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
1230         $log = MWLogger::getInstance( 'profileoutput' );
1231         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1232 }
1233
1234 /**
1235  * Increment a statistics counter
1236  *
1237  * @param string $key
1238  * @param int $count
1239  * @return void
1240  */
1241 function wfIncrStats( $key, $count = 1 ) {
1242         StatCounter::singleton()->incr( $key, $count );
1243 }
1244
1245 /**
1246  * Check whether the wiki is in read-only mode.
1247  *
1248  * @return bool
1249  */
1250 function wfReadOnly() {
1251         return wfReadOnlyReason() !== false;
1252 }
1253
1254 /**
1255  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1256  *
1257  * @return string|bool String when in read-only mode; false otherwise
1258  */
1259 function wfReadOnlyReason() {
1260         global $wgReadOnly, $wgReadOnlyFile;
1261
1262         if ( $wgReadOnly === null ) {
1263                 // Set $wgReadOnly for faster access next time
1264                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1265                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1266                 } else {
1267                         $wgReadOnly = false;
1268                 }
1269         }
1270
1271         return $wgReadOnly;
1272 }
1273
1274 /**
1275  * Return a Language object from $langcode
1276  *
1277  * @param Language|string|bool $langcode Either:
1278  *                  - a Language object
1279  *                  - code of the language to get the message for, if it is
1280  *                    a valid code create a language for that language, if
1281  *                    it is a string but not a valid code then make a basic
1282  *                    language object
1283  *                  - a boolean: if it's false then use the global object for
1284  *                    the current user's language (as a fallback for the old parameter
1285  *                    functionality), or if it is true then use global object
1286  *                    for the wiki's content language.
1287  * @return Language
1288  */
1289 function wfGetLangObj( $langcode = false ) {
1290         # Identify which language to get or create a language object for.
1291         # Using is_object here due to Stub objects.
1292         if ( is_object( $langcode ) ) {
1293                 # Great, we already have the object (hopefully)!
1294                 return $langcode;
1295         }
1296
1297         global $wgContLang, $wgLanguageCode;
1298         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1299                 # $langcode is the language code of the wikis content language object.
1300                 # or it is a boolean and value is true
1301                 return $wgContLang;
1302         }
1303
1304         global $wgLang;
1305         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1306                 # $langcode is the language code of user language object.
1307                 # or it was a boolean and value is false
1308                 return $wgLang;
1309         }
1310
1311         $validCodes = array_keys( Language::fetchLanguageNames() );
1312         if ( in_array( $langcode, $validCodes ) ) {
1313                 # $langcode corresponds to a valid language.
1314                 return Language::factory( $langcode );
1315         }
1316
1317         # $langcode is a string, but not a valid language code; use content language.
1318         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1319         return $wgContLang;
1320 }
1321
1322 /**
1323  * This is the function for getting translated interface messages.
1324  *
1325  * @see Message class for documentation how to use them.
1326  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1327  *
1328  * This function replaces all old wfMsg* functions.
1329  *
1330  * @param string|string[] $key Message key, or array of keys
1331  * @param mixed $params,... Normal message parameters
1332  * @return Message
1333  *
1334  * @since 1.17
1335  *
1336  * @see Message::__construct
1337  */
1338 function wfMessage( $key /*...*/ ) {
1339         $params = func_get_args();
1340         array_shift( $params );
1341         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1342                 $params = $params[0];
1343         }
1344         return new Message( $key, $params );
1345 }
1346
1347 /**
1348  * This function accepts multiple message keys and returns a message instance
1349  * for the first message which is non-empty. If all messages are empty then an
1350  * instance of the first message key is returned.
1351  *
1352  * @param string|string[] $keys,... Message keys
1353  * @return Message
1354  *
1355  * @since 1.18
1356  *
1357  * @see Message::newFallbackSequence
1358  */
1359 function wfMessageFallback( /*...*/ ) {
1360         $args = func_get_args();
1361         return call_user_func_array( 'Message::newFallbackSequence', $args );
1362 }
1363
1364 /**
1365  * Get a message from anywhere, for the current user language.
1366  *
1367  * Use wfMsgForContent() instead if the message should NOT
1368  * change depending on the user preferences.
1369  *
1370  * @deprecated since 1.18
1371  *
1372  * @param string $key Lookup key for the message, usually
1373  *    defined in languages/Language.php
1374  *
1375  * Parameters to the message, which can be used to insert variable text into
1376  * it, can be passed to this function in the following formats:
1377  * - One per argument, starting at the second parameter
1378  * - As an array in the second parameter
1379  * These are not shown in the function definition.
1380  *
1381  * @return string
1382  */
1383 function wfMsg( $key ) {
1384         wfDeprecated( __METHOD__, '1.21' );
1385
1386         $args = func_get_args();
1387         array_shift( $args );
1388         return wfMsgReal( $key, $args );
1389 }
1390
1391 /**
1392  * Same as above except doesn't transform the message
1393  *
1394  * @deprecated since 1.18
1395  *
1396  * @param string $key
1397  * @return string
1398  */
1399 function wfMsgNoTrans( $key ) {
1400         wfDeprecated( __METHOD__, '1.21' );
1401
1402         $args = func_get_args();
1403         array_shift( $args );
1404         return wfMsgReal( $key, $args, true, false, false );
1405 }
1406
1407 /**
1408  * Get a message from anywhere, for the current global language
1409  * set with $wgLanguageCode.
1410  *
1411  * Use this if the message should NOT change dependent on the
1412  * language set in the user's preferences. This is the case for
1413  * most text written into logs, as well as link targets (such as
1414  * the name of the copyright policy page). Link titles, on the
1415  * other hand, should be shown in the UI language.
1416  *
1417  * Note that MediaWiki allows users to change the user interface
1418  * language in their preferences, but a single installation
1419  * typically only contains content in one language.
1420  *
1421  * Be wary of this distinction: If you use wfMsg() where you should
1422  * use wfMsgForContent(), a user of the software may have to
1423  * customize potentially hundreds of messages in
1424  * order to, e.g., fix a link in every possible language.
1425  *
1426  * @deprecated since 1.18
1427  *
1428  * @param string $key Lookup key for the message, usually
1429  *     defined in languages/Language.php
1430  * @return string
1431  */
1432 function wfMsgForContent( $key ) {
1433         wfDeprecated( __METHOD__, '1.21' );
1434
1435         global $wgForceUIMsgAsContentMsg;
1436         $args = func_get_args();
1437         array_shift( $args );
1438         $forcontent = true;
1439         if ( is_array( $wgForceUIMsgAsContentMsg )
1440                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1441         ) {
1442                 $forcontent = false;
1443         }
1444         return wfMsgReal( $key, $args, true, $forcontent );
1445 }
1446
1447 /**
1448  * Same as above except doesn't transform the message
1449  *
1450  * @deprecated since 1.18
1451  *
1452  * @param string $key
1453  * @return string
1454  */
1455 function wfMsgForContentNoTrans( $key ) {
1456         wfDeprecated( __METHOD__, '1.21' );
1457
1458         global $wgForceUIMsgAsContentMsg;
1459         $args = func_get_args();
1460         array_shift( $args );
1461         $forcontent = true;
1462         if ( is_array( $wgForceUIMsgAsContentMsg )
1463                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1464         ) {
1465                 $forcontent = false;
1466         }
1467         return wfMsgReal( $key, $args, true, $forcontent, false );
1468 }
1469
1470 /**
1471  * Really get a message
1472  *
1473  * @deprecated since 1.18
1474  *
1475  * @param string $key Key to get.
1476  * @param array $args
1477  * @param bool $useDB
1478  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1479  * @param bool $transform Whether or not to transform the message.
1480  * @return string The requested message.
1481  */
1482 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1483         wfDeprecated( __METHOD__, '1.21' );
1484
1485         wfProfileIn( __METHOD__ );
1486         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1487         $message = wfMsgReplaceArgs( $message, $args );
1488         wfProfileOut( __METHOD__ );
1489         return $message;
1490 }
1491
1492 /**
1493  * Fetch a message string value, but don't replace any keys yet.
1494  *
1495  * @deprecated since 1.18
1496  *
1497  * @param string $key
1498  * @param bool $useDB
1499  * @param string|bool $langCode Code of the language to get the message for, or
1500  *   behaves as a content language switch if it is a boolean.
1501  * @param bool $transform Whether to parse magic words, etc.
1502  * @return string
1503  */
1504 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1505         wfDeprecated( __METHOD__, '1.21' );
1506
1507         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1508
1509         $cache = MessageCache::singleton();
1510         $message = $cache->get( $key, $useDB, $langCode );
1511         if ( $message === false ) {
1512                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1513         } elseif ( $transform ) {
1514                 $message = $cache->transform( $message );
1515         }
1516         return $message;
1517 }
1518
1519 /**
1520  * Replace message parameter keys on the given formatted output.
1521  *
1522  * @param string $message
1523  * @param array $args
1524  * @return string
1525  * @private
1526  */
1527 function wfMsgReplaceArgs( $message, $args ) {
1528         # Fix windows line-endings
1529         # Some messages are split with explode("\n", $msg)
1530         $message = str_replace( "\r", '', $message );
1531
1532         // Replace arguments
1533         if ( count( $args ) ) {
1534                 if ( is_array( $args[0] ) ) {
1535                         $args = array_values( $args[0] );
1536                 }
1537                 $replacementKeys = array();
1538                 foreach ( $args as $n => $param ) {
1539                         $replacementKeys['$' . ( $n + 1 )] = $param;
1540                 }
1541                 $message = strtr( $message, $replacementKeys );
1542         }
1543
1544         return $message;
1545 }
1546
1547 /**
1548  * Return an HTML-escaped version of a message.
1549  * Parameter replacements, if any, are done *after* the HTML-escaping,
1550  * so parameters may contain HTML (eg links or form controls). Be sure
1551  * to pre-escape them if you really do want plaintext, or just wrap
1552  * the whole thing in htmlspecialchars().
1553  *
1554  * @deprecated since 1.18
1555  *
1556  * @param string $key
1557  * @param string $args,... Parameters
1558  * @return string
1559  */
1560 function wfMsgHtml( $key ) {
1561         wfDeprecated( __METHOD__, '1.21' );
1562
1563         $args = func_get_args();
1564         array_shift( $args );
1565         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1566 }
1567
1568 /**
1569  * Return an HTML version of message
1570  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1571  * so parameters may contain HTML (eg links or form controls). Be sure
1572  * to pre-escape them if you really do want plaintext, or just wrap
1573  * the whole thing in htmlspecialchars().
1574  *
1575  * @deprecated since 1.18
1576  *
1577  * @param string $key
1578  * @param string $args,... Parameters
1579  * @return string
1580  */
1581 function wfMsgWikiHtml( $key ) {
1582         wfDeprecated( __METHOD__, '1.21' );
1583
1584         $args = func_get_args();
1585         array_shift( $args );
1586         return wfMsgReplaceArgs(
1587                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1588                 /* can't be set to false */ true, /* interface */ true )->getText(),
1589                 $args );
1590 }
1591
1592 /**
1593  * Returns message in the requested format
1594  *
1595  * @deprecated since 1.18
1596  *
1597  * @param string $key Key of the message
1598  * @param array $options Processing rules.
1599  *   Can take the following options:
1600  *     parse: parses wikitext to HTML
1601  *     parseinline: parses wikitext to HTML and removes the surrounding
1602  *       p's added by parser or tidy
1603  *     escape: filters message through htmlspecialchars
1604  *     escapenoentities: same, but allows entity references like &#160; through
1605  *     replaceafter: parameters are substituted after parsing or escaping
1606  *     parsemag: transform the message using magic phrases
1607  *     content: fetch message for content language instead of interface
1608  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1609  *     language: Language object or language code to fetch message for
1610  *       (overridden by content).
1611  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1612  *
1613  * @return string
1614  */
1615 function wfMsgExt( $key, $options ) {
1616         wfDeprecated( __METHOD__, '1.21' );
1617
1618         $args = func_get_args();
1619         array_shift( $args );
1620         array_shift( $args );
1621         $options = (array)$options;
1622         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1623                 'parsemag', 'content' );
1624
1625         foreach ( $options as $arrayKey => $option ) {
1626                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1627                         // An unknown index, neither numeric nor "language"
1628                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1629                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1630                         // A numeric index with unknown value
1631                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1632                 }
1633         }
1634
1635         if ( in_array( 'content', $options, true ) ) {
1636                 $forContent = true;
1637                 $langCode = true;
1638                 $langCodeObj = null;
1639         } elseif ( array_key_exists( 'language', $options ) ) {
1640                 $forContent = false;
1641                 $langCode = wfGetLangObj( $options['language'] );
1642                 $langCodeObj = $langCode;
1643         } else {
1644                 $forContent = false;
1645                 $langCode = false;
1646                 $langCodeObj = null;
1647         }
1648
1649         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1650
1651         if ( !in_array( 'replaceafter', $options, true ) ) {
1652                 $string = wfMsgReplaceArgs( $string, $args );
1653         }
1654
1655         $messageCache = MessageCache::singleton();
1656         $parseInline = in_array( 'parseinline', $options, true );
1657         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1658                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1659                 if ( $string instanceof ParserOutput ) {
1660                         $string = $string->getText();
1661                 }
1662
1663                 if ( $parseInline ) {
1664                         $string = Parser::stripOuterParagraph( $string );
1665                 }
1666         } elseif ( in_array( 'parsemag', $options, true ) ) {
1667                 $string = $messageCache->transform( $string,
1668                                 !$forContent, $langCodeObj );
1669         }
1670
1671         if ( in_array( 'escape', $options, true ) ) {
1672                 $string = htmlspecialchars ( $string );
1673         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1674                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1675         }
1676
1677         if ( in_array( 'replaceafter', $options, true ) ) {
1678                 $string = wfMsgReplaceArgs( $string, $args );
1679         }
1680
1681         return $string;
1682 }
1683
1684 /**
1685  * Since wfMsg() and co suck, they don't return false if the message key they
1686  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1687  * nonexistence of messages by checking the MessageCache::get() result directly.
1688  *
1689  * @deprecated since 1.18. Use Message::isDisabled().
1690  *
1691  * @param string $key The message key looked up
1692  * @return bool True if the message *doesn't* exist.
1693  */
1694 function wfEmptyMsg( $key ) {
1695         wfDeprecated( __METHOD__, '1.21' );
1696
1697         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1698 }
1699
1700 /**
1701  * Fetch server name for use in error reporting etc.
1702  * Use real server name if available, so we know which machine
1703  * in a server farm generated the current page.
1704  *
1705  * @return string
1706  */
1707 function wfHostname() {
1708         static $host;
1709         if ( is_null( $host ) ) {
1710
1711                 # Hostname overriding
1712                 global $wgOverrideHostname;
1713                 if ( $wgOverrideHostname !== false ) {
1714                         # Set static and skip any detection
1715                         $host = $wgOverrideHostname;
1716                         return $host;
1717                 }
1718
1719                 if ( function_exists( 'posix_uname' ) ) {
1720                         // This function not present on Windows
1721                         $uname = posix_uname();
1722                 } else {
1723                         $uname = false;
1724                 }
1725                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1726                         $host = $uname['nodename'];
1727                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1728                         # Windows computer name
1729                         $host = getenv( 'COMPUTERNAME' );
1730                 } else {
1731                         # This may be a virtual server.
1732                         $host = $_SERVER['SERVER_NAME'];
1733                 }
1734         }
1735         return $host;
1736 }
1737
1738 /**
1739  * Returns a script tag that stores the amount of time it took MediaWiki to
1740  * handle the request in milliseconds as 'wgBackendResponseTime'.
1741  *
1742  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1743  * hostname of the server handling the request.
1744  *
1745  * @return string
1746  */
1747 function wfReportTime() {
1748         global $wgRequestTime, $wgShowHostnames;
1749
1750         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1751         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1752         if ( $wgShowHostnames ) {
1753                 $reportVars['wgHostname'] = wfHostname();
1754         }
1755         return Skin::makeVariablesScript( $reportVars );
1756 }
1757
1758 /**
1759  * Safety wrapper for debug_backtrace().
1760  *
1761  * Will return an empty array if debug_backtrace is disabled, otherwise
1762  * the output from debug_backtrace() (trimmed).
1763  *
1764  * @param int $limit This parameter can be used to limit the number of stack frames returned
1765  *
1766  * @return array Array of backtrace information
1767  */
1768 function wfDebugBacktrace( $limit = 0 ) {
1769         static $disabled = null;
1770
1771         if ( is_null( $disabled ) ) {
1772                 $disabled = !function_exists( 'debug_backtrace' );
1773                 if ( $disabled ) {
1774                         wfDebug( "debug_backtrace() is disabled\n" );
1775                 }
1776         }
1777         if ( $disabled ) {
1778                 return array();
1779         }
1780
1781         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1782                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1783         } else {
1784                 return array_slice( debug_backtrace(), 1 );
1785         }
1786 }
1787
1788 /**
1789  * Get a debug backtrace as a string
1790  *
1791  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1792  *   Defaults to $wgCommandLineMode if unset.
1793  * @return string
1794  * @since 1.25 Supports $raw parameter.
1795  */
1796 function wfBacktrace( $raw = null ) {
1797         global $wgCommandLineMode;
1798
1799         if ( $raw === null ) {
1800                 $raw = $wgCommandLineMode;
1801         }
1802
1803         if ( $raw ) {
1804                 $frameFormat = "%s line %s calls %s()\n";
1805                 $traceFormat = "%s";
1806         } else {
1807                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1808                 $traceFormat = "<ul>\n%s</ul>\n";
1809         }
1810
1811         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1812                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1813                 $line = $frame['line'] ?: '-';
1814                 $call = $frame['function'];
1815                 if ( !empty( $frame['class'] ) ) {
1816                         $call = $frame['class'] . $frame['type'] . $call;
1817                 }
1818                 return sprintf( $frameFormat, $file, $line, $call );
1819         }, wfDebugBacktrace() );
1820
1821         return sprintf( $traceFormat, implode( '', $frames ) );
1822 }
1823
1824 /**
1825  * Get the name of the function which called this function
1826  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1827  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1828  * wfGetCaller( 3 ) is the parent of that.
1829  *
1830  * @param int $level
1831  * @return string
1832  */
1833 function wfGetCaller( $level = 2 ) {
1834         $backtrace = wfDebugBacktrace( $level + 1 );
1835         if ( isset( $backtrace[$level] ) ) {
1836                 return wfFormatStackFrame( $backtrace[$level] );
1837         } else {
1838                 return 'unknown';
1839         }
1840 }
1841
1842 /**
1843  * Return a string consisting of callers in the stack. Useful sometimes
1844  * for profiling specific points.
1845  *
1846  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1847  * @return string
1848  */
1849 function wfGetAllCallers( $limit = 3 ) {
1850         $trace = array_reverse( wfDebugBacktrace() );
1851         if ( !$limit || $limit > count( $trace ) - 1 ) {
1852                 $limit = count( $trace ) - 1;
1853         }
1854         $trace = array_slice( $trace, -$limit - 1, $limit );
1855         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1856 }
1857
1858 /**
1859  * Return a string representation of frame
1860  *
1861  * @param array $frame
1862  * @return string
1863  */
1864 function wfFormatStackFrame( $frame ) {
1865         return isset( $frame['class'] ) ?
1866                 $frame['class'] . '::' . $frame['function'] :
1867                 $frame['function'];
1868 }
1869
1870 /* Some generic result counters, pulled out of SearchEngine */
1871
1872 /**
1873  * @todo document
1874  *
1875  * @param int $offset
1876  * @param int $limit
1877  * @return string
1878  */
1879 function wfShowingResults( $offset, $limit ) {
1880         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1881 }
1882
1883 /**
1884  * @todo document
1885  * @todo FIXME: We may want to blacklist some broken browsers
1886  *
1887  * @param bool $force
1888  * @return bool Whereas client accept gzip compression
1889  */
1890 function wfClientAcceptsGzip( $force = false ) {
1891         static $result = null;
1892         if ( $result === null || $force ) {
1893                 $result = false;
1894                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1895                         # @todo FIXME: We may want to blacklist some broken browsers
1896                         $m = array();
1897                         if ( preg_match(
1898                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1899                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1900                                         $m
1901                                 )
1902                         ) {
1903                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1904                                         $result = false;
1905                                         return $result;
1906                                 }
1907                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1908                                 $result = true;
1909                         }
1910                 }
1911         }
1912         return $result;
1913 }
1914
1915 /**
1916  * Obtain the offset and limit values from the request string;
1917  * used in special pages
1918  *
1919  * @param int $deflimit Default limit if none supplied
1920  * @param string $optionname Name of a user preference to check against
1921  * @return array
1922  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
1923  */
1924 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1925         global $wgRequest;
1926         wfDeprecated( __METHOD__, '1.24' );
1927         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1928 }
1929
1930 /**
1931  * Escapes the given text so that it may be output using addWikiText()
1932  * without any linking, formatting, etc. making its way through. This
1933  * is achieved by substituting certain characters with HTML entities.
1934  * As required by the callers, "<nowiki>" is not used.
1935  *
1936  * @param string $text Text to be escaped
1937  * @return string
1938  */
1939 function wfEscapeWikiText( $text ) {
1940         static $repl = null, $repl2 = null;
1941         if ( $repl === null ) {
1942                 $repl = array(
1943                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1944                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1945                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
1946                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
1947                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
1948                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
1949                         "\n " => "\n&#32;", "\r " => "\r&#32;",
1950                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
1951                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
1952                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
1953                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
1954                         '__' => '_&#95;', '://' => '&#58;//',
1955                 );
1956
1957                 // We have to catch everything "\s" matches in PCRE
1958                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
1959                         $repl["$magic "] = "$magic&#32;";
1960                         $repl["$magic\t"] = "$magic&#9;";
1961                         $repl["$magic\r"] = "$magic&#13;";
1962                         $repl["$magic\n"] = "$magic&#10;";
1963                         $repl["$magic\f"] = "$magic&#12;";
1964                 }
1965
1966                 // And handle protocols that don't use "://"
1967                 global $wgUrlProtocols;
1968                 $repl2 = array();
1969                 foreach ( $wgUrlProtocols as $prot ) {
1970                         if ( substr( $prot, -1 ) === ':' ) {
1971                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
1972                         }
1973                 }
1974                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
1975         }
1976         $text = substr( strtr( "\n$text", $repl ), 1 );
1977         $text = preg_replace( $repl2, '$1&#58;', $text );
1978         return $text;
1979 }
1980
1981 /**
1982  * Sets dest to source and returns the original value of dest
1983  * If source is NULL, it just returns the value, it doesn't set the variable
1984  * If force is true, it will set the value even if source is NULL
1985  *
1986  * @param mixed $dest
1987  * @param mixed $source
1988  * @param bool $force
1989  * @return mixed
1990  */
1991 function wfSetVar( &$dest, $source, $force = false ) {
1992         $temp = $dest;
1993         if ( !is_null( $source ) || $force ) {
1994                 $dest = $source;
1995         }
1996         return $temp;
1997 }
1998
1999 /**
2000  * As for wfSetVar except setting a bit
2001  *
2002  * @param int $dest
2003  * @param int $bit
2004  * @param bool $state
2005  *
2006  * @return bool
2007  */
2008 function wfSetBit( &$dest, $bit, $state = true ) {
2009         $temp = (bool)( $dest & $bit );
2010         if ( !is_null( $state ) ) {
2011                 if ( $state ) {
2012                         $dest |= $bit;
2013                 } else {
2014                         $dest &= ~$bit;
2015                 }
2016         }
2017         return $temp;
2018 }
2019
2020 /**
2021  * A wrapper around the PHP function var_export().
2022  * Either print it or add it to the regular output ($wgOut).
2023  *
2024  * @param mixed $var A PHP variable to dump.
2025  */
2026 function wfVarDump( $var ) {
2027         global $wgOut;
2028         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2029         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2030                 print $s;
2031         } else {
2032                 $wgOut->addHTML( $s );
2033         }
2034 }
2035
2036 /**
2037  * Provide a simple HTTP error.
2038  *
2039  * @param int|string $code
2040  * @param string $label
2041  * @param string $desc
2042  */
2043 function wfHttpError( $code, $label, $desc ) {
2044         global $wgOut;
2045         $wgOut->disable();
2046         header( "HTTP/1.0 $code $label" );
2047         header( "Status: $code $label" );
2048         $wgOut->sendCacheControl();
2049
2050         header( 'Content-type: text/html; charset=utf-8' );
2051         print "<!doctype html>" .
2052                 '<html><head><title>' .
2053                 htmlspecialchars( $label ) .
2054                 '</title></head><body><h1>' .
2055                 htmlspecialchars( $label ) .
2056                 '</h1><p>' .
2057                 nl2br( htmlspecialchars( $desc ) ) .
2058                 "</p></body></html>\n";
2059 }
2060
2061 /**
2062  * Clear away any user-level output buffers, discarding contents.
2063  *
2064  * Suitable for 'starting afresh', for instance when streaming
2065  * relatively large amounts of data without buffering, or wanting to
2066  * output image files without ob_gzhandler's compression.
2067  *
2068  * The optional $resetGzipEncoding parameter controls suppression of
2069  * the Content-Encoding header sent by ob_gzhandler; by default it
2070  * is left. See comments for wfClearOutputBuffers() for why it would
2071  * be used.
2072  *
2073  * Note that some PHP configuration options may add output buffer
2074  * layers which cannot be removed; these are left in place.
2075  *
2076  * @param bool $resetGzipEncoding
2077  */
2078 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2079         if ( $resetGzipEncoding ) {
2080                 // Suppress Content-Encoding and Content-Length
2081                 // headers from 1.10+s wfOutputHandler
2082                 global $wgDisableOutputCompression;
2083                 $wgDisableOutputCompression = true;
2084         }
2085         while ( $status = ob_get_status() ) {
2086                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2087                         // Probably from zlib.output_compression or other
2088                         // PHP-internal setting which can't be removed.
2089                         //
2090                         // Give up, and hope the result doesn't break
2091                         // output behavior.
2092                         break;
2093                 }
2094                 if ( !ob_end_clean() ) {
2095                         // Could not remove output buffer handler; abort now
2096                         // to avoid getting in some kind of infinite loop.
2097                         break;
2098                 }
2099                 if ( $resetGzipEncoding ) {
2100                         if ( $status['name'] == 'ob_gzhandler' ) {
2101                                 // Reset the 'Content-Encoding' field set by this handler
2102                                 // so we can start fresh.
2103                                 header_remove( 'Content-Encoding' );
2104                                 break;
2105                         }
2106                 }
2107         }
2108 }
2109
2110 /**
2111  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2112  *
2113  * Clear away output buffers, but keep the Content-Encoding header
2114  * produced by ob_gzhandler, if any.
2115  *
2116  * This should be used for HTTP 304 responses, where you need to
2117  * preserve the Content-Encoding header of the real result, but
2118  * also need to suppress the output of ob_gzhandler to keep to spec
2119  * and avoid breaking Firefox in rare cases where the headers and
2120  * body are broken over two packets.
2121  */
2122 function wfClearOutputBuffers() {
2123         wfResetOutputBuffers( false );
2124 }
2125
2126 /**
2127  * Converts an Accept-* header into an array mapping string values to quality
2128  * factors
2129  *
2130  * @param string $accept
2131  * @param string $def Default
2132  * @return float[] Associative array of string => float pairs
2133  */
2134 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2135         # No arg means accept anything (per HTTP spec)
2136         if ( !$accept ) {
2137                 return array( $def => 1.0 );
2138         }
2139
2140         $prefs = array();
2141
2142         $parts = explode( ',', $accept );
2143
2144         foreach ( $parts as $part ) {
2145                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2146                 $values = explode( ';', trim( $part ) );
2147                 $match = array();
2148                 if ( count( $values ) == 1 ) {
2149                         $prefs[$values[0]] = 1.0;
2150                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2151                         $prefs[$values[0]] = floatval( $match[1] );
2152                 }
2153         }
2154
2155         return $prefs;
2156 }
2157
2158 /**
2159  * Checks if a given MIME type matches any of the keys in the given
2160  * array. Basic wildcards are accepted in the array keys.
2161  *
2162  * Returns the matching MIME type (or wildcard) if a match, otherwise
2163  * NULL if no match.
2164  *
2165  * @param string $type
2166  * @param array $avail
2167  * @return string
2168  * @private
2169  */
2170 function mimeTypeMatch( $type, $avail ) {
2171         if ( array_key_exists( $type, $avail ) ) {
2172                 return $type;
2173         } else {
2174                 $parts = explode( '/', $type );
2175                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2176                         return $parts[0] . '/*';
2177                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2178                         return '*/*';
2179                 } else {
2180                         return null;
2181                 }
2182         }
2183 }
2184
2185 /**
2186  * Returns the 'best' match between a client's requested internet media types
2187  * and the server's list of available types. Each list should be an associative
2188  * array of type to preference (preference is a float between 0.0 and 1.0).
2189  * Wildcards in the types are acceptable.
2190  *
2191  * @param array $cprefs Client's acceptable type list
2192  * @param array $sprefs Server's offered types
2193  * @return string
2194  *
2195  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2196  * XXX: generalize to negotiate other stuff
2197  */
2198 function wfNegotiateType( $cprefs, $sprefs ) {
2199         $combine = array();
2200
2201         foreach ( array_keys( $sprefs ) as $type ) {
2202                 $parts = explode( '/', $type );
2203                 if ( $parts[1] != '*' ) {
2204                         $ckey = mimeTypeMatch( $type, $cprefs );
2205                         if ( $ckey ) {
2206                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2207                         }
2208                 }
2209         }
2210
2211         foreach ( array_keys( $cprefs ) as $type ) {
2212                 $parts = explode( '/', $type );
2213                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2214                         $skey = mimeTypeMatch( $type, $sprefs );
2215                         if ( $skey ) {
2216                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2217                         }
2218                 }
2219         }
2220
2221         $bestq = 0;
2222         $besttype = null;
2223
2224         foreach ( array_keys( $combine ) as $type ) {
2225                 if ( $combine[$type] > $bestq ) {
2226                         $besttype = $type;
2227                         $bestq = $combine[$type];
2228                 }
2229         }
2230
2231         return $besttype;
2232 }
2233
2234 /**
2235  * Reference-counted warning suppression
2236  *
2237  * @param bool $end
2238  */
2239 function wfSuppressWarnings( $end = false ) {
2240         static $suppressCount = 0;
2241         static $originalLevel = false;
2242
2243         if ( $end ) {
2244                 if ( $suppressCount ) {
2245                         --$suppressCount;
2246                         if ( !$suppressCount ) {
2247                                 error_reporting( $originalLevel );
2248                         }
2249                 }
2250         } else {
2251                 if ( !$suppressCount ) {
2252                         $originalLevel = error_reporting( E_ALL & ~(
2253                                 E_WARNING |
2254                                 E_NOTICE |
2255                                 E_USER_WARNING |
2256                                 E_USER_NOTICE |
2257                                 E_DEPRECATED |
2258                                 E_USER_DEPRECATED |
2259                                 E_STRICT
2260                         ) );
2261                 }
2262                 ++$suppressCount;
2263         }
2264 }
2265
2266 /**
2267  * Restore error level to previous value
2268  */
2269 function wfRestoreWarnings() {
2270         wfSuppressWarnings( true );
2271 }
2272
2273 # Autodetect, convert and provide timestamps of various types
2274
2275 /**
2276  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2277  */
2278 define( 'TS_UNIX', 0 );
2279
2280 /**
2281  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2282  */
2283 define( 'TS_MW', 1 );
2284
2285 /**
2286  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2287  */
2288 define( 'TS_DB', 2 );
2289
2290 /**
2291  * RFC 2822 format, for E-mail and HTTP headers
2292  */
2293 define( 'TS_RFC2822', 3 );
2294
2295 /**
2296  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2297  *
2298  * This is used by Special:Export
2299  */
2300 define( 'TS_ISO_8601', 4 );
2301
2302 /**
2303  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2304  *
2305  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2306  *       DateTime tag and page 36 for the DateTimeOriginal and
2307  *       DateTimeDigitized tags.
2308  */
2309 define( 'TS_EXIF', 5 );
2310
2311 /**
2312  * Oracle format time.
2313  */
2314 define( 'TS_ORACLE', 6 );
2315
2316 /**
2317  * Postgres format time.
2318  */
2319 define( 'TS_POSTGRES', 7 );
2320
2321 /**
2322  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2323  */
2324 define( 'TS_ISO_8601_BASIC', 9 );
2325
2326 /**
2327  * Get a timestamp string in one of various formats
2328  *
2329  * @param mixed $outputtype A timestamp in one of the supported formats, the
2330  *   function will autodetect which format is supplied and act accordingly.
2331  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2332  * @return string|bool String / false The same date in the format specified in $outputtype or false
2333  */
2334 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2335         try {
2336                 $timestamp = new MWTimestamp( $ts );
2337                 return $timestamp->getTimestamp( $outputtype );
2338         } catch ( TimestampException $e ) {
2339                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2340                 return false;
2341         }
2342 }
2343
2344 /**
2345  * Return a formatted timestamp, or null if input is null.
2346  * For dealing with nullable timestamp columns in the database.
2347  *
2348  * @param int $outputtype
2349  * @param string $ts
2350  * @return string
2351  */
2352 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2353         if ( is_null( $ts ) ) {
2354                 return null;
2355         } else {
2356                 return wfTimestamp( $outputtype, $ts );
2357         }
2358 }
2359
2360 /**
2361  * Convenience function; returns MediaWiki timestamp for the present time.
2362  *
2363  * @return string
2364  */
2365 function wfTimestampNow() {
2366         # return NOW
2367         return wfTimestamp( TS_MW, time() );
2368 }
2369
2370 /**
2371  * Check if the operating system is Windows
2372  *
2373  * @return bool True if it's Windows, false otherwise.
2374  */
2375 function wfIsWindows() {
2376         static $isWindows = null;
2377         if ( $isWindows === null ) {
2378                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2379         }
2380         return $isWindows;
2381 }
2382
2383 /**
2384  * Check if we are running under HHVM
2385  *
2386  * @return bool
2387  */
2388 function wfIsHHVM() {
2389         return defined( 'HHVM_VERSION' );
2390 }
2391
2392 /**
2393  * Swap two variables
2394  *
2395  * @deprecated since 1.24
2396  * @param mixed $x
2397  * @param mixed $y
2398  */
2399 function swap( &$x, &$y ) {
2400         wfDeprecated( __FUNCTION__, '1.24' );
2401         $z = $x;
2402         $x = $y;
2403         $y = $z;
2404 }
2405
2406 /**
2407  * Tries to get the system directory for temporary files. First
2408  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2409  * environment variables are then checked in sequence, and if none are
2410  * set try sys_get_temp_dir().
2411  *
2412  * NOTE: When possible, use instead the tmpfile() function to create
2413  * temporary files to avoid race conditions on file creation, etc.
2414  *
2415  * @return string
2416  */
2417 function wfTempDir() {
2418         global $wgTmpDirectory;
2419
2420         if ( $wgTmpDirectory !== false ) {
2421                 return $wgTmpDirectory;
2422         }
2423
2424         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2425
2426         foreach ( $tmpDir as $tmp ) {
2427                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2428                         return $tmp;
2429                 }
2430         }
2431         return sys_get_temp_dir();
2432 }
2433
2434 /**
2435  * Make directory, and make all parent directories if they don't exist
2436  *
2437  * @param string $dir Full path to directory to create
2438  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2439  * @param string $caller Optional caller param for debugging.
2440  * @throws MWException
2441  * @return bool
2442  */
2443 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2444         global $wgDirectoryMode;
2445
2446         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2447                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2448         }
2449
2450         if ( !is_null( $caller ) ) {
2451                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2452         }
2453
2454         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2455                 return true;
2456         }
2457
2458         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2459
2460         if ( is_null( $mode ) ) {
2461                 $mode = $wgDirectoryMode;
2462         }
2463
2464         // Turn off the normal warning, we're doing our own below
2465         wfSuppressWarnings();
2466         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2467         wfRestoreWarnings();
2468
2469         if ( !$ok ) {
2470                 //directory may have been created on another request since we last checked
2471                 if ( is_dir( $dir ) ) {
2472                         return true;
2473                 }
2474
2475                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2476                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2477         }
2478         return $ok;
2479 }
2480
2481 /**
2482  * Remove a directory and all its content.
2483  * Does not hide error.
2484  * @param string $dir
2485  */
2486 function wfRecursiveRemoveDir( $dir ) {
2487         wfDebug( __FUNCTION__ . "( $dir )\n" );
2488         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2489         if ( is_dir( $dir ) ) {
2490                 $objects = scandir( $dir );
2491                 foreach ( $objects as $object ) {
2492                         if ( $object != "." && $object != ".." ) {
2493                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2494                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2495                                 } else {
2496                                         unlink( $dir . '/' . $object );
2497                                 }
2498                         }
2499                 }
2500                 reset( $objects );
2501                 rmdir( $dir );
2502         }
2503 }
2504
2505 /**
2506  * @param int $nr The number to format
2507  * @param int $acc The number of digits after the decimal point, default 2
2508  * @param bool $round Whether or not to round the value, default true
2509  * @return string
2510  */
2511 function wfPercent( $nr, $acc = 2, $round = true ) {
2512         $ret = sprintf( "%.${acc}f", $nr );
2513         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2514 }
2515
2516 /**
2517  * Safety wrapper around ini_get() for boolean settings.
2518  * The values returned from ini_get() are pre-normalized for settings
2519  * set via php.ini or php_flag/php_admin_flag... but *not*
2520  * for those set via php_value/php_admin_value.
2521  *
2522  * It's fairly common for people to use php_value instead of php_flag,
2523  * which can leave you with an 'off' setting giving a false positive
2524  * for code that just takes the ini_get() return value as a boolean.
2525  *
2526  * To make things extra interesting, setting via php_value accepts
2527  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2528  * Unrecognized values go false... again opposite PHP's own coercion
2529  * from string to bool.
2530  *
2531  * Luckily, 'properly' set settings will always come back as '0' or '1',
2532  * so we only have to worry about them and the 'improper' settings.
2533  *
2534  * I frickin' hate PHP... :P
2535  *
2536  * @param string $setting
2537  * @return bool
2538  */
2539 function wfIniGetBool( $setting ) {
2540         $val = strtolower( ini_get( $setting ) );
2541         // 'on' and 'true' can't have whitespace around them, but '1' can.
2542         return $val == 'on'
2543                 || $val == 'true'
2544                 || $val == 'yes'
2545                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2546 }
2547
2548 /**
2549  * Windows-compatible version of escapeshellarg()
2550  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2551  * function puts single quotes in regardless of OS.
2552  *
2553  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2554  * earlier distro releases of PHP)
2555  *
2556  * @param string $args,...
2557  * @return string
2558  */
2559 function wfEscapeShellArg( /*...*/ ) {
2560         wfInitShellLocale();
2561
2562         $args = func_get_args();
2563         $first = true;
2564         $retVal = '';
2565         foreach ( $args as $arg ) {
2566                 if ( !$first ) {
2567                         $retVal .= ' ';
2568                 } else {
2569                         $first = false;
2570                 }
2571
2572                 if ( wfIsWindows() ) {
2573                         // Escaping for an MSVC-style command line parser and CMD.EXE
2574                         // @codingStandardsIgnoreStart For long URLs
2575                         // Refs:
2576                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2577                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2578                         //  * Bug #13518
2579                         //  * CR r63214
2580                         // Double the backslashes before any double quotes. Escape the double quotes.
2581                         // @codingStandardsIgnoreEnd
2582                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2583                         $arg = '';
2584                         $iteration = 0;
2585                         foreach ( $tokens as $token ) {
2586                                 if ( $iteration % 2 == 1 ) {
2587                                         // Delimiter, a double quote preceded by zero or more slashes
2588                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2589                                 } elseif ( $iteration % 4 == 2 ) {
2590                                         // ^ in $token will be outside quotes, need to be escaped
2591                                         $arg .= str_replace( '^', '^^', $token );
2592                                 } else { // $iteration % 4 == 0
2593                                         // ^ in $token will appear inside double quotes, so leave as is
2594                                         $arg .= $token;
2595                                 }
2596                                 $iteration++;
2597                         }
2598                         // Double the backslashes before the end of the string, because
2599                         // we will soon add a quote
2600                         $m = array();
2601                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2602                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2603                         }
2604
2605                         // Add surrounding quotes
2606                         $retVal .= '"' . $arg . '"';
2607                 } else {
2608                         $retVal .= escapeshellarg( $arg );
2609                 }
2610         }
2611         return $retVal;
2612 }
2613
2614 /**
2615  * Check if wfShellExec() is effectively disabled via php.ini config
2616  *
2617  * @return bool|string False or one of (safemode,disabled)
2618  * @since 1.22
2619  */
2620 function wfShellExecDisabled() {
2621         static $disabled = null;
2622         if ( is_null( $disabled ) ) {
2623                 if ( wfIniGetBool( 'safe_mode' ) ) {
2624                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2625                         $disabled = 'safemode';
2626                 } elseif ( !function_exists( 'proc_open' ) ) {
2627                         wfDebug( "proc_open() is disabled\n" );
2628                         $disabled = 'disabled';
2629                 } else {
2630                         $disabled = false;
2631                 }
2632         }
2633         return $disabled;
2634 }
2635
2636 /**
2637  * Execute a shell command, with time and memory limits mirrored from the PHP
2638  * configuration if supported.
2639  *
2640  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2641  *   or an array of unescaped arguments, in which case each value will be escaped
2642  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2643  * @param null|mixed &$retval Optional, will receive the program's exit code.
2644  *   (non-zero is usually failure). If there is an error from
2645  *   read, select, or proc_open(), this will be set to -1.
2646  * @param array $environ Optional environment variables which should be
2647  *   added to the executed command environment.
2648  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2649  *   this overwrites the global wgMaxShell* limits.
2650  * @param array $options Array of options:
2651  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2652  *     including errors from limit.sh
2653  *
2654  * @return string Collected stdout as a string
2655  */
2656 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2657         $limits = array(), $options = array()
2658 ) {
2659         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2660                 $wgMaxShellWallClockTime, $wgShellCgroup;
2661
2662         $disabled = wfShellExecDisabled();
2663         if ( $disabled ) {
2664                 $retval = 1;
2665                 return $disabled == 'safemode' ?
2666                         'Unable to run external programs in safe mode.' :
2667                         'Unable to run external programs, proc_open() is disabled.';
2668         }
2669
2670         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2671
2672         wfInitShellLocale();
2673
2674         $envcmd = '';
2675         foreach ( $environ as $k => $v ) {
2676                 if ( wfIsWindows() ) {
2677                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2678                          * appear in the environment variable, so we must use carat escaping as documented in
2679                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2680                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2681                          * are listed there but doesn't appear to need it.
2682                          */
2683                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2684                 } else {
2685                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2686                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2687                          */
2688                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2689                 }
2690         }
2691         if ( is_array( $cmd ) ) {
2692                 // Command line may be given as an array, escape each value and glue them together with a space
2693                 $cmdVals = array();
2694                 foreach ( $cmd as $val ) {
2695                         $cmdVals[] = wfEscapeShellArg( $val );
2696                 }
2697                 $cmd = implode( ' ', $cmdVals );
2698         }
2699
2700         $cmd = $envcmd . $cmd;
2701
2702         $useLogPipe = false;
2703         if ( is_executable( '/bin/bash' ) ) {
2704                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2705                 if ( isset( $limits['walltime'] ) ) {
2706                         $wallTime = intval( $limits['walltime'] );
2707                 } elseif ( isset( $limits['time'] ) ) {
2708                         $wallTime = $time;
2709                 } else {
2710                         $wallTime = intval( $wgMaxShellWallClockTime );
2711                 }
2712                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2713                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2714
2715                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2716                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2717                                 escapeshellarg( $cmd ) . ' ' .
2718                                 escapeshellarg(
2719                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2720                                         "MW_CPU_LIMIT=$time; " .
2721                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2722                                         "MW_MEM_LIMIT=$mem; " .
2723                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2724                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2725                                         "MW_USE_LOG_PIPE=yes"
2726                                 );
2727                         $useLogPipe = true;
2728                 } elseif ( $includeStderr ) {
2729                         $cmd .= ' 2>&1';
2730                 }
2731         } elseif ( $includeStderr ) {
2732                 $cmd .= ' 2>&1';
2733         }
2734         wfDebug( "wfShellExec: $cmd\n" );
2735
2736         $desc = array(
2737                 0 => array( 'file', 'php://stdin', 'r' ),
2738                 1 => array( 'pipe', 'w' ),
2739                 2 => array( 'file', 'php://stderr', 'w' ) );
2740         if ( $useLogPipe ) {
2741                 $desc[3] = array( 'pipe', 'w' );
2742         }
2743         $pipes = null;
2744         $proc = proc_open( $cmd, $desc, $pipes );
2745         if ( !$proc ) {
2746                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2747                 $retval = -1;
2748                 return '';
2749         }
2750         $outBuffer = $logBuffer = '';
2751         $emptyArray = array();
2752         $status = false;
2753         $logMsg = false;
2754
2755         // According to the documentation, it is possible for stream_select()
2756         // to fail due to EINTR. I haven't managed to induce this in testing
2757         // despite sending various signals. If it did happen, the error
2758         // message would take the form:
2759         //
2760         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2761         //
2762         // where [4] is the value of the macro EINTR and "Interrupted system
2763         // call" is string which according to the Linux manual is "possibly"
2764         // localised according to LC_MESSAGES.
2765         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2766         $eintrMessage = "stream_select(): unable to select [$eintr]";
2767
2768         // Build a table mapping resource IDs to pipe FDs to work around a
2769         // PHP 5.3 issue in which stream_select() does not preserve array keys
2770         // <https://bugs.php.net/bug.php?id=53427>.
2771         $fds = array();
2772         foreach ( $pipes as $fd => $pipe ) {
2773                 $fds[(int)$pipe] = $fd;
2774         }
2775
2776         $running = true;
2777         $timeout = null;
2778         $numReadyPipes = 0;
2779
2780         while ( $running === true || $numReadyPipes !== 0 ) {
2781                 if ( $running ) {
2782                         $status = proc_get_status( $proc );
2783                         // If the process has terminated, switch to nonblocking selects
2784                         // for getting any data still waiting to be read.
2785                         if ( !$status['running'] ) {
2786                                 $running = false;
2787                                 $timeout = 0;
2788                         }
2789                 }
2790
2791                 $readyPipes = $pipes;
2792
2793                 // Clear last error
2794                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2795                 @trigger_error( '' );
2796                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2797                 if ( $numReadyPipes === false ) {
2798                         // @codingStandardsIgnoreEnd
2799                         $error = error_get_last();
2800                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2801                                 continue;
2802                         } else {
2803                                 trigger_error( $error['message'], E_USER_WARNING );
2804                                 $logMsg = $error['message'];
2805                                 break;
2806                         }
2807                 }
2808                 foreach ( $readyPipes as $pipe ) {
2809                         $block = fread( $pipe, 65536 );
2810                         $fd = $fds[(int)$pipe];
2811                         if ( $block === '' ) {
2812                                 // End of file
2813                                 fclose( $pipes[$fd] );
2814                                 unset( $pipes[$fd] );
2815                                 if ( !$pipes ) {
2816                                         break 2;
2817                                 }
2818                         } elseif ( $block === false ) {
2819                                 // Read error
2820                                 $logMsg = "Error reading from pipe";
2821                                 break 2;
2822                         } elseif ( $fd == 1 ) {
2823                                 // From stdout
2824                                 $outBuffer .= $block;
2825                         } elseif ( $fd == 3 ) {
2826                                 // From log FD
2827                                 $logBuffer .= $block;
2828                                 if ( strpos( $block, "\n" ) !== false ) {
2829                                         $lines = explode( "\n", $logBuffer );
2830                                         $logBuffer = array_pop( $lines );
2831                                         foreach ( $lines as $line ) {
2832                                                 wfDebugLog( 'exec', $line );
2833                                         }
2834                                 }
2835                         }
2836                 }
2837         }
2838
2839         foreach ( $pipes as $pipe ) {
2840                 fclose( $pipe );
2841         }
2842
2843         // Use the status previously collected if possible, since proc_get_status()
2844         // just calls waitpid() which will not return anything useful the second time.
2845         if ( $running ) {
2846                 $status = proc_get_status( $proc );
2847         }
2848
2849         if ( $logMsg !== false ) {
2850                 // Read/select error
2851                 $retval = -1;
2852                 proc_close( $proc );
2853         } elseif ( $status['signaled'] ) {
2854                 $logMsg = "Exited with signal {$status['termsig']}";
2855                 $retval = 128 + $status['termsig'];
2856                 proc_close( $proc );
2857         } else {
2858                 if ( $status['running'] ) {
2859                         $retval = proc_close( $proc );
2860                 } else {
2861                         $retval = $status['exitcode'];
2862                         proc_close( $proc );
2863                 }
2864                 if ( $retval == 127 ) {
2865                         $logMsg = "Possibly missing executable file";
2866                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2867                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2868                 }
2869         }
2870
2871         if ( $logMsg !== false ) {
2872                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2873         }
2874
2875         return $outBuffer;
2876 }
2877
2878 /**
2879  * Execute a shell command, returning both stdout and stderr. Convenience
2880  * function, as all the arguments to wfShellExec can become unwieldy.
2881  *
2882  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2883  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2884  *   or an array of unescaped arguments, in which case each value will be escaped
2885  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2886  * @param null|mixed &$retval Optional, will receive the program's exit code.
2887  *   (non-zero is usually failure)
2888  * @param array $environ Optional environment variables which should be
2889  *   added to the executed command environment.
2890  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2891  *   this overwrites the global wgMaxShell* limits.
2892  * @return string Collected stdout and stderr as a string
2893  */
2894 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2895         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
2896 }
2897
2898 /**
2899  * Workaround for http://bugs.php.net/bug.php?id=45132
2900  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2901  */
2902 function wfInitShellLocale() {
2903         static $done = false;
2904         if ( $done ) {
2905                 return;
2906         }
2907         $done = true;
2908         global $wgShellLocale;
2909         if ( !wfIniGetBool( 'safe_mode' ) ) {
2910                 putenv( "LC_CTYPE=$wgShellLocale" );
2911                 setlocale( LC_CTYPE, $wgShellLocale );
2912         }
2913 }
2914
2915 /**
2916  * Alias to wfShellWikiCmd()
2917  *
2918  * @see wfShellWikiCmd()
2919  */
2920 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2921         return wfShellWikiCmd( $script, $parameters, $options );
2922 }
2923
2924 /**
2925  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2926  * Note that $parameters should be a flat array and an option with an argument
2927  * should consist of two consecutive items in the array (do not use "--option value").
2928  *
2929  * @param string $script MediaWiki cli script path
2930  * @param array $parameters Arguments and options to the script
2931  * @param array $options Associative array of options:
2932  *              'php': The path to the php executable
2933  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2934  * @return string
2935  */
2936 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2937         global $wgPhpCli;
2938         // Give site config file a chance to run the script in a wrapper.
2939         // The caller may likely want to call wfBasename() on $script.
2940         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
2941         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2942         if ( isset( $options['wrapper'] ) ) {
2943                 $cmd[] = $options['wrapper'];
2944         }
2945         $cmd[] = $script;
2946         // Escape each parameter for shell
2947         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2948 }
2949
2950 /**
2951  * wfMerge attempts to merge differences between three texts.
2952  * Returns true for a clean merge and false for failure or a conflict.
2953  *
2954  * @param string $old
2955  * @param string $mine
2956  * @param string $yours
2957  * @param string $result
2958  * @return bool
2959  */
2960 function wfMerge( $old, $mine, $yours, &$result ) {
2961         global $wgDiff3;
2962
2963         # This check may also protect against code injection in
2964         # case of broken installations.
2965         wfSuppressWarnings();
2966         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2967         wfRestoreWarnings();
2968
2969         if ( !$haveDiff3 ) {
2970                 wfDebug( "diff3 not found\n" );
2971                 return false;
2972         }
2973
2974         # Make temporary files
2975         $td = wfTempDir();
2976         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2977         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2978         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2979
2980         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
2981         #       a newline character. To avoid this, we normalize the trailing whitespace before
2982         #       creating the diff.
2983
2984         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
2985         fclose( $oldtextFile );
2986         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
2987         fclose( $mytextFile );
2988         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
2989         fclose( $yourtextFile );
2990
2991         # Check for a conflict
2992         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
2993                 wfEscapeShellArg( $mytextName ) . ' ' .
2994                 wfEscapeShellArg( $oldtextName ) . ' ' .
2995                 wfEscapeShellArg( $yourtextName );
2996         $handle = popen( $cmd, 'r' );
2997
2998         if ( fgets( $handle, 1024 ) ) {
2999                 $conflict = true;
3000         } else {
3001                 $conflict = false;
3002         }
3003         pclose( $handle );
3004
3005         # Merge differences
3006         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3007                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3008         $handle = popen( $cmd, 'r' );
3009         $result = '';
3010         do {
3011                 $data = fread( $handle, 8192 );
3012                 if ( strlen( $data ) == 0 ) {
3013                         break;
3014                 }
3015                 $result .= $data;
3016         } while ( true );
3017         pclose( $handle );
3018         unlink( $mytextName );
3019         unlink( $oldtextName );
3020         unlink( $yourtextName );
3021
3022         if ( $result === '' && $old !== '' && !$conflict ) {
3023                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3024                 $conflict = true;
3025         }
3026         return !$conflict;
3027 }
3028
3029 /**
3030  * Returns unified plain-text diff of two texts.
3031  * Useful for machine processing of diffs.
3032  *
3033  * @param string $before The text before the changes.
3034  * @param string $after The text after the changes.
3035  * @param string $params Command-line options for the diff command.
3036  * @return string Unified diff of $before and $after
3037  */
3038 function wfDiff( $before, $after, $params = '-u' ) {
3039         if ( $before == $after ) {
3040                 return '';
3041         }
3042
3043         global $wgDiff;
3044         wfSuppressWarnings();
3045         $haveDiff = $wgDiff && file_exists( $wgDiff );
3046         wfRestoreWarnings();
3047
3048         # This check may also protect against code injection in
3049         # case of broken installations.
3050         if ( !$haveDiff ) {
3051                 wfDebug( "diff executable not found\n" );
3052                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3053                 $format = new UnifiedDiffFormatter();
3054                 return $format->format( $diffs );
3055         }
3056
3057         # Make temporary files
3058         $td = wfTempDir();
3059         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3060         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3061
3062         fwrite( $oldtextFile, $before );
3063         fclose( $oldtextFile );
3064         fwrite( $newtextFile, $after );
3065         fclose( $newtextFile );
3066
3067         // Get the diff of the two files
3068         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3069
3070         $h = popen( $cmd, 'r' );
3071
3072         $diff = '';
3073
3074         do {
3075                 $data = fread( $h, 8192 );
3076                 if ( strlen( $data ) == 0 ) {
3077                         break;
3078                 }
3079                 $diff .= $data;
3080         } while ( true );
3081
3082         // Clean up
3083         pclose( $h );
3084         unlink( $oldtextName );
3085         unlink( $newtextName );
3086
3087         // Kill the --- and +++ lines. They're not useful.
3088         $diff_lines = explode( "\n", $diff );
3089         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3090                 unset( $diff_lines[0] );
3091         }
3092         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3093                 unset( $diff_lines[1] );
3094         }
3095
3096         $diff = implode( "\n", $diff_lines );
3097
3098         return $diff;
3099 }
3100
3101 /**
3102  * This function works like "use VERSION" in Perl, the program will die with a
3103  * backtrace if the current version of PHP is less than the version provided
3104  *
3105  * This is useful for extensions which due to their nature are not kept in sync
3106  * with releases, and might depend on other versions of PHP than the main code
3107  *
3108  * Note: PHP might die due to parsing errors in some cases before it ever
3109  *       manages to call this function, such is life
3110  *
3111  * @see perldoc -f use
3112  *
3113  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3114  * @throws MWException
3115  */
3116 function wfUsePHP( $req_ver ) {
3117         $php_ver = PHP_VERSION;
3118
3119         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3120                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3121         }
3122 }
3123
3124 /**
3125  * This function works like "use VERSION" in Perl except it checks the version
3126  * of MediaWiki, the program will die with a backtrace if the current version
3127  * of MediaWiki is less than the version provided.
3128  *
3129  * This is useful for extensions which due to their nature are not kept in sync
3130  * with releases
3131  *
3132  * Note: Due to the behavior of PHP's version_compare() which is used in this
3133  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3134  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3135  * targeted version number. For example if you wanted to allow any variation
3136  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3137  * not result in the same comparison due to the internal logic of
3138  * version_compare().
3139  *
3140  * @see perldoc -f use
3141  *
3142  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3143  * @throws MWException
3144  */
3145 function wfUseMW( $req_ver ) {
3146         global $wgVersion;
3147
3148         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3149                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3150         }
3151 }
3152
3153 /**
3154  * Return the final portion of a pathname.
3155  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3156  * http://bugs.php.net/bug.php?id=33898
3157  *
3158  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3159  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3160  *
3161  * @param string $path
3162  * @param string $suffix String to remove if present
3163  * @return string
3164  */
3165 function wfBaseName( $path, $suffix = '' ) {
3166         if ( $suffix == '' ) {
3167                 $encSuffix = '';
3168         } else {
3169                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3170         }
3171
3172         $matches = array();
3173         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3174                 return $matches[1];
3175         } else {
3176                 return '';
3177         }
3178 }
3179
3180 /**
3181  * Generate a relative path name to the given file.
3182  * May explode on non-matching case-insensitive paths,
3183  * funky symlinks, etc.
3184  *
3185  * @param string $path Absolute destination path including target filename
3186  * @param string $from Absolute source path, directory only
3187  * @return string
3188  */
3189 function wfRelativePath( $path, $from ) {
3190         // Normalize mixed input on Windows...
3191         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3192         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3193
3194         // Trim trailing slashes -- fix for drive root
3195         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3196         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3197
3198         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3199         $against = explode( DIRECTORY_SEPARATOR, $from );
3200
3201         if ( $pieces[0] !== $against[0] ) {
3202                 // Non-matching Windows drive letters?
3203                 // Return a full path.
3204                 return $path;
3205         }
3206
3207         // Trim off common prefix
3208         while ( count( $pieces ) && count( $against )
3209                 && $pieces[0] == $against[0] ) {
3210                 array_shift( $pieces );
3211                 array_shift( $against );
3212         }
3213
3214         // relative dots to bump us to the parent
3215         while ( count( $against ) ) {
3216                 array_unshift( $pieces, '..' );
3217                 array_shift( $against );
3218         }
3219
3220         array_push( $pieces, wfBaseName( $path ) );
3221
3222         return implode( DIRECTORY_SEPARATOR, $pieces );
3223 }
3224
3225 /**
3226  * Convert an arbitrarily-long digit string from one numeric base
3227  * to another, optionally zero-padding to a minimum column width.
3228  *
3229  * Supports base 2 through 36; digit values 10-36 are represented
3230  * as lowercase letters a-z. Input is case-insensitive.
3231  *
3232  * @param string $input Input number
3233  * @param int $sourceBase Base of the input number
3234  * @param int $destBase Desired base of the output
3235  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3236  * @param bool $lowercase Whether to output in lowercase or uppercase
3237  * @param string $engine Either "gmp", "bcmath", or "php"
3238  * @return string|bool The output number as a string, or false on error
3239  */
3240 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3241         $lowercase = true, $engine = 'auto'
3242 ) {
3243         $input = (string)$input;
3244         if (
3245                 $sourceBase < 2 ||
3246                 $sourceBase > 36 ||
3247                 $destBase < 2 ||
3248                 $destBase > 36 ||
3249                 $sourceBase != (int)$sourceBase ||
3250                 $destBase != (int)$destBase ||
3251                 $pad != (int)$pad ||
3252                 !preg_match(
3253                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3254                         $input
3255                 )
3256         ) {
3257                 return false;
3258         }
3259
3260         static $baseChars = array(
3261                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3262                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3263                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3264                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3265                 34 => 'y', 35 => 'z',
3266
3267                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3268                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3269                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3270                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3271                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3272                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3273         );
3274
3275         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3276                 // Removing leading zeros works around broken base detection code in
3277                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3278                 // <https://bugs.php.net/bug.php?id=55398>).
3279                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ), $sourceBase ), $destBase );
3280         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3281                 $decimal = '0';
3282                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3283                         $decimal = bcmul( $decimal, $sourceBase );
3284                         $decimal = bcadd( $decimal, $baseChars[$char] );
3285                 }
3286
3287                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3288                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3289                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3290                 }
3291                 // @codingStandardsIgnoreEnd
3292
3293                 $result = strrev( $result );
3294         } else {
3295                 $inDigits = array();
3296                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3297                         $inDigits[] = $baseChars[$char];
3298                 }
3299
3300                 // Iterate over the input, modulo-ing out an output digit
3301                 // at a time until input is gone.
3302                 $result = '';
3303                 while ( $inDigits ) {
3304                         $work = 0;
3305                         $workDigits = array();
3306
3307                         // Long division...
3308                         foreach ( $inDigits as $digit ) {
3309                                 $work *= $sourceBase;
3310                                 $work += $digit;
3311
3312                                 if ( $workDigits || $work >= $destBase ) {
3313                                         $workDigits[] = (int)( $work / $destBase );
3314                                 }
3315                                 $work %= $destBase;
3316                         }
3317
3318                         // All that division leaves us with a remainder,
3319                         // which is conveniently our next output digit.
3320                         $result .= $baseChars[$work];
3321
3322                         // And we continue!
3323                         $inDigits = $workDigits;
3324                 }
3325
3326                 $result = strrev( $result );
3327         }
3328
3329         if ( !$lowercase ) {
3330                 $result = strtoupper( $result );
3331         }
3332
3333         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3334 }
3335
3336 /**
3337  * Check if there is sufficient entropy in php's built-in session generation
3338  *
3339  * @return bool True = there is sufficient entropy
3340  */
3341 function wfCheckEntropy() {
3342         return (
3343                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3344                         || ini_get( 'session.entropy_file' )
3345                 )
3346                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3347 }
3348
3349 /**
3350  * Override session_id before session startup if php's built-in
3351  * session generation code is not secure.
3352  */
3353 function wfFixSessionID() {
3354         // If the cookie or session id is already set we already have a session and should abort
3355         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3356                 return;
3357         }
3358
3359         // PHP's built-in session entropy is enabled if:
3360         // - entropy_file is set or you're on Windows with php 5.3.3+
3361         // - AND entropy_length is > 0
3362         // We treat it as disabled if it doesn't have an entropy length of at least 32
3363         $entropyEnabled = wfCheckEntropy();
3364
3365         // If built-in entropy is not enabled or not sufficient override PHP's
3366         // built in session id generation code
3367         if ( !$entropyEnabled ) {
3368                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3369                         "overriding session id generation using our cryptrand source.\n" );
3370                 session_id( MWCryptRand::generateHex( 32 ) );
3371         }
3372 }
3373
3374 /**
3375  * Reset the session_id
3376  *
3377  * @since 1.22
3378  */
3379 function wfResetSessionID() {
3380         global $wgCookieSecure;
3381         $oldSessionId = session_id();
3382         $cookieParams = session_get_cookie_params();
3383         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3384                 session_regenerate_id( false );
3385         } else {
3386                 $tmp = $_SESSION;
3387                 session_destroy();
3388                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3389                 $_SESSION = $tmp;
3390         }
3391         $newSessionId = session_id();
3392         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3393 }
3394
3395 /**
3396  * Initialise php session
3397  *
3398  * @param bool $sessionId
3399  */
3400 function wfSetupSession( $sessionId = false ) {
3401         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3402                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3403         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3404                 ObjectCacheSessionHandler::install();
3405         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3406                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3407                 # hasn't already been set to the desired value (that causes errors)
3408                 ini_set( 'session.save_handler', $wgSessionHandler );
3409         }
3410         session_set_cookie_params(
3411                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3412         session_cache_limiter( 'private, must-revalidate' );
3413         if ( $sessionId ) {
3414                 session_id( $sessionId );
3415         } else {
3416                 wfFixSessionID();
3417         }
3418         wfSuppressWarnings();
3419         session_start();
3420         wfRestoreWarnings();
3421 }
3422
3423 /**
3424  * Get an object from the precompiled serialized directory
3425  *
3426  * @param string $name
3427  * @return mixed The variable on success, false on failure
3428  */
3429 function wfGetPrecompiledData( $name ) {
3430         global $IP;
3431
3432         $file = "$IP/serialized/$name";
3433         if ( file_exists( $file ) ) {
3434                 $blob = file_get_contents( $file );
3435                 if ( $blob ) {
3436                         return unserialize( $blob );
3437                 }
3438         }
3439         return false;
3440 }
3441
3442 /**
3443  * Get a cache key
3444  *
3445  * @param string $args,...
3446  * @return string
3447  */
3448 function wfMemcKey( /*...*/ ) {
3449         global $wgCachePrefix;
3450         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3451         $args = func_get_args();
3452         $key = $prefix . ':' . implode( ':', $args );
3453         $key = str_replace( ' ', '_', $key );
3454         return $key;
3455 }
3456
3457 /**
3458  * Get a cache key for a foreign DB
3459  *
3460  * @param string $db
3461  * @param string $prefix
3462  * @param string $args,...
3463  * @return string
3464  */
3465 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3466         $args = array_slice( func_get_args(), 2 );
3467         if ( $prefix ) {
3468                 $key = "$db-$prefix:" . implode( ':', $args );
3469         } else {
3470                 $key = $db . ':' . implode( ':', $args );
3471         }
3472         return str_replace( ' ', '_', $key );
3473 }
3474
3475 /**
3476  * Get an ASCII string identifying this wiki
3477  * This is used as a prefix in memcached keys
3478  *
3479  * @return string
3480  */
3481 function wfWikiID() {
3482         global $wgDBprefix, $wgDBname;
3483         if ( $wgDBprefix ) {
3484                 return "$wgDBname-$wgDBprefix";
3485         } else {
3486                 return $wgDBname;
3487         }
3488 }
3489
3490 /**
3491  * Split a wiki ID into DB name and table prefix
3492  *
3493  * @param string $wiki
3494  *
3495  * @return array
3496  */
3497 function wfSplitWikiID( $wiki ) {
3498         $bits = explode( '-', $wiki, 2 );
3499         if ( count( $bits ) < 2 ) {
3500                 $bits[] = '';
3501         }
3502         return $bits;
3503 }
3504
3505 /**
3506  * Get a Database object.
3507  *
3508  * @param int $db Index of the connection to get. May be DB_MASTER for the
3509  *            master (for write queries), DB_SLAVE for potentially lagged read
3510  *            queries, or an integer >= 0 for a particular server.
3511  *
3512  * @param string|string[] $groups Query groups. An array of group names that this query
3513  *                belongs to. May contain a single string if the query is only
3514  *                in one group.
3515  *
3516  * @param string|bool $wiki The wiki ID, or false for the current wiki
3517  *
3518  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3519  * will always return the same object, unless the underlying connection or load
3520  * balancer is manually destroyed.
3521  *
3522  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3523  * updater to ensure that a proper database is being updated.
3524  *
3525  * @return DatabaseBase
3526  */
3527 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3528         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3529 }
3530
3531 /**
3532  * Get a load balancer object.
3533  *
3534  * @param string|bool $wiki Wiki ID, or false for the current wiki
3535  * @return LoadBalancer
3536  */
3537 function wfGetLB( $wiki = false ) {
3538         return wfGetLBFactory()->getMainLB( $wiki );
3539 }
3540
3541 /**
3542  * Get the load balancer factory object
3543  *
3544  * @return LBFactory
3545  */
3546 function &wfGetLBFactory() {
3547         return LBFactory::singleton();
3548 }
3549
3550 /**
3551  * Find a file.
3552  * Shortcut for RepoGroup::singleton()->findFile()
3553  *
3554  * @param string $title String or Title object
3555  * @param array $options Associative array of options:
3556  *     time:           requested time for an archived image, or false for the
3557  *                     current version. An image object will be returned which was
3558  *                     created at the specified time.
3559  *
3560  *     ignoreRedirect: If true, do not follow file redirects
3561  *
3562  *     private:        If true, return restricted (deleted) files if the current
3563  *                     user is allowed to view them. Otherwise, such files will not
3564  *                     be found.
3565  *
3566  *     bypassCache:    If true, do not use the process-local cache of File objects
3567  *
3568  * @return File|bool File, or false if the file does not exist
3569  */
3570 function wfFindFile( $title, $options = array() ) {
3571         return RepoGroup::singleton()->findFile( $title, $options );
3572 }
3573
3574 /**
3575  * Get an object referring to a locally registered file.
3576  * Returns a valid placeholder object if the file does not exist.
3577  *
3578  * @param Title|string $title
3579  * @return LocalFile|null A File, or null if passed an invalid Title
3580  */
3581 function wfLocalFile( $title ) {
3582         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3583 }
3584
3585 /**
3586  * Should low-performance queries be disabled?
3587  *
3588  * @return bool
3589  * @codeCoverageIgnore
3590  */
3591 function wfQueriesMustScale() {
3592         global $wgMiserMode;
3593         return $wgMiserMode
3594                 || ( SiteStats::pages() > 100000
3595                 && SiteStats::edits() > 1000000
3596                 && SiteStats::users() > 10000 );
3597 }
3598
3599 /**
3600  * Get the path to a specified script file, respecting file
3601  * extensions; this is a wrapper around $wgScriptExtension etc.
3602  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3603  *
3604  * @param string $script Script filename, sans extension
3605  * @return string
3606  */
3607 function wfScript( $script = 'index' ) {
3608         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3609         if ( $script === 'index' ) {
3610                 return $wgScript;
3611         } elseif ( $script === 'load' ) {
3612                 return $wgLoadScript;
3613         } else {
3614                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3615         }
3616 }
3617
3618 /**
3619  * Get the script URL.
3620  *
3621  * @return string Script URL
3622  */
3623 function wfGetScriptUrl() {
3624         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3625                 #
3626                 # as it was called, minus the query string.
3627                 #
3628                 # Some sites use Apache rewrite rules to handle subdomains,
3629                 # and have PHP set up in a weird way that causes PHP_SELF
3630                 # to contain the rewritten URL instead of the one that the
3631                 # outside world sees.
3632                 #
3633                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3634                 # provides containing the "before" URL.
3635                 return $_SERVER['SCRIPT_NAME'];
3636         } else {
3637                 return $_SERVER['URL'];
3638         }
3639 }
3640
3641 /**
3642  * Convenience function converts boolean values into "true"
3643  * or "false" (string) values
3644  *
3645  * @param bool $value
3646  * @return string
3647  */
3648 function wfBoolToStr( $value ) {
3649         return $value ? 'true' : 'false';
3650 }
3651
3652 /**
3653  * Get a platform-independent path to the null file, e.g. /dev/null
3654  *
3655  * @return string
3656  */
3657 function wfGetNull() {
3658         return wfIsWindows() ? 'NUL' : '/dev/null';
3659 }
3660
3661 /**
3662  * Waits for the slaves to catch up to the master position
3663  *
3664  * Use this when updating very large numbers of rows, as in maintenance scripts,
3665  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3666  *
3667  * By default this waits on the main DB cluster of the current wiki.
3668  * If $cluster is set to "*" it will wait on all DB clusters, including
3669  * external ones. If the lag being waiting on is caused by the code that
3670  * does this check, it makes since to use $ifWritesSince, particularly if
3671  * cluster is "*", to avoid excess overhead.
3672  *
3673  * Never call this function after a big DB write that is still in a transaction.
3674  * This only makes sense after the possible lag inducing changes were committed.
3675  *
3676  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3677  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3678  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3679  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3680  * @return bool Success (able to connect and no timeouts reached)
3681  */
3682 function wfWaitForSlaves(
3683         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3684 ) {
3685         // B/C: first argument used to be "max seconds of lag"; ignore such values
3686         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3687
3688         if ( $timeout === null ) {
3689                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3690         }
3691
3692         // Figure out which clusters need to be checked
3693         $lbs = array();
3694         if ( $cluster === '*' ) {
3695                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3696                         $lbs[] = $lb;
3697                 } );
3698         } elseif ( $cluster !== false ) {
3699                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3700         } else {
3701                 $lbs[] = wfGetLB( $wiki );
3702         }
3703
3704         // Get all the master positions of applicable DBs right now.
3705         // This can be faster since waiting on one cluster reduces the
3706         // time needed to wait on the next clusters.
3707         $masterPositions = array_fill( 0, count( $lbs ), false );
3708         foreach ( $lbs as $i => $lb ) {
3709                 // bug 27975 - Don't try to wait for slaves if there are none
3710                 // Prevents permission error when getting master position
3711                 if ( $lb->getServerCount() > 1 ) {
3712                         if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
3713                                 continue; // assume no writes done
3714                         }
3715                         // Use the empty string to not trigger selectDB() since the connection
3716                         // may have been to a server that does not have a DB for the current wiki.
3717                         $dbw = $lb->getConnection( DB_MASTER, array(), '' );
3718                         if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
3719                                 continue; // no writes since the last wait
3720                         }
3721                         $masterPositions[$i] = $dbw->getMasterPos();
3722                 }
3723         }
3724
3725         $ok = true;
3726         foreach ( $lbs as $i => $lb ) {
3727                 if ( $masterPositions[$i] ) {
3728                         // The DBMS may not support getMasterPos() or the whole
3729                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3730                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3731                 }
3732         }
3733
3734         return $ok;
3735 }
3736
3737 /**
3738  * Count down from $seconds to zero on the terminal, with a one-second pause
3739  * between showing each number. For use in command-line scripts.
3740  *
3741  * @codeCoverageIgnore
3742  * @param int $seconds
3743  */
3744 function wfCountDown( $seconds ) {
3745         for ( $i = $seconds; $i >= 0; $i-- ) {
3746                 if ( $i != $seconds ) {
3747                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3748                 }
3749                 echo $i;
3750                 flush();
3751                 if ( $i ) {
3752                         sleep( 1 );
3753                 }
3754         }
3755         echo "\n";
3756 }
3757
3758 /**
3759  * Replace all invalid characters with -
3760  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3761  * By default, $wgIllegalFileChars = ':'
3762  *
3763  * @param string $name Filename to process
3764  * @return string
3765  */
3766 function wfStripIllegalFilenameChars( $name ) {
3767         global $wgIllegalFileChars;
3768         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3769         $name = wfBaseName( $name );
3770         $name = preg_replace(
3771                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3772                 '-',
3773                 $name
3774         );
3775         return $name;
3776 }
3777
3778 /**
3779  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3780  *
3781  * @return int Value the memory limit was set to.
3782  */
3783 function wfMemoryLimit() {
3784         global $wgMemoryLimit;
3785         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3786         if ( $memlimit != -1 ) {
3787                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3788                 if ( $conflimit == -1 ) {
3789                         wfDebug( "Removing PHP's memory limit\n" );
3790                         wfSuppressWarnings();
3791                         ini_set( 'memory_limit', $conflimit );
3792                         wfRestoreWarnings();
3793                         return $conflimit;
3794                 } elseif ( $conflimit > $memlimit ) {
3795                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3796                         wfSuppressWarnings();
3797                         ini_set( 'memory_limit', $conflimit );
3798                         wfRestoreWarnings();
3799                         return $conflimit;
3800                 }
3801         }
3802         return $memlimit;
3803 }
3804
3805 /**
3806  * Converts shorthand byte notation to integer form
3807  *
3808  * @param string $string
3809  * @return int
3810  */
3811 function wfShorthandToInteger( $string = '' ) {
3812         $string = trim( $string );
3813         if ( $string === '' ) {
3814                 return -1;
3815         }
3816         $last = $string[strlen( $string ) - 1];
3817         $val = intval( $string );
3818         switch ( $last ) {
3819                 case 'g':
3820                 case 'G':
3821                         $val *= 1024;
3822                         // break intentionally missing
3823                 case 'm':
3824                 case 'M':
3825                         $val *= 1024;
3826                         // break intentionally missing
3827                 case 'k':
3828                 case 'K':
3829                         $val *= 1024;
3830         }
3831
3832         return $val;
3833 }
3834
3835 /**
3836  * Get the normalised IETF language tag
3837  * See unit test for examples.
3838  *
3839  * @param string $code The language code.
3840  * @return string The language code which complying with BCP 47 standards.
3841  */
3842 function wfBCP47( $code ) {
3843         $codeSegment = explode( '-', $code );
3844         $codeBCP = array();
3845         foreach ( $codeSegment as $segNo => $seg ) {
3846                 // when previous segment is x, it is a private segment and should be lc
3847                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3848                         $codeBCP[$segNo] = strtolower( $seg );
3849                 // ISO 3166 country code
3850                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3851                         $codeBCP[$segNo] = strtoupper( $seg );
3852                 // ISO 15924 script code
3853                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3854                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3855                 // Use lowercase for other cases
3856                 } else {
3857                         $codeBCP[$segNo] = strtolower( $seg );
3858                 }
3859         }
3860         $langCode = implode( '-', $codeBCP );
3861         return $langCode;
3862 }
3863
3864 /**
3865  * Get a cache object.
3866  *
3867  * @param int $inputType Cache type, one the the CACHE_* constants.
3868  * @return BagOStuff
3869  */
3870 function wfGetCache( $inputType ) {
3871         return ObjectCache::getInstance( $inputType );
3872 }
3873
3874 /**
3875  * Get the main cache object
3876  *
3877  * @return BagOStuff
3878  */
3879 function wfGetMainCache() {
3880         global $wgMainCacheType;
3881         return ObjectCache::getInstance( $wgMainCacheType );
3882 }
3883
3884 /**
3885  * Get the cache object used by the message cache
3886  *
3887  * @return BagOStuff
3888  */
3889 function wfGetMessageCacheStorage() {
3890         global $wgMessageCacheType;
3891         return ObjectCache::getInstance( $wgMessageCacheType );
3892 }
3893
3894 /**
3895  * Get the cache object used by the parser cache
3896  *
3897  * @return BagOStuff
3898  */
3899 function wfGetParserCacheStorage() {
3900         global $wgParserCacheType;
3901         return ObjectCache::getInstance( $wgParserCacheType );
3902 }
3903
3904 /**
3905  * Get the cache object used by the language converter
3906  *
3907  * @return BagOStuff
3908  */
3909 function wfGetLangConverterCacheStorage() {
3910         global $wgLanguageConverterCacheType;
3911         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3912 }
3913
3914 /**
3915  * Call hook functions defined in $wgHooks
3916  *
3917  * @param string $event Event name
3918  * @param array $args Parameters passed to hook functions
3919  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3920  *
3921  * @return bool True if no handler aborted the hook
3922  */
3923 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3924         return Hooks::run( $event, $args, $deprecatedVersion );
3925 }
3926
3927 /**
3928  * Wrapper around php's unpack.
3929  *
3930  * @param string $format The format string (See php's docs)
3931  * @param string $data A binary string of binary data
3932  * @param int|bool $length The minimum length of $data or false. This is to
3933  *      prevent reading beyond the end of $data. false to disable the check.
3934  *
3935  * Also be careful when using this function to read unsigned 32 bit integer
3936  * because php might make it negative.
3937  *
3938  * @throws MWException If $data not long enough, or if unpack fails
3939  * @return array Associative array of the extracted data
3940  */
3941 function wfUnpack( $format, $data, $length = false ) {
3942         if ( $length !== false ) {
3943                 $realLen = strlen( $data );
3944                 if ( $realLen < $length ) {
3945                         throw new MWException( "Tried to use wfUnpack on a "
3946                                 . "string of length $realLen, but needed one "
3947                                 . "of at least length $length."
3948                         );
3949                 }
3950         }
3951
3952         wfSuppressWarnings();
3953         $result = unpack( $format, $data );
3954         wfRestoreWarnings();
3955
3956         if ( $result === false ) {
3957                 // If it cannot extract the packed data.
3958                 throw new MWException( "unpack could not unpack binary data" );
3959         }
3960         return $result;
3961 }
3962
3963 /**
3964  * Determine if an image exists on the 'bad image list'.
3965  *
3966  * The format of MediaWiki:Bad_image_list is as follows:
3967  *    * Only list items (lines starting with "*") are considered
3968  *    * The first link on a line must be a link to a bad image
3969  *    * Any subsequent links on the same line are considered to be exceptions,
3970  *      i.e. articles where the image may occur inline.
3971  *
3972  * @param string $name The image name to check
3973  * @param Title|bool $contextTitle The page on which the image occurs, if known
3974  * @param string $blacklist Wikitext of a file blacklist
3975  * @return bool
3976  */
3977 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
3978         static $badImageCache = null; // based on bad_image_list msg
3979         wfProfileIn( __METHOD__ );
3980
3981         # Handle redirects
3982         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
3983         if ( $redirectTitle ) {
3984                 $name = $redirectTitle->getDBkey();
3985         }
3986
3987         # Run the extension hook
3988         $bad = false;
3989         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
3990                 wfProfileOut( __METHOD__ );
3991                 return $bad;
3992         }
3993
3994         $cacheable = ( $blacklist === null );
3995         if ( $cacheable && $badImageCache !== null ) {
3996                 $badImages = $badImageCache;
3997         } else { // cache miss
3998                 if ( $blacklist === null ) {
3999                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4000                 }
4001                 # Build the list now
4002                 $badImages = array();
4003                 $lines = explode( "\n", $blacklist );
4004                 foreach ( $lines as $line ) {
4005                         # List items only
4006                         if ( substr( $line, 0, 1 ) !== '*' ) {
4007                                 continue;
4008                         }
4009
4010                         # Find all links
4011                         $m = array();
4012                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4013                                 continue;
4014                         }
4015
4016                         $exceptions = array();
4017                         $imageDBkey = false;
4018                         foreach ( $m[1] as $i => $titleText ) {
4019                                 $title = Title::newFromText( $titleText );
4020                                 if ( !is_null( $title ) ) {
4021                                         if ( $i == 0 ) {
4022                                                 $imageDBkey = $title->getDBkey();
4023                                         } else {
4024                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4025                                         }
4026                                 }
4027                         }
4028
4029                         if ( $imageDBkey !== false ) {
4030                                 $badImages[$imageDBkey] = $exceptions;
4031                         }
4032                 }
4033                 if ( $cacheable ) {
4034                         $badImageCache = $badImages;
4035                 }
4036         }
4037
4038         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4039         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4040         wfProfileOut( __METHOD__ );
4041         return $bad;
4042 }
4043
4044 /**
4045  * Determine whether the client at a given source IP is likely to be able to
4046  * access the wiki via HTTPS.
4047  *
4048  * @param string $ip The IPv4/6 address in the normal human-readable form
4049  * @return bool
4050  */
4051 function wfCanIPUseHTTPS( $ip ) {
4052         $canDo = true;
4053         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4054         return !!$canDo;
4055 }
4056
4057 /**
4058  * Work out the IP address based on various globals
4059  * For trusted proxies, use the XFF client IP (first of the chain)
4060  *
4061  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4062  * @return string
4063  */
4064 function wfGetIP() {
4065         wfDeprecated( __METHOD__, '1.19' );
4066         global $wgRequest;
4067         return $wgRequest->getIP();
4068 }
4069
4070 /**
4071  * Checks if an IP is a trusted proxy provider.
4072  * Useful to tell if X-Forwarded-For data is possibly bogus.
4073  * Squid cache servers for the site are whitelisted.
4074  * @deprecated Since 1.24, use IP::isTrustedProxy()
4075  *
4076  * @param string $ip
4077  * @return bool
4078  */
4079 function wfIsTrustedProxy( $ip ) {
4080         return IP::isTrustedProxy( $ip );
4081 }
4082
4083 /**
4084  * Checks if an IP matches a proxy we've configured.
4085  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4086  *
4087  * @param string $ip
4088  * @return bool
4089  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4090  */
4091 function wfIsConfiguredProxy( $ip ) {
4092         return IP::isConfiguredProxy( $ip );
4093 }