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 if ( !function_exists( 'mb_strrpos' ) ) {
  87         /**
  88          * @codeCoverageIgnore
  89          * @return int
  90          */
  91         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  92                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  93         }
  94 }
  95
  96 // gzdecode function only exists in PHP >= 5.4.0
  97 // http://php.net/gzdecode
  98 if ( !function_exists( 'gzdecode' ) ) {
  99         /**
 100          * @codeCoverageIgnore
 101          * @return string
 102          */
 103         function gzdecode( $data ) {
 104                 return gzinflate( substr( $data, 10, -8 ) );
 105         }
 106 }
 107 /// @endcond
 108
 109 /**
 110  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 111  * @param $a array
 112  * @param $b array
 113  * @return array
 114  */
 115 function wfArrayDiff2( $a, $b ) {
 116         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 117 }
 118
 119 /**
 120  * @param $a array|string
 121  * @param $b array|string
 122  * @return int
 123  */
 124 function wfArrayDiff2_cmp( $a, $b ) {
 125         if ( is_string( $a ) && is_string( $b ) ) {
 126                 return strcmp( $a, $b );
 127         } elseif ( count( $a ) !== count( $b ) ) {
 128                 return count( $a ) < count( $b ) ? -1 : 1;
 129         } else {
 130                 reset( $a );
 131                 reset( $b );
 132                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 133                         $cmp = strcmp( $valueA, $valueB );
 134                         if ( $cmp !== 0 ) {
 135                                 return $cmp;
 136                         }
 137                 }
 138                 return 0;
 139         }
 140 }
 141
 142 /**
 143  * Array lookup
 144  * Returns an array where the values in array $b are replaced by the
 145  * values in array $a with the corresponding keys
 146  *
 147  * @deprecated since 1.22; use array_intersect_key()
 148  * @param $a Array
 149  * @param $b Array
 150  * @return array
 151  */
 152 function wfArrayLookup( $a, $b ) {
 153         wfDeprecated( __FUNCTION__, '1.22' );
 154         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 155 }
 156
 157 /**
 158  * Appends to second array if $value differs from that in $default
 159  *
 160  * @param $key String|Int
 161  * @param $value Mixed
 162  * @param $default Mixed
 163  * @param array $changed to alter
 164  * @throws MWException
 165  */
 166 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 167         if ( is_null( $changed ) ) {
 168                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 169         }
 170         if ( $default[$key] !== $value ) {
 171                 $changed[$key] = $value;
 172         }
 173 }
 174
 175 /**
 176  * Backwards array plus for people who haven't bothered to read the PHP manual
 177  * XXX: will not darn your socks for you.
 178  *
 179  * @deprecated since 1.22; use array_replace()
 180  * @param $array1 Array
 181  * @param [$array2, [...]] Arrays
 182  * @return Array
 183  */
 184 function wfArrayMerge( $array1/* ... */ ) {
 185         wfDeprecated( __FUNCTION__, '1.22' );
 186         $args = func_get_args();
 187         $args = array_reverse( $args, true );
 188         $out = array();
 189         foreach ( $args as $arg ) {
 190                 $out += $arg;
 191         }
 192         return $out;
 193 }
 194
 195 /**
 196  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 197  * e.g.
 198  *      wfMergeErrorArrays(
 199  *              array( array( 'x' ) ),
 200  *              array( array( 'x', '2' ) ),
 201  *              array( array( 'x' ) ),
 202  *              array( array( 'y' ) )
 203  *      );
 204  * returns:
 205  *              array(
 206  *              array( 'x', '2' ),
 207  *              array( 'x' ),
 208  *              array( 'y' )
 209  *      )
 210  * @param varargs
 211  * @return Array
 212  */
 213 function wfMergeErrorArrays( /*...*/ ) {
 214         $args = func_get_args();
 215         $out = array();
 216         foreach ( $args as $errors ) {
 217                 foreach ( $errors as $params ) {
 218                         # @todo FIXME: Sometimes get nested arrays for $params,
 219                         # which leads to E_NOTICEs
 220                         $spec = implode( "\t", $params );
 221                         $out[$spec] = $params;
 222                 }
 223         }
 224         return array_values( $out );
 225 }
 226
 227 /**
 228  * Insert array into another array after the specified *KEY*
 229  *
 230  * @param array $array The array.
 231  * @param array $insert The array to insert.
 232  * @param $after Mixed: The key to insert after
 233  * @return Array
 234  */
 235 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 236         // Find the offset of the element to insert after.
 237         $keys = array_keys( $array );
 238         $offsetByKey = array_flip( $keys );
 239
 240         $offset = $offsetByKey[$after];
 241
 242         // Insert at the specified offset
 243         $before = array_slice( $array, 0, $offset + 1, true );
 244         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 245
 246         $output = $before + $insert + $after;
 247
 248         return $output;
 249 }
 250
 251 /**
 252  * Recursively converts the parameter (an object) to an array with the same data
 253  *
 254  * @param $objOrArray Object|Array
 255  * @param $recursive Bool
 256  * @return Array
 257  */
 258 function wfObjectToArray( $objOrArray, $recursive = true ) {
 259         $array = array();
 260         if ( is_object( $objOrArray ) ) {
 261                 $objOrArray = get_object_vars( $objOrArray );
 262         }
 263         foreach ( $objOrArray as $key => $value ) {
 264                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 265                         $value = wfObjectToArray( $value );
 266                 }
 267
 268                 $array[$key] = $value;
 269         }
 270
 271         return $array;
 272 }
 273
 274 /**
 275  * Get a random decimal value between 0 and 1, in a way
 276  * not likely to give duplicate values for any realistic
 277  * number of articles.
 278  *
 279  * @return string
 280  */
 281 function wfRandom() {
 282         # The maximum random value is "only" 2^31-1, so get two random
 283         # values to reduce the chance of dupes
 284         $max = mt_getrandmax() + 1;
 285         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 286
 287         return $rand;
 288 }
 289
 290 /**
 291  * Get a random string containing a number of pseudo-random hex
 292  * characters.
 293  * @note This is not secure, if you are trying to generate some sort
 294  *       of token please use MWCryptRand instead.
 295  *
 296  * @param int $length The length of the string to generate
 297  * @return String
 298  * @since 1.20
 299  */
 300 function wfRandomString( $length = 32 ) {
 301         $str = '';
 302         for ( $n = 0; $n < $length; $n += 7 ) {
 303                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 304         }
 305         return substr( $str, 0, $length );
 306 }
 307
 308 /**
 309  * We want some things to be included as literal characters in our title URLs
 310  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 311  * all of the following should be safe:
 312  *
 313  * ;:@&=$-_.+!*'(),
 314  *
 315  * But + is not safe because it's used to indicate a space; &= are only safe in
 316  * paths and not in queries (and we don't distinguish here); ' seems kind of
 317  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 318  * is reserved, we don't care.  So the list we unescape is:
 319  *
 320  * ;:@$!*(),/
 321  *
 322  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 323  * so no fancy : for IIS7.
 324  *
 325  * %2F in the page titles seems to fatally break for some reason.
 326  *
 327  * @param $s String:
 328  * @return string
 329  */
 330 function wfUrlencode( $s ) {
 331         static $needle;
 332
 333         if ( is_null( $s ) ) {
 334                 $needle = null;
 335                 return '';
 336         }
 337
 338         if ( is_null( $needle ) ) {
 339                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 340                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 341                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 342                 ) {
 343                         $needle[] = '%3A';
 344                 }
 345         }
 346
 347         $s = urlencode( $s );
 348         $s = str_ireplace(
 349                 $needle,
 350                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 351                 $s
 352         );
 353
 354         return $s;
 355 }
 356
 357 /**
 358  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 359  * "days=7&limit=100". Options in the first array override options in the second.
 360  * Options set to null or false will not be output.
 361  *
 362  * @param array $array1 ( String|Array )
 363  * @param array $array2 ( String|Array )
 364  * @param $prefix String
 365  * @return String
 366  */
 367 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 368         if ( !is_null( $array2 ) ) {
 369                 $array1 = $array1 + $array2;
 370         }
 371
 372         $cgi = '';
 373         foreach ( $array1 as $key => $value ) {
 374                 if ( !is_null( $value ) && $value !== false ) {
 375                         if ( $cgi != '' ) {
 376                                 $cgi .= '&';
 377                         }
 378                         if ( $prefix !== '' ) {
 379                                 $key = $prefix . "[$key]";
 380                         }
 381                         if ( is_array( $value ) ) {
 382                                 $firstTime = true;
 383                                 foreach ( $value as $k => $v ) {
 384                                         $cgi .= $firstTime ? '' : '&';
 385                                         if ( is_array( $v ) ) {
 386                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 387                                         } else {
 388                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 389                                         }
 390                                         $firstTime = false;
 391                                 }
 392                         } else {
 393                                 if ( is_object( $value ) ) {
 394                                         $value = $value->__toString();
 395                                 }
 396                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 397                         }
 398                 }
 399         }
 400         return $cgi;
 401 }
 402
 403 /**
 404  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 405  * its argument and returns the same string in array form.  This allows compatibility
 406  * with legacy functions that accept raw query strings instead of nice
 407  * arrays.  Of course, keys and values are urldecode()d.
 408  *
 409  * @param string $query query string
 410  * @return array Array version of input
 411  */
 412 function wfCgiToArray( $query ) {
 413         if ( isset( $query[0] ) && $query[0] == '?' ) {
 414                 $query = substr( $query, 1 );
 415         }
 416         $bits = explode( '&', $query );
 417         $ret = array();
 418         foreach ( $bits as $bit ) {
 419                 if ( $bit === '' ) {
 420                         continue;
 421                 }
 422                 if ( strpos( $bit, '=' ) === false ) {
 423                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 424                         $key = $bit;
 425                         $value = '';
 426                 } else {
 427                         list( $key, $value ) = explode( '=', $bit );
 428                 }
 429                 $key = urldecode( $key );
 430                 $value = urldecode( $value );
 431                 if ( strpos( $key, '[' ) !== false ) {
 432                         $keys = array_reverse( explode( '[', $key ) );
 433                         $key = array_pop( $keys );
 434                         $temp = $value;
 435                         foreach ( $keys as $k ) {
 436                                 $k = substr( $k, 0, -1 );
 437                                 $temp = array( $k => $temp );
 438                         }
 439                         if ( isset( $ret[$key] ) ) {
 440                                 $ret[$key] = array_merge( $ret[$key], $temp );
 441                         } else {
 442                                 $ret[$key] = $temp;
 443                         }
 444                 } else {
 445                         $ret[$key] = $value;
 446                 }
 447         }
 448         return $ret;
 449 }
 450
 451 /**
 452  * Append a query string to an existing URL, which may or may not already
 453  * have query string parameters already. If so, they will be combined.
 454  *
 455  * @param $url String
 456  * @param $query Mixed: string or associative array
 457  * @return string
 458  */
 459 function wfAppendQuery( $url, $query ) {
 460         if ( is_array( $query ) ) {
 461                 $query = wfArrayToCgi( $query );
 462         }
 463         if ( $query != '' ) {
 464                 if ( false === strpos( $url, '?' ) ) {
 465                         $url .= '?';
 466                 } else {
 467                         $url .= '&';
 468                 }
 469                 $url .= $query;
 470         }
 471         return $url;
 472 }
 473
 474 /**
 475  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 476  * is correct.
 477  *
 478  * The meaning of the PROTO_* constants is as follows:
 479  * PROTO_HTTP: Output a URL starting with http://
 480  * PROTO_HTTPS: Output a URL starting with https://
 481  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 482  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 483  *    on which protocol was used for the current incoming request
 484  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 485  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 486  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 487  *
 488  * @todo this won't work with current-path-relative URLs
 489  * like "subdir/foo.html", etc.
 490  *
 491  * @param string $url either fully-qualified or a local path + query
 492  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 493  *    protocol to use if $url or $wgServer is protocol-relative
 494  * @return string Fully-qualified URL, current-path-relative URL or false if
 495  *    no valid URL can be constructed
 496  */
 497 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 498         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 499         $serverUrl = $wgServer;
 500         if ( $defaultProto === PROTO_CANONICAL ) {
 501                 $serverUrl = $wgCanonicalServer;
 502         }
 503         // Make $wgInternalServer fall back to $wgServer if not set
 504         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 505                 $serverUrl = $wgInternalServer;
 506         }
 507         if ( $defaultProto === PROTO_CURRENT ) {
 508                 $defaultProto = WebRequest::detectProtocol() . '://';
 509         }
 510
 511         // Analyze $serverUrl to obtain its protocol
 512         $bits = wfParseUrl( $serverUrl );
 513         $serverHasProto = $bits && $bits['scheme'] != '';
 514
 515         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 516                 if ( $serverHasProto ) {
 517                         $defaultProto = $bits['scheme'] . '://';
 518                 } else {
 519                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 520                         // This really isn't supposed to happen. Fall back to HTTP in this
 521                         // ridiculous case.
 522                         $defaultProto = PROTO_HTTP;
 523                 }
 524         }
 525
 526         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 527
 528         if ( substr( $url, 0, 2 ) == '//' ) {
 529                 $url = $defaultProtoWithoutSlashes . $url;
 530         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 531                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 532                 // otherwise leave it alone.
 533                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 534         }
 535
 536         $bits = wfParseUrl( $url );
 537         if ( $bits && isset( $bits['path'] ) ) {
 538                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 539                 return wfAssembleUrl( $bits );
 540         } elseif ( $bits ) {
 541                 # No path to expand
 542                 return $url;
 543         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 544                 # URL is a relative path
 545                 return wfRemoveDotSegments( $url );
 546         }
 547
 548         # Expanded URL is not valid.
 549         return false;
 550 }
 551
 552 /**
 553  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 554  * if you need to edit part of a URL and put it back together.
 555  *
 556  * This is the basic structure used (brackets contain keys for $urlParts):
 557  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 558  *
 559  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 560  *
 561  * @since 1.19
 562  * @param array $urlParts URL parts, as output from wfParseUrl
 563  * @return string URL assembled from its component parts
 564  */
 565 function wfAssembleUrl( $urlParts ) {
 566         $result = '';
 567
 568         if ( isset( $urlParts['delimiter'] ) ) {
 569                 if ( isset( $urlParts['scheme'] ) ) {
 570                         $result .= $urlParts['scheme'];
 571                 }
 572
 573                 $result .= $urlParts['delimiter'];
 574         }
 575
 576         if ( isset( $urlParts['host'] ) ) {
 577                 if ( isset( $urlParts['user'] ) ) {
 578                         $result .= $urlParts['user'];
 579                         if ( isset( $urlParts['pass'] ) ) {
 580                                 $result .= ':' . $urlParts['pass'];
 581                         }
 582                         $result .= '@';
 583                 }
 584
 585                 $result .= $urlParts['host'];
 586
 587                 if ( isset( $urlParts['port'] ) ) {
 588                         $result .= ':' . $urlParts['port'];
 589                 }
 590         }
 591
 592         if ( isset( $urlParts['path'] ) ) {
 593                 $result .= $urlParts['path'];
 594         }
 595
 596         if ( isset( $urlParts['query'] ) ) {
 597                 $result .= '?' . $urlParts['query'];
 598         }
 599
 600         if ( isset( $urlParts['fragment'] ) ) {
 601                 $result .= '#' . $urlParts['fragment'];
 602         }
 603
 604         return $result;
 605 }
 606
 607 /**
 608  * Remove all dot-segments in the provided URL path.  For example,
 609  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 610  * RFC3986 section 5.2.4.
 611  *
 612  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 613  *
 614  * @param string $urlPath URL path, potentially containing dot-segments
 615  * @return string URL path with all dot-segments removed
 616  */
 617 function wfRemoveDotSegments( $urlPath ) {
 618         $output = '';
 619         $inputOffset = 0;
 620         $inputLength = strlen( $urlPath );
 621
 622         while ( $inputOffset < $inputLength ) {
 623                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 624                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 625                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 626                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 627                 $trimOutput = false;
 628
 629                 if ( $prefixLengthTwo == './' ) {
 630                         # Step A, remove leading "./"
 631                         $inputOffset += 2;
 632                 } elseif ( $prefixLengthThree == '../' ) {
 633                         # Step A, remove leading "../"
 634                         $inputOffset += 3;
 635                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 636                         # Step B, replace leading "/.$" with "/"
 637                         $inputOffset += 1;
 638                         $urlPath[$inputOffset] = '/';
 639                 } elseif ( $prefixLengthThree == '/./' ) {
 640                         # Step B, replace leading "/./" with "/"
 641                         $inputOffset += 2;
 642                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 643                         # Step C, replace leading "/..$" with "/" and
 644                         # remove last path component in output
 645                         $inputOffset += 2;
 646                         $urlPath[$inputOffset] = '/';
 647                         $trimOutput = true;
 648                 } elseif ( $prefixLengthFour == '/../' ) {
 649                         # Step C, replace leading "/../" with "/" and
 650                         # remove last path component in output
 651                         $inputOffset += 3;
 652                         $trimOutput = true;
 653                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 654                         # Step D, remove "^.$"
 655                         $inputOffset += 1;
 656                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 657                         # Step D, remove "^..$"
 658                         $inputOffset += 2;
 659                 } else {
 660                         # Step E, move leading path segment to output
 661                         if ( $prefixLengthOne == '/' ) {
 662                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 663                         } else {
 664                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 665                         }
 666                         if ( $slashPos === false ) {
 667                                 $output .= substr( $urlPath, $inputOffset );
 668                                 $inputOffset = $inputLength;
 669                         } else {
 670                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 671                                 $inputOffset += $slashPos - $inputOffset;
 672                         }
 673                 }
 674
 675                 if ( $trimOutput ) {
 676                         $slashPos = strrpos( $output, '/' );
 677                         if ( $slashPos === false ) {
 678                                 $output = '';
 679                         } else {
 680                                 $output = substr( $output, 0, $slashPos );
 681                         }
 682                 }
 683         }
 684
 685         return $output;
 686 }
 687
 688 /**
 689  * Returns a regular expression of url protocols
 690  *
 691  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 692  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 693  * @return String
 694  */
 695 function wfUrlProtocols( $includeProtocolRelative = true ) {
 696         global $wgUrlProtocols;
 697
 698         // Cache return values separately based on $includeProtocolRelative
 699         static $withProtRel = null, $withoutProtRel = null;
 700         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 701         if ( !is_null( $cachedValue ) ) {
 702                 return $cachedValue;
 703         }
 704
 705         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 706         // with LocalSettings files from 1.5
 707         if ( is_array( $wgUrlProtocols ) ) {
 708                 $protocols = array();
 709                 foreach ( $wgUrlProtocols as $protocol ) {
 710                         // Filter out '//' if !$includeProtocolRelative
 711                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 712                                 $protocols[] = preg_quote( $protocol, '/' );
 713                         }
 714                 }
 715
 716                 $retval = implode( '|', $protocols );
 717         } else {
 718                 // Ignore $includeProtocolRelative in this case
 719                 // This case exists for pre-1.6 compatibility, and we can safely assume
 720                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 721                 // URLs weren't supported until 1.18
 722                 $retval = $wgUrlProtocols;
 723         }
 724
 725         // Cache return value
 726         if ( $includeProtocolRelative ) {
 727                 $withProtRel = $retval;
 728         } else {
 729                 $withoutProtRel = $retval;
 730         }
 731         return $retval;
 732 }
 733
 734 /**
 735  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 736  * you need a regex that matches all URL protocols but does not match protocol-
 737  * relative URLs
 738  * @return String
 739  */
 740 function wfUrlProtocolsWithoutProtRel() {
 741         return wfUrlProtocols( false );
 742 }
 743
 744 /**
 745  * parse_url() work-alike, but non-broken.  Differences:
 746  *
 747  * 1) Does not raise warnings on bad URLs (just returns false).
 748  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 749  *    protocol-relative URLs) correctly.
 750  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 751  *
 752  * @param string $url a URL to parse
 753  * @return Array: bits of the URL in an associative array, per PHP docs
 754  */
 755 function wfParseUrl( $url ) {
 756         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 757
 758         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 759         // bad that the easiest way to handle them is to just prepend 'http:' and
 760         // strip the protocol out later.
 761         $wasRelative = substr( $url, 0, 2 ) == '//';
 762         if ( $wasRelative ) {
 763                 $url = "http:$url";
 764         }
 765         wfSuppressWarnings();
 766         $bits = parse_url( $url );
 767         wfRestoreWarnings();
 768         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 769         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 770         if ( !$bits || !isset( $bits['scheme'] ) ) {
 771                 return false;
 772         }
 773
 774         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 775         $bits['scheme'] = strtolower( $bits['scheme'] );
 776
 777         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 778         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 779                 $bits['delimiter'] = '://';
 780         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 781                 $bits['delimiter'] = ':';
 782                 // parse_url detects for news: and mailto: the host part of an url as path
 783                 // We have to correct this wrong detection
 784                 if ( isset( $bits['path'] ) ) {
 785                         $bits['host'] = $bits['path'];
 786                         $bits['path'] = '';
 787                 }
 788         } else {
 789                 return false;
 790         }
 791
 792         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 793         if ( !isset( $bits['host'] ) ) {
 794                 $bits['host'] = '';
 795
 796                 // bug 45069
 797                 if ( isset( $bits['path'] ) ) {
 798                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 799                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 800                                 $bits['path'] = '/' . $bits['path'];
 801                         }
 802                 } else {
 803                         $bits['path'] = '';
 804                 }
 805         }
 806
 807         // If the URL was protocol-relative, fix scheme and delimiter
 808         if ( $wasRelative ) {
 809                 $bits['scheme'] = '';
 810                 $bits['delimiter'] = '//';
 811         }
 812         return $bits;
 813 }
 814
 815 /**
 816  * Take a URL, make sure it's expanded to fully qualified, and replace any
 817  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 818  * for more compact display and legibility for local audiences.
 819  *
 820  * @todo handle punycode domains too
 821  *
 822  * @param $url string
 823  * @return string
 824  */
 825 function wfExpandIRI( $url ) {
 826         return preg_replace_callback(
 827                 '/((?:%[89A-F][0-9A-F])+)/i',
 828                 'wfExpandIRI_callback',
 829                 wfExpandUrl( $url )
 830         );
 831 }
 832
 833 /**
 834  * Private callback for wfExpandIRI
 835  * @param array $matches
 836  * @return string
 837  */
 838 function wfExpandIRI_callback( $matches ) {
 839         return urldecode( $matches[1] );
 840 }
 841
 842 /**
 843  * Make URL indexes, appropriate for the el_index field of externallinks.
 844  *
 845  * @param $url String
 846  * @return array
 847  */
 848 function wfMakeUrlIndexes( $url ) {
 849         $bits = wfParseUrl( $url );
 850
 851         // Reverse the labels in the hostname, convert to lower case
 852         // For emails reverse domainpart only
 853         if ( $bits['scheme'] == 'mailto' ) {
 854                 $mailparts = explode( '@', $bits['host'], 2 );
 855                 if ( count( $mailparts ) === 2 ) {
 856                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 857                 } else {
 858                         // No domain specified, don't mangle it
 859                         $domainpart = '';
 860                 }
 861                 $reversedHost = $domainpart . '@' . $mailparts[0];
 862         } else {
 863                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 864         }
 865         // Add an extra dot to the end
 866         // Why? Is it in wrong place in mailto links?
 867         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 868                 $reversedHost .= '.';
 869         }
 870         // Reconstruct the pseudo-URL
 871         $prot = $bits['scheme'];
 872         $index = $prot . $bits['delimiter'] . $reversedHost;
 873         // Leave out user and password. Add the port, path, query and fragment
 874         if ( isset( $bits['port'] ) ) {
 875                 $index .= ':' . $bits['port'];
 876         }
 877         if ( isset( $bits['path'] ) ) {
 878                 $index .= $bits['path'];
 879         } else {
 880                 $index .= '/';
 881         }
 882         if ( isset( $bits['query'] ) ) {
 883                 $index .= '?' . $bits['query'];
 884         }
 885         if ( isset( $bits['fragment'] ) ) {
 886                 $index .= '#' . $bits['fragment'];
 887         }
 888
 889         if ( $prot == '' ) {
 890                 return array( "http:$index", "https:$index" );
 891         } else {
 892                 return array( $index );
 893         }
 894 }
 895
 896 /**
 897  * Check whether a given URL has a domain that occurs in a given set of domains
 898  * @param string $url URL
 899  * @param array $domains Array of domains (strings)
 900  * @return bool True if the host part of $url ends in one of the strings in $domains
 901  */
 902 function wfMatchesDomainList( $url, $domains ) {
 903         $bits = wfParseUrl( $url );
 904         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 905                 $host = '.' . $bits['host'];
 906                 foreach ( (array)$domains as $domain ) {
 907                         $domain = '.' . $domain;
 908                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 909                                 return true;
 910                         }
 911                 }
 912         }
 913         return false;
 914 }
 915
 916 /**
 917  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 918  * In normal operation this is a NOP.
 919  *
 920  * Controlling globals:
 921  * $wgDebugLogFile - points to the log file
 922  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 923  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 924  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 925  *
 926  * @param $text String
 927  * @param bool $logonly set true to avoid appearing in HTML when $wgDebugComments is set
 928  */
 929 function wfDebug( $text, $logonly = false ) {
 930         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 931
 932         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 933                 return;
 934         }
 935
 936         $timer = wfDebugTimer();
 937         if ( $timer !== '' ) {
 938                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 939         }
 940
 941         if ( !$logonly ) {
 942                 MWDebug::debugMsg( $text );
 943         }
 944
 945         if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 946                 # Strip unprintables; they can switch terminal modes when binary data
 947                 # gets dumped, which is pretty annoying.
 948                 $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 949                 $text = $wgDebugLogPrefix . $text;
 950                 wfErrorLog( $text, $wgDebugLogFile );
 951         }
 952 }
 953
 954 /**
 955  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 956  * @return bool
 957  */
 958 function wfIsDebugRawPage() {
 959         static $cache;
 960         if ( $cache !== null ) {
 961                 return $cache;
 962         }
 963         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 964         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 965                 || (
 966                         isset( $_SERVER['SCRIPT_NAME'] )
 967                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 968                 ) )
 969         {
 970                 $cache = true;
 971         } else {
 972                 $cache = false;
 973         }
 974         return $cache;
 975 }
 976
 977 /**
 978  * Get microsecond timestamps for debug logs
 979  *
 980  * @return string
 981  */
 982 function wfDebugTimer() {
 983         global $wgDebugTimestamps, $wgRequestTime;
 984
 985         if ( !$wgDebugTimestamps ) {
 986                 return '';
 987         }
 988
 989         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
 990         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
 991         return "$prefix $mem  ";
 992 }
 993
 994 /**
 995  * Send a line giving PHP memory usage.
 996  *
 997  * @param bool $exact print exact values instead of kilobytes (default: false)
 998  */
 999 function wfDebugMem( $exact = false ) {
1000         $mem = memory_get_usage();
1001         if ( !$exact ) {
1002                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1003         } else {
1004                 $mem .= ' bytes';
1005         }
1006         wfDebug( "Memory usage: $mem\n" );
1007 }
1008
1009 /**
1010  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1011  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
1012  *
1013  * @param $logGroup String
1014  * @param $text String
1015  * @param bool $public whether to log the event in the public log if no private
1016  *                     log file is specified, (default true)
1017  */
1018 function wfDebugLog( $logGroup, $text, $public = true ) {
1019         global $wgDebugLogGroups;
1020         $text = trim( $text ) . "\n";
1021         if ( isset( $wgDebugLogGroups[$logGroup] ) ) {
1022                 $time = wfTimestamp( TS_DB );
1023                 $wiki = wfWikiID();
1024                 $host = wfHostname();
1025                 wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
1026         } elseif ( $public === true ) {
1027                 wfDebug( "[$logGroup] $text", false );
1028         }
1029 }
1030
1031 /**
1032  * Log for database errors
1033  *
1034  * @param string $text database error message.
1035  */
1036 function wfLogDBError( $text ) {
1037         global $wgDBerrorLog, $wgDBerrorLogTZ;
1038         static $logDBErrorTimeZoneObject = null;
1039
1040         if ( $wgDBerrorLog ) {
1041                 $host = wfHostname();
1042                 $wiki = wfWikiID();
1043
1044                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1045                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1046                 }
1047
1048                 // Workaround for https://bugs.php.net/bug.php?id=52063
1049                 // Can be removed when min PHP > 5.3.2
1050                 if ( $logDBErrorTimeZoneObject === null ) {
1051                         $d = date_create( "now" );
1052                 } else {
1053                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1054                 }
1055
1056                 $date = $d->format( 'D M j G:i:s T Y' );
1057
1058                 $text = "$date\t$host\t$wiki\t$text";
1059                 wfErrorLog( $text, $wgDBerrorLog );
1060         }
1061 }
1062
1063 /**
1064  * Throws a warning that $function is deprecated
1065  *
1066  * @param $function String
1067  * @param string|bool $version Version of MediaWiki that the function
1068  *    was deprecated in (Added in 1.19).
1069  * @param string|bool $component Added in 1.19.
1070  * @param $callerOffset integer: How far up the call stack is the original
1071  *    caller. 2 = function that called the function that called
1072  *    wfDeprecated (Added in 1.20)
1073  *
1074  * @return null
1075  */
1076 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1077         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1078 }
1079
1080 /**
1081  * Send a warning either to the debug log or in a PHP error depending on
1082  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1083  *
1084  * @param string $msg message to send
1085  * @param $callerOffset Integer: number of items to go back in the backtrace to
1086  *        find the correct caller (1 = function calling wfWarn, ...)
1087  * @param $level Integer: PHP error level; defaults to E_USER_NOTICE;
1088  *        only used when $wgDevelopmentWarnings is true
1089  */
1090 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1091         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1092 }
1093
1094 /**
1095  * Send a warning as a PHP error and the debug log. This is intended for logging
1096  * warnings in production. For logging development warnings, use WfWarn instead.
1097  *
1098  * @param $msg String: message to send
1099  * @param $callerOffset Integer: number of items to go back in the backtrace to
1100  *        find the correct caller (1 = function calling wfLogWarning, ...)
1101  * @param $level Integer: PHP error level; defaults to E_USER_WARNING
1102  */
1103 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1104         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1105 }
1106
1107 /**
1108  * Log to a file without getting "file size exceeded" signals.
1109  *
1110  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1111  * send lines to the specified port, prefixed by the specified prefix and a space.
1112  *
1113  * @param $text String
1114  * @param string $file filename
1115  * @throws MWException
1116  */
1117 function wfErrorLog( $text, $file ) {
1118         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1119                 # Needs the sockets extension
1120                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1121                         // IPv6 bracketed host
1122                         $host = $m[2];
1123                         $port = intval( $m[3] );
1124                         $prefix = isset( $m[4] ) ? $m[4] : false;
1125                         $domain = AF_INET6;
1126                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1127                         $host = $m[2];
1128                         if ( !IP::isIPv4( $host ) ) {
1129                                 $host = gethostbyname( $host );
1130                         }
1131                         $port = intval( $m[3] );
1132                         $prefix = isset( $m[4] ) ? $m[4] : false;
1133                         $domain = AF_INET;
1134                 } else {
1135                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1136                 }
1137
1138                 // Clean it up for the multiplexer
1139                 if ( strval( $prefix ) !== '' ) {
1140                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1141
1142                         // Limit to 64KB
1143                         if ( strlen( $text ) > 65506 ) {
1144                                 $text = substr( $text, 0, 65506 );
1145                         }
1146
1147                         if ( substr( $text, -1 ) != "\n" ) {
1148                                 $text .= "\n";
1149                         }
1150                 } elseif ( strlen( $text ) > 65507 ) {
1151                         $text = substr( $text, 0, 65507 );
1152                 }
1153
1154                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1155                 if ( !$sock ) {
1156                         return;
1157                 }
1158
1159                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1160                 socket_close( $sock );
1161         } else {
1162                 wfSuppressWarnings();
1163                 $exists = file_exists( $file );
1164                 $size = $exists ? filesize( $file ) : false;
1165                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1166                         file_put_contents( $file, $text, FILE_APPEND );
1167                 }
1168                 wfRestoreWarnings();
1169         }
1170 }
1171
1172 /**
1173  * @todo document
1174  */
1175 function wfLogProfilingData() {
1176         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1177         global $wgProfileLimit, $wgUser;
1178
1179         StatCounter::singleton()->flush();
1180
1181         $profiler = Profiler::instance();
1182
1183         # Profiling must actually be enabled...
1184         if ( $profiler->isStub() ) {
1185                 return;
1186         }
1187
1188         // Get total page request time and only show pages that longer than
1189         // $wgProfileLimit time (default is 0)
1190         $elapsed = microtime( true ) - $wgRequestTime;
1191         if ( $elapsed <= $wgProfileLimit ) {
1192                 return;
1193         }
1194
1195         $profiler->logData();
1196
1197         // Check whether this should be logged in the debug file.
1198         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1199                 return;
1200         }
1201
1202         $forward = '';
1203         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1204                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1205         }
1206         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1207                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1208         }
1209         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1210                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1211         }
1212         if ( $forward ) {
1213                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1214         }
1215         // Don't load $wgUser at this late stage just for statistics purposes
1216         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1217         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1218                 $forward .= ' anon';
1219         }
1220
1221         // Command line script uses a FauxRequest object which does not have
1222         // any knowledge about an URL and throw an exception instead.
1223         try {
1224                 $requestUrl = $wgRequest->getRequestURL();
1225         } catch ( MWException $e ) {
1226                 $requestUrl = 'n/a';
1227         }
1228
1229         $log = sprintf( "%s\t%04.3f\t%s\n",
1230                 gmdate( 'YmdHis' ), $elapsed,
1231                 urldecode( $requestUrl . $forward ) );
1232
1233         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1234 }
1235
1236 /**
1237  * Increment a statistics counter
1238  *
1239  * @param $key String
1240  * @param $count Int
1241  * @return void
1242  */
1243 function wfIncrStats( $key, $count = 1 ) {
1244         StatCounter::singleton()->incr( $key, $count );
1245 }
1246
1247 /**
1248  * Check whether the wiki is in read-only mode.
1249  *
1250  * @return bool
1251  */
1252 function wfReadOnly() {
1253         return wfReadOnlyReason() !== false;
1254 }
1255
1256 /**
1257  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1258  *
1259  * @return string|bool: String when in read-only mode; false otherwise
1260  */
1261 function wfReadOnlyReason() {
1262         global $wgReadOnly, $wgReadOnlyFile;
1263
1264         if ( $wgReadOnly === null ) {
1265                 // Set $wgReadOnly for faster access next time
1266                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1267                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1268                 } else {
1269                         $wgReadOnly = false;
1270                 }
1271         }
1272
1273         return $wgReadOnly;
1274 }
1275
1276 /**
1277  * Return a Language object from $langcode
1278  *
1279  * @param $langcode Mixed: either:
1280  *                  - a Language object
1281  *                  - code of the language to get the message for, if it is
1282  *                    a valid code create a language for that language, if
1283  *                    it is a string but not a valid code then make a basic
1284  *                    language object
1285  *                  - a boolean: if it's false then use the global object for
1286  *                    the current user's language (as a fallback for the old parameter
1287  *                    functionality), or if it is true then use global object
1288  *                    for the wiki's content language.
1289  * @return Language object
1290  */
1291 function wfGetLangObj( $langcode = false ) {
1292         # Identify which language to get or create a language object for.
1293         # Using is_object here due to Stub objects.
1294         if ( is_object( $langcode ) ) {
1295                 # Great, we already have the object (hopefully)!
1296                 return $langcode;
1297         }
1298
1299         global $wgContLang, $wgLanguageCode;
1300         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1301                 # $langcode is the language code of the wikis content language object.
1302                 # or it is a boolean and value is true
1303                 return $wgContLang;
1304         }
1305
1306         global $wgLang;
1307         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1308                 # $langcode is the language code of user language object.
1309                 # or it was a boolean and value is false
1310                 return $wgLang;
1311         }
1312
1313         $validCodes = array_keys( Language::fetchLanguageNames() );
1314         if ( in_array( $langcode, $validCodes ) ) {
1315                 # $langcode corresponds to a valid language.
1316                 return Language::factory( $langcode );
1317         }
1318
1319         # $langcode is a string, but not a valid language code; use content language.
1320         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1321         return $wgContLang;
1322 }
1323
1324 /**
1325  * Old function when $wgBetterDirectionality existed
1326  * All usage removed, wfUILang can be removed in near future
1327  *
1328  * @deprecated since 1.18
1329  * @return Language
1330  */
1331 function wfUILang() {
1332         wfDeprecated( __METHOD__, '1.18' );
1333         global $wgLang;
1334         return $wgLang;
1335 }
1336
1337 /**
1338  * This is the function for getting translated interface messages.
1339  *
1340  * @see Message class for documentation how to use them.
1341  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1342  *
1343  * This function replaces all old wfMsg* functions.
1344  *
1345  * @param $key \string Message key.
1346  * Varargs: normal message parameters.
1347  * @return Message
1348  * @since 1.17
1349  */
1350 function wfMessage( $key /*...*/) {
1351         $params = func_get_args();
1352         array_shift( $params );
1353         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1354                 $params = $params[0];
1355         }
1356         return new Message( $key, $params );
1357 }
1358
1359 /**
1360  * This function accepts multiple message keys and returns a message instance
1361  * for the first message which is non-empty. If all messages are empty then an
1362  * instance of the first message key is returned.
1363  * @param varargs: message keys
1364  * @return Message
1365  * @since 1.18
1366  */
1367 function wfMessageFallback( /*...*/ ) {
1368         $args = func_get_args();
1369         return call_user_func_array( 'Message::newFallbackSequence', $args );
1370 }
1371
1372 /**
1373  * Get a message from anywhere, for the current user language.
1374  *
1375  * Use wfMsgForContent() instead if the message should NOT
1376  * change depending on the user preferences.
1377  *
1378  * @deprecated since 1.18
1379  *
1380  * @param string $key lookup key for the message, usually
1381  *    defined in languages/Language.php
1382  *
1383  * Parameters to the message, which can be used to insert variable text into
1384  * it, can be passed to this function in the following formats:
1385  * - One per argument, starting at the second parameter
1386  * - As an array in the second parameter
1387  * These are not shown in the function definition.
1388  *
1389  * @return String
1390  */
1391 function wfMsg( $key ) {
1392         wfDeprecated( __METHOD__, '1.21' );
1393
1394         $args = func_get_args();
1395         array_shift( $args );
1396         return wfMsgReal( $key, $args );
1397 }
1398
1399 /**
1400  * Same as above except doesn't transform the message
1401  *
1402  * @deprecated since 1.18
1403  *
1404  * @param $key String
1405  * @return String
1406  */
1407 function wfMsgNoTrans( $key ) {
1408         wfDeprecated( __METHOD__, '1.21' );
1409
1410         $args = func_get_args();
1411         array_shift( $args );
1412         return wfMsgReal( $key, $args, true, false, false );
1413 }
1414
1415 /**
1416  * Get a message from anywhere, for the current global language
1417  * set with $wgLanguageCode.
1418  *
1419  * Use this if the message should NOT change dependent on the
1420  * language set in the user's preferences. This is the case for
1421  * most text written into logs, as well as link targets (such as
1422  * the name of the copyright policy page). Link titles, on the
1423  * other hand, should be shown in the UI language.
1424  *
1425  * Note that MediaWiki allows users to change the user interface
1426  * language in their preferences, but a single installation
1427  * typically only contains content in one language.
1428  *
1429  * Be wary of this distinction: If you use wfMsg() where you should
1430  * use wfMsgForContent(), a user of the software may have to
1431  * customize potentially hundreds of messages in
1432  * order to, e.g., fix a link in every possible language.
1433  *
1434  * @deprecated since 1.18
1435  *
1436  * @param string $key lookup key for the message, usually
1437  *     defined in languages/Language.php
1438  * @return String
1439  */
1440 function wfMsgForContent( $key ) {
1441         wfDeprecated( __METHOD__, '1.21' );
1442
1443         global $wgForceUIMsgAsContentMsg;
1444         $args = func_get_args();
1445         array_shift( $args );
1446         $forcontent = true;
1447         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1448                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1449         {
1450                 $forcontent = false;
1451         }
1452         return wfMsgReal( $key, $args, true, $forcontent );
1453 }
1454
1455 /**
1456  * Same as above except doesn't transform the message
1457  *
1458  * @deprecated since 1.18
1459  *
1460  * @param $key String
1461  * @return String
1462  */
1463 function wfMsgForContentNoTrans( $key ) {
1464         wfDeprecated( __METHOD__, '1.21' );
1465
1466         global $wgForceUIMsgAsContentMsg;
1467         $args = func_get_args();
1468         array_shift( $args );
1469         $forcontent = true;
1470         if ( is_array( $wgForceUIMsgAsContentMsg ) &&
1471                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1472         {
1473                 $forcontent = false;
1474         }
1475         return wfMsgReal( $key, $args, true, $forcontent, false );
1476 }
1477
1478 /**
1479  * Really get a message
1480  *
1481  * @deprecated since 1.18
1482  *
1483  * @param string $key key to get.
1484  * @param $args
1485  * @param $useDB Boolean
1486  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1487  * @param $transform Boolean: Whether or not to transform the message.
1488  * @return String: the requested message.
1489  */
1490 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1491         wfDeprecated( __METHOD__, '1.21' );
1492
1493         wfProfileIn( __METHOD__ );
1494         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1495         $message = wfMsgReplaceArgs( $message, $args );
1496         wfProfileOut( __METHOD__ );
1497         return $message;
1498 }
1499
1500 /**
1501  * Fetch a message string value, but don't replace any keys yet.
1502  *
1503  * @deprecated since 1.18
1504  *
1505  * @param $key String
1506  * @param $useDB Bool
1507  * @param string $langCode Code of the language to get the message for, or
1508  *                  behaves as a content language switch if it is a boolean.
1509  * @param $transform Boolean: whether to parse magic words, etc.
1510  * @return string
1511  */
1512 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1513         wfDeprecated( __METHOD__, '1.21' );
1514
1515         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1516
1517         $cache = MessageCache::singleton();
1518         $message = $cache->get( $key, $useDB, $langCode );
1519         if ( $message === false ) {
1520                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1521         } elseif ( $transform ) {
1522                 $message = $cache->transform( $message );
1523         }
1524         return $message;
1525 }
1526
1527 /**
1528  * Replace message parameter keys on the given formatted output.
1529  *
1530  * @param $message String
1531  * @param $args Array
1532  * @return string
1533  * @private
1534  */
1535 function wfMsgReplaceArgs( $message, $args ) {
1536         # Fix windows line-endings
1537         # Some messages are split with explode("\n", $msg)
1538         $message = str_replace( "\r", '', $message );
1539
1540         // Replace arguments
1541         if ( count( $args ) ) {
1542                 if ( is_array( $args[0] ) ) {
1543                         $args = array_values( $args[0] );
1544                 }
1545                 $replacementKeys = array();
1546                 foreach ( $args as $n => $param ) {
1547                         $replacementKeys['$' . ( $n + 1 )] = $param;
1548                 }
1549                 $message = strtr( $message, $replacementKeys );
1550         }
1551
1552         return $message;
1553 }
1554
1555 /**
1556  * Return an HTML-escaped version of a message.
1557  * Parameter replacements, if any, are done *after* the HTML-escaping,
1558  * so parameters may contain HTML (eg links or form controls). Be sure
1559  * to pre-escape them if you really do want plaintext, or just wrap
1560  * the whole thing in htmlspecialchars().
1561  *
1562  * @deprecated since 1.18
1563  *
1564  * @param $key String
1565  * @param string ... parameters
1566  * @return string
1567  */
1568 function wfMsgHtml( $key ) {
1569         wfDeprecated( __METHOD__, '1.21' );
1570
1571         $args = func_get_args();
1572         array_shift( $args );
1573         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1574 }
1575
1576 /**
1577  * Return an HTML version of message
1578  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1579  * so parameters may contain HTML (eg links or form controls). Be sure
1580  * to pre-escape them if you really do want plaintext, or just wrap
1581  * the whole thing in htmlspecialchars().
1582  *
1583  * @deprecated since 1.18
1584  *
1585  * @param $key String
1586  * @param string ... parameters
1587  * @return string
1588  */
1589 function wfMsgWikiHtml( $key ) {
1590         wfDeprecated( __METHOD__, '1.21' );
1591
1592         $args = func_get_args();
1593         array_shift( $args );
1594         return wfMsgReplaceArgs(
1595                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1596                 /* can't be set to false */ true, /* interface */ true )->getText(),
1597                 $args );
1598 }
1599
1600 /**
1601  * Returns message in the requested format
1602  *
1603  * @deprecated since 1.18
1604  *
1605  * @param string $key key of the message
1606  * @param array $options processing rules. Can take the following options:
1607  *   <i>parse</i>: parses wikitext to HTML
1608  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1609  *       p's added by parser or tidy
1610  *   <i>escape</i>: filters message through htmlspecialchars
1611  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1612  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1613  *   <i>parsemag</i>: transform the message using magic phrases
1614  *   <i>content</i>: fetch message for content language instead of interface
1615  * Also can accept a single associative argument, of the form 'language' => 'xx':
1616  *   <i>language</i>: Language object or language code to fetch message for
1617  *       (overridden by <i>content</i>).
1618  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1619  *
1620  * @return String
1621  */
1622 function wfMsgExt( $key, $options ) {
1623         wfDeprecated( __METHOD__, '1.21' );
1624
1625         $args = func_get_args();
1626         array_shift( $args );
1627         array_shift( $args );
1628         $options = (array)$options;
1629
1630         foreach ( $options as $arrayKey => $option ) {
1631                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1632                         # An unknown index, neither numeric nor "language"
1633                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1634                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1635                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1636                 'replaceafter', 'parsemag', 'content' ) ) ) {
1637                         # A numeric index with unknown value
1638                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1639                 }
1640         }
1641
1642         if ( in_array( 'content', $options, true ) ) {
1643                 $forContent = true;
1644                 $langCode = true;
1645                 $langCodeObj = null;
1646         } elseif ( array_key_exists( 'language', $options ) ) {
1647                 $forContent = false;
1648                 $langCode = wfGetLangObj( $options['language'] );
1649                 $langCodeObj = $langCode;
1650         } else {
1651                 $forContent = false;
1652                 $langCode = false;
1653                 $langCodeObj = null;
1654         }
1655
1656         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1657
1658         if ( !in_array( 'replaceafter', $options, true ) ) {
1659                 $string = wfMsgReplaceArgs( $string, $args );
1660         }
1661
1662         $messageCache = MessageCache::singleton();
1663         $parseInline = in_array( 'parseinline', $options, true );
1664         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1665                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1666                 if ( $string instanceof ParserOutput ) {
1667                         $string = $string->getText();
1668                 }
1669
1670                 if ( $parseInline ) {
1671                         $m = array();
1672                         if ( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1673                                 $string = $m[1];
1674                         }
1675                 }
1676         } elseif ( in_array( 'parsemag', $options, true ) ) {
1677                 $string = $messageCache->transform( $string,
1678                                 !$forContent, $langCodeObj );
1679         }
1680
1681         if ( in_array( 'escape', $options, true ) ) {
1682                 $string = htmlspecialchars ( $string );
1683         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1684                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1685         }
1686
1687         if ( in_array( 'replaceafter', $options, true ) ) {
1688                 $string = wfMsgReplaceArgs( $string, $args );
1689         }
1690
1691         return $string;
1692 }
1693
1694 /**
1695  * Since wfMsg() and co suck, they don't return false if the message key they
1696  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1697  * nonexistence of messages by checking the MessageCache::get() result directly.
1698  *
1699  * @deprecated since 1.18. Use Message::isDisabled().
1700  *
1701  * @param $key      String: the message key looked up
1702  * @return Boolean True if the message *doesn't* exist.
1703  */
1704 function wfEmptyMsg( $key ) {
1705         wfDeprecated( __METHOD__, '1.21' );
1706
1707         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1708 }
1709
1710 /**
1711  * Throw a debugging exception. This function previously once exited the process,
1712  * but now throws an exception instead, with similar results.
1713  *
1714  * @deprecated since 1.22; just throw an MWException yourself
1715  * @param string $msg message shown when dying.
1716  * @throws MWException
1717  */
1718 function wfDebugDieBacktrace( $msg = '' ) {
1719         wfDeprecated( __FUNCTION__, '1.22' );
1720         throw new MWException( $msg );
1721 }
1722
1723 /**
1724  * Fetch server name for use in error reporting etc.
1725  * Use real server name if available, so we know which machine
1726  * in a server farm generated the current page.
1727  *
1728  * @return string
1729  */
1730 function wfHostname() {
1731         static $host;
1732         if ( is_null( $host ) ) {
1733
1734                 # Hostname overriding
1735                 global $wgOverrideHostname;
1736                 if ( $wgOverrideHostname !== false ) {
1737                         # Set static and skip any detection
1738                         $host = $wgOverrideHostname;
1739                         return $host;
1740                 }
1741
1742                 if ( function_exists( 'posix_uname' ) ) {
1743                         // This function not present on Windows
1744                         $uname = posix_uname();
1745                 } else {
1746                         $uname = false;
1747                 }
1748                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1749                         $host = $uname['nodename'];
1750                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1751                         # Windows computer name
1752                         $host = getenv( 'COMPUTERNAME' );
1753                 } else {
1754                         # This may be a virtual server.
1755                         $host = $_SERVER['SERVER_NAME'];
1756                 }
1757         }
1758         return $host;
1759 }
1760
1761 /**
1762  * Returns a HTML comment with the elapsed time since request.
1763  * This method has no side effects.
1764  *
1765  * @return string
1766  */
1767 function wfReportTime() {
1768         global $wgRequestTime, $wgShowHostnames;
1769
1770         $elapsed = microtime( true ) - $wgRequestTime;
1771
1772         return $wgShowHostnames
1773                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1774                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1775 }
1776
1777 /**
1778  * Safety wrapper for debug_backtrace().
1779  *
1780  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1781  * murky circumstances, which may be triggered in part by stub objects
1782  * or other fancy talking'.
1783  *
1784  * Will return an empty array if Zend Optimizer is detected or if
1785  * debug_backtrace is disabled, otherwise the output from
1786  * debug_backtrace() (trimmed).
1787  *
1788  * @param int $limit This parameter can be used to limit the number of stack frames returned
1789  *
1790  * @return array of backtrace information
1791  */
1792 function wfDebugBacktrace( $limit = 0 ) {
1793         static $disabled = null;
1794
1795         if ( extension_loaded( 'Zend Optimizer' ) ) {
1796                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1797                 return array();
1798         }
1799
1800         if ( is_null( $disabled ) ) {
1801                 $disabled = false;
1802                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1803                 $functions = array_map( 'trim', $functions );
1804                 $functions = array_map( 'strtolower', $functions );
1805                 if ( in_array( 'debug_backtrace', $functions ) ) {
1806                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1807                         $disabled = true;
1808                 }
1809         }
1810         if ( $disabled ) {
1811                 return array();
1812         }
1813
1814         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1815                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1816         } else {
1817                 return array_slice( debug_backtrace(), 1 );
1818         }
1819 }
1820
1821 /**
1822  * Get a debug backtrace as a string
1823  *
1824  * @return string
1825  */
1826 function wfBacktrace() {
1827         global $wgCommandLineMode;
1828
1829         if ( $wgCommandLineMode ) {
1830                 $msg = '';
1831         } else {
1832                 $msg = "<ul>\n";
1833         }
1834         $backtrace = wfDebugBacktrace();
1835         foreach ( $backtrace as $call ) {
1836                 if ( isset( $call['file'] ) ) {
1837                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1838                         $file = $f[count( $f ) - 1];
1839                 } else {
1840                         $file = '-';
1841                 }
1842                 if ( isset( $call['line'] ) ) {
1843                         $line = $call['line'];
1844                 } else {
1845                         $line = '-';
1846                 }
1847                 if ( $wgCommandLineMode ) {
1848                         $msg .= "$file line $line calls ";
1849                 } else {
1850                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1851                 }
1852                 if ( !empty( $call['class'] ) ) {
1853                         $msg .= $call['class'] . $call['type'];
1854                 }
1855                 $msg .= $call['function'] . '()';
1856
1857                 if ( $wgCommandLineMode ) {
1858                         $msg .= "\n";
1859                 } else {
1860                         $msg .= "</li>\n";
1861                 }
1862         }
1863         if ( $wgCommandLineMode ) {
1864                 $msg .= "\n";
1865         } else {
1866                 $msg .= "</ul>\n";
1867         }
1868
1869         return $msg;
1870 }
1871
1872 /**
1873  * Get the name of the function which called this function
1874  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1875  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1876  * wfGetCaller( 3 ) is the parent of that.
1877  *
1878  * @param $level Int
1879  * @return string
1880  */
1881 function wfGetCaller( $level = 2 ) {
1882         $backtrace = wfDebugBacktrace( $level + 1 );
1883         if ( isset( $backtrace[$level] ) ) {
1884                 return wfFormatStackFrame( $backtrace[$level] );
1885         } else {
1886                 return 'unknown';
1887         }
1888 }
1889
1890 /**
1891  * Return a string consisting of callers in the stack. Useful sometimes
1892  * for profiling specific points.
1893  *
1894  * @param int $limit The maximum depth of the stack frame to return, or false for
1895  *               the entire stack.
1896  * @return String
1897  */
1898 function wfGetAllCallers( $limit = 3 ) {
1899         $trace = array_reverse( wfDebugBacktrace() );
1900         if ( !$limit || $limit > count( $trace ) - 1 ) {
1901                 $limit = count( $trace ) - 1;
1902         }
1903         $trace = array_slice( $trace, -$limit - 1, $limit );
1904         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1905 }
1906
1907 /**
1908  * Return a string representation of frame
1909  *
1910  * @param $frame Array
1911  * @return string
1912  */
1913 function wfFormatStackFrame( $frame ) {
1914         return isset( $frame['class'] ) ?
1915                 $frame['class'] . '::' . $frame['function'] :
1916                 $frame['function'];
1917 }
1918
1919 /* Some generic result counters, pulled out of SearchEngine */
1920
1921 /**
1922  * @todo document
1923  *
1924  * @param $offset Int
1925  * @param $limit Int
1926  * @return String
1927  */
1928 function wfShowingResults( $offset, $limit ) {
1929         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1930 }
1931
1932 /**
1933  * Generate (prev x| next x) (20|50|100...) type links for paging
1934  *
1935  * @param $offset String
1936  * @param $limit Integer
1937  * @param $link String
1938  * @param string $query optional URL query parameter string
1939  * @param bool $atend optional param for specified if this is the last page
1940  * @return String
1941  * @deprecated in 1.19; use Language::viewPrevNext() instead
1942  */
1943 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1944         wfDeprecated( __METHOD__, '1.19' );
1945
1946         global $wgLang;
1947
1948         $query = wfCgiToArray( $query );
1949
1950         if ( is_object( $link ) ) {
1951                 $title = $link;
1952         } else {
1953                 $title = Title::newFromText( $link );
1954                 if ( is_null( $title ) ) {
1955                         return false;
1956                 }
1957         }
1958
1959         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1960 }
1961
1962 /**
1963  * @todo document
1964  * @todo FIXME: We may want to blacklist some broken browsers
1965  *
1966  * @param $force Bool
1967  * @return bool Whereas client accept gzip compression
1968  */
1969 function wfClientAcceptsGzip( $force = false ) {
1970         static $result = null;
1971         if ( $result === null || $force ) {
1972                 $result = false;
1973                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1974                         # @todo FIXME: We may want to blacklist some broken browsers
1975                         $m = array();
1976                         if ( preg_match(
1977                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1978                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1979                                 $m )
1980                         )
1981                         {
1982                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1983                                         $result = false;
1984                                         return $result;
1985                                 }
1986                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1987                                 $result = true;
1988                         }
1989                 }
1990         }
1991         return $result;
1992 }
1993
1994 /**
1995  * Obtain the offset and limit values from the request string;
1996  * used in special pages
1997  *
1998  * @param int $deflimit default limit if none supplied
1999  * @param string $optionname Name of a user preference to check against
2000  * @return array
2001  *
2002  */
2003 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2004         global $wgRequest;
2005         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2006 }
2007
2008 /**
2009  * Escapes the given text so that it may be output using addWikiText()
2010  * without any linking, formatting, etc. making its way through. This
2011  * is achieved by substituting certain characters with HTML entities.
2012  * As required by the callers, "<nowiki>" is not used.
2013  *
2014  * @param string $text text to be escaped
2015  * @return String
2016  */
2017 function wfEscapeWikiText( $text ) {
2018         static $repl = null, $repl2 = null;
2019         if ( $repl === null ) {
2020                 $repl = array(
2021                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2022                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2023                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2024                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2025                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2026                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2027                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2028                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2029                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2030                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2031                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2032                         '__' => '_&#95;', '://' => '&#58;//',
2033                 );
2034
2035                 // We have to catch everything "\s" matches in PCRE
2036                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2037                         $repl["$magic "] = "$magic&#32;";
2038                         $repl["$magic\t"] = "$magic&#9;";
2039                         $repl["$magic\r"] = "$magic&#13;";
2040                         $repl["$magic\n"] = "$magic&#10;";
2041                         $repl["$magic\f"] = "$magic&#12;";
2042                 }
2043
2044                 // And handle protocols that don't use "://"
2045                 global $wgUrlProtocols;
2046                 $repl2 = array();
2047                 foreach ( $wgUrlProtocols as $prot ) {
2048                         if ( substr( $prot, -1 ) === ':' ) {
2049                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2050                         }
2051                 }
2052                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2053         }
2054         $text = substr( strtr( "\n$text", $repl ), 1 );
2055         $text = preg_replace( $repl2, '$1&#58;', $text );
2056         return $text;
2057 }
2058
2059 /**
2060  * Get the current unix timestamp with microseconds.  Useful for profiling
2061  * @deprecated since 1.22; call microtime() directly
2062  * @return Float
2063  */
2064 function wfTime() {
2065         wfDeprecated( __FUNCTION__, '1.22' );
2066         return microtime( true );
2067 }
2068
2069 /**
2070  * Sets dest to source and returns the original value of dest
2071  * If source is NULL, it just returns the value, it doesn't set the variable
2072  * If force is true, it will set the value even if source is NULL
2073  *
2074  * @param $dest Mixed
2075  * @param $source Mixed
2076  * @param $force Bool
2077  * @return Mixed
2078  */
2079 function wfSetVar( &$dest, $source, $force = false ) {
2080         $temp = $dest;
2081         if ( !is_null( $source ) || $force ) {
2082                 $dest = $source;
2083         }
2084         return $temp;
2085 }
2086
2087 /**
2088  * As for wfSetVar except setting a bit
2089  *
2090  * @param $dest Int
2091  * @param $bit Int
2092  * @param $state Bool
2093  *
2094  * @return bool
2095  */
2096 function wfSetBit( &$dest, $bit, $state = true ) {
2097         $temp = (bool)( $dest & $bit );
2098         if ( !is_null( $state ) ) {
2099                 if ( $state ) {
2100                         $dest |= $bit;
2101                 } else {
2102                         $dest &= ~$bit;
2103                 }
2104         }
2105         return $temp;
2106 }
2107
2108 /**
2109  * A wrapper around the PHP function var_export().
2110  * Either print it or add it to the regular output ($wgOut).
2111  *
2112  * @param $var mixed A PHP variable to dump.
2113  */
2114 function wfVarDump( $var ) {
2115         global $wgOut;
2116         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2117         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2118                 print $s;
2119         } else {
2120                 $wgOut->addHTML( $s );
2121         }
2122 }
2123
2124 /**
2125  * Provide a simple HTTP error.
2126  *
2127  * @param $code Int|String
2128  * @param $label String
2129  * @param $desc String
2130  */
2131 function wfHttpError( $code, $label, $desc ) {
2132         global $wgOut;
2133         $wgOut->disable();
2134         header( "HTTP/1.0 $code $label" );
2135         header( "Status: $code $label" );
2136         $wgOut->sendCacheControl();
2137
2138         header( 'Content-type: text/html; charset=utf-8' );
2139         print "<!doctype html>" .
2140                 '<html><head><title>' .
2141                 htmlspecialchars( $label ) .
2142                 '</title></head><body><h1>' .
2143                 htmlspecialchars( $label ) .
2144                 '</h1><p>' .
2145                 nl2br( htmlspecialchars( $desc ) ) .
2146                 "</p></body></html>\n";
2147 }
2148
2149 /**
2150  * Clear away any user-level output buffers, discarding contents.
2151  *
2152  * Suitable for 'starting afresh', for instance when streaming
2153  * relatively large amounts of data without buffering, or wanting to
2154  * output image files without ob_gzhandler's compression.
2155  *
2156  * The optional $resetGzipEncoding parameter controls suppression of
2157  * the Content-Encoding header sent by ob_gzhandler; by default it
2158  * is left. See comments for wfClearOutputBuffers() for why it would
2159  * be used.
2160  *
2161  * Note that some PHP configuration options may add output buffer
2162  * layers which cannot be removed; these are left in place.
2163  *
2164  * @param $resetGzipEncoding Bool
2165  */
2166 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2167         if ( $resetGzipEncoding ) {
2168                 // Suppress Content-Encoding and Content-Length
2169                 // headers from 1.10+s wfOutputHandler
2170                 global $wgDisableOutputCompression;
2171                 $wgDisableOutputCompression = true;
2172         }
2173         while ( $status = ob_get_status() ) {
2174                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2175                         // Probably from zlib.output_compression or other
2176                         // PHP-internal setting which can't be removed.
2177                         //
2178                         // Give up, and hope the result doesn't break
2179                         // output behavior.
2180                         break;
2181                 }
2182                 if ( !ob_end_clean() ) {
2183                         // Could not remove output buffer handler; abort now
2184                         // to avoid getting in some kind of infinite loop.
2185                         break;
2186                 }
2187                 if ( $resetGzipEncoding ) {
2188                         if ( $status['name'] == 'ob_gzhandler' ) {
2189                                 // Reset the 'Content-Encoding' field set by this handler
2190                                 // so we can start fresh.
2191                                 header_remove( 'Content-Encoding' );
2192                                 break;
2193                         }
2194                 }
2195         }
2196 }
2197
2198 /**
2199  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2200  *
2201  * Clear away output buffers, but keep the Content-Encoding header
2202  * produced by ob_gzhandler, if any.
2203  *
2204  * This should be used for HTTP 304 responses, where you need to
2205  * preserve the Content-Encoding header of the real result, but
2206  * also need to suppress the output of ob_gzhandler to keep to spec
2207  * and avoid breaking Firefox in rare cases where the headers and
2208  * body are broken over two packets.
2209  */
2210 function wfClearOutputBuffers() {
2211         wfResetOutputBuffers( false );
2212 }
2213
2214 /**
2215  * Converts an Accept-* header into an array mapping string values to quality
2216  * factors
2217  *
2218  * @param $accept String
2219  * @param string $def default
2220  * @return Array
2221  */
2222 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2223         # No arg means accept anything (per HTTP spec)
2224         if ( !$accept ) {
2225                 return array( $def => 1.0 );
2226         }
2227
2228         $prefs = array();
2229
2230         $parts = explode( ',', $accept );
2231
2232         foreach ( $parts as $part ) {
2233                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2234                 $values = explode( ';', trim( $part ) );
2235                 $match = array();
2236                 if ( count( $values ) == 1 ) {
2237                         $prefs[$values[0]] = 1.0;
2238                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2239                         $prefs[$values[0]] = floatval( $match[1] );
2240                 }
2241         }
2242
2243         return $prefs;
2244 }
2245
2246 /**
2247  * Checks if a given MIME type matches any of the keys in the given
2248  * array. Basic wildcards are accepted in the array keys.
2249  *
2250  * Returns the matching MIME type (or wildcard) if a match, otherwise
2251  * NULL if no match.
2252  *
2253  * @param $type String
2254  * @param $avail Array
2255  * @return string
2256  * @private
2257  */
2258 function mimeTypeMatch( $type, $avail ) {
2259         if ( array_key_exists( $type, $avail ) ) {
2260                 return $type;
2261         } else {
2262                 $parts = explode( '/', $type );
2263                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2264                         return $parts[0] . '/*';
2265                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2266                         return '*/*';
2267                 } else {
2268                         return null;
2269                 }
2270         }
2271 }
2272
2273 /**
2274  * Returns the 'best' match between a client's requested internet media types
2275  * and the server's list of available types. Each list should be an associative
2276  * array of type to preference (preference is a float between 0.0 and 1.0).
2277  * Wildcards in the types are acceptable.
2278  *
2279  * @param array $cprefs client's acceptable type list
2280  * @param array $sprefs server's offered types
2281  * @return string
2282  *
2283  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2284  * XXX: generalize to negotiate other stuff
2285  */
2286 function wfNegotiateType( $cprefs, $sprefs ) {
2287         $combine = array();
2288
2289         foreach ( array_keys( $sprefs ) as $type ) {
2290                 $parts = explode( '/', $type );
2291                 if ( $parts[1] != '*' ) {
2292                         $ckey = mimeTypeMatch( $type, $cprefs );
2293                         if ( $ckey ) {
2294                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2295                         }
2296                 }
2297         }
2298
2299         foreach ( array_keys( $cprefs ) as $type ) {
2300                 $parts = explode( '/', $type );
2301                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2302                         $skey = mimeTypeMatch( $type, $sprefs );
2303                         if ( $skey ) {
2304                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2305                         }
2306                 }
2307         }
2308
2309         $bestq = 0;
2310         $besttype = null;
2311
2312         foreach ( array_keys( $combine ) as $type ) {
2313                 if ( $combine[$type] > $bestq ) {
2314                         $besttype = $type;
2315                         $bestq = $combine[$type];
2316                 }
2317         }
2318
2319         return $besttype;
2320 }
2321
2322 /**
2323  * Reference-counted warning suppression
2324  *
2325  * @param $end Bool
2326  */
2327 function wfSuppressWarnings( $end = false ) {
2328         static $suppressCount = 0;
2329         static $originalLevel = false;
2330
2331         if ( $end ) {
2332                 if ( $suppressCount ) {
2333                         --$suppressCount;
2334                         if ( !$suppressCount ) {
2335                                 error_reporting( $originalLevel );
2336                         }
2337                 }
2338         } else {
2339                 if ( !$suppressCount ) {
2340                         $originalLevel = error_reporting( E_ALL & ~(
2341                                 E_WARNING |
2342                                 E_NOTICE |
2343                                 E_USER_WARNING |
2344                                 E_USER_NOTICE |
2345                                 E_DEPRECATED |
2346                                 E_USER_DEPRECATED |
2347                                 E_STRICT
2348                         ) );
2349                 }
2350                 ++$suppressCount;
2351         }
2352 }
2353
2354 /**
2355  * Restore error level to previous value
2356  */
2357 function wfRestoreWarnings() {
2358         wfSuppressWarnings( true );
2359 }
2360
2361 # Autodetect, convert and provide timestamps of various types
2362
2363 /**
2364  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2365  */
2366 define( 'TS_UNIX', 0 );
2367
2368 /**
2369  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2370  */
2371 define( 'TS_MW', 1 );
2372
2373 /**
2374  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2375  */
2376 define( 'TS_DB', 2 );
2377
2378 /**
2379  * RFC 2822 format, for E-mail and HTTP headers
2380  */
2381 define( 'TS_RFC2822', 3 );
2382
2383 /**
2384  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2385  *
2386  * This is used by Special:Export
2387  */
2388 define( 'TS_ISO_8601', 4 );
2389
2390 /**
2391  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2392  *
2393  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2394  *       DateTime tag and page 36 for the DateTimeOriginal and
2395  *       DateTimeDigitized tags.
2396  */
2397 define( 'TS_EXIF', 5 );
2398
2399 /**
2400  * Oracle format time.
2401  */
2402 define( 'TS_ORACLE', 6 );
2403
2404 /**
2405  * Postgres format time.
2406  */
2407 define( 'TS_POSTGRES', 7 );
2408
2409 /**
2410  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2411  */
2412 define( 'TS_ISO_8601_BASIC', 9 );
2413
2414 /**
2415  * Get a timestamp string in one of various formats
2416  *
2417  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2418  *                    function will autodetect which format is supplied and act
2419  *                    accordingly.
2420  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2421  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2422  */
2423 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2424         try {
2425                 $timestamp = new MWTimestamp( $ts );
2426                 return $timestamp->getTimestamp( $outputtype );
2427         } catch ( TimestampException $e ) {
2428                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2429                 return false;
2430         }
2431 }
2432
2433 /**
2434  * Return a formatted timestamp, or null if input is null.
2435  * For dealing with nullable timestamp columns in the database.
2436  *
2437  * @param $outputtype Integer
2438  * @param $ts String
2439  * @return String
2440  */
2441 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2442         if ( is_null( $ts ) ) {
2443                 return null;
2444         } else {
2445                 return wfTimestamp( $outputtype, $ts );
2446         }
2447 }
2448
2449 /**
2450  * Convenience function; returns MediaWiki timestamp for the present time.
2451  *
2452  * @return string
2453  */
2454 function wfTimestampNow() {
2455         # return NOW
2456         return wfTimestamp( TS_MW, time() );
2457 }
2458
2459 /**
2460  * Check if the operating system is Windows
2461  *
2462  * @return Bool: true if it's Windows, False otherwise.
2463  */
2464 function wfIsWindows() {
2465         static $isWindows = null;
2466         if ( $isWindows === null ) {
2467                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2468         }
2469         return $isWindows;
2470 }
2471
2472 /**
2473  * Check if we are running under HipHop
2474  *
2475  * @return Bool
2476  */
2477 function wfIsHipHop() {
2478         return defined( 'HPHP_VERSION' );
2479 }
2480
2481 /**
2482  * Swap two variables
2483  *
2484  * @param $x Mixed
2485  * @param $y Mixed
2486  */
2487 function swap( &$x, &$y ) {
2488         $z = $x;
2489         $x = $y;
2490         $y = $z;
2491 }
2492
2493 /**
2494  * Tries to get the system directory for temporary files. First
2495  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2496  * environment variables are then checked in sequence, and if none are
2497  * set try sys_get_temp_dir().
2498  *
2499  * NOTE: When possible, use instead the tmpfile() function to create
2500  * temporary files to avoid race conditions on file creation, etc.
2501  *
2502  * @return String
2503  */
2504 function wfTempDir() {
2505         global $wgTmpDirectory;
2506
2507         if ( $wgTmpDirectory !== false ) {
2508                 return $wgTmpDirectory;
2509         }
2510
2511         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2512
2513         foreach ( $tmpDir as $tmp ) {
2514                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2515                         return $tmp;
2516                 }
2517         }
2518         return sys_get_temp_dir();
2519 }
2520
2521 /**
2522  * Make directory, and make all parent directories if they don't exist
2523  *
2524  * @param string $dir full path to directory to create
2525  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2526  * @param string $caller optional caller param for debugging.
2527  * @throws MWException
2528  * @return bool
2529  */
2530 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2531         global $wgDirectoryMode;
2532
2533         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2534                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2535         }
2536
2537         if ( !is_null( $caller ) ) {
2538                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2539         }
2540
2541         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2542                 return true;
2543         }
2544
2545         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2546
2547         if ( is_null( $mode ) ) {
2548                 $mode = $wgDirectoryMode;
2549         }
2550
2551         // Turn off the normal warning, we're doing our own below
2552         wfSuppressWarnings();
2553         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2554         wfRestoreWarnings();
2555
2556         if ( !$ok ) {
2557                 //directory may have been created on another request since we last checked
2558                 if ( is_dir( $dir ) ) {
2559                         return true;
2560                 }
2561
2562                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2563                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2564         }
2565         return $ok;
2566 }
2567
2568 /**
2569  * Remove a directory and all its content.
2570  * Does not hide error.
2571  */
2572 function wfRecursiveRemoveDir( $dir ) {
2573         wfDebug( __FUNCTION__ . "( $dir )\n" );
2574         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2575         if ( is_dir( $dir ) ) {
2576                 $objects = scandir( $dir );
2577                 foreach ( $objects as $object ) {
2578                         if ( $object != "." && $object != ".." ) {
2579                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2580                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2581                                 } else {
2582                                         unlink( $dir . '/' . $object );
2583                                 }
2584                         }
2585                 }
2586                 reset( $objects );
2587                 rmdir( $dir );
2588         }
2589 }
2590
2591 /**
2592  * @param $nr Mixed: the number to format
2593  * @param $acc Integer: the number of digits after the decimal point, default 2
2594  * @param $round Boolean: whether or not to round the value, default true
2595  * @return float
2596  */
2597 function wfPercent( $nr, $acc = 2, $round = true ) {
2598         $ret = sprintf( "%.${acc}f", $nr );
2599         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2600 }
2601
2602 /**
2603  * Find out whether or not a mixed variable exists in a string
2604  *
2605  * @deprecated Just use str(i)pos
2606  * @param $needle String
2607  * @param $str String
2608  * @param $insensitive Boolean
2609  * @return Boolean
2610  */
2611 function in_string( $needle, $str, $insensitive = false ) {
2612         wfDeprecated( __METHOD__, '1.21' );
2613         $func = 'strpos';
2614         if ( $insensitive ) {
2615                 $func = 'stripos';
2616         }
2617
2618         return $func( $str, $needle ) !== false;
2619 }
2620
2621 /**
2622  * Safety wrapper around ini_get() for boolean settings.
2623  * The values returned from ini_get() are pre-normalized for settings
2624  * set via php.ini or php_flag/php_admin_flag... but *not*
2625  * for those set via php_value/php_admin_value.
2626  *
2627  * It's fairly common for people to use php_value instead of php_flag,
2628  * which can leave you with an 'off' setting giving a false positive
2629  * for code that just takes the ini_get() return value as a boolean.
2630  *
2631  * To make things extra interesting, setting via php_value accepts
2632  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2633  * Unrecognized values go false... again opposite PHP's own coercion
2634  * from string to bool.
2635  *
2636  * Luckily, 'properly' set settings will always come back as '0' or '1',
2637  * so we only have to worry about them and the 'improper' settings.
2638  *
2639  * I frickin' hate PHP... :P
2640  *
2641  * @param $setting String
2642  * @return Bool
2643  */
2644 function wfIniGetBool( $setting ) {
2645         $val = strtolower( ini_get( $setting ) );
2646         // 'on' and 'true' can't have whitespace around them, but '1' can.
2647         return $val == 'on'
2648                 || $val == 'true'
2649                 || $val == 'yes'
2650                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2651 }
2652
2653 /**
2654  * Windows-compatible version of escapeshellarg()
2655  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2656  * function puts single quotes in regardless of OS.
2657  *
2658  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2659  * earlier distro releases of PHP)
2660  *
2661  * @param varargs
2662  * @return String
2663  */
2664 function wfEscapeShellArg() {
2665         wfInitShellLocale();
2666
2667         $args = func_get_args();
2668         $first = true;
2669         $retVal = '';
2670         foreach ( $args as $arg ) {
2671                 if ( !$first ) {
2672                         $retVal .= ' ';
2673                 } else {
2674                         $first = false;
2675                 }
2676
2677                 if ( wfIsWindows() ) {
2678                         // Escaping for an MSVC-style command line parser and CMD.EXE
2679                         // @codingStandardsIgnoreStart For long URLs
2680                         // Refs:
2681                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2682                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2683                         //  * Bug #13518
2684                         //  * CR r63214
2685                         // Double the backslashes before any double quotes. Escape the double quotes.
2686                         // @codingStandardsIgnoreEnd
2687                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2688                         $arg = '';
2689                         $iteration = 0;
2690                         foreach ( $tokens as $token ) {
2691                                 if ( $iteration % 2 == 1 ) {
2692                                         // Delimiter, a double quote preceded by zero or more slashes
2693                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2694                                 } elseif ( $iteration % 4 == 2 ) {
2695                                         // ^ in $token will be outside quotes, need to be escaped
2696                                         $arg .= str_replace( '^', '^^', $token );
2697                                 } else { // $iteration % 4 == 0
2698                                         // ^ in $token will appear inside double quotes, so leave as is
2699                                         $arg .= $token;
2700                                 }
2701                                 $iteration++;
2702                         }
2703                         // Double the backslashes before the end of the string, because
2704                         // we will soon add a quote
2705                         $m = array();
2706                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2707                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2708                         }
2709
2710                         // Add surrounding quotes
2711                         $retVal .= '"' . $arg . '"';
2712                 } else {
2713                         $retVal .= escapeshellarg( $arg );
2714                 }
2715         }
2716         return $retVal;
2717 }
2718
2719 /**
2720  * Check if wfShellExec() is effectively disabled via php.ini config
2721  * @return bool|string False or one of (safemode,disabled)
2722  * @since 1.22
2723  */
2724 function wfShellExecDisabled() {
2725         static $disabled = null;
2726         if ( is_null( $disabled ) ) {
2727                 $disabled = false;
2728                 if ( wfIniGetBool( 'safe_mode' ) ) {
2729                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2730                         $disabled = 'safemode';
2731                 } else {
2732                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2733                         $functions = array_map( 'trim', $functions );
2734                         $functions = array_map( 'strtolower', $functions );
2735                         if ( in_array( 'proc_open', $functions ) ) {
2736                                 wfDebug( "proc_open is in disabled_functions\n" );
2737                                 $disabled = 'disabled';
2738                         }
2739                 }
2740         }
2741         return $disabled;
2742 }
2743
2744 /**
2745  * Execute a shell command, with time and memory limits mirrored from the PHP
2746  * configuration if supported.
2747  * @param string $cmd Command line, properly escaped for shell.
2748  * @param &$retval null|Mixed optional, will receive the program's exit code.
2749  *                 (non-zero is usually failure). If there is an error from
2750  *                 read, select, or proc_open(), this will be set to -1.
2751  * @param array $environ optional environment variables which should be
2752  *                 added to the executed command environment.
2753  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2754  *                 this overwrites the global wgShellMax* limits.
2755  * @param array $options Array of options:
2756  *    - duplicateStderr: Set this to true to duplicate stderr to stdout,
2757  *      including errors from limit.sh
2758  *
2759  * @return string collected stdout as a string
2760  */
2761 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2762         $limits = array(), $options = array()
2763 ) {
2764         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2765                 $wgMaxShellWallClockTime, $wgShellCgroup;
2766
2767         $disabled = wfShellExecDisabled();
2768         if ( $disabled ) {
2769                 $retval = 1;
2770                 return $disabled == 'safemode' ?
2771                         'Unable to run external programs in safe mode.' :
2772                         'Unable to run external programs, proc_open() is disabled.';
2773         }
2774
2775         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2776
2777         wfInitShellLocale();
2778
2779         $envcmd = '';
2780         foreach ( $environ as $k => $v ) {
2781                 if ( wfIsWindows() ) {
2782                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2783                          * appear in the environment variable, so we must use carat escaping as documented in
2784                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2785                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2786                          * are listed there but doesn't appear to need it.
2787                          */
2788                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2789                 } else {
2790                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2791                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2792                          */
2793                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2794                 }
2795         }
2796         $cmd = $envcmd . $cmd;
2797
2798         $useLogPipe = false;
2799         if ( php_uname( 's' ) == 'Linux' ) {
2800                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2801                 if ( isset( $limits['walltime'] ) ) {
2802                         $wallTime = intval( $limits['walltime'] );
2803                 } elseif ( isset( $limits['time'] ) ) {
2804                         $wallTime = $time;
2805                 } else {
2806                         $wallTime = intval( $wgMaxShellWallClockTime );
2807                 }
2808                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2809                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2810
2811                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2812                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2813                                 escapeshellarg( $cmd ) . ' ' .
2814                                 escapeshellarg(
2815                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2816                                         "MW_CPU_LIMIT=$time; " .
2817                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2818                                         "MW_MEM_LIMIT=$mem; " .
2819                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2820                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2821                                         "MW_USE_LOG_PIPE=yes"
2822                                 );
2823                         $useLogPipe = true;
2824                 } elseif ( $includeStderr ) {
2825                         $cmd .= ' 2>&1';
2826                 }
2827         } elseif ( $includeStderr ) {
2828                 $cmd .= ' 2>&1';
2829         }
2830         wfDebug( "wfShellExec: $cmd\n" );
2831
2832         $desc = array(
2833                 0 => array( 'file', 'php://stdin', 'r' ),
2834                 1 => array( 'pipe', 'w' ),
2835                 2 => array( 'file', 'php://stderr', 'w' ) );
2836         if ( $useLogPipe ) {
2837                 $desc[3] = array( 'pipe', 'w' );
2838         }
2839         $pipes = null;
2840         $proc = proc_open( $cmd, $desc, $pipes );
2841         if ( !$proc ) {
2842                 wfDebugLog( 'exec', "proc_open() failed: $cmd\n" );
2843                 $retval = -1;
2844                 return '';
2845         }
2846         $outBuffer = $logBuffer = '';
2847         $emptyArray = array();
2848         $status = false;
2849         $logMsg = false;
2850
2851         // According to the documentation, it is possible for stream_select()
2852         // to fail due to EINTR. I haven't managed to induce this in testing
2853         // despite sending various signals. If it did happen, the error
2854         // message would take the form:
2855         //
2856         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2857         //
2858         // where [4] is the value of the macro EINTR and "Interrupted system
2859         // call" is string which according to the Linux manual is "possibly"
2860         // localised according to LC_MESSAGES.
2861         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2862         $eintrMessage = "stream_select(): unable to select [$eintr]";
2863
2864         // Build a table mapping resource IDs to pipe FDs to work around a
2865         // PHP 5.3 issue in which stream_select() does not preserve array keys
2866         // <https://bugs.php.net/bug.php?id=53427>.
2867         $fds = array();
2868         foreach ( $pipes as $fd => $pipe ) {
2869                 $fds[(int)$pipe] = $fd;
2870         }
2871
2872         while ( true ) {
2873                 $status = proc_get_status( $proc );
2874                 if ( !$status['running'] ) {
2875                         break;
2876                 }
2877                 $status = false;
2878
2879                 $readyPipes = $pipes;
2880
2881                 // Clear last error
2882                 @trigger_error( '' );
2883                 if ( @stream_select( $readyPipes, $emptyArray, $emptyArray, null ) === false ) {
2884                         $error = error_get_last();
2885                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2886                                 continue;
2887                         } else {
2888                                 trigger_error( $error['message'], E_USER_WARNING );
2889                                 $logMsg = $error['message'];
2890                                 break;
2891                         }
2892                 }
2893                 foreach ( $readyPipes as $pipe ) {
2894                         $block = fread( $pipe, 65536 );
2895                         $fd = $fds[(int)$pipe];
2896                         if ( $block === '' ) {
2897                                 // End of file
2898                                 fclose( $pipes[$fd] );
2899                                 unset( $pipes[$fd] );
2900                                 if ( !$pipes ) {
2901                                         break 2;
2902                                 }
2903                         } elseif ( $block === false ) {
2904                                 // Read error
2905                                 $logMsg = "Error reading from pipe";
2906                                 break 2;
2907                         } elseif ( $fd == 1 ) {
2908                                 // From stdout
2909                                 $outBuffer .= $block;
2910                         } elseif ( $fd == 3 ) {
2911                                 // From log FD
2912                                 $logBuffer .= $block;
2913                                 if ( strpos( $block, "\n" ) !== false ) {
2914                                         $lines = explode( "\n", $logBuffer );
2915                                         $logBuffer = array_pop( $lines );
2916                                         foreach ( $lines as $line ) {
2917                                                 wfDebugLog( 'exec', $line );
2918                                         }
2919                                 }
2920                         }
2921                 }
2922         }
2923
2924         foreach ( $pipes as $pipe ) {
2925                 fclose( $pipe );
2926         }
2927
2928         // Use the status previously collected if possible, since proc_get_status()
2929         // just calls waitpid() which will not return anything useful the second time.
2930         if ( $status === false ) {
2931                 $status = proc_get_status( $proc );
2932         }
2933
2934         if ( $logMsg !== false ) {
2935                 // Read/select error
2936                 $retval = -1;
2937                 proc_close( $proc );
2938         } elseif ( $status['signaled'] ) {
2939                 $logMsg = "Exited with signal {$status['termsig']}";
2940                 $retval = 128 + $status['termsig'];
2941                 proc_close( $proc );
2942         } else {
2943                 if ( $status['running'] ) {
2944                         $retval = proc_close( $proc );
2945                 } else {
2946                         $retval = $status['exitcode'];
2947                         proc_close( $proc );
2948                 }
2949                 if ( $retval == 127 ) {
2950                         $logMsg = "Possibly missing executable file";
2951                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2952                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2953                 }
2954         }
2955
2956         if ( $logMsg !== false ) {
2957                 wfDebugLog( 'exec', "$logMsg: $cmd\n" );
2958         }
2959
2960         return $outBuffer;
2961 }
2962
2963 /**
2964  * Execute a shell command, returning both stdout and stderr. Convenience
2965  * function, as all the arguments to wfShellExec can become unwieldy.
2966  *
2967  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2968  * @param string $cmd Command line, properly escaped for shell.
2969  * @param &$retval null|Mixed optional, will receive the program's exit code.
2970  *                 (non-zero is usually failure)
2971  * @param array $environ optional environment variables which should be
2972  *                 added to the executed command environment.
2973  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2974  *                 this overwrites the global wgShellMax* limits.
2975  * @return string collected stdout and stderr as a string
2976  */
2977 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2978         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
2979 }
2980
2981 /**
2982  * Workaround for http://bugs.php.net/bug.php?id=45132
2983  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2984  */
2985 function wfInitShellLocale() {
2986         static $done = false;
2987         if ( $done ) {
2988                 return;
2989         }
2990         $done = true;
2991         global $wgShellLocale;
2992         if ( !wfIniGetBool( 'safe_mode' ) ) {
2993                 putenv( "LC_CTYPE=$wgShellLocale" );
2994                 setlocale( LC_CTYPE, $wgShellLocale );
2995         }
2996 }
2997
2998 /**
2999  * Alias to wfShellWikiCmd()
3000  * @see wfShellWikiCmd()
3001  */
3002 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
3003         return wfShellWikiCmd( $script, $parameters, $options );
3004 }
3005
3006 /**
3007  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3008  * Note that $parameters should be a flat array and an option with an argument
3009  * should consist of two consecutive items in the array (do not use "--option value").
3010  * @param string $script MediaWiki cli script path
3011  * @param array $parameters Arguments and options to the script
3012  * @param array $options Associative array of options:
3013  *              'php': The path to the php executable
3014  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3015  * @return Array
3016  */
3017 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3018         global $wgPhpCli;
3019         // Give site config file a chance to run the script in a wrapper.
3020         // The caller may likely want to call wfBasename() on $script.
3021         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3022         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3023         if ( isset( $options['wrapper'] ) ) {
3024                 $cmd[] = $options['wrapper'];
3025         }
3026         $cmd[] = $script;
3027         // Escape each parameter for shell
3028         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
3029 }
3030
3031 /**
3032  * wfMerge attempts to merge differences between three texts.
3033  * Returns true for a clean merge and false for failure or a conflict.
3034  *
3035  * @param $old String
3036  * @param $mine String
3037  * @param $yours String
3038  * @param $result String
3039  * @return Bool
3040  */
3041 function wfMerge( $old, $mine, $yours, &$result ) {
3042         global $wgDiff3;
3043
3044         # This check may also protect against code injection in
3045         # case of broken installations.
3046         wfSuppressWarnings();
3047         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3048         wfRestoreWarnings();
3049
3050         if ( !$haveDiff3 ) {
3051                 wfDebug( "diff3 not found\n" );
3052                 return false;
3053         }
3054
3055         # Make temporary files
3056         $td = wfTempDir();
3057         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3058         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3059         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3060
3061         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3062         #       a newline character. To avoid this, we normalize the trailing whitespace before
3063         #       creating the diff.
3064
3065         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3066         fclose( $oldtextFile );
3067         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3068         fclose( $mytextFile );
3069         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3070         fclose( $yourtextFile );
3071
3072         # Check for a conflict
3073         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3074                 wfEscapeShellArg( $mytextName ) . ' ' .
3075                 wfEscapeShellArg( $oldtextName ) . ' ' .
3076                 wfEscapeShellArg( $yourtextName );
3077         $handle = popen( $cmd, 'r' );
3078
3079         if ( fgets( $handle, 1024 ) ) {
3080                 $conflict = true;
3081         } else {
3082                 $conflict = false;
3083         }
3084         pclose( $handle );
3085
3086         # Merge differences
3087         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3088                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3089         $handle = popen( $cmd, 'r' );
3090         $result = '';
3091         do {
3092                 $data = fread( $handle, 8192 );
3093                 if ( strlen( $data ) == 0 ) {
3094                         break;
3095                 }
3096                 $result .= $data;
3097         } while ( true );
3098         pclose( $handle );
3099         unlink( $mytextName );
3100         unlink( $oldtextName );
3101         unlink( $yourtextName );
3102
3103         if ( $result === '' && $old !== '' && !$conflict ) {
3104                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3105                 $conflict = true;
3106         }
3107         return !$conflict;
3108 }
3109
3110 /**
3111  * Returns unified plain-text diff of two texts.
3112  * Useful for machine processing of diffs.
3113  *
3114  * @param string $before the text before the changes.
3115  * @param string $after the text after the changes.
3116  * @param string $params command-line options for the diff command.
3117  * @return String: unified diff of $before and $after
3118  */
3119 function wfDiff( $before, $after, $params = '-u' ) {
3120         if ( $before == $after ) {
3121                 return '';
3122         }
3123
3124         global $wgDiff;
3125         wfSuppressWarnings();
3126         $haveDiff = $wgDiff && file_exists( $wgDiff );
3127         wfRestoreWarnings();
3128
3129         # This check may also protect against code injection in
3130         # case of broken installations.
3131         if ( !$haveDiff ) {
3132                 wfDebug( "diff executable not found\n" );
3133                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3134                 $format = new UnifiedDiffFormatter();
3135                 return $format->format( $diffs );
3136         }
3137
3138         # Make temporary files
3139         $td = wfTempDir();
3140         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3141         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3142
3143         fwrite( $oldtextFile, $before );
3144         fclose( $oldtextFile );
3145         fwrite( $newtextFile, $after );
3146         fclose( $newtextFile );
3147
3148         // Get the diff of the two files
3149         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3150
3151         $h = popen( $cmd, 'r' );
3152
3153         $diff = '';
3154
3155         do {
3156                 $data = fread( $h, 8192 );
3157                 if ( strlen( $data ) == 0 ) {
3158                         break;
3159                 }
3160                 $diff .= $data;
3161         } while ( true );
3162
3163         // Clean up
3164         pclose( $h );
3165         unlink( $oldtextName );
3166         unlink( $newtextName );
3167
3168         // Kill the --- and +++ lines. They're not useful.
3169         $diff_lines = explode( "\n", $diff );
3170         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3171                 unset( $diff_lines[0] );
3172         }
3173         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3174                 unset( $diff_lines[1] );
3175         }
3176
3177         $diff = implode( "\n", $diff_lines );
3178
3179         return $diff;
3180 }
3181
3182 /**
3183  * This function works like "use VERSION" in Perl, the program will die with a
3184  * backtrace if the current version of PHP is less than the version provided
3185  *
3186  * This is useful for extensions which due to their nature are not kept in sync
3187  * with releases, and might depend on other versions of PHP than the main code
3188  *
3189  * Note: PHP might die due to parsing errors in some cases before it ever
3190  *       manages to call this function, such is life
3191  *
3192  * @see perldoc -f use
3193  *
3194  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3195  *                 a float
3196  * @throws MWException
3197  */
3198 function wfUsePHP( $req_ver ) {
3199         $php_ver = PHP_VERSION;
3200
3201         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3202                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3203         }
3204 }
3205
3206 /**
3207  * This function works like "use VERSION" in Perl except it checks the version
3208  * of MediaWiki, the program will die with a backtrace if the current version
3209  * of MediaWiki is less than the version provided.
3210  *
3211  * This is useful for extensions which due to their nature are not kept in sync
3212  * with releases
3213  *
3214  * Note: Due to the behavior of PHP's version_compare() which is used in this
3215  * fuction, if you want to allow the 'wmf' development versions add a 'c' (or
3216  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3217  * targeted version number. For example if you wanted to allow any variation
3218  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3219  * not result in the same comparison due to the internal logic of
3220  * version_compare().
3221  *
3222  * @see perldoc -f use
3223  *
3224  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3225  *                 a float
3226  * @throws MWException
3227  */
3228 function wfUseMW( $req_ver ) {
3229         global $wgVersion;
3230
3231         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3232                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3233         }
3234 }
3235
3236 /**
3237  * Return the final portion of a pathname.
3238  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3239  * http://bugs.php.net/bug.php?id=33898
3240  *
3241  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3242  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3243  *
3244  * @param $path String
3245  * @param string $suffix to remove if present
3246  * @return String
3247  */
3248 function wfBaseName( $path, $suffix = '' ) {
3249         if ( $suffix == '' ) {
3250                 $encSuffix = '';
3251         } else {
3252                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3253         }
3254
3255         $matches = array();
3256         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3257                 return $matches[1];
3258         } else {
3259                 return '';
3260         }
3261 }
3262
3263 /**
3264  * Generate a relative path name to the given file.
3265  * May explode on non-matching case-insensitive paths,
3266  * funky symlinks, etc.
3267  *
3268  * @param string $path absolute destination path including target filename
3269  * @param string $from Absolute source path, directory only
3270  * @return String
3271  */
3272 function wfRelativePath( $path, $from ) {
3273         // Normalize mixed input on Windows...
3274         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3275         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3276
3277         // Trim trailing slashes -- fix for drive root
3278         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3279         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3280
3281         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3282         $against = explode( DIRECTORY_SEPARATOR, $from );
3283
3284         if ( $pieces[0] !== $against[0] ) {
3285                 // Non-matching Windows drive letters?
3286                 // Return a full path.
3287                 return $path;
3288         }
3289
3290         // Trim off common prefix
3291         while ( count( $pieces ) && count( $against )
3292                 && $pieces[0] == $against[0] ) {
3293                 array_shift( $pieces );
3294                 array_shift( $against );
3295         }
3296
3297         // relative dots to bump us to the parent
3298         while ( count( $against ) ) {
3299                 array_unshift( $pieces, '..' );
3300                 array_shift( $against );
3301         }
3302
3303         array_push( $pieces, wfBaseName( $path ) );
3304
3305         return implode( DIRECTORY_SEPARATOR, $pieces );
3306 }
3307
3308 /**
3309  * Do any deferred updates and clear the list
3310  *
3311  * @deprecated since 1.19
3312  * @see DeferredUpdates::doUpdate()
3313  * @param $commit string
3314  */
3315 function wfDoUpdates( $commit = '' ) {
3316         wfDeprecated( __METHOD__, '1.19' );
3317         DeferredUpdates::doUpdates( $commit );
3318 }
3319
3320 /**
3321  * Convert an arbitrarily-long digit string from one numeric base
3322  * to another, optionally zero-padding to a minimum column width.
3323  *
3324  * Supports base 2 through 36; digit values 10-36 are represented
3325  * as lowercase letters a-z. Input is case-insensitive.
3326  *
3327  * @param string $input Input number
3328  * @param int $sourceBase Base of the input number
3329  * @param int $destBase Desired base of the output
3330  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3331  * @param bool $lowercase Whether to output in lowercase or uppercase
3332  * @param string $engine Either "gmp", "bcmath", or "php"
3333  * @return string|bool The output number as a string, or false on error
3334  */
3335 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3336         $lowercase = true, $engine = 'auto'
3337 ) {
3338         $input = (string)$input;
3339         if (
3340                 $sourceBase < 2 ||
3341                 $sourceBase > 36 ||
3342                 $destBase < 2 ||
3343                 $destBase > 36 ||
3344                 $sourceBase != (int)$sourceBase ||
3345                 $destBase != (int)$destBase ||
3346                 $pad != (int)$pad ||
3347                 !preg_match(
3348                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3349                         $input
3350                 )
3351         ) {
3352                 return false;
3353         }
3354
3355         static $baseChars = array(
3356                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3357                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3358                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3359                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3360                 34 => 'y', 35 => 'z',
3361
3362                 '0' => 0,  '1' => 1,  '2' => 2,  '3' => 3,  '4' => 4,  '5' => 5,
3363                 '6' => 6,  '7' => 7,  '8' => 8,  '9' => 9,  'a' => 10, 'b' => 11,
3364                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3365                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3366                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3367                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3368         );
3369
3370         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3371                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3372         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3373                 $decimal = '0';
3374                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3375                         $decimal = bcmul( $decimal, $sourceBase );
3376                         $decimal = bcadd( $decimal, $baseChars[$char] );
3377                 }
3378
3379                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3380                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3381                 }
3382
3383                 $result = strrev( $result );
3384         } else {
3385                 $inDigits = array();
3386                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3387                         $inDigits[] = $baseChars[$char];
3388                 }
3389
3390                 // Iterate over the input, modulo-ing out an output digit
3391                 // at a time until input is gone.
3392                 $result = '';
3393                 while ( $inDigits ) {
3394                         $work = 0;
3395                         $workDigits = array();
3396
3397                         // Long division...
3398                         foreach ( $inDigits as $digit ) {
3399                                 $work *= $sourceBase;
3400                                 $work += $digit;
3401
3402                                 if ( $workDigits || $work >= $destBase ) {
3403                                         $workDigits[] = (int)( $work / $destBase );
3404                                 }
3405                                 $work %= $destBase;
3406                         }
3407
3408                         // All that division leaves us with a remainder,
3409                         // which is conveniently our next output digit.
3410                         $result .= $baseChars[$work];
3411
3412                         // And we continue!
3413                         $inDigits = $workDigits;
3414                 }
3415
3416                 $result = strrev( $result );
3417         }
3418
3419         if ( !$lowercase ) {
3420                 $result = strtoupper( $result );
3421         }
3422
3423         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3424 }
3425
3426 /**
3427  * Create an object with a given name and an array of construct parameters
3428  *
3429  * @param $name String
3430  * @param array $p parameters
3431  * @return object
3432  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3433  */
3434 function wfCreateObject( $name, $p ) {
3435         wfDeprecated( __FUNCTION__, '1.18' );
3436         return MWFunction::newObj( $name, $p );
3437 }
3438
3439 /**
3440  * @return bool
3441  */
3442 function wfHttpOnlySafe() {
3443         global $wgHttpOnlyBlacklist;
3444
3445         if ( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3446                 foreach ( $wgHttpOnlyBlacklist as $regex ) {
3447                         if ( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3448                                 return false;
3449                         }
3450                 }
3451         }
3452
3453         return true;
3454 }
3455
3456 /**
3457  * Check if there is sufficient entropy in php's built-in session generation
3458  * @return bool true = there is sufficient entropy
3459  */
3460 function wfCheckEntropy() {
3461         return (
3462                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3463                         || ini_get( 'session.entropy_file' )
3464                 )
3465                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3466 }
3467
3468 /**
3469  * Override session_id before session startup if php's built-in
3470  * session generation code is not secure.
3471  */
3472 function wfFixSessionID() {
3473         // If the cookie or session id is already set we already have a session and should abort
3474         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3475                 return;
3476         }
3477
3478         // PHP's built-in session entropy is enabled if:
3479         // - entropy_file is set or you're on Windows with php 5.3.3+
3480         // - AND entropy_length is > 0
3481         // We treat it as disabled if it doesn't have an entropy length of at least 32
3482         $entropyEnabled = wfCheckEntropy();
3483
3484         // If built-in entropy is not enabled or not sufficient override PHP's
3485         // built in session id generation code
3486         if ( !$entropyEnabled ) {
3487                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3488                         "overriding session id generation using our cryptrand source.\n" );
3489                 session_id( MWCryptRand::generateHex( 32 ) );
3490         }
3491 }
3492
3493 /**
3494  * Reset the session_id
3495  * @since 1.22
3496  */
3497 function wfResetSessionID() {
3498         global $wgCookieSecure;
3499         $oldSessionId = session_id();
3500         $cookieParams = session_get_cookie_params();
3501         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3502                 session_regenerate_id( false );
3503         } else {
3504                 $tmp = $_SESSION;
3505                 session_destroy();
3506                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3507                 $_SESSION = $tmp;
3508         }
3509         $newSessionId = session_id();
3510         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3511 }
3512
3513
3514 /**
3515  * Initialise php session
3516  *
3517  * @param $sessionId Bool
3518  */
3519 function wfSetupSession( $sessionId = false ) {
3520         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3521                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3522         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3523                 ObjectCacheSessionHandler::install();
3524         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3525                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3526                 # hasn't already been set to the desired value (that causes errors)
3527                 ini_set( 'session.save_handler', $wgSessionHandler );
3528         }
3529         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3530         wfDebugLog( 'cookie',
3531                 'session_set_cookie_params: "' . implode( '", "',
3532                         array(
3533                                 0,
3534                                 $wgCookiePath,
3535                                 $wgCookieDomain,
3536                                 $wgCookieSecure,
3537                                 $httpOnlySafe ) ) . '"' );
3538         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3539         session_cache_limiter( 'private, must-revalidate' );
3540         if ( $sessionId ) {
3541                 session_id( $sessionId );
3542         } else {
3543                 wfFixSessionID();
3544         }
3545         wfSuppressWarnings();
3546         session_start();
3547         wfRestoreWarnings();
3548 }
3549
3550 /**
3551  * Get an object from the precompiled serialized directory
3552  *
3553  * @param $name String
3554  * @return Mixed: the variable on success, false on failure
3555  */
3556 function wfGetPrecompiledData( $name ) {
3557         global $IP;
3558
3559         $file = "$IP/serialized/$name";
3560         if ( file_exists( $file ) ) {
3561                 $blob = file_get_contents( $file );
3562                 if ( $blob ) {
3563                         return unserialize( $blob );
3564                 }
3565         }
3566         return false;
3567 }
3568
3569 /**
3570  * Get a cache key
3571  *
3572  * @param varargs
3573  * @return String
3574  */
3575 function wfMemcKey( /*... */ ) {
3576         global $wgCachePrefix;
3577         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3578         $args = func_get_args();
3579         $key = $prefix . ':' . implode( ':', $args );
3580         $key = str_replace( ' ', '_', $key );
3581         return $key;
3582 }
3583
3584 /**
3585  * Get a cache key for a foreign DB
3586  *
3587  * @param $db String
3588  * @param $prefix String
3589  * @param varargs String
3590  * @return String
3591  */
3592 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3593         $args = array_slice( func_get_args(), 2 );
3594         if ( $prefix ) {
3595                 $key = "$db-$prefix:" . implode( ':', $args );
3596         } else {
3597                 $key = $db . ':' . implode( ':', $args );
3598         }
3599         return str_replace( ' ', '_', $key );
3600 }
3601
3602 /**
3603  * Get an ASCII string identifying this wiki
3604  * This is used as a prefix in memcached keys
3605  *
3606  * @return String
3607  */
3608 function wfWikiID() {
3609         global $wgDBprefix, $wgDBname;
3610         if ( $wgDBprefix ) {
3611                 return "$wgDBname-$wgDBprefix";
3612         } else {
3613                 return $wgDBname;
3614         }
3615 }
3616
3617 /**
3618  * Split a wiki ID into DB name and table prefix
3619  *
3620  * @param $wiki String
3621  *
3622  * @return array
3623  */
3624 function wfSplitWikiID( $wiki ) {
3625         $bits = explode( '-', $wiki, 2 );
3626         if ( count( $bits ) < 2 ) {
3627                 $bits[] = '';
3628         }
3629         return $bits;
3630 }
3631
3632 /**
3633  * Get a Database object.
3634  *
3635  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3636  *            master (for write queries), DB_SLAVE for potentially lagged read
3637  *            queries, or an integer >= 0 for a particular server.
3638  *
3639  * @param $groups Mixed: query groups. An array of group names that this query
3640  *                belongs to. May contain a single string if the query is only
3641  *                in one group.
3642  *
3643  * @param string $wiki the wiki ID, or false for the current wiki
3644  *
3645  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3646  * will always return the same object, unless the underlying connection or load
3647  * balancer is manually destroyed.
3648  *
3649  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3650  * updater to ensure that a proper database is being updated.
3651  *
3652  * @return DatabaseBase
3653  */
3654 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3655         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3656 }
3657
3658 /**
3659  * Get a load balancer object.
3660  *
3661  * @param string $wiki wiki ID, or false for the current wiki
3662  * @return LoadBalancer
3663  */
3664 function wfGetLB( $wiki = false ) {
3665         return wfGetLBFactory()->getMainLB( $wiki );
3666 }
3667
3668 /**
3669  * Get the load balancer factory object
3670  *
3671  * @return LBFactory
3672  */
3673 function &wfGetLBFactory() {
3674         return LBFactory::singleton();
3675 }
3676
3677 /**
3678  * Find a file.
3679  * Shortcut for RepoGroup::singleton()->findFile()
3680  *
3681  * @param string $title or Title object
3682  * @param array $options Associative array of options:
3683  *     time:           requested time for an archived image, or false for the
3684  *                     current version. An image object will be returned which was
3685  *                     created at the specified time.
3686  *
3687  *     ignoreRedirect: If true, do not follow file redirects
3688  *
3689  *     private:        If true, return restricted (deleted) files if the current
3690  *                     user is allowed to view them. Otherwise, such files will not
3691  *                     be found.
3692  *
3693  *     bypassCache:    If true, do not use the process-local cache of File objects
3694  *
3695  * @return File, or false if the file does not exist
3696  */
3697 function wfFindFile( $title, $options = array() ) {
3698         return RepoGroup::singleton()->findFile( $title, $options );
3699 }
3700
3701 /**
3702  * Get an object referring to a locally registered file.
3703  * Returns a valid placeholder object if the file does not exist.
3704  *
3705  * @param $title Title|String
3706  * @return LocalFile|null A File, or null if passed an invalid Title
3707  */
3708 function wfLocalFile( $title ) {
3709         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3710 }
3711
3712 /**
3713  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3714  * @deprecated since 1.19
3715  */
3716 function wfStreamFile( $fname, $headers = array() ) {
3717         wfDeprecated( __FUNCTION__, '1.19' );
3718         StreamFile::stream( $fname, $headers );
3719 }
3720
3721 /**
3722  * Should low-performance queries be disabled?
3723  *
3724  * @return Boolean
3725  * @codeCoverageIgnore
3726  */
3727 function wfQueriesMustScale() {
3728         global $wgMiserMode;
3729         return $wgMiserMode
3730                 || ( SiteStats::pages() > 100000
3731                 && SiteStats::edits() > 1000000
3732                 && SiteStats::users() > 10000 );
3733 }
3734
3735 /**
3736  * Get the path to a specified script file, respecting file
3737  * extensions; this is a wrapper around $wgScriptExtension etc.
3738  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3739  *
3740  * @param string $script script filename, sans extension
3741  * @return String
3742  */
3743 function wfScript( $script = 'index' ) {
3744         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3745         if ( $script === 'index' ) {
3746                 return $wgScript;
3747         } elseif ( $script === 'load' ) {
3748                 return $wgLoadScript;
3749         } else {
3750                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3751         }
3752 }
3753
3754 /**
3755  * Get the script URL.
3756  *
3757  * @return string script URL
3758  */
3759 function wfGetScriptUrl() {
3760         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3761                 #
3762                 # as it was called, minus the query string.
3763                 #
3764                 # Some sites use Apache rewrite rules to handle subdomains,
3765                 # and have PHP set up in a weird way that causes PHP_SELF
3766                 # to contain the rewritten URL instead of the one that the
3767                 # outside world sees.
3768                 #
3769                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3770                 # provides containing the "before" URL.
3771                 return $_SERVER['SCRIPT_NAME'];
3772         } else {
3773                 return $_SERVER['URL'];
3774         }
3775 }
3776
3777 /**
3778  * Convenience function converts boolean values into "true"
3779  * or "false" (string) values
3780  *
3781  * @param $value Boolean
3782  * @return String
3783  */
3784 function wfBoolToStr( $value ) {
3785         return $value ? 'true' : 'false';
3786 }
3787
3788 /**
3789  * Get a platform-independent path to the null file, e.g. /dev/null
3790  *
3791  * @return string
3792  */
3793 function wfGetNull() {
3794         return wfIsWindows() ? 'NUL' : '/dev/null';
3795 }
3796
3797 /**
3798  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3799  * and waiting for it to go down, this waits for the slaves to catch up to the
3800  * master position. Use this when updating very large numbers of rows, as
3801  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3802  * a no-op if there are no slaves.
3803  *
3804  * @param int|bool $maxLag (deprecated)
3805  * @param mixed $wiki Wiki identifier accepted by wfGetLB
3806  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3807  */
3808 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3809         if( $cluster !== false ) {
3810                 $lb = wfGetLBFactory()->getExternalLB( $cluster );
3811         } else {
3812                 $lb = wfGetLB( $wiki );
3813         }
3814
3815         // bug 27975 - Don't try to wait for slaves if there are none
3816         // Prevents permission error when getting master position
3817         if ( $lb->getServerCount() > 1 ) {
3818                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3819                 $pos = $dbw->getMasterPos();
3820                 // The DBMS may not support getMasterPos() or the whole
3821                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3822                 if ( $pos !== false ) {
3823                         $lb->waitForAll( $pos );
3824                 }
3825         }
3826 }
3827
3828 /**
3829  * Used to be used for outputting text in the installer/updater
3830  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3831  */
3832 function wfOut( $s ) {
3833         wfDeprecated( __FUNCTION__, '1.18' );
3834         global $wgCommandLineMode;
3835         if ( $wgCommandLineMode ) {
3836                 echo $s;
3837         } else {
3838                 echo htmlspecialchars( $s );
3839         }
3840         flush();
3841 }
3842
3843 /**
3844  * Count down from $n to zero on the terminal, with a one-second pause
3845  * between showing each number. For use in command-line scripts.
3846  * @codeCoverageIgnore
3847  * @param $n int
3848  */
3849 function wfCountDown( $n ) {
3850         for ( $i = $n; $i >= 0; $i-- ) {
3851                 if ( $i != $n ) {
3852                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3853                 }
3854                 echo $i;
3855                 flush();
3856                 if ( $i ) {
3857                         sleep( 1 );
3858                 }
3859         }
3860         echo "\n";
3861 }
3862
3863 /**
3864  * Generate a random 32-character hexadecimal token.
3865  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3866  *              characters before hashing.
3867  * @return string
3868  * @codeCoverageIgnore
3869  * @deprecated since 1.20; Please use MWCryptRand for security purposes and
3870  * wfRandomString for pseudo-random strings
3871  * @warning This method is NOT secure. Additionally it has many callers that
3872  * use it for pseudo-random purposes.
3873  */
3874 function wfGenerateToken( $salt = '' ) {
3875         wfDeprecated( __METHOD__, '1.20' );
3876         $salt = serialize( $salt );
3877         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3878 }
3879
3880 /**
3881  * Replace all invalid characters with -
3882  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3883  * By default, $wgIllegalFileChars = ':'
3884  *
3885  * @param $name Mixed: filename to process
3886  * @return String
3887  */
3888 function wfStripIllegalFilenameChars( $name ) {
3889         global $wgIllegalFileChars;
3890         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3891         $name = wfBaseName( $name );
3892         $name = preg_replace(
3893                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3894                 '-',
3895                 $name
3896         );
3897         return $name;
3898 }
3899
3900 /**
3901  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3902  *
3903  * @return Integer value memory was set to.
3904  */
3905 function wfMemoryLimit() {
3906         global $wgMemoryLimit;
3907         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3908         if ( $memlimit != -1 ) {
3909                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3910                 if ( $conflimit == -1 ) {
3911                         wfDebug( "Removing PHP's memory limit\n" );
3912                         wfSuppressWarnings();
3913                         ini_set( 'memory_limit', $conflimit );
3914                         wfRestoreWarnings();
3915                         return $conflimit;
3916                 } elseif ( $conflimit > $memlimit ) {
3917                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3918                         wfSuppressWarnings();
3919                         ini_set( 'memory_limit', $conflimit );
3920                         wfRestoreWarnings();
3921                         return $conflimit;
3922                 }
3923         }
3924         return $memlimit;
3925 }
3926
3927 /**
3928  * Converts shorthand byte notation to integer form
3929  *
3930  * @param $string String
3931  * @return Integer
3932  */
3933 function wfShorthandToInteger( $string = '' ) {
3934         $string = trim( $string );
3935         if ( $string === '' ) {
3936                 return -1;
3937         }
3938         $last = $string[strlen( $string ) - 1];
3939         $val = intval( $string );
3940         switch ( $last ) {
3941                 case 'g':
3942                 case 'G':
3943                         $val *= 1024;
3944                         // break intentionally missing
3945                 case 'm':
3946                 case 'M':
3947                         $val *= 1024;
3948                         // break intentionally missing
3949                 case 'k':
3950                 case 'K':
3951                         $val *= 1024;
3952         }
3953
3954         return $val;
3955 }
3956
3957 /**
3958  * Get the normalised IETF language tag
3959  * See unit test for examples.
3960  *
3961  * @param string $code The language code.
3962  * @return String: The language code which complying with BCP 47 standards.
3963  */
3964 function wfBCP47( $code ) {
3965         $codeSegment = explode( '-', $code );
3966         $codeBCP = array();
3967         foreach ( $codeSegment as $segNo => $seg ) {
3968                 // when previous segment is x, it is a private segment and should be lc
3969                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3970                         $codeBCP[$segNo] = strtolower( $seg );
3971                 // ISO 3166 country code
3972                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3973                         $codeBCP[$segNo] = strtoupper( $seg );
3974                 // ISO 15924 script code
3975                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3976                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3977                 // Use lowercase for other cases
3978                 } else {
3979                         $codeBCP[$segNo] = strtolower( $seg );
3980                 }
3981         }
3982         $langCode = implode( '-', $codeBCP );
3983         return $langCode;
3984 }
3985
3986 /**
3987  * Get a cache object.
3988  *
3989  * @param $inputType integer Cache type, one the the CACHE_* constants.
3990  * @return BagOStuff
3991  */
3992 function wfGetCache( $inputType ) {
3993         return ObjectCache::getInstance( $inputType );
3994 }
3995
3996 /**
3997  * Get the main cache object
3998  *
3999  * @return BagOStuff
4000  */
4001 function wfGetMainCache() {
4002         global $wgMainCacheType;
4003         return ObjectCache::getInstance( $wgMainCacheType );
4004 }
4005
4006 /**
4007  * Get the cache object used by the message cache
4008  *
4009  * @return BagOStuff
4010  */
4011 function wfGetMessageCacheStorage() {
4012         global $wgMessageCacheType;
4013         return ObjectCache::getInstance( $wgMessageCacheType );
4014 }
4015
4016 /**
4017  * Get the cache object used by the parser cache
4018  *
4019  * @return BagOStuff
4020  */
4021 function wfGetParserCacheStorage() {
4022         global $wgParserCacheType;
4023         return ObjectCache::getInstance( $wgParserCacheType );
4024 }
4025
4026 /**
4027  * Get the cache object used by the language converter
4028  *
4029  * @return BagOStuff
4030  */
4031 function wfGetLangConverterCacheStorage() {
4032         global $wgLanguageConverterCacheType;
4033         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
4034 }
4035
4036 /**
4037  * Call hook functions defined in $wgHooks
4038  *
4039  * @param string $event event name
4040  * @param array $args parameters passed to hook functions
4041  * @return Boolean True if no handler aborted the hook
4042  */
4043 function wfRunHooks( $event, array $args = array() ) {
4044         return Hooks::run( $event, $args );
4045 }
4046
4047 /**
4048  * Wrapper around php's unpack.
4049  *
4050  * @param string $format The format string (See php's docs)
4051  * @param $data: A binary string of binary data
4052  * @param $length integer or false: The minimum length of $data. This is to
4053  *      prevent reading beyond the end of $data. false to disable the check.
4054  *
4055  * Also be careful when using this function to read unsigned 32 bit integer
4056  * because php might make it negative.
4057  *
4058  * @throws MWException if $data not long enough, or if unpack fails
4059  * @return array Associative array of the extracted data
4060  */
4061 function wfUnpack( $format, $data, $length = false ) {
4062         if ( $length !== false ) {
4063                 $realLen = strlen( $data );
4064                 if ( $realLen < $length ) {
4065                         throw new MWException( "Tried to use wfUnpack on a "
4066                                 . "string of length $realLen, but needed one "
4067                                 . "of at least length $length."
4068                         );
4069                 }
4070         }
4071
4072         wfSuppressWarnings();
4073         $result = unpack( $format, $data );
4074         wfRestoreWarnings();
4075
4076         if ( $result === false ) {
4077                 // If it cannot extract the packed data.
4078                 throw new MWException( "unpack could not unpack binary data" );
4079         }
4080         return $result;
4081 }
4082
4083 /**
4084  * Determine if an image exists on the 'bad image list'.
4085  *
4086  * The format of MediaWiki:Bad_image_list is as follows:
4087  *    * Only list items (lines starting with "*") are considered
4088  *    * The first link on a line must be a link to a bad image
4089  *    * Any subsequent links on the same line are considered to be exceptions,
4090  *      i.e. articles where the image may occur inline.
4091  *
4092  * @param string $name the image name to check
4093  * @param $contextTitle Title|bool the page on which the image occurs, if known
4094  * @param string $blacklist wikitext of a file blacklist
4095  * @return bool
4096  */
4097 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4098         static $badImageCache = null; // based on bad_image_list msg
4099         wfProfileIn( __METHOD__ );
4100
4101         # Handle redirects
4102         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4103         if ( $redirectTitle ) {
4104                 $name = $redirectTitle->getDBkey();
4105         }
4106
4107         # Run the extension hook
4108         $bad = false;
4109         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
4110                 wfProfileOut( __METHOD__ );
4111                 return $bad;
4112         }
4113
4114         $cacheable = ( $blacklist === null );
4115         if ( $cacheable && $badImageCache !== null ) {
4116                 $badImages = $badImageCache;
4117         } else { // cache miss
4118                 if ( $blacklist === null ) {
4119                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4120                 }
4121                 # Build the list now
4122                 $badImages = array();
4123                 $lines = explode( "\n", $blacklist );
4124                 foreach ( $lines as $line ) {
4125                         # List items only
4126                         if ( substr( $line, 0, 1 ) !== '*' ) {
4127                                 continue;
4128                         }
4129
4130                         # Find all links
4131                         $m = array();
4132                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4133                                 continue;
4134                         }
4135
4136                         $exceptions = array();
4137                         $imageDBkey = false;
4138                         foreach ( $m[1] as $i => $titleText ) {
4139                                 $title = Title::newFromText( $titleText );
4140                                 if ( !is_null( $title ) ) {
4141                                         if ( $i == 0 ) {
4142                                                 $imageDBkey = $title->getDBkey();
4143                                         } else {
4144                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4145                                         }
4146                                 }
4147                         }
4148
4149                         if ( $imageDBkey !== false ) {
4150                                 $badImages[$imageDBkey] = $exceptions;
4151                         }
4152                 }
4153                 if ( $cacheable ) {
4154                         $badImageCache = $badImages;
4155                 }
4156         }
4157
4158         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4159         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4160         wfProfileOut( __METHOD__ );
4161         return $bad;
4162 }
4163
4164 /**
4165  * Determine whether the client at a given source IP is likely to be able to
4166  * access the wiki via HTTPS.
4167  *
4168  * @param string $ip The IPv4/6 address in the normal human-readable form
4169  * @return boolean
4170  */
4171 function wfCanIPUseHTTPS( $ip ) {
4172         $canDo = true;
4173         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4174         return !!$canDo;
4175 }