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