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\Sender\SocketSender;
  28 use MediaWiki\Logger\LoggerFactory;
  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 $ext 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( $ext, $path = null ) {
 176         if ( !$path ) {
 177                 global $wgExtensionDirectory;
 178                 $path = "$wgExtensionDirectory/$ext/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 $wgExtensionDirectory;
 197         $registry = ExtensionRegistry::getInstance();
 198         foreach ( $exts as $ext ) {
 199                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 200         }
 201 }
 202
 203 /**
 204  * Load a skin
 205  *
 206  * @see wfLoadExtension
 207  * @param string $skin 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( $skin, $path = null ) {
 211         if ( !$path ) {
 212                 global $wgStyleDirectory;
 213                 $path = "$wgStyleDirectory/$skin/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 $wgStyleDirectory;
 226         $registry = ExtensionRegistry::getInstance();
 227         foreach ( $skins as $skin ) {
 228                 $registry->queue( "$wgStyleDirectory/$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  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 405  * character which should not be encoded. More importantly, google chrome
 406  * always converts %7E back to ~, and converting it in this function can
 407  * cause a redirect loop (T105265). Similarly, encoding ' causes a
 408  * redirect loop on Opera 12 (T106793).
 409  *
 410  * But + is not safe because it's used to indicate a space; &= are only safe in
 411  * paths and not in queries (and we don't distinguish here);
 412  * and urlencode() doesn't touch -_. to begin with.  Plus, although /
 413  * is reserved, we don't care.  So the list we unescape is:
 414  *
 415  * ;:@$!*'(),/~
 416  *
 417  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 418  * so no fancy : for IIS7.
 419  *
 420  * %2F in the page titles seems to fatally break for some reason.
 421  *
 422  * @param string $s
 423  * @return string
 424  */
 425 function wfUrlencode( $s ) {
 426         static $needle;
 427
 428         if ( is_null( $s ) ) {
 429                 $needle = null;
 430                 return '';
 431         }
 432
 433         if ( is_null( $needle ) ) {
 434                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%27', '%28', '%29', '%2C', '%2F', '%7E' );
 435                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 436                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 437                 ) {
 438                         $needle[] = '%3A';
 439                 }
 440         }
 441
 442         $s = urlencode( $s );
 443         $s = str_ireplace(
 444                 $needle,
 445                 array( ';', '@', '$', '!', '*', '\'', '(', ')', ',', '/', '~', ':' ),
 446                 $s
 447         );
 448
 449         return $s;
 450 }
 451
 452 /**
 453  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 454  * "days=7&limit=100". Options in the first array override options in the second.
 455  * Options set to null or false will not be output.
 456  *
 457  * @param array $array1 ( String|Array )
 458  * @param array $array2 ( String|Array )
 459  * @param string $prefix
 460  * @return string
 461  */
 462 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 463         if ( !is_null( $array2 ) ) {
 464                 $array1 = $array1 + $array2;
 465         }
 466
 467         $cgi = '';
 468         foreach ( $array1 as $key => $value ) {
 469                 if ( !is_null( $value ) && $value !== false ) {
 470                         if ( $cgi != '' ) {
 471                                 $cgi .= '&';
 472                         }
 473                         if ( $prefix !== '' ) {
 474                                 $key = $prefix . "[$key]";
 475                         }
 476                         if ( is_array( $value ) ) {
 477                                 $firstTime = true;
 478                                 foreach ( $value as $k => $v ) {
 479                                         $cgi .= $firstTime ? '' : '&';
 480                                         if ( is_array( $v ) ) {
 481                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 482                                         } else {
 483                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 484                                         }
 485                                         $firstTime = false;
 486                                 }
 487                         } else {
 488                                 if ( is_object( $value ) ) {
 489                                         $value = $value->__toString();
 490                                 }
 491                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 492                         }
 493                 }
 494         }
 495         return $cgi;
 496 }
 497
 498 /**
 499  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 500  * its argument and returns the same string in array form.  This allows compatibility
 501  * with legacy functions that accept raw query strings instead of nice
 502  * arrays.  Of course, keys and values are urldecode()d.
 503  *
 504  * @param string $query Query string
 505  * @return string[] Array version of input
 506  */
 507 function wfCgiToArray( $query ) {
 508         if ( isset( $query[0] ) && $query[0] == '?' ) {
 509                 $query = substr( $query, 1 );
 510         }
 511         $bits = explode( '&', $query );
 512         $ret = array();
 513         foreach ( $bits as $bit ) {
 514                 if ( $bit === '' ) {
 515                         continue;
 516                 }
 517                 if ( strpos( $bit, '=' ) === false ) {
 518                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 519                         $key = $bit;
 520                         $value = '';
 521                 } else {
 522                         list( $key, $value ) = explode( '=', $bit );
 523                 }
 524                 $key = urldecode( $key );
 525                 $value = urldecode( $value );
 526                 if ( strpos( $key, '[' ) !== false ) {
 527                         $keys = array_reverse( explode( '[', $key ) );
 528                         $key = array_pop( $keys );
 529                         $temp = $value;
 530                         foreach ( $keys as $k ) {
 531                                 $k = substr( $k, 0, -1 );
 532                                 $temp = array( $k => $temp );
 533                         }
 534                         if ( isset( $ret[$key] ) ) {
 535                                 $ret[$key] = array_merge( $ret[$key], $temp );
 536                         } else {
 537                                 $ret[$key] = $temp;
 538                         }
 539                 } else {
 540                         $ret[$key] = $value;
 541                 }
 542         }
 543         return $ret;
 544 }
 545
 546 /**
 547  * Append a query string to an existing URL, which may or may not already
 548  * have query string parameters already. If so, they will be combined.
 549  *
 550  * @param string $url
 551  * @param string|string[] $query String or associative array
 552  * @return string
 553  */
 554 function wfAppendQuery( $url, $query ) {
 555         if ( is_array( $query ) ) {
 556                 $query = wfArrayToCgi( $query );
 557         }
 558         if ( $query != '' ) {
 559                 if ( false === strpos( $url, '?' ) ) {
 560                         $url .= '?';
 561                 } else {
 562                         $url .= '&';
 563                 }
 564                 $url .= $query;
 565         }
 566         return $url;
 567 }
 568
 569 /**
 570  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 571  * is correct.
 572  *
 573  * The meaning of the PROTO_* constants is as follows:
 574  * PROTO_HTTP: Output a URL starting with http://
 575  * PROTO_HTTPS: Output a URL starting with https://
 576  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 577  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 578  *    on which protocol was used for the current incoming request
 579  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 580  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 581  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 582  *
 583  * @todo this won't work with current-path-relative URLs
 584  * like "subdir/foo.html", etc.
 585  *
 586  * @param string $url Either fully-qualified or a local path + query
 587  * @param string $defaultProto One of the PROTO_* constants. Determines the
 588  *    protocol to use if $url or $wgServer is protocol-relative
 589  * @return string Fully-qualified URL, current-path-relative URL or false if
 590  *    no valid URL can be constructed
 591  */
 592 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 593         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 594                 $wgHttpsPort;
 595         if ( $defaultProto === PROTO_CANONICAL ) {
 596                 $serverUrl = $wgCanonicalServer;
 597         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 598                 // Make $wgInternalServer fall back to $wgServer if not set
 599                 $serverUrl = $wgInternalServer;
 600         } else {
 601                 $serverUrl = $wgServer;
 602                 if ( $defaultProto === PROTO_CURRENT ) {
 603                         $defaultProto = $wgRequest->getProtocol() . '://';
 604                 }
 605         }
 606
 607         // Analyze $serverUrl to obtain its protocol
 608         $bits = wfParseUrl( $serverUrl );
 609         $serverHasProto = $bits && $bits['scheme'] != '';
 610
 611         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 612                 if ( $serverHasProto ) {
 613                         $defaultProto = $bits['scheme'] . '://';
 614                 } else {
 615                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 616                         // This really isn't supposed to happen. Fall back to HTTP in this
 617                         // ridiculous case.
 618                         $defaultProto = PROTO_HTTP;
 619                 }
 620         }
 621
 622         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 623
 624         if ( substr( $url, 0, 2 ) == '//' ) {
 625                 $url = $defaultProtoWithoutSlashes . $url;
 626         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 627                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 628                 // otherwise leave it alone.
 629                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 630         }
 631
 632         $bits = wfParseUrl( $url );
 633
 634         // ensure proper port for HTTPS arrives in URL
 635         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 636         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 637                 $bits['port'] = $wgHttpsPort;
 638         }
 639
 640         if ( $bits && isset( $bits['path'] ) ) {
 641                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 642                 return wfAssembleUrl( $bits );
 643         } elseif ( $bits ) {
 644                 # No path to expand
 645                 return $url;
 646         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 647                 # URL is a relative path
 648                 return wfRemoveDotSegments( $url );
 649         }
 650
 651         # Expanded URL is not valid.
 652         return false;
 653 }
 654
 655 /**
 656  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 657  * if you need to edit part of a URL and put it back together.
 658  *
 659  * This is the basic structure used (brackets contain keys for $urlParts):
 660  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 661  *
 662  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 663  *
 664  * @since 1.19
 665  * @param array $urlParts URL parts, as output from wfParseUrl
 666  * @return string URL assembled from its component parts
 667  */
 668 function wfAssembleUrl( $urlParts ) {
 669         $result = '';
 670
 671         if ( isset( $urlParts['delimiter'] ) ) {
 672                 if ( isset( $urlParts['scheme'] ) ) {
 673                         $result .= $urlParts['scheme'];
 674                 }
 675
 676                 $result .= $urlParts['delimiter'];
 677         }
 678
 679         if ( isset( $urlParts['host'] ) ) {
 680                 if ( isset( $urlParts['user'] ) ) {
 681                         $result .= $urlParts['user'];
 682                         if ( isset( $urlParts['pass'] ) ) {
 683                                 $result .= ':' . $urlParts['pass'];
 684                         }
 685                         $result .= '@';
 686                 }
 687
 688                 $result .= $urlParts['host'];
 689
 690                 if ( isset( $urlParts['port'] ) ) {
 691                         $result .= ':' . $urlParts['port'];
 692                 }
 693         }
 694
 695         if ( isset( $urlParts['path'] ) ) {
 696                 $result .= $urlParts['path'];
 697         }
 698
 699         if ( isset( $urlParts['query'] ) ) {
 700                 $result .= '?' . $urlParts['query'];
 701         }
 702
 703         if ( isset( $urlParts['fragment'] ) ) {
 704                 $result .= '#' . $urlParts['fragment'];
 705         }
 706
 707         return $result;
 708 }
 709
 710 /**
 711  * Remove all dot-segments in the provided URL path.  For example,
 712  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 713  * RFC3986 section 5.2.4.
 714  *
 715  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 716  *
 717  * @param string $urlPath URL path, potentially containing dot-segments
 718  * @return string URL path with all dot-segments removed
 719  */
 720 function wfRemoveDotSegments( $urlPath ) {
 721         $output = '';
 722         $inputOffset = 0;
 723         $inputLength = strlen( $urlPath );
 724
 725         while ( $inputOffset < $inputLength ) {
 726                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 727                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 728                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 729                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 730                 $trimOutput = false;
 731
 732                 if ( $prefixLengthTwo == './' ) {
 733                         # Step A, remove leading "./"
 734                         $inputOffset += 2;
 735                 } elseif ( $prefixLengthThree == '../' ) {
 736                         # Step A, remove leading "../"
 737                         $inputOffset += 3;
 738                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 739                         # Step B, replace leading "/.$" with "/"
 740                         $inputOffset += 1;
 741                         $urlPath[$inputOffset] = '/';
 742                 } elseif ( $prefixLengthThree == '/./' ) {
 743                         # Step B, replace leading "/./" with "/"
 744                         $inputOffset += 2;
 745                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 746                         # Step C, replace leading "/..$" with "/" and
 747                         # remove last path component in output
 748                         $inputOffset += 2;
 749                         $urlPath[$inputOffset] = '/';
 750                         $trimOutput = true;
 751                 } elseif ( $prefixLengthFour == '/../' ) {
 752                         # Step C, replace leading "/../" with "/" and
 753                         # remove last path component in output
 754                         $inputOffset += 3;
 755                         $trimOutput = true;
 756                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 757                         # Step D, remove "^.$"
 758                         $inputOffset += 1;
 759                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 760                         # Step D, remove "^..$"
 761                         $inputOffset += 2;
 762                 } else {
 763                         # Step E, move leading path segment to output
 764                         if ( $prefixLengthOne == '/' ) {
 765                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 766                         } else {
 767                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 768                         }
 769                         if ( $slashPos === false ) {
 770                                 $output .= substr( $urlPath, $inputOffset );
 771                                 $inputOffset = $inputLength;
 772                         } else {
 773                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 774                                 $inputOffset += $slashPos - $inputOffset;
 775                         }
 776                 }
 777
 778                 if ( $trimOutput ) {
 779                         $slashPos = strrpos( $output, '/' );
 780                         if ( $slashPos === false ) {
 781                                 $output = '';
 782                         } else {
 783                                 $output = substr( $output, 0, $slashPos );
 784                         }
 785                 }
 786         }
 787
 788         return $output;
 789 }
 790
 791 /**
 792  * Returns a regular expression of url protocols
 793  *
 794  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 795  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 796  * @return string
 797  */
 798 function wfUrlProtocols( $includeProtocolRelative = true ) {
 799         global $wgUrlProtocols;
 800
 801         // Cache return values separately based on $includeProtocolRelative
 802         static $withProtRel = null, $withoutProtRel = null;
 803         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 804         if ( !is_null( $cachedValue ) ) {
 805                 return $cachedValue;
 806         }
 807
 808         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 809         // with LocalSettings files from 1.5
 810         if ( is_array( $wgUrlProtocols ) ) {
 811                 $protocols = array();
 812                 foreach ( $wgUrlProtocols as $protocol ) {
 813                         // Filter out '//' if !$includeProtocolRelative
 814                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 815                                 $protocols[] = preg_quote( $protocol, '/' );
 816                         }
 817                 }
 818
 819                 $retval = implode( '|', $protocols );
 820         } else {
 821                 // Ignore $includeProtocolRelative in this case
 822                 // This case exists for pre-1.6 compatibility, and we can safely assume
 823                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 824                 // URLs weren't supported until 1.18
 825                 $retval = $wgUrlProtocols;
 826         }
 827
 828         // Cache return value
 829         if ( $includeProtocolRelative ) {
 830                 $withProtRel = $retval;
 831         } else {
 832                 $withoutProtRel = $retval;
 833         }
 834         return $retval;
 835 }
 836
 837 /**
 838  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 839  * you need a regex that matches all URL protocols but does not match protocol-
 840  * relative URLs
 841  * @return string
 842  */
 843 function wfUrlProtocolsWithoutProtRel() {
 844         return wfUrlProtocols( false );
 845 }
 846
 847 /**
 848  * parse_url() work-alike, but non-broken.  Differences:
 849  *
 850  * 1) Does not raise warnings on bad URLs (just returns false).
 851  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 852  *    protocol-relative URLs) correctly.
 853  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 854  *
 855  * @param string $url A URL to parse
 856  * @return string[] Bits of the URL in an associative array, per PHP docs
 857  */
 858 function wfParseUrl( $url ) {
 859         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 860
 861         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 862         // bad that the easiest way to handle them is to just prepend 'http:' and
 863         // strip the protocol out later.
 864         $wasRelative = substr( $url, 0, 2 ) == '//';
 865         if ( $wasRelative ) {
 866                 $url = "http:$url";
 867         }
 868         MediaWiki\suppressWarnings();
 869         $bits = parse_url( $url );
 870         MediaWiki\restoreWarnings();
 871         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 872         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 873         if ( !$bits || !isset( $bits['scheme'] ) ) {
 874                 return false;
 875         }
 876
 877         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 878         $bits['scheme'] = strtolower( $bits['scheme'] );
 879
 880         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 881         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 882                 $bits['delimiter'] = '://';
 883         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 884                 $bits['delimiter'] = ':';
 885                 // parse_url detects for news: and mailto: the host part of an url as path
 886                 // We have to correct this wrong detection
 887                 if ( isset( $bits['path'] ) ) {
 888                         $bits['host'] = $bits['path'];
 889                         $bits['path'] = '';
 890                 }
 891         } else {
 892                 return false;
 893         }
 894
 895         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 896         if ( !isset( $bits['host'] ) ) {
 897                 $bits['host'] = '';
 898
 899                 // bug 45069
 900                 if ( isset( $bits['path'] ) ) {
 901                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 902                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 903                                 $bits['path'] = '/' . $bits['path'];
 904                         }
 905                 } else {
 906                         $bits['path'] = '';
 907                 }
 908         }
 909
 910         // If the URL was protocol-relative, fix scheme and delimiter
 911         if ( $wasRelative ) {
 912                 $bits['scheme'] = '';
 913                 $bits['delimiter'] = '//';
 914         }
 915         return $bits;
 916 }
 917
 918 /**
 919  * Take a URL, make sure it's expanded to fully qualified, and replace any
 920  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 921  * for more compact display and legibility for local audiences.
 922  *
 923  * @todo handle punycode domains too
 924  *
 925  * @param string $url
 926  * @return string
 927  */
 928 function wfExpandIRI( $url ) {
 929         return preg_replace_callback(
 930                 '/((?:%[89A-F][0-9A-F])+)/i',
 931                 'wfExpandIRI_callback',
 932                 wfExpandUrl( $url )
 933         );
 934 }
 935
 936 /**
 937  * Private callback for wfExpandIRI
 938  * @param array $matches
 939  * @return string
 940  */
 941 function wfExpandIRI_callback( $matches ) {
 942         return urldecode( $matches[1] );
 943 }
 944
 945 /**
 946  * Make URL indexes, appropriate for the el_index field of externallinks.
 947  *
 948  * @param string $url
 949  * @return array
 950  */
 951 function wfMakeUrlIndexes( $url ) {
 952         $bits = wfParseUrl( $url );
 953
 954         // Reverse the labels in the hostname, convert to lower case
 955         // For emails reverse domainpart only
 956         if ( $bits['scheme'] == 'mailto' ) {
 957                 $mailparts = explode( '@', $bits['host'], 2 );
 958                 if ( count( $mailparts ) === 2 ) {
 959                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 960                 } else {
 961                         // No domain specified, don't mangle it
 962                         $domainpart = '';
 963                 }
 964                 $reversedHost = $domainpart . '@' . $mailparts[0];
 965         } else {
 966                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 967         }
 968         // Add an extra dot to the end
 969         // Why? Is it in wrong place in mailto links?
 970         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 971                 $reversedHost .= '.';
 972         }
 973         // Reconstruct the pseudo-URL
 974         $prot = $bits['scheme'];
 975         $index = $prot . $bits['delimiter'] . $reversedHost;
 976         // Leave out user and password. Add the port, path, query and fragment
 977         if ( isset( $bits['port'] ) ) {
 978                 $index .= ':' . $bits['port'];
 979         }
 980         if ( isset( $bits['path'] ) ) {
 981                 $index .= $bits['path'];
 982         } else {
 983                 $index .= '/';
 984         }
 985         if ( isset( $bits['query'] ) ) {
 986                 $index .= '?' . $bits['query'];
 987         }
 988         if ( isset( $bits['fragment'] ) ) {
 989                 $index .= '#' . $bits['fragment'];
 990         }
 991
 992         if ( $prot == '' ) {
 993                 return array( "http:$index", "https:$index" );
 994         } else {
 995                 return array( $index );
 996         }
 997 }
 998
 999 /**
1000  * Check whether a given URL has a domain that occurs in a given set of domains
1001  * @param string $url URL
1002  * @param array $domains Array of domains (strings)
1003  * @return bool True if the host part of $url ends in one of the strings in $domains
1004  */
1005 function wfMatchesDomainList( $url, $domains ) {
1006         $bits = wfParseUrl( $url );
1007         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1008                 $host = '.' . $bits['host'];
1009                 foreach ( (array)$domains as $domain ) {
1010                         $domain = '.' . $domain;
1011                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1012                                 return true;
1013                         }
1014                 }
1015         }
1016         return false;
1017 }
1018
1019 /**
1020  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1021  * In normal operation this is a NOP.
1022  *
1023  * Controlling globals:
1024  * $wgDebugLogFile - points to the log file
1025  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1026  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1027  *
1028  * @since 1.25 support for additional context data
1029  *
1030  * @param string $text
1031  * @param string|bool $dest Unused
1032  * @param array $context Additional logging context data
1033  */
1034 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1035         global $wgDebugRawPage, $wgDebugLogPrefix;
1036         global $wgDebugTimestamps, $wgRequestTime;
1037
1038         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1039                 return;
1040         }
1041
1042         $text = trim( $text );
1043
1044         // Inline logic from deprecated wfDebugTimer()
1045         if ( $wgDebugTimestamps ) {
1046                 $context['seconds_elapsed'] = sprintf(
1047                         '%6.4f',
1048                         microtime( true ) - $wgRequestTime
1049                 );
1050                 $context['memory_used'] = sprintf(
1051                         '%5.1fM',
1052                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1053                 );
1054         }
1055
1056         if ( $wgDebugLogPrefix !== '' ) {
1057                 $context['prefix'] = $wgDebugLogPrefix;
1058         }
1059
1060         $logger = LoggerFactory::getInstance( 'wfDebug' );
1061         $logger->debug( $text, $context );
1062 }
1063
1064 /**
1065  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1066  * @return bool
1067  */
1068 function wfIsDebugRawPage() {
1069         static $cache;
1070         if ( $cache !== null ) {
1071                 return $cache;
1072         }
1073         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1074         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1075                 || (
1076                         isset( $_SERVER['SCRIPT_NAME'] )
1077                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1078                 )
1079         ) {
1080                 $cache = true;
1081         } else {
1082                 $cache = false;
1083         }
1084         return $cache;
1085 }
1086
1087 /**
1088  * Get microsecond timestamps for debug logs
1089  *
1090  * @deprecated since 1.25
1091  * @return string
1092  */
1093 function wfDebugTimer() {
1094         global $wgDebugTimestamps, $wgRequestTime;
1095
1096         wfDeprecated( __METHOD__, '1.25' );
1097
1098         if ( !$wgDebugTimestamps ) {
1099                 return '';
1100         }
1101
1102         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1103         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1104         return "$prefix $mem  ";
1105 }
1106
1107 /**
1108  * Send a line giving PHP memory usage.
1109  *
1110  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1111  */
1112 function wfDebugMem( $exact = false ) {
1113         $mem = memory_get_usage();
1114         if ( !$exact ) {
1115                 $mem = floor( $mem / 1024 ) . ' KiB';
1116         } else {
1117                 $mem .= ' B';
1118         }
1119         wfDebug( "Memory usage: $mem\n" );
1120 }
1121
1122 /**
1123  * Send a line to a supplementary debug log file, if configured, or main debug
1124  * log if not.
1125  *
1126  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1127  * a string filename or an associative array mapping 'destination' to the
1128  * desired filename. The associative array may also contain a 'sample' key
1129  * with an integer value, specifying a sampling factor. Sampled log events
1130  * will be emitted with a 1 in N random chance.
1131  *
1132  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1133  * @since 1.25 support for additional context data
1134  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1135  *
1136  * @param string $logGroup
1137  * @param string $text
1138  * @param string|bool $dest Destination of the message:
1139  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1140  *     - 'log': only to the log and not in HTML
1141  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1142  *       discarded otherwise
1143  *   For backward compatibility, it can also take a boolean:
1144  *     - true: same as 'all'
1145  *     - false: same as 'private'
1146  * @param array $context Additional logging context data
1147  */
1148 function wfDebugLog(
1149         $logGroup, $text, $dest = 'all', array $context = array()
1150 ) {
1151         // Turn $dest into a string if it's a boolean (for b/c)
1152         if ( $dest === true ) {
1153                 $dest = 'all';
1154         } elseif ( $dest === false ) {
1155                 $dest = 'private';
1156         }
1157
1158         $text = trim( $text );
1159
1160         $logger = LoggerFactory::getInstance( $logGroup );
1161         $context['private'] = ( $dest === 'private' );
1162         $logger->info( $text, $context );
1163 }
1164
1165 /**
1166  * Log for database errors
1167  *
1168  * @since 1.25 support for additional context data
1169  *
1170  * @param string $text Database error message.
1171  * @param array $context Additional logging context data
1172  */
1173 function wfLogDBError( $text, array $context = array() ) {
1174         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1175         $logger->error( trim( $text ), $context );
1176 }
1177
1178 /**
1179  * Throws a warning that $function is deprecated
1180  *
1181  * @param string $function
1182  * @param string|bool $version Version of MediaWiki that the function
1183  *    was deprecated in (Added in 1.19).
1184  * @param string|bool $component Added in 1.19.
1185  * @param int $callerOffset How far up the call stack is the original
1186  *    caller. 2 = function that called the function that called
1187  *    wfDeprecated (Added in 1.20)
1188  *
1189  * @return null
1190  */
1191 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1192         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1193 }
1194
1195 /**
1196  * Send a warning either to the debug log or in a PHP error depending on
1197  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1198  *
1199  * @param string $msg Message to send
1200  * @param int $callerOffset Number of items to go back in the backtrace to
1201  *        find the correct caller (1 = function calling wfWarn, ...)
1202  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1203  *        only used when $wgDevelopmentWarnings is true
1204  */
1205 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1206         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1207 }
1208
1209 /**
1210  * Send a warning as a PHP error and the debug log. This is intended for logging
1211  * warnings in production. For logging development warnings, use WfWarn instead.
1212  *
1213  * @param string $msg Message to send
1214  * @param int $callerOffset Number of items to go back in the backtrace to
1215  *        find the correct caller (1 = function calling wfLogWarning, ...)
1216  * @param int $level PHP error level; defaults to E_USER_WARNING
1217  */
1218 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1219         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1220 }
1221
1222 /**
1223  * Log to a file without getting "file size exceeded" signals.
1224  *
1225  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1226  * send lines to the specified port, prefixed by the specified prefix and a space.
1227  * @since 1.25 support for additional context data
1228  *
1229  * @param string $text
1230  * @param string $file Filename
1231  * @param array $context Additional logging context data
1232  * @throws MWException
1233  * @deprecated since 1.25 Use MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1234  */
1235 function wfErrorLog( $text, $file, array $context = array() ) {
1236         wfDeprecated( __METHOD__, '1.25' );
1237         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1238         $context['destination'] = $file;
1239         $logger->info( trim( $text ), $context );
1240 }
1241
1242 /**
1243  * @todo document
1244  */
1245 function wfLogProfilingData() {
1246         global $wgDebugLogGroups, $wgDebugRawPage;
1247
1248         $context = RequestContext::getMain();
1249         $request = $context->getRequest();
1250
1251         $profiler = Profiler::instance();
1252         $profiler->setContext( $context );
1253         $profiler->logData();
1254
1255         $config = $context->getConfig();
1256         if ( $config->get( 'StatsdServer' ) ) {
1257                 try {
1258                         $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1259                         $statsdHost = $statsdServer[0];
1260                         $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1261                         $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1262                         $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
1263                         $statsdClient->send( $context->getStats()->getBuffer() );
1264                 } catch ( Exception $ex ) {
1265                         MWExceptionHandler::logException( $ex );
1266                 }
1267         }
1268
1269         # Profiling must actually be enabled...
1270         if ( $profiler instanceof ProfilerStub ) {
1271                 return;
1272         }
1273
1274         if ( isset( $wgDebugLogGroups['profileoutput'] )
1275                 && $wgDebugLogGroups['profileoutput'] === false
1276         ) {
1277                 // Explicitly disabled
1278                 return;
1279         }
1280         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1281                 return;
1282         }
1283
1284         $ctx = array( 'elapsed' => $request->getElapsedTime() );
1285         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1286                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1287         }
1288         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1289                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1290         }
1291         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1292                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1293         }
1294         if ( isset( $ctx['forwarded_for'] ) ||
1295                 isset( $ctx['client_ip'] ) ||
1296                 isset( $ctx['from'] ) ) {
1297                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1298         }
1299
1300         // Don't load $wgUser at this late stage just for statistics purposes
1301         // @todo FIXME: We can detect some anons even if it is not loaded.
1302         // See User::getId()
1303         $user = $context->getUser();
1304         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1305
1306         // Command line script uses a FauxRequest object which does not have
1307         // any knowledge about an URL and throw an exception instead.
1308         try {
1309                 $ctx['url'] = urldecode( $request->getRequestURL() );
1310         } catch ( Exception $ignored ) {
1311                 // no-op
1312         }
1313
1314         $ctx['output'] = $profiler->getOutput();
1315
1316         $log = LoggerFactory::getInstance( 'profileoutput' );
1317         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1318 }
1319
1320 /**
1321  * Increment a statistics counter
1322  *
1323  * @param string $key
1324  * @param int $count
1325  * @return void
1326  */
1327 function wfIncrStats( $key, $count = 1 ) {
1328         $stats = RequestContext::getMain()->getStats();
1329         $stats->updateCount( $key, $count );
1330 }
1331
1332 /**
1333  * Check whether the wiki is in read-only mode.
1334  *
1335  * @return bool
1336  */
1337 function wfReadOnly() {
1338         return wfReadOnlyReason() !== false;
1339 }
1340
1341 /**
1342  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1343  *
1344  * @return string|bool String when in read-only mode; false otherwise
1345  */
1346 function wfReadOnlyReason() {
1347         global $wgReadOnly, $wgReadOnlyFile;
1348
1349         if ( $wgReadOnly === null ) {
1350                 // Set $wgReadOnly for faster access next time
1351                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1352                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1353                 } else {
1354                         $wgReadOnly = false;
1355                 }
1356                 // Callers use this method to be aware that data presented to a user
1357                 // may be very stale and thus allowing submissions can be problematic.
1358                 try {
1359                         if ( $wgReadOnly === false && wfGetLB()->getLaggedSlaveMode() ) {
1360                                 $wgReadOnly = 'The database has been automatically locked ' .
1361                                         'while the slave database servers catch up to the master';
1362                         }
1363                 } catch ( DBConnectionError $e ) {
1364                         $wgReadOnly = 'The database has been automatically locked ' .
1365                                 'until the slave database servers become available';
1366                 }
1367         }
1368
1369         return $wgReadOnly;
1370 }
1371
1372 /**
1373  * Return a Language object from $langcode
1374  *
1375  * @param Language|string|bool $langcode Either:
1376  *                  - a Language object
1377  *                  - code of the language to get the message for, if it is
1378  *                    a valid code create a language for that language, if
1379  *                    it is a string but not a valid code then make a basic
1380  *                    language object
1381  *                  - a boolean: if it's false then use the global object for
1382  *                    the current user's language (as a fallback for the old parameter
1383  *                    functionality), or if it is true then use global object
1384  *                    for the wiki's content language.
1385  * @return Language
1386  */
1387 function wfGetLangObj( $langcode = false ) {
1388         # Identify which language to get or create a language object for.
1389         # Using is_object here due to Stub objects.
1390         if ( is_object( $langcode ) ) {
1391                 # Great, we already have the object (hopefully)!
1392                 return $langcode;
1393         }
1394
1395         global $wgContLang, $wgLanguageCode;
1396         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1397                 # $langcode is the language code of the wikis content language object.
1398                 # or it is a boolean and value is true
1399                 return $wgContLang;
1400         }
1401
1402         global $wgLang;
1403         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1404                 # $langcode is the language code of user language object.
1405                 # or it was a boolean and value is false
1406                 return $wgLang;
1407         }
1408
1409         $validCodes = array_keys( Language::fetchLanguageNames() );
1410         if ( in_array( $langcode, $validCodes ) ) {
1411                 # $langcode corresponds to a valid language.
1412                 return Language::factory( $langcode );
1413         }
1414
1415         # $langcode is a string, but not a valid language code; use content language.
1416         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1417         return $wgContLang;
1418 }
1419
1420 /**
1421  * This is the function for getting translated interface messages.
1422  *
1423  * @see Message class for documentation how to use them.
1424  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1425  *
1426  * This function replaces all old wfMsg* functions.
1427  *
1428  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1429  * @param mixed $params,... Normal message parameters
1430  * @return Message
1431  *
1432  * @since 1.17
1433  *
1434  * @see Message::__construct
1435  */
1436 function wfMessage( $key /*...*/ ) {
1437         $params = func_get_args();
1438         array_shift( $params );
1439         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1440                 $params = $params[0];
1441         }
1442         return new Message( $key, $params );
1443 }
1444
1445 /**
1446  * This function accepts multiple message keys and returns a message instance
1447  * for the first message which is non-empty. If all messages are empty then an
1448  * instance of the first message key is returned.
1449  *
1450  * @param string|string[] $keys,... Message keys
1451  * @return Message
1452  *
1453  * @since 1.18
1454  *
1455  * @see Message::newFallbackSequence
1456  */
1457 function wfMessageFallback( /*...*/ ) {
1458         $args = func_get_args();
1459         return call_user_func_array( 'Message::newFallbackSequence', $args );
1460 }
1461
1462 /**
1463  * Get a message from anywhere, for the current user language.
1464  *
1465  * Use wfMsgForContent() instead if the message should NOT
1466  * change depending on the user preferences.
1467  *
1468  * @deprecated since 1.18
1469  *
1470  * @param string $key Lookup key for the message, usually
1471  *    defined in languages/Language.php
1472  *
1473  * Parameters to the message, which can be used to insert variable text into
1474  * it, can be passed to this function in the following formats:
1475  * - One per argument, starting at the second parameter
1476  * - As an array in the second parameter
1477  * These are not shown in the function definition.
1478  *
1479  * @return string
1480  */
1481 function wfMsg( $key ) {
1482         wfDeprecated( __METHOD__, '1.21' );
1483
1484         $args = func_get_args();
1485         array_shift( $args );
1486         return wfMsgReal( $key, $args );
1487 }
1488
1489 /**
1490  * Same as above except doesn't transform the message
1491  *
1492  * @deprecated since 1.18
1493  *
1494  * @param string $key
1495  * @return string
1496  */
1497 function wfMsgNoTrans( $key ) {
1498         wfDeprecated( __METHOD__, '1.21' );
1499
1500         $args = func_get_args();
1501         array_shift( $args );
1502         return wfMsgReal( $key, $args, true, false, false );
1503 }
1504
1505 /**
1506  * Get a message from anywhere, for the current global language
1507  * set with $wgLanguageCode.
1508  *
1509  * Use this if the message should NOT change dependent on the
1510  * language set in the user's preferences. This is the case for
1511  * most text written into logs, as well as link targets (such as
1512  * the name of the copyright policy page). Link titles, on the
1513  * other hand, should be shown in the UI language.
1514  *
1515  * Note that MediaWiki allows users to change the user interface
1516  * language in their preferences, but a single installation
1517  * typically only contains content in one language.
1518  *
1519  * Be wary of this distinction: If you use wfMsg() where you should
1520  * use wfMsgForContent(), a user of the software may have to
1521  * customize potentially hundreds of messages in
1522  * order to, e.g., fix a link in every possible language.
1523  *
1524  * @deprecated since 1.18
1525  *
1526  * @param string $key Lookup key for the message, usually
1527  *     defined in languages/Language.php
1528  * @return string
1529  */
1530 function wfMsgForContent( $key ) {
1531         wfDeprecated( __METHOD__, '1.21' );
1532
1533         global $wgForceUIMsgAsContentMsg;
1534         $args = func_get_args();
1535         array_shift( $args );
1536         $forcontent = true;
1537         if ( is_array( $wgForceUIMsgAsContentMsg )
1538                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1539         ) {
1540                 $forcontent = false;
1541         }
1542         return wfMsgReal( $key, $args, true, $forcontent );
1543 }
1544
1545 /**
1546  * Same as above except doesn't transform the message
1547  *
1548  * @deprecated since 1.18
1549  *
1550  * @param string $key
1551  * @return string
1552  */
1553 function wfMsgForContentNoTrans( $key ) {
1554         wfDeprecated( __METHOD__, '1.21' );
1555
1556         global $wgForceUIMsgAsContentMsg;
1557         $args = func_get_args();
1558         array_shift( $args );
1559         $forcontent = true;
1560         if ( is_array( $wgForceUIMsgAsContentMsg )
1561                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1562         ) {
1563                 $forcontent = false;
1564         }
1565         return wfMsgReal( $key, $args, true, $forcontent, false );
1566 }
1567
1568 /**
1569  * Really get a message
1570  *
1571  * @deprecated since 1.18
1572  *
1573  * @param string $key Key to get.
1574  * @param array $args
1575  * @param bool $useDB
1576  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1577  * @param bool $transform Whether or not to transform the message.
1578  * @return string The requested message.
1579  */
1580 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1581         wfDeprecated( __METHOD__, '1.21' );
1582
1583         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1584         $message = wfMsgReplaceArgs( $message, $args );
1585         return $message;
1586 }
1587
1588 /**
1589  * Fetch a message string value, but don't replace any keys yet.
1590  *
1591  * @deprecated since 1.18
1592  *
1593  * @param string $key
1594  * @param bool $useDB
1595  * @param string|bool $langCode Code of the language to get the message for, or
1596  *   behaves as a content language switch if it is a boolean.
1597  * @param bool $transform Whether to parse magic words, etc.
1598  * @return string
1599  */
1600 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1601         wfDeprecated( __METHOD__, '1.21' );
1602
1603         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1604
1605         $cache = MessageCache::singleton();
1606         $message = $cache->get( $key, $useDB, $langCode );
1607         if ( $message === false ) {
1608                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1609         } elseif ( $transform ) {
1610                 $message = $cache->transform( $message );
1611         }
1612         return $message;
1613 }
1614
1615 /**
1616  * Replace message parameter keys on the given formatted output.
1617  *
1618  * @param string $message
1619  * @param array $args
1620  * @return string
1621  * @private
1622  */
1623 function wfMsgReplaceArgs( $message, $args ) {
1624         # Fix windows line-endings
1625         # Some messages are split with explode("\n", $msg)
1626         $message = str_replace( "\r", '', $message );
1627
1628         // Replace arguments
1629         if ( count( $args ) ) {
1630                 if ( is_array( $args[0] ) ) {
1631                         $args = array_values( $args[0] );
1632                 }
1633                 $replacementKeys = array();
1634                 foreach ( $args as $n => $param ) {
1635                         $replacementKeys['$' . ( $n + 1 )] = $param;
1636                 }
1637                 $message = strtr( $message, $replacementKeys );
1638         }
1639
1640         return $message;
1641 }
1642
1643 /**
1644  * Return an HTML-escaped version of a message.
1645  * Parameter replacements, if any, are done *after* the HTML-escaping,
1646  * so parameters may contain HTML (eg links or form controls). Be sure
1647  * to pre-escape them if you really do want plaintext, or just wrap
1648  * the whole thing in htmlspecialchars().
1649  *
1650  * @deprecated since 1.18
1651  *
1652  * @param string $key
1653  * @param string $args,... Parameters
1654  * @return string
1655  */
1656 function wfMsgHtml( $key ) {
1657         wfDeprecated( __METHOD__, '1.21' );
1658
1659         $args = func_get_args();
1660         array_shift( $args );
1661         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1662 }
1663
1664 /**
1665  * Return an HTML version of message
1666  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1667  * so parameters may contain HTML (eg links or form controls). Be sure
1668  * to pre-escape them if you really do want plaintext, or just wrap
1669  * the whole thing in htmlspecialchars().
1670  *
1671  * @deprecated since 1.18
1672  *
1673  * @param string $key
1674  * @param string $args,... Parameters
1675  * @return string
1676  */
1677 function wfMsgWikiHtml( $key ) {
1678         wfDeprecated( __METHOD__, '1.21' );
1679
1680         $args = func_get_args();
1681         array_shift( $args );
1682         return wfMsgReplaceArgs(
1683                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1684                 /* can't be set to false */ true, /* interface */ true )->getText(),
1685                 $args );
1686 }
1687
1688 /**
1689  * Returns message in the requested format
1690  *
1691  * @deprecated since 1.18
1692  *
1693  * @param string $key Key of the message
1694  * @param array $options Processing rules.
1695  *   Can take the following options:
1696  *     parse: parses wikitext to HTML
1697  *     parseinline: parses wikitext to HTML and removes the surrounding
1698  *       p's added by parser or tidy
1699  *     escape: filters message through htmlspecialchars
1700  *     escapenoentities: same, but allows entity references like &#160; through
1701  *     replaceafter: parameters are substituted after parsing or escaping
1702  *     parsemag: transform the message using magic phrases
1703  *     content: fetch message for content language instead of interface
1704  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1705  *     language: Language object or language code to fetch message for
1706  *       (overridden by content).
1707  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1708  *
1709  * @return string
1710  */
1711 function wfMsgExt( $key, $options ) {
1712         wfDeprecated( __METHOD__, '1.21' );
1713
1714         $args = func_get_args();
1715         array_shift( $args );
1716         array_shift( $args );
1717         $options = (array)$options;
1718         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1719                 'parsemag', 'content' );
1720
1721         foreach ( $options as $arrayKey => $option ) {
1722                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1723                         // An unknown index, neither numeric nor "language"
1724                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1725                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1726                         // A numeric index with unknown value
1727                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1728                 }
1729         }
1730
1731         if ( in_array( 'content', $options, true ) ) {
1732                 $forContent = true;
1733                 $langCode = true;
1734                 $langCodeObj = null;
1735         } elseif ( array_key_exists( 'language', $options ) ) {
1736                 $forContent = false;
1737                 $langCode = wfGetLangObj( $options['language'] );
1738                 $langCodeObj = $langCode;
1739         } else {
1740                 $forContent = false;
1741                 $langCode = false;
1742                 $langCodeObj = null;
1743         }
1744
1745         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1746
1747         if ( !in_array( 'replaceafter', $options, true ) ) {
1748                 $string = wfMsgReplaceArgs( $string, $args );
1749         }
1750
1751         $messageCache = MessageCache::singleton();
1752         $parseInline = in_array( 'parseinline', $options, true );
1753         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1754                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1755                 if ( $string instanceof ParserOutput ) {
1756                         $string = $string->getText();
1757                 }
1758
1759                 if ( $parseInline ) {
1760                         $string = Parser::stripOuterParagraph( $string );
1761                 }
1762         } elseif ( in_array( 'parsemag', $options, true ) ) {
1763                 $string = $messageCache->transform( $string,
1764                                 !$forContent, $langCodeObj );
1765         }
1766
1767         if ( in_array( 'escape', $options, true ) ) {
1768                 $string = htmlspecialchars( $string );
1769         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1770                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1771         }
1772
1773         if ( in_array( 'replaceafter', $options, true ) ) {
1774                 $string = wfMsgReplaceArgs( $string, $args );
1775         }
1776
1777         return $string;
1778 }
1779
1780 /**
1781  * Since wfMsg() and co suck, they don't return false if the message key they
1782  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1783  * nonexistence of messages by checking the MessageCache::get() result directly.
1784  *
1785  * @deprecated since 1.18. Use Message::isDisabled().
1786  *
1787  * @param string $key The message key looked up
1788  * @return bool True if the message *doesn't* exist.
1789  */
1790 function wfEmptyMsg( $key ) {
1791         wfDeprecated( __METHOD__, '1.21' );
1792
1793         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1794 }
1795
1796 /**
1797  * Fetch server name for use in error reporting etc.
1798  * Use real server name if available, so we know which machine
1799  * in a server farm generated the current page.
1800  *
1801  * @return string
1802  */
1803 function wfHostname() {
1804         static $host;
1805         if ( is_null( $host ) ) {
1806
1807                 # Hostname overriding
1808                 global $wgOverrideHostname;
1809                 if ( $wgOverrideHostname !== false ) {
1810                         # Set static and skip any detection
1811                         $host = $wgOverrideHostname;
1812                         return $host;
1813                 }
1814
1815                 if ( function_exists( 'posix_uname' ) ) {
1816                         // This function not present on Windows
1817                         $uname = posix_uname();
1818                 } else {
1819                         $uname = false;
1820                 }
1821                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1822                         $host = $uname['nodename'];
1823                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1824                         # Windows computer name
1825                         $host = getenv( 'COMPUTERNAME' );
1826                 } else {
1827                         # This may be a virtual server.
1828                         $host = $_SERVER['SERVER_NAME'];
1829                 }
1830         }
1831         return $host;
1832 }
1833
1834 /**
1835  * Returns a script tag that stores the amount of time it took MediaWiki to
1836  * handle the request in milliseconds as 'wgBackendResponseTime'.
1837  *
1838  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1839  * hostname of the server handling the request.
1840  *
1841  * @return string
1842  */
1843 function wfReportTime() {
1844         global $wgRequestTime, $wgShowHostnames;
1845
1846         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1847         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1848         if ( $wgShowHostnames ) {
1849                 $reportVars['wgHostname'] = wfHostname();
1850         }
1851         return Skin::makeVariablesScript( $reportVars );
1852 }
1853
1854 /**
1855  * Safety wrapper for debug_backtrace().
1856  *
1857  * Will return an empty array if debug_backtrace is disabled, otherwise
1858  * the output from debug_backtrace() (trimmed).
1859  *
1860  * @param int $limit This parameter can be used to limit the number of stack frames returned
1861  *
1862  * @return array Array of backtrace information
1863  */
1864 function wfDebugBacktrace( $limit = 0 ) {
1865         static $disabled = null;
1866
1867         if ( is_null( $disabled ) ) {
1868                 $disabled = !function_exists( 'debug_backtrace' );
1869                 if ( $disabled ) {
1870                         wfDebug( "debug_backtrace() is disabled\n" );
1871                 }
1872         }
1873         if ( $disabled ) {
1874                 return array();
1875         }
1876
1877         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1878                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1879         } else {
1880                 return array_slice( debug_backtrace(), 1 );
1881         }
1882 }
1883
1884 /**
1885  * Get a debug backtrace as a string
1886  *
1887  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1888  *   Defaults to $wgCommandLineMode if unset.
1889  * @return string
1890  * @since 1.25 Supports $raw parameter.
1891  */
1892 function wfBacktrace( $raw = null ) {
1893         global $wgCommandLineMode;
1894
1895         if ( $raw === null ) {
1896                 $raw = $wgCommandLineMode;
1897         }
1898
1899         if ( $raw ) {
1900                 $frameFormat = "%s line %s calls %s()\n";
1901                 $traceFormat = "%s";
1902         } else {
1903                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1904                 $traceFormat = "<ul>\n%s</ul>\n";
1905         }
1906
1907         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1908                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1909                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1910                 $call = $frame['function'];
1911                 if ( !empty( $frame['class'] ) ) {
1912                         $call = $frame['class'] . $frame['type'] . $call;
1913                 }
1914                 return sprintf( $frameFormat, $file, $line, $call );
1915         }, wfDebugBacktrace() );
1916
1917         return sprintf( $traceFormat, implode( '', $frames ) );
1918 }
1919
1920 /**
1921  * Get the name of the function which called this function
1922  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1923  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1924  * wfGetCaller( 3 ) is the parent of that.
1925  *
1926  * @param int $level
1927  * @return string
1928  */
1929 function wfGetCaller( $level = 2 ) {
1930         $backtrace = wfDebugBacktrace( $level + 1 );
1931         if ( isset( $backtrace[$level] ) ) {
1932                 return wfFormatStackFrame( $backtrace[$level] );
1933         } else {
1934                 return 'unknown';
1935         }
1936 }
1937
1938 /**
1939  * Return a string consisting of callers in the stack. Useful sometimes
1940  * for profiling specific points.
1941  *
1942  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1943  * @return string
1944  */
1945 function wfGetAllCallers( $limit = 3 ) {
1946         $trace = array_reverse( wfDebugBacktrace() );
1947         if ( !$limit || $limit > count( $trace ) - 1 ) {
1948                 $limit = count( $trace ) - 1;
1949         }
1950         $trace = array_slice( $trace, -$limit - 1, $limit );
1951         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1952 }
1953
1954 /**
1955  * Return a string representation of frame
1956  *
1957  * @param array $frame
1958  * @return string
1959  */
1960 function wfFormatStackFrame( $frame ) {
1961         return isset( $frame['class'] ) ?
1962                 $frame['class'] . '::' . $frame['function'] :
1963                 $frame['function'];
1964 }
1965
1966 /* Some generic result counters, pulled out of SearchEngine */
1967
1968 /**
1969  * @todo document
1970  *
1971  * @param int $offset
1972  * @param int $limit
1973  * @return string
1974  */
1975 function wfShowingResults( $offset, $limit ) {
1976         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1977 }
1978
1979 /**
1980  * @todo document
1981  * @todo FIXME: We may want to blacklist some broken browsers
1982  *
1983  * @param bool $force
1984  * @return bool Whereas client accept gzip compression
1985  */
1986 function wfClientAcceptsGzip( $force = false ) {
1987         static $result = null;
1988         if ( $result === null || $force ) {
1989                 $result = false;
1990                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1991                         # @todo FIXME: We may want to blacklist some broken browsers
1992                         $m = array();
1993                         if ( preg_match(
1994                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1995                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1996                                         $m
1997                                 )
1998                         ) {
1999                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2000                                         $result = false;
2001                                         return $result;
2002                                 }
2003                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2004                                 $result = true;
2005                         }
2006                 }
2007         }
2008         return $result;
2009 }
2010
2011 /**
2012  * Obtain the offset and limit values from the request string;
2013  * used in special pages
2014  *
2015  * @param int $deflimit Default limit if none supplied
2016  * @param string $optionname Name of a user preference to check against
2017  * @return array
2018  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2019  */
2020 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2021         global $wgRequest;
2022         wfDeprecated( __METHOD__, '1.24' );
2023         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2024 }
2025
2026 /**
2027  * Escapes the given text so that it may be output using addWikiText()
2028  * without any linking, formatting, etc. making its way through. This
2029  * is achieved by substituting certain characters with HTML entities.
2030  * As required by the callers, "<nowiki>" is not used.
2031  *
2032  * @param string $text Text to be escaped
2033  * @return string
2034  */
2035 function wfEscapeWikiText( $text ) {
2036         static $repl = null, $repl2 = null;
2037         if ( $repl === null ) {
2038                 $repl = array(
2039                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2040                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2041                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2042                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2043                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2044                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2045                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2046                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2047                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2048                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2049                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2050                         '__' => '_&#95;', '://' => '&#58;//',
2051                 );
2052
2053                 // We have to catch everything "\s" matches in PCRE
2054                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2055                         $repl["$magic "] = "$magic&#32;";
2056                         $repl["$magic\t"] = "$magic&#9;";
2057                         $repl["$magic\r"] = "$magic&#13;";
2058                         $repl["$magic\n"] = "$magic&#10;";
2059                         $repl["$magic\f"] = "$magic&#12;";
2060                 }
2061
2062                 // And handle protocols that don't use "://"
2063                 global $wgUrlProtocols;
2064                 $repl2 = array();
2065                 foreach ( $wgUrlProtocols as $prot ) {
2066                         if ( substr( $prot, -1 ) === ':' ) {
2067                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2068                         }
2069                 }
2070                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2071         }
2072         $text = substr( strtr( "\n$text", $repl ), 1 );
2073         $text = preg_replace( $repl2, '$1&#58;', $text );
2074         return $text;
2075 }
2076
2077 /**
2078  * Sets dest to source and returns the original value of dest
2079  * If source is NULL, it just returns the value, it doesn't set the variable
2080  * If force is true, it will set the value even if source is NULL
2081  *
2082  * @param mixed $dest
2083  * @param mixed $source
2084  * @param bool $force
2085  * @return mixed
2086  */
2087 function wfSetVar( &$dest, $source, $force = false ) {
2088         $temp = $dest;
2089         if ( !is_null( $source ) || $force ) {
2090                 $dest = $source;
2091         }
2092         return $temp;
2093 }
2094
2095 /**
2096  * As for wfSetVar except setting a bit
2097  *
2098  * @param int $dest
2099  * @param int $bit
2100  * @param bool $state
2101  *
2102  * @return bool
2103  */
2104 function wfSetBit( &$dest, $bit, $state = true ) {
2105         $temp = (bool)( $dest & $bit );
2106         if ( !is_null( $state ) ) {
2107                 if ( $state ) {
2108                         $dest |= $bit;
2109                 } else {
2110                         $dest &= ~$bit;
2111                 }
2112         }
2113         return $temp;
2114 }
2115
2116 /**
2117  * A wrapper around the PHP function var_export().
2118  * Either print it or add it to the regular output ($wgOut).
2119  *
2120  * @param mixed $var A PHP variable to dump.
2121  */
2122 function wfVarDump( $var ) {
2123         global $wgOut;
2124         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2125         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2126                 print $s;
2127         } else {
2128                 $wgOut->addHTML( $s );
2129         }
2130 }
2131
2132 /**
2133  * Provide a simple HTTP error.
2134  *
2135  * @param int|string $code
2136  * @param string $label
2137  * @param string $desc
2138  */
2139 function wfHttpError( $code, $label, $desc ) {
2140         global $wgOut;
2141         HttpStatus::header( $code );
2142         if ( $wgOut ) {
2143                 $wgOut->disable();
2144                 $wgOut->sendCacheControl();
2145         }
2146
2147         header( 'Content-type: text/html; charset=utf-8' );
2148         print '<!DOCTYPE html>' .
2149                 '<html><head><title>' .
2150                 htmlspecialchars( $label ) .
2151                 '</title></head><body><h1>' .
2152                 htmlspecialchars( $label ) .
2153                 '</h1><p>' .
2154                 nl2br( htmlspecialchars( $desc ) ) .
2155                 "</p></body></html>\n";
2156 }
2157
2158 /**
2159  * Clear away any user-level output buffers, discarding contents.
2160  *
2161  * Suitable for 'starting afresh', for instance when streaming
2162  * relatively large amounts of data without buffering, or wanting to
2163  * output image files without ob_gzhandler's compression.
2164  *
2165  * The optional $resetGzipEncoding parameter controls suppression of
2166  * the Content-Encoding header sent by ob_gzhandler; by default it
2167  * is left. See comments for wfClearOutputBuffers() for why it would
2168  * be used.
2169  *
2170  * Note that some PHP configuration options may add output buffer
2171  * layers which cannot be removed; these are left in place.
2172  *
2173  * @param bool $resetGzipEncoding
2174  */
2175 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2176         if ( $resetGzipEncoding ) {
2177                 // Suppress Content-Encoding and Content-Length
2178                 // headers from 1.10+s wfOutputHandler
2179                 global $wgDisableOutputCompression;
2180                 $wgDisableOutputCompression = true;
2181         }
2182         while ( $status = ob_get_status() ) {
2183                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2184                         // Probably from zlib.output_compression or other
2185                         // PHP-internal setting which can't be removed.
2186                         //
2187                         // Give up, and hope the result doesn't break
2188                         // output behavior.
2189                         break;
2190                 }
2191                 if ( !ob_end_clean() ) {
2192                         // Could not remove output buffer handler; abort now
2193                         // to avoid getting in some kind of infinite loop.
2194                         break;
2195                 }
2196                 if ( $resetGzipEncoding ) {
2197                         if ( $status['name'] == 'ob_gzhandler' ) {
2198                                 // Reset the 'Content-Encoding' field set by this handler
2199                                 // so we can start fresh.
2200                                 header_remove( 'Content-Encoding' );
2201                                 break;
2202                         }
2203                 }
2204         }
2205 }
2206
2207 /**
2208  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2209  *
2210  * Clear away output buffers, but keep the Content-Encoding header
2211  * produced by ob_gzhandler, if any.
2212  *
2213  * This should be used for HTTP 304 responses, where you need to
2214  * preserve the Content-Encoding header of the real result, but
2215  * also need to suppress the output of ob_gzhandler to keep to spec
2216  * and avoid breaking Firefox in rare cases where the headers and
2217  * body are broken over two packets.
2218  */
2219 function wfClearOutputBuffers() {
2220         wfResetOutputBuffers( false );
2221 }
2222
2223 /**
2224  * Converts an Accept-* header into an array mapping string values to quality
2225  * factors
2226  *
2227  * @param string $accept
2228  * @param string $def Default
2229  * @return float[] Associative array of string => float pairs
2230  */
2231 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2232         # No arg means accept anything (per HTTP spec)
2233         if ( !$accept ) {
2234                 return array( $def => 1.0 );
2235         }
2236
2237         $prefs = array();
2238
2239         $parts = explode( ',', $accept );
2240
2241         foreach ( $parts as $part ) {
2242                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2243                 $values = explode( ';', trim( $part ) );
2244                 $match = array();
2245                 if ( count( $values ) == 1 ) {
2246                         $prefs[$values[0]] = 1.0;
2247                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2248                         $prefs[$values[0]] = floatval( $match[1] );
2249                 }
2250         }
2251
2252         return $prefs;
2253 }
2254
2255 /**
2256  * Checks if a given MIME type matches any of the keys in the given
2257  * array. Basic wildcards are accepted in the array keys.
2258  *
2259  * Returns the matching MIME type (or wildcard) if a match, otherwise
2260  * NULL if no match.
2261  *
2262  * @param string $type
2263  * @param array $avail
2264  * @return string
2265  * @private
2266  */
2267 function mimeTypeMatch( $type, $avail ) {
2268         if ( array_key_exists( $type, $avail ) ) {
2269                 return $type;
2270         } else {
2271                 $parts = explode( '/', $type );
2272                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2273                         return $parts[0] . '/*';
2274                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2275                         return '*/*';
2276                 } else {
2277                         return null;
2278                 }
2279         }
2280 }
2281
2282 /**
2283  * Returns the 'best' match between a client's requested internet media types
2284  * and the server's list of available types. Each list should be an associative
2285  * array of type to preference (preference is a float between 0.0 and 1.0).
2286  * Wildcards in the types are acceptable.
2287  *
2288  * @param array $cprefs Client's acceptable type list
2289  * @param array $sprefs Server's offered types
2290  * @return string
2291  *
2292  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2293  * XXX: generalize to negotiate other stuff
2294  */
2295 function wfNegotiateType( $cprefs, $sprefs ) {
2296         $combine = array();
2297
2298         foreach ( array_keys( $sprefs ) as $type ) {
2299                 $parts = explode( '/', $type );
2300                 if ( $parts[1] != '*' ) {
2301                         $ckey = mimeTypeMatch( $type, $cprefs );
2302                         if ( $ckey ) {
2303                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2304                         }
2305                 }
2306         }
2307
2308         foreach ( array_keys( $cprefs ) as $type ) {
2309                 $parts = explode( '/', $type );
2310                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2311                         $skey = mimeTypeMatch( $type, $sprefs );
2312                         if ( $skey ) {
2313                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2314                         }
2315                 }
2316         }
2317
2318         $bestq = 0;
2319         $besttype = null;
2320
2321         foreach ( array_keys( $combine ) as $type ) {
2322                 if ( $combine[$type] > $bestq ) {
2323                         $besttype = $type;
2324                         $bestq = $combine[$type];
2325                 }
2326         }
2327
2328         return $besttype;
2329 }
2330
2331 /**
2332  * Reference-counted warning suppression
2333  *
2334  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
2335  * @param bool $end
2336  */
2337 function wfSuppressWarnings( $end = false ) {
2338         MediaWiki\suppressWarnings( $end );
2339 }
2340
2341 /**
2342  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
2343  * Restore error level to previous value
2344  */
2345 function wfRestoreWarnings() {
2346         MediaWiki\suppressWarnings( true );
2347 }
2348
2349 # Autodetect, convert and provide timestamps of various types
2350
2351 /**
2352  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2353  */
2354 define( 'TS_UNIX', 0 );
2355
2356 /**
2357  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2358  */
2359 define( 'TS_MW', 1 );
2360
2361 /**
2362  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2363  */
2364 define( 'TS_DB', 2 );
2365
2366 /**
2367  * RFC 2822 format, for E-mail and HTTP headers
2368  */
2369 define( 'TS_RFC2822', 3 );
2370
2371 /**
2372  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2373  *
2374  * This is used by Special:Export
2375  */
2376 define( 'TS_ISO_8601', 4 );
2377
2378 /**
2379  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2380  *
2381  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2382  *       DateTime tag and page 36 for the DateTimeOriginal and
2383  *       DateTimeDigitized tags.
2384  */
2385 define( 'TS_EXIF', 5 );
2386
2387 /**
2388  * Oracle format time.
2389  */
2390 define( 'TS_ORACLE', 6 );
2391
2392 /**
2393  * Postgres format time.
2394  */
2395 define( 'TS_POSTGRES', 7 );
2396
2397 /**
2398  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2399  */
2400 define( 'TS_ISO_8601_BASIC', 9 );
2401
2402 /**
2403  * Get a timestamp string in one of various formats
2404  *
2405  * @param mixed $outputtype A timestamp in one of the supported formats, the
2406  *   function will autodetect which format is supplied and act accordingly.
2407  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2408  * @return string|bool String / false The same date in the format specified in $outputtype or false
2409  */
2410 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2411         try {
2412                 $timestamp = new MWTimestamp( $ts );
2413                 return $timestamp->getTimestamp( $outputtype );
2414         } catch ( TimestampException $e ) {
2415                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2416                 return false;
2417         }
2418 }
2419
2420 /**
2421  * Return a formatted timestamp, or null if input is null.
2422  * For dealing with nullable timestamp columns in the database.
2423  *
2424  * @param int $outputtype
2425  * @param string $ts
2426  * @return string
2427  */
2428 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2429         if ( is_null( $ts ) ) {
2430                 return null;
2431         } else {
2432                 return wfTimestamp( $outputtype, $ts );
2433         }
2434 }
2435
2436 /**
2437  * Convenience function; returns MediaWiki timestamp for the present time.
2438  *
2439  * @return string
2440  */
2441 function wfTimestampNow() {
2442         # return NOW
2443         return wfTimestamp( TS_MW, time() );
2444 }
2445
2446 /**
2447  * Check if the operating system is Windows
2448  *
2449  * @return bool True if it's Windows, false otherwise.
2450  */
2451 function wfIsWindows() {
2452         static $isWindows = null;
2453         if ( $isWindows === null ) {
2454                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2455         }
2456         return $isWindows;
2457 }
2458
2459 /**
2460  * Check if we are running under HHVM
2461  *
2462  * @return bool
2463  */
2464 function wfIsHHVM() {
2465         return defined( 'HHVM_VERSION' );
2466 }
2467
2468 /**
2469  * Tries to get the system directory for temporary files. First
2470  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2471  * environment variables are then checked in sequence, and if none are
2472  * set try sys_get_temp_dir().
2473  *
2474  * NOTE: When possible, use instead the tmpfile() function to create
2475  * temporary files to avoid race conditions on file creation, etc.
2476  *
2477  * @return string
2478  */
2479 function wfTempDir() {
2480         global $wgTmpDirectory;
2481
2482         if ( $wgTmpDirectory !== false ) {
2483                 return $wgTmpDirectory;
2484         }
2485
2486         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2487
2488         foreach ( $tmpDir as $tmp ) {
2489                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2490                         return $tmp;
2491                 }
2492         }
2493         return sys_get_temp_dir();
2494 }
2495
2496 /**
2497  * Make directory, and make all parent directories if they don't exist
2498  *
2499  * @param string $dir Full path to directory to create
2500  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2501  * @param string $caller Optional caller param for debugging.
2502  * @throws MWException
2503  * @return bool
2504  */
2505 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2506         global $wgDirectoryMode;
2507
2508         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2509                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2510         }
2511
2512         if ( !is_null( $caller ) ) {
2513                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2514         }
2515
2516         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2517                 return true;
2518         }
2519
2520         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2521
2522         if ( is_null( $mode ) ) {
2523                 $mode = $wgDirectoryMode;
2524         }
2525
2526         // Turn off the normal warning, we're doing our own below
2527         MediaWiki\suppressWarnings();
2528         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2529         MediaWiki\restoreWarnings();
2530
2531         if ( !$ok ) {
2532                 //directory may have been created on another request since we last checked
2533                 if ( is_dir( $dir ) ) {
2534                         return true;
2535                 }
2536
2537                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2538                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2539         }
2540         return $ok;
2541 }
2542
2543 /**
2544  * Remove a directory and all its content.
2545  * Does not hide error.
2546  * @param string $dir
2547  */
2548 function wfRecursiveRemoveDir( $dir ) {
2549         wfDebug( __FUNCTION__ . "( $dir )\n" );
2550         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2551         if ( is_dir( $dir ) ) {
2552                 $objects = scandir( $dir );
2553                 foreach ( $objects as $object ) {
2554                         if ( $object != "." && $object != ".." ) {
2555                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2556                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2557                                 } else {
2558                                         unlink( $dir . '/' . $object );
2559                                 }
2560                         }
2561                 }
2562                 reset( $objects );
2563                 rmdir( $dir );
2564         }
2565 }
2566
2567 /**
2568  * @param int $nr The number to format
2569  * @param int $acc The number of digits after the decimal point, default 2
2570  * @param bool $round Whether or not to round the value, default true
2571  * @return string
2572  */
2573 function wfPercent( $nr, $acc = 2, $round = true ) {
2574         $ret = sprintf( "%.${acc}f", $nr );
2575         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2576 }
2577
2578 /**
2579  * Safety wrapper around ini_get() for boolean settings.
2580  * The values returned from ini_get() are pre-normalized for settings
2581  * set via php.ini or php_flag/php_admin_flag... but *not*
2582  * for those set via php_value/php_admin_value.
2583  *
2584  * It's fairly common for people to use php_value instead of php_flag,
2585  * which can leave you with an 'off' setting giving a false positive
2586  * for code that just takes the ini_get() return value as a boolean.
2587  *
2588  * To make things extra interesting, setting via php_value accepts
2589  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2590  * Unrecognized values go false... again opposite PHP's own coercion
2591  * from string to bool.
2592  *
2593  * Luckily, 'properly' set settings will always come back as '0' or '1',
2594  * so we only have to worry about them and the 'improper' settings.
2595  *
2596  * I frickin' hate PHP... :P
2597  *
2598  * @param string $setting
2599  * @return bool
2600  */
2601 function wfIniGetBool( $setting ) {
2602         $val = strtolower( ini_get( $setting ) );
2603         // 'on' and 'true' can't have whitespace around them, but '1' can.
2604         return $val == 'on'
2605                 || $val == 'true'
2606                 || $val == 'yes'
2607                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2608 }
2609
2610 /**
2611  * Windows-compatible version of escapeshellarg()
2612  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2613  * function puts single quotes in regardless of OS.
2614  *
2615  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2616  * earlier distro releases of PHP)
2617  *
2618  * @param string ... strings to escape and glue together, or a single array of strings parameter
2619  * @return string
2620  */
2621 function wfEscapeShellArg( /*...*/ ) {
2622         wfInitShellLocale();
2623
2624         $args = func_get_args();
2625         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2626                 // If only one argument has been passed, and that argument is an array,
2627                 // treat it as a list of arguments
2628                 $args = reset( $args );
2629         }
2630
2631         $first = true;
2632         $retVal = '';
2633         foreach ( $args as $arg ) {
2634                 if ( !$first ) {
2635                         $retVal .= ' ';
2636                 } else {
2637                         $first = false;
2638                 }
2639
2640                 if ( wfIsWindows() ) {
2641                         // Escaping for an MSVC-style command line parser and CMD.EXE
2642                         // @codingStandardsIgnoreStart For long URLs
2643                         // Refs:
2644                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2645                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2646                         //  * Bug #13518
2647                         //  * CR r63214
2648                         // Double the backslashes before any double quotes. Escape the double quotes.
2649                         // @codingStandardsIgnoreEnd
2650                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2651                         $arg = '';
2652                         $iteration = 0;
2653                         foreach ( $tokens as $token ) {
2654                                 if ( $iteration % 2 == 1 ) {
2655                                         // Delimiter, a double quote preceded by zero or more slashes
2656                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2657                                 } elseif ( $iteration % 4 == 2 ) {
2658                                         // ^ in $token will be outside quotes, need to be escaped
2659                                         $arg .= str_replace( '^', '^^', $token );
2660                                 } else { // $iteration % 4 == 0
2661                                         // ^ in $token will appear inside double quotes, so leave as is
2662                                         $arg .= $token;
2663                                 }
2664                                 $iteration++;
2665                         }
2666                         // Double the backslashes before the end of the string, because
2667                         // we will soon add a quote
2668                         $m = array();
2669                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2670                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2671                         }
2672
2673                         // Add surrounding quotes
2674                         $retVal .= '"' . $arg . '"';
2675                 } else {
2676                         $retVal .= escapeshellarg( $arg );
2677                 }
2678         }
2679         return $retVal;
2680 }
2681
2682 /**
2683  * Check if wfShellExec() is effectively disabled via php.ini config
2684  *
2685  * @return bool|string False or one of (safemode,disabled)
2686  * @since 1.22
2687  */
2688 function wfShellExecDisabled() {
2689         static $disabled = null;
2690         if ( is_null( $disabled ) ) {
2691                 if ( wfIniGetBool( 'safe_mode' ) ) {
2692                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2693                         $disabled = 'safemode';
2694                 } elseif ( !function_exists( 'proc_open' ) ) {
2695                         wfDebug( "proc_open() is disabled\n" );
2696                         $disabled = 'disabled';
2697                 } else {
2698                         $disabled = false;
2699                 }
2700         }
2701         return $disabled;
2702 }
2703
2704 /**
2705  * Execute a shell command, with time and memory limits mirrored from the PHP
2706  * configuration if supported.
2707  *
2708  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2709  *   or an array of unescaped arguments, in which case each value will be escaped
2710  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2711  * @param null|mixed &$retval Optional, will receive the program's exit code.
2712  *   (non-zero is usually failure). If there is an error from
2713  *   read, select, or proc_open(), this will be set to -1.
2714  * @param array $environ Optional environment variables which should be
2715  *   added to the executed command environment.
2716  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2717  *   this overwrites the global wgMaxShell* limits.
2718  * @param array $options Array of options:
2719  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2720  *     including errors from limit.sh
2721  *   - profileMethod: By default this function will profile based on the calling
2722  *     method. Set this to a string for an alternative method to profile from
2723  *
2724  * @return string Collected stdout as a string
2725  */
2726 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2727         $limits = array(), $options = array()
2728 ) {
2729         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2730                 $wgMaxShellWallClockTime, $wgShellCgroup;
2731
2732         $disabled = wfShellExecDisabled();
2733         if ( $disabled ) {
2734                 $retval = 1;
2735                 return $disabled == 'safemode' ?
2736                         'Unable to run external programs in safe mode.' :
2737                         'Unable to run external programs, proc_open() is disabled.';
2738         }
2739
2740         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2741         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2742
2743         wfInitShellLocale();
2744
2745         $envcmd = '';
2746         foreach ( $environ as $k => $v ) {
2747                 if ( wfIsWindows() ) {
2748                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2749                          * appear in the environment variable, so we must use carat escaping as documented in
2750                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2751                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2752                          * are listed there but doesn't appear to need it.
2753                          */
2754                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2755                 } else {
2756                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2757                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2758                          */
2759                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2760                 }
2761         }
2762         if ( is_array( $cmd ) ) {
2763                 $cmd = wfEscapeShellArg( $cmd );
2764         }
2765
2766         $cmd = $envcmd . $cmd;
2767
2768         $useLogPipe = false;
2769         if ( is_executable( '/bin/bash' ) ) {
2770                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2771                 if ( isset( $limits['walltime'] ) ) {
2772                         $wallTime = intval( $limits['walltime'] );
2773                 } elseif ( isset( $limits['time'] ) ) {
2774                         $wallTime = $time;
2775                 } else {
2776                         $wallTime = intval( $wgMaxShellWallClockTime );
2777                 }
2778                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2779                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2780
2781                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2782                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2783                                 escapeshellarg( $cmd ) . ' ' .
2784                                 escapeshellarg(
2785                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2786                                         "MW_CPU_LIMIT=$time; " .
2787                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2788                                         "MW_MEM_LIMIT=$mem; " .
2789                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2790                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2791                                         "MW_USE_LOG_PIPE=yes"
2792                                 );
2793                         $useLogPipe = true;
2794                 } elseif ( $includeStderr ) {
2795                         $cmd .= ' 2>&1';
2796                 }
2797         } elseif ( $includeStderr ) {
2798                 $cmd .= ' 2>&1';
2799         }
2800         wfDebug( "wfShellExec: $cmd\n" );
2801
2802         $desc = array(
2803                 0 => array( 'file', 'php://stdin', 'r' ),
2804                 1 => array( 'pipe', 'w' ),
2805                 2 => array( 'file', 'php://stderr', 'w' ) );
2806         if ( $useLogPipe ) {
2807                 $desc[3] = array( 'pipe', 'w' );
2808         }
2809         $pipes = null;
2810         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2811         $proc = proc_open( $cmd, $desc, $pipes );
2812         if ( !$proc ) {
2813                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2814                 $retval = -1;
2815                 return '';
2816         }
2817         $outBuffer = $logBuffer = '';
2818         $emptyArray = array();
2819         $status = false;
2820         $logMsg = false;
2821
2822         // According to the documentation, it is possible for stream_select()
2823         // to fail due to EINTR. I haven't managed to induce this in testing
2824         // despite sending various signals. If it did happen, the error
2825         // message would take the form:
2826         //
2827         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2828         //
2829         // where [4] is the value of the macro EINTR and "Interrupted system
2830         // call" is string which according to the Linux manual is "possibly"
2831         // localised according to LC_MESSAGES.
2832         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2833         $eintrMessage = "stream_select(): unable to select [$eintr]";
2834
2835         // Build a table mapping resource IDs to pipe FDs to work around a
2836         // PHP 5.3 issue in which stream_select() does not preserve array keys
2837         // <https://bugs.php.net/bug.php?id=53427>.
2838         $fds = array();
2839         foreach ( $pipes as $fd => $pipe ) {
2840                 $fds[(int)$pipe] = $fd;
2841         }
2842
2843         $running = true;
2844         $timeout = null;
2845         $numReadyPipes = 0;
2846
2847         while ( $running === true || $numReadyPipes !== 0 ) {
2848                 if ( $running ) {
2849                         $status = proc_get_status( $proc );
2850                         // If the process has terminated, switch to nonblocking selects
2851                         // for getting any data still waiting to be read.
2852                         if ( !$status['running'] ) {
2853                                 $running = false;
2854                                 $timeout = 0;
2855                         }
2856                 }
2857
2858                 $readyPipes = $pipes;
2859
2860                 // Clear last error
2861                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2862                 @trigger_error( '' );
2863                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2864                 if ( $numReadyPipes === false ) {
2865                         // @codingStandardsIgnoreEnd
2866                         $error = error_get_last();
2867                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2868                                 continue;
2869                         } else {
2870                                 trigger_error( $error['message'], E_USER_WARNING );
2871                                 $logMsg = $error['message'];
2872                                 break;
2873                         }
2874                 }
2875                 foreach ( $readyPipes as $pipe ) {
2876                         $block = fread( $pipe, 65536 );
2877                         $fd = $fds[(int)$pipe];
2878                         if ( $block === '' ) {
2879                                 // End of file
2880                                 fclose( $pipes[$fd] );
2881                                 unset( $pipes[$fd] );
2882                                 if ( !$pipes ) {
2883                                         break 2;
2884                                 }
2885                         } elseif ( $block === false ) {
2886                                 // Read error
2887                                 $logMsg = "Error reading from pipe";
2888                                 break 2;
2889                         } elseif ( $fd == 1 ) {
2890                                 // From stdout
2891                                 $outBuffer .= $block;
2892                         } elseif ( $fd == 3 ) {
2893                                 // From log FD
2894                                 $logBuffer .= $block;
2895                                 if ( strpos( $block, "\n" ) !== false ) {
2896                                         $lines = explode( "\n", $logBuffer );
2897                                         $logBuffer = array_pop( $lines );
2898                                         foreach ( $lines as $line ) {
2899                                                 wfDebugLog( 'exec', $line );
2900                                         }
2901                                 }
2902                         }
2903                 }
2904         }
2905
2906         foreach ( $pipes as $pipe ) {
2907                 fclose( $pipe );
2908         }
2909
2910         // Use the status previously collected if possible, since proc_get_status()
2911         // just calls waitpid() which will not return anything useful the second time.
2912         if ( $running ) {
2913                 $status = proc_get_status( $proc );
2914         }
2915
2916         if ( $logMsg !== false ) {
2917                 // Read/select error
2918                 $retval = -1;
2919                 proc_close( $proc );
2920         } elseif ( $status['signaled'] ) {
2921                 $logMsg = "Exited with signal {$status['termsig']}";
2922                 $retval = 128 + $status['termsig'];
2923                 proc_close( $proc );
2924         } else {
2925                 if ( $status['running'] ) {
2926                         $retval = proc_close( $proc );
2927                 } else {
2928                         $retval = $status['exitcode'];
2929                         proc_close( $proc );
2930                 }
2931                 if ( $retval == 127 ) {
2932                         $logMsg = "Possibly missing executable file";
2933                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2934                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2935                 }
2936         }
2937
2938         if ( $logMsg !== false ) {
2939                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2940         }
2941
2942         return $outBuffer;
2943 }
2944
2945 /**
2946  * Execute a shell command, returning both stdout and stderr. Convenience
2947  * function, as all the arguments to wfShellExec can become unwieldy.
2948  *
2949  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2950  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2951  *   or an array of unescaped arguments, in which case each value will be escaped
2952  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2953  * @param null|mixed &$retval Optional, will receive the program's exit code.
2954  *   (non-zero is usually failure)
2955  * @param array $environ Optional environment variables which should be
2956  *   added to the executed command environment.
2957  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2958  *   this overwrites the global wgMaxShell* limits.
2959  * @return string Collected stdout and stderr as a string
2960  */
2961 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2962         return wfShellExec( $cmd, $retval, $environ, $limits,
2963                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2964 }
2965
2966 /**
2967  * Workaround for http://bugs.php.net/bug.php?id=45132
2968  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2969  */
2970 function wfInitShellLocale() {
2971         static $done = false;
2972         if ( $done ) {
2973                 return;
2974         }
2975         $done = true;
2976         global $wgShellLocale;
2977         if ( !wfIniGetBool( 'safe_mode' ) ) {
2978                 putenv( "LC_CTYPE=$wgShellLocale" );
2979                 setlocale( LC_CTYPE, $wgShellLocale );
2980         }
2981 }
2982
2983 /**
2984  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2985  * Note that $parameters should be a flat array and an option with an argument
2986  * should consist of two consecutive items in the array (do not use "--option value").
2987  *
2988  * @param string $script MediaWiki cli script path
2989  * @param array $parameters Arguments and options to the script
2990  * @param array $options Associative array of options:
2991  *              'php': The path to the php executable
2992  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2993  * @return string
2994  */
2995 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
2996         global $wgPhpCli;
2997         // Give site config file a chance to run the script in a wrapper.
2998         // The caller may likely want to call wfBasename() on $script.
2999         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3000         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3001         if ( isset( $options['wrapper'] ) ) {
3002                 $cmd[] = $options['wrapper'];
3003         }
3004         $cmd[] = $script;
3005         // Escape each parameter for shell
3006         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
3007 }
3008
3009 /**
3010  * wfMerge attempts to merge differences between three texts.
3011  * Returns true for a clean merge and false for failure or a conflict.
3012  *
3013  * @param string $old
3014  * @param string $mine
3015  * @param string $yours
3016  * @param string $result
3017  * @return bool
3018  */
3019 function wfMerge( $old, $mine, $yours, &$result ) {
3020         global $wgDiff3;
3021
3022         # This check may also protect against code injection in
3023         # case of broken installations.
3024         MediaWiki\suppressWarnings();
3025         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3026         MediaWiki\restoreWarnings();
3027
3028         if ( !$haveDiff3 ) {
3029                 wfDebug( "diff3 not found\n" );
3030                 return false;
3031         }
3032
3033         # Make temporary files
3034         $td = wfTempDir();
3035         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3036         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3037         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3038
3039         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3040         #       a newline character. To avoid this, we normalize the trailing whitespace before
3041         #       creating the diff.
3042
3043         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3044         fclose( $oldtextFile );
3045         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3046         fclose( $mytextFile );
3047         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3048         fclose( $yourtextFile );
3049
3050         # Check for a conflict
3051         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
3052                 $oldtextName, $yourtextName );
3053         $handle = popen( $cmd, 'r' );
3054
3055         if ( fgets( $handle, 1024 ) ) {
3056                 $conflict = true;
3057         } else {
3058                 $conflict = false;
3059         }
3060         pclose( $handle );
3061
3062         # Merge differences
3063         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
3064                 $oldtextName, $yourtextName );
3065         $handle = popen( $cmd, 'r' );
3066         $result = '';
3067         do {
3068                 $data = fread( $handle, 8192 );
3069                 if ( strlen( $data ) == 0 ) {
3070                         break;
3071                 }
3072                 $result .= $data;
3073         } while ( true );
3074         pclose( $handle );
3075         unlink( $mytextName );
3076         unlink( $oldtextName );
3077         unlink( $yourtextName );
3078
3079         if ( $result === '' && $old !== '' && !$conflict ) {
3080                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3081                 $conflict = true;
3082         }
3083         return !$conflict;
3084 }
3085
3086 /**
3087  * Returns unified plain-text diff of two texts.
3088  * "Useful" for machine processing of diffs.
3089  *
3090  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3091  *
3092  * @param string $before The text before the changes.
3093  * @param string $after The text after the changes.
3094  * @param string $params Command-line options for the diff command.
3095  * @return string Unified diff of $before and $after
3096  */
3097 function wfDiff( $before, $after, $params = '-u' ) {
3098         if ( $before == $after ) {
3099                 return '';
3100         }
3101
3102         global $wgDiff;
3103         MediaWiki\suppressWarnings();
3104         $haveDiff = $wgDiff && file_exists( $wgDiff );
3105         MediaWiki\restoreWarnings();
3106
3107         # This check may also protect against code injection in
3108         # case of broken installations.
3109         if ( !$haveDiff ) {
3110                 wfDebug( "diff executable not found\n" );
3111                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3112                 $format = new UnifiedDiffFormatter();
3113                 return $format->format( $diffs );
3114         }
3115
3116         # Make temporary files
3117         $td = wfTempDir();
3118         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3119         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3120
3121         fwrite( $oldtextFile, $before );
3122         fclose( $oldtextFile );
3123         fwrite( $newtextFile, $after );
3124         fclose( $newtextFile );
3125
3126         // Get the diff of the two files
3127         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3128
3129         $h = popen( $cmd, 'r' );
3130         if ( !$h ) {
3131                 unlink( $oldtextName );
3132                 unlink( $newtextName );
3133                 throw new Exception( __METHOD__ . '(): popen() failed' );
3134         }
3135
3136         $diff = '';
3137
3138         do {
3139                 $data = fread( $h, 8192 );
3140                 if ( strlen( $data ) == 0 ) {
3141                         break;
3142                 }
3143                 $diff .= $data;
3144         } while ( true );
3145
3146         // Clean up
3147         pclose( $h );
3148         unlink( $oldtextName );
3149         unlink( $newtextName );
3150
3151         // Kill the --- and +++ lines. They're not useful.
3152         $diff_lines = explode( "\n", $diff );
3153         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3154                 unset( $diff_lines[0] );
3155         }
3156         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3157                 unset( $diff_lines[1] );
3158         }
3159
3160         $diff = implode( "\n", $diff_lines );
3161
3162         return $diff;
3163 }
3164
3165 /**
3166  * This function works like "use VERSION" in Perl, the program will die with a
3167  * backtrace if the current version of PHP is less than the version provided
3168  *
3169  * This is useful for extensions which due to their nature are not kept in sync
3170  * with releases, and might depend on other versions of PHP than the main code
3171  *
3172  * Note: PHP might die due to parsing errors in some cases before it ever
3173  *       manages to call this function, such is life
3174  *
3175  * @see perldoc -f use
3176  *
3177  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3178  * @throws MWException
3179  */
3180 function wfUsePHP( $req_ver ) {
3181         $php_ver = PHP_VERSION;
3182
3183         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3184                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3185         }
3186 }
3187
3188 /**
3189  * This function works like "use VERSION" in Perl except it checks the version
3190  * of MediaWiki, the program will die with a backtrace if the current version
3191  * of MediaWiki is less than the version provided.
3192  *
3193  * This is useful for extensions which due to their nature are not kept in sync
3194  * with releases
3195  *
3196  * Note: Due to the behavior of PHP's version_compare() which is used in this
3197  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3198  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3199  * targeted version number. For example if you wanted to allow any variation
3200  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3201  * not result in the same comparison due to the internal logic of
3202  * version_compare().
3203  *
3204  * @see perldoc -f use
3205  *
3206  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3207  * @throws MWException
3208  */
3209 function wfUseMW( $req_ver ) {
3210         global $wgVersion;
3211
3212         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3213                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3214         }
3215 }
3216
3217 /**
3218  * Return the final portion of a pathname.
3219  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3220  * http://bugs.php.net/bug.php?id=33898
3221  *
3222  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3223  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3224  *
3225  * @param string $path
3226  * @param string $suffix String to remove if present
3227  * @return string
3228  */
3229 function wfBaseName( $path, $suffix = '' ) {
3230         if ( $suffix == '' ) {
3231                 $encSuffix = '';
3232         } else {
3233                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3234         }
3235
3236         $matches = array();
3237         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3238                 return $matches[1];
3239         } else {
3240                 return '';
3241         }
3242 }
3243
3244 /**
3245  * Generate a relative path name to the given file.
3246  * May explode on non-matching case-insensitive paths,
3247  * funky symlinks, etc.
3248  *
3249  * @param string $path Absolute destination path including target filename
3250  * @param string $from Absolute source path, directory only
3251  * @return string
3252  */
3253 function wfRelativePath( $path, $from ) {
3254         // Normalize mixed input on Windows...
3255         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3256         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3257
3258         // Trim trailing slashes -- fix for drive root
3259         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3260         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3261
3262         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3263         $against = explode( DIRECTORY_SEPARATOR, $from );
3264
3265         if ( $pieces[0] !== $against[0] ) {
3266                 // Non-matching Windows drive letters?
3267                 // Return a full path.
3268                 return $path;
3269         }
3270
3271         // Trim off common prefix
3272         while ( count( $pieces ) && count( $against )
3273                 && $pieces[0] == $against[0] ) {
3274                 array_shift( $pieces );
3275                 array_shift( $against );
3276         }
3277
3278         // relative dots to bump us to the parent
3279         while ( count( $against ) ) {
3280                 array_unshift( $pieces, '..' );
3281                 array_shift( $against );
3282         }
3283
3284         array_push( $pieces, wfBaseName( $path ) );
3285
3286         return implode( DIRECTORY_SEPARATOR, $pieces );
3287 }
3288
3289 /**
3290  * Convert an arbitrarily-long digit string from one numeric base
3291  * to another, optionally zero-padding to a minimum column width.
3292  *
3293  * Supports base 2 through 36; digit values 10-36 are represented
3294  * as lowercase letters a-z. Input is case-insensitive.
3295  *
3296  * @param string $input Input number
3297  * @param int $sourceBase Base of the input number
3298  * @param int $destBase Desired base of the output
3299  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3300  * @param bool $lowercase Whether to output in lowercase or uppercase
3301  * @param string $engine Either "gmp", "bcmath", or "php"
3302  * @return string|bool The output number as a string, or false on error
3303  */
3304 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3305         $lowercase = true, $engine = 'auto'
3306 ) {
3307         $input = (string)$input;
3308         if (
3309                 $sourceBase < 2 ||
3310                 $sourceBase > 36 ||
3311                 $destBase < 2 ||
3312                 $destBase > 36 ||
3313                 $sourceBase != (int)$sourceBase ||
3314                 $destBase != (int)$destBase ||
3315                 $pad != (int)$pad ||
3316                 !preg_match(
3317                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3318                         $input
3319                 )
3320         ) {
3321                 return false;
3322         }
3323
3324         static $baseChars = array(
3325                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3326                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3327                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3328                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3329                 34 => 'y', 35 => 'z',
3330
3331                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3332                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3333                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3334                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3335                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3336                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3337         );
3338
3339         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3340                 // Removing leading zeros works around broken base detection code in
3341                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3342                 // <https://bugs.php.net/bug.php?id=55398>).
3343                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ) ?: '0', $sourceBase ), $destBase );
3344         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3345                 $decimal = '0';
3346                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3347                         $decimal = bcmul( $decimal, $sourceBase );
3348                         $decimal = bcadd( $decimal, $baseChars[$char] );
3349                 }
3350
3351                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3352                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3353                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3354                 }
3355                 // @codingStandardsIgnoreEnd
3356
3357                 $result = strrev( $result );
3358         } else {
3359                 $inDigits = array();
3360                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3361                         $inDigits[] = $baseChars[$char];
3362                 }
3363
3364                 // Iterate over the input, modulo-ing out an output digit
3365                 // at a time until input is gone.
3366                 $result = '';
3367                 while ( $inDigits ) {
3368                         $work = 0;
3369                         $workDigits = array();
3370
3371                         // Long division...
3372                         foreach ( $inDigits as $digit ) {
3373                                 $work *= $sourceBase;
3374                                 $work += $digit;
3375
3376                                 if ( $workDigits || $work >= $destBase ) {
3377                                         $workDigits[] = (int)( $work / $destBase );
3378                                 }
3379                                 $work %= $destBase;
3380                         }
3381
3382                         // All that division leaves us with a remainder,
3383                         // which is conveniently our next output digit.
3384                         $result .= $baseChars[$work];
3385
3386                         // And we continue!
3387                         $inDigits = $workDigits;
3388                 }
3389
3390                 $result = strrev( $result );
3391         }
3392
3393         if ( !$lowercase ) {
3394                 $result = strtoupper( $result );
3395         }
3396
3397         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3398 }
3399
3400 /**
3401  * Check if there is sufficient entropy in php's built-in session generation
3402  *
3403  * @return bool True = there is sufficient entropy
3404  */
3405 function wfCheckEntropy() {
3406         return (
3407                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3408                         || ini_get( 'session.entropy_file' )
3409                 )
3410                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3411 }
3412
3413 /**
3414  * Override session_id before session startup if php's built-in
3415  * session generation code is not secure.
3416  */
3417 function wfFixSessionID() {
3418         // If the cookie or session id is already set we already have a session and should abort
3419         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3420                 return;
3421         }
3422
3423         // PHP's built-in session entropy is enabled if:
3424         // - entropy_file is set or you're on Windows with php 5.3.3+
3425         // - AND entropy_length is > 0
3426         // We treat it as disabled if it doesn't have an entropy length of at least 32
3427         $entropyEnabled = wfCheckEntropy();
3428
3429         // If built-in entropy is not enabled or not sufficient override PHP's
3430         // built in session id generation code
3431         if ( !$entropyEnabled ) {
3432                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3433                         "overriding session id generation using our cryptrand source.\n" );
3434                 session_id( MWCryptRand::generateHex( 32 ) );
3435         }
3436 }
3437
3438 /**
3439  * Reset the session_id
3440  *
3441  * @since 1.22
3442  */
3443 function wfResetSessionID() {
3444         global $wgCookieSecure;
3445         $oldSessionId = session_id();
3446         $cookieParams = session_get_cookie_params();
3447         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3448                 session_regenerate_id( false );
3449         } else {
3450                 $tmp = $_SESSION;
3451                 session_destroy();
3452                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3453                 $_SESSION = $tmp;
3454         }
3455         $newSessionId = session_id();
3456         Hooks::run( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3457 }
3458
3459 /**
3460  * Initialise php session
3461  *
3462  * @param bool $sessionId
3463  */
3464 function wfSetupSession( $sessionId = false ) {
3465         global $wgSessionsInObjectCache, $wgSessionHandler;
3466         global $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly;
3467
3468         if ( $wgSessionsInObjectCache ) {
3469                 ObjectCacheSessionHandler::install();
3470         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3471                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3472                 # hasn't already been set to the desired value (that causes errors)
3473                 ini_set( 'session.save_handler', $wgSessionHandler );
3474         }
3475
3476         session_set_cookie_params(
3477                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3478         session_cache_limiter( 'private, must-revalidate' );
3479         if ( $sessionId ) {
3480                 session_id( $sessionId );
3481         } else {
3482                 wfFixSessionID();
3483         }
3484
3485         MediaWiki\suppressWarnings();
3486         session_start();
3487         MediaWiki\restoreWarnings();
3488
3489         if ( $wgSessionsInObjectCache ) {
3490                 ObjectCacheSessionHandler::renewCurrentSession();
3491         }
3492 }
3493
3494 /**
3495  * Get an object from the precompiled serialized directory
3496  *
3497  * @param string $name
3498  * @return mixed The variable on success, false on failure
3499  */
3500 function wfGetPrecompiledData( $name ) {
3501         global $IP;
3502
3503         $file = "$IP/serialized/$name";
3504         if ( file_exists( $file ) ) {
3505                 $blob = file_get_contents( $file );
3506                 if ( $blob ) {
3507                         return unserialize( $blob );
3508                 }
3509         }
3510         return false;
3511 }
3512
3513 /**
3514  * Make a cache key for the local wiki.
3515  *
3516  * @param string $args,...
3517  * @return string
3518  */
3519 function wfMemcKey( /*...*/ ) {
3520         global $wgCachePrefix;
3521         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3522         $args = func_get_args();
3523         $key = $prefix . ':' . implode( ':', $args );
3524         return strtr( $key, ' ', '_' );
3525 }
3526
3527 /**
3528  * Make a cache key for a foreign DB.
3529  *
3530  * Must match what wfMemcKey() would produce in context of the foreign wiki.
3531  *
3532  * @param string $db
3533  * @param string $prefix
3534  * @param string $args,...
3535  * @return string
3536  */
3537 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3538         $args = array_slice( func_get_args(), 2 );
3539         if ( $prefix ) {
3540                 // Match wfWikiID() logic
3541                 $key = "$db-$prefix:" . implode( ':', $args );
3542         } else {
3543                 $key = $db . ':' . implode( ':', $args );
3544         }
3545         return strtr( $key, ' ', '_' );
3546 }
3547
3548 /**
3549  * Make a cache key with database-agnostic prefix.
3550  *
3551  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3552  * instead. Must have a prefix as otherwise keys that use a database name
3553  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3554  *
3555  * @since 1.26
3556  * @param string $args,...
3557  * @return string
3558  */
3559 function wfGlobalCacheKey( /*...*/ ) {
3560         $args = func_get_args();
3561         $key = 'global:' . implode( ':', $args );
3562         return strtr( $key, ' ', '_' );
3563 }
3564
3565 /**
3566  * Get an ASCII string identifying this wiki
3567  * This is used as a prefix in memcached keys
3568  *
3569  * @return string
3570  */
3571 function wfWikiID() {
3572         global $wgDBprefix, $wgDBname;
3573         if ( $wgDBprefix ) {
3574                 return "$wgDBname-$wgDBprefix";
3575         } else {
3576                 return $wgDBname;
3577         }
3578 }
3579
3580 /**
3581  * Split a wiki ID into DB name and table prefix
3582  *
3583  * @param string $wiki
3584  *
3585  * @return array
3586  */
3587 function wfSplitWikiID( $wiki ) {
3588         $bits = explode( '-', $wiki, 2 );
3589         if ( count( $bits ) < 2 ) {
3590                 $bits[] = '';
3591         }
3592         return $bits;
3593 }
3594
3595 /**
3596  * Get a Database object.
3597  *
3598  * @param int $db Index of the connection to get. May be DB_MASTER for the
3599  *            master (for write queries), DB_SLAVE for potentially lagged read
3600  *            queries, or an integer >= 0 for a particular server.
3601  *
3602  * @param string|string[] $groups Query groups. An array of group names that this query
3603  *                belongs to. May contain a single string if the query is only
3604  *                in one group.
3605  *
3606  * @param string|bool $wiki The wiki ID, or false for the current wiki
3607  *
3608  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3609  * will always return the same object, unless the underlying connection or load
3610  * balancer is manually destroyed.
3611  *
3612  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3613  * updater to ensure that a proper database is being updated.
3614  *
3615  * @return DatabaseBase
3616  */
3617 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3618         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3619 }
3620
3621 /**
3622  * Get a load balancer object.
3623  *
3624  * @param string|bool $wiki Wiki ID, or false for the current wiki
3625  * @return LoadBalancer
3626  */
3627 function wfGetLB( $wiki = false ) {
3628         return wfGetLBFactory()->getMainLB( $wiki );
3629 }
3630
3631 /**
3632  * Get the load balancer factory object
3633  *
3634  * @return LBFactory
3635  */
3636 function wfGetLBFactory() {
3637         return LBFactory::singleton();
3638 }
3639
3640 /**
3641  * Find a file.
3642  * Shortcut for RepoGroup::singleton()->findFile()
3643  *
3644  * @param string $title String or Title object
3645  * @param array $options Associative array of options (see RepoGroup::findFile)
3646  * @return File|bool File, or false if the file does not exist
3647  */
3648 function wfFindFile( $title, $options = array() ) {
3649         return RepoGroup::singleton()->findFile( $title, $options );
3650 }
3651
3652 /**
3653  * Get an object referring to a locally registered file.
3654  * Returns a valid placeholder object if the file does not exist.
3655  *
3656  * @param Title|string $title
3657  * @return LocalFile|null A File, or null if passed an invalid Title
3658  */
3659 function wfLocalFile( $title ) {
3660         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3661 }
3662
3663 /**
3664  * Should low-performance queries be disabled?
3665  *
3666  * @return bool
3667  * @codeCoverageIgnore
3668  */
3669 function wfQueriesMustScale() {
3670         global $wgMiserMode;
3671         return $wgMiserMode
3672                 || ( SiteStats::pages() > 100000
3673                 && SiteStats::edits() > 1000000
3674                 && SiteStats::users() > 10000 );
3675 }
3676
3677 /**
3678  * Get the path to a specified script file, respecting file
3679  * extensions; this is a wrapper around $wgScriptExtension etc.
3680  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3681  *
3682  * @param string $script Script filename, sans extension
3683  * @return string
3684  */
3685 function wfScript( $script = 'index' ) {
3686         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3687         if ( $script === 'index' ) {
3688                 return $wgScript;
3689         } elseif ( $script === 'load' ) {
3690                 return $wgLoadScript;
3691         } else {
3692                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3693         }
3694 }
3695
3696 /**
3697  * Get the script URL.
3698  *
3699  * @return string Script URL
3700  */
3701 function wfGetScriptUrl() {
3702         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3703                 #
3704                 # as it was called, minus the query string.
3705                 #
3706                 # Some sites use Apache rewrite rules to handle subdomains,
3707                 # and have PHP set up in a weird way that causes PHP_SELF
3708                 # to contain the rewritten URL instead of the one that the
3709                 # outside world sees.
3710                 #
3711                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3712                 # provides containing the "before" URL.
3713                 return $_SERVER['SCRIPT_NAME'];
3714         } else {
3715                 return $_SERVER['URL'];
3716         }
3717 }
3718
3719 /**
3720  * Convenience function converts boolean values into "true"
3721  * or "false" (string) values
3722  *
3723  * @param bool $value
3724  * @return string
3725  */
3726 function wfBoolToStr( $value ) {
3727         return $value ? 'true' : 'false';
3728 }
3729
3730 /**
3731  * Get a platform-independent path to the null file, e.g. /dev/null
3732  *
3733  * @return string
3734  */
3735 function wfGetNull() {
3736         return wfIsWindows() ? 'NUL' : '/dev/null';
3737 }
3738
3739 /**
3740  * Waits for the slaves to catch up to the master position
3741  *
3742  * Use this when updating very large numbers of rows, as in maintenance scripts,
3743  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3744  *
3745  * By default this waits on the main DB cluster of the current wiki.
3746  * If $cluster is set to "*" it will wait on all DB clusters, including
3747  * external ones. If the lag being waiting on is caused by the code that
3748  * does this check, it makes since to use $ifWritesSince, particularly if
3749  * cluster is "*", to avoid excess overhead.
3750  *
3751  * Never call this function after a big DB write that is still in a transaction.
3752  * This only makes sense after the possible lag inducing changes were committed.
3753  *
3754  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3755  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3756  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3757  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3758  * @return bool Success (able to connect and no timeouts reached)
3759  */
3760 function wfWaitForSlaves(
3761         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3762 ) {
3763         // B/C: first argument used to be "max seconds of lag"; ignore such values
3764         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3765
3766         if ( $timeout === null ) {
3767                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3768         }
3769
3770         // Figure out which clusters need to be checked
3771         /** @var LoadBalancer[] $lbs */
3772         $lbs = array();
3773         if ( $cluster === '*' ) {
3774                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3775                         $lbs[] = $lb;
3776                 } );
3777         } elseif ( $cluster !== false ) {
3778                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3779         } else {
3780                 $lbs[] = wfGetLB( $wiki );
3781         }
3782
3783         // Get all the master positions of applicable DBs right now.
3784         // This can be faster since waiting on one cluster reduces the
3785         // time needed to wait on the next clusters.
3786         $masterPositions = array_fill( 0, count( $lbs ), false );
3787         foreach ( $lbs as $i => $lb ) {
3788                 if ( $lb->getServerCount() <= 1 ) {
3789                         // Bug 27975 - Don't try to wait for slaves if there are none
3790                         // Prevents permission error when getting master position
3791                         continue;
3792                 } elseif ( $ifWritesSince && $lb->lastMasterChangeTimestamp() < $ifWritesSince ) {
3793                         continue; // no writes since the last wait
3794                 }
3795                 $masterPositions[$i] = $lb->getMasterPos();
3796         }
3797
3798         $ok = true;
3799         foreach ( $lbs as $i => $lb ) {
3800                 if ( $masterPositions[$i] ) {
3801                         // The DBMS may not support getMasterPos() or the whole
3802                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3803                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3804                 }
3805         }
3806
3807         return $ok;
3808 }
3809
3810 /**
3811  * Count down from $seconds to zero on the terminal, with a one-second pause
3812  * between showing each number. For use in command-line scripts.
3813  *
3814  * @codeCoverageIgnore
3815  * @param int $seconds
3816  */
3817 function wfCountDown( $seconds ) {
3818         for ( $i = $seconds; $i >= 0; $i-- ) {
3819                 if ( $i != $seconds ) {
3820                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3821                 }
3822                 echo $i;
3823                 flush();
3824                 if ( $i ) {
3825                         sleep( 1 );
3826                 }
3827         }
3828         echo "\n";
3829 }
3830
3831 /**
3832  * Replace all invalid characters with -
3833  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3834  * By default, $wgIllegalFileChars = ':'
3835  *
3836  * @param string $name Filename to process
3837  * @return string
3838  */
3839 function wfStripIllegalFilenameChars( $name ) {
3840         global $wgIllegalFileChars;
3841         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3842         $name = wfBaseName( $name );
3843         $name = preg_replace(
3844                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3845                 '-',
3846                 $name
3847         );
3848         return $name;
3849 }
3850
3851 /**
3852  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3853  *
3854  * @return int Resulting value of the memory limit.
3855  */
3856 function wfMemoryLimit() {
3857         global $wgMemoryLimit;
3858         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3859         if ( $memlimit != -1 ) {
3860                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3861                 if ( $conflimit == -1 ) {
3862                         wfDebug( "Removing PHP's memory limit\n" );
3863                         MediaWiki\suppressWarnings();
3864                         ini_set( 'memory_limit', $conflimit );
3865                         MediaWiki\restoreWarnings();
3866                         return $conflimit;
3867                 } elseif ( $conflimit > $memlimit ) {
3868                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3869                         MediaWiki\suppressWarnings();
3870                         ini_set( 'memory_limit', $conflimit );
3871                         MediaWiki\restoreWarnings();
3872                         return $conflimit;
3873                 }
3874         }
3875         return $memlimit;
3876 }
3877
3878 /**
3879  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3880  *
3881  * @return int Prior time limit
3882  * @since 1.26
3883  */
3884 function wfTransactionalTimeLimit() {
3885         global $wgTransactionalTimeLimit;
3886
3887         $timeLimit = ini_get( 'max_execution_time' );
3888         // Note that CLI scripts use 0
3889         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3890                 set_time_limit( $wgTransactionalTimeLimit );
3891         }
3892
3893         ignore_user_abort( true ); // ignore client disconnects
3894
3895         return $timeLimit;
3896 }
3897
3898 /**
3899  * Converts shorthand byte notation to integer form
3900  *
3901  * @param string $string
3902  * @return int
3903  */
3904 function wfShorthandToInteger( $string = '' ) {
3905         $string = trim( $string );
3906         if ( $string === '' ) {
3907                 return -1;
3908         }
3909         $last = $string[strlen( $string ) - 1];
3910         $val = intval( $string );
3911         switch ( $last ) {
3912                 case 'g':
3913                 case 'G':
3914                         $val *= 1024;
3915                         // break intentionally missing
3916                 case 'm':
3917                 case 'M':
3918                         $val *= 1024;
3919                         // break intentionally missing
3920                 case 'k':
3921                 case 'K':
3922                         $val *= 1024;
3923         }
3924
3925         return $val;
3926 }
3927
3928 /**
3929  * Get the normalised IETF language tag
3930  * See unit test for examples.
3931  *
3932  * @param string $code The language code.
3933  * @return string The language code which complying with BCP 47 standards.
3934  */
3935 function wfBCP47( $code ) {
3936         $codeSegment = explode( '-', $code );
3937         $codeBCP = array();
3938         foreach ( $codeSegment as $segNo => $seg ) {
3939                 // when previous segment is x, it is a private segment and should be lc
3940                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3941                         $codeBCP[$segNo] = strtolower( $seg );
3942                 // ISO 3166 country code
3943                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3944                         $codeBCP[$segNo] = strtoupper( $seg );
3945                 // ISO 15924 script code
3946                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3947                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3948                 // Use lowercase for other cases
3949                 } else {
3950                         $codeBCP[$segNo] = strtolower( $seg );
3951                 }
3952         }
3953         $langCode = implode( '-', $codeBCP );
3954         return $langCode;
3955 }
3956
3957 /**
3958  * Get a specific cache object.
3959  *
3960  * @param int|string $cacheType A CACHE_* constants, or other key in $wgObjectCaches
3961  * @return BagOStuff
3962  */
3963 function wfGetCache( $cacheType ) {
3964         return ObjectCache::getInstance( $cacheType );
3965 }
3966
3967 /**
3968  * Get the main cache object
3969  *
3970  * @return BagOStuff
3971  */
3972 function wfGetMainCache() {
3973         global $wgMainCacheType;
3974         return ObjectCache::getInstance( $wgMainCacheType );
3975 }
3976
3977 /**
3978  * Get the cache object used by the message cache
3979  *
3980  * @return BagOStuff
3981  */
3982 function wfGetMessageCacheStorage() {
3983         global $wgMessageCacheType;
3984         return ObjectCache::getInstance( $wgMessageCacheType );
3985 }
3986
3987 /**
3988  * Get the cache object used by the parser cache
3989  *
3990  * @return BagOStuff
3991  */
3992 function wfGetParserCacheStorage() {
3993         global $wgParserCacheType;
3994         return ObjectCache::getInstance( $wgParserCacheType );
3995 }
3996
3997 /**
3998  * Call hook functions defined in $wgHooks
3999  *
4000  * @param string $event Event name
4001  * @param array $args Parameters passed to hook functions
4002  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
4003  *
4004  * @return bool True if no handler aborted the hook
4005  * @deprecated 1.25 - use Hooks::run
4006  */
4007 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
4008         return Hooks::run( $event, $args, $deprecatedVersion );
4009 }
4010
4011 /**
4012  * Wrapper around php's unpack.
4013  *
4014  * @param string $format The format string (See php's docs)
4015  * @param string $data A binary string of binary data
4016  * @param int|bool $length The minimum length of $data or false. This is to
4017  *      prevent reading beyond the end of $data. false to disable the check.
4018  *
4019  * Also be careful when using this function to read unsigned 32 bit integer
4020  * because php might make it negative.
4021  *
4022  * @throws MWException If $data not long enough, or if unpack fails
4023  * @return array Associative array of the extracted data
4024  */
4025 function wfUnpack( $format, $data, $length = false ) {
4026         if ( $length !== false ) {
4027                 $realLen = strlen( $data );
4028                 if ( $realLen < $length ) {
4029                         throw new MWException( "Tried to use wfUnpack on a "
4030                                 . "string of length $realLen, but needed one "
4031                                 . "of at least length $length."
4032                         );
4033                 }
4034         }
4035
4036         MediaWiki\suppressWarnings();
4037         $result = unpack( $format, $data );
4038         MediaWiki\restoreWarnings();
4039
4040         if ( $result === false ) {
4041                 // If it cannot extract the packed data.
4042                 throw new MWException( "unpack could not unpack binary data" );
4043         }
4044         return $result;
4045 }
4046
4047 /**
4048  * Determine if an image exists on the 'bad image list'.
4049  *
4050  * The format of MediaWiki:Bad_image_list is as follows:
4051  *    * Only list items (lines starting with "*") are considered
4052  *    * The first link on a line must be a link to a bad image
4053  *    * Any subsequent links on the same line are considered to be exceptions,
4054  *      i.e. articles where the image may occur inline.
4055  *
4056  * @param string $name The image name to check
4057  * @param Title|bool $contextTitle The page on which the image occurs, if known
4058  * @param string $blacklist Wikitext of a file blacklist
4059  * @return bool
4060  */
4061 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4062         static $badImageCache = null; // based on bad_image_list msg
4063
4064         # Handle redirects
4065         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4066         if ( $redirectTitle ) {
4067                 $name = $redirectTitle->getDBkey();
4068         }
4069
4070         # Run the extension hook
4071         $bad = false;
4072         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4073                 return $bad;
4074         }
4075
4076         $cacheable = ( $blacklist === null );
4077         if ( $cacheable && $badImageCache !== null ) {
4078                 $badImages = $badImageCache;
4079         } else { // cache miss
4080                 if ( $blacklist === null ) {
4081                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4082                 }
4083                 # Build the list now
4084                 $badImages = array();
4085                 $lines = explode( "\n", $blacklist );
4086                 foreach ( $lines as $line ) {
4087                         # List items only
4088                         if ( substr( $line, 0, 1 ) !== '*' ) {
4089                                 continue;
4090                         }
4091
4092                         # Find all links
4093                         $m = array();
4094                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4095                                 continue;
4096                         }
4097
4098                         $exceptions = array();
4099                         $imageDBkey = false;
4100                         foreach ( $m[1] as $i => $titleText ) {
4101                                 $title = Title::newFromText( $titleText );
4102                                 if ( !is_null( $title ) ) {
4103                                         if ( $i == 0 ) {
4104                                                 $imageDBkey = $title->getDBkey();
4105                                         } else {
4106                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4107                                         }
4108                                 }
4109                         }
4110
4111                         if ( $imageDBkey !== false ) {
4112                                 $badImages[$imageDBkey] = $exceptions;
4113                         }
4114                 }
4115                 if ( $cacheable ) {
4116                         $badImageCache = $badImages;
4117                 }
4118         }
4119
4120         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4121         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4122         return $bad;
4123 }
4124
4125 /**
4126  * Determine whether the client at a given source IP is likely to be able to
4127  * access the wiki via HTTPS.
4128  *
4129  * @param string $ip The IPv4/6 address in the normal human-readable form
4130  * @return bool
4131  */
4132 function wfCanIPUseHTTPS( $ip ) {
4133         $canDo = true;
4134         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4135         return !!$canDo;
4136 }
4137
4138 /**
4139  * Determine input string is represents as infinity
4140  *
4141  * @param string $str The string to determine
4142  * @return bool
4143  * @since 1.25
4144  */
4145 function wfIsInfinity( $str ) {
4146         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4147         return in_array( $str, $infinityValues );
4148 }
4149
4150 /**
4151  * Work out the IP address based on various globals
4152  * For trusted proxies, use the XFF client IP (first of the chain)
4153  *
4154  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4155  * @return string
4156  */
4157 function wfGetIP() {
4158         wfDeprecated( __METHOD__, '1.19' );
4159         global $wgRequest;
4160         return $wgRequest->getIP();
4161 }
4162
4163 /**
4164  * Checks if an IP is a trusted proxy provider.
4165  * Useful to tell if X-Forwarded-For data is possibly bogus.
4166  * Squid cache servers for the site are whitelisted.
4167  * @deprecated Since 1.24, use IP::isTrustedProxy()
4168  *
4169  * @param string $ip
4170  * @return bool
4171  */
4172 function wfIsTrustedProxy( $ip ) {
4173         wfDeprecated( __METHOD__, '1.24' );
4174         return IP::isTrustedProxy( $ip );
4175 }
4176
4177 /**
4178  * Checks if an IP matches a proxy we've configured.
4179  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4180  *
4181  * @param string $ip
4182  * @return bool
4183  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4184  */
4185 function wfIsConfiguredProxy( $ip ) {
4186         wfDeprecated( __METHOD__, '1.24' );
4187         return IP::isConfiguredProxy( $ip );
4188 }
4189
4190 /**
4191  * Returns true if these thumbnail parameters match one that MediaWiki
4192  * requests from file description pages and/or parser output.
4193  *
4194  * $params is considered non-standard if they involve a non-standard
4195  * width or any non-default parameters aside from width and page number.
4196  * The number of possible files with standard parameters is far less than
4197  * that of all combinations; rate-limiting for them can thus be more generious.
4198  *
4199  * @param File $file
4200  * @param array $params
4201  * @return bool
4202  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4203  */
4204 function wfThumbIsStandard( File $file, array $params ) {
4205         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4206
4207         $multipliers = array( 1 );
4208         if ( $wgResponsiveImages ) {
4209                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4210                 // @see Linker::processResponsiveImages
4211                 $multipliers[] = 1.5;
4212                 $multipliers[] = 2;
4213         }
4214
4215         $handler = $file->getHandler();
4216         if ( !$handler || !isset( $params['width'] ) ) {
4217                 return false;
4218         }
4219
4220         $basicParams = array();
4221         if ( isset( $params['page'] ) ) {
4222                 $basicParams['page'] = $params['page'];
4223         }
4224
4225         $thumbLimits = array();
4226         $imageLimits = array();
4227         // Expand limits to account for multipliers
4228         foreach ( $multipliers as $multiplier ) {
4229                 $thumbLimits = array_merge( $thumbLimits, array_map(
4230                         function ( $width ) use ( $multiplier ) {
4231                                 return round( $width * $multiplier );
4232                         }, $wgThumbLimits )
4233                 );
4234                 $imageLimits = array_merge( $imageLimits, array_map(
4235                         function ( $pair ) use ( $multiplier ) {
4236                                 return array(
4237                                         round( $pair[0] * $multiplier ),
4238                                         round( $pair[1] * $multiplier ),
4239                                 );
4240                         }, $wgImageLimits )
4241                 );
4242         }
4243
4244         // Check if the width matches one of $wgThumbLimits
4245         if ( in_array( $params['width'], $thumbLimits ) ) {
4246                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4247                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4248                 $handler->normaliseParams( $file, $normalParams );
4249         } else {
4250                 // If not, then check if the width matchs one of $wgImageLimits
4251                 $match = false;
4252                 foreach ( $imageLimits as $pair ) {
4253                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4254                         // Decide whether the thumbnail should be scaled on width or height.
4255                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4256                         $handler->normaliseParams( $file, $normalParams );
4257                         // Check if this standard thumbnail size maps to the given width
4258                         if ( $normalParams['width'] == $params['width'] ) {
4259                                 $match = true;
4260                                 break;
4261                         }
4262                 }
4263                 if ( !$match ) {
4264                         return false; // not standard for description pages
4265                 }
4266         }
4267
4268         // Check that the given values for non-page, non-width, params are just defaults
4269         foreach ( $params as $key => $value ) {
4270                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4271                         return false;
4272                 }
4273         }
4274
4275         return true;
4276 }
4277
4278 /**
4279  * Merges two (possibly) 2 dimensional arrays into the target array ($baseArray).
4280  *
4281  * Values that exist in both values will be combined with += (all values of the array
4282  * of $newValues will be added to the values of the array of $baseArray, while values,
4283  * that exists in both, the value of $baseArray will be used).
4284  *
4285  * @param array $baseArray The array where you want to add the values of $newValues to
4286  * @param array $newValues An array with new values
4287  * @return array The combined array
4288  * @since 1.26
4289  */
4290 function wfArrayPlus2d( array $baseArray, array $newValues ) {
4291         // First merge items that are in both arrays
4292         foreach ( $baseArray as $name => &$groupVal ) {
4293                 if ( isset( $newValues[$name] ) ) {
4294                         $groupVal += $newValues[$name];
4295                 }
4296         }
4297         // Now add items that didn't exist yet
4298         $baseArray += $newValues;
4299
4300         return $baseArray;
4301 }