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 5.3.3 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( 'mb_substr' ) ) {
  39         /**
  40          * @codeCoverageIgnore
  41          * @see Fallback::mb_substr
  42          * @return string
  43          */
  44         function mb_substr( $str, $start, $count = 'end' ) {
  45                 return Fallback::mb_substr( $str, $start, $count );
  46         }
  47
  48         /**
  49          * @codeCoverageIgnore
  50          * @see Fallback::mb_substr_split_unicode
  51          * @return int
  52          */
  53         function mb_substr_split_unicode( $str, $splitPos ) {
  54                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  55         }
  56 }
  57
  58 if ( !function_exists( 'mb_strlen' ) ) {
  59         /**
  60          * @codeCoverageIgnore
  61          * @see Fallback::mb_strlen
  62          * @return int
  63          */
  64         function mb_strlen( $str, $enc = '' ) {
  65                 return Fallback::mb_strlen( $str, $enc );
  66         }
  67 }
  68
  69 if ( !function_exists( 'mb_strpos' ) ) {
  70         /**
  71          * @codeCoverageIgnore
  72          * @see Fallback::mb_strpos
  73          * @return int
  74          */
  75         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  76                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  77         }
  78 }
  79
  80 if ( !function_exists( 'mb_strrpos' ) ) {
  81         /**
  82          * @codeCoverageIgnore
  83          * @see Fallback::mb_strrpos
  84          * @return int
  85          */
  86         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  87                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  88         }
  89 }
  90
  91 // gzdecode function only exists in PHP >= 5.4.0
  92 // http://php.net/gzdecode
  93 if ( !function_exists( 'gzdecode' ) ) {
  94         /**
  95          * @codeCoverageIgnore
  96          * @param string $data
  97          * @return string
  98          */
  99         function gzdecode( $data ) {
 100                 return gzinflate( substr( $data, 10, -8 ) );
 101         }
 102 }
 103
 104 // hash_equals function only exists in PHP >= 5.6.0
 105 // http://php.net/hash_equals
 106 if ( !function_exists( 'hash_equals' ) ) {
 107         /**
 108          * Check whether a user-provided string is equal to a fixed-length secret string
 109          * without revealing bytes of the secret string through timing differences.
 110          *
 111          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 112          * function in C) is to compare corresponding bytes and stop at the first difference,
 113          * which would take longer for a partial match than for a complete mismatch. This
 114          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 115          * and the other may come from an attacker. Statistical analysis of timing measurements
 116          * over many requests may allow the attacker to guess the string's bytes one at a time
 117          * (and check his guesses) even if the timing differences are extremely small.
 118          *
 119          * When making such a security-sensitive comparison, it is essential that the sequence
 120          * in which instructions are executed and memory locations are accessed not depend on
 121          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 122          * the inevitable leakage of the string's length. That is generally known anyway as
 123          * a chararacteristic of the hash function used to compute the secret value.
 124          *
 125          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 126          *
 127          * @codeCoverageIgnore
 128          * @param string $known_string Fixed-length secret string to compare against
 129          * @param string $user_string User-provided string
 130          * @return bool True if the strings are the same, false otherwise
 131          */
 132         function hash_equals( $known_string, $user_string ) {
 133                 // Strict type checking as in PHP's native implementation
 134                 if ( !is_string( $known_string ) ) {
 135                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 136                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 137
 138                         return false;
 139                 }
 140
 141                 if ( !is_string( $user_string ) ) {
 142                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 143                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 144
 145                         return false;
 146                 }
 147
 148                 $known_string_len = strlen( $known_string );
 149                 if ( $known_string_len !== strlen( $user_string ) ) {
 150                         return false;
 151                 }
 152
 153                 $result = 0;
 154                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 155                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 156                 }
 157
 158                 return ( $result === 0 );
 159         }
 160 }
 161 /// @endcond
 162
 163 /**
 164  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 165  * @param array $a
 166  * @param array $b
 167  * @return array
 168  */
 169 function wfArrayDiff2( $a, $b ) {
 170         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 171 }
 172
 173 /**
 174  * @param array|string $a
 175  * @param array|string $b
 176  * @return int
 177  */
 178 function wfArrayDiff2_cmp( $a, $b ) {
 179         if ( is_string( $a ) && is_string( $b ) ) {
 180                 return strcmp( $a, $b );
 181         } elseif ( count( $a ) !== count( $b ) ) {
 182                 return count( $a ) < count( $b ) ? -1 : 1;
 183         } else {
 184                 reset( $a );
 185                 reset( $b );
 186                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 187                         $cmp = strcmp( $valueA, $valueB );
 188                         if ( $cmp !== 0 ) {
 189                                 return $cmp;
 190                         }
 191                 }
 192                 return 0;
 193         }
 194 }
 195
 196 /**
 197  * Appends to second array if $value differs from that in $default
 198  *
 199  * @param string|int $key
 200  * @param mixed $value
 201  * @param mixed $default
 202  * @param array $changed Array to alter
 203  * @throws MWException
 204  */
 205 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 206         if ( is_null( $changed ) ) {
 207                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 208         }
 209         if ( $default[$key] !== $value ) {
 210                 $changed[$key] = $value;
 211         }
 212 }
 213
 214 /**
 215  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 216  * e.g.
 217  *      wfMergeErrorArrays(
 218  *              array( array( 'x' ) ),
 219  *              array( array( 'x', '2' ) ),
 220  *              array( array( 'x' ) ),
 221  *              array( array( 'y' ) )
 222  *      );
 223  * returns:
 224  *              array(
 225  *              array( 'x', '2' ),
 226  *              array( 'x' ),
 227  *              array( 'y' )
 228  *      )
 229  *
 230  * @param array $array1,...
 231  * @return array
 232  */
 233 function wfMergeErrorArrays( /*...*/ ) {
 234         $args = func_get_args();
 235         $out = array();
 236         foreach ( $args as $errors ) {
 237                 foreach ( $errors as $params ) {
 238                         # @todo FIXME: Sometimes get nested arrays for $params,
 239                         # which leads to E_NOTICEs
 240                         $spec = implode( "\t", $params );
 241                         $out[$spec] = $params;
 242                 }
 243         }
 244         return array_values( $out );
 245 }
 246
 247 /**
 248  * Insert array into another array after the specified *KEY*
 249  *
 250  * @param array $array The array.
 251  * @param array $insert The array to insert.
 252  * @param mixed $after The key to insert after
 253  * @return array
 254  */
 255 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 256         // Find the offset of the element to insert after.
 257         $keys = array_keys( $array );
 258         $offsetByKey = array_flip( $keys );
 259
 260         $offset = $offsetByKey[$after];
 261
 262         // Insert at the specified offset
 263         $before = array_slice( $array, 0, $offset + 1, true );
 264         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 265
 266         $output = $before + $insert + $after;
 267
 268         return $output;
 269 }
 270
 271 /**
 272  * Recursively converts the parameter (an object) to an array with the same data
 273  *
 274  * @param object|array $objOrArray
 275  * @param bool $recursive
 276  * @return array
 277  */
 278 function wfObjectToArray( $objOrArray, $recursive = true ) {
 279         $array = array();
 280         if ( is_object( $objOrArray ) ) {
 281                 $objOrArray = get_object_vars( $objOrArray );
 282         }
 283         foreach ( $objOrArray as $key => $value ) {
 284                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 285                         $value = wfObjectToArray( $value );
 286                 }
 287
 288                 $array[$key] = $value;
 289         }
 290
 291         return $array;
 292 }
 293
 294 /**
 295  * Get a random decimal value between 0 and 1, in a way
 296  * not likely to give duplicate values for any realistic
 297  * number of articles.
 298  *
 299  * @return string
 300  */
 301 function wfRandom() {
 302         # The maximum random value is "only" 2^31-1, so get two random
 303         # values to reduce the chance of dupes
 304         $max = mt_getrandmax() + 1;
 305         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 306
 307         return $rand;
 308 }
 309
 310 /**
 311  * Get a random string containing a number of pseudo-random hex
 312  * characters.
 313  * @note This is not secure, if you are trying to generate some sort
 314  *       of token please use MWCryptRand instead.
 315  *
 316  * @param int $length The length of the string to generate
 317  * @return string
 318  * @since 1.20
 319  */
 320 function wfRandomString( $length = 32 ) {
 321         $str = '';
 322         for ( $n = 0; $n < $length; $n += 7 ) {
 323                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 324         }
 325         return substr( $str, 0, $length );
 326 }
 327
 328 /**
 329  * We want some things to be included as literal characters in our title URLs
 330  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 331  * all of the following should be safe:
 332  *
 333  * ;:@&=$-_.+!*'(),
 334  *
 335  * But + is not safe because it's used to indicate a space; &= are only safe in
 336  * paths and not in queries (and we don't distinguish here); ' seems kind of
 337  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 338  * is reserved, we don't care.  So the list we unescape is:
 339  *
 340  * ;:@$!*(),/
 341  *
 342  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 343  * so no fancy : for IIS7.
 344  *
 345  * %2F in the page titles seems to fatally break for some reason.
 346  *
 347  * @param string $s
 348  * @return string
 349  */
 350 function wfUrlencode( $s ) {
 351         static $needle;
 352
 353         if ( is_null( $s ) ) {
 354                 $needle = null;
 355                 return '';
 356         }
 357
 358         if ( is_null( $needle ) ) {
 359                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 360                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 361                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 362                 ) {
 363                         $needle[] = '%3A';
 364                 }
 365         }
 366
 367         $s = urlencode( $s );
 368         $s = str_ireplace(
 369                 $needle,
 370                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 371                 $s
 372         );
 373
 374         return $s;
 375 }
 376
 377 /**
 378  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 379  * "days=7&limit=100". Options in the first array override options in the second.
 380  * Options set to null or false will not be output.
 381  *
 382  * @param array $array1 ( String|Array )
 383  * @param array $array2 ( String|Array )
 384  * @param string $prefix
 385  * @return string
 386  */
 387 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 388         if ( !is_null( $array2 ) ) {
 389                 $array1 = $array1 + $array2;
 390         }
 391
 392         $cgi = '';
 393         foreach ( $array1 as $key => $value ) {
 394                 if ( !is_null( $value ) && $value !== false ) {
 395                         if ( $cgi != '' ) {
 396                                 $cgi .= '&';
 397                         }
 398                         if ( $prefix !== '' ) {
 399                                 $key = $prefix . "[$key]";
 400                         }
 401                         if ( is_array( $value ) ) {
 402                                 $firstTime = true;
 403                                 foreach ( $value as $k => $v ) {
 404                                         $cgi .= $firstTime ? '' : '&';
 405                                         if ( is_array( $v ) ) {
 406                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 407                                         } else {
 408                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 409                                         }
 410                                         $firstTime = false;
 411                                 }
 412                         } else {
 413                                 if ( is_object( $value ) ) {
 414                                         $value = $value->__toString();
 415                                 }
 416                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 417                         }
 418                 }
 419         }
 420         return $cgi;
 421 }
 422
 423 /**
 424  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 425  * its argument and returns the same string in array form.  This allows compatibility
 426  * with legacy functions that accept raw query strings instead of nice
 427  * arrays.  Of course, keys and values are urldecode()d.
 428  *
 429  * @param string $query Query string
 430  * @return string[] Array version of input
 431  */
 432 function wfCgiToArray( $query ) {
 433         if ( isset( $query[0] ) && $query[0] == '?' ) {
 434                 $query = substr( $query, 1 );
 435         }
 436         $bits = explode( '&', $query );
 437         $ret = array();
 438         foreach ( $bits as $bit ) {
 439                 if ( $bit === '' ) {
 440                         continue;
 441                 }
 442                 if ( strpos( $bit, '=' ) === false ) {
 443                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 444                         $key = $bit;
 445                         $value = '';
 446                 } else {
 447                         list( $key, $value ) = explode( '=', $bit );
 448                 }
 449                 $key = urldecode( $key );
 450                 $value = urldecode( $value );
 451                 if ( strpos( $key, '[' ) !== false ) {
 452                         $keys = array_reverse( explode( '[', $key ) );
 453                         $key = array_pop( $keys );
 454                         $temp = $value;
 455                         foreach ( $keys as $k ) {
 456                                 $k = substr( $k, 0, -1 );
 457                                 $temp = array( $k => $temp );
 458                         }
 459                         if ( isset( $ret[$key] ) ) {
 460                                 $ret[$key] = array_merge( $ret[$key], $temp );
 461                         } else {
 462                                 $ret[$key] = $temp;
 463                         }
 464                 } else {
 465                         $ret[$key] = $value;
 466                 }
 467         }
 468         return $ret;
 469 }
 470
 471 /**
 472  * Append a query string to an existing URL, which may or may not already
 473  * have query string parameters already. If so, they will be combined.
 474  *
 475  * @param string $url
 476  * @param string|string[] $query String or associative array
 477  * @return string
 478  */
 479 function wfAppendQuery( $url, $query ) {
 480         if ( is_array( $query ) ) {
 481                 $query = wfArrayToCgi( $query );
 482         }
 483         if ( $query != '' ) {
 484                 if ( false === strpos( $url, '?' ) ) {
 485                         $url .= '?';
 486                 } else {
 487                         $url .= '&';
 488                 }
 489                 $url .= $query;
 490         }
 491         return $url;
 492 }
 493
 494 /**
 495  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 496  * is correct.
 497  *
 498  * The meaning of the PROTO_* constants is as follows:
 499  * PROTO_HTTP: Output a URL starting with http://
 500  * PROTO_HTTPS: Output a URL starting with https://
 501  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 502  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 503  *    on which protocol was used for the current incoming request
 504  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 505  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 506  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 507  *
 508  * @todo this won't work with current-path-relative URLs
 509  * like "subdir/foo.html", etc.
 510  *
 511  * @param string $url Either fully-qualified or a local path + query
 512  * @param string $defaultProto One of the PROTO_* constants. Determines the
 513  *    protocol to use if $url or $wgServer is protocol-relative
 514  * @return string Fully-qualified URL, current-path-relative URL or false if
 515  *    no valid URL can be constructed
 516  */
 517 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 518         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 519                 $wgHttpsPort;
 520         if ( $defaultProto === PROTO_CANONICAL ) {
 521                 $serverUrl = $wgCanonicalServer;
 522         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 523                 // Make $wgInternalServer fall back to $wgServer if not set
 524                 $serverUrl = $wgInternalServer;
 525         } else {
 526                 $serverUrl = $wgServer;
 527                 if ( $defaultProto === PROTO_CURRENT ) {
 528                         $defaultProto = $wgRequest->getProtocol() . '://';
 529                 }
 530         }
 531
 532         // Analyze $serverUrl to obtain its protocol
 533         $bits = wfParseUrl( $serverUrl );
 534         $serverHasProto = $bits && $bits['scheme'] != '';
 535
 536         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 537                 if ( $serverHasProto ) {
 538                         $defaultProto = $bits['scheme'] . '://';
 539                 } else {
 540                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 541                         // This really isn't supposed to happen. Fall back to HTTP in this
 542                         // ridiculous case.
 543                         $defaultProto = PROTO_HTTP;
 544                 }
 545         }
 546
 547         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 548
 549         if ( substr( $url, 0, 2 ) == '//' ) {
 550                 $url = $defaultProtoWithoutSlashes . $url;
 551         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 552                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 553                 // otherwise leave it alone.
 554                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 555         }
 556
 557         $bits = wfParseUrl( $url );
 558
 559         // ensure proper port for HTTPS arrives in URL
 560         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 561         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 562                 $bits['port'] = $wgHttpsPort;
 563         }
 564
 565         if ( $bits && isset( $bits['path'] ) ) {
 566                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 567                 return wfAssembleUrl( $bits );
 568         } elseif ( $bits ) {
 569                 # No path to expand
 570                 return $url;
 571         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 572                 # URL is a relative path
 573                 return wfRemoveDotSegments( $url );
 574         }
 575
 576         # Expanded URL is not valid.
 577         return false;
 578 }
 579
 580 /**
 581  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 582  * if you need to edit part of a URL and put it back together.
 583  *
 584  * This is the basic structure used (brackets contain keys for $urlParts):
 585  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 586  *
 587  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 588  *
 589  * @since 1.19
 590  * @param array $urlParts URL parts, as output from wfParseUrl
 591  * @return string URL assembled from its component parts
 592  */
 593 function wfAssembleUrl( $urlParts ) {
 594         $result = '';
 595
 596         if ( isset( $urlParts['delimiter'] ) ) {
 597                 if ( isset( $urlParts['scheme'] ) ) {
 598                         $result .= $urlParts['scheme'];
 599                 }
 600
 601                 $result .= $urlParts['delimiter'];
 602         }
 603
 604         if ( isset( $urlParts['host'] ) ) {
 605                 if ( isset( $urlParts['user'] ) ) {
 606                         $result .= $urlParts['user'];
 607                         if ( isset( $urlParts['pass'] ) ) {
 608                                 $result .= ':' . $urlParts['pass'];
 609                         }
 610                         $result .= '@';
 611                 }
 612
 613                 $result .= $urlParts['host'];
 614
 615                 if ( isset( $urlParts['port'] ) ) {
 616                         $result .= ':' . $urlParts['port'];
 617                 }
 618         }
 619
 620         if ( isset( $urlParts['path'] ) ) {
 621                 $result .= $urlParts['path'];
 622         }
 623
 624         if ( isset( $urlParts['query'] ) ) {
 625                 $result .= '?' . $urlParts['query'];
 626         }
 627
 628         if ( isset( $urlParts['fragment'] ) ) {
 629                 $result .= '#' . $urlParts['fragment'];
 630         }
 631
 632         return $result;
 633 }
 634
 635 /**
 636  * Remove all dot-segments in the provided URL path.  For example,
 637  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 638  * RFC3986 section 5.2.4.
 639  *
 640  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 641  *
 642  * @param string $urlPath URL path, potentially containing dot-segments
 643  * @return string URL path with all dot-segments removed
 644  */
 645 function wfRemoveDotSegments( $urlPath ) {
 646         $output = '';
 647         $inputOffset = 0;
 648         $inputLength = strlen( $urlPath );
 649
 650         while ( $inputOffset < $inputLength ) {
 651                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 652                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 653                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 654                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 655                 $trimOutput = false;
 656
 657                 if ( $prefixLengthTwo == './' ) {
 658                         # Step A, remove leading "./"
 659                         $inputOffset += 2;
 660                 } elseif ( $prefixLengthThree == '../' ) {
 661                         # Step A, remove leading "../"
 662                         $inputOffset += 3;
 663                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 664                         # Step B, replace leading "/.$" with "/"
 665                         $inputOffset += 1;
 666                         $urlPath[$inputOffset] = '/';
 667                 } elseif ( $prefixLengthThree == '/./' ) {
 668                         # Step B, replace leading "/./" with "/"
 669                         $inputOffset += 2;
 670                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 671                         # Step C, replace leading "/..$" with "/" and
 672                         # remove last path component in output
 673                         $inputOffset += 2;
 674                         $urlPath[$inputOffset] = '/';
 675                         $trimOutput = true;
 676                 } elseif ( $prefixLengthFour == '/../' ) {
 677                         # Step C, replace leading "/../" with "/" and
 678                         # remove last path component in output
 679                         $inputOffset += 3;
 680                         $trimOutput = true;
 681                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 682                         # Step D, remove "^.$"
 683                         $inputOffset += 1;
 684                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 685                         # Step D, remove "^..$"
 686                         $inputOffset += 2;
 687                 } else {
 688                         # Step E, move leading path segment to output
 689                         if ( $prefixLengthOne == '/' ) {
 690                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 691                         } else {
 692                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 693                         }
 694                         if ( $slashPos === false ) {
 695                                 $output .= substr( $urlPath, $inputOffset );
 696                                 $inputOffset = $inputLength;
 697                         } else {
 698                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 699                                 $inputOffset += $slashPos - $inputOffset;
 700                         }
 701                 }
 702
 703                 if ( $trimOutput ) {
 704                         $slashPos = strrpos( $output, '/' );
 705                         if ( $slashPos === false ) {
 706                                 $output = '';
 707                         } else {
 708                                 $output = substr( $output, 0, $slashPos );
 709                         }
 710                 }
 711         }
 712
 713         return $output;
 714 }
 715
 716 /**
 717  * Returns a regular expression of url protocols
 718  *
 719  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 720  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 721  * @return string
 722  */
 723 function wfUrlProtocols( $includeProtocolRelative = true ) {
 724         global $wgUrlProtocols;
 725
 726         // Cache return values separately based on $includeProtocolRelative
 727         static $withProtRel = null, $withoutProtRel = null;
 728         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 729         if ( !is_null( $cachedValue ) ) {
 730                 return $cachedValue;
 731         }
 732
 733         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 734         // with LocalSettings files from 1.5
 735         if ( is_array( $wgUrlProtocols ) ) {
 736                 $protocols = array();
 737                 foreach ( $wgUrlProtocols as $protocol ) {
 738                         // Filter out '//' if !$includeProtocolRelative
 739                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 740                                 $protocols[] = preg_quote( $protocol, '/' );
 741                         }
 742                 }
 743
 744                 $retval = implode( '|', $protocols );
 745         } else {
 746                 // Ignore $includeProtocolRelative in this case
 747                 // This case exists for pre-1.6 compatibility, and we can safely assume
 748                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 749                 // URLs weren't supported until 1.18
 750                 $retval = $wgUrlProtocols;
 751         }
 752
 753         // Cache return value
 754         if ( $includeProtocolRelative ) {
 755                 $withProtRel = $retval;
 756         } else {
 757                 $withoutProtRel = $retval;
 758         }
 759         return $retval;
 760 }
 761
 762 /**
 763  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 764  * you need a regex that matches all URL protocols but does not match protocol-
 765  * relative URLs
 766  * @return string
 767  */
 768 function wfUrlProtocolsWithoutProtRel() {
 769         return wfUrlProtocols( false );
 770 }
 771
 772 /**
 773  * parse_url() work-alike, but non-broken.  Differences:
 774  *
 775  * 1) Does not raise warnings on bad URLs (just returns false).
 776  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 777  *    protocol-relative URLs) correctly.
 778  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 779  *
 780  * @param string $url A URL to parse
 781  * @return string[] Bits of the URL in an associative array, per PHP docs
 782  */
 783 function wfParseUrl( $url ) {
 784         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 785
 786         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 787         // bad that the easiest way to handle them is to just prepend 'http:' and
 788         // strip the protocol out later.
 789         $wasRelative = substr( $url, 0, 2 ) == '//';
 790         if ( $wasRelative ) {
 791                 $url = "http:$url";
 792         }
 793         wfSuppressWarnings();
 794         $bits = parse_url( $url );
 795         wfRestoreWarnings();
 796         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 797         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 798         if ( !$bits || !isset( $bits['scheme'] ) ) {
 799                 return false;
 800         }
 801
 802         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 803         $bits['scheme'] = strtolower( $bits['scheme'] );
 804
 805         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 806         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 807                 $bits['delimiter'] = '://';
 808         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 809                 $bits['delimiter'] = ':';
 810                 // parse_url detects for news: and mailto: the host part of an url as path
 811                 // We have to correct this wrong detection
 812                 if ( isset( $bits['path'] ) ) {
 813                         $bits['host'] = $bits['path'];
 814                         $bits['path'] = '';
 815                 }
 816         } else {
 817                 return false;
 818         }
 819
 820         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 821         if ( !isset( $bits['host'] ) ) {
 822                 $bits['host'] = '';
 823
 824                 // bug 45069
 825                 if ( isset( $bits['path'] ) ) {
 826                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 827                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 828                                 $bits['path'] = '/' . $bits['path'];
 829                         }
 830                 } else {
 831                         $bits['path'] = '';
 832                 }
 833         }
 834
 835         // If the URL was protocol-relative, fix scheme and delimiter
 836         if ( $wasRelative ) {
 837                 $bits['scheme'] = '';
 838                 $bits['delimiter'] = '//';
 839         }
 840         return $bits;
 841 }
 842
 843 /**
 844  * Take a URL, make sure it's expanded to fully qualified, and replace any
 845  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 846  * for more compact display and legibility for local audiences.
 847  *
 848  * @todo handle punycode domains too
 849  *
 850  * @param string $url
 851  * @return string
 852  */
 853 function wfExpandIRI( $url ) {
 854         return preg_replace_callback(
 855                 '/((?:%[89A-F][0-9A-F])+)/i',
 856                 'wfExpandIRI_callback',
 857                 wfExpandUrl( $url )
 858         );
 859 }
 860
 861 /**
 862  * Private callback for wfExpandIRI
 863  * @param array $matches
 864  * @return string
 865  */
 866 function wfExpandIRI_callback( $matches ) {
 867         return urldecode( $matches[1] );
 868 }
 869
 870 /**
 871  * Make URL indexes, appropriate for the el_index field of externallinks.
 872  *
 873  * @param string $url
 874  * @return array
 875  */
 876 function wfMakeUrlIndexes( $url ) {
 877         $bits = wfParseUrl( $url );
 878
 879         // Reverse the labels in the hostname, convert to lower case
 880         // For emails reverse domainpart only
 881         if ( $bits['scheme'] == 'mailto' ) {
 882                 $mailparts = explode( '@', $bits['host'], 2 );
 883                 if ( count( $mailparts ) === 2 ) {
 884                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 885                 } else {
 886                         // No domain specified, don't mangle it
 887                         $domainpart = '';
 888                 }
 889                 $reversedHost = $domainpart . '@' . $mailparts[0];
 890         } else {
 891                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 892         }
 893         // Add an extra dot to the end
 894         // Why? Is it in wrong place in mailto links?
 895         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 896                 $reversedHost .= '.';
 897         }
 898         // Reconstruct the pseudo-URL
 899         $prot = $bits['scheme'];
 900         $index = $prot . $bits['delimiter'] . $reversedHost;
 901         // Leave out user and password. Add the port, path, query and fragment
 902         if ( isset( $bits['port'] ) ) {
 903                 $index .= ':' . $bits['port'];
 904         }
 905         if ( isset( $bits['path'] ) ) {
 906                 $index .= $bits['path'];
 907         } else {
 908                 $index .= '/';
 909         }
 910         if ( isset( $bits['query'] ) ) {
 911                 $index .= '?' . $bits['query'];
 912         }
 913         if ( isset( $bits['fragment'] ) ) {
 914                 $index .= '#' . $bits['fragment'];
 915         }
 916
 917         if ( $prot == '' ) {
 918                 return array( "http:$index", "https:$index" );
 919         } else {
 920                 return array( $index );
 921         }
 922 }
 923
 924 /**
 925  * Check whether a given URL has a domain that occurs in a given set of domains
 926  * @param string $url URL
 927  * @param array $domains Array of domains (strings)
 928  * @return bool True if the host part of $url ends in one of the strings in $domains
 929  */
 930 function wfMatchesDomainList( $url, $domains ) {
 931         $bits = wfParseUrl( $url );
 932         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 933                 $host = '.' . $bits['host'];
 934                 foreach ( (array)$domains as $domain ) {
 935                         $domain = '.' . $domain;
 936                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 937                                 return true;
 938                         }
 939                 }
 940         }
 941         return false;
 942 }
 943
 944 /**
 945  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 946  * In normal operation this is a NOP.
 947  *
 948  * Controlling globals:
 949  * $wgDebugLogFile - points to the log file
 950  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 951  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 952  *
 953  * @param string $text
 954  * @param string|bool $dest Destination of the message:
 955  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 956  *     - 'log': only to the log and not in HTML
 957  *   For backward compatibility, it can also take a boolean:
 958  *     - true: same as 'all'
 959  *     - false: same as 'log'
 960  */
 961 function wfDebug( $text, $dest = 'all' ) {
 962         global $wgDebugRawPage, $wgDebugLogPrefix;
 963
 964         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 965                 return;
 966         }
 967
 968         // Turn $dest into a string if it's a boolean (for b/c)
 969         if ( $dest === true ) {
 970                 $dest = 'all';
 971         } elseif ( $dest === false ) {
 972                 $dest = 'log';
 973         }
 974
 975         $timer = wfDebugTimer();
 976         if ( $timer !== '' ) {
 977                 // Prepend elapsed request time and real memory usage to each line
 978                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 979         }
 980
 981         if ( $dest === 'all' ) {
 982                 MWDebug::debugMsg( $text );
 983         }
 984
 985         $ctx = array();
 986         if ( $wgDebugLogPrefix !== '' ) {
 987                 $ctx['prefix'] = $wgDebugLogPrefix;
 988         }
 989
 990         $logger = MWLogger::getInstance( 'wfDebug' );
 991         $logger->debug( rtrim( $text, "\n" ), $ctx );
 992 }
 993
 994 /**
 995  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 996  * @return bool
 997  */
 998 function wfIsDebugRawPage() {
 999         static $cache;
1000         if ( $cache !== null ) {
1001                 return $cache;
1002         }
1003         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1004         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1005                 || (
1006                         isset( $_SERVER['SCRIPT_NAME'] )
1007                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1008                 )
1009         ) {
1010                 $cache = true;
1011         } else {
1012                 $cache = false;
1013         }
1014         return $cache;
1015 }
1016
1017 /**
1018  * Get microsecond timestamps for debug logs
1019  *
1020  * @return string
1021  */
1022 function wfDebugTimer() {
1023         global $wgDebugTimestamps, $wgRequestTime;
1024
1025         if ( !$wgDebugTimestamps ) {
1026                 return '';
1027         }
1028
1029         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1030         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1031         return "$prefix $mem  ";
1032 }
1033
1034 /**
1035  * Send a line giving PHP memory usage.
1036  *
1037  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1038  */
1039 function wfDebugMem( $exact = false ) {
1040         $mem = memory_get_usage();
1041         if ( !$exact ) {
1042                 $mem = floor( $mem / 1024 ) . ' KiB';
1043         } else {
1044                 $mem .= ' B';
1045         }
1046         wfDebug( "Memory usage: $mem\n" );
1047 }
1048
1049 /**
1050  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1051  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to a string
1052  * filename or an associative array mapping 'destination' to the desired filename. The
1053  * associative array may also contain a 'sample' key with an integer value, specifying
1054  * a sampling factor.
1055  *
1056  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1057  *
1058  * @param string $logGroup
1059  * @param string $text
1060  * @param string|bool $dest Destination of the message:
1061  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1062  *     - 'log': only to the log and not in HTML
1063  *     - 'private': only to the specifc log if set in $wgDebugLogGroups and
1064  *       discarded otherwise
1065  *   For backward compatibility, it can also take a boolean:
1066  *     - true: same as 'all'
1067  *     - false: same as 'private'
1068  */
1069 function wfDebugLog( $logGroup, $text, $dest = 'all' ) {
1070         // Turn $dest into a string if it's a boolean (for b/c)
1071         if ( $dest === true ) {
1072                 $dest = 'all';
1073         } elseif ( $dest === false ) {
1074                 $dest = 'private';
1075         }
1076
1077         $text = trim( $text );
1078
1079         if ( $dest === 'all' ) {
1080                 MWDebug::debugMsg( "[{$logGroup}] {$text}\n" );
1081         }
1082
1083         $logger = MWLogger::getInstance( $logGroup );
1084         $logger->debug( $text, array(
1085                 'private' => ( $dest === 'private' ),
1086         ) );
1087 }
1088
1089 /**
1090  * Log for database errors
1091  *
1092  * @param string $text Database error message.
1093  */
1094 function wfLogDBError( $text ) {
1095         $logger = MWLogger::getInstance( 'wfLogDBError' );
1096         $logger->error( trim( $text ) );
1097 }
1098
1099 /**
1100  * Throws a warning that $function is deprecated
1101  *
1102  * @param string $function
1103  * @param string|bool $version Version of MediaWiki that the function
1104  *    was deprecated in (Added in 1.19).
1105  * @param string|bool $component Added in 1.19.
1106  * @param int $callerOffset How far up the call stack is the original
1107  *    caller. 2 = function that called the function that called
1108  *    wfDeprecated (Added in 1.20)
1109  *
1110  * @return null
1111  */
1112 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1113         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1114 }
1115
1116 /**
1117  * Send a warning either to the debug log or in a PHP error depending on
1118  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1119  *
1120  * @param string $msg Message to send
1121  * @param int $callerOffset Number of items to go back in the backtrace to
1122  *        find the correct caller (1 = function calling wfWarn, ...)
1123  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1124  *        only used when $wgDevelopmentWarnings is true
1125  */
1126 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1127         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1128 }
1129
1130 /**
1131  * Send a warning as a PHP error and the debug log. This is intended for logging
1132  * warnings in production. For logging development warnings, use WfWarn instead.
1133  *
1134  * @param string $msg Message to send
1135  * @param int $callerOffset Number of items to go back in the backtrace to
1136  *        find the correct caller (1 = function calling wfLogWarning, ...)
1137  * @param int $level PHP error level; defaults to E_USER_WARNING
1138  */
1139 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1140         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1141 }
1142
1143 /**
1144  * Log to a file without getting "file size exceeded" signals.
1145  *
1146  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1147  * send lines to the specified port, prefixed by the specified prefix and a space.
1148  *
1149  * @param string $text
1150  * @param string $file Filename
1151  * @throws MWException
1152  */
1153 function wfErrorLog( $text, $file ) {
1154         $logger = MWLogger::getInstance( 'wfErrorLog' );
1155         $logger->info( trim( $text ), array(
1156                 'destination' => $file,
1157         ) );
1158 }
1159
1160 /**
1161  * @todo document
1162  */
1163 function wfLogProfilingData() {
1164         global $wgRequestTime, $wgDebugLogFile, $wgDebugLogGroups, $wgDebugRawPage;
1165         global $wgProfileLimit, $wgUser, $wgRequest;
1166
1167         StatCounter::singleton()->flush();
1168
1169         $profiler = Profiler::instance();
1170
1171         # Profiling must actually be enabled...
1172         if ( $profiler->isStub() ) {
1173                 return;
1174         }
1175
1176         // Get total page request time and only show pages that longer than
1177         // $wgProfileLimit time (default is 0)
1178         $elapsed = microtime( true ) - $wgRequestTime;
1179         if ( $elapsed <= $wgProfileLimit ) {
1180                 return;
1181         }
1182
1183         $profiler->logData();
1184
1185         // Check whether this should be logged in the debug file.
1186         if ( isset( $wgDebugLogGroups['profileoutput'] )
1187                 && $wgDebugLogGroups['profileoutput'] === false
1188         ) {
1189                 // Explicitely disabled
1190                 return;
1191         }
1192         if ( !isset( $wgDebugLogGroups['profileoutput'] ) && $wgDebugLogFile == '' ) {
1193                 // Logging not enabled; no point going further
1194                 return;
1195         }
1196         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1197                 return;
1198         }
1199
1200         $forward = '';
1201         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1202                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1203         }
1204         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1205                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1206         }
1207         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1208                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1209         }
1210         if ( $forward ) {
1211                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1212         }
1213         // Don't load $wgUser at this late stage just for statistics purposes
1214         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1215         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1216                 $forward .= ' anon';
1217         }
1218
1219         // Command line script uses a FauxRequest object which does not have
1220         // any knowledge about an URL and throw an exception instead.
1221         try {
1222                 $requestUrl = $wgRequest->getRequestURL();
1223         } catch ( MWException $e ) {
1224                 $requestUrl = 'n/a';
1225         }
1226
1227         $log = sprintf( "%s\t%04.3f\t%s\n",
1228                 gmdate( 'YmdHis' ), $elapsed,
1229                 urldecode( $requestUrl . $forward ) );
1230
1231         wfDebugLog( 'profileoutput', $log . $profiler->getOutput() );
1232 }
1233
1234 /**
1235  * Increment a statistics counter
1236  *
1237  * @param string $key
1238  * @param int $count
1239  * @return void
1240  */
1241 function wfIncrStats( $key, $count = 1 ) {
1242         StatCounter::singleton()->incr( $key, $count );
1243 }
1244
1245 /**
1246  * Check whether the wiki is in read-only mode.
1247  *
1248  * @return bool
1249  */
1250 function wfReadOnly() {
1251         return wfReadOnlyReason() !== false;
1252 }
1253
1254 /**
1255  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1256  *
1257  * @return string|bool String when in read-only mode; false otherwise
1258  */
1259 function wfReadOnlyReason() {
1260         global $wgReadOnly, $wgReadOnlyFile;
1261
1262         if ( $wgReadOnly === null ) {
1263                 // Set $wgReadOnly for faster access next time
1264                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1265                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1266                 } else {
1267                         $wgReadOnly = false;
1268                 }
1269         }
1270
1271         return $wgReadOnly;
1272 }
1273
1274 /**
1275  * Return a Language object from $langcode
1276  *
1277  * @param Language|string|bool $langcode Either:
1278  *                  - a Language object
1279  *                  - code of the language to get the message for, if it is
1280  *                    a valid code create a language for that language, if
1281  *                    it is a string but not a valid code then make a basic
1282  *                    language object
1283  *                  - a boolean: if it's false then use the global object for
1284  *                    the current user's language (as a fallback for the old parameter
1285  *                    functionality), or if it is true then use global object
1286  *                    for the wiki's content language.
1287  * @return Language
1288  */
1289 function wfGetLangObj( $langcode = false ) {
1290         # Identify which language to get or create a language object for.
1291         # Using is_object here due to Stub objects.
1292         if ( is_object( $langcode ) ) {
1293                 # Great, we already have the object (hopefully)!
1294                 return $langcode;
1295         }
1296
1297         global $wgContLang, $wgLanguageCode;
1298         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1299                 # $langcode is the language code of the wikis content language object.
1300                 # or it is a boolean and value is true
1301                 return $wgContLang;
1302         }
1303
1304         global $wgLang;
1305         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1306                 # $langcode is the language code of user language object.
1307                 # or it was a boolean and value is false
1308                 return $wgLang;
1309         }
1310
1311         $validCodes = array_keys( Language::fetchLanguageNames() );
1312         if ( in_array( $langcode, $validCodes ) ) {
1313                 # $langcode corresponds to a valid language.
1314                 return Language::factory( $langcode );
1315         }
1316
1317         # $langcode is a string, but not a valid language code; use content language.
1318         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1319         return $wgContLang;
1320 }
1321
1322 /**
1323  * This is the function for getting translated interface messages.
1324  *
1325  * @see Message class for documentation how to use them.
1326  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1327  *
1328  * This function replaces all old wfMsg* functions.
1329  *
1330  * @param string|string[] $key Message key, or array of keys
1331  * @param mixed $params,... Normal message parameters
1332  * @return Message
1333  *
1334  * @since 1.17
1335  *
1336  * @see Message::__construct
1337  */
1338 function wfMessage( $key /*...*/ ) {
1339         $params = func_get_args();
1340         array_shift( $params );
1341         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1342                 $params = $params[0];
1343         }
1344         return new Message( $key, $params );
1345 }
1346
1347 /**
1348  * This function accepts multiple message keys and returns a message instance
1349  * for the first message which is non-empty. If all messages are empty then an
1350  * instance of the first message key is returned.
1351  *
1352  * @param string|string[] $keys,... Message keys
1353  * @return Message
1354  *
1355  * @since 1.18
1356  *
1357  * @see Message::newFallbackSequence
1358  */
1359 function wfMessageFallback( /*...*/ ) {
1360         $args = func_get_args();
1361         return call_user_func_array( 'Message::newFallbackSequence', $args );
1362 }
1363
1364 /**
1365  * Get a message from anywhere, for the current user language.
1366  *
1367  * Use wfMsgForContent() instead if the message should NOT
1368  * change depending on the user preferences.
1369  *
1370  * @deprecated since 1.18
1371  *
1372  * @param string $key Lookup key for the message, usually
1373  *    defined in languages/Language.php
1374  *
1375  * Parameters to the message, which can be used to insert variable text into
1376  * it, can be passed to this function in the following formats:
1377  * - One per argument, starting at the second parameter
1378  * - As an array in the second parameter
1379  * These are not shown in the function definition.
1380  *
1381  * @return string
1382  */
1383 function wfMsg( $key ) {
1384         wfDeprecated( __METHOD__, '1.21' );
1385
1386         $args = func_get_args();
1387         array_shift( $args );
1388         return wfMsgReal( $key, $args );
1389 }
1390
1391 /**
1392  * Same as above except doesn't transform the message
1393  *
1394  * @deprecated since 1.18
1395  *
1396  * @param string $key
1397  * @return string
1398  */
1399 function wfMsgNoTrans( $key ) {
1400         wfDeprecated( __METHOD__, '1.21' );
1401
1402         $args = func_get_args();
1403         array_shift( $args );
1404         return wfMsgReal( $key, $args, true, false, false );
1405 }
1406
1407 /**
1408  * Get a message from anywhere, for the current global language
1409  * set with $wgLanguageCode.
1410  *
1411  * Use this if the message should NOT change dependent on the
1412  * language set in the user's preferences. This is the case for
1413  * most text written into logs, as well as link targets (such as
1414  * the name of the copyright policy page). Link titles, on the
1415  * other hand, should be shown in the UI language.
1416  *
1417  * Note that MediaWiki allows users to change the user interface
1418  * language in their preferences, but a single installation
1419  * typically only contains content in one language.
1420  *
1421  * Be wary of this distinction: If you use wfMsg() where you should
1422  * use wfMsgForContent(), a user of the software may have to
1423  * customize potentially hundreds of messages in
1424  * order to, e.g., fix a link in every possible language.
1425  *
1426  * @deprecated since 1.18
1427  *
1428  * @param string $key Lookup key for the message, usually
1429  *     defined in languages/Language.php
1430  * @return string
1431  */
1432 function wfMsgForContent( $key ) {
1433         wfDeprecated( __METHOD__, '1.21' );
1434
1435         global $wgForceUIMsgAsContentMsg;
1436         $args = func_get_args();
1437         array_shift( $args );
1438         $forcontent = true;
1439         if ( is_array( $wgForceUIMsgAsContentMsg )
1440                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1441         ) {
1442                 $forcontent = false;
1443         }
1444         return wfMsgReal( $key, $args, true, $forcontent );
1445 }
1446
1447 /**
1448  * Same as above except doesn't transform the message
1449  *
1450  * @deprecated since 1.18
1451  *
1452  * @param string $key
1453  * @return string
1454  */
1455 function wfMsgForContentNoTrans( $key ) {
1456         wfDeprecated( __METHOD__, '1.21' );
1457
1458         global $wgForceUIMsgAsContentMsg;
1459         $args = func_get_args();
1460         array_shift( $args );
1461         $forcontent = true;
1462         if ( is_array( $wgForceUIMsgAsContentMsg )
1463                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1464         ) {
1465                 $forcontent = false;
1466         }
1467         return wfMsgReal( $key, $args, true, $forcontent, false );
1468 }
1469
1470 /**
1471  * Really get a message
1472  *
1473  * @deprecated since 1.18
1474  *
1475  * @param string $key Key to get.
1476  * @param array $args
1477  * @param bool $useDB
1478  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1479  * @param bool $transform Whether or not to transform the message.
1480  * @return string The requested message.
1481  */
1482 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1483         wfDeprecated( __METHOD__, '1.21' );
1484
1485         wfProfileIn( __METHOD__ );
1486         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1487         $message = wfMsgReplaceArgs( $message, $args );
1488         wfProfileOut( __METHOD__ );
1489         return $message;
1490 }
1491
1492 /**
1493  * Fetch a message string value, but don't replace any keys yet.
1494  *
1495  * @deprecated since 1.18
1496  *
1497  * @param string $key
1498  * @param bool $useDB
1499  * @param string|bool $langCode Code of the language to get the message for, or
1500  *   behaves as a content language switch if it is a boolean.
1501  * @param bool $transform Whether to parse magic words, etc.
1502  * @return string
1503  */
1504 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1505         wfDeprecated( __METHOD__, '1.21' );
1506
1507         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1508
1509         $cache = MessageCache::singleton();
1510         $message = $cache->get( $key, $useDB, $langCode );
1511         if ( $message === false ) {
1512                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1513         } elseif ( $transform ) {
1514                 $message = $cache->transform( $message );
1515         }
1516         return $message;
1517 }
1518
1519 /**
1520  * Replace message parameter keys on the given formatted output.
1521  *
1522  * @param string $message
1523  * @param array $args
1524  * @return string
1525  * @private
1526  */
1527 function wfMsgReplaceArgs( $message, $args ) {
1528         # Fix windows line-endings
1529         # Some messages are split with explode("\n", $msg)
1530         $message = str_replace( "\r", '', $message );
1531
1532         // Replace arguments
1533         if ( count( $args ) ) {
1534                 if ( is_array( $args[0] ) ) {
1535                         $args = array_values( $args[0] );
1536                 }
1537                 $replacementKeys = array();
1538                 foreach ( $args as $n => $param ) {
1539                         $replacementKeys['$' . ( $n + 1 )] = $param;
1540                 }
1541                 $message = strtr( $message, $replacementKeys );
1542         }
1543
1544         return $message;
1545 }
1546
1547 /**
1548  * Return an HTML-escaped version of a message.
1549  * Parameter replacements, if any, are done *after* the HTML-escaping,
1550  * so parameters may contain HTML (eg links or form controls). Be sure
1551  * to pre-escape them if you really do want plaintext, or just wrap
1552  * the whole thing in htmlspecialchars().
1553  *
1554  * @deprecated since 1.18
1555  *
1556  * @param string $key
1557  * @param string $args,... Parameters
1558  * @return string
1559  */
1560 function wfMsgHtml( $key ) {
1561         wfDeprecated( __METHOD__, '1.21' );
1562
1563         $args = func_get_args();
1564         array_shift( $args );
1565         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1566 }
1567
1568 /**
1569  * Return an HTML version of message
1570  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1571  * so parameters may contain HTML (eg links or form controls). Be sure
1572  * to pre-escape them if you really do want plaintext, or just wrap
1573  * the whole thing in htmlspecialchars().
1574  *
1575  * @deprecated since 1.18
1576  *
1577  * @param string $key
1578  * @param string $args,... Parameters
1579  * @return string
1580  */
1581 function wfMsgWikiHtml( $key ) {
1582         wfDeprecated( __METHOD__, '1.21' );
1583
1584         $args = func_get_args();
1585         array_shift( $args );
1586         return wfMsgReplaceArgs(
1587                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1588                 /* can't be set to false */ true, /* interface */ true )->getText(),
1589                 $args );
1590 }
1591
1592 /**
1593  * Returns message in the requested format
1594  *
1595  * @deprecated since 1.18
1596  *
1597  * @param string $key Key of the message
1598  * @param array $options Processing rules.
1599  *   Can take the following options:
1600  *     parse: parses wikitext to HTML
1601  *     parseinline: parses wikitext to HTML and removes the surrounding
1602  *       p's added by parser or tidy
1603  *     escape: filters message through htmlspecialchars
1604  *     escapenoentities: same, but allows entity references like &#160; through
1605  *     replaceafter: parameters are substituted after parsing or escaping
1606  *     parsemag: transform the message using magic phrases
1607  *     content: fetch message for content language instead of interface
1608  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1609  *     language: Language object or language code to fetch message for
1610  *       (overridden by content).
1611  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1612  *
1613  * @return string
1614  */
1615 function wfMsgExt( $key, $options ) {
1616         wfDeprecated( __METHOD__, '1.21' );
1617
1618         $args = func_get_args();
1619         array_shift( $args );
1620         array_shift( $args );
1621         $options = (array)$options;
1622
1623         foreach ( $options as $arrayKey => $option ) {
1624                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1625                         # An unknown index, neither numeric nor "language"
1626                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1627                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1628                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1629                 'replaceafter', 'parsemag', 'content' ) ) ) {
1630                         # A numeric index with unknown value
1631                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1632                 }
1633         }
1634
1635         if ( in_array( 'content', $options, true ) ) {
1636                 $forContent = true;
1637                 $langCode = true;
1638                 $langCodeObj = null;
1639         } elseif ( array_key_exists( 'language', $options ) ) {
1640                 $forContent = false;
1641                 $langCode = wfGetLangObj( $options['language'] );
1642                 $langCodeObj = $langCode;
1643         } else {
1644                 $forContent = false;
1645                 $langCode = false;
1646                 $langCodeObj = null;
1647         }
1648
1649         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1650
1651         if ( !in_array( 'replaceafter', $options, true ) ) {
1652                 $string = wfMsgReplaceArgs( $string, $args );
1653         }
1654
1655         $messageCache = MessageCache::singleton();
1656         $parseInline = in_array( 'parseinline', $options, true );
1657         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1658                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1659                 if ( $string instanceof ParserOutput ) {
1660                         $string = $string->getText();
1661                 }
1662
1663                 if ( $parseInline ) {
1664                         $string = Parser::stripOuterParagraph( $string );
1665                 }
1666         } elseif ( in_array( 'parsemag', $options, true ) ) {
1667                 $string = $messageCache->transform( $string,
1668                                 !$forContent, $langCodeObj );
1669         }
1670
1671         if ( in_array( 'escape', $options, true ) ) {
1672                 $string = htmlspecialchars ( $string );
1673         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1674                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1675         }
1676
1677         if ( in_array( 'replaceafter', $options, true ) ) {
1678                 $string = wfMsgReplaceArgs( $string, $args );
1679         }
1680
1681         return $string;
1682 }
1683
1684 /**
1685  * Since wfMsg() and co suck, they don't return false if the message key they
1686  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1687  * nonexistence of messages by checking the MessageCache::get() result directly.
1688  *
1689  * @deprecated since 1.18. Use Message::isDisabled().
1690  *
1691  * @param string $key The message key looked up
1692  * @return bool True if the message *doesn't* exist.
1693  */
1694 function wfEmptyMsg( $key ) {
1695         wfDeprecated( __METHOD__, '1.21' );
1696
1697         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1698 }
1699
1700 /**
1701  * Fetch server name for use in error reporting etc.
1702  * Use real server name if available, so we know which machine
1703  * in a server farm generated the current page.
1704  *
1705  * @return string
1706  */
1707 function wfHostname() {
1708         static $host;
1709         if ( is_null( $host ) ) {
1710
1711                 # Hostname overriding
1712                 global $wgOverrideHostname;
1713                 if ( $wgOverrideHostname !== false ) {
1714                         # Set static and skip any detection
1715                         $host = $wgOverrideHostname;
1716                         return $host;
1717                 }
1718
1719                 if ( function_exists( 'posix_uname' ) ) {
1720                         // This function not present on Windows
1721                         $uname = posix_uname();
1722                 } else {
1723                         $uname = false;
1724                 }
1725                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1726                         $host = $uname['nodename'];
1727                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1728                         # Windows computer name
1729                         $host = getenv( 'COMPUTERNAME' );
1730                 } else {
1731                         # This may be a virtual server.
1732                         $host = $_SERVER['SERVER_NAME'];
1733                 }
1734         }
1735         return $host;
1736 }
1737
1738 /**
1739  * Returns a script tag that stores the amount of time it took MediaWiki to
1740  * handle the request in milliseconds as 'wgBackendResponseTime'.
1741  *
1742  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1743  * hostname of the server handling the request.
1744  *
1745  * @return string
1746  */
1747 function wfReportTime() {
1748         global $wgRequestTime, $wgShowHostnames;
1749
1750         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1751         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1752         if ( $wgShowHostnames ) {
1753                 $reportVars['wgHostname'] = wfHostname();
1754         }
1755         return Skin::makeVariablesScript( $reportVars );
1756 }
1757
1758 /**
1759  * Safety wrapper for debug_backtrace().
1760  *
1761  * Will return an empty array if debug_backtrace is disabled, otherwise
1762  * the output from debug_backtrace() (trimmed).
1763  *
1764  * @param int $limit This parameter can be used to limit the number of stack frames returned
1765  *
1766  * @return array Array of backtrace information
1767  */
1768 function wfDebugBacktrace( $limit = 0 ) {
1769         static $disabled = null;
1770
1771         if ( is_null( $disabled ) ) {
1772                 $disabled = !function_exists( 'debug_backtrace' );
1773                 if ( $disabled ) {
1774                         wfDebug( "debug_backtrace() is disabled\n" );
1775                 }
1776         }
1777         if ( $disabled ) {
1778                 return array();
1779         }
1780
1781         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1782                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1783         } else {
1784                 return array_slice( debug_backtrace(), 1 );
1785         }
1786 }
1787
1788 /**
1789  * Get a debug backtrace as a string
1790  *
1791  * @return string
1792  */
1793 function wfBacktrace() {
1794         global $wgCommandLineMode;
1795
1796         if ( $wgCommandLineMode ) {
1797                 $msg = '';
1798         } else {
1799                 $msg = "<ul>\n";
1800         }
1801         $backtrace = wfDebugBacktrace();
1802         foreach ( $backtrace as $call ) {
1803                 if ( isset( $call['file'] ) ) {
1804                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1805                         $file = $f[count( $f ) - 1];
1806                 } else {
1807                         $file = '-';
1808                 }
1809                 if ( isset( $call['line'] ) ) {
1810                         $line = $call['line'];
1811                 } else {
1812                         $line = '-';
1813                 }
1814                 if ( $wgCommandLineMode ) {
1815                         $msg .= "$file line $line calls ";
1816                 } else {
1817                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1818                 }
1819                 if ( !empty( $call['class'] ) ) {
1820                         $msg .= $call['class'] . $call['type'];
1821                 }
1822                 $msg .= $call['function'] . '()';
1823
1824                 if ( $wgCommandLineMode ) {
1825                         $msg .= "\n";
1826                 } else {
1827                         $msg .= "</li>\n";
1828                 }
1829         }
1830         if ( $wgCommandLineMode ) {
1831                 $msg .= "\n";
1832         } else {
1833                 $msg .= "</ul>\n";
1834         }
1835
1836         return $msg;
1837 }
1838
1839 /**
1840  * Get the name of the function which called this function
1841  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1842  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1843  * wfGetCaller( 3 ) is the parent of that.
1844  *
1845  * @param int $level
1846  * @return string
1847  */
1848 function wfGetCaller( $level = 2 ) {
1849         $backtrace = wfDebugBacktrace( $level + 1 );
1850         if ( isset( $backtrace[$level] ) ) {
1851                 return wfFormatStackFrame( $backtrace[$level] );
1852         } else {
1853                 return 'unknown';
1854         }
1855 }
1856
1857 /**
1858  * Return a string consisting of callers in the stack. Useful sometimes
1859  * for profiling specific points.
1860  *
1861  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1862  * @return string
1863  */
1864 function wfGetAllCallers( $limit = 3 ) {
1865         $trace = array_reverse( wfDebugBacktrace() );
1866         if ( !$limit || $limit > count( $trace ) - 1 ) {
1867                 $limit = count( $trace ) - 1;
1868         }
1869         $trace = array_slice( $trace, -$limit - 1, $limit );
1870         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1871 }
1872
1873 /**
1874  * Return a string representation of frame
1875  *
1876  * @param array $frame
1877  * @return string
1878  */
1879 function wfFormatStackFrame( $frame ) {
1880         return isset( $frame['class'] ) ?
1881                 $frame['class'] . '::' . $frame['function'] :
1882                 $frame['function'];
1883 }
1884
1885 /* Some generic result counters, pulled out of SearchEngine */
1886
1887 /**
1888  * @todo document
1889  *
1890  * @param int $offset
1891  * @param int $limit
1892  * @return string
1893  */
1894 function wfShowingResults( $offset, $limit ) {
1895         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1896 }
1897
1898 /**
1899  * @todo document
1900  * @todo FIXME: We may want to blacklist some broken browsers
1901  *
1902  * @param bool $force
1903  * @return bool Whereas client accept gzip compression
1904  */
1905 function wfClientAcceptsGzip( $force = false ) {
1906         static $result = null;
1907         if ( $result === null || $force ) {
1908                 $result = false;
1909                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1910                         # @todo FIXME: We may want to blacklist some broken browsers
1911                         $m = array();
1912                         if ( preg_match(
1913                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1914                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1915                                         $m
1916                                 )
1917                         ) {
1918                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1919                                         $result = false;
1920                                         return $result;
1921                                 }
1922                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1923                                 $result = true;
1924                         }
1925                 }
1926         }
1927         return $result;
1928 }
1929
1930 /**
1931  * Obtain the offset and limit values from the request string;
1932  * used in special pages
1933  *
1934  * @param int $deflimit Default limit if none supplied
1935  * @param string $optionname Name of a user preference to check against
1936  * @return array
1937  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
1938  */
1939 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1940         global $wgRequest;
1941         wfDeprecated( __METHOD__, '1.24' );
1942         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1943 }
1944
1945 /**
1946  * Escapes the given text so that it may be output using addWikiText()
1947  * without any linking, formatting, etc. making its way through. This
1948  * is achieved by substituting certain characters with HTML entities.
1949  * As required by the callers, "<nowiki>" is not used.
1950  *
1951  * @param string $text Text to be escaped
1952  * @return string
1953  */
1954 function wfEscapeWikiText( $text ) {
1955         static $repl = null, $repl2 = null;
1956         if ( $repl === null ) {
1957                 $repl = array(
1958                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1959                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1960                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1961                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1962                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1963                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1964                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1965                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1966                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1967                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1968                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1969                         '__' => '_&#95;', '://' => '&#58;//',
1970                 );
1971
1972                 // We have to catch everything "\s" matches in PCRE
1973                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
1974                         $repl["$magic "] = "$magic&#32;";
1975                         $repl["$magic\t"] = "$magic&#9;";
1976                         $repl["$magic\r"] = "$magic&#13;";
1977                         $repl["$magic\n"] = "$magic&#10;";
1978                         $repl["$magic\f"] = "$magic&#12;";
1979                 }
1980
1981                 // And handle protocols that don't use "://"
1982                 global $wgUrlProtocols;
1983                 $repl2 = array();
1984                 foreach ( $wgUrlProtocols as $prot ) {
1985                         if ( substr( $prot, -1 ) === ':' ) {
1986                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1987                         }
1988                 }
1989                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
1990         }
1991         $text = substr( strtr( "\n$text", $repl ), 1 );
1992         $text = preg_replace( $repl2, '$1&#58;', $text );
1993         return $text;
1994 }
1995
1996 /**
1997  * Sets dest to source and returns the original value of dest
1998  * If source is NULL, it just returns the value, it doesn't set the variable
1999  * If force is true, it will set the value even if source is NULL
2000  *
2001  * @param mixed $dest
2002  * @param mixed $source
2003  * @param bool $force
2004  * @return mixed
2005  */
2006 function wfSetVar( &$dest, $source, $force = false ) {
2007         $temp = $dest;
2008         if ( !is_null( $source ) || $force ) {
2009                 $dest = $source;
2010         }
2011         return $temp;
2012 }
2013
2014 /**
2015  * As for wfSetVar except setting a bit
2016  *
2017  * @param int $dest
2018  * @param int $bit
2019  * @param bool $state
2020  *
2021  * @return bool
2022  */
2023 function wfSetBit( &$dest, $bit, $state = true ) {
2024         $temp = (bool)( $dest & $bit );
2025         if ( !is_null( $state ) ) {
2026                 if ( $state ) {
2027                         $dest |= $bit;
2028                 } else {
2029                         $dest &= ~$bit;
2030                 }
2031         }
2032         return $temp;
2033 }
2034
2035 /**
2036  * A wrapper around the PHP function var_export().
2037  * Either print it or add it to the regular output ($wgOut).
2038  *
2039  * @param mixed $var A PHP variable to dump.
2040  */
2041 function wfVarDump( $var ) {
2042         global $wgOut;
2043         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2044         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2045                 print $s;
2046         } else {
2047                 $wgOut->addHTML( $s );
2048         }
2049 }
2050
2051 /**
2052  * Provide a simple HTTP error.
2053  *
2054  * @param int|string $code
2055  * @param string $label
2056  * @param string $desc
2057  */
2058 function wfHttpError( $code, $label, $desc ) {
2059         global $wgOut;
2060         $wgOut->disable();
2061         header( "HTTP/1.0 $code $label" );
2062         header( "Status: $code $label" );
2063         $wgOut->sendCacheControl();
2064
2065         header( 'Content-type: text/html; charset=utf-8' );
2066         print "<!doctype html>" .
2067                 '<html><head><title>' .
2068                 htmlspecialchars( $label ) .
2069                 '</title></head><body><h1>' .
2070                 htmlspecialchars( $label ) .
2071                 '</h1><p>' .
2072                 nl2br( htmlspecialchars( $desc ) ) .
2073                 "</p></body></html>\n";
2074 }
2075
2076 /**
2077  * Clear away any user-level output buffers, discarding contents.
2078  *
2079  * Suitable for 'starting afresh', for instance when streaming
2080  * relatively large amounts of data without buffering, or wanting to
2081  * output image files without ob_gzhandler's compression.
2082  *
2083  * The optional $resetGzipEncoding parameter controls suppression of
2084  * the Content-Encoding header sent by ob_gzhandler; by default it
2085  * is left. See comments for wfClearOutputBuffers() for why it would
2086  * be used.
2087  *
2088  * Note that some PHP configuration options may add output buffer
2089  * layers which cannot be removed; these are left in place.
2090  *
2091  * @param bool $resetGzipEncoding
2092  */
2093 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2094         if ( $resetGzipEncoding ) {
2095                 // Suppress Content-Encoding and Content-Length
2096                 // headers from 1.10+s wfOutputHandler
2097                 global $wgDisableOutputCompression;
2098                 $wgDisableOutputCompression = true;
2099         }
2100         while ( $status = ob_get_status() ) {
2101                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2102                         // Probably from zlib.output_compression or other
2103                         // PHP-internal setting which can't be removed.
2104                         //
2105                         // Give up, and hope the result doesn't break
2106                         // output behavior.
2107                         break;
2108                 }
2109                 if ( !ob_end_clean() ) {
2110                         // Could not remove output buffer handler; abort now
2111                         // to avoid getting in some kind of infinite loop.
2112                         break;
2113                 }
2114                 if ( $resetGzipEncoding ) {
2115                         if ( $status['name'] == 'ob_gzhandler' ) {
2116                                 // Reset the 'Content-Encoding' field set by this handler
2117                                 // so we can start fresh.
2118                                 header_remove( 'Content-Encoding' );
2119                                 break;
2120                         }
2121                 }
2122         }
2123 }
2124
2125 /**
2126  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2127  *
2128  * Clear away output buffers, but keep the Content-Encoding header
2129  * produced by ob_gzhandler, if any.
2130  *
2131  * This should be used for HTTP 304 responses, where you need to
2132  * preserve the Content-Encoding header of the real result, but
2133  * also need to suppress the output of ob_gzhandler to keep to spec
2134  * and avoid breaking Firefox in rare cases where the headers and
2135  * body are broken over two packets.
2136  */
2137 function wfClearOutputBuffers() {
2138         wfResetOutputBuffers( false );
2139 }
2140
2141 /**
2142  * Converts an Accept-* header into an array mapping string values to quality
2143  * factors
2144  *
2145  * @param string $accept
2146  * @param string $def Default
2147  * @return float[] Associative array of string => float pairs
2148  */
2149 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2150         # No arg means accept anything (per HTTP spec)
2151         if ( !$accept ) {
2152                 return array( $def => 1.0 );
2153         }
2154
2155         $prefs = array();
2156
2157         $parts = explode( ',', $accept );
2158
2159         foreach ( $parts as $part ) {
2160                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2161                 $values = explode( ';', trim( $part ) );
2162                 $match = array();
2163                 if ( count( $values ) == 1 ) {
2164                         $prefs[$values[0]] = 1.0;
2165                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2166                         $prefs[$values[0]] = floatval( $match[1] );
2167                 }
2168         }
2169
2170         return $prefs;
2171 }
2172
2173 /**
2174  * Checks if a given MIME type matches any of the keys in the given
2175  * array. Basic wildcards are accepted in the array keys.
2176  *
2177  * Returns the matching MIME type (or wildcard) if a match, otherwise
2178  * NULL if no match.
2179  *
2180  * @param string $type
2181  * @param array $avail
2182  * @return string
2183  * @private
2184  */
2185 function mimeTypeMatch( $type, $avail ) {
2186         if ( array_key_exists( $type, $avail ) ) {
2187                 return $type;
2188         } else {
2189                 $parts = explode( '/', $type );
2190                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2191                         return $parts[0] . '/*';
2192                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2193                         return '*/*';
2194                 } else {
2195                         return null;
2196                 }
2197         }
2198 }
2199
2200 /**
2201  * Returns the 'best' match between a client's requested internet media types
2202  * and the server's list of available types. Each list should be an associative
2203  * array of type to preference (preference is a float between 0.0 and 1.0).
2204  * Wildcards in the types are acceptable.
2205  *
2206  * @param array $cprefs Client's acceptable type list
2207  * @param array $sprefs Server's offered types
2208  * @return string
2209  *
2210  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2211  * XXX: generalize to negotiate other stuff
2212  */
2213 function wfNegotiateType( $cprefs, $sprefs ) {
2214         $combine = array();
2215
2216         foreach ( array_keys( $sprefs ) as $type ) {
2217                 $parts = explode( '/', $type );
2218                 if ( $parts[1] != '*' ) {
2219                         $ckey = mimeTypeMatch( $type, $cprefs );
2220                         if ( $ckey ) {
2221                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2222                         }
2223                 }
2224         }
2225
2226         foreach ( array_keys( $cprefs ) as $type ) {
2227                 $parts = explode( '/', $type );
2228                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2229                         $skey = mimeTypeMatch( $type, $sprefs );
2230                         if ( $skey ) {
2231                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2232                         }
2233                 }
2234         }
2235
2236         $bestq = 0;
2237         $besttype = null;
2238
2239         foreach ( array_keys( $combine ) as $type ) {
2240                 if ( $combine[$type] > $bestq ) {
2241                         $besttype = $type;
2242                         $bestq = $combine[$type];
2243                 }
2244         }
2245
2246         return $besttype;
2247 }
2248
2249 /**
2250  * Reference-counted warning suppression
2251  *
2252  * @param bool $end
2253  */
2254 function wfSuppressWarnings( $end = false ) {
2255         static $suppressCount = 0;
2256         static $originalLevel = false;
2257
2258         if ( $end ) {
2259                 if ( $suppressCount ) {
2260                         --$suppressCount;
2261                         if ( !$suppressCount ) {
2262                                 error_reporting( $originalLevel );
2263                         }
2264                 }
2265         } else {
2266                 if ( !$suppressCount ) {
2267                         $originalLevel = error_reporting( E_ALL & ~(
2268                                 E_WARNING |
2269                                 E_NOTICE |
2270                                 E_USER_WARNING |
2271                                 E_USER_NOTICE |
2272                                 E_DEPRECATED |
2273                                 E_USER_DEPRECATED |
2274                                 E_STRICT
2275                         ) );
2276                 }
2277                 ++$suppressCount;
2278         }
2279 }
2280
2281 /**
2282  * Restore error level to previous value
2283  */
2284 function wfRestoreWarnings() {
2285         wfSuppressWarnings( true );
2286 }
2287
2288 # Autodetect, convert and provide timestamps of various types
2289
2290 /**
2291  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2292  */
2293 define( 'TS_UNIX', 0 );
2294
2295 /**
2296  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2297  */
2298 define( 'TS_MW', 1 );
2299
2300 /**
2301  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2302  */
2303 define( 'TS_DB', 2 );
2304
2305 /**
2306  * RFC 2822 format, for E-mail and HTTP headers
2307  */
2308 define( 'TS_RFC2822', 3 );
2309
2310 /**
2311  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2312  *
2313  * This is used by Special:Export
2314  */
2315 define( 'TS_ISO_8601', 4 );
2316
2317 /**
2318  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2319  *
2320  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2321  *       DateTime tag and page 36 for the DateTimeOriginal and
2322  *       DateTimeDigitized tags.
2323  */
2324 define( 'TS_EXIF', 5 );
2325
2326 /**
2327  * Oracle format time.
2328  */
2329 define( 'TS_ORACLE', 6 );
2330
2331 /**
2332  * Postgres format time.
2333  */
2334 define( 'TS_POSTGRES', 7 );
2335
2336 /**
2337  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2338  */
2339 define( 'TS_ISO_8601_BASIC', 9 );
2340
2341 /**
2342  * Get a timestamp string in one of various formats
2343  *
2344  * @param mixed $outputtype A timestamp in one of the supported formats, the
2345  *   function will autodetect which format is supplied and act accordingly.
2346  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2347  * @return string|bool String / false The same date in the format specified in $outputtype or false
2348  */
2349 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2350         try {
2351                 $timestamp = new MWTimestamp( $ts );
2352                 return $timestamp->getTimestamp( $outputtype );
2353         } catch ( TimestampException $e ) {
2354                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2355                 return false;
2356         }
2357 }
2358
2359 /**
2360  * Return a formatted timestamp, or null if input is null.
2361  * For dealing with nullable timestamp columns in the database.
2362  *
2363  * @param int $outputtype
2364  * @param string $ts
2365  * @return string
2366  */
2367 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2368         if ( is_null( $ts ) ) {
2369                 return null;
2370         } else {
2371                 return wfTimestamp( $outputtype, $ts );
2372         }
2373 }
2374
2375 /**
2376  * Convenience function; returns MediaWiki timestamp for the present time.
2377  *
2378  * @return string
2379  */
2380 function wfTimestampNow() {
2381         # return NOW
2382         return wfTimestamp( TS_MW, time() );
2383 }
2384
2385 /**
2386  * Check if the operating system is Windows
2387  *
2388  * @return bool True if it's Windows, false otherwise.
2389  */
2390 function wfIsWindows() {
2391         static $isWindows = null;
2392         if ( $isWindows === null ) {
2393                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2394         }
2395         return $isWindows;
2396 }
2397
2398 /**
2399  * Check if we are running under HHVM
2400  *
2401  * @return bool
2402  */
2403 function wfIsHHVM() {
2404         return defined( 'HHVM_VERSION' );
2405 }
2406
2407 /**
2408  * Swap two variables
2409  *
2410  * @deprecated since 1.24
2411  * @param mixed $x
2412  * @param mixed $y
2413  */
2414 function swap( &$x, &$y ) {
2415         wfDeprecated( __FUNCTION__, '1.24' );
2416         $z = $x;
2417         $x = $y;
2418         $y = $z;
2419 }
2420
2421 /**
2422  * Tries to get the system directory for temporary files. First
2423  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2424  * environment variables are then checked in sequence, and if none are
2425  * set try sys_get_temp_dir().
2426  *
2427  * NOTE: When possible, use instead the tmpfile() function to create
2428  * temporary files to avoid race conditions on file creation, etc.
2429  *
2430  * @return string
2431  */
2432 function wfTempDir() {
2433         global $wgTmpDirectory;
2434
2435         if ( $wgTmpDirectory !== false ) {
2436                 return $wgTmpDirectory;
2437         }
2438
2439         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2440
2441         foreach ( $tmpDir as $tmp ) {
2442                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2443                         return $tmp;
2444                 }
2445         }
2446         return sys_get_temp_dir();
2447 }
2448
2449 /**
2450  * Make directory, and make all parent directories if they don't exist
2451  *
2452  * @param string $dir Full path to directory to create
2453  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2454  * @param string $caller Optional caller param for debugging.
2455  * @throws MWException
2456  * @return bool
2457  */
2458 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2459         global $wgDirectoryMode;
2460
2461         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2462                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2463         }
2464
2465         if ( !is_null( $caller ) ) {
2466                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2467         }
2468
2469         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2470                 return true;
2471         }
2472
2473         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2474
2475         if ( is_null( $mode ) ) {
2476                 $mode = $wgDirectoryMode;
2477         }
2478
2479         // Turn off the normal warning, we're doing our own below
2480         wfSuppressWarnings();
2481         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2482         wfRestoreWarnings();
2483
2484         if ( !$ok ) {
2485                 //directory may have been created on another request since we last checked
2486                 if ( is_dir( $dir ) ) {
2487                         return true;
2488                 }
2489
2490                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2491                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2492         }
2493         return $ok;
2494 }
2495
2496 /**
2497  * Remove a directory and all its content.
2498  * Does not hide error.
2499  * @param string $dir
2500  */
2501 function wfRecursiveRemoveDir( $dir ) {
2502         wfDebug( __FUNCTION__ . "( $dir )\n" );
2503         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2504         if ( is_dir( $dir ) ) {
2505                 $objects = scandir( $dir );
2506                 foreach ( $objects as $object ) {
2507                         if ( $object != "." && $object != ".." ) {
2508                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2509                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2510                                 } else {
2511                                         unlink( $dir . '/' . $object );
2512                                 }
2513                         }
2514                 }
2515                 reset( $objects );
2516                 rmdir( $dir );
2517         }
2518 }
2519
2520 /**
2521  * @param int $nr The number to format
2522  * @param int $acc The number of digits after the decimal point, default 2
2523  * @param bool $round Whether or not to round the value, default true
2524  * @return string
2525  */
2526 function wfPercent( $nr, $acc = 2, $round = true ) {
2527         $ret = sprintf( "%.${acc}f", $nr );
2528         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2529 }
2530
2531 /**
2532  * Safety wrapper around ini_get() for boolean settings.
2533  * The values returned from ini_get() are pre-normalized for settings
2534  * set via php.ini or php_flag/php_admin_flag... but *not*
2535  * for those set via php_value/php_admin_value.
2536  *
2537  * It's fairly common for people to use php_value instead of php_flag,
2538  * which can leave you with an 'off' setting giving a false positive
2539  * for code that just takes the ini_get() return value as a boolean.
2540  *
2541  * To make things extra interesting, setting via php_value accepts
2542  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2543  * Unrecognized values go false... again opposite PHP's own coercion
2544  * from string to bool.
2545  *
2546  * Luckily, 'properly' set settings will always come back as '0' or '1',
2547  * so we only have to worry about them and the 'improper' settings.
2548  *
2549  * I frickin' hate PHP... :P
2550  *
2551  * @param string $setting
2552  * @return bool
2553  */
2554 function wfIniGetBool( $setting ) {
2555         $val = strtolower( ini_get( $setting ) );
2556         // 'on' and 'true' can't have whitespace around them, but '1' can.
2557         return $val == 'on'
2558                 || $val == 'true'
2559                 || $val == 'yes'
2560                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2561 }
2562
2563 /**
2564  * Windows-compatible version of escapeshellarg()
2565  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2566  * function puts single quotes in regardless of OS.
2567  *
2568  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2569  * earlier distro releases of PHP)
2570  *
2571  * @param string $args,...
2572  * @return string
2573  */
2574 function wfEscapeShellArg( /*...*/ ) {
2575         wfInitShellLocale();
2576
2577         $args = func_get_args();
2578         $first = true;
2579         $retVal = '';
2580         foreach ( $args as $arg ) {
2581                 if ( !$first ) {
2582                         $retVal .= ' ';
2583                 } else {
2584                         $first = false;
2585                 }
2586
2587                 if ( wfIsWindows() ) {
2588                         // Escaping for an MSVC-style command line parser and CMD.EXE
2589                         // @codingStandardsIgnoreStart For long URLs
2590                         // Refs:
2591                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2592                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2593                         //  * Bug #13518
2594                         //  * CR r63214
2595                         // Double the backslashes before any double quotes. Escape the double quotes.
2596                         // @codingStandardsIgnoreEnd
2597                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2598                         $arg = '';
2599                         $iteration = 0;
2600                         foreach ( $tokens as $token ) {
2601                                 if ( $iteration % 2 == 1 ) {
2602                                         // Delimiter, a double quote preceded by zero or more slashes
2603                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2604                                 } elseif ( $iteration % 4 == 2 ) {
2605                                         // ^ in $token will be outside quotes, need to be escaped
2606                                         $arg .= str_replace( '^', '^^', $token );
2607                                 } else { // $iteration % 4 == 0
2608                                         // ^ in $token will appear inside double quotes, so leave as is
2609                                         $arg .= $token;
2610                                 }
2611                                 $iteration++;
2612                         }
2613                         // Double the backslashes before the end of the string, because
2614                         // we will soon add a quote
2615                         $m = array();
2616                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2617                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2618                         }
2619
2620                         // Add surrounding quotes
2621                         $retVal .= '"' . $arg . '"';
2622                 } else {
2623                         $retVal .= escapeshellarg( $arg );
2624                 }
2625         }
2626         return $retVal;
2627 }
2628
2629 /**
2630  * Check if wfShellExec() is effectively disabled via php.ini config
2631  *
2632  * @return bool|string False or one of (safemode,disabled)
2633  * @since 1.22
2634  */
2635 function wfShellExecDisabled() {
2636         static $disabled = null;
2637         if ( is_null( $disabled ) ) {
2638                 if ( wfIniGetBool( 'safe_mode' ) ) {
2639                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2640                         $disabled = 'safemode';
2641                 } elseif ( !function_exists( 'proc_open' ) ) {
2642                         wfDebug( "proc_open() is disabled\n" );
2643                         $disabled = 'disabled';
2644                 } else {
2645                         $disabled = false;
2646                 }
2647         }
2648         return $disabled;
2649 }
2650
2651 /**
2652  * Execute a shell command, with time and memory limits mirrored from the PHP
2653  * configuration if supported.
2654  *
2655  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2656  *   or an array of unescaped arguments, in which case each value will be escaped
2657  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2658  * @param null|mixed &$retval Optional, will receive the program's exit code.
2659  *   (non-zero is usually failure). If there is an error from
2660  *   read, select, or proc_open(), this will be set to -1.
2661  * @param array $environ Optional environment variables which should be
2662  *   added to the executed command environment.
2663  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2664  *   this overwrites the global wgMaxShell* limits.
2665  * @param array $options Array of options:
2666  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2667  *     including errors from limit.sh
2668  *
2669  * @return string Collected stdout as a string
2670  */
2671 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2672         $limits = array(), $options = array()
2673 ) {
2674         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2675                 $wgMaxShellWallClockTime, $wgShellCgroup;
2676
2677         $disabled = wfShellExecDisabled();
2678         if ( $disabled ) {
2679                 $retval = 1;
2680                 return $disabled == 'safemode' ?
2681                         'Unable to run external programs in safe mode.' :
2682                         'Unable to run external programs, proc_open() is disabled.';
2683         }
2684
2685         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2686
2687         wfInitShellLocale();
2688
2689         $envcmd = '';
2690         foreach ( $environ as $k => $v ) {
2691                 if ( wfIsWindows() ) {
2692                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2693                          * appear in the environment variable, so we must use carat escaping as documented in
2694                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2695                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2696                          * are listed there but doesn't appear to need it.
2697                          */
2698                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2699                 } else {
2700                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2701                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2702                          */
2703                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2704                 }
2705         }
2706         if ( is_array( $cmd ) ) {
2707                 // Command line may be given as an array, escape each value and glue them together with a space
2708                 $cmdVals = array();
2709                 foreach ( $cmd as $val ) {
2710                         $cmdVals[] = wfEscapeShellArg( $val );
2711                 }
2712                 $cmd = implode( ' ', $cmdVals );
2713         }
2714
2715         $cmd = $envcmd . $cmd;
2716
2717         $useLogPipe = false;
2718         if ( is_executable( '/bin/bash' ) ) {
2719                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2720                 if ( isset( $limits['walltime'] ) ) {
2721                         $wallTime = intval( $limits['walltime'] );
2722                 } elseif ( isset( $limits['time'] ) ) {
2723                         $wallTime = $time;
2724                 } else {
2725                         $wallTime = intval( $wgMaxShellWallClockTime );
2726                 }
2727                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2728                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2729
2730                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2731                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2732                                 escapeshellarg( $cmd ) . ' ' .
2733                                 escapeshellarg(
2734                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2735                                         "MW_CPU_LIMIT=$time; " .
2736                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2737                                         "MW_MEM_LIMIT=$mem; " .
2738                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2739                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2740                                         "MW_USE_LOG_PIPE=yes"
2741                                 );
2742                         $useLogPipe = true;
2743                 } elseif ( $includeStderr ) {
2744                         $cmd .= ' 2>&1';
2745                 }
2746         } elseif ( $includeStderr ) {
2747                 $cmd .= ' 2>&1';
2748         }
2749         wfDebug( "wfShellExec: $cmd\n" );
2750
2751         $desc = array(
2752                 0 => array( 'file', 'php://stdin', 'r' ),
2753                 1 => array( 'pipe', 'w' ),
2754                 2 => array( 'file', 'php://stderr', 'w' ) );
2755         if ( $useLogPipe ) {
2756                 $desc[3] = array( 'pipe', 'w' );
2757         }
2758         $pipes = null;
2759         $proc = proc_open( $cmd, $desc, $pipes );
2760         if ( !$proc ) {
2761                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2762                 $retval = -1;
2763                 return '';
2764         }
2765         $outBuffer = $logBuffer = '';
2766         $emptyArray = array();
2767         $status = false;
2768         $logMsg = false;
2769
2770         // According to the documentation, it is possible for stream_select()
2771         // to fail due to EINTR. I haven't managed to induce this in testing
2772         // despite sending various signals. If it did happen, the error
2773         // message would take the form:
2774         //
2775         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2776         //
2777         // where [4] is the value of the macro EINTR and "Interrupted system
2778         // call" is string which according to the Linux manual is "possibly"
2779         // localised according to LC_MESSAGES.
2780         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2781         $eintrMessage = "stream_select(): unable to select [$eintr]";
2782
2783         // Build a table mapping resource IDs to pipe FDs to work around a
2784         // PHP 5.3 issue in which stream_select() does not preserve array keys
2785         // <https://bugs.php.net/bug.php?id=53427>.
2786         $fds = array();
2787         foreach ( $pipes as $fd => $pipe ) {
2788                 $fds[(int)$pipe] = $fd;
2789         }
2790
2791         $running = true;
2792         $timeout = null;
2793         $numReadyPipes = 0;
2794
2795         while ( $running === true || $numReadyPipes !== 0 ) {
2796                 if ( $running ) {
2797                         $status = proc_get_status( $proc );
2798                         // If the process has terminated, switch to nonblocking selects
2799                         // for getting any data still waiting to be read.
2800                         if ( !$status['running'] ) {
2801                                 $running = false;
2802                                 $timeout = 0;
2803                         }
2804                 }
2805
2806                 $readyPipes = $pipes;
2807
2808                 // Clear last error
2809                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2810                 @trigger_error( '' );
2811                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2812                 if ( $numReadyPipes === false ) {
2813                         // @codingStandardsIgnoreEnd
2814                         $error = error_get_last();
2815                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2816                                 continue;
2817                         } else {
2818                                 trigger_error( $error['message'], E_USER_WARNING );
2819                                 $logMsg = $error['message'];
2820                                 break;
2821                         }
2822                 }
2823                 foreach ( $readyPipes as $pipe ) {
2824                         $block = fread( $pipe, 65536 );
2825                         $fd = $fds[(int)$pipe];
2826                         if ( $block === '' ) {
2827                                 // End of file
2828                                 fclose( $pipes[$fd] );
2829                                 unset( $pipes[$fd] );
2830                                 if ( !$pipes ) {
2831                                         break 2;
2832                                 }
2833                         } elseif ( $block === false ) {
2834                                 // Read error
2835                                 $logMsg = "Error reading from pipe";
2836                                 break 2;
2837                         } elseif ( $fd == 1 ) {
2838                                 // From stdout
2839                                 $outBuffer .= $block;
2840                         } elseif ( $fd == 3 ) {
2841                                 // From log FD
2842                                 $logBuffer .= $block;
2843                                 if ( strpos( $block, "\n" ) !== false ) {
2844                                         $lines = explode( "\n", $logBuffer );
2845                                         $logBuffer = array_pop( $lines );
2846                                         foreach ( $lines as $line ) {
2847                                                 wfDebugLog( 'exec', $line );
2848                                         }
2849                                 }
2850                         }
2851                 }
2852         }
2853
2854         foreach ( $pipes as $pipe ) {
2855                 fclose( $pipe );
2856         }
2857
2858         // Use the status previously collected if possible, since proc_get_status()
2859         // just calls waitpid() which will not return anything useful the second time.
2860         if ( $running ) {
2861                 $status = proc_get_status( $proc );
2862         }
2863
2864         if ( $logMsg !== false ) {
2865                 // Read/select error
2866                 $retval = -1;
2867                 proc_close( $proc );
2868         } elseif ( $status['signaled'] ) {
2869                 $logMsg = "Exited with signal {$status['termsig']}";
2870                 $retval = 128 + $status['termsig'];
2871                 proc_close( $proc );
2872         } else {
2873                 if ( $status['running'] ) {
2874                         $retval = proc_close( $proc );
2875                 } else {
2876                         $retval = $status['exitcode'];
2877                         proc_close( $proc );
2878                 }
2879                 if ( $retval == 127 ) {
2880                         $logMsg = "Possibly missing executable file";
2881                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2882                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2883                 }
2884         }
2885
2886         if ( $logMsg !== false ) {
2887                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2888         }
2889
2890         return $outBuffer;
2891 }
2892
2893 /**
2894  * Execute a shell command, returning both stdout and stderr. Convenience
2895  * function, as all the arguments to wfShellExec can become unwieldy.
2896  *
2897  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2898  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2899  *   or an array of unescaped arguments, in which case each value will be escaped
2900  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2901  * @param null|mixed &$retval Optional, will receive the program's exit code.
2902  *   (non-zero is usually failure)
2903  * @param array $environ Optional environment variables which should be
2904  *   added to the executed command environment.
2905  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2906  *   this overwrites the global wgMaxShell* limits.
2907  * @return string Collected stdout and stderr as a string
2908  */
2909 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2910         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
2911 }
2912
2913 /**
2914  * Workaround for http://bugs.php.net/bug.php?id=45132
2915  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2916  */
2917 function wfInitShellLocale() {
2918         static $done = false;
2919         if ( $done ) {
2920                 return;
2921         }
2922         $done = true;
2923         global $wgShellLocale;
2924         if ( !wfIniGetBool( 'safe_mode' ) ) {
2925                 putenv( "LC_CTYPE=$wgShellLocale" );
2926                 setlocale( LC_CTYPE, $wgShellLocale );
2927         }
2928 }
2929
2930 /**
2931  * Alias to wfShellWikiCmd()
2932  *
2933  * @see wfShellWikiCmd()
2934  */
2935 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2936         return wfShellWikiCmd( $script, $parameters, $options );
2937 }
2938
2939 /**
2940  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2941  * Note that $parameters should be a flat array and an option with an argument
2942  * should consist of two consecutive items in the array (do not use "--option value").
2943  *
2944  * @param string $script MediaWiki cli script path
2945  * @param array $parameters Arguments and options to the script
2946  * @param array $options Associative array of options:
2947  *              'php': The path to the php executable
2948  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2949  * @return string
2950  */
2951 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2952         global $wgPhpCli;
2953         // Give site config file a chance to run the script in a wrapper.
2954         // The caller may likely want to call wfBasename() on $script.
2955         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2956         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2957         if ( isset( $options['wrapper'] ) ) {
2958                 $cmd[] = $options['wrapper'];
2959         }
2960         $cmd[] = $script;
2961         // Escape each parameter for shell
2962         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2963 }
2964
2965 /**
2966  * wfMerge attempts to merge differences between three texts.
2967  * Returns true for a clean merge and false for failure or a conflict.
2968  *
2969  * @param string $old
2970  * @param string $mine
2971  * @param string $yours
2972  * @param string $result
2973  * @return bool
2974  */
2975 function wfMerge( $old, $mine, $yours, &$result ) {
2976         global $wgDiff3;
2977
2978         # This check may also protect against code injection in
2979         # case of broken installations.
2980         wfSuppressWarnings();
2981         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2982         wfRestoreWarnings();
2983
2984         if ( !$haveDiff3 ) {
2985                 wfDebug( "diff3 not found\n" );
2986                 return false;
2987         }
2988
2989         # Make temporary files
2990         $td = wfTempDir();
2991         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2992         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2993         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2994
2995         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2996         #       a newline character. To avoid this, we normalize the trailing whitespace before
2997         #       creating the diff.
2998
2999         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3000         fclose( $oldtextFile );
3001         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3002         fclose( $mytextFile );
3003         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3004         fclose( $yourtextFile );
3005
3006         # Check for a conflict
3007         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3008                 wfEscapeShellArg( $mytextName ) . ' ' .
3009                 wfEscapeShellArg( $oldtextName ) . ' ' .
3010                 wfEscapeShellArg( $yourtextName );
3011         $handle = popen( $cmd, 'r' );
3012
3013         if ( fgets( $handle, 1024 ) ) {
3014                 $conflict = true;
3015         } else {
3016                 $conflict = false;
3017         }
3018         pclose( $handle );
3019
3020         # Merge differences
3021         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3022                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3023         $handle = popen( $cmd, 'r' );
3024         $result = '';
3025         do {
3026                 $data = fread( $handle, 8192 );
3027                 if ( strlen( $data ) == 0 ) {
3028                         break;
3029                 }
3030                 $result .= $data;
3031         } while ( true );
3032         pclose( $handle );
3033         unlink( $mytextName );
3034         unlink( $oldtextName );
3035         unlink( $yourtextName );
3036
3037         if ( $result === '' && $old !== '' && !$conflict ) {
3038                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3039                 $conflict = true;
3040         }
3041         return !$conflict;
3042 }
3043
3044 /**
3045  * Returns unified plain-text diff of two texts.
3046  * Useful for machine processing of diffs.
3047  *
3048  * @param string $before The text before the changes.
3049  * @param string $after The text after the changes.
3050  * @param string $params Command-line options for the diff command.
3051  * @return string Unified diff of $before and $after
3052  */
3053 function wfDiff( $before, $after, $params = '-u' ) {
3054         if ( $before == $after ) {
3055                 return '';
3056         }
3057
3058         global $wgDiff;
3059         wfSuppressWarnings();
3060         $haveDiff = $wgDiff && file_exists( $wgDiff );
3061         wfRestoreWarnings();
3062
3063         # This check may also protect against code injection in
3064         # case of broken installations.
3065         if ( !$haveDiff ) {
3066                 wfDebug( "diff executable not found\n" );
3067                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3068                 $format = new UnifiedDiffFormatter();
3069                 return $format->format( $diffs );
3070         }
3071
3072         # Make temporary files
3073         $td = wfTempDir();
3074         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3075         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3076
3077         fwrite( $oldtextFile, $before );
3078         fclose( $oldtextFile );
3079         fwrite( $newtextFile, $after );
3080         fclose( $newtextFile );
3081
3082         // Get the diff of the two files
3083         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3084
3085         $h = popen( $cmd, 'r' );
3086
3087         $diff = '';
3088
3089         do {
3090                 $data = fread( $h, 8192 );
3091                 if ( strlen( $data ) == 0 ) {
3092                         break;
3093                 }
3094                 $diff .= $data;
3095         } while ( true );
3096
3097         // Clean up
3098         pclose( $h );
3099         unlink( $oldtextName );
3100         unlink( $newtextName );
3101
3102         // Kill the --- and +++ lines. They're not useful.
3103         $diff_lines = explode( "\n", $diff );
3104         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3105                 unset( $diff_lines[0] );
3106         }
3107         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3108                 unset( $diff_lines[1] );
3109         }
3110
3111         $diff = implode( "\n", $diff_lines );
3112
3113         return $diff;
3114 }
3115
3116 /**
3117  * This function works like "use VERSION" in Perl, the program will die with a
3118  * backtrace if the current version of PHP is less than the version provided
3119  *
3120  * This is useful for extensions which due to their nature are not kept in sync
3121  * with releases, and might depend on other versions of PHP than the main code
3122  *
3123  * Note: PHP might die due to parsing errors in some cases before it ever
3124  *       manages to call this function, such is life
3125  *
3126  * @see perldoc -f use
3127  *
3128  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3129  * @throws MWException
3130  */
3131 function wfUsePHP( $req_ver ) {
3132         $php_ver = PHP_VERSION;
3133
3134         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3135                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3136         }
3137 }
3138
3139 /**
3140  * This function works like "use VERSION" in Perl except it checks the version
3141  * of MediaWiki, the program will die with a backtrace if the current version
3142  * of MediaWiki is less than the version provided.
3143  *
3144  * This is useful for extensions which due to their nature are not kept in sync
3145  * with releases
3146  *
3147  * Note: Due to the behavior of PHP's version_compare() which is used in this
3148  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3149  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3150  * targeted version number. For example if you wanted to allow any variation
3151  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3152  * not result in the same comparison due to the internal logic of
3153  * version_compare().
3154  *
3155  * @see perldoc -f use
3156  *
3157  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3158  * @throws MWException
3159  */
3160 function wfUseMW( $req_ver ) {
3161         global $wgVersion;
3162
3163         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3164                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3165         }
3166 }
3167
3168 /**
3169  * Return the final portion of a pathname.
3170  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3171  * http://bugs.php.net/bug.php?id=33898
3172  *
3173  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3174  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3175  *
3176  * @param string $path
3177  * @param string $suffix String to remove if present
3178  * @return string
3179  */
3180 function wfBaseName( $path, $suffix = '' ) {
3181         if ( $suffix == '' ) {
3182                 $encSuffix = '';
3183         } else {
3184                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3185         }
3186
3187         $matches = array();
3188         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3189                 return $matches[1];
3190         } else {
3191                 return '';
3192         }
3193 }
3194
3195 /**
3196  * Generate a relative path name to the given file.
3197  * May explode on non-matching case-insensitive paths,
3198  * funky symlinks, etc.
3199  *
3200  * @param string $path Absolute destination path including target filename
3201  * @param string $from Absolute source path, directory only
3202  * @return string
3203  */
3204 function wfRelativePath( $path, $from ) {
3205         // Normalize mixed input on Windows...
3206         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3207         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3208
3209         // Trim trailing slashes -- fix for drive root
3210         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3211         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3212
3213         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3214         $against = explode( DIRECTORY_SEPARATOR, $from );
3215
3216         if ( $pieces[0] !== $against[0] ) {
3217                 // Non-matching Windows drive letters?
3218                 // Return a full path.
3219                 return $path;
3220         }
3221
3222         // Trim off common prefix
3223         while ( count( $pieces ) && count( $against )
3224                 && $pieces[0] == $against[0] ) {
3225                 array_shift( $pieces );
3226                 array_shift( $against );
3227         }
3228
3229         // relative dots to bump us to the parent
3230         while ( count( $against ) ) {
3231                 array_unshift( $pieces, '..' );
3232                 array_shift( $against );
3233         }
3234
3235         array_push( $pieces, wfBaseName( $path ) );
3236
3237         return implode( DIRECTORY_SEPARATOR, $pieces );
3238 }
3239
3240 /**
3241  * Convert an arbitrarily-long digit string from one numeric base
3242  * to another, optionally zero-padding to a minimum column width.
3243  *
3244  * Supports base 2 through 36; digit values 10-36 are represented
3245  * as lowercase letters a-z. Input is case-insensitive.
3246  *
3247  * @param string $input Input number
3248  * @param int $sourceBase Base of the input number
3249  * @param int $destBase Desired base of the output
3250  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3251  * @param bool $lowercase Whether to output in lowercase or uppercase
3252  * @param string $engine Either "gmp", "bcmath", or "php"
3253  * @return string|bool The output number as a string, or false on error
3254  */
3255 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3256         $lowercase = true, $engine = 'auto'
3257 ) {
3258         $input = (string)$input;
3259         if (
3260                 $sourceBase < 2 ||
3261                 $sourceBase > 36 ||
3262                 $destBase < 2 ||
3263                 $destBase > 36 ||
3264                 $sourceBase != (int)$sourceBase ||
3265                 $destBase != (int)$destBase ||
3266                 $pad != (int)$pad ||
3267                 !preg_match(
3268                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3269                         $input
3270                 )
3271         ) {
3272                 return false;
3273         }
3274
3275         static $baseChars = array(
3276                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3277                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3278                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3279                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3280                 34 => 'y', 35 => 'z',
3281
3282                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3283                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3284                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3285                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3286                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3287                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3288         );
3289
3290         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3291                 // Removing leading zeros works around broken base detection code in
3292                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3293                 // <https://bugs.php.net/bug.php?id=55398>).
3294                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ), $sourceBase ), $destBase );
3295         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3296                 $decimal = '0';
3297                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3298                         $decimal = bcmul( $decimal, $sourceBase );
3299                         $decimal = bcadd( $decimal, $baseChars[$char] );
3300                 }
3301
3302                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3303                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3304                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3305                 }
3306                 // @codingStandardsIgnoreEnd
3307
3308                 $result = strrev( $result );
3309         } else {
3310                 $inDigits = array();
3311                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3312                         $inDigits[] = $baseChars[$char];
3313                 }
3314
3315                 // Iterate over the input, modulo-ing out an output digit
3316                 // at a time until input is gone.
3317                 $result = '';
3318                 while ( $inDigits ) {
3319                         $work = 0;
3320                         $workDigits = array();
3321
3322                         // Long division...
3323                         foreach ( $inDigits as $digit ) {
3324                                 $work *= $sourceBase;
3325                                 $work += $digit;
3326
3327                                 if ( $workDigits || $work >= $destBase ) {
3328                                         $workDigits[] = (int)( $work / $destBase );
3329                                 }
3330                                 $work %= $destBase;
3331                         }
3332
3333                         // All that division leaves us with a remainder,
3334                         // which is conveniently our next output digit.
3335                         $result .= $baseChars[$work];
3336
3337                         // And we continue!
3338                         $inDigits = $workDigits;
3339                 }
3340
3341                 $result = strrev( $result );
3342         }
3343
3344         if ( !$lowercase ) {
3345                 $result = strtoupper( $result );
3346         }
3347
3348         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3349 }
3350
3351 /**
3352  * Check if there is sufficient entropy in php's built-in session generation
3353  *
3354  * @return bool True = there is sufficient entropy
3355  */
3356 function wfCheckEntropy() {
3357         return (
3358                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3359                         || ini_get( 'session.entropy_file' )
3360                 )
3361                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3362 }
3363
3364 /**
3365  * Override session_id before session startup if php's built-in
3366  * session generation code is not secure.
3367  */
3368 function wfFixSessionID() {
3369         // If the cookie or session id is already set we already have a session and should abort
3370         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3371                 return;
3372         }
3373
3374         // PHP's built-in session entropy is enabled if:
3375         // - entropy_file is set or you're on Windows with php 5.3.3+
3376         // - AND entropy_length is > 0
3377         // We treat it as disabled if it doesn't have an entropy length of at least 32
3378         $entropyEnabled = wfCheckEntropy();
3379
3380         // If built-in entropy is not enabled or not sufficient override PHP's
3381         // built in session id generation code
3382         if ( !$entropyEnabled ) {
3383                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3384                         "overriding session id generation using our cryptrand source.\n" );
3385                 session_id( MWCryptRand::generateHex( 32 ) );
3386         }
3387 }
3388
3389 /**
3390  * Reset the session_id
3391  *
3392  * @since 1.22
3393  */
3394 function wfResetSessionID() {
3395         global $wgCookieSecure;
3396         $oldSessionId = session_id();
3397         $cookieParams = session_get_cookie_params();
3398         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3399                 session_regenerate_id( false );
3400         } else {
3401                 $tmp = $_SESSION;
3402                 session_destroy();
3403                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3404                 $_SESSION = $tmp;
3405         }
3406         $newSessionId = session_id();
3407         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3408 }
3409
3410 /**
3411  * Initialise php session
3412  *
3413  * @param bool $sessionId
3414  */
3415 function wfSetupSession( $sessionId = false ) {
3416         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3417                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3418         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3419                 ObjectCacheSessionHandler::install();
3420         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3421                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3422                 # hasn't already been set to the desired value (that causes errors)
3423                 ini_set( 'session.save_handler', $wgSessionHandler );
3424         }
3425         session_set_cookie_params(
3426                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3427         session_cache_limiter( 'private, must-revalidate' );
3428         if ( $sessionId ) {
3429                 session_id( $sessionId );
3430         } else {
3431                 wfFixSessionID();
3432         }
3433         wfSuppressWarnings();
3434         session_start();
3435         wfRestoreWarnings();
3436 }
3437
3438 /**
3439  * Get an object from the precompiled serialized directory
3440  *
3441  * @param string $name
3442  * @return mixed The variable on success, false on failure
3443  */
3444 function wfGetPrecompiledData( $name ) {
3445         global $IP;
3446
3447         $file = "$IP/serialized/$name";
3448         if ( file_exists( $file ) ) {
3449                 $blob = file_get_contents( $file );
3450                 if ( $blob ) {
3451                         return unserialize( $blob );
3452                 }
3453         }
3454         return false;
3455 }
3456
3457 /**
3458  * Get a cache key
3459  *
3460  * @param string $args,...
3461  * @return string
3462  */
3463 function wfMemcKey( /*...*/ ) {
3464         global $wgCachePrefix;
3465         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3466         $args = func_get_args();
3467         $key = $prefix . ':' . implode( ':', $args );
3468         $key = str_replace( ' ', '_', $key );
3469         return $key;
3470 }
3471
3472 /**
3473  * Get a cache key for a foreign DB
3474  *
3475  * @param string $db
3476  * @param string $prefix
3477  * @param string $args,...
3478  * @return string
3479  */
3480 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3481         $args = array_slice( func_get_args(), 2 );
3482         if ( $prefix ) {
3483                 $key = "$db-$prefix:" . implode( ':', $args );
3484         } else {
3485                 $key = $db . ':' . implode( ':', $args );
3486         }
3487         return str_replace( ' ', '_', $key );
3488 }
3489
3490 /**
3491  * Get an ASCII string identifying this wiki
3492  * This is used as a prefix in memcached keys
3493  *
3494  * @return string
3495  */
3496 function wfWikiID() {
3497         global $wgDBprefix, $wgDBname;
3498         if ( $wgDBprefix ) {
3499                 return "$wgDBname-$wgDBprefix";
3500         } else {
3501                 return $wgDBname;
3502         }
3503 }
3504
3505 /**
3506  * Split a wiki ID into DB name and table prefix
3507  *
3508  * @param string $wiki
3509  *
3510  * @return array
3511  */
3512 function wfSplitWikiID( $wiki ) {
3513         $bits = explode( '-', $wiki, 2 );
3514         if ( count( $bits ) < 2 ) {
3515                 $bits[] = '';
3516         }
3517         return $bits;
3518 }
3519
3520 /**
3521  * Get a Database object.
3522  *
3523  * @param int $db Index of the connection to get. May be DB_MASTER for the
3524  *            master (for write queries), DB_SLAVE for potentially lagged read
3525  *            queries, or an integer >= 0 for a particular server.
3526  *
3527  * @param string|string[] $groups Query groups. An array of group names that this query
3528  *                belongs to. May contain a single string if the query is only
3529  *                in one group.
3530  *
3531  * @param string|bool $wiki The wiki ID, or false for the current wiki
3532  *
3533  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3534  * will always return the same object, unless the underlying connection or load
3535  * balancer is manually destroyed.
3536  *
3537  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3538  * updater to ensure that a proper database is being updated.
3539  *
3540  * @return DatabaseBase
3541  */
3542 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3543         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3544 }
3545
3546 /**
3547  * Get a load balancer object.
3548  *
3549  * @param string|bool $wiki Wiki ID, or false for the current wiki
3550  * @return LoadBalancer
3551  */
3552 function wfGetLB( $wiki = false ) {
3553         return wfGetLBFactory()->getMainLB( $wiki );
3554 }
3555
3556 /**
3557  * Get the load balancer factory object
3558  *
3559  * @return LBFactory
3560  */
3561 function &wfGetLBFactory() {
3562         return LBFactory::singleton();
3563 }
3564
3565 /**
3566  * Find a file.
3567  * Shortcut for RepoGroup::singleton()->findFile()
3568  *
3569  * @param string $title String or Title object
3570  * @param array $options Associative array of options:
3571  *     time:           requested time for an archived image, or false for the
3572  *                     current version. An image object will be returned which was
3573  *                     created at the specified time.
3574  *
3575  *     ignoreRedirect: If true, do not follow file redirects
3576  *
3577  *     private:        If true, return restricted (deleted) files if the current
3578  *                     user is allowed to view them. Otherwise, such files will not
3579  *                     be found.
3580  *
3581  *     bypassCache:    If true, do not use the process-local cache of File objects
3582  *
3583  * @return File|bool File, or false if the file does not exist
3584  */
3585 function wfFindFile( $title, $options = array() ) {
3586         return RepoGroup::singleton()->findFile( $title, $options );
3587 }
3588
3589 /**
3590  * Get an object referring to a locally registered file.
3591  * Returns a valid placeholder object if the file does not exist.
3592  *
3593  * @param Title|string $title
3594  * @return LocalFile|null A File, or null if passed an invalid Title
3595  */
3596 function wfLocalFile( $title ) {
3597         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3598 }
3599
3600 /**
3601  * Should low-performance queries be disabled?
3602  *
3603  * @return bool
3604  * @codeCoverageIgnore
3605  */
3606 function wfQueriesMustScale() {
3607         global $wgMiserMode;
3608         return $wgMiserMode
3609                 || ( SiteStats::pages() > 100000
3610                 && SiteStats::edits() > 1000000
3611                 && SiteStats::users() > 10000 );
3612 }
3613
3614 /**
3615  * Get the path to a specified script file, respecting file
3616  * extensions; this is a wrapper around $wgScriptExtension etc.
3617  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3618  *
3619  * @param string $script Script filename, sans extension
3620  * @return string
3621  */
3622 function wfScript( $script = 'index' ) {
3623         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3624         if ( $script === 'index' ) {
3625                 return $wgScript;
3626         } elseif ( $script === 'load' ) {
3627                 return $wgLoadScript;
3628         } else {
3629                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3630         }
3631 }
3632
3633 /**
3634  * Get the script URL.
3635  *
3636  * @return string Script URL
3637  */
3638 function wfGetScriptUrl() {
3639         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3640                 #
3641                 # as it was called, minus the query string.
3642                 #
3643                 # Some sites use Apache rewrite rules to handle subdomains,
3644                 # and have PHP set up in a weird way that causes PHP_SELF
3645                 # to contain the rewritten URL instead of the one that the
3646                 # outside world sees.
3647                 #
3648                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3649                 # provides containing the "before" URL.
3650                 return $_SERVER['SCRIPT_NAME'];
3651         } else {
3652                 return $_SERVER['URL'];
3653         }
3654 }
3655
3656 /**
3657  * Convenience function converts boolean values into "true"
3658  * or "false" (string) values
3659  *
3660  * @param bool $value
3661  * @return string
3662  */
3663 function wfBoolToStr( $value ) {
3664         return $value ? 'true' : 'false';
3665 }
3666
3667 /**
3668  * Get a platform-independent path to the null file, e.g. /dev/null
3669  *
3670  * @return string
3671  */
3672 function wfGetNull() {
3673         return wfIsWindows() ? 'NUL' : '/dev/null';
3674 }
3675
3676 /**
3677  * Waits for the slaves to catch up to the master position
3678  *
3679  * Use this when updating very large numbers of rows, as in maintenance scripts,
3680  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3681  *
3682  * By default this waits on the main DB cluster of the current wiki.
3683  * If $cluster is set to "*" it will wait on all DB clusters, including
3684  * external ones. If the lag being waiting on is caused by the code that
3685  * does this check, it makes since to use $ifWritesSince, particularly if
3686  * cluster is "*", to avoid excess overhead.
3687  *
3688  * Never call this function after a big DB write that is still in a transaction.
3689  * This only makes sense after the possible lag inducing changes were committed.
3690  *
3691  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3692  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3693  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3694  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3695  * @return bool Success (able to connect and no timeouts reached)
3696  */
3697 function wfWaitForSlaves(
3698         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3699 ) {
3700         // B/C: first argument used to be "max seconds of lag"; ignore such values
3701         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3702
3703         if ( $timeout === null ) {
3704                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3705         }
3706
3707         // Figure out which clusters need to be checked
3708         $lbs = array();
3709         if ( $cluster === '*' ) {
3710                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3711                         $lbs[] = $lb;
3712                 } );
3713         } elseif ( $cluster !== false ) {
3714                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3715         } else {
3716                 $lbs[] = wfGetLB( $wiki );
3717         }
3718
3719         // Get all the master positions of applicable DBs right now.
3720         // This can be faster since waiting on one cluster reduces the
3721         // time needed to wait on the next clusters.
3722         $masterPositions = array_fill( 0, count( $lbs ), false );
3723         foreach ( $lbs as $i => $lb ) {
3724                 // bug 27975 - Don't try to wait for slaves if there are none
3725                 // Prevents permission error when getting master position
3726                 if ( $lb->getServerCount() > 1 ) {
3727                         if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
3728                                 continue; // assume no writes done
3729                         }
3730                         // Use the empty string to not trigger selectDB() since the connection
3731                         // may have been to a server that does not have a DB for the current wiki.
3732                         $dbw = $lb->getConnection( DB_MASTER, array(), '' );
3733                         if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
3734                                 continue; // no writes since the last wait
3735                         }
3736                         $masterPositions[$i] = $dbw->getMasterPos();
3737                 }
3738         }
3739
3740         $ok = true;
3741         foreach ( $lbs as $i => $lb ) {
3742                 if ( $masterPositions[$i] ) {
3743                         // The DBMS may not support getMasterPos() or the whole
3744                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3745                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3746                 }
3747         }
3748
3749         return $ok;
3750 }
3751
3752 /**
3753  * Count down from $seconds to zero on the terminal, with a one-second pause
3754  * between showing each number. For use in command-line scripts.
3755  *
3756  * @codeCoverageIgnore
3757  * @param int $seconds
3758  */
3759 function wfCountDown( $seconds ) {
3760         for ( $i = $seconds; $i >= 0; $i-- ) {
3761                 if ( $i != $seconds ) {
3762                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3763                 }
3764                 echo $i;
3765                 flush();
3766                 if ( $i ) {
3767                         sleep( 1 );
3768                 }
3769         }
3770         echo "\n";
3771 }
3772
3773 /**
3774  * Replace all invalid characters with -
3775  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3776  * By default, $wgIllegalFileChars = ':'
3777  *
3778  * @param string $name Filename to process
3779  * @return string
3780  */
3781 function wfStripIllegalFilenameChars( $name ) {
3782         global $wgIllegalFileChars;
3783         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3784         $name = wfBaseName( $name );
3785         $name = preg_replace(
3786                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3787                 '-',
3788                 $name
3789         );
3790         return $name;
3791 }
3792
3793 /**
3794  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3795  *
3796  * @return int Value the memory limit was set to.
3797  */
3798 function wfMemoryLimit() {
3799         global $wgMemoryLimit;
3800         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3801         if ( $memlimit != -1 ) {
3802                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3803                 if ( $conflimit == -1 ) {
3804                         wfDebug( "Removing PHP's memory limit\n" );
3805                         wfSuppressWarnings();
3806                         ini_set( 'memory_limit', $conflimit );
3807                         wfRestoreWarnings();
3808                         return $conflimit;
3809                 } elseif ( $conflimit > $memlimit ) {
3810                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3811                         wfSuppressWarnings();
3812                         ini_set( 'memory_limit', $conflimit );
3813                         wfRestoreWarnings();
3814                         return $conflimit;
3815                 }
3816         }
3817         return $memlimit;
3818 }
3819
3820 /**
3821  * Converts shorthand byte notation to integer form
3822  *
3823  * @param string $string
3824  * @return int
3825  */
3826 function wfShorthandToInteger( $string = '' ) {
3827         $string = trim( $string );
3828         if ( $string === '' ) {
3829                 return -1;
3830         }
3831         $last = $string[strlen( $string ) - 1];
3832         $val = intval( $string );
3833         switch ( $last ) {
3834                 case 'g':
3835                 case 'G':
3836                         $val *= 1024;
3837                         // break intentionally missing
3838                 case 'm':
3839                 case 'M':
3840                         $val *= 1024;
3841                         // break intentionally missing
3842                 case 'k':
3843                 case 'K':
3844                         $val *= 1024;
3845         }
3846
3847         return $val;
3848 }
3849
3850 /**
3851  * Get the normalised IETF language tag
3852  * See unit test for examples.
3853  *
3854  * @param string $code The language code.
3855  * @return string The language code which complying with BCP 47 standards.
3856  */
3857 function wfBCP47( $code ) {
3858         $codeSegment = explode( '-', $code );
3859         $codeBCP = array();
3860         foreach ( $codeSegment as $segNo => $seg ) {
3861                 // when previous segment is x, it is a private segment and should be lc
3862                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3863                         $codeBCP[$segNo] = strtolower( $seg );
3864                 // ISO 3166 country code
3865                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3866                         $codeBCP[$segNo] = strtoupper( $seg );
3867                 // ISO 15924 script code
3868                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3869                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3870                 // Use lowercase for other cases
3871                 } else {
3872                         $codeBCP[$segNo] = strtolower( $seg );
3873                 }
3874         }
3875         $langCode = implode( '-', $codeBCP );
3876         return $langCode;
3877 }
3878
3879 /**
3880  * Get a cache object.
3881  *
3882  * @param int $inputType Cache type, one the the CACHE_* constants.
3883  * @return BagOStuff
3884  */
3885 function wfGetCache( $inputType ) {
3886         return ObjectCache::getInstance( $inputType );
3887 }
3888
3889 /**
3890  * Get the main cache object
3891  *
3892  * @return BagOStuff
3893  */
3894 function wfGetMainCache() {
3895         global $wgMainCacheType;
3896         return ObjectCache::getInstance( $wgMainCacheType );
3897 }
3898
3899 /**
3900  * Get the cache object used by the message cache
3901  *
3902  * @return BagOStuff
3903  */
3904 function wfGetMessageCacheStorage() {
3905         global $wgMessageCacheType;
3906         return ObjectCache::getInstance( $wgMessageCacheType );
3907 }
3908
3909 /**
3910  * Get the cache object used by the parser cache
3911  *
3912  * @return BagOStuff
3913  */
3914 function wfGetParserCacheStorage() {
3915         global $wgParserCacheType;
3916         return ObjectCache::getInstance( $wgParserCacheType );
3917 }
3918
3919 /**
3920  * Get the cache object used by the language converter
3921  *
3922  * @return BagOStuff
3923  */
3924 function wfGetLangConverterCacheStorage() {
3925         global $wgLanguageConverterCacheType;
3926         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3927 }
3928
3929 /**
3930  * Call hook functions defined in $wgHooks
3931  *
3932  * @param string $event Event name
3933  * @param array $args Parameters passed to hook functions
3934  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3935  *
3936  * @return bool True if no handler aborted the hook
3937  */
3938 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3939         return Hooks::run( $event, $args, $deprecatedVersion );
3940 }
3941
3942 /**
3943  * Wrapper around php's unpack.
3944  *
3945  * @param string $format The format string (See php's docs)
3946  * @param string $data A binary string of binary data
3947  * @param int|bool $length The minimum length of $data or false. This is to
3948  *      prevent reading beyond the end of $data. false to disable the check.
3949  *
3950  * Also be careful when using this function to read unsigned 32 bit integer
3951  * because php might make it negative.
3952  *
3953  * @throws MWException If $data not long enough, or if unpack fails
3954  * @return array Associative array of the extracted data
3955  */
3956 function wfUnpack( $format, $data, $length = false ) {
3957         if ( $length !== false ) {
3958                 $realLen = strlen( $data );
3959                 if ( $realLen < $length ) {
3960                         throw new MWException( "Tried to use wfUnpack on a "
3961                                 . "string of length $realLen, but needed one "
3962                                 . "of at least length $length."
3963                         );
3964                 }
3965         }
3966
3967         wfSuppressWarnings();
3968         $result = unpack( $format, $data );
3969         wfRestoreWarnings();
3970
3971         if ( $result === false ) {
3972                 // If it cannot extract the packed data.
3973                 throw new MWException( "unpack could not unpack binary data" );
3974         }
3975         return $result;
3976 }
3977
3978 /**
3979  * Determine if an image exists on the 'bad image list'.
3980  *
3981  * The format of MediaWiki:Bad_image_list is as follows:
3982  *    * Only list items (lines starting with "*") are considered
3983  *    * The first link on a line must be a link to a bad image
3984  *    * Any subsequent links on the same line are considered to be exceptions,
3985  *      i.e. articles where the image may occur inline.
3986  *
3987  * @param string $name The image name to check
3988  * @param Title|bool $contextTitle The page on which the image occurs, if known
3989  * @param string $blacklist Wikitext of a file blacklist
3990  * @return bool
3991  */
3992 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3993         static $badImageCache = null; // based on bad_image_list msg
3994         wfProfileIn( __METHOD__ );
3995
3996         # Handle redirects
3997         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3998         if ( $redirectTitle ) {
3999                 $name = $redirectTitle->getDBkey();
4000         }
4001
4002         # Run the extension hook
4003         $bad = false;
4004         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
4005                 wfProfileOut( __METHOD__ );
4006                 return $bad;
4007         }
4008
4009         $cacheable = ( $blacklist === null );
4010         if ( $cacheable && $badImageCache !== null ) {
4011                 $badImages = $badImageCache;
4012         } else { // cache miss
4013                 if ( $blacklist === null ) {
4014                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4015                 }
4016                 # Build the list now
4017                 $badImages = array();
4018                 $lines = explode( "\n", $blacklist );
4019                 foreach ( $lines as $line ) {
4020                         # List items only
4021                         if ( substr( $line, 0, 1 ) !== '*' ) {
4022                                 continue;
4023                         }
4024
4025                         # Find all links
4026                         $m = array();
4027                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4028                                 continue;
4029                         }
4030
4031                         $exceptions = array();
4032                         $imageDBkey = false;
4033                         foreach ( $m[1] as $i => $titleText ) {
4034                                 $title = Title::newFromText( $titleText );
4035                                 if ( !is_null( $title ) ) {
4036                                         if ( $i == 0 ) {
4037                                                 $imageDBkey = $title->getDBkey();
4038                                         } else {
4039                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4040                                         }
4041                                 }
4042                         }
4043
4044                         if ( $imageDBkey !== false ) {
4045                                 $badImages[$imageDBkey] = $exceptions;
4046                         }
4047                 }
4048                 if ( $cacheable ) {
4049                         $badImageCache = $badImages;
4050                 }
4051         }
4052
4053         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4054         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4055         wfProfileOut( __METHOD__ );
4056         return $bad;
4057 }
4058
4059 /**
4060  * Determine whether the client at a given source IP is likely to be able to
4061  * access the wiki via HTTPS.
4062  *
4063  * @param string $ip The IPv4/6 address in the normal human-readable form
4064  * @return bool
4065  */
4066 function wfCanIPUseHTTPS( $ip ) {
4067         $canDo = true;
4068         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4069         return !!$canDo;
4070 }
4071
4072 /**
4073  * Work out the IP address based on various globals
4074  * For trusted proxies, use the XFF client IP (first of the chain)
4075  *
4076  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4077  * @return string
4078  */
4079 function wfGetIP() {
4080         wfDeprecated( __METHOD__, '1.19' );
4081         global $wgRequest;
4082         return $wgRequest->getIP();
4083 }
4084
4085 /**
4086  * Checks if an IP is a trusted proxy provider.
4087  * Useful to tell if X-Forwarded-For data is possibly bogus.
4088  * Squid cache servers for the site are whitelisted.
4089  * @deprecated Since 1.24, use IP::isTrustedProxy()
4090  *
4091  * @param string $ip
4092  * @return bool
4093  */
4094 function wfIsTrustedProxy( $ip ) {
4095         return IP::isTrustedProxy( $ip );
4096 }
4097
4098 /**
4099  * Checks if an IP matches a proxy we've configured.
4100  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4101  *
4102  * @param string $ip
4103  * @return bool
4104  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4105  */
4106 function wfIsConfiguredProxy( $ip ) {
4107         return IP::isConfiguredProxy( $ip );
4108 }