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, $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         if ( isset( $wgDebugLogGroups['profileoutput'] )
1186                 && $wgDebugLogGroups['profileoutput'] === false
1187         ) {
1188                 // Explicitly disabled
1189                 return;
1190         }
1191         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1192                 return;
1193         }
1194
1195         $ctx = array( 'elapsed' => $elapsed );
1196         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1197                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1198         }
1199         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1200                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1201         }
1202         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1203                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1204         }
1205         if ( isset( $ctx['forwarded_for'] ) ||
1206                 isset( $ctx['client_ip'] ) ||
1207                 isset( $ctx['from'] ) ) {
1208                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1209         }
1210
1211         // Don't load $wgUser at this late stage just for statistics purposes
1212         // @todo FIXME: We can detect some anons even if it is not loaded.
1213         // See User::getId()
1214         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1215                 $ctx['anon'] = true;
1216         } else {
1217                 $ctx['anon'] = false;
1218         }
1219
1220         // Command line script uses a FauxRequest object which does not have
1221         // any knowledge about an URL and throw an exception instead.
1222         try {
1223                 $ctx['url'] = urldecode( $wgRequest->getRequestURL() );
1224         } catch ( MWException $ignored ) {
1225                 // no-op
1226         }
1227
1228         $ctx['output'] = $profiler->getOutput();
1229         $ctx['profile'] = $profiler->getRawData();
1230
1231         $log = MWLogger::getInstance( 'profileoutput' );
1232         $log->info( 'Elapsed: {elapsed}', $ctx );
1233 }
1234
1235 /**
1236  * Increment a statistics counter
1237  *
1238  * @param string $key
1239  * @param int $count
1240  * @return void
1241  */
1242 function wfIncrStats( $key, $count = 1 ) {
1243         StatCounter::singleton()->incr( $key, $count );
1244 }
1245
1246 /**
1247  * Check whether the wiki is in read-only mode.
1248  *
1249  * @return bool
1250  */
1251 function wfReadOnly() {
1252         return wfReadOnlyReason() !== false;
1253 }
1254
1255 /**
1256  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1257  *
1258  * @return string|bool String when in read-only mode; false otherwise
1259  */
1260 function wfReadOnlyReason() {
1261         global $wgReadOnly, $wgReadOnlyFile;
1262
1263         if ( $wgReadOnly === null ) {
1264                 // Set $wgReadOnly for faster access next time
1265                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1266                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1267                 } else {
1268                         $wgReadOnly = false;
1269                 }
1270         }
1271
1272         return $wgReadOnly;
1273 }
1274
1275 /**
1276  * Return a Language object from $langcode
1277  *
1278  * @param Language|string|bool $langcode Either:
1279  *                  - a Language object
1280  *                  - code of the language to get the message for, if it is
1281  *                    a valid code create a language for that language, if
1282  *                    it is a string but not a valid code then make a basic
1283  *                    language object
1284  *                  - a boolean: if it's false then use the global object for
1285  *                    the current user's language (as a fallback for the old parameter
1286  *                    functionality), or if it is true then use global object
1287  *                    for the wiki's content language.
1288  * @return Language
1289  */
1290 function wfGetLangObj( $langcode = false ) {
1291         # Identify which language to get or create a language object for.
1292         # Using is_object here due to Stub objects.
1293         if ( is_object( $langcode ) ) {
1294                 # Great, we already have the object (hopefully)!
1295                 return $langcode;
1296         }
1297
1298         global $wgContLang, $wgLanguageCode;
1299         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1300                 # $langcode is the language code of the wikis content language object.
1301                 # or it is a boolean and value is true
1302                 return $wgContLang;
1303         }
1304
1305         global $wgLang;
1306         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1307                 # $langcode is the language code of user language object.
1308                 # or it was a boolean and value is false
1309                 return $wgLang;
1310         }
1311
1312         $validCodes = array_keys( Language::fetchLanguageNames() );
1313         if ( in_array( $langcode, $validCodes ) ) {
1314                 # $langcode corresponds to a valid language.
1315                 return Language::factory( $langcode );
1316         }
1317
1318         # $langcode is a string, but not a valid language code; use content language.
1319         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1320         return $wgContLang;
1321 }
1322
1323 /**
1324  * This is the function for getting translated interface messages.
1325  *
1326  * @see Message class for documentation how to use them.
1327  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1328  *
1329  * This function replaces all old wfMsg* functions.
1330  *
1331  * @param string|string[] $key Message key, or array of keys
1332  * @param mixed $params,... Normal message parameters
1333  * @return Message
1334  *
1335  * @since 1.17
1336  *
1337  * @see Message::__construct
1338  */
1339 function wfMessage( $key /*...*/ ) {
1340         $params = func_get_args();
1341         array_shift( $params );
1342         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1343                 $params = $params[0];
1344         }
1345         return new Message( $key, $params );
1346 }
1347
1348 /**
1349  * This function accepts multiple message keys and returns a message instance
1350  * for the first message which is non-empty. If all messages are empty then an
1351  * instance of the first message key is returned.
1352  *
1353  * @param string|string[] $keys,... Message keys
1354  * @return Message
1355  *
1356  * @since 1.18
1357  *
1358  * @see Message::newFallbackSequence
1359  */
1360 function wfMessageFallback( /*...*/ ) {
1361         $args = func_get_args();
1362         return call_user_func_array( 'Message::newFallbackSequence', $args );
1363 }
1364
1365 /**
1366  * Get a message from anywhere, for the current user language.
1367  *
1368  * Use wfMsgForContent() instead if the message should NOT
1369  * change depending on the user preferences.
1370  *
1371  * @deprecated since 1.18
1372  *
1373  * @param string $key Lookup key for the message, usually
1374  *    defined in languages/Language.php
1375  *
1376  * Parameters to the message, which can be used to insert variable text into
1377  * it, can be passed to this function in the following formats:
1378  * - One per argument, starting at the second parameter
1379  * - As an array in the second parameter
1380  * These are not shown in the function definition.
1381  *
1382  * @return string
1383  */
1384 function wfMsg( $key ) {
1385         wfDeprecated( __METHOD__, '1.21' );
1386
1387         $args = func_get_args();
1388         array_shift( $args );
1389         return wfMsgReal( $key, $args );
1390 }
1391
1392 /**
1393  * Same as above except doesn't transform the message
1394  *
1395  * @deprecated since 1.18
1396  *
1397  * @param string $key
1398  * @return string
1399  */
1400 function wfMsgNoTrans( $key ) {
1401         wfDeprecated( __METHOD__, '1.21' );
1402
1403         $args = func_get_args();
1404         array_shift( $args );
1405         return wfMsgReal( $key, $args, true, false, false );
1406 }
1407
1408 /**
1409  * Get a message from anywhere, for the current global language
1410  * set with $wgLanguageCode.
1411  *
1412  * Use this if the message should NOT change dependent on the
1413  * language set in the user's preferences. This is the case for
1414  * most text written into logs, as well as link targets (such as
1415  * the name of the copyright policy page). Link titles, on the
1416  * other hand, should be shown in the UI language.
1417  *
1418  * Note that MediaWiki allows users to change the user interface
1419  * language in their preferences, but a single installation
1420  * typically only contains content in one language.
1421  *
1422  * Be wary of this distinction: If you use wfMsg() where you should
1423  * use wfMsgForContent(), a user of the software may have to
1424  * customize potentially hundreds of messages in
1425  * order to, e.g., fix a link in every possible language.
1426  *
1427  * @deprecated since 1.18
1428  *
1429  * @param string $key Lookup key for the message, usually
1430  *     defined in languages/Language.php
1431  * @return string
1432  */
1433 function wfMsgForContent( $key ) {
1434         wfDeprecated( __METHOD__, '1.21' );
1435
1436         global $wgForceUIMsgAsContentMsg;
1437         $args = func_get_args();
1438         array_shift( $args );
1439         $forcontent = true;
1440         if ( is_array( $wgForceUIMsgAsContentMsg )
1441                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1442         ) {
1443                 $forcontent = false;
1444         }
1445         return wfMsgReal( $key, $args, true, $forcontent );
1446 }
1447
1448 /**
1449  * Same as above except doesn't transform the message
1450  *
1451  * @deprecated since 1.18
1452  *
1453  * @param string $key
1454  * @return string
1455  */
1456 function wfMsgForContentNoTrans( $key ) {
1457         wfDeprecated( __METHOD__, '1.21' );
1458
1459         global $wgForceUIMsgAsContentMsg;
1460         $args = func_get_args();
1461         array_shift( $args );
1462         $forcontent = true;
1463         if ( is_array( $wgForceUIMsgAsContentMsg )
1464                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1465         ) {
1466                 $forcontent = false;
1467         }
1468         return wfMsgReal( $key, $args, true, $forcontent, false );
1469 }
1470
1471 /**
1472  * Really get a message
1473  *
1474  * @deprecated since 1.18
1475  *
1476  * @param string $key Key to get.
1477  * @param array $args
1478  * @param bool $useDB
1479  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1480  * @param bool $transform Whether or not to transform the message.
1481  * @return string The requested message.
1482  */
1483 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1484         wfDeprecated( __METHOD__, '1.21' );
1485
1486         wfProfileIn( __METHOD__ );
1487         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1488         $message = wfMsgReplaceArgs( $message, $args );
1489         wfProfileOut( __METHOD__ );
1490         return $message;
1491 }
1492
1493 /**
1494  * Fetch a message string value, but don't replace any keys yet.
1495  *
1496  * @deprecated since 1.18
1497  *
1498  * @param string $key
1499  * @param bool $useDB
1500  * @param string|bool $langCode Code of the language to get the message for, or
1501  *   behaves as a content language switch if it is a boolean.
1502  * @param bool $transform Whether to parse magic words, etc.
1503  * @return string
1504  */
1505 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1506         wfDeprecated( __METHOD__, '1.21' );
1507
1508         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1509
1510         $cache = MessageCache::singleton();
1511         $message = $cache->get( $key, $useDB, $langCode );
1512         if ( $message === false ) {
1513                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1514         } elseif ( $transform ) {
1515                 $message = $cache->transform( $message );
1516         }
1517         return $message;
1518 }
1519
1520 /**
1521  * Replace message parameter keys on the given formatted output.
1522  *
1523  * @param string $message
1524  * @param array $args
1525  * @return string
1526  * @private
1527  */
1528 function wfMsgReplaceArgs( $message, $args ) {
1529         # Fix windows line-endings
1530         # Some messages are split with explode("\n", $msg)
1531         $message = str_replace( "\r", '', $message );
1532
1533         // Replace arguments
1534         if ( count( $args ) ) {
1535                 if ( is_array( $args[0] ) ) {
1536                         $args = array_values( $args[0] );
1537                 }
1538                 $replacementKeys = array();
1539                 foreach ( $args as $n => $param ) {
1540                         $replacementKeys['$' . ( $n + 1 )] = $param;
1541                 }
1542                 $message = strtr( $message, $replacementKeys );
1543         }
1544
1545         return $message;
1546 }
1547
1548 /**
1549  * Return an HTML-escaped version of a message.
1550  * Parameter replacements, if any, are done *after* the HTML-escaping,
1551  * so parameters may contain HTML (eg links or form controls). Be sure
1552  * to pre-escape them if you really do want plaintext, or just wrap
1553  * the whole thing in htmlspecialchars().
1554  *
1555  * @deprecated since 1.18
1556  *
1557  * @param string $key
1558  * @param string $args,... Parameters
1559  * @return string
1560  */
1561 function wfMsgHtml( $key ) {
1562         wfDeprecated( __METHOD__, '1.21' );
1563
1564         $args = func_get_args();
1565         array_shift( $args );
1566         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1567 }
1568
1569 /**
1570  * Return an HTML version of message
1571  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1572  * so parameters may contain HTML (eg links or form controls). Be sure
1573  * to pre-escape them if you really do want plaintext, or just wrap
1574  * the whole thing in htmlspecialchars().
1575  *
1576  * @deprecated since 1.18
1577  *
1578  * @param string $key
1579  * @param string $args,... Parameters
1580  * @return string
1581  */
1582 function wfMsgWikiHtml( $key ) {
1583         wfDeprecated( __METHOD__, '1.21' );
1584
1585         $args = func_get_args();
1586         array_shift( $args );
1587         return wfMsgReplaceArgs(
1588                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1589                 /* can't be set to false */ true, /* interface */ true )->getText(),
1590                 $args );
1591 }
1592
1593 /**
1594  * Returns message in the requested format
1595  *
1596  * @deprecated since 1.18
1597  *
1598  * @param string $key Key of the message
1599  * @param array $options Processing rules.
1600  *   Can take the following options:
1601  *     parse: parses wikitext to HTML
1602  *     parseinline: parses wikitext to HTML and removes the surrounding
1603  *       p's added by parser or tidy
1604  *     escape: filters message through htmlspecialchars
1605  *     escapenoentities: same, but allows entity references like &#160; through
1606  *     replaceafter: parameters are substituted after parsing or escaping
1607  *     parsemag: transform the message using magic phrases
1608  *     content: fetch message for content language instead of interface
1609  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1610  *     language: Language object or language code to fetch message for
1611  *       (overridden by content).
1612  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1613  *
1614  * @return string
1615  */
1616 function wfMsgExt( $key, $options ) {
1617         wfDeprecated( __METHOD__, '1.21' );
1618
1619         $args = func_get_args();
1620         array_shift( $args );
1621         array_shift( $args );
1622         $options = (array)$options;
1623
1624         foreach ( $options as $arrayKey => $option ) {
1625                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1626                         # An unknown index, neither numeric nor "language"
1627                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1628                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1629                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1630                 'replaceafter', 'parsemag', 'content' ) ) ) {
1631                         # A numeric index with unknown value
1632                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1633                 }
1634         }
1635
1636         if ( in_array( 'content', $options, true ) ) {
1637                 $forContent = true;
1638                 $langCode = true;
1639                 $langCodeObj = null;
1640         } elseif ( array_key_exists( 'language', $options ) ) {
1641                 $forContent = false;
1642                 $langCode = wfGetLangObj( $options['language'] );
1643                 $langCodeObj = $langCode;
1644         } else {
1645                 $forContent = false;
1646                 $langCode = false;
1647                 $langCodeObj = null;
1648         }
1649
1650         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1651
1652         if ( !in_array( 'replaceafter', $options, true ) ) {
1653                 $string = wfMsgReplaceArgs( $string, $args );
1654         }
1655
1656         $messageCache = MessageCache::singleton();
1657         $parseInline = in_array( 'parseinline', $options, true );
1658         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1659                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1660                 if ( $string instanceof ParserOutput ) {
1661                         $string = $string->getText();
1662                 }
1663
1664                 if ( $parseInline ) {
1665                         $string = Parser::stripOuterParagraph( $string );
1666                 }
1667         } elseif ( in_array( 'parsemag', $options, true ) ) {
1668                 $string = $messageCache->transform( $string,
1669                                 !$forContent, $langCodeObj );
1670         }
1671
1672         if ( in_array( 'escape', $options, true ) ) {
1673                 $string = htmlspecialchars ( $string );
1674         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1675                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1676         }
1677
1678         if ( in_array( 'replaceafter', $options, true ) ) {
1679                 $string = wfMsgReplaceArgs( $string, $args );
1680         }
1681
1682         return $string;
1683 }
1684
1685 /**
1686  * Since wfMsg() and co suck, they don't return false if the message key they
1687  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1688  * nonexistence of messages by checking the MessageCache::get() result directly.
1689  *
1690  * @deprecated since 1.18. Use Message::isDisabled().
1691  *
1692  * @param string $key The message key looked up
1693  * @return bool True if the message *doesn't* exist.
1694  */
1695 function wfEmptyMsg( $key ) {
1696         wfDeprecated( __METHOD__, '1.21' );
1697
1698         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1699 }
1700
1701 /**
1702  * Fetch server name for use in error reporting etc.
1703  * Use real server name if available, so we know which machine
1704  * in a server farm generated the current page.
1705  *
1706  * @return string
1707  */
1708 function wfHostname() {
1709         static $host;
1710         if ( is_null( $host ) ) {
1711
1712                 # Hostname overriding
1713                 global $wgOverrideHostname;
1714                 if ( $wgOverrideHostname !== false ) {
1715                         # Set static and skip any detection
1716                         $host = $wgOverrideHostname;
1717                         return $host;
1718                 }
1719
1720                 if ( function_exists( 'posix_uname' ) ) {
1721                         // This function not present on Windows
1722                         $uname = posix_uname();
1723                 } else {
1724                         $uname = false;
1725                 }
1726                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1727                         $host = $uname['nodename'];
1728                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1729                         # Windows computer name
1730                         $host = getenv( 'COMPUTERNAME' );
1731                 } else {
1732                         # This may be a virtual server.
1733                         $host = $_SERVER['SERVER_NAME'];
1734                 }
1735         }
1736         return $host;
1737 }
1738
1739 /**
1740  * Returns a script tag that stores the amount of time it took MediaWiki to
1741  * handle the request in milliseconds as 'wgBackendResponseTime'.
1742  *
1743  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1744  * hostname of the server handling the request.
1745  *
1746  * @return string
1747  */
1748 function wfReportTime() {
1749         global $wgRequestTime, $wgShowHostnames;
1750
1751         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1752         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1753         if ( $wgShowHostnames ) {
1754                 $reportVars['wgHostname'] = wfHostname();
1755         }
1756         return Skin::makeVariablesScript( $reportVars );
1757 }
1758
1759 /**
1760  * Safety wrapper for debug_backtrace().
1761  *
1762  * Will return an empty array if debug_backtrace is disabled, otherwise
1763  * the output from debug_backtrace() (trimmed).
1764  *
1765  * @param int $limit This parameter can be used to limit the number of stack frames returned
1766  *
1767  * @return array Array of backtrace information
1768  */
1769 function wfDebugBacktrace( $limit = 0 ) {
1770         static $disabled = null;
1771
1772         if ( is_null( $disabled ) ) {
1773                 $disabled = !function_exists( 'debug_backtrace' );
1774                 if ( $disabled ) {
1775                         wfDebug( "debug_backtrace() is disabled\n" );
1776                 }
1777         }
1778         if ( $disabled ) {
1779                 return array();
1780         }
1781
1782         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1783                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1784         } else {
1785                 return array_slice( debug_backtrace(), 1 );
1786         }
1787 }
1788
1789 /**
1790  * Get a debug backtrace as a string
1791  *
1792  * @return string
1793  */
1794 function wfBacktrace() {
1795         global $wgCommandLineMode;
1796
1797         if ( $wgCommandLineMode ) {
1798                 $msg = '';
1799         } else {
1800                 $msg = "<ul>\n";
1801         }
1802         $backtrace = wfDebugBacktrace();
1803         foreach ( $backtrace as $call ) {
1804                 if ( isset( $call['file'] ) ) {
1805                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1806                         $file = $f[count( $f ) - 1];
1807                 } else {
1808                         $file = '-';
1809                 }
1810                 if ( isset( $call['line'] ) ) {
1811                         $line = $call['line'];
1812                 } else {
1813                         $line = '-';
1814                 }
1815                 if ( $wgCommandLineMode ) {
1816                         $msg .= "$file line $line calls ";
1817                 } else {
1818                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1819                 }
1820                 if ( !empty( $call['class'] ) ) {
1821                         $msg .= $call['class'] . $call['type'];
1822                 }
1823                 $msg .= $call['function'] . '()';
1824
1825                 if ( $wgCommandLineMode ) {
1826                         $msg .= "\n";
1827                 } else {
1828                         $msg .= "</li>\n";
1829                 }
1830         }
1831         if ( $wgCommandLineMode ) {
1832                 $msg .= "\n";
1833         } else {
1834                 $msg .= "</ul>\n";
1835         }
1836
1837         return $msg;
1838 }
1839
1840 /**
1841  * Get the name of the function which called this function
1842  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1843  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1844  * wfGetCaller( 3 ) is the parent of that.
1845  *
1846  * @param int $level
1847  * @return string
1848  */
1849 function wfGetCaller( $level = 2 ) {
1850         $backtrace = wfDebugBacktrace( $level + 1 );
1851         if ( isset( $backtrace[$level] ) ) {
1852                 return wfFormatStackFrame( $backtrace[$level] );
1853         } else {
1854                 return 'unknown';
1855         }
1856 }
1857
1858 /**
1859  * Return a string consisting of callers in the stack. Useful sometimes
1860  * for profiling specific points.
1861  *
1862  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1863  * @return string
1864  */
1865 function wfGetAllCallers( $limit = 3 ) {
1866         $trace = array_reverse( wfDebugBacktrace() );
1867         if ( !$limit || $limit > count( $trace ) - 1 ) {
1868                 $limit = count( $trace ) - 1;
1869         }
1870         $trace = array_slice( $trace, -$limit - 1, $limit );
1871         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1872 }
1873
1874 /**
1875  * Return a string representation of frame
1876  *
1877  * @param array $frame
1878  * @return string
1879  */
1880 function wfFormatStackFrame( $frame ) {
1881         return isset( $frame['class'] ) ?
1882                 $frame['class'] . '::' . $frame['function'] :
1883                 $frame['function'];
1884 }
1885
1886 /* Some generic result counters, pulled out of SearchEngine */
1887
1888 /**
1889  * @todo document
1890  *
1891  * @param int $offset
1892  * @param int $limit
1893  * @return string
1894  */
1895 function wfShowingResults( $offset, $limit ) {
1896         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1897 }
1898
1899 /**
1900  * @todo document
1901  * @todo FIXME: We may want to blacklist some broken browsers
1902  *
1903  * @param bool $force
1904  * @return bool Whereas client accept gzip compression
1905  */
1906 function wfClientAcceptsGzip( $force = false ) {
1907         static $result = null;
1908         if ( $result === null || $force ) {
1909                 $result = false;
1910                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1911                         # @todo FIXME: We may want to blacklist some broken browsers
1912                         $m = array();
1913                         if ( preg_match(
1914                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1915                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1916                                         $m
1917                                 )
1918                         ) {
1919                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1920                                         $result = false;
1921                                         return $result;
1922                                 }
1923                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1924                                 $result = true;
1925                         }
1926                 }
1927         }
1928         return $result;
1929 }
1930
1931 /**
1932  * Obtain the offset and limit values from the request string;
1933  * used in special pages
1934  *
1935  * @param int $deflimit Default limit if none supplied
1936  * @param string $optionname Name of a user preference to check against
1937  * @return array
1938  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
1939  */
1940 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1941         global $wgRequest;
1942         wfDeprecated( __METHOD__, '1.24' );
1943         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1944 }
1945
1946 /**
1947  * Escapes the given text so that it may be output using addWikiText()
1948  * without any linking, formatting, etc. making its way through. This
1949  * is achieved by substituting certain characters with HTML entities.
1950  * As required by the callers, "<nowiki>" is not used.
1951  *
1952  * @param string $text Text to be escaped
1953  * @return string
1954  */
1955 function wfEscapeWikiText( $text ) {
1956         static $repl = null, $repl2 = null;
1957         if ( $repl === null ) {
1958                 $repl = array(
1959                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1960                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1961                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1962                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1963                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1964                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1965                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1966                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1967                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1968                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1969                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1970                         '__' => '_&#95;', '://' => '&#58;//',
1971                 );
1972
1973                 // We have to catch everything "\s" matches in PCRE
1974                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
1975                         $repl["$magic "] = "$magic&#32;";
1976                         $repl["$magic\t"] = "$magic&#9;";
1977                         $repl["$magic\r"] = "$magic&#13;";
1978                         $repl["$magic\n"] = "$magic&#10;";
1979                         $repl["$magic\f"] = "$magic&#12;";
1980                 }
1981
1982                 // And handle protocols that don't use "://"
1983                 global $wgUrlProtocols;
1984                 $repl2 = array();
1985                 foreach ( $wgUrlProtocols as $prot ) {
1986                         if ( substr( $prot, -1 ) === ':' ) {
1987                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1988                         }
1989                 }
1990                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
1991         }
1992         $text = substr( strtr( "\n$text", $repl ), 1 );
1993         $text = preg_replace( $repl2, '$1&#58;', $text );
1994         return $text;
1995 }
1996
1997 /**
1998  * Sets dest to source and returns the original value of dest
1999  * If source is NULL, it just returns the value, it doesn't set the variable
2000  * If force is true, it will set the value even if source is NULL
2001  *
2002  * @param mixed $dest
2003  * @param mixed $source
2004  * @param bool $force
2005  * @return mixed
2006  */
2007 function wfSetVar( &$dest, $source, $force = false ) {
2008         $temp = $dest;
2009         if ( !is_null( $source ) || $force ) {
2010                 $dest = $source;
2011         }
2012         return $temp;
2013 }
2014
2015 /**
2016  * As for wfSetVar except setting a bit
2017  *
2018  * @param int $dest
2019  * @param int $bit
2020  * @param bool $state
2021  *
2022  * @return bool
2023  */
2024 function wfSetBit( &$dest, $bit, $state = true ) {
2025         $temp = (bool)( $dest & $bit );
2026         if ( !is_null( $state ) ) {
2027                 if ( $state ) {
2028                         $dest |= $bit;
2029                 } else {
2030                         $dest &= ~$bit;
2031                 }
2032         }
2033         return $temp;
2034 }
2035
2036 /**
2037  * A wrapper around the PHP function var_export().
2038  * Either print it or add it to the regular output ($wgOut).
2039  *
2040  * @param mixed $var A PHP variable to dump.
2041  */
2042 function wfVarDump( $var ) {
2043         global $wgOut;
2044         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2045         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2046                 print $s;
2047         } else {
2048                 $wgOut->addHTML( $s );
2049         }
2050 }
2051
2052 /**
2053  * Provide a simple HTTP error.
2054  *
2055  * @param int|string $code
2056  * @param string $label
2057  * @param string $desc
2058  */
2059 function wfHttpError( $code, $label, $desc ) {
2060         global $wgOut;
2061         $wgOut->disable();
2062         header( "HTTP/1.0 $code $label" );
2063         header( "Status: $code $label" );
2064         $wgOut->sendCacheControl();
2065
2066         header( 'Content-type: text/html; charset=utf-8' );
2067         print "<!doctype html>" .
2068                 '<html><head><title>' .
2069                 htmlspecialchars( $label ) .
2070                 '</title></head><body><h1>' .
2071                 htmlspecialchars( $label ) .
2072                 '</h1><p>' .
2073                 nl2br( htmlspecialchars( $desc ) ) .
2074                 "</p></body></html>\n";
2075 }
2076
2077 /**
2078  * Clear away any user-level output buffers, discarding contents.
2079  *
2080  * Suitable for 'starting afresh', for instance when streaming
2081  * relatively large amounts of data without buffering, or wanting to
2082  * output image files without ob_gzhandler's compression.
2083  *
2084  * The optional $resetGzipEncoding parameter controls suppression of
2085  * the Content-Encoding header sent by ob_gzhandler; by default it
2086  * is left. See comments for wfClearOutputBuffers() for why it would
2087  * be used.
2088  *
2089  * Note that some PHP configuration options may add output buffer
2090  * layers which cannot be removed; these are left in place.
2091  *
2092  * @param bool $resetGzipEncoding
2093  */
2094 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2095         if ( $resetGzipEncoding ) {
2096                 // Suppress Content-Encoding and Content-Length
2097                 // headers from 1.10+s wfOutputHandler
2098                 global $wgDisableOutputCompression;
2099                 $wgDisableOutputCompression = true;
2100         }
2101         while ( $status = ob_get_status() ) {
2102                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2103                         // Probably from zlib.output_compression or other
2104                         // PHP-internal setting which can't be removed.
2105                         //
2106                         // Give up, and hope the result doesn't break
2107                         // output behavior.
2108                         break;
2109                 }
2110                 if ( !ob_end_clean() ) {
2111                         // Could not remove output buffer handler; abort now
2112                         // to avoid getting in some kind of infinite loop.
2113                         break;
2114                 }
2115                 if ( $resetGzipEncoding ) {
2116                         if ( $status['name'] == 'ob_gzhandler' ) {
2117                                 // Reset the 'Content-Encoding' field set by this handler
2118                                 // so we can start fresh.
2119                                 header_remove( 'Content-Encoding' );
2120                                 break;
2121                         }
2122                 }
2123         }
2124 }
2125
2126 /**
2127  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2128  *
2129  * Clear away output buffers, but keep the Content-Encoding header
2130  * produced by ob_gzhandler, if any.
2131  *
2132  * This should be used for HTTP 304 responses, where you need to
2133  * preserve the Content-Encoding header of the real result, but
2134  * also need to suppress the output of ob_gzhandler to keep to spec
2135  * and avoid breaking Firefox in rare cases where the headers and
2136  * body are broken over two packets.
2137  */
2138 function wfClearOutputBuffers() {
2139         wfResetOutputBuffers( false );
2140 }
2141
2142 /**
2143  * Converts an Accept-* header into an array mapping string values to quality
2144  * factors
2145  *
2146  * @param string $accept
2147  * @param string $def Default
2148  * @return float[] Associative array of string => float pairs
2149  */
2150 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2151         # No arg means accept anything (per HTTP spec)
2152         if ( !$accept ) {
2153                 return array( $def => 1.0 );
2154         }
2155
2156         $prefs = array();
2157
2158         $parts = explode( ',', $accept );
2159
2160         foreach ( $parts as $part ) {
2161                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2162                 $values = explode( ';', trim( $part ) );
2163                 $match = array();
2164                 if ( count( $values ) == 1 ) {
2165                         $prefs[$values[0]] = 1.0;
2166                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2167                         $prefs[$values[0]] = floatval( $match[1] );
2168                 }
2169         }
2170
2171         return $prefs;
2172 }
2173
2174 /**
2175  * Checks if a given MIME type matches any of the keys in the given
2176  * array. Basic wildcards are accepted in the array keys.
2177  *
2178  * Returns the matching MIME type (or wildcard) if a match, otherwise
2179  * NULL if no match.
2180  *
2181  * @param string $type
2182  * @param array $avail
2183  * @return string
2184  * @private
2185  */
2186 function mimeTypeMatch( $type, $avail ) {
2187         if ( array_key_exists( $type, $avail ) ) {
2188                 return $type;
2189         } else {
2190                 $parts = explode( '/', $type );
2191                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2192                         return $parts[0] . '/*';
2193                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2194                         return '*/*';
2195                 } else {
2196                         return null;
2197                 }
2198         }
2199 }
2200
2201 /**
2202  * Returns the 'best' match between a client's requested internet media types
2203  * and the server's list of available types. Each list should be an associative
2204  * array of type to preference (preference is a float between 0.0 and 1.0).
2205  * Wildcards in the types are acceptable.
2206  *
2207  * @param array $cprefs Client's acceptable type list
2208  * @param array $sprefs Server's offered types
2209  * @return string
2210  *
2211  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2212  * XXX: generalize to negotiate other stuff
2213  */
2214 function wfNegotiateType( $cprefs, $sprefs ) {
2215         $combine = array();
2216
2217         foreach ( array_keys( $sprefs ) as $type ) {
2218                 $parts = explode( '/', $type );
2219                 if ( $parts[1] != '*' ) {
2220                         $ckey = mimeTypeMatch( $type, $cprefs );
2221                         if ( $ckey ) {
2222                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2223                         }
2224                 }
2225         }
2226
2227         foreach ( array_keys( $cprefs ) as $type ) {
2228                 $parts = explode( '/', $type );
2229                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2230                         $skey = mimeTypeMatch( $type, $sprefs );
2231                         if ( $skey ) {
2232                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2233                         }
2234                 }
2235         }
2236
2237         $bestq = 0;
2238         $besttype = null;
2239
2240         foreach ( array_keys( $combine ) as $type ) {
2241                 if ( $combine[$type] > $bestq ) {
2242                         $besttype = $type;
2243                         $bestq = $combine[$type];
2244                 }
2245         }
2246
2247         return $besttype;
2248 }
2249
2250 /**
2251  * Reference-counted warning suppression
2252  *
2253  * @param bool $end
2254  */
2255 function wfSuppressWarnings( $end = false ) {
2256         static $suppressCount = 0;
2257         static $originalLevel = false;
2258
2259         if ( $end ) {
2260                 if ( $suppressCount ) {
2261                         --$suppressCount;
2262                         if ( !$suppressCount ) {
2263                                 error_reporting( $originalLevel );
2264                         }
2265                 }
2266         } else {
2267                 if ( !$suppressCount ) {
2268                         $originalLevel = error_reporting( E_ALL & ~(
2269                                 E_WARNING |
2270                                 E_NOTICE |
2271                                 E_USER_WARNING |
2272                                 E_USER_NOTICE |
2273                                 E_DEPRECATED |
2274                                 E_USER_DEPRECATED |
2275                                 E_STRICT
2276                         ) );
2277                 }
2278                 ++$suppressCount;
2279         }
2280 }
2281
2282 /**
2283  * Restore error level to previous value
2284  */
2285 function wfRestoreWarnings() {
2286         wfSuppressWarnings( true );
2287 }
2288
2289 # Autodetect, convert and provide timestamps of various types
2290
2291 /**
2292  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2293  */
2294 define( 'TS_UNIX', 0 );
2295
2296 /**
2297  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2298  */
2299 define( 'TS_MW', 1 );
2300
2301 /**
2302  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2303  */
2304 define( 'TS_DB', 2 );
2305
2306 /**
2307  * RFC 2822 format, for E-mail and HTTP headers
2308  */
2309 define( 'TS_RFC2822', 3 );
2310
2311 /**
2312  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2313  *
2314  * This is used by Special:Export
2315  */
2316 define( 'TS_ISO_8601', 4 );
2317
2318 /**
2319  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2320  *
2321  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2322  *       DateTime tag and page 36 for the DateTimeOriginal and
2323  *       DateTimeDigitized tags.
2324  */
2325 define( 'TS_EXIF', 5 );
2326
2327 /**
2328  * Oracle format time.
2329  */
2330 define( 'TS_ORACLE', 6 );
2331
2332 /**
2333  * Postgres format time.
2334  */
2335 define( 'TS_POSTGRES', 7 );
2336
2337 /**
2338  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2339  */
2340 define( 'TS_ISO_8601_BASIC', 9 );
2341
2342 /**
2343  * Get a timestamp string in one of various formats
2344  *
2345  * @param mixed $outputtype A timestamp in one of the supported formats, the
2346  *   function will autodetect which format is supplied and act accordingly.
2347  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2348  * @return string|bool String / false The same date in the format specified in $outputtype or false
2349  */
2350 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2351         try {
2352                 $timestamp = new MWTimestamp( $ts );
2353                 return $timestamp->getTimestamp( $outputtype );
2354         } catch ( TimestampException $e ) {
2355                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2356                 return false;
2357         }
2358 }
2359
2360 /**
2361  * Return a formatted timestamp, or null if input is null.
2362  * For dealing with nullable timestamp columns in the database.
2363  *
2364  * @param int $outputtype
2365  * @param string $ts
2366  * @return string
2367  */
2368 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2369         if ( is_null( $ts ) ) {
2370                 return null;
2371         } else {
2372                 return wfTimestamp( $outputtype, $ts );
2373         }
2374 }
2375
2376 /**
2377  * Convenience function; returns MediaWiki timestamp for the present time.
2378  *
2379  * @return string
2380  */
2381 function wfTimestampNow() {
2382         # return NOW
2383         return wfTimestamp( TS_MW, time() );
2384 }
2385
2386 /**
2387  * Check if the operating system is Windows
2388  *
2389  * @return bool True if it's Windows, false otherwise.
2390  */
2391 function wfIsWindows() {
2392         static $isWindows = null;
2393         if ( $isWindows === null ) {
2394                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2395         }
2396         return $isWindows;
2397 }
2398
2399 /**
2400  * Check if we are running under HHVM
2401  *
2402  * @return bool
2403  */
2404 function wfIsHHVM() {
2405         return defined( 'HHVM_VERSION' );
2406 }
2407
2408 /**
2409  * Swap two variables
2410  *
2411  * @deprecated since 1.24
2412  * @param mixed $x
2413  * @param mixed $y
2414  */
2415 function swap( &$x, &$y ) {
2416         wfDeprecated( __FUNCTION__, '1.24' );
2417         $z = $x;
2418         $x = $y;
2419         $y = $z;
2420 }
2421
2422 /**
2423  * Tries to get the system directory for temporary files. First
2424  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2425  * environment variables are then checked in sequence, and if none are
2426  * set try sys_get_temp_dir().
2427  *
2428  * NOTE: When possible, use instead the tmpfile() function to create
2429  * temporary files to avoid race conditions on file creation, etc.
2430  *
2431  * @return string
2432  */
2433 function wfTempDir() {
2434         global $wgTmpDirectory;
2435
2436         if ( $wgTmpDirectory !== false ) {
2437                 return $wgTmpDirectory;
2438         }
2439
2440         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2441
2442         foreach ( $tmpDir as $tmp ) {
2443                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2444                         return $tmp;
2445                 }
2446         }
2447         return sys_get_temp_dir();
2448 }
2449
2450 /**
2451  * Make directory, and make all parent directories if they don't exist
2452  *
2453  * @param string $dir Full path to directory to create
2454  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2455  * @param string $caller Optional caller param for debugging.
2456  * @throws MWException
2457  * @return bool
2458  */
2459 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2460         global $wgDirectoryMode;
2461
2462         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2463                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2464         }
2465
2466         if ( !is_null( $caller ) ) {
2467                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2468         }
2469
2470         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2471                 return true;
2472         }
2473
2474         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2475
2476         if ( is_null( $mode ) ) {
2477                 $mode = $wgDirectoryMode;
2478         }
2479
2480         // Turn off the normal warning, we're doing our own below
2481         wfSuppressWarnings();
2482         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2483         wfRestoreWarnings();
2484
2485         if ( !$ok ) {
2486                 //directory may have been created on another request since we last checked
2487                 if ( is_dir( $dir ) ) {
2488                         return true;
2489                 }
2490
2491                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2492                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2493         }
2494         return $ok;
2495 }
2496
2497 /**
2498  * Remove a directory and all its content.
2499  * Does not hide error.
2500  * @param string $dir
2501  */
2502 function wfRecursiveRemoveDir( $dir ) {
2503         wfDebug( __FUNCTION__ . "( $dir )\n" );
2504         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2505         if ( is_dir( $dir ) ) {
2506                 $objects = scandir( $dir );
2507                 foreach ( $objects as $object ) {
2508                         if ( $object != "." && $object != ".." ) {
2509                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2510                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2511                                 } else {
2512                                         unlink( $dir . '/' . $object );
2513                                 }
2514                         }
2515                 }
2516                 reset( $objects );
2517                 rmdir( $dir );
2518         }
2519 }
2520
2521 /**
2522  * @param int $nr The number to format
2523  * @param int $acc The number of digits after the decimal point, default 2
2524  * @param bool $round Whether or not to round the value, default true
2525  * @return string
2526  */
2527 function wfPercent( $nr, $acc = 2, $round = true ) {
2528         $ret = sprintf( "%.${acc}f", $nr );
2529         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2530 }
2531
2532 /**
2533  * Safety wrapper around ini_get() for boolean settings.
2534  * The values returned from ini_get() are pre-normalized for settings
2535  * set via php.ini or php_flag/php_admin_flag... but *not*
2536  * for those set via php_value/php_admin_value.
2537  *
2538  * It's fairly common for people to use php_value instead of php_flag,
2539  * which can leave you with an 'off' setting giving a false positive
2540  * for code that just takes the ini_get() return value as a boolean.
2541  *
2542  * To make things extra interesting, setting via php_value accepts
2543  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2544  * Unrecognized values go false... again opposite PHP's own coercion
2545  * from string to bool.
2546  *
2547  * Luckily, 'properly' set settings will always come back as '0' or '1',
2548  * so we only have to worry about them and the 'improper' settings.
2549  *
2550  * I frickin' hate PHP... :P
2551  *
2552  * @param string $setting
2553  * @return bool
2554  */
2555 function wfIniGetBool( $setting ) {
2556         $val = strtolower( ini_get( $setting ) );
2557         // 'on' and 'true' can't have whitespace around them, but '1' can.
2558         return $val == 'on'
2559                 || $val == 'true'
2560                 || $val == 'yes'
2561                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2562 }
2563
2564 /**
2565  * Windows-compatible version of escapeshellarg()
2566  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2567  * function puts single quotes in regardless of OS.
2568  *
2569  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2570  * earlier distro releases of PHP)
2571  *
2572  * @param string $args,...
2573  * @return string
2574  */
2575 function wfEscapeShellArg( /*...*/ ) {
2576         wfInitShellLocale();
2577
2578         $args = func_get_args();
2579         $first = true;
2580         $retVal = '';
2581         foreach ( $args as $arg ) {
2582                 if ( !$first ) {
2583                         $retVal .= ' ';
2584                 } else {
2585                         $first = false;
2586                 }
2587
2588                 if ( wfIsWindows() ) {
2589                         // Escaping for an MSVC-style command line parser and CMD.EXE
2590                         // @codingStandardsIgnoreStart For long URLs
2591                         // Refs:
2592                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2593                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2594                         //  * Bug #13518
2595                         //  * CR r63214
2596                         // Double the backslashes before any double quotes. Escape the double quotes.
2597                         // @codingStandardsIgnoreEnd
2598                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2599                         $arg = '';
2600                         $iteration = 0;
2601                         foreach ( $tokens as $token ) {
2602                                 if ( $iteration % 2 == 1 ) {
2603                                         // Delimiter, a double quote preceded by zero or more slashes
2604                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2605                                 } elseif ( $iteration % 4 == 2 ) {
2606                                         // ^ in $token will be outside quotes, need to be escaped
2607                                         $arg .= str_replace( '^', '^^', $token );
2608                                 } else { // $iteration % 4 == 0
2609                                         // ^ in $token will appear inside double quotes, so leave as is
2610                                         $arg .= $token;
2611                                 }
2612                                 $iteration++;
2613                         }
2614                         // Double the backslashes before the end of the string, because
2615                         // we will soon add a quote
2616                         $m = array();
2617                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2618                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2619                         }
2620
2621                         // Add surrounding quotes
2622                         $retVal .= '"' . $arg . '"';
2623                 } else {
2624                         $retVal .= escapeshellarg( $arg );
2625                 }
2626         }
2627         return $retVal;
2628 }
2629
2630 /**
2631  * Check if wfShellExec() is effectively disabled via php.ini config
2632  *
2633  * @return bool|string False or one of (safemode,disabled)
2634  * @since 1.22
2635  */
2636 function wfShellExecDisabled() {
2637         static $disabled = null;
2638         if ( is_null( $disabled ) ) {
2639                 if ( wfIniGetBool( 'safe_mode' ) ) {
2640                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2641                         $disabled = 'safemode';
2642                 } elseif ( !function_exists( 'proc_open' ) ) {
2643                         wfDebug( "proc_open() is disabled\n" );
2644                         $disabled = 'disabled';
2645                 } else {
2646                         $disabled = false;
2647                 }
2648         }
2649         return $disabled;
2650 }
2651
2652 /**
2653  * Execute a shell command, with time and memory limits mirrored from the PHP
2654  * configuration if supported.
2655  *
2656  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2657  *   or an array of unescaped arguments, in which case each value will be escaped
2658  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2659  * @param null|mixed &$retval Optional, will receive the program's exit code.
2660  *   (non-zero is usually failure). If there is an error from
2661  *   read, select, or proc_open(), this will be set to -1.
2662  * @param array $environ Optional environment variables which should be
2663  *   added to the executed command environment.
2664  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2665  *   this overwrites the global wgMaxShell* limits.
2666  * @param array $options Array of options:
2667  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2668  *     including errors from limit.sh
2669  *
2670  * @return string Collected stdout as a string
2671  */
2672 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2673         $limits = array(), $options = array()
2674 ) {
2675         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2676                 $wgMaxShellWallClockTime, $wgShellCgroup;
2677
2678         $disabled = wfShellExecDisabled();
2679         if ( $disabled ) {
2680                 $retval = 1;
2681                 return $disabled == 'safemode' ?
2682                         'Unable to run external programs in safe mode.' :
2683                         'Unable to run external programs, proc_open() is disabled.';
2684         }
2685
2686         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2687
2688         wfInitShellLocale();
2689
2690         $envcmd = '';
2691         foreach ( $environ as $k => $v ) {
2692                 if ( wfIsWindows() ) {
2693                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2694                          * appear in the environment variable, so we must use carat escaping as documented in
2695                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2696                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2697                          * are listed there but doesn't appear to need it.
2698                          */
2699                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2700                 } else {
2701                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2702                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2703                          */
2704                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2705                 }
2706         }
2707         if ( is_array( $cmd ) ) {
2708                 // Command line may be given as an array, escape each value and glue them together with a space
2709                 $cmdVals = array();
2710                 foreach ( $cmd as $val ) {
2711                         $cmdVals[] = wfEscapeShellArg( $val );
2712                 }
2713                 $cmd = implode( ' ', $cmdVals );
2714         }
2715
2716         $cmd = $envcmd . $cmd;
2717
2718         $useLogPipe = false;
2719         if ( is_executable( '/bin/bash' ) ) {
2720                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2721                 if ( isset( $limits['walltime'] ) ) {
2722                         $wallTime = intval( $limits['walltime'] );
2723                 } elseif ( isset( $limits['time'] ) ) {
2724                         $wallTime = $time;
2725                 } else {
2726                         $wallTime = intval( $wgMaxShellWallClockTime );
2727                 }
2728                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2729                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2730
2731                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2732                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2733                                 escapeshellarg( $cmd ) . ' ' .
2734                                 escapeshellarg(
2735                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2736                                         "MW_CPU_LIMIT=$time; " .
2737                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2738                                         "MW_MEM_LIMIT=$mem; " .
2739                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2740                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2741                                         "MW_USE_LOG_PIPE=yes"
2742                                 );
2743                         $useLogPipe = true;
2744                 } elseif ( $includeStderr ) {
2745                         $cmd .= ' 2>&1';
2746                 }
2747         } elseif ( $includeStderr ) {
2748                 $cmd .= ' 2>&1';
2749         }
2750         wfDebug( "wfShellExec: $cmd\n" );
2751
2752         $desc = array(
2753                 0 => array( 'file', 'php://stdin', 'r' ),
2754                 1 => array( 'pipe', 'w' ),
2755                 2 => array( 'file', 'php://stderr', 'w' ) );
2756         if ( $useLogPipe ) {
2757                 $desc[3] = array( 'pipe', 'w' );
2758         }
2759         $pipes = null;
2760         $proc = proc_open( $cmd, $desc, $pipes );
2761         if ( !$proc ) {
2762                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2763                 $retval = -1;
2764                 return '';
2765         }
2766         $outBuffer = $logBuffer = '';
2767         $emptyArray = array();
2768         $status = false;
2769         $logMsg = false;
2770
2771         // According to the documentation, it is possible for stream_select()
2772         // to fail due to EINTR. I haven't managed to induce this in testing
2773         // despite sending various signals. If it did happen, the error
2774         // message would take the form:
2775         //
2776         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2777         //
2778         // where [4] is the value of the macro EINTR and "Interrupted system
2779         // call" is string which according to the Linux manual is "possibly"
2780         // localised according to LC_MESSAGES.
2781         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2782         $eintrMessage = "stream_select(): unable to select [$eintr]";
2783
2784         // Build a table mapping resource IDs to pipe FDs to work around a
2785         // PHP 5.3 issue in which stream_select() does not preserve array keys
2786         // <https://bugs.php.net/bug.php?id=53427>.
2787         $fds = array();
2788         foreach ( $pipes as $fd => $pipe ) {
2789                 $fds[(int)$pipe] = $fd;
2790         }
2791
2792         $running = true;
2793         $timeout = null;
2794         $numReadyPipes = 0;
2795
2796         while ( $running === true || $numReadyPipes !== 0 ) {
2797                 if ( $running ) {
2798                         $status = proc_get_status( $proc );
2799                         // If the process has terminated, switch to nonblocking selects
2800                         // for getting any data still waiting to be read.
2801                         if ( !$status['running'] ) {
2802                                 $running = false;
2803                                 $timeout = 0;
2804                         }
2805                 }
2806
2807                 $readyPipes = $pipes;
2808
2809                 // Clear last error
2810                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2811                 @trigger_error( '' );
2812                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2813                 if ( $numReadyPipes === false ) {
2814                         // @codingStandardsIgnoreEnd
2815                         $error = error_get_last();
2816                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2817                                 continue;
2818                         } else {
2819                                 trigger_error( $error['message'], E_USER_WARNING );
2820                                 $logMsg = $error['message'];
2821                                 break;
2822                         }
2823                 }
2824                 foreach ( $readyPipes as $pipe ) {
2825                         $block = fread( $pipe, 65536 );
2826                         $fd = $fds[(int)$pipe];
2827                         if ( $block === '' ) {
2828                                 // End of file
2829                                 fclose( $pipes[$fd] );
2830                                 unset( $pipes[$fd] );
2831                                 if ( !$pipes ) {
2832                                         break 2;
2833                                 }
2834                         } elseif ( $block === false ) {
2835                                 // Read error
2836                                 $logMsg = "Error reading from pipe";
2837                                 break 2;
2838                         } elseif ( $fd == 1 ) {
2839                                 // From stdout
2840                                 $outBuffer .= $block;
2841                         } elseif ( $fd == 3 ) {
2842                                 // From log FD
2843                                 $logBuffer .= $block;
2844                                 if ( strpos( $block, "\n" ) !== false ) {
2845                                         $lines = explode( "\n", $logBuffer );
2846                                         $logBuffer = array_pop( $lines );
2847                                         foreach ( $lines as $line ) {
2848                                                 wfDebugLog( 'exec', $line );
2849                                         }
2850                                 }
2851                         }
2852                 }
2853         }
2854
2855         foreach ( $pipes as $pipe ) {
2856                 fclose( $pipe );
2857         }
2858
2859         // Use the status previously collected if possible, since proc_get_status()
2860         // just calls waitpid() which will not return anything useful the second time.
2861         if ( $running ) {
2862                 $status = proc_get_status( $proc );
2863         }
2864
2865         if ( $logMsg !== false ) {
2866                 // Read/select error
2867                 $retval = -1;
2868                 proc_close( $proc );
2869         } elseif ( $status['signaled'] ) {
2870                 $logMsg = "Exited with signal {$status['termsig']}";
2871                 $retval = 128 + $status['termsig'];
2872                 proc_close( $proc );
2873         } else {
2874                 if ( $status['running'] ) {
2875                         $retval = proc_close( $proc );
2876                 } else {
2877                         $retval = $status['exitcode'];
2878                         proc_close( $proc );
2879                 }
2880                 if ( $retval == 127 ) {
2881                         $logMsg = "Possibly missing executable file";
2882                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2883                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2884                 }
2885         }
2886
2887         if ( $logMsg !== false ) {
2888                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2889         }
2890
2891         return $outBuffer;
2892 }
2893
2894 /**
2895  * Execute a shell command, returning both stdout and stderr. Convenience
2896  * function, as all the arguments to wfShellExec can become unwieldy.
2897  *
2898  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2899  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2900  *   or an array of unescaped arguments, in which case each value will be escaped
2901  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2902  * @param null|mixed &$retval Optional, will receive the program's exit code.
2903  *   (non-zero is usually failure)
2904  * @param array $environ Optional environment variables which should be
2905  *   added to the executed command environment.
2906  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2907  *   this overwrites the global wgMaxShell* limits.
2908  * @return string Collected stdout and stderr as a string
2909  */
2910 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2911         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
2912 }
2913
2914 /**
2915  * Workaround for http://bugs.php.net/bug.php?id=45132
2916  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2917  */
2918 function wfInitShellLocale() {
2919         static $done = false;
2920         if ( $done ) {
2921                 return;
2922         }
2923         $done = true;
2924         global $wgShellLocale;
2925         if ( !wfIniGetBool( 'safe_mode' ) ) {
2926                 putenv( "LC_CTYPE=$wgShellLocale" );
2927                 setlocale( LC_CTYPE, $wgShellLocale );
2928         }
2929 }
2930
2931 /**
2932  * Alias to wfShellWikiCmd()
2933  *
2934  * @see wfShellWikiCmd()
2935  */
2936 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2937         return wfShellWikiCmd( $script, $parameters, $options );
2938 }
2939
2940 /**
2941  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2942  * Note that $parameters should be a flat array and an option with an argument
2943  * should consist of two consecutive items in the array (do not use "--option value").
2944  *
2945  * @param string $script MediaWiki cli script path
2946  * @param array $parameters Arguments and options to the script
2947  * @param array $options Associative array of options:
2948  *              'php': The path to the php executable
2949  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2950  * @return string
2951  */
2952 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2953         global $wgPhpCli;
2954         // Give site config file a chance to run the script in a wrapper.
2955         // The caller may likely want to call wfBasename() on $script.
2956         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2957         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2958         if ( isset( $options['wrapper'] ) ) {
2959                 $cmd[] = $options['wrapper'];
2960         }
2961         $cmd[] = $script;
2962         // Escape each parameter for shell
2963         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2964 }
2965
2966 /**
2967  * wfMerge attempts to merge differences between three texts.
2968  * Returns true for a clean merge and false for failure or a conflict.
2969  *
2970  * @param string $old
2971  * @param string $mine
2972  * @param string $yours
2973  * @param string $result
2974  * @return bool
2975  */
2976 function wfMerge( $old, $mine, $yours, &$result ) {
2977         global $wgDiff3;
2978
2979         # This check may also protect against code injection in
2980         # case of broken installations.
2981         wfSuppressWarnings();
2982         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2983         wfRestoreWarnings();
2984
2985         if ( !$haveDiff3 ) {
2986                 wfDebug( "diff3 not found\n" );
2987                 return false;
2988         }
2989
2990         # Make temporary files
2991         $td = wfTempDir();
2992         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2993         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2994         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2995
2996         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2997         #       a newline character. To avoid this, we normalize the trailing whitespace before
2998         #       creating the diff.
2999
3000         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3001         fclose( $oldtextFile );
3002         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3003         fclose( $mytextFile );
3004         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3005         fclose( $yourtextFile );
3006
3007         # Check for a conflict
3008         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3009                 wfEscapeShellArg( $mytextName ) . ' ' .
3010                 wfEscapeShellArg( $oldtextName ) . ' ' .
3011                 wfEscapeShellArg( $yourtextName );
3012         $handle = popen( $cmd, 'r' );
3013
3014         if ( fgets( $handle, 1024 ) ) {
3015                 $conflict = true;
3016         } else {
3017                 $conflict = false;
3018         }
3019         pclose( $handle );
3020
3021         # Merge differences
3022         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3023                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3024         $handle = popen( $cmd, 'r' );
3025         $result = '';
3026         do {
3027                 $data = fread( $handle, 8192 );
3028                 if ( strlen( $data ) == 0 ) {
3029                         break;
3030                 }
3031                 $result .= $data;
3032         } while ( true );
3033         pclose( $handle );
3034         unlink( $mytextName );
3035         unlink( $oldtextName );
3036         unlink( $yourtextName );
3037
3038         if ( $result === '' && $old !== '' && !$conflict ) {
3039                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3040                 $conflict = true;
3041         }
3042         return !$conflict;
3043 }
3044
3045 /**
3046  * Returns unified plain-text diff of two texts.
3047  * Useful for machine processing of diffs.
3048  *
3049  * @param string $before The text before the changes.
3050  * @param string $after The text after the changes.
3051  * @param string $params Command-line options for the diff command.
3052  * @return string Unified diff of $before and $after
3053  */
3054 function wfDiff( $before, $after, $params = '-u' ) {
3055         if ( $before == $after ) {
3056                 return '';
3057         }
3058
3059         global $wgDiff;
3060         wfSuppressWarnings();
3061         $haveDiff = $wgDiff && file_exists( $wgDiff );
3062         wfRestoreWarnings();
3063
3064         # This check may also protect against code injection in
3065         # case of broken installations.
3066         if ( !$haveDiff ) {
3067                 wfDebug( "diff executable not found\n" );
3068                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3069                 $format = new UnifiedDiffFormatter();
3070                 return $format->format( $diffs );
3071         }
3072
3073         # Make temporary files
3074         $td = wfTempDir();
3075         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3076         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3077
3078         fwrite( $oldtextFile, $before );
3079         fclose( $oldtextFile );
3080         fwrite( $newtextFile, $after );
3081         fclose( $newtextFile );
3082
3083         // Get the diff of the two files
3084         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3085
3086         $h = popen( $cmd, 'r' );
3087
3088         $diff = '';
3089
3090         do {
3091                 $data = fread( $h, 8192 );
3092                 if ( strlen( $data ) == 0 ) {
3093                         break;
3094                 }
3095                 $diff .= $data;
3096         } while ( true );
3097
3098         // Clean up
3099         pclose( $h );
3100         unlink( $oldtextName );
3101         unlink( $newtextName );
3102
3103         // Kill the --- and +++ lines. They're not useful.
3104         $diff_lines = explode( "\n", $diff );
3105         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3106                 unset( $diff_lines[0] );
3107         }
3108         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3109                 unset( $diff_lines[1] );
3110         }
3111
3112         $diff = implode( "\n", $diff_lines );
3113
3114         return $diff;
3115 }
3116
3117 /**
3118  * This function works like "use VERSION" in Perl, the program will die with a
3119  * backtrace if the current version of PHP is less than the version provided
3120  *
3121  * This is useful for extensions which due to their nature are not kept in sync
3122  * with releases, and might depend on other versions of PHP than the main code
3123  *
3124  * Note: PHP might die due to parsing errors in some cases before it ever
3125  *       manages to call this function, such is life
3126  *
3127  * @see perldoc -f use
3128  *
3129  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3130  * @throws MWException
3131  */
3132 function wfUsePHP( $req_ver ) {
3133         $php_ver = PHP_VERSION;
3134
3135         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3136                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3137         }
3138 }
3139
3140 /**
3141  * This function works like "use VERSION" in Perl except it checks the version
3142  * of MediaWiki, the program will die with a backtrace if the current version
3143  * of MediaWiki is less than the version provided.
3144  *
3145  * This is useful for extensions which due to their nature are not kept in sync
3146  * with releases
3147  *
3148  * Note: Due to the behavior of PHP's version_compare() which is used in this
3149  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3150  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3151  * targeted version number. For example if you wanted to allow any variation
3152  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3153  * not result in the same comparison due to the internal logic of
3154  * version_compare().
3155  *
3156  * @see perldoc -f use
3157  *
3158  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3159  * @throws MWException
3160  */
3161 function wfUseMW( $req_ver ) {
3162         global $wgVersion;
3163
3164         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3165                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3166         }
3167 }
3168
3169 /**
3170  * Return the final portion of a pathname.
3171  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3172  * http://bugs.php.net/bug.php?id=33898
3173  *
3174  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3175  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3176  *
3177  * @param string $path
3178  * @param string $suffix String to remove if present
3179  * @return string
3180  */
3181 function wfBaseName( $path, $suffix = '' ) {
3182         if ( $suffix == '' ) {
3183                 $encSuffix = '';
3184         } else {
3185                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3186         }
3187
3188         $matches = array();
3189         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3190                 return $matches[1];
3191         } else {
3192                 return '';
3193         }
3194 }
3195
3196 /**
3197  * Generate a relative path name to the given file.
3198  * May explode on non-matching case-insensitive paths,
3199  * funky symlinks, etc.
3200  *
3201  * @param string $path Absolute destination path including target filename
3202  * @param string $from Absolute source path, directory only
3203  * @return string
3204  */
3205 function wfRelativePath( $path, $from ) {
3206         // Normalize mixed input on Windows...
3207         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3208         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3209
3210         // Trim trailing slashes -- fix for drive root
3211         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3212         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3213
3214         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3215         $against = explode( DIRECTORY_SEPARATOR, $from );
3216
3217         if ( $pieces[0] !== $against[0] ) {
3218                 // Non-matching Windows drive letters?
3219                 // Return a full path.
3220                 return $path;
3221         }
3222
3223         // Trim off common prefix
3224         while ( count( $pieces ) && count( $against )
3225                 && $pieces[0] == $against[0] ) {
3226                 array_shift( $pieces );
3227                 array_shift( $against );
3228         }
3229
3230         // relative dots to bump us to the parent
3231         while ( count( $against ) ) {
3232                 array_unshift( $pieces, '..' );
3233                 array_shift( $against );
3234         }
3235
3236         array_push( $pieces, wfBaseName( $path ) );
3237
3238         return implode( DIRECTORY_SEPARATOR, $pieces );
3239 }
3240
3241 /**
3242  * Convert an arbitrarily-long digit string from one numeric base
3243  * to another, optionally zero-padding to a minimum column width.
3244  *
3245  * Supports base 2 through 36; digit values 10-36 are represented
3246  * as lowercase letters a-z. Input is case-insensitive.
3247  *
3248  * @param string $input Input number
3249  * @param int $sourceBase Base of the input number
3250  * @param int $destBase Desired base of the output
3251  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3252  * @param bool $lowercase Whether to output in lowercase or uppercase
3253  * @param string $engine Either "gmp", "bcmath", or "php"
3254  * @return string|bool The output number as a string, or false on error
3255  */
3256 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3257         $lowercase = true, $engine = 'auto'
3258 ) {
3259         $input = (string)$input;
3260         if (
3261                 $sourceBase < 2 ||
3262                 $sourceBase > 36 ||
3263                 $destBase < 2 ||
3264                 $destBase > 36 ||
3265                 $sourceBase != (int)$sourceBase ||
3266                 $destBase != (int)$destBase ||
3267                 $pad != (int)$pad ||
3268                 !preg_match(
3269                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3270                         $input
3271                 )
3272         ) {
3273                 return false;
3274         }
3275
3276         static $baseChars = array(
3277                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3278                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3279                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3280                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3281                 34 => 'y', 35 => 'z',
3282
3283                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3284                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3285                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3286                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3287                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3288                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3289         );
3290
3291         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3292                 // Removing leading zeros works around broken base detection code in
3293                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3294                 // <https://bugs.php.net/bug.php?id=55398>).
3295                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ), $sourceBase ), $destBase );
3296         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3297                 $decimal = '0';
3298                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3299                         $decimal = bcmul( $decimal, $sourceBase );
3300                         $decimal = bcadd( $decimal, $baseChars[$char] );
3301                 }
3302
3303                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3304                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3305                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3306                 }
3307                 // @codingStandardsIgnoreEnd
3308
3309                 $result = strrev( $result );
3310         } else {
3311                 $inDigits = array();
3312                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3313                         $inDigits[] = $baseChars[$char];
3314                 }
3315
3316                 // Iterate over the input, modulo-ing out an output digit
3317                 // at a time until input is gone.
3318                 $result = '';
3319                 while ( $inDigits ) {
3320                         $work = 0;
3321                         $workDigits = array();
3322
3323                         // Long division...
3324                         foreach ( $inDigits as $digit ) {
3325                                 $work *= $sourceBase;
3326                                 $work += $digit;
3327
3328                                 if ( $workDigits || $work >= $destBase ) {
3329                                         $workDigits[] = (int)( $work / $destBase );
3330                                 }
3331                                 $work %= $destBase;
3332                         }
3333
3334                         // All that division leaves us with a remainder,
3335                         // which is conveniently our next output digit.
3336                         $result .= $baseChars[$work];
3337
3338                         // And we continue!
3339                         $inDigits = $workDigits;
3340                 }
3341
3342                 $result = strrev( $result );
3343         }
3344
3345         if ( !$lowercase ) {
3346                 $result = strtoupper( $result );
3347         }
3348
3349         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3350 }
3351
3352 /**
3353  * Check if there is sufficient entropy in php's built-in session generation
3354  *
3355  * @return bool True = there is sufficient entropy
3356  */
3357 function wfCheckEntropy() {
3358         return (
3359                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3360                         || ini_get( 'session.entropy_file' )
3361                 )
3362                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3363 }
3364
3365 /**
3366  * Override session_id before session startup if php's built-in
3367  * session generation code is not secure.
3368  */
3369 function wfFixSessionID() {
3370         // If the cookie or session id is already set we already have a session and should abort
3371         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3372                 return;
3373         }
3374
3375         // PHP's built-in session entropy is enabled if:
3376         // - entropy_file is set or you're on Windows with php 5.3.3+
3377         // - AND entropy_length is > 0
3378         // We treat it as disabled if it doesn't have an entropy length of at least 32
3379         $entropyEnabled = wfCheckEntropy();
3380
3381         // If built-in entropy is not enabled or not sufficient override PHP's
3382         // built in session id generation code
3383         if ( !$entropyEnabled ) {
3384                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3385                         "overriding session id generation using our cryptrand source.\n" );
3386                 session_id( MWCryptRand::generateHex( 32 ) );
3387         }
3388 }
3389
3390 /**
3391  * Reset the session_id
3392  *
3393  * @since 1.22
3394  */
3395 function wfResetSessionID() {
3396         global $wgCookieSecure;
3397         $oldSessionId = session_id();
3398         $cookieParams = session_get_cookie_params();
3399         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3400                 session_regenerate_id( false );
3401         } else {
3402                 $tmp = $_SESSION;
3403                 session_destroy();
3404                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3405                 $_SESSION = $tmp;
3406         }
3407         $newSessionId = session_id();
3408         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3409 }
3410
3411 /**
3412  * Initialise php session
3413  *
3414  * @param bool $sessionId
3415  */
3416 function wfSetupSession( $sessionId = false ) {
3417         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3418                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3419         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3420                 ObjectCacheSessionHandler::install();
3421         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3422                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3423                 # hasn't already been set to the desired value (that causes errors)
3424                 ini_set( 'session.save_handler', $wgSessionHandler );
3425         }
3426         session_set_cookie_params(
3427                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3428         session_cache_limiter( 'private, must-revalidate' );
3429         if ( $sessionId ) {
3430                 session_id( $sessionId );
3431         } else {
3432                 wfFixSessionID();
3433         }
3434         wfSuppressWarnings();
3435         session_start();
3436         wfRestoreWarnings();
3437 }
3438
3439 /**
3440  * Get an object from the precompiled serialized directory
3441  *
3442  * @param string $name
3443  * @return mixed The variable on success, false on failure
3444  */
3445 function wfGetPrecompiledData( $name ) {
3446         global $IP;
3447
3448         $file = "$IP/serialized/$name";
3449         if ( file_exists( $file ) ) {
3450                 $blob = file_get_contents( $file );
3451                 if ( $blob ) {
3452                         return unserialize( $blob );
3453                 }
3454         }
3455         return false;
3456 }
3457
3458 /**
3459  * Get a cache key
3460  *
3461  * @param string $args,...
3462  * @return string
3463  */
3464 function wfMemcKey( /*...*/ ) {
3465         global $wgCachePrefix;
3466         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3467         $args = func_get_args();
3468         $key = $prefix . ':' . implode( ':', $args );
3469         $key = str_replace( ' ', '_', $key );
3470         return $key;
3471 }
3472
3473 /**
3474  * Get a cache key for a foreign DB
3475  *
3476  * @param string $db
3477  * @param string $prefix
3478  * @param string $args,...
3479  * @return string
3480  */
3481 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3482         $args = array_slice( func_get_args(), 2 );
3483         if ( $prefix ) {
3484                 $key = "$db-$prefix:" . implode( ':', $args );
3485         } else {
3486                 $key = $db . ':' . implode( ':', $args );
3487         }
3488         return str_replace( ' ', '_', $key );
3489 }
3490
3491 /**
3492  * Get an ASCII string identifying this wiki
3493  * This is used as a prefix in memcached keys
3494  *
3495  * @return string
3496  */
3497 function wfWikiID() {
3498         global $wgDBprefix, $wgDBname;
3499         if ( $wgDBprefix ) {
3500                 return "$wgDBname-$wgDBprefix";
3501         } else {
3502                 return $wgDBname;
3503         }
3504 }
3505
3506 /**
3507  * Split a wiki ID into DB name and table prefix
3508  *
3509  * @param string $wiki
3510  *
3511  * @return array
3512  */
3513 function wfSplitWikiID( $wiki ) {
3514         $bits = explode( '-', $wiki, 2 );
3515         if ( count( $bits ) < 2 ) {
3516                 $bits[] = '';
3517         }
3518         return $bits;
3519 }
3520
3521 /**
3522  * Get a Database object.
3523  *
3524  * @param int $db Index of the connection to get. May be DB_MASTER for the
3525  *            master (for write queries), DB_SLAVE for potentially lagged read
3526  *            queries, or an integer >= 0 for a particular server.
3527  *
3528  * @param string|string[] $groups Query groups. An array of group names that this query
3529  *                belongs to. May contain a single string if the query is only
3530  *                in one group.
3531  *
3532  * @param string|bool $wiki The wiki ID, or false for the current wiki
3533  *
3534  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3535  * will always return the same object, unless the underlying connection or load
3536  * balancer is manually destroyed.
3537  *
3538  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3539  * updater to ensure that a proper database is being updated.
3540  *
3541  * @return DatabaseBase
3542  */
3543 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3544         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3545 }
3546
3547 /**
3548  * Get a load balancer object.
3549  *
3550  * @param string|bool $wiki Wiki ID, or false for the current wiki
3551  * @return LoadBalancer
3552  */
3553 function wfGetLB( $wiki = false ) {
3554         return wfGetLBFactory()->getMainLB( $wiki );
3555 }
3556
3557 /**
3558  * Get the load balancer factory object
3559  *
3560  * @return LBFactory
3561  */
3562 function &wfGetLBFactory() {
3563         return LBFactory::singleton();
3564 }
3565
3566 /**
3567  * Find a file.
3568  * Shortcut for RepoGroup::singleton()->findFile()
3569  *
3570  * @param string $title String or Title object
3571  * @param array $options Associative array of options:
3572  *     time:           requested time for an archived image, or false for the
3573  *                     current version. An image object will be returned which was
3574  *                     created at the specified time.
3575  *
3576  *     ignoreRedirect: If true, do not follow file redirects
3577  *
3578  *     private:        If true, return restricted (deleted) files if the current
3579  *                     user is allowed to view them. Otherwise, such files will not
3580  *                     be found.
3581  *
3582  *     bypassCache:    If true, do not use the process-local cache of File objects
3583  *
3584  * @return File|bool File, or false if the file does not exist
3585  */
3586 function wfFindFile( $title, $options = array() ) {
3587         return RepoGroup::singleton()->findFile( $title, $options );
3588 }
3589
3590 /**
3591  * Get an object referring to a locally registered file.
3592  * Returns a valid placeholder object if the file does not exist.
3593  *
3594  * @param Title|string $title
3595  * @return LocalFile|null A File, or null if passed an invalid Title
3596  */
3597 function wfLocalFile( $title ) {
3598         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3599 }
3600
3601 /**
3602  * Should low-performance queries be disabled?
3603  *
3604  * @return bool
3605  * @codeCoverageIgnore
3606  */
3607 function wfQueriesMustScale() {
3608         global $wgMiserMode;
3609         return $wgMiserMode
3610                 || ( SiteStats::pages() > 100000
3611                 && SiteStats::edits() > 1000000
3612                 && SiteStats::users() > 10000 );
3613 }
3614
3615 /**
3616  * Get the path to a specified script file, respecting file
3617  * extensions; this is a wrapper around $wgScriptExtension etc.
3618  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3619  *
3620  * @param string $script Script filename, sans extension
3621  * @return string
3622  */
3623 function wfScript( $script = 'index' ) {
3624         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3625         if ( $script === 'index' ) {
3626                 return $wgScript;
3627         } elseif ( $script === 'load' ) {
3628                 return $wgLoadScript;
3629         } else {
3630                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3631         }
3632 }
3633
3634 /**
3635  * Get the script URL.
3636  *
3637  * @return string Script URL
3638  */
3639 function wfGetScriptUrl() {
3640         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3641                 #
3642                 # as it was called, minus the query string.
3643                 #
3644                 # Some sites use Apache rewrite rules to handle subdomains,
3645                 # and have PHP set up in a weird way that causes PHP_SELF
3646                 # to contain the rewritten URL instead of the one that the
3647                 # outside world sees.
3648                 #
3649                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3650                 # provides containing the "before" URL.
3651                 return $_SERVER['SCRIPT_NAME'];
3652         } else {
3653                 return $_SERVER['URL'];
3654         }
3655 }
3656
3657 /**
3658  * Convenience function converts boolean values into "true"
3659  * or "false" (string) values
3660  *
3661  * @param bool $value
3662  * @return string
3663  */
3664 function wfBoolToStr( $value ) {
3665         return $value ? 'true' : 'false';
3666 }
3667
3668 /**
3669  * Get a platform-independent path to the null file, e.g. /dev/null
3670  *
3671  * @return string
3672  */
3673 function wfGetNull() {
3674         return wfIsWindows() ? 'NUL' : '/dev/null';
3675 }
3676
3677 /**
3678  * Waits for the slaves to catch up to the master position
3679  *
3680  * Use this when updating very large numbers of rows, as in maintenance scripts,
3681  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3682  *
3683  * By default this waits on the main DB cluster of the current wiki.
3684  * If $cluster is set to "*" it will wait on all DB clusters, including
3685  * external ones. If the lag being waiting on is caused by the code that
3686  * does this check, it makes since to use $ifWritesSince, particularly if
3687  * cluster is "*", to avoid excess overhead.
3688  *
3689  * Never call this function after a big DB write that is still in a transaction.
3690  * This only makes sense after the possible lag inducing changes were committed.
3691  *
3692  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3693  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3694  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3695  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3696  * @return bool Success (able to connect and no timeouts reached)
3697  */
3698 function wfWaitForSlaves(
3699         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3700 ) {
3701         // B/C: first argument used to be "max seconds of lag"; ignore such values
3702         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3703
3704         if ( $timeout === null ) {
3705                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3706         }
3707
3708         // Figure out which clusters need to be checked
3709         $lbs = array();
3710         if ( $cluster === '*' ) {
3711                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3712                         $lbs[] = $lb;
3713                 } );
3714         } elseif ( $cluster !== false ) {
3715                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3716         } else {
3717                 $lbs[] = wfGetLB( $wiki );
3718         }
3719
3720         // Get all the master positions of applicable DBs right now.
3721         // This can be faster since waiting on one cluster reduces the
3722         // time needed to wait on the next clusters.
3723         $masterPositions = array_fill( 0, count( $lbs ), false );
3724         foreach ( $lbs as $i => $lb ) {
3725                 // bug 27975 - Don't try to wait for slaves if there are none
3726                 // Prevents permission error when getting master position
3727                 if ( $lb->getServerCount() > 1 ) {
3728                         if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
3729                                 continue; // assume no writes done
3730                         }
3731                         // Use the empty string to not trigger selectDB() since the connection
3732                         // may have been to a server that does not have a DB for the current wiki.
3733                         $dbw = $lb->getConnection( DB_MASTER, array(), '' );
3734                         if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
3735                                 continue; // no writes since the last wait
3736                         }
3737                         $masterPositions[$i] = $dbw->getMasterPos();
3738                 }
3739         }
3740
3741         $ok = true;
3742         foreach ( $lbs as $i => $lb ) {
3743                 if ( $masterPositions[$i] ) {
3744                         // The DBMS may not support getMasterPos() or the whole
3745                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3746                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3747                 }
3748         }
3749
3750         return $ok;
3751 }
3752
3753 /**
3754  * Count down from $seconds to zero on the terminal, with a one-second pause
3755  * between showing each number. For use in command-line scripts.
3756  *
3757  * @codeCoverageIgnore
3758  * @param int $seconds
3759  */
3760 function wfCountDown( $seconds ) {
3761         for ( $i = $seconds; $i >= 0; $i-- ) {
3762                 if ( $i != $seconds ) {
3763                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3764                 }
3765                 echo $i;
3766                 flush();
3767                 if ( $i ) {
3768                         sleep( 1 );
3769                 }
3770         }
3771         echo "\n";
3772 }
3773
3774 /**
3775  * Replace all invalid characters with -
3776  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3777  * By default, $wgIllegalFileChars = ':'
3778  *
3779  * @param string $name Filename to process
3780  * @return string
3781  */
3782 function wfStripIllegalFilenameChars( $name ) {
3783         global $wgIllegalFileChars;
3784         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3785         $name = wfBaseName( $name );
3786         $name = preg_replace(
3787                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3788                 '-',
3789                 $name
3790         );
3791         return $name;
3792 }
3793
3794 /**
3795  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3796  *
3797  * @return int Value the memory limit was set to.
3798  */
3799 function wfMemoryLimit() {
3800         global $wgMemoryLimit;
3801         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3802         if ( $memlimit != -1 ) {
3803                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3804                 if ( $conflimit == -1 ) {
3805                         wfDebug( "Removing PHP's memory limit\n" );
3806                         wfSuppressWarnings();
3807                         ini_set( 'memory_limit', $conflimit );
3808                         wfRestoreWarnings();
3809                         return $conflimit;
3810                 } elseif ( $conflimit > $memlimit ) {
3811                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3812                         wfSuppressWarnings();
3813                         ini_set( 'memory_limit', $conflimit );
3814                         wfRestoreWarnings();
3815                         return $conflimit;
3816                 }
3817         }
3818         return $memlimit;
3819 }
3820
3821 /**
3822  * Converts shorthand byte notation to integer form
3823  *
3824  * @param string $string
3825  * @return int
3826  */
3827 function wfShorthandToInteger( $string = '' ) {
3828         $string = trim( $string );
3829         if ( $string === '' ) {
3830                 return -1;
3831         }
3832         $last = $string[strlen( $string ) - 1];
3833         $val = intval( $string );
3834         switch ( $last ) {
3835                 case 'g':
3836                 case 'G':
3837                         $val *= 1024;
3838                         // break intentionally missing
3839                 case 'm':
3840                 case 'M':
3841                         $val *= 1024;
3842                         // break intentionally missing
3843                 case 'k':
3844                 case 'K':
3845                         $val *= 1024;
3846         }
3847
3848         return $val;
3849 }
3850
3851 /**
3852  * Get the normalised IETF language tag
3853  * See unit test for examples.
3854  *
3855  * @param string $code The language code.
3856  * @return string The language code which complying with BCP 47 standards.
3857  */
3858 function wfBCP47( $code ) {
3859         $codeSegment = explode( '-', $code );
3860         $codeBCP = array();
3861         foreach ( $codeSegment as $segNo => $seg ) {
3862                 // when previous segment is x, it is a private segment and should be lc
3863                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3864                         $codeBCP[$segNo] = strtolower( $seg );
3865                 // ISO 3166 country code
3866                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3867                         $codeBCP[$segNo] = strtoupper( $seg );
3868                 // ISO 15924 script code
3869                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3870                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3871                 // Use lowercase for other cases
3872                 } else {
3873                         $codeBCP[$segNo] = strtolower( $seg );
3874                 }
3875         }
3876         $langCode = implode( '-', $codeBCP );
3877         return $langCode;
3878 }
3879
3880 /**
3881  * Get a cache object.
3882  *
3883  * @param int $inputType Cache type, one the the CACHE_* constants.
3884  * @return BagOStuff
3885  */
3886 function wfGetCache( $inputType ) {
3887         return ObjectCache::getInstance( $inputType );
3888 }
3889
3890 /**
3891  * Get the main cache object
3892  *
3893  * @return BagOStuff
3894  */
3895 function wfGetMainCache() {
3896         global $wgMainCacheType;
3897         return ObjectCache::getInstance( $wgMainCacheType );
3898 }
3899
3900 /**
3901  * Get the cache object used by the message cache
3902  *
3903  * @return BagOStuff
3904  */
3905 function wfGetMessageCacheStorage() {
3906         global $wgMessageCacheType;
3907         return ObjectCache::getInstance( $wgMessageCacheType );
3908 }
3909
3910 /**
3911  * Get the cache object used by the parser cache
3912  *
3913  * @return BagOStuff
3914  */
3915 function wfGetParserCacheStorage() {
3916         global $wgParserCacheType;
3917         return ObjectCache::getInstance( $wgParserCacheType );
3918 }
3919
3920 /**
3921  * Get the cache object used by the language converter
3922  *
3923  * @return BagOStuff
3924  */
3925 function wfGetLangConverterCacheStorage() {
3926         global $wgLanguageConverterCacheType;
3927         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3928 }
3929
3930 /**
3931  * Call hook functions defined in $wgHooks
3932  *
3933  * @param string $event Event name
3934  * @param array $args Parameters passed to hook functions
3935  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3936  *
3937  * @return bool True if no handler aborted the hook
3938  */
3939 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3940         return Hooks::run( $event, $args, $deprecatedVersion );
3941 }
3942
3943 /**
3944  * Wrapper around php's unpack.
3945  *
3946  * @param string $format The format string (See php's docs)
3947  * @param string $data A binary string of binary data
3948  * @param int|bool $length The minimum length of $data or false. This is to
3949  *      prevent reading beyond the end of $data. false to disable the check.
3950  *
3951  * Also be careful when using this function to read unsigned 32 bit integer
3952  * because php might make it negative.
3953  *
3954  * @throws MWException If $data not long enough, or if unpack fails
3955  * @return array Associative array of the extracted data
3956  */
3957 function wfUnpack( $format, $data, $length = false ) {
3958         if ( $length !== false ) {
3959                 $realLen = strlen( $data );
3960                 if ( $realLen < $length ) {
3961                         throw new MWException( "Tried to use wfUnpack on a "
3962                                 . "string of length $realLen, but needed one "
3963                                 . "of at least length $length."
3964                         );
3965                 }
3966         }
3967
3968         wfSuppressWarnings();
3969         $result = unpack( $format, $data );
3970         wfRestoreWarnings();
3971
3972         if ( $result === false ) {
3973                 // If it cannot extract the packed data.
3974                 throw new MWException( "unpack could not unpack binary data" );
3975         }
3976         return $result;
3977 }
3978
3979 /**
3980  * Determine if an image exists on the 'bad image list'.
3981  *
3982  * The format of MediaWiki:Bad_image_list is as follows:
3983  *    * Only list items (lines starting with "*") are considered
3984  *    * The first link on a line must be a link to a bad image
3985  *    * Any subsequent links on the same line are considered to be exceptions,
3986  *      i.e. articles where the image may occur inline.
3987  *
3988  * @param string $name The image name to check
3989  * @param Title|bool $contextTitle The page on which the image occurs, if known
3990  * @param string $blacklist Wikitext of a file blacklist
3991  * @return bool
3992  */
3993 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3994         static $badImageCache = null; // based on bad_image_list msg
3995         wfProfileIn( __METHOD__ );
3996
3997         # Handle redirects
3998         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3999         if ( $redirectTitle ) {
4000                 $name = $redirectTitle->getDBkey();
4001         }
4002
4003         # Run the extension hook
4004         $bad = false;
4005         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
4006                 wfProfileOut( __METHOD__ );
4007                 return $bad;
4008         }
4009
4010         $cacheable = ( $blacklist === null );
4011         if ( $cacheable && $badImageCache !== null ) {
4012                 $badImages = $badImageCache;
4013         } else { // cache miss
4014                 if ( $blacklist === null ) {
4015                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4016                 }
4017                 # Build the list now
4018                 $badImages = array();
4019                 $lines = explode( "\n", $blacklist );
4020                 foreach ( $lines as $line ) {
4021                         # List items only
4022                         if ( substr( $line, 0, 1 ) !== '*' ) {
4023                                 continue;
4024                         }
4025
4026                         # Find all links
4027                         $m = array();
4028                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4029                                 continue;
4030                         }
4031
4032                         $exceptions = array();
4033                         $imageDBkey = false;
4034                         foreach ( $m[1] as $i => $titleText ) {
4035                                 $title = Title::newFromText( $titleText );
4036                                 if ( !is_null( $title ) ) {
4037                                         if ( $i == 0 ) {
4038                                                 $imageDBkey = $title->getDBkey();
4039                                         } else {
4040                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4041                                         }
4042                                 }
4043                         }
4044
4045                         if ( $imageDBkey !== false ) {
4046                                 $badImages[$imageDBkey] = $exceptions;
4047                         }
4048                 }
4049                 if ( $cacheable ) {
4050                         $badImageCache = $badImages;
4051                 }
4052         }
4053
4054         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4055         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4056         wfProfileOut( __METHOD__ );
4057         return $bad;
4058 }
4059
4060 /**
4061  * Determine whether the client at a given source IP is likely to be able to
4062  * access the wiki via HTTPS.
4063  *
4064  * @param string $ip The IPv4/6 address in the normal human-readable form
4065  * @return bool
4066  */
4067 function wfCanIPUseHTTPS( $ip ) {
4068         $canDo = true;
4069         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4070         return !!$canDo;
4071 }
4072
4073 /**
4074  * Work out the IP address based on various globals
4075  * For trusted proxies, use the XFF client IP (first of the chain)
4076  *
4077  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4078  * @return string
4079  */
4080 function wfGetIP() {
4081         wfDeprecated( __METHOD__, '1.19' );
4082         global $wgRequest;
4083         return $wgRequest->getIP();
4084 }
4085
4086 /**
4087  * Checks if an IP is a trusted proxy provider.
4088  * Useful to tell if X-Forwarded-For data is possibly bogus.
4089  * Squid cache servers for the site are whitelisted.
4090  * @deprecated Since 1.24, use IP::isTrustedProxy()
4091  *
4092  * @param string $ip
4093  * @return bool
4094  */
4095 function wfIsTrustedProxy( $ip ) {
4096         return IP::isTrustedProxy( $ip );
4097 }
4098
4099 /**
4100  * Checks if an IP matches a proxy we've configured.
4101  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4102  *
4103  * @param string $ip
4104  * @return bool
4105  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4106  */
4107 function wfIsConfiguredProxy( $ip ) {
4108         return IP::isConfiguredProxy( $ip );
4109 }