includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 use Liuggio\StatsdClient\Sender\SocketSender;
  28 use MediaWiki\Logger\LoggerFactory;
  29
  30 // Hide compatibility functions from Doxygen
  31 /// @cond
  32
  33 /**
  34  * Compatibility functions
  35  *
  36  * We support PHP 5.3.3 and up.
  37  * Re-implementations of newer functions or functions in non-standard
  38  * PHP extensions may be included here.
  39  */
  40
  41 if ( !function_exists( 'mb_substr' ) ) {
  42         /**
  43          * @codeCoverageIgnore
  44          * @see Fallback::mb_substr
  45          * @return string
  46          */
  47         function mb_substr( $str, $start, $count = 'end' ) {
  48                 return Fallback::mb_substr( $str, $start, $count );
  49         }
  50
  51         /**
  52          * @codeCoverageIgnore
  53          * @see Fallback::mb_substr_split_unicode
  54          * @return int
  55          */
  56         function mb_substr_split_unicode( $str, $splitPos ) {
  57                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  58         }
  59 }
  60
  61 if ( !function_exists( 'mb_strlen' ) ) {
  62         /**
  63          * @codeCoverageIgnore
  64          * @see Fallback::mb_strlen
  65          * @return int
  66          */
  67         function mb_strlen( $str, $enc = '' ) {
  68                 return Fallback::mb_strlen( $str, $enc );
  69         }
  70 }
  71
  72 if ( !function_exists( 'mb_strpos' ) ) {
  73         /**
  74          * @codeCoverageIgnore
  75          * @see Fallback::mb_strpos
  76          * @return int
  77          */
  78         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  79                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  80         }
  81 }
  82
  83 if ( !function_exists( 'mb_strrpos' ) ) {
  84         /**
  85          * @codeCoverageIgnore
  86          * @see Fallback::mb_strrpos
  87          * @return int
  88          */
  89         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  90                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  91         }
  92 }
  93
  94 // gzdecode function only exists in PHP >= 5.4.0
  95 // http://php.net/gzdecode
  96 if ( !function_exists( 'gzdecode' ) ) {
  97         /**
  98          * @codeCoverageIgnore
  99          * @param string $data
 100          * @return string
 101          */
 102         function gzdecode( $data ) {
 103                 return gzinflate( substr( $data, 10, -8 ) );
 104         }
 105 }
 106
 107 // hash_equals function only exists in PHP >= 5.6.0
 108 // http://php.net/hash_equals
 109 if ( !function_exists( 'hash_equals' ) ) {
 110         /**
 111          * Check whether a user-provided string is equal to a fixed-length secret string
 112          * without revealing bytes of the secret string through timing differences.
 113          *
 114          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 115          * function in C) is to compare corresponding bytes and stop at the first difference,
 116          * which would take longer for a partial match than for a complete mismatch. This
 117          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 118          * and the other may come from an attacker. Statistical analysis of timing measurements
 119          * over many requests may allow the attacker to guess the string's bytes one at a time
 120          * (and check his guesses) even if the timing differences are extremely small.
 121          *
 122          * When making such a security-sensitive comparison, it is essential that the sequence
 123          * in which instructions are executed and memory locations are accessed not depend on
 124          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 125          * the inevitable leakage of the string's length. That is generally known anyway as
 126          * a chararacteristic of the hash function used to compute the secret value.
 127          *
 128          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 129          *
 130          * @codeCoverageIgnore
 131          * @param string $known_string Fixed-length secret string to compare against
 132          * @param string $user_string User-provided string
 133          * @return bool True if the strings are the same, false otherwise
 134          */
 135         function hash_equals( $known_string, $user_string ) {
 136                 // Strict type checking as in PHP's native implementation
 137                 if ( !is_string( $known_string ) ) {
 138                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 139                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 140
 141                         return false;
 142                 }
 143
 144                 if ( !is_string( $user_string ) ) {
 145                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 146                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 147
 148                         return false;
 149                 }
 150
 151                 $known_string_len = strlen( $known_string );
 152                 if ( $known_string_len !== strlen( $user_string ) ) {
 153                         return false;
 154                 }
 155
 156                 $result = 0;
 157                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 158                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 159                 }
 160
 161                 return ( $result === 0 );
 162         }
 163 }
 164 /// @endcond
 165
 166 /**
 167  * Load an extension
 168  *
 169  * This queues an extension to be loaded through
 170  * the ExtensionRegistry system.
 171  *
 172  * @param string $ext Name of the extension to load
 173  * @param string|null $path Absolute path of where to find the extension.json file
 174  */
 175 function wfLoadExtension( $ext, $path = null ) {
 176         if ( !$path ) {
 177                 global $wgExtensionDirectory;
 178                 $path = "$wgExtensionDirectory/$ext/extension.json";
 179         }
 180         ExtensionRegistry::getInstance()->queue( $path );
 181 }
 182
 183 /**
 184  * Load multiple extensions at once
 185  *
 186  * Same as wfLoadExtension, but more efficient if you
 187  * are loading multiple extensions.
 188  *
 189  * If you want to specify custom paths, you should interact with
 190  * ExtensionRegistry directly.
 191  *
 192  * @see wfLoadExtension
 193  * @param string[] $exts Array of extension names to load
 194  */
 195 function wfLoadExtensions( array $exts ) {
 196         global $wgExtensionDirectory;
 197         $registry = ExtensionRegistry::getInstance();
 198         foreach ( $exts as $ext ) {
 199                 $registry->queue( "$wgExtensionDirectory/$ext/extension.json" );
 200         }
 201 }
 202
 203 /**
 204  * Load a skin
 205  *
 206  * @see wfLoadExtension
 207  * @param string $skin Name of the extension to load
 208  * @param string|null $path Absolute path of where to find the skin.json file
 209  */
 210 function wfLoadSkin( $skin, $path = null ) {
 211         if ( !$path ) {
 212                 global $wgStyleDirectory;
 213                 $path = "$wgStyleDirectory/$skin/skin.json";
 214         }
 215         ExtensionRegistry::getInstance()->queue( $path );
 216 }
 217
 218 /**
 219  * Load multiple skins at once
 220  *
 221  * @see wfLoadExtensions
 222  * @param string[] $skins Array of extension names to load
 223  */
 224 function wfLoadSkins( array $skins ) {
 225         global $wgStyleDirectory;
 226         $registry = ExtensionRegistry::getInstance();
 227         foreach ( $skins as $skin ) {
 228                 $registry->queue( "$wgStyleDirectory/$skin/skin.json" );
 229         }
 230 }
 231
 232 /**
 233  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 234  * @param array $a
 235  * @param array $b
 236  * @return array
 237  */
 238 function wfArrayDiff2( $a, $b ) {
 239         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 240 }
 241
 242 /**
 243  * @param array|string $a
 244  * @param array|string $b
 245  * @return int
 246  */
 247 function wfArrayDiff2_cmp( $a, $b ) {
 248         if ( is_string( $a ) && is_string( $b ) ) {
 249                 return strcmp( $a, $b );
 250         } elseif ( count( $a ) !== count( $b ) ) {
 251                 return count( $a ) < count( $b ) ? -1 : 1;
 252         } else {
 253                 reset( $a );
 254                 reset( $b );
 255                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 256                         $cmp = strcmp( $valueA, $valueB );
 257                         if ( $cmp !== 0 ) {
 258                                 return $cmp;
 259                         }
 260                 }
 261                 return 0;
 262         }
 263 }
 264
 265 /**
 266  * Appends to second array if $value differs from that in $default
 267  *
 268  * @param string|int $key
 269  * @param mixed $value
 270  * @param mixed $default
 271  * @param array $changed Array to alter
 272  * @throws MWException
 273  */
 274 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 275         if ( is_null( $changed ) ) {
 276                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 277         }
 278         if ( $default[$key] !== $value ) {
 279                 $changed[$key] = $value;
 280         }
 281 }
 282
 283 /**
 284  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 285  * e.g.
 286  *      wfMergeErrorArrays(
 287  *              array( array( 'x' ) ),
 288  *              array( array( 'x', '2' ) ),
 289  *              array( array( 'x' ) ),
 290  *              array( array( 'y' ) )
 291  *      );
 292  * returns:
 293  *              array(
 294  *              array( 'x', '2' ),
 295  *              array( 'x' ),
 296  *              array( 'y' )
 297  *      )
 298  *
 299  * @param array $array1,...
 300  * @return array
 301  */
 302 function wfMergeErrorArrays( /*...*/ ) {
 303         $args = func_get_args();
 304         $out = array();
 305         foreach ( $args as $errors ) {
 306                 foreach ( $errors as $params ) {
 307                         # @todo FIXME: Sometimes get nested arrays for $params,
 308                         # which leads to E_NOTICEs
 309                         $spec = implode( "\t", $params );
 310                         $out[$spec] = $params;
 311                 }
 312         }
 313         return array_values( $out );
 314 }
 315
 316 /**
 317  * Insert array into another array after the specified *KEY*
 318  *
 319  * @param array $array The array.
 320  * @param array $insert The array to insert.
 321  * @param mixed $after The key to insert after
 322  * @return array
 323  */
 324 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 325         // Find the offset of the element to insert after.
 326         $keys = array_keys( $array );
 327         $offsetByKey = array_flip( $keys );
 328
 329         $offset = $offsetByKey[$after];
 330
 331         // Insert at the specified offset
 332         $before = array_slice( $array, 0, $offset + 1, true );
 333         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 334
 335         $output = $before + $insert + $after;
 336
 337         return $output;
 338 }
 339
 340 /**
 341  * Recursively converts the parameter (an object) to an array with the same data
 342  *
 343  * @param object|array $objOrArray
 344  * @param bool $recursive
 345  * @return array
 346  */
 347 function wfObjectToArray( $objOrArray, $recursive = true ) {
 348         $array = array();
 349         if ( is_object( $objOrArray ) ) {
 350                 $objOrArray = get_object_vars( $objOrArray );
 351         }
 352         foreach ( $objOrArray as $key => $value ) {
 353                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 354                         $value = wfObjectToArray( $value );
 355                 }
 356
 357                 $array[$key] = $value;
 358         }
 359
 360         return $array;
 361 }
 362
 363 /**
 364  * Get a random decimal value between 0 and 1, in a way
 365  * not likely to give duplicate values for any realistic
 366  * number of articles.
 367  *
 368  * @return string
 369  */
 370 function wfRandom() {
 371         # The maximum random value is "only" 2^31-1, so get two random
 372         # values to reduce the chance of dupes
 373         $max = mt_getrandmax() + 1;
 374         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 375
 376         return $rand;
 377 }
 378
 379 /**
 380  * Get a random string containing a number of pseudo-random hex
 381  * characters.
 382  * @note This is not secure, if you are trying to generate some sort
 383  *       of token please use MWCryptRand instead.
 384  *
 385  * @param int $length The length of the string to generate
 386  * @return string
 387  * @since 1.20
 388  */
 389 function wfRandomString( $length = 32 ) {
 390         $str = '';
 391         for ( $n = 0; $n < $length; $n += 7 ) {
 392                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 393         }
 394         return substr( $str, 0, $length );
 395 }
 396
 397 /**
 398  * We want some things to be included as literal characters in our title URLs
 399  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 400  * all of the following should be safe:
 401  *
 402  * ;:@&=$-_.+!*'(),
 403  *
 404  * RFC 1738 says ~ is unsafe, however RFC 3986 considers it an unreserved
 405  * character which should not be encoded. More importantly, google chrome
 406  * always converts %7E back to ~, and converting it in this function can
 407  * cause a redirect loop (T105265).
 408  *
 409  * But + is not safe because it's used to indicate a space; &= are only safe in
 410  * paths and not in queries (and we don't distinguish here); ' seems kind of
 411  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 412  * is reserved, we don't care.  So the list we unescape is:
 413  *
 414  * ;:@$!*(),/~
 415  *
 416  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 417  * so no fancy : for IIS7.
 418  *
 419  * %2F in the page titles seems to fatally break for some reason.
 420  *
 421  * @param string $s
 422  * @return string
 423  */
 424 function wfUrlencode( $s ) {
 425         static $needle;
 426
 427         if ( is_null( $s ) ) {
 428                 $needle = null;
 429                 return '';
 430         }
 431
 432         if ( is_null( $needle ) ) {
 433                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F', '%7E' );
 434                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 435                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 436                 ) {
 437                         $needle[] = '%3A';
 438                 }
 439         }
 440
 441         $s = urlencode( $s );
 442         $s = str_ireplace(
 443                 $needle,
 444                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', '~', ':' ),
 445                 $s
 446         );
 447
 448         return $s;
 449 }
 450
 451 /**
 452  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 453  * "days=7&limit=100". Options in the first array override options in the second.
 454  * Options set to null or false will not be output.
 455  *
 456  * @param array $array1 ( String|Array )
 457  * @param array $array2 ( String|Array )
 458  * @param string $prefix
 459  * @return string
 460  */
 461 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 462         if ( !is_null( $array2 ) ) {
 463                 $array1 = $array1 + $array2;
 464         }
 465
 466         $cgi = '';
 467         foreach ( $array1 as $key => $value ) {
 468                 if ( !is_null( $value ) && $value !== false ) {
 469                         if ( $cgi != '' ) {
 470                                 $cgi .= '&';
 471                         }
 472                         if ( $prefix !== '' ) {
 473                                 $key = $prefix . "[$key]";
 474                         }
 475                         if ( is_array( $value ) ) {
 476                                 $firstTime = true;
 477                                 foreach ( $value as $k => $v ) {
 478                                         $cgi .= $firstTime ? '' : '&';
 479                                         if ( is_array( $v ) ) {
 480                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 481                                         } else {
 482                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 483                                         }
 484                                         $firstTime = false;
 485                                 }
 486                         } else {
 487                                 if ( is_object( $value ) ) {
 488                                         $value = $value->__toString();
 489                                 }
 490                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 491                         }
 492                 }
 493         }
 494         return $cgi;
 495 }
 496
 497 /**
 498  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 499  * its argument and returns the same string in array form.  This allows compatibility
 500  * with legacy functions that accept raw query strings instead of nice
 501  * arrays.  Of course, keys and values are urldecode()d.
 502  *
 503  * @param string $query Query string
 504  * @return string[] Array version of input
 505  */
 506 function wfCgiToArray( $query ) {
 507         if ( isset( $query[0] ) && $query[0] == '?' ) {
 508                 $query = substr( $query, 1 );
 509         }
 510         $bits = explode( '&', $query );
 511         $ret = array();
 512         foreach ( $bits as $bit ) {
 513                 if ( $bit === '' ) {
 514                         continue;
 515                 }
 516                 if ( strpos( $bit, '=' ) === false ) {
 517                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 518                         $key = $bit;
 519                         $value = '';
 520                 } else {
 521                         list( $key, $value ) = explode( '=', $bit );
 522                 }
 523                 $key = urldecode( $key );
 524                 $value = urldecode( $value );
 525                 if ( strpos( $key, '[' ) !== false ) {
 526                         $keys = array_reverse( explode( '[', $key ) );
 527                         $key = array_pop( $keys );
 528                         $temp = $value;
 529                         foreach ( $keys as $k ) {
 530                                 $k = substr( $k, 0, -1 );
 531                                 $temp = array( $k => $temp );
 532                         }
 533                         if ( isset( $ret[$key] ) ) {
 534                                 $ret[$key] = array_merge( $ret[$key], $temp );
 535                         } else {
 536                                 $ret[$key] = $temp;
 537                         }
 538                 } else {
 539                         $ret[$key] = $value;
 540                 }
 541         }
 542         return $ret;
 543 }
 544
 545 /**
 546  * Append a query string to an existing URL, which may or may not already
 547  * have query string parameters already. If so, they will be combined.
 548  *
 549  * @param string $url
 550  * @param string|string[] $query String or associative array
 551  * @return string
 552  */
 553 function wfAppendQuery( $url, $query ) {
 554         if ( is_array( $query ) ) {
 555                 $query = wfArrayToCgi( $query );
 556         }
 557         if ( $query != '' ) {
 558                 if ( false === strpos( $url, '?' ) ) {
 559                         $url .= '?';
 560                 } else {
 561                         $url .= '&';
 562                 }
 563                 $url .= $query;
 564         }
 565         return $url;
 566 }
 567
 568 /**
 569  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 570  * is correct.
 571  *
 572  * The meaning of the PROTO_* constants is as follows:
 573  * PROTO_HTTP: Output a URL starting with http://
 574  * PROTO_HTTPS: Output a URL starting with https://
 575  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 576  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 577  *    on which protocol was used for the current incoming request
 578  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 579  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 580  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 581  *
 582  * @todo this won't work with current-path-relative URLs
 583  * like "subdir/foo.html", etc.
 584  *
 585  * @param string $url Either fully-qualified or a local path + query
 586  * @param string $defaultProto One of the PROTO_* constants. Determines the
 587  *    protocol to use if $url or $wgServer is protocol-relative
 588  * @return string Fully-qualified URL, current-path-relative URL or false if
 589  *    no valid URL can be constructed
 590  */
 591 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 592         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 593                 $wgHttpsPort;
 594         if ( $defaultProto === PROTO_CANONICAL ) {
 595                 $serverUrl = $wgCanonicalServer;
 596         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 597                 // Make $wgInternalServer fall back to $wgServer if not set
 598                 $serverUrl = $wgInternalServer;
 599         } else {
 600                 $serverUrl = $wgServer;
 601                 if ( $defaultProto === PROTO_CURRENT ) {
 602                         $defaultProto = $wgRequest->getProtocol() . '://';
 603                 }
 604         }
 605
 606         // Analyze $serverUrl to obtain its protocol
 607         $bits = wfParseUrl( $serverUrl );
 608         $serverHasProto = $bits && $bits['scheme'] != '';
 609
 610         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 611                 if ( $serverHasProto ) {
 612                         $defaultProto = $bits['scheme'] . '://';
 613                 } else {
 614                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 615                         // This really isn't supposed to happen. Fall back to HTTP in this
 616                         // ridiculous case.
 617                         $defaultProto = PROTO_HTTP;
 618                 }
 619         }
 620
 621         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 622
 623         if ( substr( $url, 0, 2 ) == '//' ) {
 624                 $url = $defaultProtoWithoutSlashes . $url;
 625         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 626                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 627                 // otherwise leave it alone.
 628                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 629         }
 630
 631         $bits = wfParseUrl( $url );
 632
 633         // ensure proper port for HTTPS arrives in URL
 634         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 635         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 636                 $bits['port'] = $wgHttpsPort;
 637         }
 638
 639         if ( $bits && isset( $bits['path'] ) ) {
 640                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 641                 return wfAssembleUrl( $bits );
 642         } elseif ( $bits ) {
 643                 # No path to expand
 644                 return $url;
 645         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 646                 # URL is a relative path
 647                 return wfRemoveDotSegments( $url );
 648         }
 649
 650         # Expanded URL is not valid.
 651         return false;
 652 }
 653
 654 /**
 655  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 656  * if you need to edit part of a URL and put it back together.
 657  *
 658  * This is the basic structure used (brackets contain keys for $urlParts):
 659  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 660  *
 661  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 662  *
 663  * @since 1.19
 664  * @param array $urlParts URL parts, as output from wfParseUrl
 665  * @return string URL assembled from its component parts
 666  */
 667 function wfAssembleUrl( $urlParts ) {
 668         $result = '';
 669
 670         if ( isset( $urlParts['delimiter'] ) ) {
 671                 if ( isset( $urlParts['scheme'] ) ) {
 672                         $result .= $urlParts['scheme'];
 673                 }
 674
 675                 $result .= $urlParts['delimiter'];
 676         }
 677
 678         if ( isset( $urlParts['host'] ) ) {
 679                 if ( isset( $urlParts['user'] ) ) {
 680                         $result .= $urlParts['user'];
 681                         if ( isset( $urlParts['pass'] ) ) {
 682                                 $result .= ':' . $urlParts['pass'];
 683                         }
 684                         $result .= '@';
 685                 }
 686
 687                 $result .= $urlParts['host'];
 688
 689                 if ( isset( $urlParts['port'] ) ) {
 690                         $result .= ':' . $urlParts['port'];
 691                 }
 692         }
 693
 694         if ( isset( $urlParts['path'] ) ) {
 695                 $result .= $urlParts['path'];
 696         }
 697
 698         if ( isset( $urlParts['query'] ) ) {
 699                 $result .= '?' . $urlParts['query'];
 700         }
 701
 702         if ( isset( $urlParts['fragment'] ) ) {
 703                 $result .= '#' . $urlParts['fragment'];
 704         }
 705
 706         return $result;
 707 }
 708
 709 /**
 710  * Remove all dot-segments in the provided URL path.  For example,
 711  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 712  * RFC3986 section 5.2.4.
 713  *
 714  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 715  *
 716  * @param string $urlPath URL path, potentially containing dot-segments
 717  * @return string URL path with all dot-segments removed
 718  */
 719 function wfRemoveDotSegments( $urlPath ) {
 720         $output = '';
 721         $inputOffset = 0;
 722         $inputLength = strlen( $urlPath );
 723
 724         while ( $inputOffset < $inputLength ) {
 725                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 726                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 727                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 728                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 729                 $trimOutput = false;
 730
 731                 if ( $prefixLengthTwo == './' ) {
 732                         # Step A, remove leading "./"
 733                         $inputOffset += 2;
 734                 } elseif ( $prefixLengthThree == '../' ) {
 735                         # Step A, remove leading "../"
 736                         $inputOffset += 3;
 737                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 738                         # Step B, replace leading "/.$" with "/"
 739                         $inputOffset += 1;
 740                         $urlPath[$inputOffset] = '/';
 741                 } elseif ( $prefixLengthThree == '/./' ) {
 742                         # Step B, replace leading "/./" with "/"
 743                         $inputOffset += 2;
 744                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 745                         # Step C, replace leading "/..$" with "/" and
 746                         # remove last path component in output
 747                         $inputOffset += 2;
 748                         $urlPath[$inputOffset] = '/';
 749                         $trimOutput = true;
 750                 } elseif ( $prefixLengthFour == '/../' ) {
 751                         # Step C, replace leading "/../" with "/" and
 752                         # remove last path component in output
 753                         $inputOffset += 3;
 754                         $trimOutput = true;
 755                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 756                         # Step D, remove "^.$"
 757                         $inputOffset += 1;
 758                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 759                         # Step D, remove "^..$"
 760                         $inputOffset += 2;
 761                 } else {
 762                         # Step E, move leading path segment to output
 763                         if ( $prefixLengthOne == '/' ) {
 764                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 765                         } else {
 766                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 767                         }
 768                         if ( $slashPos === false ) {
 769                                 $output .= substr( $urlPath, $inputOffset );
 770                                 $inputOffset = $inputLength;
 771                         } else {
 772                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 773                                 $inputOffset += $slashPos - $inputOffset;
 774                         }
 775                 }
 776
 777                 if ( $trimOutput ) {
 778                         $slashPos = strrpos( $output, '/' );
 779                         if ( $slashPos === false ) {
 780                                 $output = '';
 781                         } else {
 782                                 $output = substr( $output, 0, $slashPos );
 783                         }
 784                 }
 785         }
 786
 787         return $output;
 788 }
 789
 790 /**
 791  * Returns a regular expression of url protocols
 792  *
 793  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 794  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 795  * @return string
 796  */
 797 function wfUrlProtocols( $includeProtocolRelative = true ) {
 798         global $wgUrlProtocols;
 799
 800         // Cache return values separately based on $includeProtocolRelative
 801         static $withProtRel = null, $withoutProtRel = null;
 802         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 803         if ( !is_null( $cachedValue ) ) {
 804                 return $cachedValue;
 805         }
 806
 807         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 808         // with LocalSettings files from 1.5
 809         if ( is_array( $wgUrlProtocols ) ) {
 810                 $protocols = array();
 811                 foreach ( $wgUrlProtocols as $protocol ) {
 812                         // Filter out '//' if !$includeProtocolRelative
 813                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 814                                 $protocols[] = preg_quote( $protocol, '/' );
 815                         }
 816                 }
 817
 818                 $retval = implode( '|', $protocols );
 819         } else {
 820                 // Ignore $includeProtocolRelative in this case
 821                 // This case exists for pre-1.6 compatibility, and we can safely assume
 822                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 823                 // URLs weren't supported until 1.18
 824                 $retval = $wgUrlProtocols;
 825         }
 826
 827         // Cache return value
 828         if ( $includeProtocolRelative ) {
 829                 $withProtRel = $retval;
 830         } else {
 831                 $withoutProtRel = $retval;
 832         }
 833         return $retval;
 834 }
 835
 836 /**
 837  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 838  * you need a regex that matches all URL protocols but does not match protocol-
 839  * relative URLs
 840  * @return string
 841  */
 842 function wfUrlProtocolsWithoutProtRel() {
 843         return wfUrlProtocols( false );
 844 }
 845
 846 /**
 847  * parse_url() work-alike, but non-broken.  Differences:
 848  *
 849  * 1) Does not raise warnings on bad URLs (just returns false).
 850  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 851  *    protocol-relative URLs) correctly.
 852  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 853  *
 854  * @param string $url A URL to parse
 855  * @return string[] Bits of the URL in an associative array, per PHP docs
 856  */
 857 function wfParseUrl( $url ) {
 858         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 859
 860         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 861         // bad that the easiest way to handle them is to just prepend 'http:' and
 862         // strip the protocol out later.
 863         $wasRelative = substr( $url, 0, 2 ) == '//';
 864         if ( $wasRelative ) {
 865                 $url = "http:$url";
 866         }
 867         MediaWiki\suppressWarnings();
 868         $bits = parse_url( $url );
 869         MediaWiki\restoreWarnings();
 870         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 871         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 872         if ( !$bits || !isset( $bits['scheme'] ) ) {
 873                 return false;
 874         }
 875
 876         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 877         $bits['scheme'] = strtolower( $bits['scheme'] );
 878
 879         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 880         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 881                 $bits['delimiter'] = '://';
 882         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 883                 $bits['delimiter'] = ':';
 884                 // parse_url detects for news: and mailto: the host part of an url as path
 885                 // We have to correct this wrong detection
 886                 if ( isset( $bits['path'] ) ) {
 887                         $bits['host'] = $bits['path'];
 888                         $bits['path'] = '';
 889                 }
 890         } else {
 891                 return false;
 892         }
 893
 894         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 895         if ( !isset( $bits['host'] ) ) {
 896                 $bits['host'] = '';
 897
 898                 // bug 45069
 899                 if ( isset( $bits['path'] ) ) {
 900                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 901                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 902                                 $bits['path'] = '/' . $bits['path'];
 903                         }
 904                 } else {
 905                         $bits['path'] = '';
 906                 }
 907         }
 908
 909         // If the URL was protocol-relative, fix scheme and delimiter
 910         if ( $wasRelative ) {
 911                 $bits['scheme'] = '';
 912                 $bits['delimiter'] = '//';
 913         }
 914         return $bits;
 915 }
 916
 917 /**
 918  * Take a URL, make sure it's expanded to fully qualified, and replace any
 919  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 920  * for more compact display and legibility for local audiences.
 921  *
 922  * @todo handle punycode domains too
 923  *
 924  * @param string $url
 925  * @return string
 926  */
 927 function wfExpandIRI( $url ) {
 928         return preg_replace_callback(
 929                 '/((?:%[89A-F][0-9A-F])+)/i',
 930                 'wfExpandIRI_callback',
 931                 wfExpandUrl( $url )
 932         );
 933 }
 934
 935 /**
 936  * Private callback for wfExpandIRI
 937  * @param array $matches
 938  * @return string
 939  */
 940 function wfExpandIRI_callback( $matches ) {
 941         return urldecode( $matches[1] );
 942 }
 943
 944 /**
 945  * Make URL indexes, appropriate for the el_index field of externallinks.
 946  *
 947  * @param string $url
 948  * @return array
 949  */
 950 function wfMakeUrlIndexes( $url ) {
 951         $bits = wfParseUrl( $url );
 952
 953         // Reverse the labels in the hostname, convert to lower case
 954         // For emails reverse domainpart only
 955         if ( $bits['scheme'] == 'mailto' ) {
 956                 $mailparts = explode( '@', $bits['host'], 2 );
 957                 if ( count( $mailparts ) === 2 ) {
 958                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 959                 } else {
 960                         // No domain specified, don't mangle it
 961                         $domainpart = '';
 962                 }
 963                 $reversedHost = $domainpart . '@' . $mailparts[0];
 964         } else {
 965                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 966         }
 967         // Add an extra dot to the end
 968         // Why? Is it in wrong place in mailto links?
 969         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 970                 $reversedHost .= '.';
 971         }
 972         // Reconstruct the pseudo-URL
 973         $prot = $bits['scheme'];
 974         $index = $prot . $bits['delimiter'] . $reversedHost;
 975         // Leave out user and password. Add the port, path, query and fragment
 976         if ( isset( $bits['port'] ) ) {
 977                 $index .= ':' . $bits['port'];
 978         }
 979         if ( isset( $bits['path'] ) ) {
 980                 $index .= $bits['path'];
 981         } else {
 982                 $index .= '/';
 983         }
 984         if ( isset( $bits['query'] ) ) {
 985                 $index .= '?' . $bits['query'];
 986         }
 987         if ( isset( $bits['fragment'] ) ) {
 988                 $index .= '#' . $bits['fragment'];
 989         }
 990
 991         if ( $prot == '' ) {
 992                 return array( "http:$index", "https:$index" );
 993         } else {
 994                 return array( $index );
 995         }
 996 }
 997
 998 /**
 999  * Check whether a given URL has a domain that occurs in a given set of domains
1000  * @param string $url URL
1001  * @param array $domains Array of domains (strings)
1002  * @return bool True if the host part of $url ends in one of the strings in $domains
1003  */
1004 function wfMatchesDomainList( $url, $domains ) {
1005         $bits = wfParseUrl( $url );
1006         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1007                 $host = '.' . $bits['host'];
1008                 foreach ( (array)$domains as $domain ) {
1009                         $domain = '.' . $domain;
1010                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1011                                 return true;
1012                         }
1013                 }
1014         }
1015         return false;
1016 }
1017
1018 /**
1019  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1020  * In normal operation this is a NOP.
1021  *
1022  * Controlling globals:
1023  * $wgDebugLogFile - points to the log file
1024  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1025  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1026  *
1027  * @since 1.25 support for additional context data
1028  *
1029  * @param string $text
1030  * @param string|bool $dest Unused
1031  * @param array $context Additional logging context data
1032  */
1033 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1034         global $wgDebugRawPage, $wgDebugLogPrefix;
1035         global $wgDebugTimestamps, $wgRequestTime;
1036
1037         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1038                 return;
1039         }
1040
1041         $text = trim( $text );
1042
1043         // Inline logic from deprecated wfDebugTimer()
1044         if ( $wgDebugTimestamps ) {
1045                 $context['seconds_elapsed'] = sprintf(
1046                         '%6.4f',
1047                         microtime( true ) - $wgRequestTime
1048                 );
1049                 $context['memory_used'] = sprintf(
1050                         '%5.1fM',
1051                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1052                 );
1053         }
1054
1055         if ( $wgDebugLogPrefix !== '' ) {
1056                 $context['prefix'] = $wgDebugLogPrefix;
1057         }
1058
1059         $logger = LoggerFactory::getInstance( 'wfDebug' );
1060         $logger->debug( $text, $context );
1061 }
1062
1063 /**
1064  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1065  * @return bool
1066  */
1067 function wfIsDebugRawPage() {
1068         static $cache;
1069         if ( $cache !== null ) {
1070                 return $cache;
1071         }
1072         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1073         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1074                 || (
1075                         isset( $_SERVER['SCRIPT_NAME'] )
1076                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1077                 )
1078         ) {
1079                 $cache = true;
1080         } else {
1081                 $cache = false;
1082         }
1083         return $cache;
1084 }
1085
1086 /**
1087  * Get microsecond timestamps for debug logs
1088  *
1089  * @deprecated since 1.25
1090  * @return string
1091  */
1092 function wfDebugTimer() {
1093         global $wgDebugTimestamps, $wgRequestTime;
1094
1095         wfDeprecated( __METHOD__, '1.25' );
1096
1097         if ( !$wgDebugTimestamps ) {
1098                 return '';
1099         }
1100
1101         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1102         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1103         return "$prefix $mem  ";
1104 }
1105
1106 /**
1107  * Send a line giving PHP memory usage.
1108  *
1109  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1110  */
1111 function wfDebugMem( $exact = false ) {
1112         $mem = memory_get_usage();
1113         if ( !$exact ) {
1114                 $mem = floor( $mem / 1024 ) . ' KiB';
1115         } else {
1116                 $mem .= ' B';
1117         }
1118         wfDebug( "Memory usage: $mem\n" );
1119 }
1120
1121 /**
1122  * Send a line to a supplementary debug log file, if configured, or main debug
1123  * log if not.
1124  *
1125  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1126  * a string filename or an associative array mapping 'destination' to the
1127  * desired filename. The associative array may also contain a 'sample' key
1128  * with an integer value, specifying a sampling factor. Sampled log events
1129  * will be emitted with a 1 in N random chance.
1130  *
1131  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1132  * @since 1.25 support for additional context data
1133  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1134  *
1135  * @param string $logGroup
1136  * @param string $text
1137  * @param string|bool $dest Destination of the message:
1138  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1139  *     - 'log': only to the log and not in HTML
1140  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1141  *       discarded otherwise
1142  *   For backward compatibility, it can also take a boolean:
1143  *     - true: same as 'all'
1144  *     - false: same as 'private'
1145  * @param array $context Additional logging context data
1146  */
1147 function wfDebugLog(
1148         $logGroup, $text, $dest = 'all', array $context = array()
1149 ) {
1150         // Turn $dest into a string if it's a boolean (for b/c)
1151         if ( $dest === true ) {
1152                 $dest = 'all';
1153         } elseif ( $dest === false ) {
1154                 $dest = 'private';
1155         }
1156
1157         $text = trim( $text );
1158
1159         $logger = LoggerFactory::getInstance( $logGroup );
1160         $context['private'] = ( $dest === 'private' );
1161         $logger->info( $text, $context );
1162 }
1163
1164 /**
1165  * Log for database errors
1166  *
1167  * @since 1.25 support for additional context data
1168  *
1169  * @param string $text Database error message.
1170  * @param array $context Additional logging context data
1171  */
1172 function wfLogDBError( $text, array $context = array() ) {
1173         $logger = LoggerFactory::getInstance( 'wfLogDBError' );
1174         $logger->error( trim( $text ), $context );
1175 }
1176
1177 /**
1178  * Throws a warning that $function is deprecated
1179  *
1180  * @param string $function
1181  * @param string|bool $version Version of MediaWiki that the function
1182  *    was deprecated in (Added in 1.19).
1183  * @param string|bool $component Added in 1.19.
1184  * @param int $callerOffset How far up the call stack is the original
1185  *    caller. 2 = function that called the function that called
1186  *    wfDeprecated (Added in 1.20)
1187  *
1188  * @return null
1189  */
1190 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1191         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1192 }
1193
1194 /**
1195  * Send a warning either to the debug log or in a PHP error depending on
1196  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1197  *
1198  * @param string $msg Message to send
1199  * @param int $callerOffset Number of items to go back in the backtrace to
1200  *        find the correct caller (1 = function calling wfWarn, ...)
1201  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1202  *        only used when $wgDevelopmentWarnings is true
1203  */
1204 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1205         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1206 }
1207
1208 /**
1209  * Send a warning as a PHP error and the debug log. This is intended for logging
1210  * warnings in production. For logging development warnings, use WfWarn instead.
1211  *
1212  * @param string $msg Message to send
1213  * @param int $callerOffset Number of items to go back in the backtrace to
1214  *        find the correct caller (1 = function calling wfLogWarning, ...)
1215  * @param int $level PHP error level; defaults to E_USER_WARNING
1216  */
1217 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1218         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1219 }
1220
1221 /**
1222  * Log to a file without getting "file size exceeded" signals.
1223  *
1224  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1225  * send lines to the specified port, prefixed by the specified prefix and a space.
1226  * @since 1.25 support for additional context data
1227  *
1228  * @param string $text
1229  * @param string $file Filename
1230  * @param array $context Additional logging context data
1231  * @throws MWException
1232  * @deprecated since 1.25 Use MediaWiki\Logger\LegacyLogger::emit or UDPTransport
1233  */
1234 function wfErrorLog( $text, $file, array $context = array() ) {
1235         wfDeprecated( __METHOD__, '1.25' );
1236         $logger = LoggerFactory::getInstance( 'wfErrorLog' );
1237         $context['destination'] = $file;
1238         $logger->info( trim( $text ), $context );
1239 }
1240
1241 /**
1242  * @todo document
1243  */
1244 function wfLogProfilingData() {
1245         global $wgDebugLogGroups, $wgDebugRawPage;
1246
1247         $context = RequestContext::getMain();
1248         $request = $context->getRequest();
1249
1250         $profiler = Profiler::instance();
1251         $profiler->setContext( $context );
1252         $profiler->logData();
1253
1254         $config = $context->getConfig();
1255         if ( $config->get( 'StatsdServer' ) ) {
1256                 try {
1257                         $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1258                         $statsdHost = $statsdServer[0];
1259                         $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1260                         $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1261                         $statsdClient = new SamplingStatsdClient( $statsdSender, true, false );
1262                         $statsdClient->send( $context->getStats()->getBuffer() );
1263                 } catch ( Exception $ex ) {
1264                         MWExceptionHandler::logException( $ex );
1265                 }
1266         }
1267
1268         # Profiling must actually be enabled...
1269         if ( $profiler instanceof ProfilerStub ) {
1270                 return;
1271         }
1272
1273         if ( isset( $wgDebugLogGroups['profileoutput'] )
1274                 && $wgDebugLogGroups['profileoutput'] === false
1275         ) {
1276                 // Explicitly disabled
1277                 return;
1278         }
1279         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1280                 return;
1281         }
1282
1283         $ctx = array( 'elapsed' => $request->getElapsedTime() );
1284         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1285                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1286         }
1287         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1288                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1289         }
1290         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1291                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1292         }
1293         if ( isset( $ctx['forwarded_for'] ) ||
1294                 isset( $ctx['client_ip'] ) ||
1295                 isset( $ctx['from'] ) ) {
1296                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1297         }
1298
1299         // Don't load $wgUser at this late stage just for statistics purposes
1300         // @todo FIXME: We can detect some anons even if it is not loaded.
1301         // See User::getId()
1302         $user = $context->getUser();
1303         $ctx['anon'] = $user->isItemLoaded( 'id' ) && $user->isAnon();
1304
1305         // Command line script uses a FauxRequest object which does not have
1306         // any knowledge about an URL and throw an exception instead.
1307         try {
1308                 $ctx['url'] = urldecode( $request->getRequestURL() );
1309         } catch ( Exception $ignored ) {
1310                 // no-op
1311         }
1312
1313         $ctx['output'] = $profiler->getOutput();
1314
1315         $log = LoggerFactory::getInstance( 'profileoutput' );
1316         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1317 }
1318
1319 /**
1320  * Increment a statistics counter
1321  *
1322  * @param string $key
1323  * @param int $count
1324  * @return void
1325  */
1326 function wfIncrStats( $key, $count = 1 ) {
1327         $stats = RequestContext::getMain()->getStats();
1328         $stats->updateCount( $key, $count );
1329 }
1330
1331 /**
1332  * Check whether the wiki is in read-only mode.
1333  *
1334  * @return bool
1335  */
1336 function wfReadOnly() {
1337         return wfReadOnlyReason() !== false;
1338 }
1339
1340 /**
1341  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1342  *
1343  * @return string|bool String when in read-only mode; false otherwise
1344  */
1345 function wfReadOnlyReason() {
1346         global $wgReadOnly, $wgReadOnlyFile;
1347
1348         if ( $wgReadOnly === null ) {
1349                 // Set $wgReadOnly for faster access next time
1350                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1351                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1352                 } else {
1353                         $wgReadOnly = false;
1354                 }
1355                 // Callers use this method to be aware that data presented to a user
1356                 // may be very stale and thus allowing submissions can be problematic.
1357                 try {
1358                         if ( $wgReadOnly === false && wfGetLB()->getLaggedSlaveMode() ) {
1359                                 $wgReadOnly = 'The database has been automatically locked ' .
1360                                         'while the slave database servers catch up to the master';
1361                         }
1362                 } catch ( DBConnectionError $e ) {
1363                         $wgReadOnly = 'The database has been automatically locked ' .
1364                                 'until the slave database servers become available';
1365                 }
1366         }
1367
1368         return $wgReadOnly;
1369 }
1370
1371 /**
1372  * Return a Language object from $langcode
1373  *
1374  * @param Language|string|bool $langcode Either:
1375  *                  - a Language object
1376  *                  - code of the language to get the message for, if it is
1377  *                    a valid code create a language for that language, if
1378  *                    it is a string but not a valid code then make a basic
1379  *                    language object
1380  *                  - a boolean: if it's false then use the global object for
1381  *                    the current user's language (as a fallback for the old parameter
1382  *                    functionality), or if it is true then use global object
1383  *                    for the wiki's content language.
1384  * @return Language
1385  */
1386 function wfGetLangObj( $langcode = false ) {
1387         # Identify which language to get or create a language object for.
1388         # Using is_object here due to Stub objects.
1389         if ( is_object( $langcode ) ) {
1390                 # Great, we already have the object (hopefully)!
1391                 return $langcode;
1392         }
1393
1394         global $wgContLang, $wgLanguageCode;
1395         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1396                 # $langcode is the language code of the wikis content language object.
1397                 # or it is a boolean and value is true
1398                 return $wgContLang;
1399         }
1400
1401         global $wgLang;
1402         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1403                 # $langcode is the language code of user language object.
1404                 # or it was a boolean and value is false
1405                 return $wgLang;
1406         }
1407
1408         $validCodes = array_keys( Language::fetchLanguageNames() );
1409         if ( in_array( $langcode, $validCodes ) ) {
1410                 # $langcode corresponds to a valid language.
1411                 return Language::factory( $langcode );
1412         }
1413
1414         # $langcode is a string, but not a valid language code; use content language.
1415         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1416         return $wgContLang;
1417 }
1418
1419 /**
1420  * This is the function for getting translated interface messages.
1421  *
1422  * @see Message class for documentation how to use them.
1423  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1424  *
1425  * This function replaces all old wfMsg* functions.
1426  *
1427  * @param string|string[]|MessageSpecifier $key Message key, or array of keys, or a MessageSpecifier
1428  * @param mixed $params,... Normal message parameters
1429  * @return Message
1430  *
1431  * @since 1.17
1432  *
1433  * @see Message::__construct
1434  */
1435 function wfMessage( $key /*...*/ ) {
1436         $params = func_get_args();
1437         array_shift( $params );
1438         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1439                 $params = $params[0];
1440         }
1441         return new Message( $key, $params );
1442 }
1443
1444 /**
1445  * This function accepts multiple message keys and returns a message instance
1446  * for the first message which is non-empty. If all messages are empty then an
1447  * instance of the first message key is returned.
1448  *
1449  * @param string|string[] $keys,... Message keys
1450  * @return Message
1451  *
1452  * @since 1.18
1453  *
1454  * @see Message::newFallbackSequence
1455  */
1456 function wfMessageFallback( /*...*/ ) {
1457         $args = func_get_args();
1458         return call_user_func_array( 'Message::newFallbackSequence', $args );
1459 }
1460
1461 /**
1462  * Get a message from anywhere, for the current user language.
1463  *
1464  * Use wfMsgForContent() instead if the message should NOT
1465  * change depending on the user preferences.
1466  *
1467  * @deprecated since 1.18
1468  *
1469  * @param string $key Lookup key for the message, usually
1470  *    defined in languages/Language.php
1471  *
1472  * Parameters to the message, which can be used to insert variable text into
1473  * it, can be passed to this function in the following formats:
1474  * - One per argument, starting at the second parameter
1475  * - As an array in the second parameter
1476  * These are not shown in the function definition.
1477  *
1478  * @return string
1479  */
1480 function wfMsg( $key ) {
1481         wfDeprecated( __METHOD__, '1.21' );
1482
1483         $args = func_get_args();
1484         array_shift( $args );
1485         return wfMsgReal( $key, $args );
1486 }
1487
1488 /**
1489  * Same as above except doesn't transform the message
1490  *
1491  * @deprecated since 1.18
1492  *
1493  * @param string $key
1494  * @return string
1495  */
1496 function wfMsgNoTrans( $key ) {
1497         wfDeprecated( __METHOD__, '1.21' );
1498
1499         $args = func_get_args();
1500         array_shift( $args );
1501         return wfMsgReal( $key, $args, true, false, false );
1502 }
1503
1504 /**
1505  * Get a message from anywhere, for the current global language
1506  * set with $wgLanguageCode.
1507  *
1508  * Use this if the message should NOT change dependent on the
1509  * language set in the user's preferences. This is the case for
1510  * most text written into logs, as well as link targets (such as
1511  * the name of the copyright policy page). Link titles, on the
1512  * other hand, should be shown in the UI language.
1513  *
1514  * Note that MediaWiki allows users to change the user interface
1515  * language in their preferences, but a single installation
1516  * typically only contains content in one language.
1517  *
1518  * Be wary of this distinction: If you use wfMsg() where you should
1519  * use wfMsgForContent(), a user of the software may have to
1520  * customize potentially hundreds of messages in
1521  * order to, e.g., fix a link in every possible language.
1522  *
1523  * @deprecated since 1.18
1524  *
1525  * @param string $key Lookup key for the message, usually
1526  *     defined in languages/Language.php
1527  * @return string
1528  */
1529 function wfMsgForContent( $key ) {
1530         wfDeprecated( __METHOD__, '1.21' );
1531
1532         global $wgForceUIMsgAsContentMsg;
1533         $args = func_get_args();
1534         array_shift( $args );
1535         $forcontent = true;
1536         if ( is_array( $wgForceUIMsgAsContentMsg )
1537                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1538         ) {
1539                 $forcontent = false;
1540         }
1541         return wfMsgReal( $key, $args, true, $forcontent );
1542 }
1543
1544 /**
1545  * Same as above except doesn't transform the message
1546  *
1547  * @deprecated since 1.18
1548  *
1549  * @param string $key
1550  * @return string
1551  */
1552 function wfMsgForContentNoTrans( $key ) {
1553         wfDeprecated( __METHOD__, '1.21' );
1554
1555         global $wgForceUIMsgAsContentMsg;
1556         $args = func_get_args();
1557         array_shift( $args );
1558         $forcontent = true;
1559         if ( is_array( $wgForceUIMsgAsContentMsg )
1560                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1561         ) {
1562                 $forcontent = false;
1563         }
1564         return wfMsgReal( $key, $args, true, $forcontent, false );
1565 }
1566
1567 /**
1568  * Really get a message
1569  *
1570  * @deprecated since 1.18
1571  *
1572  * @param string $key Key to get.
1573  * @param array $args
1574  * @param bool $useDB
1575  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1576  * @param bool $transform Whether or not to transform the message.
1577  * @return string The requested message.
1578  */
1579 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1580         wfDeprecated( __METHOD__, '1.21' );
1581
1582         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1583         $message = wfMsgReplaceArgs( $message, $args );
1584         return $message;
1585 }
1586
1587 /**
1588  * Fetch a message string value, but don't replace any keys yet.
1589  *
1590  * @deprecated since 1.18
1591  *
1592  * @param string $key
1593  * @param bool $useDB
1594  * @param string|bool $langCode Code of the language to get the message for, or
1595  *   behaves as a content language switch if it is a boolean.
1596  * @param bool $transform Whether to parse magic words, etc.
1597  * @return string
1598  */
1599 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1600         wfDeprecated( __METHOD__, '1.21' );
1601
1602         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1603
1604         $cache = MessageCache::singleton();
1605         $message = $cache->get( $key, $useDB, $langCode );
1606         if ( $message === false ) {
1607                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1608         } elseif ( $transform ) {
1609                 $message = $cache->transform( $message );
1610         }
1611         return $message;
1612 }
1613
1614 /**
1615  * Replace message parameter keys on the given formatted output.
1616  *
1617  * @param string $message
1618  * @param array $args
1619  * @return string
1620  * @private
1621  */
1622 function wfMsgReplaceArgs( $message, $args ) {
1623         # Fix windows line-endings
1624         # Some messages are split with explode("\n", $msg)
1625         $message = str_replace( "\r", '', $message );
1626
1627         // Replace arguments
1628         if ( count( $args ) ) {
1629                 if ( is_array( $args[0] ) ) {
1630                         $args = array_values( $args[0] );
1631                 }
1632                 $replacementKeys = array();
1633                 foreach ( $args as $n => $param ) {
1634                         $replacementKeys['$' . ( $n + 1 )] = $param;
1635                 }
1636                 $message = strtr( $message, $replacementKeys );
1637         }
1638
1639         return $message;
1640 }
1641
1642 /**
1643  * Return an HTML-escaped version of a message.
1644  * Parameter replacements, if any, are done *after* the HTML-escaping,
1645  * so parameters may contain HTML (eg links or form controls). Be sure
1646  * to pre-escape them if you really do want plaintext, or just wrap
1647  * the whole thing in htmlspecialchars().
1648  *
1649  * @deprecated since 1.18
1650  *
1651  * @param string $key
1652  * @param string $args,... Parameters
1653  * @return string
1654  */
1655 function wfMsgHtml( $key ) {
1656         wfDeprecated( __METHOD__, '1.21' );
1657
1658         $args = func_get_args();
1659         array_shift( $args );
1660         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1661 }
1662
1663 /**
1664  * Return an HTML version of message
1665  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1666  * so parameters may contain HTML (eg links or form controls). Be sure
1667  * to pre-escape them if you really do want plaintext, or just wrap
1668  * the whole thing in htmlspecialchars().
1669  *
1670  * @deprecated since 1.18
1671  *
1672  * @param string $key
1673  * @param string $args,... Parameters
1674  * @return string
1675  */
1676 function wfMsgWikiHtml( $key ) {
1677         wfDeprecated( __METHOD__, '1.21' );
1678
1679         $args = func_get_args();
1680         array_shift( $args );
1681         return wfMsgReplaceArgs(
1682                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1683                 /* can't be set to false */ true, /* interface */ true )->getText(),
1684                 $args );
1685 }
1686
1687 /**
1688  * Returns message in the requested format
1689  *
1690  * @deprecated since 1.18
1691  *
1692  * @param string $key Key of the message
1693  * @param array $options Processing rules.
1694  *   Can take the following options:
1695  *     parse: parses wikitext to HTML
1696  *     parseinline: parses wikitext to HTML and removes the surrounding
1697  *       p's added by parser or tidy
1698  *     escape: filters message through htmlspecialchars
1699  *     escapenoentities: same, but allows entity references like &#160; through
1700  *     replaceafter: parameters are substituted after parsing or escaping
1701  *     parsemag: transform the message using magic phrases
1702  *     content: fetch message for content language instead of interface
1703  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1704  *     language: Language object or language code to fetch message for
1705  *       (overridden by content).
1706  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1707  *
1708  * @return string
1709  */
1710 function wfMsgExt( $key, $options ) {
1711         wfDeprecated( __METHOD__, '1.21' );
1712
1713         $args = func_get_args();
1714         array_shift( $args );
1715         array_shift( $args );
1716         $options = (array)$options;
1717         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1718                 'parsemag', 'content' );
1719
1720         foreach ( $options as $arrayKey => $option ) {
1721                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1722                         // An unknown index, neither numeric nor "language"
1723                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1724                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1725                         // A numeric index with unknown value
1726                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1727                 }
1728         }
1729
1730         if ( in_array( 'content', $options, true ) ) {
1731                 $forContent = true;
1732                 $langCode = true;
1733                 $langCodeObj = null;
1734         } elseif ( array_key_exists( 'language', $options ) ) {
1735                 $forContent = false;
1736                 $langCode = wfGetLangObj( $options['language'] );
1737                 $langCodeObj = $langCode;
1738         } else {
1739                 $forContent = false;
1740                 $langCode = false;
1741                 $langCodeObj = null;
1742         }
1743
1744         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1745
1746         if ( !in_array( 'replaceafter', $options, true ) ) {
1747                 $string = wfMsgReplaceArgs( $string, $args );
1748         }
1749
1750         $messageCache = MessageCache::singleton();
1751         $parseInline = in_array( 'parseinline', $options, true );
1752         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1753                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1754                 if ( $string instanceof ParserOutput ) {
1755                         $string = $string->getText();
1756                 }
1757
1758                 if ( $parseInline ) {
1759                         $string = Parser::stripOuterParagraph( $string );
1760                 }
1761         } elseif ( in_array( 'parsemag', $options, true ) ) {
1762                 $string = $messageCache->transform( $string,
1763                                 !$forContent, $langCodeObj );
1764         }
1765
1766         if ( in_array( 'escape', $options, true ) ) {
1767                 $string = htmlspecialchars( $string );
1768         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1769                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1770         }
1771
1772         if ( in_array( 'replaceafter', $options, true ) ) {
1773                 $string = wfMsgReplaceArgs( $string, $args );
1774         }
1775
1776         return $string;
1777 }
1778
1779 /**
1780  * Since wfMsg() and co suck, they don't return false if the message key they
1781  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1782  * nonexistence of messages by checking the MessageCache::get() result directly.
1783  *
1784  * @deprecated since 1.18. Use Message::isDisabled().
1785  *
1786  * @param string $key The message key looked up
1787  * @return bool True if the message *doesn't* exist.
1788  */
1789 function wfEmptyMsg( $key ) {
1790         wfDeprecated( __METHOD__, '1.21' );
1791
1792         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1793 }
1794
1795 /**
1796  * Fetch server name for use in error reporting etc.
1797  * Use real server name if available, so we know which machine
1798  * in a server farm generated the current page.
1799  *
1800  * @return string
1801  */
1802 function wfHostname() {
1803         static $host;
1804         if ( is_null( $host ) ) {
1805
1806                 # Hostname overriding
1807                 global $wgOverrideHostname;
1808                 if ( $wgOverrideHostname !== false ) {
1809                         # Set static and skip any detection
1810                         $host = $wgOverrideHostname;
1811                         return $host;
1812                 }
1813
1814                 if ( function_exists( 'posix_uname' ) ) {
1815                         // This function not present on Windows
1816                         $uname = posix_uname();
1817                 } else {
1818                         $uname = false;
1819                 }
1820                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1821                         $host = $uname['nodename'];
1822                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1823                         # Windows computer name
1824                         $host = getenv( 'COMPUTERNAME' );
1825                 } else {
1826                         # This may be a virtual server.
1827                         $host = $_SERVER['SERVER_NAME'];
1828                 }
1829         }
1830         return $host;
1831 }
1832
1833 /**
1834  * Returns a script tag that stores the amount of time it took MediaWiki to
1835  * handle the request in milliseconds as 'wgBackendResponseTime'.
1836  *
1837  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1838  * hostname of the server handling the request.
1839  *
1840  * @return string
1841  */
1842 function wfReportTime() {
1843         global $wgRequestTime, $wgShowHostnames;
1844
1845         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1846         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1847         if ( $wgShowHostnames ) {
1848                 $reportVars['wgHostname'] = wfHostname();
1849         }
1850         return Skin::makeVariablesScript( $reportVars );
1851 }
1852
1853 /**
1854  * Safety wrapper for debug_backtrace().
1855  *
1856  * Will return an empty array if debug_backtrace is disabled, otherwise
1857  * the output from debug_backtrace() (trimmed).
1858  *
1859  * @param int $limit This parameter can be used to limit the number of stack frames returned
1860  *
1861  * @return array Array of backtrace information
1862  */
1863 function wfDebugBacktrace( $limit = 0 ) {
1864         static $disabled = null;
1865
1866         if ( is_null( $disabled ) ) {
1867                 $disabled = !function_exists( 'debug_backtrace' );
1868                 if ( $disabled ) {
1869                         wfDebug( "debug_backtrace() is disabled\n" );
1870                 }
1871         }
1872         if ( $disabled ) {
1873                 return array();
1874         }
1875
1876         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1877                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1878         } else {
1879                 return array_slice( debug_backtrace(), 1 );
1880         }
1881 }
1882
1883 /**
1884  * Get a debug backtrace as a string
1885  *
1886  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1887  *   Defaults to $wgCommandLineMode if unset.
1888  * @return string
1889  * @since 1.25 Supports $raw parameter.
1890  */
1891 function wfBacktrace( $raw = null ) {
1892         global $wgCommandLineMode;
1893
1894         if ( $raw === null ) {
1895                 $raw = $wgCommandLineMode;
1896         }
1897
1898         if ( $raw ) {
1899                 $frameFormat = "%s line %s calls %s()\n";
1900                 $traceFormat = "%s";
1901         } else {
1902                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1903                 $traceFormat = "<ul>\n%s</ul>\n";
1904         }
1905
1906         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1907                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1908                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1909                 $call = $frame['function'];
1910                 if ( !empty( $frame['class'] ) ) {
1911                         $call = $frame['class'] . $frame['type'] . $call;
1912                 }
1913                 return sprintf( $frameFormat, $file, $line, $call );
1914         }, wfDebugBacktrace() );
1915
1916         return sprintf( $traceFormat, implode( '', $frames ) );
1917 }
1918
1919 /**
1920  * Get the name of the function which called this function
1921  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1922  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1923  * wfGetCaller( 3 ) is the parent of that.
1924  *
1925  * @param int $level
1926  * @return string
1927  */
1928 function wfGetCaller( $level = 2 ) {
1929         $backtrace = wfDebugBacktrace( $level + 1 );
1930         if ( isset( $backtrace[$level] ) ) {
1931                 return wfFormatStackFrame( $backtrace[$level] );
1932         } else {
1933                 return 'unknown';
1934         }
1935 }
1936
1937 /**
1938  * Return a string consisting of callers in the stack. Useful sometimes
1939  * for profiling specific points.
1940  *
1941  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1942  * @return string
1943  */
1944 function wfGetAllCallers( $limit = 3 ) {
1945         $trace = array_reverse( wfDebugBacktrace() );
1946         if ( !$limit || $limit > count( $trace ) - 1 ) {
1947                 $limit = count( $trace ) - 1;
1948         }
1949         $trace = array_slice( $trace, -$limit - 1, $limit );
1950         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1951 }
1952
1953 /**
1954  * Return a string representation of frame
1955  *
1956  * @param array $frame
1957  * @return string
1958  */
1959 function wfFormatStackFrame( $frame ) {
1960         return isset( $frame['class'] ) ?
1961                 $frame['class'] . '::' . $frame['function'] :
1962                 $frame['function'];
1963 }
1964
1965 /* Some generic result counters, pulled out of SearchEngine */
1966
1967 /**
1968  * @todo document
1969  *
1970  * @param int $offset
1971  * @param int $limit
1972  * @return string
1973  */
1974 function wfShowingResults( $offset, $limit ) {
1975         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1976 }
1977
1978 /**
1979  * @todo document
1980  * @todo FIXME: We may want to blacklist some broken browsers
1981  *
1982  * @param bool $force
1983  * @return bool Whereas client accept gzip compression
1984  */
1985 function wfClientAcceptsGzip( $force = false ) {
1986         static $result = null;
1987         if ( $result === null || $force ) {
1988                 $result = false;
1989                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1990                         # @todo FIXME: We may want to blacklist some broken browsers
1991                         $m = array();
1992                         if ( preg_match(
1993                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1994                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1995                                         $m
1996                                 )
1997                         ) {
1998                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1999                                         $result = false;
2000                                         return $result;
2001                                 }
2002                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2003                                 $result = true;
2004                         }
2005                 }
2006         }
2007         return $result;
2008 }
2009
2010 /**
2011  * Obtain the offset and limit values from the request string;
2012  * used in special pages
2013  *
2014  * @param int $deflimit Default limit if none supplied
2015  * @param string $optionname Name of a user preference to check against
2016  * @return array
2017  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2018  */
2019 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2020         global $wgRequest;
2021         wfDeprecated( __METHOD__, '1.24' );
2022         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2023 }
2024
2025 /**
2026  * Escapes the given text so that it may be output using addWikiText()
2027  * without any linking, formatting, etc. making its way through. This
2028  * is achieved by substituting certain characters with HTML entities.
2029  * As required by the callers, "<nowiki>" is not used.
2030  *
2031  * @param string $text Text to be escaped
2032  * @return string
2033  */
2034 function wfEscapeWikiText( $text ) {
2035         static $repl = null, $repl2 = null;
2036         if ( $repl === null ) {
2037                 $repl = array(
2038                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2039                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2040                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2041                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2042                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2043                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2044                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2045                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2046                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2047                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2048                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2049                         '__' => '_&#95;', '://' => '&#58;//',
2050                 );
2051
2052                 // We have to catch everything "\s" matches in PCRE
2053                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2054                         $repl["$magic "] = "$magic&#32;";
2055                         $repl["$magic\t"] = "$magic&#9;";
2056                         $repl["$magic\r"] = "$magic&#13;";
2057                         $repl["$magic\n"] = "$magic&#10;";
2058                         $repl["$magic\f"] = "$magic&#12;";
2059                 }
2060
2061                 // And handle protocols that don't use "://"
2062                 global $wgUrlProtocols;
2063                 $repl2 = array();
2064                 foreach ( $wgUrlProtocols as $prot ) {
2065                         if ( substr( $prot, -1 ) === ':' ) {
2066                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2067                         }
2068                 }
2069                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2070         }
2071         $text = substr( strtr( "\n$text", $repl ), 1 );
2072         $text = preg_replace( $repl2, '$1&#58;', $text );
2073         return $text;
2074 }
2075
2076 /**
2077  * Sets dest to source and returns the original value of dest
2078  * If source is NULL, it just returns the value, it doesn't set the variable
2079  * If force is true, it will set the value even if source is NULL
2080  *
2081  * @param mixed $dest
2082  * @param mixed $source
2083  * @param bool $force
2084  * @return mixed
2085  */
2086 function wfSetVar( &$dest, $source, $force = false ) {
2087         $temp = $dest;
2088         if ( !is_null( $source ) || $force ) {
2089                 $dest = $source;
2090         }
2091         return $temp;
2092 }
2093
2094 /**
2095  * As for wfSetVar except setting a bit
2096  *
2097  * @param int $dest
2098  * @param int $bit
2099  * @param bool $state
2100  *
2101  * @return bool
2102  */
2103 function wfSetBit( &$dest, $bit, $state = true ) {
2104         $temp = (bool)( $dest & $bit );
2105         if ( !is_null( $state ) ) {
2106                 if ( $state ) {
2107                         $dest |= $bit;
2108                 } else {
2109                         $dest &= ~$bit;
2110                 }
2111         }
2112         return $temp;
2113 }
2114
2115 /**
2116  * A wrapper around the PHP function var_export().
2117  * Either print it or add it to the regular output ($wgOut).
2118  *
2119  * @param mixed $var A PHP variable to dump.
2120  */
2121 function wfVarDump( $var ) {
2122         global $wgOut;
2123         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2124         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2125                 print $s;
2126         } else {
2127                 $wgOut->addHTML( $s );
2128         }
2129 }
2130
2131 /**
2132  * Provide a simple HTTP error.
2133  *
2134  * @param int|string $code
2135  * @param string $label
2136  * @param string $desc
2137  */
2138 function wfHttpError( $code, $label, $desc ) {
2139         global $wgOut;
2140         HttpStatus::header( $code );
2141         if ( $wgOut ) {
2142                 $wgOut->disable();
2143                 $wgOut->sendCacheControl();
2144         }
2145
2146         header( 'Content-type: text/html; charset=utf-8' );
2147         print '<!DOCTYPE html>' .
2148                 '<html><head><title>' .
2149                 htmlspecialchars( $label ) .
2150                 '</title></head><body><h1>' .
2151                 htmlspecialchars( $label ) .
2152                 '</h1><p>' .
2153                 nl2br( htmlspecialchars( $desc ) ) .
2154                 "</p></body></html>\n";
2155 }
2156
2157 /**
2158  * Clear away any user-level output buffers, discarding contents.
2159  *
2160  * Suitable for 'starting afresh', for instance when streaming
2161  * relatively large amounts of data without buffering, or wanting to
2162  * output image files without ob_gzhandler's compression.
2163  *
2164  * The optional $resetGzipEncoding parameter controls suppression of
2165  * the Content-Encoding header sent by ob_gzhandler; by default it
2166  * is left. See comments for wfClearOutputBuffers() for why it would
2167  * be used.
2168  *
2169  * Note that some PHP configuration options may add output buffer
2170  * layers which cannot be removed; these are left in place.
2171  *
2172  * @param bool $resetGzipEncoding
2173  */
2174 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2175         if ( $resetGzipEncoding ) {
2176                 // Suppress Content-Encoding and Content-Length
2177                 // headers from 1.10+s wfOutputHandler
2178                 global $wgDisableOutputCompression;
2179                 $wgDisableOutputCompression = true;
2180         }
2181         while ( $status = ob_get_status() ) {
2182                 if ( isset( $status['flags'] ) ) {
2183                         $flags = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_REMOVABLE;
2184                         $deleteable = ( $status['flags'] & $flags ) === $flags;
2185                 } elseif ( isset( $status['del'] ) ) {
2186                         $deleteable = $status['del'];
2187                 } else {
2188                         // Guess that any PHP-internal setting can't be removed.
2189                         $deleteable = $status['type'] !== 0; /* PHP_OUTPUT_HANDLER_INTERNAL */
2190                 }
2191                 if ( !$deleteable ) {
2192                         // Give up, and hope the result doesn't break
2193                         // output behavior.
2194                         break;
2195                 }
2196                 if ( !ob_end_clean() ) {
2197                         // Could not remove output buffer handler; abort now
2198                         // to avoid getting in some kind of infinite loop.
2199                         break;
2200                 }
2201                 if ( $resetGzipEncoding ) {
2202                         if ( $status['name'] == 'ob_gzhandler' ) {
2203                                 // Reset the 'Content-Encoding' field set by this handler
2204                                 // so we can start fresh.
2205                                 header_remove( 'Content-Encoding' );
2206                                 break;
2207                         }
2208                 }
2209         }
2210 }
2211
2212 /**
2213  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2214  *
2215  * Clear away output buffers, but keep the Content-Encoding header
2216  * produced by ob_gzhandler, if any.
2217  *
2218  * This should be used for HTTP 304 responses, where you need to
2219  * preserve the Content-Encoding header of the real result, but
2220  * also need to suppress the output of ob_gzhandler to keep to spec
2221  * and avoid breaking Firefox in rare cases where the headers and
2222  * body are broken over two packets.
2223  */
2224 function wfClearOutputBuffers() {
2225         wfResetOutputBuffers( false );
2226 }
2227
2228 /**
2229  * Converts an Accept-* header into an array mapping string values to quality
2230  * factors
2231  *
2232  * @param string $accept
2233  * @param string $def Default
2234  * @return float[] Associative array of string => float pairs
2235  */
2236 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2237         # No arg means accept anything (per HTTP spec)
2238         if ( !$accept ) {
2239                 return array( $def => 1.0 );
2240         }
2241
2242         $prefs = array();
2243
2244         $parts = explode( ',', $accept );
2245
2246         foreach ( $parts as $part ) {
2247                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2248                 $values = explode( ';', trim( $part ) );
2249                 $match = array();
2250                 if ( count( $values ) == 1 ) {
2251                         $prefs[$values[0]] = 1.0;
2252                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2253                         $prefs[$values[0]] = floatval( $match[1] );
2254                 }
2255         }
2256
2257         return $prefs;
2258 }
2259
2260 /**
2261  * Checks if a given MIME type matches any of the keys in the given
2262  * array. Basic wildcards are accepted in the array keys.
2263  *
2264  * Returns the matching MIME type (or wildcard) if a match, otherwise
2265  * NULL if no match.
2266  *
2267  * @param string $type
2268  * @param array $avail
2269  * @return string
2270  * @private
2271  */
2272 function mimeTypeMatch( $type, $avail ) {
2273         if ( array_key_exists( $type, $avail ) ) {
2274                 return $type;
2275         } else {
2276                 $parts = explode( '/', $type );
2277                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2278                         return $parts[0] . '/*';
2279                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2280                         return '*/*';
2281                 } else {
2282                         return null;
2283                 }
2284         }
2285 }
2286
2287 /**
2288  * Returns the 'best' match between a client's requested internet media types
2289  * and the server's list of available types. Each list should be an associative
2290  * array of type to preference (preference is a float between 0.0 and 1.0).
2291  * Wildcards in the types are acceptable.
2292  *
2293  * @param array $cprefs Client's acceptable type list
2294  * @param array $sprefs Server's offered types
2295  * @return string
2296  *
2297  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2298  * XXX: generalize to negotiate other stuff
2299  */
2300 function wfNegotiateType( $cprefs, $sprefs ) {
2301         $combine = array();
2302
2303         foreach ( array_keys( $sprefs ) as $type ) {
2304                 $parts = explode( '/', $type );
2305                 if ( $parts[1] != '*' ) {
2306                         $ckey = mimeTypeMatch( $type, $cprefs );
2307                         if ( $ckey ) {
2308                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2309                         }
2310                 }
2311         }
2312
2313         foreach ( array_keys( $cprefs ) as $type ) {
2314                 $parts = explode( '/', $type );
2315                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2316                         $skey = mimeTypeMatch( $type, $sprefs );
2317                         if ( $skey ) {
2318                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2319                         }
2320                 }
2321         }
2322
2323         $bestq = 0;
2324         $besttype = null;
2325
2326         foreach ( array_keys( $combine ) as $type ) {
2327                 if ( $combine[$type] > $bestq ) {
2328                         $besttype = $type;
2329                         $bestq = $combine[$type];
2330                 }
2331         }
2332
2333         return $besttype;
2334 }
2335
2336 /**
2337  * Reference-counted warning suppression
2338  *
2339  * @deprecated since 1.26, use MediaWiki\suppressWarnings() directly
2340  * @param bool $end
2341  */
2342 function wfSuppressWarnings( $end = false ) {
2343         MediaWiki\suppressWarnings( $end );
2344 }
2345
2346 /**
2347  * @deprecated since 1.26, use MediaWiki\restoreWarnings() directly
2348  * Restore error level to previous value
2349  */
2350 function wfRestoreWarnings() {
2351         MediaWiki\suppressWarnings( true );
2352 }
2353
2354 # Autodetect, convert and provide timestamps of various types
2355
2356 /**
2357  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2358  */
2359 define( 'TS_UNIX', 0 );
2360
2361 /**
2362  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2363  */
2364 define( 'TS_MW', 1 );
2365
2366 /**
2367  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2368  */
2369 define( 'TS_DB', 2 );
2370
2371 /**
2372  * RFC 2822 format, for E-mail and HTTP headers
2373  */
2374 define( 'TS_RFC2822', 3 );
2375
2376 /**
2377  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2378  *
2379  * This is used by Special:Export
2380  */
2381 define( 'TS_ISO_8601', 4 );
2382
2383 /**
2384  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2385  *
2386  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2387  *       DateTime tag and page 36 for the DateTimeOriginal and
2388  *       DateTimeDigitized tags.
2389  */
2390 define( 'TS_EXIF', 5 );
2391
2392 /**
2393  * Oracle format time.
2394  */
2395 define( 'TS_ORACLE', 6 );
2396
2397 /**
2398  * Postgres format time.
2399  */
2400 define( 'TS_POSTGRES', 7 );
2401
2402 /**
2403  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2404  */
2405 define( 'TS_ISO_8601_BASIC', 9 );
2406
2407 /**
2408  * Get a timestamp string in one of various formats
2409  *
2410  * @param mixed $outputtype A timestamp in one of the supported formats, the
2411  *   function will autodetect which format is supplied and act accordingly.
2412  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2413  * @return string|bool String / false The same date in the format specified in $outputtype or false
2414  */
2415 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2416         try {
2417                 $timestamp = new MWTimestamp( $ts );
2418                 return $timestamp->getTimestamp( $outputtype );
2419         } catch ( TimestampException $e ) {
2420                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2421                 return false;
2422         }
2423 }
2424
2425 /**
2426  * Return a formatted timestamp, or null if input is null.
2427  * For dealing with nullable timestamp columns in the database.
2428  *
2429  * @param int $outputtype
2430  * @param string $ts
2431  * @return string
2432  */
2433 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2434         if ( is_null( $ts ) ) {
2435                 return null;
2436         } else {
2437                 return wfTimestamp( $outputtype, $ts );
2438         }
2439 }
2440
2441 /**
2442  * Convenience function; returns MediaWiki timestamp for the present time.
2443  *
2444  * @return string
2445  */
2446 function wfTimestampNow() {
2447         # return NOW
2448         return wfTimestamp( TS_MW, time() );
2449 }
2450
2451 /**
2452  * Check if the operating system is Windows
2453  *
2454  * @return bool True if it's Windows, false otherwise.
2455  */
2456 function wfIsWindows() {
2457         static $isWindows = null;
2458         if ( $isWindows === null ) {
2459                 $isWindows = strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN';
2460         }
2461         return $isWindows;
2462 }
2463
2464 /**
2465  * Check if we are running under HHVM
2466  *
2467  * @return bool
2468  */
2469 function wfIsHHVM() {
2470         return defined( 'HHVM_VERSION' );
2471 }
2472
2473 /**
2474  * Tries to get the system directory for temporary files. First
2475  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2476  * environment variables are then checked in sequence, and if none are
2477  * set try sys_get_temp_dir().
2478  *
2479  * NOTE: When possible, use instead the tmpfile() function to create
2480  * temporary files to avoid race conditions on file creation, etc.
2481  *
2482  * @return string
2483  */
2484 function wfTempDir() {
2485         global $wgTmpDirectory;
2486
2487         if ( $wgTmpDirectory !== false ) {
2488                 return $wgTmpDirectory;
2489         }
2490
2491         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2492
2493         foreach ( $tmpDir as $tmp ) {
2494                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2495                         return $tmp;
2496                 }
2497         }
2498         return sys_get_temp_dir();
2499 }
2500
2501 /**
2502  * Make directory, and make all parent directories if they don't exist
2503  *
2504  * @param string $dir Full path to directory to create
2505  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2506  * @param string $caller Optional caller param for debugging.
2507  * @throws MWException
2508  * @return bool
2509  */
2510 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2511         global $wgDirectoryMode;
2512
2513         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2514                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2515         }
2516
2517         if ( !is_null( $caller ) ) {
2518                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2519         }
2520
2521         if ( strval( $dir ) === '' || is_dir( $dir ) ) {
2522                 return true;
2523         }
2524
2525         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2526
2527         if ( is_null( $mode ) ) {
2528                 $mode = $wgDirectoryMode;
2529         }
2530
2531         // Turn off the normal warning, we're doing our own below
2532         MediaWiki\suppressWarnings();
2533         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2534         MediaWiki\restoreWarnings();
2535
2536         if ( !$ok ) {
2537                 //directory may have been created on another request since we last checked
2538                 if ( is_dir( $dir ) ) {
2539                         return true;
2540                 }
2541
2542                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2543                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2544         }
2545         return $ok;
2546 }
2547
2548 /**
2549  * Remove a directory and all its content.
2550  * Does not hide error.
2551  * @param string $dir
2552  */
2553 function wfRecursiveRemoveDir( $dir ) {
2554         wfDebug( __FUNCTION__ . "( $dir )\n" );
2555         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2556         if ( is_dir( $dir ) ) {
2557                 $objects = scandir( $dir );
2558                 foreach ( $objects as $object ) {
2559                         if ( $object != "." && $object != ".." ) {
2560                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2561                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2562                                 } else {
2563                                         unlink( $dir . '/' . $object );
2564                                 }
2565                         }
2566                 }
2567                 reset( $objects );
2568                 rmdir( $dir );
2569         }
2570 }
2571
2572 /**
2573  * @param int $nr The number to format
2574  * @param int $acc The number of digits after the decimal point, default 2
2575  * @param bool $round Whether or not to round the value, default true
2576  * @return string
2577  */
2578 function wfPercent( $nr, $acc = 2, $round = true ) {
2579         $ret = sprintf( "%.${acc}f", $nr );
2580         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2581 }
2582
2583 /**
2584  * Safety wrapper around ini_get() for boolean settings.
2585  * The values returned from ini_get() are pre-normalized for settings
2586  * set via php.ini or php_flag/php_admin_flag... but *not*
2587  * for those set via php_value/php_admin_value.
2588  *
2589  * It's fairly common for people to use php_value instead of php_flag,
2590  * which can leave you with an 'off' setting giving a false positive
2591  * for code that just takes the ini_get() return value as a boolean.
2592  *
2593  * To make things extra interesting, setting via php_value accepts
2594  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2595  * Unrecognized values go false... again opposite PHP's own coercion
2596  * from string to bool.
2597  *
2598  * Luckily, 'properly' set settings will always come back as '0' or '1',
2599  * so we only have to worry about them and the 'improper' settings.
2600  *
2601  * I frickin' hate PHP... :P
2602  *
2603  * @param string $setting
2604  * @return bool
2605  */
2606 function wfIniGetBool( $setting ) {
2607         $val = strtolower( ini_get( $setting ) );
2608         // 'on' and 'true' can't have whitespace around them, but '1' can.
2609         return $val == 'on'
2610                 || $val == 'true'
2611                 || $val == 'yes'
2612                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2613 }
2614
2615 /**
2616  * Windows-compatible version of escapeshellarg()
2617  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2618  * function puts single quotes in regardless of OS.
2619  *
2620  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2621  * earlier distro releases of PHP)
2622  *
2623  * @param string ... strings to escape and glue together, or a single array of strings parameter
2624  * @return string
2625  */
2626 function wfEscapeShellArg( /*...*/ ) {
2627         wfInitShellLocale();
2628
2629         $args = func_get_args();
2630         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2631                 // If only one argument has been passed, and that argument is an array,
2632                 // treat it as a list of arguments
2633                 $args = reset( $args );
2634         }
2635
2636         $first = true;
2637         $retVal = '';
2638         foreach ( $args as $arg ) {
2639                 if ( !$first ) {
2640                         $retVal .= ' ';
2641                 } else {
2642                         $first = false;
2643                 }
2644
2645                 if ( wfIsWindows() ) {
2646                         // Escaping for an MSVC-style command line parser and CMD.EXE
2647                         // @codingStandardsIgnoreStart For long URLs
2648                         // Refs:
2649                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2650                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2651                         //  * Bug #13518
2652                         //  * CR r63214
2653                         // Double the backslashes before any double quotes. Escape the double quotes.
2654                         // @codingStandardsIgnoreEnd
2655                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2656                         $arg = '';
2657                         $iteration = 0;
2658                         foreach ( $tokens as $token ) {
2659                                 if ( $iteration % 2 == 1 ) {
2660                                         // Delimiter, a double quote preceded by zero or more slashes
2661                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2662                                 } elseif ( $iteration % 4 == 2 ) {
2663                                         // ^ in $token will be outside quotes, need to be escaped
2664                                         $arg .= str_replace( '^', '^^', $token );
2665                                 } else { // $iteration % 4 == 0
2666                                         // ^ in $token will appear inside double quotes, so leave as is
2667                                         $arg .= $token;
2668                                 }
2669                                 $iteration++;
2670                         }
2671                         // Double the backslashes before the end of the string, because
2672                         // we will soon add a quote
2673                         $m = array();
2674                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2675                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2676                         }
2677
2678                         // Add surrounding quotes
2679                         $retVal .= '"' . $arg . '"';
2680                 } else {
2681                         $retVal .= escapeshellarg( $arg );
2682                 }
2683         }
2684         return $retVal;
2685 }
2686
2687 /**
2688  * Check if wfShellExec() is effectively disabled via php.ini config
2689  *
2690  * @return bool|string False or one of (safemode,disabled)
2691  * @since 1.22
2692  */
2693 function wfShellExecDisabled() {
2694         static $disabled = null;
2695         if ( is_null( $disabled ) ) {
2696                 if ( wfIniGetBool( 'safe_mode' ) ) {
2697                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2698                         $disabled = 'safemode';
2699                 } elseif ( !function_exists( 'proc_open' ) ) {
2700                         wfDebug( "proc_open() is disabled\n" );
2701                         $disabled = 'disabled';
2702                 } else {
2703                         $disabled = false;
2704                 }
2705         }
2706         return $disabled;
2707 }
2708
2709 /**
2710  * Execute a shell command, with time and memory limits mirrored from the PHP
2711  * configuration if supported.
2712  *
2713  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2714  *   or an array of unescaped arguments, in which case each value will be escaped
2715  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2716  * @param null|mixed &$retval Optional, will receive the program's exit code.
2717  *   (non-zero is usually failure). If there is an error from
2718  *   read, select, or proc_open(), this will be set to -1.
2719  * @param array $environ Optional environment variables which should be
2720  *   added to the executed command environment.
2721  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2722  *   this overwrites the global wgMaxShell* limits.
2723  * @param array $options Array of options:
2724  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2725  *     including errors from limit.sh
2726  *   - profileMethod: By default this function will profile based on the calling
2727  *     method. Set this to a string for an alternative method to profile from
2728  *
2729  * @return string Collected stdout as a string
2730  */
2731 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2732         $limits = array(), $options = array()
2733 ) {
2734         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2735                 $wgMaxShellWallClockTime, $wgShellCgroup;
2736
2737         $disabled = wfShellExecDisabled();
2738         if ( $disabled ) {
2739                 $retval = 1;
2740                 return $disabled == 'safemode' ?
2741                         'Unable to run external programs in safe mode.' :
2742                         'Unable to run external programs, proc_open() is disabled.';
2743         }
2744
2745         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2746         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2747
2748         wfInitShellLocale();
2749
2750         $envcmd = '';
2751         foreach ( $environ as $k => $v ) {
2752                 if ( wfIsWindows() ) {
2753                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2754                          * appear in the environment variable, so we must use carat escaping as documented in
2755                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2756                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2757                          * are listed there but doesn't appear to need it.
2758                          */
2759                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2760                 } else {
2761                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2762                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2763                          */
2764                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2765                 }
2766         }
2767         if ( is_array( $cmd ) ) {
2768                 $cmd = wfEscapeShellArg( $cmd );
2769         }
2770
2771         $cmd = $envcmd . $cmd;
2772
2773         $useLogPipe = false;
2774         if ( is_executable( '/bin/bash' ) ) {
2775                 $time = intval( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2776                 if ( isset( $limits['walltime'] ) ) {
2777                         $wallTime = intval( $limits['walltime'] );
2778                 } elseif ( isset( $limits['time'] ) ) {
2779                         $wallTime = $time;
2780                 } else {
2781                         $wallTime = intval( $wgMaxShellWallClockTime );
2782                 }
2783                 $mem = intval( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2784                 $filesize = intval( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2785
2786                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2787                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2788                                 escapeshellarg( $cmd ) . ' ' .
2789                                 escapeshellarg(
2790                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2791                                         "MW_CPU_LIMIT=$time; " .
2792                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2793                                         "MW_MEM_LIMIT=$mem; " .
2794                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2795                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2796                                         "MW_USE_LOG_PIPE=yes"
2797                                 );
2798                         $useLogPipe = true;
2799                 } elseif ( $includeStderr ) {
2800                         $cmd .= ' 2>&1';
2801                 }
2802         } elseif ( $includeStderr ) {
2803                 $cmd .= ' 2>&1';
2804         }
2805         wfDebug( "wfShellExec: $cmd\n" );
2806
2807         $desc = array(
2808                 0 => array( 'file', 'php://stdin', 'r' ),
2809                 1 => array( 'pipe', 'w' ),
2810                 2 => array( 'file', 'php://stderr', 'w' ) );
2811         if ( $useLogPipe ) {
2812                 $desc[3] = array( 'pipe', 'w' );
2813         }
2814         $pipes = null;
2815         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2816         $proc = proc_open( $cmd, $desc, $pipes );
2817         if ( !$proc ) {
2818                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2819                 $retval = -1;
2820                 return '';
2821         }
2822         $outBuffer = $logBuffer = '';
2823         $emptyArray = array();
2824         $status = false;
2825         $logMsg = false;
2826
2827         // According to the documentation, it is possible for stream_select()
2828         // to fail due to EINTR. I haven't managed to induce this in testing
2829         // despite sending various signals. If it did happen, the error
2830         // message would take the form:
2831         //
2832         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2833         //
2834         // where [4] is the value of the macro EINTR and "Interrupted system
2835         // call" is string which according to the Linux manual is "possibly"
2836         // localised according to LC_MESSAGES.
2837         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2838         $eintrMessage = "stream_select(): unable to select [$eintr]";
2839
2840         // Build a table mapping resource IDs to pipe FDs to work around a
2841         // PHP 5.3 issue in which stream_select() does not preserve array keys
2842         // <https://bugs.php.net/bug.php?id=53427>.
2843         $fds = array();
2844         foreach ( $pipes as $fd => $pipe ) {
2845                 $fds[(int)$pipe] = $fd;
2846         }
2847
2848         $running = true;
2849         $timeout = null;
2850         $numReadyPipes = 0;
2851
2852         while ( $running === true || $numReadyPipes !== 0 ) {
2853                 if ( $running ) {
2854                         $status = proc_get_status( $proc );
2855                         // If the process has terminated, switch to nonblocking selects
2856                         // for getting any data still waiting to be read.
2857                         if ( !$status['running'] ) {
2858                                 $running = false;
2859                                 $timeout = 0;
2860                         }
2861                 }
2862
2863                 $readyPipes = $pipes;
2864
2865                 // Clear last error
2866                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2867                 @trigger_error( '' );
2868                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2869                 if ( $numReadyPipes === false ) {
2870                         // @codingStandardsIgnoreEnd
2871                         $error = error_get_last();
2872                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2873                                 continue;
2874                         } else {
2875                                 trigger_error( $error['message'], E_USER_WARNING );
2876                                 $logMsg = $error['message'];
2877                                 break;
2878                         }
2879                 }
2880                 foreach ( $readyPipes as $pipe ) {
2881                         $block = fread( $pipe, 65536 );
2882                         $fd = $fds[(int)$pipe];
2883                         if ( $block === '' ) {
2884                                 // End of file
2885                                 fclose( $pipes[$fd] );
2886                                 unset( $pipes[$fd] );
2887                                 if ( !$pipes ) {
2888                                         break 2;
2889                                 }
2890                         } elseif ( $block === false ) {
2891                                 // Read error
2892                                 $logMsg = "Error reading from pipe";
2893                                 break 2;
2894                         } elseif ( $fd == 1 ) {
2895                                 // From stdout
2896                                 $outBuffer .= $block;
2897                         } elseif ( $fd == 3 ) {
2898                                 // From log FD
2899                                 $logBuffer .= $block;
2900                                 if ( strpos( $block, "\n" ) !== false ) {
2901                                         $lines = explode( "\n", $logBuffer );
2902                                         $logBuffer = array_pop( $lines );
2903                                         foreach ( $lines as $line ) {
2904                                                 wfDebugLog( 'exec', $line );
2905                                         }
2906                                 }
2907                         }
2908                 }
2909         }
2910
2911         foreach ( $pipes as $pipe ) {
2912                 fclose( $pipe );
2913         }
2914
2915         // Use the status previously collected if possible, since proc_get_status()
2916         // just calls waitpid() which will not return anything useful the second time.
2917         if ( $running ) {
2918                 $status = proc_get_status( $proc );
2919         }
2920
2921         if ( $logMsg !== false ) {
2922                 // Read/select error
2923                 $retval = -1;
2924                 proc_close( $proc );
2925         } elseif ( $status['signaled'] ) {
2926                 $logMsg = "Exited with signal {$status['termsig']}";
2927                 $retval = 128 + $status['termsig'];
2928                 proc_close( $proc );
2929         } else {
2930                 if ( $status['running'] ) {
2931                         $retval = proc_close( $proc );
2932                 } else {
2933                         $retval = $status['exitcode'];
2934                         proc_close( $proc );
2935                 }
2936                 if ( $retval == 127 ) {
2937                         $logMsg = "Possibly missing executable file";
2938                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2939                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2940                 }
2941         }
2942
2943         if ( $logMsg !== false ) {
2944                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2945         }
2946
2947         return $outBuffer;
2948 }
2949
2950 /**
2951  * Execute a shell command, returning both stdout and stderr. Convenience
2952  * function, as all the arguments to wfShellExec can become unwieldy.
2953  *
2954  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2955  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2956  *   or an array of unescaped arguments, in which case each value will be escaped
2957  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2958  * @param null|mixed &$retval Optional, will receive the program's exit code.
2959  *   (non-zero is usually failure)
2960  * @param array $environ Optional environment variables which should be
2961  *   added to the executed command environment.
2962  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2963  *   this overwrites the global wgMaxShell* limits.
2964  * @return string Collected stdout and stderr as a string
2965  */
2966 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2967         return wfShellExec( $cmd, $retval, $environ, $limits,
2968                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2969 }
2970
2971 /**
2972  * Workaround for http://bugs.php.net/bug.php?id=45132
2973  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2974  */
2975 function wfInitShellLocale() {
2976         static $done = false;
2977         if ( $done ) {
2978                 return;
2979         }
2980         $done = true;
2981         global $wgShellLocale;
2982         if ( !wfIniGetBool( 'safe_mode' ) ) {
2983                 putenv( "LC_CTYPE=$wgShellLocale" );
2984                 setlocale( LC_CTYPE, $wgShellLocale );
2985         }
2986 }
2987
2988 /**
2989  * Generate a shell-escaped command line string to run a MediaWiki cli script.
2990  * Note that $parameters should be a flat array and an option with an argument
2991  * should consist of two consecutive items in the array (do not use "--option value").
2992  *
2993  * @param string $script MediaWiki cli script path
2994  * @param array $parameters Arguments and options to the script
2995  * @param array $options Associative array of options:
2996  *              'php': The path to the php executable
2997  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2998  * @return string
2999  */
3000 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3001         global $wgPhpCli;
3002         // Give site config file a chance to run the script in a wrapper.
3003         // The caller may likely want to call wfBasename() on $script.
3004         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3005         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3006         if ( isset( $options['wrapper'] ) ) {
3007                 $cmd[] = $options['wrapper'];
3008         }
3009         $cmd[] = $script;
3010         // Escape each parameter for shell
3011         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
3012 }
3013
3014 /**
3015  * wfMerge attempts to merge differences between three texts.
3016  * Returns true for a clean merge and false for failure or a conflict.
3017  *
3018  * @param string $old
3019  * @param string $mine
3020  * @param string $yours
3021  * @param string $result
3022  * @return bool
3023  */
3024 function wfMerge( $old, $mine, $yours, &$result ) {
3025         global $wgDiff3;
3026
3027         # This check may also protect against code injection in
3028         # case of broken installations.
3029         MediaWiki\suppressWarnings();
3030         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3031         MediaWiki\restoreWarnings();
3032
3033         if ( !$haveDiff3 ) {
3034                 wfDebug( "diff3 not found\n" );
3035                 return false;
3036         }
3037
3038         # Make temporary files
3039         $td = wfTempDir();
3040         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3041         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3042         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3043
3044         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3045         #       a newline character. To avoid this, we normalize the trailing whitespace before
3046         #       creating the diff.
3047
3048         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3049         fclose( $oldtextFile );
3050         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3051         fclose( $mytextFile );
3052         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3053         fclose( $yourtextFile );
3054
3055         # Check for a conflict
3056         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName,
3057                 $oldtextName, $yourtextName );
3058         $handle = popen( $cmd, 'r' );
3059
3060         if ( fgets( $handle, 1024 ) ) {
3061                 $conflict = true;
3062         } else {
3063                 $conflict = false;
3064         }
3065         pclose( $handle );
3066
3067         # Merge differences
3068         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName,
3069                 $oldtextName, $yourtextName );
3070         $handle = popen( $cmd, 'r' );
3071         $result = '';
3072         do {
3073                 $data = fread( $handle, 8192 );
3074                 if ( strlen( $data ) == 0 ) {
3075                         break;
3076                 }
3077                 $result .= $data;
3078         } while ( true );
3079         pclose( $handle );
3080         unlink( $mytextName );
3081         unlink( $oldtextName );
3082         unlink( $yourtextName );
3083
3084         if ( $result === '' && $old !== '' && !$conflict ) {
3085                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3086                 $conflict = true;
3087         }
3088         return !$conflict;
3089 }
3090
3091 /**
3092  * Returns unified plain-text diff of two texts.
3093  * "Useful" for machine processing of diffs.
3094  *
3095  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3096  *
3097  * @param string $before The text before the changes.
3098  * @param string $after The text after the changes.
3099  * @param string $params Command-line options for the diff command.
3100  * @return string Unified diff of $before and $after
3101  */
3102 function wfDiff( $before, $after, $params = '-u' ) {
3103         if ( $before == $after ) {
3104                 return '';
3105         }
3106
3107         global $wgDiff;
3108         MediaWiki\suppressWarnings();
3109         $haveDiff = $wgDiff && file_exists( $wgDiff );
3110         MediaWiki\restoreWarnings();
3111
3112         # This check may also protect against code injection in
3113         # case of broken installations.
3114         if ( !$haveDiff ) {
3115                 wfDebug( "diff executable not found\n" );
3116                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3117                 $format = new UnifiedDiffFormatter();
3118                 return $format->format( $diffs );
3119         }
3120
3121         # Make temporary files
3122         $td = wfTempDir();
3123         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3124         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3125
3126         fwrite( $oldtextFile, $before );
3127         fclose( $oldtextFile );
3128         fwrite( $newtextFile, $after );
3129         fclose( $newtextFile );
3130
3131         // Get the diff of the two files
3132         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3133
3134         $h = popen( $cmd, 'r' );
3135         if ( !$h ) {
3136                 unlink( $oldtextName );
3137                 unlink( $newtextName );
3138                 throw new Exception( __METHOD__ . '(): popen() failed' );
3139         }
3140
3141         $diff = '';
3142
3143         do {
3144                 $data = fread( $h, 8192 );
3145                 if ( strlen( $data ) == 0 ) {
3146                         break;
3147                 }
3148                 $diff .= $data;
3149         } while ( true );
3150
3151         // Clean up
3152         pclose( $h );
3153         unlink( $oldtextName );
3154         unlink( $newtextName );
3155
3156         // Kill the --- and +++ lines. They're not useful.
3157         $diff_lines = explode( "\n", $diff );
3158         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3159                 unset( $diff_lines[0] );
3160         }
3161         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3162                 unset( $diff_lines[1] );
3163         }
3164
3165         $diff = implode( "\n", $diff_lines );
3166
3167         return $diff;
3168 }
3169
3170 /**
3171  * This function works like "use VERSION" in Perl, the program will die with a
3172  * backtrace if the current version of PHP is less than the version provided
3173  *
3174  * This is useful for extensions which due to their nature are not kept in sync
3175  * with releases, and might depend on other versions of PHP than the main code
3176  *
3177  * Note: PHP might die due to parsing errors in some cases before it ever
3178  *       manages to call this function, such is life
3179  *
3180  * @see perldoc -f use
3181  *
3182  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3183  * @throws MWException
3184  */
3185 function wfUsePHP( $req_ver ) {
3186         $php_ver = PHP_VERSION;
3187
3188         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3189                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3190         }
3191 }
3192
3193 /**
3194  * This function works like "use VERSION" in Perl except it checks the version
3195  * of MediaWiki, the program will die with a backtrace if the current version
3196  * of MediaWiki is less than the version provided.
3197  *
3198  * This is useful for extensions which due to their nature are not kept in sync
3199  * with releases
3200  *
3201  * Note: Due to the behavior of PHP's version_compare() which is used in this
3202  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3203  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3204  * targeted version number. For example if you wanted to allow any variation
3205  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3206  * not result in the same comparison due to the internal logic of
3207  * version_compare().
3208  *
3209  * @see perldoc -f use
3210  *
3211  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3212  * @throws MWException
3213  */
3214 function wfUseMW( $req_ver ) {
3215         global $wgVersion;
3216
3217         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3218                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3219         }
3220 }
3221
3222 /**
3223  * Return the final portion of a pathname.
3224  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3225  * http://bugs.php.net/bug.php?id=33898
3226  *
3227  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3228  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3229  *
3230  * @param string $path
3231  * @param string $suffix String to remove if present
3232  * @return string
3233  */
3234 function wfBaseName( $path, $suffix = '' ) {
3235         if ( $suffix == '' ) {
3236                 $encSuffix = '';
3237         } else {
3238                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3239         }
3240
3241         $matches = array();
3242         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3243                 return $matches[1];
3244         } else {
3245                 return '';
3246         }
3247 }
3248
3249 /**
3250  * Generate a relative path name to the given file.
3251  * May explode on non-matching case-insensitive paths,
3252  * funky symlinks, etc.
3253  *
3254  * @param string $path Absolute destination path including target filename
3255  * @param string $from Absolute source path, directory only
3256  * @return string
3257  */
3258 function wfRelativePath( $path, $from ) {
3259         // Normalize mixed input on Windows...
3260         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3261         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3262
3263         // Trim trailing slashes -- fix for drive root
3264         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3265         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3266
3267         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3268         $against = explode( DIRECTORY_SEPARATOR, $from );
3269
3270         if ( $pieces[0] !== $against[0] ) {
3271                 // Non-matching Windows drive letters?
3272                 // Return a full path.
3273                 return $path;
3274         }
3275
3276         // Trim off common prefix
3277         while ( count( $pieces ) && count( $against )
3278                 && $pieces[0] == $against[0] ) {
3279                 array_shift( $pieces );
3280                 array_shift( $against );
3281         }
3282
3283         // relative dots to bump us to the parent
3284         while ( count( $against ) ) {
3285                 array_unshift( $pieces, '..' );
3286                 array_shift( $against );
3287         }
3288
3289         array_push( $pieces, wfBaseName( $path ) );
3290
3291         return implode( DIRECTORY_SEPARATOR, $pieces );
3292 }
3293
3294 /**
3295  * Convert an arbitrarily-long digit string from one numeric base
3296  * to another, optionally zero-padding to a minimum column width.
3297  *
3298  * Supports base 2 through 36; digit values 10-36 are represented
3299  * as lowercase letters a-z. Input is case-insensitive.
3300  *
3301  * @param string $input Input number
3302  * @param int $sourceBase Base of the input number
3303  * @param int $destBase Desired base of the output
3304  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3305  * @param bool $lowercase Whether to output in lowercase or uppercase
3306  * @param string $engine Either "gmp", "bcmath", or "php"
3307  * @return string|bool The output number as a string, or false on error
3308  */
3309 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3310         $lowercase = true, $engine = 'auto'
3311 ) {
3312         $input = (string)$input;
3313         if (
3314                 $sourceBase < 2 ||
3315                 $sourceBase > 36 ||
3316                 $destBase < 2 ||
3317                 $destBase > 36 ||
3318                 $sourceBase != (int)$sourceBase ||
3319                 $destBase != (int)$destBase ||
3320                 $pad != (int)$pad ||
3321                 !preg_match(
3322                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3323                         $input
3324                 )
3325         ) {
3326                 return false;
3327         }
3328
3329         static $baseChars = array(
3330                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3331                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3332                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3333                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3334                 34 => 'y', 35 => 'z',
3335
3336                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3337                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3338                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3339                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3340                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3341                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3342         );
3343
3344         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3345                 // Removing leading zeros works around broken base detection code in
3346                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3347                 // <https://bugs.php.net/bug.php?id=55398>).
3348                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ) ?: '0', $sourceBase ), $destBase );
3349         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3350                 $decimal = '0';
3351                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3352                         $decimal = bcmul( $decimal, $sourceBase );
3353                         $decimal = bcadd( $decimal, $baseChars[$char] );
3354                 }
3355
3356                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3357                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3358                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3359                 }
3360                 // @codingStandardsIgnoreEnd
3361
3362                 $result = strrev( $result );
3363         } else {
3364                 $inDigits = array();
3365                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3366                         $inDigits[] = $baseChars[$char];
3367                 }
3368
3369                 // Iterate over the input, modulo-ing out an output digit
3370                 // at a time until input is gone.
3371                 $result = '';
3372                 while ( $inDigits ) {
3373                         $work = 0;
3374                         $workDigits = array();
3375
3376                         // Long division...
3377                         foreach ( $inDigits as $digit ) {
3378                                 $work *= $sourceBase;
3379                                 $work += $digit;
3380
3381                                 if ( $workDigits || $work >= $destBase ) {
3382                                         $workDigits[] = (int)( $work / $destBase );
3383                                 }
3384                                 $work %= $destBase;
3385                         }
3386
3387                         // All that division leaves us with a remainder,
3388                         // which is conveniently our next output digit.
3389                         $result .= $baseChars[$work];
3390
3391                         // And we continue!
3392                         $inDigits = $workDigits;
3393                 }
3394
3395                 $result = strrev( $result );
3396         }
3397
3398         if ( !$lowercase ) {
3399                 $result = strtoupper( $result );
3400         }
3401
3402         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3403 }
3404
3405 /**
3406  * Check if there is sufficient entropy in php's built-in session generation
3407  *
3408  * @return bool True = there is sufficient entropy
3409  */
3410 function wfCheckEntropy() {
3411         return (
3412                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3413                         || ini_get( 'session.entropy_file' )
3414                 )
3415                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3416 }
3417
3418 /**
3419  * Override session_id before session startup if php's built-in
3420  * session generation code is not secure.
3421  */
3422 function wfFixSessionID() {
3423         // If the cookie or session id is already set we already have a session and should abort
3424         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3425                 return;
3426         }
3427
3428         // PHP's built-in session entropy is enabled if:
3429         // - entropy_file is set or you're on Windows with php 5.3.3+
3430         // - AND entropy_length is > 0
3431         // We treat it as disabled if it doesn't have an entropy length of at least 32
3432         $entropyEnabled = wfCheckEntropy();
3433
3434         // If built-in entropy is not enabled or not sufficient override PHP's
3435         // built in session id generation code
3436         if ( !$entropyEnabled ) {
3437                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3438                         "overriding session id generation using our cryptrand source.\n" );
3439                 session_id( MWCryptRand::generateHex( 32 ) );
3440         }
3441 }
3442
3443 /**
3444  * Reset the session_id
3445  *
3446  * @since 1.22
3447  */
3448 function wfResetSessionID() {
3449         global $wgCookieSecure;
3450         $oldSessionId = session_id();
3451         $cookieParams = session_get_cookie_params();
3452         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3453                 session_regenerate_id( false );
3454         } else {
3455                 $tmp = $_SESSION;
3456                 session_destroy();
3457                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3458                 $_SESSION = $tmp;
3459         }
3460         $newSessionId = session_id();
3461         Hooks::run( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3462 }
3463
3464 /**
3465  * Initialise php session
3466  *
3467  * @param bool $sessionId
3468  */
3469 function wfSetupSession( $sessionId = false ) {
3470         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgSessionHandler;
3471         global $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly;
3472
3473         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3474                 ObjectCacheSessionHandler::install();
3475         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3476                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3477                 # hasn't already been set to the desired value (that causes errors)
3478                 ini_set( 'session.save_handler', $wgSessionHandler );
3479         }
3480
3481         session_set_cookie_params(
3482                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3483         session_cache_limiter( 'private, must-revalidate' );
3484         if ( $sessionId ) {
3485                 session_id( $sessionId );
3486         } else {
3487                 wfFixSessionID();
3488         }
3489
3490         MediaWiki\suppressWarnings();
3491         session_start();
3492         MediaWiki\restoreWarnings();
3493
3494         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3495                 ObjectCacheSessionHandler::renewCurrentSession();
3496         }
3497 }
3498
3499 /**
3500  * Get an object from the precompiled serialized directory
3501  *
3502  * @param string $name
3503  * @return mixed The variable on success, false on failure
3504  */
3505 function wfGetPrecompiledData( $name ) {
3506         global $IP;
3507
3508         $file = "$IP/serialized/$name";
3509         if ( file_exists( $file ) ) {
3510                 $blob = file_get_contents( $file );
3511                 if ( $blob ) {
3512                         return unserialize( $blob );
3513                 }
3514         }
3515         return false;
3516 }
3517
3518 /**
3519  * Make a cache key for the local wiki.
3520  *
3521  * @param string $args,...
3522  * @return string
3523  */
3524 function wfMemcKey( /*...*/ ) {
3525         global $wgCachePrefix;
3526         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3527         $args = func_get_args();
3528         $key = $prefix . ':' . implode( ':', $args );
3529         return strtr( $key, ' ', '_' );
3530 }
3531
3532 /**
3533  * Make a cache key for a foreign DB.
3534  *
3535  * Must match what wfMemcKey() would produce in context of the foreign wiki.
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                 // Match wfWikiID() logic
3546                 $key = "$db-$prefix:" . implode( ':', $args );
3547         } else {
3548                 $key = $db . ':' . implode( ':', $args );
3549         }
3550         return strtr( $key, ' ', '_' );
3551 }
3552
3553 /**
3554  * Make a cache key with database-agnostic prefix.
3555  *
3556  * Doesn't have a wiki-specific namespace. Uses a generic 'global' prefix
3557  * instead. Must have a prefix as otherwise keys that use a database name
3558  * in the first segment will clash with wfMemcKey/wfForeignMemcKey.
3559  *
3560  * @since 1.26
3561  * @param string $args,...
3562  * @return string
3563  */
3564 function wfGlobalCacheKey( /*...*/ ) {
3565         $args = func_get_args();
3566         $key = 'global:' . implode( ':', $args );
3567         return strtr( $key, ' ', '_' );
3568 }
3569
3570 /**
3571  * Get an ASCII string identifying this wiki
3572  * This is used as a prefix in memcached keys
3573  *
3574  * @return string
3575  */
3576 function wfWikiID() {
3577         global $wgDBprefix, $wgDBname;
3578         if ( $wgDBprefix ) {
3579                 return "$wgDBname-$wgDBprefix";
3580         } else {
3581                 return $wgDBname;
3582         }
3583 }
3584
3585 /**
3586  * Split a wiki ID into DB name and table prefix
3587  *
3588  * @param string $wiki
3589  *
3590  * @return array
3591  */
3592 function wfSplitWikiID( $wiki ) {
3593         $bits = explode( '-', $wiki, 2 );
3594         if ( count( $bits ) < 2 ) {
3595                 $bits[] = '';
3596         }
3597         return $bits;
3598 }
3599
3600 /**
3601  * Get a Database object.
3602  *
3603  * @param int $db Index of the connection to get. May be DB_MASTER for the
3604  *            master (for write queries), DB_SLAVE for potentially lagged read
3605  *            queries, or an integer >= 0 for a particular server.
3606  *
3607  * @param string|string[] $groups Query groups. An array of group names that this query
3608  *                belongs to. May contain a single string if the query is only
3609  *                in one group.
3610  *
3611  * @param string|bool $wiki The wiki ID, or false for the current wiki
3612  *
3613  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3614  * will always return the same object, unless the underlying connection or load
3615  * balancer is manually destroyed.
3616  *
3617  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3618  * updater to ensure that a proper database is being updated.
3619  *
3620  * @return DatabaseBase
3621  */
3622 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3623         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3624 }
3625
3626 /**
3627  * Get a load balancer object.
3628  *
3629  * @param string|bool $wiki Wiki ID, or false for the current wiki
3630  * @return LoadBalancer
3631  */
3632 function wfGetLB( $wiki = false ) {
3633         return wfGetLBFactory()->getMainLB( $wiki );
3634 }
3635
3636 /**
3637  * Get the load balancer factory object
3638  *
3639  * @return LBFactory
3640  */
3641 function wfGetLBFactory() {
3642         return LBFactory::singleton();
3643 }
3644
3645 /**
3646  * Find a file.
3647  * Shortcut for RepoGroup::singleton()->findFile()
3648  *
3649  * @param string $title String or Title object
3650  * @param array $options Associative array of options (see RepoGroup::findFile)
3651  * @return File|bool File, or false if the file does not exist
3652  */
3653 function wfFindFile( $title, $options = array() ) {
3654         return RepoGroup::singleton()->findFile( $title, $options );
3655 }
3656
3657 /**
3658  * Get an object referring to a locally registered file.
3659  * Returns a valid placeholder object if the file does not exist.
3660  *
3661  * @param Title|string $title
3662  * @return LocalFile|null A File, or null if passed an invalid Title
3663  */
3664 function wfLocalFile( $title ) {
3665         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3666 }
3667
3668 /**
3669  * Should low-performance queries be disabled?
3670  *
3671  * @return bool
3672  * @codeCoverageIgnore
3673  */
3674 function wfQueriesMustScale() {
3675         global $wgMiserMode;
3676         return $wgMiserMode
3677                 || ( SiteStats::pages() > 100000
3678                 && SiteStats::edits() > 1000000
3679                 && SiteStats::users() > 10000 );
3680 }
3681
3682 /**
3683  * Get the path to a specified script file, respecting file
3684  * extensions; this is a wrapper around $wgScriptExtension etc.
3685  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3686  *
3687  * @param string $script Script filename, sans extension
3688  * @return string
3689  */
3690 function wfScript( $script = 'index' ) {
3691         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3692         if ( $script === 'index' ) {
3693                 return $wgScript;
3694         } elseif ( $script === 'load' ) {
3695                 return $wgLoadScript;
3696         } else {
3697                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3698         }
3699 }
3700
3701 /**
3702  * Get the script URL.
3703  *
3704  * @return string Script URL
3705  */
3706 function wfGetScriptUrl() {
3707         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3708                 #
3709                 # as it was called, minus the query string.
3710                 #
3711                 # Some sites use Apache rewrite rules to handle subdomains,
3712                 # and have PHP set up in a weird way that causes PHP_SELF
3713                 # to contain the rewritten URL instead of the one that the
3714                 # outside world sees.
3715                 #
3716                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3717                 # provides containing the "before" URL.
3718                 return $_SERVER['SCRIPT_NAME'];
3719         } else {
3720                 return $_SERVER['URL'];
3721         }
3722 }
3723
3724 /**
3725  * Convenience function converts boolean values into "true"
3726  * or "false" (string) values
3727  *
3728  * @param bool $value
3729  * @return string
3730  */
3731 function wfBoolToStr( $value ) {
3732         return $value ? 'true' : 'false';
3733 }
3734
3735 /**
3736  * Get a platform-independent path to the null file, e.g. /dev/null
3737  *
3738  * @return string
3739  */
3740 function wfGetNull() {
3741         return wfIsWindows() ? 'NUL' : '/dev/null';
3742 }
3743
3744 /**
3745  * Waits for the slaves to catch up to the master position
3746  *
3747  * Use this when updating very large numbers of rows, as in maintenance scripts,
3748  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3749  *
3750  * By default this waits on the main DB cluster of the current wiki.
3751  * If $cluster is set to "*" it will wait on all DB clusters, including
3752  * external ones. If the lag being waiting on is caused by the code that
3753  * does this check, it makes since to use $ifWritesSince, particularly if
3754  * cluster is "*", to avoid excess overhead.
3755  *
3756  * Never call this function after a big DB write that is still in a transaction.
3757  * This only makes sense after the possible lag inducing changes were committed.
3758  *
3759  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3760  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3761  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3762  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3763  * @return bool Success (able to connect and no timeouts reached)
3764  */
3765 function wfWaitForSlaves(
3766         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3767 ) {
3768         // B/C: first argument used to be "max seconds of lag"; ignore such values
3769         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3770
3771         if ( $timeout === null ) {
3772                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3773         }
3774
3775         // Figure out which clusters need to be checked
3776         /** @var LoadBalancer[] $lbs */
3777         $lbs = array();
3778         if ( $cluster === '*' ) {
3779                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3780                         $lbs[] = $lb;
3781                 } );
3782         } elseif ( $cluster !== false ) {
3783                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3784         } else {
3785                 $lbs[] = wfGetLB( $wiki );
3786         }
3787
3788         // Get all the master positions of applicable DBs right now.
3789         // This can be faster since waiting on one cluster reduces the
3790         // time needed to wait on the next clusters.
3791         $masterPositions = array_fill( 0, count( $lbs ), false );
3792         foreach ( $lbs as $i => $lb ) {
3793                 if ( $lb->getServerCount() <= 1 ) {
3794                         // Bug 27975 - Don't try to wait for slaves if there are none
3795                         // Prevents permission error when getting master position
3796                         continue;
3797                 } elseif ( $ifWritesSince && $lb->lastMasterChangeTimestamp() < $ifWritesSince ) {
3798                         continue; // no writes since the last wait
3799                 }
3800                 $masterPositions[$i] = $lb->getMasterPos();
3801         }
3802
3803         $ok = true;
3804         foreach ( $lbs as $i => $lb ) {
3805                 if ( $masterPositions[$i] ) {
3806                         // The DBMS may not support getMasterPos() or the whole
3807                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3808                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3809                 }
3810         }
3811
3812         return $ok;
3813 }
3814
3815 /**
3816  * Count down from $seconds to zero on the terminal, with a one-second pause
3817  * between showing each number. For use in command-line scripts.
3818  *
3819  * @codeCoverageIgnore
3820  * @param int $seconds
3821  */
3822 function wfCountDown( $seconds ) {
3823         for ( $i = $seconds; $i >= 0; $i-- ) {
3824                 if ( $i != $seconds ) {
3825                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3826                 }
3827                 echo $i;
3828                 flush();
3829                 if ( $i ) {
3830                         sleep( 1 );
3831                 }
3832         }
3833         echo "\n";
3834 }
3835
3836 /**
3837  * Replace all invalid characters with -
3838  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3839  * By default, $wgIllegalFileChars = ':'
3840  *
3841  * @param string $name Filename to process
3842  * @return string
3843  */
3844 function wfStripIllegalFilenameChars( $name ) {
3845         global $wgIllegalFileChars;
3846         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3847         $name = wfBaseName( $name );
3848         $name = preg_replace(
3849                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3850                 '-',
3851                 $name
3852         );
3853         return $name;
3854 }
3855
3856 /**
3857  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit
3858  *
3859  * @return int Resulting value of the memory limit.
3860  */
3861 function wfMemoryLimit() {
3862         global $wgMemoryLimit;
3863         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3864         if ( $memlimit != -1 ) {
3865                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3866                 if ( $conflimit == -1 ) {
3867                         wfDebug( "Removing PHP's memory limit\n" );
3868                         MediaWiki\suppressWarnings();
3869                         ini_set( 'memory_limit', $conflimit );
3870                         MediaWiki\restoreWarnings();
3871                         return $conflimit;
3872                 } elseif ( $conflimit > $memlimit ) {
3873                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3874                         MediaWiki\suppressWarnings();
3875                         ini_set( 'memory_limit', $conflimit );
3876                         MediaWiki\restoreWarnings();
3877                         return $conflimit;
3878                 }
3879         }
3880         return $memlimit;
3881 }
3882
3883 /**
3884  * Set PHP's time limit to the larger of php.ini or $wgTransactionalTimeLimit
3885  *
3886  * @return int Prior time limit
3887  * @since 1.26
3888  */
3889 function wfTransactionalTimeLimit() {
3890         global $wgTransactionalTimeLimit;
3891
3892         $timeLimit = ini_get( 'max_execution_time' );
3893         // Note that CLI scripts use 0
3894         if ( $timeLimit > 0 && $wgTransactionalTimeLimit > $timeLimit ) {
3895                 set_time_limit( $wgTransactionalTimeLimit );
3896         }
3897
3898         ignore_user_abort( true ); // ignore client disconnects
3899
3900         return $timeLimit;
3901 }
3902
3903 /**
3904  * Converts shorthand byte notation to integer form
3905  *
3906  * @param string $string
3907  * @return int
3908  */
3909 function wfShorthandToInteger( $string = '' ) {
3910         $string = trim( $string );
3911         if ( $string === '' ) {
3912                 return -1;
3913         }
3914         $last = $string[strlen( $string ) - 1];
3915         $val = intval( $string );
3916         switch ( $last ) {
3917                 case 'g':
3918                 case 'G':
3919                         $val *= 1024;
3920                         // break intentionally missing
3921                 case 'm':
3922                 case 'M':
3923                         $val *= 1024;
3924                         // break intentionally missing
3925                 case 'k':
3926                 case 'K':
3927                         $val *= 1024;
3928         }
3929
3930         return $val;
3931 }
3932
3933 /**
3934  * Get the normalised IETF language tag
3935  * See unit test for examples.
3936  *
3937  * @param string $code The language code.
3938  * @return string The language code which complying with BCP 47 standards.
3939  */
3940 function wfBCP47( $code ) {
3941         $codeSegment = explode( '-', $code );
3942         $codeBCP = array();
3943         foreach ( $codeSegment as $segNo => $seg ) {
3944                 // when previous segment is x, it is a private segment and should be lc
3945                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3946                         $codeBCP[$segNo] = strtolower( $seg );
3947                 // ISO 3166 country code
3948                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3949                         $codeBCP[$segNo] = strtoupper( $seg );
3950                 // ISO 15924 script code
3951                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3952                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3953                 // Use lowercase for other cases
3954                 } else {
3955                         $codeBCP[$segNo] = strtolower( $seg );
3956                 }
3957         }
3958         $langCode = implode( '-', $codeBCP );
3959         return $langCode;
3960 }
3961
3962 /**
3963  * Get a cache object.
3964  *
3965  * @param int $inputType Cache type, one of the CACHE_* constants.
3966  * @return BagOStuff
3967  */
3968 function wfGetCache( $inputType ) {
3969         return ObjectCache::getInstance( $inputType );
3970 }
3971
3972 /**
3973  * Get the main cache object
3974  *
3975  * @return BagOStuff
3976  */
3977 function wfGetMainCache() {
3978         global $wgMainCacheType;
3979         return ObjectCache::getInstance( $wgMainCacheType );
3980 }
3981
3982 /**
3983  * Get the cache object used by the message cache
3984  *
3985  * @return BagOStuff
3986  */
3987 function wfGetMessageCacheStorage() {
3988         global $wgMessageCacheType;
3989         return ObjectCache::getInstance( $wgMessageCacheType );
3990 }
3991
3992 /**
3993  * Get the cache object used by the parser cache
3994  *
3995  * @return BagOStuff
3996  */
3997 function wfGetParserCacheStorage() {
3998         global $wgParserCacheType;
3999         return ObjectCache::getInstance( $wgParserCacheType );
4000 }
4001
4002 /**
4003  * Call hook functions defined in $wgHooks
4004  *
4005  * @param string $event Event name
4006  * @param array $args Parameters passed to hook functions
4007  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
4008  *
4009  * @return bool True if no handler aborted the hook
4010  * @deprecated 1.25 - use Hooks::run
4011  */
4012 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
4013         return Hooks::run( $event, $args, $deprecatedVersion );
4014 }
4015
4016 /**
4017  * Wrapper around php's unpack.
4018  *
4019  * @param string $format The format string (See php's docs)
4020  * @param string $data A binary string of binary data
4021  * @param int|bool $length The minimum length of $data or false. This is to
4022  *      prevent reading beyond the end of $data. false to disable the check.
4023  *
4024  * Also be careful when using this function to read unsigned 32 bit integer
4025  * because php might make it negative.
4026  *
4027  * @throws MWException If $data not long enough, or if unpack fails
4028  * @return array Associative array of the extracted data
4029  */
4030 function wfUnpack( $format, $data, $length = false ) {
4031         if ( $length !== false ) {
4032                 $realLen = strlen( $data );
4033                 if ( $realLen < $length ) {
4034                         throw new MWException( "Tried to use wfUnpack on a "
4035                                 . "string of length $realLen, but needed one "
4036                                 . "of at least length $length."
4037                         );
4038                 }
4039         }
4040
4041         MediaWiki\suppressWarnings();
4042         $result = unpack( $format, $data );
4043         MediaWiki\restoreWarnings();
4044
4045         if ( $result === false ) {
4046                 // If it cannot extract the packed data.
4047                 throw new MWException( "unpack could not unpack binary data" );
4048         }
4049         return $result;
4050 }
4051
4052 /**
4053  * Determine if an image exists on the 'bad image list'.
4054  *
4055  * The format of MediaWiki:Bad_image_list is as follows:
4056  *    * Only list items (lines starting with "*") are considered
4057  *    * The first link on a line must be a link to a bad image
4058  *    * Any subsequent links on the same line are considered to be exceptions,
4059  *      i.e. articles where the image may occur inline.
4060  *
4061  * @param string $name The image name to check
4062  * @param Title|bool $contextTitle The page on which the image occurs, if known
4063  * @param string $blacklist Wikitext of a file blacklist
4064  * @return bool
4065  */
4066 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4067         static $badImageCache = null; // based on bad_image_list msg
4068
4069         # Handle redirects
4070         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4071         if ( $redirectTitle ) {
4072                 $name = $redirectTitle->getDBkey();
4073         }
4074
4075         # Run the extension hook
4076         $bad = false;
4077         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4078                 return $bad;
4079         }
4080
4081         $cacheable = ( $blacklist === null );
4082         if ( $cacheable && $badImageCache !== null ) {
4083                 $badImages = $badImageCache;
4084         } else { // cache miss
4085                 if ( $blacklist === null ) {
4086                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4087                 }
4088                 # Build the list now
4089                 $badImages = array();
4090                 $lines = explode( "\n", $blacklist );
4091                 foreach ( $lines as $line ) {
4092                         # List items only
4093                         if ( substr( $line, 0, 1 ) !== '*' ) {
4094                                 continue;
4095                         }
4096
4097                         # Find all links
4098                         $m = array();
4099                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4100                                 continue;
4101                         }
4102
4103                         $exceptions = array();
4104                         $imageDBkey = false;
4105                         foreach ( $m[1] as $i => $titleText ) {
4106                                 $title = Title::newFromText( $titleText );
4107                                 if ( !is_null( $title ) ) {
4108                                         if ( $i == 0 ) {
4109                                                 $imageDBkey = $title->getDBkey();
4110                                         } else {
4111                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4112                                         }
4113                                 }
4114                         }
4115
4116                         if ( $imageDBkey !== false ) {
4117                                 $badImages[$imageDBkey] = $exceptions;
4118                         }
4119                 }
4120                 if ( $cacheable ) {
4121                         $badImageCache = $badImages;
4122                 }
4123         }
4124
4125         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4126         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4127         return $bad;
4128 }
4129
4130 /**
4131  * Determine whether the client at a given source IP is likely to be able to
4132  * access the wiki via HTTPS.
4133  *
4134  * @param string $ip The IPv4/6 address in the normal human-readable form
4135  * @return bool
4136  */
4137 function wfCanIPUseHTTPS( $ip ) {
4138         $canDo = true;
4139         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4140         return !!$canDo;
4141 }
4142
4143 /**
4144  * Determine input string is represents as infinity
4145  *
4146  * @param string $str The string to determine
4147  * @return bool
4148  * @since 1.25
4149  */
4150 function wfIsInfinity( $str ) {
4151         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4152         return in_array( $str, $infinityValues );
4153 }
4154
4155 /**
4156  * Work out the IP address based on various globals
4157  * For trusted proxies, use the XFF client IP (first of the chain)
4158  *
4159  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4160  * @return string
4161  */
4162 function wfGetIP() {
4163         wfDeprecated( __METHOD__, '1.19' );
4164         global $wgRequest;
4165         return $wgRequest->getIP();
4166 }
4167
4168 /**
4169  * Checks if an IP is a trusted proxy provider.
4170  * Useful to tell if X-Forwarded-For data is possibly bogus.
4171  * Squid cache servers for the site are whitelisted.
4172  * @deprecated Since 1.24, use IP::isTrustedProxy()
4173  *
4174  * @param string $ip
4175  * @return bool
4176  */
4177 function wfIsTrustedProxy( $ip ) {
4178         wfDeprecated( __METHOD__, '1.24' );
4179         return IP::isTrustedProxy( $ip );
4180 }
4181
4182 /**
4183  * Checks if an IP matches a proxy we've configured.
4184  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4185  *
4186  * @param string $ip
4187  * @return bool
4188  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4189  */
4190 function wfIsConfiguredProxy( $ip ) {
4191         wfDeprecated( __METHOD__, '1.24' );
4192         return IP::isConfiguredProxy( $ip );
4193 }
4194
4195 /**
4196  * Returns true if these thumbnail parameters match one that MediaWiki
4197  * requests from file description pages and/or parser output.
4198  *
4199  * $params is considered non-standard if they involve a non-standard
4200  * width or any non-default parameters aside from width and page number.
4201  * The number of possible files with standard parameters is far less than
4202  * that of all combinations; rate-limiting for them can thus be more generious.
4203  *
4204  * @param File $file
4205  * @param array $params
4206  * @return bool
4207  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4208  */
4209 function wfThumbIsStandard( File $file, array $params ) {
4210         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4211
4212         $multipliers = array( 1 );
4213         if ( $wgResponsiveImages ) {
4214                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4215                 // @see Linker::processResponsiveImages
4216                 $multipliers[] = 1.5;
4217                 $multipliers[] = 2;
4218         }
4219
4220         $handler = $file->getHandler();
4221         if ( !$handler || !isset( $params['width'] ) ) {
4222                 return false;
4223         }
4224
4225         $basicParams = array();
4226         if ( isset( $params['page'] ) ) {
4227                 $basicParams['page'] = $params['page'];
4228         }
4229
4230         $thumbLimits = array();
4231         $imageLimits = array();
4232         // Expand limits to account for multipliers
4233         foreach ( $multipliers as $multiplier ) {
4234                 $thumbLimits = array_merge( $thumbLimits, array_map(
4235                         function ( $width ) use ( $multiplier ) {
4236                                 return round( $width * $multiplier );
4237                         }, $wgThumbLimits )
4238                 );
4239                 $imageLimits = array_merge( $imageLimits, array_map(
4240                         function ( $pair ) use ( $multiplier ) {
4241                                 return array(
4242                                         round( $pair[0] * $multiplier ),
4243                                         round( $pair[1] * $multiplier ),
4244                                 );
4245                         }, $wgImageLimits )
4246                 );
4247         }
4248
4249         // Check if the width matches one of $wgThumbLimits
4250         if ( in_array( $params['width'], $thumbLimits ) ) {
4251                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4252                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4253                 $handler->normaliseParams( $file, $normalParams );
4254         } else {
4255                 // If not, then check if the width matchs one of $wgImageLimits
4256                 $match = false;
4257                 foreach ( $imageLimits as $pair ) {
4258                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4259                         // Decide whether the thumbnail should be scaled on width or height.
4260                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4261                         $handler->normaliseParams( $file, $normalParams );
4262                         // Check if this standard thumbnail size maps to the given width
4263                         if ( $normalParams['width'] == $params['width'] ) {
4264                                 $match = true;
4265                                 break;
4266                         }
4267                 }
4268                 if ( !$match ) {
4269                         return false; // not standard for description pages
4270                 }
4271         }
4272
4273         // Check that the given values for non-page, non-width, params are just defaults
4274         foreach ( $params as $key => $value ) {
4275                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4276                         return false;
4277                 }
4278         }
4279
4280         return true;
4281 }