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
  30 // Hide compatibility functions from Doxygen
  31 /// @cond
  32
  33 /**
  34  * Compatibility functions
  35  *
  36  * We support PHP 5.3.3 and up.
  37  * Re-implementations of newer functions or functions in non-standard
  38  * PHP extensions may be included here.
  39  */
  40
  41 if ( !function_exists( 'mb_substr' ) ) {
  42         /**
  43          * @codeCoverageIgnore
  44          * @see Fallback::mb_substr
  45          * @return string
  46          */
  47         function mb_substr( $str, $start, $count = 'end' ) {
  48                 return Fallback::mb_substr( $str, $start, $count );
  49         }
  50
  51         /**
  52          * @codeCoverageIgnore
  53          * @see Fallback::mb_substr_split_unicode
  54          * @return int
  55          */
  56         function mb_substr_split_unicode( $str, $splitPos ) {
  57                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  58         }
  59 }
  60
  61 if ( !function_exists( 'mb_strlen' ) ) {
  62         /**
  63          * @codeCoverageIgnore
  64          * @see Fallback::mb_strlen
  65          * @return int
  66          */
  67         function mb_strlen( $str, $enc = '' ) {
  68                 return Fallback::mb_strlen( $str, $enc );
  69         }
  70 }
  71
  72 if ( !function_exists( 'mb_strpos' ) ) {
  73         /**
  74          * @codeCoverageIgnore
  75          * @see Fallback::mb_strpos
  76          * @return int
  77          */
  78         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  79                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  80         }
  81 }
  82
  83 if ( !function_exists( 'mb_strrpos' ) ) {
  84         /**
  85          * @codeCoverageIgnore
  86          * @see Fallback::mb_strrpos
  87          * @return int
  88          */
  89         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  90                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  91         }
  92 }
  93
  94 // gzdecode function only exists in PHP >= 5.4.0
  95 // http://php.net/gzdecode
  96 if ( !function_exists( 'gzdecode' ) ) {
  97         /**
  98          * @codeCoverageIgnore
  99          * @param string $data
 100          * @return string
 101          */
 102         function gzdecode( $data ) {
 103                 return gzinflate( substr( $data, 10, -8 ) );
 104         }
 105 }
 106
 107 // hash_equals function only exists in PHP >= 5.6.0
 108 // http://php.net/hash_equals
 109 if ( !function_exists( 'hash_equals' ) ) {
 110         /**
 111          * Check whether a user-provided string is equal to a fixed-length secret string
 112          * without revealing bytes of the secret string through timing differences.
 113          *
 114          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 115          * function in C) is to compare corresponding bytes and stop at the first difference,
 116          * which would take longer for a partial match than for a complete mismatch. This
 117          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 118          * and the other may come from an attacker. Statistical analysis of timing measurements
 119          * over many requests may allow the attacker to guess the string's bytes one at a time
 120          * (and check his guesses) even if the timing differences are extremely small.
 121          *
 122          * When making such a security-sensitive comparison, it is essential that the sequence
 123          * in which instructions are executed and memory locations are accessed not depend on
 124          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 125          * the inevitable leakage of the string's length. That is generally known anyway as
 126          * a chararacteristic of the hash function used to compute the secret value.
 127          *
 128          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 129          *
 130          * @codeCoverageIgnore
 131          * @param string $known_string Fixed-length secret string to compare against
 132          * @param string $user_string User-provided string
 133          * @return bool True if the strings are the same, false otherwise
 134          */
 135         function hash_equals( $known_string, $user_string ) {
 136                 // Strict type checking as in PHP's native implementation
 137                 if ( !is_string( $known_string ) ) {
 138                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 139                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 140
 141                         return false;
 142                 }
 143
 144                 if ( !is_string( $user_string ) ) {
 145                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 146                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 147
 148                         return false;
 149                 }
 150
 151                 $known_string_len = strlen( $known_string );
 152                 if ( $known_string_len !== strlen( $user_string ) ) {
 153                         return false;
 154                 }
 155
 156                 $result = 0;
 157                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 158                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 159                 }
 160
 161                 return ( $result === 0 );
 162         }
 163 }
 164 /// @endcond
 165
 166 /**
 167  * Load an extension
 168  *
 169  * This queues an extension to be loaded through
 170  * the ExtensionRegistry system.
 171  *
 172  * @param string $name Name of the extension to load
 173  * @param string|null $path Absolute path of where to find the extension.json file
 174  */
 175 function wfLoadExtension( $name, $path = null ) {
 176         if ( !$path ) {
 177                 global $IP;
 178                 $path = "$IP/extensions/$name/extension.json";
 179         }
 180         ExtensionRegistry::getInstance()->queue( $path );
 181 }
 182
 183 /**
 184  * Load multiple extensions at once
 185  *
 186  * Same as wfLoadExtension, but more efficient if you
 187  * are loading multiple extensions.
 188  *
 189  * If you want to specify custom paths, you should interact with
 190  * ExtensionRegistry directly.
 191  *
 192  * @see wfLoadExtension
 193  * @param string[] $exts Array of extension names to load
 194  */
 195 function wfLoadExtensions( array $exts ) {
 196         global $IP;
 197         $registry = ExtensionRegistry::getInstance();
 198         foreach ( $exts as $ext ) {
 199                 $registry->queue( "$IP/extensions/$ext/extension.json" );
 200         }
 201 }
 202
 203 /**
 204  * Load a skin
 205  *
 206  * @see wfLoadExtension
 207  * @param string $name Name of the extension to load
 208  * @param string|null $path Absolute path of where to find the skin.json file
 209  */
 210 function wfLoadSkin( $name, $path = null ) {
 211         if ( !$path ) {
 212                 global $IP;
 213                 $path = "$IP/skins/$name/skin.json";
 214         }
 215         ExtensionRegistry::getInstance()->queue( $path );
 216 }
 217
 218 /**
 219  * Load multiple skins at once
 220  *
 221  * @see wfLoadExtensions
 222  * @param string[] $skins Array of extension names to load
 223  */
 224 function wfLoadSkins( array $skins ) {
 225         global $IP;
 226         $registry = ExtensionRegistry::getInstance();
 227         foreach ( $skins as $skin ) {
 228                 $registry->queue( "$IP/skins/$skin/skin.json" );
 229         }
 230 }
 231
 232 /**
 233  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 234  * @param array $a
 235  * @param array $b
 236  * @return array
 237  */
 238 function wfArrayDiff2( $a, $b ) {
 239         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 240 }
 241
 242 /**
 243  * @param array|string $a
 244  * @param array|string $b
 245  * @return int
 246  */
 247 function wfArrayDiff2_cmp( $a, $b ) {
 248         if ( is_string( $a ) && is_string( $b ) ) {
 249                 return strcmp( $a, $b );
 250         } elseif ( count( $a ) !== count( $b ) ) {
 251                 return count( $a ) < count( $b ) ? -1 : 1;
 252         } else {
 253                 reset( $a );
 254                 reset( $b );
 255                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 256                         $cmp = strcmp( $valueA, $valueB );
 257                         if ( $cmp !== 0 ) {
 258                                 return $cmp;
 259                         }
 260                 }
 261                 return 0;
 262         }
 263 }
 264
 265 /**
 266  * Appends to second array if $value differs from that in $default
 267  *
 268  * @param string|int $key
 269  * @param mixed $value
 270  * @param mixed $default
 271  * @param array $changed Array to alter
 272  * @throws MWException
 273  */
 274 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 275         if ( is_null( $changed ) ) {
 276                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 277         }
 278         if ( $default[$key] !== $value ) {
 279                 $changed[$key] = $value;
 280         }
 281 }
 282
 283 /**
 284  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 285  * e.g.
 286  *      wfMergeErrorArrays(
 287  *              array( array( 'x' ) ),
 288  *              array( array( 'x', '2' ) ),
 289  *              array( array( 'x' ) ),
 290  *              array( array( 'y' ) )
 291  *      );
 292  * returns:
 293  *              array(
 294  *              array( 'x', '2' ),
 295  *              array( 'x' ),
 296  *              array( 'y' )
 297  *      )
 298  *
 299  * @param array $array1,...
 300  * @return array
 301  */
 302 function wfMergeErrorArrays( /*...*/ ) {
 303         $args = func_get_args();
 304         $out = array();
 305         foreach ( $args as $errors ) {
 306                 foreach ( $errors as $params ) {
 307                         # @todo FIXME: Sometimes get nested arrays for $params,
 308                         # which leads to E_NOTICEs
 309                         $spec = implode( "\t", $params );
 310                         $out[$spec] = $params;
 311                 }
 312         }
 313         return array_values( $out );
 314 }
 315
 316 /**
 317  * Insert array into another array after the specified *KEY*
 318  *
 319  * @param array $array The array.
 320  * @param array $insert The array to insert.
 321  * @param mixed $after The key to insert after
 322  * @return array
 323  */
 324 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 325         // Find the offset of the element to insert after.
 326         $keys = array_keys( $array );
 327         $offsetByKey = array_flip( $keys );
 328
 329         $offset = $offsetByKey[$after];
 330
 331         // Insert at the specified offset
 332         $before = array_slice( $array, 0, $offset + 1, true );
 333         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 334
 335         $output = $before + $insert + $after;
 336
 337         return $output;
 338 }
 339
 340 /**
 341  * Recursively converts the parameter (an object) to an array with the same data
 342  *
 343  * @param object|array $objOrArray
 344  * @param bool $recursive
 345  * @return array
 346  */
 347 function wfObjectToArray( $objOrArray, $recursive = true ) {
 348         $array = array();
 349         if ( is_object( $objOrArray ) ) {
 350                 $objOrArray = get_object_vars( $objOrArray );
 351         }
 352         foreach ( $objOrArray as $key => $value ) {
 353                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 354                         $value = wfObjectToArray( $value );
 355                 }
 356
 357                 $array[$key] = $value;
 358         }
 359
 360         return $array;
 361 }
 362
 363 /**
 364  * Get a random decimal value between 0 and 1, in a way
 365  * not likely to give duplicate values for any realistic
 366  * number of articles.
 367  *
 368  * @return string
 369  */
 370 function wfRandom() {
 371         # The maximum random value is "only" 2^31-1, so get two random
 372         # values to reduce the chance of dupes
 373         $max = mt_getrandmax() + 1;
 374         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 375
 376         return $rand;
 377 }
 378
 379 /**
 380  * Get a random string containing a number of pseudo-random hex
 381  * characters.
 382  * @note This is not secure, if you are trying to generate some sort
 383  *       of token please use MWCryptRand instead.
 384  *
 385  * @param int $length The length of the string to generate
 386  * @return string
 387  * @since 1.20
 388  */
 389 function wfRandomString( $length = 32 ) {
 390         $str = '';
 391         for ( $n = 0; $n < $length; $n += 7 ) {
 392                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 393         }
 394         return substr( $str, 0, $length );
 395 }
 396
 397 /**
 398  * We want some things to be included as literal characters in our title URLs
 399  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 400  * all of the following should be safe:
 401  *
 402  * ;:@&=$-_.+!*'(),
 403  *
 404  * But + is not safe because it's used to indicate a space; &= are only safe in
 405  * paths and not in queries (and we don't distinguish here); ' seems kind of
 406  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 407  * is reserved, we don't care.  So the list we unescape is:
 408  *
 409  * ;:@$!*(),/
 410  *
 411  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 412  * so no fancy : for IIS7.
 413  *
 414  * %2F in the page titles seems to fatally break for some reason.
 415  *
 416  * @param string $s
 417  * @return string
 418  */
 419 function wfUrlencode( $s ) {
 420         static $needle;
 421
 422         if ( is_null( $s ) ) {
 423                 $needle = null;
 424                 return '';
 425         }
 426
 427         if ( is_null( $needle ) ) {
 428                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 429                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 430                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 431                 ) {
 432                         $needle[] = '%3A';
 433                 }
 434         }
 435
 436         $s = urlencode( $s );
 437         $s = str_ireplace(
 438                 $needle,
 439                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 440                 $s
 441         );
 442
 443         return $s;
 444 }
 445
 446 /**
 447  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 448  * "days=7&limit=100". Options in the first array override options in the second.
 449  * Options set to null or false will not be output.
 450  *
 451  * @param array $array1 ( String|Array )
 452  * @param array $array2 ( String|Array )
 453  * @param string $prefix
 454  * @return string
 455  */
 456 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 457         if ( !is_null( $array2 ) ) {
 458                 $array1 = $array1 + $array2;
 459         }
 460
 461         $cgi = '';
 462         foreach ( $array1 as $key => $value ) {
 463                 if ( !is_null( $value ) && $value !== false ) {
 464                         if ( $cgi != '' ) {
 465                                 $cgi .= '&';
 466                         }
 467                         if ( $prefix !== '' ) {
 468                                 $key = $prefix . "[$key]";
 469                         }
 470                         if ( is_array( $value ) ) {
 471                                 $firstTime = true;
 472                                 foreach ( $value as $k => $v ) {
 473                                         $cgi .= $firstTime ? '' : '&';
 474                                         if ( is_array( $v ) ) {
 475                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 476                                         } else {
 477                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 478                                         }
 479                                         $firstTime = false;
 480                                 }
 481                         } else {
 482                                 if ( is_object( $value ) ) {
 483                                         $value = $value->__toString();
 484                                 }
 485                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 486                         }
 487                 }
 488         }
 489         return $cgi;
 490 }
 491
 492 /**
 493  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 494  * its argument and returns the same string in array form.  This allows compatibility
 495  * with legacy functions that accept raw query strings instead of nice
 496  * arrays.  Of course, keys and values are urldecode()d.
 497  *
 498  * @param string $query Query string
 499  * @return string[] Array version of input
 500  */
 501 function wfCgiToArray( $query ) {
 502         if ( isset( $query[0] ) && $query[0] == '?' ) {
 503                 $query = substr( $query, 1 );
 504         }
 505         $bits = explode( '&', $query );
 506         $ret = array();
 507         foreach ( $bits as $bit ) {
 508                 if ( $bit === '' ) {
 509                         continue;
 510                 }
 511                 if ( strpos( $bit, '=' ) === false ) {
 512                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 513                         $key = $bit;
 514                         $value = '';
 515                 } else {
 516                         list( $key, $value ) = explode( '=', $bit );
 517                 }
 518                 $key = urldecode( $key );
 519                 $value = urldecode( $value );
 520                 if ( strpos( $key, '[' ) !== false ) {
 521                         $keys = array_reverse( explode( '[', $key ) );
 522                         $key = array_pop( $keys );
 523                         $temp = $value;
 524                         foreach ( $keys as $k ) {
 525                                 $k = substr( $k, 0, -1 );
 526                                 $temp = array( $k => $temp );
 527                         }
 528                         if ( isset( $ret[$key] ) ) {
 529                                 $ret[$key] = array_merge( $ret[$key], $temp );
 530                         } else {
 531                                 $ret[$key] = $temp;
 532                         }
 533                 } else {
 534                         $ret[$key] = $value;
 535                 }
 536         }
 537         return $ret;
 538 }
 539
 540 /**
 541  * Append a query string to an existing URL, which may or may not already
 542  * have query string parameters already. If so, they will be combined.
 543  *
 544  * @param string $url
 545  * @param string|string[] $query String or associative array
 546  * @return string
 547  */
 548 function wfAppendQuery( $url, $query ) {
 549         if ( is_array( $query ) ) {
 550                 $query = wfArrayToCgi( $query );
 551         }
 552         if ( $query != '' ) {
 553                 if ( false === strpos( $url, '?' ) ) {
 554                         $url .= '?';
 555                 } else {
 556                         $url .= '&';
 557                 }
 558                 $url .= $query;
 559         }
 560         return $url;
 561 }
 562
 563 /**
 564  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 565  * is correct.
 566  *
 567  * The meaning of the PROTO_* constants is as follows:
 568  * PROTO_HTTP: Output a URL starting with http://
 569  * PROTO_HTTPS: Output a URL starting with https://
 570  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 571  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 572  *    on which protocol was used for the current incoming request
 573  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 574  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 575  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 576  *
 577  * @todo this won't work with current-path-relative URLs
 578  * like "subdir/foo.html", etc.
 579  *
 580  * @param string $url Either fully-qualified or a local path + query
 581  * @param string $defaultProto One of the PROTO_* constants. Determines the
 582  *    protocol to use if $url or $wgServer is protocol-relative
 583  * @return string Fully-qualified URL, current-path-relative URL or false if
 584  *    no valid URL can be constructed
 585  */
 586 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 587         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 588                 $wgHttpsPort;
 589         if ( $defaultProto === PROTO_CANONICAL ) {
 590                 $serverUrl = $wgCanonicalServer;
 591         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 592                 // Make $wgInternalServer fall back to $wgServer if not set
 593                 $serverUrl = $wgInternalServer;
 594         } else {
 595                 $serverUrl = $wgServer;
 596                 if ( $defaultProto === PROTO_CURRENT ) {
 597                         $defaultProto = $wgRequest->getProtocol() . '://';
 598                 }
 599         }
 600
 601         // Analyze $serverUrl to obtain its protocol
 602         $bits = wfParseUrl( $serverUrl );
 603         $serverHasProto = $bits && $bits['scheme'] != '';
 604
 605         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 606                 if ( $serverHasProto ) {
 607                         $defaultProto = $bits['scheme'] . '://';
 608                 } else {
 609                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 610                         // This really isn't supposed to happen. Fall back to HTTP in this
 611                         // ridiculous case.
 612                         $defaultProto = PROTO_HTTP;
 613                 }
 614         }
 615
 616         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 617
 618         if ( substr( $url, 0, 2 ) == '//' ) {
 619                 $url = $defaultProtoWithoutSlashes . $url;
 620         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 621                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 622                 // otherwise leave it alone.
 623                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 624         }
 625
 626         $bits = wfParseUrl( $url );
 627
 628         // ensure proper port for HTTPS arrives in URL
 629         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 630         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 631                 $bits['port'] = $wgHttpsPort;
 632         }
 633
 634         if ( $bits && isset( $bits['path'] ) ) {
 635                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 636                 return wfAssembleUrl( $bits );
 637         } elseif ( $bits ) {
 638                 # No path to expand
 639                 return $url;
 640         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 641                 # URL is a relative path
 642                 return wfRemoveDotSegments( $url );
 643         }
 644
 645         # Expanded URL is not valid.
 646         return false;
 647 }
 648
 649 /**
 650  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 651  * if you need to edit part of a URL and put it back together.
 652  *
 653  * This is the basic structure used (brackets contain keys for $urlParts):
 654  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 655  *
 656  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 657  *
 658  * @since 1.19
 659  * @param array $urlParts URL parts, as output from wfParseUrl
 660  * @return string URL assembled from its component parts
 661  */
 662 function wfAssembleUrl( $urlParts ) {
 663         $result = '';
 664
 665         if ( isset( $urlParts['delimiter'] ) ) {
 666                 if ( isset( $urlParts['scheme'] ) ) {
 667                         $result .= $urlParts['scheme'];
 668                 }
 669
 670                 $result .= $urlParts['delimiter'];
 671         }
 672
 673         if ( isset( $urlParts['host'] ) ) {
 674                 if ( isset( $urlParts['user'] ) ) {
 675                         $result .= $urlParts['user'];
 676                         if ( isset( $urlParts['pass'] ) ) {
 677                                 $result .= ':' . $urlParts['pass'];
 678                         }
 679                         $result .= '@';
 680                 }
 681
 682                 $result .= $urlParts['host'];
 683
 684                 if ( isset( $urlParts['port'] ) ) {
 685                         $result .= ':' . $urlParts['port'];
 686                 }
 687         }
 688
 689         if ( isset( $urlParts['path'] ) ) {
 690                 $result .= $urlParts['path'];
 691         }
 692
 693         if ( isset( $urlParts['query'] ) ) {
 694                 $result .= '?' . $urlParts['query'];
 695         }
 696
 697         if ( isset( $urlParts['fragment'] ) ) {
 698                 $result .= '#' . $urlParts['fragment'];
 699         }
 700
 701         return $result;
 702 }
 703
 704 /**
 705  * Remove all dot-segments in the provided URL path.  For example,
 706  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 707  * RFC3986 section 5.2.4.
 708  *
 709  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 710  *
 711  * @param string $urlPath URL path, potentially containing dot-segments
 712  * @return string URL path with all dot-segments removed
 713  */
 714 function wfRemoveDotSegments( $urlPath ) {
 715         $output = '';
 716         $inputOffset = 0;
 717         $inputLength = strlen( $urlPath );
 718
 719         while ( $inputOffset < $inputLength ) {
 720                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 721                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 722                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 723                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 724                 $trimOutput = false;
 725
 726                 if ( $prefixLengthTwo == './' ) {
 727                         # Step A, remove leading "./"
 728                         $inputOffset += 2;
 729                 } elseif ( $prefixLengthThree == '../' ) {
 730                         # Step A, remove leading "../"
 731                         $inputOffset += 3;
 732                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 733                         # Step B, replace leading "/.$" with "/"
 734                         $inputOffset += 1;
 735                         $urlPath[$inputOffset] = '/';
 736                 } elseif ( $prefixLengthThree == '/./' ) {
 737                         # Step B, replace leading "/./" with "/"
 738                         $inputOffset += 2;
 739                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 740                         # Step C, replace leading "/..$" with "/" and
 741                         # remove last path component in output
 742                         $inputOffset += 2;
 743                         $urlPath[$inputOffset] = '/';
 744                         $trimOutput = true;
 745                 } elseif ( $prefixLengthFour == '/../' ) {
 746                         # Step C, replace leading "/../" with "/" and
 747                         # remove last path component in output
 748                         $inputOffset += 3;
 749                         $trimOutput = true;
 750                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 751                         # Step D, remove "^.$"
 752                         $inputOffset += 1;
 753                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 754                         # Step D, remove "^..$"
 755                         $inputOffset += 2;
 756                 } else {
 757                         # Step E, move leading path segment to output
 758                         if ( $prefixLengthOne == '/' ) {
 759                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 760                         } else {
 761                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 762                         }
 763                         if ( $slashPos === false ) {
 764                                 $output .= substr( $urlPath, $inputOffset );
 765                                 $inputOffset = $inputLength;
 766                         } else {
 767                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 768                                 $inputOffset += $slashPos - $inputOffset;
 769                         }
 770                 }
 771
 772                 if ( $trimOutput ) {
 773                         $slashPos = strrpos( $output, '/' );
 774                         if ( $slashPos === false ) {
 775                                 $output = '';
 776                         } else {
 777                                 $output = substr( $output, 0, $slashPos );
 778                         }
 779                 }
 780         }
 781
 782         return $output;
 783 }
 784
 785 /**
 786  * Returns a regular expression of url protocols
 787  *
 788  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 789  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 790  * @return string
 791  */
 792 function wfUrlProtocols( $includeProtocolRelative = true ) {
 793         global $wgUrlProtocols;
 794
 795         // Cache return values separately based on $includeProtocolRelative
 796         static $withProtRel = null, $withoutProtRel = null;
 797         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 798         if ( !is_null( $cachedValue ) ) {
 799                 return $cachedValue;
 800         }
 801
 802         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 803         // with LocalSettings files from 1.5
 804         if ( is_array( $wgUrlProtocols ) ) {
 805                 $protocols = array();
 806                 foreach ( $wgUrlProtocols as $protocol ) {
 807                         // Filter out '//' if !$includeProtocolRelative
 808                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 809                                 $protocols[] = preg_quote( $protocol, '/' );
 810                         }
 811                 }
 812
 813                 $retval = implode( '|', $protocols );
 814         } else {
 815                 // Ignore $includeProtocolRelative in this case
 816                 // This case exists for pre-1.6 compatibility, and we can safely assume
 817                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 818                 // URLs weren't supported until 1.18
 819                 $retval = $wgUrlProtocols;
 820         }
 821
 822         // Cache return value
 823         if ( $includeProtocolRelative ) {
 824                 $withProtRel = $retval;
 825         } else {
 826                 $withoutProtRel = $retval;
 827         }
 828         return $retval;
 829 }
 830
 831 /**
 832  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 833  * you need a regex that matches all URL protocols but does not match protocol-
 834  * relative URLs
 835  * @return string
 836  */
 837 function wfUrlProtocolsWithoutProtRel() {
 838         return wfUrlProtocols( false );
 839 }
 840
 841 /**
 842  * parse_url() work-alike, but non-broken.  Differences:
 843  *
 844  * 1) Does not raise warnings on bad URLs (just returns false).
 845  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 846  *    protocol-relative URLs) correctly.
 847  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 848  *
 849  * @param string $url A URL to parse
 850  * @return string[] Bits of the URL in an associative array, per PHP docs
 851  */
 852 function wfParseUrl( $url ) {
 853         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 854
 855         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 856         // bad that the easiest way to handle them is to just prepend 'http:' and
 857         // strip the protocol out later.
 858         $wasRelative = substr( $url, 0, 2 ) == '//';
 859         if ( $wasRelative ) {
 860                 $url = "http:$url";
 861         }
 862         wfSuppressWarnings();
 863         $bits = parse_url( $url );
 864         wfRestoreWarnings();
 865         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 866         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 867         if ( !$bits || !isset( $bits['scheme'] ) ) {
 868                 return false;
 869         }
 870
 871         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 872         $bits['scheme'] = strtolower( $bits['scheme'] );
 873
 874         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 875         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 876                 $bits['delimiter'] = '://';
 877         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 878                 $bits['delimiter'] = ':';
 879                 // parse_url detects for news: and mailto: the host part of an url as path
 880                 // We have to correct this wrong detection
 881                 if ( isset( $bits['path'] ) ) {
 882                         $bits['host'] = $bits['path'];
 883                         $bits['path'] = '';
 884                 }
 885         } else {
 886                 return false;
 887         }
 888
 889         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 890         if ( !isset( $bits['host'] ) ) {
 891                 $bits['host'] = '';
 892
 893                 // bug 45069
 894                 if ( isset( $bits['path'] ) ) {
 895                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 896                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 897                                 $bits['path'] = '/' . $bits['path'];
 898                         }
 899                 } else {
 900                         $bits['path'] = '';
 901                 }
 902         }
 903
 904         // If the URL was protocol-relative, fix scheme and delimiter
 905         if ( $wasRelative ) {
 906                 $bits['scheme'] = '';
 907                 $bits['delimiter'] = '//';
 908         }
 909         return $bits;
 910 }
 911
 912 /**
 913  * Take a URL, make sure it's expanded to fully qualified, and replace any
 914  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 915  * for more compact display and legibility for local audiences.
 916  *
 917  * @todo handle punycode domains too
 918  *
 919  * @param string $url
 920  * @return string
 921  */
 922 function wfExpandIRI( $url ) {
 923         return preg_replace_callback(
 924                 '/((?:%[89A-F][0-9A-F])+)/i',
 925                 'wfExpandIRI_callback',
 926                 wfExpandUrl( $url )
 927         );
 928 }
 929
 930 /**
 931  * Private callback for wfExpandIRI
 932  * @param array $matches
 933  * @return string
 934  */
 935 function wfExpandIRI_callback( $matches ) {
 936         return urldecode( $matches[1] );
 937 }
 938
 939 /**
 940  * Make URL indexes, appropriate for the el_index field of externallinks.
 941  *
 942  * @param string $url
 943  * @return array
 944  */
 945 function wfMakeUrlIndexes( $url ) {
 946         $bits = wfParseUrl( $url );
 947
 948         // Reverse the labels in the hostname, convert to lower case
 949         // For emails reverse domainpart only
 950         if ( $bits['scheme'] == 'mailto' ) {
 951                 $mailparts = explode( '@', $bits['host'], 2 );
 952                 if ( count( $mailparts ) === 2 ) {
 953                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 954                 } else {
 955                         // No domain specified, don't mangle it
 956                         $domainpart = '';
 957                 }
 958                 $reversedHost = $domainpart . '@' . $mailparts[0];
 959         } else {
 960                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 961         }
 962         // Add an extra dot to the end
 963         // Why? Is it in wrong place in mailto links?
 964         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 965                 $reversedHost .= '.';
 966         }
 967         // Reconstruct the pseudo-URL
 968         $prot = $bits['scheme'];
 969         $index = $prot . $bits['delimiter'] . $reversedHost;
 970         // Leave out user and password. Add the port, path, query and fragment
 971         if ( isset( $bits['port'] ) ) {
 972                 $index .= ':' . $bits['port'];
 973         }
 974         if ( isset( $bits['path'] ) ) {
 975                 $index .= $bits['path'];
 976         } else {
 977                 $index .= '/';
 978         }
 979         if ( isset( $bits['query'] ) ) {
 980                 $index .= '?' . $bits['query'];
 981         }
 982         if ( isset( $bits['fragment'] ) ) {
 983                 $index .= '#' . $bits['fragment'];
 984         }
 985
 986         if ( $prot == '' ) {
 987                 return array( "http:$index", "https:$index" );
 988         } else {
 989                 return array( $index );
 990         }
 991 }
 992
 993 /**
 994  * Check whether a given URL has a domain that occurs in a given set of domains
 995  * @param string $url URL
 996  * @param array $domains Array of domains (strings)
 997  * @return bool True if the host part of $url ends in one of the strings in $domains
 998  */
 999 function wfMatchesDomainList( $url, $domains ) {
1000         $bits = wfParseUrl( $url );
1001         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1002                 $host = '.' . $bits['host'];
1003                 foreach ( (array)$domains as $domain ) {
1004                         $domain = '.' . $domain;
1005                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1006                                 return true;
1007                         }
1008                 }
1009         }
1010         return false;
1011 }
1012
1013 /**
1014  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1015  * In normal operation this is a NOP.
1016  *
1017  * Controlling globals:
1018  * $wgDebugLogFile - points to the log file
1019  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1020  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1021  *
1022  * @since 1.25 support for additional context data
1023  *
1024  * @param string $text
1025  * @param string|bool $dest Unused
1026  * @param array $context Additional logging context data
1027  */
1028 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1029         global $wgDebugRawPage, $wgDebugLogPrefix;
1030         global $wgDebugTimestamps, $wgRequestTime;
1031
1032         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1033                 return;
1034         }
1035
1036         $text = trim( $text );
1037
1038         // Inline logic from deprecated wfDebugTimer()
1039         if ( $wgDebugTimestamps ) {
1040                 $context['seconds_elapsed'] = sprintf(
1041                         '%6.4f',
1042                         microtime( true ) - $wgRequestTime
1043                 );
1044                 $context['memory_used'] = sprintf(
1045                         '%5.1fM',
1046                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1047                 );
1048         }
1049
1050         if ( $wgDebugLogPrefix !== '' ) {
1051                 $context['prefix'] = $wgDebugLogPrefix;
1052         }
1053
1054         $logger = MWLoggerFactory::getInstance( 'wfDebug' );
1055         $logger->debug( $text, $context );
1056 }
1057
1058 /**
1059  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1060  * @return bool
1061  */
1062 function wfIsDebugRawPage() {
1063         static $cache;
1064         if ( $cache !== null ) {
1065                 return $cache;
1066         }
1067         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1068         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1069                 || (
1070                         isset( $_SERVER['SCRIPT_NAME'] )
1071                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1072                 )
1073         ) {
1074                 $cache = true;
1075         } else {
1076                 $cache = false;
1077         }
1078         return $cache;
1079 }
1080
1081 /**
1082  * Get microsecond timestamps for debug logs
1083  *
1084  * @deprecated since 1.25
1085  * @return string
1086  */
1087 function wfDebugTimer() {
1088         global $wgDebugTimestamps, $wgRequestTime;
1089
1090         wfDeprecated( __METHOD__, '1.25' );
1091
1092         if ( !$wgDebugTimestamps ) {
1093                 return '';
1094         }
1095
1096         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1097         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1098         return "$prefix $mem  ";
1099 }
1100
1101 /**
1102  * Send a line giving PHP memory usage.
1103  *
1104  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1105  */
1106 function wfDebugMem( $exact = false ) {
1107         $mem = memory_get_usage();
1108         if ( !$exact ) {
1109                 $mem = floor( $mem / 1024 ) . ' KiB';
1110         } else {
1111                 $mem .= ' B';
1112         }
1113         wfDebug( "Memory usage: $mem\n" );
1114 }
1115
1116 /**
1117  * Send a line to a supplementary debug log file, if configured, or main debug
1118  * log if not.
1119  *
1120  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1121  * a string filename or an associative array mapping 'destination' to the
1122  * desired filename. The associative array may also contain a 'sample' key
1123  * with an integer value, specifying a sampling factor. Sampled log events
1124  * will be emitted with a 1 in N random chance.
1125  *
1126  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1127  * @since 1.25 support for additional context data
1128  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1129  *
1130  * @param string $logGroup
1131  * @param string $text
1132  * @param string|bool $dest Destination of the message:
1133  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1134  *     - 'log': only to the log and not in HTML
1135  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1136  *       discarded otherwise
1137  *   For backward compatibility, it can also take a boolean:
1138  *     - true: same as 'all'
1139  *     - false: same as 'private'
1140  * @param array $context Additional logging context data
1141  */
1142 function wfDebugLog(
1143         $logGroup, $text, $dest = 'all', array $context = array()
1144 ) {
1145         // Turn $dest into a string if it's a boolean (for b/c)
1146         if ( $dest === true ) {
1147                 $dest = 'all';
1148         } elseif ( $dest === false ) {
1149                 $dest = 'private';
1150         }
1151
1152         $text = trim( $text );
1153
1154         $logger = MWLoggerFactory::getInstance( $logGroup );
1155         $context['private'] = ( $dest === 'private' );
1156         $logger->info( $text, $context );
1157 }
1158
1159 /**
1160  * Log for database errors
1161  *
1162  * @since 1.25 support for additional context data
1163  *
1164  * @param string $text Database error message.
1165  * @param array $context Additional logging context data
1166  */
1167 function wfLogDBError( $text, array $context = array() ) {
1168         $logger = MWLoggerFactory::getInstance( 'wfLogDBError' );
1169         $logger->error( trim( $text ), $context );
1170 }
1171
1172 /**
1173  * Throws a warning that $function is deprecated
1174  *
1175  * @param string $function
1176  * @param string|bool $version Version of MediaWiki that the function
1177  *    was deprecated in (Added in 1.19).
1178  * @param string|bool $component Added in 1.19.
1179  * @param int $callerOffset How far up the call stack is the original
1180  *    caller. 2 = function that called the function that called
1181  *    wfDeprecated (Added in 1.20)
1182  *
1183  * @return null
1184  */
1185 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1186         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1187 }
1188
1189 /**
1190  * Send a warning either to the debug log or in a PHP error depending on
1191  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1192  *
1193  * @param string $msg Message to send
1194  * @param int $callerOffset Number of items to go back in the backtrace to
1195  *        find the correct caller (1 = function calling wfWarn, ...)
1196  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1197  *        only used when $wgDevelopmentWarnings is true
1198  */
1199 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1200         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1201 }
1202
1203 /**
1204  * Send a warning as a PHP error and the debug log. This is intended for logging
1205  * warnings in production. For logging development warnings, use WfWarn instead.
1206  *
1207  * @param string $msg Message to send
1208  * @param int $callerOffset Number of items to go back in the backtrace to
1209  *        find the correct caller (1 = function calling wfLogWarning, ...)
1210  * @param int $level PHP error level; defaults to E_USER_WARNING
1211  */
1212 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1213         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1214 }
1215
1216 /**
1217  * Log to a file without getting "file size exceeded" signals.
1218  *
1219  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1220  * send lines to the specified port, prefixed by the specified prefix and a space.
1221  * @since 1.25 support for additional context data
1222  *
1223  * @param string $text
1224  * @param string $file Filename
1225  * @param array $context Additional logging context data
1226  * @throws MWException
1227  * @deprecated since 1.25 Use MWLoggerLegacyLogger::emit or UDPTransport
1228  */
1229 function wfErrorLog( $text, $file, array $context = array() ) {
1230         wfDeprecated( __METHOD__, '1.25' );
1231         $logger = MWLoggerFactory::getInstance( 'wfErrorLog' );
1232         $context['destination'] = $file;
1233         $logger->info( trim( $text ), $context );
1234 }
1235
1236 /**
1237  * @todo document
1238  */
1239 function wfLogProfilingData() {
1240         global $wgDebugLogGroups, $wgDebugRawPage, $wgProfileLimit;
1241
1242         $context = RequestContext::getMain();
1243         $request = $context->getRequest();
1244         $config = $context->getConfig();
1245         if ( $config->has( 'StatsdServer' ) ) {
1246                 $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1247                 $statsdHost = $statsdServer[0];
1248                 $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1249                 $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1250                 $statsdClient = new StatsdClient( $statsdSender );
1251                 $statsdClient->send( $context->getStats()->getBuffer() );
1252         }
1253
1254         $profiler = Profiler::instance();
1255
1256         # Profiling must actually be enabled...
1257         if ( $profiler instanceof ProfilerStub ) {
1258                 return;
1259         }
1260
1261         // Get total page request time and only show pages that longer than
1262         // $wgProfileLimit time (default is 0)
1263         $elapsed = $request->getElapsedTime();
1264         if ( $elapsed <= $wgProfileLimit ) {
1265                 return;
1266         }
1267
1268         $profiler->logData();
1269
1270         if ( isset( $wgDebugLogGroups['profileoutput'] )
1271                 && $wgDebugLogGroups['profileoutput'] === false
1272         ) {
1273                 // Explicitly disabled
1274                 return;
1275         }
1276         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1277                 return;
1278         }
1279
1280         $ctx = array( 'elapsed' => $elapsed );
1281         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1282                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1283         }
1284         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1285                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1286         }
1287         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1288                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1289         }
1290         if ( isset( $ctx['forwarded_for'] ) ||
1291                 isset( $ctx['client_ip'] ) ||
1292                 isset( $ctx['from'] ) ) {
1293                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1294         }
1295
1296         // Don't load $wgUser at this late stage just for statistics purposes
1297         // @todo FIXME: We can detect some anons even if it is not loaded.
1298         // See User::getId()
1299         $user = $context->getUser();
1300         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1301
1302         // Command line script uses a FauxRequest object which does not have
1303         // any knowledge about an URL and throw an exception instead.
1304         try {
1305                 $ctx['url'] = urldecode( $request->getRequestURL() );
1306         } catch ( Exception $ignored ) {
1307                 // no-op
1308         }
1309
1310         $ctx['output'] = $profiler->getOutput();
1311
1312         $log = MWLoggerFactory::getInstance( 'profileoutput' );
1313         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1314 }
1315
1316 /**
1317  * Increment a statistics counter
1318  *
1319  * @param string $key
1320  * @param int $count
1321  * @return void
1322  */
1323 function wfIncrStats( $key, $count = 1 ) {
1324         $stats = RequestContext::getMain()->getStats();
1325         $stats->updateCount( $key, $count );
1326 }
1327
1328 /**
1329  * Check whether the wiki is in read-only mode.
1330  *
1331  * @return bool
1332  */
1333 function wfReadOnly() {
1334         return wfReadOnlyReason() !== false;
1335 }
1336
1337 /**
1338  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1339  *
1340  * @return string|bool String when in read-only mode; false otherwise
1341  */
1342 function wfReadOnlyReason() {
1343         global $wgReadOnly, $wgReadOnlyFile;
1344
1345         if ( $wgReadOnly === null ) {
1346                 // Set $wgReadOnly for faster access next time
1347                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1348                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1349                 } else {
1350                         $wgReadOnly = false;
1351                 }
1352         }
1353
1354         return $wgReadOnly;
1355 }
1356
1357 /**
1358  * Return a Language object from $langcode
1359  *
1360  * @param Language|string|bool $langcode Either:
1361  *                  - a Language object
1362  *                  - code of the language to get the message for, if it is
1363  *                    a valid code create a language for that language, if
1364  *                    it is a string but not a valid code then make a basic
1365  *                    language object
1366  *                  - a boolean: if it's false then use the global object for
1367  *                    the current user's language (as a fallback for the old parameter
1368  *                    functionality), or if it is true then use global object
1369  *                    for the wiki's content language.
1370  * @return Language
1371  */
1372 function wfGetLangObj( $langcode = false ) {
1373         # Identify which language to get or create a language object for.
1374         # Using is_object here due to Stub objects.
1375         if ( is_object( $langcode ) ) {
1376                 # Great, we already have the object (hopefully)!
1377                 return $langcode;
1378         }
1379
1380         global $wgContLang, $wgLanguageCode;
1381         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1382                 # $langcode is the language code of the wikis content language object.
1383                 # or it is a boolean and value is true
1384                 return $wgContLang;
1385         }
1386
1387         global $wgLang;
1388         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1389                 # $langcode is the language code of user language object.
1390                 # or it was a boolean and value is false
1391                 return $wgLang;
1392         }
1393
1394         $validCodes = array_keys( Language::fetchLanguageNames() );
1395         if ( in_array( $langcode, $validCodes ) ) {
1396                 # $langcode corresponds to a valid language.
1397                 return Language::factory( $langcode );
1398         }
1399
1400         # $langcode is a string, but not a valid language code; use content language.
1401         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1402         return $wgContLang;
1403 }
1404
1405 /**
1406  * This is the function for getting translated interface messages.
1407  *
1408  * @see Message class for documentation how to use them.
1409  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1410  *
1411  * This function replaces all old wfMsg* functions.
1412  *
1413  * @param string|string[] $key Message key, or array of keys
1414  * @param mixed $params,... Normal message parameters
1415  * @return Message
1416  *
1417  * @since 1.17
1418  *
1419  * @see Message::__construct
1420  */
1421 function wfMessage( $key /*...*/ ) {
1422         $params = func_get_args();
1423         array_shift( $params );
1424         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1425                 $params = $params[0];
1426         }
1427         return new Message( $key, $params );
1428 }
1429
1430 /**
1431  * This function accepts multiple message keys and returns a message instance
1432  * for the first message which is non-empty. If all messages are empty then an
1433  * instance of the first message key is returned.
1434  *
1435  * @param string|string[] $keys,... Message keys
1436  * @return Message
1437  *
1438  * @since 1.18
1439  *
1440  * @see Message::newFallbackSequence
1441  */
1442 function wfMessageFallback( /*...*/ ) {
1443         $args = func_get_args();
1444         return call_user_func_array( 'Message::newFallbackSequence', $args );
1445 }
1446
1447 /**
1448  * Get a message from anywhere, for the current user language.
1449  *
1450  * Use wfMsgForContent() instead if the message should NOT
1451  * change depending on the user preferences.
1452  *
1453  * @deprecated since 1.18
1454  *
1455  * @param string $key Lookup key for the message, usually
1456  *    defined in languages/Language.php
1457  *
1458  * Parameters to the message, which can be used to insert variable text into
1459  * it, can be passed to this function in the following formats:
1460  * - One per argument, starting at the second parameter
1461  * - As an array in the second parameter
1462  * These are not shown in the function definition.
1463  *
1464  * @return string
1465  */
1466 function wfMsg( $key ) {
1467         wfDeprecated( __METHOD__, '1.21' );
1468
1469         $args = func_get_args();
1470         array_shift( $args );
1471         return wfMsgReal( $key, $args );
1472 }
1473
1474 /**
1475  * Same as above except doesn't transform the message
1476  *
1477  * @deprecated since 1.18
1478  *
1479  * @param string $key
1480  * @return string
1481  */
1482 function wfMsgNoTrans( $key ) {
1483         wfDeprecated( __METHOD__, '1.21' );
1484
1485         $args = func_get_args();
1486         array_shift( $args );
1487         return wfMsgReal( $key, $args, true, false, false );
1488 }
1489
1490 /**
1491  * Get a message from anywhere, for the current global language
1492  * set with $wgLanguageCode.
1493  *
1494  * Use this if the message should NOT change dependent on the
1495  * language set in the user's preferences. This is the case for
1496  * most text written into logs, as well as link targets (such as
1497  * the name of the copyright policy page). Link titles, on the
1498  * other hand, should be shown in the UI language.
1499  *
1500  * Note that MediaWiki allows users to change the user interface
1501  * language in their preferences, but a single installation
1502  * typically only contains content in one language.
1503  *
1504  * Be wary of this distinction: If you use wfMsg() where you should
1505  * use wfMsgForContent(), a user of the software may have to
1506  * customize potentially hundreds of messages in
1507  * order to, e.g., fix a link in every possible language.
1508  *
1509  * @deprecated since 1.18
1510  *
1511  * @param string $key Lookup key for the message, usually
1512  *     defined in languages/Language.php
1513  * @return string
1514  */
1515 function wfMsgForContent( $key ) {
1516         wfDeprecated( __METHOD__, '1.21' );
1517
1518         global $wgForceUIMsgAsContentMsg;
1519         $args = func_get_args();
1520         array_shift( $args );
1521         $forcontent = true;
1522         if ( is_array( $wgForceUIMsgAsContentMsg )
1523                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1524         ) {
1525                 $forcontent = false;
1526         }
1527         return wfMsgReal( $key, $args, true, $forcontent );
1528 }
1529
1530 /**
1531  * Same as above except doesn't transform the message
1532  *
1533  * @deprecated since 1.18
1534  *
1535  * @param string $key
1536  * @return string
1537  */
1538 function wfMsgForContentNoTrans( $key ) {
1539         wfDeprecated( __METHOD__, '1.21' );
1540
1541         global $wgForceUIMsgAsContentMsg;
1542         $args = func_get_args();
1543         array_shift( $args );
1544         $forcontent = true;
1545         if ( is_array( $wgForceUIMsgAsContentMsg )
1546                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1547         ) {
1548                 $forcontent = false;
1549         }
1550         return wfMsgReal( $key, $args, true, $forcontent, false );
1551 }
1552
1553 /**
1554  * Really get a message
1555  *
1556  * @deprecated since 1.18
1557  *
1558  * @param string $key Key to get.
1559  * @param array $args
1560  * @param bool $useDB
1561  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1562  * @param bool $transform Whether or not to transform the message.
1563  * @return string The requested message.
1564  */
1565 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1566         wfDeprecated( __METHOD__, '1.21' );
1567
1568         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1569         $message = wfMsgReplaceArgs( $message, $args );
1570         return $message;
1571 }
1572
1573 /**
1574  * Fetch a message string value, but don't replace any keys yet.
1575  *
1576  * @deprecated since 1.18
1577  *
1578  * @param string $key
1579  * @param bool $useDB
1580  * @param string|bool $langCode Code of the language to get the message for, or
1581  *   behaves as a content language switch if it is a boolean.
1582  * @param bool $transform Whether to parse magic words, etc.
1583  * @return string
1584  */
1585 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1586         wfDeprecated( __METHOD__, '1.21' );
1587
1588         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1589
1590         $cache = MessageCache::singleton();
1591         $message = $cache->get( $key, $useDB, $langCode );
1592         if ( $message === false ) {
1593                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1594         } elseif ( $transform ) {
1595                 $message = $cache->transform( $message );
1596         }
1597         return $message;
1598 }
1599
1600 /**
1601  * Replace message parameter keys on the given formatted output.
1602  *
1603  * @param string $message
1604  * @param array $args
1605  * @return string
1606  * @private
1607  */
1608 function wfMsgReplaceArgs( $message, $args ) {
1609         # Fix windows line-endings
1610         # Some messages are split with explode("\n", $msg)
1611         $message = str_replace( "\r", '', $message );
1612
1613         // Replace arguments
1614         if ( count( $args ) ) {
1615                 if ( is_array( $args[0] ) ) {
1616                         $args = array_values( $args[0] );
1617                 }
1618                 $replacementKeys = array();
1619                 foreach ( $args as $n => $param ) {
1620                         $replacementKeys['$' . ( $n + 1 )] = $param;
1621                 }
1622                 $message = strtr( $message, $replacementKeys );
1623         }
1624
1625         return $message;
1626 }
1627
1628 /**
1629  * Return an HTML-escaped version of a message.
1630  * Parameter replacements, if any, are done *after* the HTML-escaping,
1631  * so parameters may contain HTML (eg links or form controls). Be sure
1632  * to pre-escape them if you really do want plaintext, or just wrap
1633  * the whole thing in htmlspecialchars().
1634  *
1635  * @deprecated since 1.18
1636  *
1637  * @param string $key
1638  * @param string $args,... Parameters
1639  * @return string
1640  */
1641 function wfMsgHtml( $key ) {
1642         wfDeprecated( __METHOD__, '1.21' );
1643
1644         $args = func_get_args();
1645         array_shift( $args );
1646         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1647 }
1648
1649 /**
1650  * Return an HTML version of message
1651  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1652  * so parameters may contain HTML (eg links or form controls). Be sure
1653  * to pre-escape them if you really do want plaintext, or just wrap
1654  * the whole thing in htmlspecialchars().
1655  *
1656  * @deprecated since 1.18
1657  *
1658  * @param string $key
1659  * @param string $args,... Parameters
1660  * @return string
1661  */
1662 function wfMsgWikiHtml( $key ) {
1663         wfDeprecated( __METHOD__, '1.21' );
1664
1665         $args = func_get_args();
1666         array_shift( $args );
1667         return wfMsgReplaceArgs(
1668                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1669                 /* can't be set to false */ true, /* interface */ true )->getText(),
1670                 $args );
1671 }
1672
1673 /**
1674  * Returns message in the requested format
1675  *
1676  * @deprecated since 1.18
1677  *
1678  * @param string $key Key of the message
1679  * @param array $options Processing rules.
1680  *   Can take the following options:
1681  *     parse: parses wikitext to HTML
1682  *     parseinline: parses wikitext to HTML and removes the surrounding
1683  *       p's added by parser or tidy
1684  *     escape: filters message through htmlspecialchars
1685  *     escapenoentities: same, but allows entity references like &#160; through
1686  *     replaceafter: parameters are substituted after parsing or escaping
1687  *     parsemag: transform the message using magic phrases
1688  *     content: fetch message for content language instead of interface
1689  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1690  *     language: Language object or language code to fetch message for
1691  *       (overridden by content).
1692  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1693  *
1694  * @return string
1695  */
1696 function wfMsgExt( $key, $options ) {
1697         wfDeprecated( __METHOD__, '1.21' );
1698
1699         $args = func_get_args();
1700         array_shift( $args );
1701         array_shift( $args );
1702         $options = (array)$options;
1703         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1704                 'parsemag', 'content' );
1705
1706         foreach ( $options as $arrayKey => $option ) {
1707                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1708                         // An unknown index, neither numeric nor "language"
1709                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1710                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1711                         // A numeric index with unknown value
1712                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1713                 }
1714         }
1715
1716         if ( in_array( 'content', $options, true ) ) {
1717                 $forContent = true;
1718                 $langCode = true;
1719                 $langCodeObj = null;
1720         } elseif ( array_key_exists( 'language', $options ) ) {
1721                 $forContent = false;
1722                 $langCode = wfGetLangObj( $options['language'] );
1723                 $langCodeObj = $langCode;
1724         } else {
1725                 $forContent = false;
1726                 $langCode = false;
1727                 $langCodeObj = null;
1728         }
1729
1730         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1731
1732         if ( !in_array( 'replaceafter', $options, true ) ) {
1733                 $string = wfMsgReplaceArgs( $string, $args );
1734         }
1735
1736         $messageCache = MessageCache::singleton();
1737         $parseInline = in_array( 'parseinline', $options, true );
1738         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1739                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1740                 if ( $string instanceof ParserOutput ) {
1741                         $string = $string->getText();
1742                 }
1743
1744                 if ( $parseInline ) {
1745                         $string = Parser::stripOuterParagraph( $string );
1746                 }
1747         } elseif ( in_array( 'parsemag', $options, true ) ) {
1748                 $string = $messageCache->transform( $string,
1749                                 !$forContent, $langCodeObj );
1750         }
1751
1752         if ( in_array( 'escape', $options, true ) ) {
1753                 $string = htmlspecialchars ( $string );
1754         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1755                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1756         }
1757
1758         if ( in_array( 'replaceafter', $options, true ) ) {
1759                 $string = wfMsgReplaceArgs( $string, $args );
1760         }
1761
1762         return $string;
1763 }
1764
1765 /**
1766  * Since wfMsg() and co suck, they don't return false if the message key they
1767  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1768  * nonexistence of messages by checking the MessageCache::get() result directly.
1769  *
1770  * @deprecated since 1.18. Use Message::isDisabled().
1771  *
1772  * @param string $key The message key looked up
1773  * @return bool True if the message *doesn't* exist.
1774  */
1775 function wfEmptyMsg( $key ) {
1776         wfDeprecated( __METHOD__, '1.21' );
1777
1778         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1779 }
1780
1781 /**
1782  * Fetch server name for use in error reporting etc.
1783  * Use real server name if available, so we know which machine
1784  * in a server farm generated the current page.
1785  *
1786  * @return string
1787  */
1788 function wfHostname() {
1789         static $host;
1790         if ( is_null( $host ) ) {
1791
1792                 # Hostname overriding
1793                 global $wgOverrideHostname;
1794                 if ( $wgOverrideHostname !== false ) {
1795                         # Set static and skip any detection
1796                         $host = $wgOverrideHostname;
1797                         return $host;
1798                 }
1799
1800                 if ( function_exists( 'posix_uname' ) ) {
1801                         // This function not present on Windows
1802                         $uname = posix_uname();
1803                 } else {
1804                         $uname = false;
1805                 }
1806                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1807                         $host = $uname['nodename'];
1808                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1809                         # Windows computer name
1810                         $host = getenv( 'COMPUTERNAME' );
1811                 } else {
1812                         # This may be a virtual server.
1813                         $host = $_SERVER['SERVER_NAME'];
1814                 }
1815         }
1816         return $host;
1817 }
1818
1819 /**
1820  * Returns a script tag that stores the amount of time it took MediaWiki to
1821  * handle the request in milliseconds as 'wgBackendResponseTime'.
1822  *
1823  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1824  * hostname of the server handling the request.
1825  *
1826  * @return string
1827  */
1828 function wfReportTime() {
1829         global $wgRequestTime, $wgShowHostnames;
1830
1831         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1832         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1833         if ( $wgShowHostnames ) {
1834                 $reportVars['wgHostname'] = wfHostname();
1835         }
1836         return Skin::makeVariablesScript( $reportVars );
1837 }
1838
1839 /**
1840  * Safety wrapper for debug_backtrace().
1841  *
1842  * Will return an empty array if debug_backtrace is disabled, otherwise
1843  * the output from debug_backtrace() (trimmed).
1844  *
1845  * @param int $limit This parameter can be used to limit the number of stack frames returned
1846  *
1847  * @return array Array of backtrace information
1848  */
1849 function wfDebugBacktrace( $limit = 0 ) {
1850         static $disabled = null;
1851
1852         if ( is_null( $disabled ) ) {
1853                 $disabled = !function_exists( 'debug_backtrace' );
1854                 if ( $disabled ) {
1855                         wfDebug( "debug_backtrace() is disabled\n" );
1856                 }
1857         }
1858         if ( $disabled ) {
1859                 return array();
1860         }
1861
1862         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1863                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1864         } else {
1865                 return array_slice( debug_backtrace(), 1 );
1866         }
1867 }
1868
1869 /**
1870  * Get a debug backtrace as a string
1871  *
1872  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1873  *   Defaults to $wgCommandLineMode if unset.
1874  * @return string
1875  * @since 1.25 Supports $raw parameter.
1876  */
1877 function wfBacktrace( $raw = null ) {
1878         global $wgCommandLineMode;
1879
1880         if ( $raw === null ) {
1881                 $raw = $wgCommandLineMode;
1882         }
1883
1884         if ( $raw ) {
1885                 $frameFormat = "%s line %s calls %s()\n";
1886                 $traceFormat = "%s";
1887         } else {
1888                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1889                 $traceFormat = "<ul>\n%s</ul>\n";
1890         }
1891
1892         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1893                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1894                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1895                 $call = $frame['function'];
1896                 if ( !empty( $frame['class'] ) ) {
1897                         $call = $frame['class'] . $frame['type'] . $call;
1898                 }
1899                 return sprintf( $frameFormat, $file, $line, $call );
1900         }, wfDebugBacktrace() );
1901
1902         return sprintf( $traceFormat, implode( '', $frames ) );
1903 }
1904
1905 /**
1906  * Get the name of the function which called this function
1907  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1908  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1909  * wfGetCaller( 3 ) is the parent of that.
1910  *
1911  * @param int $level
1912  * @return string
1913  */
1914 function wfGetCaller( $level = 2 ) {
1915         $backtrace = wfDebugBacktrace( $level + 1 );
1916         if ( isset( $backtrace[$level] ) ) {
1917                 return wfFormatStackFrame( $backtrace[$level] );
1918         } else {
1919                 return 'unknown';
1920         }
1921 }
1922
1923 /**
1924  * Return a string consisting of callers in the stack. Useful sometimes
1925  * for profiling specific points.
1926  *
1927  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1928  * @return string
1929  */
1930 function wfGetAllCallers( $limit = 3 ) {
1931         $trace = array_reverse( wfDebugBacktrace() );
1932         if ( !$limit || $limit > count( $trace ) - 1 ) {
1933                 $limit = count( $trace ) - 1;
1934         }
1935         $trace = array_slice( $trace, -$limit - 1, $limit );
1936         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1937 }
1938
1939 /**
1940  * Return a string representation of frame
1941  *
1942  * @param array $frame
1943  * @return string
1944  */
1945 function wfFormatStackFrame( $frame ) {
1946         return isset( $frame['class'] ) ?
1947                 $frame['class'] . '::' . $frame['function'] :
1948                 $frame['function'];
1949 }
1950
1951 /* Some generic result counters, pulled out of SearchEngine */
1952
1953 /**
1954  * @todo document
1955  *
1956  * @param int $offset
1957  * @param int $limit
1958  * @return string
1959  */
1960 function wfShowingResults( $offset, $limit ) {
1961         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1962 }
1963
1964 /**
1965  * @todo document
1966  * @todo FIXME: We may want to blacklist some broken browsers
1967  *
1968  * @param bool $force
1969  * @return bool Whereas client accept gzip compression
1970  */
1971 function wfClientAcceptsGzip( $force = false ) {
1972         static $result = null;
1973         if ( $result === null || $force ) {
1974                 $result = false;
1975                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1976                         # @todo FIXME: We may want to blacklist some broken browsers
1977                         $m = array();
1978                         if ( preg_match(
1979                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1980                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1981                                         $m
1982                                 )
1983                         ) {
1984                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1985                                         $result = false;
1986                                         return $result;
1987                                 }
1988                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1989                                 $result = true;
1990                         }
1991                 }
1992         }
1993         return $result;
1994 }
1995
1996 /**
1997  * Obtain the offset and limit values from the request string;
1998  * used in special pages
1999  *
2000  * @param int $deflimit Default limit if none supplied
2001  * @param string $optionname Name of a user preference to check against
2002  * @return array
2003  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2004  */
2005 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2006         global $wgRequest;
2007         wfDeprecated( __METHOD__, '1.24' );
2008         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2009 }
2010
2011 /**
2012  * Escapes the given text so that it may be output using addWikiText()
2013  * without any linking, formatting, etc. making its way through. This
2014  * is achieved by substituting certain characters with HTML entities.
2015  * As required by the callers, "<nowiki>" is not used.
2016  *
2017  * @param string $text Text to be escaped
2018  * @return string
2019  */
2020 function wfEscapeWikiText( $text ) {
2021         static $repl = null, $repl2 = null;
2022         if ( $repl === null ) {
2023                 $repl = array(
2024                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2025                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2026                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2027                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2028                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2029                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2030                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2031                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2032                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2033                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2034                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2035                         '__' => '_&#95;', '://' => '&#58;//',
2036                 );
2037
2038                 // We have to catch everything "\s" matches in PCRE
2039                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2040                         $repl["$magic "] = "$magic&#32;";
2041                         $repl["$magic\t"] = "$magic&#9;";
2042                         $repl["$magic\r"] = "$magic&#13;";
2043                         $repl["$magic\n"] = "$magic&#10;";
2044                         $repl["$magic\f"] = "$magic&#12;";
2045                 }
2046
2047                 // And handle protocols that don't use "://"
2048                 global $wgUrlProtocols;
2049                 $repl2 = array();
2050                 foreach ( $wgUrlProtocols as $prot ) {
2051                         if ( substr( $prot, -1 ) === ':' ) {
2052                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2053                         }
2054                 }
2055                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2056         }
2057         $text = substr( strtr( "\n$text", $repl ), 1 );
2058         $text = preg_replace( $repl2, '$1&#58;', $text );
2059         return $text;
2060 }
2061
2062 /**
2063  * Sets dest to source and returns the original value of dest
2064  * If source is NULL, it just returns the value, it doesn't set the variable
2065  * If force is true, it will set the value even if source is NULL
2066  *
2067  * @param mixed $dest
2068  * @param mixed $source
2069  * @param bool $force
2070  * @return mixed
2071  */
2072 function wfSetVar( &$dest, $source, $force = false ) {
2073         $temp = $dest;
2074         if ( !is_null( $source ) || $force ) {
2075                 $dest = $source;
2076         }
2077         return $temp;
2078 }
2079
2080 /**
2081  * As for wfSetVar except setting a bit
2082  *
2083  * @param int $dest
2084  * @param int $bit
2085  * @param bool $state
2086  *
2087  * @return bool
2088  */
2089 function wfSetBit( &$dest, $bit, $state = true ) {
2090         $temp = (bool)( $dest & $bit );
2091         if ( !is_null( $state ) ) {
2092                 if ( $state ) {
2093                         $dest |= $bit;
2094                 } else {
2095                         $dest &= ~$bit;
2096                 }
2097         }
2098         return $temp;
2099 }
2100
2101 /**
2102  * A wrapper around the PHP function var_export().
2103  * Either print it or add it to the regular output ($wgOut).
2104  *
2105  * @param mixed $var A PHP variable to dump.
2106  */
2107 function wfVarDump( $var ) {
2108         global $wgOut;
2109         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2110         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2111                 print $s;
2112         } else {
2113                 $wgOut->addHTML( $s );
2114         }
2115 }
2116
2117 /**
2118  * Provide a simple HTTP error.
2119  *
2120  * @param int|string $code
2121  * @param string $label
2122  * @param string $desc
2123  */
2124 function wfHttpError( $code, $label, $desc ) {
2125         global $wgOut;
2126         header( "HTTP/1.0 $code $label" );
2127         header( "Status: $code $label" );
2128         if ( $wgOut ) {
2129                 $wgOut->disable();
2130                 $wgOut->sendCacheControl();
2131         }
2132
2133         header( 'Content-type: text/html; charset=utf-8' );
2134         print "<!doctype html>" .
2135                 '<html><head><title>' .
2136                 htmlspecialchars( $label ) .
2137                 '</title></head><body><h1>' .
2138                 htmlspecialchars( $label ) .
2139                 '</h1><p>' .
2140                 nl2br( htmlspecialchars( $desc ) ) .
2141                 "</p></body></html>\n";
2142 }
2143
2144 /**
2145  * Clear away any user-level output buffers, discarding contents.
2146  *
2147  * Suitable for 'starting afresh', for instance when streaming
2148  * relatively large amounts of data without buffering, or wanting to
2149  * output image files without ob_gzhandler's compression.
2150  *
2151  * The optional $resetGzipEncoding parameter controls suppression of
2152  * the Content-Encoding header sent by ob_gzhandler; by default it
2153  * is left. See comments for wfClearOutputBuffers() for why it would
2154  * be used.
2155  *
2156  * Note that some PHP configuration options may add output buffer
2157  * layers which cannot be removed; these are left in place.
2158  *
2159  * @param bool $resetGzipEncoding
2160  */
2161 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2162         if ( $resetGzipEncoding ) {
2163                 // Suppress Content-Encoding and Content-Length
2164                 // headers from 1.10+s wfOutputHandler
2165                 global $wgDisableOutputCompression;
2166                 $wgDisableOutputCompression = true;
2167         }
2168         while ( $status = ob_get_status() ) {
2169                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2170                         // Probably from zlib.output_compression or other
2171                         // PHP-internal setting which can't be removed.
2172                         //
2173                         // Give up, and hope the result doesn't break
2174                         // output behavior.
2175                         break;
2176                 }
2177                 if ( !ob_end_clean() ) {
2178                         // Could not remove output buffer handler; abort now
2179                         // to avoid getting in some kind of infinite loop.
2180                         break;
2181                 }
2182                 if ( $resetGzipEncoding ) {
2183                         if ( $status['name'] == 'ob_gzhandler' ) {
2184                                 // Reset the 'Content-Encoding' field set by this handler
2185                                 // so we can start fresh.
2186                                 header_remove( 'Content-Encoding' );
2187                                 break;
2188                         }
2189                 }
2190         }
2191 }
2192
2193 /**
2194  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2195  *
2196  * Clear away output buffers, but keep the Content-Encoding header
2197  * produced by ob_gzhandler, if any.
2198  *
2199  * This should be used for HTTP 304 responses, where you need to
2200  * preserve the Content-Encoding header of the real result, but
2201  * also need to suppress the output of ob_gzhandler to keep to spec
2202  * and avoid breaking Firefox in rare cases where the headers and
2203  * body are broken over two packets.
2204  */
2205 function wfClearOutputBuffers() {
2206         wfResetOutputBuffers( false );
2207 }
2208
2209 /**
2210  * Converts an Accept-* header into an array mapping string values to quality
2211  * factors
2212  *
2213  * @param string $accept
2214  * @param string $def Default
2215  * @return float[] Associative array of string => float pairs
2216  */
2217 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2218         # No arg means accept anything (per HTTP spec)
2219         if ( !$accept ) {
2220                 return array( $def => 1.0 );
2221         }
2222
2223         $prefs = array();
2224
2225         $parts = explode( ',', $accept );
2226
2227         foreach ( $parts as $part ) {
2228                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2229                 $values = explode( ';', trim( $part ) );
2230                 $match = array();
2231                 if ( count( $values ) == 1 ) {
2232                         $prefs[$values[0]] = 1.0;
2233                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2234                         $prefs[$values[0]] = floatval( $match[1] );
2235                 }
2236         }
2237
2238         return $prefs;
2239 }
2240
2241 /**
2242  * Checks if a given MIME type matches any of the keys in the given
2243  * array. Basic wildcards are accepted in the array keys.
2244  *
2245  * Returns the matching MIME type (or wildcard) if a match, otherwise
2246  * NULL if no match.
2247  *
2248  * @param string $type
2249  * @param array $avail
2250  * @return string
2251  * @private
2252  */
2253 function mimeTypeMatch( $type, $avail ) {
2254         if ( array_key_exists( $type, $avail ) ) {
2255                 return $type;
2256         } else {
2257                 $parts = explode( '/', $type );
2258                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2259                         return $parts[0] . '/*';
2260                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2261                         return '*/*';
2262                 } else {
2263                         return null;
2264                 }
2265         }
2266 }
2267
2268 /**
2269  * Returns the 'best' match between a client's requested internet media types
2270  * and the server's list of available types. Each list should be an associative
2271  * array of type to preference (preference is a float between 0.0 and 1.0).
2272  * Wildcards in the types are acceptable.
2273  *
2274  * @param array $cprefs Client's acceptable type list
2275  * @param array $sprefs Server's offered types
2276  * @return string
2277  *
2278  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2279  * XXX: generalize to negotiate other stuff
2280  */
2281 function wfNegotiateType( $cprefs, $sprefs ) {
2282         $combine = array();
2283
2284         foreach ( array_keys( $sprefs ) as $type ) {
2285                 $parts = explode( '/', $type );
2286                 if ( $parts[1] != '*' ) {
2287                         $ckey = mimeTypeMatch( $type, $cprefs );
2288                         if ( $ckey ) {
2289                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2290                         }
2291                 }
2292         }
2293
2294         foreach ( array_keys( $cprefs ) as $type ) {
2295                 $parts = explode( '/', $type );
2296                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2297                         $skey = mimeTypeMatch( $type, $sprefs );
2298                         if ( $skey ) {
2299                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2300                         }
2301                 }
2302         }
2303
2304         $bestq = 0;
2305         $besttype = null;
2306
2307         foreach ( array_keys( $combine ) as $type ) {
2308                 if ( $combine[$type] > $bestq ) {
2309                         $besttype = $type;
2310                         $bestq = $combine[$type];
2311                 }
2312         }
2313
2314         return $besttype;
2315 }
2316
2317 /**
2318  * Reference-counted warning suppression
2319  *
2320  * @param bool $end
2321  */
2322 function wfSuppressWarnings( $end = false ) {
2323         static $suppressCount = 0;
2324         static $originalLevel = false;
2325
2326         if ( $end ) {
2327                 if ( $suppressCount ) {
2328                         --$suppressCount;
2329                         if ( !$suppressCount ) {
2330                                 error_reporting( $originalLevel );
2331                         }
2332                 }
2333         } else {
2334                 if ( !$suppressCount ) {
2335                         $originalLevel = error_reporting( E_ALL & ~(
2336                                 E_WARNING |
2337                                 E_NOTICE |
2338                                 E_USER_WARNING |
2339                                 E_USER_NOTICE |
2340                                 E_DEPRECATED |
2341                                 E_USER_DEPRECATED |
2342                                 E_STRICT
2343                         ) );
2344                 }
2345                 ++$suppressCount;
2346         }
2347 }
2348
2349 /**
2350  * Restore error level to previous value
2351  */
2352 function wfRestoreWarnings() {
2353         wfSuppressWarnings( true );
2354 }
2355
2356 # Autodetect, convert and provide timestamps of various types
2357
2358 /**
2359  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2360  */
2361 define( 'TS_UNIX', 0 );
2362
2363 /**
2364  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2365  */
2366 define( 'TS_MW', 1 );
2367
2368 /**
2369  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2370  */
2371 define( 'TS_DB', 2 );
2372
2373 /**
2374  * RFC 2822 format, for E-mail and HTTP headers
2375  */
2376 define( 'TS_RFC2822', 3 );
2377
2378 /**
2379  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2380  *
2381  * This is used by Special:Export
2382  */
2383 define( 'TS_ISO_8601', 4 );
2384
2385 /**
2386  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2387  *
2388  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2389  *       DateTime tag and page 36 for the DateTimeOriginal and
2390  *       DateTimeDigitized tags.
2391  */
2392 define( 'TS_EXIF', 5 );
2393
2394 /**
2395  * Oracle format time.
2396  */
2397 define( 'TS_ORACLE', 6 );
2398
2399 /**
2400  * Postgres format time.
2401  */
2402 define( 'TS_POSTGRES', 7 );
2403
2404 /**
2405  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2406  */
2407 define( 'TS_ISO_8601_BASIC', 9 );
2408
2409 /**
2410  * Get a timestamp string in one of various formats
2411  *
2412  * @param mixed $outputtype A timestamp in one of the supported formats, the
2413  *   function will autodetect which format is supplied and act accordingly.
2414  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2415  * @return string|bool String / false The same date in the format specified in $outputtype or false
2416  */
2417 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2418         try {
2419                 $timestamp = new MWTimestamp( $ts );
2420                 return $timestamp->getTimestamp( $outputtype );
2421         } catch ( TimestampException $e ) {
2422                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2423                 return false;
2424         }
2425 }
2426
2427 /**
2428  * Return a formatted timestamp, or null if input is null.
2429  * For dealing with nullable timestamp columns in the database.
2430  *
2431  * @param int $outputtype
2432  * @param string $ts
2433  * @return string
2434  */
2435 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2436         if ( is_null( $ts ) ) {
2437                 return null;
2438         } else {
2439                 return wfTimestamp( $outputtype, $ts );
2440         }
2441 }
2442
2443 /**
2444  * Convenience function; returns MediaWiki timestamp for the present time.
2445  *
2446  * @return string
2447  */
2448 function wfTimestampNow() {
2449         # return NOW
2450         return wfTimestamp( TS_MW, time() );
2451 }
2452
2453 /**
2454  * Check if the operating system is Windows
2455  *
2456  * @return bool True if it's Windows, false otherwise.
2457  */
2458 function wfIsWindows() {
2459         static $isWindows = null;
2460         if ( $isWindows === null ) {
2461                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2462         }
2463         return $isWindows;
2464 }
2465
2466 /**
2467  * Check if we are running under HHVM
2468  *
2469  * @return bool
2470  */
2471 function wfIsHHVM() {
2472         return defined( 'HHVM_VERSION' );
2473 }
2474
2475 /**
2476  * Swap two variables
2477  *
2478  * @deprecated since 1.24
2479  * @param mixed $x
2480  * @param mixed $y
2481  */
2482 function swap( &$x, &$y ) {
2483         wfDeprecated( __FUNCTION__, '1.24' );
2484         $z = $x;
2485         $x = $y;
2486         $y = $z;
2487 }
2488
2489 /**
2490  * Tries to get the system directory for temporary files. First
2491  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2492  * environment variables are then checked in sequence, and if none are
2493  * set try sys_get_temp_dir().
2494  *
2495  * NOTE: When possible, use instead the tmpfile() function to create
2496  * temporary files to avoid race conditions on file creation, etc.
2497  *
2498  * @return string
2499  */
2500 function wfTempDir() {
2501         global $wgTmpDirectory;
2502
2503         if ( $wgTmpDirectory !== false ) {
2504                 return $wgTmpDirectory;
2505         }
2506
2507         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2508
2509         foreach ( $tmpDir as $tmp ) {
2510                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2511                         return $tmp;
2512                 }
2513         }
2514         return sys_get_temp_dir();
2515 }
2516
2517 /**
2518  * Make directory, and make all parent directories if they don't exist
2519  *
2520  * @param string $dir Full path to directory to create
2521  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2522  * @param string $caller Optional caller param for debugging.
2523  * @throws MWException
2524  * @return bool
2525  */
2526 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2527         global $wgDirectoryMode;
2528
2529         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2530                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2531         }
2532
2533         if ( !is_null( $caller ) ) {
2534                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2535         }
2536
2537         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2538                 return true;
2539         }
2540
2541         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2542
2543         if ( is_null( $mode ) ) {
2544                 $mode = $wgDirectoryMode;
2545         }
2546
2547         // Turn off the normal warning, we're doing our own below
2548         wfSuppressWarnings();
2549         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2550         wfRestoreWarnings();
2551
2552         if ( !$ok ) {
2553                 //directory may have been created on another request since we last checked
2554                 if ( is_dir( $dir ) ) {
2555                         return true;
2556                 }
2557
2558                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2559                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2560         }
2561         return $ok;
2562 }
2563
2564 /**
2565  * Remove a directory and all its content.
2566  * Does not hide error.
2567  * @param string $dir
2568  */
2569 function wfRecursiveRemoveDir( $dir ) {
2570         wfDebug( __FUNCTION__ . "( $dir )\n" );
2571         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2572         if ( is_dir( $dir ) ) {
2573                 $objects = scandir( $dir );
2574                 foreach ( $objects as $object ) {
2575                         if ( $object != "." && $object != ".." ) {
2576                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2577                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2578                                 } else {
2579                                         unlink( $dir . '/' . $object );
2580                                 }
2581                         }
2582                 }
2583                 reset( $objects );
2584                 rmdir( $dir );
2585         }
2586 }
2587
2588 /**
2589  * @param int $nr The number to format
2590  * @param int $acc The number of digits after the decimal point, default 2
2591  * @param bool $round Whether or not to round the value, default true
2592  * @return string
2593  */
2594 function wfPercent( $nr, $acc = 2, $round = true ) {
2595         $ret = sprintf( "%.${acc}f", $nr );
2596         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2597 }
2598
2599 /**
2600  * Safety wrapper around ini_get() for boolean settings.
2601  * The values returned from ini_get() are pre-normalized for settings
2602  * set via php.ini or php_flag/php_admin_flag... but *not*
2603  * for those set via php_value/php_admin_value.
2604  *
2605  * It's fairly common for people to use php_value instead of php_flag,
2606  * which can leave you with an 'off' setting giving a false positive
2607  * for code that just takes the ini_get() return value as a boolean.
2608  *
2609  * To make things extra interesting, setting via php_value accepts
2610  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2611  * Unrecognized values go false... again opposite PHP's own coercion
2612  * from string to bool.
2613  *
2614  * Luckily, 'properly' set settings will always come back as '0' or '1',
2615  * so we only have to worry about them and the 'improper' settings.
2616  *
2617  * I frickin' hate PHP... :P
2618  *
2619  * @param string $setting
2620  * @return bool
2621  */
2622 function wfIniGetBool( $setting ) {
2623         $val = strtolower( ini_get( $setting ) );
2624         // 'on' and 'true' can't have whitespace around them, but '1' can.
2625         return $val == 'on'
2626                 || $val == 'true'
2627                 || $val == 'yes'
2628                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2629 }
2630
2631 /**
2632  * Windows-compatible version of escapeshellarg()
2633  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2634  * function puts single quotes in regardless of OS.
2635  *
2636  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2637  * earlier distro releases of PHP)
2638  *
2639  * @param string ... strings to escape and glue together, or a single array of strings parameter
2640  * @return string
2641  */
2642 function wfEscapeShellArg( /*...*/ ) {
2643         wfInitShellLocale();
2644
2645         $args = func_get_args();
2646         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2647                 // If only one argument has been passed, and that argument is an array,
2648                 // treat it as a list of arguments
2649                 $args = reset( $args );
2650         }
2651
2652         $first = true;
2653         $retVal = '';
2654         foreach ( $args as $arg ) {
2655                 if ( !$first ) {
2656                         $retVal .= ' ';
2657                 } else {
2658                         $first = false;
2659                 }
2660
2661                 if ( wfIsWindows() ) {
2662                         // Escaping for an MSVC-style command line parser and CMD.EXE
2663                         // @codingStandardsIgnoreStart For long URLs
2664                         // Refs:
2665                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2666                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2667                         //  * Bug #13518
2668                         //  * CR r63214
2669                         // Double the backslashes before any double quotes. Escape the double quotes.
2670                         // @codingStandardsIgnoreEnd
2671                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2672                         $arg = '';
2673                         $iteration = 0;
2674                         foreach ( $tokens as $token ) {
2675                                 if ( $iteration % 2 == 1 ) {
2676                                         // Delimiter, a double quote preceded by zero or more slashes
2677                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2678                                 } elseif ( $iteration % 4 == 2 ) {
2679                                         // ^ in $token will be outside quotes, need to be escaped
2680                                         $arg .= str_replace( '^', '^^', $token );
2681                                 } else { // $iteration % 4 == 0
2682                                         // ^ in $token will appear inside double quotes, so leave as is
2683                                         $arg .= $token;
2684                                 }
2685                                 $iteration++;
2686                         }
2687                         // Double the backslashes before the end of the string, because
2688                         // we will soon add a quote
2689                         $m = array();
2690                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2691                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2692                         }
2693
2694                         // Add surrounding quotes
2695                         $retVal .= '"' . $arg . '"';
2696                 } else {
2697                         $retVal .= escapeshellarg( $arg );
2698                 }
2699         }
2700         return $retVal;
2701 }
2702
2703 /**
2704  * Check if wfShellExec() is effectively disabled via php.ini config
2705  *
2706  * @return bool|string False or one of (safemode,disabled)
2707  * @since 1.22
2708  */
2709 function wfShellExecDisabled() {
2710         static $disabled = null;
2711         if ( is_null( $disabled ) ) {
2712                 if ( wfIniGetBool( 'safe_mode' ) ) {
2713                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2714                         $disabled = 'safemode';
2715                 } elseif ( !function_exists( 'proc_open' ) ) {
2716                         wfDebug( "proc_open() is disabled\n" );
2717                         $disabled = 'disabled';
2718                 } else {
2719                         $disabled = false;
2720                 }
2721         }
2722         return $disabled;
2723 }
2724
2725 /**
2726  * Execute a shell command, with time and memory limits mirrored from the PHP
2727  * configuration if supported.
2728  *
2729  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2730  *   or an array of unescaped arguments, in which case each value will be escaped
2731  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2732  * @param null|mixed &$retval Optional, will receive the program's exit code.
2733  *   (non-zero is usually failure). If there is an error from
2734  *   read, select, or proc_open(), this will be set to -1.
2735  * @param array $environ Optional environment variables which should be
2736  *   added to the executed command environment.
2737  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2738  *   this overwrites the global wgMaxShell* limits.
2739  * @param array $options Array of options:
2740  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2741  *     including errors from limit.sh
2742  *   - profileMethod: By default this function will profile based on the calling
2743  *     method. Set this to a string for an alternative method to profile from
2744  *
2745  * @return string Collected stdout as a string
2746  */
2747 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2748         $limits = array(), $options = array()
2749 ) {
2750         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2751                 $wgMaxShellWallClockTime, $wgShellCgroup;
2752
2753         $disabled = wfShellExecDisabled();
2754         if ( $disabled ) {
2755                 $retval = 1;
2756                 return $disabled == 'safemode' ?
2757                         'Unable to run external programs in safe mode.' :
2758                         'Unable to run external programs, proc_open() is disabled.';
2759         }
2760
2761         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2762         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2763
2764         wfInitShellLocale();
2765
2766         $envcmd = '';
2767         foreach ( $environ as $k => $v ) {
2768                 if ( wfIsWindows() ) {
2769                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2770                          * appear in the environment variable, so we must use carat escaping as documented in
2771                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2772                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2773                          * are listed there but doesn't appear to need it.
2774                          */
2775                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2776                 } else {
2777                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2778                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2779                          */
2780                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2781                 }
2782         }
2783         if ( is_array( $cmd ) ) {
2784                 $cmd = wfEscapeShellArg( $cmd );
2785         }
2786
2787         $cmd = $envcmd . $cmd;
2788
2789         $useLogPipe = false;
2790         if ( is_executable( '/bin/bash' ) ) {
2791                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2792                 if ( isset( $limits['walltime'] ) ) {
2793                         $wallTime = intval( $limits['walltime'] );
2794                 } elseif ( isset( $limits['time'] ) ) {
2795                         $wallTime = $time;
2796                 } else {
2797                         $wallTime = intval( $wgMaxShellWallClockTime );
2798                 }
2799                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2800                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2801
2802                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2803                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2804                                 escapeshellarg( $cmd ) . ' ' .
2805                                 escapeshellarg(
2806                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2807                                         "MW_CPU_LIMIT=$time; " .
2808                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2809                                         "MW_MEM_LIMIT=$mem; " .
2810                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2811                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2812                                         "MW_USE_LOG_PIPE=yes"
2813                                 );
2814                         $useLogPipe = true;
2815                 } elseif ( $includeStderr ) {
2816                         $cmd .= ' 2>&1';
2817                 }
2818         } elseif ( $includeStderr ) {
2819                 $cmd .= ' 2>&1';
2820         }
2821         wfDebug( "wfShellExec: $cmd\n" );
2822
2823         $desc = array(
2824                 0 => array( 'file', 'php://stdin', 'r' ),
2825                 1 => array( 'pipe', 'w' ),
2826                 2 => array( 'file', 'php://stderr', 'w' ) );
2827         if ( $useLogPipe ) {
2828                 $desc[3] = array( 'pipe', 'w' );
2829         }
2830         $pipes = null;
2831         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2832         $proc = proc_open( $cmd, $desc, $pipes );
2833         if ( !$proc ) {
2834                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2835                 $retval = -1;
2836                 return '';
2837         }
2838         $outBuffer = $logBuffer = '';
2839         $emptyArray = array();
2840         $status = false;
2841         $logMsg = false;
2842
2843         // According to the documentation, it is possible for stream_select()
2844         // to fail due to EINTR. I haven't managed to induce this in testing
2845         // despite sending various signals. If it did happen, the error
2846         // message would take the form:
2847         //
2848         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2849         //
2850         // where [4] is the value of the macro EINTR and "Interrupted system
2851         // call" is string which according to the Linux manual is "possibly"
2852         // localised according to LC_MESSAGES.
2853         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2854         $eintrMessage = "stream_select(): unable to select [$eintr]";
2855
2856         // Build a table mapping resource IDs to pipe FDs to work around a
2857         // PHP 5.3 issue in which stream_select() does not preserve array keys
2858         // <https://bugs.php.net/bug.php?id=53427>.
2859         $fds = array();
2860         foreach ( $pipes as $fd => $pipe ) {
2861                 $fds[(int)$pipe] = $fd;
2862         }
2863
2864         $running = true;
2865         $timeout = null;
2866         $numReadyPipes = 0;
2867
2868         while ( $running === true || $numReadyPipes !== 0 ) {
2869                 if ( $running ) {
2870                         $status = proc_get_status( $proc );
2871                         // If the process has terminated, switch to nonblocking selects
2872                         // for getting any data still waiting to be read.
2873                         if ( !$status['running'] ) {
2874                                 $running = false;
2875                                 $timeout = 0;
2876                         }
2877                 }
2878
2879                 $readyPipes = $pipes;
2880
2881                 // Clear last error
2882                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2883                 @trigger_error( '' );
2884                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2885                 if ( $numReadyPipes === false ) {
2886                         // @codingStandardsIgnoreEnd
2887                         $error = error_get_last();
2888                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2889                                 continue;
2890                         } else {
2891                                 trigger_error( $error['message'], E_USER_WARNING );
2892                                 $logMsg = $error['message'];
2893                                 break;
2894                         }
2895                 }
2896                 foreach ( $readyPipes as $pipe ) {
2897                         $block = fread( $pipe, 65536 );
2898                         $fd = $fds[(int)$pipe];
2899                         if ( $block === '' ) {
2900                                 // End of file
2901                                 fclose( $pipes[$fd] );
2902                                 unset( $pipes[$fd] );
2903                                 if ( !$pipes ) {
2904                                         break 2;
2905                                 }
2906                         } elseif ( $block === false ) {
2907                                 // Read error
2908                                 $logMsg = "Error reading from pipe";
2909                                 break 2;
2910                         } elseif ( $fd == 1 ) {
2911                                 // From stdout
2912                                 $outBuffer .= $block;
2913                         } elseif ( $fd == 3 ) {
2914                                 // From log FD
2915                                 $logBuffer .= $block;
2916                                 if ( strpos( $block, "\n" ) !== false ) {
2917                                         $lines = explode( "\n", $logBuffer );
2918                                         $logBuffer = array_pop( $lines );
2919                                         foreach ( $lines as $line ) {
2920                                                 wfDebugLog( 'exec', $line );
2921                                         }
2922                                 }
2923                         }
2924                 }
2925         }
2926
2927         foreach ( $pipes as $pipe ) {
2928                 fclose( $pipe );
2929         }
2930
2931         // Use the status previously collected if possible, since proc_get_status()
2932         // just calls waitpid() which will not return anything useful the second time.
2933         if ( $running ) {
2934                 $status = proc_get_status( $proc );
2935         }
2936
2937         if ( $logMsg !== false ) {
2938                 // Read/select error
2939                 $retval = -1;
2940                 proc_close( $proc );
2941         } elseif ( $status['signaled'] ) {
2942                 $logMsg = "Exited with signal {$status['termsig']}";
2943                 $retval = 128 + $status['termsig'];
2944                 proc_close( $proc );
2945         } else {
2946                 if ( $status['running'] ) {
2947                         $retval = proc_close( $proc );
2948                 } else {
2949                         $retval = $status['exitcode'];
2950                         proc_close( $proc );
2951                 }
2952                 if ( $retval == 127 ) {
2953                         $logMsg = "Possibly missing executable file";
2954                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2955                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2956                 }
2957         }
2958
2959         if ( $logMsg !== false ) {
2960                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2961         }
2962
2963         return $outBuffer;
2964 }
2965
2966 /**
2967  * Execute a shell command, returning both stdout and stderr. Convenience
2968  * function, as all the arguments to wfShellExec can become unwieldy.
2969  *
2970  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2971  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2972  *   or an array of unescaped arguments, in which case each value will be escaped
2973  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2974  * @param null|mixed &$retval Optional, will receive the program's exit code.
2975  *   (non-zero is usually failure)
2976  * @param array $environ Optional environment variables which should be
2977  *   added to the executed command environment.
2978  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2979  *   this overwrites the global wgMaxShell* limits.
2980  * @return string Collected stdout and stderr as a string
2981  */
2982 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2983         return wfShellExec( $cmd, $retval, $environ, $limits,
2984                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2985 }
2986
2987 /**
2988  * Workaround for http://bugs.php.net/bug.php?id=45132
2989  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2990  */
2991 function wfInitShellLocale() {
2992         static $done = false;
2993         if ( $done ) {
2994                 return;
2995         }
2996         $done = true;
2997         global $wgShellLocale;
2998         if ( !wfIniGetBool( 'safe_mode' ) ) {
2999                 putenv( "LC_CTYPE=$wgShellLocale" );
3000                 setlocale( LC_CTYPE, $wgShellLocale );
3001         }
3002 }
3003
3004 /**
3005  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3006  * Note that $parameters should be a flat array and an option with an argument
3007  * should consist of two consecutive items in the array (do not use "--option value").
3008  *
3009  * @param string $script MediaWiki cli script path
3010  * @param array $parameters Arguments and options to the script
3011  * @param array $options Associative array of options:
3012  *              'php': The path to the php executable
3013  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3014  * @return string
3015  */
3016 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3017         global $wgPhpCli;
3018         // Give site config file a chance to run the script in a wrapper.
3019         // The caller may likely want to call wfBasename() on $script.
3020         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3021         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3022         if ( isset( $options['wrapper'] ) ) {
3023                 $cmd[] = $options['wrapper'];
3024         }
3025         $cmd[] = $script;
3026         // Escape each parameter for shell
3027         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
3028 }
3029
3030 /**
3031  * wfMerge attempts to merge differences between three texts.
3032  * Returns true for a clean merge and false for failure or a conflict.
3033  *
3034  * @param string $old
3035  * @param string $mine
3036  * @param string $yours
3037  * @param string $result
3038  * @return bool
3039  */
3040 function wfMerge( $old, $mine, $yours, &$result ) {
3041         global $wgDiff3;
3042
3043         # This check may also protect against code injection in
3044         # case of broken installations.
3045         wfSuppressWarnings();
3046         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3047         wfRestoreWarnings();
3048
3049         if ( !$haveDiff3 ) {
3050                 wfDebug( "diff3 not found\n" );
3051                 return false;
3052         }
3053
3054         # Make temporary files
3055         $td = wfTempDir();
3056         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3057         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3058         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3059
3060         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3061         #       a newline character. To avoid this, we normalize the trailing whitespace before
3062         #       creating the diff.
3063
3064         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3065         fclose( $oldtextFile );
3066         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3067         fclose( $mytextFile );
3068         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3069         fclose( $yourtextFile );
3070
3071         # Check for a conflict
3072         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName, $oldtextName, $yourtextName );
3073         $handle = popen( $cmd, 'r' );
3074
3075         if ( fgets( $handle, 1024 ) ) {
3076                 $conflict = true;
3077         } else {
3078                 $conflict = false;
3079         }
3080         pclose( $handle );
3081
3082         # Merge differences
3083         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName, $oldtextName, $yourtextName );
3084         $handle = popen( $cmd, 'r' );
3085         $result = '';
3086         do {
3087                 $data = fread( $handle, 8192 );
3088                 if ( strlen( $data ) == 0 ) {
3089                         break;
3090                 }
3091                 $result .= $data;
3092         } while ( true );
3093         pclose( $handle );
3094         unlink( $mytextName );
3095         unlink( $oldtextName );
3096         unlink( $yourtextName );
3097
3098         if ( $result === '' && $old !== '' && !$conflict ) {
3099                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3100                 $conflict = true;
3101         }
3102         return !$conflict;
3103 }
3104
3105 /**
3106  * Returns unified plain-text diff of two texts.
3107  * "Useful" for machine processing of diffs.
3108  *
3109  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3110  *
3111  * @param string $before The text before the changes.
3112  * @param string $after The text after the changes.
3113  * @param string $params Command-line options for the diff command.
3114  * @return string Unified diff of $before and $after
3115  */
3116 function wfDiff( $before, $after, $params = '-u' ) {
3117         if ( $before == $after ) {
3118                 return '';
3119         }
3120
3121         global $wgDiff;
3122         wfSuppressWarnings();
3123         $haveDiff = $wgDiff && file_exists( $wgDiff );
3124         wfRestoreWarnings();
3125
3126         # This check may also protect against code injection in
3127         # case of broken installations.
3128         if ( !$haveDiff ) {
3129                 wfDebug( "diff executable not found\n" );
3130                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3131                 $format = new UnifiedDiffFormatter();
3132                 return $format->format( $diffs );
3133         }
3134
3135         # Make temporary files
3136         $td = wfTempDir();
3137         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3138         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3139
3140         fwrite( $oldtextFile, $before );
3141         fclose( $oldtextFile );
3142         fwrite( $newtextFile, $after );
3143         fclose( $newtextFile );
3144
3145         // Get the diff of the two files
3146         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3147
3148         $h = popen( $cmd, 'r' );
3149         if ( !$h ) {
3150                 unlink( $oldtextName );
3151                 unlink( $newtextName );
3152                 throw new Exception( __METHOD__ . '(): popen() failed' );
3153         }
3154
3155         $diff = '';
3156
3157         do {
3158                 $data = fread( $h, 8192 );
3159                 if ( strlen( $data ) == 0 ) {
3160                         break;
3161                 }
3162                 $diff .= $data;
3163         } while ( true );
3164
3165         // Clean up
3166         pclose( $h );
3167         unlink( $oldtextName );
3168         unlink( $newtextName );
3169
3170         // Kill the --- and +++ lines. They're not useful.
3171         $diff_lines = explode( "\n", $diff );
3172         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3173                 unset( $diff_lines[0] );
3174         }
3175         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3176                 unset( $diff_lines[1] );
3177         }
3178
3179         $diff = implode( "\n", $diff_lines );
3180
3181         return $diff;
3182 }
3183
3184 /**
3185  * This function works like "use VERSION" in Perl, the program will die with a
3186  * backtrace if the current version of PHP is less than the version provided
3187  *
3188  * This is useful for extensions which due to their nature are not kept in sync
3189  * with releases, and might depend on other versions of PHP than the main code
3190  *
3191  * Note: PHP might die due to parsing errors in some cases before it ever
3192  *       manages to call this function, such is life
3193  *
3194  * @see perldoc -f use
3195  *
3196  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3197  * @throws MWException
3198  */
3199 function wfUsePHP( $req_ver ) {
3200         $php_ver = PHP_VERSION;
3201
3202         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3203                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3204         }
3205 }
3206
3207 /**
3208  * This function works like "use VERSION" in Perl except it checks the version
3209  * of MediaWiki, the program will die with a backtrace if the current version
3210  * of MediaWiki is less than the version provided.
3211  *
3212  * This is useful for extensions which due to their nature are not kept in sync
3213  * with releases
3214  *
3215  * Note: Due to the behavior of PHP's version_compare() which is used in this
3216  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3217  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3218  * targeted version number. For example if you wanted to allow any variation
3219  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3220  * not result in the same comparison due to the internal logic of
3221  * version_compare().
3222  *
3223  * @see perldoc -f use
3224  *
3225  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3226  * @throws MWException
3227  */
3228 function wfUseMW( $req_ver ) {
3229         global $wgVersion;
3230
3231         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3232                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3233         }
3234 }
3235
3236 /**
3237  * Return the final portion of a pathname.
3238  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3239  * http://bugs.php.net/bug.php?id=33898
3240  *
3241  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3242  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3243  *
3244  * @param string $path
3245  * @param string $suffix String to remove if present
3246  * @return string
3247  */
3248 function wfBaseName( $path, $suffix = '' ) {
3249         if ( $suffix == '' ) {
3250                 $encSuffix = '';
3251         } else {
3252                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3253         }
3254
3255         $matches = array();
3256         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3257                 return $matches[1];
3258         } else {
3259                 return '';
3260         }
3261 }
3262
3263 /**
3264  * Generate a relative path name to the given file.
3265  * May explode on non-matching case-insensitive paths,
3266  * funky symlinks, etc.
3267  *
3268  * @param string $path Absolute destination path including target filename
3269  * @param string $from Absolute source path, directory only
3270  * @return string
3271  */
3272 function wfRelativePath( $path, $from ) {
3273         // Normalize mixed input on Windows...
3274         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3275         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3276
3277         // Trim trailing slashes -- fix for drive root
3278         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3279         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3280
3281         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3282         $against = explode( DIRECTORY_SEPARATOR, $from );
3283
3284         if ( $pieces[0] !== $against[0] ) {
3285                 // Non-matching Windows drive letters?
3286                 // Return a full path.
3287                 return $path;
3288         }
3289
3290         // Trim off common prefix
3291         while ( count( $pieces ) && count( $against )
3292                 && $pieces[0] == $against[0] ) {
3293                 array_shift( $pieces );
3294                 array_shift( $against );
3295         }
3296
3297         // relative dots to bump us to the parent
3298         while ( count( $against ) ) {
3299                 array_unshift( $pieces, '..' );
3300                 array_shift( $against );
3301         }
3302
3303         array_push( $pieces, wfBaseName( $path ) );
3304
3305         return implode( DIRECTORY_SEPARATOR, $pieces );
3306 }
3307
3308 /**
3309  * Convert an arbitrarily-long digit string from one numeric base
3310  * to another, optionally zero-padding to a minimum column width.
3311  *
3312  * Supports base 2 through 36; digit values 10-36 are represented
3313  * as lowercase letters a-z. Input is case-insensitive.
3314  *
3315  * @param string $input Input number
3316  * @param int $sourceBase Base of the input number
3317  * @param int $destBase Desired base of the output
3318  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3319  * @param bool $lowercase Whether to output in lowercase or uppercase
3320  * @param string $engine Either "gmp", "bcmath", or "php"
3321  * @return string|bool The output number as a string, or false on error
3322  */
3323 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3324         $lowercase = true, $engine = 'auto'
3325 ) {
3326         $input = (string)$input;
3327         if (
3328                 $sourceBase < 2 ||
3329                 $sourceBase > 36 ||
3330                 $destBase < 2 ||
3331                 $destBase > 36 ||
3332                 $sourceBase != (int)$sourceBase ||
3333                 $destBase != (int)$destBase ||
3334                 $pad != (int)$pad ||
3335                 !preg_match(
3336                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3337                         $input
3338                 )
3339         ) {
3340                 return false;
3341         }
3342
3343         static $baseChars = array(
3344                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3345                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3346                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3347                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3348                 34 => 'y', 35 => 'z',
3349
3350                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3351                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3352                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3353                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3354                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3355                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3356         );
3357
3358         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3359                 // Removing leading zeros works around broken base detection code in
3360                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3361                 // <https://bugs.php.net/bug.php?id=55398>).
3362                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ), $sourceBase ), $destBase );
3363         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3364                 $decimal = '0';
3365                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3366                         $decimal = bcmul( $decimal, $sourceBase );
3367                         $decimal = bcadd( $decimal, $baseChars[$char] );
3368                 }
3369
3370                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3371                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3372                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3373                 }
3374                 // @codingStandardsIgnoreEnd
3375
3376                 $result = strrev( $result );
3377         } else {
3378                 $inDigits = array();
3379                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3380                         $inDigits[] = $baseChars[$char];
3381                 }
3382
3383                 // Iterate over the input, modulo-ing out an output digit
3384                 // at a time until input is gone.
3385                 $result = '';
3386                 while ( $inDigits ) {
3387                         $work = 0;
3388                         $workDigits = array();
3389
3390                         // Long division...
3391                         foreach ( $inDigits as $digit ) {
3392                                 $work *= $sourceBase;
3393                                 $work += $digit;
3394
3395                                 if ( $workDigits || $work >= $destBase ) {
3396                                         $workDigits[] = (int)( $work / $destBase );
3397                                 }
3398                                 $work %= $destBase;
3399                         }
3400
3401                         // All that division leaves us with a remainder,
3402                         // which is conveniently our next output digit.
3403                         $result .= $baseChars[$work];
3404
3405                         // And we continue!
3406                         $inDigits = $workDigits;
3407                 }
3408
3409                 $result = strrev( $result );
3410         }
3411
3412         if ( !$lowercase ) {
3413                 $result = strtoupper( $result );
3414         }
3415
3416         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3417 }
3418
3419 /**
3420  * Check if there is sufficient entropy in php's built-in session generation
3421  *
3422  * @return bool True = there is sufficient entropy
3423  */
3424 function wfCheckEntropy() {
3425         return (
3426                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3427                         || ini_get( 'session.entropy_file' )
3428                 )
3429                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3430 }
3431
3432 /**
3433  * Override session_id before session startup if php's built-in
3434  * session generation code is not secure.
3435  */
3436 function wfFixSessionID() {
3437         // If the cookie or session id is already set we already have a session and should abort
3438         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3439                 return;
3440         }
3441
3442         // PHP's built-in session entropy is enabled if:
3443         // - entropy_file is set or you're on Windows with php 5.3.3+
3444         // - AND entropy_length is > 0
3445         // We treat it as disabled if it doesn't have an entropy length of at least 32
3446         $entropyEnabled = wfCheckEntropy();
3447
3448         // If built-in entropy is not enabled or not sufficient override PHP's
3449         // built in session id generation code
3450         if ( !$entropyEnabled ) {
3451                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3452                         "overriding session id generation using our cryptrand source.\n" );
3453                 session_id( MWCryptRand::generateHex( 32 ) );
3454         }
3455 }
3456
3457 /**
3458  * Reset the session_id
3459  *
3460  * @since 1.22
3461  */
3462 function wfResetSessionID() {
3463         global $wgCookieSecure;
3464         $oldSessionId = session_id();
3465         $cookieParams = session_get_cookie_params();
3466         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3467                 session_regenerate_id( false );
3468         } else {
3469                 $tmp = $_SESSION;
3470                 session_destroy();
3471                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3472                 $_SESSION = $tmp;
3473         }
3474         $newSessionId = session_id();
3475         Hooks::run( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3476 }
3477
3478 /**
3479  * Initialise php session
3480  *
3481  * @param bool $sessionId
3482  */
3483 function wfSetupSession( $sessionId = false ) {
3484         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3485                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3486         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3487                 ObjectCacheSessionHandler::install();
3488         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3489                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3490                 # hasn't already been set to the desired value (that causes errors)
3491                 ini_set( 'session.save_handler', $wgSessionHandler );
3492         }
3493         session_set_cookie_params(
3494                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3495         session_cache_limiter( 'private, must-revalidate' );
3496         if ( $sessionId ) {
3497                 session_id( $sessionId );
3498         } else {
3499                 wfFixSessionID();
3500         }
3501         wfSuppressWarnings();
3502         session_start();
3503         wfRestoreWarnings();
3504 }
3505
3506 /**
3507  * Get an object from the precompiled serialized directory
3508  *
3509  * @param string $name
3510  * @return mixed The variable on success, false on failure
3511  */
3512 function wfGetPrecompiledData( $name ) {
3513         global $IP;
3514
3515         $file = "$IP/serialized/$name";
3516         if ( file_exists( $file ) ) {
3517                 $blob = file_get_contents( $file );
3518                 if ( $blob ) {
3519                         return unserialize( $blob );
3520                 }
3521         }
3522         return false;
3523 }
3524
3525 /**
3526  * Get a cache key
3527  *
3528  * @param string $args,...
3529  * @return string
3530  */
3531 function wfMemcKey( /*...*/ ) {
3532         global $wgCachePrefix;
3533         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3534         $args = func_get_args();
3535         $key = $prefix . ':' . implode( ':', $args );
3536         $key = str_replace( ' ', '_', $key );
3537         return $key;
3538 }
3539
3540 /**
3541  * Get a cache key for a foreign DB
3542  *
3543  * @param string $db
3544  * @param string $prefix
3545  * @param string $args,...
3546  * @return string
3547  */
3548 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3549         $args = array_slice( func_get_args(), 2 );
3550         if ( $prefix ) {
3551                 $key = "$db-$prefix:" . implode( ':', $args );
3552         } else {
3553                 $key = $db . ':' . implode( ':', $args );
3554         }
3555         return str_replace( ' ', '_', $key );
3556 }
3557
3558 /**
3559  * Get an ASCII string identifying this wiki
3560  * This is used as a prefix in memcached keys
3561  *
3562  * @return string
3563  */
3564 function wfWikiID() {
3565         global $wgDBprefix, $wgDBname;
3566         if ( $wgDBprefix ) {
3567                 return "$wgDBname-$wgDBprefix";
3568         } else {
3569                 return $wgDBname;
3570         }
3571 }
3572
3573 /**
3574  * Split a wiki ID into DB name and table prefix
3575  *
3576  * @param string $wiki
3577  *
3578  * @return array
3579  */
3580 function wfSplitWikiID( $wiki ) {
3581         $bits = explode( '-', $wiki, 2 );
3582         if ( count( $bits ) < 2 ) {
3583                 $bits[] = '';
3584         }
3585         return $bits;
3586 }
3587
3588 /**
3589  * Get a Database object.
3590  *
3591  * @param int $db Index of the connection to get. May be DB_MASTER for the
3592  *            master (for write queries), DB_SLAVE for potentially lagged read
3593  *            queries, or an integer >= 0 for a particular server.
3594  *
3595  * @param string|string[] $groups Query groups. An array of group names that this query
3596  *                belongs to. May contain a single string if the query is only
3597  *                in one group.
3598  *
3599  * @param string|bool $wiki The wiki ID, or false for the current wiki
3600  *
3601  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3602  * will always return the same object, unless the underlying connection or load
3603  * balancer is manually destroyed.
3604  *
3605  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3606  * updater to ensure that a proper database is being updated.
3607  *
3608  * @return DatabaseBase
3609  */
3610 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3611         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3612 }
3613
3614 /**
3615  * Get a load balancer object.
3616  *
3617  * @param string|bool $wiki Wiki ID, or false for the current wiki
3618  * @return LoadBalancer
3619  */
3620 function wfGetLB( $wiki = false ) {
3621         return wfGetLBFactory()->getMainLB( $wiki );
3622 }
3623
3624 /**
3625  * Get the load balancer factory object
3626  *
3627  * @return LBFactory
3628  */
3629 function wfGetLBFactory() {
3630         return LBFactory::singleton();
3631 }
3632
3633 /**
3634  * Find a file.
3635  * Shortcut for RepoGroup::singleton()->findFile()
3636  *
3637  * @param string $title String or Title object
3638  * @param array $options Associative array of options (see RepoGroup::findFile)
3639  * @return File|bool File, or false if the file does not exist
3640  */
3641 function wfFindFile( $title, $options = array() ) {
3642         return RepoGroup::singleton()->findFile( $title, $options );
3643 }
3644
3645 /**
3646  * Get an object referring to a locally registered file.
3647  * Returns a valid placeholder object if the file does not exist.
3648  *
3649  * @param Title|string $title
3650  * @return LocalFile|null A File, or null if passed an invalid Title
3651  */
3652 function wfLocalFile( $title ) {
3653         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3654 }
3655
3656 /**
3657  * Should low-performance queries be disabled?
3658  *
3659  * @return bool
3660  * @codeCoverageIgnore
3661  */
3662 function wfQueriesMustScale() {
3663         global $wgMiserMode;
3664         return $wgMiserMode
3665                 || ( SiteStats::pages() > 100000
3666                 && SiteStats::edits() > 1000000
3667                 && SiteStats::users() > 10000 );
3668 }
3669
3670 /**
3671  * Get the path to a specified script file, respecting file
3672  * extensions; this is a wrapper around $wgScriptExtension etc.
3673  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3674  *
3675  * @param string $script Script filename, sans extension
3676  * @return string
3677  */
3678 function wfScript( $script = 'index' ) {
3679         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3680         if ( $script === 'index' ) {
3681                 return $wgScript;
3682         } elseif ( $script === 'load' ) {
3683                 return $wgLoadScript;
3684         } else {
3685                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3686         }
3687 }
3688
3689 /**
3690  * Get the script URL.
3691  *
3692  * @return string Script URL
3693  */
3694 function wfGetScriptUrl() {
3695         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3696                 #
3697                 # as it was called, minus the query string.
3698                 #
3699                 # Some sites use Apache rewrite rules to handle subdomains,
3700                 # and have PHP set up in a weird way that causes PHP_SELF
3701                 # to contain the rewritten URL instead of the one that the
3702                 # outside world sees.
3703                 #
3704                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3705                 # provides containing the "before" URL.
3706                 return $_SERVER['SCRIPT_NAME'];
3707         } else {
3708                 return $_SERVER['URL'];
3709         }
3710 }
3711
3712 /**
3713  * Convenience function converts boolean values into "true"
3714  * or "false" (string) values
3715  *
3716  * @param bool $value
3717  * @return string
3718  */
3719 function wfBoolToStr( $value ) {
3720         return $value ? 'true' : 'false';
3721 }
3722
3723 /**
3724  * Get a platform-independent path to the null file, e.g. /dev/null
3725  *
3726  * @return string
3727  */
3728 function wfGetNull() {
3729         return wfIsWindows() ? 'NUL' : '/dev/null';
3730 }
3731
3732 /**
3733  * Waits for the slaves to catch up to the master position
3734  *
3735  * Use this when updating very large numbers of rows, as in maintenance scripts,
3736  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3737  *
3738  * By default this waits on the main DB cluster of the current wiki.
3739  * If $cluster is set to "*" it will wait on all DB clusters, including
3740  * external ones. If the lag being waiting on is caused by the code that
3741  * does this check, it makes since to use $ifWritesSince, particularly if
3742  * cluster is "*", to avoid excess overhead.
3743  *
3744  * Never call this function after a big DB write that is still in a transaction.
3745  * This only makes sense after the possible lag inducing changes were committed.
3746  *
3747  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3748  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3749  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3750  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3751  * @return bool Success (able to connect and no timeouts reached)
3752  */
3753 function wfWaitForSlaves(
3754         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3755 ) {
3756         // B/C: first argument used to be "max seconds of lag"; ignore such values
3757         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3758
3759         if ( $timeout === null ) {
3760                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3761         }
3762
3763         // Figure out which clusters need to be checked
3764         $lbs = array();
3765         if ( $cluster === '*' ) {
3766                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3767                         $lbs[] = $lb;
3768                 } );
3769         } elseif ( $cluster !== false ) {
3770                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3771         } else {
3772                 $lbs[] = wfGetLB( $wiki );
3773         }
3774
3775         // Get all the master positions of applicable DBs right now.
3776         // This can be faster since waiting on one cluster reduces the
3777         // time needed to wait on the next clusters.
3778         $masterPositions = array_fill( 0, count( $lbs ), false );
3779         foreach ( $lbs as $i => $lb ) {
3780                 // bug 27975 - Don't try to wait for slaves if there are none
3781                 // Prevents permission error when getting master position
3782                 if ( $lb->getServerCount() > 1 ) {
3783                         if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
3784                                 continue; // assume no writes done
3785                         }
3786                         // Use the empty string to not trigger selectDB() since the connection
3787                         // may have been to a server that does not have a DB for the current wiki.
3788                         $dbw = $lb->getConnection( DB_MASTER, array(), '' );
3789                         if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
3790                                 continue; // no writes since the last wait
3791                         }
3792                         $masterPositions[$i] = $dbw->getMasterPos();
3793                 }
3794         }
3795
3796         $ok = true;
3797         foreach ( $lbs as $i => $lb ) {
3798                 if ( $masterPositions[$i] ) {
3799                         // The DBMS may not support getMasterPos() or the whole
3800                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3801                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3802                 }
3803         }
3804
3805         return $ok;
3806 }
3807
3808 /**
3809  * Count down from $seconds to zero on the terminal, with a one-second pause
3810  * between showing each number. For use in command-line scripts.
3811  *
3812  * @codeCoverageIgnore
3813  * @param int $seconds
3814  */
3815 function wfCountDown( $seconds ) {
3816         for ( $i = $seconds; $i >= 0; $i-- ) {
3817                 if ( $i != $seconds ) {
3818                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3819                 }
3820                 echo $i;
3821                 flush();
3822                 if ( $i ) {
3823                         sleep( 1 );
3824                 }
3825         }
3826         echo "\n";
3827 }
3828
3829 /**
3830  * Replace all invalid characters with -
3831  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3832  * By default, $wgIllegalFileChars = ':'
3833  *
3834  * @param string $name Filename to process
3835  * @return string
3836  */
3837 function wfStripIllegalFilenameChars( $name ) {
3838         global $wgIllegalFileChars;
3839         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3840         $name = wfBaseName( $name );
3841         $name = preg_replace(
3842                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3843                 '-',
3844                 $name
3845         );
3846         return $name;
3847 }
3848
3849 /**
3850  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3851  *
3852  * @return int Value the memory limit was set to.
3853  */
3854 function wfMemoryLimit() {
3855         global $wgMemoryLimit;
3856         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3857         if ( $memlimit != -1 ) {
3858                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3859                 if ( $conflimit == -1 ) {
3860                         wfDebug( "Removing PHP's memory limit\n" );
3861                         wfSuppressWarnings();
3862                         ini_set( 'memory_limit', $conflimit );
3863                         wfRestoreWarnings();
3864                         return $conflimit;
3865                 } elseif ( $conflimit > $memlimit ) {
3866                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3867                         wfSuppressWarnings();
3868                         ini_set( 'memory_limit', $conflimit );
3869                         wfRestoreWarnings();
3870                         return $conflimit;
3871                 }
3872         }
3873         return $memlimit;
3874 }
3875
3876 /**
3877  * Converts shorthand byte notation to integer form
3878  *
3879  * @param string $string
3880  * @return int
3881  */
3882 function wfShorthandToInteger( $string = '' ) {
3883         $string = trim( $string );
3884         if ( $string === '' ) {
3885                 return -1;
3886         }
3887         $last = $string[strlen( $string ) - 1];
3888         $val = intval( $string );
3889         switch ( $last ) {
3890                 case 'g':
3891                 case 'G':
3892                         $val *= 1024;
3893                         // break intentionally missing
3894                 case 'm':
3895                 case 'M':
3896                         $val *= 1024;
3897                         // break intentionally missing
3898                 case 'k':
3899                 case 'K':
3900                         $val *= 1024;
3901         }
3902
3903         return $val;
3904 }
3905
3906 /**
3907  * Get the normalised IETF language tag
3908  * See unit test for examples.
3909  *
3910  * @param string $code The language code.
3911  * @return string The language code which complying with BCP 47 standards.
3912  */
3913 function wfBCP47( $code ) {
3914         $codeSegment = explode( '-', $code );
3915         $codeBCP = array();
3916         foreach ( $codeSegment as $segNo => $seg ) {
3917                 // when previous segment is x, it is a private segment and should be lc
3918                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3919                         $codeBCP[$segNo] = strtolower( $seg );
3920                 // ISO 3166 country code
3921                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3922                         $codeBCP[$segNo] = strtoupper( $seg );
3923                 // ISO 15924 script code
3924                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3925                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3926                 // Use lowercase for other cases
3927                 } else {
3928                         $codeBCP[$segNo] = strtolower( $seg );
3929                 }
3930         }
3931         $langCode = implode( '-', $codeBCP );
3932         return $langCode;
3933 }
3934
3935 /**
3936  * Get a cache object.
3937  *
3938  * @param int $inputType Cache type, one of the CACHE_* constants.
3939  * @return BagOStuff
3940  */
3941 function wfGetCache( $inputType ) {
3942         return ObjectCache::getInstance( $inputType );
3943 }
3944
3945 /**
3946  * Get the main cache object
3947  *
3948  * @return BagOStuff
3949  */
3950 function wfGetMainCache() {
3951         global $wgMainCacheType;
3952         return ObjectCache::getInstance( $wgMainCacheType );
3953 }
3954
3955 /**
3956  * Get the cache object used by the message cache
3957  *
3958  * @return BagOStuff
3959  */
3960 function wfGetMessageCacheStorage() {
3961         global $wgMessageCacheType;
3962         return ObjectCache::getInstance( $wgMessageCacheType );
3963 }
3964
3965 /**
3966  * Get the cache object used by the parser cache
3967  *
3968  * @return BagOStuff
3969  */
3970 function wfGetParserCacheStorage() {
3971         global $wgParserCacheType;
3972         return ObjectCache::getInstance( $wgParserCacheType );
3973 }
3974
3975 /**
3976  * Call hook functions defined in $wgHooks
3977  *
3978  * @param string $event Event name
3979  * @param array $args Parameters passed to hook functions
3980  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3981  *
3982  * @return bool True if no handler aborted the hook
3983  * @deprecated 1.25 - use Hooks::run
3984  */
3985 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3986         return Hooks::run( $event, $args, $deprecatedVersion );
3987 }
3988
3989 /**
3990  * Wrapper around php's unpack.
3991  *
3992  * @param string $format The format string (See php's docs)
3993  * @param string $data A binary string of binary data
3994  * @param int|bool $length The minimum length of $data or false. This is to
3995  *      prevent reading beyond the end of $data. false to disable the check.
3996  *
3997  * Also be careful when using this function to read unsigned 32 bit integer
3998  * because php might make it negative.
3999  *
4000  * @throws MWException If $data not long enough, or if unpack fails
4001  * @return array Associative array of the extracted data
4002  */
4003 function wfUnpack( $format, $data, $length = false ) {
4004         if ( $length !== false ) {
4005                 $realLen = strlen( $data );
4006                 if ( $realLen < $length ) {
4007                         throw new MWException( "Tried to use wfUnpack on a "
4008                                 . "string of length $realLen, but needed one "
4009                                 . "of at least length $length."
4010                         );
4011                 }
4012         }
4013
4014         wfSuppressWarnings();
4015         $result = unpack( $format, $data );
4016         wfRestoreWarnings();
4017
4018         if ( $result === false ) {
4019                 // If it cannot extract the packed data.
4020                 throw new MWException( "unpack could not unpack binary data" );
4021         }
4022         return $result;
4023 }
4024
4025 /**
4026  * Determine if an image exists on the 'bad image list'.
4027  *
4028  * The format of MediaWiki:Bad_image_list is as follows:
4029  *    * Only list items (lines starting with "*") are considered
4030  *    * The first link on a line must be a link to a bad image
4031  *    * Any subsequent links on the same line are considered to be exceptions,
4032  *      i.e. articles where the image may occur inline.
4033  *
4034  * @param string $name The image name to check
4035  * @param Title|bool $contextTitle The page on which the image occurs, if known
4036  * @param string $blacklist Wikitext of a file blacklist
4037  * @return bool
4038  */
4039 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4040         static $badImageCache = null; // based on bad_image_list msg
4041
4042         # Handle redirects
4043         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4044         if ( $redirectTitle ) {
4045                 $name = $redirectTitle->getDBkey();
4046         }
4047
4048         # Run the extension hook
4049         $bad = false;
4050         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4051                 return $bad;
4052         }
4053
4054         $cacheable = ( $blacklist === null );
4055         if ( $cacheable && $badImageCache !== null ) {
4056                 $badImages = $badImageCache;
4057         } else { // cache miss
4058                 if ( $blacklist === null ) {
4059                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4060                 }
4061                 # Build the list now
4062                 $badImages = array();
4063                 $lines = explode( "\n", $blacklist );
4064                 foreach ( $lines as $line ) {
4065                         # List items only
4066                         if ( substr( $line, 0, 1 ) !== '*' ) {
4067                                 continue;
4068                         }
4069
4070                         # Find all links
4071                         $m = array();
4072                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4073                                 continue;
4074                         }
4075
4076                         $exceptions = array();
4077                         $imageDBkey = false;
4078                         foreach ( $m[1] as $i => $titleText ) {
4079                                 $title = Title::newFromText( $titleText );
4080                                 if ( !is_null( $title ) ) {
4081                                         if ( $i == 0 ) {
4082                                                 $imageDBkey = $title->getDBkey();
4083                                         } else {
4084                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4085                                         }
4086                                 }
4087                         }
4088
4089                         if ( $imageDBkey !== false ) {
4090                                 $badImages[$imageDBkey] = $exceptions;
4091                         }
4092                 }
4093                 if ( $cacheable ) {
4094                         $badImageCache = $badImages;
4095                 }
4096         }
4097
4098         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4099         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4100         return $bad;
4101 }
4102
4103 /**
4104  * Determine whether the client at a given source IP is likely to be able to
4105  * access the wiki via HTTPS.
4106  *
4107  * @param string $ip The IPv4/6 address in the normal human-readable form
4108  * @return bool
4109  */
4110 function wfCanIPUseHTTPS( $ip ) {
4111         $canDo = true;
4112         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4113         return !!$canDo;
4114 }
4115
4116 /**
4117  * Determine input string is represents as infinity
4118  *
4119  * @param string $str The string to determine
4120  * @return bool
4121  * @since 1.25
4122  */
4123 function wfIsInfinity( $str ) {
4124         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4125         return in_array( $str, $infinityValues );
4126 }
4127
4128 /**
4129  * Work out the IP address based on various globals
4130  * For trusted proxies, use the XFF client IP (first of the chain)
4131  *
4132  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4133  * @return string
4134  */
4135 function wfGetIP() {
4136         wfDeprecated( __METHOD__, '1.19' );
4137         global $wgRequest;
4138         return $wgRequest->getIP();
4139 }
4140
4141 /**
4142  * Checks if an IP is a trusted proxy provider.
4143  * Useful to tell if X-Forwarded-For data is possibly bogus.
4144  * Squid cache servers for the site are whitelisted.
4145  * @deprecated Since 1.24, use IP::isTrustedProxy()
4146  *
4147  * @param string $ip
4148  * @return bool
4149  */
4150 function wfIsTrustedProxy( $ip ) {
4151         wfDeprecated( __METHOD__, '1.24' );
4152         return IP::isTrustedProxy( $ip );
4153 }
4154
4155 /**
4156  * Checks if an IP matches a proxy we've configured.
4157  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4158  *
4159  * @param string $ip
4160  * @return bool
4161  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4162  */
4163 function wfIsConfiguredProxy( $ip ) {
4164         wfDeprecated( __METHOD__, '1.24' );
4165         return IP::isConfiguredProxy( $ip );
4166 }
4167
4168 /**
4169  * Returns true if these thumbnail parameters match one that MediaWiki
4170  * requests from file description pages and/or parser output.
4171  *
4172  * $params is considered non-standard if they involve a non-standard
4173  * width or any non-default parameters aside from width and page number.
4174  * The number of possible files with standard parameters is far less than
4175  * that of all combinations; rate-limiting for them can thus be more generious.
4176  *
4177  * @param File $file
4178  * @param array $params
4179  * @return bool
4180  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4181  */
4182 function wfThumbIsStandard( File $file, array $params ) {
4183         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4184
4185         $multipliers = array( 1 );
4186         if ( $wgResponsiveImages ) {
4187                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4188                 // @see Linker::processResponsiveImages
4189                 $multipliers[] = 1.5;
4190                 $multipliers[] = 2;
4191         }
4192
4193         $handler = $file->getHandler();
4194         if ( !$handler || !isset( $params['width'] ) ) {
4195                 return false;
4196         }
4197
4198         $basicParams = array();
4199         if ( isset( $params['page'] ) ) {
4200                 $basicParams['page'] = $params['page'];
4201         }
4202
4203         $thumbLimits = array();
4204         $imageLimits = array();
4205         // Expand limits to account for multipliers
4206         foreach ( $multipliers as $multiplier ) {
4207                 $thumbLimits = array_merge( $thumbLimits, array_map(
4208                         function ( $width ) use ( $multiplier ) {
4209                                 return round( $width * $multiplier );
4210                         }, $wgThumbLimits )
4211                 );
4212                 $imageLimits = array_merge( $imageLimits, array_map(
4213                         function ( $pair ) use ( $multiplier ) {
4214                                 return array(
4215                                         round( $pair[0] * $multiplier ),
4216                                         round( $pair[1] * $multiplier ),
4217                                 );
4218                         }, $wgImageLimits )
4219                 );
4220         }
4221
4222         // Check if the width matches one of $wgThumbLimits
4223         if ( in_array( $params['width'], $thumbLimits ) ) {
4224                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4225                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4226                 $handler->normaliseParams( $file, $normalParams );
4227         } else {
4228                 // If not, then check if the width matchs one of $wgImageLimits
4229                 $match = false;
4230                 foreach ( $imageLimits as $pair ) {
4231                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4232                         // Decide whether the thumbnail should be scaled on width or height.
4233                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4234                         $handler->normaliseParams( $file, $normalParams );
4235                         // Check if this standard thumbnail size maps to the given width
4236                         if ( $normalParams['width'] == $params['width'] ) {
4237                                 $match = true;
4238                                 break;
4239                         }
4240                 }
4241                 if ( !$match ) {
4242                         return false; // not standard for description pages
4243                 }
4244         }
4245
4246         // Check that the given values for non-page, non-width, params are just defaults
4247         foreach ( $params as $key => $value ) {
4248                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4249                         return false;
4250                 }
4251         }
4252
4253         return true;
4254 }