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 use Liuggio\StatsdClient\StatsdClient;
  28 use Liuggio\StatsdClient\Sender\SocketSender;
  29 use MediaWiki\Logger\LoggerFactory;
  30
  31 // Hide compatibility functions from Doxygen
  32 /// @cond
  33
  34 /**
  35  * Compatibility functions
  36  *
  37  * We support PHP 5.3.3 and up.
  38  * Re-implementations of newer functions or functions in non-standard
  39  * PHP extensions may be included here.
  40  */
  41
  42 if ( !function_exists( 'mb_substr' ) ) {
  43         /**
  44          * @codeCoverageIgnore
  45          * @see Fallback::mb_substr
  46          * @return string
  47          */
  48         function mb_substr( $str, $start, $count = 'end' ) {
  49                 return Fallback::mb_substr( $str, $start, $count );
  50         }
  51
  52         /**
  53          * @codeCoverageIgnore
  54          * @see Fallback::mb_substr_split_unicode
  55          * @return int
  56          */
  57         function mb_substr_split_unicode( $str, $splitPos ) {
  58                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  59         }
  60 }
  61
  62 if ( !function_exists( 'mb_strlen' ) ) {
  63         /**
  64          * @codeCoverageIgnore
  65          * @see Fallback::mb_strlen
  66          * @return int
  67          */
  68         function mb_strlen( $str, $enc = '' ) {
  69                 return Fallback::mb_strlen( $str, $enc );
  70         }
  71 }
  72
  73 if ( !function_exists( 'mb_strpos' ) ) {
  74         /**
  75          * @codeCoverageIgnore
  76          * @see Fallback::mb_strpos
  77          * @return int
  78          */
  79         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  80                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  81         }
  82 }
  83
  84 if ( !function_exists( 'mb_strrpos' ) ) {
  85         /**
  86          * @codeCoverageIgnore
  87          * @see Fallback::mb_strrpos
  88          * @return int
  89          */
  90         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  91                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  92         }
  93 }
  94
  95 // gzdecode function only exists in PHP >= 5.4.0
  96 // http://php.net/gzdecode
  97 if ( !function_exists( 'gzdecode' ) ) {
  98         /**
  99          * @codeCoverageIgnore
 100          * @param string $data
 101          * @return string
 102          */
 103         function gzdecode( $data ) {
 104                 return gzinflate( substr( $data, 10, -8 ) );
 105         }
 106 }
 107
 108 // hash_equals function only exists in PHP >= 5.6.0
 109 // http://php.net/hash_equals
 110 if ( !function_exists( 'hash_equals' ) ) {
 111         /**
 112          * Check whether a user-provided string is equal to a fixed-length secret string
 113          * without revealing bytes of the secret string through timing differences.
 114          *
 115          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 116          * function in C) is to compare corresponding bytes and stop at the first difference,
 117          * which would take longer for a partial match than for a complete mismatch. This
 118          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 119          * and the other may come from an attacker. Statistical analysis of timing measurements
 120          * over many requests may allow the attacker to guess the string's bytes one at a time
 121          * (and check his guesses) even if the timing differences are extremely small.
 122          *
 123          * When making such a security-sensitive comparison, it is essential that the sequence
 124          * in which instructions are executed and memory locations are accessed not depend on
 125          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 126          * the inevitable leakage of the string's length. That is generally known anyway as
 127          * a chararacteristic of the hash function used to compute the secret value.
 128          *
 129          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 130          *
 131          * @codeCoverageIgnore
 132          * @param string $known_string Fixed-length secret string to compare against
 133          * @param string $user_string User-provided string
 134          * @return bool True if the strings are the same, false otherwise
 135          */
 136         function hash_equals( $known_string, $user_string ) {
 137                 // Strict type checking as in PHP's native implementation
 138                 if ( !is_string( $known_string ) ) {
 139                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 140                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 141
 142                         return false;
 143                 }
 144
 145                 if ( !is_string( $user_string ) ) {
 146                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 147                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 148
 149                         return false;
 150                 }
 151
 152                 $known_string_len = strlen( $known_string );
 153                 if ( $known_string_len !== strlen( $user_string ) ) {
 154                         return false;
 155                 }
 156
 157                 $result = 0;
 158                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 159                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 160                 }
 161
 162                 return ( $result === 0 );
 163         }
 164 }
 165 /// @endcond
 166
 167 /**
 168  * Load an extension
 169  *
 170  * This queues an extension to be loaded through
 171  * the ExtensionRegistry system.
 172  *
 173  * @param string $name Name of the extension to load
 174  * @param string|null $path Absolute path of where to find the extension.json file
 175  */
 176 function wfLoadExtension( $name, $path = null ) {
 177         if ( !$path ) {
 178                 global $IP;
 179                 $path = "$IP/extensions/$name/extension.json";
 180         }
 181         ExtensionRegistry::getInstance()->queue( $path );
 182 }
 183
 184 /**
 185  * Load multiple extensions at once
 186  *
 187  * Same as wfLoadExtension, but more efficient if you
 188  * are loading multiple extensions.
 189  *
 190  * If you want to specify custom paths, you should interact with
 191  * ExtensionRegistry directly.
 192  *
 193  * @see wfLoadExtension
 194  * @param string[] $exts Array of extension names to load
 195  */
 196 function wfLoadExtensions( array $exts ) {
 197         global $IP;
 198         $registry = ExtensionRegistry::getInstance();
 199         foreach ( $exts as $ext ) {
 200                 $registry->queue( "$IP/extensions/$ext/extension.json" );
 201         }
 202 }
 203
 204 /**
 205  * Load a skin
 206  *
 207  * @see wfLoadExtension
 208  * @param string $name Name of the extension to load
 209  * @param string|null $path Absolute path of where to find the skin.json file
 210  */
 211 function wfLoadSkin( $name, $path = null ) {
 212         if ( !$path ) {
 213                 global $IP;
 214                 $path = "$IP/skins/$name/skin.json";
 215         }
 216         ExtensionRegistry::getInstance()->queue( $path );
 217 }
 218
 219 /**
 220  * Load multiple skins at once
 221  *
 222  * @see wfLoadExtensions
 223  * @param string[] $skins Array of extension names to load
 224  */
 225 function wfLoadSkins( array $skins ) {
 226         global $IP;
 227         $registry = ExtensionRegistry::getInstance();
 228         foreach ( $skins as $skin ) {
 229                 $registry->queue( "$IP/skins/$skin/skin.json" );
 230         }
 231 }
 232
 233 /**
 234  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 235  * @param array $a
 236  * @param array $b
 237  * @return array
 238  */
 239 function wfArrayDiff2( $a, $b ) {
 240         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 241 }
 242
 243 /**
 244  * @param array|string $a
 245  * @param array|string $b
 246  * @return int
 247  */
 248 function wfArrayDiff2_cmp( $a, $b ) {
 249         if ( is_string( $a ) && is_string( $b ) ) {
 250                 return strcmp( $a, $b );
 251         } elseif ( count( $a ) !== count( $b ) ) {
 252                 return count( $a ) < count( $b ) ? -1 : 1;
 253         } else {
 254                 reset( $a );
 255                 reset( $b );
 256                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 257                         $cmp = strcmp( $valueA, $valueB );
 258                         if ( $cmp !== 0 ) {
 259                                 return $cmp;
 260                         }
 261                 }
 262                 return 0;
 263         }
 264 }
 265
 266 /**
 267  * Appends to second array if $value differs from that in $default
 268  *
 269  * @param string|int $key
 270  * @param mixed $value
 271  * @param mixed $default
 272  * @param array $changed Array to alter
 273  * @throws MWException
 274  */
 275 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 276         if ( is_null( $changed ) ) {
 277                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 278         }
 279         if ( $default[$key] !== $value ) {
 280                 $changed[$key] = $value;
 281         }
 282 }
 283
 284 /**
 285  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 286  * e.g.
 287  *      wfMergeErrorArrays(
 288  *              array( array( 'x' ) ),
 289  *              array( array( 'x', '2' ) ),
 290  *              array( array( 'x' ) ),
 291  *              array( array( 'y' ) )
 292  *      );
 293  * returns:
 294  *              array(
 295  *              array( 'x', '2' ),
 296  *              array( 'x' ),
 297  *              array( 'y' )
 298  *      )
 299  *
 300  * @param array $array1,...
 301  * @return array
 302  */
 303 function wfMergeErrorArrays( /*...*/ ) {
 304         $args = func_get_args();
 305         $out = array();
 306         foreach ( $args as $errors ) {
 307                 foreach ( $errors as $params ) {
 308                         # @todo FIXME: Sometimes get nested arrays for $params,
 309                         # which leads to E_NOTICEs
 310                         $spec = implode( "\t", $params );
 311                         $out[$spec] = $params;
 312                 }
 313         }
 314         return array_values( $out );
 315 }
 316
 317 /**
 318  * Insert array into another array after the specified *KEY*
 319  *
 320  * @param array $array The array.
 321  * @param array $insert The array to insert.
 322  * @param mixed $after The key to insert after
 323  * @return array
 324  */
 325 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 326         // Find the offset of the element to insert after.
 327         $keys = array_keys( $array );
 328         $offsetByKey = array_flip( $keys );
 329
 330         $offset = $offsetByKey[$after];
 331
 332         // Insert at the specified offset
 333         $before = array_slice( $array, 0, $offset + 1, true );
 334         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 335
 336         $output = $before + $insert + $after;
 337
 338         return $output;
 339 }
 340
 341 /**
 342  * Recursively converts the parameter (an object) to an array with the same data
 343  *
 344  * @param object|array $objOrArray
 345  * @param bool $recursive
 346  * @return array
 347  */
 348 function wfObjectToArray( $objOrArray, $recursive = true ) {
 349         $array = array();
 350         if ( is_object( $objOrArray ) ) {
 351                 $objOrArray = get_object_vars( $objOrArray );
 352         }
 353         foreach ( $objOrArray as $key => $value ) {
 354                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 355                         $value = wfObjectToArray( $value );
 356                 }
 357
 358                 $array[$key] = $value;
 359         }
 360
 361         return $array;
 362 }
 363
 364 /**
 365  * Get a random decimal value between 0 and 1, in a way
 366  * not likely to give duplicate values for any realistic
 367  * number of articles.
 368  *
 369  * @return string
 370  */
 371 function wfRandom() {
 372         # The maximum random value is "only" 2^31-1, so get two random
 373         # values to reduce the chance of dupes
 374         $max = mt_getrandmax() + 1;
 375         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 376
 377         return $rand;
 378 }
 379
 380 /**
 381  * Get a random string containing a number of pseudo-random hex
 382  * characters.
 383  * @note This is not secure, if you are trying to generate some sort
 384  *       of token please use MWCryptRand instead.
 385  *
 386  * @param int $length The length of the string to generate
 387  * @return string
 388  * @since 1.20
 389  */
 390 function wfRandomString( $length = 32 ) {
 391         $str = '';
 392         for ( $n = 0; $n < $length; $n += 7 ) {
 393                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 394         }
 395         return substr( $str, 0, $length );
 396 }
 397
 398 /**
 399  * We want some things to be included as literal characters in our title URLs
 400  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 401  * all of the following should be safe:
 402  *
 403  * ;:@&=$-_.+!*'(),
 404  *
 405  * But + is not safe because it's used to indicate a space; &= are only safe in
 406  * paths and not in queries (and we don't distinguish here); ' seems kind of
 407  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 408  * is reserved, we don't care.  So the list we unescape is:
 409  *
 410  * ;:@$!*(),/
 411  *
 412  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 413  * so no fancy : for IIS7.
 414  *
 415  * %2F in the page titles seems to fatally break for some reason.
 416  *
 417  * @param string $s
 418  * @return string
 419  */
 420 function wfUrlencode( $s ) {
 421         static $needle;
 422
 423         if ( is_null( $s ) ) {
 424                 $needle = null;
 425                 return '';
 426         }
 427
 428         if ( is_null( $needle ) ) {
 429                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 430                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 431                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 432                 ) {
 433                         $needle[] = '%3A';
 434                 }
 435         }
 436
 437         $s = urlencode( $s );
 438         $s = str_ireplace(
 439                 $needle,
 440                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 441                 $s
 442         );
 443
 444         return $s;
 445 }
 446
 447 /**
 448  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 449  * "days=7&limit=100". Options in the first array override options in the second.
 450  * Options set to null or false will not be output.
 451  *
 452  * @param array $array1 ( String|Array )
 453  * @param array $array2 ( String|Array )
 454  * @param string $prefix
 455  * @return string
 456  */
 457 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 458         if ( !is_null( $array2 ) ) {
 459                 $array1 = $array1 + $array2;
 460         }
 461
 462         $cgi = '';
 463         foreach ( $array1 as $key => $value ) {
 464                 if ( !is_null( $value ) && $value !== false ) {
 465                         if ( $cgi != '' ) {
 466                                 $cgi .= '&';
 467                         }
 468                         if ( $prefix !== '' ) {
 469                                 $key = $prefix . "[$key]";
 470                         }
 471                         if ( is_array( $value ) ) {
 472                                 $firstTime = true;
 473                                 foreach ( $value as $k => $v ) {
 474                                         $cgi .= $firstTime ? '' : '&';
 475                                         if ( is_array( $v ) ) {
 476                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 477                                         } else {
 478                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 479                                         }
 480                                         $firstTime = false;
 481                                 }
 482                         } else {
 483                                 if ( is_object( $value ) ) {
 484                                         $value = $value->__toString();
 485                                 }
 486                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 487                         }
 488                 }
 489         }
 490         return $cgi;
 491 }
 492
 493 /**
 494  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 495  * its argument and returns the same string in array form.  This allows compatibility
 496  * with legacy functions that accept raw query strings instead of nice
 497  * arrays.  Of course, keys and values are urldecode()d.
 498  *
 499  * @param string $query Query string
 500  * @return string[] Array version of input
 501  */
 502 function wfCgiToArray( $query ) {
 503         if ( isset( $query[0] ) && $query[0] == '?' ) {
 504                 $query = substr( $query, 1 );
 505         }
 506         $bits = explode( '&', $query );
 507         $ret = array();
 508         foreach ( $bits as $bit ) {
 509                 if ( $bit === '' ) {
 510                         continue;
 511                 }
 512                 if ( strpos( $bit, '=' ) === false ) {
 513                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 514                         $key = $bit;
 515                         $value = '';
 516                 } else {
 517                         list( $key, $value ) = explode( '=', $bit );
 518                 }
 519                 $key = urldecode( $key );
 520                 $value = urldecode( $value );
 521                 if ( strpos( $key, '[' ) !== false ) {
 522                         $keys = array_reverse( explode( '[', $key ) );
 523                         $key = array_pop( $keys );
 524                         $temp = $value;
 525                         foreach ( $keys as $k ) {
 526                                 $k = substr( $k, 0, -1 );
 527                                 $temp = array( $k => $temp );
 528                         }
 529                         if ( isset( $ret[$key] ) ) {
 530                                 $ret[$key] = array_merge( $ret[$key], $temp );
 531                         } else {
 532                                 $ret[$key] = $temp;
 533                         }
 534                 } else {
 535                         $ret[$key] = $value;
 536                 }
 537         }
 538         return $ret;
 539 }
 540
 541 /**
 542  * Append a query string to an existing URL, which may or may not already
 543  * have query string parameters already. If so, they will be combined.
 544  *
 545  * @param string $url
 546  * @param string|string[] $query String or associative array
 547  * @return string
 548  */
 549 function wfAppendQuery( $url, $query ) {
 550         if ( is_array( $query ) ) {
 551                 $query = wfArrayToCgi( $query );
 552         }
 553         if ( $query != '' ) {
 554                 if ( false === strpos( $url, '?' ) ) {
 555                         $url .= '?';
 556                 } else {
 557                         $url .= '&';
 558                 }
 559                 $url .= $query;
 560         }
 561         return $url;
 562 }
 563
 564 /**
 565  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 566  * is correct.
 567  *
 568  * The meaning of the PROTO_* constants is as follows:
 569  * PROTO_HTTP: Output a URL starting with http://
 570  * PROTO_HTTPS: Output a URL starting with https://
 571  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 572  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 573  *    on which protocol was used for the current incoming request
 574  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 575  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 576  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 577  *
 578  * @todo this won't work with current-path-relative URLs
 579  * like "subdir/foo.html", etc.
 580  *
 581  * @param string $url Either fully-qualified or a local path + query
 582  * @param string $defaultProto One of the PROTO_* constants. Determines the
 583  *    protocol to use if $url or $wgServer is protocol-relative
 584  * @return string Fully-qualified URL, current-path-relative URL or false if
 585  *    no valid URL can be constructed
 586  */
 587 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 588         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 589                 $wgHttpsPort;
 590         if ( $defaultProto === PROTO_CANONICAL ) {
 591                 $serverUrl = $wgCanonicalServer;
 592         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 593                 // Make $wgInternalServer fall back to $wgServer if not set
 594                 $serverUrl = $wgInternalServer;
 595         } else {
 596                 $serverUrl = $wgServer;
 597                 if ( $defaultProto === PROTO_CURRENT ) {
 598                         $defaultProto = $wgRequest->getProtocol() . '://';
 599                 }
 600         }
 601
 602         // Analyze $serverUrl to obtain its protocol
 603         $bits = wfParseUrl( $serverUrl );
 604         $serverHasProto = $bits && $bits['scheme'] != '';
 605
 606         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 607                 if ( $serverHasProto ) {
 608                         $defaultProto = $bits['scheme'] . '://';
 609                 } else {
 610                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 611                         // This really isn't supposed to happen. Fall back to HTTP in this
 612                         // ridiculous case.
 613                         $defaultProto = PROTO_HTTP;
 614                 }
 615         }
 616
 617         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 618
 619         if ( substr( $url, 0, 2 ) == '//' ) {
 620                 $url = $defaultProtoWithoutSlashes . $url;
 621         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 622                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 623                 // otherwise leave it alone.
 624                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 625         }
 626
 627         $bits = wfParseUrl( $url );
 628
 629         // ensure proper port for HTTPS arrives in URL
 630         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 631         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 632                 $bits['port'] = $wgHttpsPort;
 633         }
 634
 635         if ( $bits && isset( $bits['path'] ) ) {
 636                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 637                 return wfAssembleUrl( $bits );
 638         } elseif ( $bits ) {
 639                 # No path to expand
 640                 return $url;
 641         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 642                 # URL is a relative path
 643                 return wfRemoveDotSegments( $url );
 644         }
 645
 646         # Expanded URL is not valid.
 647         return false;
 648 }
 649
 650 /**
 651  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 652  * if you need to edit part of a URL and put it back together.
 653  *
 654  * This is the basic structure used (brackets contain keys for $urlParts):
 655  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 656  *
 657  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 658  *
 659  * @since 1.19
 660  * @param array $urlParts URL parts, as output from wfParseUrl
 661  * @return string URL assembled from its component parts
 662  */
 663 function wfAssembleUrl( $urlParts ) {
 664         $result = '';
 665
 666         if ( isset( $urlParts['delimiter'] ) ) {
 667                 if ( isset( $urlParts['scheme'] ) ) {
 668                         $result .= $urlParts['scheme'];
 669                 }
 670
 671                 $result .= $urlParts['delimiter'];
 672         }
 673
 674         if ( isset( $urlParts['host'] ) ) {
 675                 if ( isset( $urlParts['user'] ) ) {
 676                         $result .= $urlParts['user'];
 677                         if ( isset( $urlParts['pass'] ) ) {
 678                                 $result .= ':' . $urlParts['pass'];
 679                         }
 680                         $result .= '@';
 681                 }
 682
 683                 $result .= $urlParts['host'];
 684
 685                 if ( isset( $urlParts['port'] ) ) {
 686                         $result .= ':' . $urlParts['port'];
 687                 }
 688         }
 689
 690         if ( isset( $urlParts['path'] ) ) {
 691                 $result .= $urlParts['path'];
 692         }
 693
 694         if ( isset( $urlParts['query'] ) ) {
 695                 $result .= '?' . $urlParts['query'];
 696         }
 697
 698         if ( isset( $urlParts['fragment'] ) ) {
 699                 $result .= '#' . $urlParts['fragment'];
 700         }
 701
 702         return $result;
 703 }
 704
 705 /**
 706  * Remove all dot-segments in the provided URL path.  For example,
 707  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 708  * RFC3986 section 5.2.4.
 709  *
 710  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 711  *
 712  * @param string $urlPath URL path, potentially containing dot-segments
 713  * @return string URL path with all dot-segments removed
 714  */
 715 function wfRemoveDotSegments( $urlPath ) {
 716         $output = '';
 717         $inputOffset = 0;
 718         $inputLength = strlen( $urlPath );
 719
 720         while ( $inputOffset < $inputLength ) {
 721                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 722                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 723                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 724                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 725                 $trimOutput = false;
 726
 727                 if ( $prefixLengthTwo == './' ) {
 728                         # Step A, remove leading "./"
 729                         $inputOffset += 2;
 730                 } elseif ( $prefixLengthThree == '../' ) {
 731                         # Step A, remove leading "../"
 732                         $inputOffset += 3;
 733                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 734                         # Step B, replace leading "/.$" with "/"
 735                         $inputOffset += 1;
 736                         $urlPath[$inputOffset] = '/';
 737                 } elseif ( $prefixLengthThree == '/./' ) {
 738                         # Step B, replace leading "/./" with "/"
 739                         $inputOffset += 2;
 740                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 741                         # Step C, replace leading "/..$" with "/" and
 742                         # remove last path component in output
 743                         $inputOffset += 2;
 744                         $urlPath[$inputOffset] = '/';
 745                         $trimOutput = true;
 746                 } elseif ( $prefixLengthFour == '/../' ) {
 747                         # Step C, replace leading "/../" with "/" and
 748                         # remove last path component in output
 749                         $inputOffset += 3;
 750                         $trimOutput = true;
 751                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 752                         # Step D, remove "^.$"
 753                         $inputOffset += 1;
 754                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 755                         # Step D, remove "^..$"
 756                         $inputOffset += 2;
 757                 } else {
 758                         # Step E, move leading path segment to output
 759                         if ( $prefixLengthOne == '/' ) {
 760                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 761                         } else {
 762                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 763                         }
 764                         if ( $slashPos === false ) {
 765                                 $output .= substr( $urlPath, $inputOffset );
 766                                 $inputOffset = $inputLength;
 767                         } else {
 768                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 769                                 $inputOffset += $slashPos - $inputOffset;
 770                         }
 771                 }
 772
 773                 if ( $trimOutput ) {
 774                         $slashPos = strrpos( $output, '/' );
 775                         if ( $slashPos === false ) {
 776                                 $output = '';
 777                         } else {
 778                                 $output = substr( $output, 0, $slashPos );
 779                         }
 780                 }
 781         }
 782
 783         return $output;
 784 }
 785
 786 /**
 787  * Returns a regular expression of url protocols
 788  *
 789  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 790  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 791  * @return string
 792  */
 793 function wfUrlProtocols( $includeProtocolRelative = true ) {
 794         global $wgUrlProtocols;
 795
 796         // Cache return values separately based on $includeProtocolRelative
 797         static $withProtRel = null, $withoutProtRel = null;
 798         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 799         if ( !is_null( $cachedValue ) ) {
 800                 return $cachedValue;
 801         }
 802
 803         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 804         // with LocalSettings files from 1.5
 805         if ( is_array( $wgUrlProtocols ) ) {
 806                 $protocols = array();
 807                 foreach ( $wgUrlProtocols as $protocol ) {
 808                         // Filter out '//' if !$includeProtocolRelative
 809                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 810                                 $protocols[] = preg_quote( $protocol, '/' );
 811                         }
 812                 }
 813
 814                 $retval = implode( '|', $protocols );
 815         } else {
 816                 // Ignore $includeProtocolRelative in this case
 817                 // This case exists for pre-1.6 compatibility, and we can safely assume
 818                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 819                 // URLs weren't supported until 1.18
 820                 $retval = $wgUrlProtocols;
 821         }
 822
 823         // Cache return value
 824         if ( $includeProtocolRelative ) {
 825                 $withProtRel = $retval;
 826         } else {
 827                 $withoutProtRel = $retval;
 828         }
 829         return $retval;
 830 }
 831
 832 /**
 833  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 834  * you need a regex that matches all URL protocols but does not match protocol-
 835  * relative URLs
 836  * @return string
 837  */
 838 function wfUrlProtocolsWithoutProtRel() {
 839         return wfUrlProtocols( false );
 840 }
 841
 842 /**
 843  * parse_url() work-alike, but non-broken.  Differences:
 844  *
 845  * 1) Does not raise warnings on bad URLs (just returns false).
 846  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 847  *    protocol-relative URLs) correctly.
 848  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 849  *
 850  * @param string $url A URL to parse
 851  * @return string[] Bits of the URL in an associative array, per PHP docs
 852  */
 853 function wfParseUrl( $url ) {
 854         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 855
 856         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 857         // bad that the easiest way to handle them is to just prepend 'http:' and
 858         // strip the protocol out later.
 859         $wasRelative = substr( $url, 0, 2 ) == '//';
 860         if ( $wasRelative ) {
 861                 $url = "http:$url";
 862         }
 863         wfSuppressWarnings();
 864         $bits = parse_url( $url );
 865         wfRestoreWarnings();
 866         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 867         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 868         if ( !$bits || !isset( $bits['scheme'] ) ) {
 869                 return false;
 870         }
 871
 872         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 873         $bits['scheme'] = strtolower( $bits['scheme'] );
 874
 875         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 876         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 877                 $bits['delimiter'] = '://';
 878         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 879                 $bits['delimiter'] = ':';
 880                 // parse_url detects for news: and mailto: the host part of an url as path
 881                 // We have to correct this wrong detection
 882                 if ( isset( $bits['path'] ) ) {
 883                         $bits['host'] = $bits['path'];
 884                         $bits['path'] = '';
 885                 }
 886         } else {
 887                 return false;
 888         }
 889
 890         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 891         if ( !isset( $bits['host'] ) ) {
 892                 $bits['host'] = '';
 893
 894                 // bug 45069
 895                 if ( isset( $bits['path'] ) ) {
 896                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 897                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 898                                 $bits['path'] = '/' . $bits['path'];
 899                         }
 900                 } else {
 901                         $bits['path'] = '';
 902                 }
 903         }
 904
 905         // If the URL was protocol-relative, fix scheme and delimiter
 906         if ( $wasRelative ) {
 907                 $bits['scheme'] = '';
 908                 $bits['delimiter'] = '//';
 909         }
 910         return $bits;
 911 }
 912
 913 /**
 914  * Take a URL, make sure it's expanded to fully qualified, and replace any
 915  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 916  * for more compact display and legibility for local audiences.
 917  *
 918  * @todo handle punycode domains too
 919  *
 920  * @param string $url
 921  * @return string
 922  */
 923 function wfExpandIRI( $url ) {
 924         return preg_replace_callback(
 925                 '/((?:%[89A-F][0-9A-F])+)/i',
 926                 'wfExpandIRI_callback',
 927                 wfExpandUrl( $url )
 928         );
 929 }
 930
 931 /**
 932  * Private callback for wfExpandIRI
 933  * @param array $matches
 934  * @return string
 935  */
 936 function wfExpandIRI_callback( $matches ) {
 937         return urldecode( $matches[1] );
 938 }
 939
 940 /**
 941  * Make URL indexes, appropriate for the el_index field of externallinks.
 942  *
 943  * @param string $url
 944  * @return array
 945  */
 946 function wfMakeUrlIndexes( $url ) {
 947         $bits = wfParseUrl( $url );
 948
 949         // Reverse the labels in the hostname, convert to lower case
 950         // For emails reverse domainpart only
 951         if ( $bits['scheme'] == 'mailto' ) {
 952                 $mailparts = explode( '@', $bits['host'], 2 );
 953                 if ( count( $mailparts ) === 2 ) {
 954                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 955                 } else {
 956                         // No domain specified, don't mangle it
 957                         $domainpart = '';
 958                 }
 959                 $reversedHost = $domainpart . '@' . $mailparts[0];
 960         } else {
 961                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 962         }
 963         // Add an extra dot to the end
 964         // Why? Is it in wrong place in mailto links?
 965         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 966                 $reversedHost .= '.';
 967         }
 968         // Reconstruct the pseudo-URL
 969         $prot = $bits['scheme'];
 970         $index = $prot . $bits['delimiter'] . $reversedHost;
 971         // Leave out user and password. Add the port, path, query and fragment
 972         if ( isset( $bits['port'] ) ) {
 973                 $index .= ':' . $bits['port'];
 974         }
 975         if ( isset( $bits['path'] ) ) {
 976                 $index .= $bits['path'];
 977         } else {
 978                 $index .= '/';
 979         }
 980         if ( isset( $bits['query'] ) ) {
 981                 $index .= '?' . $bits['query'];
 982         }
 983         if ( isset( $bits['fragment'] ) ) {
 984                 $index .= '#' . $bits['fragment'];
 985         }
 986
 987         if ( $prot == '' ) {
 988                 return array( "http:$index", "https:$index" );
 989         } else {
 990                 return array( $index );
 991         }
 992 }
 993
 994 /**
 995  * Check whether a given URL has a domain that occurs in a given set of domains
 996  * @param string $url URL
 997  * @param array $domains Array of domains (strings)
 998  * @return bool True if the host part of $url ends in one of the strings in $domains
 999  */
1000 function wfMatchesDomainList( $url, $domains ) {
1001         $bits = wfParseUrl( $url );
1002         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1003                 $host = '.' . $bits['host'];
1004                 foreach ( (array)$domains as $domain ) {
1005                         $domain = '.' . $domain;
1006                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1007                                 return true;
1008                         }
1009                 }
1010         }
1011         return false;
1012 }
1013
1014 /**
1015  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1016  * In normal operation this is a NOP.
1017  *
1018  * Controlling globals:
1019  * $wgDebugLogFile - points to the log file
1020  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1021  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1022  *
1023  * @since 1.25 support for additional context data
1024  *
1025  * @param string $text
1026  * @param string|bool $dest Unused
1027  * @param array $context Additional logging context data
1028  */
1029 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1030         global $wgDebugRawPage, $wgDebugLogPrefix;
1031         global $wgDebugTimestamps, $wgRequestTime;
1032
1033         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1034                 return;
1035         }
1036
1037         $text = trim( $text );
1038
1039         // Inline logic from deprecated wfDebugTimer()
1040         if ( $wgDebugTimestamps ) {
1041                 $context['seconds_elapsed'] = sprintf(
1042                         '%6.4f',
1043                         microtime( true ) - $wgRequestTime
1044                 );
1045                 $context['memory_used'] = sprintf(
1046                         '%5.1fM',
1047                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1048                 );
1049         }
1050
1051         if ( $wgDebugLogPrefix !== '' ) {
1052                 $context['prefix'] = $wgDebugLogPrefix;
1053         }
1054
1055         $logger = LoggerFactory::getInstance( 'wfDebug' );
1056         $logger->debug( $text, $context );
1057 }
1058
1059 /**
1060  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1061  * @return bool
1062  */
1063 function wfIsDebugRawPage() {
1064         static $cache;
1065         if ( $cache !== null ) {
1066                 return $cache;
1067         }
1068         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1069         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1070                 || (
1071                         isset( $_SERVER['SCRIPT_NAME'] )
1072                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1073                 )
1074         ) {
1075                 $cache = true;
1076         } else {
1077                 $cache = false;
1078         }
1079         return $cache;
1080 }
1081
1082 /**
1083  * Get microsecond timestamps for debug logs
1084  *
1085  * @deprecated since 1.25
1086  * @return string
1087  */
1088 function wfDebugTimer() {
1089         global $wgDebugTimestamps, $wgRequestTime;
1090
1091         wfDeprecated( __METHOD__, '1.25' );
1092
1093         if ( !$wgDebugTimestamps ) {
1094                 return '';
1095         }
1096
1097         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1098         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1099         return "$prefix $mem  ";
1100 }
1101
1102 /**
1103  * Send a line giving PHP memory usage.
1104  *
1105  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1106  */
1107 function wfDebugMem( $exact = false ) {
1108         $mem = memory_get_usage();
1109         if ( !$exact ) {
1110                 $mem = floor( $mem / 1024 ) . ' KiB';
1111         } else {
1112                 $mem .= ' B';
1113         }
1114         wfDebug( "Memory usage: $mem\n" );
1115 }
1116
1117 /**
1118  * Send a line to a supplementary debug log file, if configured, or main debug
1119  * log if not.
1120  *
1121  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1122  * a string filename or an associative array mapping 'destination' to the
1123  * desired filename. The associative array may also contain a 'sample' key
1124  * with an integer value, specifying a sampling factor. Sampled log events
1125  * will be emitted with a 1 in N random chance.
1126  *
1127  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1128  * @since 1.25 support for additional context data
1129  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1130  *
1131  * @param string $logGroup
1132  * @param string $text
1133  * @param string|bool $dest Destination of the message:
1134  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1135  *     - 'log': only to the log and not in HTML
1136  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1137  *       discarded otherwise
1138  *   For backward compatibility, it can also take a boolean:
1139  *     - true: same as 'all'
1140  *     - false: same as 'private'
1141  * @param array $context Additional logging context data
1142  */
1143 function wfDebugLog(
1144         $logGroup, $text, $dest = 'all', array $context = array()
1145 ) {
1146         // Turn $dest into a string if it's a boolean (for b/c)
1147         if ( $dest === true ) {
1148                 $dest = 'all';
1149         } elseif ( $dest === false ) {
1150                 $dest = 'private';
1151         }
1152
1153         $text = trim( $text );
1154
1155         $logger = LoggerFactory::getInstance( $logGroup );
1156         $context['private'] = ( $dest === 'private' );
1157         $logger->info( $text, $context );
1158 }
1159
1160 /**
1161  * Log for database errors
1162  *
1163  * @since 1.25 support for additional context data
1164  *
1165  * @param string $text Database error message.
1166  * @param array $context Additional logging context data
1167  */
1168 function wfLogDBError( $text, array $context = array() ) {
1169         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1170         $logger->error( trim( $text ), $context );
1171 }
1172
1173 /**
1174  * Throws a warning that $function is deprecated
1175  *
1176  * @param string $function
1177  * @param string|bool $version Version of MediaWiki that the function
1178  *    was deprecated in (Added in 1.19).
1179  * @param string|bool $component Added in 1.19.
1180  * @param int $callerOffset How far up the call stack is the original
1181  *    caller. 2 = function that called the function that called
1182  *    wfDeprecated (Added in 1.20)
1183  *
1184  * @return null
1185  */
1186 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1187         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1188 }
1189
1190 /**
1191  * Send a warning either to the debug log or in a PHP error depending on
1192  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1193  *
1194  * @param string $msg Message to send
1195  * @param int $callerOffset Number of items to go back in the backtrace to
1196  *        find the correct caller (1 = function calling wfWarn, ...)
1197  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1198  *        only used when $wgDevelopmentWarnings is true
1199  */
1200 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1201         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1202 }
1203
1204 /**
1205  * Send a warning as a PHP error and the debug log. This is intended for logging
1206  * warnings in production. For logging development warnings, use WfWarn instead.
1207  *
1208  * @param string $msg Message to send
1209  * @param int $callerOffset Number of items to go back in the backtrace to
1210  *        find the correct caller (1 = function calling wfLogWarning, ...)
1211  * @param int $level PHP error level; defaults to E_USER_WARNING
1212  */
1213 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1214         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1215 }
1216
1217 /**
1218  * Log to a file without getting "file size exceeded" signals.
1219  *
1220  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1221  * send lines to the specified port, prefixed by the specified prefix and a space.
1222  * @since 1.25 support for additional context data
1223  *
1224  * @param string $text
1225  * @param string $file Filename
1226  * @param array $context Additional logging context data
1227  * @throws MWException
1228  * @deprecated since 1.25 Use MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1229  */
1230 function wfErrorLog( $text, $file, array $context = array() ) {
1231         wfDeprecated( __METHOD__, '1.25' );
1232         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1233         $context['destination'] = $file;
1234         $logger->info( trim( $text ), $context );
1235 }
1236
1237 /**
1238  * @todo document
1239  */
1240 function wfLogProfilingData() {
1241         global $wgDebugLogGroups, $wgDebugRawPage;
1242
1243         $context = RequestContext::getMain();
1244         $request = $context->getRequest();
1245
1246         $profiler = Profiler::instance();
1247         $profiler->setContext( $context );
1248         $profiler->logData();
1249
1250         $config = $context->getConfig();
1251         if ( $config->has( 'StatsdServer' ) ) {
1252                 $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1253                 $statsdHost = $statsdServer[0];
1254                 $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1255                 $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1256                 $statsdClient = new StatsdClient( $statsdSender );
1257                 $statsdClient->send( $context->getStats()->getBuffer() );
1258         }
1259
1260         # Profiling must actually be enabled...
1261         if ( $profiler instanceof ProfilerStub ) {
1262                 return;
1263         }
1264
1265         if ( isset( $wgDebugLogGroups['profileoutput'] )
1266                 && $wgDebugLogGroups['profileoutput'] === false
1267         ) {
1268                 // Explicitly disabled
1269                 return;
1270         }
1271         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1272                 return;
1273         }
1274
1275         $ctx = array( 'elapsed' => $request->getElapsedTime() );
1276         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1277                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1278         }
1279         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1280                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1281         }
1282         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1283                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1284         }
1285         if ( isset( $ctx['forwarded_for'] ) ||
1286                 isset( $ctx['client_ip'] ) ||
1287                 isset( $ctx['from'] ) ) {
1288                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1289         }
1290
1291         // Don't load $wgUser at this late stage just for statistics purposes
1292         // @todo FIXME: We can detect some anons even if it is not loaded.
1293         // See User::getId()
1294         $user = $context->getUser();
1295         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1296
1297         // Command line script uses a FauxRequest object which does not have
1298         // any knowledge about an URL and throw an exception instead.
1299         try {
1300                 $ctx['url'] = urldecode( $request->getRequestURL() );
1301         } catch ( Exception $ignored ) {
1302                 // no-op
1303         }
1304
1305         $ctx['output'] = $profiler->getOutput();
1306
1307         $log = LoggerFactory::getInstance( 'profileoutput' );
1308         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1309 }
1310
1311 /**
1312  * Increment a statistics counter
1313  *
1314  * @param string $key
1315  * @param int $count
1316  * @return void
1317  */
1318 function wfIncrStats( $key, $count = 1 ) {
1319         $stats = RequestContext::getMain()->getStats();
1320         $stats->updateCount( $key, $count );
1321 }
1322
1323 /**
1324  * Check whether the wiki is in read-only mode.
1325  *
1326  * @return bool
1327  */
1328 function wfReadOnly() {
1329         return wfReadOnlyReason() !== false;
1330 }
1331
1332 /**
1333  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1334  *
1335  * @return string|bool String when in read-only mode; false otherwise
1336  */
1337 function wfReadOnlyReason() {
1338         global $wgReadOnly, $wgReadOnlyFile;
1339
1340         if ( $wgReadOnly === null ) {
1341                 // Set $wgReadOnly for faster access next time
1342                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1343                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1344                 } else {
1345                         $wgReadOnly = false;
1346                 }
1347         }
1348
1349         return $wgReadOnly;
1350 }
1351
1352 /**
1353  * Return a Language object from $langcode
1354  *
1355  * @param Language|string|bool $langcode Either:
1356  *                  - a Language object
1357  *                  - code of the language to get the message for, if it is
1358  *                    a valid code create a language for that language, if
1359  *                    it is a string but not a valid code then make a basic
1360  *                    language object
1361  *                  - a boolean: if it's false then use the global object for
1362  *                    the current user's language (as a fallback for the old parameter
1363  *                    functionality), or if it is true then use global object
1364  *                    for the wiki's content language.
1365  * @return Language
1366  */
1367 function wfGetLangObj( $langcode = false ) {
1368         # Identify which language to get or create a language object for.
1369         # Using is_object here due to Stub objects.
1370         if ( is_object( $langcode ) ) {
1371                 # Great, we already have the object (hopefully)!
1372                 return $langcode;
1373         }
1374
1375         global $wgContLang, $wgLanguageCode;
1376         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1377                 # $langcode is the language code of the wikis content language object.
1378                 # or it is a boolean and value is true
1379                 return $wgContLang;
1380         }
1381
1382         global $wgLang;
1383         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1384                 # $langcode is the language code of user language object.
1385                 # or it was a boolean and value is false
1386                 return $wgLang;
1387         }
1388
1389         $validCodes = array_keys( Language::fetchLanguageNames() );
1390         if ( in_array( $langcode, $validCodes ) ) {
1391                 # $langcode corresponds to a valid language.
1392                 return Language::factory( $langcode );
1393         }
1394
1395         # $langcode is a string, but not a valid language code; use content language.
1396         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1397         return $wgContLang;
1398 }
1399
1400 /**
1401  * This is the function for getting translated interface messages.
1402  *
1403  * @see Message class for documentation how to use them.
1404  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1405  *
1406  * This function replaces all old wfMsg* functions.
1407  *
1408  * @param string|string[] $key Message key, or array of keys
1409  * @param mixed $params,... Normal message parameters
1410  * @return Message
1411  *
1412  * @since 1.17
1413  *
1414  * @see Message::__construct
1415  */
1416 function wfMessage( $key /*...*/ ) {
1417         $params = func_get_args();
1418         array_shift( $params );
1419         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1420                 $params = $params[0];
1421         }
1422         return new Message( $key, $params );
1423 }
1424
1425 /**
1426  * This function accepts multiple message keys and returns a message instance
1427  * for the first message which is non-empty. If all messages are empty then an
1428  * instance of the first message key is returned.
1429  *
1430  * @param string|string[] $keys,... Message keys
1431  * @return Message
1432  *
1433  * @since 1.18
1434  *
1435  * @see Message::newFallbackSequence
1436  */
1437 function wfMessageFallback( /*...*/ ) {
1438         $args = func_get_args();
1439         return call_user_func_array( 'Message::newFallbackSequence', $args );
1440 }
1441
1442 /**
1443  * Get a message from anywhere, for the current user language.
1444  *
1445  * Use wfMsgForContent() instead if the message should NOT
1446  * change depending on the user preferences.
1447  *
1448  * @deprecated since 1.18
1449  *
1450  * @param string $key Lookup key for the message, usually
1451  *    defined in languages/Language.php
1452  *
1453  * Parameters to the message, which can be used to insert variable text into
1454  * it, can be passed to this function in the following formats:
1455  * - One per argument, starting at the second parameter
1456  * - As an array in the second parameter
1457  * These are not shown in the function definition.
1458  *
1459  * @return string
1460  */
1461 function wfMsg( $key ) {
1462         wfDeprecated( __METHOD__, '1.21' );
1463
1464         $args = func_get_args();
1465         array_shift( $args );
1466         return wfMsgReal( $key, $args );
1467 }
1468
1469 /**
1470  * Same as above except doesn't transform the message
1471  *
1472  * @deprecated since 1.18
1473  *
1474  * @param string $key
1475  * @return string
1476  */
1477 function wfMsgNoTrans( $key ) {
1478         wfDeprecated( __METHOD__, '1.21' );
1479
1480         $args = func_get_args();
1481         array_shift( $args );
1482         return wfMsgReal( $key, $args, true, false, false );
1483 }
1484
1485 /**
1486  * Get a message from anywhere, for the current global language
1487  * set with $wgLanguageCode.
1488  *
1489  * Use this if the message should NOT change dependent on the
1490  * language set in the user's preferences. This is the case for
1491  * most text written into logs, as well as link targets (such as
1492  * the name of the copyright policy page). Link titles, on the
1493  * other hand, should be shown in the UI language.
1494  *
1495  * Note that MediaWiki allows users to change the user interface
1496  * language in their preferences, but a single installation
1497  * typically only contains content in one language.
1498  *
1499  * Be wary of this distinction: If you use wfMsg() where you should
1500  * use wfMsgForContent(), a user of the software may have to
1501  * customize potentially hundreds of messages in
1502  * order to, e.g., fix a link in every possible language.
1503  *
1504  * @deprecated since 1.18
1505  *
1506  * @param string $key Lookup key for the message, usually
1507  *     defined in languages/Language.php
1508  * @return string
1509  */
1510 function wfMsgForContent( $key ) {
1511         wfDeprecated( __METHOD__, '1.21' );
1512
1513         global $wgForceUIMsgAsContentMsg;
1514         $args = func_get_args();
1515         array_shift( $args );
1516         $forcontent = true;
1517         if ( is_array( $wgForceUIMsgAsContentMsg )
1518                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1519         ) {
1520                 $forcontent = false;
1521         }
1522         return wfMsgReal( $key, $args, true, $forcontent );
1523 }
1524
1525 /**
1526  * Same as above except doesn't transform the message
1527  *
1528  * @deprecated since 1.18
1529  *
1530  * @param string $key
1531  * @return string
1532  */
1533 function wfMsgForContentNoTrans( $key ) {
1534         wfDeprecated( __METHOD__, '1.21' );
1535
1536         global $wgForceUIMsgAsContentMsg;
1537         $args = func_get_args();
1538         array_shift( $args );
1539         $forcontent = true;
1540         if ( is_array( $wgForceUIMsgAsContentMsg )
1541                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1542         ) {
1543                 $forcontent = false;
1544         }
1545         return wfMsgReal( $key, $args, true, $forcontent, false );
1546 }
1547
1548 /**
1549  * Really get a message
1550  *
1551  * @deprecated since 1.18
1552  *
1553  * @param string $key Key to get.
1554  * @param array $args
1555  * @param bool $useDB
1556  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1557  * @param bool $transform Whether or not to transform the message.
1558  * @return string The requested message.
1559  */
1560 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1561         wfDeprecated( __METHOD__, '1.21' );
1562
1563         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1564         $message = wfMsgReplaceArgs( $message, $args );
1565         return $message;
1566 }
1567
1568 /**
1569  * Fetch a message string value, but don't replace any keys yet.
1570  *
1571  * @deprecated since 1.18
1572  *
1573  * @param string $key
1574  * @param bool $useDB
1575  * @param string|bool $langCode Code of the language to get the message for, or
1576  *   behaves as a content language switch if it is a boolean.
1577  * @param bool $transform Whether to parse magic words, etc.
1578  * @return string
1579  */
1580 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1581         wfDeprecated( __METHOD__, '1.21' );
1582
1583         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1584
1585         $cache = MessageCache::singleton();
1586         $message = $cache->get( $key, $useDB, $langCode );
1587         if ( $message === false ) {
1588                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1589         } elseif ( $transform ) {
1590                 $message = $cache->transform( $message );
1591         }
1592         return $message;
1593 }
1594
1595 /**
1596  * Replace message parameter keys on the given formatted output.
1597  *
1598  * @param string $message
1599  * @param array $args
1600  * @return string
1601  * @private
1602  */
1603 function wfMsgReplaceArgs( $message, $args ) {
1604         # Fix windows line-endings
1605         # Some messages are split with explode("\n", $msg)
1606         $message = str_replace( "\r", '', $message );
1607
1608         // Replace arguments
1609         if ( count( $args ) ) {
1610                 if ( is_array( $args[0] ) ) {
1611                         $args = array_values( $args[0] );
1612                 }
1613                 $replacementKeys = array();
1614                 foreach ( $args as $n => $param ) {
1615                         $replacementKeys['$' . ( $n + 1 )] = $param;
1616                 }
1617                 $message = strtr( $message, $replacementKeys );
1618         }
1619
1620         return $message;
1621 }
1622
1623 /**
1624  * Return an HTML-escaped version of a message.
1625  * Parameter replacements, if any, are done *after* the HTML-escaping,
1626  * so parameters may contain HTML (eg links or form controls). Be sure
1627  * to pre-escape them if you really do want plaintext, or just wrap
1628  * the whole thing in htmlspecialchars().
1629  *
1630  * @deprecated since 1.18
1631  *
1632  * @param string $key
1633  * @param string $args,... Parameters
1634  * @return string
1635  */
1636 function wfMsgHtml( $key ) {
1637         wfDeprecated( __METHOD__, '1.21' );
1638
1639         $args = func_get_args();
1640         array_shift( $args );
1641         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1642 }
1643
1644 /**
1645  * Return an HTML version of message
1646  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1647  * so parameters may contain HTML (eg links or form controls). Be sure
1648  * to pre-escape them if you really do want plaintext, or just wrap
1649  * the whole thing in htmlspecialchars().
1650  *
1651  * @deprecated since 1.18
1652  *
1653  * @param string $key
1654  * @param string $args,... Parameters
1655  * @return string
1656  */
1657 function wfMsgWikiHtml( $key ) {
1658         wfDeprecated( __METHOD__, '1.21' );
1659
1660         $args = func_get_args();
1661         array_shift( $args );
1662         return wfMsgReplaceArgs(
1663                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1664                 /* can't be set to false */ true, /* interface */ true )->getText(),
1665                 $args );
1666 }
1667
1668 /**
1669  * Returns message in the requested format
1670  *
1671  * @deprecated since 1.18
1672  *
1673  * @param string $key Key of the message
1674  * @param array $options Processing rules.
1675  *   Can take the following options:
1676  *     parse: parses wikitext to HTML
1677  *     parseinline: parses wikitext to HTML and removes the surrounding
1678  *       p's added by parser or tidy
1679  *     escape: filters message through htmlspecialchars
1680  *     escapenoentities: same, but allows entity references like &#160; through
1681  *     replaceafter: parameters are substituted after parsing or escaping
1682  *     parsemag: transform the message using magic phrases
1683  *     content: fetch message for content language instead of interface
1684  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1685  *     language: Language object or language code to fetch message for
1686  *       (overridden by content).
1687  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1688  *
1689  * @return string
1690  */
1691 function wfMsgExt( $key, $options ) {
1692         wfDeprecated( __METHOD__, '1.21' );
1693
1694         $args = func_get_args();
1695         array_shift( $args );
1696         array_shift( $args );
1697         $options = (array)$options;
1698         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1699                 'parsemag', 'content' );
1700
1701         foreach ( $options as $arrayKey => $option ) {
1702                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1703                         // An unknown index, neither numeric nor "language"
1704                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1705                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1706                         // A numeric index with unknown value
1707                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1708                 }
1709         }
1710
1711         if ( in_array( 'content', $options, true ) ) {
1712                 $forContent = true;
1713                 $langCode = true;
1714                 $langCodeObj = null;
1715         } elseif ( array_key_exists( 'language', $options ) ) {
1716                 $forContent = false;
1717                 $langCode = wfGetLangObj( $options['language'] );
1718                 $langCodeObj = $langCode;
1719         } else {
1720                 $forContent = false;
1721                 $langCode = false;
1722                 $langCodeObj = null;
1723         }
1724
1725         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1726
1727         if ( !in_array( 'replaceafter', $options, true ) ) {
1728                 $string = wfMsgReplaceArgs( $string, $args );
1729         }
1730
1731         $messageCache = MessageCache::singleton();
1732         $parseInline = in_array( 'parseinline', $options, true );
1733         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1734                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1735                 if ( $string instanceof ParserOutput ) {
1736                         $string = $string->getText();
1737                 }
1738
1739                 if ( $parseInline ) {
1740                         $string = Parser::stripOuterParagraph( $string );
1741                 }
1742         } elseif ( in_array( 'parsemag', $options, true ) ) {
1743                 $string = $messageCache->transform( $string,
1744                                 !$forContent, $langCodeObj );
1745         }
1746
1747         if ( in_array( 'escape', $options, true ) ) {
1748                 $string = htmlspecialchars ( $string );
1749         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1750                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1751         }
1752
1753         if ( in_array( 'replaceafter', $options, true ) ) {
1754                 $string = wfMsgReplaceArgs( $string, $args );
1755         }
1756
1757         return $string;
1758 }
1759
1760 /**
1761  * Since wfMsg() and co suck, they don't return false if the message key they
1762  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1763  * nonexistence of messages by checking the MessageCache::get() result directly.
1764  *
1765  * @deprecated since 1.18. Use Message::isDisabled().
1766  *
1767  * @param string $key The message key looked up
1768  * @return bool True if the message *doesn't* exist.
1769  */
1770 function wfEmptyMsg( $key ) {
1771         wfDeprecated( __METHOD__, '1.21' );
1772
1773         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1774 }
1775
1776 /**
1777  * Fetch server name for use in error reporting etc.
1778  * Use real server name if available, so we know which machine
1779  * in a server farm generated the current page.
1780  *
1781  * @return string
1782  */
1783 function wfHostname() {
1784         static $host;
1785         if ( is_null( $host ) ) {
1786
1787                 # Hostname overriding
1788                 global $wgOverrideHostname;
1789                 if ( $wgOverrideHostname !== false ) {
1790                         # Set static and skip any detection
1791                         $host = $wgOverrideHostname;
1792                         return $host;
1793                 }
1794
1795                 if ( function_exists( 'posix_uname' ) ) {
1796                         // This function not present on Windows
1797                         $uname = posix_uname();
1798                 } else {
1799                         $uname = false;
1800                 }
1801                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1802                         $host = $uname['nodename'];
1803                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1804                         # Windows computer name
1805                         $host = getenv( 'COMPUTERNAME' );
1806                 } else {
1807                         # This may be a virtual server.
1808                         $host = $_SERVER['SERVER_NAME'];
1809                 }
1810         }
1811         return $host;
1812 }
1813
1814 /**
1815  * Returns a script tag that stores the amount of time it took MediaWiki to
1816  * handle the request in milliseconds as 'wgBackendResponseTime'.
1817  *
1818  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1819  * hostname of the server handling the request.
1820  *
1821  * @return string
1822  */
1823 function wfReportTime() {
1824         global $wgRequestTime, $wgShowHostnames;
1825
1826         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1827         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1828         if ( $wgShowHostnames ) {
1829                 $reportVars['wgHostname'] = wfHostname();
1830         }
1831         return Skin::makeVariablesScript( $reportVars );
1832 }
1833
1834 /**
1835  * Safety wrapper for debug_backtrace().
1836  *
1837  * Will return an empty array if debug_backtrace is disabled, otherwise
1838  * the output from debug_backtrace() (trimmed).
1839  *
1840  * @param int $limit This parameter can be used to limit the number of stack frames returned
1841  *
1842  * @return array Array of backtrace information
1843  */
1844 function wfDebugBacktrace( $limit = 0 ) {
1845         static $disabled = null;
1846
1847         if ( is_null( $disabled ) ) {
1848                 $disabled = !function_exists( 'debug_backtrace' );
1849                 if ( $disabled ) {
1850                         wfDebug( "debug_backtrace() is disabled\n" );
1851                 }
1852         }
1853         if ( $disabled ) {
1854                 return array();
1855         }
1856
1857         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1858                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1859         } else {
1860                 return array_slice( debug_backtrace(), 1 );
1861         }
1862 }
1863
1864 /**
1865  * Get a debug backtrace as a string
1866  *
1867  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1868  *   Defaults to $wgCommandLineMode if unset.
1869  * @return string
1870  * @since 1.25 Supports $raw parameter.
1871  */
1872 function wfBacktrace( $raw = null ) {
1873         global $wgCommandLineMode;
1874
1875         if ( $raw === null ) {
1876                 $raw = $wgCommandLineMode;
1877         }
1878
1879         if ( $raw ) {
1880                 $frameFormat = "%s line %s calls %s()\n";
1881                 $traceFormat = "%s";
1882         } else {
1883                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1884                 $traceFormat = "<ul>\n%s</ul>\n";
1885         }
1886
1887         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1888                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1889                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1890                 $call = $frame['function'];
1891                 if ( !empty( $frame['class'] ) ) {
1892                         $call = $frame['class'] . $frame['type'] . $call;
1893                 }
1894                 return sprintf( $frameFormat, $file, $line, $call );
1895         }, wfDebugBacktrace() );
1896
1897         return sprintf( $traceFormat, implode( '', $frames ) );
1898 }
1899
1900 /**
1901  * Get the name of the function which called this function
1902  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1903  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1904  * wfGetCaller( 3 ) is the parent of that.
1905  *
1906  * @param int $level
1907  * @return string
1908  */
1909 function wfGetCaller( $level = 2 ) {
1910         $backtrace = wfDebugBacktrace( $level + 1 );
1911         if ( isset( $backtrace[$level] ) ) {
1912                 return wfFormatStackFrame( $backtrace[$level] );
1913         } else {
1914                 return 'unknown';
1915         }
1916 }
1917
1918 /**
1919  * Return a string consisting of callers in the stack. Useful sometimes
1920  * for profiling specific points.
1921  *
1922  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1923  * @return string
1924  */
1925 function wfGetAllCallers( $limit = 3 ) {
1926         $trace = array_reverse( wfDebugBacktrace() );
1927         if ( !$limit || $limit > count( $trace ) - 1 ) {
1928                 $limit = count( $trace ) - 1;
1929         }
1930         $trace = array_slice( $trace, -$limit - 1, $limit );
1931         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1932 }
1933
1934 /**
1935  * Return a string representation of frame
1936  *
1937  * @param array $frame
1938  * @return string
1939  */
1940 function wfFormatStackFrame( $frame ) {
1941         return isset( $frame['class'] ) ?
1942                 $frame['class'] . '::' . $frame['function'] :
1943                 $frame['function'];
1944 }
1945
1946 /* Some generic result counters, pulled out of SearchEngine */
1947
1948 /**
1949  * @todo document
1950  *
1951  * @param int $offset
1952  * @param int $limit
1953  * @return string
1954  */
1955 function wfShowingResults( $offset, $limit ) {
1956         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1957 }
1958
1959 /**
1960  * @todo document
1961  * @todo FIXME: We may want to blacklist some broken browsers
1962  *
1963  * @param bool $force
1964  * @return bool Whereas client accept gzip compression
1965  */
1966 function wfClientAcceptsGzip( $force = false ) {
1967         static $result = null;
1968         if ( $result === null || $force ) {
1969                 $result = false;
1970                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1971                         # @todo FIXME: We may want to blacklist some broken browsers
1972                         $m = array();
1973                         if ( preg_match(
1974                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1975                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1976                                         $m
1977                                 )
1978                         ) {
1979                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1980                                         $result = false;
1981                                         return $result;
1982                                 }
1983                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1984                                 $result = true;
1985                         }
1986                 }
1987         }
1988         return $result;
1989 }
1990
1991 /**
1992  * Obtain the offset and limit values from the request string;
1993  * used in special pages
1994  *
1995  * @param int $deflimit Default limit if none supplied
1996  * @param string $optionname Name of a user preference to check against
1997  * @return array
1998  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
1999  */
2000 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2001         global $wgRequest;
2002         wfDeprecated( __METHOD__, '1.24' );
2003         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2004 }
2005
2006 /**
2007  * Escapes the given text so that it may be output using addWikiText()
2008  * without any linking, formatting, etc. making its way through. This
2009  * is achieved by substituting certain characters with HTML entities.
2010  * As required by the callers, "<nowiki>" is not used.
2011  *
2012  * @param string $text Text to be escaped
2013  * @return string
2014  */
2015 function wfEscapeWikiText( $text ) {
2016         static $repl = null, $repl2 = null;
2017         if ( $repl === null ) {
2018                 $repl = array(
2019                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2020                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2021                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2022                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2023                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2024                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2025                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2026                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2027                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2028                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2029                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2030                         '__' => '_&#95;', '://' => '&#58;//',
2031                 );
2032
2033                 // We have to catch everything "\s" matches in PCRE
2034                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2035                         $repl["$magic "] = "$magic&#32;";
2036                         $repl["$magic\t"] = "$magic&#9;";
2037                         $repl["$magic\r"] = "$magic&#13;";
2038                         $repl["$magic\n"] = "$magic&#10;";
2039                         $repl["$magic\f"] = "$magic&#12;";
2040                 }
2041
2042                 // And handle protocols that don't use "://"
2043                 global $wgUrlProtocols;
2044                 $repl2 = array();
2045                 foreach ( $wgUrlProtocols as $prot ) {
2046                         if ( substr( $prot, -1 ) === ':' ) {
2047                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2048                         }
2049                 }
2050                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2051         }
2052         $text = substr( strtr( "\n$text", $repl ), 1 );
2053         $text = preg_replace( $repl2, '$1&#58;', $text );
2054         return $text;
2055 }
2056
2057 /**
2058  * Sets dest to source and returns the original value of dest
2059  * If source is NULL, it just returns the value, it doesn't set the variable
2060  * If force is true, it will set the value even if source is NULL
2061  *
2062  * @param mixed $dest
2063  * @param mixed $source
2064  * @param bool $force
2065  * @return mixed
2066  */
2067 function wfSetVar( &$dest, $source, $force = false ) {
2068         $temp = $dest;
2069         if ( !is_null( $source ) || $force ) {
2070                 $dest = $source;
2071         }
2072         return $temp;
2073 }
2074
2075 /**
2076  * As for wfSetVar except setting a bit
2077  *
2078  * @param int $dest
2079  * @param int $bit
2080  * @param bool $state
2081  *
2082  * @return bool
2083  */
2084 function wfSetBit( &$dest, $bit, $state = true ) {
2085         $temp = (bool)( $dest & $bit );
2086         if ( !is_null( $state ) ) {
2087                 if ( $state ) {
2088                         $dest |= $bit;
2089                 } else {
2090                         $dest &= ~$bit;
2091                 }
2092         }
2093         return $temp;
2094 }
2095
2096 /**
2097  * A wrapper around the PHP function var_export().
2098  * Either print it or add it to the regular output ($wgOut).
2099  *
2100  * @param mixed $var A PHP variable to dump.
2101  */
2102 function wfVarDump( $var ) {
2103         global $wgOut;
2104         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2105         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2106                 print $s;
2107         } else {
2108                 $wgOut->addHTML( $s );
2109         }
2110 }
2111
2112 /**
2113  * Provide a simple HTTP error.
2114  *
2115  * @param int|string $code
2116  * @param string $label
2117  * @param string $desc
2118  */
2119 function wfHttpError( $code, $label, $desc ) {
2120         global $wgOut;
2121         header( "HTTP/1.0 $code $label" );
2122         header( "Status: $code $label" );
2123         if ( $wgOut ) {
2124                 $wgOut->disable();
2125                 $wgOut->sendCacheControl();
2126         }
2127
2128         header( 'Content-type: text/html; charset=utf-8' );
2129         print "<!doctype html>" .
2130                 '<html><head><title>' .
2131                 htmlspecialchars( $label ) .
2132                 '</title></head><body><h1>' .
2133                 htmlspecialchars( $label ) .
2134                 '</h1><p>' .
2135                 nl2br( htmlspecialchars( $desc ) ) .
2136                 "</p></body></html>\n";
2137 }
2138
2139 /**
2140  * Clear away any user-level output buffers, discarding contents.
2141  *
2142  * Suitable for 'starting afresh', for instance when streaming
2143  * relatively large amounts of data without buffering, or wanting to
2144  * output image files without ob_gzhandler's compression.
2145  *
2146  * The optional $resetGzipEncoding parameter controls suppression of
2147  * the Content-Encoding header sent by ob_gzhandler; by default it
2148  * is left. See comments for wfClearOutputBuffers() for why it would
2149  * be used.
2150  *
2151  * Note that some PHP configuration options may add output buffer
2152  * layers which cannot be removed; these are left in place.
2153  *
2154  * @param bool $resetGzipEncoding
2155  */
2156 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2157         if ( $resetGzipEncoding ) {
2158                 // Suppress Content-Encoding and Content-Length
2159                 // headers from 1.10+s wfOutputHandler
2160                 global $wgDisableOutputCompression;
2161                 $wgDisableOutputCompression = true;
2162         }
2163         while ( $status = ob_get_status() ) {
2164                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2165                         // Probably from zlib.output_compression or other
2166                         // PHP-internal setting which can't be removed.
2167                         //
2168                         // Give up, and hope the result doesn't break
2169                         // output behavior.
2170                         break;
2171                 }
2172                 if ( !ob_end_clean() ) {
2173                         // Could not remove output buffer handler; abort now
2174                         // to avoid getting in some kind of infinite loop.
2175                         break;
2176                 }
2177                 if ( $resetGzipEncoding ) {
2178                         if ( $status['name'] == 'ob_gzhandler' ) {
2179                                 // Reset the 'Content-Encoding' field set by this handler
2180                                 // so we can start fresh.
2181                                 header_remove( 'Content-Encoding' );
2182                                 break;
2183                         }
2184                 }
2185         }
2186 }
2187
2188 /**
2189  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2190  *
2191  * Clear away output buffers, but keep the Content-Encoding header
2192  * produced by ob_gzhandler, if any.
2193  *
2194  * This should be used for HTTP 304 responses, where you need to
2195  * preserve the Content-Encoding header of the real result, but
2196  * also need to suppress the output of ob_gzhandler to keep to spec
2197  * and avoid breaking Firefox in rare cases where the headers and
2198  * body are broken over two packets.
2199  */
2200 function wfClearOutputBuffers() {
2201         wfResetOutputBuffers( false );
2202 }
2203
2204 /**
2205  * Converts an Accept-* header into an array mapping string values to quality
2206  * factors
2207  *
2208  * @param string $accept
2209  * @param string $def Default
2210  * @return float[] Associative array of string => float pairs
2211  */
2212 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2213         # No arg means accept anything (per HTTP spec)
2214         if ( !$accept ) {
2215                 return array( $def => 1.0 );
2216         }
2217
2218         $prefs = array();
2219
2220         $parts = explode( ',', $accept );
2221
2222         foreach ( $parts as $part ) {
2223                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2224                 $values = explode( ';', trim( $part ) );
2225                 $match = array();
2226                 if ( count( $values ) == 1 ) {
2227                         $prefs[$values[0]] = 1.0;
2228                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2229                         $prefs[$values[0]] = floatval( $match[1] );
2230                 }
2231         }
2232
2233         return $prefs;
2234 }
2235
2236 /**
2237  * Checks if a given MIME type matches any of the keys in the given
2238  * array. Basic wildcards are accepted in the array keys.
2239  *
2240  * Returns the matching MIME type (or wildcard) if a match, otherwise
2241  * NULL if no match.
2242  *
2243  * @param string $type
2244  * @param array $avail
2245  * @return string
2246  * @private
2247  */
2248 function mimeTypeMatch( $type, $avail ) {
2249         if ( array_key_exists( $type, $avail ) ) {
2250                 return $type;
2251         } else {
2252                 $parts = explode( '/', $type );
2253                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2254                         return $parts[0] . '/*';
2255                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2256                         return '*/*';
2257                 } else {
2258                         return null;
2259                 }
2260         }
2261 }
2262
2263 /**
2264  * Returns the 'best' match between a client's requested internet media types
2265  * and the server's list of available types. Each list should be an associative
2266  * array of type to preference (preference is a float between 0.0 and 1.0).
2267  * Wildcards in the types are acceptable.
2268  *
2269  * @param array $cprefs Client's acceptable type list
2270  * @param array $sprefs Server's offered types
2271  * @return string
2272  *
2273  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2274  * XXX: generalize to negotiate other stuff
2275  */
2276 function wfNegotiateType( $cprefs, $sprefs ) {
2277         $combine = array();
2278
2279         foreach ( array_keys( $sprefs ) as $type ) {
2280                 $parts = explode( '/', $type );
2281                 if ( $parts[1] != '*' ) {
2282                         $ckey = mimeTypeMatch( $type, $cprefs );
2283                         if ( $ckey ) {
2284                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2285                         }
2286                 }
2287         }
2288
2289         foreach ( array_keys( $cprefs ) as $type ) {
2290                 $parts = explode( '/', $type );
2291                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2292                         $skey = mimeTypeMatch( $type, $sprefs );
2293                         if ( $skey ) {
2294                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2295                         }
2296                 }
2297         }
2298
2299         $bestq = 0;
2300         $besttype = null;
2301
2302         foreach ( array_keys( $combine ) as $type ) {
2303                 if ( $combine[$type] > $bestq ) {
2304                         $besttype = $type;
2305                         $bestq = $combine[$type];
2306                 }
2307         }
2308
2309         return $besttype;
2310 }
2311
2312 /**
2313  * Reference-counted warning suppression
2314  *
2315  * @param bool $end
2316  */
2317 function wfSuppressWarnings( $end = false ) {
2318         static $suppressCount = 0;
2319         static $originalLevel = false;
2320
2321         if ( $end ) {
2322                 if ( $suppressCount ) {
2323                         --$suppressCount;
2324                         if ( !$suppressCount ) {
2325                                 error_reporting( $originalLevel );
2326                         }
2327                 }
2328         } else {
2329                 if ( !$suppressCount ) {
2330                         $originalLevel = error_reporting( E_ALL & ~(
2331                                 E_WARNING |
2332                                 E_NOTICE |
2333                                 E_USER_WARNING |
2334                                 E_USER_NOTICE |
2335                                 E_DEPRECATED |
2336                                 E_USER_DEPRECATED |
2337                                 E_STRICT
2338                         ) );
2339                 }
2340                 ++$suppressCount;
2341         }
2342 }
2343
2344 /**
2345  * Restore error level to previous value
2346  */
2347 function wfRestoreWarnings() {
2348         wfSuppressWarnings( true );
2349 }
2350
2351 # Autodetect, convert and provide timestamps of various types
2352
2353 /**
2354  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2355  */
2356 define( 'TS_UNIX', 0 );
2357
2358 /**
2359  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2360  */
2361 define( 'TS_MW', 1 );
2362
2363 /**
2364  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2365  */
2366 define( 'TS_DB', 2 );
2367
2368 /**
2369  * RFC 2822 format, for E-mail and HTTP headers
2370  */
2371 define( 'TS_RFC2822', 3 );
2372
2373 /**
2374  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2375  *
2376  * This is used by Special:Export
2377  */
2378 define( 'TS_ISO_8601', 4 );
2379
2380 /**
2381  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2382  *
2383  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2384  *       DateTime tag and page 36 for the DateTimeOriginal and
2385  *       DateTimeDigitized tags.
2386  */
2387 define( 'TS_EXIF', 5 );
2388
2389 /**
2390  * Oracle format time.
2391  */
2392 define( 'TS_ORACLE', 6 );
2393
2394 /**
2395  * Postgres format time.
2396  */
2397 define( 'TS_POSTGRES', 7 );
2398
2399 /**
2400  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2401  */
2402 define( 'TS_ISO_8601_BASIC', 9 );
2403
2404 /**
2405  * Get a timestamp string in one of various formats
2406  *
2407  * @param mixed $outputtype A timestamp in one of the supported formats, the
2408  *   function will autodetect which format is supplied and act accordingly.
2409  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2410  * @return string|bool String / false The same date in the format specified in $outputtype or false
2411  */
2412 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2413         try {
2414                 $timestamp = new MWTimestamp( $ts );
2415                 return $timestamp->getTimestamp( $outputtype );
2416         } catch ( TimestampException $e ) {
2417                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2418                 return false;
2419         }
2420 }
2421
2422 /**
2423  * Return a formatted timestamp, or null if input is null.
2424  * For dealing with nullable timestamp columns in the database.
2425  *
2426  * @param int $outputtype
2427  * @param string $ts
2428  * @return string
2429  */
2430 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2431         if ( is_null( $ts ) ) {
2432                 return null;
2433         } else {
2434                 return wfTimestamp( $outputtype, $ts );
2435         }
2436 }
2437
2438 /**
2439  * Convenience function; returns MediaWiki timestamp for the present time.
2440  *
2441  * @return string
2442  */
2443 function wfTimestampNow() {
2444         # return NOW
2445         return wfTimestamp( TS_MW, time() );
2446 }
2447
2448 /**
2449  * Check if the operating system is Windows
2450  *
2451  * @return bool True if it's Windows, false otherwise.
2452  */
2453 function wfIsWindows() {
2454         static $isWindows = null;
2455         if ( $isWindows === null ) {
2456                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2457         }
2458         return $isWindows;
2459 }
2460
2461 /**
2462  * Check if we are running under HHVM
2463  *
2464  * @return bool
2465  */
2466 function wfIsHHVM() {
2467         return defined( 'HHVM_VERSION' );
2468 }
2469
2470 /**
2471  * Swap two variables
2472  *
2473  * @deprecated since 1.24
2474  * @param mixed $x
2475  * @param mixed $y
2476  */
2477 function swap( &$x, &$y ) {
2478         wfDeprecated( __FUNCTION__, '1.24' );
2479         $z = $x;
2480         $x = $y;
2481         $y = $z;
2482 }
2483
2484 /**
2485  * Tries to get the system directory for temporary files. First
2486  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2487  * environment variables are then checked in sequence, and if none are
2488  * set try sys_get_temp_dir().
2489  *
2490  * NOTE: When possible, use instead the tmpfile() function to create
2491  * temporary files to avoid race conditions on file creation, etc.
2492  *
2493  * @return string
2494  */
2495 function wfTempDir() {
2496         global $wgTmpDirectory;
2497
2498         if ( $wgTmpDirectory !== false ) {
2499                 return $wgTmpDirectory;
2500         }
2501
2502         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2503
2504         foreach ( $tmpDir as $tmp ) {
2505                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2506                         return $tmp;
2507                 }
2508         }
2509         return sys_get_temp_dir();
2510 }
2511
2512 /**
2513  * Make directory, and make all parent directories if they don't exist
2514  *
2515  * @param string $dir Full path to directory to create
2516  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2517  * @param string $caller Optional caller param for debugging.
2518  * @throws MWException
2519  * @return bool
2520  */
2521 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2522         global $wgDirectoryMode;
2523
2524         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2525                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2526         }
2527
2528         if ( !is_null( $caller ) ) {
2529                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2530         }
2531
2532         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2533                 return true;
2534         }
2535
2536         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2537
2538         if ( is_null( $mode ) ) {
2539                 $mode = $wgDirectoryMode;
2540         }
2541
2542         // Turn off the normal warning, we're doing our own below
2543         wfSuppressWarnings();
2544         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2545         wfRestoreWarnings();
2546
2547         if ( !$ok ) {
2548                 //directory may have been created on another request since we last checked
2549                 if ( is_dir( $dir ) ) {
2550                         return true;
2551                 }
2552
2553                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2554                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2555         }
2556         return $ok;
2557 }
2558
2559 /**
2560  * Remove a directory and all its content.
2561  * Does not hide error.
2562  * @param string $dir
2563  */
2564 function wfRecursiveRemoveDir( $dir ) {
2565         wfDebug( __FUNCTION__ . "( $dir )\n" );
2566         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2567         if ( is_dir( $dir ) ) {
2568                 $objects = scandir( $dir );
2569                 foreach ( $objects as $object ) {
2570                         if ( $object != "." && $object != ".." ) {
2571                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2572                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2573                                 } else {
2574                                         unlink( $dir . '/' . $object );
2575                                 }
2576                         }
2577                 }
2578                 reset( $objects );
2579                 rmdir( $dir );
2580         }
2581 }
2582
2583 /**
2584  * @param int $nr The number to format
2585  * @param int $acc The number of digits after the decimal point, default 2
2586  * @param bool $round Whether or not to round the value, default true
2587  * @return string
2588  */
2589 function wfPercent( $nr, $acc = 2, $round = true ) {
2590         $ret = sprintf( "%.${acc}f", $nr );
2591         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2592 }
2593
2594 /**
2595  * Safety wrapper around ini_get() for boolean settings.
2596  * The values returned from ini_get() are pre-normalized for settings
2597  * set via php.ini or php_flag/php_admin_flag... but *not*
2598  * for those set via php_value/php_admin_value.
2599  *
2600  * It's fairly common for people to use php_value instead of php_flag,
2601  * which can leave you with an 'off' setting giving a false positive
2602  * for code that just takes the ini_get() return value as a boolean.
2603  *
2604  * To make things extra interesting, setting via php_value accepts
2605  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2606  * Unrecognized values go false... again opposite PHP's own coercion
2607  * from string to bool.
2608  *
2609  * Luckily, 'properly' set settings will always come back as '0' or '1',
2610  * so we only have to worry about them and the 'improper' settings.
2611  *
2612  * I frickin' hate PHP... :P
2613  *
2614  * @param string $setting
2615  * @return bool
2616  */
2617 function wfIniGetBool( $setting ) {
2618         $val = strtolower( ini_get( $setting ) );
2619         // 'on' and 'true' can't have whitespace around them, but '1' can.
2620         return $val == 'on'
2621                 || $val == 'true'
2622                 || $val == 'yes'
2623                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2624 }
2625
2626 /**
2627  * Windows-compatible version of escapeshellarg()
2628  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2629  * function puts single quotes in regardless of OS.
2630  *
2631  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2632  * earlier distro releases of PHP)
2633  *
2634  * @param string ... strings to escape and glue together, or a single array of strings parameter
2635  * @return string
2636  */
2637 function wfEscapeShellArg( /*...*/ ) {
2638         wfInitShellLocale();
2639
2640         $args = func_get_args();
2641         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2642                 // If only one argument has been passed, and that argument is an array,
2643                 // treat it as a list of arguments
2644                 $args = reset( $args );
2645         }
2646
2647         $first = true;
2648         $retVal = '';
2649         foreach ( $args as $arg ) {
2650                 if ( !$first ) {
2651                         $retVal .= ' ';
2652                 } else {
2653                         $first = false;
2654                 }
2655
2656                 if ( wfIsWindows() ) {
2657                         // Escaping for an MSVC-style command line parser and CMD.EXE
2658                         // @codingStandardsIgnoreStart For long URLs
2659                         // Refs:
2660                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2661                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2662                         //  * Bug #13518
2663                         //  * CR r63214
2664                         // Double the backslashes before any double quotes. Escape the double quotes.
2665                         // @codingStandardsIgnoreEnd
2666                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2667                         $arg = '';
2668                         $iteration = 0;
2669                         foreach ( $tokens as $token ) {
2670                                 if ( $iteration % 2 == 1 ) {
2671                                         // Delimiter, a double quote preceded by zero or more slashes
2672                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2673                                 } elseif ( $iteration % 4 == 2 ) {
2674                                         // ^ in $token will be outside quotes, need to be escaped
2675                                         $arg .= str_replace( '^', '^^', $token );
2676                                 } else { // $iteration % 4 == 0
2677                                         // ^ in $token will appear inside double quotes, so leave as is
2678                                         $arg .= $token;
2679                                 }
2680                                 $iteration++;
2681                         }
2682                         // Double the backslashes before the end of the string, because
2683                         // we will soon add a quote
2684                         $m = array();
2685                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2686                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2687                         }
2688
2689                         // Add surrounding quotes
2690                         $retVal .= '"' . $arg . '"';
2691                 } else {
2692                         $retVal .= escapeshellarg( $arg );
2693                 }
2694         }
2695         return $retVal;
2696 }
2697
2698 /**
2699  * Check if wfShellExec() is effectively disabled via php.ini config
2700  *
2701  * @return bool|string False or one of (safemode,disabled)
2702  * @since 1.22
2703  */
2704 function wfShellExecDisabled() {
2705         static $disabled = null;
2706         if ( is_null( $disabled ) ) {
2707                 if ( wfIniGetBool( 'safe_mode' ) ) {
2708                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2709                         $disabled = 'safemode';
2710                 } elseif ( !function_exists( 'proc_open' ) ) {
2711                         wfDebug( "proc_open() is disabled\n" );
2712                         $disabled = 'disabled';
2713                 } else {
2714                         $disabled = false;
2715                 }
2716         }
2717         return $disabled;
2718 }
2719
2720 /**
2721  * Execute a shell command, with time and memory limits mirrored from the PHP
2722  * configuration if supported.
2723  *
2724  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2725  *   or an array of unescaped arguments, in which case each value will be escaped
2726  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2727  * @param null|mixed &$retval Optional, will receive the program's exit code.
2728  *   (non-zero is usually failure). If there is an error from
2729  *   read, select, or proc_open(), this will be set to -1.
2730  * @param array $environ Optional environment variables which should be
2731  *   added to the executed command environment.
2732  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2733  *   this overwrites the global wgMaxShell* limits.
2734  * @param array $options Array of options:
2735  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2736  *     including errors from limit.sh
2737  *   - profileMethod: By default this function will profile based on the calling
2738  *     method. Set this to a string for an alternative method to profile from
2739  *
2740  * @return string Collected stdout as a string
2741  */
2742 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2743         $limits = array(), $options = array()
2744 ) {
2745         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2746                 $wgMaxShellWallClockTime, $wgShellCgroup;
2747
2748         $disabled = wfShellExecDisabled();
2749         if ( $disabled ) {
2750                 $retval = 1;
2751                 return $disabled == 'safemode' ?
2752                         'Unable to run external programs in safe mode.' :
2753                         'Unable to run external programs, proc_open() is disabled.';
2754         }
2755
2756         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2757         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2758
2759         wfInitShellLocale();
2760
2761         $envcmd = '';
2762         foreach ( $environ as $k => $v ) {
2763                 if ( wfIsWindows() ) {
2764                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2765                          * appear in the environment variable, so we must use carat escaping as documented in
2766                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2767                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2768                          * are listed there but doesn't appear to need it.
2769                          */
2770                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2771                 } else {
2772                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2773                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2774                          */
2775                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2776                 }
2777         }
2778         if ( is_array( $cmd ) ) {
2779                 $cmd = wfEscapeShellArg( $cmd );
2780         }
2781
2782         $cmd = $envcmd . $cmd;
2783
2784         $useLogPipe = false;
2785         if ( is_executable( '/bin/bash' ) ) {
2786                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2787                 if ( isset( $limits['walltime'] ) ) {
2788                         $wallTime = intval( $limits['walltime'] );
2789                 } elseif ( isset( $limits['time'] ) ) {
2790                         $wallTime = $time;
2791                 } else {
2792                         $wallTime = intval( $wgMaxShellWallClockTime );
2793                 }
2794                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2795                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2796
2797                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2798                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2799                                 escapeshellarg( $cmd ) . ' ' .
2800                                 escapeshellarg(
2801                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2802                                         "MW_CPU_LIMIT=$time; " .
2803                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2804                                         "MW_MEM_LIMIT=$mem; " .
2805                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2806                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2807                                         "MW_USE_LOG_PIPE=yes"
2808                                 );
2809                         $useLogPipe = true;
2810                 } elseif ( $includeStderr ) {
2811                         $cmd .= ' 2>&1';
2812                 }
2813         } elseif ( $includeStderr ) {
2814                 $cmd .= ' 2>&1';
2815         }
2816         wfDebug( "wfShellExec: $cmd\n" );
2817
2818         $desc = array(
2819                 0 => array( 'file', 'php://stdin', 'r' ),
2820                 1 => array( 'pipe', 'w' ),
2821                 2 => array( 'file', 'php://stderr', 'w' ) );
2822         if ( $useLogPipe ) {
2823                 $desc[3] = array( 'pipe', 'w' );
2824         }
2825         $pipes = null;
2826         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2827         $proc = proc_open( $cmd, $desc, $pipes );
2828         if ( !$proc ) {
2829                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2830                 $retval = -1;
2831                 return '';
2832         }
2833         $outBuffer = $logBuffer = '';
2834         $emptyArray = array();
2835         $status = false;
2836         $logMsg = false;
2837
2838         // According to the documentation, it is possible for stream_select()
2839         // to fail due to EINTR. I haven't managed to induce this in testing
2840         // despite sending various signals. If it did happen, the error
2841         // message would take the form:
2842         //
2843         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2844         //
2845         // where [4] is the value of the macro EINTR and "Interrupted system
2846         // call" is string which according to the Linux manual is "possibly"
2847         // localised according to LC_MESSAGES.
2848         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2849         $eintrMessage = "stream_select(): unable to select [$eintr]";
2850
2851         // Build a table mapping resource IDs to pipe FDs to work around a
2852         // PHP 5.3 issue in which stream_select() does not preserve array keys
2853         // <https://bugs.php.net/bug.php?id=53427>.
2854         $fds = array();
2855         foreach ( $pipes as $fd => $pipe ) {
2856                 $fds[(int)$pipe] = $fd;
2857         }
2858
2859         $running = true;
2860         $timeout = null;
2861         $numReadyPipes = 0;
2862
2863         while ( $running === true || $numReadyPipes !== 0 ) {
2864                 if ( $running ) {
2865                         $status = proc_get_status( $proc );
2866                         // If the process has terminated, switch to nonblocking selects
2867                         // for getting any data still waiting to be read.
2868                         if ( !$status['running'] ) {
2869                                 $running = false;
2870                                 $timeout = 0;
2871                         }
2872                 }
2873
2874                 $readyPipes = $pipes;
2875
2876                 // Clear last error
2877                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2878                 @trigger_error( '' );
2879                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2880                 if ( $numReadyPipes === false ) {
2881                         // @codingStandardsIgnoreEnd
2882                         $error = error_get_last();
2883                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2884                                 continue;
2885                         } else {
2886                                 trigger_error( $error['message'], E_USER_WARNING );
2887                                 $logMsg = $error['message'];
2888                                 break;
2889                         }
2890                 }
2891                 foreach ( $readyPipes as $pipe ) {
2892                         $block = fread( $pipe, 65536 );
2893                         $fd = $fds[(int)$pipe];
2894                         if ( $block === '' ) {
2895                                 // End of file
2896                                 fclose( $pipes[$fd] );
2897                                 unset( $pipes[$fd] );
2898                                 if ( !$pipes ) {
2899                                         break 2;
2900                                 }
2901                         } elseif ( $block === false ) {
2902                                 // Read error
2903                                 $logMsg = "Error reading from pipe";
2904                                 break 2;
2905                         } elseif ( $fd == 1 ) {
2906                                 // From stdout
2907                                 $outBuffer .= $block;
2908                         } elseif ( $fd == 3 ) {
2909                                 // From log FD
2910                                 $logBuffer .= $block;
2911                                 if ( strpos( $block, "\n" ) !== false ) {
2912                                         $lines = explode( "\n", $logBuffer );
2913                                         $logBuffer = array_pop( $lines );
2914                                         foreach ( $lines as $line ) {
2915                                                 wfDebugLog( 'exec', $line );
2916                                         }
2917                                 }
2918                         }
2919                 }
2920         }
2921
2922         foreach ( $pipes as $pipe ) {
2923                 fclose( $pipe );
2924         }
2925
2926         // Use the status previously collected if possible, since proc_get_status()
2927         // just calls waitpid() which will not return anything useful the second time.
2928         if ( $running ) {
2929                 $status = proc_get_status( $proc );
2930         }
2931
2932         if ( $logMsg !== false ) {
2933                 // Read/select error
2934                 $retval = -1;
2935                 proc_close( $proc );
2936         } elseif ( $status['signaled'] ) {
2937                 $logMsg = "Exited with signal {$status['termsig']}";
2938                 $retval = 128 + $status['termsig'];
2939                 proc_close( $proc );
2940         } else {
2941                 if ( $status['running'] ) {
2942                         $retval = proc_close( $proc );
2943                 } else {
2944                         $retval = $status['exitcode'];
2945                         proc_close( $proc );
2946                 }
2947                 if ( $retval == 127 ) {
2948                         $logMsg = "Possibly missing executable file";
2949                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2950                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2951                 }
2952         }
2953
2954         if ( $logMsg !== false ) {
2955                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2956         }
2957
2958         return $outBuffer;
2959 }
2960
2961 /**
2962  * Execute a shell command, returning both stdout and stderr. Convenience
2963  * function, as all the arguments to wfShellExec can become unwieldy.
2964  *
2965  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2966  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2967  *   or an array of unescaped arguments, in which case each value will be escaped
2968  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2969  * @param null|mixed &$retval Optional, will receive the program's exit code.
2970  *   (non-zero is usually failure)
2971  * @param array $environ Optional environment variables which should be
2972  *   added to the executed command environment.
2973  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2974  *   this overwrites the global wgMaxShell* limits.
2975  * @return string Collected stdout and stderr as a string
2976  */
2977 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2978         return wfShellExec( $cmd, $retval, $environ, $limits,
2979                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2980 }
2981
2982 /**
2983  * Workaround for http://bugs.php.net/bug.php?id=45132
2984  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2985  */
2986 function wfInitShellLocale() {
2987         static $done = false;
2988         if ( $done ) {
2989                 return;
2990         }
2991         $done = true;
2992         global $wgShellLocale;
2993         if ( !wfIniGetBool( 'safe_mode' ) ) {
2994                 putenv( "LC_CTYPE=$wgShellLocale" );
2995                 setlocale( LC_CTYPE, $wgShellLocale );
2996         }
2997 }
2998
2999 /**
3000  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3001  * Note that $parameters should be a flat array and an option with an argument
3002  * should consist of two consecutive items in the array (do not use "--option value").
3003  *
3004  * @param string $script MediaWiki cli script path
3005  * @param array $parameters Arguments and options to the script
3006  * @param array $options Associative array of options:
3007  *              'php': The path to the php executable
3008  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3009  * @return string
3010  */
3011 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3012         global $wgPhpCli;
3013         // Give site config file a chance to run the script in a wrapper.
3014         // The caller may likely want to call wfBasename() on $script.
3015         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3016         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3017         if ( isset( $options['wrapper'] ) ) {
3018                 $cmd[] = $options['wrapper'];
3019         }
3020         $cmd[] = $script;
3021         // Escape each parameter for shell
3022         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
3023 }
3024
3025 /**
3026  * wfMerge attempts to merge differences between three texts.
3027  * Returns true for a clean merge and false for failure or a conflict.
3028  *
3029  * @param string $old
3030  * @param string $mine
3031  * @param string $yours
3032  * @param string $result
3033  * @return bool
3034  */
3035 function wfMerge( $old, $mine, $yours, &$result ) {
3036         global $wgDiff3;
3037
3038         # This check may also protect against code injection in
3039         # case of broken installations.
3040         wfSuppressWarnings();
3041         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3042         wfRestoreWarnings();
3043
3044         if ( !$haveDiff3 ) {
3045                 wfDebug( "diff3 not found\n" );
3046                 return false;
3047         }
3048
3049         # Make temporary files
3050         $td = wfTempDir();
3051         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3052         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3053         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3054
3055         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3056         #       a newline character. To avoid this, we normalize the trailing whitespace before
3057         #       creating the diff.
3058
3059         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3060         fclose( $oldtextFile );
3061         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3062         fclose( $mytextFile );
3063         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3064         fclose( $yourtextFile );
3065
3066         # Check for a conflict
3067         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
3068                 $oldtextName, $yourtextName );
3069         $handle = popen( $cmd, 'r' );
3070
3071         if ( fgets( $handle, 1024 ) ) {
3072                 $conflict = true;
3073         } else {
3074                 $conflict = false;
3075         }
3076         pclose( $handle );
3077
3078         # Merge differences
3079         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
3080                 $oldtextName, $yourtextName );
3081         $handle = popen( $cmd, 'r' );
3082         $result = '';
3083         do {
3084                 $data = fread( $handle, 8192 );
3085                 if ( strlen( $data ) == 0 ) {
3086                         break;
3087                 }
3088                 $result .= $data;
3089         } while ( true );
3090         pclose( $handle );
3091         unlink( $mytextName );
3092         unlink( $oldtextName );
3093         unlink( $yourtextName );
3094
3095         if ( $result === '' && $old !== '' && !$conflict ) {
3096                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3097                 $conflict = true;
3098         }
3099         return !$conflict;
3100 }
3101
3102 /**
3103  * Returns unified plain-text diff of two texts.
3104  * "Useful" for machine processing of diffs.
3105  *
3106  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3107  *
3108  * @param string $before The text before the changes.
3109  * @param string $after The text after the changes.
3110  * @param string $params Command-line options for the diff command.
3111  * @return string Unified diff of $before and $after
3112  */
3113 function wfDiff( $before, $after, $params = '-u' ) {
3114         if ( $before == $after ) {
3115                 return '';
3116         }
3117
3118         global $wgDiff;
3119         wfSuppressWarnings();
3120         $haveDiff = $wgDiff && file_exists( $wgDiff );
3121         wfRestoreWarnings();
3122
3123         # This check may also protect against code injection in
3124         # case of broken installations.
3125         if ( !$haveDiff ) {
3126                 wfDebug( "diff executable not found\n" );
3127                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3128                 $format = new UnifiedDiffFormatter();
3129                 return $format->format( $diffs );
3130         }
3131
3132         # Make temporary files
3133         $td = wfTempDir();
3134         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3135         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3136
3137         fwrite( $oldtextFile, $before );
3138         fclose( $oldtextFile );
3139         fwrite( $newtextFile, $after );
3140         fclose( $newtextFile );
3141
3142         // Get the diff of the two files
3143         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3144
3145         $h = popen( $cmd, 'r' );
3146         if ( !$h ) {
3147                 unlink( $oldtextName );
3148                 unlink( $newtextName );
3149                 throw new Exception( __METHOD__ . '(): popen() failed' );
3150         }
3151
3152         $diff = '';
3153
3154         do {
3155                 $data = fread( $h, 8192 );
3156                 if ( strlen( $data ) == 0 ) {
3157                         break;
3158                 }
3159                 $diff .= $data;
3160         } while ( true );
3161
3162         // Clean up
3163         pclose( $h );
3164         unlink( $oldtextName );
3165         unlink( $newtextName );
3166
3167         // Kill the --- and +++ lines. They're not useful.
3168         $diff_lines = explode( "\n", $diff );
3169         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3170                 unset( $diff_lines[0] );
3171         }
3172         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3173                 unset( $diff_lines[1] );
3174         }
3175
3176         $diff = implode( "\n", $diff_lines );
3177
3178         return $diff;
3179 }
3180
3181 /**
3182  * This function works like "use VERSION" in Perl, the program will die with a
3183  * backtrace if the current version of PHP is less than the version provided
3184  *
3185  * This is useful for extensions which due to their nature are not kept in sync
3186  * with releases, and might depend on other versions of PHP than the main code
3187  *
3188  * Note: PHP might die due to parsing errors in some cases before it ever
3189  *       manages to call this function, such is life
3190  *
3191  * @see perldoc -f use
3192  *
3193  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3194  * @throws MWException
3195  */
3196 function wfUsePHP( $req_ver ) {
3197         $php_ver = PHP_VERSION;
3198
3199         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3200                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3201         }
3202 }
3203
3204 /**
3205  * This function works like "use VERSION" in Perl except it checks the version
3206  * of MediaWiki, the program will die with a backtrace if the current version
3207  * of MediaWiki is less than the version provided.
3208  *
3209  * This is useful for extensions which due to their nature are not kept in sync
3210  * with releases
3211  *
3212  * Note: Due to the behavior of PHP's version_compare() which is used in this
3213  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3214  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3215  * targeted version number. For example if you wanted to allow any variation
3216  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3217  * not result in the same comparison due to the internal logic of
3218  * version_compare().
3219  *
3220  * @see perldoc -f use
3221  *
3222  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3223  * @throws MWException
3224  */
3225 function wfUseMW( $req_ver ) {
3226         global $wgVersion;
3227
3228         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3229                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3230         }
3231 }
3232
3233 /**
3234  * Return the final portion of a pathname.
3235  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3236  * http://bugs.php.net/bug.php?id=33898
3237  *
3238  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3239  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3240  *
3241  * @param string $path
3242  * @param string $suffix String to remove if present
3243  * @return string
3244  */
3245 function wfBaseName( $path, $suffix = '' ) {
3246         if ( $suffix == '' ) {
3247                 $encSuffix = '';
3248         } else {
3249                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3250         }
3251
3252         $matches = array();
3253         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3254                 return $matches[1];
3255         } else {
3256                 return '';
3257         }
3258 }
3259
3260 /**
3261  * Generate a relative path name to the given file.
3262  * May explode on non-matching case-insensitive paths,
3263  * funky symlinks, etc.
3264  *
3265  * @param string $path Absolute destination path including target filename
3266  * @param string $from Absolute source path, directory only
3267  * @return string
3268  */
3269 function wfRelativePath( $path, $from ) {
3270         // Normalize mixed input on Windows...
3271         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3272         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3273
3274         // Trim trailing slashes -- fix for drive root
3275         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3276         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3277
3278         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3279         $against = explode( DIRECTORY_SEPARATOR, $from );
3280
3281         if ( $pieces[0] !== $against[0] ) {
3282                 // Non-matching Windows drive letters?
3283                 // Return a full path.
3284                 return $path;
3285         }
3286
3287         // Trim off common prefix
3288         while ( count( $pieces ) && count( $against )
3289                 && $pieces[0] == $against[0] ) {
3290                 array_shift( $pieces );
3291                 array_shift( $against );
3292         }
3293
3294         // relative dots to bump us to the parent
3295         while ( count( $against ) ) {
3296                 array_unshift( $pieces, '..' );
3297                 array_shift( $against );
3298         }
3299
3300         array_push( $pieces, wfBaseName( $path ) );
3301
3302         return implode( DIRECTORY_SEPARATOR, $pieces );
3303 }
3304
3305 /**
3306  * Convert an arbitrarily-long digit string from one numeric base
3307  * to another, optionally zero-padding to a minimum column width.
3308  *
3309  * Supports base 2 through 36; digit values 10-36 are represented
3310  * as lowercase letters a-z. Input is case-insensitive.
3311  *
3312  * @param string $input Input number
3313  * @param int $sourceBase Base of the input number
3314  * @param int $destBase Desired base of the output
3315  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3316  * @param bool $lowercase Whether to output in lowercase or uppercase
3317  * @param string $engine Either "gmp", "bcmath", or "php"
3318  * @return string|bool The output number as a string, or false on error
3319  */
3320 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3321         $lowercase = true, $engine = 'auto'
3322 ) {
3323         $input = (string)$input;
3324         if (
3325                 $sourceBase < 2 ||
3326                 $sourceBase > 36 ||
3327                 $destBase < 2 ||
3328                 $destBase > 36 ||
3329                 $sourceBase != (int)$sourceBase ||
3330                 $destBase != (int)$destBase ||
3331                 $pad != (int)$pad ||
3332                 !preg_match(
3333                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3334                         $input
3335                 )
3336         ) {
3337                 return false;
3338         }
3339
3340         static $baseChars = array(
3341                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3342                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3343                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3344                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3345                 34 => 'y', 35 => 'z',
3346
3347                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3348                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3349                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3350                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3351                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3352                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3353         );
3354
3355         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3356                 // Removing leading zeros works around broken base detection code in
3357                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3358                 // <https://bugs.php.net/bug.php?id=55398>).
3359                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ), $sourceBase ), $destBase );
3360         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3361                 $decimal = '0';
3362                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3363                         $decimal = bcmul( $decimal, $sourceBase );
3364                         $decimal = bcadd( $decimal, $baseChars[$char] );
3365                 }
3366
3367                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3368                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3369                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3370                 }
3371                 // @codingStandardsIgnoreEnd
3372
3373                 $result = strrev( $result );
3374         } else {
3375                 $inDigits = array();
3376                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3377                         $inDigits[] = $baseChars[$char];
3378                 }
3379
3380                 // Iterate over the input, modulo-ing out an output digit
3381                 // at a time until input is gone.
3382                 $result = '';
3383                 while ( $inDigits ) {
3384                         $work = 0;
3385                         $workDigits = array();
3386
3387                         // Long division...
3388                         foreach ( $inDigits as $digit ) {
3389                                 $work *= $sourceBase;
3390                                 $work += $digit;
3391
3392                                 if ( $workDigits || $work >= $destBase ) {
3393                                         $workDigits[] = (int)( $work / $destBase );
3394                                 }
3395                                 $work %= $destBase;
3396                         }
3397
3398                         // All that division leaves us with a remainder,
3399                         // which is conveniently our next output digit.
3400                         $result .= $baseChars[$work];
3401
3402                         // And we continue!
3403                         $inDigits = $workDigits;
3404                 }
3405
3406                 $result = strrev( $result );
3407         }
3408
3409         if ( !$lowercase ) {
3410                 $result = strtoupper( $result );
3411         }
3412
3413         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3414 }
3415
3416 /**
3417  * Check if there is sufficient entropy in php's built-in session generation
3418  *
3419  * @return bool True = there is sufficient entropy
3420  */
3421 function wfCheckEntropy() {
3422         return (
3423                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3424                         || ini_get( 'session.entropy_file' )
3425                 )
3426                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3427 }
3428
3429 /**
3430  * Override session_id before session startup if php's built-in
3431  * session generation code is not secure.
3432  */
3433 function wfFixSessionID() {
3434         // If the cookie or session id is already set we already have a session and should abort
3435         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3436                 return;
3437         }
3438
3439         // PHP's built-in session entropy is enabled if:
3440         // - entropy_file is set or you're on Windows with php 5.3.3+
3441         // - AND entropy_length is > 0
3442         // We treat it as disabled if it doesn't have an entropy length of at least 32
3443         $entropyEnabled = wfCheckEntropy();
3444
3445         // If built-in entropy is not enabled or not sufficient override PHP's
3446         // built in session id generation code
3447         if ( !$entropyEnabled ) {
3448                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3449                         "overriding session id generation using our cryptrand source.\n" );
3450                 session_id( MWCryptRand::generateHex( 32 ) );
3451         }
3452 }
3453
3454 /**
3455  * Reset the session_id
3456  *
3457  * @since 1.22
3458  */
3459 function wfResetSessionID() {
3460         global $wgCookieSecure;
3461         $oldSessionId = session_id();
3462         $cookieParams = session_get_cookie_params();
3463         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3464                 session_regenerate_id( false );
3465         } else {
3466                 $tmp = $_SESSION;
3467                 session_destroy();
3468                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3469                 $_SESSION = $tmp;
3470         }
3471         $newSessionId = session_id();
3472         Hooks::run( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3473 }
3474
3475 /**
3476  * Initialise php session
3477  *
3478  * @param bool $sessionId
3479  */
3480 function wfSetupSession( $sessionId = false ) {
3481         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3482                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3483         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3484                 ObjectCacheSessionHandler::install();
3485         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3486                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3487                 # hasn't already been set to the desired value (that causes errors)
3488                 ini_set( 'session.save_handler', $wgSessionHandler );
3489         }
3490         session_set_cookie_params(
3491                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3492         session_cache_limiter( 'private, must-revalidate' );
3493         if ( $sessionId ) {
3494                 session_id( $sessionId );
3495         } else {
3496                 wfFixSessionID();
3497         }
3498         wfSuppressWarnings();
3499         session_start();
3500         wfRestoreWarnings();
3501 }
3502
3503 /**
3504  * Get an object from the precompiled serialized directory
3505  *
3506  * @param string $name
3507  * @return mixed The variable on success, false on failure
3508  */
3509 function wfGetPrecompiledData( $name ) {
3510         global $IP;
3511
3512         $file = "$IP/serialized/$name";
3513         if ( file_exists( $file ) ) {
3514                 $blob = file_get_contents( $file );
3515                 if ( $blob ) {
3516                         return unserialize( $blob );
3517                 }
3518         }
3519         return false;
3520 }
3521
3522 /**
3523  * Get a cache key
3524  *
3525  * @param string $args,...
3526  * @return string
3527  */
3528 function wfMemcKey( /*...*/ ) {
3529         global $wgCachePrefix;
3530         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3531         $args = func_get_args();
3532         $key = $prefix . ':' . implode( ':', $args );
3533         $key = str_replace( ' ', '_', $key );
3534         return $key;
3535 }
3536
3537 /**
3538  * Get a cache key for a foreign DB
3539  *
3540  * @param string $db
3541  * @param string $prefix
3542  * @param string $args,...
3543  * @return string
3544  */
3545 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3546         $args = array_slice( func_get_args(), 2 );
3547         if ( $prefix ) {
3548                 $key = "$db-$prefix:" . implode( ':', $args );
3549         } else {
3550                 $key = $db . ':' . implode( ':', $args );
3551         }
3552         return str_replace( ' ', '_', $key );
3553 }
3554
3555 /**
3556  * Get an ASCII string identifying this wiki
3557  * This is used as a prefix in memcached keys
3558  *
3559  * @return string
3560  */
3561 function wfWikiID() {
3562         global $wgDBprefix, $wgDBname;
3563         if ( $wgDBprefix ) {
3564                 return "$wgDBname-$wgDBprefix";
3565         } else {
3566                 return $wgDBname;
3567         }
3568 }
3569
3570 /**
3571  * Split a wiki ID into DB name and table prefix
3572  *
3573  * @param string $wiki
3574  *
3575  * @return array
3576  */
3577 function wfSplitWikiID( $wiki ) {
3578         $bits = explode( '-', $wiki, 2 );
3579         if ( count( $bits ) < 2 ) {
3580                 $bits[] = '';
3581         }
3582         return $bits;
3583 }
3584
3585 /**
3586  * Get a Database object.
3587  *
3588  * @param int $db Index of the connection to get. May be DB_MASTER for the
3589  *            master (for write queries), DB_SLAVE for potentially lagged read
3590  *            queries, or an integer >= 0 for a particular server.
3591  *
3592  * @param string|string[] $groups Query groups. An array of group names that this query
3593  *                belongs to. May contain a single string if the query is only
3594  *                in one group.
3595  *
3596  * @param string|bool $wiki The wiki ID, or false for the current wiki
3597  *
3598  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3599  * will always return the same object, unless the underlying connection or load
3600  * balancer is manually destroyed.
3601  *
3602  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3603  * updater to ensure that a proper database is being updated.
3604  *
3605  * @return DatabaseBase
3606  */
3607 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3608         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3609 }
3610
3611 /**
3612  * Get a load balancer object.
3613  *
3614  * @param string|bool $wiki Wiki ID, or false for the current wiki
3615  * @return LoadBalancer
3616  */
3617 function wfGetLB( $wiki = false ) {
3618         return wfGetLBFactory()->getMainLB( $wiki );
3619 }
3620
3621 /**
3622  * Get the load balancer factory object
3623  *
3624  * @return LBFactory
3625  */
3626 function wfGetLBFactory() {
3627         return LBFactory::singleton();
3628 }
3629
3630 /**
3631  * Find a file.
3632  * Shortcut for RepoGroup::singleton()->findFile()
3633  *
3634  * @param string $title String or Title object
3635  * @param array $options Associative array of options (see RepoGroup::findFile)
3636  * @return File|bool File, or false if the file does not exist
3637  */
3638 function wfFindFile( $title, $options = array() ) {
3639         return RepoGroup::singleton()->findFile( $title, $options );
3640 }
3641
3642 /**
3643  * Get an object referring to a locally registered file.
3644  * Returns a valid placeholder object if the file does not exist.
3645  *
3646  * @param Title|string $title
3647  * @return LocalFile|null A File, or null if passed an invalid Title
3648  */
3649 function wfLocalFile( $title ) {
3650         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3651 }
3652
3653 /**
3654  * Should low-performance queries be disabled?
3655  *
3656  * @return bool
3657  * @codeCoverageIgnore
3658  */
3659 function wfQueriesMustScale() {
3660         global $wgMiserMode;
3661         return $wgMiserMode
3662                 || ( SiteStats::pages() > 100000
3663                 && SiteStats::edits() > 1000000
3664                 && SiteStats::users() > 10000 );
3665 }
3666
3667 /**
3668  * Get the path to a specified script file, respecting file
3669  * extensions; this is a wrapper around $wgScriptExtension etc.
3670  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3671  *
3672  * @param string $script Script filename, sans extension
3673  * @return string
3674  */
3675 function wfScript( $script = 'index' ) {
3676         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3677         if ( $script === 'index' ) {
3678                 return $wgScript;
3679         } elseif ( $script === 'load' ) {
3680                 return $wgLoadScript;
3681         } else {
3682                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3683         }
3684 }
3685
3686 /**
3687  * Get the script URL.
3688  *
3689  * @return string Script URL
3690  */
3691 function wfGetScriptUrl() {
3692         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3693                 #
3694                 # as it was called, minus the query string.
3695                 #
3696                 # Some sites use Apache rewrite rules to handle subdomains,
3697                 # and have PHP set up in a weird way that causes PHP_SELF
3698                 # to contain the rewritten URL instead of the one that the
3699                 # outside world sees.
3700                 #
3701                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3702                 # provides containing the "before" URL.
3703                 return $_SERVER['SCRIPT_NAME'];
3704         } else {
3705                 return $_SERVER['URL'];
3706         }
3707 }
3708
3709 /**
3710  * Convenience function converts boolean values into "true"
3711  * or "false" (string) values
3712  *
3713  * @param bool $value
3714  * @return string
3715  */
3716 function wfBoolToStr( $value ) {
3717         return $value ? 'true' : 'false';
3718 }
3719
3720 /**
3721  * Get a platform-independent path to the null file, e.g. /dev/null
3722  *
3723  * @return string
3724  */
3725 function wfGetNull() {
3726         return wfIsWindows() ? 'NUL' : '/dev/null';
3727 }
3728
3729 /**
3730  * Waits for the slaves to catch up to the master position
3731  *
3732  * Use this when updating very large numbers of rows, as in maintenance scripts,
3733  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3734  *
3735  * By default this waits on the main DB cluster of the current wiki.
3736  * If $cluster is set to "*" it will wait on all DB clusters, including
3737  * external ones. If the lag being waiting on is caused by the code that
3738  * does this check, it makes since to use $ifWritesSince, particularly if
3739  * cluster is "*", to avoid excess overhead.
3740  *
3741  * Never call this function after a big DB write that is still in a transaction.
3742  * This only makes sense after the possible lag inducing changes were committed.
3743  *
3744  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3745  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3746  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3747  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3748  * @return bool Success (able to connect and no timeouts reached)
3749  */
3750 function wfWaitForSlaves(
3751         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3752 ) {
3753         // B/C: first argument used to be "max seconds of lag"; ignore such values
3754         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3755
3756         if ( $timeout === null ) {
3757                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3758         }
3759
3760         // Figure out which clusters need to be checked
3761         $lbs = array();
3762         if ( $cluster === '*' ) {
3763                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3764                         $lbs[] = $lb;
3765                 } );
3766         } elseif ( $cluster !== false ) {
3767                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3768         } else {
3769                 $lbs[] = wfGetLB( $wiki );
3770         }
3771
3772         // Get all the master positions of applicable DBs right now.
3773         // This can be faster since waiting on one cluster reduces the
3774         // time needed to wait on the next clusters.
3775         $masterPositions = array_fill( 0, count( $lbs ), false );
3776         foreach ( $lbs as $i => $lb ) {
3777                 // bug 27975 - Don't try to wait for slaves if there are none
3778                 // Prevents permission error when getting master position
3779                 if ( $lb->getServerCount() > 1 ) {
3780                         if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
3781                                 continue; // assume no writes done
3782                         }
3783                         // Use the empty string to not trigger selectDB() since the connection
3784                         // may have been to a server that does not have a DB for the current wiki.
3785                         $dbw = $lb->getConnection( DB_MASTER, array(), '' );
3786                         if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
3787                                 continue; // no writes since the last wait
3788                         }
3789                         $masterPositions[$i] = $dbw->getMasterPos();
3790                 }
3791         }
3792
3793         $ok = true;
3794         foreach ( $lbs as $i => $lb ) {
3795                 if ( $masterPositions[$i] ) {
3796                         // The DBMS may not support getMasterPos() or the whole
3797                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3798                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3799                 }
3800         }
3801
3802         return $ok;
3803 }
3804
3805 /**
3806  * Count down from $seconds to zero on the terminal, with a one-second pause
3807  * between showing each number. For use in command-line scripts.
3808  *
3809  * @codeCoverageIgnore
3810  * @param int $seconds
3811  */
3812 function wfCountDown( $seconds ) {
3813         for ( $i = $seconds; $i >= 0; $i-- ) {
3814                 if ( $i != $seconds ) {
3815                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3816                 }
3817                 echo $i;
3818                 flush();
3819                 if ( $i ) {
3820                         sleep( 1 );
3821                 }
3822         }
3823         echo "\n";
3824 }
3825
3826 /**
3827  * Replace all invalid characters with -
3828  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3829  * By default, $wgIllegalFileChars = ':'
3830  *
3831  * @param string $name Filename to process
3832  * @return string
3833  */
3834 function wfStripIllegalFilenameChars( $name ) {
3835         global $wgIllegalFileChars;
3836         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3837         $name = wfBaseName( $name );
3838         $name = preg_replace(
3839                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3840                 '-',
3841                 $name
3842         );
3843         return $name;
3844 }
3845
3846 /**
3847  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3848  *
3849  * @return int Value the memory limit was set to.
3850  */
3851 function wfMemoryLimit() {
3852         global $wgMemoryLimit;
3853         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3854         if ( $memlimit != -1 ) {
3855                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3856                 if ( $conflimit == -1 ) {
3857                         wfDebug( "Removing PHP's memory limit\n" );
3858                         wfSuppressWarnings();
3859                         ini_set( 'memory_limit', $conflimit );
3860                         wfRestoreWarnings();
3861                         return $conflimit;
3862                 } elseif ( $conflimit > $memlimit ) {
3863                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3864                         wfSuppressWarnings();
3865                         ini_set( 'memory_limit', $conflimit );
3866                         wfRestoreWarnings();
3867                         return $conflimit;
3868                 }
3869         }
3870         return $memlimit;
3871 }
3872
3873 /**
3874  * Converts shorthand byte notation to integer form
3875  *
3876  * @param string $string
3877  * @return int
3878  */
3879 function wfShorthandToInteger( $string = '' ) {
3880         $string = trim( $string );
3881         if ( $string === '' ) {
3882                 return -1;
3883         }
3884         $last = $string[strlen( $string ) - 1];
3885         $val = intval( $string );
3886         switch ( $last ) {
3887                 case 'g':
3888                 case 'G':
3889                         $val *= 1024;
3890                         // break intentionally missing
3891                 case 'm':
3892                 case 'M':
3893                         $val *= 1024;
3894                         // break intentionally missing
3895                 case 'k':
3896                 case 'K':
3897                         $val *= 1024;
3898         }
3899
3900         return $val;
3901 }
3902
3903 /**
3904  * Get the normalised IETF language tag
3905  * See unit test for examples.
3906  *
3907  * @param string $code The language code.
3908  * @return string The language code which complying with BCP 47 standards.
3909  */
3910 function wfBCP47( $code ) {
3911         $codeSegment = explode( '-', $code );
3912         $codeBCP = array();
3913         foreach ( $codeSegment as $segNo => $seg ) {
3914                 // when previous segment is x, it is a private segment and should be lc
3915                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3916                         $codeBCP[$segNo] = strtolower( $seg );
3917                 // ISO 3166 country code
3918                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3919                         $codeBCP[$segNo] = strtoupper( $seg );
3920                 // ISO 15924 script code
3921                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3922                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3923                 // Use lowercase for other cases
3924                 } else {
3925                         $codeBCP[$segNo] = strtolower( $seg );
3926                 }
3927         }
3928         $langCode = implode( '-', $codeBCP );
3929         return $langCode;
3930 }
3931
3932 /**
3933  * Get a cache object.
3934  *
3935  * @param int $inputType Cache type, one of the CACHE_* constants.
3936  * @return BagOStuff
3937  */
3938 function wfGetCache( $inputType ) {
3939         return ObjectCache::getInstance( $inputType );
3940 }
3941
3942 /**
3943  * Get the main cache object
3944  *
3945  * @return BagOStuff
3946  */
3947 function wfGetMainCache() {
3948         global $wgMainCacheType;
3949         return ObjectCache::getInstance( $wgMainCacheType );
3950 }
3951
3952 /**
3953  * Get the cache object used by the message cache
3954  *
3955  * @return BagOStuff
3956  */
3957 function wfGetMessageCacheStorage() {
3958         global $wgMessageCacheType;
3959         return ObjectCache::getInstance( $wgMessageCacheType );
3960 }
3961
3962 /**
3963  * Get the cache object used by the parser cache
3964  *
3965  * @return BagOStuff
3966  */
3967 function wfGetParserCacheStorage() {
3968         global $wgParserCacheType;
3969         return ObjectCache::getInstance( $wgParserCacheType );
3970 }
3971
3972 /**
3973  * Call hook functions defined in $wgHooks
3974  *
3975  * @param string $event Event name
3976  * @param array $args Parameters passed to hook functions
3977  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3978  *
3979  * @return bool True if no handler aborted the hook
3980  * @deprecated 1.25 - use Hooks::run
3981  */
3982 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3983         return Hooks::run( $event, $args, $deprecatedVersion );
3984 }
3985
3986 /**
3987  * Wrapper around php's unpack.
3988  *
3989  * @param string $format The format string (See php's docs)
3990  * @param string $data A binary string of binary data
3991  * @param int|bool $length The minimum length of $data or false. This is to
3992  *      prevent reading beyond the end of $data. false to disable the check.
3993  *
3994  * Also be careful when using this function to read unsigned 32 bit integer
3995  * because php might make it negative.
3996  *
3997  * @throws MWException If $data not long enough, or if unpack fails
3998  * @return array Associative array of the extracted data
3999  */
4000 function wfUnpack( $format, $data, $length = false ) {
4001         if ( $length !== false ) {
4002                 $realLen = strlen( $data );
4003                 if ( $realLen < $length ) {
4004                         throw new MWException( "Tried to use wfUnpack on a "
4005                                 . "string of length $realLen, but needed one "
4006                                 . "of at least length $length."
4007                         );
4008                 }
4009         }
4010
4011         wfSuppressWarnings();
4012         $result = unpack( $format, $data );
4013         wfRestoreWarnings();
4014
4015         if ( $result === false ) {
4016                 // If it cannot extract the packed data.
4017                 throw new MWException( "unpack could not unpack binary data" );
4018         }
4019         return $result;
4020 }
4021
4022 /**
4023  * Determine if an image exists on the 'bad image list'.
4024  *
4025  * The format of MediaWiki:Bad_image_list is as follows:
4026  *    * Only list items (lines starting with "*") are considered
4027  *    * The first link on a line must be a link to a bad image
4028  *    * Any subsequent links on the same line are considered to be exceptions,
4029  *      i.e. articles where the image may occur inline.
4030  *
4031  * @param string $name The image name to check
4032  * @param Title|bool $contextTitle The page on which the image occurs, if known
4033  * @param string $blacklist Wikitext of a file blacklist
4034  * @return bool
4035  */
4036 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4037         static $badImageCache = null; // based on bad_image_list msg
4038
4039         # Handle redirects
4040         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4041         if ( $redirectTitle ) {
4042                 $name = $redirectTitle->getDBkey();
4043         }
4044
4045         # Run the extension hook
4046         $bad = false;
4047         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4048                 return $bad;
4049         }
4050
4051         $cacheable = ( $blacklist === null );
4052         if ( $cacheable && $badImageCache !== null ) {
4053                 $badImages = $badImageCache;
4054         } else { // cache miss
4055                 if ( $blacklist === null ) {
4056                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4057                 }
4058                 # Build the list now
4059                 $badImages = array();
4060                 $lines = explode( "\n", $blacklist );
4061                 foreach ( $lines as $line ) {
4062                         # List items only
4063                         if ( substr( $line, 0, 1 ) !== '*' ) {
4064                                 continue;
4065                         }
4066
4067                         # Find all links
4068                         $m = array();
4069                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4070                                 continue;
4071                         }
4072
4073                         $exceptions = array();
4074                         $imageDBkey = false;
4075                         foreach ( $m[1] as $i => $titleText ) {
4076                                 $title = Title::newFromText( $titleText );
4077                                 if ( !is_null( $title ) ) {
4078                                         if ( $i == 0 ) {
4079                                                 $imageDBkey = $title->getDBkey();
4080                                         } else {
4081                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4082                                         }
4083                                 }
4084                         }
4085
4086                         if ( $imageDBkey !== false ) {
4087                                 $badImages[$imageDBkey] = $exceptions;
4088                         }
4089                 }
4090                 if ( $cacheable ) {
4091                         $badImageCache = $badImages;
4092                 }
4093         }
4094
4095         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4096         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4097         return $bad;
4098 }
4099
4100 /**
4101  * Determine whether the client at a given source IP is likely to be able to
4102  * access the wiki via HTTPS.
4103  *
4104  * @param string $ip The IPv4/6 address in the normal human-readable form
4105  * @return bool
4106  */
4107 function wfCanIPUseHTTPS( $ip ) {
4108         $canDo = true;
4109         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4110         return !!$canDo;
4111 }
4112
4113 /**
4114  * Determine input string is represents as infinity
4115  *
4116  * @param string $str The string to determine
4117  * @return bool
4118  * @since 1.25
4119  */
4120 function wfIsInfinity( $str ) {
4121         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4122         return in_array( $str, $infinityValues );
4123 }
4124
4125 /**
4126  * Work out the IP address based on various globals
4127  * For trusted proxies, use the XFF client IP (first of the chain)
4128  *
4129  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4130  * @return string
4131  */
4132 function wfGetIP() {
4133         wfDeprecated( __METHOD__, '1.19' );
4134         global $wgRequest;
4135         return $wgRequest->getIP();
4136 }
4137
4138 /**
4139  * Checks if an IP is a trusted proxy provider.
4140  * Useful to tell if X-Forwarded-For data is possibly bogus.
4141  * Squid cache servers for the site are whitelisted.
4142  * @deprecated Since 1.24, use IP::isTrustedProxy()
4143  *
4144  * @param string $ip
4145  * @return bool
4146  */
4147 function wfIsTrustedProxy( $ip ) {
4148         wfDeprecated( __METHOD__, '1.24' );
4149         return IP::isTrustedProxy( $ip );
4150 }
4151
4152 /**
4153  * Checks if an IP matches a proxy we've configured.
4154  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4155  *
4156  * @param string $ip
4157  * @return bool
4158  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4159  */
4160 function wfIsConfiguredProxy( $ip ) {
4161         wfDeprecated( __METHOD__, '1.24' );
4162         return IP::isConfiguredProxy( $ip );
4163 }
4164
4165 /**
4166  * Returns true if these thumbnail parameters match one that MediaWiki
4167  * requests from file description pages and/or parser output.
4168  *
4169  * $params is considered non-standard if they involve a non-standard
4170  * width or any non-default parameters aside from width and page number.
4171  * The number of possible files with standard parameters is far less than
4172  * that of all combinations; rate-limiting for them can thus be more generious.
4173  *
4174  * @param File $file
4175  * @param array $params
4176  * @return bool
4177  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4178  */
4179 function wfThumbIsStandard( File $file, array $params ) {
4180         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4181
4182         $multipliers = array( 1 );
4183         if ( $wgResponsiveImages ) {
4184                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4185                 // @see Linker::processResponsiveImages
4186                 $multipliers[] = 1.5;
4187                 $multipliers[] = 2;
4188         }
4189
4190         $handler = $file->getHandler();
4191         if ( !$handler || !isset( $params['width'] ) ) {
4192                 return false;
4193         }
4194
4195         $basicParams = array();
4196         if ( isset( $params['page'] ) ) {
4197                 $basicParams['page'] = $params['page'];
4198         }
4199
4200         $thumbLimits = array();
4201         $imageLimits = array();
4202         // Expand limits to account for multipliers
4203         foreach ( $multipliers as $multiplier ) {
4204                 $thumbLimits = array_merge( $thumbLimits, array_map(
4205                         function ( $width ) use ( $multiplier ) {
4206                                 return round( $width * $multiplier );
4207                         }, $wgThumbLimits )
4208                 );
4209                 $imageLimits = array_merge( $imageLimits, array_map(
4210                         function ( $pair ) use ( $multiplier ) {
4211                                 return array(
4212                                         round( $pair[0] * $multiplier ),
4213                                         round( $pair[1] * $multiplier ),
4214                                 );
4215                         }, $wgImageLimits )
4216                 );
4217         }
4218
4219         // Check if the width matches one of $wgThumbLimits
4220         if ( in_array( $params['width'], $thumbLimits ) ) {
4221                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4222                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4223                 $handler->normaliseParams( $file, $normalParams );
4224         } else {
4225                 // If not, then check if the width matchs one of $wgImageLimits
4226                 $match = false;
4227                 foreach ( $imageLimits as $pair ) {
4228                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4229                         // Decide whether the thumbnail should be scaled on width or height.
4230                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4231                         $handler->normaliseParams( $file, $normalParams );
4232                         // Check if this standard thumbnail size maps to the given width
4233                         if ( $normalParams['width'] == $params['width'] ) {
4234                                 $match = true;
4235                                 break;
4236                         }
4237                 }
4238                 if ( !$match ) {
4239                         return false; // not standard for description pages
4240                 }
4241         }
4242
4243         // Check that the given values for non-page, non-width, params are just defaults
4244         foreach ( $params as $key => $value ) {
4245                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4246                         return false;
4247                 }
4248         }
4249
4250         return true;
4251 }