix, $wgDBname;
3423         if ( $wgDBprefix ) {
3424                 return "$wgDBname-$wgDBprefix";
3425         } else {
3426                 return $wgDBname;
3427         }
3428 }
3429
3430 /**
3431  * Split a wiki ID into DB name and table prefix
3432  *
3433  * @param $wiki String
3434  *
3435  * @return array
3436  */
3437 function wfSplitWikiID( $wiki ) {
3438         $bits = explode( '-', $wiki, 2 );
3439         if ( count( $bits ) < 2 ) {
3440                 $bits[] = '';
3441         }
3442         return $bits;
3443 }
3444
3445 /**
3446  * Get a Database object.
3447  *
3448  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3449  *            master (for write queries), DB_SLAVE for potentially lagged read
3450  *            queries, or an integer >= 0 for a particular server.
3451  *
3452  * @param $groups Mixed: query groups. An array of group names that this query
3453  *                belongs to. May contain a single string if the query is only
3454  *                in one group.
3455  *
3456  * @param $wiki String: the wiki ID, or false for the current wiki
3457  *
3458  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3459  * will always return the same object, unless the underlying connection or load
3460  * balancer is manually destroyed.
3461  *
3462  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3463  * updater to ensure that a proper database is being updated.
3464  *
3465  * @return DatabaseBase
3466  */
3467 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3468         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3469 }
3470
3471 /**
3472  * Get a load balancer object.
3473  *
3474  * @param $wiki String: wiki ID, or false for the current wiki
3475  * @return LoadBalancer
3476  */
3477 function wfGetLB( $wiki = false ) {
3478         return wfGetLBFactory()->getMainLB( $wiki );
3479 }
3480
3481 /**
3482  * Get the load balancer factory object
3483  *
3484  * @return LBFactory
3485  */
3486 function &wfGetLBFactory() {
3487         return LBFactory::singleton();
3488 }
3489
3490 /**
3491  * Find a file.
3492  * Shortcut for RepoGroup::singleton()->findFile()
3493  *
3494  * @param $title String or Title object
3495  * @param $options array Associative array of options:
3496  *     time:           requested time for an archived image, or false for the
3497  *                     current version. An image object will be returned which was
3498  *                     created at the specified time.
3499  *
3500  *     ignoreRedirect: If true, do not follow file redirects
3501  *
3502  *     private:        If true, return restricted (deleted) files if the current
3503  *                     user is allowed to view them. Otherwise, such files will not
3504  *                     be found.
3505  *
3506  *     bypassCache:    If true, do not use the process-local cache of File objects
3507  *
3508  * @return File, or false if the file does not exist
3509  */
3510 function wfFindFile( $title, $options = array() ) {
3511         return RepoGroup::singleton()->findFile( $title, $options );
3512 }
3513
3514 /**
3515  * Get an object referring to a locally registered file.
3516  * Returns a valid placeholder object if the file does not exist.
3517  *
3518  * @param $title Title|String
3519  * @return LocalFile|null A File, or null if passed an invalid Title
3520  */
3521 function wfLocalFile( $title ) {
3522         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3523 }
3524
3525 /**
3526  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3527  * @deprecated since 1.19
3528  */
3529 function wfStreamFile( $fname, $headers = array() ) {
3530         wfDeprecated( __FUNCTION__, '1.19' );
3531         StreamFile::stream( $fname, $headers );
3532 }
3533
3534 /**
3535  * Should low-performance queries be disabled?
3536  *
3537  * @return Boolean
3538  * @codeCoverageIgnore
3539  */
3540 function wfQueriesMustScale() {
3541         global $wgMiserMode;
3542         return $wgMiserMode
3543                 || ( SiteStats::pages() > 100000
3544                 && SiteStats::edits() > 1000000
3545                 && SiteStats::users() > 10000 );
3546 }
3547
3548 /**
3549  * Get the path to a specified script file, respecting file
3550  * extensions; this is a wrapper around $wgScriptExtension etc.
3551  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3552  *
3553  * @param $script String: script filename, sans extension
3554  * @return String
3555  */
3556 function wfScript( $script = 'index' ) {
3557         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3558         if ( $script === 'index' ) {
3559                 return $wgScript;
3560         } else if ( $script === 'load' ) {
3561                 return $wgLoadScript;
3562         } else {
3563                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3564         }
3565 }
3566
3567 /**
3568  * Get the script URL.
3569  *
3570  * @return string script URL
3571  */
3572 function wfGetScriptUrl() {
3573         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3574                 #
3575                 # as it was called, minus the query string.
3576                 #
3577                 # Some sites use Apache rewrite rules to handle subdomains,
3578                 # and have PHP set up in a weird way that causes PHP_SELF
3579                 # to contain the rewritten URL instead of the one that the
3580                 # outside world sees.
3581                 #
3582                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3583                 # provides containing the "before" URL.
3584                 return $_SERVER['SCRIPT_NAME'];
3585         } else {
3586                 return $_SERVER['URL'];
3587         }
3588 }
3589
3590 /**
3591  * Convenience function converts boolean values into "true"
3592  * or "false" (string) values
3593  *
3594  * @param $value Boolean
3595  * @return String
3596  */
3597 function wfBoolToStr( $value ) {
3598         return $value ? 'true' : 'false';
3599 }
3600
3601 /**
3602  * Get a platform-independent path to the null file, e.g. /dev/null
3603  *
3604  * @return string
3605  */
3606 function wfGetNull() {
3607         return wfIsWindows()
3608                 ? 'NUL'
3609                 : '/dev/null';
3610 }
3611
3612 /**
3613  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3614  * and waiting for it to go down, this waits for the slaves to catch up to the
3615  * master position. Use this when updating very large numbers of rows, as
3616  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3617  * a no-op if there are no slaves.
3618  *
3619  * @param $maxLag Integer (deprecated)
3620  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3621  */
3622 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3623         $lb = wfGetLB( $wiki );
3624         // bug 27975 - Don't try to wait for slaves if there are none
3625         // Prevents permission error when getting master position
3626         if ( $lb->getServerCount() > 1 ) {
3627                 $dbw = $lb->getConnection( DB_MASTER );
3628                 $pos = $dbw->getMasterPos();
3629                 $lb->waitForAll( $pos );
3630         }
3631 }
3632
3633 /**
3634  * Used to be used for outputting text in the installer/updater
3635  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3636  */
3637 function wfOut( $s ) {
3638         wfDeprecated( __FUNCTION__, '1.18' );
3639         global $wgCommandLineMode;
3640         if ( $wgCommandLineMode ) {
3641                 echo $s;
3642         } else {
3643                 echo htmlspecialchars( $s );
3644         }
3645         flush();
3646 }
3647
3648 /**
3649  * Count down from $n to zero on the terminal, with a one-second pause
3650  * between showing each number. For use in command-line scripts.
3651  * @codeCoverageIgnore
3652  * @param $n int
3653  */
3654 function wfCountDown( $n ) {
3655         for ( $i = $n; $i >= 0; $i-- ) {
3656                 if ( $i != $n ) {
3657                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3658                 }
3659                 echo $i;
3660                 flush();
3661                 if ( $i ) {
3662                         sleep( 1 );
3663                 }
3664         }
3665         echo "\n";
3666 }
3667
3668 /**
3669  * Generate a random 32-character hexadecimal token.
3670  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3671  *              characters before hashing.
3672  * @return string
3673  * @codeCoverageIgnore
3674  * @deprecated since 1.20; Please use MWCryptRand for security purposes and wfRandomString for pesudo-random strings
3675  * @warning This method is NOT secure. Additionally it has many callers that use it for pesudo-random purposes.
3676  */
3677 function wfGenerateToken( $salt = '' ) {
3678         wfDeprecated( __METHOD__, '1.20' );
3679         $salt = serialize( $salt );
3680         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3681 }
3682
3683 /**
3684  * Replace all invalid characters with -
3685  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3686  * By default, $wgIllegalFileChars = ':'
3687  *
3688  * @param $name Mixed: filename to process
3689  * @return String
3690  */
3691 function wfStripIllegalFilenameChars( $name ) {
3692         global $wgIllegalFileChars;
3693         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3694         $name = wfBaseName( $name );
3695         $name = preg_replace(
3696                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3697                 '-',
3698                 $name
3699         );
3700         return $name;
3701 }
3702
3703 /**
3704  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3705  *
3706  * @return Integer value memory was set to.
3707  */
3708 function wfMemoryLimit() {
3709         global $wgMemoryLimit;
3710         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3711         if( $memlimit != -1 ) {
3712                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3713                 if( $conflimit == -1 ) {
3714                         wfDebug( "Removing PHP's memory limit\n" );
3715                         wfSuppressWarnings();
3716                         ini_set( 'memory_limit', $conflimit );
3717                         wfRestoreWarnings();
3718                         return $conflimit;
3719                 } elseif ( $conflimit > $memlimit ) {
3720                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3721                         wfSuppressWarnings();
3722                         ini_set( 'memory_limit', $conflimit );
3723                         wfRestoreWarnings();
3724                         return $conflimit;
3725                 }
3726         }
3727         return $memlimit;
3728 }
3729
3730 /**
3731  * Converts shorthand byte notation to integer form
3732  *
3733  * @param $string String
3734  * @return Integer
3735  */
3736 function wfShorthandToInteger( $string = '' ) {
3737         $string = trim( $string );
3738         if( $string === '' ) {
3739                 return -1;
3740         }
3741         $last = $string[strlen( $string ) - 1];
3742         $val = intval( $string );
3743         switch( $last ) {
3744                 case 'g':
3745                 case 'G':
3746                         $val *= 1024;
3747                         // break intentionally missing
3748                 case 'm':
3749                 case 'M':
3750                         $val *= 1024;
3751                         // break intentionally missing
3752                 case 'k':
3753                 case 'K':
3754                         $val *= 1024;
3755         }
3756
3757         return $val;
3758 }
3759
3760 /**
3761  * Get the normalised IETF language tag
3762  * See unit test for examples.
3763  *
3764  * @param $code String: The language code.
3765  * @return String: The language code which complying with BCP 47 standards.
3766  */
3767 function wfBCP47( $code ) {
3768         $codeSegment = explode( '-', $code );
3769         $codeBCP = array();
3770         foreach ( $codeSegment as $segNo => $seg ) {
3771                 if ( count( $codeSegment ) > 0 ) {
3772                         // when previous segment is x, it is a private segment and should be lc
3773                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3774                                 $codeBCP[$segNo] = strtolower( $seg );
3775                         // ISO 3166 country code
3776                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3777                                 $codeBCP[$segNo] = strtoupper( $seg );
3778                         // ISO 15924 script code
3779                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3780                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3781                         // Use lowercase for other cases
3782                         } else {
3783                                 $codeBCP[$segNo] = strtolower( $seg );
3784                         }
3785                 } else {
3786                 // Use lowercase for single segment
3787                         $codeBCP[$segNo] = strtolower( $seg );
3788                 }
3789         }
3790         $langCode = implode( '-', $codeBCP );
3791         return $langCode;
3792 }
3793
3794 /**
3795  * Get a cache object.
3796  *
3797  * @param $inputType integer Cache type, one the the CACHE_* constants.
3798  * @return BagOStuff
3799  */
3800 function wfGetCache( $inputType ) {
3801         return ObjectCache::getInstance( $inputType );
3802 }
3803
3804 /**
3805  * Get the main cache object
3806  *
3807  * @return BagOStuff
3808  */
3809 function wfGetMainCache() {
3810         global $wgMainCacheType;
3811         return ObjectCache::getInstance( $wgMainCacheType );
3812 }
3813
3814 /**
3815  * Get the cache object used by the message cache
3816  *
3817  * @return BagOStuff
3818  */
3819 function wfGetMessageCacheStorage() {
3820         global $wgMessageCacheType;
3821         return ObjectCache::getInstance( $wgMessageCacheType );
3822 }
3823
3824 /**
3825  * Get the cache object used by the parser cache
3826  *
3827  * @return BagOStuff
3828  */
3829 function wfGetParserCacheStorage() {
3830         global $wgParserCacheType;
3831         return ObjectCache::getInstance( $wgParserCacheType );
3832 }
3833
3834 /**
3835  * Get the cache object used by the language converter
3836  *
3837  * @return BagOStuff
3838  */
3839 function wfGetLangConverterCacheStorage() {
3840         global $wgLanguageConverterCacheType;
3841         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3842 }
3843
3844 /**
3845  * Call hook functions defined in $wgHooks
3846  *
3847  * @param $event String: event name
3848  * @param $args Array: parameters passed to hook functions
3849  * @return Boolean True if no handler aborted the hook
3850  */
3851 function wfRunHooks( $event, $args = array() ) {
3852         return Hooks::run( $event, $args );
3853 }
3854
3855 /**
3856  * Wrapper around php's unpack.
3857  *
3858  * @param $format String: The format string (See php's docs)
3859  * @param $data: A binary string of binary data
3860  * @param $length integer or false: The minimun length of $data. This is to
3861  *      prevent reading beyond the end of $data. false to disable the check.
3862  *
3863  * Also be careful when using this function to read unsigned 32 bit integer
3864  * because php might make it negative.
3865  *
3866  * @throws MWException if $data not long enough, or if unpack fails
3867  * @return array Associative array of the extracted data
3868  */
3869 function wfUnpack( $format, $data, $length=false ) {
3870         if ( $length !== false ) {
3871                 $realLen = strlen( $data );
3872                 if ( $realLen < $length ) {
3873                         throw new MWException( "Tried to use wfUnpack on a "
3874                                 . "string of length $realLen, but needed one "
3875                                 . "of at least length $length."
3876                         );
3877                 }
3878         }
3879
3880         wfSuppressWarnings();
3881         $result = unpack( $format, $data );
3882         wfRestoreWarnings();
3883
3884         if ( $result === false ) {
3885                 // If it cannot extract the packed data.
3886                 throw new MWException( "unpack could not unpack binary data" );
3887         }
3888         return $result;
3889 }
3890
3891 /**
3892  * Determine if an image exists on the 'bad image list'.
3893  *
3894  * The format of MediaWiki:Bad_image_list is as follows:
3895  *    * Only list items (lines starting with "*") are considered
3896  *    * The first link on a line must be a link to a bad image
3897  *    * Any subsequent links on the same line are considered to be exceptions,
3898  *      i.e. articles where the image may occur inline.
3899  *
3900  * @param $name string the image name to check
3901  * @param $contextTitle Title|bool the page on which the image occurs, if known
3902  * @param $blacklist string wikitext of a file blacklist
3903  * @return bool
3904  */
3905 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3906         static $badImageCache = null; // based on bad_image_list msg
3907         wfProfileIn( __METHOD__ );
3908
3909         # Handle redirects
3910         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3911         if( $redirectTitle ) {
3912                 $name = $redirectTitle->getDbKey();
3913         }
3914
3915         # Run the extension hook
3916         $bad = false;
3917         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3918                 wfProfileOut( __METHOD__ );
3919                 return $bad;
3920         }
3921
3922         $cacheable = ( $blacklist === null );
3923         if( $cacheable && $badImageCache !== null ) {
3924                 $badImages = $badImageCache;
3925         } else { // cache miss
3926                 if ( $blacklist === null ) {
3927                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
3928                 }
3929                 # Build the list now
3930                 $badImages = array();
3931                 $lines = explode( "\n", $blacklist );
3932                 foreach( $lines as $line ) {
3933                         # List items only
3934                         if ( substr( $line, 0, 1 ) !== '*' ) {
3935                                 continue;
3936                         }
3937
3938                         # Find all links
3939                         $m = array();
3940                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
3941                                 continue;
3942                         }
3943
3944                         $exceptions = array();
3945                         $imageDBkey = false;
3946                         foreach ( $m[1] as $i => $titleText ) {
3947                                 $title = Title::newFromText( $titleText );
3948                                 if ( !is_null( $title ) ) {
3949                                         if ( $i == 0 ) {
3950                                                 $imageDBkey = $title->getDBkey();
3951                                         } else {
3952                                                 $exceptions[$title->getPrefixedDBkey()] = true;
3953                                         }
3954                                 }
3955                         }
3956
3957                         if ( $imageDBkey !== false ) {
3958                                 $badImages[$imageDBkey] = $exceptions;
3959                         }
3960                 }
3961                 if ( $cacheable ) {
3962                         $badImageCache = $badImages;
3963                 }
3964         }
3965
3966         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
3967         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
3968         wfProfileOut( __METHOD__ );
3969         return $bad;
3970 }