includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 use Liuggio\StatsdClient\StatsdClient;
  28 use Liuggio\StatsdClient\Sender\SocketSender;
  29 use MediaWiki\Logger\LoggerFactory;
  30
  31 // Hide compatibility functions from Doxygen
  32 /// @cond
  33
  34 /**
  35  * Compatibility functions
  36  *
  37  * We support PHP 5.3.3 and up.
  38  * Re-implementations of newer functions or functions in non-standard
  39  * PHP extensions may be included here.
  40  */
  41
  42 if ( !function_exists( 'mb_substr' ) ) {
  43         /**
  44          * @codeCoverageIgnore
  45          * @see Fallback::mb_substr
  46          * @return string
  47          */
  48         function mb_substr( $str, $start, $count = 'end' ) {
  49                 return Fallback::mb_substr( $str, $start, $count );
  50         }
  51
  52         /**
  53          * @codeCoverageIgnore
  54          * @see Fallback::mb_substr_split_unicode
  55          * @return int
  56          */
  57         function mb_substr_split_unicode( $str, $splitPos ) {
  58                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  59         }
  60 }
  61
  62 if ( !function_exists( 'mb_strlen' ) ) {
  63         /**
  64          * @codeCoverageIgnore
  65          * @see Fallback::mb_strlen
  66          * @return int
  67          */
  68         function mb_strlen( $str, $enc = '' ) {
  69                 return Fallback::mb_strlen( $str, $enc );
  70         }
  71 }
  72
  73 if ( !function_exists( 'mb_strpos' ) ) {
  74         /**
  75          * @codeCoverageIgnore
  76          * @see Fallback::mb_strpos
  77          * @return int
  78          */
  79         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  80                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  81         }
  82 }
  83
  84 if ( !function_exists( 'mb_strrpos' ) ) {
  85         /**
  86          * @codeCoverageIgnore
  87          * @see Fallback::mb_strrpos
  88          * @return int
  89          */
  90         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  91                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  92         }
  93 }
  94
  95 // gzdecode function only exists in PHP >= 5.4.0
  96 // http://php.net/gzdecode
  97 if ( !function_exists( 'gzdecode' ) ) {
  98         /**
  99          * @codeCoverageIgnore
 100          * @param string $data
 101          * @return string
 102          */
 103         function gzdecode( $data ) {
 104                 return gzinflate( substr( $data, 10, -8 ) );
 105         }
 106 }
 107
 108 // hash_equals function only exists in PHP >= 5.6.0
 109 // http://php.net/hash_equals
 110 if ( !function_exists( 'hash_equals' ) ) {
 111         /**
 112          * Check whether a user-provided string is equal to a fixed-length secret string
 113          * without revealing bytes of the secret string through timing differences.
 114          *
 115          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 116          * function in C) is to compare corresponding bytes and stop at the first difference,
 117          * which would take longer for a partial match than for a complete mismatch. This
 118          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 119          * and the other may come from an attacker. Statistical analysis of timing measurements
 120          * over many requests may allow the attacker to guess the string's bytes one at a time
 121          * (and check his guesses) even if the timing differences are extremely small.
 122          *
 123          * When making such a security-sensitive comparison, it is essential that the sequence
 124          * in which instructions are executed and memory locations are accessed not depend on
 125          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 126          * the inevitable leakage of the string's length. That is generally known anyway as
 127          * a chararacteristic of the hash function used to compute the secret value.
 128          *
 129          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 130          *
 131          * @codeCoverageIgnore
 132          * @param string $known_string Fixed-length secret string to compare against
 133          * @param string $user_string User-provided string
 134          * @return bool True if the strings are the same, false otherwise
 135          */
 136         function hash_equals( $known_string, $user_string ) {
 137                 // Strict type checking as in PHP's native implementation
 138                 if ( !is_string( $known_string ) ) {
 139                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 140                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 141
 142                         return false;
 143                 }
 144
 145                 if ( !is_string( $user_string ) ) {
 146                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 147                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 148
 149                         return false;
 150                 }
 151
 152                 $known_string_len = strlen( $known_string );
 153                 if ( $known_string_len !== strlen( $user_string ) ) {
 154                         return false;
 155                 }
 156
 157                 $result = 0;
 158                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 159                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 160                 }
 161
 162                 return ( $result === 0 );
 163         }
 164 }
 165 /// @endcond
 166
 167 /**
 168  * Load an extension
 169  *
 170  * This queues an extension to be loaded through
 171  * the ExtensionRegistry system.
 172  *
 173  * @param string $ext Name of the extension to load
 174  * @param string|null $path Absolute path of where to find the extension.json file
 175  */
 176 function wfLoadExtension( $ext, $path = null ) {
 177         if ( !$path ) {
 178                 global $wgExtensionDirectory;
 179                 $path = "$wgExtensionDirectory/$ext/extension.json";
 180         }
 181         ExtensionRegistry::getInstance()->queue( $path );
 182 }
 183
 184 /**
 185  * Load multiple extensions at once
 186  *
 187  * Same as wfLoadExtension, but more efficient if you
 188  * are loading multiple extensions.
 189  *
 190  * If you want to specify custom paths, you should interact with
 191  * ExtensionRegistry directly.
 192  *
 193  * @see wfLoadExtension
 194  * @param string[] $exts Array of extension names to load
 195  */
 196 function wfLoadExtensions( array $exts ) {
 197         global $wgExtensionDirectory;
 198         $registry = ExtensionRegistry::getInstance();
 199         foreach ( $exts as $ext ) {
 200                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 201         }
 202 }
 203
 204 /**
 205  * Load a skin
 206  *
 207  * @see wfLoadExtension
 208  * @param string $skin Name of the extension to load
 209  * @param string|null $path Absolute path of where to find the skin.json file
 210  */
 211 function wfLoadSkin( $skin, $path = null ) {
 212         if ( !$path ) {
 213                 global $wgStyleDirectory;
 214                 $path = "$wgStyleDirectory/$skin/skin.json";
 215         }
 216         ExtensionRegistry::getInstance()->queue( $path );
 217 }
 218
 219 /**
 220  * Load multiple skins at once
 221  *
 222  * @see wfLoadExtensions
 223  * @param string[] $skins Array of extension names to load
 224  */
 225 function wfLoadSkins( array $skins ) {
 226         global $wgStyleDirectory;
 227         $registry = ExtensionRegistry::getInstance();
 228         foreach ( $skins as $skin ) {
 229                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 230         }
 231 }
 232
 233 /**
 234  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 235  * @param array $a
 236  * @param array $b
 237  * @return array
 238  */
 239 function wfArrayDiff2( $a, $b ) {
 240         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 241 }
 242
 243 /**
 244  * @param array|string $a
 245  * @param array|string $b
 246  * @return int
 247  */
 248 function wfArrayDiff2_cmp( $a, $b ) {
 249         if ( is_string( $a ) && is_string( $b ) ) {
 250                 return strcmp( $a, $b );
 251         } elseif ( count( $a ) !== count( $b ) ) {
 252                 return count( $a ) < count( $b ) ? -1 : 1;
 253         } else {
 254                 reset( $a );
 255                 reset( $b );
 256                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 257                         $cmp = strcmp( $valueA, $valueB );
 258                         if ( $cmp !== 0 ) {
 259                                 return $cmp;
 260                         }
 261                 }
 262                 return 0;
 263         }
 264 }
 265
 266 /**
 267  * Appends to second array if $value differs from that in $default
 268  *
 269  * @param string|int $key
 270  * @param mixed $value
 271  * @param mixed $default
 272  * @param array $changed Array to alter
 273  * @throws MWException
 274  */
 275 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 276         if ( is_null( $changed ) ) {
 277                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 278         }
 279         if ( $default[$key] !== $value ) {
 280                 $changed[$key] = $value;
 281         }
 282 }
 283
 284 /**
 285  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 286  * e.g.
 287  *      wfMergeErrorArrays(
 288  *              array( array( 'x' ) ),
 289  *              array( array( 'x', '2' ) ),
 290  *              array( array( 'x' ) ),
 291  *              array( array( 'y' ) )
 292  *      );
 293  * returns:
 294  *              array(
 295  *              array( 'x', '2' ),
 296  *              array( 'x' ),
 297  *              array( 'y' )
 298  *      )
 299  *
 300  * @param array $array1,...
 301  * @return array
 302  */
 303 function wfMergeErrorArrays( /*...*/ ) {
 304         $args = func_get_args();
 305         $out = array();
 306         foreach ( $args as $errors ) {
 307                 foreach ( $errors as $params ) {
 308                         # @todo FIXME: Sometimes get nested arrays for $params,
 309                         # which leads to E_NOTICEs
 310                         $spec = implode( "\t", $params );
 311                         $out[$spec] = $params;
 312                 }
 313         }
 314         return array_values( $out );
 315 }
 316
 317 /**
 318  * Insert array into another array after the specified *KEY*
 319  *
 320  * @param array $array The array.
 321  * @param array $insert The array to insert.
 322  * @param mixed $after The key to insert after
 323  * @return array
 324  */
 325 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 326         // Find the offset of the element to insert after.
 327         $keys = array_keys( $array );
 328         $offsetByKey = array_flip( $keys );
 329
 330         $offset = $offsetByKey[$after];
 331
 332         // Insert at the specified offset
 333         $before = array_slice( $array, 0, $offset + 1, true );
 334         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 335
 336         $output = $before + $insert + $after;
 337
 338         return $output;
 339 }
 340
 341 /**
 342  * Recursively converts the parameter (an object) to an array with the same data
 343  *
 344  * @param object|array $objOrArray
 345  * @param bool $recursive
 346  * @return array
 347  */
 348 function wfObjectToArray( $objOrArray, $recursive = true ) {
 349         $array = array();
 350         if ( is_object( $objOrArray ) ) {
 351                 $objOrArray = get_object_vars( $objOrArray );
 352         }
 353         foreach ( $objOrArray as $key => $value ) {
 354                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 355                         $value = wfObjectToArray( $value );
 356                 }
 357
 358                 $array[$key] = $value;
 359         }
 360
 361         return $array;
 362 }
 363
 364 /**
 365  * Get a random decimal value between 0 and 1, in a way
 366  * not likely to give duplicate values for any realistic
 367  * number of articles.
 368  *
 369  * @return string
 370  */
 371 function wfRandom() {
 372         # The maximum random value is "only" 2^31-1, so get two random
 373         # values to reduce the chance of dupes
 374         $max = mt_getrandmax() + 1;
 375         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 376
 377         return $rand;
 378 }
 379
 380 /**
 381  * Get a random string containing a number of pseudo-random hex
 382  * characters.
 383  * @note This is not secure, if you are trying to generate some sort
 384  *       of token please use MWCryptRand instead.
 385  *
 386  * @param int $length The length of the string to generate
 387  * @return string
 388  * @since 1.20
 389  */
 390 function wfRandomString( $length = 32 ) {
 391         $str = '';
 392         for ( $n = 0; $n < $length; $n += 7 ) {
 393                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 394         }
 395         return substr( $str, 0, $length );
 396 }
 397
 398 /**
 399  * We want some things to be included as literal characters in our title URLs
 400  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 401  * all of the following should be safe:
 402  *
 403  * ;:@&=$-_.+!*'(),
 404  *
 405  * But + is not safe because it's used to indicate a space; &= are only safe in
 406  * paths and not in queries (and we don't distinguish here); ' seems kind of
 407  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 408  * is reserved, we don't care.  So the list we unescape is:
 409  *
 410  * ;:@$!*(),/
 411  *
 412  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 413  * so no fancy : for IIS7.
 414  *
 415  * %2F in the page titles seems to fatally break for some reason.
 416  *
 417  * @param string $s
 418  * @return string
 419  */
 420 function wfUrlencode( $s ) {
 421         static $needle;
 422
 423         if ( is_null( $s ) ) {
 424                 $needle = null;
 425                 return '';
 426         }
 427
 428         if ( is_null( $needle ) ) {
 429                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 430                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 431                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 432                 ) {
 433                         $needle[] = '%3A';
 434                 }
 435         }
 436
 437         $s = urlencode( $s );
 438         $s = str_ireplace(
 439                 $needle,
 440                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 441                 $s
 442         );
 443
 444         return $s;
 445 }
 446
 447 /**
 448  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 449  * "days=7&limit=100". Options in the first array override options in the second.
 450  * Options set to null or false will not be output.
 451  *
 452  * @param array $array1 ( String|Array )
 453  * @param array $array2 ( String|Array )
 454  * @param string $prefix
 455  * @return string
 456  */
 457 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 458         if ( !is_null( $array2 ) ) {
 459                 $array1 = $array1 + $array2;
 460         }
 461
 462         $cgi = '';
 463         foreach ( $array1 as $key => $value ) {
 464                 if ( !is_null( $value ) && $value !== false ) {
 465                         if ( $cgi != '' ) {
 466                                 $cgi .= '&';
 467                         }
 468                         if ( $prefix !== '' ) {
 469                                 $key = $prefix . "[$key]";
 470                         }
 471                         if ( is_array( $value ) ) {
 472                                 $firstTime = true;
 473                                 foreach ( $value as $k => $v ) {
 474                                         $cgi .= $firstTime ? '' : '&';
 475                                         if ( is_array( $v ) ) {
 476                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 477                                         } else {
 478                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 479                                         }
 480                                         $firstTime = false;
 481                                 }
 482                         } else {
 483                                 if ( is_object( $value ) ) {
 484                                         $value = $value->__toString();
 485                                 }
 486                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 487                         }
 488                 }
 489         }
 490         return $cgi;
 491 }
 492
 493 /**
 494  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 495  * its argument and returns the same string in array form.  This allows compatibility
 496  * with legacy functions that accept raw query strings instead of nice
 497  * arrays.  Of course, keys and values are urldecode()d.
 498  *
 499  * @param string $query Query string
 500  * @return string[] Array version of input
 501  */
 502 function wfCgiToArray( $query ) {
 503         if ( isset( $query[0] ) && $query[0] == '?' ) {
 504                 $query = substr( $query, 1 );
 505         }
 506         $bits = explode( '&', $query );
 507         $ret = array();
 508         foreach ( $bits as $bit ) {
 509                 if ( $bit === '' ) {
 510                         continue;
 511                 }
 512                 if ( strpos( $bit, '=' ) === false ) {
 513                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 514                         $key = $bit;
 515                         $value = '';
 516                 } else {
 517                         list( $key, $value ) = explode( '=', $bit );
 518                 }
 519                 $key = urldecode( $key );
 520                 $value = urldecode( $value );
 521                 if ( strpos( $key, '[' ) !== false ) {
 522                         $keys = array_reverse( explode( '[', $key ) );
 523                         $key = array_pop( $keys );
 524                         $temp = $value;
 525                         foreach ( $keys as $k ) {
 526                                 $k = substr( $k, 0, -1 );
 527                                 $temp = array( $k => $temp );
 528                         }
 529                         if ( isset( $ret[$key] ) ) {
 530                                 $ret[$key] = array_merge( $ret[$key], $temp );
 531                         } else {
 532                                 $ret[$key] = $temp;
 533                         }
 534                 } else {
 535                         $ret[$key] = $value;
 536                 }
 537         }
 538         return $ret;
 539 }
 540
 541 /**
 542  * Append a query string to an existing URL, which may or may not already
 543  * have query string parameters already. If so, they will be combined.
 544  *
 545  * @param string $url
 546  * @param string|string[] $query String or associative array
 547  * @return string
 548  */
 549 function wfAppendQuery( $url, $query ) {
 550         if ( is_array( $query ) ) {
 551                 $query = wfArrayToCgi( $query );
 552         }
 553         if ( $query != '' ) {
 554                 if ( false === strpos( $url, '?' ) ) {
 555                         $url .= '?';
 556                 } else {
 557                         $url .= '&';
 558                 }
 559                 $url .= $query;
 560         }
 561         return $url;
 562 }
 563
 564 /**
 565  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 566  * is correct.
 567  *
 568  * The meaning of the PROTO_* constants is as follows:
 569  * PROTO_HTTP: Output a URL starting with http://
 570  * PROTO_HTTPS: Output a URL starting with https://
 571  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 572  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 573  *    on which protocol was used for the current incoming request
 574  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 575  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 576  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 577  *
 578  * @todo this won't work with current-path-relative URLs
 579  * like "subdir/foo.html", etc.
 580  *
 581  * @param string $url Either fully-qualified or a local path + query
 582  * @param string $defaultProto One of the PROTO_* constants. Determines the
 583  *    protocol to use if $url or $wgServer is protocol-relative
 584  * @return string Fully-qualified URL, current-path-relative URL or false if
 585  *    no valid URL can be constructed
 586  */
 587 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 588         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 589                 $wgHttpsPort;
 590         if ( $defaultProto === PROTO_CANONICAL ) {
 591                 $serverUrl = $wgCanonicalServer;
 592         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 593                 // Make $wgInternalServer fall back to $wgServer if not set
 594                 $serverUrl = $wgInternalServer;
 595         } else {
 596                 $serverUrl = $wgServer;
 597                 if ( $defaultProto === PROTO_CURRENT ) {
 598                         $defaultProto = $wgRequest->getProtocol() . '://';
 599                 }
 600         }
 601
 602         // Analyze $serverUrl to obtain its protocol
 603         $bits = wfParseUrl( $serverUrl );
 604         $serverHasProto = $bits && $bits['scheme'] != '';
 605
 606         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 607                 if ( $serverHasProto ) {
 608                         $defaultProto = $bits['scheme'] . '://';
 609                 } else {
 610                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 611                         // This really isn't supposed to happen. Fall back to HTTP in this
 612                         // ridiculous case.
 613                         $defaultProto = PROTO_HTTP;
 614                 }
 615         }
 616
 617         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 618
 619         if ( substr( $url, 0, 2 ) == '//' ) {
 620                 $url = $defaultProtoWithoutSlashes . $url;
 621         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 622                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 623                 // otherwise leave it alone.
 624                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 625         }
 626
 627         $bits = wfParseUrl( $url );
 628
 629         // ensure proper port for HTTPS arrives in URL
 630         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 631         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 632                 $bits['port'] = $wgHttpsPort;
 633         }
 634
 635         if ( $bits && isset( $bits['path'] ) ) {
 636                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 637                 return wfAssembleUrl( $bits );
 638         } elseif ( $bits ) {
 639                 # No path to expand
 640                 return $url;
 641         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 642                 # URL is a relative path
 643                 return wfRemoveDotSegments( $url );
 644         }
 645
 646         # Expanded URL is not valid.
 647         return false;
 648 }
 649
 650 /**
 651  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 652  * if you need to edit part of a URL and put it back together.
 653  *
 654  * This is the basic structure used (brackets contain keys for $urlParts):
 655  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 656  *
 657  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 658  *
 659  * @since 1.19
 660  * @param array $urlParts URL parts, as output from wfParseUrl
 661  * @return string URL assembled from its component parts
 662  */
 663 function wfAssembleUrl( $urlParts ) {
 664         $result = '';
 665
 666         if ( isset( $urlParts['delimiter'] ) ) {
 667                 if ( isset( $urlParts['scheme'] ) ) {
 668                         $result .= $urlParts['scheme'];
 669                 }
 670
 671                 $result .= $urlParts['delimiter'];
 672         }
 673
 674         if ( isset( $urlParts['host'] ) ) {
 675                 if ( isset( $urlParts['user'] ) ) {
 676                         $result .= $urlParts['user'];
 677                         if ( isset( $urlParts['pass'] ) ) {
 678                                 $result .= ':' . $urlParts['pass'];
 679                         }
 680                         $result .= '@';
 681                 }
 682
 683                 $result .= $urlParts['host'];
 684
 685                 if ( isset( $urlParts['port'] ) ) {
 686                         $result .= ':' . $urlParts['port'];
 687                 }
 688         }
 689
 690         if ( isset( $urlParts['path'] ) ) {
 691                 $result .= $urlParts['path'];
 692         }
 693
 694         if ( isset( $urlParts['query'] ) ) {
 695                 $result .= '?' . $urlParts['query'];
 696         }
 697
 698         if ( isset( $urlParts['fragment'] ) ) {
 699                 $result .= '#' . $urlParts['fragment'];
 700         }
 701
 702         return $result;
 703 }
 704
 705 /**
 706  * Remove all dot-segments in the provided URL path.  For example,
 707  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 708  * RFC3986 section 5.2.4.
 709  *
 710  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 711  *
 712  * @param string $urlPath URL path, potentially containing dot-segments
 713  * @return string URL path with all dot-segments removed
 714  */
 715 function wfRemoveDotSegments( $urlPath ) {
 716         $output = '';
 717         $inputOffset = 0;
 718         $inputLength = strlen( $urlPath );
 719
 720         while ( $inputOffset < $inputLength ) {
 721                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 722                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 723                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 724                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 725                 $trimOutput = false;
 726
 727                 if ( $prefixLengthTwo == './' ) {
 728                         # Step A, remove leading "./"
 729                         $inputOffset += 2;
 730                 } elseif ( $prefixLengthThree == '../' ) {
 731                         # Step A, remove leading "../"
 732                         $inputOffset += 3;
 733                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 734                         # Step B, replace leading "/.$" with "/"
 735                         $inputOffset += 1;
 736                         $urlPath[$inputOffset] = '/';
 737                 } elseif ( $prefixLengthThree == '/./' ) {
 738                         # Step B, replace leading "/./" with "/"
 739                         $inputOffset += 2;
 740                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 741                         # Step C, replace leading "/..$" with "/" and
 742                         # remove last path component in output
 743                         $inputOffset += 2;
 744                         $urlPath[$inputOffset] = '/';
 745                         $trimOutput = true;
 746                 } elseif ( $prefixLengthFour == '/../' ) {
 747                         # Step C, replace leading "/../" with "/" and
 748                         # remove last path component in output
 749                         $inputOffset += 3;
 750                         $trimOutput = true;
 751                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 752                         # Step D, remove "^.$"
 753                         $inputOffset += 1;
 754                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 755                         # Step D, remove "^..$"
 756                         $inputOffset += 2;
 757                 } else {
 758                         # Step E, move leading path segment to output
 759                         if ( $prefixLengthOne == '/' ) {
 760                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 761                         } else {
 762                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 763                         }
 764                         if ( $slashPos === false ) {
 765                                 $output .= substr( $urlPath, $inputOffset );
 766                                 $inputOffset = $inputLength;
 767                         } else {
 768                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 769                                 $inputOffset += $slashPos - $inputOffset;
 770                         }
 771                 }
 772
 773                 if ( $trimOutput ) {
 774                         $slashPos = strrpos( $output, '/' );
 775                         if ( $slashPos === false ) {
 776                                 $output = '';
 777                         } else {
 778                                 $output = substr( $output, 0, $slashPos );
 779                         }
 780                 }
 781         }
 782
 783         return $output;
 784 }
 785
 786 /**
 787  * Returns a regular expression of url protocols
 788  *
 789  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 790  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 791  * @return string
 792  */
 793 function wfUrlProtocols( $includeProtocolRelative = true ) {
 794         global $wgUrlProtocols;
 795
 796         // Cache return values separately based on $includeProtocolRelative
 797         static $withProtRel = null, $withoutProtRel = null;
 798         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 799         if ( !is_null( $cachedValue ) ) {
 800                 return $cachedValue;
 801         }
 802
 803         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 804         // with LocalSettings files from 1.5
 805         if ( is_array( $wgUrlProtocols ) ) {
 806                 $protocols = array();
 807                 foreach ( $wgUrlProtocols as $protocol ) {
 808                         // Filter out '//' if !$includeProtocolRelative
 809                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 810                                 $protocols[] = preg_quote( $protocol, '/' );
 811                         }
 812                 }
 813
 814                 $retval = implode( '|', $protocols );
 815         } else {
 816                 // Ignore $includeProtocolRelative in this case
 817                 // This case exists for pre-1.6 compatibility, and we can safely assume
 818                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 819                 // URLs weren't supported until 1.18
 820                 $retval = $wgUrlProtocols;
 821         }
 822
 823         // Cache return value
 824         if ( $includeProtocolRelative ) {
 825                 $withProtRel = $retval;
 826         } else {
 827                 $withoutProtRel = $retval;
 828         }
 829         return $retval;
 830 }
 831
 832 /**
 833  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 834  * you need a regex that matches all URL protocols but does not match protocol-
 835  * relative URLs
 836  * @return string
 837  */
 838 function wfUrlProtocolsWithoutProtRel() {
 839         return wfUrlProtocols( false );
 840 }
 841
 842 /**
 843  * parse_url() work-alike, but non-broken.  Differences:
 844  *
 845  * 1) Does not raise warnings on bad URLs (just returns false).
 846  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 847  *    protocol-relative URLs) correctly.
 848  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 849  *
 850  * @param string $url A URL to parse
 851  * @return string[] Bits of the URL in an associative array, per PHP docs
 852  */
 853 function wfParseUrl( $url ) {
 854         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 855
 856         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 857         // bad that the easiest way to handle them is to just prepend 'http:' and
 858         // strip the protocol out later.
 859         $wasRelative = substr( $url, 0, 2 ) == '//';
 860         if ( $wasRelative ) {
 861                 $url = "http:$url";
 862         }
 863         wfSuppressWarnings();
 864         $bits = parse_url( $url );
 865         wfRestoreWarnings();
 866         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 867         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 868         if ( !$bits || !isset( $bits['scheme'] ) ) {
 869                 return false;
 870         }
 871
 872         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 873         $bits['scheme'] = strtolower( $bits['scheme'] );
 874
 875         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 876         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 877                 $bits['delimiter'] = '://';
 878         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 879                 $bits['delimiter'] = ':';
 880                 // parse_url detects for news: and mailto: the host part of an url as path
 881                 // We have to correct this wrong detection
 882                 if ( isset( $bits['path'] ) ) {
 883                         $bits['host'] = $bits['path'];
 884                         $bits['path'] = '';
 885                 }
 886         } else {
 887                 return false;
 888         }
 889
 890         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 891         if ( !isset( $bits['host'] ) ) {
 892                 $bits['host'] = '';
 893
 894                 // bug 45069
 895                 if ( isset( $bits['path'] ) ) {
 896                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 897                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 898                                 $bits['path'] = '/' . $bits['path'];
 899                         }
 900                 } else {
 901                         $bits['path'] = '';
 902                 }
 903         }
 904
 905         // If the URL was protocol-relative, fix scheme and delimiter
 906         if ( $wasRelative ) {
 907                 $bits['scheme'] = '';
 908                 $bits['delimiter'] = '//';
 909         }
 910         return $bits;
 911 }
 912
 913 /**
 914  * Take a URL, make sure it's expanded to fully qualified, and replace any
 915  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 916  * for more compact display and legibility for local audiences.
 917  *
 918  * @todo handle punycode domains too
 919  *
 920  * @param string $url
 921  * @return string
 922  */
 923 function wfExpandIRI( $url ) {
 924         return preg_replace_callback(
 925                 '/((?:%[89A-F][0-9A-F])+)/i',
 926                 'wfExpandIRI_callback',
 927                 wfExpandUrl( $url )
 928         );
 929 }
 930
 931 /**
 932  * Private callback for wfExpandIRI
 933  * @param array $matches
 934  * @return string
 935  */
 936 function wfExpandIRI_callback( $matches ) {
 937         return urldecode( $matches[1] );
 938 }
 939
 940 /**
 941  * Make URL indexes, appropriate for the el_index field of externallinks.
 942  *
 943  * @param string $url
 944  * @return array
 945  */
 946 function wfMakeUrlIndexes( $url ) {
 947         $bits = wfParseUrl( $url );
 948
 949         // Reverse the labels in the hostname, convert to lower case
 950         // For emails reverse domainpart only
 951         if ( $bits['scheme'] == 'mailto' ) {
 952                 $mailparts = explode( '@', $bits['host'], 2 );
 953                 if ( count( $mailparts ) === 2 ) {
 954                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 955                 } else {
 956                         // No domain specified, don't mangle it
 957                         $domainpart = '';
 958                 }
 959                 $reversedHost = $domainpart . '@' . $mailparts[0];
 960         } else {
 961                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 962         }
 963         // Add an extra dot to the end
 964         // Why? Is it in wrong place in mailto links?
 965         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 966                 $reversedHost .= '.';
 967         }
 968         // Reconstruct the pseudo-URL
 969         $prot = $bits['scheme'];
 970         $index = $prot . $bits['delimiter'] . $reversedHost;
 971         // Leave out user and password. Add the port, path, query and fragment
 972         if ( isset( $bits['port'] ) ) {
 973                 $index .= ':' . $bits['port'];
 974         }
 975         if ( isset( $bits['path'] ) ) {
 976                 $index .= $bits['path'];
 977         } else {
 978                 $index .= '/';
 979         }
 980         if ( isset( $bits['query'] ) ) {
 981                 $index .= '?' . $bits['query'];
 982         }
 983         if ( isset( $bits['fragment'] ) ) {
 984                 $index .= '#' . $bits['fragment'];
 985         }
 986
 987         if ( $prot == '' ) {
 988                 return array( "http:$index", "https:$index" );
 989         } else {
 990                 return array( $index );
 991         }
 992 }
 993
 994 /**
 995  * Check whether a given URL has a domain that occurs in a given set of domains
 996  * @param string $url URL
 997  * @param array $domains Array of domains (strings)
 998  * @return bool True if the host part of $url ends in one of the strings in $domains
 999  */
1000 function wfMatchesDomainList( $url, $domains ) {
1001         $bits = wfParseUrl( $url );
1002         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1003                 $host = '.' . $bits['host'];
1004                 foreach ( (array)$domains as $domain ) {
1005                         $domain = '.' . $domain;
1006                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1007                                 return true;
1008                         }
1009                 }
1010         }
1011         return false;
1012 }
1013
1014 /**
1015  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1016  * In normal operation this is a NOP.
1017  *
1018  * Controlling globals:
1019  * $wgDebugLogFile - points to the log file
1020  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1021  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1022  *
1023  * @since 1.25 support for additional context data
1024  *
1025  * @param string $text
1026  * @param string|bool $dest Unused
1027  * @param array $context Additional logging context data
1028  */
1029 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1030         global $wgDebugRawPage, $wgDebugLogPrefix;
1031         global $wgDebugTimestamps, $wgRequestTime;
1032
1033         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1034                 return;
1035         }
1036
1037         $text = trim( $text );
1038
1039         // Inline logic from deprecated wfDebugTimer()
1040         if ( $wgDebugTimestamps ) {
1041                 $context['seconds_elapsed'] = sprintf(
1042                         '%6.4f',
1043                         microtime( true ) - $wgRequestTime
1044                 );
1045                 $context['memory_used'] = sprintf(
1046                         '%5.1fM',
1047                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1048                 );
1049         }
1050
1051         if ( $wgDebugLogPrefix !== '' ) {
1052                 $context['prefix'] = $wgDebugLogPrefix;
1053         }
1054
1055         $logger = LoggerFactory::getInstance( 'wfDebug' );
1056         $logger->debug( $text, $context );
1057 }
1058
1059 /**
1060  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1061  * @return bool
1062  */
1063 function wfIsDebugRawPage() {
1064         static $cache;
1065         if ( $cache !== null ) {
1066                 return $cache;
1067         }
1068         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1069         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1070                 || (
1071                         isset( $_SERVER['SCRIPT_NAME'] )
1072                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1073                 )
1074         ) {
1075                 $cache = true;
1076         } else {
1077                 $cache = false;
1078         }
1079         return $cache;
1080 }
1081
1082 /**
1083  * Get microsecond timestamps for debug logs
1084  *
1085  * @deprecated since 1.25
1086  * @return string
1087  */
1088 function wfDebugTimer() {
1089         global $wgDebugTimestamps, $wgRequestTime;
1090
1091         wfDeprecated( __METHOD__, '1.25' );
1092
1093         if ( !$wgDebugTimestamps ) {
1094                 return '';
1095         }
1096
1097         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1098         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1099         return "$prefix $mem  ";
1100 }
1101
1102 /**
1103  * Send a line giving PHP memory usage.
1104  *
1105  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1106  */
1107 function wfDebugMem( $exact = false ) {
1108         $mem = memory_get_usage();
1109         if ( !$exact ) {
1110                 $mem = floor( $mem / 1024 ) . ' KiB';
1111         } else {
1112                 $mem .= ' B';
1113         }
1114         wfDebug( "Memory usage: $mem\n" );
1115 }
1116
1117 /**
1118  * Send a line to a supplementary debug log file, if configured, or main debug
1119  * log if not.
1120  *
1121  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1122  * a string filename or an associative array mapping 'destination' to the
1123  * desired filename. The associative array may also contain a 'sample' key
1124  * with an integer value, specifying a sampling factor. Sampled log events
1125  * will be emitted with a 1 in N random chance.
1126  *
1127  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1128  * @since 1.25 support for additional context data
1129  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1130  *
1131  * @param string $logGroup
1132  * @param string $text
1133  * @param string|bool $dest Destination of the message:
1134  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1135  *     - 'log': only to the log and not in HTML
1136  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1137  *       discarded otherwise
1138  *   For backward compatibility, it can also take a boolean:
1139  *     - true: same as 'all'
1140  *     - false: same as 'private'
1141  * @param array $context Additional logging context data
1142  */
1143 function wfDebugLog(
1144         $logGroup, $text, $dest = 'all', array $context = array()
1145 ) {
1146         // Turn $dest into a string if it's a boolean (for b/c)
1147         if ( $dest === true ) {
1148                 $dest = 'all';
1149         } elseif ( $dest === false ) {
1150                 $dest = 'private';
1151         }
1152
1153         $text = trim( $text );
1154
1155         $logger = LoggerFactory::getInstance( $logGroup );
1156         $context['private'] = ( $dest === 'private' );
1157         $logger->info( $text, $context );
1158 }
1159
1160 /**
1161  * Log for database errors
1162  *
1163  * @since 1.25 support for additional context data
1164  *
1165  * @param string $text Database error message.
1166  * @param array $context Additional logging context data
1167  */
1168 function wfLogDBError( $text, array $context = array() ) {
1169         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1170         $logger->error( trim( $text ), $context );
1171 }
1172
1173 /**
1174  * Throws a warning that $function is deprecated
1175  *
1176  * @param string $function
1177  * @param string|bool $version Version of MediaWiki that the function
1178  *    was deprecated in (Added in 1.19).
1179  * @param string|bool $component Added in 1.19.
1180  * @param int $callerOffset How far up the call stack is the original
1181  *    caller. 2 = function that called the function that called
1182  *    wfDeprecated (Added in 1.20)
1183  *
1184  * @return null
1185  */
1186 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1187         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1188 }
1189
1190 /**
1191  * Send a warning either to the debug log or in a PHP error depending on
1192  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1193  *
1194  * @param string $msg Message to send
1195  * @param int $callerOffset Number of items to go back in the backtrace to
1196  *        find the correct caller (1 = function calling wfWarn, ...)
1197  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1198  *        only used when $wgDevelopmentWarnings is true
1199  */
1200 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1201         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1202 }
1203
1204 /**
1205  * Send a warning as a PHP error and the debug log. This is intended for logging
1206  * warnings in production. For logging development warnings, use WfWarn instead.
1207  *
1208  * @param string $msg Message to send
1209  * @param int $callerOffset Number of items to go back in the backtrace to
1210  *        find the correct caller (1 = function calling wfLogWarning, ...)
1211  * @param int $level PHP error level; defaults to E_USER_WARNING
1212  */
1213 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1214         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1215 }
1216
1217 /**
1218  * Log to a file without getting "file size exceeded" signals.
1219  *
1220  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1221  * send lines to the specified port, prefixed by the specified prefix and a space.
1222  * @since 1.25 support for additional context data
1223  *
1224  * @param string $text
1225  * @param string $file Filename
1226  * @param array $context Additional logging context data
1227  * @throws MWException
1228  * @deprecated since 1.25 Use MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1229  */
1230 function wfErrorLog( $text, $file, array $context = array() ) {
1231         wfDeprecated( __METHOD__, '1.25' );
1232         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1233         $context['destination'] = $file;
1234         $logger->info( trim( $text ), $context );
1235 }
1236
1237 /**
1238  * @todo document
1239  */
1240 function wfLogProfilingData() {
1241         global $wgDebugLogGroups, $wgDebugRawPage;
1242
1243         $context = RequestContext::getMain();
1244         $request = $context->getRequest();
1245
1246         $profiler = Profiler::instance();
1247         $profiler->setContext( $context );
1248         $profiler->logData();
1249
1250         $config = $context->getConfig();
1251         if ( $config->has( 'StatsdServer' ) ) {
1252                 $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1253                 $statsdHost = $statsdServer[0];
1254                 $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1255                 $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1256                 $statsdClient = new StatsdClient( $statsdSender );
1257                 $statsdClient->send( $context->getStats()->getBuffer() );
1258         }
1259
1260         # Profiling must actually be enabled...
1261         if ( $profiler instanceof ProfilerStub ) {
1262                 return;
1263         }
1264
1265         if ( isset( $wgDebugLogGroups['profileoutput'] )
1266                 && $wgDebugLogGroups['profileoutput'] === false
1267         ) {
1268                 // Explicitly disabled
1269                 return;
1270         }
1271         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1272                 return;
1273         }
1274
1275         $ctx = array( 'elapsed' => $request->getElapsedTime() );
1276         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1277                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1278         }
1279         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1280                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1281         }
1282         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1283                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1284         }
1285         if ( isset( $ctx['forwarded_for'] ) ||
1286                 isset( $ctx['client_ip'] ) ||
1287                 isset( $ctx['from'] ) ) {
1288                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1289         }
1290
1291         // Don't load $wgUser at this late stage just for statistics purposes
1292         // @todo FIXME: We can detect some anons even if it is not loaded.
1293         // See User::getId()
1294         $user = $context->getUser();
1295         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1296
1297         // Command line script uses a FauxRequest object which does not have
1298         // any knowledge about an URL and throw an exception instead.
1299         try {
1300                 $ctx['url'] = urldecode( $request->getRequestURL() );
1301         } catch ( Exception $ignored ) {
1302                 // no-op
1303         }
1304
1305         $ctx['output'] = $profiler->getOutput();
1306
1307         $log = LoggerFactory::getInstance( 'profileoutput' );
1308         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1309 }
1310
1311 /**
1312  * Increment a statistics counter
1313  *
1314  * @param string $key
1315  * @param int $count
1316  * @return void
1317  */
1318 function wfIncrStats( $key, $count = 1 ) {
1319         $stats = RequestContext::getMain()->getStats();
1320         $stats->updateCount( $key, $count );
1321 }
1322
1323 /**
1324  * Check whether the wiki is in read-only mode.
1325  *
1326  * @return bool
1327  */
1328 function wfReadOnly() {
1329         return wfReadOnlyReason() !== false;
1330 }
1331
1332 /**
1333  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1334  *
1335  * @return string|bool String when in read-only mode; false otherwise
1336  */
1337 function wfReadOnlyReason() {
1338         global $wgReadOnly, $wgReadOnlyFile;
1339
1340         if ( $wgReadOnly === null ) {
1341                 // Set $wgReadOnly for faster access next time
1342                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1343                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1344                 } else {
1345                         $wgReadOnly = false;
1346                 }
1347                 // Callers use this method to be aware that data presented to a user
1348                 // may be very stale and thus allowing submissions can be problematic.
1349                 try {
1350                         if ( $wgReadOnly === false && wfGetLB()->getLaggedSlaveMode() ) {
1351                                 $wgReadOnly = 'The database has been automatically locked ' .
1352                                         'while the slave database servers catch up to the master';
1353                         }
1354                 } catch ( DBConnectionError $e ) {
1355                         $wgReadOnly = 'The database has been automatically locked ' .
1356                                 'until the slave database servers become available';
1357                 }
1358         }
1359
1360         return $wgReadOnly;
1361 }
1362
1363 /**
1364  * Return a Language object from $langcode
1365  *
1366  * @param Language|string|bool $langcode Either:
1367  *                  - a Language object
1368  *                  - code of the language to get the message for, if it is
1369  *                    a valid code create a language for that language, if
1370  *                    it is a string but not a valid code then make a basic
1371  *                    language object
1372  *                  - a boolean: if it's false then use the global object for
1373  *                    the current user's language (as a fallback for the old parameter
1374  *                    functionality), or if it is true then use global object
1375  *                    for the wiki's content language.
1376  * @return Language
1377  */
1378 function wfGetLangObj( $langcode = false ) {
1379         # Identify which language to get or create a language object for.
1380         # Using is_object here due to Stub objects.
1381         if ( is_object( $langcode ) ) {
1382                 # Great, we already have the object (hopefully)!
1383                 return $langcode;
1384         }
1385
1386         global $wgContLang, $wgLanguageCode;
1387         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1388                 # $langcode is the language code of the wikis content language object.
1389                 # or it is a boolean and value is true
1390                 return $wgContLang;
1391         }
1392
1393         global $wgLang;
1394         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1395                 # $langcode is the language code of user language object.
1396                 # or it was a boolean and value is false
1397                 return $wgLang;
1398         }
1399
1400         $validCodes = array_keys( Language::fetchLanguageNames() );
1401         if ( in_array( $langcode, $validCodes ) ) {
1402                 # $langcode corresponds to a valid language.
1403                 return Language::factory( $langcode );
1404         }
1405
1406         # $langcode is a string, but not a valid language code; use content language.
1407         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1408         return $wgContLang;
1409 }
1410
1411 /**
1412  * This is the function for getting translated interface messages.
1413  *
1414  * @see Message class for documentation how to use them.
1415  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1416  *
1417  * This function replaces all old wfMsg* functions.
1418  *
1419  * @param string|string[] $key Message key, or array of keys
1420  * @param mixed $params,... Normal message parameters
1421  * @return Message
1422  *
1423  * @since 1.17
1424  *
1425  * @see Message::__construct
1426  */
1427 function wfMessage( $key /*...*/ ) {
1428         $params = func_get_args();
1429         array_shift( $params );
1430         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1431                 $params = $params[0];
1432         }
1433         return new Message( $key, $params );
1434 }
1435
1436 /**
1437  * This function accepts multiple message keys and returns a message instance
1438  * for the first message which is non-empty. If all messages are empty then an
1439  * instance of the first message key is returned.
1440  *
1441  * @param string|string[] $keys,... Message keys
1442  * @return Message
1443  *
1444  * @since 1.18
1445  *
1446  * @see Message::newFallbackSequence
1447  */
1448 function wfMessageFallback( /*...*/ ) {
1449         $args = func_get_args();
1450         return call_user_func_array( 'Message::newFallbackSequence', $args );
1451 }
1452
1453 /**
1454  * Get a message from anywhere, for the current user language.
1455  *
1456  * Use wfMsgForContent() instead if the message should NOT
1457  * change depending on the user preferences.
1458  *
1459  * @deprecated since 1.18
1460  *
1461  * @param string $key Lookup key for the message, usually
1462  *    defined in languages/Language.php
1463  *
1464  * Parameters to the message, which can be used to insert variable text into
1465  * it, can be passed to this function in the following formats:
1466  * - One per argument, starting at the second parameter
1467  * - As an array in the second parameter
1468  * These are not shown in the function definition.
1469  *
1470  * @return string
1471  */
1472 function wfMsg( $key ) {
1473         wfDeprecated( __METHOD__, '1.21' );
1474
1475         $args = func_get_args();
1476         array_shift( $args );
1477         return wfMsgReal( $key, $args );
1478 }
1479
1480 /**
1481  * Same as above except doesn't transform the message
1482  *
1483  * @deprecated since 1.18
1484  *
1485  * @param string $key
1486  * @return string
1487  */
1488 function wfMsgNoTrans( $key ) {
1489         wfDeprecated( __METHOD__, '1.21' );
1490
1491         $args = func_get_args();
1492         array_shift( $args );
1493         return wfMsgReal( $key, $args, true, false, false );
1494 }
1495
1496 /**
1497  * Get a message from anywhere, for the current global language
1498  * set with $wgLanguageCode.
1499  *
1500  * Use this if the message should NOT change dependent on the
1501  * language set in the user's preferences. This is the case for
1502  * most text written into logs, as well as link targets (such as
1503  * the name of the copyright policy page). Link titles, on the
1504  * other hand, should be shown in the UI language.
1505  *
1506  * Note that MediaWiki allows users to change the user interface
1507  * language in their preferences, but a single installation
1508  * typically only contains content in one language.
1509  *
1510  * Be wary of this distinction: If you use wfMsg() where you should
1511  * use wfMsgForContent(), a user of the software may have to
1512  * customize potentially hundreds of messages in
1513  * order to, e.g., fix a link in every possible language.
1514  *
1515  * @deprecated since 1.18
1516  *
1517  * @param string $key Lookup key for the message, usually
1518  *     defined in languages/Language.php
1519  * @return string
1520  */
1521 function wfMsgForContent( $key ) {
1522         wfDeprecated( __METHOD__, '1.21' );
1523
1524         global $wgForceUIMsgAsContentMsg;
1525         $args = func_get_args();
1526         array_shift( $args );
1527         $forcontent = true;
1528         if ( is_array( $wgForceUIMsgAsContentMsg )
1529                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1530         ) {
1531                 $forcontent = false;
1532         }
1533         return wfMsgReal( $key, $args, true, $forcontent );
1534 }
1535
1536 /**
1537  * Same as above except doesn't transform the message
1538  *
1539  * @deprecated since 1.18
1540  *
1541  * @param string $key
1542  * @return string
1543  */
1544 function wfMsgForContentNoTrans( $key ) {
1545         wfDeprecated( __METHOD__, '1.21' );
1546
1547         global $wgForceUIMsgAsContentMsg;
1548         $args = func_get_args();
1549         array_shift( $args );
1550         $forcontent = true;
1551         if ( is_array( $wgForceUIMsgAsContentMsg )
1552                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1553         ) {
1554                 $forcontent = false;
1555         }
1556         return wfMsgReal( $key, $args, true, $forcontent, false );
1557 }
1558
1559 /**
1560  * Really get a message
1561  *
1562  * @deprecated since 1.18
1563  *
1564  * @param string $key Key to get.
1565  * @param array $args
1566  * @param bool $useDB
1567  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1568  * @param bool $transform Whether or not to transform the message.
1569  * @return string The requested message.
1570  */
1571 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1572         wfDeprecated( __METHOD__, '1.21' );
1573
1574         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1575         $message = wfMsgReplaceArgs( $message, $args );
1576         return $message;
1577 }
1578
1579 /**
1580  * Fetch a message string value, but don't replace any keys yet.
1581  *
1582  * @deprecated since 1.18
1583  *
1584  * @param string $key
1585  * @param bool $useDB
1586  * @param string|bool $langCode Code of the language to get the message for, or
1587  *   behaves as a content language switch if it is a boolean.
1588  * @param bool $transform Whether to parse magic words, etc.
1589  * @return string
1590  */
1591 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1592         wfDeprecated( __METHOD__, '1.21' );
1593
1594         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1595
1596         $cache = MessageCache::singleton();
1597         $message = $cache->get( $key, $useDB, $langCode );
1598         if ( $message === false ) {
1599                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1600         } elseif ( $transform ) {
1601                 $message = $cache->transform( $message );
1602         }
1603         return $message;
1604 }
1605
1606 /**
1607  * Replace message parameter keys on the given formatted output.
1608  *
1609  * @param string $message
1610  * @param array $args
1611  * @return string
1612  * @private
1613  */
1614 function wfMsgReplaceArgs( $message, $args ) {
1615         # Fix windows line-endings
1616         # Some messages are split with explode("\n", $msg)
1617         $message = str_replace( "\r", '', $message );
1618
1619         // Replace arguments
1620         if ( count( $args ) ) {
1621                 if ( is_array( $args[0] ) ) {
1622                         $args = array_values( $args[0] );
1623                 }
1624                 $replacementKeys = array();
1625                 foreach ( $args as $n => $param ) {
1626                         $replacementKeys['$' . ( $n + 1 )] = $param;
1627                 }
1628                 $message = strtr( $message, $replacementKeys );
1629         }
1630
1631         return $message;
1632 }
1633
1634 /**
1635  * Return an HTML-escaped version of a message.
1636  * Parameter replacements, if any, are done *after* the HTML-escaping,
1637  * so parameters may contain HTML (eg links or form controls). Be sure
1638  * to pre-escape them if you really do want plaintext, or just wrap
1639  * the whole thing in htmlspecialchars().
1640  *
1641  * @deprecated since 1.18
1642  *
1643  * @param string $key
1644  * @param string $args,... Parameters
1645  * @return string
1646  */
1647 function wfMsgHtml( $key ) {
1648         wfDeprecated( __METHOD__, '1.21' );
1649
1650         $args = func_get_args();
1651         array_shift( $args );
1652         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1653 }
1654
1655 /**
1656  * Return an HTML version of message
1657  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1658  * so parameters may contain HTML (eg links or form controls). Be sure
1659  * to pre-escape them if you really do want plaintext, or just wrap
1660  * the whole thing in htmlspecialchars().
1661  *
1662  * @deprecated since 1.18
1663  *
1664  * @param string $key
1665  * @param string $args,... Parameters
1666  * @return string
1667  */
1668 function wfMsgWikiHtml( $key ) {
1669         wfDeprecated( __METHOD__, '1.21' );
1670
1671         $args = func_get_args();
1672         array_shift( $args );
1673         return wfMsgReplaceArgs(
1674                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1675                 /* can't be set to false */ true, /* interface */ true )->getText(),
1676                 $args );
1677 }
1678
1679 /**
1680  * Returns message in the requested format
1681  *
1682  * @deprecated since 1.18
1683  *
1684  * @param string $key Key of the message
1685  * @param array $options Processing rules.
1686  *   Can take the following options:
1687  *     parse: parses wikitext to HTML
1688  *     parseinline: parses wikitext to HTML and removes the surrounding
1689  *       p's added by parser or tidy
1690  *     escape: filters message through htmlspecialchars
1691  *     escapenoentities: same, but allows entity references like &#160; through
1692  *     replaceafter: parameters are substituted after parsing or escaping
1693  *     parsemag: transform the message using magic phrases
1694  *     content: fetch message for content language instead of interface
1695  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1696  *     language: Language object or language code to fetch message for
1697  *       (overridden by content).
1698  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1699  *
1700  * @return string
1701  */
1702 function wfMsgExt( $key, $options ) {
1703         wfDeprecated( __METHOD__, '1.21' );
1704
1705         $args = func_get_args();
1706         array_shift( $args );
1707         array_shift( $args );
1708         $options = (array)$options;
1709         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1710                 'parsemag', 'content' );
1711
1712         foreach ( $options as $arrayKey => $option ) {
1713                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1714                         // An unknown index, neither numeric nor "language"
1715                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1716                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1717                         // A numeric index with unknown value
1718                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1719                 }
1720         }
1721
1722         if ( in_array( 'content', $options, true ) ) {
1723                 $forContent = true;
1724                 $langCode = true;
1725                 $langCodeObj = null;
1726         } elseif ( array_key_exists( 'language', $options ) ) {
1727                 $forContent = false;
1728                 $langCode = wfGetLangObj( $options['language'] );
1729                 $langCodeObj = $langCode;
1730         } else {
1731                 $forContent = false;
1732                 $langCode = false;
1733                 $langCodeObj = null;
1734         }
1735
1736         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1737
1738         if ( !in_array( 'replaceafter', $options, true ) ) {
1739                 $string = wfMsgReplaceArgs( $string, $args );
1740         }
1741
1742         $messageCache = MessageCache::singleton();
1743         $parseInline = in_array( 'parseinline', $options, true );
1744         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1745                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1746                 if ( $string instanceof ParserOutput ) {
1747                         $string = $string->getText();
1748                 }
1749
1750                 if ( $parseInline ) {
1751                         $string = Parser::stripOuterParagraph( $string );
1752                 }
1753         } elseif ( in_array( 'parsemag', $options, true ) ) {
1754                 $string = $messageCache->transform( $string,
1755                                 !$forContent, $langCodeObj );
1756         }
1757
1758         if ( in_array( 'escape', $options, true ) ) {
1759                 $string = htmlspecialchars ( $string );
1760         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1761                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1762         }
1763
1764         if ( in_array( 'replaceafter', $options, true ) ) {
1765                 $string = wfMsgReplaceArgs( $string, $args );
1766         }
1767
1768         return $string;
1769 }
1770
1771 /**
1772  * Since wfMsg() and co suck, they don't return false if the message key they
1773  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1774  * nonexistence of messages by checking the MessageCache::get() result directly.
1775  *
1776  * @deprecated since 1.18. Use Message::isDisabled().
1777  *
1778  * @param string $key The message key looked up
1779  * @return bool True if the message *doesn't* exist.
1780  */
1781 function wfEmptyMsg( $key ) {
1782         wfDeprecated( __METHOD__, '1.21' );
1783
1784         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1785 }
1786
1787 /**
1788  * Fetch server name for use in error reporting etc.
1789  * Use real server name if available, so we know which machine
1790  * in a server farm generated the current page.
1791  *
1792  * @return string
1793  */
1794 function wfHostname() {
1795         static $host;
1796         if ( is_null( $host ) ) {
1797
1798                 # Hostname overriding
1799                 global $wgOverrideHostname;
1800                 if ( $wgOverrideHostname !== false ) {
1801                         # Set static and skip any detection
1802                         $host = $wgOverrideHostname;
1803                         return $host;
1804                 }
1805
1806                 if ( function_exists( 'posix_uname' ) ) {
1807                         // This function not present on Windows
1808                         $uname = posix_uname();
1809                 } else {
1810                         $uname = false;
1811                 }
1812                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1813                         $host = $uname['nodename'];
1814                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1815                         # Windows computer name
1816                         $host = getenv( 'COMPUTERNAME' );
1817                 } else {
1818                         # This may be a virtual server.
1819                         $host = $_SERVER['SERVER_NAME'];
1820                 }
1821         }
1822         return $host;
1823 }
1824
1825 /**
1826  * Returns a script tag that stores the amount of time it took MediaWiki to
1827  * handle the request in milliseconds as 'wgBackendResponseTime'.
1828  *
1829  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1830  * hostname of the server handling the request.
1831  *
1832  * @return string
1833  */
1834 function wfReportTime() {
1835         global $wgRequestTime, $wgShowHostnames;
1836
1837         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1838         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1839         if ( $wgShowHostnames ) {
1840                 $reportVars['wgHostname'] = wfHostname();
1841         }
1842         return Skin::makeVariablesScript( $reportVars );
1843 }
1844
1845 /**
1846  * Safety wrapper for debug_backtrace().
1847  *
1848  * Will return an empty array if debug_backtrace is disabled, otherwise
1849  * the output from debug_backtrace() (trimmed).
1850  *
1851  * @param int $limit This parameter can be used to limit the number of stack frames returned
1852  *
1853  * @return array Array of backtrace information
1854  */
1855 function wfDebugBacktrace( $limit = 0 ) {
1856         static $disabled = null;
1857
1858         if ( is_null( $disabled ) ) {
1859                 $disabled = !function_exists( 'debug_backtrace' );
1860                 if ( $disabled ) {
1861                         wfDebug( "debug_backtrace() is disabled\n" );
1862                 }
1863         }
1864         if ( $disabled ) {
1865                 return array();
1866         }
1867
1868         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1869                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1870         } else {
1871                 return array_slice( debug_backtrace(), 1 );
1872         }
1873 }
1874
1875 /**
1876  * Get a debug backtrace as a string
1877  *
1878  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1879  *   Defaults to $wgCommandLineMode if unset.
1880  * @return string
1881  * @since 1.25 Supports $raw parameter.
1882  */
1883 function wfBacktrace( $raw = null ) {
1884         global $wgCommandLineMode;
1885
1886         if ( $raw === null ) {
1887                 $raw = $wgCommandLineMode;
1888         }
1889
1890         if ( $raw ) {
1891                 $frameFormat = "%s line %s calls %s()\n";
1892                 $traceFormat = "%s";
1893         } else {
1894                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1895                 $traceFormat = "<ul>\n%s</ul>\n";
1896         }
1897
1898         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1899                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1900                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1901                 $call = $frame['function'];
1902                 if ( !empty( $frame['class'] ) ) {
1903                         $call = $frame['class'] . $frame['type'] . $call;
1904                 }
1905                 return sprintf( $frameFormat, $file, $line, $call );
1906         }, wfDebugBacktrace() );
1907
1908         return sprintf( $traceFormat, implode( '', $frames ) );
1909 }
1910
1911 /**
1912  * Get the name of the function which called this function
1913  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1914  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1915  * wfGetCaller( 3 ) is the parent of that.
1916  *
1917  * @param int $level
1918  * @return string
1919  */
1920 function wfGetCaller( $level = 2 ) {
1921         $backtrace = wfDebugBacktrace( $level + 1 );
1922         if ( isset( $backtrace[$level] ) ) {
1923                 return wfFormatStackFrame( $backtrace[$level] );
1924         } else {
1925                 return 'unknown';
1926         }
1927 }
1928
1929 /**
1930  * Return a string consisting of callers in the stack. Useful sometimes
1931  * for profiling specific points.
1932  *
1933  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1934  * @return string
1935  */
1936 function wfGetAllCallers( $limit = 3 ) {
1937         $trace = array_reverse( wfDebugBacktrace() );
1938         if ( !$limit || $limit > count( $trace ) - 1 ) {
1939                 $limit = count( $trace ) - 1;
1940         }
1941         $trace = array_slice( $trace, -$limit - 1, $limit );
1942         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1943 }
1944
1945 /**
1946  * Return a string representation of frame
1947  *
1948  * @param array $frame
1949  * @return string
1950  */
1951 function wfFormatStackFrame( $frame ) {
1952         return isset( $frame['class'] ) ?
1953                 $frame['class'] . '::' . $frame['function'] :
1954                 $frame['function'];
1955 }
1956
1957 /* Some generic result counters, pulled out of SearchEngine */
1958
1959 /**
1960  * @todo document
1961  *
1962  * @param int $offset
1963  * @param int $limit
1964  * @return string
1965  */
1966 function wfShowingResults( $offset, $limit ) {
1967         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1968 }
1969
1970 /**
1971  * @todo document
1972  * @todo FIXME: We may want to blacklist some broken browsers
1973  *
1974  * @param bool $force
1975  * @return bool Whereas client accept gzip compression
1976  */
1977 function wfClientAcceptsGzip( $force = false ) {
1978         static $result = null;
1979         if ( $result === null || $force ) {
1980                 $result = false;
1981                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1982                         # @todo FIXME: We may want to blacklist some broken browsers
1983                         $m = array();
1984                         if ( preg_match(
1985                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1986                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1987                                         $m
1988                                 )
1989                         ) {
1990                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1991                                         $result = false;
1992                                         return $result;
1993                                 }
1994                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1995                                 $result = true;
1996                         }
1997                 }
1998         }
1999         return $result;
2000 }
2001
2002 /**
2003  * Obtain the offset and limit values from the request string;
2004  * used in special pages
2005  *
2006  * @param int $deflimit Default limit if none supplied
2007  * @param string $optionname Name of a user preference to check against
2008  * @return array
2009  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2010  */
2011 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2012         global $wgRequest;
2013         wfDeprecated( __METHOD__, '1.24' );
2014         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2015 }
2016
2017 /**
2018  * Escapes the given text so that it may be output using addWikiText()
2019  * without any linking, formatting, etc. making its way through. This
2020  * is achieved by substituting certain characters with HTML entities.
2021  * As required by the callers, "<nowiki>" is not used.
2022  *
2023  * @param string $text Text to be escaped
2024  * @return string
2025  */
2026 function wfEscapeWikiText( $text ) {
2027         static $repl = null, $repl2 = null;
2028         if ( $repl === null ) {
2029                 $repl = array(
2030                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2031                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2032                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2033                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2034                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2035                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2036                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2037                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2038                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2039                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2040                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2041                         '__' => '_&#95;', '://' => '&#58;//',
2042                 );
2043
2044                 // We have to catch everything "\s" matches in PCRE
2045                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2046                         $repl["$magic "] = "$magic&#32;";
2047                         $repl["$magic\t"] = "$magic&#9;";
2048                         $repl["$magic\r"] = "$magic&#13;";
2049                         $repl["$magic\n"] = "$magic&#10;";
2050                         $repl["$magic\f"] = "$magic&#12;";
2051                 }
2052
2053                 // And handle protocols that don't use "://"
2054                 global $wgUrlProtocols;
2055                 $repl2 = array();
2056                 foreach ( $wgUrlProtocols as $prot ) {
2057                         if ( substr( $prot, -1 ) === ':' ) {
2058                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2059                         }
2060                 }
2061                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2062         }
2063         $text = substr( strtr( "\n$text", $repl ), 1 );
2064         $text = preg_replace( $repl2, '$1&#58;', $text );
2065         return $text;
2066 }
2067
2068 /**
2069  * Sets dest to source and returns the original value of dest
2070  * If source is NULL, it just returns the value, it doesn't set the variable
2071  * If force is true, it will set the value even if source is NULL
2072  *
2073  * @param mixed $dest
2074  * @param mixed $source
2075  * @param bool $force
2076  * @return mixed
2077  */
2078 function wfSetVar( &$dest, $source, $force = false ) {
2079         $temp = $dest;
2080         if ( !is_null( $source ) || $force ) {
2081                 $dest = $source;
2082         }
2083         return $temp;
2084 }
2085
2086 /**
2087  * As for wfSetVar except setting a bit
2088  *
2089  * @param int $dest
2090  * @param int $bit
2091  * @param bool $state
2092  *
2093  * @return bool
2094  */
2095 function wfSetBit( &$dest, $bit, $state = true ) {
2096         $temp = (bool)( $dest & $bit );
2097         if ( !is_null( $state ) ) {
2098                 if ( $state ) {
2099                         $dest |= $bit;
2100                 } else {
2101                         $dest &= ~$bit;
2102                 }
2103         }
2104         return $temp;
2105 }
2106
2107 /**
2108  * A wrapper around the PHP function var_export().
2109  * Either print it or add it to the regular output ($wgOut).
2110  *
2111  * @param mixed $var A PHP variable to dump.
2112  */
2113 function wfVarDump( $var ) {
2114         global $wgOut;
2115         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2116         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2117                 print $s;
2118         } else {
2119                 $wgOut->addHTML( $s );
2120         }
2121 }
2122
2123 /**
2124  * Provide a simple HTTP error.
2125  *
2126  * @param int|string $code
2127  * @param string $label
2128  * @param string $desc
2129  */
2130 function wfHttpError( $code, $label, $desc ) {
2131         global $wgOut;
2132         header( "HTTP/1.0 $code $label" );
2133         header( "Status: $code $label" );
2134         if ( $wgOut ) {
2135                 $wgOut->disable();
2136                 $wgOut->sendCacheControl();
2137         }
2138
2139         header( 'Content-type: text/html; charset=utf-8' );
2140         print "<!doctype html>" .
2141                 '<html><head><title>' .
2142                 htmlspecialchars( $label ) .
2143                 '</title></head><body><h1>' .
2144                 htmlspecialchars( $label ) .
2145                 '</h1><p>' .
2146                 nl2br( htmlspecialchars( $desc ) ) .
2147                 "</p></body></html>\n";
2148 }
2149
2150 /**
2151  * Clear away any user-level output buffers, discarding contents.
2152  *
2153  * Suitable for 'starting afresh', for instance when streaming
2154  * relatively large amounts of data without buffering, or wanting to
2155  * output image files without ob_gzhandler's compression.
2156  *
2157  * The optional $resetGzipEncoding parameter controls suppression of
2158  * the Content-Encoding header sent by ob_gzhandler; by default it
2159  * is left. See comments for wfClearOutputBuffers() for why it would
2160  * be used.
2161  *
2162  * Note that some PHP configuration options may add output buffer
2163  * layers which cannot be removed; these are left in place.
2164  *
2165  * @param bool $resetGzipEncoding
2166  */
2167 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2168         if ( $resetGzipEncoding ) {
2169                 // Suppress Content-Encoding and Content-Length
2170                 // headers from 1.10+s wfOutputHandler
2171                 global $wgDisableOutputCompression;
2172                 $wgDisableOutputCompression = true;
2173         }
2174         while ( $status = ob_get_status() ) {
2175                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2176                         // Probably from zlib.output_compression or other
2177                         // PHP-internal setting which can't be removed.
2178                         //
2179                         // Give up, and hope the result doesn't break
2180                         // output behavior.
2181                         break;
2182                 }
2183                 if ( !ob_end_clean() ) {
2184                         // Could not remove output buffer handler; abort now
2185                         // to avoid getting in some kind of infinite loop.
2186                         break;
2187                 }
2188                 if ( $resetGzipEncoding ) {
2189                         if ( $status['name'] == 'ob_gzhandler' ) {
2190                                 // Reset the 'Content-Encoding' field set by this handler
2191                                 // so we can start fresh.
2192                                 header_remove( 'Content-Encoding' );
2193                                 break;
2194                         }
2195                 }
2196         }
2197 }
2198
2199 /**
2200  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2201  *
2202  * Clear away output buffers, but keep the Content-Encoding header
2203  * produced by ob_gzhandler, if any.
2204  *
2205  * This should be used for HTTP 304 responses, where you need to
2206  * preserve the Content-Encoding header of the real result, but
2207  * also need to suppress the output of ob_gzhandler to keep to spec
2208  * and avoid breaking Firefox in rare cases where the headers and
2209  * body are broken over two packets.
2210  */
2211 function wfClearOutputBuffers() {
2212         wfResetOutputBuffers( false );
2213 }
2214
2215 /**
2216  * Converts an Accept-* header into an array mapping string values to quality
2217  * factors
2218  *
2219  * @param string $accept
2220  * @param string $def Default
2221  * @return float[] Associative array of string => float pairs
2222  */
2223 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2224         # No arg means accept anything (per HTTP spec)
2225         if ( !$accept ) {
2226                 return array( $def => 1.0 );
2227         }
2228
2229         $prefs = array();
2230
2231         $parts = explode( ',', $accept );
2232
2233         foreach ( $parts as $part ) {
2234                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2235                 $values = explode( ';', trim( $part ) );
2236                 $match = array();
2237                 if ( count( $values ) == 1 ) {
2238                         $prefs[$values[0]] = 1.0;
2239                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2240                         $prefs[$values[0]] = floatval( $match[1] );
2241                 }
2242         }
2243
2244         return $prefs;
2245 }
2246
2247 /**
2248  * Checks if a given MIME type matches any of the keys in the given
2249  * array. Basic wildcards are accepted in the array keys.
2250  *
2251  * Returns the matching MIME type (or wildcard) if a match, otherwise
2252  * NULL if no match.
2253  *
2254  * @param string $type
2255  * @param array $avail
2256  * @return string
2257  * @private
2258  */
2259 function mimeTypeMatch( $type, $avail ) {
2260         if ( array_key_exists( $type, $avail ) ) {
2261                 return $type;
2262         } else {
2263                 $parts = explode( '/', $type );
2264                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2265                         return $parts[0] . '/*';
2266                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2267                         return '*/*';
2268                 } else {
2269                         return null;
2270                 }
2271         }
2272 }
2273
2274 /**
2275  * Returns the 'best' match between a client's requested internet media types
2276  * and the server's list of available types. Each list should be an associative
2277  * array of type to preference (preference is a float between 0.0 and 1.0).
2278  * Wildcards in the types are acceptable.
2279  *
2280  * @param array $cprefs Client's acceptable type list
2281  * @param array $sprefs Server's offered types
2282  * @return string
2283  *
2284  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2285  * XXX: generalize to negotiate other stuff
2286  */
2287 function wfNegotiateType( $cprefs, $sprefs ) {
2288         $combine = array();
2289
2290         foreach ( array_keys( $sprefs ) as $type ) {
2291                 $parts = explode( '/', $type );
2292                 if ( $parts[1] != '*' ) {
2293                         $ckey = mimeTypeMatch( $type, $cprefs );
2294                         if ( $ckey ) {
2295                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2296                         }
2297                 }
2298         }
2299
2300         foreach ( array_keys( $cprefs ) as $type ) {
2301                 $parts = explode( '/', $type );
2302                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2303                         $skey = mimeTypeMatch( $type, $sprefs );
2304                         if ( $skey ) {
2305                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2306                         }
2307                 }
2308         }
2309
2310         $bestq = 0;
2311         $besttype = null;
2312
2313         foreach ( array_keys( $combine ) as $type ) {
2314                 if ( $combine[$type] > $bestq ) {
2315                         $besttype = $type;
2316                         $bestq = $combine[$type];
2317                 }
2318         }
2319
2320         return $besttype;
2321 }
2322
2323 /**
2324  * Reference-counted warning suppression
2325  *
2326  * @param bool $end
2327  */
2328 function wfSuppressWarnings( $end = false ) {
2329         static $suppressCount = 0;
2330         static $originalLevel = false;
2331
2332         if ( $end ) {
2333                 if ( $suppressCount ) {
2334                         --$suppressCount;
2335                         if ( !$suppressCount ) {
2336                                 error_reporting( $originalLevel );
2337                         }
2338                 }
2339         } else {
2340                 if ( !$suppressCount ) {
2341                         $originalLevel = error_reporting( E_ALL & ~(
2342                                 E_WARNING |
2343                                 E_NOTICE |
2344                                 E_USER_WARNING |
2345                                 E_USER_NOTICE |
2346                                 E_DEPRECATED |
2347                                 E_USER_DEPRECATED |
2348                                 E_STRICT
2349                         ) );
2350                 }
2351                 ++$suppressCount;
2352         }
2353 }
2354
2355 /**
2356  * Restore error level to previous value
2357  */
2358 function wfRestoreWarnings() {
2359         wfSuppressWarnings( true );
2360 }
2361
2362 # Autodetect, convert and provide timestamps of various types
2363
2364 /**
2365  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2366  */
2367 define( 'TS_UNIX', 0 );
2368
2369 /**
2370  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2371  */
2372 define( 'TS_MW', 1 );
2373
2374 /**
2375  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2376  */
2377 define( 'TS_DB', 2 );
2378
2379 /**
2380  * RFC 2822 format, for E-mail and HTTP headers
2381  */
2382 define( 'TS_RFC2822', 3 );
2383
2384 /**
2385  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2386  *
2387  * This is used by Special:Export
2388  */
2389 define( 'TS_ISO_8601', 4 );
2390
2391 /**
2392  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2393  *
2394  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2395  *       DateTime tag and page 36 for the DateTimeOriginal and
2396  *       DateTimeDigitized tags.
2397  */
2398 define( 'TS_EXIF', 5 );
2399
2400 /**
2401  * Oracle format time.
2402  */
2403 define( 'TS_ORACLE', 6 );
2404
2405 /**
2406  * Postgres format time.
2407  */
2408 define( 'TS_POSTGRES', 7 );
2409
2410 /**
2411  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2412  */
2413 define( 'TS_ISO_8601_BASIC', 9 );
2414
2415 /**
2416  * Get a timestamp string in one of various formats
2417  *
2418  * @param mixed $outputtype A timestamp in one of the supported formats, the
2419  *   function will autodetect which format is supplied and act accordingly.
2420  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2421  * @return string|bool String / false The same date in the format specified in $outputtype or false
2422  */
2423 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2424         try {
2425                 $timestamp = new MWTimestamp( $ts );
2426                 return $timestamp->getTimestamp( $outputtype );
2427         } catch ( TimestampException $e ) {
2428                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2429                 return false;
2430         }
2431 }
2432
2433 /**
2434  * Return a formatted timestamp, or null if input is null.
2435  * For dealing with nullable timestamp columns in the database.
2436  *
2437  * @param int $outputtype
2438  * @param string $ts
2439  * @return string
2440  */
2441 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2442         if ( is_null( $ts ) ) {
2443                 return null;
2444         } else {
2445                 return wfTimestamp( $outputtype, $ts );
2446         }
2447 }
2448
2449 /**
2450  * Convenience function; returns MediaWiki timestamp for the present time.
2451  *
2452  * @return string
2453  */
2454 function wfTimestampNow() {
2455         # return NOW
2456         return wfTimestamp( TS_MW, time() );
2457 }
2458
2459 /**
2460  * Check if the operating system is Windows
2461  *
2462  * @return bool True if it's Windows, false otherwise.
2463  */
2464 function wfIsWindows() {
2465         static $isWindows = null;
2466         if ( $isWindows === null ) {
2467                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2468         }
2469         return $isWindows;
2470 }
2471
2472 /**
2473  * Check if we are running under HHVM
2474  *
2475  * @return bool
2476  */
2477 function wfIsHHVM() {
2478         return defined( 'HHVM_VERSION' );
2479 }
2480
2481 /**
2482  * Tries to get the system directory for temporary files. First
2483  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2484  * environment variables are then checked in sequence, and if none are
2485  * set try sys_get_temp_dir().
2486  *
2487  * NOTE: When possible, use instead the tmpfile() function to create
2488  * temporary files to avoid race conditions on file creation, etc.
2489  *
2490  * @return string
2491  */
2492 function wfTempDir() {
2493         global $wgTmpDirectory;
2494
2495         if ( $wgTmpDirectory !== false ) {
2496                 return $wgTmpDirectory;
2497         }
2498
2499         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2500
2501         foreach ( $tmpDir as $tmp ) {
2502                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2503                         return $tmp;
2504                 }
2505         }
2506         return sys_get_temp_dir();
2507 }
2508
2509 /**
2510  * Make directory, and make all parent directories if they don't exist
2511  *
2512  * @param string $dir Full path to directory to create
2513  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2514  * @param string $caller Optional caller param for debugging.
2515  * @throws MWException
2516  * @return bool
2517  */
2518 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2519         global $wgDirectoryMode;
2520
2521         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2522                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2523         }
2524
2525         if ( !is_null( $caller ) ) {
2526                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2527         }
2528
2529         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2530                 return true;
2531         }
2532
2533         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2534
2535         if ( is_null( $mode ) ) {
2536                 $mode = $wgDirectoryMode;
2537         }
2538
2539         // Turn off the normal warning, we're doing our own below
2540         wfSuppressWarnings();
2541         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2542         wfRestoreWarnings();
2543
2544         if ( !$ok ) {
2545                 //directory may have been created on another request since we last checked
2546                 if ( is_dir( $dir ) ) {
2547                         return true;
2548                 }
2549
2550                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2551                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2552         }
2553         return $ok;
2554 }
2555
2556 /**
2557  * Remove a directory and all its content.
2558  * Does not hide error.
2559  * @param string $dir
2560  */
2561 function wfRecursiveRemoveDir( $dir ) {
2562         wfDebug( __FUNCTION__ . "( $dir )\n" );
2563         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2564         if ( is_dir( $dir ) ) {
2565                 $objects = scandir( $dir );
2566                 foreach ( $objects as $object ) {
2567                         if ( $object != "." && $object != ".." ) {
2568                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2569                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2570                                 } else {
2571                                         unlink( $dir . '/' . $object );
2572                                 }
2573                         }
2574                 }
2575                 reset( $objects );
2576                 rmdir( $dir );
2577         }
2578 }
2579
2580 /**
2581  * @param int $nr The number to format
2582  * @param int $acc The number of digits after the decimal point, default 2
2583  * @param bool $round Whether or not to round the value, default true
2584  * @return string
2585  */
2586 function wfPercent( $nr, $acc = 2, $round = true ) {
2587         $ret = sprintf( "%.${acc}f", $nr );
2588         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2589 }
2590
2591 /**
2592  * Safety wrapper around ini_get() for boolean settings.
2593  * The values returned from ini_get() are pre-normalized for settings
2594  * set via php.ini or php_flag/php_admin_flag... but *not*
2595  * for those set via php_value/php_admin_value.
2596  *
2597  * It's fairly common for people to use php_value instead of php_flag,
2598  * which can leave you with an 'off' setting giving a false positive
2599  * for code that just takes the ini_get() return value as a boolean.
2600  *
2601  * To make things extra interesting, setting via php_value accepts
2602  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2603  * Unrecognized values go false... again opposite PHP's own coercion
2604  * from string to bool.
2605  *
2606  * Luckily, 'properly' set settings will always come back as '0' or '1',
2607  * so we only have to worry about them and the 'improper' settings.
2608  *
2609  * I frickin' hate PHP... :P
2610  *
2611  * @param string $setting
2612  * @return bool
2613  */
2614 function wfIniGetBool( $setting ) {
2615         $val = strtolower( ini_get( $setting ) );
2616         // 'on' and 'true' can't have whitespace around them, but '1' can.
2617         return $val == 'on'
2618                 || $val == 'true'
2619                 || $val == 'yes'
2620                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2621 }
2622
2623 /**
2624  * Windows-compatible version of escapeshellarg()
2625  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2626  * function puts single quotes in regardless of OS.
2627  *
2628  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2629  * earlier distro releases of PHP)
2630  *
2631  * @param string ... strings to escape and glue together, or a single array of strings parameter
2632  * @return string
2633  */
2634 function wfEscapeShellArg( /*...*/ ) {
2635         wfInitShellLocale();
2636
2637         $args = func_get_args();
2638         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2639                 // If only one argument has been passed, and that argument is an array,
2640                 // treat it as a list of arguments
2641                 $args = reset( $args );
2642         }
2643
2644         $first = true;
2645         $retVal = '';
2646         foreach ( $args as $arg ) {
2647                 if ( !$first ) {
2648                         $retVal .= ' ';
2649                 } else {
2650                         $first = false;
2651                 }
2652
2653                 if ( wfIsWindows() ) {
2654                         // Escaping for an MSVC-style command line parser and CMD.EXE
2655                         // @codingStandardsIgnoreStart For long URLs
2656                         // Refs:
2657                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2658                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2659                         //  * Bug #13518
2660                         //  * CR r63214
2661                         // Double the backslashes before any double quotes. Escape the double quotes.
2662                         // @codingStandardsIgnoreEnd
2663                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2664                         $arg = '';
2665                         $iteration = 0;
2666                         foreach ( $tokens as $token ) {
2667                                 if ( $iteration % 2 == 1 ) {
2668                                         // Delimiter, a double quote preceded by zero or more slashes
2669                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2670                                 } elseif ( $iteration % 4 == 2 ) {
2671                                         // ^ in $token will be outside quotes, need to be escaped
2672                                         $arg .= str_replace( '^', '^^', $token );
2673                                 } else { // $iteration % 4 == 0
2674                                         // ^ in $token will appear inside double quotes, so leave as is
2675                                         $arg .= $token;
2676                                 }
2677                                 $iteration++;
2678                         }
2679                         // Double the backslashes before the end of the string, because
2680                         // we will soon add a quote
2681                         $m = array();
2682                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2683                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2684                         }
2685
2686                         // Add surrounding quotes
2687                         $retVal .= '"' . $arg . '"';
2688                 } else {
2689                         $retVal .= escapeshellarg( $arg );
2690                 }
2691         }
2692         return $retVal;
2693 }
2694
2695 /**
2696  * Check if wfShellExec() is effectively disabled via php.ini config
2697  *
2698  * @return bool|string False or one of (safemode,disabled)
2699  * @since 1.22
2700  */
2701 function wfShellExecDisabled() {
2702         static $disabled = null;
2703         if ( is_null( $disabled ) ) {
2704                 if ( wfIniGetBool( 'safe_mode' ) ) {
2705                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2706                         $disabled = 'safemode';
2707                 } elseif ( !function_exists( 'proc_open' ) ) {
2708                         wfDebug( "proc_open() is disabled\n" );
2709                         $disabled = 'disabled';
2710                 } else {
2711                         $disabled = false;
2712                 }
2713         }
2714         return $disabled;
2715 }
2716
2717 /**
2718  * Execute a shell command, with time and memory limits mirrored from the PHP
2719  * configuration if supported.
2720  *
2721  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2722  *   or an array of unescaped arguments, in which case each value will be escaped
2723  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2724  * @param null|mixed &$retval Optional, will receive the program's exit code.
2725  *   (non-zero is usually failure). If there is an error from
2726  *   read, select, or proc_open(), this will be set to -1.
2727  * @param array $environ Optional environment variables which should be
2728  *   added to the executed command environment.
2729  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2730  *   this overwrites the global wgMaxShell* limits.
2731  * @param array $options Array of options:
2732  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2733  *     including errors from limit.sh
2734  *   - profileMethod: By default this function will profile based on the calling
2735  *     method. Set this to a string for an alternative method to profile from
2736  *
2737  * @return string Collected stdout as a string
2738  */
2739 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2740         $limits = array(), $options = array()
2741 ) {
2742         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2743                 $wgMaxShellWallClockTime, $wgShellCgroup;
2744
2745         $disabled = wfShellExecDisabled();
2746         if ( $disabled ) {
2747                 $retval = 1;
2748                 return $disabled == 'safemode' ?
2749                         'Unable to run external programs in safe mode.' :
2750                         'Unable to run external programs, proc_open() is disabled.';
2751         }
2752
2753         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2754         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2755
2756         wfInitShellLocale();
2757
2758         $envcmd = '';
2759         foreach ( $environ as $k => $v ) {
2760                 if ( wfIsWindows() ) {
2761                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2762                          * appear in the environment variable, so we must use carat escaping as documented in
2763                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2764                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2765                          * are listed there but doesn't appear to need it.
2766                          */
2767                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2768                 } else {
2769                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2770                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2771                          */
2772                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2773                 }
2774         }
2775         if ( is_array( $cmd ) ) {
2776                 $cmd = wfEscapeShellArg( $cmd );
2777         }
2778
2779         $cmd = $envcmd . $cmd;
2780
2781         $useLogPipe = false;
2782         if ( is_executable( '/bin/bash' ) ) {
2783                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2784                 if ( isset( $limits['walltime'] ) ) {
2785                         $wallTime = intval( $limits['walltime'] );
2786                 } elseif ( isset( $limits['time'] ) ) {
2787                         $wallTime = $time;
2788                 } else {
2789                         $wallTime = intval( $wgMaxShellWallClockTime );
2790                 }
2791                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2792                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2793
2794                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2795                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2796                                 escapeshellarg( $cmd ) . ' ' .
2797                                 escapeshellarg(
2798                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2799                                         "MW_CPU_LIMIT=$time; " .
2800                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2801                                         "MW_MEM_LIMIT=$mem; " .
2802                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2803                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2804                                         "MW_USE_LOG_PIPE=yes"
2805                                 );
2806                         $useLogPipe = true;
2807                 } elseif ( $includeStderr ) {
2808                         $cmd .= ' 2>&1';
2809                 }
2810         } elseif ( $includeStderr ) {
2811                 $cmd .= ' 2>&1';
2812         }
2813         wfDebug( "wfShellExec: $cmd\n" );
2814
2815         $desc = array(
2816                 0 => array( 'file', 'php://stdin', 'r' ),
2817                 1 => array( 'pipe', 'w' ),
2818                 2 => array( 'file', 'php://stderr', 'w' ) );
2819         if ( $useLogPipe ) {
2820                 $desc[3] = array( 'pipe', 'w' );
2821         }
2822         $pipes = null;
2823         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2824         $proc = proc_open( $cmd, $desc, $pipes );
2825         if ( !$proc ) {
2826                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2827                 $retval = -1;
2828                 return '';
2829         }
2830         $outBuffer = $logBuffer = '';
2831         $emptyArray = array();
2832         $status = false;
2833         $logMsg = false;
2834
2835         // According to the documentation, it is possible for stream_select()
2836         // to fail due to EINTR. I haven't managed to induce this in testing
2837         // despite sending various signals. If it did happen, the error
2838         // message would take the form:
2839         //
2840         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2841         //
2842         // where [4] is the value of the macro EINTR and "Interrupted system
2843         // call" is string which according to the Linux manual is "possibly"
2844         // localised according to LC_MESSAGES.
2845         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2846         $eintrMessage = "stream_select(): unable to select [$eintr]";
2847
2848         // Build a table mapping resource IDs to pipe FDs to work around a
2849         // PHP 5.3 issue in which stream_select() does not preserve array keys
2850         // <https://bugs.php.net/bug.php?id=53427>.
2851         $fds = array();
2852         foreach ( $pipes as $fd => $pipe ) {
2853                 $fds[(int)$pipe] = $fd;
2854         }
2855
2856         $running = true;
2857         $timeout = null;
2858         $numReadyPipes = 0;
2859
2860         while ( $running === true || $numReadyPipes !== 0 ) {
2861                 if ( $running ) {
2862                         $status = proc_get_status( $proc );
2863                         // If the process has terminated, switch to nonblocking selects
2864                         // for getting any data still waiting to be read.
2865                         if ( !$status['running'] ) {
2866                                 $running = false;
2867                                 $timeout = 0;
2868                         }
2869                 }
2870
2871                 $readyPipes = $pipes;
2872
2873                 // Clear last error
2874                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2875                 @trigger_error( '' );
2876                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2877                 if ( $numReadyPipes === false ) {
2878                         // @codingStandardsIgnoreEnd
2879                         $error = error_get_last();
2880                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2881                                 continue;
2882                         } else {
2883                                 trigger_error( $error['message'], E_USER_WARNING );
2884                                 $logMsg = $error['message'];
2885                                 break;
2886                         }
2887                 }
2888                 foreach ( $readyPipes as $pipe ) {
2889                         $block = fread( $pipe, 65536 );
2890                         $fd = $fds[(int)$pipe];
2891                         if ( $block === '' ) {
2892                                 // End of file
2893                                 fclose( $pipes[$fd] );
2894                                 unset( $pipes[$fd] );
2895                                 if ( !$pipes ) {
2896                                         break 2;
2897                                 }
2898                         } elseif ( $block === false ) {
2899                                 // Read error
2900                                 $logMsg = "Error reading from pipe";
2901                                 break 2;
2902                         } elseif ( $fd == 1 ) {
2903                                 // From stdout
2904                                 $outBuffer .= $block;
2905                         } elseif ( $fd == 3 ) {
2906                                 // From log FD
2907                                 $logBuffer .= $block;
2908                                 if ( strpos( $block, "\n" ) !== false ) {
2909                                         $lines = explode( "\n", $logBuffer );
2910                                         $logBuffer = array_pop( $lines );
2911                                         foreach ( $lines as $line ) {
2912                                                 wfDebugLog( 'exec', $line );
2913                                         }
2914                                 }
2915                         }
2916                 }
2917         }
2918
2919         foreach ( $pipes as $pipe ) {
2920                 fclose( $pipe );
2921         }
2922
2923         // Use the status previously collected if possible, since proc_get_status()
2924         // just calls waitpid() which will not return anything useful the second time.
2925         if ( $running ) {
2926                 $status = proc_get_status( $proc );
2927         }
2928
2929         if ( $logMsg !== false ) {
2930                 // Read/select error
2931                 $retval = -1;
2932                 proc_close( $proc );
2933         } elseif ( $status['signaled'] ) {
2934                 $logMsg = "Exited with signal {$status['termsig']}";
2935                 $retval = 128 + $status['termsig'];
2936                 proc_close( $proc );
2937         } else {
2938                 if ( $status['running'] ) {
2939                         $retval = proc_close( $proc );
2940                 } else {
2941                         $retval = $status['exitcode'];
2942                         proc_close( $proc );
2943                 }
2944                 if ( $retval == 127 ) {
2945                         $logMsg = "Possibly missing executable file";
2946                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2947                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2948                 }
2949         }
2950
2951         if ( $logMsg !== false ) {
2952                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2953         }
2954
2955         return $outBuffer;
2956 }
2957
2958 /**
2959  * Execute a shell command, returning both stdout and stderr. Convenience
2960  * function, as all the arguments to wfShellExec can become unwieldy.
2961  *
2962  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2963  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2964  *   or an array of unescaped arguments, in which case each value will be escaped
2965  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2966  * @param null|mixed &$retval Optional, will receive the program's exit code.
2967  *   (non-zero is usually failure)
2968  * @param array $environ Optional environment variables which should be
2969  *   added to the executed command environment.
2970  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2971  *   this overwrites the global wgMaxShell* limits.
2972  * @return string Collected stdout and stderr as a string
2973  */
2974 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2975         return wfShellExec( $cmd, $retval, $environ, $limits,
2976                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2977 }
2978
2979 /**
2980  * Workaround for http://bugs.php.net/bug.php?id=45132
2981  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2982  */
2983 function wfInitShellLocale() {
2984         static $done = false;
2985         if ( $done ) {
2986                 return;
2987         }
2988         $done = true;
2989         global $wgShellLocale;
2990         if ( !wfIniGetBool( 'safe_mode' ) ) {
2991                 putenv( "LC_CTYPE=$wgShellLocale" );
2992                 setlocale( LC_CTYPE, $wgShellLocale );
2993         }
2994 }
2995
2996 /**
2997  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2998  * Note that $parameters should be a flat array and an option with an argument
2999  * should consist of two consecutive items in the array (do not use "--option value").
3000  *
3001  * @param string $script MediaWiki cli script path
3002  * @param array $parameters Arguments and options to the script
3003  * @param array $options Associative array of options:
3004  *              'php': The path to the php executable
3005  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3006  * @return string
3007  */
3008 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3009         global $wgPhpCli;
3010         // Give site config file a chance to run the script in a wrapper.
3011         // The caller may likely want to call wfBasename() on $script.
3012         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3013         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3014         if ( isset( $options['wrapper'] ) ) {
3015                 $cmd[] = $options['wrapper'];
3016         }
3017         $cmd[] = $script;
3018         // Escape each parameter for shell
3019         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
3020 }
3021
3022 /**
3023  * wfMerge attempts to merge differences between three texts.
3024  * Returns true for a clean merge and false for failure or a conflict.
3025  *
3026  * @param string $old
3027  * @param string $mine
3028  * @param string $yours
3029  * @param string $result
3030  * @return bool
3031  */
3032 function wfMerge( $old, $mine, $yours, &$result ) {
3033         global $wgDiff3;
3034
3035         # This check may also protect against code injection in
3036         # case of broken installations.
3037         wfSuppressWarnings();
3038         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3039         wfRestoreWarnings();
3040
3041         if ( !$haveDiff3 ) {
3042                 wfDebug( "diff3 not found\n" );
3043                 return false;
3044         }
3045
3046         # Make temporary files
3047         $td = wfTempDir();
3048         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3049         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3050         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3051
3052         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3053         #       a newline character. To avoid this, we normalize the trailing whitespace before
3054         #       creating the diff.
3055
3056         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3057         fclose( $oldtextFile );
3058         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3059         fclose( $mytextFile );
3060         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3061         fclose( $yourtextFile );
3062
3063         # Check for a conflict
3064         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
3065                 $oldtextName, $yourtextName );
3066         $handle = popen( $cmd, 'r' );
3067
3068         if ( fgets( $handle, 1024 ) ) {
3069                 $conflict = true;
3070         } else {
3071                 $conflict = false;
3072         }
3073         pclose( $handle );
3074
3075         # Merge differences
3076         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
3077                 $oldtextName, $yourtextName );
3078         $handle = popen( $cmd, 'r' );
3079         $result = '';
3080         do {
3081                 $data = fread( $handle, 8192 );
3082                 if ( strlen( $data ) == 0 ) {
3083                         break;
3084                 }
3085                 $result .= $data;
3086         } while ( true );
3087         pclose( $handle );
3088         unlink( $mytextName );
3089         unlink( $oldtextName );
3090         unlink( $yourtextName );
3091
3092         if ( $result === '' && $old !== '' && !$conflict ) {
3093                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3094                 $conflict = true;
3095         }
3096         return !$conflict;
3097 }
3098
3099 /**
3100  * Returns unified plain-text diff of two texts.
3101  * "Useful" for machine processing of diffs.
3102  *
3103  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3104  *
3105  * @param string $before The text before the changes.
3106  * @param string $after The text after the changes.
3107  * @param string $params Command-line options for the diff command.
3108  * @return string Unified diff of $before and $after
3109  */
3110 function wfDiff( $before, $after, $params = '-u' ) {
3111         if ( $before == $after ) {
3112                 return '';
3113         }
3114
3115         global $wgDiff;
3116         wfSuppressWarnings();
3117         $haveDiff = $wgDiff && file_exists( $wgDiff );
3118         wfRestoreWarnings();
3119
3120         # This check may also protect against code injection in
3121         # case of broken installations.
3122         if ( !$haveDiff ) {
3123                 wfDebug( "diff executable not found\n" );
3124                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3125                 $format = new UnifiedDiffFormatter();
3126                 return $format->format( $diffs );
3127         }
3128
3129         # Make temporary files
3130         $td = wfTempDir();
3131         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3132         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3133
3134         fwrite( $oldtextFile, $before );
3135         fclose( $oldtextFile );
3136         fwrite( $newtextFile, $after );
3137         fclose( $newtextFile );
3138
3139         // Get the diff of the two files
3140         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3141
3142         $h = popen( $cmd, 'r' );
3143         if ( !$h ) {
3144                 unlink( $oldtextName );
3145                 unlink( $newtextName );
3146                 throw new Exception( __METHOD__ . '(): popen() failed' );
3147         }
3148
3149         $diff = '';
3150
3151         do {
3152                 $data = fread( $h, 8192 );
3153                 if ( strlen( $data ) == 0 ) {
3154                         break;
3155                 }
3156                 $diff .= $data;
3157         } while ( true );
3158
3159         // Clean up
3160         pclose( $h );
3161         unlink( $oldtextName );
3162         unlink( $newtextName );
3163
3164         // Kill the --- and +++ lines. They're not useful.
3165         $diff_lines = explode( "\n", $diff );
3166         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3167                 unset( $diff_lines[0] );
3168         }
3169         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3170                 unset( $diff_lines[1] );
3171         }
3172
3173         $diff = implode( "\n", $diff_lines );
3174
3175         return $diff;
3176 }
3177
3178 /**
3179  * This function works like "use VERSION" in Perl, the program will die with a
3180  * backtrace if the current version of PHP is less than the version provided
3181  *
3182  * This is useful for extensions which due to their nature are not kept in sync
3183  * with releases, and might depend on other versions of PHP than the main code
3184  *
3185  * Note: PHP might die due to parsing errors in some cases before it ever
3186  *       manages to call this function, such is life
3187  *
3188  * @see perldoc -f use
3189  *
3190  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3191  * @throws MWException
3192  */
3193 function wfUsePHP( $req_ver ) {
3194         $php_ver = PHP_VERSION;
3195
3196         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3197                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3198         }
3199 }
3200
3201 /**
3202  * This function works like "use VERSION" in Perl except it checks the version
3203  * of MediaWiki, the program will die with a backtrace if the current version
3204  * of MediaWiki is less than the version provided.
3205  *
3206  * This is useful for extensions which due to their nature are not kept in sync
3207  * with releases
3208  *
3209  * Note: Due to the behavior of PHP's version_compare() which is used in this
3210  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3211  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3212  * targeted version number. For example if you wanted to allow any variation
3213  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3214  * not result in the same comparison due to the internal logic of
3215  * version_compare().
3216  *
3217  * @see perldoc -f use
3218  *
3219  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3220  * @throws MWException
3221  */
3222 function wfUseMW( $req_ver ) {
3223         global $wgVersion;
3224
3225         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3226                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3227         }
3228 }
3229
3230 /**
3231  * Return the final portion of a pathname.
3232  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3233  * http://bugs.php.net/bug.php?id=33898
3234  *
3235  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3236  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3237  *
3238  * @param string $path
3239  * @param string $suffix String to remove if present
3240  * @return string
3241  */
3242 function wfBaseName( $path, $suffix = '' ) {
3243         if ( $suffix == '' ) {
3244                 $encSuffix = '';
3245         } else {
3246                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3247         }
3248
3249         $matches = array();
3250         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3251                 return $matches[1];
3252         } else {
3253                 return '';
3254         }
3255 }
3256
3257 /**
3258  * Generate a relative path name to the given file.
3259  * May explode on non-matching case-insensitive paths,
3260  * funky symlinks, etc.
3261  *
3262  * @param string $path Absolute destination path including target filename
3263  * @param string $from Absolute source path, directory only
3264  * @return string
3265  */
3266 function wfRelativePath( $path, $from ) {
3267         // Normalize mixed input on Windows...
3268         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3269         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3270
3271         // Trim trailing slashes -- fix for drive root
3272         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3273         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3274
3275         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3276         $against = explode( DIRECTORY_SEPARATOR, $from );
3277
3278         if ( $pieces[0] !== $against[0] ) {
3279                 // Non-matching Windows drive letters?
3280                 // Return a full path.
3281                 return $path;
3282         }
3283
3284         // Trim off common prefix
3285         while ( count( $pieces ) && count( $against )
3286                 && $pieces[0] == $against[0] ) {
3287                 array_shift( $pieces );
3288                 array_shift( $against );
3289         }
3290
3291         // relative dots to bump us to the parent
3292         while ( count( $against ) ) {
3293                 array_unshift( $pieces, '..' );
3294                 array_shift( $against );
3295         }
3296
3297         array_push( $pieces, wfBaseName( $path ) );
3298
3299         return implode( DIRECTORY_SEPARATOR, $pieces );
3300 }
3301
3302 /**
3303  * Convert an arbitrarily-long digit string from one numeric base
3304  * to another, optionally zero-padding to a minimum column width.
3305  *
3306  * Supports base 2 through 36; digit values 10-36 are represented
3307  * as lowercase letters a-z. Input is case-insensitive.
3308  *
3309  * @param string $input Input number
3310  * @param int $sourceBase Base of the input number
3311  * @param int $destBase Desired base of the output
3312  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3313  * @param bool $lowercase Whether to output in lowercase or uppercase
3314  * @param string $engine Either "gmp", "bcmath", or "php"
3315  * @return string|bool The output number as a string, or false on error
3316  */
3317 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3318         $lowercase = true, $engine = 'auto'
3319 ) {
3320         $input = (string)$input;
3321         if (
3322                 $sourceBase < 2 ||
3323                 $sourceBase > 36 ||
3324                 $destBase < 2 ||
3325                 $destBase > 36 ||
3326                 $sourceBase != (int)$sourceBase ||
3327                 $destBase != (int)$destBase ||
3328                 $pad != (int)$pad ||
3329                 !preg_match(
3330                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3331                         $input
3332                 )
3333         ) {
3334                 return false;
3335         }
3336
3337         static $baseChars = array(
3338                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3339                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3340                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3341                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3342                 34 => 'y', 35 => 'z',
3343
3344                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3345                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3346                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3347                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3348                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3349                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3350         );
3351
3352         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3353                 // Removing leading zeros works around broken base detection code in
3354                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3355                 // <https://bugs.php.net/bug.php?id=55398>).
3356                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ) ?: '0', $sourceBase ), $destBase );
3357         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3358                 $decimal = '0';
3359                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3360                         $decimal = bcmul( $decimal, $sourceBase );
3361                         $decimal = bcadd( $decimal, $baseChars[$char] );
3362                 }
3363
3364                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3365                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3366                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3367                 }
3368                 // @codingStandardsIgnoreEnd
3369
3370                 $result = strrev( $result );
3371         } else {
3372                 $inDigits = array();
3373                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3374                         $inDigits[] = $baseChars[$char];
3375                 }
3376
3377                 // Iterate over the input, modulo-ing out an output digit
3378                 // at a time until input is gone.
3379                 $result = '';
3380                 while ( $inDigits ) {
3381                         $work = 0;
3382                         $workDigits = array();
3383
3384                         // Long division...
3385                         foreach ( $inDigits as $digit ) {
3386                                 $work *= $sourceBase;
3387                                 $work += $digit;
3388
3389                                 if ( $workDigits || $work >= $destBase ) {
3390                                         $workDigits[] = (int)( $work / $destBase );
3391                                 }
3392                                 $work %= $destBase;
3393                         }
3394
3395                         // All that division leaves us with a remainder,
3396                         // which is conveniently our next output digit.
3397                         $result .= $baseChars[$work];
3398
3399                         // And we continue!
3400                         $inDigits = $workDigits;
3401                 }
3402
3403                 $result = strrev( $result );
3404         }
3405
3406         if ( !$lowercase ) {
3407                 $result = strtoupper( $result );
3408         }
3409
3410         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3411 }
3412
3413 /**
3414  * Check if there is sufficient entropy in php's built-in session generation
3415  *
3416  * @return bool True = there is sufficient entropy
3417  */
3418 function wfCheckEntropy() {
3419         return (
3420                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3421                         || ini_get( 'session.entropy_file' )
3422                 )
3423                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3424 }
3425
3426 /**
3427  * Override session_id before session startup if php's built-in
3428  * session generation code is not secure.
3429  */
3430 function wfFixSessionID() {
3431         // If the cookie or session id is already set we already have a session and should abort
3432         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3433                 return;
3434         }
3435
3436         // PHP's built-in session entropy is enabled if:
3437         // - entropy_file is set or you're on Windows with php 5.3.3+
3438         // - AND entropy_length is > 0
3439         // We treat it as disabled if it doesn't have an entropy length of at least 32
3440         $entropyEnabled = wfCheckEntropy();
3441
3442         // If built-in entropy is not enabled or not sufficient override PHP's
3443         // built in session id generation code
3444         if ( !$entropyEnabled ) {
3445                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3446                         "overriding session id generation using our cryptrand source.\n" );
3447                 session_id( MWCryptRand::generateHex( 32 ) );
3448         }
3449 }
3450
3451 /**
3452  * Reset the session_id
3453  *
3454  * @since 1.22
3455  */
3456 function wfResetSessionID() {
3457         global $wgCookieSecure;
3458         $oldSessionId = session_id();
3459         $cookieParams = session_get_cookie_params();
3460         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3461                 session_regenerate_id( false );
3462         } else {
3463                 $tmp = $_SESSION;
3464                 session_destroy();
3465                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3466                 $_SESSION = $tmp;
3467         }
3468         $newSessionId = session_id();
3469         Hooks::run( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3470 }
3471
3472 /**
3473  * Initialise php session
3474  *
3475  * @param bool $sessionId
3476  */
3477 function wfSetupSession( $sessionId = false ) {
3478         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3479                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3480         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3481                 ObjectCacheSessionHandler::install();
3482         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3483                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3484                 # hasn't already been set to the desired value (that causes errors)
3485                 ini_set( 'session.save_handler', $wgSessionHandler );
3486         }
3487         session_set_cookie_params(
3488                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3489         session_cache_limiter( 'private, must-revalidate' );
3490         if ( $sessionId ) {
3491                 session_id( $sessionId );
3492         } else {
3493                 wfFixSessionID();
3494         }
3495         wfSuppressWarnings();
3496         session_start();
3497         wfRestoreWarnings();
3498 }
3499
3500 /**
3501  * Get an object from the precompiled serialized directory
3502  *
3503  * @param string $name
3504  * @return mixed The variable on success, false on failure
3505  */
3506 function wfGetPrecompiledData( $name ) {
3507         global $IP;
3508
3509         $file = "$IP/serialized/$name";
3510         if ( file_exists( $file ) ) {
3511                 $blob = file_get_contents( $file );
3512                 if ( $blob ) {
3513                         return unserialize( $blob );
3514                 }
3515         }
3516         return false;
3517 }
3518
3519 /**
3520  * Get a cache key
3521  *
3522  * @param string $args,...
3523  * @return string
3524  */
3525 function wfMemcKey( /*...*/ ) {
3526         global $wgCachePrefix;
3527         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3528         $args = func_get_args();
3529         $key = $prefix . ':' . implode( ':', $args );
3530         $key = str_replace( ' ', '_', $key );
3531         return $key;
3532 }
3533
3534 /**
3535  * Get a cache key for a foreign DB
3536  *
3537  * @param string $db
3538  * @param string $prefix
3539  * @param string $args,...
3540  * @return string
3541  */
3542 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3543         $args = array_slice( func_get_args(), 2 );
3544         if ( $prefix ) {
3545                 $key = "$db-$prefix:" . implode( ':', $args );
3546         } else {
3547                 $key = $db . ':' . implode( ':', $args );
3548         }
3549         return str_replace( ' ', '_', $key );
3550 }
3551
3552 /**
3553  * Get an ASCII string identifying this wiki
3554  * This is used as a prefix in memcached keys
3555  *
3556  * @return string
3557  */
3558 function wfWikiID() {
3559         global $wgDBprefix, $wgDBname;
3560         if ( $wgDBprefix ) {
3561                 return "$wgDBname-$wgDBprefix";
3562         } else {
3563                 return $wgDBname;
3564         }
3565 }
3566
3567 /**
3568  * Split a wiki ID into DB name and table prefix
3569  *
3570  * @param string $wiki
3571  *
3572  * @return array
3573  */
3574 function wfSplitWikiID( $wiki ) {
3575         $bits = explode( '-', $wiki, 2 );
3576         if ( count( $bits ) < 2 ) {
3577                 $bits[] = '';
3578         }
3579         return $bits;
3580 }
3581
3582 /**
3583  * Get a Database object.
3584  *
3585  * @param int $db Index of the connection to get. May be DB_MASTER for the
3586  *            master (for write queries), DB_SLAVE for potentially lagged read
3587  *            queries, or an integer >= 0 for a particular server.
3588  *
3589  * @param string|string[] $groups Query groups. An array of group names that this query
3590  *                belongs to. May contain a single string if the query is only
3591  *                in one group.
3592  *
3593  * @param string|bool $wiki The wiki ID, or false for the current wiki
3594  *
3595  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3596  * will always return the same object, unless the underlying connection or load
3597  * balancer is manually destroyed.
3598  *
3599  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3600  * updater to ensure that a proper database is being updated.
3601  *
3602  * @return DatabaseBase
3603  */
3604 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3605         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3606 }
3607
3608 /**
3609  * Get a load balancer object.
3610  *
3611  * @param string|bool $wiki Wiki ID, or false for the current wiki
3612  * @return LoadBalancer
3613  */
3614 function wfGetLB( $wiki = false ) {
3615         return wfGetLBFactory()->getMainLB( $wiki );
3616 }
3617
3618 /**
3619  * Get the load balancer factory object
3620  *
3621  * @return LBFactory
3622  */
3623 function wfGetLBFactory() {
3624         return LBFactory::singleton();
3625 }
3626
3627 /**
3628  * Find a file.
3629  * Shortcut for RepoGroup::singleton()->findFile()
3630  *
3631  * @param string $title String or Title object
3632  * @param array $options Associative array of options (see RepoGroup::findFile)
3633  * @return File|bool File, or false if the file does not exist
3634  */
3635 function wfFindFile( $title, $options = array() ) {
3636         return RepoGroup::singleton()->findFile( $title, $options );
3637 }
3638
3639 /**
3640  * Get an object referring to a locally registered file.
3641  * Returns a valid placeholder object if the file does not exist.
3642  *
3643  * @param Title|string $title
3644  * @return LocalFile|null A File, or null if passed an invalid Title
3645  */
3646 function wfLocalFile( $title ) {
3647         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3648 }
3649
3650 /**
3651  * Should low-performance queries be disabled?
3652  *
3653  * @return bool
3654  * @codeCoverageIgnore
3655  */
3656 function wfQueriesMustScale() {
3657         global $wgMiserMode;
3658         return $wgMiserMode
3659                 || ( SiteStats::pages() > 100000
3660                 && SiteStats::edits() > 1000000
3661                 && SiteStats::users() > 10000 );
3662 }
3663
3664 /**
3665  * Get the path to a specified script file, respecting file
3666  * extensions; this is a wrapper around $wgScriptExtension etc.
3667  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3668  *
3669  * @param string $script Script filename, sans extension
3670  * @return string
3671  */
3672 function wfScript( $script = 'index' ) {
3673         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3674         if ( $script === 'index' ) {
3675                 return $wgScript;
3676         } elseif ( $script === 'load' ) {
3677                 return $wgLoadScript;
3678         } else {
3679                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3680         }
3681 }
3682
3683 /**
3684  * Get the script URL.
3685  *
3686  * @return string Script URL
3687  */
3688 function wfGetScriptUrl() {
3689         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3690                 #
3691                 # as it was called, minus the query string.
3692                 #
3693                 # Some sites use Apache rewrite rules to handle subdomains,
3694                 # and have PHP set up in a weird way that causes PHP_SELF
3695                 # to contain the rewritten URL instead of the one that the
3696                 # outside world sees.
3697                 #
3698                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3699                 # provides containing the "before" URL.
3700                 return $_SERVER['SCRIPT_NAME'];
3701         } else {
3702                 return $_SERVER['URL'];
3703         }
3704 }
3705
3706 /**
3707  * Convenience function converts boolean values into "true"
3708  * or "false" (string) values
3709  *
3710  * @param bool $value
3711  * @return string
3712  */
3713 function wfBoolToStr( $value ) {
3714         return $value ? 'true' : 'false';
3715 }
3716
3717 /**
3718  * Get a platform-independent path to the null file, e.g. /dev/null
3719  *
3720  * @return string
3721  */
3722 function wfGetNull() {
3723         return wfIsWindows() ? 'NUL' : '/dev/null';
3724 }
3725
3726 /**
3727  * Waits for the slaves to catch up to the master position
3728  *
3729  * Use this when updating very large numbers of rows, as in maintenance scripts,
3730  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3731  *
3732  * By default this waits on the main DB cluster of the current wiki.
3733  * If $cluster is set to "*" it will wait on all DB clusters, including
3734  * external ones. If the lag being waiting on is caused by the code that
3735  * does this check, it makes since to use $ifWritesSince, particularly if
3736  * cluster is "*", to avoid excess overhead.
3737  *
3738  * Never call this function after a big DB write that is still in a transaction.
3739  * This only makes sense after the possible lag inducing changes were committed.
3740  *
3741  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3742  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3743  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3744  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3745  * @return bool Success (able to connect and no timeouts reached)
3746  */
3747 function wfWaitForSlaves(
3748         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3749 ) {
3750         // B/C: first argument used to be "max seconds of lag"; ignore such values
3751         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3752
3753         if ( $timeout === null ) {
3754                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3755         }
3756
3757         // Figure out which clusters need to be checked
3758         /** @var LoadBalancer[] $lbs */
3759         $lbs = array();
3760         if ( $cluster === '*' ) {
3761                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3762                         $lbs[] = $lb;
3763                 } );
3764         } elseif ( $cluster !== false ) {
3765                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3766         } else {
3767                 $lbs[] = wfGetLB( $wiki );
3768         }
3769
3770         // Get all the master positions of applicable DBs right now.
3771         // This can be faster since waiting on one cluster reduces the
3772         // time needed to wait on the next clusters.
3773         $masterPositions = array_fill( 0, count( $lbs ), false );
3774         foreach ( $lbs as $i => $lb ) {
3775                 if ( $lb->getServerCount() <= 1 ) {
3776                         // Bug 27975 - Don't try to wait for slaves if there are none
3777                         // Prevents permission error when getting master position
3778                         continue;
3779                 } elseif ( $ifWritesSince && $lb->lastMasterChangeTimestamp() < $ifWritesSince ) {
3780                         continue; // no writes since the last wait
3781                 }
3782                 $masterPositions[$i] = $lb->getMasterPos();
3783         }
3784
3785         $ok = true;
3786         foreach ( $lbs as $i => $lb ) {
3787                 if ( $masterPositions[$i] ) {
3788                         // The DBMS may not support getMasterPos() or the whole
3789                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3790                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3791                 }
3792         }
3793
3794         return $ok;
3795 }
3796
3797 /**
3798  * Count down from $seconds to zero on the terminal, with a one-second pause
3799  * between showing each number. For use in command-line scripts.
3800  *
3801  * @codeCoverageIgnore
3802  * @param int $seconds
3803  */
3804 function wfCountDown( $seconds ) {
3805         for ( $i = $seconds; $i >= 0; $i-- ) {
3806                 if ( $i != $seconds ) {
3807                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3808                 }
3809                 echo $i;
3810                 flush();
3811                 if ( $i ) {
3812                         sleep( 1 );
3813                 }
3814         }
3815         echo "\n";
3816 }
3817
3818 /**
3819  * Replace all invalid characters with -
3820  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3821  * By default, $wgIllegalFileChars = ':'
3822  *
3823  * @param string $name Filename to process
3824  * @return string
3825  */
3826 function wfStripIllegalFilenameChars( $name ) {
3827         global $wgIllegalFileChars;
3828         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3829         $name = wfBaseName( $name );
3830         $name = preg_replace(
3831                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3832                 '-',
3833                 $name
3834         );
3835         return $name;
3836 }
3837
3838 /**
3839  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3840  *
3841  * @return int Value the memory limit was set to.
3842  */
3843 function wfMemoryLimit() {
3844         global $wgMemoryLimit;
3845         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3846         if ( $memlimit != -1 ) {
3847                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3848                 if ( $conflimit == -1 ) {
3849                         wfDebug( "Removing PHP's memory limit\n" );
3850                         wfSuppressWarnings();
3851                         ini_set( 'memory_limit', $conflimit );
3852                         wfRestoreWarnings();
3853                         return $conflimit;
3854                 } elseif ( $conflimit > $memlimit ) {
3855                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3856                         wfSuppressWarnings();
3857                         ini_set( 'memory_limit', $conflimit );
3858                         wfRestoreWarnings();
3859                         return $conflimit;
3860                 }
3861         }
3862         return $memlimit;
3863 }
3864
3865 /**
3866  * Converts shorthand byte notation to integer form
3867  *
3868  * @param string $string
3869  * @return int
3870  */
3871 function wfShorthandToInteger( $string = '' ) {
3872         $string = trim( $string );
3873         if ( $string === '' ) {
3874                 return -1;
3875         }
3876         $last = $string[strlen( $string ) - 1];
3877         $val = intval( $string );
3878         switch ( $last ) {
3879                 case 'g':
3880                 case 'G':
3881                         $val *= 1024;
3882                         // break intentionally missing
3883                 case 'm':
3884                 case 'M':
3885                         $val *= 1024;
3886                         // break intentionally missing
3887                 case 'k':
3888                 case 'K':
3889                         $val *= 1024;
3890         }
3891
3892         return $val;
3893 }
3894
3895 /**
3896  * Get the normalised IETF language tag
3897  * See unit test for examples.
3898  *
3899  * @param string $code The language code.
3900  * @return string The language code which complying with BCP 47 standards.
3901  */
3902 function wfBCP47( $code ) {
3903         $codeSegment = explode( '-', $code );
3904         $codeBCP = array();
3905         foreach ( $codeSegment as $segNo => $seg ) {
3906                 // when previous segment is x, it is a private segment and should be lc
3907                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3908                         $codeBCP[$segNo] = strtolower( $seg );
3909                 // ISO 3166 country code
3910                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3911                         $codeBCP[$segNo] = strtoupper( $seg );
3912                 // ISO 15924 script code
3913                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3914                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3915                 // Use lowercase for other cases
3916                 } else {
3917                         $codeBCP[$segNo] = strtolower( $seg );
3918                 }
3919         }
3920         $langCode = implode( '-', $codeBCP );
3921         return $langCode;
3922 }
3923
3924 /**
3925  * Get a cache object.
3926  *
3927  * @param int $inputType Cache type, one of the CACHE_* constants.
3928  * @return BagOStuff
3929  */
3930 function wfGetCache( $inputType ) {
3931         return ObjectCache::getInstance( $inputType );
3932 }
3933
3934 /**
3935  * Get the main cache object
3936  *
3937  * @return BagOStuff
3938  */
3939 function wfGetMainCache() {
3940         global $wgMainCacheType;
3941         return ObjectCache::getInstance( $wgMainCacheType );
3942 }
3943
3944 /**
3945  * Get the cache object used by the message cache
3946  *
3947  * @return BagOStuff
3948  */
3949 function wfGetMessageCacheStorage() {
3950         global $wgMessageCacheType;
3951         return ObjectCache::getInstance( $wgMessageCacheType );
3952 }
3953
3954 /**
3955  * Get the cache object used by the parser cache
3956  *
3957  * @return BagOStuff
3958  */
3959 function wfGetParserCacheStorage() {
3960         global $wgParserCacheType;
3961         return ObjectCache::getInstance( $wgParserCacheType );
3962 }
3963
3964 /**
3965  * Call hook functions defined in $wgHooks
3966  *
3967  * @param string $event Event name
3968  * @param array $args Parameters passed to hook functions
3969  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3970  *
3971  * @return bool True if no handler aborted the hook
3972  * @deprecated 1.25 - use Hooks::run
3973  */
3974 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3975         return Hooks::run( $event, $args, $deprecatedVersion );
3976 }
3977
3978 /**
3979  * Wrapper around php's unpack.
3980  *
3981  * @param string $format The format string (See php's docs)
3982  * @param string $data A binary string of binary data
3983  * @param int|bool $length The minimum length of $data or false. This is to
3984  *      prevent reading beyond the end of $data. false to disable the check.
3985  *
3986  * Also be careful when using this function to read unsigned 32 bit integer
3987  * because php might make it negative.
3988  *
3989  * @throws MWException If $data not long enough, or if unpack fails
3990  * @return array Associative array of the extracted data
3991  */
3992 function wfUnpack( $format, $data, $length = false ) {
3993         if ( $length !== false ) {
3994                 $realLen = strlen( $data );
3995                 if ( $realLen < $length ) {
3996                         throw new MWException( "Tried to use wfUnpack on a "
3997                                 . "string of length $realLen, but needed one "
3998                                 . "of at least length $length."
3999                         );
4000                 }
4001         }
4002
4003         wfSuppressWarnings();
4004         $result = unpack( $format, $data );
4005         wfRestoreWarnings();
4006
4007         if ( $result === false ) {
4008                 // If it cannot extract the packed data.
4009                 throw new MWException( "unpack could not unpack binary data" );
4010         }
4011         return $result;
4012 }
4013
4014 /**
4015  * Determine if an image exists on the 'bad image list'.
4016  *
4017  * The format of MediaWiki:Bad_image_list is as follows:
4018  *    * Only list items (lines starting with "*") are considered
4019  *    * The first link on a line must be a link to a bad image
4020  *    * Any subsequent links on the same line are considered to be exceptions,
4021  *      i.e. articles where the image may occur inline.
4022  *
4023  * @param string $name The image name to check
4024  * @param Title|bool $contextTitle The page on which the image occurs, if known
4025  * @param string $blacklist Wikitext of a file blacklist
4026  * @return bool
4027  */
4028 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4029         static $badImageCache = null; // based on bad_image_list msg
4030
4031         # Handle redirects
4032         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4033         if ( $redirectTitle ) {
4034                 $name = $redirectTitle->getDBkey();
4035         }
4036
4037         # Run the extension hook
4038         $bad = false;
4039         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4040                 return $bad;
4041         }
4042
4043         $cacheable = ( $blacklist === null );
4044         if ( $cacheable && $badImageCache !== null ) {
4045                 $badImages = $badImageCache;
4046         } else { // cache miss
4047                 if ( $blacklist === null ) {
4048                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4049                 }
4050                 # Build the list now
4051                 $badImages = array();
4052                 $lines = explode( "\n", $blacklist );
4053                 foreach ( $lines as $line ) {
4054                         # List items only
4055                         if ( substr( $line, 0, 1 ) !== '*' ) {
4056                                 continue;
4057                         }
4058
4059                         # Find all links
4060                         $m = array();
4061                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4062                                 continue;
4063                         }
4064
4065                         $exceptions = array();
4066                         $imageDBkey = false;
4067                         foreach ( $m[1] as $i => $titleText ) {
4068                                 $title = Title::newFromText( $titleText );
4069                                 if ( !is_null( $title ) ) {
4070                                         if ( $i == 0 ) {
4071                                                 $imageDBkey = $title->getDBkey();
4072                                         } else {
4073                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4074                                         }
4075                                 }
4076                         }
4077
4078                         if ( $imageDBkey !== false ) {
4079                                 $badImages[$imageDBkey] = $exceptions;
4080                         }
4081                 }
4082                 if ( $cacheable ) {
4083                         $badImageCache = $badImages;
4084                 }
4085         }
4086
4087         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4088         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4089         return $bad;
4090 }
4091
4092 /**
4093  * Determine whether the client at a given source IP is likely to be able to
4094  * access the wiki via HTTPS.
4095  *
4096  * @param string $ip The IPv4/6 address in the normal human-readable form
4097  * @return bool
4098  */
4099 function wfCanIPUseHTTPS( $ip ) {
4100         $canDo = true;
4101         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4102         return !!$canDo;
4103 }
4104
4105 /**
4106  * Determine input string is represents as infinity
4107  *
4108  * @param string $str The string to determine
4109  * @return bool
4110  * @since 1.25
4111  */
4112 function wfIsInfinity( $str ) {
4113         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4114         return in_array( $str, $infinityValues );
4115 }
4116
4117 /**
4118  * Work out the IP address based on various globals
4119  * For trusted proxies, use the XFF client IP (first of the chain)
4120  *
4121  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4122  * @return string
4123  */
4124 function wfGetIP() {
4125         wfDeprecated( __METHOD__, '1.19' );
4126         global $wgRequest;
4127         return $wgRequest->getIP();
4128 }
4129
4130 /**
4131  * Checks if an IP is a trusted proxy provider.
4132  * Useful to tell if X-Forwarded-For data is possibly bogus.
4133  * Squid cache servers for the site are whitelisted.
4134  * @deprecated Since 1.24, use IP::isTrustedProxy()
4135  *
4136  * @param string $ip
4137  * @return bool
4138  */
4139 function wfIsTrustedProxy( $ip ) {
4140         wfDeprecated( __METHOD__, '1.24' );
4141         return IP::isTrustedProxy( $ip );
4142 }
4143
4144 /**
4145  * Checks if an IP matches a proxy we've configured.
4146  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4147  *
4148  * @param string $ip
4149  * @return bool
4150  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4151  */
4152 function wfIsConfiguredProxy( $ip ) {
4153         wfDeprecated( __METHOD__, '1.24' );
4154         return IP::isConfiguredProxy( $ip );
4155 }
4156
4157 /**
4158  * Returns true if these thumbnail parameters match one that MediaWiki
4159  * requests from file description pages and/or parser output.
4160  *
4161  * $params is considered non-standard if they involve a non-standard
4162  * width or any non-default parameters aside from width and page number.
4163  * The number of possible files with standard parameters is far less than
4164  * that of all combinations; rate-limiting for them can thus be more generious.
4165  *
4166  * @param File $file
4167  * @param array $params
4168  * @return bool
4169  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4170  */
4171 function wfThumbIsStandard( File $file, array $params ) {
4172         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4173
4174         $multipliers = array( 1 );
4175         if ( $wgResponsiveImages ) {
4176                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4177                 // @see Linker::processResponsiveImages
4178                 $multipliers[] = 1.5;
4179                 $multipliers[] = 2;
4180         }
4181
4182         $handler = $file->getHandler();
4183         if ( !$handler || !isset( $params['width'] ) ) {
4184                 return false;
4185         }
4186
4187         $basicParams = array();
4188         if ( isset( $params['page'] ) ) {
4189                 $basicParams['page'] = $params['page'];
4190         }
4191
4192         $thumbLimits = array();
4193         $imageLimits = array();
4194         // Expand limits to account for multipliers
4195         foreach ( $multipliers as $multiplier ) {
4196                 $thumbLimits = array_merge( $thumbLimits, array_map(
4197                         function ( $width ) use ( $multiplier ) {
4198                                 return round( $width * $multiplier );
4199                         }, $wgThumbLimits )
4200                 );
4201                 $imageLimits = array_merge( $imageLimits, array_map(
4202                         function ( $pair ) use ( $multiplier ) {
4203                                 return array(
4204                                         round( $pair[0] * $multiplier ),
4205                                         round( $pair[1] * $multiplier ),
4206                                 );
4207                         }, $wgImageLimits )
4208                 );
4209         }
4210
4211         // Check if the width matches one of $wgThumbLimits
4212         if ( in_array( $params['width'], $thumbLimits ) ) {
4213                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4214                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4215                 $handler->normaliseParams( $file, $normalParams );
4216         } else {
4217                 // If not, then check if the width matchs one of $wgImageLimits
4218                 $match = false;
4219                 foreach ( $imageLimits as $pair ) {
4220                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4221                         // Decide whether the thumbnail should be scaled on width or height.
4222                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4223                         $handler->normaliseParams( $file, $normalParams );
4224                         // Check if this standard thumbnail size maps to the given width
4225                         if ( $normalParams['width'] == $params['width'] ) {
4226                                 $match = true;
4227                                 break;
4228                         }
4229                 }
4230                 if ( !$match ) {
4231                         return false; // not standard for description pages
4232                 }
4233         }
4234
4235         // Check that the given values for non-page, non-width, params are just defaults
4236         foreach ( $params as $key => $value ) {
4237                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4238                         return false;
4239                 }
4240         }
4241
4242         return true;
4243 }