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 // Hide compatibility functions from Doxygen
  28 /// @cond
  29
  30 /**
  31  * Compatibility functions
  32  *
  33  * We support PHP 5.3.3 and up.
  34  * Re-implementations of newer functions or functions in non-standard
  35  * PHP extensions may be included here.
  36  */
  37
  38 if ( !function_exists( 'mb_substr' ) ) {
  39         /**
  40          * @codeCoverageIgnore
  41          * @see Fallback::mb_substr
  42          * @return string
  43          */
  44         function mb_substr( $str, $start, $count = 'end' ) {
  45                 return Fallback::mb_substr( $str, $start, $count );
  46         }
  47
  48         /**
  49          * @codeCoverageIgnore
  50          * @see Fallback::mb_substr_split_unicode
  51          * @return int
  52          */
  53         function mb_substr_split_unicode( $str, $splitPos ) {
  54                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  55         }
  56 }
  57
  58 if ( !function_exists( 'mb_strlen' ) ) {
  59         /**
  60          * @codeCoverageIgnore
  61          * @see Fallback::mb_strlen
  62          * @return int
  63          */
  64         function mb_strlen( $str, $enc = '' ) {
  65                 return Fallback::mb_strlen( $str, $enc );
  66         }
  67 }
  68
  69 if ( !function_exists( 'mb_strpos' ) ) {
  70         /**
  71          * @codeCoverageIgnore
  72          * @see Fallback::mb_strpos
  73          * @return int
  74          */
  75         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  76                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  77         }
  78 }
  79
  80 if ( !function_exists( 'mb_strrpos' ) ) {
  81         /**
  82          * @codeCoverageIgnore
  83          * @see Fallback::mb_strrpos
  84          * @return int
  85          */
  86         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  87                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  88         }
  89 }
  90
  91 // gzdecode function only exists in PHP >= 5.4.0
  92 // http://php.net/gzdecode
  93 if ( !function_exists( 'gzdecode' ) ) {
  94         /**
  95          * @codeCoverageIgnore
  96          * @param string $data
  97          * @return string
  98          */
  99         function gzdecode( $data ) {
 100                 return gzinflate( substr( $data, 10, -8 ) );
 101         }
 102 }
 103
 104 // hash_equals function only exists in PHP >= 5.6.0
 105 // http://php.net/hash_equals
 106 if ( !function_exists( 'hash_equals' ) ) {
 107         /**
 108          * Check whether a user-provided string is equal to a fixed-length secret string
 109          * without revealing bytes of the secret string through timing differences.
 110          *
 111          * The usual way to compare strings (PHP's === operator or the underlying memcmp()
 112          * function in C) is to compare corresponding bytes and stop at the first difference,
 113          * which would take longer for a partial match than for a complete mismatch. This
 114          * is not secure when one of the strings (e.g. an HMAC or token) must remain secret
 115          * and the other may come from an attacker. Statistical analysis of timing measurements
 116          * over many requests may allow the attacker to guess the string's bytes one at a time
 117          * (and check his guesses) even if the timing differences are extremely small.
 118          *
 119          * When making such a security-sensitive comparison, it is essential that the sequence
 120          * in which instructions are executed and memory locations are accessed not depend on
 121          * the secret string's value. HOWEVER, for simplicity, we do not attempt to minimize
 122          * the inevitable leakage of the string's length. That is generally known anyway as
 123          * a chararacteristic of the hash function used to compute the secret value.
 124          *
 125          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 126          *
 127          * @codeCoverageIgnore
 128          * @param string $known_string Fixed-length secret string to compare against
 129          * @param string $user_string User-provided string
 130          * @return bool True if the strings are the same, false otherwise
 131          */
 132         function hash_equals( $known_string, $user_string ) {
 133                 // Strict type checking as in PHP's native implementation
 134                 if ( !is_string( $known_string ) ) {
 135                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 136                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 137
 138                         return false;
 139                 }
 140
 141                 if ( !is_string( $user_string ) ) {
 142                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 143                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 144
 145                         return false;
 146                 }
 147
 148                 $known_string_len = strlen( $known_string );
 149                 if ( $known_string_len !== strlen( $user_string ) ) {
 150                         return false;
 151                 }
 152
 153                 $result = 0;
 154                 for ( $i = 0; $i < $known_string_len; $i++ ) {
 155                         $result |= ord( $known_string[$i] ) ^ ord( $user_string[$i] );
 156                 }
 157
 158                 return ( $result === 0 );
 159         }
 160 }
 161 /// @endcond
 162
 163 /**
 164  * Load an extension
 165  *
 166  * This is the closest equivalent to:
 167  *   require_once "$IP/extensions/$name/$name.php";
 168  * as it will process and load the extension immediately.
 169  *
 170  * However, batch loading with wfLoadExtensions will
 171  * be more performant.
 172  *
 173  * @param string $name Name of the extension to load
 174  * @param string|null $path Absolute path of where to find the extension.json file
 175  */
 176 function wfLoadExtension( $name, $path = null ) {
 177         if ( !$path ) {
 178                 global $IP;
 179                 $path = "$IP/extensions/$name/extension.json";
 180         }
 181         ExtensionRegistry::getInstance()->load( $path );
 182 }
 183
 184 /**
 185  * Load multiple extensions at once
 186  *
 187  * Same as wfLoadExtension, but more efficient if you
 188  * are loading multiple extensions.
 189  *
 190  * If you want to specify custom paths, you should interact with
 191  * ExtensionRegistry directly.
 192  *
 193  * @see wfLoadExtension
 194  * @param string[] $exts Array of extension names to load
 195  */
 196 function wfLoadExtensions( array $exts ) {
 197         global $IP;
 198         $registry = ExtensionRegistry::getInstance();
 199         foreach ( $exts as $ext ) {
 200                 $registry->queue( "$IP/extensions/$ext/extension.json" );
 201         }
 202
 203         $registry->loadFromQueue();
 204 }
 205
 206 /**
 207  * Load a skin
 208  *
 209  * @see wfLoadExtension
 210  * @param string $name Name of the extension to load
 211  * @param string|null $path Absolute path of where to find the skin.json file
 212  */
 213 function wfLoadSkin( $name, $path = null ) {
 214         if ( !$path ) {
 215                 global $IP;
 216                 $path = "$IP/skins/$name/skin.json";
 217         }
 218         ExtensionRegistry::getInstance()->load( $path );
 219 }
 220
 221 /**
 222  * Load multiple skins at once
 223  *
 224  * @see wfLoadExtensions
 225  * @param string[] $skins Array of extension names to load
 226  */
 227 function wfLoadSkins( array $skins ) {
 228         global $IP;
 229         $registry = ExtensionRegistry::getInstance();
 230         foreach ( $skins as $skin ) {
 231                 $registry->queue( "$IP/skins/$skin/skin.json" );
 232         }
 233
 234         $registry->loadFromQueue();
 235 }
 236
 237 /**
 238  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 239  * @param array $a
 240  * @param array $b
 241  * @return array
 242  */
 243 function wfArrayDiff2( $a, $b ) {
 244         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 245 }
 246
 247 /**
 248  * @param array|string $a
 249  * @param array|string $b
 250  * @return int
 251  */
 252 function wfArrayDiff2_cmp( $a, $b ) {
 253         if ( is_string( $a ) && is_string( $b ) ) {
 254                 return strcmp( $a, $b );
 255         } elseif ( count( $a ) !== count( $b ) ) {
 256                 return count( $a ) < count( $b ) ? -1 : 1;
 257         } else {
 258                 reset( $a );
 259                 reset( $b );
 260                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 261                         $cmp = strcmp( $valueA, $valueB );
 262                         if ( $cmp !== 0 ) {
 263                                 return $cmp;
 264                         }
 265                 }
 266                 return 0;
 267         }
 268 }
 269
 270 /**
 271  * Appends to second array if $value differs from that in $default
 272  *
 273  * @param string|int $key
 274  * @param mixed $value
 275  * @param mixed $default
 276  * @param array $changed Array to alter
 277  * @throws MWException
 278  */
 279 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 280         if ( is_null( $changed ) ) {
 281                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 282         }
 283         if ( $default[$key] !== $value ) {
 284                 $changed[$key] = $value;
 285         }
 286 }
 287
 288 /**
 289  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 290  * e.g.
 291  *      wfMergeErrorArrays(
 292  *              array( array( 'x' ) ),
 293  *              array( array( 'x', '2' ) ),
 294  *              array( array( 'x' ) ),
 295  *              array( array( 'y' ) )
 296  *      );
 297  * returns:
 298  *              array(
 299  *              array( 'x', '2' ),
 300  *              array( 'x' ),
 301  *              array( 'y' )
 302  *      )
 303  *
 304  * @param array $array1,...
 305  * @return array
 306  */
 307 function wfMergeErrorArrays( /*...*/ ) {
 308         $args = func_get_args();
 309         $out = array();
 310         foreach ( $args as $errors ) {
 311                 foreach ( $errors as $params ) {
 312                         # @todo FIXME: Sometimes get nested arrays for $params,
 313                         # which leads to E_NOTICEs
 314                         $spec = implode( "\t", $params );
 315                         $out[$spec] = $params;
 316                 }
 317         }
 318         return array_values( $out );
 319 }
 320
 321 /**
 322  * Insert array into another array after the specified *KEY*
 323  *
 324  * @param array $array The array.
 325  * @param array $insert The array to insert.
 326  * @param mixed $after The key to insert after
 327  * @return array
 328  */
 329 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 330         // Find the offset of the element to insert after.
 331         $keys = array_keys( $array );
 332         $offsetByKey = array_flip( $keys );
 333
 334         $offset = $offsetByKey[$after];
 335
 336         // Insert at the specified offset
 337         $before = array_slice( $array, 0, $offset + 1, true );
 338         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 339
 340         $output = $before + $insert + $after;
 341
 342         return $output;
 343 }
 344
 345 /**
 346  * Recursively converts the parameter (an object) to an array with the same data
 347  *
 348  * @param object|array $objOrArray
 349  * @param bool $recursive
 350  * @return array
 351  */
 352 function wfObjectToArray( $objOrArray, $recursive = true ) {
 353         $array = array();
 354         if ( is_object( $objOrArray ) ) {
 355                 $objOrArray = get_object_vars( $objOrArray );
 356         }
 357         foreach ( $objOrArray as $key => $value ) {
 358                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 359                         $value = wfObjectToArray( $value );
 360                 }
 361
 362                 $array[$key] = $value;
 363         }
 364
 365         return $array;
 366 }
 367
 368 /**
 369  * Get a random decimal value between 0 and 1, in a way
 370  * not likely to give duplicate values for any realistic
 371  * number of articles.
 372  *
 373  * @return string
 374  */
 375 function wfRandom() {
 376         # The maximum random value is "only" 2^31-1, so get two random
 377         # values to reduce the chance of dupes
 378         $max = mt_getrandmax() + 1;
 379         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 380
 381         return $rand;
 382 }
 383
 384 /**
 385  * Get a random string containing a number of pseudo-random hex
 386  * characters.
 387  * @note This is not secure, if you are trying to generate some sort
 388  *       of token please use MWCryptRand instead.
 389  *
 390  * @param int $length The length of the string to generate
 391  * @return string
 392  * @since 1.20
 393  */
 394 function wfRandomString( $length = 32 ) {
 395         $str = '';
 396         for ( $n = 0; $n < $length; $n += 7 ) {
 397                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 398         }
 399         return substr( $str, 0, $length );
 400 }
 401
 402 /**
 403  * We want some things to be included as literal characters in our title URLs
 404  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 405  * all of the following should be safe:
 406  *
 407  * ;:@&=$-_.+!*'(),
 408  *
 409  * But + is not safe because it's used to indicate a space; &= are only safe in
 410  * paths and not in queries (and we don't distinguish here); ' seems kind of
 411  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 412  * is reserved, we don't care.  So the list we unescape is:
 413  *
 414  * ;:@$!*(),/
 415  *
 416  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 417  * so no fancy : for IIS7.
 418  *
 419  * %2F in the page titles seems to fatally break for some reason.
 420  *
 421  * @param string $s
 422  * @return string
 423  */
 424 function wfUrlencode( $s ) {
 425         static $needle;
 426
 427         if ( is_null( $s ) ) {
 428                 $needle = null;
 429                 return '';
 430         }
 431
 432         if ( is_null( $needle ) ) {
 433                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 434                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 435                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 436                 ) {
 437                         $needle[] = '%3A';
 438                 }
 439         }
 440
 441         $s = urlencode( $s );
 442         $s = str_ireplace(
 443                 $needle,
 444                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 445                 $s
 446         );
 447
 448         return $s;
 449 }
 450
 451 /**
 452  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 453  * "days=7&limit=100". Options in the first array override options in the second.
 454  * Options set to null or false will not be output.
 455  *
 456  * @param array $array1 ( String|Array )
 457  * @param array $array2 ( String|Array )
 458  * @param string $prefix
 459  * @return string
 460  */
 461 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 462         if ( !is_null( $array2 ) ) {
 463                 $array1 = $array1 + $array2;
 464         }
 465
 466         $cgi = '';
 467         foreach ( $array1 as $key => $value ) {
 468                 if ( !is_null( $value ) && $value !== false ) {
 469                         if ( $cgi != '' ) {
 470                                 $cgi .= '&';
 471                         }
 472                         if ( $prefix !== '' ) {
 473                                 $key = $prefix . "[$key]";
 474                         }
 475                         if ( is_array( $value ) ) {
 476                                 $firstTime = true;
 477                                 foreach ( $value as $k => $v ) {
 478                                         $cgi .= $firstTime ? '' : '&';
 479                                         if ( is_array( $v ) ) {
 480                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 481                                         } else {
 482                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 483                                         }
 484                                         $firstTime = false;
 485                                 }
 486                         } else {
 487                                 if ( is_object( $value ) ) {
 488                                         $value = $value->__toString();
 489                                 }
 490                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 491                         }
 492                 }
 493         }
 494         return $cgi;
 495 }
 496
 497 /**
 498  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 499  * its argument and returns the same string in array form.  This allows compatibility
 500  * with legacy functions that accept raw query strings instead of nice
 501  * arrays.  Of course, keys and values are urldecode()d.
 502  *
 503  * @param string $query Query string
 504  * @return string[] Array version of input
 505  */
 506 function wfCgiToArray( $query ) {
 507         if ( isset( $query[0] ) && $query[0] == '?' ) {
 508                 $query = substr( $query, 1 );
 509         }
 510         $bits = explode( '&', $query );
 511         $ret = array();
 512         foreach ( $bits as $bit ) {
 513                 if ( $bit === '' ) {
 514                         continue;
 515                 }
 516                 if ( strpos( $bit, '=' ) === false ) {
 517                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 518                         $key = $bit;
 519                         $value = '';
 520                 } else {
 521                         list( $key, $value ) = explode( '=', $bit );
 522                 }
 523                 $key = urldecode( $key );
 524                 $value = urldecode( $value );
 525                 if ( strpos( $key, '[' ) !== false ) {
 526                         $keys = array_reverse( explode( '[', $key ) );
 527                         $key = array_pop( $keys );
 528                         $temp = $value;
 529                         foreach ( $keys as $k ) {
 530                                 $k = substr( $k, 0, -1 );
 531                                 $temp = array( $k => $temp );
 532                         }
 533                         if ( isset( $ret[$key] ) ) {
 534                                 $ret[$key] = array_merge( $ret[$key], $temp );
 535                         } else {
 536                                 $ret[$key] = $temp;
 537                         }
 538                 } else {
 539                         $ret[$key] = $value;
 540                 }
 541         }
 542         return $ret;
 543 }
 544
 545 /**
 546  * Append a query string to an existing URL, which may or may not already
 547  * have query string parameters already. If so, they will be combined.
 548  *
 549  * @param string $url
 550  * @param string|string[] $query String or associative array
 551  * @return string
 552  */
 553 function wfAppendQuery( $url, $query ) {
 554         if ( is_array( $query ) ) {
 555                 $query = wfArrayToCgi( $query );
 556         }
 557         if ( $query != '' ) {
 558                 if ( false === strpos( $url, '?' ) ) {
 559                         $url .= '?';
 560                 } else {
 561                         $url .= '&';
 562                 }
 563                 $url .= $query;
 564         }
 565         return $url;
 566 }
 567
 568 /**
 569  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 570  * is correct.
 571  *
 572  * The meaning of the PROTO_* constants is as follows:
 573  * PROTO_HTTP: Output a URL starting with http://
 574  * PROTO_HTTPS: Output a URL starting with https://
 575  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 576  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 577  *    on which protocol was used for the current incoming request
 578  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 579  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 580  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 581  *
 582  * @todo this won't work with current-path-relative URLs
 583  * like "subdir/foo.html", etc.
 584  *
 585  * @param string $url Either fully-qualified or a local path + query
 586  * @param string $defaultProto One of the PROTO_* constants. Determines the
 587  *    protocol to use if $url or $wgServer is protocol-relative
 588  * @return string Fully-qualified URL, current-path-relative URL or false if
 589  *    no valid URL can be constructed
 590  */
 591 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 592         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 593                 $wgHttpsPort;
 594         if ( $defaultProto === PROTO_CANONICAL ) {
 595                 $serverUrl = $wgCanonicalServer;
 596         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 597                 // Make $wgInternalServer fall back to $wgServer if not set
 598                 $serverUrl = $wgInternalServer;
 599         } else {
 600                 $serverUrl = $wgServer;
 601                 if ( $defaultProto === PROTO_CURRENT ) {
 602                         $defaultProto = $wgRequest->getProtocol() . '://';
 603                 }
 604         }
 605
 606         // Analyze $serverUrl to obtain its protocol
 607         $bits = wfParseUrl( $serverUrl );
 608         $serverHasProto = $bits && $bits['scheme'] != '';
 609
 610         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 611                 if ( $serverHasProto ) {
 612                         $defaultProto = $bits['scheme'] . '://';
 613                 } else {
 614                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 615                         // This really isn't supposed to happen. Fall back to HTTP in this
 616                         // ridiculous case.
 617                         $defaultProto = PROTO_HTTP;
 618                 }
 619         }
 620
 621         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 622
 623         if ( substr( $url, 0, 2 ) == '//' ) {
 624                 $url = $defaultProtoWithoutSlashes . $url;
 625         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 626                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 627                 // otherwise leave it alone.
 628                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 629         }
 630
 631         $bits = wfParseUrl( $url );
 632
 633         // ensure proper port for HTTPS arrives in URL
 634         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 635         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 636                 $bits['port'] = $wgHttpsPort;
 637         }
 638
 639         if ( $bits && isset( $bits['path'] ) ) {
 640                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 641                 return wfAssembleUrl( $bits );
 642         } elseif ( $bits ) {
 643                 # No path to expand
 644                 return $url;
 645         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 646                 # URL is a relative path
 647                 return wfRemoveDotSegments( $url );
 648         }
 649
 650         # Expanded URL is not valid.
 651         return false;
 652 }
 653
 654 /**
 655  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 656  * if you need to edit part of a URL and put it back together.
 657  *
 658  * This is the basic structure used (brackets contain keys for $urlParts):
 659  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 660  *
 661  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 662  *
 663  * @since 1.19
 664  * @param array $urlParts URL parts, as output from wfParseUrl
 665  * @return string URL assembled from its component parts
 666  */
 667 function wfAssembleUrl( $urlParts ) {
 668         $result = '';
 669
 670         if ( isset( $urlParts['delimiter'] ) ) {
 671                 if ( isset( $urlParts['scheme'] ) ) {
 672                         $result .= $urlParts['scheme'];
 673                 }
 674
 675                 $result .= $urlParts['delimiter'];
 676         }
 677
 678         if ( isset( $urlParts['host'] ) ) {
 679                 if ( isset( $urlParts['user'] ) ) {
 680                         $result .= $urlParts['user'];
 681                         if ( isset( $urlParts['pass'] ) ) {
 682                                 $result .= ':' . $urlParts['pass'];
 683                         }
 684                         $result .= '@';
 685                 }
 686
 687                 $result .= $urlParts['host'];
 688
 689                 if ( isset( $urlParts['port'] ) ) {
 690                         $result .= ':' . $urlParts['port'];
 691                 }
 692         }
 693
 694         if ( isset( $urlParts['path'] ) ) {
 695                 $result .= $urlParts['path'];
 696         }
 697
 698         if ( isset( $urlParts['query'] ) ) {
 699                 $result .= '?' . $urlParts['query'];
 700         }
 701
 702         if ( isset( $urlParts['fragment'] ) ) {
 703                 $result .= '#' . $urlParts['fragment'];
 704         }
 705
 706         return $result;
 707 }
 708
 709 /**
 710  * Remove all dot-segments in the provided URL path.  For example,
 711  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 712  * RFC3986 section 5.2.4.
 713  *
 714  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 715  *
 716  * @param string $urlPath URL path, potentially containing dot-segments
 717  * @return string URL path with all dot-segments removed
 718  */
 719 function wfRemoveDotSegments( $urlPath ) {
 720         $output = '';
 721         $inputOffset = 0;
 722         $inputLength = strlen( $urlPath );
 723
 724         while ( $inputOffset < $inputLength ) {
 725                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 726                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 727                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 728                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 729                 $trimOutput = false;
 730
 731                 if ( $prefixLengthTwo == './' ) {
 732                         # Step A, remove leading "./"
 733                         $inputOffset += 2;
 734                 } elseif ( $prefixLengthThree == '../' ) {
 735                         # Step A, remove leading "../"
 736                         $inputOffset += 3;
 737                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 738                         # Step B, replace leading "/.$" with "/"
 739                         $inputOffset += 1;
 740                         $urlPath[$inputOffset] = '/';
 741                 } elseif ( $prefixLengthThree == '/./' ) {
 742                         # Step B, replace leading "/./" with "/"
 743                         $inputOffset += 2;
 744                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 745                         # Step C, replace leading "/..$" with "/" and
 746                         # remove last path component in output
 747                         $inputOffset += 2;
 748                         $urlPath[$inputOffset] = '/';
 749                         $trimOutput = true;
 750                 } elseif ( $prefixLengthFour == '/../' ) {
 751                         # Step C, replace leading "/../" with "/" and
 752                         # remove last path component in output
 753                         $inputOffset += 3;
 754                         $trimOutput = true;
 755                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 756                         # Step D, remove "^.$"
 757                         $inputOffset += 1;
 758                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 759                         # Step D, remove "^..$"
 760                         $inputOffset += 2;
 761                 } else {
 762                         # Step E, move leading path segment to output
 763                         if ( $prefixLengthOne == '/' ) {
 764                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 765                         } else {
 766                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 767                         }
 768                         if ( $slashPos === false ) {
 769                                 $output .= substr( $urlPath, $inputOffset );
 770                                 $inputOffset = $inputLength;
 771                         } else {
 772                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 773                                 $inputOffset += $slashPos - $inputOffset;
 774                         }
 775                 }
 776
 777                 if ( $trimOutput ) {
 778                         $slashPos = strrpos( $output, '/' );
 779                         if ( $slashPos === false ) {
 780                                 $output = '';
 781                         } else {
 782                                 $output = substr( $output, 0, $slashPos );
 783                         }
 784                 }
 785         }
 786
 787         return $output;
 788 }
 789
 790 /**
 791  * Returns a regular expression of url protocols
 792  *
 793  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 794  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 795  * @return string
 796  */
 797 function wfUrlProtocols( $includeProtocolRelative = true ) {
 798         global $wgUrlProtocols;
 799
 800         // Cache return values separately based on $includeProtocolRelative
 801         static $withProtRel = null, $withoutProtRel = null;
 802         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 803         if ( !is_null( $cachedValue ) ) {
 804                 return $cachedValue;
 805         }
 806
 807         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 808         // with LocalSettings files from 1.5
 809         if ( is_array( $wgUrlProtocols ) ) {
 810                 $protocols = array();
 811                 foreach ( $wgUrlProtocols as $protocol ) {
 812                         // Filter out '//' if !$includeProtocolRelative
 813                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 814                                 $protocols[] = preg_quote( $protocol, '/' );
 815                         }
 816                 }
 817
 818                 $retval = implode( '|', $protocols );
 819         } else {
 820                 // Ignore $includeProtocolRelative in this case
 821                 // This case exists for pre-1.6 compatibility, and we can safely assume
 822                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 823                 // URLs weren't supported until 1.18
 824                 $retval = $wgUrlProtocols;
 825         }
 826
 827         // Cache return value
 828         if ( $includeProtocolRelative ) {
 829                 $withProtRel = $retval;
 830         } else {
 831                 $withoutProtRel = $retval;
 832         }
 833         return $retval;
 834 }
 835
 836 /**
 837  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 838  * you need a regex that matches all URL protocols but does not match protocol-
 839  * relative URLs
 840  * @return string
 841  */
 842 function wfUrlProtocolsWithoutProtRel() {
 843         return wfUrlProtocols( false );
 844 }
 845
 846 /**
 847  * parse_url() work-alike, but non-broken.  Differences:
 848  *
 849  * 1) Does not raise warnings on bad URLs (just returns false).
 850  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 851  *    protocol-relative URLs) correctly.
 852  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 853  *
 854  * @param string $url A URL to parse
 855  * @return string[] Bits of the URL in an associative array, per PHP docs
 856  */
 857 function wfParseUrl( $url ) {
 858         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 859
 860         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 861         // bad that the easiest way to handle them is to just prepend 'http:' and
 862         // strip the protocol out later.
 863         $wasRelative = substr( $url, 0, 2 ) == '//';
 864         if ( $wasRelative ) {
 865                 $url = "http:$url";
 866         }
 867         wfSuppressWarnings();
 868         $bits = parse_url( $url );
 869         wfRestoreWarnings();
 870         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 871         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 872         if ( !$bits || !isset( $bits['scheme'] ) ) {
 873                 return false;
 874         }
 875
 876         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 877         $bits['scheme'] = strtolower( $bits['scheme'] );
 878
 879         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 880         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 881                 $bits['delimiter'] = '://';
 882         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 883                 $bits['delimiter'] = ':';
 884                 // parse_url detects for news: and mailto: the host part of an url as path
 885                 // We have to correct this wrong detection
 886                 if ( isset( $bits['path'] ) ) {
 887                         $bits['host'] = $bits['path'];
 888                         $bits['path'] = '';
 889                 }
 890         } else {
 891                 return false;
 892         }
 893
 894         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 895         if ( !isset( $bits['host'] ) ) {
 896                 $bits['host'] = '';
 897
 898                 // bug 45069
 899                 if ( isset( $bits['path'] ) ) {
 900                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 901                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 902                                 $bits['path'] = '/' . $bits['path'];
 903                         }
 904                 } else {
 905                         $bits['path'] = '';
 906                 }
 907         }
 908
 909         // If the URL was protocol-relative, fix scheme and delimiter
 910         if ( $wasRelative ) {
 911                 $bits['scheme'] = '';
 912                 $bits['delimiter'] = '//';
 913         }
 914         return $bits;
 915 }
 916
 917 /**
 918  * Take a URL, make sure it's expanded to fully qualified, and replace any
 919  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 920  * for more compact display and legibility for local audiences.
 921  *
 922  * @todo handle punycode domains too
 923  *
 924  * @param string $url
 925  * @return string
 926  */
 927 function wfExpandIRI( $url ) {
 928         return preg_replace_callback(
 929                 '/((?:%[89A-F][0-9A-F])+)/i',
 930                 'wfExpandIRI_callback',
 931                 wfExpandUrl( $url )
 932         );
 933 }
 934
 935 /**
 936  * Private callback for wfExpandIRI
 937  * @param array $matches
 938  * @return string
 939  */
 940 function wfExpandIRI_callback( $matches ) {
 941         return urldecode( $matches[1] );
 942 }
 943
 944 /**
 945  * Make URL indexes, appropriate for the el_index field of externallinks.
 946  *
 947  * @param string $url
 948  * @return array
 949  */
 950 function wfMakeUrlIndexes( $url ) {
 951         $bits = wfParseUrl( $url );
 952
 953         // Reverse the labels in the hostname, convert to lower case
 954         // For emails reverse domainpart only
 955         if ( $bits['scheme'] == 'mailto' ) {
 956                 $mailparts = explode( '@', $bits['host'], 2 );
 957                 if ( count( $mailparts ) === 2 ) {
 958                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 959                 } else {
 960                         // No domain specified, don't mangle it
 961                         $domainpart = '';
 962                 }
 963                 $reversedHost = $domainpart . '@' . $mailparts[0];
 964         } else {
 965                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 966         }
 967         // Add an extra dot to the end
 968         // Why? Is it in wrong place in mailto links?
 969         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 970                 $reversedHost .= '.';
 971         }
 972         // Reconstruct the pseudo-URL
 973         $prot = $bits['scheme'];
 974         $index = $prot . $bits['delimiter'] . $reversedHost;
 975         // Leave out user and password. Add the port, path, query and fragment
 976         if ( isset( $bits['port'] ) ) {
 977                 $index .= ':' . $bits['port'];
 978         }
 979         if ( isset( $bits['path'] ) ) {
 980                 $index .= $bits['path'];
 981         } else {
 982                 $index .= '/';
 983         }
 984         if ( isset( $bits['query'] ) ) {
 985                 $index .= '?' . $bits['query'];
 986         }
 987         if ( isset( $bits['fragment'] ) ) {
 988                 $index .= '#' . $bits['fragment'];
 989         }
 990
 991         if ( $prot == '' ) {
 992                 return array( "http:$index", "https:$index" );
 993         } else {
 994                 return array( $index );
 995         }
 996 }
 997
 998 /**
 999  * Check whether a given URL has a domain that occurs in a given set of domains
1000  * @param string $url URL
1001  * @param array $domains Array of domains (strings)
1002  * @return bool True if the host part of $url ends in one of the strings in $domains
1003  */
1004 function wfMatchesDomainList( $url, $domains ) {
1005         $bits = wfParseUrl( $url );
1006         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
1007                 $host = '.' . $bits['host'];
1008                 foreach ( (array)$domains as $domain ) {
1009                         $domain = '.' . $domain;
1010                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
1011                                 return true;
1012                         }
1013                 }
1014         }
1015         return false;
1016 }
1017
1018 /**
1019  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
1020  * In normal operation this is a NOP.
1021  *
1022  * Controlling globals:
1023  * $wgDebugLogFile - points to the log file
1024  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
1025  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
1026  *
1027  * @since 1.25 support for additional context data
1028  *
1029  * @param string $text
1030  * @param string|bool $dest Destination of the message:
1031  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1032  *     - 'log': only to the log and not in HTML
1033  *   For backward compatibility, it can also take a boolean:
1034  *     - true: same as 'all'
1035  *     - false: same as 'log'
1036  * @param array $context Additional logging context data
1037  */
1038 function wfDebug( $text, $dest = 'all', array $context = array() ) {
1039         global $wgDebugRawPage, $wgDebugLogPrefix;
1040         global $wgDebugTimestamps, $wgRequestTime;
1041
1042         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1043                 return;
1044         }
1045
1046         // Turn $dest into a string if it's a boolean (for b/c)
1047         if ( $dest === true ) {
1048                 $dest = 'all';
1049         } elseif ( $dest === false ) {
1050                 $dest = 'log';
1051         }
1052
1053         $text = trim( $text );
1054
1055         // Inline logic from deprecated wfDebugTimer()
1056         if ( $wgDebugTimestamps ) {
1057                 $context['seconds_elapsed'] = sprintf(
1058                         '%6.4f',
1059                         microtime( true ) - $wgRequestTime
1060                 );
1061                 $context['memory_used'] = sprintf(
1062                         '%5.1fM',
1063                         ( memory_get_usage( true ) / ( 1024 * 1024 ) )
1064                 );
1065         }
1066
1067         if ( $dest === 'all' ) {
1068                 $prefix = '';
1069                 if ( $wgDebugTimestamps ) {
1070                         // Prepend elapsed request time and real memory usage with two
1071                         // trailing spaces.
1072                         $prefix = "{$context['seconds_elapsed']} {$context['memory_used']}  ";
1073                 }
1074                 MWDebug::debugMsg( "{$prefix}{$text}" );
1075         }
1076
1077         if ( $wgDebugLogPrefix !== '' ) {
1078                 $context['prefix'] = $wgDebugLogPrefix;
1079         }
1080
1081         $logger = MWLoggerFactory::getInstance( 'wfDebug' );
1082         $logger->debug( $text, $context );
1083 }
1084
1085 /**
1086  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
1087  * @return bool
1088  */
1089 function wfIsDebugRawPage() {
1090         static $cache;
1091         if ( $cache !== null ) {
1092                 return $cache;
1093         }
1094         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
1095         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
1096                 || (
1097                         isset( $_SERVER['SCRIPT_NAME'] )
1098                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
1099                 )
1100         ) {
1101                 $cache = true;
1102         } else {
1103                 $cache = false;
1104         }
1105         return $cache;
1106 }
1107
1108 /**
1109  * Get microsecond timestamps for debug logs
1110  *
1111  * @deprecated since 1.25
1112  * @return string
1113  */
1114 function wfDebugTimer() {
1115         global $wgDebugTimestamps, $wgRequestTime;
1116
1117         wfDeprecated( __METHOD__, '1.25' );
1118
1119         if ( !$wgDebugTimestamps ) {
1120                 return '';
1121         }
1122
1123         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1124         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1125         return "$prefix $mem  ";
1126 }
1127
1128 /**
1129  * Send a line giving PHP memory usage.
1130  *
1131  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1132  */
1133 function wfDebugMem( $exact = false ) {
1134         $mem = memory_get_usage();
1135         if ( !$exact ) {
1136                 $mem = floor( $mem / 1024 ) . ' KiB';
1137         } else {
1138                 $mem .= ' B';
1139         }
1140         wfDebug( "Memory usage: $mem\n" );
1141 }
1142
1143 /**
1144  * Send a line to a supplementary debug log file, if configured, or main debug
1145  * log if not.
1146  *
1147  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to
1148  * a string filename or an associative array mapping 'destination' to the
1149  * desired filename. The associative array may also contain a 'sample' key
1150  * with an integer value, specifying a sampling factor. Sampled log events
1151  * will be emitted with a 1 in N random chance.
1152  *
1153  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1154  * @since 1.25 support for additional context data
1155  * @since 1.25 sample behavior dependent on configured $wgMWLoggerDefaultSpi
1156  *
1157  * @param string $logGroup
1158  * @param string $text
1159  * @param string|bool $dest Destination of the message:
1160  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1161  *     - 'log': only to the log and not in HTML
1162  *     - 'private': only to the specific log if set in $wgDebugLogGroups and
1163  *       discarded otherwise
1164  *   For backward compatibility, it can also take a boolean:
1165  *     - true: same as 'all'
1166  *     - false: same as 'private'
1167  * @param array $context Additional logging context data
1168  */
1169 function wfDebugLog(
1170         $logGroup, $text, $dest = 'all', array $context = array()
1171 ) {
1172         // Turn $dest into a string if it's a boolean (for b/c)
1173         if ( $dest === true ) {
1174                 $dest = 'all';
1175         } elseif ( $dest === false ) {
1176                 $dest = 'private';
1177         }
1178
1179         $text = trim( $text );
1180
1181         if ( $dest === 'all' ) {
1182                 MWDebug::debugMsg( "[{$logGroup}] {$text}\n" );
1183         }
1184
1185         $logger = MWLoggerFactory::getInstance( $logGroup );
1186         $context['private'] = ( $dest === 'private' );
1187         $logger->info( $text, $context );
1188 }
1189
1190 /**
1191  * Log for database errors
1192  *
1193  * @since 1.25 support for additional context data
1194  *
1195  * @param string $text Database error message.
1196  * @param array $context Additional logging context data
1197  */
1198 function wfLogDBError( $text, array $context = array() ) {
1199         $logger = MWLoggerFactory::getInstance( 'wfLogDBError' );
1200         $logger->error( trim( $text ), $context );
1201 }
1202
1203 /**
1204  * Throws a warning that $function is deprecated
1205  *
1206  * @param string $function
1207  * @param string|bool $version Version of MediaWiki that the function
1208  *    was deprecated in (Added in 1.19).
1209  * @param string|bool $component Added in 1.19.
1210  * @param int $callerOffset How far up the call stack is the original
1211  *    caller. 2 = function that called the function that called
1212  *    wfDeprecated (Added in 1.20)
1213  *
1214  * @return null
1215  */
1216 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1217         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1218 }
1219
1220 /**
1221  * Send a warning either to the debug log or in a PHP error depending on
1222  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1223  *
1224  * @param string $msg Message to send
1225  * @param int $callerOffset Number of items to go back in the backtrace to
1226  *        find the correct caller (1 = function calling wfWarn, ...)
1227  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1228  *        only used when $wgDevelopmentWarnings is true
1229  */
1230 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1231         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1232 }
1233
1234 /**
1235  * Send a warning as a PHP error and the debug log. This is intended for logging
1236  * warnings in production. For logging development warnings, use WfWarn instead.
1237  *
1238  * @param string $msg Message to send
1239  * @param int $callerOffset Number of items to go back in the backtrace to
1240  *        find the correct caller (1 = function calling wfLogWarning, ...)
1241  * @param int $level PHP error level; defaults to E_USER_WARNING
1242  */
1243 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1244         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1245 }
1246
1247 /**
1248  * Log to a file without getting "file size exceeded" signals.
1249  *
1250  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1251  * send lines to the specified port, prefixed by the specified prefix and a space.
1252  * @since 1.25 support for additional context data
1253  *
1254  * @param string $text
1255  * @param string $file Filename
1256  * @param array $context Additional logging context data
1257  * @throws MWException
1258  * @deprecated since 1.25 Use MWLoggerLegacyLogger::emit or UDPTransport
1259  */
1260 function wfErrorLog( $text, $file, array $context = array() ) {
1261         wfDeprecated( __METHOD__, '1.25' );
1262         $logger = MWLoggerFactory::getInstance( 'wfErrorLog' );
1263         $context['destination'] = $file;
1264         $logger->info( trim( $text ), $context );
1265 }
1266
1267 /**
1268  * @todo document
1269  */
1270 function wfLogProfilingData() {
1271         global $wgRequestTime, $wgDebugLogGroups, $wgDebugRawPage;
1272         global $wgProfileLimit, $wgUser, $wgRequest;
1273
1274         StatCounter::singleton()->flush();
1275
1276         $profiler = Profiler::instance();
1277
1278         # Profiling must actually be enabled...
1279         if ( $profiler instanceof ProfilerStub ) {
1280                 return;
1281         }
1282
1283         // Get total page request time and only show pages that longer than
1284         // $wgProfileLimit time (default is 0)
1285         $elapsed = microtime( true ) - $wgRequestTime;
1286         if ( $elapsed <= $wgProfileLimit ) {
1287                 return;
1288         }
1289
1290         $profiler->logData();
1291
1292         if ( isset( $wgDebugLogGroups['profileoutput'] )
1293                 && $wgDebugLogGroups['profileoutput'] === false
1294         ) {
1295                 // Explicitly disabled
1296                 return;
1297         }
1298         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1299                 return;
1300         }
1301
1302         $ctx = array( 'elapsed' => $elapsed );
1303         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1304                 $ctx['forwarded_for'] = $_SERVER['HTTP_X_FORWARDED_FOR'];
1305         }
1306         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1307                 $ctx['client_ip'] = $_SERVER['HTTP_CLIENT_IP'];
1308         }
1309         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1310                 $ctx['from'] = $_SERVER['HTTP_FROM'];
1311         }
1312         if ( isset( $ctx['forwarded_for'] ) ||
1313                 isset( $ctx['client_ip'] ) ||
1314                 isset( $ctx['from'] ) ) {
1315                 $ctx['proxy'] = $_SERVER['REMOTE_ADDR'];
1316         }
1317
1318         // Don't load $wgUser at this late stage just for statistics purposes
1319         // @todo FIXME: We can detect some anons even if it is not loaded.
1320         // See User::getId()
1321         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1322                 $ctx['anon'] = true;
1323         } else {
1324                 $ctx['anon'] = false;
1325         }
1326
1327         // Command line script uses a FauxRequest object which does not have
1328         // any knowledge about an URL and throw an exception instead.
1329         try {
1330                 $ctx['url'] = urldecode( $wgRequest->getRequestURL() );
1331         } catch ( Exception $ignored ) {
1332                 // no-op
1333         }
1334
1335         $ctx['output'] = $profiler->getOutput();
1336
1337         $log = MWLoggerFactory::getInstance( 'profileoutput' );
1338         $log->info( "Elapsed: {elapsed}; URL: <{url}>\n{output}", $ctx );
1339 }
1340
1341 /**
1342  * Increment a statistics counter
1343  *
1344  * @param string $key
1345  * @param int $count
1346  * @return void
1347  */
1348 function wfIncrStats( $key, $count = 1 ) {
1349         StatCounter::singleton()->incr( $key, $count );
1350 }
1351
1352 /**
1353  * Check whether the wiki is in read-only mode.
1354  *
1355  * @return bool
1356  */
1357 function wfReadOnly() {
1358         return wfReadOnlyReason() !== false;
1359 }
1360
1361 /**
1362  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1363  *
1364  * @return string|bool String when in read-only mode; false otherwise
1365  */
1366 function wfReadOnlyReason() {
1367         global $wgReadOnly, $wgReadOnlyFile;
1368
1369         if ( $wgReadOnly === null ) {
1370                 // Set $wgReadOnly for faster access next time
1371                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1372                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1373                 } else {
1374                         $wgReadOnly = false;
1375                 }
1376         }
1377
1378         return $wgReadOnly;
1379 }
1380
1381 /**
1382  * Return a Language object from $langcode
1383  *
1384  * @param Language|string|bool $langcode Either:
1385  *                  - a Language object
1386  *                  - code of the language to get the message for, if it is
1387  *                    a valid code create a language for that language, if
1388  *                    it is a string but not a valid code then make a basic
1389  *                    language object
1390  *                  - a boolean: if it's false then use the global object for
1391  *                    the current user's language (as a fallback for the old parameter
1392  *                    functionality), or if it is true then use global object
1393  *                    for the wiki's content language.
1394  * @return Language
1395  */
1396 function wfGetLangObj( $langcode = false ) {
1397         # Identify which language to get or create a language object for.
1398         # Using is_object here due to Stub objects.
1399         if ( is_object( $langcode ) ) {
1400                 # Great, we already have the object (hopefully)!
1401                 return $langcode;
1402         }
1403
1404         global $wgContLang, $wgLanguageCode;
1405         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1406                 # $langcode is the language code of the wikis content language object.
1407                 # or it is a boolean and value is true
1408                 return $wgContLang;
1409         }
1410
1411         global $wgLang;
1412         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1413                 # $langcode is the language code of user language object.
1414                 # or it was a boolean and value is false
1415                 return $wgLang;
1416         }
1417
1418         $validCodes = array_keys( Language::fetchLanguageNames() );
1419         if ( in_array( $langcode, $validCodes ) ) {
1420                 # $langcode corresponds to a valid language.
1421                 return Language::factory( $langcode );
1422         }
1423
1424         # $langcode is a string, but not a valid language code; use content language.
1425         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1426         return $wgContLang;
1427 }
1428
1429 /**
1430  * This is the function for getting translated interface messages.
1431  *
1432  * @see Message class for documentation how to use them.
1433  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1434  *
1435  * This function replaces all old wfMsg* functions.
1436  *
1437  * @param string|string[] $key Message key, or array of keys
1438  * @param mixed $params,... Normal message parameters
1439  * @return Message
1440  *
1441  * @since 1.17
1442  *
1443  * @see Message::__construct
1444  */
1445 function wfMessage( $key /*...*/ ) {
1446         $params = func_get_args();
1447         array_shift( $params );
1448         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1449                 $params = $params[0];
1450         }
1451         return new Message( $key, $params );
1452 }
1453
1454 /**
1455  * This function accepts multiple message keys and returns a message instance
1456  * for the first message which is non-empty. If all messages are empty then an
1457  * instance of the first message key is returned.
1458  *
1459  * @param string|string[] $keys,... Message keys
1460  * @return Message
1461  *
1462  * @since 1.18
1463  *
1464  * @see Message::newFallbackSequence
1465  */
1466 function wfMessageFallback( /*...*/ ) {
1467         $args = func_get_args();
1468         return call_user_func_array( 'Message::newFallbackSequence', $args );
1469 }
1470
1471 /**
1472  * Get a message from anywhere, for the current user language.
1473  *
1474  * Use wfMsgForContent() instead if the message should NOT
1475  * change depending on the user preferences.
1476  *
1477  * @deprecated since 1.18
1478  *
1479  * @param string $key Lookup key for the message, usually
1480  *    defined in languages/Language.php
1481  *
1482  * Parameters to the message, which can be used to insert variable text into
1483  * it, can be passed to this function in the following formats:
1484  * - One per argument, starting at the second parameter
1485  * - As an array in the second parameter
1486  * These are not shown in the function definition.
1487  *
1488  * @return string
1489  */
1490 function wfMsg( $key ) {
1491         wfDeprecated( __METHOD__, '1.21' );
1492
1493         $args = func_get_args();
1494         array_shift( $args );
1495         return wfMsgReal( $key, $args );
1496 }
1497
1498 /**
1499  * Same as above except doesn't transform the message
1500  *
1501  * @deprecated since 1.18
1502  *
1503  * @param string $key
1504  * @return string
1505  */
1506 function wfMsgNoTrans( $key ) {
1507         wfDeprecated( __METHOD__, '1.21' );
1508
1509         $args = func_get_args();
1510         array_shift( $args );
1511         return wfMsgReal( $key, $args, true, false, false );
1512 }
1513
1514 /**
1515  * Get a message from anywhere, for the current global language
1516  * set with $wgLanguageCode.
1517  *
1518  * Use this if the message should NOT change dependent on the
1519  * language set in the user's preferences. This is the case for
1520  * most text written into logs, as well as link targets (such as
1521  * the name of the copyright policy page). Link titles, on the
1522  * other hand, should be shown in the UI language.
1523  *
1524  * Note that MediaWiki allows users to change the user interface
1525  * language in their preferences, but a single installation
1526  * typically only contains content in one language.
1527  *
1528  * Be wary of this distinction: If you use wfMsg() where you should
1529  * use wfMsgForContent(), a user of the software may have to
1530  * customize potentially hundreds of messages in
1531  * order to, e.g., fix a link in every possible language.
1532  *
1533  * @deprecated since 1.18
1534  *
1535  * @param string $key Lookup key for the message, usually
1536  *     defined in languages/Language.php
1537  * @return string
1538  */
1539 function wfMsgForContent( $key ) {
1540         wfDeprecated( __METHOD__, '1.21' );
1541
1542         global $wgForceUIMsgAsContentMsg;
1543         $args = func_get_args();
1544         array_shift( $args );
1545         $forcontent = true;
1546         if ( is_array( $wgForceUIMsgAsContentMsg )
1547                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1548         ) {
1549                 $forcontent = false;
1550         }
1551         return wfMsgReal( $key, $args, true, $forcontent );
1552 }
1553
1554 /**
1555  * Same as above except doesn't transform the message
1556  *
1557  * @deprecated since 1.18
1558  *
1559  * @param string $key
1560  * @return string
1561  */
1562 function wfMsgForContentNoTrans( $key ) {
1563         wfDeprecated( __METHOD__, '1.21' );
1564
1565         global $wgForceUIMsgAsContentMsg;
1566         $args = func_get_args();
1567         array_shift( $args );
1568         $forcontent = true;
1569         if ( is_array( $wgForceUIMsgAsContentMsg )
1570                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1571         ) {
1572                 $forcontent = false;
1573         }
1574         return wfMsgReal( $key, $args, true, $forcontent, false );
1575 }
1576
1577 /**
1578  * Really get a message
1579  *
1580  * @deprecated since 1.18
1581  *
1582  * @param string $key Key to get.
1583  * @param array $args
1584  * @param bool $useDB
1585  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1586  * @param bool $transform Whether or not to transform the message.
1587  * @return string The requested message.
1588  */
1589 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1590         wfDeprecated( __METHOD__, '1.21' );
1591
1592         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1593         $message = wfMsgReplaceArgs( $message, $args );
1594         return $message;
1595 }
1596
1597 /**
1598  * Fetch a message string value, but don't replace any keys yet.
1599  *
1600  * @deprecated since 1.18
1601  *
1602  * @param string $key
1603  * @param bool $useDB
1604  * @param string|bool $langCode Code of the language to get the message for, or
1605  *   behaves as a content language switch if it is a boolean.
1606  * @param bool $transform Whether to parse magic words, etc.
1607  * @return string
1608  */
1609 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1610         wfDeprecated( __METHOD__, '1.21' );
1611
1612         Hooks::run( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1613
1614         $cache = MessageCache::singleton();
1615         $message = $cache->get( $key, $useDB, $langCode );
1616         if ( $message === false ) {
1617                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1618         } elseif ( $transform ) {
1619                 $message = $cache->transform( $message );
1620         }
1621         return $message;
1622 }
1623
1624 /**
1625  * Replace message parameter keys on the given formatted output.
1626  *
1627  * @param string $message
1628  * @param array $args
1629  * @return string
1630  * @private
1631  */
1632 function wfMsgReplaceArgs( $message, $args ) {
1633         # Fix windows line-endings
1634         # Some messages are split with explode("\n", $msg)
1635         $message = str_replace( "\r", '', $message );
1636
1637         // Replace arguments
1638         if ( count( $args ) ) {
1639                 if ( is_array( $args[0] ) ) {
1640                         $args = array_values( $args[0] );
1641                 }
1642                 $replacementKeys = array();
1643                 foreach ( $args as $n => $param ) {
1644                         $replacementKeys['$' . ( $n + 1 )] = $param;
1645                 }
1646                 $message = strtr( $message, $replacementKeys );
1647         }
1648
1649         return $message;
1650 }
1651
1652 /**
1653  * Return an HTML-escaped version of a message.
1654  * Parameter replacements, if any, are done *after* the HTML-escaping,
1655  * so parameters may contain HTML (eg links or form controls). Be sure
1656  * to pre-escape them if you really do want plaintext, or just wrap
1657  * the whole thing in htmlspecialchars().
1658  *
1659  * @deprecated since 1.18
1660  *
1661  * @param string $key
1662  * @param string $args,... Parameters
1663  * @return string
1664  */
1665 function wfMsgHtml( $key ) {
1666         wfDeprecated( __METHOD__, '1.21' );
1667
1668         $args = func_get_args();
1669         array_shift( $args );
1670         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1671 }
1672
1673 /**
1674  * Return an HTML version of message
1675  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1676  * so parameters may contain HTML (eg links or form controls). Be sure
1677  * to pre-escape them if you really do want plaintext, or just wrap
1678  * the whole thing in htmlspecialchars().
1679  *
1680  * @deprecated since 1.18
1681  *
1682  * @param string $key
1683  * @param string $args,... Parameters
1684  * @return string
1685  */
1686 function wfMsgWikiHtml( $key ) {
1687         wfDeprecated( __METHOD__, '1.21' );
1688
1689         $args = func_get_args();
1690         array_shift( $args );
1691         return wfMsgReplaceArgs(
1692                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1693                 /* can't be set to false */ true, /* interface */ true )->getText(),
1694                 $args );
1695 }
1696
1697 /**
1698  * Returns message in the requested format
1699  *
1700  * @deprecated since 1.18
1701  *
1702  * @param string $key Key of the message
1703  * @param array $options Processing rules.
1704  *   Can take the following options:
1705  *     parse: parses wikitext to HTML
1706  *     parseinline: parses wikitext to HTML and removes the surrounding
1707  *       p's added by parser or tidy
1708  *     escape: filters message through htmlspecialchars
1709  *     escapenoentities: same, but allows entity references like &#160; through
1710  *     replaceafter: parameters are substituted after parsing or escaping
1711  *     parsemag: transform the message using magic phrases
1712  *     content: fetch message for content language instead of interface
1713  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1714  *     language: Language object or language code to fetch message for
1715  *       (overridden by content).
1716  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1717  *
1718  * @return string
1719  */
1720 function wfMsgExt( $key, $options ) {
1721         wfDeprecated( __METHOD__, '1.21' );
1722
1723         $args = func_get_args();
1724         array_shift( $args );
1725         array_shift( $args );
1726         $options = (array)$options;
1727         $validOptions = array( 'parse', 'parseinline', 'escape', 'escapenoentities', 'replaceafter',
1728                 'parsemag', 'content' );
1729
1730         foreach ( $options as $arrayKey => $option ) {
1731                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1732                         // An unknown index, neither numeric nor "language"
1733                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1734                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option, $validOptions ) ) {
1735                         // A numeric index with unknown value
1736                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1737                 }
1738         }
1739
1740         if ( in_array( 'content', $options, true ) ) {
1741                 $forContent = true;
1742                 $langCode = true;
1743                 $langCodeObj = null;
1744         } elseif ( array_key_exists( 'language', $options ) ) {
1745                 $forContent = false;
1746                 $langCode = wfGetLangObj( $options['language'] );
1747                 $langCodeObj = $langCode;
1748         } else {
1749                 $forContent = false;
1750                 $langCode = false;
1751                 $langCodeObj = null;
1752         }
1753
1754         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1755
1756         if ( !in_array( 'replaceafter', $options, true ) ) {
1757                 $string = wfMsgReplaceArgs( $string, $args );
1758         }
1759
1760         $messageCache = MessageCache::singleton();
1761         $parseInline = in_array( 'parseinline', $options, true );
1762         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1763                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1764                 if ( $string instanceof ParserOutput ) {
1765                         $string = $string->getText();
1766                 }
1767
1768                 if ( $parseInline ) {
1769                         $string = Parser::stripOuterParagraph( $string );
1770                 }
1771         } elseif ( in_array( 'parsemag', $options, true ) ) {
1772                 $string = $messageCache->transform( $string,
1773                                 !$forContent, $langCodeObj );
1774         }
1775
1776         if ( in_array( 'escape', $options, true ) ) {
1777                 $string = htmlspecialchars ( $string );
1778         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1779                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1780         }
1781
1782         if ( in_array( 'replaceafter', $options, true ) ) {
1783                 $string = wfMsgReplaceArgs( $string, $args );
1784         }
1785
1786         return $string;
1787 }
1788
1789 /**
1790  * Since wfMsg() and co suck, they don't return false if the message key they
1791  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1792  * nonexistence of messages by checking the MessageCache::get() result directly.
1793  *
1794  * @deprecated since 1.18. Use Message::isDisabled().
1795  *
1796  * @param string $key The message key looked up
1797  * @return bool True if the message *doesn't* exist.
1798  */
1799 function wfEmptyMsg( $key ) {
1800         wfDeprecated( __METHOD__, '1.21' );
1801
1802         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1803 }
1804
1805 /**
1806  * Fetch server name for use in error reporting etc.
1807  * Use real server name if available, so we know which machine
1808  * in a server farm generated the current page.
1809  *
1810  * @return string
1811  */
1812 function wfHostname() {
1813         static $host;
1814         if ( is_null( $host ) ) {
1815
1816                 # Hostname overriding
1817                 global $wgOverrideHostname;
1818                 if ( $wgOverrideHostname !== false ) {
1819                         # Set static and skip any detection
1820                         $host = $wgOverrideHostname;
1821                         return $host;
1822                 }
1823
1824                 if ( function_exists( 'posix_uname' ) ) {
1825                         // This function not present on Windows
1826                         $uname = posix_uname();
1827                 } else {
1828                         $uname = false;
1829                 }
1830                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1831                         $host = $uname['nodename'];
1832                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1833                         # Windows computer name
1834                         $host = getenv( 'COMPUTERNAME' );
1835                 } else {
1836                         # This may be a virtual server.
1837                         $host = $_SERVER['SERVER_NAME'];
1838                 }
1839         }
1840         return $host;
1841 }
1842
1843 /**
1844  * Returns a script tag that stores the amount of time it took MediaWiki to
1845  * handle the request in milliseconds as 'wgBackendResponseTime'.
1846  *
1847  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1848  * hostname of the server handling the request.
1849  *
1850  * @return string
1851  */
1852 function wfReportTime() {
1853         global $wgRequestTime, $wgShowHostnames;
1854
1855         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1856         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1857         if ( $wgShowHostnames ) {
1858                 $reportVars['wgHostname'] = wfHostname();
1859         }
1860         return Skin::makeVariablesScript( $reportVars );
1861 }
1862
1863 /**
1864  * Safety wrapper for debug_backtrace().
1865  *
1866  * Will return an empty array if debug_backtrace is disabled, otherwise
1867  * the output from debug_backtrace() (trimmed).
1868  *
1869  * @param int $limit This parameter can be used to limit the number of stack frames returned
1870  *
1871  * @return array Array of backtrace information
1872  */
1873 function wfDebugBacktrace( $limit = 0 ) {
1874         static $disabled = null;
1875
1876         if ( is_null( $disabled ) ) {
1877                 $disabled = !function_exists( 'debug_backtrace' );
1878                 if ( $disabled ) {
1879                         wfDebug( "debug_backtrace() is disabled\n" );
1880                 }
1881         }
1882         if ( $disabled ) {
1883                 return array();
1884         }
1885
1886         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1887                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1888         } else {
1889                 return array_slice( debug_backtrace(), 1 );
1890         }
1891 }
1892
1893 /**
1894  * Get a debug backtrace as a string
1895  *
1896  * @param bool|null $raw If true, the return value is plain text. If false, HTML.
1897  *   Defaults to $wgCommandLineMode if unset.
1898  * @return string
1899  * @since 1.25 Supports $raw parameter.
1900  */
1901 function wfBacktrace( $raw = null ) {
1902         global $wgCommandLineMode;
1903
1904         if ( $raw === null ) {
1905                 $raw = $wgCommandLineMode;
1906         }
1907
1908         if ( $raw ) {
1909                 $frameFormat = "%s line %s calls %s()\n";
1910                 $traceFormat = "%s";
1911         } else {
1912                 $frameFormat = "<li>%s line %s calls %s()</li>\n";
1913                 $traceFormat = "<ul>\n%s</ul>\n";
1914         }
1915
1916         $frames = array_map( function ( $frame ) use ( $frameFormat ) {
1917                 $file = !empty( $frame['file'] ) ? basename( $frame['file'] ) : '-';
1918                 $line = isset( $frame['line'] ) ? $frame['line'] : '-';
1919                 $call = $frame['function'];
1920                 if ( !empty( $frame['class'] ) ) {
1921                         $call = $frame['class'] . $frame['type'] . $call;
1922                 }
1923                 return sprintf( $frameFormat, $file, $line, $call );
1924         }, wfDebugBacktrace() );
1925
1926         return sprintf( $traceFormat, implode( '', $frames ) );
1927 }
1928
1929 /**
1930  * Get the name of the function which called this function
1931  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1932  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1933  * wfGetCaller( 3 ) is the parent of that.
1934  *
1935  * @param int $level
1936  * @return string
1937  */
1938 function wfGetCaller( $level = 2 ) {
1939         $backtrace = wfDebugBacktrace( $level + 1 );
1940         if ( isset( $backtrace[$level] ) ) {
1941                 return wfFormatStackFrame( $backtrace[$level] );
1942         } else {
1943                 return 'unknown';
1944         }
1945 }
1946
1947 /**
1948  * Return a string consisting of callers in the stack. Useful sometimes
1949  * for profiling specific points.
1950  *
1951  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1952  * @return string
1953  */
1954 function wfGetAllCallers( $limit = 3 ) {
1955         $trace = array_reverse( wfDebugBacktrace() );
1956         if ( !$limit || $limit > count( $trace ) - 1 ) {
1957                 $limit = count( $trace ) - 1;
1958         }
1959         $trace = array_slice( $trace, -$limit - 1, $limit );
1960         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1961 }
1962
1963 /**
1964  * Return a string representation of frame
1965  *
1966  * @param array $frame
1967  * @return string
1968  */
1969 function wfFormatStackFrame( $frame ) {
1970         return isset( $frame['class'] ) ?
1971                 $frame['class'] . '::' . $frame['function'] :
1972                 $frame['function'];
1973 }
1974
1975 /* Some generic result counters, pulled out of SearchEngine */
1976
1977 /**
1978  * @todo document
1979  *
1980  * @param int $offset
1981  * @param int $limit
1982  * @return string
1983  */
1984 function wfShowingResults( $offset, $limit ) {
1985         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1986 }
1987
1988 /**
1989  * @todo document
1990  * @todo FIXME: We may want to blacklist some broken browsers
1991  *
1992  * @param bool $force
1993  * @return bool Whereas client accept gzip compression
1994  */
1995 function wfClientAcceptsGzip( $force = false ) {
1996         static $result = null;
1997         if ( $result === null || $force ) {
1998                 $result = false;
1999                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2000                         # @todo FIXME: We may want to blacklist some broken browsers
2001                         $m = array();
2002                         if ( preg_match(
2003                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2004                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
2005                                         $m
2006                                 )
2007                         ) {
2008                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2009                                         $result = false;
2010                                         return $result;
2011                                 }
2012                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2013                                 $result = true;
2014                         }
2015                 }
2016         }
2017         return $result;
2018 }
2019
2020 /**
2021  * Obtain the offset and limit values from the request string;
2022  * used in special pages
2023  *
2024  * @param int $deflimit Default limit if none supplied
2025  * @param string $optionname Name of a user preference to check against
2026  * @return array
2027  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2028  */
2029 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2030         global $wgRequest;
2031         wfDeprecated( __METHOD__, '1.24' );
2032         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2033 }
2034
2035 /**
2036  * Escapes the given text so that it may be output using addWikiText()
2037  * without any linking, formatting, etc. making its way through. This
2038  * is achieved by substituting certain characters with HTML entities.
2039  * As required by the callers, "<nowiki>" is not used.
2040  *
2041  * @param string $text Text to be escaped
2042  * @return string
2043  */
2044 function wfEscapeWikiText( $text ) {
2045         static $repl = null, $repl2 = null;
2046         if ( $repl === null ) {
2047                 $repl = array(
2048                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2049                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2050                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2051                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2052                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2053                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2054                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2055                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2056                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2057                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2058                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2059                         '__' => '_&#95;', '://' => '&#58;//',
2060                 );
2061
2062                 // We have to catch everything "\s" matches in PCRE
2063                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2064                         $repl["$magic "] = "$magic&#32;";
2065                         $repl["$magic\t"] = "$magic&#9;";
2066                         $repl["$magic\r"] = "$magic&#13;";
2067                         $repl["$magic\n"] = "$magic&#10;";
2068                         $repl["$magic\f"] = "$magic&#12;";
2069                 }
2070
2071                 // And handle protocols that don't use "://"
2072                 global $wgUrlProtocols;
2073                 $repl2 = array();
2074                 foreach ( $wgUrlProtocols as $prot ) {
2075                         if ( substr( $prot, -1 ) === ':' ) {
2076                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2077                         }
2078                 }
2079                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2080         }
2081         $text = substr( strtr( "\n$text", $repl ), 1 );
2082         $text = preg_replace( $repl2, '$1&#58;', $text );
2083         return $text;
2084 }
2085
2086 /**
2087  * Sets dest to source and returns the original value of dest
2088  * If source is NULL, it just returns the value, it doesn't set the variable
2089  * If force is true, it will set the value even if source is NULL
2090  *
2091  * @param mixed $dest
2092  * @param mixed $source
2093  * @param bool $force
2094  * @return mixed
2095  */
2096 function wfSetVar( &$dest, $source, $force = false ) {
2097         $temp = $dest;
2098         if ( !is_null( $source ) || $force ) {
2099                 $dest = $source;
2100         }
2101         return $temp;
2102 }
2103
2104 /**
2105  * As for wfSetVar except setting a bit
2106  *
2107  * @param int $dest
2108  * @param int $bit
2109  * @param bool $state
2110  *
2111  * @return bool
2112  */
2113 function wfSetBit( &$dest, $bit, $state = true ) {
2114         $temp = (bool)( $dest & $bit );
2115         if ( !is_null( $state ) ) {
2116                 if ( $state ) {
2117                         $dest |= $bit;
2118                 } else {
2119                         $dest &= ~$bit;
2120                 }
2121         }
2122         return $temp;
2123 }
2124
2125 /**
2126  * A wrapper around the PHP function var_export().
2127  * Either print it or add it to the regular output ($wgOut).
2128  *
2129  * @param mixed $var A PHP variable to dump.
2130  */
2131 function wfVarDump( $var ) {
2132         global $wgOut;
2133         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2134         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2135                 print $s;
2136         } else {
2137                 $wgOut->addHTML( $s );
2138         }
2139 }
2140
2141 /**
2142  * Provide a simple HTTP error.
2143  *
2144  * @param int|string $code
2145  * @param string $label
2146  * @param string $desc
2147  */
2148 function wfHttpError( $code, $label, $desc ) {
2149         global $wgOut;
2150         header( "HTTP/1.0 $code $label" );
2151         header( "Status: $code $label" );
2152         if ( $wgOut ) {
2153                 $wgOut->disable();
2154                 $wgOut->sendCacheControl();
2155         }
2156
2157         header( 'Content-type: text/html; charset=utf-8' );
2158         print "<!doctype html>" .
2159                 '<html><head><title>' .
2160                 htmlspecialchars( $label ) .
2161                 '</title></head><body><h1>' .
2162                 htmlspecialchars( $label ) .
2163                 '</h1><p>' .
2164                 nl2br( htmlspecialchars( $desc ) ) .
2165                 "</p></body></html>\n";
2166 }
2167
2168 /**
2169  * Clear away any user-level output buffers, discarding contents.
2170  *
2171  * Suitable for 'starting afresh', for instance when streaming
2172  * relatively large amounts of data without buffering, or wanting to
2173  * output image files without ob_gzhandler's compression.
2174  *
2175  * The optional $resetGzipEncoding parameter controls suppression of
2176  * the Content-Encoding header sent by ob_gzhandler; by default it
2177  * is left. See comments for wfClearOutputBuffers() for why it would
2178  * be used.
2179  *
2180  * Note that some PHP configuration options may add output buffer
2181  * layers which cannot be removed; these are left in place.
2182  *
2183  * @param bool $resetGzipEncoding
2184  */
2185 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2186         if ( $resetGzipEncoding ) {
2187                 // Suppress Content-Encoding and Content-Length
2188                 // headers from 1.10+s wfOutputHandler
2189                 global $wgDisableOutputCompression;
2190                 $wgDisableOutputCompression = true;
2191         }
2192         while ( $status = ob_get_status() ) {
2193                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2194                         // Probably from zlib.output_compression or other
2195                         // PHP-internal setting which can't be removed.
2196                         //
2197                         // Give up, and hope the result doesn't break
2198                         // output behavior.
2199                         break;
2200                 }
2201                 if ( !ob_end_clean() ) {
2202                         // Could not remove output buffer handler; abort now
2203                         // to avoid getting in some kind of infinite loop.
2204                         break;
2205                 }
2206                 if ( $resetGzipEncoding ) {
2207                         if ( $status['name'] == 'ob_gzhandler' ) {
2208                                 // Reset the 'Content-Encoding' field set by this handler
2209                                 // so we can start fresh.
2210                                 header_remove( 'Content-Encoding' );
2211                                 break;
2212                         }
2213                 }
2214         }
2215 }
2216
2217 /**
2218  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2219  *
2220  * Clear away output buffers, but keep the Content-Encoding header
2221  * produced by ob_gzhandler, if any.
2222  *
2223  * This should be used for HTTP 304 responses, where you need to
2224  * preserve the Content-Encoding header of the real result, but
2225  * also need to suppress the output of ob_gzhandler to keep to spec
2226  * and avoid breaking Firefox in rare cases where the headers and
2227  * body are broken over two packets.
2228  */
2229 function wfClearOutputBuffers() {
2230         wfResetOutputBuffers( false );
2231 }
2232
2233 /**
2234  * Converts an Accept-* header into an array mapping string values to quality
2235  * factors
2236  *
2237  * @param string $accept
2238  * @param string $def Default
2239  * @return float[] Associative array of string => float pairs
2240  */
2241 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2242         # No arg means accept anything (per HTTP spec)
2243         if ( !$accept ) {
2244                 return array( $def => 1.0 );
2245         }
2246
2247         $prefs = array();
2248
2249         $parts = explode( ',', $accept );
2250
2251         foreach ( $parts as $part ) {
2252                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2253                 $values = explode( ';', trim( $part ) );
2254                 $match = array();
2255                 if ( count( $values ) == 1 ) {
2256                         $prefs[$values[0]] = 1.0;
2257                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2258                         $prefs[$values[0]] = floatval( $match[1] );
2259                 }
2260         }
2261
2262         return $prefs;
2263 }
2264
2265 /**
2266  * Checks if a given MIME type matches any of the keys in the given
2267  * array. Basic wildcards are accepted in the array keys.
2268  *
2269  * Returns the matching MIME type (or wildcard) if a match, otherwise
2270  * NULL if no match.
2271  *
2272  * @param string $type
2273  * @param array $avail
2274  * @return string
2275  * @private
2276  */
2277 function mimeTypeMatch( $type, $avail ) {
2278         if ( array_key_exists( $type, $avail ) ) {
2279                 return $type;
2280         } else {
2281                 $parts = explode( '/', $type );
2282                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2283                         return $parts[0] . '/*';
2284                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2285                         return '*/*';
2286                 } else {
2287                         return null;
2288                 }
2289         }
2290 }
2291
2292 /**
2293  * Returns the 'best' match between a client's requested internet media types
2294  * and the server's list of available types. Each list should be an associative
2295  * array of type to preference (preference is a float between 0.0 and 1.0).
2296  * Wildcards in the types are acceptable.
2297  *
2298  * @param array $cprefs Client's acceptable type list
2299  * @param array $sprefs Server's offered types
2300  * @return string
2301  *
2302  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2303  * XXX: generalize to negotiate other stuff
2304  */
2305 function wfNegotiateType( $cprefs, $sprefs ) {
2306         $combine = array();
2307
2308         foreach ( array_keys( $sprefs ) as $type ) {
2309                 $parts = explode( '/', $type );
2310                 if ( $parts[1] != '*' ) {
2311                         $ckey = mimeTypeMatch( $type, $cprefs );
2312                         if ( $ckey ) {
2313                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2314                         }
2315                 }
2316         }
2317
2318         foreach ( array_keys( $cprefs ) as $type ) {
2319                 $parts = explode( '/', $type );
2320                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2321                         $skey = mimeTypeMatch( $type, $sprefs );
2322                         if ( $skey ) {
2323                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2324                         }
2325                 }
2326         }
2327
2328         $bestq = 0;
2329         $besttype = null;
2330
2331         foreach ( array_keys( $combine ) as $type ) {
2332                 if ( $combine[$type] > $bestq ) {
2333                         $besttype = $type;
2334                         $bestq = $combine[$type];
2335                 }
2336         }
2337
2338         return $besttype;
2339 }
2340
2341 /**
2342  * Reference-counted warning suppression
2343  *
2344  * @param bool $end
2345  */
2346 function wfSuppressWarnings( $end = false ) {
2347         static $suppressCount = 0;
2348         static $originalLevel = false;
2349
2350         if ( $end ) {
2351                 if ( $suppressCount ) {
2352                         --$suppressCount;
2353                         if ( !$suppressCount ) {
2354                                 error_reporting( $originalLevel );
2355                         }
2356                 }
2357         } else {
2358                 if ( !$suppressCount ) {
2359                         $originalLevel = error_reporting( E_ALL & ~(
2360                                 E_WARNING |
2361                                 E_NOTICE |
2362                                 E_USER_WARNING |
2363                                 E_USER_NOTICE |
2364                                 E_DEPRECATED |
2365                                 E_USER_DEPRECATED |
2366                                 E_STRICT
2367                         ) );
2368                 }
2369                 ++$suppressCount;
2370         }
2371 }
2372
2373 /**
2374  * Restore error level to previous value
2375  */
2376 function wfRestoreWarnings() {
2377         wfSuppressWarnings( true );
2378 }
2379
2380 # Autodetect, convert and provide timestamps of various types
2381
2382 /**
2383  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2384  */
2385 define( 'TS_UNIX', 0 );
2386
2387 /**
2388  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2389  */
2390 define( 'TS_MW', 1 );
2391
2392 /**
2393  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2394  */
2395 define( 'TS_DB', 2 );
2396
2397 /**
2398  * RFC 2822 format, for E-mail and HTTP headers
2399  */
2400 define( 'TS_RFC2822', 3 );
2401
2402 /**
2403  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2404  *
2405  * This is used by Special:Export
2406  */
2407 define( 'TS_ISO_8601', 4 );
2408
2409 /**
2410  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2411  *
2412  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2413  *       DateTime tag and page 36 for the DateTimeOriginal and
2414  *       DateTimeDigitized tags.
2415  */
2416 define( 'TS_EXIF', 5 );
2417
2418 /**
2419  * Oracle format time.
2420  */
2421 define( 'TS_ORACLE', 6 );
2422
2423 /**
2424  * Postgres format time.
2425  */
2426 define( 'TS_POSTGRES', 7 );
2427
2428 /**
2429  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2430  */
2431 define( 'TS_ISO_8601_BASIC', 9 );
2432
2433 /**
2434  * Get a timestamp string in one of various formats
2435  *
2436  * @param mixed $outputtype A timestamp in one of the supported formats, the
2437  *   function will autodetect which format is supplied and act accordingly.
2438  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2439  * @return string|bool String / false The same date in the format specified in $outputtype or false
2440  */
2441 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2442         try {
2443                 $timestamp = new MWTimestamp( $ts );
2444                 return $timestamp->getTimestamp( $outputtype );
2445         } catch ( TimestampException $e ) {
2446                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2447                 return false;
2448         }
2449 }
2450
2451 /**
2452  * Return a formatted timestamp, or null if input is null.
2453  * For dealing with nullable timestamp columns in the database.
2454  *
2455  * @param int $outputtype
2456  * @param string $ts
2457  * @return string
2458  */
2459 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2460         if ( is_null( $ts ) ) {
2461                 return null;
2462         } else {
2463                 return wfTimestamp( $outputtype, $ts );
2464         }
2465 }
2466
2467 /**
2468  * Convenience function; returns MediaWiki timestamp for the present time.
2469  *
2470  * @return string
2471  */
2472 function wfTimestampNow() {
2473         # return NOW
2474         return wfTimestamp( TS_MW, time() );
2475 }
2476
2477 /**
2478  * Check if the operating system is Windows
2479  *
2480  * @return bool True if it's Windows, false otherwise.
2481  */
2482 function wfIsWindows() {
2483         static $isWindows = null;
2484         if ( $isWindows === null ) {
2485                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2486         }
2487         return $isWindows;
2488 }
2489
2490 /**
2491  * Check if we are running under HHVM
2492  *
2493  * @return bool
2494  */
2495 function wfIsHHVM() {
2496         return defined( 'HHVM_VERSION' );
2497 }
2498
2499 /**
2500  * Swap two variables
2501  *
2502  * @deprecated since 1.24
2503  * @param mixed $x
2504  * @param mixed $y
2505  */
2506 function swap( &$x, &$y ) {
2507         wfDeprecated( __FUNCTION__, '1.24' );
2508         $z = $x;
2509         $x = $y;
2510         $y = $z;
2511 }
2512
2513 /**
2514  * Tries to get the system directory for temporary files. First
2515  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2516  * environment variables are then checked in sequence, and if none are
2517  * set try sys_get_temp_dir().
2518  *
2519  * NOTE: When possible, use instead the tmpfile() function to create
2520  * temporary files to avoid race conditions on file creation, etc.
2521  *
2522  * @return string
2523  */
2524 function wfTempDir() {
2525         global $wgTmpDirectory;
2526
2527         if ( $wgTmpDirectory !== false ) {
2528                 return $wgTmpDirectory;
2529         }
2530
2531         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2532
2533         foreach ( $tmpDir as $tmp ) {
2534                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2535                         return $tmp;
2536                 }
2537         }
2538         return sys_get_temp_dir();
2539 }
2540
2541 /**
2542  * Make directory, and make all parent directories if they don't exist
2543  *
2544  * @param string $dir Full path to directory to create
2545  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2546  * @param string $caller Optional caller param for debugging.
2547  * @throws MWException
2548  * @return bool
2549  */
2550 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2551         global $wgDirectoryMode;
2552
2553         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2554                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2555         }
2556
2557         if ( !is_null( $caller ) ) {
2558                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2559         }
2560
2561         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2562                 return true;
2563         }
2564
2565         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2566
2567         if ( is_null( $mode ) ) {
2568                 $mode = $wgDirectoryMode;
2569         }
2570
2571         // Turn off the normal warning, we're doing our own below
2572         wfSuppressWarnings();
2573         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2574         wfRestoreWarnings();
2575
2576         if ( !$ok ) {
2577                 //directory may have been created on another request since we last checked
2578                 if ( is_dir( $dir ) ) {
2579                         return true;
2580                 }
2581
2582                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2583                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2584         }
2585         return $ok;
2586 }
2587
2588 /**
2589  * Remove a directory and all its content.
2590  * Does not hide error.
2591  * @param string $dir
2592  */
2593 function wfRecursiveRemoveDir( $dir ) {
2594         wfDebug( __FUNCTION__ . "( $dir )\n" );
2595         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2596         if ( is_dir( $dir ) ) {
2597                 $objects = scandir( $dir );
2598                 foreach ( $objects as $object ) {
2599                         if ( $object != "." && $object != ".." ) {
2600                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2601                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2602                                 } else {
2603                                         unlink( $dir . '/' . $object );
2604                                 }
2605                         }
2606                 }
2607                 reset( $objects );
2608                 rmdir( $dir );
2609         }
2610 }
2611
2612 /**
2613  * @param int $nr The number to format
2614  * @param int $acc The number of digits after the decimal point, default 2
2615  * @param bool $round Whether or not to round the value, default true
2616  * @return string
2617  */
2618 function wfPercent( $nr, $acc = 2, $round = true ) {
2619         $ret = sprintf( "%.${acc}f", $nr );
2620         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2621 }
2622
2623 /**
2624  * Safety wrapper around ini_get() for boolean settings.
2625  * The values returned from ini_get() are pre-normalized for settings
2626  * set via php.ini or php_flag/php_admin_flag... but *not*
2627  * for those set via php_value/php_admin_value.
2628  *
2629  * It's fairly common for people to use php_value instead of php_flag,
2630  * which can leave you with an 'off' setting giving a false positive
2631  * for code that just takes the ini_get() return value as a boolean.
2632  *
2633  * To make things extra interesting, setting via php_value accepts
2634  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2635  * Unrecognized values go false... again opposite PHP's own coercion
2636  * from string to bool.
2637  *
2638  * Luckily, 'properly' set settings will always come back as '0' or '1',
2639  * so we only have to worry about them and the 'improper' settings.
2640  *
2641  * I frickin' hate PHP... :P
2642  *
2643  * @param string $setting
2644  * @return bool
2645  */
2646 function wfIniGetBool( $setting ) {
2647         $val = strtolower( ini_get( $setting ) );
2648         // 'on' and 'true' can't have whitespace around them, but '1' can.
2649         return $val == 'on'
2650                 || $val == 'true'
2651                 || $val == 'yes'
2652                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2653 }
2654
2655 /**
2656  * Windows-compatible version of escapeshellarg()
2657  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2658  * function puts single quotes in regardless of OS.
2659  *
2660  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2661  * earlier distro releases of PHP)
2662  *
2663  * @param string $args,...
2664  * @return string
2665  */
2666 function wfEscapeShellArg( /*...*/ ) {
2667         wfInitShellLocale();
2668
2669         $args = func_get_args();
2670         $first = true;
2671         $retVal = '';
2672         foreach ( $args as $arg ) {
2673                 if ( !$first ) {
2674                         $retVal .= ' ';
2675                 } else {
2676                         $first = false;
2677                 }
2678
2679                 if ( wfIsWindows() ) {
2680                         // Escaping for an MSVC-style command line parser and CMD.EXE
2681                         // @codingStandardsIgnoreStart For long URLs
2682                         // Refs:
2683                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2684                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2685                         //  * Bug #13518
2686                         //  * CR r63214
2687                         // Double the backslashes before any double quotes. Escape the double quotes.
2688                         // @codingStandardsIgnoreEnd
2689                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2690                         $arg = '';
2691                         $iteration = 0;
2692                         foreach ( $tokens as $token ) {
2693                                 if ( $iteration % 2 == 1 ) {
2694                                         // Delimiter, a double quote preceded by zero or more slashes
2695                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2696                                 } elseif ( $iteration % 4 == 2 ) {
2697                                         // ^ in $token will be outside quotes, need to be escaped
2698                                         $arg .= str_replace( '^', '^^', $token );
2699                                 } else { // $iteration % 4 == 0
2700                                         // ^ in $token will appear inside double quotes, so leave as is
2701                                         $arg .= $token;
2702                                 }
2703                                 $iteration++;
2704                         }
2705                         // Double the backslashes before the end of the string, because
2706                         // we will soon add a quote
2707                         $m = array();
2708                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2709                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2710                         }
2711
2712                         // Add surrounding quotes
2713                         $retVal .= '"' . $arg . '"';
2714                 } else {
2715                         $retVal .= escapeshellarg( $arg );
2716                 }
2717         }
2718         return $retVal;
2719 }
2720
2721 /**
2722  * Check if wfShellExec() is effectively disabled via php.ini config
2723  *
2724  * @return bool|string False or one of (safemode,disabled)
2725  * @since 1.22
2726  */
2727 function wfShellExecDisabled() {
2728         static $disabled = null;
2729         if ( is_null( $disabled ) ) {
2730                 if ( wfIniGetBool( 'safe_mode' ) ) {
2731                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2732                         $disabled = 'safemode';
2733                 } elseif ( !function_exists( 'proc_open' ) ) {
2734                         wfDebug( "proc_open() is disabled\n" );
2735                         $disabled = 'disabled';
2736                 } else {
2737                         $disabled = false;
2738                 }
2739         }
2740         return $disabled;
2741 }
2742
2743 /**
2744  * Execute a shell command, with time and memory limits mirrored from the PHP
2745  * configuration if supported.
2746  *
2747  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2748  *   or an array of unescaped arguments, in which case each value will be escaped
2749  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2750  * @param null|mixed &$retval Optional, will receive the program's exit code.
2751  *   (non-zero is usually failure). If there is an error from
2752  *   read, select, or proc_open(), this will be set to -1.
2753  * @param array $environ Optional environment variables which should be
2754  *   added to the executed command environment.
2755  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2756  *   this overwrites the global wgMaxShell* limits.
2757  * @param array $options Array of options:
2758  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2759  *     including errors from limit.sh
2760  *
2761  * @return string Collected stdout as a string
2762  */
2763 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2764         $limits = array(), $options = array()
2765 ) {
2766         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2767                 $wgMaxShellWallClockTime, $wgShellCgroup;
2768
2769         $disabled = wfShellExecDisabled();
2770         if ( $disabled ) {
2771                 $retval = 1;
2772                 return $disabled == 'safemode' ?
2773                         'Unable to run external programs in safe mode.' :
2774                         'Unable to run external programs, proc_open() is disabled.';
2775         }
2776
2777         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2778
2779         wfInitShellLocale();
2780
2781         $envcmd = '';
2782         foreach ( $environ as $k => $v ) {
2783                 if ( wfIsWindows() ) {
2784                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2785                          * appear in the environment variable, so we must use carat escaping as documented in
2786                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2787                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2788                          * are listed there but doesn't appear to need it.
2789                          */
2790                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2791                 } else {
2792                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2793                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2794                          */
2795                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2796                 }
2797         }
2798         if ( is_array( $cmd ) ) {
2799                 // Command line may be given as an array, escape each value and glue them together with a space
2800                 $cmdVals = array();
2801                 foreach ( $cmd as $val ) {
2802                         $cmdVals[] = wfEscapeShellArg( $val );
2803                 }
2804                 $cmd = implode( ' ', $cmdVals );
2805         }
2806
2807         $cmd = $envcmd . $cmd;
2808
2809         $useLogPipe = false;
2810         if ( is_executable( '/bin/bash' ) ) {
2811                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2812                 if ( isset( $limits['walltime'] ) ) {
2813                         $wallTime = intval( $limits['walltime'] );
2814                 } elseif ( isset( $limits['time'] ) ) {
2815                         $wallTime = $time;
2816                 } else {
2817                         $wallTime = intval( $wgMaxShellWallClockTime );
2818                 }
2819                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2820                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2821
2822                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2823                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2824                                 escapeshellarg( $cmd ) . ' ' .
2825                                 escapeshellarg(
2826                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2827                                         "MW_CPU_LIMIT=$time; " .
2828                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2829                                         "MW_MEM_LIMIT=$mem; " .
2830                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2831                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2832                                         "MW_USE_LOG_PIPE=yes"
2833                                 );
2834                         $useLogPipe = true;
2835                 } elseif ( $includeStderr ) {
2836                         $cmd .= ' 2>&1';
2837                 }
2838         } elseif ( $includeStderr ) {
2839                 $cmd .= ' 2>&1';
2840         }
2841         wfDebug( "wfShellExec: $cmd\n" );
2842
2843         $desc = array(
2844                 0 => array( 'file', 'php://stdin', 'r' ),
2845                 1 => array( 'pipe', 'w' ),
2846                 2 => array( 'file', 'php://stderr', 'w' ) );
2847         if ( $useLogPipe ) {
2848                 $desc[3] = array( 'pipe', 'w' );
2849         }
2850         $pipes = null;
2851         $proc = proc_open( $cmd, $desc, $pipes );
2852         if ( !$proc ) {
2853                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2854                 $retval = -1;
2855                 return '';
2856         }
2857         $outBuffer = $logBuffer = '';
2858         $emptyArray = array();
2859         $status = false;
2860         $logMsg = false;
2861
2862         // According to the documentation, it is possible for stream_select()
2863         // to fail due to EINTR. I haven't managed to induce this in testing
2864         // despite sending various signals. If it did happen, the error
2865         // message would take the form:
2866         //
2867         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2868         //
2869         // where [4] is the value of the macro EINTR and "Interrupted system
2870         // call" is string which according to the Linux manual is "possibly"
2871         // localised according to LC_MESSAGES.
2872         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2873         $eintrMessage = "stream_select(): unable to select [$eintr]";
2874
2875         // Build a table mapping resource IDs to pipe FDs to work around a
2876         // PHP 5.3 issue in which stream_select() does not preserve array keys
2877         // <https://bugs.php.net/bug.php?id=53427>.
2878         $fds = array();
2879         foreach ( $pipes as $fd => $pipe ) {
2880                 $fds[(int)$pipe] = $fd;
2881         }
2882
2883         $running = true;
2884         $timeout = null;
2885         $numReadyPipes = 0;
2886
2887         while ( $running === true || $numReadyPipes !== 0 ) {
2888                 if ( $running ) {
2889                         $status = proc_get_status( $proc );
2890                         // If the process has terminated, switch to nonblocking selects
2891                         // for getting any data still waiting to be read.
2892                         if ( !$status['running'] ) {
2893                                 $running = false;
2894                                 $timeout = 0;
2895                         }
2896                 }
2897
2898                 $readyPipes = $pipes;
2899
2900                 // Clear last error
2901                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2902                 @trigger_error( '' );
2903                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2904                 if ( $numReadyPipes === false ) {
2905                         // @codingStandardsIgnoreEnd
2906                         $error = error_get_last();
2907                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2908                                 continue;
2909                         } else {
2910                                 trigger_error( $error['message'], E_USER_WARNING );
2911                                 $logMsg = $error['message'];
2912                                 break;
2913                         }
2914                 }
2915                 foreach ( $readyPipes as $pipe ) {
2916                         $block = fread( $pipe, 65536 );
2917                         $fd = $fds[(int)$pipe];
2918                         if ( $block === '' ) {
2919                                 // End of file
2920                                 fclose( $pipes[$fd] );
2921                                 unset( $pipes[$fd] );
2922                                 if ( !$pipes ) {
2923                                         break 2;
2924                                 }
2925                         } elseif ( $block === false ) {
2926                                 // Read error
2927                                 $logMsg = "Error reading from pipe";
2928                                 break 2;
2929                         } elseif ( $fd == 1 ) {
2930                                 // From stdout
2931                                 $outBuffer .= $block;
2932                         } elseif ( $fd == 3 ) {
2933                                 // From log FD
2934                                 $logBuffer .= $block;
2935                                 if ( strpos( $block, "\n" ) !== false ) {
2936                                         $lines = explode( "\n", $logBuffer );
2937                                         $logBuffer = array_pop( $lines );
2938                                         foreach ( $lines as $line ) {
2939                                                 wfDebugLog( 'exec', $line );
2940                                         }
2941                                 }
2942                         }
2943                 }
2944         }
2945
2946         foreach ( $pipes as $pipe ) {
2947                 fclose( $pipe );
2948         }
2949
2950         // Use the status previously collected if possible, since proc_get_status()
2951         // just calls waitpid() which will not return anything useful the second time.
2952         if ( $running ) {
2953                 $status = proc_get_status( $proc );
2954         }
2955
2956         if ( $logMsg !== false ) {
2957                 // Read/select error
2958                 $retval = -1;
2959                 proc_close( $proc );
2960         } elseif ( $status['signaled'] ) {
2961                 $logMsg = "Exited with signal {$status['termsig']}";
2962                 $retval = 128 + $status['termsig'];
2963                 proc_close( $proc );
2964         } else {
2965                 if ( $status['running'] ) {
2966                         $retval = proc_close( $proc );
2967                 } else {
2968                         $retval = $status['exitcode'];
2969                         proc_close( $proc );
2970                 }
2971                 if ( $retval == 127 ) {
2972                         $logMsg = "Possibly missing executable file";
2973                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2974                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2975                 }
2976         }
2977
2978         if ( $logMsg !== false ) {
2979                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2980         }
2981
2982         return $outBuffer;
2983 }
2984
2985 /**
2986  * Execute a shell command, returning both stdout and stderr. Convenience
2987  * function, as all the arguments to wfShellExec can become unwieldy.
2988  *
2989  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2990  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2991  *   or an array of unescaped arguments, in which case each value will be escaped
2992  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2993  * @param null|mixed &$retval Optional, will receive the program's exit code.
2994  *   (non-zero is usually failure)
2995  * @param array $environ Optional environment variables which should be
2996  *   added to the executed command environment.
2997  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2998  *   this overwrites the global wgMaxShell* limits.
2999  * @return string Collected stdout and stderr as a string
3000  */
3001 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
3002         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
3003 }
3004
3005 /**
3006  * Workaround for http://bugs.php.net/bug.php?id=45132
3007  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
3008  */
3009 function wfInitShellLocale() {
3010         static $done = false;
3011         if ( $done ) {
3012                 return;
3013         }
3014         $done = true;
3015         global $wgShellLocale;
3016         if ( !wfIniGetBool( 'safe_mode' ) ) {
3017                 putenv( "LC_CTYPE=$wgShellLocale" );
3018                 setlocale( LC_CTYPE, $wgShellLocale );
3019         }
3020 }
3021
3022 /**
3023  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3024  * Note that $parameters should be a flat array and an option with an argument
3025  * should consist of two consecutive items in the array (do not use "--option value").
3026  *
3027  * @param string $script MediaWiki cli script path
3028  * @param array $parameters Arguments and options to the script
3029  * @param array $options Associative array of options:
3030  *              'php': The path to the php executable
3031  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3032  * @return string
3033  */
3034 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3035         global $wgPhpCli;
3036         // Give site config file a chance to run the script in a wrapper.
3037         // The caller may likely want to call wfBasename() on $script.
3038         Hooks::run( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3039         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3040         if ( isset( $options['wrapper'] ) ) {
3041                 $cmd[] = $options['wrapper'];
3042         }
3043         $cmd[] = $script;
3044         // Escape each parameter for shell
3045         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
3046 }
3047
3048 /**
3049  * wfMerge attempts to merge differences between three texts.
3050  * Returns true for a clean merge and false for failure or a conflict.
3051  *
3052  * @param string $old
3053  * @param string $mine
3054  * @param string $yours
3055  * @param string $result
3056  * @return bool
3057  */
3058 function wfMerge( $old, $mine, $yours, &$result ) {
3059         global $wgDiff3;
3060
3061         # This check may also protect against code injection in
3062         # case of broken installations.
3063         wfSuppressWarnings();
3064         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3065         wfRestoreWarnings();
3066
3067         if ( !$haveDiff3 ) {
3068                 wfDebug( "diff3 not found\n" );
3069                 return false;
3070         }
3071
3072         # Make temporary files
3073         $td = wfTempDir();
3074         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3075         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3076         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3077
3078         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3079         #       a newline character. To avoid this, we normalize the trailing whitespace before
3080         #       creating the diff.
3081
3082         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3083         fclose( $oldtextFile );
3084         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3085         fclose( $mytextFile );
3086         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3087         fclose( $yourtextFile );
3088
3089         # Check for a conflict
3090         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3091                 wfEscapeShellArg( $mytextName ) . ' ' .
3092                 wfEscapeShellArg( $oldtextName ) . ' ' .
3093                 wfEscapeShellArg( $yourtextName );
3094         $handle = popen( $cmd, 'r' );
3095
3096         if ( fgets( $handle, 1024 ) ) {
3097                 $conflict = true;
3098         } else {
3099                 $conflict = false;
3100         }
3101         pclose( $handle );
3102
3103         # Merge differences
3104         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3105                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3106         $handle = popen( $cmd, 'r' );
3107         $result = '';
3108         do {
3109                 $data = fread( $handle, 8192 );
3110                 if ( strlen( $data ) == 0 ) {
3111                         break;
3112                 }
3113                 $result .= $data;
3114         } while ( true );
3115         pclose( $handle );
3116         unlink( $mytextName );
3117         unlink( $oldtextName );
3118         unlink( $yourtextName );
3119
3120         if ( $result === '' && $old !== '' && !$conflict ) {
3121                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3122                 $conflict = true;
3123         }
3124         return !$conflict;
3125 }
3126
3127 /**
3128  * Returns unified plain-text diff of two texts.
3129  * Useful for machine processing of diffs.
3130  *
3131  * @param string $before The text before the changes.
3132  * @param string $after The text after the changes.
3133  * @param string $params Command-line options for the diff command.
3134  * @return string Unified diff of $before and $after
3135  */
3136 function wfDiff( $before, $after, $params = '-u' ) {
3137         if ( $before == $after ) {
3138                 return '';
3139         }
3140
3141         global $wgDiff;
3142         wfSuppressWarnings();
3143         $haveDiff = $wgDiff && file_exists( $wgDiff );
3144         wfRestoreWarnings();
3145
3146         # This check may also protect against code injection in
3147         # case of broken installations.
3148         if ( !$haveDiff ) {
3149                 wfDebug( "diff executable not found\n" );
3150                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3151                 $format = new UnifiedDiffFormatter();
3152                 return $format->format( $diffs );
3153         }
3154
3155         # Make temporary files
3156         $td = wfTempDir();
3157         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3158         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3159
3160         fwrite( $oldtextFile, $before );
3161         fclose( $oldtextFile );
3162         fwrite( $newtextFile, $after );
3163         fclose( $newtextFile );
3164
3165         // Get the diff of the two files
3166         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3167
3168         $h = popen( $cmd, 'r' );
3169
3170         $diff = '';
3171
3172         do {
3173                 $data = fread( $h, 8192 );
3174                 if ( strlen( $data ) == 0 ) {
3175                         break;
3176                 }
3177                 $diff .= $data;
3178         } while ( true );
3179
3180         // Clean up
3181         pclose( $h );
3182         unlink( $oldtextName );
3183         unlink( $newtextName );
3184
3185         // Kill the --- and +++ lines. They're not useful.
3186         $diff_lines = explode( "\n", $diff );
3187         if ( isset( $diff_lines[0] ) && strpos( $diff_lines[0], '---' ) === 0 ) {
3188                 unset( $diff_lines[0] );
3189         }
3190         if ( isset( $diff_lines[1] ) && strpos( $diff_lines[1], '+++' ) === 0 ) {
3191                 unset( $diff_lines[1] );
3192         }
3193
3194         $diff = implode( "\n", $diff_lines );
3195
3196         return $diff;
3197 }
3198
3199 /**
3200  * This function works like "use VERSION" in Perl, the program will die with a
3201  * backtrace if the current version of PHP is less than the version provided
3202  *
3203  * This is useful for extensions which due to their nature are not kept in sync
3204  * with releases, and might depend on other versions of PHP than the main code
3205  *
3206  * Note: PHP might die due to parsing errors in some cases before it ever
3207  *       manages to call this function, such is life
3208  *
3209  * @see perldoc -f use
3210  *
3211  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3212  * @throws MWException
3213  */
3214 function wfUsePHP( $req_ver ) {
3215         $php_ver = PHP_VERSION;
3216
3217         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3218                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3219         }
3220 }
3221
3222 /**
3223  * This function works like "use VERSION" in Perl except it checks the version
3224  * of MediaWiki, the program will die with a backtrace if the current version
3225  * of MediaWiki is less than the version provided.
3226  *
3227  * This is useful for extensions which due to their nature are not kept in sync
3228  * with releases
3229  *
3230  * Note: Due to the behavior of PHP's version_compare() which is used in this
3231  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3232  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3233  * targeted version number. For example if you wanted to allow any variation
3234  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3235  * not result in the same comparison due to the internal logic of
3236  * version_compare().
3237  *
3238  * @see perldoc -f use
3239  *
3240  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3241  * @throws MWException
3242  */
3243 function wfUseMW( $req_ver ) {
3244         global $wgVersion;
3245
3246         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3247                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3248         }
3249 }
3250
3251 /**
3252  * Return the final portion of a pathname.
3253  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3254  * http://bugs.php.net/bug.php?id=33898
3255  *
3256  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3257  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3258  *
3259  * @param string $path
3260  * @param string $suffix String to remove if present
3261  * @return string
3262  */
3263 function wfBaseName( $path, $suffix = '' ) {
3264         if ( $suffix == '' ) {
3265                 $encSuffix = '';
3266         } else {
3267                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3268         }
3269
3270         $matches = array();
3271         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3272                 return $matches[1];
3273         } else {
3274                 return '';
3275         }
3276 }
3277
3278 /**
3279  * Generate a relative path name to the given file.
3280  * May explode on non-matching case-insensitive paths,
3281  * funky symlinks, etc.
3282  *
3283  * @param string $path Absolute destination path including target filename
3284  * @param string $from Absolute source path, directory only
3285  * @return string
3286  */
3287 function wfRelativePath( $path, $from ) {
3288         // Normalize mixed input on Windows...
3289         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3290         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3291
3292         // Trim trailing slashes -- fix for drive root
3293         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3294         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3295
3296         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3297         $against = explode( DIRECTORY_SEPARATOR, $from );
3298
3299         if ( $pieces[0] !== $against[0] ) {
3300                 // Non-matching Windows drive letters?
3301                 // Return a full path.
3302                 return $path;
3303         }
3304
3305         // Trim off common prefix
3306         while ( count( $pieces ) && count( $against )
3307                 && $pieces[0] == $against[0] ) {
3308                 array_shift( $pieces );
3309                 array_shift( $against );
3310         }
3311
3312         // relative dots to bump us to the parent
3313         while ( count( $against ) ) {
3314                 array_unshift( $pieces, '..' );
3315                 array_shift( $against );
3316         }
3317
3318         array_push( $pieces, wfBaseName( $path ) );
3319
3320         return implode( DIRECTORY_SEPARATOR, $pieces );
3321 }
3322
3323 /**
3324  * Convert an arbitrarily-long digit string from one numeric base
3325  * to another, optionally zero-padding to a minimum column width.
3326  *
3327  * Supports base 2 through 36; digit values 10-36 are represented
3328  * as lowercase letters a-z. Input is case-insensitive.
3329  *
3330  * @param string $input Input number
3331  * @param int $sourceBase Base of the input number
3332  * @param int $destBase Desired base of the output
3333  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3334  * @param bool $lowercase Whether to output in lowercase or uppercase
3335  * @param string $engine Either "gmp", "bcmath", or "php"
3336  * @return string|bool The output number as a string, or false on error
3337  */
3338 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3339         $lowercase = true, $engine = 'auto'
3340 ) {
3341         $input = (string)$input;
3342         if (
3343                 $sourceBase < 2 ||
3344                 $sourceBase > 36 ||
3345                 $destBase < 2 ||
3346                 $destBase > 36 ||
3347                 $sourceBase != (int)$sourceBase ||
3348                 $destBase != (int)$destBase ||
3349                 $pad != (int)$pad ||
3350                 !preg_match(
3351                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3352                         $input
3353                 )
3354         ) {
3355                 return false;
3356         }
3357
3358         static $baseChars = array(
3359                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3360                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3361                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3362                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3363                 34 => 'y', 35 => 'z',
3364
3365                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3366                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3367                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3368                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3369                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3370                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3371         );
3372
3373         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3374                 // Removing leading zeros works around broken base detection code in
3375                 // some PHP versions (see <https://bugs.php.net/bug.php?id=50175> and
3376                 // <https://bugs.php.net/bug.php?id=55398>).
3377                 $result = gmp_strval( gmp_init( ltrim( $input, '0' ), $sourceBase ), $destBase );
3378         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3379                 $decimal = '0';
3380                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3381                         $decimal = bcmul( $decimal, $sourceBase );
3382                         $decimal = bcadd( $decimal, $baseChars[$char] );
3383                 }
3384
3385                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3386                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3387                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3388                 }
3389                 // @codingStandardsIgnoreEnd
3390
3391                 $result = strrev( $result );
3392         } else {
3393                 $inDigits = array();
3394                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3395                         $inDigits[] = $baseChars[$char];
3396                 }
3397
3398                 // Iterate over the input, modulo-ing out an output digit
3399                 // at a time until input is gone.
3400                 $result = '';
3401                 while ( $inDigits ) {
3402                         $work = 0;
3403                         $workDigits = array();
3404
3405                         // Long division...
3406                         foreach ( $inDigits as $digit ) {
3407                                 $work *= $sourceBase;
3408                                 $work += $digit;
3409
3410                                 if ( $workDigits || $work >= $destBase ) {
3411                                         $workDigits[] = (int)( $work / $destBase );
3412                                 }
3413                                 $work %= $destBase;
3414                         }
3415
3416                         // All that division leaves us with a remainder,
3417                         // which is conveniently our next output digit.
3418                         $result .= $baseChars[$work];
3419
3420                         // And we continue!
3421                         $inDigits = $workDigits;
3422                 }
3423
3424                 $result = strrev( $result );
3425         }
3426
3427         if ( !$lowercase ) {
3428                 $result = strtoupper( $result );
3429         }
3430
3431         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3432 }
3433
3434 /**
3435  * Check if there is sufficient entropy in php's built-in session generation
3436  *
3437  * @return bool True = there is sufficient entropy
3438  */
3439 function wfCheckEntropy() {
3440         return (
3441                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3442                         || ini_get( 'session.entropy_file' )
3443                 )
3444                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3445 }
3446
3447 /**
3448  * Override session_id before session startup if php's built-in
3449  * session generation code is not secure.
3450  */
3451 function wfFixSessionID() {
3452         // If the cookie or session id is already set we already have a session and should abort
3453         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3454                 return;
3455         }
3456
3457         // PHP's built-in session entropy is enabled if:
3458         // - entropy_file is set or you're on Windows with php 5.3.3+
3459         // - AND entropy_length is > 0
3460         // We treat it as disabled if it doesn't have an entropy length of at least 32
3461         $entropyEnabled = wfCheckEntropy();
3462
3463         // If built-in entropy is not enabled or not sufficient override PHP's
3464         // built in session id generation code
3465         if ( !$entropyEnabled ) {
3466                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3467                         "overriding session id generation using our cryptrand source.\n" );
3468                 session_id( MWCryptRand::generateHex( 32 ) );
3469         }
3470 }
3471
3472 /**
3473  * Reset the session_id
3474  *
3475  * @since 1.22
3476  */
3477 function wfResetSessionID() {
3478         global $wgCookieSecure;
3479         $oldSessionId = session_id();
3480         $cookieParams = session_get_cookie_params();
3481         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3482                 session_regenerate_id( false );
3483         } else {
3484                 $tmp = $_SESSION;
3485                 session_destroy();
3486                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3487                 $_SESSION = $tmp;
3488         }
3489         $newSessionId = session_id();
3490         Hooks::run( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3491 }
3492
3493 /**
3494  * Initialise php session
3495  *
3496  * @param bool $sessionId
3497  */
3498 function wfSetupSession( $sessionId = false ) {
3499         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3500                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3501         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3502                 ObjectCacheSessionHandler::install();
3503         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3504                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3505                 # hasn't already been set to the desired value (that causes errors)
3506                 ini_set( 'session.save_handler', $wgSessionHandler );
3507         }
3508         session_set_cookie_params(
3509                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3510         session_cache_limiter( 'private, must-revalidate' );
3511         if ( $sessionId ) {
3512                 session_id( $sessionId );
3513         } else {
3514                 wfFixSessionID();
3515         }
3516         wfSuppressWarnings();
3517         session_start();
3518         wfRestoreWarnings();
3519 }
3520
3521 /**
3522  * Get an object from the precompiled serialized directory
3523  *
3524  * @param string $name
3525  * @return mixed The variable on success, false on failure
3526  */
3527 function wfGetPrecompiledData( $name ) {
3528         global $IP;
3529
3530         $file = "$IP/serialized/$name";
3531         if ( file_exists( $file ) ) {
3532                 $blob = file_get_contents( $file );
3533                 if ( $blob ) {
3534                         return unserialize( $blob );
3535                 }
3536         }
3537         return false;
3538 }
3539
3540 /**
3541  * Get a cache key
3542  *
3543  * @param string $args,...
3544  * @return string
3545  */
3546 function wfMemcKey( /*...*/ ) {
3547         global $wgCachePrefix;
3548         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3549         $args = func_get_args();
3550         $key = $prefix . ':' . implode( ':', $args );
3551         $key = str_replace( ' ', '_', $key );
3552         return $key;
3553 }
3554
3555 /**
3556  * Get a cache key for a foreign DB
3557  *
3558  * @param string $db
3559  * @param string $prefix
3560  * @param string $args,...
3561  * @return string
3562  */
3563 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3564         $args = array_slice( func_get_args(), 2 );
3565         if ( $prefix ) {
3566                 $key = "$db-$prefix:" . implode( ':', $args );
3567         } else {
3568                 $key = $db . ':' . implode( ':', $args );
3569         }
3570         return str_replace( ' ', '_', $key );
3571 }
3572
3573 /**
3574  * Get an ASCII string identifying this wiki
3575  * This is used as a prefix in memcached keys
3576  *
3577  * @return string
3578  */
3579 function wfWikiID() {
3580         global $wgDBprefix, $wgDBname;
3581         if ( $wgDBprefix ) {
3582                 return "$wgDBname-$wgDBprefix";
3583         } else {
3584                 return $wgDBname;
3585         }
3586 }
3587
3588 /**
3589  * Split a wiki ID into DB name and table prefix
3590  *
3591  * @param string $wiki
3592  *
3593  * @return array
3594  */
3595 function wfSplitWikiID( $wiki ) {
3596         $bits = explode( '-', $wiki, 2 );
3597         if ( count( $bits ) < 2 ) {
3598                 $bits[] = '';
3599         }
3600         return $bits;
3601 }
3602
3603 /**
3604  * Get a Database object.
3605  *
3606  * @param int $db Index of the connection to get. May be DB_MASTER for the
3607  *            master (for write queries), DB_SLAVE for potentially lagged read
3608  *            queries, or an integer >= 0 for a particular server.
3609  *
3610  * @param string|string[] $groups Query groups. An array of group names that this query
3611  *                belongs to. May contain a single string if the query is only
3612  *                in one group.
3613  *
3614  * @param string|bool $wiki The wiki ID, or false for the current wiki
3615  *
3616  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3617  * will always return the same object, unless the underlying connection or load
3618  * balancer is manually destroyed.
3619  *
3620  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3621  * updater to ensure that a proper database is being updated.
3622  *
3623  * @return DatabaseBase
3624  */
3625 function wfGetDB( $db, $groups = array(), $wiki = false ) {
3626         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3627 }
3628
3629 /**
3630  * Get a load balancer object.
3631  *
3632  * @param string|bool $wiki Wiki ID, or false for the current wiki
3633  * @return LoadBalancer
3634  */
3635 function wfGetLB( $wiki = false ) {
3636         return wfGetLBFactory()->getMainLB( $wiki );
3637 }
3638
3639 /**
3640  * Get the load balancer factory object
3641  *
3642  * @return LBFactory
3643  */
3644 function wfGetLBFactory() {
3645         return LBFactory::singleton();
3646 }
3647
3648 /**
3649  * Find a file.
3650  * Shortcut for RepoGroup::singleton()->findFile()
3651  *
3652  * @param string $title String or Title object
3653  * @param array $options Associative array of options:
3654  *     time:           requested time for an archived image, or false for the
3655  *                     current version. An image object will be returned which was
3656  *                     created at the specified time.
3657  *
3658  *     ignoreRedirect: If true, do not follow file redirects
3659  *
3660  *     private:        If true, return restricted (deleted) files if the current
3661  *                     user is allowed to view them. Otherwise, such files will not
3662  *                     be found.
3663  *
3664  *     bypassCache:    If true, do not use the process-local cache of File objects
3665  *
3666  * @return File|bool File, or false if the file does not exist
3667  */
3668 function wfFindFile( $title, $options = array() ) {
3669         return RepoGroup::singleton()->findFile( $title, $options );
3670 }
3671
3672 /**
3673  * Get an object referring to a locally registered file.
3674  * Returns a valid placeholder object if the file does not exist.
3675  *
3676  * @param Title|string $title
3677  * @return LocalFile|null A File, or null if passed an invalid Title
3678  */
3679 function wfLocalFile( $title ) {
3680         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3681 }
3682
3683 /**
3684  * Should low-performance queries be disabled?
3685  *
3686  * @return bool
3687  * @codeCoverageIgnore
3688  */
3689 function wfQueriesMustScale() {
3690         global $wgMiserMode;
3691         return $wgMiserMode
3692                 || ( SiteStats::pages() > 100000
3693                 && SiteStats::edits() > 1000000
3694                 && SiteStats::users() > 10000 );
3695 }
3696
3697 /**
3698  * Get the path to a specified script file, respecting file
3699  * extensions; this is a wrapper around $wgScriptExtension etc.
3700  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3701  *
3702  * @param string $script Script filename, sans extension
3703  * @return string
3704  */
3705 function wfScript( $script = 'index' ) {
3706         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3707         if ( $script === 'index' ) {
3708                 return $wgScript;
3709         } elseif ( $script === 'load' ) {
3710                 return $wgLoadScript;
3711         } else {
3712                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3713         }
3714 }
3715
3716 /**
3717  * Get the script URL.
3718  *
3719  * @return string Script URL
3720  */
3721 function wfGetScriptUrl() {
3722         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3723                 #
3724                 # as it was called, minus the query string.
3725                 #
3726                 # Some sites use Apache rewrite rules to handle subdomains,
3727                 # and have PHP set up in a weird way that causes PHP_SELF
3728                 # to contain the rewritten URL instead of the one that the
3729                 # outside world sees.
3730                 #
3731                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3732                 # provides containing the "before" URL.
3733                 return $_SERVER['SCRIPT_NAME'];
3734         } else {
3735                 return $_SERVER['URL'];
3736         }
3737 }
3738
3739 /**
3740  * Convenience function converts boolean values into "true"
3741  * or "false" (string) values
3742  *
3743  * @param bool $value
3744  * @return string
3745  */
3746 function wfBoolToStr( $value ) {
3747         return $value ? 'true' : 'false';
3748 }
3749
3750 /**
3751  * Get a platform-independent path to the null file, e.g. /dev/null
3752  *
3753  * @return string
3754  */
3755 function wfGetNull() {
3756         return wfIsWindows() ? 'NUL' : '/dev/null';
3757 }
3758
3759 /**
3760  * Waits for the slaves to catch up to the master position
3761  *
3762  * Use this when updating very large numbers of rows, as in maintenance scripts,
3763  * to avoid causing too much lag. Of course, this is a no-op if there are no slaves.
3764  *
3765  * By default this waits on the main DB cluster of the current wiki.
3766  * If $cluster is set to "*" it will wait on all DB clusters, including
3767  * external ones. If the lag being waiting on is caused by the code that
3768  * does this check, it makes since to use $ifWritesSince, particularly if
3769  * cluster is "*", to avoid excess overhead.
3770  *
3771  * Never call this function after a big DB write that is still in a transaction.
3772  * This only makes sense after the possible lag inducing changes were committed.
3773  *
3774  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3775  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3776  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3777  * @param int|null $timeout Max wait time. Default: 1 day (cli), ~10 seconds (web)
3778  * @return bool Success (able to connect and no timeouts reached)
3779  */
3780 function wfWaitForSlaves(
3781         $ifWritesSince = null, $wiki = false, $cluster = false, $timeout = null
3782 ) {
3783         // B/C: first argument used to be "max seconds of lag"; ignore such values
3784         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : null;
3785
3786         if ( $timeout === null ) {
3787                 $timeout = ( PHP_SAPI === 'cli' ) ? 86400 : 10;
3788         }
3789
3790         // Figure out which clusters need to be checked
3791         $lbs = array();
3792         if ( $cluster === '*' ) {
3793                 wfGetLBFactory()->forEachLB( function ( LoadBalancer $lb ) use ( &$lbs ) {
3794                         $lbs[] = $lb;
3795                 } );
3796         } elseif ( $cluster !== false ) {
3797                 $lbs[] = wfGetLBFactory()->getExternalLB( $cluster );
3798         } else {
3799                 $lbs[] = wfGetLB( $wiki );
3800         }
3801
3802         // Get all the master positions of applicable DBs right now.
3803         // This can be faster since waiting on one cluster reduces the
3804         // time needed to wait on the next clusters.
3805         $masterPositions = array_fill( 0, count( $lbs ), false );
3806         foreach ( $lbs as $i => $lb ) {
3807                 // bug 27975 - Don't try to wait for slaves if there are none
3808                 // Prevents permission error when getting master position
3809                 if ( $lb->getServerCount() > 1 ) {
3810                         if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
3811                                 continue; // assume no writes done
3812                         }
3813                         // Use the empty string to not trigger selectDB() since the connection
3814                         // may have been to a server that does not have a DB for the current wiki.
3815                         $dbw = $lb->getConnection( DB_MASTER, array(), '' );
3816                         if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
3817                                 continue; // no writes since the last wait
3818                         }
3819                         $masterPositions[$i] = $dbw->getMasterPos();
3820                 }
3821         }
3822
3823         $ok = true;
3824         foreach ( $lbs as $i => $lb ) {
3825                 if ( $masterPositions[$i] ) {
3826                         // The DBMS may not support getMasterPos() or the whole
3827                         // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3828                         $ok = $lb->waitForAll( $masterPositions[$i], $timeout ) && $ok;
3829                 }
3830         }
3831
3832         return $ok;
3833 }
3834
3835 /**
3836  * Count down from $seconds to zero on the terminal, with a one-second pause
3837  * between showing each number. For use in command-line scripts.
3838  *
3839  * @codeCoverageIgnore
3840  * @param int $seconds
3841  */
3842 function wfCountDown( $seconds ) {
3843         for ( $i = $seconds; $i >= 0; $i-- ) {
3844                 if ( $i != $seconds ) {
3845                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3846                 }
3847                 echo $i;
3848                 flush();
3849                 if ( $i ) {
3850                         sleep( 1 );
3851                 }
3852         }
3853         echo "\n";
3854 }
3855
3856 /**
3857  * Replace all invalid characters with -
3858  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3859  * By default, $wgIllegalFileChars = ':'
3860  *
3861  * @param string $name Filename to process
3862  * @return string
3863  */
3864 function wfStripIllegalFilenameChars( $name ) {
3865         global $wgIllegalFileChars;
3866         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3867         $name = wfBaseName( $name );
3868         $name = preg_replace(
3869                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3870                 '-',
3871                 $name
3872         );
3873         return $name;
3874 }
3875
3876 /**
3877  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3878  *
3879  * @return int Value the memory limit was set to.
3880  */
3881 function wfMemoryLimit() {
3882         global $wgMemoryLimit;
3883         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3884         if ( $memlimit != -1 ) {
3885                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3886                 if ( $conflimit == -1 ) {
3887                         wfDebug( "Removing PHP's memory limit\n" );
3888                         wfSuppressWarnings();
3889                         ini_set( 'memory_limit', $conflimit );
3890                         wfRestoreWarnings();
3891                         return $conflimit;
3892                 } elseif ( $conflimit > $memlimit ) {
3893                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3894                         wfSuppressWarnings();
3895                         ini_set( 'memory_limit', $conflimit );
3896                         wfRestoreWarnings();
3897                         return $conflimit;
3898                 }
3899         }
3900         return $memlimit;
3901 }
3902
3903 /**
3904  * Converts shorthand byte notation to integer form
3905  *
3906  * @param string $string
3907  * @return int
3908  */
3909 function wfShorthandToInteger( $string = '' ) {
3910         $string = trim( $string );
3911         if ( $string === '' ) {
3912                 return -1;
3913         }
3914         $last = $string[strlen( $string ) - 1];
3915         $val = intval( $string );
3916         switch ( $last ) {
3917                 case 'g':
3918                 case 'G':
3919                         $val *= 1024;
3920                         // break intentionally missing
3921                 case 'm':
3922                 case 'M':
3923                         $val *= 1024;
3924                         // break intentionally missing
3925                 case 'k':
3926                 case 'K':
3927                         $val *= 1024;
3928         }
3929
3930         return $val;
3931 }
3932
3933 /**
3934  * Get the normalised IETF language tag
3935  * See unit test for examples.
3936  *
3937  * @param string $code The language code.
3938  * @return string The language code which complying with BCP 47 standards.
3939  */
3940 function wfBCP47( $code ) {
3941         $codeSegment = explode( '-', $code );
3942         $codeBCP = array();
3943         foreach ( $codeSegment as $segNo => $seg ) {
3944                 // when previous segment is x, it is a private segment and should be lc
3945                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3946                         $codeBCP[$segNo] = strtolower( $seg );
3947                 // ISO 3166 country code
3948                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3949                         $codeBCP[$segNo] = strtoupper( $seg );
3950                 // ISO 15924 script code
3951                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3952                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3953                 // Use lowercase for other cases
3954                 } else {
3955                         $codeBCP[$segNo] = strtolower( $seg );
3956                 }
3957         }
3958         $langCode = implode( '-', $codeBCP );
3959         return $langCode;
3960 }
3961
3962 /**
3963  * Get a cache object.
3964  *
3965  * @param int $inputType Cache type, one of the CACHE_* constants.
3966  * @return BagOStuff
3967  */
3968 function wfGetCache( $inputType ) {
3969         return ObjectCache::getInstance( $inputType );
3970 }
3971
3972 /**
3973  * Get the main cache object
3974  *
3975  * @return BagOStuff
3976  */
3977 function wfGetMainCache() {
3978         global $wgMainCacheType;
3979         return ObjectCache::getInstance( $wgMainCacheType );
3980 }
3981
3982 /**
3983  * Get the cache object used by the message cache
3984  *
3985  * @return BagOStuff
3986  */
3987 function wfGetMessageCacheStorage() {
3988         global $wgMessageCacheType;
3989         return ObjectCache::getInstance( $wgMessageCacheType );
3990 }
3991
3992 /**
3993  * Get the cache object used by the parser cache
3994  *
3995  * @return BagOStuff
3996  */
3997 function wfGetParserCacheStorage() {
3998         global $wgParserCacheType;
3999         return ObjectCache::getInstance( $wgParserCacheType );
4000 }
4001
4002 /**
4003  * Call hook functions defined in $wgHooks
4004  *
4005  * @param string $event Event name
4006  * @param array $args Parameters passed to hook functions
4007  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
4008  *
4009  * @return bool True if no handler aborted the hook
4010  * @deprecated 1.25 - use Hooks::run
4011  */
4012 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
4013         return Hooks::run( $event, $args, $deprecatedVersion );
4014 }
4015
4016 /**
4017  * Wrapper around php's unpack.
4018  *
4019  * @param string $format The format string (See php's docs)
4020  * @param string $data A binary string of binary data
4021  * @param int|bool $length The minimum length of $data or false. This is to
4022  *      prevent reading beyond the end of $data. false to disable the check.
4023  *
4024  * Also be careful when using this function to read unsigned 32 bit integer
4025  * because php might make it negative.
4026  *
4027  * @throws MWException If $data not long enough, or if unpack fails
4028  * @return array Associative array of the extracted data
4029  */
4030 function wfUnpack( $format, $data, $length = false ) {
4031         if ( $length !== false ) {
4032                 $realLen = strlen( $data );
4033                 if ( $realLen < $length ) {
4034                         throw new MWException( "Tried to use wfUnpack on a "
4035                                 . "string of length $realLen, but needed one "
4036                                 . "of at least length $length."
4037                         );
4038                 }
4039         }
4040
4041         wfSuppressWarnings();
4042         $result = unpack( $format, $data );
4043         wfRestoreWarnings();
4044
4045         if ( $result === false ) {
4046                 // If it cannot extract the packed data.
4047                 throw new MWException( "unpack could not unpack binary data" );
4048         }
4049         return $result;
4050 }
4051
4052 /**
4053  * Determine if an image exists on the 'bad image list'.
4054  *
4055  * The format of MediaWiki:Bad_image_list is as follows:
4056  *    * Only list items (lines starting with "*") are considered
4057  *    * The first link on a line must be a link to a bad image
4058  *    * Any subsequent links on the same line are considered to be exceptions,
4059  *      i.e. articles where the image may occur inline.
4060  *
4061  * @param string $name The image name to check
4062  * @param Title|bool $contextTitle The page on which the image occurs, if known
4063  * @param string $blacklist Wikitext of a file blacklist
4064  * @return bool
4065  */
4066 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4067         static $badImageCache = null; // based on bad_image_list msg
4068
4069         # Handle redirects
4070         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4071         if ( $redirectTitle ) {
4072                 $name = $redirectTitle->getDBkey();
4073         }
4074
4075         # Run the extension hook
4076         $bad = false;
4077         if ( !Hooks::run( 'BadImage', array( $name, &$bad ) ) ) {
4078                 return $bad;
4079         }
4080
4081         $cacheable = ( $blacklist === null );
4082         if ( $cacheable && $badImageCache !== null ) {
4083                 $badImages = $badImageCache;
4084         } else { // cache miss
4085                 if ( $blacklist === null ) {
4086                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4087                 }
4088                 # Build the list now
4089                 $badImages = array();
4090                 $lines = explode( "\n", $blacklist );
4091                 foreach ( $lines as $line ) {
4092                         # List items only
4093                         if ( substr( $line, 0, 1 ) !== '*' ) {
4094                                 continue;
4095                         }
4096
4097                         # Find all links
4098                         $m = array();
4099                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4100                                 continue;
4101                         }
4102
4103                         $exceptions = array();
4104                         $imageDBkey = false;
4105                         foreach ( $m[1] as $i => $titleText ) {
4106                                 $title = Title::newFromText( $titleText );
4107                                 if ( !is_null( $title ) ) {
4108                                         if ( $i == 0 ) {
4109                                                 $imageDBkey = $title->getDBkey();
4110                                         } else {
4111                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4112                                         }
4113                                 }
4114                         }
4115
4116                         if ( $imageDBkey !== false ) {
4117                                 $badImages[$imageDBkey] = $exceptions;
4118                         }
4119                 }
4120                 if ( $cacheable ) {
4121                         $badImageCache = $badImages;
4122                 }
4123         }
4124
4125         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4126         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4127         return $bad;
4128 }
4129
4130 /**
4131  * Determine whether the client at a given source IP is likely to be able to
4132  * access the wiki via HTTPS.
4133  *
4134  * @param string $ip The IPv4/6 address in the normal human-readable form
4135  * @return bool
4136  */
4137 function wfCanIPUseHTTPS( $ip ) {
4138         $canDo = true;
4139         Hooks::run( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4140         return !!$canDo;
4141 }
4142
4143 /**
4144  * Work out the IP address based on various globals
4145  * For trusted proxies, use the XFF client IP (first of the chain)
4146  *
4147  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4148  * @return string
4149  */
4150 function wfGetIP() {
4151         wfDeprecated( __METHOD__, '1.19' );
4152         global $wgRequest;
4153         return $wgRequest->getIP();
4154 }
4155
4156 /**
4157  * Checks if an IP is a trusted proxy provider.
4158  * Useful to tell if X-Forwarded-For data is possibly bogus.
4159  * Squid cache servers for the site are whitelisted.
4160  * @deprecated Since 1.24, use IP::isTrustedProxy()
4161  *
4162  * @param string $ip
4163  * @return bool
4164  */
4165 function wfIsTrustedProxy( $ip ) {
4166         wfDeprecated( __METHOD__, '1.24' );
4167         return IP::isTrustedProxy( $ip );
4168 }
4169
4170 /**
4171  * Checks if an IP matches a proxy we've configured.
4172  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4173  *
4174  * @param string $ip
4175  * @return bool
4176  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4177  */
4178 function wfIsConfiguredProxy( $ip ) {
4179         wfDeprecated( __METHOD__, '1.24' );
4180         return IP::isConfiguredProxy( $ip );
4181 }
4182
4183 /**
4184  * Returns true if these thumbnail parameters match one that MediaWiki
4185  * requests from file description pages and/or parser output.
4186  *
4187  * $params is considered non-standard if they involve a non-standard
4188  * width or any non-default parameters aside from width and page number.
4189  * The number of possible files with standard parameters is far less than
4190  * that of all combinations; rate-limiting for them can thus be more generious.
4191  *
4192  * @param File $file
4193  * @param array $params
4194  * @return bool
4195  * @since 1.24 Moved from thumb.php to GlobalFunctions in 1.25
4196  */
4197 function wfThumbIsStandard( File $file, array $params ) {
4198         global $wgThumbLimits, $wgImageLimits, $wgResponsiveImages;
4199
4200         $multipliers = array( 1 );
4201         if ( $wgResponsiveImages ) {
4202                 // These available sizes are hardcoded currently elsewhere in MediaWiki.
4203                 // @see Linker::processResponsiveImages
4204                 $multipliers[] = 1.5;
4205                 $multipliers[] = 2;
4206         }
4207
4208         $handler = $file->getHandler();
4209         if ( !$handler || !isset( $params['width'] ) ) {
4210                 return false;
4211         }
4212
4213         $basicParams = array();
4214         if ( isset( $params['page'] ) ) {
4215                 $basicParams['page'] = $params['page'];
4216         }
4217
4218         $thumbLimits = array();
4219         $imageLimits = array();
4220         // Expand limits to account for multipliers
4221         foreach ( $multipliers as $multiplier ) {
4222                 $thumbLimits = array_merge( $thumbLimits, array_map(
4223                         function ( $width ) use ( $multiplier ) {
4224                                 return round( $width * $multiplier );
4225                         }, $wgThumbLimits )
4226                 );
4227                 $imageLimits = array_merge( $imageLimits, array_map(
4228                         function ( $pair ) use ( $multiplier ) {
4229                                 return array(
4230                                         round( $pair[0] * $multiplier ),
4231                                         round( $pair[1] * $multiplier ),
4232                                 );
4233                         }, $wgImageLimits )
4234                 );
4235         }
4236
4237         // Check if the width matches one of $wgThumbLimits
4238         if ( in_array( $params['width'], $thumbLimits ) ) {
4239                 $normalParams = $basicParams + array( 'width' => $params['width'] );
4240                 // Append any default values to the map (e.g. "lossy", "lossless", ...)
4241                 $handler->normaliseParams( $file, $normalParams );
4242         } else {
4243                 // If not, then check if the width matchs one of $wgImageLimits
4244                 $match = false;
4245                 foreach ( $imageLimits as $pair ) {
4246                         $normalParams = $basicParams + array( 'width' => $pair[0], 'height' => $pair[1] );
4247                         // Decide whether the thumbnail should be scaled on width or height.
4248                         // Also append any default values to the map (e.g. "lossy", "lossless", ...)
4249                         $handler->normaliseParams( $file, $normalParams );
4250                         // Check if this standard thumbnail size maps to the given width
4251                         if ( $normalParams['width'] == $params['width'] ) {
4252                                 $match = true;
4253                                 break;
4254                         }
4255                 }
4256                 if ( !$match ) {
4257                         return false; // not standard for description pages
4258                 }
4259         }
4260
4261         // Check that the given values for non-page, non-width, params are just defaults
4262         foreach ( $params as $key => $value ) {
4263                 if ( !isset( $normalParams[$key] ) || $normalParams[$key] != $value ) {
4264                         return false;
4265                 }
4266         }
4267
4268         return true;
4269 }