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                 // Callers use this method to be aware that data presented to a user
1348                 // may be very stale and thus allowing submissions can be problematic.
1349                 if ( $wgReadOnly === false && wfGetLB()->getLaggedSlaveMode() ) {
1350                         $wgReadOnly = 'The database has been automatically locked ' .
1351                                 'while the slave database servers catch up to the master';
1352                 }
1353         }
1354
1355         return $wgReadOnly;
1356 }
1357
1358 /**
1359  * Return a Language object from $langcode
1360  *
1361  * @param Language|string|bool $langcode Either:
1362  *                  - a Language object
1363  *                  - code of the language to get the message for, if it is
1364  *                    a valid code create a language for that language, if
1365  *                    it is a string but not a valid code then make a basic
1366  *                    language object
1367  *                  - a boolean: if it's false then use the global object for
1368  *                    the current user's language (as a fallback for the old parameter
1369  *                    functionality), or if it is true then use global object
1370  *                    for the wiki's content language.
1371  * @return Language
1372  */
1373 function wfGetLangObj( $langcode = false ) {
1374         # Identify which language to get or create a language object for.
1375         # Using is_object here due to Stub objects.
1376         if ( is_object( $langcode ) ) {
1377                 # Great, we already have the object (hopefully)!
1378                 return $langcode;
1379         }
1380
1381         global $wgContLang, $wgLanguageCode;
1382         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1383                 # $langcode is the language code of the wikis content language object.
1384                 # or it is a boolean and value is true
1385                 return $wgContLang;
1386         }
1387
1388         global $wgLang;
1389         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1390                 # $langcode is the language code of user language object.
1391                 # or it was a boolean and value is false
1392                 return $wgLang;
1393         }
1394
1395         $validCodes = array_keys( Language::fetchLanguageNames() );
1396         if ( in_array( $langcode, $validCodes ) ) {
1397                 # $langcode corresponds to a valid language.
1398                 return Language::factory( $langcode );
1399         }
1400
1401         # $langcode is a string, but not a valid language code; use content language.
1402         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1403         return $wgContLang;
1404 }
1405
1406 /**
1407  * This is the function for getting translated interface messages.
1408  *
1409  * @see Message class for documentation how to use them.
1410  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1411  *
1412  * This function replaces all old wfMsg* functions.
1413  *
1414  * @param string|string[] $key Message key, or array of keys
1415  * @param mixed $params,... Normal message parameters
1416  * @return Message
1417  *
1418  * @since 1.17
1419  *
1420  * @see Message::__construct
1421  */
1422 function wfMessage( $key /*...*/ ) {
1423         $params = func_get_args();
1424         array_shift( $params );
1425         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1426                 $params = $params[0];
1427         }
1428         return new Message( $key, $params );
1429 }
1430
1431 /**
1432  * This function accepts multiple message keys and returns a message instance
1433  * for the first message which is non-empty. If all messages are empty then an
1434  * instance of the first message key is returned.
1435  *
1436  * @param string|string[] $keys,... Message keys
1437  * @return Message
1438  *
1439  * @since 1.18
1440  *
1441  * @see Message::newFallbackSequence
1442  */
1443 function wfMessageFallback( /*...*/ ) {
1444         $args = func_get_args();
1445         return call_user_func_array( 'Message::newFallbackSequence', $args );
1446 }
1447
1448 /**
1449  * Get a message from anywhere, for the current user language.
1450  *
1451  * Use wfMsgForContent() instead if the message should NOT
1452  * change depending on the user preferences.
1453  *
1454  * @deprecated since 1.18
1455  *
1456  * @param string $key Lookup key for the message, usually
1457  *    defined in languages/Language.php
1458  *
1459  * Parameters to the message, which can be used to insert variable text into
1460  * it, can be passed to this function in the following formats:
1461  * - One per argument, starting at the second parameter
1462  * - As an array in the second parameter
1463  * These are not shown in the function definition.
1464  *
1465  * @return string
1466  */
1467 function wfMsg( $key ) {
1468         wfDeprecated( __METHOD__, '1.21' );
1469
1470         $args = func_get_args();
1471         array_shift( $args );
1472         return wfMsgReal( $key, $args );
1473 }
1474
1475 /**
1476  * Same as above except doesn't transform the message
1477  *
1478  * @deprecated since 1.18
1479  *
1480  * @param string $key
1481  * @return string
1482  */
1483 function wfMsgNoTrans( $key ) {
1484         wfDeprecated( __METHOD__, '1.21' );
1485
1486         $args = func_get_args();
1487         array_shift( $args );
1488         return wfMsgReal( $key, $args, true, false, false );
1489 }
1490
1491 /**
1492  * Get a message from anywhere, for the current global language
1493  * set with $wgLanguageCode.
1494  *
1495  * Use this if the message should NOT change dependent on the
1496  * language set in the user's preferences. This is the case for
1497  * most text written into logs, as well as link targets (such as
1498  * the name of the copyright policy page). Link titles, on the
1499  * other hand, should be shown in the UI language.
1500  *
1501  * Note that MediaWiki allows users to change the user interface
1502  * language in their preferences, but a single installation
1503  * typically only contains content in one language.
1504  *
1505  * Be wary of this distinction: If you use wfMsg() where you should
1506  * use wfMsgForContent(), a user of the software may have to
1507  * customize potentially hundreds of messages in
1508  * order to, e.g., fix a link in every possible language.
1509  *
1510  * @deprecated since 1.18
1511  *
1512  * @param string $key Lookup key for the message, usually
1513  *     defined in languages/Language.php
1514  * @return string
1515  */
1516 function wfMsgForContent( $key ) {
1517         wfDeprecated( __METHOD__, '1.21' );
1518
1519         global $wgForceUIMsgAsContentMsg;
1520         $args = func_get_args();
1521         array_shift( $args );
1522         $forcontent = true;
1523         if ( is_array( $wgForceUIMsgAsContentMsg )
1524                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1525         ) {
1526                 $forcontent = false;
1527         }
1528         return wfMsgReal( $key, $args, true, $forcontent );
1529 }
1530
1531 /**
1532  * Same as above except doesn't transform the message
1533  *
1534  * @deprecated since 1.18
1535  *
1536  * @param string $key
1537  * @return string
1538  */
1539 function wfMsgForContentNoTrans( $key ) {
1540         wfDeprecated( __METHOD__, '1.21' );
1541
1542         global $wgForceUIMsgAsContentMsg;
1543         $args = func_get_args();
1544         array_shift( $args );
1545         $forcontent = true;
1546         if ( is_array( $wgForceUIMsgAsContentMsg )
1547                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1548         ) {
1549                 $forcontent = false;
1550         }
1551         return wfMsgReal( $key, $args, true, $forcontent, false );
1552 }
1553
1554 /**
1555  * Really get a message
1556  *
1557  * @deprecated since 1.18
1558  *
1559  * @param string $key Key to get.
1560  * @param array $args
1561  * @param bool $useDB
1562  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1563  * @param bool $transform Whether or not to transform the message.
1564  * @return string The requested message.
1565  */
1566 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1567         wfDeprecated( __METHOD__, '1.21' );
1568
1569         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1570         $message = wfMsgReplaceArgs( $message, $args );
1571         return $message;
1572 }
1573
1574 /**
1575  * Fetch a message string value, but don't replace any keys yet.
1576  *
1577  * @deprecated since 1.18
1578  *
1579  * @param string $key
1580  * @param bool $useDB
1581  * @param string|bool $langCode Code of the language to get the message for, or
1582  *   behaves as a content language switch if it is a boolean.
1583  * @param bool $transform Whether to parse magic words, etc.
1584  * @return string
1585  */
1586 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1587         wfDeprecated( __METHOD__, '1.21' );
1588
1589         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1590
1591         $cache = MessageCache::singleton();
1592         $message = $cache->get( $key, $useDB, $langCode );
1593         if ( $message === false ) {
1594                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1595         } elseif ( $transform ) {
1596                 $message = $cache->transform( $message );
1597         }
1598         return $message;
1599 }
1600
1601 /**
1602  * Replace message parameter keys on the given formatted output.
1603  *
1604  * @param string $message
1605  * @param array $args
1606  * @return string
1607  * @private
1608  */
1609 function wfMsgReplaceArgs( $message, $args ) {
1610         # Fix windows line-endings
1611         # Some messages are split with explode("\n", $msg)
1612         $message = str_replace( "\r", '', $message );
1613
1614         // Replace arguments
1615         if ( count( $args ) ) {
1616                 if ( is_array( $args[0] ) ) {
1617                         $args = array_values( $args[0] );
1618                 }
1619                 $replacementKeys = array();
1620                 foreach ( $args as $n => $param ) {
1621                         $replacementKeys['$' . ( $n + 1 )] = $param;
1622                 }
1623                 $message = strtr( $message, $replacementKeys );
1624         }
1625
1626         return $message;
1627 }
1628
1629 /**
1630  * Return an HTML-escaped version of a message.
1631  * Parameter replacements, if any, are done *after* the HTML-escaping,
1632  * so parameters may contain HTML (eg links or form controls). Be sure
1633  * to pre-escape them if you really do want plaintext, or just wrap
1634  * the whole thing in htmlspecialchars().
1635  *
1636  * @deprecated since 1.18
1637  *
1638  * @param string $key
1639  * @param string $args,... Parameters
1640  * @return string
1641  */
1642 function wfMsgHtml( $key ) {
1643         wfDeprecated( __METHOD__, '1.21' );
1644
1645         $args = func_get_args();
1646         array_shift( $args );
1647         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1648 }
1649
1650 /**
1651  * Return an HTML version of message
1652  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1653  * so parameters may contain HTML (eg links or form controls). Be sure
1654  * to pre-escape them if you really do want plaintext, or just wrap
1655  * the whole thing in htmlspecialchars().
1656  *
1657  * @deprecated since 1.18
1658  *
1659  * @param string $key
1660  * @param string $args,... Parameters
1661  * @return string
1662  */
1663 function wfMsgWikiHtml( $key ) {
1664         wfDeprecated( __METHOD__, '1.21' );
1665
1666         $args = func_get_args();
1667         array_shift( $args );
1668         return wfMsgReplaceArgs(
1669                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1670                 /* can't be set to false */ true, /* interface */ true )->getText(),
1671                 $args );
1672 }
1673
1674 /**
1675  * Returns message in the requested format
1676  *
1677  * @deprecated since 1.18
1678  *
1679  * @param string $key Key of the message
1680  * @param array $options Processing rules.
1681  *   Can take the following options:
1682  *     parse: parses wikitext to HTML
1683  *     parseinline: parses wikitext to HTML and removes the surrounding
1684  *       p's added by parser or tidy
1685  *     escape: filters message through htmlspecialchars
1686  *     escapenoentities: same, but allows entity references like &#160; through
1687  *     replaceafter: parameters are substituted after parsing or escaping
1688  *     parsemag: transform the message using magic phrases
1689  *     content: fetch message for content language instead of interface
1690  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1691  *     language: Language object or language code to fetch message for
1692  *       (overridden by content).
1693  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1694  *
1695  * @return string
1696  */
1697 function wfMsgExt( $key, $options ) {
1698         wfDeprecated( __METHOD__, '1.21' );
1699
1700         $args = func_get_args();
1701         array_shift( $args );
1702         array_shift( $args );
1703         $options = (array)$options;
1704         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1705                 'parsemag', 'content' );
1706
1707         foreach ( $options as $arrayKey => $option ) {
1708                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1709                         // An unknown index, neither numeric nor "language"
1710                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1711                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1712                         // A numeric index with unknown value
1713                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1714                 }
1715         }
1716
1717         if ( in_array( 'content', $options, true ) ) {
1718                 $forContent = true;
1719                 $langCode = true;
1720                 $langCodeObj = null;
1721         } elseif ( array_key_exists( 'language', $options ) ) {
1722                 $forContent = false;
1723                 $langCode = wfGetLangObj( $options['language'] );
1724                 $langCodeObj = $langCode;
1725         } else {
1726                 $forContent = false;
1727                 $langCode = false;
1728                 $langCodeObj = null;
1729         }
1730
1731         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1732
1733         if ( !in_array( 'replaceafter', $options, true ) ) {
1734                 $string = wfMsgReplaceArgs( $string, $args );
1735         }
1736
1737         $messageCache = MessageCache::singleton();
1738         $parseInline = in_array( 'parseinline', $options, true );
1739         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1740                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1741                 if ( $string instanceof ParserOutput ) {
1742                         $string = $string->getText();
1743                 }
1744
1745                 if ( $parseInline ) {
1746                         $string = Parser::stripOuterParagraph( $string );
1747                 }
1748         } elseif ( in_array( 'parsemag', $options, true ) ) {
1749                 $string = $messageCache->transform( $string,
1750                                 !$forContent, $langCodeObj );
1751         }
1752
1753         if ( in_array( 'escape', $options, true ) ) {
1754                 $string = htmlspecialchars ( $string );
1755         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1756                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1757         }
1758
1759         if ( in_array( 'replaceafter', $options, true ) ) {
1760                 $string = wfMsgReplaceArgs( $string, $args );
1761         }
1762
1763         return $string;
1764 }
1765
1766 /**
1767  * Since wfMsg() and co suck, they don't return false if the message key they
1768  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1769  * nonexistence of messages by checking the MessageCache::get() result directly.
1770  *
1771  * @deprecated since 1.18. Use Message::isDisabled().
1772  *
1773  * @param string $key The message key looked up
1774  * @return bool True if the message *doesn't* exist.
1775  */
1776 function wfEmptyMsg( $key ) {
1777         wfDeprecated( __METHOD__, '1.21' );
1778
1779         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1780 }
1781
1782 /**
1783  * Fetch server name for use in error reporting etc.
1784  * Use real server name if available, so we know which machine
1785  * in a server farm generated the current page.
1786  *
1787  * @return string
1788  */
1789 function wfHostname() {
1790         static $host;
1791         if ( is_null( $host ) ) {
1792
1793                 # Hostname overriding
1794                 global $wgOverrideHostname;
1795                 if ( $wgOverrideHostname !== false ) {
1796                         # Set static and skip any detection
1797                         $host = $wgOverrideHostname;
1798                         return $host;
1799                 }
1800
1801                 if ( function_exists( 'posix_uname' ) ) {
1802                         // This function not present on Windows
1803                         $uname = posix_uname();
1804                 } else {
1805                         $uname = false;
1806                 }
1807                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1808                         $host = $uname['nodename'];
1809                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1810                         # Windows computer name
1811                         $host = getenv( 'COMPUTERNAME' );
1812                 } else {
1813                         # This may be a virtual server.
1814                         $host = $_SERVER['SERVER_NAME'];
1815                 }
1816         }
1817         return $host;
1818 }
1819
1820 /**
1821  * Returns a script tag that stores the amount of time it took MediaWiki to
1822  * handle the request in milliseconds as 'wgBackendResponseTime'.
1823  *
1824  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1825  * hostname of the server handling the request.
1826  *
1827  * @return string
1828  */
1829 function wfReportTime() {
1830         global $wgRequestTime, $wgShowHostnames;
1831
1832         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1833         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1834         if ( $wgShowHostnames ) {
1835                 $reportVars['wgHostname'] = wfHostname();
1836         }
1837         return Skin::makeVariablesScript( $reportVars );
1838 }
1839
1840 /**
1841  * Safety wrapper for debug_backtrace().
1842  *
1843  * Will return an empty array if debug_backtrace is disabled, otherwise
1844  * the output from debug_backtrace() (trimmed).
1845  *
1846  * @param int $limit This parameter can be used to limit the number of stack frames returned
1847  *
1848  * @return array Array of backtrace information
1849  */
1850 function wfDebugBacktrace( $limit = 0 ) {
1851         static $disabled = null;
1852
1853         if ( is_null( $disabled ) ) {
1854                 $disabled = !function_exists( 'debug_backtrace' );
1855                 if ( $disabled ) {
1856                         wfDebug( "debug_backtrace() is disabled\n" );
1857                 }
1858         }
1859         if ( $disabled ) {
1860                 return array();
1861         }
1862
1863         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1864                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1865         } else {
1866                 return array_slice( debug_backtrace(), 1 );
1867         }
1868 }
1869
1870 /**
1871  * Get a debug backtrace as a string
1872  *
1873  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1874  *   Defaults to $wgCommandLineMode if unset.
1875  * @return string
1876  * @since 1.25 Supports $raw parameter.
1877  */
1878 function wfBacktrace( $raw = null ) {
1879         global $wgCommandLineMode;
1880
1881         if ( $raw === null ) {
1882                 $raw = $wgCommandLineMode;
1883         }
1884
1885         if ( $raw ) {
1886                 $frameFormat = "%s line %s calls %s()\n";
1887                 $traceFormat = "%s";
1888         } else {
1889                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1890                 $traceFormat = "<ul>\n%s</ul>\n";
1891         }
1892
1893         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1894                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1895                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1896                 $call = $frame['function'];
1897                 if ( !empty( $frame['class'] ) ) {
1898                         $call = $frame['class'] . $frame['type'] . $call;
1899                 }
1900                 return sprintf( $frameFormat, $file, $line, $call );
1901         }, wfDebugBacktrace() );
1902
1903         return sprintf( $traceFormat, implode( '', $frames ) );
1904 }
1905
1906 /**
1907  * Get the name of the function which called this function
1908  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1909  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1910  * wfGetCaller( 3 ) is the parent of that.
1911  *
1912  * @param int $level
1913  * @return string
1914  */
1915 function wfGetCaller( $level = 2 ) {
1916         $backtrace = wfDebugBacktrace( $level + 1 );
1917         if ( isset( $backtrace[$level] ) ) {
1918                 return wfFormatStackFrame( $backtrace[$level] );
1919         } else {
1920                 return 'unknown';
1921         }
1922 }
1923
1924 /**
1925  * Return a string consisting of callers in the stack. Useful sometimes
1926  * for profiling specific points.
1927  *
1928  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1929  * @return string
1930  */
1931 function wfGetAllCallers( $limit = 3 ) {
1932         $trace = array_reverse( wfDebugBacktrace() );
1933         if ( !$limit || $limit > count( $trace ) - 1 ) {
1934                 $limit = count( $trace ) - 1;
1935         }
1936         $trace = array_slice( $trace, -$limit - 1, $limit );
1937         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1938 }
1939
1940 /**
1941  * Return a string representation of frame
1942  *
1943  * @param array $frame
1944  * @return string
1945  */
1946 function wfFormatStackFrame( $frame ) {
1947         return isset( $frame['class'] ) ?
1948                 $frame['class'] . '::' . $frame['function'] :
1949                 $frame['function'];
1950 }
1951
1952 /* Some generic result counters, pulled out of SearchEngine */
1953
1954 /**
1955  * @todo document
1956  *
1957  * @param int $offset
1958  * @param int $limit
1959  * @return string
1960  */
1961 function wfShowingResults( $offset, $limit ) {
1962         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1963 }
1964
1965 /**
1966  * @todo document
1967  * @todo FIXME: We may want to blacklist some broken browsers
1968  *
1969  * @param bool $force
1970  * @return bool Whereas client accept gzip compression
1971  */
1972 function wfClientAcceptsGzip( $force = false ) {
1973         static $result = null;
1974         if ( $result === null || $force ) {
1975                 $result = false;
1976                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1977                         # @todo FIXME: We may want to blacklist some broken browsers
1978                         $m = array();
1979                         if ( preg_match(
1980                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1981                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1982                                         $m
1983                                 )
1984                         ) {
1985                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1986                                         $result = false;
1987                                         return $result;
1988                                 }
1989                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1990                                 $result = true;
1991                         }
1992                 }
1993         }
1994         return $result;
1995 }
1996
1997 /**
1998  * Obtain the offset and limit values from the request string;
1999  * used in special pages
2000  *
2001  * @param int $deflimit Default limit if none supplied
2002  * @param string $optionname Name of a user preference to check against
2003  * @return array
2004  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2005  */
2006 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2007         global $wgRequest;
2008         wfDeprecated( __METHOD__, '1.24' );
2009         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2010 }
2011
2012 /**
2013  * Escapes the given text so that it may be output using addWikiText()
2014  * without any linking, formatting, etc. making its way through. This
2015  * is achieved by substituting certain characters with HTML entities.
2016  * As required by the callers, "<nowiki>" is not used.
2017  *
2018  * @param string $text Text to be escaped
2019  * @return string
2020  */
2021 function wfEscapeWikiText( $text ) {
2022         static $repl = null, $repl2 = null;
2023         if ( $repl === null ) {
2024                 $repl = array(
2025                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2026                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2027                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2028                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2029                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2030                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2031                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2032                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2033                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2034                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2035                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2036                         '__' => '_&#95;', '://' => '&#58;//',
2037                 );
2038
2039                 // We have to catch everything "\s" matches in PCRE
2040                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2041                         $repl["$magic "] = "$magic&#32;";
2042                         $repl["$magic\t"] = "$magic&#9;";
2043                         $repl["$magic\r"] = "$magic&#13;";
2044                         $repl["$magic\n"] = "$magic&#10;";
2045                         $repl["$magic\f"] = "$magic&#12;";
2046                 }
2047
2048                 // And handle protocols that don't use "://"
2049                 global $wgUrlProtocols;
2050                 $repl2 = array();
2051                 foreach ( $wgUrlProtocols as $prot ) {
2052                         if ( substr( $prot, -1 ) === ':' ) {
2053                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2054                         }
2055                 }
2056                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2057         }
2058         $text = substr( strtr( "\n$text", $repl ), 1 );
2059         $text = preg_replace( $repl2, '$1&#58;', $text );
2060         return $text;
2061 }
2062
2063 /**
2064  * Sets dest to source and returns the original value of dest
2065  * If source is NULL, it just returns the value, it doesn't set the variable
2066  * If force is true, it will set the value even if source is NULL
2067  *
2068  * @param mixed $dest
2069  * @param mixed $source
2070  * @param bool $force
2071  * @return mixed
2072  */
2073 function wfSetVar( &$dest, $source, $force = false ) {
2074         $temp = $dest;
2075         if ( !is_null( $source ) || $force ) {
2076                 $dest = $source;
2077         }
2078         return $temp;
2079 }
2080
2081 /**
2082  * As for wfSetVar except setting a bit
2083  *
2084  * @param int $dest
2085  * @param int $bit
2086  * @param bool $state
2087  *
2088  * @return bool
2089  */
2090 function wfSetBit( &$dest, $bit, $state = true ) {
2091         $temp = (bool)( $dest & $bit );
2092         if ( !is_null( $state ) ) {
2093                 if ( $state ) {
2094                         $dest |= $bit;
2095                 } else {
2096                         $dest &= ~$bit;
2097                 }
2098         }
2099         return $temp;
2100 }
2101
2102 /**
2103  * A wrapper around the PHP function var_export().
2104  * Either print it or add it to the regular output ($wgOut).
2105  *
2106  * @param mixed $var A PHP variable to dump.
2107  */
2108 function wfVarDump( $var ) {
2109         global $wgOut;
2110         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2111         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2112                 print $s;
2113         } else {
2114                 $wgOut->addHTML( $s );
2115         }
2116 }
2117
2118 /**
2119  * Provide a simple HTTP error.
2120  *
2121  * @param int|string $code
2122  * @param string $label
2123  * @param string $desc
2124  */
2125 function wfHttpError( $code, $label, $desc ) {
2126         global $wgOut;
2127         header( "HTTP/1.0 $code $label" );
2128         header( "Status: $code $label" );
2129         if ( $wgOut ) {
2130                 $wgOut->disable();
2131                 $wgOut->sendCacheControl();
2132         }
2133
2134         header( 'Content-type: text/html; charset=utf-8' );
2135         print "<!doctype html>" .
2136                 '<html><head><title>' .
2137                 htmlspecialchars( $label ) .
2138                 '</title></head><body><h1>' .
2139                 htmlspecialchars( $label ) .
2140                 '</h1><p>' .
2141                 nl2br( htmlspecialchars( $desc ) ) .
2142                 "</p></body></html>\n";
2143 }
2144
2145 /**
2146  * Clear away any user-level output buffers, discarding contents.
2147  *
2148  * Suitable for 'starting afresh', for instance when streaming
2149  * relatively large amounts of data without buffering, or wanting to
2150  * output image files without ob_gzhandler's compression.
2151  *
2152  * The optional $resetGzipEncoding parameter controls suppression of
2153  * the Content-Encoding header sent by ob_gzhandler; by default it
2154  * is left. See comments for wfClearOutputBuffers() for why it would
2155  * be used.
2156  *
2157  * Note that some PHP configuration options may add output buffer
2158  * layers which cannot be removed; these are left in place.
2159  *
2160  * @param bool $resetGzipEncoding
2161  */
2162 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2163         if ( $resetGzipEncoding ) {
2164                 // Suppress Content-Encoding and Content-Length
2165                 // headers from 1.10+s wfOutputHandler
2166                 global $wgDisableOutputCompression;
2167                 $wgDisableOutputCompression = true;
2168         }
2169         while ( $status = ob_get_status() ) {
2170                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2171                         // Probably from zlib.output_compression or other
2172                         // PHP-internal setting which can't be removed.
2173                         //
2174                         // Give up, and hope the result doesn't break
2175                         // output behavior.
2176                         break;
2177                 }
2178                 if ( !ob_end_clean() ) {
2179                         // Could not remove output buffer handler; abort now
2180                         // to avoid getting in some kind of infinite loop.
2181                         break;
2182                 }
2183                 if ( $resetGzipEncoding ) {
2184                         if ( $status['name'] == 'ob_gzhandler' ) {
2185                                 // Reset the 'Content-Encoding' field set by this handler
2186                                 // so we can start fresh.
2187                                 header_remove( 'Content-Encoding' );
2188                                 break;
2189                         }
2190                 }
2191         }
2192 }
2193
2194 /**
2195  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2196  *
2197  * Clear away output buffers, but keep the Content-Encoding header
2198  * produced by ob_gzhandler, if any.
2199  *
2200  * This should be used for HTTP 304 responses, where you need to
2201  * preserve the Content-Encoding header of the real result, but
2202  * also need to suppress the output of ob_gzhandler to keep to spec
2203  * and avoid breaking Firefox in rare cases where the headers and
2204  * body are broken over two packets.
2205  */
2206 function wfClearOutputBuffers() {
2207         wfResetOutputBuffers( false );
2208 }
2209
2210 /**
2211  * Converts an Accept-* header into an array mapping string values to quality
2212  * factors
2213  *
2214  * @param string $accept
2215  * @param string $def Default
2216  * @return float[] Associative array of string => float pairs
2217  */
2218 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2219         # No arg means accept anything (per HTTP spec)
2220         if ( !$accept ) {
2221                 return array( $def => 1.0 );
2222         }
2223
2224         $prefs = array();
2225
2226         $parts = explode( ',', $accept );
2227
2228         foreach ( $parts as $part ) {
2229                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2230                 $values = explode( ';', trim( $part ) );
2231                 $match = array();
2232                 if ( count( $values ) == 1 ) {
2233                         $prefs[$values[0]] = 1.0;
2234                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2235                         $prefs[$values[0]] = floatval( $match[1] );
2236                 }
2237         }
2238
2239         return $prefs;
2240 }
2241
2242 /**
2243  * Checks if a given MIME type matches any of the keys in the given
2244  * array. Basic wildcards are accepted in the array keys.
2245  *
2246  * Returns the matching MIME type (or wildcard) if a match, otherwise
2247  * NULL if no match.
2248  *
2249  * @param string $type
2250  * @param array $avail
2251  * @return string
2252  * @private
2253  */
2254 function mimeTypeMatch( $type, $avail ) {
2255         if ( array_key_exists( $type, $avail ) ) {
2256                 return $type;
2257         } else {
2258                 $parts = explode( '/', $type );
2259                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2260                         return $parts[0] . '/*';
2261                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2262                         return '*/*';
2263                 } else {
2264                         return null;
2265                 }
2266         }
2267 }
2268
2269 /**
2270  * Returns the 'best' match between a client's requested internet media types
2271  * and the server's list of available types. Each list should be an associative
2272  * array of type to preference (preference is a float between 0.0 and 1.0).
2273  * Wildcards in the types are acceptable.
2274  *
2275  * @param array $cprefs Client's acceptable type list
2276  * @param array $sprefs Server's offered types
2277  * @return string
2278  *
2279  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2280  * XXX: generalize to negotiate other stuff
2281  */
2282 function wfNegotiateType( $cprefs, $sprefs ) {
2283         $combine = array();
2284
2285         foreach ( array_keys( $sprefs ) as $type ) {
2286                 $parts = explode( '/', $type );
2287                 if ( $parts[1] != '*' ) {
2288                         $ckey = mimeTypeMatch( $type, $cprefs );
2289                         if ( $ckey ) {
2290                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2291                         }
2292                 }
2293         }
2294
2295         foreach ( array_keys( $cprefs ) as $type ) {
2296                 $parts = explode( '/', $type );
2297                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2298                         $skey = mimeTypeMatch( $type, $sprefs );
2299                         if ( $skey ) {
2300                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2301                         }
2302                 }
2303         }
2304
2305         $bestq = 0;
2306         $besttype = null;
2307
2308         foreach ( array_keys( $combine ) as $type ) {
2309                 if ( $combine[$type] > $bestq ) {
2310                         $besttype = $type;
2311                         $bestq = $combine[$type];
2312                 }
2313         }
2314
2315         return $besttype;
2316 }
2317
2318 /**
2319  * Reference-counted warning suppression
2320  *
2321  * @param bool $end
2322  */
2323 function wfSuppressWarnings( $end = false ) {
2324         static $suppressCount = 0;
2325         static $originalLevel = false;
2326
2327         if ( $end ) {
2328                 if ( $suppressCount ) {
2329                         --$suppressCount;
2330                         if ( !$suppressCount ) {
2331                                 error_reporting( $originalLevel );
2332                         }
2333                 }
2334         } else {
2335                 if ( !$suppressCount ) {
2336                         $originalLevel = error_reporting( E_ALL & ~(
2337                                 E_WARNING |
2338                                 E_NOTICE |
2339                                 E_USER_WARNING |
2340                                 E_USER_NOTICE |
2341                                 E_DEPRECATED |
2342                                 E_USER_DEPRECATED |
2343                                 E_STRICT
2344                         ) );
2345                 }
2346                 ++$suppressCount;
2347         }
2348 }
2349
2350 /**
2351  * Restore error level to previous value
2352  */
2353 function wfRestoreWarnings() {
2354         wfSuppressWarnings( true );
2355 }
2356
2357 # Autodetect, convert and provide timestamps of various types
2358
2359 /**
2360  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2361  */
2362 define( 'TS_UNIX', 0 );
2363
2364 /**
2365  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2366  */
2367 define( 'TS_MW', 1 );
2368
2369 /**
2370  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2371  */
2372 define( 'TS_DB', 2 );
2373
2374 /**
2375  * RFC 2822 format, for E-mail and HTTP headers
2376  */
2377 define( 'TS_RFC2822', 3 );
2378
2379 /**
2380  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2381  *
2382  * This is used by Special:Export
2383  */
2384 define( 'TS_ISO_8601', 4 );
2385
2386 /**
2387  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2388  *
2389  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2390  *       DateTime tag and page 36 for the DateTimeOriginal and
2391  *       DateTimeDigitized tags.
2392  */
2393 define( 'TS_EXIF', 5 );
2394
2395 /**
2396  * Oracle format time.
2397  */
2398 define( 'TS_ORACLE', 6 );
2399
2400 /**
2401  * Postgres format time.
2402  */
2403 define( 'TS_POSTGRES', 7 );
2404
2405 /**
2406  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2407  */
2408 define( 'TS_ISO_8601_BASIC', 9 );
2409
2410 /**
2411  * Get a timestamp string in one of various formats
2412  *
2413  * @param mixed $outputtype A timestamp in one of the supported formats, the
2414  *   function will autodetect which format is supplied and act accordingly.
2415  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2416  * @return string|bool String / false The same date in the format specified in $outputtype or false
2417  */
2418 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2419         try {
2420                 $timestamp = new MWTimestamp( $ts );
2421                 return $timestamp->getTimestamp( $outputtype );
2422         } catch ( TimestampException $e ) {
2423                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2424                 return false;
2425         }
2426 }
2427
2428 /**
2429  * Return a formatted timestamp, or null if input is null.
2430  * For dealing with nullable timestamp columns in the database.
2431  *
2432  * @param int $outputtype
2433  * @param string $ts
2434  * @return string
2435  */
2436 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2437         if ( is_null( $ts ) ) {
2438                 return null;
2439         } else {
2440                 return wfTimestamp( $outputtype, $ts );
2441         }
2442 }
2443
2444 /**
2445  * Convenience function; returns MediaWiki timestamp for the present time.
2446  *
2447  * @return string
2448  */
2449 function wfTimestampNow() {
2450         # return NOW
2451         return wfTimestamp( TS_MW, time() );
2452 }
2453
2454 /**
2455  * Check if the operating system is Windows
2456  *
2457  * @return bool True if it's Windows, false otherwise.
2458  */
2459 function wfIsWindows() {
2460         static $isWindows = null;
2461         if ( $isWindows === null ) {
2462                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2463         }
2464         return $isWindows;
2465 }
2466
2467 /**
2468  * Check if we are running under HHVM
2469  *
2470  * @return bool
2471  */
2472 function wfIsHHVM() {
2473         return defined( 'HHVM_VERSION' );
2474 }
2475
2476 /**
2477  * Swap two variables
2478  *
2479  * @deprecated since 1.24
2480  * @param mixed $x
2481  * @param mixed $y
2482  */
2483 function swap( &$x, &$y ) {
2484         wfDeprecated( __FUNCTION__, '1.24' );
2485         $z = $x;
2486         $x = $y;
2487         $y = $z;
2488 }
2489
2490 /**
2491  * Tries to get the system directory for temporary files. First
2492  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2493  * environment variables are then checked in sequence, and if none are
2494  * set try sys_get_temp_dir().
2495  *
2496  * NOTE: When possible, use instead the tmpfile() function to create
2497  * temporary files to avoid race conditions on file creation, etc.
2498  *
2499  * @return string
2500  */
2501 function wfTempDir() {
2502         global $wgTmpDirectory;
2503
2504         if ( $wgTmpDirectory !== false ) {
2505                 return $wgTmpDirectory;
2506         }
2507
2508         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2509
2510         foreach ( $tmpDir as $tmp ) {
2511                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2512                         return $tmp;
2513                 }
2514         }
2515         return sys_get_temp_dir();
2516 }
2517
2518 /**
2519  * Make directory, and make all parent directories if they don't exist
2520  *
2521  * @param string $dir Full path to directory to create
2522  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2523  * @param string $caller Optional caller param for debugging.
2524  * @throws MWException
2525  * @return bool
2526  */
2527 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2528         global $wgDirectoryMode;
2529
2530         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2531                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2532         }
2533
2534         if ( !is_null( $caller ) ) {
2535                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2536         }
2537
2538         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2539                 return true;
2540         }
2541
2542         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2543
2544         if ( is_null( $mode ) ) {
2545                 $mode = $wgDirectoryMode;
2546         }
2547
2548         // Turn off the normal warning, we're doing our own below
2549         wfSuppressWarnings();
2550         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2551         wfRestoreWarnings();
2552
2553         if ( !$ok ) {
2554                 //directory may have been created on another request since we last checked
2555                 if ( is_dir( $dir ) ) {
2556                         return true;
2557                 }
2558
2559                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2560                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2561         }
2562         return $ok;
2563 }
2564
2565 /**
2566  * Remove a directory and all its content.
2567  * Does not hide error.
2568  * @param string $dir
2569  */
2570 function wfRecursiveRemoveDir( $dir ) {
2571         wfDebug( __FUNCTION__ . "( $dir )\n" );
2572         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2573         if ( is_dir( $dir ) ) {
2574                 $objects = scandir( $dir );
2575                 foreach ( $objects as $object ) {
2576                         if ( $object != "." && $object != ".." ) {
2577                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2578                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2579                                 } else {
2580                                         unlink( $dir . '/' . $object );
2581                                 }
2582                         }
2583                 }
2584                 reset( $objects );
2585                 rmdir( $dir );
2586         }
2587 }
2588
2589 /**
2590  * @param int $nr The number to format
2591  * @param int $acc The number of digits after the decimal point, default 2
2592  * @param bool $round Whether or not to round the value, default true
2593  * @return string
2594  */
2595 function wfPercent( $nr, $acc = 2, $round = true ) {
2596         $ret = sprintf( "%.${acc}f", $nr );
2597         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2598 }
2599
2600 /**
2601  * Safety wrapper around ini_get() for boolean settings.
2602  * The values returned from ini_get() are pre-normalized for settings
2603  * set via php.ini or php_flag/php_admin_flag... but *not*
2604  * for those set via php_value/php_admin_value.
2605  *
2606  * It's fairly common for people to use php_value instead of php_flag,
2607  * which can leave you with an 'off' setting giving a false positive
2608  * for code that just takes the ini_get() return value as a boolean.
2609  *
2610  * To make things extra interesting, setting via php_value accepts
2611  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2612  * Unrecognized values go false... again opposite PHP's own coercion
2613  * from string to bool.
2614  *
2615  * Luckily, 'properly' set settings will always come back as '0' or '1',
2616  * so we only have to worry about them and the 'improper' settings.
2617  *
2618  * I frickin' hate PHP... :P
2619  *
2620  * @param string $setting
2621  * @return bool
2622  */
2623 function wfIniGetBool( $setting ) {
2624         $val = strtolower( ini_get( $setting ) );
2625         // 'on' and 'true' can't have whitespace around them, but '1' can.
2626         return $val == 'on'
2627                 || $val == 'true'
2628                 || $val == 'yes'
2629                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2630 }
2631
2632 /**
2633  * Windows-compatible version of escapeshellarg()
2634  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2635  * function puts single quotes in regardless of OS.
2636  *
2637  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2638  * earlier distro releases of PHP)
2639  *
2640  * @param string ... strings to escape and glue together, or a single array of strings parameter
2641  * @return string
2642  */
2643 function wfEscapeShellArg( /*...*/ ) {
2644         wfInitShellLocale();
2645
2646         $args = func_get_args();
2647         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2648                 // If only one argument has been passed, and that argument is an array,
2649                 // treat it as a list of arguments
2650                 $args = reset( $args );
2651         }
2652
2653         $first = true;
2654         $retVal = '';
2655         foreach ( $args as $arg ) {
2656                 if ( !$first ) {
2657                         $retVal .= ' ';
2658                 } else {
2659                         $first = false;
2660                 }
2661
2662                 if ( wfIsWindows() ) {
2663                         // Escaping for an MSVC-style command line parser and CMD.EXE
2664                         // @codingStandardsIgnoreStart For long URLs
2665                         // Refs:
2666                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2667                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2668                         //  * Bug #13518
2669                         //  * CR r63214
2670                         // Double the backslashes before any double quotes. Escape the double quotes.
2671                         // @codingStandardsIgnoreEnd
2672                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2673                         $arg = '';
2674                         $iteration = 0;
2675                         foreach ( $tokens as $token ) {
2676                                 if ( $iteration % 2 == 1 ) {
2677                                         // Delimiter, a double quote preceded by zero or more slashes
2678                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2679                                 } elseif ( $iteration % 4 == 2 ) {
2680                                         // ^ in $token will be outside quotes, need to be escaped
2681                                         $arg .= str_replace( '^', '^^', $token );
2682                                 } else { // $iteration % 4 == 0
2683                                         // ^ in $token will appear inside double quotes, so leave as is
2684                                         $arg .= $token;
2685                                 }
2686                                 $iteration++;
2687                         }
2688                         // Double the backslashes before the end of the string, because
2689                         // we will soon add a quote
2690                         $m = array();
2691                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2692                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2693                         }
2694
2695                         // Add surrounding quotes
2696                         $retVal .= '"' . $arg . '"';
2697                 } else {
2698                         $retVal .= escapeshellarg( $arg );
2699                 }
2700         }
2701         return $retVal;
2702 }
2703
2704 /**
2705  * Check if wfShellExec() is effectively disabled via php.ini config
2706  *
2707  * @return bool|string False or one of (safemode,disabled)
2708  * @since 1.22
2709  */
2710 function wfShellExecDisabled() {
2711         static $disabled = null;
2712         if ( is_null( $disabled ) ) {
2713                 if ( wfIniGetBool( 'safe_mode' ) ) {
2714                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2715                         $disabled = 'safemode';
2716                 } elseif ( !function_exists( 'proc_open' ) ) {
2717                         wfDebug( "proc_open() is disabled\n" );
2718                         $disabled = 'disabled';
2719                 } else {
2720                         $disabled = false;
2721                 }
2722         }
2723         return $disabled;
2724 }
2725
2726 /**
2727  * Execute a shell command, with time and memory limits mirrored from the PHP
2728  * configuration if supported.
2729  *
2730  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2731  *   or an array of unescaped arguments, in which case each value will be escaped
2732  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2733  * @param null|mixed &$retval Optional, will receive the program's exit code.
2734  *   (non-zero is usually failure). If there is an error from
2735  *   read, select, or proc_open(), this will be set to -1.
2736  * @param array $environ Optional environment variables which should be
2737  *   added to the executed command environment.
2738  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2739  *   this overwrites the global wgMaxShell* limits.
2740  * @param array $options Array of options:
2741  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2742  *     including errors from limit.sh
2743  *   - profileMethod: By default this function will profile based on the calling
2744  *     method. Set this to a string for an alternative method to profile from
2745  *
2746  * @return string Collected stdout as a string
2747  */
2748 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2749         $limits = array(), $options = array()
2750 ) {
2751         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2752                 $wgMaxShellWallClockTime, $wgShellCgroup;
2753
2754         $disabled = wfShellExecDisabled();
2755         if ( $disabled ) {
2756                 $retval = 1;
2757                 return $disabled == 'safemode' ?
2758                         'Unable to run external programs in safe mode.' :
2759                         'Unable to run external programs, proc_open() is disabled.';
2760         }
2761
2762         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2763         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2764
2765         wfInitShellLocale();
2766
2767         $envcmd = '';
2768         foreach ( $environ as $k => $v ) {
2769                 if ( wfIsWindows() ) {
2770                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2771                          * appear in the environment variable, so we must use carat escaping as documented in
2772                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2773                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2774                          * are listed there but doesn't appear to need it.
2775                          */
2776                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2777                 } else {
2778                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2779                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2780                          */
2781                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2782                 }
2783         }
2784         if ( is_array( $cmd ) ) {
2785                 $cmd = wfEscapeShellArg( $cmd );
2786         }
2787
2788         $cmd = $envcmd . $cmd;
2789
2790         $useLogPipe = false;
2791         if ( is_executable( '/bin/bash' ) ) {
2792                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2793                 if ( isset( $limits['walltime'] ) ) {
2794                         $wallTime = intval( $limits['walltime'] );
2795                 } elseif ( isset( $limits['time'] ) ) {
2796                         $wallTime = $time;
2797                 } else {
2798                         $wallTime = intval( $wgMaxShellWallClockTime );
2799                 }
2800                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2801                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2802
2803                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2804                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2805                                 escapeshellarg( $cmd ) . ' ' .
2806                                 escapeshellarg(
2807                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2808                                         "MW_CPU_LIMIT=$time; " .
2809                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2810                                         "MW_MEM_LIMIT=$mem; " .
2811                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2812                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2813                                         "MW_USE_LOG_PIPE=yes"
2814                                 );
2815                         $useLogPipe = true;
2816                 } elseif ( $includeStderr ) {
2817                         $cmd .= ' 2>&1';
2818                 }
2819         } elseif ( $includeStderr ) {
2820                 $cmd .= ' 2>&1';
2821         }
2822         wfDebug( "wfShellExec: $cmd\n" );
2823
2824         $desc = array(
2825                 0 => array( 'file', 'php://stdin', 'r' ),
2826                 1 => array( 'pipe', 'w' ),
2827                 2 => array( 'file', 'php://stderr', 'w' ) );
2828         if ( $useLogPipe ) {
2829                 $desc[3] = array( 'pipe', 'w' );
2830         }
2831         $pipes = null;
2832         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2833         $proc = proc_open( $cmd, $desc, $pipes );
2834         if ( !$proc ) {
2835                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2836                 $retval = -1;
2837                 return '';
2838         }
2839         $outBuffer = $logBuffer = '';
2840         $emptyArray = array();
2841         $status = false;
2842         $logMsg = false;
2843
2844         // According to the documentation, it is possible for stream_select()
2845         // to fail due to EINTR. I haven't managed to induce this in testing
2846         // despite sending various signals. If it did happen, the error
2847         // message would take the form:
2848         //
2849         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2850         //
2851         // where [4] is the value of the macro EINTR and "Interrupted system
2852         // call" is string which according to the Linux manual is "possibly"
2853         // localised according to LC_MESSAGES.
2854         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2855         $eintrMessage = "stream_select(): unable to select [$eintr]";
2856
2857         // Build a table mapping resource IDs to pipe FDs to work around a
2858         // PHP 5.3 issue in which stream_select() does not preserve array keys
2859         // <https://bugs.php.net/bug.php?id=53427>.
2860         $fds = array();
2861         foreach ( $pipes as $fd => $pipe ) {
2862                 $fds[(int)$pipe] = $fd;
2863         }
2864
2865         $running = true;
2866         $timeout = null;
2867         $numReadyPipes = 0;
2868
2869         while ( $running === true || $numReadyPipes !== 0 ) {
2870                 if ( $running ) {
2871                         $status = proc_get_status( $proc );
2872                         // If the process has terminated, switch to nonblocking selects
2873                         // for getting any data still waiting to be read.
2874                         if ( !$status['running'] ) {
2875                                 $running = false;
2876                                 $timeout = 0;
2877                         }
2878                 }
2879
2880                 $readyPipes = $pipes;
2881
2882                 // Clear last error
2883                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2884                 @trigger_error( '' );
2885                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2886                 if ( $numReadyPipes === false ) {
2887                         // @codingStandardsIgnoreEnd
2888                         $error = error_get_last();
2889                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2890                                 continue;
2891                         } else {
2892                                 trigger_error( $error['message'], E_USER_WARNING );
2893                                 $logMsg = $error['message'];
2894                                 break;
2895                         }
2896                 }
2897                 foreach ( $readyPipes as $pipe ) {
2898                         $block = fread( $pipe, 65536 );
2899                         $fd = $fds[(int)$pipe];
2900                         if ( $block === '' ) {
2901                                 // End of file
2902                                 fclose( $pipes[$fd] );
2903                                 unset( $pipes[$fd] );
2904                                 if ( !$pipes ) {
2905                                         break 2;
2906                                 }
2907                         } elseif ( $block === false ) {
2908                                 // Read error
2909                                 $logMsg = "Error reading from pipe";
2910                                 break 2;
2911                         } elseif ( $fd == 1 ) {
2912                                 // From stdout
2913                                 $outBuffer .= $block;
2914                         } elseif ( $fd == 3 ) {
2915                                 // From log FD
2916                                 $logBuffer .= $block;
2917                                 if ( strpos( $block, "\n" ) !== false ) {
2918                                         $lines = explode( "\n", $logBuffer );
2919                                         $logBuffer = array_pop( $lines );
2920                                         foreach ( $lines as $line ) {
2921                                                 wfDebugLog( 'exec', $line );
2922                                         }
2923                                 }
2924                         }
2925                 }
2926         }
2927
2928         foreach ( $pipes as $pipe ) {
2929                 fclose( $pipe );
2930         }
2931
2932         // Use the status previously collected if possible, since proc_get_status()
2933         // just calls waitpid() which will not return anything useful the second time.
2934         if ( $running ) {
2935                 $status = proc_get_status( $proc );
2936         }
2937
2938         if ( $logMsg !== false ) {
2939                 // Read/select error
2940                 $retval = -1;
2941                 proc_close( $proc );
2942         } elseif ( $status['signaled'] ) {
2943                 $logMsg = "Exited with signal {$status['termsig']}";
2944                 $retval = 128 + $status['termsig'];
2945                 proc_close( $proc );
2946         } else {
2947                 if ( $status['running'] ) {
2948                         $retval = proc_close( $proc );
2949                 } else {
2950                         $retval = $status['exitcode'];
2951                         proc_close( $proc );
2952                 }
2953                 if ( $retval == 127 ) {
2954                         $logMsg = "Possibly missing executable file";
2955                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2956                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2957                 }
2958         }
2959
2960         if ( $logMsg !== false ) {
2961                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2962         }
2963
2964         return $outBuffer;
2965 }
2966
2967 /**
2968  * Execute a shell command, returning both stdout and stderr. Convenience
2969  * function, as all the arguments to wfShellExec can become unwieldy.
2970  *
2971  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2972  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2973  *   or an array of unescaped arguments, in which case each value will be escaped
2974  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2975  * @param null|mixed &$retval Optional, will receive the program's exit code.
2976  *   (non-zero is usually failure)
2977  * @param array $environ Optional environment variables which should be
2978  *   added to the executed command environment.
2979  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2980  *   this overwrites the global wgMaxShell* limits.
2981  * @return string Collected stdout and stderr as a string
2982  */
2983 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2984         return wfShellExec( $cmd, $retval, $environ, $limits,
2985                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2986 }
2987
2988 /**
2989  * Workaround for http://bugs.php.net/bug.php?id=45132
2990  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2991  */
2992 function wfInitShellLocale() {
2993         static $done = false;
2994         if ( $done ) {
2995                 return;
2996         }
2997         $done = true;
2998         global $wgShellLocale;
2999         if ( !wfIniGetBool( 'safe_mode' ) ) {
3000                 putenv( "LC_CTYPE=$wgShellLocale" );
3001                 setlocale( LC_CTYPE, $wgShellLocale );
3002         }
3003 }
3004
3005 /**
3006  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3007  * Note that $parameters should be a flat array and an option with an argument
3008  * should consist of two consecutive items in the array (do not use "--option value").
3009  *
3010  * @param string $script MediaWiki cli script path
3011  * @param array $parameters Arguments and options to the script
3012  * @param array $options Associative array of options:
3013  *              'php': The path to the php executable
3014  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3015  * @return string
3016  */
3017 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3018         global $wgPhpCli;
3019         // Give site config file a chance to run the script in a wrapper.
3020         // The caller may likely want to call wfBasename() on $script.
3021         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3022         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3023         if ( isset( $options['wrapper'] ) ) {
3024                 $cmd[] = $options['wrapper'];
3025         }
3026         $cmd[] = $script;
3027         // Escape each parameter for shell
3028         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
3029 }
3030
3031 /**
3032  * wfMerge attempts to merge differences between three texts.
3033  * Returns true for a clean merge and false for failure or a conflict.
3034  *
3035  * @param string $old
3036  * @param string $mine
3037  * @param string $yours
3038  * @param string $result
3039  * @return bool
3040  */
3041 function wfMerge( $old, $mine, $yours, &$result ) {
3042         global $wgDiff3;
3043
3044         # This check may also protect against code injection in
3045         # case of broken installations.
3046         wfSuppressWarnings();
3047         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3048         wfRestoreWarnings();
3049
3050         if ( !$haveDiff3 ) {
3051                 wfDebug( "diff3 not found\n" );
3052                 return false;
3053         }
3054
3055         # Make temporary files
3056         $td = wfTempDir();
3057         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3058         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3059         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3060
3061         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3062         #       a newline character. To avoid this, we normalize the trailing whitespace before
3063         #       creating the diff.
3064
3065         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3066         fclose( $oldtextFile );
3067         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3068         fclose( $mytextFile );
3069         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3070         fclose( $yourtextFile );
3071
3072         # Check for a conflict
3073         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
3074                 $oldtextName, $yourtextName );
3075         $handle = popen( $cmd, 'r' );
3076
3077         if ( fgets( $handle, 1024 ) ) {
3078                 $conflict = true;
3079         } else {
3080                 $conflict = false;
3081         }
3082         pclose( $handle );
3083
3084         # Merge differences
3085         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
3086                 $oldtextName, $yourtextName );
3087         $handle = popen( $cmd, 'r' );
3088         $result = '';
3089         do {
3090                 $data = fread( $handle, 8192 );
3091                 if ( strlen( $data ) == 0 ) {
3092                         break;
3093                 }
3094                 $result .= $data;
3095         } while ( true );
3096         pclose( $handle );
3097         unlink( $mytextName );
3098         unlink( $oldtextName );
3099         unlink( $yourtextName );
3100
3101         if ( $result === '' && $old !== '' && !$conflict ) {
3102                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3103                 $conflict = true;
3104         }
3105         return !$conflict;
3106 }
3107
3108 /**
3109  * Returns unified plain-text diff of two texts.
3110  * "Useful" for machine processing of diffs.
3111  *
3112  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3113  *
3114  * @param string $before The text before the changes.
3115  * @param string $after The text after the changes.
3116  * @param string $params Command-line options for the diff command.
3117  * @return string Unified diff of $before and $after
3118  */
3119 function wfDiff( $before, $after, $params = '-u' ) {
3120         if ( $before == $after ) {
3121                 return '';
3122         }
3123
3124         global $wgDiff;
3125         wfSuppressWarnings();
3126         $haveDiff = $wgDiff && file_exists( $wgDiff );
3127         wfRestoreWarnings();
3128
3129         # This check may also protect against code injection in
3130         # case of broken installations.
3131         if ( !$haveDiff ) {
3132                 wfDebug( "diff executable not found\n" );
3133                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3134                 $format = new UnifiedDiffFormatter();
3135                 return $format->format( $diffs );
3136         }
3137
3138         # Make temporary files
3139         $td = wfTempDir();
3140         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3141         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3142
3143         fwrite( $oldtextFile, $before );
3144         fclose( $oldtextFile );
3145         fwrite( $newtextFile, $after );
3146         fclose( $newtextFile );
3147
3148         // Get the diff of the two files
3149         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3150
3151         $h = popen( $cmd, 'r' );
3152         if ( !$h ) {
3153                 unlink( $oldtextName );
3154                 unlink( $newtextName );
3155                 throw new Exception( __METHOD__ . '(): popen() failed' );
3156         }
3157
3158         $diff = '';
3159
3160         do {
3161                 $data = fread( $h, 8192 );
3162                 if ( strlen( $data ) == 0 ) {
3163                         break;
3164                 }
3165                 $diff .= $data;
3166         } while ( true );
3167
3168         // Clean up
3169         pclose( $h );
3170         unlink( $oldtextName );
3171         unlink( $newtextName );
3172
3173         // Kill the --- and +++ lines. They're not useful.
3174         $diff_lines = explode( "\n", $diff );
3175         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3176                 unset( $diff_lines[0] );
3177         }
3178         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3179                 unset( $diff_lines[1] );
3180         }
3181
3182         $diff = implode( "\n", $diff_lines );
3183
3184         return $diff;
3185 }
3186
3187 /**
3188  * This function works like "use VERSION" in Perl, the program will die with a
3189  * backtrace if the current version of PHP is less than the version provided
3190  *
3191  * This is useful for extensions which due to their nature are not kept in sync
3192  * with releases, and might depend on other versions of PHP than the main code
3193  *
3194  * Note: PHP might die due to parsing errors in some cases before it ever
3195  *       manages to call this function, such is life
3196  *
3197  * @see perldoc -f use
3198  *
3199  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3200  * @throws MWException
3201  */
3202 function wfUsePHP( $req_ver ) {
3203         $php_ver = PHP_VERSION;
3204
3205         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3206                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3207         }
3208 }
3209
3210 /**
3211  * This function works like "use VERSION" in Perl except it checks the version
3212  * of MediaWiki, the program will die with a backtrace if the current version
3213  * of MediaWiki is less than the version provided.
3214  *
3215  * This is useful for extensions which due to their nature are not kept in sync
3216  * with releases
3217  *
3218  * Note: Due to the behavior of PHP's version_compare() which is used in this
3219  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3220  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3221  * targeted version number. For example if you wanted to allow any variation
3222  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3223  * not result in the same comparison due to the internal logic of
3224  * version_compare().
3225  *
3226  * @see perldoc -f use
3227  *
3228  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3229  * @throws MWException
3230  */
3231 function wfUseMW( $req_ver ) {
3232         global $wgVersion;
3233
3234         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3235                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3236         }
3237 }
3238
3239 /**
3240  * Return the final portion of a pathname.
3241  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3242  * http://bugs.php.net/bug.php?id=33898
3243  *
3244  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3245  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3246  *
3247  * @param string $path
3248  * @param string $suffix String to remove if present
3249  * @return string
3250  */
3251 function wfBaseName( $path, $suffix = '' ) {
3252         if ( $suffix == '' ) {
3253                 $encSuffix = '';
3254         } else {
3255                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3256         }
3257
3258         $matches = array();
3259         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3260                 return $matches[1];
3261         } else {
3262                 return '';
3263         }
3264 }
3265
3266 /**
3267  * Generate a relative path name to the given file.
3268  * May explode on non-matching case-insensitive paths,
3269  * funky symlinks, etc.
3270  *
3271  * @param string $path Absolute destination path including target filename
3272  * @param string $from Absolute source path, directory only
3273  * @return string
3274  */
3275 function wfRelativePath( $path, $from ) {
3276         // Normalize mixed input on Windows...
3277         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3278         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3279
3280         // Trim trailing slashes -- fix for drive root
3281         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3282         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3283
3284         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3285         $against = explode( DIRECTORY_SEPARATOR, $from );
3286
3287         if ( $pieces[0] !== $against[0] ) {
3288                 // Non-matching Windows drive letters?
3289                 // Return a full path.
3290                 return $path;
3291         }
3292
3293         // Trim off common prefix
3294         while ( count( $pieces ) && count( $against )
3295                 && $pieces[0] == $against[0] ) {
3296                 array_shift( $pieces );
3297                 array_shift( $against );
3298         }
3299
3300         // relative dots to bump us to the parent
3301         while ( count( $against ) ) {
3302                 array_unshift( $pieces, '..' );
3303                 array_shift( $against );
3304         }
3305
3306         array_push( $pieces, wfBaseName( $path ) );
3307
3308         return implode( DIRECTORY_SEPARATOR, $pieces );
3309 }
3310
3311 /**
3312  * Convert an arbitrarily-long digit string from one numeric base
3313  * to another, optionally zero-padding to a minimum column width.
3314  *
3315  * Supports base 2 through 36; digit values 10-36 are represented
3316  * as lowercase letters a-z. Input is case-insensitive.
3317  *
3318  * @param string $input Input number
3319  * @param int $sourceBase Base of the input number
3320  * @param int $destBase Desired base of the output
3321  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3322  * @param bool $lowercase Whether to output in lowercase or uppercase
3323  * @param string $engine Either "gmp", "bcmath", or "php"
3324  * @return string|bool The output number as a string, or false on error
3325  */
3326 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3327         $lowercase = true, $engine = 'auto'
3328 ) {
3329         $input = (string)$input;
3330         if (
3331                 $sourceBase < 2 ||
3332                 $sourceBase > 36 ||
3333                 $destBase < 2 ||
3334                 $destBase > 36 ||
3335                 $sourceBase != (int)$sourceBase ||
3336                 $destBase != (int)$destBase ||
3337                 $pad != (int)$pad ||
3338                 !preg_match(
3339                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3340                         $input
3341                 )
3342         ) {
3343                 return false;
3344         }
3345
3346         static $baseChars = array(
3347                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3348                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3349                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3350                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3351                 34 => 'y', 35 => 'z',
3352
3353                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3354                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3355                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3356                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3357                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3358                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3359         );
3360
3361         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3362                 // Removing leading zeros works around broken base detection code in
3363                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3364                 // <https://bugs.php.net/bug.php?id=55398>).
3365                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ), $sourceBase ), $destBase );
3366         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3367                 $decimal = '0';
3368                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3369                         $decimal = bcmul( $decimal, $sourceBase );
3370                         $decimal = bcadd( $decimal, $baseChars[$char] );
3371                 }
3372
3373                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3374                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3375                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3376                 }
3377                 // @codingStandardsIgnoreEnd
3378
3379                 $result = strrev( $result );
3380         } else {
3381                 $inDigits = array();
3382                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3383                         $inDigits[] = $baseChars[$char];
3384                 }
3385
3386                 // Iterate over the input, modulo-ing out an output digit
3387                 // at a time until input is gone.
3388                 $result = '';
3389                 while ( $inDigits ) {
3390                         $work = 0;
3391                         $workDigits = array();
3392
3393                         // Long division...
3394                         foreach ( $inDigits as $digit ) {
3395                                 $work *= $sourceBase;
3396                                 $work += $digit;
3397
3398                                 if ( $workDigits || $work >= $destBase ) {
3399                                         $workDigits[] = (int)( $work / $destBase );
3400                                 }
3401                                 $work %= $destBase;
3402                         }
3403
3404                         // All that division leaves us with a remainder,
3405                         // which is conveniently our next output digit.
3406                         $result .= $baseChars[$work];
3407
3408                         // And we continue!
3409                         $inDigits = $workDigits;
3410                 }
3411
3412                 $result = strrev( $result );
3413         }
3414
3415         if ( !$lowercase ) {
3416                 $result = strtoupper( $result );
3417         }
3418
3419         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3420 }
3421
3422 /**
3423  * Check if there is sufficient entropy in php's built-in session generation
3424  *
3425  * @return bool True = there is sufficient entropy
3426  */
3427 function wfCheckEntropy() {
3428         return (
3429                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3430                         || ini_get( 'session.entropy_file' )
3431                 )
3432                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3433 }
3434
3435 /**
3436  * Override session_id before session startup if php's built-in
3437  * session generation code is not secure.
3438  */
3439 function wfFixSessionID() {
3440         // If the cookie or session id is already set we already have a session and should abort
3441         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3442                 return;
3443         }
3444
3445         // PHP's built-in session entropy is enabled if:
3446         // - entropy_file is set or you're on Windows with php 5.3.3+
3447         // - AND entropy_length is > 0
3448         // We treat it as disabled if it doesn't have an entropy length of at least 32
3449         $entropyEnabled = wfCheckEntropy();
3450
3451         // If built-in entropy is not enabled or not sufficient override PHP's
3452         // built in session id generation code
3453         if ( !$entropyEnabled ) {
3454                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3455                         "overriding session id generation using our cryptrand source.\n" );
3456                 session_id( MWCryptRand::generateHex( 32 ) );
3457         }
3458 }
3459
3460 /**
3461  * Reset the session_id
3462  *
3463  * @since 1.22
3464  */
3465 function wfResetSessionID() {
3466         global $wgCookieSecure;
3467         $oldSessionId = session_id();
3468         $cookieParams = session_get_cookie_params();
3469         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3470                 session_regenerate_id( false );
3471         } else {
3472                 $tmp = $_SESSION;
3473                 session_destroy();
3474                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3475                 $_SESSION = $tmp;
3476         }
3477         $newSessionId = session_id();
3478         Hooks::run( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3479 }
3480
3481 /**
3482  * Initialise php session
3483  *
3484  * @param bool $sessionId
3485  */
3486 function wfSetupSession( $sessionId = false ) {
3487         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3488                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3489         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3490                 ObjectCacheSessionHandler::install();
3491         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3492                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3493                 # hasn't already been set to the desired value (that causes errors)
3494                 ini_set( 'session.save_handler', $wgSessionHandler );
3495         }
3496         session_set_cookie_params(
3497                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3498         session_cache_limiter( 'private, must-revalidate' );
3499         if ( $sessionId ) {
3500                 session_id( $sessionId );
3501         } else {
3502                 wfFixSessionID();
3503         }
3504         wfSuppressWarnings();
3505         session_start();
3506         wfRestoreWarnings();
3507 }
3508
3509 /**
3510  * Get an object from the precompiled serialized directory
3511  *
3512  * @param string $name
3513  * @return mixed The variable on success, false on failure
3514  */
3515 function wfGetPrecompiledData( $name ) {
3516         global $IP;
3517
3518         $file = "$IP/serialized/$name";
3519         if ( file_exists( $file ) ) {
3520                 $blob = file_get_contents( $file );
3521                 if ( $blob ) {
3522                         return unserialize( $blob );
3523                 }
3524         }
3525         return false;
3526 }
3527
3528 /**
3529  * Get a cache key
3530  *
3531  * @param string $args,...
3532  * @return string
3533  */
3534 function wfMemcKey( /*...*/ ) {
3535         global $wgCachePrefix;
3536         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3537         $args = func_get_args();
3538         $key = $prefix . ':' . implode( ':', $args );
3539         $key = str_replace( ' ', '_', $key );
3540         return $key;
3541 }
3542
3543 /**
3544  * Get a cache key for a foreign DB
3545  *
3546  * @param string $db
3547  * @param string $prefix
3548  * @param string $args,...
3549  * @return string
3550  */
3551 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3552         $args = array_slice( func_get_args(), 2 );
3553         if ( $prefix ) {
3554                 $key = "$db-$prefix:" . implode( ':', $args );
3555         } else {
3556                 $key = $db . ':' . implode( ':', $args );
3557         }
3558         return str_replace( ' ', '_', $key );
3559 }
3560
3561 /**
3562  * Get an ASCII string identifying this wiki
3563  * This is used as a prefix in memcached keys
3564  *
3565  * @return string
3566  */
3567 function wfWikiID() {
3568         global $wgDBprefix, $wgDBname;
3569         if ( $wgDBprefix ) {
3570                 return "$wgDBname-$wgDBprefix";
3571         } else {
3572                 return $wgDBname;
3573         }
3574 }
3575
3576 /**
3577  * Split a wiki ID into DB name and table prefix
3578  *
3579  * @param string $wiki
3580  *
3581  * @return array
3582  */
3583 function wfSplitWikiID( $wiki ) {
3584         $bits = explode( '-', $wiki, 2 );
3585         if ( count( $bits ) < 2 ) {
3586                 $bits[] = '';
3587         }
3588         return $bits;
3589 }
3590
3591 /**
3592  * Get a Database object.
3593  *
3594  * @param int $db Index of the connection to get. May be DB_MASTER for the
3595  *            master (for write queries), DB_SLAVE for potentially lagged read
3596  *            queries, or an integer >= 0 for a particular server.
3597  *
3598  * @param string|string[] $groups Query groups. An array of group names that this query
3599  *                belongs to. May contain a single string if the query is only
3600  *                in one group.
3601  *
3602  * @param string|bool $wiki The wiki ID, or false for the current wiki
3603  *
3604  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3605  * will always return the same object, unless the underlying connection or load
3606  * balancer is manually destroyed.
3607  *
3608  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3609  * updater to ensure that a proper database is being updated.
3610  *
3611  * @return DatabaseBase
3612  */
3613 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3614         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3615 }
3616
3617 /**
3618  * Get a load balancer object.
3619  *
3620  * @param string|bool $wiki Wiki ID, or false for the current wiki
3621  * @return LoadBalancer
3622  */
3623 function wfGetLB( $wiki = false ) {
3624         return wfGetLBFactory()->getMainLB( $wiki );
3625 }
3626
3627 /**
3628  * Get the load balancer factory object
3629  *
3630  * @return LBFactory
3631  */
3632 function wfGetLBFactory() {
3633         return LBFactory::singleton();
3634 }
3635
3636 /**
3637  * Find a file.
3638  * Shortcut for RepoGroup::singleton()->findFile()
3639  *
3640  * @param string $title String or Title object
3641  * @param array $options Associative array of options (see RepoGroup::findFile)
3642  * @return File|bool File, or false if the file does not exist
3643  */
3644 function wfFindFile( $title, $options = array() ) {
3645         return RepoGroup::singleton()->findFile( $title, $options );
3646 }
3647
3648 /**
3649  * Get an object referring to a locally registered file.
3650  * Returns a valid placeholder object if the file does not exist.
3651  *
3652  * @param Title|string $title
3653  * @return LocalFile|null A File, or null if passed an invalid Title
3654  */
3655 function wfLocalFile( $title ) {
3656         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3657 }
3658
3659 /**
3660  * Should low-performance queries be disabled?
3661  *
3662  * @return bool
3663  * @codeCoverageIgnore
3664  */
3665 function wfQueriesMustScale() {
3666         global $wgMiserMode;
3667         return $wgMiserMode
3668                 || ( SiteStats::pages() > 100000
3669                 && SiteStats::edits() > 1000000
3670                 && SiteStats::users() > 10000 );
3671 }
3672
3673 /**
3674  * Get the path to a specified script file, respecting file
3675  * extensions; this is a wrapper around $wgScriptExtension etc.
3676  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3677  *
3678  * @param string $script Script filename, sans extension
3679  * @return string
3680  */
3681 function wfScript( $script = 'index' ) {
3682         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3683         if ( $script === 'index' ) {
3684                 return $wgScript;
3685         } elseif ( $script === 'load' ) {
3686                 return $wgLoadScript;
3687         } else {
3688                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3689         }
3690 }
3691
3692 /**
3693  * Get the script URL.
3694  *
3695  * @return string Script URL
3696  */
3697 function wfGetScriptUrl() {
3698         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3699                 #
3700                 # as it was called, minus the query string.
3701                 #
3702                 # Some sites use Apache rewrite rules to handle subdomains,
3703                 # and have PHP set up in a weird way that causes PHP_SELF
3704                 # to contain the rewritten URL instead of the one that the
3705                 # outside world sees.
3706                 #
3707                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3708                 # provides containing the "before" URL.
3709                 return $_SERVER['SCRIPT_NAME'];
3710         } else {
3711                 return $_SERVER['URL'];
3712         }
3713 }
3714
3715 /**
3716  * Convenience function converts boolean values into "true"
3717  * or "false" (string) values
3718  *
3719  * @param bool $value
3720  * @return string
3721  */
3722 function wfBoolToStr( $value ) {
3723         return $value ? 'true' : 'false';
3724 }
3725
3726 /**
3727  * Get a platform-independent path to the null file, e.g. /dev/null
3728  *
3729  * @return string
3730  */
3731 function wfGetNull() {
3732         return wfIsWindows() ? 'NUL' : '/dev/null';
3733 }
3734
3735 /**
3736  * Waits for the slaves to catch up to the master position
3737  *
3738  * Use this when updating very large numbers of rows, as in maintenance scripts,
3739  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3740  *
3741  * By default this waits on the main DB cluster of the current wiki.
3742  * If $cluster is set to "*" it will wait on all DB clusters, including
3743  * external ones. If the lag being waiting on is caused by the code that
3744  * does this check, it makes since to use $ifWritesSince, particularly if
3745  * cluster is "*", to avoid excess overhead.
3746  *
3747  * Never call this function after a big DB write that is still in a transaction.
3748  * This only makes sense after the possible lag inducing changes were committed.
3749  *
3750  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3751  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3752  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3753  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3754  * @return bool Success (able to connect and no timeouts reached)
3755  */
3756 function wfWaitForSlaves(
3757         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3758 ) {
3759         // B/C: first argument used to be "max seconds of lag"; ignore such values
3760         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3761
3762         if ( $timeout === null ) {
3763                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3764         }
3765
3766         // Figure out which clusters need to be checked
3767         $lbs = array();
3768         if ( $cluster === '*' ) {
3769                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3770                         $lbs[] = $lb;
3771                 } );
3772         } elseif ( $cluster !== false ) {
3773                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3774         } else {
3775                 $lbs[] = wfGetLB( $wiki );
3776         }
3777
3778         // Get all the master positions of applicable DBs right now.
3779         // This can be faster since waiting on one cluster reduces the
3780         // time needed to wait on the next clusters.
3781         $masterPositions = array_fill( 0, count( $lbs ), false );
3782         foreach ( $lbs as $i => $lb ) {
3783                 // bug 27975 - Don't try to wait for slaves if there are none
3784                 // Prevents permission error when getting master position
3785                 if ( $lb->getServerCount() > 1 ) {
3786                         if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
3787                                 continue; // assume no writes done
3788                         }
3789                         // Use the empty string to not trigger selectDB() since the connection
3790                         // may have been to a server that does not have a DB for the current wiki.
3791                         $dbw = $lb->getConnection( DB_MASTER, array(), '' );
3792                         if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
3793                                 continue; // no writes since the last wait
3794                         }
3795                         $masterPositions[$i] = $dbw->getMasterPos();
3796                 }
3797         }
3798
3799         $ok = true;
3800         foreach ( $lbs as $i => $lb ) {
3801                 if ( $masterPositions[$i] ) {
3802                         // The DBMS may not support getMasterPos() or the whole
3803                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3804                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3805                 }
3806         }
3807
3808         return $ok;
3809 }
3810
3811 /**
3812  * Count down from $seconds to zero on the terminal, with a one-second pause
3813  * between showing each number. For use in command-line scripts.
3814  *
3815  * @codeCoverageIgnore
3816  * @param int $seconds
3817  */
3818 function wfCountDown( $seconds ) {
3819         for ( $i = $seconds; $i >= 0; $i-- ) {
3820                 if ( $i != $seconds ) {
3821                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3822                 }
3823                 echo $i;
3824                 flush();
3825                 if ( $i ) {
3826                         sleep( 1 );
3827                 }
3828         }
3829         echo "\n";
3830 }
3831
3832 /**
3833  * Replace all invalid characters with -
3834  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3835  * By default, $wgIllegalFileChars = ':'
3836  *
3837  * @param string $name Filename to process
3838  * @return string
3839  */
3840 function wfStripIllegalFilenameChars( $name ) {
3841         global $wgIllegalFileChars;
3842         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3843         $name = wfBaseName( $name );
3844         $name = preg_replace(
3845                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3846                 '-',
3847                 $name
3848         );
3849         return $name;
3850 }
3851
3852 /**
3853  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3854  *
3855  * @return int Value the memory limit was set to.
3856  */
3857 function wfMemoryLimit() {
3858         global $wgMemoryLimit;
3859         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3860         if ( $memlimit != -1 ) {
3861                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3862                 if ( $conflimit == -1 ) {
3863                         wfDebug( "Removing PHP's memory limit\n" );
3864                         wfSuppressWarnings();
3865                         ini_set( 'memory_limit', $conflimit );
3866                         wfRestoreWarnings();
3867                         return $conflimit;
3868                 } elseif ( $conflimit > $memlimit ) {
3869                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3870                         wfSuppressWarnings();
3871                         ini_set( 'memory_limit', $conflimit );
3872                         wfRestoreWarnings();
3873                         return $conflimit;
3874                 }
3875         }
3876         return $memlimit;
3877 }
3878
3879 /**
3880  * Converts shorthand byte notation to integer form
3881  *
3882  * @param string $string
3883  * @return int
3884  */
3885 function wfShorthandToInteger( $string = '' ) {
3886         $string = trim( $string );
3887         if ( $string === '' ) {
3888                 return -1;
3889         }
3890         $last = $string[strlen( $string ) - 1];
3891         $val = intval( $string );
3892         switch ( $last ) {
3893                 case 'g':
3894                 case 'G':
3895                         $val *= 1024;
3896                         // break intentionally missing
3897                 case 'm':
3898                 case 'M':
3899                         $val *= 1024;
3900                         // break intentionally missing
3901                 case 'k':
3902                 case 'K':
3903                         $val *= 1024;
3904         }
3905
3906         return $val;
3907 }
3908
3909 /**
3910  * Get the normalised IETF language tag
3911  * See unit test for examples.
3912  *
3913  * @param string $code The language code.
3914  * @return string The language code which complying with BCP 47 standards.
3915  */
3916 function wfBCP47( $code ) {
3917         $codeSegment = explode( '-', $code );
3918         $codeBCP = array();
3919         foreach ( $codeSegment as $segNo => $seg ) {
3920                 // when previous segment is x, it is a private segment and should be lc
3921                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3922                         $codeBCP[$segNo] = strtolower( $seg );
3923                 // ISO 3166 country code
3924                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3925                         $codeBCP[$segNo] = strtoupper( $seg );
3926                 // ISO 15924 script code
3927                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3928                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3929                 // Use lowercase for other cases
3930                 } else {
3931                         $codeBCP[$segNo] = strtolower( $seg );
3932                 }
3933         }
3934         $langCode = implode( '-', $codeBCP );
3935         return $langCode;
3936 }
3937
3938 /**
3939  * Get a cache object.
3940  *
3941  * @param int $inputType Cache type, one of the CACHE_* constants.
3942  * @return BagOStuff
3943  */
3944 function wfGetCache( $inputType ) {
3945         return ObjectCache::getInstance( $inputType );
3946 }
3947
3948 /**
3949  * Get the main cache object
3950  *
3951  * @return BagOStuff
3952  */
3953 function wfGetMainCache() {
3954         global $wgMainCacheType;
3955         return ObjectCache::getInstance( $wgMainCacheType );
3956 }
3957
3958 /**
3959  * Get the cache object used by the message cache
3960  *
3961  * @return BagOStuff
3962  */
3963 function wfGetMessageCacheStorage() {
3964         global $wgMessageCacheType;
3965         return ObjectCache::getInstance( $wgMessageCacheType );
3966 }
3967
3968 /**
3969  * Get the cache object used by the parser cache
3970  *
3971  * @return BagOStuff
3972  */
3973 function wfGetParserCacheStorage() {
3974         global $wgParserCacheType;
3975         return ObjectCache::getInstance( $wgParserCacheType );
3976 }
3977
3978 /**
3979  * Call hook functions defined in $wgHooks
3980  *
3981  * @param string $event Event name
3982  * @param array $args Parameters passed to hook functions
3983  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3984  *
3985  * @return bool True if no handler aborted the hook
3986  * @deprecated 1.25 - use Hooks::run
3987  */
3988 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3989         return Hooks::run( $event, $args, $deprecatedVersion );
3990 }
3991
3992 /**
3993  * Wrapper around php's unpack.
3994  *
3995  * @param string $format The format string (See php's docs)
3996  * @param string $data A binary string of binary data
3997  * @param int|bool $length The minimum length of $data or false. This is to
3998  *      prevent reading beyond the end of $data. false to disable the check.
3999  *
4000  * Also be careful when using this function to read unsigned 32 bit integer
4001  * because php might make it negative.
4002  *
4003  * @throws MWException If $data not long enough, or if unpack fails
4004  * @return array Associative array of the extracted data
4005  */
4006 function wfUnpack( $format, $data, $length = false ) {
4007         if ( $length !== false ) {
4008                 $realLen = strlen( $data );
4009                 if ( $realLen < $length ) {
4010                         throw new MWException( "Tried to use wfUnpack on a "
4011                                 . "string of length $realLen, but needed one "
4012                                 . "of at least length $length."
4013                         );
4014                 }
4015         }
4016
4017         wfSuppressWarnings();
4018         $result = unpack( $format, $data );
4019         wfRestoreWarnings();
4020
4021         if ( $result === false ) {
4022                 // If it cannot extract the packed data.
4023                 throw new MWException( "unpack could not unpack binary data" );
4024         }
4025         return $result;
4026 }
4027
4028 /**
4029  * Determine if an image exists on the 'bad image list'.
4030  *
4031  * The format of MediaWiki:Bad_image_list is as follows:
4032  *    * Only list items (lines starting with "*") are considered
4033  *    * The first link on a line must be a link to a bad image
4034  *    * Any subsequent links on the same line are considered to be exceptions,
4035  *      i.e. articles where the image may occur inline.
4036  *
4037  * @param string $name The image name to check
4038  * @param Title|bool $contextTitle The page on which the image occurs, if known
4039  * @param string $blacklist Wikitext of a file blacklist
4040  * @return bool
4041  */
4042 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4043         static $badImageCache = null; // based on bad_image_list msg
4044
4045         # Handle redirects
4046         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4047         if ( $redirectTitle ) {
4048                 $name = $redirectTitle->getDBkey();
4049         }
4050
4051         # Run the extension hook
4052         $bad = false;
4053         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4054                 return $bad;
4055         }
4056
4057         $cacheable = ( $blacklist === null );
4058         if ( $cacheable && $badImageCache !== null ) {
4059                 $badImages = $badImageCache;
4060         } else { // cache miss
4061                 if ( $blacklist === null ) {
4062                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4063                 }
4064                 # Build the list now
4065                 $badImages = array();
4066                 $lines = explode( "\n", $blacklist );
4067                 foreach ( $lines as $line ) {
4068                         # List items only
4069                         if ( substr( $line, 0, 1 ) !== '*' ) {
4070                                 continue;
4071                         }
4072
4073                         # Find all links
4074                         $m = array();
4075                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4076                                 continue;
4077                         }
4078
4079                         $exceptions = array();
4080                         $imageDBkey = false;
4081                         foreach ( $m[1] as $i => $titleText ) {
4082                                 $title = Title::newFromText( $titleText );
4083                                 if ( !is_null( $title ) ) {
4084                                         if ( $i == 0 ) {
4085                                                 $imageDBkey = $title->getDBkey();
4086                                         } else {
4087                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4088                                         }
4089                                 }
4090                         }
4091
4092                         if ( $imageDBkey !== false ) {
4093                                 $badImages[$imageDBkey] = $exceptions;
4094                         }
4095                 }
4096                 if ( $cacheable ) {
4097                         $badImageCache = $badImages;
4098                 }
4099         }
4100
4101         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4102         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4103         return $bad;
4104 }
4105
4106 /**
4107  * Determine whether the client at a given source IP is likely to be able to
4108  * access the wiki via HTTPS.
4109  *
4110  * @param string $ip The IPv4/6 address in the normal human-readable form
4111  * @return bool
4112  */
4113 function wfCanIPUseHTTPS( $ip ) {
4114         $canDo = true;
4115         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4116         return !!$canDo;
4117 }
4118
4119 /**
4120  * Determine input string is represents as infinity
4121  *
4122  * @param string $str The string to determine
4123  * @return bool
4124  * @since 1.25
4125  */
4126 function wfIsInfinity( $str ) {
4127         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4128         return in_array( $str, $infinityValues );
4129 }
4130
4131 /**
4132  * Work out the IP address based on various globals
4133  * For trusted proxies, use the XFF client IP (first of the chain)
4134  *
4135  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4136  * @return string
4137  */
4138 function wfGetIP() {
4139         wfDeprecated( __METHOD__, '1.19' );
4140         global $wgRequest;
4141         return $wgRequest->getIP();
4142 }
4143
4144 /**
4145  * Checks if an IP is a trusted proxy provider.
4146  * Useful to tell if X-Forwarded-For data is possibly bogus.
4147  * Squid cache servers for the site are whitelisted.
4148  * @deprecated Since 1.24, use IP::isTrustedProxy()
4149  *
4150  * @param string $ip
4151  * @return bool
4152  */
4153 function wfIsTrustedProxy( $ip ) {
4154         wfDeprecated( __METHOD__, '1.24' );
4155         return IP::isTrustedProxy( $ip );
4156 }
4157
4158 /**
4159  * Checks if an IP matches a proxy we've configured.
4160  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4161  *
4162  * @param string $ip
4163  * @return bool
4164  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4165  */
4166 function wfIsConfiguredProxy( $ip ) {
4167         wfDeprecated( __METHOD__, '1.24' );
4168         return IP::isConfiguredProxy( $ip );
4169 }
4170
4171 /**
4172  * Returns true if these thumbnail parameters match one that MediaWiki
4173  * requests from file description pages and/or parser output.
4174  *
4175  * $params is considered non-standard if they involve a non-standard
4176  * width or any non-default parameters aside from width and page number.
4177  * The number of possible files with standard parameters is far less than
4178  * that of all combinations; rate-limiting for them can thus be more generious.
4179  *
4180  * @param File $file
4181  * @param array $params
4182  * @return bool
4183  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4184  */
4185 function wfThumbIsStandard( File $file, array $params ) {
4186         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4187
4188         $multipliers = array( 1 );
4189         if ( $wgResponsiveImages ) {
4190                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4191                 // @see Linker::processResponsiveImages
4192                 $multipliers[] = 1.5;
4193                 $multipliers[] = 2;
4194         }
4195
4196         $handler = $file->getHandler();
4197         if ( !$handler || !isset( $params['width'] ) ) {
4198                 return false;
4199         }
4200
4201         $basicParams = array();
4202         if ( isset( $params['page'] ) ) {
4203                 $basicParams['page'] = $params['page'];
4204         }
4205
4206         $thumbLimits = array();
4207         $imageLimits = array();
4208         // Expand limits to account for multipliers
4209         foreach ( $multipliers as $multiplier ) {
4210                 $thumbLimits = array_merge( $thumbLimits, array_map(
4211                         function ( $width ) use ( $multiplier ) {
4212                                 return round( $width * $multiplier );
4213                         }, $wgThumbLimits )
4214                 );
4215                 $imageLimits = array_merge( $imageLimits, array_map(
4216                         function ( $pair ) use ( $multiplier ) {
4217                                 return array(
4218                                         round( $pair[0] * $multiplier ),
4219                                         round( $pair[1] * $multiplier ),
4220                                 );
4221                         }, $wgImageLimits )
4222                 );
4223         }
4224
4225         // Check if the width matches one of $wgThumbLimits
4226         if ( in_array( $params['width'], $thumbLimits ) ) {
4227                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4228                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4229                 $handler->normaliseParams( $file, $normalParams );
4230         } else {
4231                 // If not, then check if the width matchs one of $wgImageLimits
4232                 $match = false;
4233                 foreach ( $imageLimits as $pair ) {
4234                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4235                         // Decide whether the thumbnail should be scaled on width or height.
4236                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4237                         $handler->normaliseParams( $file, $normalParams );
4238                         // Check if this standard thumbnail size maps to the given width
4239                         if ( $normalParams['width'] == $params['width'] ) {
4240                                 $match = true;
4241                                 break;
4242                         }
4243                 }
4244                 if ( !$match ) {
4245                         return false; // not standard for description pages
4246                 }
4247         }
4248
4249         // Check that the given values for non-page, non-width, params are just defaults
4250         foreach ( $params as $key => $value ) {
4251                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4252                         return false;
4253                 }
4254         }
4255
4256         return true;
4257 }