includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 if ( !defined( 'MEDIAWIKI' ) ) {
  24         die( "This file is part of MediaWiki, it is not a valid entry point" );
  25 }
  26
  27 use Liuggio\StatsdClient\StatsdClient;
  28 use Liuggio\StatsdClient\Sender\SocketSender;
  29
  30 // Hide compatibility functions from Doxygen
  31 /// @cond
  32
  33 /**
  34  * Compatibility functions
  35  *
  36  * We support PHP 5.3.3 and up.
  37  * Re-implementations of newer functions or functions in non-standard
  38  * PHP extensions may be included here.
  39  */
  40
  41 if ( !function_exists( 'mb_substr' ) ) {
  42         /**
  43          * @codeCoverageIgnore
  44          * @see Fallback::mb_substr
  45          * @return string
  46          */
  47         function mb_substr( $str, $start, $count = 'end' ) {
  48                 return Fallback::mb_substr( $str, $start, $count );
  49         }
  50
  51         /**
  52          * @codeCoverageIgnore
  53          * @see Fallback::mb_substr_split_unicode
  54          * @return int
  55          */
  56         function mb_substr_split_unicode( $str, $splitPos ) {
  57                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  58         }
  59 }
  60
  61 if ( !function_exists( 'mb_strlen' ) ) {
  62         /**
  63          * @codeCoverageIgnore
  64          * @see Fallback::mb_strlen
  65          * @return int
  66          */
  67         function mb_strlen( $str, $enc = '' ) {
  68                 return Fallback::mb_strlen( $str, $enc );
  69         }
  70 }
  71
  72 if ( !function_exists( 'mb_strpos' ) ) {
  73         /**
  74          * @codeCoverageIgnore
  75          * @see Fallback::mb_strpos
  76          * @return int
  77          */
  78         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  79                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  80         }
  81 }
  82
  83 if ( !function_exists( 'mb_strrpos' ) ) {
  84         /**
  85          * @codeCoverageIgnore
  86          * @see Fallback::mb_strrpos
  87          * @return int
  88          */
  89         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  90                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  91         }
  92 }
  93
  94 // gzdecode function only exists in PHP >= 5.4.0
  95 // http://php.net/gzdecode
  96 if ( !function_exists( 'gzdecode' ) ) {
  97         /**
  98          * @codeCoverageIgnore
  99          * @param string $data
 100          * @return string
 101          */
 102         function gzdecode( $data ) {
 103                 return gzinflate( substr( $data, 10, -8 ) );
 104         }
 105 }
 106
 107 // hash_equals function only exists in PHP >= 5.6.0
 108 // http://php.net/hash_equals
 109 if ( !function_exists( 'hash_equals' ) ) {
 110         /**
 111          * Check whether a user-provided string is equal to a fixed-length secret string
 112          * without revealing bytes of the secret string through timing differences.
 113          *
 114          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 115          * function in C) is to compare corresponding bytes and stop at the first difference,
 116          * which would take longer for a partial match than for a complete mismatch. This
 117          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 118          * and the other may come from an attacker. Statistical analysis of timing measurements
 119          * over many requests may allow the attacker to guess the string's bytes one at a time
 120          * (and check his guesses) even if the timing differences are extremely small.
 121          *
 122          * When making such a security-sensitive comparison, it is essential that the sequence
 123          * in which instructions are executed and memory locations are accessed not depend on
 124          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 125          * the inevitable leakage of the string's length. That is generally known anyway as
 126          * a chararacteristic of the hash function used to compute the secret value.
 127          *
 128          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 129          *
 130          * @codeCoverageIgnore
 131          * @param string $known_string Fixed-length secret string to compare against
 132          * @param string $user_string User-provided string
 133          * @return bool True if the strings are the same, false otherwise
 134          */
 135         function hash_equals( $known_string, $user_string ) {
 136                 // Strict type checking as in PHP's native implementation
 137                 if ( !is_string( $known_string ) ) {
 138                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 139                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 140
 141                         return false;
 142                 }
 143
 144                 if ( !is_string( $user_string ) ) {
 145                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 146                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 147
 148                         return false;
 149                 }
 150
 151                 $known_string_len = strlen( $known_string );
 152                 if ( $known_string_len !== strlen( $user_string ) ) {
 153                         return false;
 154                 }
 155
 156                 $result = 0;
 157                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 158                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 159                 }
 160
 161                 return ( $result === 0 );
 162         }
 163 }
 164 /// @endcond
 165
 166 /**
 167  * Load an extension
 168  *
 169  * This is the closest equivalent to:
 170  *   require_once "$IP/extensions/$name/$name.php";
 171  * as it will process and load the extension immediately.
 172  *
 173  * However, batch loading with wfLoadExtensions will
 174  * be more performant.
 175  *
 176  * @param string $name Name of the extension to load
 177  * @param string|null $path Absolute path of where to find the extension.json file
 178  */
 179 function wfLoadExtension( $name, $path = null ) {
 180         if ( !$path ) {
 181                 global $IP;
 182                 $path = "$IP/extensions/$name/extension.json";
 183         }
 184         ExtensionRegistry::getInstance()->load( $path );
 185 }
 186
 187 /**
 188  * Load multiple extensions at once
 189  *
 190  * Same as wfLoadExtension, but more efficient if you
 191  * are loading multiple extensions.
 192  *
 193  * If you want to specify custom paths, you should interact with
 194  * ExtensionRegistry directly.
 195  *
 196  * @see wfLoadExtension
 197  * @param string[] $exts Array of extension names to load
 198  */
 199 function wfLoadExtensions( array $exts ) {
 200         global $IP;
 201         $registry = ExtensionRegistry::getInstance();
 202         foreach ( $exts as $ext ) {
 203                 $registry->queue( "$IP/extensions/$ext/extension.json" );
 204         }
 205
 206         $registry->loadFromQueue();
 207 }
 208
 209 /**
 210  * Load a skin
 211  *
 212  * @see wfLoadExtension
 213  * @param string $name Name of the extension to load
 214  * @param string|null $path Absolute path of where to find the skin.json file
 215  */
 216 function wfLoadSkin( $name, $path = null ) {
 217         if ( !$path ) {
 218                 global $IP;
 219                 $path = "$IP/skins/$name/skin.json";
 220         }
 221         ExtensionRegistry::getInstance()->load( $path );
 222 }
 223
 224 /**
 225  * Load multiple skins at once
 226  *
 227  * @see wfLoadExtensions
 228  * @param string[] $skins Array of extension names to load
 229  */
 230 function wfLoadSkins( array $skins ) {
 231         global $IP;
 232         $registry = ExtensionRegistry::getInstance();
 233         foreach ( $skins as $skin ) {
 234                 $registry->queue( "$IP/skins/$skin/skin.json" );
 235         }
 236
 237         $registry->loadFromQueue();
 238 }
 239
 240 /**
 241  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 242  * @param array $a
 243  * @param array $b
 244  * @return array
 245  */
 246 function wfArrayDiff2( $a, $b ) {
 247         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 248 }
 249
 250 /**
 251  * @param array|string $a
 252  * @param array|string $b
 253  * @return int
 254  */
 255 function wfArrayDiff2_cmp( $a, $b ) {
 256         if ( is_string( $a ) && is_string( $b ) ) {
 257                 return strcmp( $a, $b );
 258         } elseif ( count( $a ) !== count( $b ) ) {
 259                 return count( $a ) < count( $b ) ? -1 : 1;
 260         } else {
 261                 reset( $a );
 262                 reset( $b );
 263                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 264                         $cmp = strcmp( $valueA, $valueB );
 265                         if ( $cmp !== 0 ) {
 266                                 return $cmp;
 267                         }
 268                 }
 269                 return 0;
 270         }
 271 }
 272
 273 /**
 274  * Appends to second array if $value differs from that in $default
 275  *
 276  * @param string|int $key
 277  * @param mixed $value
 278  * @param mixed $default
 279  * @param array $changed Array to alter
 280  * @throws MWException
 281  */
 282 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 283         if ( is_null( $changed ) ) {
 284                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 285         }
 286         if ( $default[$key] !== $value ) {
 287                 $changed[$key] = $value;
 288         }
 289 }
 290
 291 /**
 292  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 293  * e.g.
 294  *      wfMergeErrorArrays(
 295  *              array( array( 'x' ) ),
 296  *              array( array( 'x', '2' ) ),
 297  *              array( array( 'x' ) ),
 298  *              array( array( 'y' ) )
 299  *      );
 300  * returns:
 301  *              array(
 302  *              array( 'x', '2' ),
 303  *              array( 'x' ),
 304  *              array( 'y' )
 305  *      )
 306  *
 307  * @param array $array1,...
 308  * @return array
 309  */
 310 function wfMergeErrorArrays( /*...*/ ) {
 311         $args = func_get_args();
 312         $out = array();
 313         foreach ( $args as $errors ) {
 314                 foreach ( $errors as $params ) {
 315                         # @todo FIXME: Sometimes get nested arrays for $params,
 316                         # which leads to E_NOTICEs
 317                         $spec = implode( "\t", $params );
 318                         $out[$spec] = $params;
 319                 }
 320         }
 321         return array_values( $out );
 322 }
 323
 324 /**
 325  * Insert array into another array after the specified *KEY*
 326  *
 327  * @param array $array The array.
 328  * @param array $insert The array to insert.
 329  * @param mixed $after The key to insert after
 330  * @return array
 331  */
 332 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 333         // Find the offset of the element to insert after.
 334         $keys = array_keys( $array );
 335         $offsetByKey = array_flip( $keys );
 336
 337         $offset = $offsetByKey[$after];
 338
 339         // Insert at the specified offset
 340         $before = array_slice( $array, 0, $offset + 1, true );
 341         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 342
 343         $output = $before + $insert + $after;
 344
 345         return $output;
 346 }
 347
 348 /**
 349  * Recursively converts the parameter (an object) to an array with the same data
 350  *
 351  * @param object|array $objOrArray
 352  * @param bool $recursive
 353  * @return array
 354  */
 355 function wfObjectToArray( $objOrArray, $recursive = true ) {
 356         $array = array();
 357         if ( is_object( $objOrArray ) ) {
 358                 $objOrArray = get_object_vars( $objOrArray );
 359         }
 360         foreach ( $objOrArray as $key => $value ) {
 361                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 362                         $value = wfObjectToArray( $value );
 363                 }
 364
 365                 $array[$key] = $value;
 366         }
 367
 368         return $array;
 369 }
 370
 371 /**
 372  * Get a random decimal value between 0 and 1, in a way
 373  * not likely to give duplicate values for any realistic
 374  * number of articles.
 375  *
 376  * @return string
 377  */
 378 function wfRandom() {
 379         # The maximum random value is "only" 2^31-1, so get two random
 380         # values to reduce the chance of dupes
 381         $max = mt_getrandmax() + 1;
 382         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 383
 384         return $rand;
 385 }
 386
 387 /**
 388  * Get a random string containing a number of pseudo-random hex
 389  * characters.
 390  * @note This is not secure, if you are trying to generate some sort
 391  *       of token please use MWCryptRand instead.
 392  *
 393  * @param int $length The length of the string to generate
 394  * @return string
 395  * @since 1.20
 396  */
 397 function wfRandomString( $length = 32 ) {
 398         $str = '';
 399         for ( $n = 0; $n < $length; $n += 7 ) {
 400                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 401         }
 402         return substr( $str, 0, $length );
 403 }
 404
 405 /**
 406  * We want some things to be included as literal characters in our title URLs
 407  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 408  * all of the following should be safe:
 409  *
 410  * ;:@&=$-_.+!*'(),
 411  *
 412  * But + is not safe because it's used to indicate a space; &= are only safe in
 413  * paths and not in queries (and we don't distinguish here); ' seems kind of
 414  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 415  * is reserved, we don't care.  So the list we unescape is:
 416  *
 417  * ;:@$!*(),/
 418  *
 419  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 420  * so no fancy : for IIS7.
 421  *
 422  * %2F in the page titles seems to fatally break for some reason.
 423  *
 424  * @param string $s
 425  * @return string
 426  */
 427 function wfUrlencode( $s ) {
 428         static $needle;
 429
 430         if ( is_null( $s ) ) {
 431                 $needle = null;
 432                 return '';
 433         }
 434
 435         if ( is_null( $needle ) ) {
 436                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 437                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 438                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 439                 ) {
 440                         $needle[] = '%3A';
 441                 }
 442         }
 443
 444         $s = urlencode( $s );
 445         $s = str_ireplace(
 446                 $needle,
 447                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 448                 $s
 449         );
 450
 451         return $s;
 452 }
 453
 454 /**
 455  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 456  * "days=7&limit=100". Options in the first array override options in the second.
 457  * Options set to null or false will not be output.
 458  *
 459  * @param array $array1 ( String|Array )
 460  * @param array $array2 ( String|Array )
 461  * @param string $prefix
 462  * @return string
 463  */
 464 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 465         if ( !is_null( $array2 ) ) {
 466                 $array1 = $array1 + $array2;
 467         }
 468
 469         $cgi = '';
 470         foreach ( $array1 as $key => $value ) {
 471                 if ( !is_null( $value ) && $value !== false ) {
 472                         if ( $cgi != '' ) {
 473                                 $cgi .= '&';
 474                         }
 475                         if ( $prefix !== '' ) {
 476                                 $key = $prefix . "[$key]";
 477                         }
 478                         if ( is_array( $value ) ) {
 479                                 $firstTime = true;
 480                                 foreach ( $value as $k => $v ) {
 481                                         $cgi .= $firstTime ? '' : '&';
 482                                         if ( is_array( $v ) ) {
 483                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 484                                         } else {
 485                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 486                                         }
 487                                         $firstTime = false;
 488                                 }
 489                         } else {
 490                                 if ( is_object( $value ) ) {
 491                                         $value = $value->__toString();
 492                                 }
 493                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 494                         }
 495                 }
 496         }
 497         return $cgi;
 498 }
 499
 500 /**
 501  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 502  * its argument and returns the same string in array form.  This allows compatibility
 503  * with legacy functions that accept raw query strings instead of nice
 504  * arrays.  Of course, keys and values are urldecode()d.
 505  *
 506  * @param string $query Query string
 507  * @return string[] Array version of input
 508  */
 509 function wfCgiToArray( $query ) {
 510         if ( isset( $query[0] ) && $query[0] == '?' ) {
 511                 $query = substr( $query, 1 );
 512         }
 513         $bits = explode( '&', $query );
 514         $ret = array();
 515         foreach ( $bits as $bit ) {
 516                 if ( $bit === '' ) {
 517                         continue;
 518                 }
 519                 if ( strpos( $bit, '=' ) === false ) {
 520                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 521                         $key = $bit;
 522                         $value = '';
 523                 } else {
 524                         list( $key, $value ) = explode( '=', $bit );
 525                 }
 526                 $key = urldecode( $key );
 527                 $value = urldecode( $value );
 528                 if ( strpos( $key, '[' ) !== false ) {
 529                         $keys = array_reverse( explode( '[', $key ) );
 530                         $key = array_pop( $keys );
 531                         $temp = $value;
 532                         foreach ( $keys as $k ) {
 533                                 $k = substr( $k, 0, -1 );
 534                                 $temp = array( $k => $temp );
 535                         }
 536                         if ( isset( $ret[$key] ) ) {
 537                                 $ret[$key] = array_merge( $ret[$key], $temp );
 538                         } else {
 539                                 $ret[$key] = $temp;
 540                         }
 541                 } else {
 542                         $ret[$key] = $value;
 543                 }
 544         }
 545         return $ret;
 546 }
 547
 548 /**
 549  * Append a query string to an existing URL, which may or may not already
 550  * have query string parameters already. If so, they will be combined.
 551  *
 552  * @param string $url
 553  * @param string|string[] $query String or associative array
 554  * @return string
 555  */
 556 function wfAppendQuery( $url, $query ) {
 557         if ( is_array( $query ) ) {
 558                 $query = wfArrayToCgi( $query );
 559         }
 560         if ( $query != '' ) {
 561                 if ( false === strpos( $url, '?' ) ) {
 562                         $url .= '?';
 563                 } else {
 564                         $url .= '&';
 565                 }
 566                 $url .= $query;
 567         }
 568         return $url;
 569 }
 570
 571 /**
 572  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 573  * is correct.
 574  *
 575  * The meaning of the PROTO_* constants is as follows:
 576  * PROTO_HTTP: Output a URL starting with http://
 577  * PROTO_HTTPS: Output a URL starting with https://
 578  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 579  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 580  *    on which protocol was used for the current incoming request
 581  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 582  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 583  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 584  *
 585  * @todo this won't work with current-path-relative URLs
 586  * like "subdir/foo.html", etc.
 587  *
 588  * @param string $url Either fully-qualified or a local path + query
 589  * @param string $defaultProto One of the PROTO_* constants. Determines the
 590  *    protocol to use if $url or $wgServer is protocol-relative
 591  * @return string Fully-qualified URL, current-path-relative URL or false if
 592  *    no valid URL can be constructed
 593  */
 594 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 595         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 596                 $wgHttpsPort;
 597         if ( $defaultProto === PROTO_CANONICAL ) {
 598                 $serverUrl = $wgCanonicalServer;
 599         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 600                 // Make $wgInternalServer fall back to $wgServer if not set
 601                 $serverUrl = $wgInternalServer;
 602         } else {
 603                 $serverUrl = $wgServer;
 604                 if ( $defaultProto === PROTO_CURRENT ) {
 605                         $defaultProto = $wgRequest->getProtocol() . '://';
 606                 }
 607         }
 608
 609         // Analyze $serverUrl to obtain its protocol
 610         $bits = wfParseUrl( $serverUrl );
 611         $serverHasProto = $bits && $bits['scheme'] != '';
 612
 613         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 614                 if ( $serverHasProto ) {
 615                         $defaultProto = $bits['scheme'] . '://';
 616                 } else {
 617                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 618                         // This really isn't supposed to happen. Fall back to HTTP in this
 619                         // ridiculous case.
 620                         $defaultProto = PROTO_HTTP;
 621                 }
 622         }
 623
 624         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 625
 626         if ( substr( $url, 0, 2 ) == '//' ) {
 627                 $url = $defaultProtoWithoutSlashes . $url;
 628         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 629                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 630                 // otherwise leave it alone.
 631                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 632         }
 633
 634         $bits = wfParseUrl( $url );
 635
 636         // ensure proper port for HTTPS arrives in URL
 637         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 638         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 639                 $bits['port'] = $wgHttpsPort;
 640         }
 641
 642         if ( $bits && isset( $bits['path'] ) ) {
 643                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 644                 return wfAssembleUrl( $bits );
 645         } elseif ( $bits ) {
 646                 # No path to expand
 647                 return $url;
 648         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 649                 # URL is a relative path
 650                 return wfRemoveDotSegments( $url );
 651         }
 652
 653         # Expanded URL is not valid.
 654         return false;
 655 }
 656
 657 /**
 658  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 659  * if you need to edit part of a URL and put it back together.
 660  *
 661  * This is the basic structure used (brackets contain keys for $urlParts):
 662  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 663  *
 664  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 665  *
 666  * @since 1.19
 667  * @param array $urlParts URL parts, as output from wfParseUrl
 668  * @return string URL assembled from its component parts
 669  */
 670 function wfAssembleUrl( $urlParts ) {
 671         $result = '';
 672
 673         if ( isset( $urlParts['delimiter'] ) ) {
 674                 if ( isset( $urlParts['scheme'] ) ) {
 675                         $result .= $urlParts['scheme'];
 676                 }
 677
 678                 $result .= $urlParts['delimiter'];
 679         }
 680
 681         if ( isset( $urlParts['host'] ) ) {
 682                 if ( isset( $urlParts['user'] ) ) {
 683                         $result .= $urlParts['user'];
 684                         if ( isset( $urlParts['pass'] ) ) {
 685                                 $result .= ':' . $urlParts['pass'];
 686                         }
 687                         $result .= '@';
 688                 }
 689
 690                 $result .= $urlParts['host'];
 691
 692                 if ( isset( $urlParts['port'] ) ) {
 693                         $result .= ':' . $urlParts['port'];
 694                 }
 695         }
 696
 697         if ( isset( $urlParts['path'] ) ) {
 698                 $result .= $urlParts['path'];
 699         }
 700
 701         if ( isset( $urlParts['query'] ) ) {
 702                 $result .= '?' . $urlParts['query'];
 703         }
 704
 705         if ( isset( $urlParts['fragment'] ) ) {
 706                 $result .= '#' . $urlParts['fragment'];
 707         }
 708
 709         return $result;
 710 }
 711
 712 /**
 713  * Remove all dot-segments in the provided URL path.  For example,
 714  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 715  * RFC3986 section 5.2.4.
 716  *
 717  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 718  *
 719  * @param string $urlPath URL path, potentially containing dot-segments
 720  * @return string URL path with all dot-segments removed
 721  */
 722 function wfRemoveDotSegments( $urlPath ) {
 723         $output = '';
 724         $inputOffset = 0;
 725         $inputLength = strlen( $urlPath );
 726
 727         while ( $inputOffset < $inputLength ) {
 728                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 729                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 730                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 731                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 732                 $trimOutput = false;
 733
 734                 if ( $prefixLengthTwo == './' ) {
 735                         # Step A, remove leading "./"
 736                         $inputOffset += 2;
 737                 } elseif ( $prefixLengthThree == '../' ) {
 738                         # Step A, remove leading "../"
 739                         $inputOffset += 3;
 740                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 741                         # Step B, replace leading "/.$" with "/"
 742                         $inputOffset += 1;
 743                         $urlPath[$inputOffset] = '/';
 744                 } elseif ( $prefixLengthThree == '/./' ) {
 745                         # Step B, replace leading "/./" with "/"
 746                         $inputOffset += 2;
 747                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 748                         # Step C, replace leading "/..$" with "/" and
 749                         # remove last path component in output
 750                         $inputOffset += 2;
 751                         $urlPath[$inputOffset] = '/';
 752                         $trimOutput = true;
 753                 } elseif ( $prefixLengthFour == '/../' ) {
 754                         # Step C, replace leading "/../" with "/" and
 755                         # remove last path component in output
 756                         $inputOffset += 3;
 757                         $trimOutput = true;
 758                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 759                         # Step D, remove "^.$"
 760                         $inputOffset += 1;
 761                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 762                         # Step D, remove "^..$"
 763                         $inputOffset += 2;
 764                 } else {
 765                         # Step E, move leading path segment to output
 766                         if ( $prefixLengthOne == '/' ) {
 767                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 768                         } else {
 769                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 770                         }
 771                         if ( $slashPos === false ) {
 772                                 $output .= substr( $urlPath, $inputOffset );
 773                                 $inputOffset = $inputLength;
 774                         } else {
 775                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 776                                 $inputOffset += $slashPos - $inputOffset;
 777                         }
 778                 }
 779
 780                 if ( $trimOutput ) {
 781                         $slashPos = strrpos( $output, '/' );
 782                         if ( $slashPos === false ) {
 783                                 $output = '';
 784                         } else {
 785                                 $output = substr( $output, 0, $slashPos );
 786                         }
 787                 }
 788         }
 789
 790         return $output;
 791 }
 792
 793 /**
 794  * Returns a regular expression of url protocols
 795  *
 796  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 797  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 798  * @return string
 799  */
 800 function wfUrlProtocols( $includeProtocolRelative = true ) {
 801         global $wgUrlProtocols;
 802
 803         // Cache return values separately based on $includeProtocolRelative
 804         static $withProtRel = null, $withoutProtRel = null;
 805         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 806         if ( !is_null( $cachedValue ) ) {
 807                 return $cachedValue;
 808         }
 809
 810         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 811         // with LocalSettings files from 1.5
 812         if ( is_array( $wgUrlProtocols ) ) {
 813                 $protocols = array();
 814                 foreach ( $wgUrlProtocols as $protocol ) {
 815                         // Filter out '//' if !$includeProtocolRelative
 816                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 817                                 $protocols[] = preg_quote( $protocol, '/' );
 818                         }
 819                 }
 820
 821                 $retval = implode( '|', $protocols );
 822         } else {
 823                 // Ignore $includeProtocolRelative in this case
 824                 // This case exists for pre-1.6 compatibility, and we can safely assume
 825                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 826                 // URLs weren't supported until 1.18
 827                 $retval = $wgUrlProtocols;
 828         }
 829
 830         // Cache return value
 831         if ( $includeProtocolRelative ) {
 832                 $withProtRel = $retval;
 833         } else {
 834                 $withoutProtRel = $retval;
 835         }
 836         return $retval;
 837 }
 838
 839 /**
 840  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 841  * you need a regex that matches all URL protocols but does not match protocol-
 842  * relative URLs
 843  * @return string
 844  */
 845 function wfUrlProtocolsWithoutProtRel() {
 846         return wfUrlProtocols( false );
 847 }
 848
 849 /**
 850  * parse_url() work-alike, but non-broken.  Differences:
 851  *
 852  * 1) Does not raise warnings on bad URLs (just returns false).
 853  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 854  *    protocol-relative URLs) correctly.
 855  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 856  *
 857  * @param string $url A URL to parse
 858  * @return string[] Bits of the URL in an associative array, per PHP docs
 859  */
 860 function wfParseUrl( $url ) {
 861         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 862
 863         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 864         // bad that the easiest way to handle them is to just prepend 'http:' and
 865         // strip the protocol out later.
 866         $wasRelative = substr( $url, 0, 2 ) == '//';
 867         if ( $wasRelative ) {
 868                 $url = "http:$url";
 869         }
 870         wfSuppressWarnings();
 871         $bits = parse_url( $url );
 872         wfRestoreWarnings();
 873         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 874         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 875         if ( !$bits || !isset( $bits['scheme'] ) ) {
 876                 return false;
 877         }
 878
 879         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 880         $bits['scheme'] = strtolower( $bits['scheme'] );
 881
 882         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 883         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 884                 $bits['delimiter'] = '://';
 885         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 886                 $bits['delimiter'] = ':';
 887                 // parse_url detects for news: and mailto: the host part of an url as path
 888                 // We have to correct this wrong detection
 889                 if ( isset( $bits['path'] ) ) {
 890                         $bits['host'] = $bits['path'];
 891                         $bits['path'] = '';
 892                 }
 893         } else {
 894                 return false;
 895         }
 896
 897         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 898         if ( !isset( $bits['host'] ) ) {
 899                 $bits['host'] = '';
 900
 901                 // bug 45069
 902                 if ( isset( $bits['path'] ) ) {
 903                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 904                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 905                                 $bits['path'] = '/' . $bits['path'];
 906                         }
 907                 } else {
 908                         $bits['path'] = '';
 909                 }
 910         }
 911
 912         // If the URL was protocol-relative, fix scheme and delimiter
 913         if ( $wasRelative ) {
 914                 $bits['scheme'] = '';
 915                 $bits['delimiter'] = '//';
 916         }
 917         return $bits;
 918 }
 919
 920 /**
 921  * Take a URL, make sure it's expanded to fully qualified, and replace any
 922  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 923  * for more compact display and legibility for local audiences.
 924  *
 925  * @todo handle punycode domains too
 926  *
 927  * @param string $url
 928  * @return string
 929  */
 930 function wfExpandIRI( $url ) {
 931         return preg_replace_callback(
 932                 '/((?:%[89A-F][0-9A-F])+)/i',
 933                 'wfExpandIRI_callback',
 934                 wfExpandUrl( $url )
 935         );
 936 }
 937
 938 /**
 939  * Private callback for wfExpandIRI
 940  * @param array $matches
 941  * @return string
 942  */
 943 function wfExpandIRI_callback( $matches ) {
 944         return urldecode( $matches[1] );
 945 }
 946
 947 /**
 948  * Make URL indexes, appropriate for the el_index field of externallinks.
 949  *
 950  * @param string $url
 951  * @return array
 952  */
 953 function wfMakeUrlIndexes( $url ) {
 954         $bits = wfParseUrl( $url );
 955
 956         // Reverse the labels in the hostname, convert to lower case
 957         // For emails reverse domainpart only
 958         if ( $bits['scheme'] == 'mailto' ) {
 959                 $mailparts = explode( '@', $bits['host'], 2 );
 960                 if ( count( $mailparts ) === 2 ) {
 961                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 962                 } else {
 963                         // No domain specified, don't mangle it
 964                         $domainpart = '';
 965                 }
 966                 $reversedHost = $domainpart . '@' . $mailparts[0];
 967         } else {
 968                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 969         }
 970         // Add an extra dot to the end
 971         // Why? Is it in wrong place in mailto links?
 972         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 973                 $reversedHost .= '.';
 974         }
 975         // Reconstruct the pseudo-URL
 976         $prot = $bits['scheme'];
 977         $index = $prot . $bits['delimiter'] . $reversedHost;
 978         // Leave out user and password. Add the port, path, query and fragment
 979         if ( isset( $bits['port'] ) ) {
 980                 $index .= ':' . $bits['port'];
 981         }
 982         if ( isset( $bits['path'] ) ) {
 983                 $index .= $bits['path'];
 984         } else {
 985                 $index .= '/';
 986         }
 987         if ( isset( $bits['query'] ) ) {
 988                 $index .= '?' . $bits['query'];
 989         }
 990         if ( isset( $bits['fragment'] ) ) {
 991                 $index .= '#' . $bits['fragment'];
 992         }
 993
 994         if ( $prot == '' ) {
 995                 return array( "http:$index", "https:$index" );
 996         } else {
 997                 return array( $index );
 998         }
 999 }
1000
1001 /**
1002  * Check whether a given URL has a domain that occurs in a given set of domains
1003  * @param string $url URL
1004  * @param array $domains Array of domains (strings)
1005  * @return bool True if the host part of $url ends in one of the strings in $domains
1006  */
1007 function wfMatchesDomainList( $url, $domains ) {
1008         $bits = wfParseUrl( $url );
1009         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1010                 $host = '.' . $bits['host'];
1011                 foreach ( (array)$domains as $domain ) {
1012                         $domain = '.' . $domain;
1013                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1014                                 return true;
1015                         }
1016                 }
1017         }
1018         return false;
1019 }
1020
1021 /**
1022  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1023  * In normal operation this is a NOP.
1024  *
1025  * Controlling globals:
1026  * $wgDebugLogFile - points to the log file
1027  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1028  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1029  *
1030  * @since 1.25 support for additional context data
1031  *
1032  * @param string $text
1033  * @param string|bool $dest Unused
1034  * @param array $context Additional logging context data
1035  */
1036 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1037         global $wgDebugRawPage, $wgDebugLogPrefix;
1038         global $wgDebugTimestamps, $wgRequestTime;
1039
1040         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1041                 return;
1042         }
1043
1044         $text = trim( $text );
1045
1046         // Inline logic from deprecated wfDebugTimer()
1047         if ( $wgDebugTimestamps ) {
1048                 $context['seconds_elapsed'] = sprintf(
1049                         '%6.4f',
1050                         microtime( true ) - $wgRequestTime
1051                 );
1052                 $context['memory_used'] = sprintf(
1053                         '%5.1fM',
1054                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1055                 );
1056         }
1057
1058         if ( $wgDebugLogPrefix !== '' ) {
1059                 $context['prefix'] = $wgDebugLogPrefix;
1060         }
1061
1062         $logger = MWLoggerFactory::getInstance( 'wfDebug' );
1063         $logger->debug( $text, $context );
1064 }
1065
1066 /**
1067  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1068  * @return bool
1069  */
1070 function wfIsDebugRawPage() {
1071         static $cache;
1072         if ( $cache !== null ) {
1073                 return $cache;
1074         }
1075         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1076         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1077                 || (
1078                         isset( $_SERVER['SCRIPT_NAME'] )
1079                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1080                 )
1081         ) {
1082                 $cache = true;
1083         } else {
1084                 $cache = false;
1085         }
1086         return $cache;
1087 }
1088
1089 /**
1090  * Get microsecond timestamps for debug logs
1091  *
1092  * @deprecated since 1.25
1093  * @return string
1094  */
1095 function wfDebugTimer() {
1096         global $wgDebugTimestamps, $wgRequestTime;
1097
1098         wfDeprecated( __METHOD__, '1.25' );
1099
1100         if ( !$wgDebugTimestamps ) {
1101                 return '';
1102         }
1103
1104         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1105         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1106         return "$prefix $mem  ";
1107 }
1108
1109 /**
1110  * Send a line giving PHP memory usage.
1111  *
1112  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1113  */
1114 function wfDebugMem( $exact = false ) {
1115         $mem = memory_get_usage();
1116         if ( !$exact ) {
1117                 $mem = floor( $mem / 1024 ) . ' KiB';
1118         } else {
1119                 $mem .= ' B';
1120         }
1121         wfDebug( "Memory usage: $mem\n" );
1122 }
1123
1124 /**
1125  * Send a line to a supplementary debug log file, if configured, or main debug
1126  * log if not.
1127  *
1128  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1129  * a string filename or an associative array mapping 'destination' to the
1130  * desired filename. The associative array may also contain a 'sample' key
1131  * with an integer value, specifying a sampling factor. Sampled log events
1132  * will be emitted with a 1 in N random chance.
1133  *
1134  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1135  * @since 1.25 support for additional context data
1136  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1137  *
1138  * @param string $logGroup
1139  * @param string $text
1140  * @param string|bool $dest Destination of the message:
1141  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1142  *     - 'log': only to the log and not in HTML
1143  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1144  *       discarded otherwise
1145  *   For backward compatibility, it can also take a boolean:
1146  *     - true: same as 'all'
1147  *     - false: same as 'private'
1148  * @param array $context Additional logging context data
1149  */
1150 function wfDebugLog(
1151         $logGroup, $text, $dest = 'all', array $context = array()
1152 ) {
1153         // Turn $dest into a string if it's a boolean (for b/c)
1154         if ( $dest === true ) {
1155                 $dest = 'all';
1156         } elseif ( $dest === false ) {
1157                 $dest = 'private';
1158         }
1159
1160         $text = trim( $text );
1161
1162         $logger = MWLoggerFactory::getInstance( $logGroup );
1163         $context['private'] = ( $dest === 'private' );
1164         $logger->info( $text, $context );
1165 }
1166
1167 /**
1168  * Log for database errors
1169  *
1170  * @since 1.25 support for additional context data
1171  *
1172  * @param string $text Database error message.
1173  * @param array $context Additional logging context data
1174  */
1175 function wfLogDBError( $text, array $context = array() ) {
1176         $logger = MWLoggerFactory::getInstance( 'wfLogDBError' );
1177         $logger->error( trim( $text ), $context );
1178 }
1179
1180 /**
1181  * Throws a warning that $function is deprecated
1182  *
1183  * @param string $function
1184  * @param string|bool $version Version of MediaWiki that the function
1185  *    was deprecated in (Added in 1.19).
1186  * @param string|bool $component Added in 1.19.
1187  * @param int $callerOffset How far up the call stack is the original
1188  *    caller. 2 = function that called the function that called
1189  *    wfDeprecated (Added in 1.20)
1190  *
1191  * @return null
1192  */
1193 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1194         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1195 }
1196
1197 /**
1198  * Send a warning either to the debug log or in a PHP error depending on
1199  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1200  *
1201  * @param string $msg Message to send
1202  * @param int $callerOffset Number of items to go back in the backtrace to
1203  *        find the correct caller (1 = function calling wfWarn, ...)
1204  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1205  *        only used when $wgDevelopmentWarnings is true
1206  */
1207 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1208         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1209 }
1210
1211 /**
1212  * Send a warning as a PHP error and the debug log. This is intended for logging
1213  * warnings in production. For logging development warnings, use WfWarn instead.
1214  *
1215  * @param string $msg Message to send
1216  * @param int $callerOffset Number of items to go back in the backtrace to
1217  *        find the correct caller (1 = function calling wfLogWarning, ...)
1218  * @param int $level PHP error level; defaults to E_USER_WARNING
1219  */
1220 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1221         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1222 }
1223
1224 /**
1225  * Log to a file without getting "file size exceeded" signals.
1226  *
1227  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1228  * send lines to the specified port, prefixed by the specified prefix and a space.
1229  * @since 1.25 support for additional context data
1230  *
1231  * @param string $text
1232  * @param string $file Filename
1233  * @param array $context Additional logging context data
1234  * @throws MWException
1235  * @deprecated since 1.25 Use MWLoggerLegacyLogger::emit or UDPTransport
1236  */
1237 function wfErrorLog( $text, $file, array $context = array() ) {
1238         wfDeprecated( __METHOD__, '1.25' );
1239         $logger = MWLoggerFactory::getInstance( 'wfErrorLog' );
1240         $context['destination'] = $file;
1241         $logger->info( trim( $text ), $context );
1242 }
1243
1244 /**
1245  * @todo document
1246  */
1247 function wfLogProfilingData() {
1248         global $wgRequestTime, $wgDebugLogGroups, $wgDebugRawPage;
1249         global $wgProfileLimit, $wgUser, $wgRequest;
1250
1251         $context = RequestContext::getMain();
1252         $config = $context->getConfig();
1253         if ( $config->has( 'StatsdServer' ) ) {
1254                 $statsdServer = explode( ':', $config->get( 'StatsdServer' ) );
1255                 $statsdHost = $statsdServer[0];
1256                 $statsdPort = isset( $statsdServer[1] ) ? $statsdServer[1] : 8125;
1257                 $statsdSender = new SocketSender( $statsdHost, $statsdPort );
1258                 $statsdClient = new StatsdClient( $statsdSender );
1259                 $statsdClient->send( $context->getStats()->getBuffer() );
1260         }
1261
1262         $profiler = Profiler::instance();
1263
1264         # Profiling must actually be enabled...
1265         if ( $profiler instanceof ProfilerStub ) {
1266                 return;
1267         }
1268
1269         // Get total page request time and only show pages that longer than
1270         // $wgProfileLimit time (default is 0)
1271         $elapsed = microtime( true ) - $wgRequestTime;
1272         if ( $elapsed <= $wgProfileLimit ) {
1273                 return;
1274         }
1275
1276         $profiler->logData();
1277
1278         if ( isset( $wgDebugLogGroups['profileoutput'] )
1279                 && $wgDebugLogGroups['profileoutput'] === false
1280         ) {
1281                 // Explicitly disabled
1282                 return;
1283         }
1284         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1285                 return;
1286         }
1287
1288         $ctx = array( 'elapsed' => $elapsed );
1289         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1290                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1291         }
1292         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1293                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1294         }
1295         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1296                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1297         }
1298         if ( isset( $ctx['forwarded_for'] ) ||
1299                 isset( $ctx['client_ip'] ) ||
1300                 isset( $ctx['from'] ) ) {
1301                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1302         }
1303
1304         // Don't load $wgUser at this late stage just for statistics purposes
1305         // @todo FIXME: We can detect some anons even if it is not loaded.
1306         // See User::getId()
1307         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1308                 $ctx['anon'] = true;
1309         } else {
1310                 $ctx['anon'] = false;
1311         }
1312
1313         // Command line script uses a FauxRequest object which does not have
1314         // any knowledge about an URL and throw an exception instead.
1315         try {
1316                 $ctx['url'] = urldecode( $wgRequest->getRequestURL() );
1317         } catch ( Exception $ignored ) {
1318                 // no-op
1319         }
1320
1321         $ctx['output'] = $profiler->getOutput();
1322
1323         $log = MWLoggerFactory::getInstance( 'profileoutput' );
1324         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1325 }
1326
1327 /**
1328  * Increment a statistics counter
1329  *
1330  * @param string $key
1331  * @param int $count
1332  * @return void
1333  */
1334 function wfIncrStats( $key, $count = 1 ) {
1335         $stats = RequestContext::getMain()->getStats();
1336         $stats->updateCount( $key, $count );
1337 }
1338
1339 /**
1340  * Check whether the wiki is in read-only mode.
1341  *
1342  * @return bool
1343  */
1344 function wfReadOnly() {
1345         return wfReadOnlyReason() !== false;
1346 }
1347
1348 /**
1349  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1350  *
1351  * @return string|bool String when in read-only mode; false otherwise
1352  */
1353 function wfReadOnlyReason() {
1354         global $wgReadOnly, $wgReadOnlyFile;
1355
1356         if ( $wgReadOnly === null ) {
1357                 // Set $wgReadOnly for faster access next time
1358                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1359                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1360                 } else {
1361                         $wgReadOnly = false;
1362                 }
1363         }
1364
1365         return $wgReadOnly;
1366 }
1367
1368 /**
1369  * Return a Language object from $langcode
1370  *
1371  * @param Language|string|bool $langcode Either:
1372  *                  - a Language object
1373  *                  - code of the language to get the message for, if it is
1374  *                    a valid code create a language for that language, if
1375  *                    it is a string but not a valid code then make a basic
1376  *                    language object
1377  *                  - a boolean: if it's false then use the global object for
1378  *                    the current user's language (as a fallback for the old parameter
1379  *                    functionality), or if it is true then use global object
1380  *                    for the wiki's content language.
1381  * @return Language
1382  */
1383 function wfGetLangObj( $langcode = false ) {
1384         # Identify which language to get or create a language object for.
1385         # Using is_object here due to Stub objects.
1386         if ( is_object( $langcode ) ) {
1387                 # Great, we already have the object (hopefully)!
1388                 return $langcode;
1389         }
1390
1391         global $wgContLang, $wgLanguageCode;
1392         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1393                 # $langcode is the language code of the wikis content language object.
1394                 # or it is a boolean and value is true
1395                 return $wgContLang;
1396         }
1397
1398         global $wgLang;
1399         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1400                 # $langcode is the language code of user language object.
1401                 # or it was a boolean and value is false
1402                 return $wgLang;
1403         }
1404
1405         $validCodes = array_keys( Language::fetchLanguageNames() );
1406         if ( in_array( $langcode, $validCodes ) ) {
1407                 # $langcode corresponds to a valid language.
1408                 return Language::factory( $langcode );
1409         }
1410
1411         # $langcode is a string, but not a valid language code; use content language.
1412         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1413         return $wgContLang;
1414 }
1415
1416 /**
1417  * This is the function for getting translated interface messages.
1418  *
1419  * @see Message class for documentation how to use them.
1420  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1421  *
1422  * This function replaces all old wfMsg* functions.
1423  *
1424  * @param string|string[] $key Message key, or array of keys
1425  * @param mixed $params,... Normal message parameters
1426  * @return Message
1427  *
1428  * @since 1.17
1429  *
1430  * @see Message::__construct
1431  */
1432 function wfMessage( $key /*...*/ ) {
1433         $params = func_get_args();
1434         array_shift( $params );
1435         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1436                 $params = $params[0];
1437         }
1438         return new Message( $key, $params );
1439 }
1440
1441 /**
1442  * This function accepts multiple message keys and returns a message instance
1443  * for the first message which is non-empty. If all messages are empty then an
1444  * instance of the first message key is returned.
1445  *
1446  * @param string|string[] $keys,... Message keys
1447  * @return Message
1448  *
1449  * @since 1.18
1450  *
1451  * @see Message::newFallbackSequence
1452  */
1453 function wfMessageFallback( /*...*/ ) {
1454         $args = func_get_args();
1455         return call_user_func_array( 'Message::newFallbackSequence', $args );
1456 }
1457
1458 /**
1459  * Get a message from anywhere, for the current user language.
1460  *
1461  * Use wfMsgForContent() instead if the message should NOT
1462  * change depending on the user preferences.
1463  *
1464  * @deprecated since 1.18
1465  *
1466  * @param string $key Lookup key for the message, usually
1467  *    defined in languages/Language.php
1468  *
1469  * Parameters to the message, which can be used to insert variable text into
1470  * it, can be passed to this function in the following formats:
1471  * - One per argument, starting at the second parameter
1472  * - As an array in the second parameter
1473  * These are not shown in the function definition.
1474  *
1475  * @return string
1476  */
1477 function wfMsg( $key ) {
1478         wfDeprecated( __METHOD__, '1.21' );
1479
1480         $args = func_get_args();
1481         array_shift( $args );
1482         return wfMsgReal( $key, $args );
1483 }
1484
1485 /**
1486  * Same as above except doesn't transform the message
1487  *
1488  * @deprecated since 1.18
1489  *
1490  * @param string $key
1491  * @return string
1492  */
1493 function wfMsgNoTrans( $key ) {
1494         wfDeprecated( __METHOD__, '1.21' );
1495
1496         $args = func_get_args();
1497         array_shift( $args );
1498         return wfMsgReal( $key, $args, true, false, false );
1499 }
1500
1501 /**
1502  * Get a message from anywhere, for the current global language
1503  * set with $wgLanguageCode.
1504  *
1505  * Use this if the message should NOT change dependent on the
1506  * language set in the user's preferences. This is the case for
1507  * most text written into logs, as well as link targets (such as
1508  * the name of the copyright policy page). Link titles, on the
1509  * other hand, should be shown in the UI language.
1510  *
1511  * Note that MediaWiki allows users to change the user interface
1512  * language in their preferences, but a single installation
1513  * typically only contains content in one language.
1514  *
1515  * Be wary of this distinction: If you use wfMsg() where you should
1516  * use wfMsgForContent(), a user of the software may have to
1517  * customize potentially hundreds of messages in
1518  * order to, e.g., fix a link in every possible language.
1519  *
1520  * @deprecated since 1.18
1521  *
1522  * @param string $key Lookup key for the message, usually
1523  *     defined in languages/Language.php
1524  * @return string
1525  */
1526 function wfMsgForContent( $key ) {
1527         wfDeprecated( __METHOD__, '1.21' );
1528
1529         global $wgForceUIMsgAsContentMsg;
1530         $args = func_get_args();
1531         array_shift( $args );
1532         $forcontent = true;
1533         if ( is_array( $wgForceUIMsgAsContentMsg )
1534                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1535         ) {
1536                 $forcontent = false;
1537         }
1538         return wfMsgReal( $key, $args, true, $forcontent );
1539 }
1540
1541 /**
1542  * Same as above except doesn't transform the message
1543  *
1544  * @deprecated since 1.18
1545  *
1546  * @param string $key
1547  * @return string
1548  */
1549 function wfMsgForContentNoTrans( $key ) {
1550         wfDeprecated( __METHOD__, '1.21' );
1551
1552         global $wgForceUIMsgAsContentMsg;
1553         $args = func_get_args();
1554         array_shift( $args );
1555         $forcontent = true;
1556         if ( is_array( $wgForceUIMsgAsContentMsg )
1557                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1558         ) {
1559                 $forcontent = false;
1560         }
1561         return wfMsgReal( $key, $args, true, $forcontent, false );
1562 }
1563
1564 /**
1565  * Really get a message
1566  *
1567  * @deprecated since 1.18
1568  *
1569  * @param string $key Key to get.
1570  * @param array $args
1571  * @param bool $useDB
1572  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1573  * @param bool $transform Whether or not to transform the message.
1574  * @return string The requested message.
1575  */
1576 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1577         wfDeprecated( __METHOD__, '1.21' );
1578
1579         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1580         $message = wfMsgReplaceArgs( $message, $args );
1581         return $message;
1582 }
1583
1584 /**
1585  * Fetch a message string value, but don't replace any keys yet.
1586  *
1587  * @deprecated since 1.18
1588  *
1589  * @param string $key
1590  * @param bool $useDB
1591  * @param string|bool $langCode Code of the language to get the message for, or
1592  *   behaves as a content language switch if it is a boolean.
1593  * @param bool $transform Whether to parse magic words, etc.
1594  * @return string
1595  */
1596 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1597         wfDeprecated( __METHOD__, '1.21' );
1598
1599         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1600
1601         $cache = MessageCache::singleton();
1602         $message = $cache->get( $key, $useDB, $langCode );
1603         if ( $message === false ) {
1604                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1605         } elseif ( $transform ) {
1606                 $message = $cache->transform( $message );
1607         }
1608         return $message;
1609 }
1610
1611 /**
1612  * Replace message parameter keys on the given formatted output.
1613  *
1614  * @param string $message
1615  * @param array $args
1616  * @return string
1617  * @private
1618  */
1619 function wfMsgReplaceArgs( $message, $args ) {
1620         # Fix windows line-endings
1621         # Some messages are split with explode("\n", $msg)
1622         $message = str_replace( "\r", '', $message );
1623
1624         // Replace arguments
1625         if ( count( $args ) ) {
1626                 if ( is_array( $args[0] ) ) {
1627                         $args = array_values( $args[0] );
1628                 }
1629                 $replacementKeys = array();
1630                 foreach ( $args as $n => $param ) {
1631                         $replacementKeys['$' . ( $n + 1 )] = $param;
1632                 }
1633                 $message = strtr( $message, $replacementKeys );
1634         }
1635
1636         return $message;
1637 }
1638
1639 /**
1640  * Return an HTML-escaped version of a message.
1641  * Parameter replacements, if any, are done *after* the HTML-escaping,
1642  * so parameters may contain HTML (eg links or form controls). Be sure
1643  * to pre-escape them if you really do want plaintext, or just wrap
1644  * the whole thing in htmlspecialchars().
1645  *
1646  * @deprecated since 1.18
1647  *
1648  * @param string $key
1649  * @param string $args,... Parameters
1650  * @return string
1651  */
1652 function wfMsgHtml( $key ) {
1653         wfDeprecated( __METHOD__, '1.21' );
1654
1655         $args = func_get_args();
1656         array_shift( $args );
1657         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1658 }
1659
1660 /**
1661  * Return an HTML version of message
1662  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1663  * so parameters may contain HTML (eg links or form controls). Be sure
1664  * to pre-escape them if you really do want plaintext, or just wrap
1665  * the whole thing in htmlspecialchars().
1666  *
1667  * @deprecated since 1.18
1668  *
1669  * @param string $key
1670  * @param string $args,... Parameters
1671  * @return string
1672  */
1673 function wfMsgWikiHtml( $key ) {
1674         wfDeprecated( __METHOD__, '1.21' );
1675
1676         $args = func_get_args();
1677         array_shift( $args );
1678         return wfMsgReplaceArgs(
1679                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1680                 /* can't be set to false */ true, /* interface */ true )->getText(),
1681                 $args );
1682 }
1683
1684 /**
1685  * Returns message in the requested format
1686  *
1687  * @deprecated since 1.18
1688  *
1689  * @param string $key Key of the message
1690  * @param array $options Processing rules.
1691  *   Can take the following options:
1692  *     parse: parses wikitext to HTML
1693  *     parseinline: parses wikitext to HTML and removes the surrounding
1694  *       p's added by parser or tidy
1695  *     escape: filters message through htmlspecialchars
1696  *     escapenoentities: same, but allows entity references like &#160; through
1697  *     replaceafter: parameters are substituted after parsing or escaping
1698  *     parsemag: transform the message using magic phrases
1699  *     content: fetch message for content language instead of interface
1700  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1701  *     language: Language object or language code to fetch message for
1702  *       (overridden by content).
1703  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1704  *
1705  * @return string
1706  */
1707 function wfMsgExt( $key, $options ) {
1708         wfDeprecated( __METHOD__, '1.21' );
1709
1710         $args = func_get_args();
1711         array_shift( $args );
1712         array_shift( $args );
1713         $options = (array)$options;
1714         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1715                 'parsemag', 'content' );
1716
1717         foreach ( $options as $arrayKey => $option ) {
1718                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1719                         // An unknown index, neither numeric nor "language"
1720                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1721                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1722                         // A numeric index with unknown value
1723                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1724                 }
1725         }
1726
1727         if ( in_array( 'content', $options, true ) ) {
1728                 $forContent = true;
1729                 $langCode = true;
1730                 $langCodeObj = null;
1731         } elseif ( array_key_exists( 'language', $options ) ) {
1732                 $forContent = false;
1733                 $langCode = wfGetLangObj( $options['language'] );
1734                 $langCodeObj = $langCode;
1735         } else {
1736                 $forContent = false;
1737                 $langCode = false;
1738                 $langCodeObj = null;
1739         }
1740
1741         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1742
1743         if ( !in_array( 'replaceafter', $options, true ) ) {
1744                 $string = wfMsgReplaceArgs( $string, $args );
1745         }
1746
1747         $messageCache = MessageCache::singleton();
1748         $parseInline = in_array( 'parseinline', $options, true );
1749         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1750                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1751                 if ( $string instanceof ParserOutput ) {
1752                         $string = $string->getText();
1753                 }
1754
1755                 if ( $parseInline ) {
1756                         $string = Parser::stripOuterParagraph( $string );
1757                 }
1758         } elseif ( in_array( 'parsemag', $options, true ) ) {
1759                 $string = $messageCache->transform( $string,
1760                                 !$forContent, $langCodeObj );
1761         }
1762
1763         if ( in_array( 'escape', $options, true ) ) {
1764                 $string = htmlspecialchars ( $string );
1765         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1766                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1767         }
1768
1769         if ( in_array( 'replaceafter', $options, true ) ) {
1770                 $string = wfMsgReplaceArgs( $string, $args );
1771         }
1772
1773         return $string;
1774 }
1775
1776 /**
1777  * Since wfMsg() and co suck, they don't return false if the message key they
1778  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1779  * nonexistence of messages by checking the MessageCache::get() result directly.
1780  *
1781  * @deprecated since 1.18. Use Message::isDisabled().
1782  *
1783  * @param string $key The message key looked up
1784  * @return bool True if the message *doesn't* exist.
1785  */
1786 function wfEmptyMsg( $key ) {
1787         wfDeprecated( __METHOD__, '1.21' );
1788
1789         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1790 }
1791
1792 /**
1793  * Fetch server name for use in error reporting etc.
1794  * Use real server name if available, so we know which machine
1795  * in a server farm generated the current page.
1796  *
1797  * @return string
1798  */
1799 function wfHostname() {
1800         static $host;
1801         if ( is_null( $host ) ) {
1802
1803                 # Hostname overriding
1804                 global $wgOverrideHostname;
1805                 if ( $wgOverrideHostname !== false ) {
1806                         # Set static and skip any detection
1807                         $host = $wgOverrideHostname;
1808                         return $host;
1809                 }
1810
1811                 if ( function_exists( 'posix_uname' ) ) {
1812                         // This function not present on Windows
1813                         $uname = posix_uname();
1814                 } else {
1815                         $uname = false;
1816                 }
1817                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1818                         $host = $uname['nodename'];
1819                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1820                         # Windows computer name
1821                         $host = getenv( 'COMPUTERNAME' );
1822                 } else {
1823                         # This may be a virtual server.
1824                         $host = $_SERVER['SERVER_NAME'];
1825                 }
1826         }
1827         return $host;
1828 }
1829
1830 /**
1831  * Returns a script tag that stores the amount of time it took MediaWiki to
1832  * handle the request in milliseconds as 'wgBackendResponseTime'.
1833  *
1834  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1835  * hostname of the server handling the request.
1836  *
1837  * @return string
1838  */
1839 function wfReportTime() {
1840         global $wgRequestTime, $wgShowHostnames;
1841
1842         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1843         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1844         if ( $wgShowHostnames ) {
1845                 $reportVars['wgHostname'] = wfHostname();
1846         }
1847         return Skin::makeVariablesScript( $reportVars );
1848 }
1849
1850 /**
1851  * Safety wrapper for debug_backtrace().
1852  *
1853  * Will return an empty array if debug_backtrace is disabled, otherwise
1854  * the output from debug_backtrace() (trimmed).
1855  *
1856  * @param int $limit This parameter can be used to limit the number of stack frames returned
1857  *
1858  * @return array Array of backtrace information
1859  */
1860 function wfDebugBacktrace( $limit = 0 ) {
1861         static $disabled = null;
1862
1863         if ( is_null( $disabled ) ) {
1864                 $disabled = !function_exists( 'debug_backtrace' );
1865                 if ( $disabled ) {
1866                         wfDebug( "debug_backtrace() is disabled\n" );
1867                 }
1868         }
1869         if ( $disabled ) {
1870                 return array();
1871         }
1872
1873         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1874                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1875         } else {
1876                 return array_slice( debug_backtrace(), 1 );
1877         }
1878 }
1879
1880 /**
1881  * Get a debug backtrace as a string
1882  *
1883  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1884  *   Defaults to $wgCommandLineMode if unset.
1885  * @return string
1886  * @since 1.25 Supports $raw parameter.
1887  */
1888 function wfBacktrace( $raw = null ) {
1889         global $wgCommandLineMode;
1890
1891         if ( $raw === null ) {
1892                 $raw = $wgCommandLineMode;
1893         }
1894
1895         if ( $raw ) {
1896                 $frameFormat = "%s line %s calls %s()\n";
1897                 $traceFormat = "%s";
1898         } else {
1899                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1900                 $traceFormat = "<ul>\n%s</ul>\n";
1901         }
1902
1903         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1904                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1905                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1906                 $call = $frame['function'];
1907                 if ( !empty( $frame['class'] ) ) {
1908                         $call = $frame['class'] . $frame['type'] . $call;
1909                 }
1910                 return sprintf( $frameFormat, $file, $line, $call );
1911         }, wfDebugBacktrace() );
1912
1913         return sprintf( $traceFormat, implode( '', $frames ) );
1914 }
1915
1916 /**
1917  * Get the name of the function which called this function
1918  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1919  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1920  * wfGetCaller( 3 ) is the parent of that.
1921  *
1922  * @param int $level
1923  * @return string
1924  */
1925 function wfGetCaller( $level = 2 ) {
1926         $backtrace = wfDebugBacktrace( $level + 1 );
1927         if ( isset( $backtrace[$level] ) ) {
1928                 return wfFormatStackFrame( $backtrace[$level] );
1929         } else {
1930                 return 'unknown';
1931         }
1932 }
1933
1934 /**
1935  * Return a string consisting of callers in the stack. Useful sometimes
1936  * for profiling specific points.
1937  *
1938  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1939  * @return string
1940  */
1941 function wfGetAllCallers( $limit = 3 ) {
1942         $trace = array_reverse( wfDebugBacktrace() );
1943         if ( !$limit || $limit > count( $trace ) - 1 ) {
1944                 $limit = count( $trace ) - 1;
1945         }
1946         $trace = array_slice( $trace, -$limit - 1, $limit );
1947         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1948 }
1949
1950 /**
1951  * Return a string representation of frame
1952  *
1953  * @param array $frame
1954  * @return string
1955  */
1956 function wfFormatStackFrame( $frame ) {
1957         return isset( $frame['class'] ) ?
1958                 $frame['class'] . '::' . $frame['function'] :
1959                 $frame['function'];
1960 }
1961
1962 /* Some generic result counters, pulled out of SearchEngine */
1963
1964 /**
1965  * @todo document
1966  *
1967  * @param int $offset
1968  * @param int $limit
1969  * @return string
1970  */
1971 function wfShowingResults( $offset, $limit ) {
1972         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1973 }
1974
1975 /**
1976  * @todo document
1977  * @todo FIXME: We may want to blacklist some broken browsers
1978  *
1979  * @param bool $force
1980  * @return bool Whereas client accept gzip compression
1981  */
1982 function wfClientAcceptsGzip( $force = false ) {
1983         static $result = null;
1984         if ( $result === null || $force ) {
1985                 $result = false;
1986                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1987                         # @todo FIXME: We may want to blacklist some broken browsers
1988                         $m = array();
1989                         if ( preg_match(
1990                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1991                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1992                                         $m
1993                                 )
1994                         ) {
1995                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1996                                         $result = false;
1997                                         return $result;
1998                                 }
1999                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2000                                 $result = true;
2001                         }
2002                 }
2003         }
2004         return $result;
2005 }
2006
2007 /**
2008  * Obtain the offset and limit values from the request string;
2009  * used in special pages
2010  *
2011  * @param int $deflimit Default limit if none supplied
2012  * @param string $optionname Name of a user preference to check against
2013  * @return array
2014  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2015  */
2016 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2017         global $wgRequest;
2018         wfDeprecated( __METHOD__, '1.24' );
2019         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2020 }
2021
2022 /**
2023  * Escapes the given text so that it may be output using addWikiText()
2024  * without any linking, formatting, etc. making its way through. This
2025  * is achieved by substituting certain characters with HTML entities.
2026  * As required by the callers, "<nowiki>" is not used.
2027  *
2028  * @param string $text Text to be escaped
2029  * @return string
2030  */
2031 function wfEscapeWikiText( $text ) {
2032         static $repl = null, $repl2 = null;
2033         if ( $repl === null ) {
2034                 $repl = array(
2035                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2036                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2037                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2038                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2039                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2040                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2041                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2042                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2043                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2044                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2045                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2046                         '__' => '_&#95;', '://' => '&#58;//',
2047                 );
2048
2049                 // We have to catch everything "\s" matches in PCRE
2050                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2051                         $repl["$magic "] = "$magic&#32;";
2052                         $repl["$magic\t"] = "$magic&#9;";
2053                         $repl["$magic\r"] = "$magic&#13;";
2054                         $repl["$magic\n"] = "$magic&#10;";
2055                         $repl["$magic\f"] = "$magic&#12;";
2056                 }
2057
2058                 // And handle protocols that don't use "://"
2059                 global $wgUrlProtocols;
2060                 $repl2 = array();
2061                 foreach ( $wgUrlProtocols as $prot ) {
2062                         if ( substr( $prot, -1 ) === ':' ) {
2063                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2064                         }
2065                 }
2066                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2067         }
2068         $text = substr( strtr( "\n$text", $repl ), 1 );
2069         $text = preg_replace( $repl2, '$1&#58;', $text );
2070         return $text;
2071 }
2072
2073 /**
2074  * Sets dest to source and returns the original value of dest
2075  * If source is NULL, it just returns the value, it doesn't set the variable
2076  * If force is true, it will set the value even if source is NULL
2077  *
2078  * @param mixed $dest
2079  * @param mixed $source
2080  * @param bool $force
2081  * @return mixed
2082  */
2083 function wfSetVar( &$dest, $source, $force = false ) {
2084         $temp = $dest;
2085         if ( !is_null( $source ) || $force ) {
2086                 $dest = $source;
2087         }
2088         return $temp;
2089 }
2090
2091 /**
2092  * As for wfSetVar except setting a bit
2093  *
2094  * @param int $dest
2095  * @param int $bit
2096  * @param bool $state
2097  *
2098  * @return bool
2099  */
2100 function wfSetBit( &$dest, $bit, $state = true ) {
2101         $temp = (bool)( $dest & $bit );
2102         if ( !is_null( $state ) ) {
2103                 if ( $state ) {
2104                         $dest |= $bit;
2105                 } else {
2106                         $dest &= ~$bit;
2107                 }
2108         }
2109         return $temp;
2110 }
2111
2112 /**
2113  * A wrapper around the PHP function var_export().
2114  * Either print it or add it to the regular output ($wgOut).
2115  *
2116  * @param mixed $var A PHP variable to dump.
2117  */
2118 function wfVarDump( $var ) {
2119         global $wgOut;
2120         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2121         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2122                 print $s;
2123         } else {
2124                 $wgOut->addHTML( $s );
2125         }
2126 }
2127
2128 /**
2129  * Provide a simple HTTP error.
2130  *
2131  * @param int|string $code
2132  * @param string $label
2133  * @param string $desc
2134  */
2135 function wfHttpError( $code, $label, $desc ) {
2136         global $wgOut;
2137         header( "HTTP/1.0 $code $label" );
2138         header( "Status: $code $label" );
2139         if ( $wgOut ) {
2140                 $wgOut->disable();
2141                 $wgOut->sendCacheControl();
2142         }
2143
2144         header( 'Content-type: text/html; charset=utf-8' );
2145         print "<!doctype html>" .
2146                 '<html><head><title>' .
2147                 htmlspecialchars( $label ) .
2148                 '</title></head><body><h1>' .
2149                 htmlspecialchars( $label ) .
2150                 '</h1><p>' .
2151                 nl2br( htmlspecialchars( $desc ) ) .
2152                 "</p></body></html>\n";
2153 }
2154
2155 /**
2156  * Clear away any user-level output buffers, discarding contents.
2157  *
2158  * Suitable for 'starting afresh', for instance when streaming
2159  * relatively large amounts of data without buffering, or wanting to
2160  * output image files without ob_gzhandler's compression.
2161  *
2162  * The optional $resetGzipEncoding parameter controls suppression of
2163  * the Content-Encoding header sent by ob_gzhandler; by default it
2164  * is left. See comments for wfClearOutputBuffers() for why it would
2165  * be used.
2166  *
2167  * Note that some PHP configuration options may add output buffer
2168  * layers which cannot be removed; these are left in place.
2169  *
2170  * @param bool $resetGzipEncoding
2171  */
2172 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2173         if ( $resetGzipEncoding ) {
2174                 // Suppress Content-Encoding and Content-Length
2175                 // headers from 1.10+s wfOutputHandler
2176                 global $wgDisableOutputCompression;
2177                 $wgDisableOutputCompression = true;
2178         }
2179         while ( $status = ob_get_status() ) {
2180                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2181                         // Probably from zlib.output_compression or other
2182                         // PHP-internal setting which can't be removed.
2183                         //
2184                         // Give up, and hope the result doesn't break
2185                         // output behavior.
2186                         break;
2187                 }
2188                 if ( !ob_end_clean() ) {
2189                         // Could not remove output buffer handler; abort now
2190                         // to avoid getting in some kind of infinite loop.
2191                         break;
2192                 }
2193                 if ( $resetGzipEncoding ) {
2194                         if ( $status['name'] == 'ob_gzhandler' ) {
2195                                 // Reset the 'Content-Encoding' field set by this handler
2196                                 // so we can start fresh.
2197                                 header_remove( 'Content-Encoding' );
2198                                 break;
2199                         }
2200                 }
2201         }
2202 }
2203
2204 /**
2205  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2206  *
2207  * Clear away output buffers, but keep the Content-Encoding header
2208  * produced by ob_gzhandler, if any.
2209  *
2210  * This should be used for HTTP 304 responses, where you need to
2211  * preserve the Content-Encoding header of the real result, but
2212  * also need to suppress the output of ob_gzhandler to keep to spec
2213  * and avoid breaking Firefox in rare cases where the headers and
2214  * body are broken over two packets.
2215  */
2216 function wfClearOutputBuffers() {
2217         wfResetOutputBuffers( false );
2218 }
2219
2220 /**
2221  * Converts an Accept-* header into an array mapping string values to quality
2222  * factors
2223  *
2224  * @param string $accept
2225  * @param string $def Default
2226  * @return float[] Associative array of string => float pairs
2227  */
2228 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2229         # No arg means accept anything (per HTTP spec)
2230         if ( !$accept ) {
2231                 return array( $def => 1.0 );
2232         }
2233
2234         $prefs = array();
2235
2236         $parts = explode( ',', $accept );
2237
2238         foreach ( $parts as $part ) {
2239                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2240                 $values = explode( ';', trim( $part ) );
2241                 $match = array();
2242                 if ( count( $values ) == 1 ) {
2243                         $prefs[$values[0]] = 1.0;
2244                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2245                         $prefs[$values[0]] = floatval( $match[1] );
2246                 }
2247         }
2248
2249         return $prefs;
2250 }
2251
2252 /**
2253  * Checks if a given MIME type matches any of the keys in the given
2254  * array. Basic wildcards are accepted in the array keys.
2255  *
2256  * Returns the matching MIME type (or wildcard) if a match, otherwise
2257  * NULL if no match.
2258  *
2259  * @param string $type
2260  * @param array $avail
2261  * @return string
2262  * @private
2263  */
2264 function mimeTypeMatch( $type, $avail ) {
2265         if ( array_key_exists( $type, $avail ) ) {
2266                 return $type;
2267         } else {
2268                 $parts = explode( '/', $type );
2269                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2270                         return $parts[0] . '/*';
2271                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2272                         return '*/*';
2273                 } else {
2274                         return null;
2275                 }
2276         }
2277 }
2278
2279 /**
2280  * Returns the 'best' match between a client's requested internet media types
2281  * and the server's list of available types. Each list should be an associative
2282  * array of type to preference (preference is a float between 0.0 and 1.0).
2283  * Wildcards in the types are acceptable.
2284  *
2285  * @param array $cprefs Client's acceptable type list
2286  * @param array $sprefs Server's offered types
2287  * @return string
2288  *
2289  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2290  * XXX: generalize to negotiate other stuff
2291  */
2292 function wfNegotiateType( $cprefs, $sprefs ) {
2293         $combine = array();
2294
2295         foreach ( array_keys( $sprefs ) as $type ) {
2296                 $parts = explode( '/', $type );
2297                 if ( $parts[1] != '*' ) {
2298                         $ckey = mimeTypeMatch( $type, $cprefs );
2299                         if ( $ckey ) {
2300                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2301                         }
2302                 }
2303         }
2304
2305         foreach ( array_keys( $cprefs ) as $type ) {
2306                 $parts = explode( '/', $type );
2307                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2308                         $skey = mimeTypeMatch( $type, $sprefs );
2309                         if ( $skey ) {
2310                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2311                         }
2312                 }
2313         }
2314
2315         $bestq = 0;
2316         $besttype = null;
2317
2318         foreach ( array_keys( $combine ) as $type ) {
2319                 if ( $combine[$type] > $bestq ) {
2320                         $besttype = $type;
2321                         $bestq = $combine[$type];
2322                 }
2323         }
2324
2325         return $besttype;
2326 }
2327
2328 /**
2329  * Reference-counted warning suppression
2330  *
2331  * @param bool $end
2332  */
2333 function wfSuppressWarnings( $end = false ) {
2334         static $suppressCount = 0;
2335         static $originalLevel = false;
2336
2337         if ( $end ) {
2338                 if ( $suppressCount ) {
2339                         --$suppressCount;
2340                         if ( !$suppressCount ) {
2341                                 error_reporting( $originalLevel );
2342                         }
2343                 }
2344         } else {
2345                 if ( !$suppressCount ) {
2346                         $originalLevel = error_reporting( E_ALL & ~(
2347                                 E_WARNING |
2348                                 E_NOTICE |
2349                                 E_USER_WARNING |
2350                                 E_USER_NOTICE |
2351                                 E_DEPRECATED |
2352                                 E_USER_DEPRECATED |
2353                                 E_STRICT
2354                         ) );
2355                 }
2356                 ++$suppressCount;
2357         }
2358 }
2359
2360 /**
2361  * Restore error level to previous value
2362  */
2363 function wfRestoreWarnings() {
2364         wfSuppressWarnings( true );
2365 }
2366
2367 # Autodetect, convert and provide timestamps of various types
2368
2369 /**
2370  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2371  */
2372 define( 'TS_UNIX', 0 );
2373
2374 /**
2375  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2376  */
2377 define( 'TS_MW', 1 );
2378
2379 /**
2380  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2381  */
2382 define( 'TS_DB', 2 );
2383
2384 /**
2385  * RFC 2822 format, for E-mail and HTTP headers
2386  */
2387 define( 'TS_RFC2822', 3 );
2388
2389 /**
2390  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2391  *
2392  * This is used by Special:Export
2393  */
2394 define( 'TS_ISO_8601', 4 );
2395
2396 /**
2397  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2398  *
2399  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2400  *       DateTime tag and page 36 for the DateTimeOriginal and
2401  *       DateTimeDigitized tags.
2402  */
2403 define( 'TS_EXIF', 5 );
2404
2405 /**
2406  * Oracle format time.
2407  */
2408 define( 'TS_ORACLE', 6 );
2409
2410 /**
2411  * Postgres format time.
2412  */
2413 define( 'TS_POSTGRES', 7 );
2414
2415 /**
2416  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2417  */
2418 define( 'TS_ISO_8601_BASIC', 9 );
2419
2420 /**
2421  * Get a timestamp string in one of various formats
2422  *
2423  * @param mixed $outputtype A timestamp in one of the supported formats, the
2424  *   function will autodetect which format is supplied and act accordingly.
2425  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2426  * @return string|bool String / false The same date in the format specified in $outputtype or false
2427  */
2428 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2429         try {
2430                 $timestamp = new MWTimestamp( $ts );
2431                 return $timestamp->getTimestamp( $outputtype );
2432         } catch ( TimestampException $e ) {
2433                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2434                 return false;
2435         }
2436 }
2437
2438 /**
2439  * Return a formatted timestamp, or null if input is null.
2440  * For dealing with nullable timestamp columns in the database.
2441  *
2442  * @param int $outputtype
2443  * @param string $ts
2444  * @return string
2445  */
2446 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2447         if ( is_null( $ts ) ) {
2448                 return null;
2449         } else {
2450                 return wfTimestamp( $outputtype, $ts );
2451         }
2452 }
2453
2454 /**
2455  * Convenience function; returns MediaWiki timestamp for the present time.
2456  *
2457  * @return string
2458  */
2459 function wfTimestampNow() {
2460         # return NOW
2461         return wfTimestamp( TS_MW, time() );
2462 }
2463
2464 /**
2465  * Check if the operating system is Windows
2466  *
2467  * @return bool True if it's Windows, false otherwise.
2468  */
2469 function wfIsWindows() {
2470         static $isWindows = null;
2471         if ( $isWindows === null ) {
2472                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2473         }
2474         return $isWindows;
2475 }
2476
2477 /**
2478  * Check if we are running under HHVM
2479  *
2480  * @return bool
2481  */
2482 function wfIsHHVM() {
2483         return defined( 'HHVM_VERSION' );
2484 }
2485
2486 /**
2487  * Swap two variables
2488  *
2489  * @deprecated since 1.24
2490  * @param mixed $x
2491  * @param mixed $y
2492  */
2493 function swap( &$x, &$y ) {
2494         wfDeprecated( __FUNCTION__, '1.24' );
2495         $z = $x;
2496         $x = $y;
2497         $y = $z;
2498 }
2499
2500 /**
2501  * Tries to get the system directory for temporary files. First
2502  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2503  * environment variables are then checked in sequence, and if none are
2504  * set try sys_get_temp_dir().
2505  *
2506  * NOTE: When possible, use instead the tmpfile() function to create
2507  * temporary files to avoid race conditions on file creation, etc.
2508  *
2509  * @return string
2510  */
2511 function wfTempDir() {
2512         global $wgTmpDirectory;
2513
2514         if ( $wgTmpDirectory !== false ) {
2515                 return $wgTmpDirectory;
2516         }
2517
2518         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2519
2520         foreach ( $tmpDir as $tmp ) {
2521                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2522                         return $tmp;
2523                 }
2524         }
2525         return sys_get_temp_dir();
2526 }
2527
2528 /**
2529  * Make directory, and make all parent directories if they don't exist
2530  *
2531  * @param string $dir Full path to directory to create
2532  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2533  * @param string $caller Optional caller param for debugging.
2534  * @throws MWException
2535  * @return bool
2536  */
2537 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2538         global $wgDirectoryMode;
2539
2540         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2541                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2542         }
2543
2544         if ( !is_null( $caller ) ) {
2545                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2546         }
2547
2548         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2549                 return true;
2550         }
2551
2552         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2553
2554         if ( is_null( $mode ) ) {
2555                 $mode = $wgDirectoryMode;
2556         }
2557
2558         // Turn off the normal warning, we're doing our own below
2559         wfSuppressWarnings();
2560         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2561         wfRestoreWarnings();
2562
2563         if ( !$ok ) {
2564                 //directory may have been created on another request since we last checked
2565                 if ( is_dir( $dir ) ) {
2566                         return true;
2567                 }
2568
2569                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2570                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2571         }
2572         return $ok;
2573 }
2574
2575 /**
2576  * Remove a directory and all its content.
2577  * Does not hide error.
2578  * @param string $dir
2579  */
2580 function wfRecursiveRemoveDir( $dir ) {
2581         wfDebug( __FUNCTION__ . "( $dir )\n" );
2582         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2583         if ( is_dir( $dir ) ) {
2584                 $objects = scandir( $dir );
2585                 foreach ( $objects as $object ) {
2586                         if ( $object != "." && $object != ".." ) {
2587                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2588                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2589                                 } else {
2590                                         unlink( $dir . '/' . $object );
2591                                 }
2592                         }
2593                 }
2594                 reset( $objects );
2595                 rmdir( $dir );
2596         }
2597 }
2598
2599 /**
2600  * @param int $nr The number to format
2601  * @param int $acc The number of digits after the decimal point, default 2
2602  * @param bool $round Whether or not to round the value, default true
2603  * @return string
2604  */
2605 function wfPercent( $nr, $acc = 2, $round = true ) {
2606         $ret = sprintf( "%.${acc}f", $nr );
2607         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2608 }
2609
2610 /**
2611  * Safety wrapper around ini_get() for boolean settings.
2612  * The values returned from ini_get() are pre-normalized for settings
2613  * set via php.ini or php_flag/php_admin_flag... but *not*
2614  * for those set via php_value/php_admin_value.
2615  *
2616  * It's fairly common for people to use php_value instead of php_flag,
2617  * which can leave you with an 'off' setting giving a false positive
2618  * for code that just takes the ini_get() return value as a boolean.
2619  *
2620  * To make things extra interesting, setting via php_value accepts
2621  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2622  * Unrecognized values go false... again opposite PHP's own coercion
2623  * from string to bool.
2624  *
2625  * Luckily, 'properly' set settings will always come back as '0' or '1',
2626  * so we only have to worry about them and the 'improper' settings.
2627  *
2628  * I frickin' hate PHP... :P
2629  *
2630  * @param string $setting
2631  * @return bool
2632  */
2633 function wfIniGetBool( $setting ) {
2634         $val = strtolower( ini_get( $setting ) );
2635         // 'on' and 'true' can't have whitespace around them, but '1' can.
2636         return $val == 'on'
2637                 || $val == 'true'
2638                 || $val == 'yes'
2639                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2640 }
2641
2642 /**
2643  * Windows-compatible version of escapeshellarg()
2644  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2645  * function puts single quotes in regardless of OS.
2646  *
2647  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2648  * earlier distro releases of PHP)
2649  *
2650  * @param string ... strings to escape and glue together, or a single array of strings parameter
2651  * @return string
2652  */
2653 function wfEscapeShellArg( /*...*/ ) {
2654         wfInitShellLocale();
2655
2656         $args = func_get_args();
2657         if ( count( $args ) === 1 && is_array( reset( $args ) ) ) {
2658                 // If only one argument has been passed, and that argument is an array,
2659                 // treat it as a list of arguments
2660                 $args = reset( $args );
2661         }
2662
2663         $first = true;
2664         $retVal = '';
2665         foreach ( $args as $arg ) {
2666                 if ( !$first ) {
2667                         $retVal .= ' ';
2668                 } else {
2669                         $first = false;
2670                 }
2671
2672                 if ( wfIsWindows() ) {
2673                         // Escaping for an MSVC-style command line parser and CMD.EXE
2674                         // @codingStandardsIgnoreStart For long URLs
2675                         // Refs:
2676                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2677                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2678                         //  * Bug #13518
2679                         //  * CR r63214
2680                         // Double the backslashes before any double quotes. Escape the double quotes.
2681                         // @codingStandardsIgnoreEnd
2682                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2683                         $arg = '';
2684                         $iteration = 0;
2685                         foreach ( $tokens as $token ) {
2686                                 if ( $iteration % 2 == 1 ) {
2687                                         // Delimiter, a double quote preceded by zero or more slashes
2688                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2689                                 } elseif ( $iteration % 4 == 2 ) {
2690                                         // ^ in $token will be outside quotes, need to be escaped
2691                                         $arg .= str_replace( '^', '^^', $token );
2692                                 } else { // $iteration % 4 == 0
2693                                         // ^ in $token will appear inside double quotes, so leave as is
2694                                         $arg .= $token;
2695                                 }
2696                                 $iteration++;
2697                         }
2698                         // Double the backslashes before the end of the string, because
2699                         // we will soon add a quote
2700                         $m = array();
2701                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2702                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2703                         }
2704
2705                         // Add surrounding quotes
2706                         $retVal .= '"' . $arg . '"';
2707                 } else {
2708                         $retVal .= escapeshellarg( $arg );
2709                 }
2710         }
2711         return $retVal;
2712 }
2713
2714 /**
2715  * Check if wfShellExec() is effectively disabled via php.ini config
2716  *
2717  * @return bool|string False or one of (safemode,disabled)
2718  * @since 1.22
2719  */
2720 function wfShellExecDisabled() {
2721         static $disabled = null;
2722         if ( is_null( $disabled ) ) {
2723                 if ( wfIniGetBool( 'safe_mode' ) ) {
2724                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2725                         $disabled = 'safemode';
2726                 } elseif ( !function_exists( 'proc_open' ) ) {
2727                         wfDebug( "proc_open() is disabled\n" );
2728                         $disabled = 'disabled';
2729                 } else {
2730                         $disabled = false;
2731                 }
2732         }
2733         return $disabled;
2734 }
2735
2736 /**
2737  * Execute a shell command, with time and memory limits mirrored from the PHP
2738  * configuration if supported.
2739  *
2740  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2741  *   or an array of unescaped arguments, in which case each value will be escaped
2742  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2743  * @param null|mixed &$retval Optional, will receive the program's exit code.
2744  *   (non-zero is usually failure). If there is an error from
2745  *   read, select, or proc_open(), this will be set to -1.
2746  * @param array $environ Optional environment variables which should be
2747  *   added to the executed command environment.
2748  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2749  *   this overwrites the global wgMaxShell* limits.
2750  * @param array $options Array of options:
2751  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2752  *     including errors from limit.sh
2753  *   - profileMethod: By default this function will profile based on the calling
2754  *     method. Set this to a string for an alternative method to profile from
2755  *
2756  * @return string Collected stdout as a string
2757  */
2758 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2759         $limits = array(), $options = array()
2760 ) {
2761         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2762                 $wgMaxShellWallClockTime, $wgShellCgroup;
2763
2764         $disabled = wfShellExecDisabled();
2765         if ( $disabled ) {
2766                 $retval = 1;
2767                 return $disabled == 'safemode' ?
2768                         'Unable to run external programs in safe mode.' :
2769                         'Unable to run external programs, proc_open() is disabled.';
2770         }
2771
2772         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2773         $profileMethod = isset( $options['profileMethod'] ) ? $options['profileMethod'] : wfGetCaller();
2774
2775         wfInitShellLocale();
2776
2777         $envcmd = '';
2778         foreach ( $environ as $k => $v ) {
2779                 if ( wfIsWindows() ) {
2780                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2781                          * appear in the environment variable, so we must use carat escaping as documented in
2782                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2783                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2784                          * are listed there but doesn't appear to need it.
2785                          */
2786                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2787                 } else {
2788                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2789                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2790                          */
2791                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2792                 }
2793         }
2794         if ( is_array( $cmd ) ) {
2795                 $cmd = wfEscapeShellArg( $cmd );
2796         }
2797
2798         $cmd = $envcmd . $cmd;
2799
2800         $useLogPipe = false;
2801         if ( is_executable( '/bin/bash' ) ) {
2802                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2803                 if ( isset( $limits['walltime'] ) ) {
2804                         $wallTime = intval( $limits['walltime'] );
2805                 } elseif ( isset( $limits['time'] ) ) {
2806                         $wallTime = $time;
2807                 } else {
2808                         $wallTime = intval( $wgMaxShellWallClockTime );
2809                 }
2810                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2811                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2812
2813                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2814                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2815                                 escapeshellarg( $cmd ) . ' ' .
2816                                 escapeshellarg(
2817                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2818                                         "MW_CPU_LIMIT=$time; " .
2819                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2820                                         "MW_MEM_LIMIT=$mem; " .
2821                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2822                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2823                                         "MW_USE_LOG_PIPE=yes"
2824                                 );
2825                         $useLogPipe = true;
2826                 } elseif ( $includeStderr ) {
2827                         $cmd .= ' 2>&1';
2828                 }
2829         } elseif ( $includeStderr ) {
2830                 $cmd .= ' 2>&1';
2831         }
2832         wfDebug( "wfShellExec: $cmd\n" );
2833
2834         $desc = array(
2835                 0 => array( 'file', 'php://stdin', 'r' ),
2836                 1 => array( 'pipe', 'w' ),
2837                 2 => array( 'file', 'php://stderr', 'w' ) );
2838         if ( $useLogPipe ) {
2839                 $desc[3] = array( 'pipe', 'w' );
2840         }
2841         $pipes = null;
2842         $scoped = Profiler::instance()->scopedProfileIn( __FUNCTION__ . '-' . $profileMethod );
2843         $proc = proc_open( $cmd, $desc, $pipes );
2844         if ( !$proc ) {
2845                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2846                 $retval = -1;
2847                 return '';
2848         }
2849         $outBuffer = $logBuffer = '';
2850         $emptyArray = array();
2851         $status = false;
2852         $logMsg = false;
2853
2854         // According to the documentation, it is possible for stream_select()
2855         // to fail due to EINTR. I haven't managed to induce this in testing
2856         // despite sending various signals. If it did happen, the error
2857         // message would take the form:
2858         //
2859         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2860         //
2861         // where [4] is the value of the macro EINTR and "Interrupted system
2862         // call" is string which according to the Linux manual is "possibly"
2863         // localised according to LC_MESSAGES.
2864         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2865         $eintrMessage = "stream_select(): unable to select [$eintr]";
2866
2867         // Build a table mapping resource IDs to pipe FDs to work around a
2868         // PHP 5.3 issue in which stream_select() does not preserve array keys
2869         // <https://bugs.php.net/bug.php?id=53427>.
2870         $fds = array();
2871         foreach ( $pipes as $fd => $pipe ) {
2872                 $fds[(int)$pipe] = $fd;
2873         }
2874
2875         $running = true;
2876         $timeout = null;
2877         $numReadyPipes = 0;
2878
2879         while ( $running === true || $numReadyPipes !== 0 ) {
2880                 if ( $running ) {
2881                         $status = proc_get_status( $proc );
2882                         // If the process has terminated, switch to nonblocking selects
2883                         // for getting any data still waiting to be read.
2884                         if ( !$status['running'] ) {
2885                                 $running = false;
2886                                 $timeout = 0;
2887                         }
2888                 }
2889
2890                 $readyPipes = $pipes;
2891
2892                 // Clear last error
2893                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2894                 @trigger_error( '' );
2895                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2896                 if ( $numReadyPipes === false ) {
2897                         // @codingStandardsIgnoreEnd
2898                         $error = error_get_last();
2899                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2900                                 continue;
2901                         } else {
2902                                 trigger_error( $error['message'], E_USER_WARNING );
2903                                 $logMsg = $error['message'];
2904                                 break;
2905                         }
2906                 }
2907                 foreach ( $readyPipes as $pipe ) {
2908                         $block = fread( $pipe, 65536 );
2909                         $fd = $fds[(int)$pipe];
2910                         if ( $block === '' ) {
2911                                 // End of file
2912                                 fclose( $pipes[$fd] );
2913                                 unset( $pipes[$fd] );
2914                                 if ( !$pipes ) {
2915                                         break 2;
2916                                 }
2917                         } elseif ( $block === false ) {
2918                                 // Read error
2919                                 $logMsg = "Error reading from pipe";
2920                                 break 2;
2921                         } elseif ( $fd == 1 ) {
2922                                 // From stdout
2923                                 $outBuffer .= $block;
2924                         } elseif ( $fd == 3 ) {
2925                                 // From log FD
2926                                 $logBuffer .= $block;
2927                                 if ( strpos( $block, "\n" ) !== false ) {
2928                                         $lines = explode( "\n", $logBuffer );
2929                                         $logBuffer = array_pop( $lines );
2930                                         foreach ( $lines as $line ) {
2931                                                 wfDebugLog( 'exec', $line );
2932                                         }
2933                                 }
2934                         }
2935                 }
2936         }
2937
2938         foreach ( $pipes as $pipe ) {
2939                 fclose( $pipe );
2940         }
2941
2942         // Use the status previously collected if possible, since proc_get_status()
2943         // just calls waitpid() which will not return anything useful the second time.
2944         if ( $running ) {
2945                 $status = proc_get_status( $proc );
2946         }
2947
2948         if ( $logMsg !== false ) {
2949                 // Read/select error
2950                 $retval = -1;
2951                 proc_close( $proc );
2952         } elseif ( $status['signaled'] ) {
2953                 $logMsg = "Exited with signal {$status['termsig']}";
2954                 $retval = 128 + $status['termsig'];
2955                 proc_close( $proc );
2956         } else {
2957                 if ( $status['running'] ) {
2958                         $retval = proc_close( $proc );
2959                 } else {
2960                         $retval = $status['exitcode'];
2961                         proc_close( $proc );
2962                 }
2963                 if ( $retval == 127 ) {
2964                         $logMsg = "Possibly missing executable file";
2965                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2966                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2967                 }
2968         }
2969
2970         if ( $logMsg !== false ) {
2971                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2972         }
2973
2974         return $outBuffer;
2975 }
2976
2977 /**
2978  * Execute a shell command, returning both stdout and stderr. Convenience
2979  * function, as all the arguments to wfShellExec can become unwieldy.
2980  *
2981  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2982  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2983  *   or an array of unescaped arguments, in which case each value will be escaped
2984  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2985  * @param null|mixed &$retval Optional, will receive the program's exit code.
2986  *   (non-zero is usually failure)
2987  * @param array $environ Optional environment variables which should be
2988  *   added to the executed command environment.
2989  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2990  *   this overwrites the global wgMaxShell* limits.
2991  * @return string Collected stdout and stderr as a string
2992  */
2993 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2994         return wfShellExec( $cmd, $retval, $environ, $limits,
2995                 array( 'duplicateStderr' => true, 'profileMethod' => wfGetCaller() ) );
2996 }
2997
2998 /**
2999  * Workaround for http://bugs.php.net/bug.php?id=45132
3000  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
3001  */
3002 function wfInitShellLocale() {
3003         static $done = false;
3004         if ( $done ) {
3005                 return;
3006         }
3007         $done = true;
3008         global $wgShellLocale;
3009         if ( !wfIniGetBool( 'safe_mode' ) ) {
3010                 putenv( "LC_CTYPE=$wgShellLocale" );
3011                 setlocale( LC_CTYPE, $wgShellLocale );
3012         }
3013 }
3014
3015 /**
3016  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3017  * Note that $parameters should be a flat array and an option with an argument
3018  * should consist of two consecutive items in the array (do not use "--option value").
3019  *
3020  * @param string $script MediaWiki cli script path
3021  * @param array $parameters Arguments and options to the script
3022  * @param array $options Associative array of options:
3023  *              'php': The path to the php executable
3024  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3025  * @return string
3026  */
3027 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3028         global $wgPhpCli;
3029         // Give site config file a chance to run the script in a wrapper.
3030         // The caller may likely want to call wfBasename() on $script.
3031         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3032         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3033         if ( isset( $options['wrapper'] ) ) {
3034                 $cmd[] = $options['wrapper'];
3035         }
3036         $cmd[] = $script;
3037         // Escape each parameter for shell
3038         return wfEscapeShellArg( array_merge( $cmd, $parameters ) );
3039 }
3040
3041 /**
3042  * wfMerge attempts to merge differences between three texts.
3043  * Returns true for a clean merge and false for failure or a conflict.
3044  *
3045  * @param string $old
3046  * @param string $mine
3047  * @param string $yours
3048  * @param string $result
3049  * @return bool
3050  */
3051 function wfMerge( $old, $mine, $yours, &$result ) {
3052         global $wgDiff3;
3053
3054         # This check may also protect against code injection in
3055         # case of broken installations.
3056         wfSuppressWarnings();
3057         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3058         wfRestoreWarnings();
3059
3060         if ( !$haveDiff3 ) {
3061                 wfDebug( "diff3 not found\n" );
3062                 return false;
3063         }
3064
3065         # Make temporary files
3066         $td = wfTempDir();
3067         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3068         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3069         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3070
3071         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3072         #       a newline character. To avoid this, we normalize the trailing whitespace before
3073         #       creating the diff.
3074
3075         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3076         fclose( $oldtextFile );
3077         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3078         fclose( $mytextFile );
3079         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3080         fclose( $yourtextFile );
3081
3082         # Check for a conflict
3083         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '--overlap-only', $mytextName, $oldtextName, $yourtextName );
3084         $handle = popen( $cmd, 'r' );
3085
3086         if ( fgets( $handle, 1024 ) ) {
3087                 $conflict = true;
3088         } else {
3089                 $conflict = false;
3090         }
3091         pclose( $handle );
3092
3093         # Merge differences
3094         $cmd = wfEscapeShellArg( $wgDiff3, '-a', '-e', '--merge', $mytextName, $oldtextName, $yourtextName );
3095         $handle = popen( $cmd, 'r' );
3096         $result = '';
3097         do {
3098                 $data = fread( $handle, 8192 );
3099                 if ( strlen( $data ) == 0 ) {
3100                         break;
3101                 }
3102                 $result .= $data;
3103         } while ( true );
3104         pclose( $handle );
3105         unlink( $mytextName );
3106         unlink( $oldtextName );
3107         unlink( $yourtextName );
3108
3109         if ( $result === '' && $old !== '' && !$conflict ) {
3110                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3111                 $conflict = true;
3112         }
3113         return !$conflict;
3114 }
3115
3116 /**
3117  * Returns unified plain-text diff of two texts.
3118  * "Useful" for machine processing of diffs.
3119  *
3120  * @deprecated since 1.25, use DiffEngine/UnifiedDiffFormatter directly
3121  *
3122  * @param string $before The text before the changes.
3123  * @param string $after The text after the changes.
3124  * @param string $params Command-line options for the diff command.
3125  * @return string Unified diff of $before and $after
3126  */
3127 function wfDiff( $before, $after, $params = '-u' ) {
3128         if ( $before == $after ) {
3129                 return '';
3130         }
3131
3132         global $wgDiff;
3133         wfSuppressWarnings();
3134         $haveDiff = $wgDiff && file_exists( $wgDiff );
3135         wfRestoreWarnings();
3136
3137         # This check may also protect against code injection in
3138         # case of broken installations.
3139         if ( !$haveDiff ) {
3140                 wfDebug( "diff executable not found\n" );
3141                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3142                 $format = new UnifiedDiffFormatter();
3143                 return $format->format( $diffs );
3144         }
3145
3146         # Make temporary files
3147         $td = wfTempDir();
3148         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3149         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3150
3151         fwrite( $oldtextFile, $before );
3152         fclose( $oldtextFile );
3153         fwrite( $newtextFile, $after );
3154         fclose( $newtextFile );
3155
3156         // Get the diff of the two files
3157         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3158
3159         $h = popen( $cmd, 'r' );
3160         if ( !$h ) {
3161                 unlink( $oldtextName );
3162                 unlink( $newtextName );
3163                 throw new Exception( __METHOD__ . '(): popen() failed' );
3164         }
3165
3166         $diff = '';
3167
3168         do {
3169                 $data = fread( $h, 8192 );
3170                 if ( strlen( $data ) == 0 ) {
3171                         break;
3172                 }
3173                 $diff .= $data;
3174         } while ( true );
3175
3176         // Clean up
3177         pclose( $h );
3178         unlink( $oldtextName );
3179         unlink( $newtextName );
3180
3181         // Kill the --- and +++ lines. They're not useful.
3182         $diff_lines = explode( "\n", $diff );
3183         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3184                 unset( $diff_lines[0] );
3185         }
3186         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3187                 unset( $diff_lines[1] );
3188         }
3189
3190         $diff = implode( "\n", $diff_lines );
3191
3192         return $diff;
3193 }
3194
3195 /**
3196  * This function works like "use VERSION" in Perl, the program will die with a
3197  * backtrace if the current version of PHP is less than the version provided
3198  *
3199  * This is useful for extensions which due to their nature are not kept in sync
3200  * with releases, and might depend on other versions of PHP than the main code
3201  *
3202  * Note: PHP might die due to parsing errors in some cases before it ever
3203  *       manages to call this function, such is life
3204  *
3205  * @see perldoc -f use
3206  *
3207  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3208  * @throws MWException
3209  */
3210 function wfUsePHP( $req_ver ) {
3211         $php_ver = PHP_VERSION;
3212
3213         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3214                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3215         }
3216 }
3217
3218 /**
3219  * This function works like "use VERSION" in Perl except it checks the version
3220  * of MediaWiki, the program will die with a backtrace if the current version
3221  * of MediaWiki is less than the version provided.
3222  *
3223  * This is useful for extensions which due to their nature are not kept in sync
3224  * with releases
3225  *
3226  * Note: Due to the behavior of PHP's version_compare() which is used in this
3227  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3228  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3229  * targeted version number. For example if you wanted to allow any variation
3230  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3231  * not result in the same comparison due to the internal logic of
3232  * version_compare().
3233  *
3234  * @see perldoc -f use
3235  *
3236  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3237  * @throws MWException
3238  */
3239 function wfUseMW( $req_ver ) {
3240         global $wgVersion;
3241
3242         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3243                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3244         }
3245 }
3246
3247 /**
3248  * Return the final portion of a pathname.
3249  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3250  * http://bugs.php.net/bug.php?id=33898
3251  *
3252  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3253  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3254  *
3255  * @param string $path
3256  * @param string $suffix String to remove if present
3257  * @return string
3258  */
3259 function wfBaseName( $path, $suffix = '' ) {
3260         if ( $suffix == '' ) {
3261                 $encSuffix = '';
3262         } else {
3263                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3264         }
3265
3266         $matches = array();
3267         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3268                 return $matches[1];
3269         } else {
3270                 return '';
3271         }
3272 }
3273
3274 /**
3275  * Generate a relative path name to the given file.
3276  * May explode on non-matching case-insensitive paths,
3277  * funky symlinks, etc.
3278  *
3279  * @param string $path Absolute destination path including target filename
3280  * @param string $from Absolute source path, directory only
3281  * @return string
3282  */
3283 function wfRelativePath( $path, $from ) {
3284         // Normalize mixed input on Windows...
3285         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3286         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3287
3288         // Trim trailing slashes -- fix for drive root
3289         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3290         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3291
3292         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3293         $against = explode( DIRECTORY_SEPARATOR, $from );
3294
3295         if ( $pieces[0] !== $against[0] ) {
3296                 // Non-matching Windows drive letters?
3297                 // Return a full path.
3298                 return $path;
3299         }
3300
3301         // Trim off common prefix
3302         while ( count( $pieces ) && count( $against )
3303                 && $pieces[0] == $against[0] ) {
3304                 array_shift( $pieces );
3305                 array_shift( $against );
3306         }
3307
3308         // relative dots to bump us to the parent
3309         while ( count( $against ) ) {
3310                 array_unshift( $pieces, '..' );
3311                 array_shift( $against );
3312         }
3313
3314         array_push( $pieces, wfBaseName( $path ) );
3315
3316         return implode( DIRECTORY_SEPARATOR, $pieces );
3317 }
3318
3319 /**
3320  * Convert an arbitrarily-long digit string from one numeric base
3321  * to another, optionally zero-padding to a minimum column width.
3322  *
3323  * Supports base 2 through 36; digit values 10-36 are represented
3324  * as lowercase letters a-z. Input is case-insensitive.
3325  *
3326  * @param string $input Input number
3327  * @param int $sourceBase Base of the input number
3328  * @param int $destBase Desired base of the output
3329  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3330  * @param bool $lowercase Whether to output in lowercase or uppercase
3331  * @param string $engine Either "gmp", "bcmath", or "php"
3332  * @return string|bool The output number as a string, or false on error
3333  */
3334 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3335         $lowercase = true, $engine = 'auto'
3336 ) {
3337         $input = (string)$input;
3338         if (
3339                 $sourceBase < 2 ||
3340                 $sourceBase > 36 ||
3341                 $destBase < 2 ||
3342                 $destBase > 36 ||
3343                 $sourceBase != (int)$sourceBase ||
3344                 $destBase != (int)$destBase ||
3345                 $pad != (int)$pad ||
3346                 !preg_match(
3347                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3348                         $input
3349                 )
3350         ) {
3351                 return false;
3352         }
3353
3354         static $baseChars = array(
3355                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3356                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3357                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3358                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3359                 34 => 'y', 35 => 'z',
3360
3361                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3362                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3363                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3364                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3365                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3366                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3367         );
3368
3369         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3370                 // Removing leading zeros works around broken base detection code in
3371                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3372                 // <https://bugs.php.net/bug.php?id=55398>).
3373                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ), $sourceBase ), $destBase );
3374         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3375                 $decimal = '0';
3376                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3377                         $decimal = bcmul( $decimal, $sourceBase );
3378                         $decimal = bcadd( $decimal, $baseChars[$char] );
3379                 }
3380
3381                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3382                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3383                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3384                 }
3385                 // @codingStandardsIgnoreEnd
3386
3387                 $result = strrev( $result );
3388         } else {
3389                 $inDigits = array();
3390                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3391                         $inDigits[] = $baseChars[$char];
3392                 }
3393
3394                 // Iterate over the input, modulo-ing out an output digit
3395                 // at a time until input is gone.
3396                 $result = '';
3397                 while ( $inDigits ) {
3398                         $work = 0;
3399                         $workDigits = array();
3400
3401                         // Long division...
3402                         foreach ( $inDigits as $digit ) {
3403                                 $work *= $sourceBase;
3404                                 $work += $digit;
3405
3406                                 if ( $workDigits || $work >= $destBase ) {
3407                                         $workDigits[] = (int)( $work / $destBase );
3408                                 }
3409                                 $work %= $destBase;
3410                         }
3411
3412                         // All that division leaves us with a remainder,
3413                         // which is conveniently our next output digit.
3414                         $result .= $baseChars[$work];
3415
3416                         // And we continue!
3417                         $inDigits = $workDigits;
3418                 }
3419
3420                 $result = strrev( $result );
3421         }
3422
3423         if ( !$lowercase ) {
3424                 $result = strtoupper( $result );
3425         }
3426
3427         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3428 }
3429
3430 /**
3431  * Check if there is sufficient entropy in php's built-in session generation
3432  *
3433  * @return bool True = there is sufficient entropy
3434  */
3435 function wfCheckEntropy() {
3436         return (
3437                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3438                         || ini_get( 'session.entropy_file' )
3439                 )
3440                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3441 }
3442
3443 /**
3444  * Override session_id before session startup if php's built-in
3445  * session generation code is not secure.
3446  */
3447 function wfFixSessionID() {
3448         // If the cookie or session id is already set we already have a session and should abort
3449         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3450                 return;
3451         }
3452
3453         // PHP's built-in session entropy is enabled if:
3454         // - entropy_file is set or you're on Windows with php 5.3.3+
3455         // - AND entropy_length is > 0
3456         // We treat it as disabled if it doesn't have an entropy length of at least 32
3457         $entropyEnabled = wfCheckEntropy();
3458
3459         // If built-in entropy is not enabled or not sufficient override PHP's
3460         // built in session id generation code
3461         if ( !$entropyEnabled ) {
3462                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3463                         "overriding session id generation using our cryptrand source.\n" );
3464                 session_id( MWCryptRand::generateHex( 32 ) );
3465         }
3466 }
3467
3468 /**
3469  * Reset the session_id
3470  *
3471  * @since 1.22
3472  */
3473 function wfResetSessionID() {
3474         global $wgCookieSecure;
3475         $oldSessionId = session_id();
3476         $cookieParams = session_get_cookie_params();
3477         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3478                 session_regenerate_id( false );
3479         } else {
3480                 $tmp = $_SESSION;
3481                 session_destroy();
3482                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3483                 $_SESSION = $tmp;
3484         }
3485         $newSessionId = session_id();
3486         Hooks::run( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3487 }
3488
3489 /**
3490  * Initialise php session
3491  *
3492  * @param bool $sessionId
3493  */
3494 function wfSetupSession( $sessionId = false ) {
3495         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3496                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3497         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3498                 ObjectCacheSessionHandler::install();
3499         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3500                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3501                 # hasn't already been set to the desired value (that causes errors)
3502                 ini_set( 'session.save_handler', $wgSessionHandler );
3503         }
3504         session_set_cookie_params(
3505                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3506         session_cache_limiter( 'private, must-revalidate' );
3507         if ( $sessionId ) {
3508                 session_id( $sessionId );
3509         } else {
3510                 wfFixSessionID();
3511         }
3512         wfSuppressWarnings();
3513         session_start();
3514         wfRestoreWarnings();
3515 }
3516
3517 /**
3518  * Get an object from the precompiled serialized directory
3519  *
3520  * @param string $name
3521  * @return mixed The variable on success, false on failure
3522  */
3523 function wfGetPrecompiledData( $name ) {
3524         global $IP;
3525
3526         $file = "$IP/serialized/$name";
3527         if ( file_exists( $file ) ) {
3528                 $blob = file_get_contents( $file );
3529                 if ( $blob ) {
3530                         return unserialize( $blob );
3531                 }
3532         }
3533         return false;
3534 }
3535
3536 /**
3537  * Get a cache key
3538  *
3539  * @param string $args,...
3540  * @return string
3541  */
3542 function wfMemcKey( /*...*/ ) {
3543         global $wgCachePrefix;
3544         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3545         $args = func_get_args();
3546         $key = $prefix . ':' . implode( ':', $args );
3547         $key = str_replace( ' ', '_', $key );
3548         return $key;
3549 }
3550
3551 /**
3552  * Get a cache key for a foreign DB
3553  *
3554  * @param string $db
3555  * @param string $prefix
3556  * @param string $args,...
3557  * @return string
3558  */
3559 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3560         $args = array_slice( func_get_args(), 2 );
3561         if ( $prefix ) {
3562                 $key = "$db-$prefix:" . implode( ':', $args );
3563         } else {
3564                 $key = $db . ':' . implode( ':', $args );
3565         }
3566         return str_replace( ' ', '_', $key );
3567 }
3568
3569 /**
3570  * Get an ASCII string identifying this wiki
3571  * This is used as a prefix in memcached keys
3572  *
3573  * @return string
3574  */
3575 function wfWikiID() {
3576         global $wgDBprefix, $wgDBname;
3577         if ( $wgDBprefix ) {
3578                 return "$wgDBname-$wgDBprefix";
3579         } else {
3580                 return $wgDBname;
3581         }
3582 }
3583
3584 /**
3585  * Split a wiki ID into DB name and table prefix
3586  *
3587  * @param string $wiki
3588  *
3589  * @return array
3590  */
3591 function wfSplitWikiID( $wiki ) {
3592         $bits = explode( '-', $wiki, 2 );
3593         if ( count( $bits ) < 2 ) {
3594                 $bits[] = '';
3595         }
3596         return $bits;
3597 }
3598
3599 /**
3600  * Get a Database object.
3601  *
3602  * @param int $db Index of the connection to get. May be DB_MASTER for the
3603  *            master (for write queries), DB_SLAVE for potentially lagged read
3604  *            queries, or an integer >= 0 for a particular server.
3605  *
3606  * @param string|string[] $groups Query groups. An array of group names that this query
3607  *                belongs to. May contain a single string if the query is only
3608  *                in one group.
3609  *
3610  * @param string|bool $wiki The wiki ID, or false for the current wiki
3611  *
3612  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3613  * will always return the same object, unless the underlying connection or load
3614  * balancer is manually destroyed.
3615  *
3616  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3617  * updater to ensure that a proper database is being updated.
3618  *
3619  * @return DatabaseBase
3620  */
3621 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3622         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3623 }
3624
3625 /**
3626  * Get a load balancer object.
3627  *
3628  * @param string|bool $wiki Wiki ID, or false for the current wiki
3629  * @return LoadBalancer
3630  */
3631 function wfGetLB( $wiki = false ) {
3632         return wfGetLBFactory()->getMainLB( $wiki );
3633 }
3634
3635 /**
3636  * Get the load balancer factory object
3637  *
3638  * @return LBFactory
3639  */
3640 function wfGetLBFactory() {
3641         return LBFactory::singleton();
3642 }
3643
3644 /**
3645  * Find a file.
3646  * Shortcut for RepoGroup::singleton()->findFile()
3647  *
3648  * @param string $title String or Title object
3649  * @param array $options Associative array of options (see RepoGroup::findFile)
3650  * @return File|bool File, or false if the file does not exist
3651  */
3652 function wfFindFile( $title, $options = array() ) {
3653         return RepoGroup::singleton()->findFile( $title, $options );
3654 }
3655
3656 /**
3657  * Get an object referring to a locally registered file.
3658  * Returns a valid placeholder object if the file does not exist.
3659  *
3660  * @param Title|string $title
3661  * @return LocalFile|null A File, or null if passed an invalid Title
3662  */
3663 function wfLocalFile( $title ) {
3664         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3665 }
3666
3667 /**
3668  * Should low-performance queries be disabled?
3669  *
3670  * @return bool
3671  * @codeCoverageIgnore
3672  */
3673 function wfQueriesMustScale() {
3674         global $wgMiserMode;
3675         return $wgMiserMode
3676                 || ( SiteStats::pages() > 100000
3677                 && SiteStats::edits() > 1000000
3678                 && SiteStats::users() > 10000 );
3679 }
3680
3681 /**
3682  * Get the path to a specified script file, respecting file
3683  * extensions; this is a wrapper around $wgScriptExtension etc.
3684  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3685  *
3686  * @param string $script Script filename, sans extension
3687  * @return string
3688  */
3689 function wfScript( $script = 'index' ) {
3690         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3691         if ( $script === 'index' ) {
3692                 return $wgScript;
3693         } elseif ( $script === 'load' ) {
3694                 return $wgLoadScript;
3695         } else {
3696                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3697         }
3698 }
3699
3700 /**
3701  * Get the script URL.
3702  *
3703  * @return string Script URL
3704  */
3705 function wfGetScriptUrl() {
3706         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3707                 #
3708                 # as it was called, minus the query string.
3709                 #
3710                 # Some sites use Apache rewrite rules to handle subdomains,
3711                 # and have PHP set up in a weird way that causes PHP_SELF
3712                 # to contain the rewritten URL instead of the one that the
3713                 # outside world sees.
3714                 #
3715                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3716                 # provides containing the "before" URL.
3717                 return $_SERVER['SCRIPT_NAME'];
3718         } else {
3719                 return $_SERVER['URL'];
3720         }
3721 }
3722
3723 /**
3724  * Convenience function converts boolean values into "true"
3725  * or "false" (string) values
3726  *
3727  * @param bool $value
3728  * @return string
3729  */
3730 function wfBoolToStr( $value ) {
3731         return $value ? 'true' : 'false';
3732 }
3733
3734 /**
3735  * Get a platform-independent path to the null file, e.g. /dev/null
3736  *
3737  * @return string
3738  */
3739 function wfGetNull() {
3740         return wfIsWindows() ? 'NUL' : '/dev/null';
3741 }
3742
3743 /**
3744  * Waits for the slaves to catch up to the master position
3745  *
3746  * Use this when updating very large numbers of rows, as in maintenance scripts,
3747  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3748  *
3749  * By default this waits on the main DB cluster of the current wiki.
3750  * If $cluster is set to "*" it will wait on all DB clusters, including
3751  * external ones. If the lag being waiting on is caused by the code that
3752  * does this check, it makes since to use $ifWritesSince, particularly if
3753  * cluster is "*", to avoid excess overhead.
3754  *
3755  * Never call this function after a big DB write that is still in a transaction.
3756  * This only makes sense after the possible lag inducing changes were committed.
3757  *
3758  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3759  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3760  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3761  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3762  * @return bool Success (able to connect and no timeouts reached)
3763  */
3764 function wfWaitForSlaves(
3765         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3766 ) {
3767         // B/C: first argument used to be "max seconds of lag"; ignore such values
3768         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3769
3770         if ( $timeout === null ) {
3771                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3772         }
3773
3774         // Figure out which clusters need to be checked
3775         $lbs = array();
3776         if ( $cluster === '*' ) {
3777                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3778                         $lbs[] = $lb;
3779                 } );
3780         } elseif ( $cluster !== false ) {
3781                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3782         } else {
3783                 $lbs[] = wfGetLB( $wiki );
3784         }
3785
3786         // Get all the master positions of applicable DBs right now.
3787         // This can be faster since waiting on one cluster reduces the
3788         // time needed to wait on the next clusters.
3789         $masterPositions = array_fill( 0, count( $lbs ), false );
3790         foreach ( $lbs as $i => $lb ) {
3791                 // bug 27975 - Don't try to wait for slaves if there are none
3792                 // Prevents permission error when getting master position
3793                 if ( $lb->getServerCount() > 1 ) {
3794                         if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
3795                                 continue; // assume no writes done
3796                         }
3797                         // Use the empty string to not trigger selectDB() since the connection
3798                         // may have been to a server that does not have a DB for the current wiki.
3799                         $dbw = $lb->getConnection( DB_MASTER, array(), '' );
3800                         if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
3801                                 continue; // no writes since the last wait
3802                         }
3803                         $masterPositions[$i] = $dbw->getMasterPos();
3804                 }
3805         }
3806
3807         $ok = true;
3808         foreach ( $lbs as $i => $lb ) {
3809                 if ( $masterPositions[$i] ) {
3810                         // The DBMS may not support getMasterPos() or the whole
3811                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3812                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3813                 }
3814         }
3815
3816         return $ok;
3817 }
3818
3819 /**
3820  * Count down from $seconds to zero on the terminal, with a one-second pause
3821  * between showing each number. For use in command-line scripts.
3822  *
3823  * @codeCoverageIgnore
3824  * @param int $seconds
3825  */
3826 function wfCountDown( $seconds ) {
3827         for ( $i = $seconds; $i >= 0; $i-- ) {
3828                 if ( $i != $seconds ) {
3829                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3830                 }
3831                 echo $i;
3832                 flush();
3833                 if ( $i ) {
3834                         sleep( 1 );
3835                 }
3836         }
3837         echo "\n";
3838 }
3839
3840 /**
3841  * Replace all invalid characters with -
3842  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3843  * By default, $wgIllegalFileChars = ':'
3844  *
3845  * @param string $name Filename to process
3846  * @return string
3847  */
3848 function wfStripIllegalFilenameChars( $name ) {
3849         global $wgIllegalFileChars;
3850         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3851         $name = wfBaseName( $name );
3852         $name = preg_replace(
3853                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3854                 '-',
3855                 $name
3856         );
3857         return $name;
3858 }
3859
3860 /**
3861  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3862  *
3863  * @return int Value the memory limit was set to.
3864  */
3865 function wfMemoryLimit() {
3866         global $wgMemoryLimit;
3867         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3868         if ( $memlimit != -1 ) {
3869                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3870                 if ( $conflimit == -1 ) {
3871                         wfDebug( "Removing PHP's memory limit\n" );
3872                         wfSuppressWarnings();
3873                         ini_set( 'memory_limit', $conflimit );
3874                         wfRestoreWarnings();
3875                         return $conflimit;
3876                 } elseif ( $conflimit > $memlimit ) {
3877                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3878                         wfSuppressWarnings();
3879                         ini_set( 'memory_limit', $conflimit );
3880                         wfRestoreWarnings();
3881                         return $conflimit;
3882                 }
3883         }
3884         return $memlimit;
3885 }
3886
3887 /**
3888  * Converts shorthand byte notation to integer form
3889  *
3890  * @param string $string
3891  * @return int
3892  */
3893 function wfShorthandToInteger( $string = '' ) {
3894         $string = trim( $string );
3895         if ( $string === '' ) {
3896                 return -1;
3897         }
3898         $last = $string[strlen( $string ) - 1];
3899         $val = intval( $string );
3900         switch ( $last ) {
3901                 case 'g':
3902                 case 'G':
3903                         $val *= 1024;
3904                         // break intentionally missing
3905                 case 'm':
3906                 case 'M':
3907                         $val *= 1024;
3908                         // break intentionally missing
3909                 case 'k':
3910                 case 'K':
3911                         $val *= 1024;
3912         }
3913
3914         return $val;
3915 }
3916
3917 /**
3918  * Get the normalised IETF language tag
3919  * See unit test for examples.
3920  *
3921  * @param string $code The language code.
3922  * @return string The language code which complying with BCP 47 standards.
3923  */
3924 function wfBCP47( $code ) {
3925         $codeSegment = explode( '-', $code );
3926         $codeBCP = array();
3927         foreach ( $codeSegment as $segNo => $seg ) {
3928                 // when previous segment is x, it is a private segment and should be lc
3929                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3930                         $codeBCP[$segNo] = strtolower( $seg );
3931                 // ISO 3166 country code
3932                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3933                         $codeBCP[$segNo] = strtoupper( $seg );
3934                 // ISO 15924 script code
3935                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3936                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3937                 // Use lowercase for other cases
3938                 } else {
3939                         $codeBCP[$segNo] = strtolower( $seg );
3940                 }
3941         }
3942         $langCode = implode( '-', $codeBCP );
3943         return $langCode;
3944 }
3945
3946 /**
3947  * Get a cache object.
3948  *
3949  * @param int $inputType Cache type, one of the CACHE_* constants.
3950  * @return BagOStuff
3951  */
3952 function wfGetCache( $inputType ) {
3953         return ObjectCache::getInstance( $inputType );
3954 }
3955
3956 /**
3957  * Get the main cache object
3958  *
3959  * @return BagOStuff
3960  */
3961 function wfGetMainCache() {
3962         global $wgMainCacheType;
3963         return ObjectCache::getInstance( $wgMainCacheType );
3964 }
3965
3966 /**
3967  * Get the cache object used by the message cache
3968  *
3969  * @return BagOStuff
3970  */
3971 function wfGetMessageCacheStorage() {
3972         global $wgMessageCacheType;
3973         return ObjectCache::getInstance( $wgMessageCacheType );
3974 }
3975
3976 /**
3977  * Get the cache object used by the parser cache
3978  *
3979  * @return BagOStuff
3980  */
3981 function wfGetParserCacheStorage() {
3982         global $wgParserCacheType;
3983         return ObjectCache::getInstance( $wgParserCacheType );
3984 }
3985
3986 /**
3987  * Call hook functions defined in $wgHooks
3988  *
3989  * @param string $event Event name
3990  * @param array $args Parameters passed to hook functions
3991  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3992  *
3993  * @return bool True if no handler aborted the hook
3994  * @deprecated 1.25 - use Hooks::run
3995  */
3996 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3997         return Hooks::run( $event, $args, $deprecatedVersion );
3998 }
3999
4000 /**
4001  * Wrapper around php's unpack.
4002  *
4003  * @param string $format The format string (See php's docs)
4004  * @param string $data A binary string of binary data
4005  * @param int|bool $length The minimum length of $data or false. This is to
4006  *      prevent reading beyond the end of $data. false to disable the check.
4007  *
4008  * Also be careful when using this function to read unsigned 32 bit integer
4009  * because php might make it negative.
4010  *
4011  * @throws MWException If $data not long enough, or if unpack fails
4012  * @return array Associative array of the extracted data
4013  */
4014 function wfUnpack( $format, $data, $length = false ) {
4015         if ( $length !== false ) {
4016                 $realLen = strlen( $data );
4017                 if ( $realLen < $length ) {
4018                         throw new MWException( "Tried to use wfUnpack on a "
4019                                 . "string of length $realLen, but needed one "
4020                                 . "of at least length $length."
4021                         );
4022                 }
4023         }
4024
4025         wfSuppressWarnings();
4026         $result = unpack( $format, $data );
4027         wfRestoreWarnings();
4028
4029         if ( $result === false ) {
4030                 // If it cannot extract the packed data.
4031                 throw new MWException( "unpack could not unpack binary data" );
4032         }
4033         return $result;
4034 }
4035
4036 /**
4037  * Determine if an image exists on the 'bad image list'.
4038  *
4039  * The format of MediaWiki:Bad_image_list is as follows:
4040  *    * Only list items (lines starting with "*") are considered
4041  *    * The first link on a line must be a link to a bad image
4042  *    * Any subsequent links on the same line are considered to be exceptions,
4043  *      i.e. articles where the image may occur inline.
4044  *
4045  * @param string $name The image name to check
4046  * @param Title|bool $contextTitle The page on which the image occurs, if known
4047  * @param string $blacklist Wikitext of a file blacklist
4048  * @return bool
4049  */
4050 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4051         static $badImageCache = null; // based on bad_image_list msg
4052
4053         # Handle redirects
4054         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4055         if ( $redirectTitle ) {
4056                 $name = $redirectTitle->getDBkey();
4057         }
4058
4059         # Run the extension hook
4060         $bad = false;
4061         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4062                 return $bad;
4063         }
4064
4065         $cacheable = ( $blacklist === null );
4066         if ( $cacheable && $badImageCache !== null ) {
4067                 $badImages = $badImageCache;
4068         } else { // cache miss
4069                 if ( $blacklist === null ) {
4070                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4071                 }
4072                 # Build the list now
4073                 $badImages = array();
4074                 $lines = explode( "\n", $blacklist );
4075                 foreach ( $lines as $line ) {
4076                         # List items only
4077                         if ( substr( $line, 0, 1 ) !== '*' ) {
4078                                 continue;
4079                         }
4080
4081                         # Find all links
4082                         $m = array();
4083                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4084                                 continue;
4085                         }
4086
4087                         $exceptions = array();
4088                         $imageDBkey = false;
4089                         foreach ( $m[1] as $i => $titleText ) {
4090                                 $title = Title::newFromText( $titleText );
4091                                 if ( !is_null( $title ) ) {
4092                                         if ( $i == 0 ) {
4093                                                 $imageDBkey = $title->getDBkey();
4094                                         } else {
4095                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4096                                         }
4097                                 }
4098                         }
4099
4100                         if ( $imageDBkey !== false ) {
4101                                 $badImages[$imageDBkey] = $exceptions;
4102                         }
4103                 }
4104                 if ( $cacheable ) {
4105                         $badImageCache = $badImages;
4106                 }
4107         }
4108
4109         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4110         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4111         return $bad;
4112 }
4113
4114 /**
4115  * Determine whether the client at a given source IP is likely to be able to
4116  * access the wiki via HTTPS.
4117  *
4118  * @param string $ip The IPv4/6 address in the normal human-readable form
4119  * @return bool
4120  */
4121 function wfCanIPUseHTTPS( $ip ) {
4122         $canDo = true;
4123         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4124         return !!$canDo;
4125 }
4126
4127 /**
4128  * Determine input string is represents as infinity
4129  *
4130  * @param string $str The string to determine
4131  * @return bool
4132  * @since 1.25
4133  */
4134 function wfIsInfinity( $str ) {
4135         $infinityValues = array( 'infinite', 'indefinite', 'infinity', 'never' );
4136         return in_array( $str, $infinityValues );
4137 }
4138
4139 /**
4140  * Work out the IP address based on various globals
4141  * For trusted proxies, use the XFF client IP (first of the chain)
4142  *
4143  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4144  * @return string
4145  */
4146 function wfGetIP() {
4147         wfDeprecated( __METHOD__, '1.19' );
4148         global $wgRequest;
4149         return $wgRequest->getIP();
4150 }
4151
4152 /**
4153  * Checks if an IP is a trusted proxy provider.
4154  * Useful to tell if X-Forwarded-For data is possibly bogus.
4155  * Squid cache servers for the site are whitelisted.
4156  * @deprecated Since 1.24, use IP::isTrustedProxy()
4157  *
4158  * @param string $ip
4159  * @return bool
4160  */
4161 function wfIsTrustedProxy( $ip ) {
4162         wfDeprecated( __METHOD__, '1.24' );
4163         return IP::isTrustedProxy( $ip );
4164 }
4165
4166 /**
4167  * Checks if an IP matches a proxy we've configured.
4168  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4169  *
4170  * @param string $ip
4171  * @return bool
4172  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4173  */
4174 function wfIsConfiguredProxy( $ip ) {
4175         wfDeprecated( __METHOD__, '1.24' );
4176         return IP::isConfiguredProxy( $ip );
4177 }
4178
4179 /**
4180  * Returns true if these thumbnail parameters match one that MediaWiki
4181  * requests from file description pages and/or parser output.
4182  *
4183  * $params is considered non-standard if they involve a non-standard
4184  * width or any non-default parameters aside from width and page number.
4185  * The number of possible files with standard parameters is far less than
4186  * that of all combinations; rate-limiting for them can thus be more generious.
4187  *
4188  * @param File $file
4189  * @param array $params
4190  * @return bool
4191  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4192  */
4193 function wfThumbIsStandard( File $file, array $params ) {
4194         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4195
4196         $multipliers = array( 1 );
4197         if ( $wgResponsiveImages ) {
4198                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4199                 // @see Linker::processResponsiveImages
4200                 $multipliers[] = 1.5;
4201                 $multipliers[] = 2;
4202         }
4203
4204         $handler = $file->getHandler();
4205         if ( !$handler || !isset( $params['width'] ) ) {
4206                 return false;
4207         }
4208
4209         $basicParams = array();
4210         if ( isset( $params['page'] ) ) {
4211                 $basicParams['page'] = $params['page'];
4212         }
4213
4214         $thumbLimits = array();
4215         $imageLimits = array();
4216         // Expand limits to account for multipliers
4217         foreach ( $multipliers as $multiplier ) {
4218                 $thumbLimits = array_merge( $thumbLimits, array_map(
4219                         function ( $width ) use ( $multiplier ) {
4220                                 return round( $width * $multiplier );
4221                         }, $wgThumbLimits )
4222                 );
4223                 $imageLimits = array_merge( $imageLimits, array_map(
4224                         function ( $pair ) use ( $multiplier ) {
4225                                 return array(
4226                                         round( $pair[0] * $multiplier ),
4227                                         round( $pair[1] * $multiplier ),
4228                                 );
4229                         }, $wgImageLimits )
4230                 );
4231         }
4232
4233         // Check if the width matches one of $wgThumbLimits
4234         if ( in_array( $params['width'], $thumbLimits ) ) {
4235                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4236                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4237                 $handler->normaliseParams( $file, $normalParams );
4238         } else {
4239                 // If not, then check if the width matchs one of $wgImageLimits
4240                 $match = false;
4241                 foreach ( $imageLimits as $pair ) {
4242                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4243                         // Decide whether the thumbnail should be scaled on width or height.
4244                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4245                         $handler->normaliseParams( $file, $normalParams );
4246                         // Check if this standard thumbnail size maps to the given width
4247                         if ( $normalParams['width'] == $params['width'] ) {
4248                                 $match = true;
4249                                 break;
4250                         }
4251                 }
4252                 if ( !$match ) {
4253                         return false; // not standard for description pages
4254                 }
4255         }
4256
4257         // Check that the given values for non-page, non-width, params are just defaults
4258         foreach ( $params as $key => $value ) {
4259                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4260                         return false;
4261                 }
4262         }
4263
4264         return true;
4265 }