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 5.3.2 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          * @return string
  42          */
  43         function mb_substr( $str, $start, $count = 'end' ) {
  44                 return Fallback::mb_substr( $str, $start, $count );
  45         }
  46
  47         /**
  48          * @codeCoverageIgnore
  49          * @return int
  50          */
  51         function mb_substr_split_unicode( $str, $splitPos ) {
  52                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  53         }
  54 }
  55
  56 if ( !function_exists( 'mb_strlen' ) ) {
  57         /**
  58          * @codeCoverageIgnore
  59          * @return int
  60          */
  61         function mb_strlen( $str, $enc = '' ) {
  62                 return Fallback::mb_strlen( $str, $enc );
  63         }
  64 }
  65
  66 if ( !function_exists( 'mb_strpos' ) ) {
  67         /**
  68          * @codeCoverageIgnore
  69          * @return int
  70          */
  71         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  72                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  73         }
  74 }
  75
  76 if ( !function_exists( 'mb_strrpos' ) ) {
  77         /**
  78          * @codeCoverageIgnore
  79          * @return int
  80          */
  81         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  82                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  83         }
  84 }
  85
  86 // gzdecode function only exists in PHP >= 5.4.0
  87 // http://php.net/gzdecode
  88 if ( !function_exists( 'gzdecode' ) ) {
  89         /**
  90          * @codeCoverageIgnore
  91          * @return string
  92          */
  93         function gzdecode( $data ) {
  94                 return gzinflate( substr( $data, 10, -8 ) );
  95         }
  96 }
  97
  98 // hash_equals function only exists in PHP >= 5.6.0
  99 if ( !function_exists( 'hash_equals' ) ) {
 100         /**
 101          * Check whether a user-provided string is equal to a fixed-length secret without
 102          * revealing bytes of the secret through timing differences.
 103          *
 104          * This timing guarantee -- that a partial match takes the same time as a complete
 105          * mismatch -- is why this function is used in some security-sensitive parts of the code.
 106          * For example, it shouldn't be possible to guess an HMAC signature one byte at a time.
 107          *
 108          * Longer explanation: http://www.emerose.com/timing-attacks-explained
 109          *
 110          * @codeCoverageIgnore
 111          * @param string $known_string Fixed-length secret to compare against
 112          * @param string $user_string User-provided string
 113          * @return bool True if the strings are the same, false otherwise
 114          */
 115         function hash_equals( $known_string, $user_string ) {
 116                 // Strict type checking as in PHP's native implementation
 117                 if ( !is_string( $known_string ) ) {
 118                         trigger_error( 'hash_equals(): Expected known_string to be a string, ' .
 119                                 gettype( $known_string ) . ' given', E_USER_WARNING );
 120
 121                         return false;
 122                 }
 123
 124                 if ( !is_string( $user_string ) ) {
 125                         trigger_error( 'hash_equals(): Expected user_string to be a string, ' .
 126                                 gettype( $user_string ) . ' given', E_USER_WARNING );
 127
 128                         return false;
 129                 }
 130
 131                 // Note that we do one thing PHP doesn't: try to avoid leaking information about
 132                 // relative lengths of $known_string and $user_string, and of multiple $known_strings.
 133                 // However, lengths may still inevitably leak through, for example, CPU cache misses.
 134                 $known_string_len = strlen( $known_string );
 135                 $user_string_len = strlen( $user_string );
 136                 $result = $known_string_len ^ $user_string_len;
 137                 for ( $i = 0; $i < $user_string_len; $i++ ) {
 138                         $result |= ord( $known_string[$i % $known_string_len] ) ^ ord( $user_string[$i] );
 139                 }
 140
 141                 return ( $result === 0 );
 142         }
 143 }
 144 /// @endcond
 145
 146 /**
 147  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 148  * @param array $a
 149  * @param array $b
 150  * @return array
 151  */
 152 function wfArrayDiff2( $a, $b ) {
 153         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 154 }
 155
 156 /**
 157  * @param array|string $a
 158  * @param array|string $b
 159  * @return int
 160  */
 161 function wfArrayDiff2_cmp( $a, $b ) {
 162         if ( is_string( $a ) && is_string( $b ) ) {
 163                 return strcmp( $a, $b );
 164         } elseif ( count( $a ) !== count( $b ) ) {
 165                 return count( $a ) < count( $b ) ? -1 : 1;
 166         } else {
 167                 reset( $a );
 168                 reset( $b );
 169                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 170                         $cmp = strcmp( $valueA, $valueB );
 171                         if ( $cmp !== 0 ) {
 172                                 return $cmp;
 173                         }
 174                 }
 175                 return 0;
 176         }
 177 }
 178
 179 /**
 180  * Appends to second array if $value differs from that in $default
 181  *
 182  * @param string|int $key
 183  * @param mixed $value
 184  * @param mixed $default
 185  * @param array $changed Array to alter
 186  * @throws MWException
 187  */
 188 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 189         if ( is_null( $changed ) ) {
 190                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 191         }
 192         if ( $default[$key] !== $value ) {
 193                 $changed[$key] = $value;
 194         }
 195 }
 196
 197 /**
 198  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 199  * e.g.
 200  *      wfMergeErrorArrays(
 201  *              array( array( 'x' ) ),
 202  *              array( array( 'x', '2' ) ),
 203  *              array( array( 'x' ) ),
 204  *              array( array( 'y' ) )
 205  *      );
 206  * returns:
 207  *              array(
 208  *              array( 'x', '2' ),
 209  *              array( 'x' ),
 210  *              array( 'y' )
 211  *      )
 212  *
 213  * @param array $array1,...
 214  * @return array
 215  */
 216 function wfMergeErrorArrays( /*...*/ ) {
 217         $args = func_get_args();
 218         $out = array();
 219         foreach ( $args as $errors ) {
 220                 foreach ( $errors as $params ) {
 221                         # @todo FIXME: Sometimes get nested arrays for $params,
 222                         # which leads to E_NOTICEs
 223                         $spec = implode( "\t", $params );
 224                         $out[$spec] = $params;
 225                 }
 226         }
 227         return array_values( $out );
 228 }
 229
 230 /**
 231  * Insert array into another array after the specified *KEY*
 232  *
 233  * @param array $array The array.
 234  * @param array $insert The array to insert.
 235  * @param mixed $after The key to insert after
 236  * @return array
 237  */
 238 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 239         // Find the offset of the element to insert after.
 240         $keys = array_keys( $array );
 241         $offsetByKey = array_flip( $keys );
 242
 243         $offset = $offsetByKey[$after];
 244
 245         // Insert at the specified offset
 246         $before = array_slice( $array, 0, $offset + 1, true );
 247         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 248
 249         $output = $before + $insert + $after;
 250
 251         return $output;
 252 }
 253
 254 /**
 255  * Recursively converts the parameter (an object) to an array with the same data
 256  *
 257  * @param object|array $objOrArray
 258  * @param bool $recursive
 259  * @return array
 260  */
 261 function wfObjectToArray( $objOrArray, $recursive = true ) {
 262         $array = array();
 263         if ( is_object( $objOrArray ) ) {
 264                 $objOrArray = get_object_vars( $objOrArray );
 265         }
 266         foreach ( $objOrArray as $key => $value ) {
 267                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 268                         $value = wfObjectToArray( $value );
 269                 }
 270
 271                 $array[$key] = $value;
 272         }
 273
 274         return $array;
 275 }
 276
 277 /**
 278  * Get a random decimal value between 0 and 1, in a way
 279  * not likely to give duplicate values for any realistic
 280  * number of articles.
 281  *
 282  * @return string
 283  */
 284 function wfRandom() {
 285         # The maximum random value is "only" 2^31-1, so get two random
 286         # values to reduce the chance of dupes
 287         $max = mt_getrandmax() + 1;
 288         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 289
 290         return $rand;
 291 }
 292
 293 /**
 294  * Get a random string containing a number of pseudo-random hex
 295  * characters.
 296  * @note This is not secure, if you are trying to generate some sort
 297  *       of token please use MWCryptRand instead.
 298  *
 299  * @param int $length The length of the string to generate
 300  * @return string
 301  * @since 1.20
 302  */
 303 function wfRandomString( $length = 32 ) {
 304         $str = '';
 305         for ( $n = 0; $n < $length; $n += 7 ) {
 306                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 307         }
 308         return substr( $str, 0, $length );
 309 }
 310
 311 /**
 312  * We want some things to be included as literal characters in our title URLs
 313  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 314  * all of the following should be safe:
 315  *
 316  * ;:@&=$-_.+!*'(),
 317  *
 318  * But + is not safe because it's used to indicate a space; &= are only safe in
 319  * paths and not in queries (and we don't distinguish here); ' seems kind of
 320  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 321  * is reserved, we don't care.  So the list we unescape is:
 322  *
 323  * ;:@$!*(),/
 324  *
 325  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 326  * so no fancy : for IIS7.
 327  *
 328  * %2F in the page titles seems to fatally break for some reason.
 329  *
 330  * @param string $s
 331  * @return string
 332  */
 333 function wfUrlencode( $s ) {
 334         static $needle;
 335
 336         if ( is_null( $s ) ) {
 337                 $needle = null;
 338                 return '';
 339         }
 340
 341         if ( is_null( $needle ) ) {
 342                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 343                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 344                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 345                 ) {
 346                         $needle[] = '%3A';
 347                 }
 348         }
 349
 350         $s = urlencode( $s );
 351         $s = str_ireplace(
 352                 $needle,
 353                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 354                 $s
 355         );
 356
 357         return $s;
 358 }
 359
 360 /**
 361  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 362  * "days=7&limit=100". Options in the first array override options in the second.
 363  * Options set to null or false will not be output.
 364  *
 365  * @param array $array1 ( String|Array )
 366  * @param array $array2 ( String|Array )
 367  * @param string $prefix
 368  * @return string
 369  */
 370 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 371         if ( !is_null( $array2 ) ) {
 372                 $array1 = $array1 + $array2;
 373         }
 374
 375         $cgi = '';
 376         foreach ( $array1 as $key => $value ) {
 377                 if ( !is_null( $value ) && $value !== false ) {
 378                         if ( $cgi != '' ) {
 379                                 $cgi .= '&';
 380                         }
 381                         if ( $prefix !== '' ) {
 382                                 $key = $prefix . "[$key]";
 383                         }
 384                         if ( is_array( $value ) ) {
 385                                 $firstTime = true;
 386                                 foreach ( $value as $k => $v ) {
 387                                         $cgi .= $firstTime ? '' : '&';
 388                                         if ( is_array( $v ) ) {
 389                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 390                                         } else {
 391                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 392                                         }
 393                                         $firstTime = false;
 394                                 }
 395                         } else {
 396                                 if ( is_object( $value ) ) {
 397                                         $value = $value->__toString();
 398                                 }
 399                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 400                         }
 401                 }
 402         }
 403         return $cgi;
 404 }
 405
 406 /**
 407  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 408  * its argument and returns the same string in array form.  This allows compatibility
 409  * with legacy functions that accept raw query strings instead of nice
 410  * arrays.  Of course, keys and values are urldecode()d.
 411  *
 412  * @param string $query Query string
 413  * @return string[] Array version of input
 414  */
 415 function wfCgiToArray( $query ) {
 416         if ( isset( $query[0] ) && $query[0] == '?' ) {
 417                 $query = substr( $query, 1 );
 418         }
 419         $bits = explode( '&', $query );
 420         $ret = array();
 421         foreach ( $bits as $bit ) {
 422                 if ( $bit === '' ) {
 423                         continue;
 424                 }
 425                 if ( strpos( $bit, '=' ) === false ) {
 426                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 427                         $key = $bit;
 428                         $value = '';
 429                 } else {
 430                         list( $key, $value ) = explode( '=', $bit );
 431                 }
 432                 $key = urldecode( $key );
 433                 $value = urldecode( $value );
 434                 if ( strpos( $key, '[' ) !== false ) {
 435                         $keys = array_reverse( explode( '[', $key ) );
 436                         $key = array_pop( $keys );
 437                         $temp = $value;
 438                         foreach ( $keys as $k ) {
 439                                 $k = substr( $k, 0, -1 );
 440                                 $temp = array( $k => $temp );
 441                         }
 442                         if ( isset( $ret[$key] ) ) {
 443                                 $ret[$key] = array_merge( $ret[$key], $temp );
 444                         } else {
 445                                 $ret[$key] = $temp;
 446                         }
 447                 } else {
 448                         $ret[$key] = $value;
 449                 }
 450         }
 451         return $ret;
 452 }
 453
 454 /**
 455  * Append a query string to an existing URL, which may or may not already
 456  * have query string parameters already. If so, they will be combined.
 457  *
 458  * @param string $url
 459  * @param string|string[] $query String or associative array
 460  * @return string
 461  */
 462 function wfAppendQuery( $url, $query ) {
 463         if ( is_array( $query ) ) {
 464                 $query = wfArrayToCgi( $query );
 465         }
 466         if ( $query != '' ) {
 467                 if ( false === strpos( $url, '?' ) ) {
 468                         $url .= '?';
 469                 } else {
 470                         $url .= '&';
 471                 }
 472                 $url .= $query;
 473         }
 474         return $url;
 475 }
 476
 477 /**
 478  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 479  * is correct.
 480  *
 481  * The meaning of the PROTO_* constants is as follows:
 482  * PROTO_HTTP: Output a URL starting with http://
 483  * PROTO_HTTPS: Output a URL starting with https://
 484  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 485  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 486  *    on which protocol was used for the current incoming request
 487  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 488  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 489  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 490  *
 491  * @todo this won't work with current-path-relative URLs
 492  * like "subdir/foo.html", etc.
 493  *
 494  * @param string $url Either fully-qualified or a local path + query
 495  * @param string $defaultProto One of the PROTO_* constants. Determines the
 496  *    protocol to use if $url or $wgServer is protocol-relative
 497  * @return string Fully-qualified URL, current-path-relative URL or false if
 498  *    no valid URL can be constructed
 499  */
 500 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 501         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 502                 $wgHttpsPort;
 503         if ( $defaultProto === PROTO_CANONICAL ) {
 504                 $serverUrl = $wgCanonicalServer;
 505         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 506                 // Make $wgInternalServer fall back to $wgServer if not set
 507                 $serverUrl = $wgInternalServer;
 508         } else {
 509                 $serverUrl = $wgServer;
 510                 if ( $defaultProto === PROTO_CURRENT ) {
 511                         $defaultProto = $wgRequest->getProtocol() . '://';
 512                 }
 513         }
 514
 515         // Analyze $serverUrl to obtain its protocol
 516         $bits = wfParseUrl( $serverUrl );
 517         $serverHasProto = $bits && $bits['scheme'] != '';
 518
 519         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 520                 if ( $serverHasProto ) {
 521                         $defaultProto = $bits['scheme'] . '://';
 522                 } else {
 523                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 524                         // This really isn't supposed to happen. Fall back to HTTP in this
 525                         // ridiculous case.
 526                         $defaultProto = PROTO_HTTP;
 527                 }
 528         }
 529
 530         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 531
 532         if ( substr( $url, 0, 2 ) == '//' ) {
 533                 $url = $defaultProtoWithoutSlashes . $url;
 534         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 535                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 536                 // otherwise leave it alone.
 537                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 538         }
 539
 540         $bits = wfParseUrl( $url );
 541
 542         // ensure proper port for HTTPS arrives in URL
 543         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 544         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 545                 $bits['port'] = $wgHttpsPort;
 546         }
 547
 548         if ( $bits && isset( $bits['path'] ) ) {
 549                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 550                 return wfAssembleUrl( $bits );
 551         } elseif ( $bits ) {
 552                 # No path to expand
 553                 return $url;
 554         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 555                 # URL is a relative path
 556                 return wfRemoveDotSegments( $url );
 557         }
 558
 559         # Expanded URL is not valid.
 560         return false;
 561 }
 562
 563 /**
 564  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 565  * if you need to edit part of a URL and put it back together.
 566  *
 567  * This is the basic structure used (brackets contain keys for $urlParts):
 568  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 569  *
 570  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 571  *
 572  * @since 1.19
 573  * @param array $urlParts URL parts, as output from wfParseUrl
 574  * @return string URL assembled from its component parts
 575  */
 576 function wfAssembleUrl( $urlParts ) {
 577         $result = '';
 578
 579         if ( isset( $urlParts['delimiter'] ) ) {
 580                 if ( isset( $urlParts['scheme'] ) ) {
 581                         $result .= $urlParts['scheme'];
 582                 }
 583
 584                 $result .= $urlParts['delimiter'];
 585         }
 586
 587         if ( isset( $urlParts['host'] ) ) {
 588                 if ( isset( $urlParts['user'] ) ) {
 589                         $result .= $urlParts['user'];
 590                         if ( isset( $urlParts['pass'] ) ) {
 591                                 $result .= ':' . $urlParts['pass'];
 592                         }
 593                         $result .= '@';
 594                 }
 595
 596                 $result .= $urlParts['host'];
 597
 598                 if ( isset( $urlParts['port'] ) ) {
 599                         $result .= ':' . $urlParts['port'];
 600                 }
 601         }
 602
 603         if ( isset( $urlParts['path'] ) ) {
 604                 $result .= $urlParts['path'];
 605         }
 606
 607         if ( isset( $urlParts['query'] ) ) {
 608                 $result .= '?' . $urlParts['query'];
 609         }
 610
 611         if ( isset( $urlParts['fragment'] ) ) {
 612                 $result .= '#' . $urlParts['fragment'];
 613         }
 614
 615         return $result;
 616 }
 617
 618 /**
 619  * Remove all dot-segments in the provided URL path.  For example,
 620  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 621  * RFC3986 section 5.2.4.
 622  *
 623  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 624  *
 625  * @param string $urlPath URL path, potentially containing dot-segments
 626  * @return string URL path with all dot-segments removed
 627  */
 628 function wfRemoveDotSegments( $urlPath ) {
 629         $output = '';
 630         $inputOffset = 0;
 631         $inputLength = strlen( $urlPath );
 632
 633         while ( $inputOffset < $inputLength ) {
 634                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 635                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 636                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 637                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 638                 $trimOutput = false;
 639
 640                 if ( $prefixLengthTwo == './' ) {
 641                         # Step A, remove leading "./"
 642                         $inputOffset += 2;
 643                 } elseif ( $prefixLengthThree == '../' ) {
 644                         # Step A, remove leading "../"
 645                         $inputOffset += 3;
 646                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 647                         # Step B, replace leading "/.$" with "/"
 648                         $inputOffset += 1;
 649                         $urlPath[$inputOffset] = '/';
 650                 } elseif ( $prefixLengthThree == '/./' ) {
 651                         # Step B, replace leading "/./" with "/"
 652                         $inputOffset += 2;
 653                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 654                         # Step C, replace leading "/..$" with "/" and
 655                         # remove last path component in output
 656                         $inputOffset += 2;
 657                         $urlPath[$inputOffset] = '/';
 658                         $trimOutput = true;
 659                 } elseif ( $prefixLengthFour == '/../' ) {
 660                         # Step C, replace leading "/../" with "/" and
 661                         # remove last path component in output
 662                         $inputOffset += 3;
 663                         $trimOutput = true;
 664                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 665                         # Step D, remove "^.$"
 666                         $inputOffset += 1;
 667                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 668                         # Step D, remove "^..$"
 669                         $inputOffset += 2;
 670                 } else {
 671                         # Step E, move leading path segment to output
 672                         if ( $prefixLengthOne == '/' ) {
 673                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 674                         } else {
 675                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 676                         }
 677                         if ( $slashPos === false ) {
 678                                 $output .= substr( $urlPath, $inputOffset );
 679                                 $inputOffset = $inputLength;
 680                         } else {
 681                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 682                                 $inputOffset += $slashPos - $inputOffset;
 683                         }
 684                 }
 685
 686                 if ( $trimOutput ) {
 687                         $slashPos = strrpos( $output, '/' );
 688                         if ( $slashPos === false ) {
 689                                 $output = '';
 690                         } else {
 691                                 $output = substr( $output, 0, $slashPos );
 692                         }
 693                 }
 694         }
 695
 696         return $output;
 697 }
 698
 699 /**
 700  * Returns a regular expression of url protocols
 701  *
 702  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 703  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 704  * @return string
 705  */
 706 function wfUrlProtocols( $includeProtocolRelative = true ) {
 707         global $wgUrlProtocols;
 708
 709         // Cache return values separately based on $includeProtocolRelative
 710         static $withProtRel = null, $withoutProtRel = null;
 711         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 712         if ( !is_null( $cachedValue ) ) {
 713                 return $cachedValue;
 714         }
 715
 716         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 717         // with LocalSettings files from 1.5
 718         if ( is_array( $wgUrlProtocols ) ) {
 719                 $protocols = array();
 720                 foreach ( $wgUrlProtocols as $protocol ) {
 721                         // Filter out '//' if !$includeProtocolRelative
 722                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 723                                 $protocols[] = preg_quote( $protocol, '/' );
 724                         }
 725                 }
 726
 727                 $retval = implode( '|', $protocols );
 728         } else {
 729                 // Ignore $includeProtocolRelative in this case
 730                 // This case exists for pre-1.6 compatibility, and we can safely assume
 731                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 732                 // URLs weren't supported until 1.18
 733                 $retval = $wgUrlProtocols;
 734         }
 735
 736         // Cache return value
 737         if ( $includeProtocolRelative ) {
 738                 $withProtRel = $retval;
 739         } else {
 740                 $withoutProtRel = $retval;
 741         }
 742         return $retval;
 743 }
 744
 745 /**
 746  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 747  * you need a regex that matches all URL protocols but does not match protocol-
 748  * relative URLs
 749  * @return string
 750  */
 751 function wfUrlProtocolsWithoutProtRel() {
 752         return wfUrlProtocols( false );
 753 }
 754
 755 /**
 756  * parse_url() work-alike, but non-broken.  Differences:
 757  *
 758  * 1) Does not raise warnings on bad URLs (just returns false).
 759  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 760  *    protocol-relative URLs) correctly.
 761  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 762  *
 763  * @param string $url A URL to parse
 764  * @return string[] Bits of the URL in an associative array, per PHP docs
 765  */
 766 function wfParseUrl( $url ) {
 767         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 768
 769         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 770         // bad that the easiest way to handle them is to just prepend 'http:' and
 771         // strip the protocol out later.
 772         $wasRelative = substr( $url, 0, 2 ) == '//';
 773         if ( $wasRelative ) {
 774                 $url = "http:$url";
 775         }
 776         wfSuppressWarnings();
 777         $bits = parse_url( $url );
 778         wfRestoreWarnings();
 779         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 780         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 781         if ( !$bits || !isset( $bits['scheme'] ) ) {
 782                 return false;
 783         }
 784
 785         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 786         $bits['scheme'] = strtolower( $bits['scheme'] );
 787
 788         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 789         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 790                 $bits['delimiter'] = '://';
 791         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 792                 $bits['delimiter'] = ':';
 793                 // parse_url detects for news: and mailto: the host part of an url as path
 794                 // We have to correct this wrong detection
 795                 if ( isset( $bits['path'] ) ) {
 796                         $bits['host'] = $bits['path'];
 797                         $bits['path'] = '';
 798                 }
 799         } else {
 800                 return false;
 801         }
 802
 803         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 804         if ( !isset( $bits['host'] ) ) {
 805                 $bits['host'] = '';
 806
 807                 // bug 45069
 808                 if ( isset( $bits['path'] ) ) {
 809                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 810                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 811                                 $bits['path'] = '/' . $bits['path'];
 812                         }
 813                 } else {
 814                         $bits['path'] = '';
 815                 }
 816         }
 817
 818         // If the URL was protocol-relative, fix scheme and delimiter
 819         if ( $wasRelative ) {
 820                 $bits['scheme'] = '';
 821                 $bits['delimiter'] = '//';
 822         }
 823         return $bits;
 824 }
 825
 826 /**
 827  * Take a URL, make sure it's expanded to fully qualified, and replace any
 828  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 829  * for more compact display and legibility for local audiences.
 830  *
 831  * @todo handle punycode domains too
 832  *
 833  * @param string $url
 834  * @return string
 835  */
 836 function wfExpandIRI( $url ) {
 837         return preg_replace_callback(
 838                 '/((?:%[89A-F][0-9A-F])+)/i',
 839                 'wfExpandIRI_callback',
 840                 wfExpandUrl( $url )
 841         );
 842 }
 843
 844 /**
 845  * Private callback for wfExpandIRI
 846  * @param array $matches
 847  * @return string
 848  */
 849 function wfExpandIRI_callback( $matches ) {
 850         return urldecode( $matches[1] );
 851 }
 852
 853 /**
 854  * Make URL indexes, appropriate for the el_index field of externallinks.
 855  *
 856  * @param string $url
 857  * @return array
 858  */
 859 function wfMakeUrlIndexes( $url ) {
 860         $bits = wfParseUrl( $url );
 861
 862         // Reverse the labels in the hostname, convert to lower case
 863         // For emails reverse domainpart only
 864         if ( $bits['scheme'] == 'mailto' ) {
 865                 $mailparts = explode( '@', $bits['host'], 2 );
 866                 if ( count( $mailparts ) === 2 ) {
 867                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 868                 } else {
 869                         // No domain specified, don't mangle it
 870                         $domainpart = '';
 871                 }
 872                 $reversedHost = $domainpart . '@' . $mailparts[0];
 873         } else {
 874                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 875         }
 876         // Add an extra dot to the end
 877         // Why? Is it in wrong place in mailto links?
 878         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 879                 $reversedHost .= '.';
 880         }
 881         // Reconstruct the pseudo-URL
 882         $prot = $bits['scheme'];
 883         $index = $prot . $bits['delimiter'] . $reversedHost;
 884         // Leave out user and password. Add the port, path, query and fragment
 885         if ( isset( $bits['port'] ) ) {
 886                 $index .= ':' . $bits['port'];
 887         }
 888         if ( isset( $bits['path'] ) ) {
 889                 $index .= $bits['path'];
 890         } else {
 891                 $index .= '/';
 892         }
 893         if ( isset( $bits['query'] ) ) {
 894                 $index .= '?' . $bits['query'];
 895         }
 896         if ( isset( $bits['fragment'] ) ) {
 897                 $index .= '#' . $bits['fragment'];
 898         }
 899
 900         if ( $prot == '' ) {
 901                 return array( "http:$index", "https:$index" );
 902         } else {
 903                 return array( $index );
 904         }
 905 }
 906
 907 /**
 908  * Check whether a given URL has a domain that occurs in a given set of domains
 909  * @param string $url URL
 910  * @param array $domains Array of domains (strings)
 911  * @return bool True if the host part of $url ends in one of the strings in $domains
 912  */
 913 function wfMatchesDomainList( $url, $domains ) {
 914         $bits = wfParseUrl( $url );
 915         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 916                 $host = '.' . $bits['host'];
 917                 foreach ( (array)$domains as $domain ) {
 918                         $domain = '.' . $domain;
 919                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 920                                 return true;
 921                         }
 922                 }
 923         }
 924         return false;
 925 }
 926
 927 /**
 928  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 929  * In normal operation this is a NOP.
 930  *
 931  * Controlling globals:
 932  * $wgDebugLogFile - points to the log file
 933  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 934  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 935  *
 936  * @param string $text
 937  * @param string|bool $dest Destination of the message:
 938  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 939  *     - 'log': only to the log and not in HTML
 940  *   For backward compatibility, it can also take a boolean:
 941  *     - true: same as 'all'
 942  *     - false: same as 'log'
 943  */
 944 function wfDebug( $text, $dest = 'all' ) {
 945         global $wgDebugLogFile, $wgDebugRawPage, $wgDebugLogPrefix;
 946
 947         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 948                 return;
 949         }
 950
 951         // Turn $dest into a string if it's a boolean (for b/c)
 952         if ( $dest === true ) {
 953                 $dest = 'all';
 954         } elseif ( $dest === false ) {
 955                 $dest = 'log';
 956         }
 957
 958         $timer = wfDebugTimer();
 959         if ( $timer !== '' ) {
 960                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 961         }
 962
 963         if ( $dest === 'all' ) {
 964                 MWDebug::debugMsg( $text );
 965         }
 966
 967         if ( $wgDebugLogFile != '' ) {
 968                 # Strip unprintables; they can switch terminal modes when binary data
 969                 # gets dumped, which is pretty annoying.
 970                 $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 971                 $text = $wgDebugLogPrefix . $text;
 972                 wfErrorLog( $text, $wgDebugLogFile );
 973         }
 974 }
 975
 976 /**
 977  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 978  * @return bool
 979  */
 980 function wfIsDebugRawPage() {
 981         static $cache;
 982         if ( $cache !== null ) {
 983                 return $cache;
 984         }
 985         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 986         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 987                 || (
 988                         isset( $_SERVER['SCRIPT_NAME'] )
 989                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 990                 )
 991         ) {
 992                 $cache = true;
 993         } else {
 994                 $cache = false;
 995         }
 996         return $cache;
 997 }
 998
 999 /**
1000  * Get microsecond timestamps for debug logs
1001  *
1002  * @return string
1003  */
1004 function wfDebugTimer() {
1005         global $wgDebugTimestamps, $wgRequestTime;
1006
1007         if ( !$wgDebugTimestamps ) {
1008                 return '';
1009         }
1010
1011         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1012         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1013         return "$prefix $mem  ";
1014 }
1015
1016 /**
1017  * Send a line giving PHP memory usage.
1018  *
1019  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1020  */
1021 function wfDebugMem( $exact = false ) {
1022         $mem = memory_get_usage();
1023         if ( !$exact ) {
1024                 $mem = floor( $mem / 1024 ) . ' KiB';
1025         } else {
1026                 $mem .= ' B';
1027         }
1028         wfDebug( "Memory usage: $mem\n" );
1029 }
1030
1031 /**
1032  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1033  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to a string
1034  * filename or an associative array mapping 'destination' to the desired filename. The
1035  * associative array may also contain a 'sample' key with an integer value, specifying
1036  * a sampling factor.
1037  *
1038  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1039  *
1040  * @param string $logGroup
1041  * @param string $text
1042  * @param string|bool $dest Destination of the message:
1043  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1044  *     - 'log': only to the log and not in HTML
1045  *     - 'private': only to the specifc log if set in $wgDebugLogGroups and
1046  *       discarded otherwise
1047  *   For backward compatibility, it can also take a boolean:
1048  *     - true: same as 'all'
1049  *     - false: same as 'private'
1050  */
1051 function wfDebugLog( $logGroup, $text, $dest = 'all' ) {
1052         global $wgDebugLogGroups;
1053
1054         $text = trim( $text ) . "\n";
1055
1056         // Turn $dest into a string if it's a boolean (for b/c)
1057         if ( $dest === true ) {
1058                 $dest = 'all';
1059         } elseif ( $dest === false ) {
1060                 $dest = 'private';
1061         }
1062
1063         if ( !isset( $wgDebugLogGroups[$logGroup] ) ) {
1064                 if ( $dest !== 'private' ) {
1065                         wfDebug( "[$logGroup] $text", $dest );
1066                 }
1067                 return;
1068         }
1069
1070         if ( $dest === 'all' ) {
1071                 MWDebug::debugMsg( "[$logGroup] $text" );
1072         }
1073
1074         $logConfig = $wgDebugLogGroups[$logGroup];
1075         if ( $logConfig === false ) {
1076                 return;
1077         }
1078         if ( is_array( $logConfig ) ) {
1079                 if ( isset( $logConfig['sample'] ) && mt_rand( 1, $logConfig['sample'] ) !== 1 ) {
1080                         return;
1081                 }
1082                 $destination = $logConfig['destination'];
1083         } else {
1084                 $destination = strval( $logConfig );
1085         }
1086
1087         $time = wfTimestamp( TS_DB );
1088         $wiki = wfWikiID();
1089         $host = wfHostname();
1090         wfErrorLog( "$time $host $wiki: $text", $destination );
1091 }
1092
1093 /**
1094  * Log for database errors
1095  *
1096  * @param string $text Database error message.
1097  */
1098 function wfLogDBError( $text ) {
1099         global $wgDBerrorLog, $wgDBerrorLogTZ;
1100         static $logDBErrorTimeZoneObject = null;
1101
1102         if ( $wgDBerrorLog ) {
1103                 $host = wfHostname();
1104                 $wiki = wfWikiID();
1105
1106                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1107                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1108                 }
1109
1110                 // Workaround for https://bugs.php.net/bug.php?id=52063
1111                 // Can be removed when min PHP > 5.3.2
1112                 if ( $logDBErrorTimeZoneObject === null ) {
1113                         $d = date_create( "now" );
1114                 } else {
1115                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1116                 }
1117
1118                 $date = $d->format( 'D M j G:i:s T Y' );
1119
1120                 $text = "$date\t$host\t$wiki\t" . trim( $text ) . "\n";
1121                 wfErrorLog( $text, $wgDBerrorLog );
1122         }
1123 }
1124
1125 /**
1126  * Throws a warning that $function is deprecated
1127  *
1128  * @param string $function
1129  * @param string|bool $version Version of MediaWiki that the function
1130  *    was deprecated in (Added in 1.19).
1131  * @param string|bool $component Added in 1.19.
1132  * @param int $callerOffset How far up the call stack is the original
1133  *    caller. 2 = function that called the function that called
1134  *    wfDeprecated (Added in 1.20)
1135  *
1136  * @return null
1137  */
1138 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1139         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1140 }
1141
1142 /**
1143  * Send a warning either to the debug log or in a PHP error depending on
1144  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1145  *
1146  * @param string $msg Message to send
1147  * @param int $callerOffset Number of items to go back in the backtrace to
1148  *        find the correct caller (1 = function calling wfWarn, ...)
1149  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1150  *        only used when $wgDevelopmentWarnings is true
1151  */
1152 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1153         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1154 }
1155
1156 /**
1157  * Send a warning as a PHP error and the debug log. This is intended for logging
1158  * warnings in production. For logging development warnings, use WfWarn instead.
1159  *
1160  * @param string $msg Message to send
1161  * @param int $callerOffset Number of items to go back in the backtrace to
1162  *        find the correct caller (1 = function calling wfLogWarning, ...)
1163  * @param int $level PHP error level; defaults to E_USER_WARNING
1164  */
1165 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1166         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1167 }
1168
1169 /**
1170  * Log to a file without getting "file size exceeded" signals.
1171  *
1172  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1173  * send lines to the specified port, prefixed by the specified prefix and a space.
1174  *
1175  * @param string $text
1176  * @param string $file Filename
1177  * @throws MWException
1178  */
1179 function wfErrorLog( $text, $file ) {
1180         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1181                 # Needs the sockets extension
1182                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1183                         // IPv6 bracketed host
1184                         $host = $m[2];
1185                         $port = intval( $m[3] );
1186                         $prefix = isset( $m[4] ) ? $m[4] : false;
1187                         $domain = AF_INET6;
1188                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1189                         $host = $m[2];
1190                         if ( !IP::isIPv4( $host ) ) {
1191                                 $host = gethostbyname( $host );
1192                         }
1193                         $port = intval( $m[3] );
1194                         $prefix = isset( $m[4] ) ? $m[4] : false;
1195                         $domain = AF_INET;
1196                 } else {
1197                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1198                 }
1199
1200                 // Clean it up for the multiplexer
1201                 if ( strval( $prefix ) !== '' ) {
1202                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1203
1204                         // Limit to 64KB
1205                         if ( strlen( $text ) > 65506 ) {
1206                                 $text = substr( $text, 0, 65506 );
1207                         }
1208
1209                         if ( substr( $text, -1 ) != "\n" ) {
1210                                 $text .= "\n";
1211                         }
1212                 } elseif ( strlen( $text ) > 65507 ) {
1213                         $text = substr( $text, 0, 65507 );
1214                 }
1215
1216                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1217                 if ( !$sock ) {
1218                         return;
1219                 }
1220
1221                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1222                 socket_close( $sock );
1223         } else {
1224                 wfSuppressWarnings();
1225                 $exists = file_exists( $file );
1226                 $size = $exists ? filesize( $file ) : false;
1227                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1228                         file_put_contents( $file, $text, FILE_APPEND );
1229                 }
1230                 wfRestoreWarnings();
1231         }
1232 }
1233
1234 /**
1235  * @todo document
1236  */
1237 function wfLogProfilingData() {
1238         global $wgRequestTime, $wgDebugLogFile, $wgDebugLogGroups, $wgDebugRawPage;
1239         global $wgProfileLimit, $wgUser, $wgRequest;
1240
1241         StatCounter::singleton()->flush();
1242
1243         $profiler = Profiler::instance();
1244
1245         # Profiling must actually be enabled...
1246         if ( $profiler->isStub() ) {
1247                 return;
1248         }
1249
1250         // Get total page request time and only show pages that longer than
1251         // $wgProfileLimit time (default is 0)
1252         $elapsed = microtime( true ) - $wgRequestTime;
1253         if ( $elapsed <= $wgProfileLimit ) {
1254                 return;
1255         }
1256
1257         $profiler->logData();
1258
1259         // Check whether this should be logged in the debug file.
1260         if ( isset( $wgDebugLogGroups['profileoutput'] )
1261                 && $wgDebugLogGroups['profileoutput'] === false
1262         ) {
1263                 // Explicitely disabled
1264                 return;
1265         }
1266         if ( !isset( $wgDebugLogGroups['profileoutput'] ) && $wgDebugLogFile == '' ) {
1267                 // Logging not enabled; no point going further
1268                 return;
1269         }
1270         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1271                 return;
1272         }
1273
1274         $forward = '';
1275         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1276                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1277         }
1278         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1279                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1280         }
1281         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1282                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1283         }
1284         if ( $forward ) {
1285                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1286         }
1287         // Don't load $wgUser at this late stage just for statistics purposes
1288         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1289         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1290                 $forward .= ' anon';
1291         }
1292
1293         // Command line script uses a FauxRequest object which does not have
1294         // any knowledge about an URL and throw an exception instead.
1295         try {
1296                 $requestUrl = $wgRequest->getRequestURL();
1297         } catch ( MWException $e ) {
1298                 $requestUrl = 'n/a';
1299         }
1300
1301         $log = sprintf( "%s\t%04.3f\t%s\n",
1302                 gmdate( 'YmdHis' ), $elapsed,
1303                 urldecode( $requestUrl . $forward ) );
1304
1305         wfDebugLog( 'profileoutput', $log . $profiler->getOutput() );
1306 }
1307
1308 /**
1309  * Increment a statistics counter
1310  *
1311  * @param string $key
1312  * @param int $count
1313  * @return void
1314  */
1315 function wfIncrStats( $key, $count = 1 ) {
1316         StatCounter::singleton()->incr( $key, $count );
1317 }
1318
1319 /**
1320  * Check whether the wiki is in read-only mode.
1321  *
1322  * @return bool
1323  */
1324 function wfReadOnly() {
1325         return wfReadOnlyReason() !== false;
1326 }
1327
1328 /**
1329  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1330  *
1331  * @return string|bool String when in read-only mode; false otherwise
1332  */
1333 function wfReadOnlyReason() {
1334         global $wgReadOnly, $wgReadOnlyFile;
1335
1336         if ( $wgReadOnly === null ) {
1337                 // Set $wgReadOnly for faster access next time
1338                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1339                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1340                 } else {
1341                         $wgReadOnly = false;
1342                 }
1343         }
1344
1345         return $wgReadOnly;
1346 }
1347
1348 /**
1349  * Return a Language object from $langcode
1350  *
1351  * @param Language|string|bool $langcode Either:
1352  *                  - a Language object
1353  *                  - code of the language to get the message for, if it is
1354  *                    a valid code create a language for that language, if
1355  *                    it is a string but not a valid code then make a basic
1356  *                    language object
1357  *                  - a boolean: if it's false then use the global object for
1358  *                    the current user's language (as a fallback for the old parameter
1359  *                    functionality), or if it is true then use global object
1360  *                    for the wiki's content language.
1361  * @return Language
1362  */
1363 function wfGetLangObj( $langcode = false ) {
1364         # Identify which language to get or create a language object for.
1365         # Using is_object here due to Stub objects.
1366         if ( is_object( $langcode ) ) {
1367                 # Great, we already have the object (hopefully)!
1368                 return $langcode;
1369         }
1370
1371         global $wgContLang, $wgLanguageCode;
1372         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1373                 # $langcode is the language code of the wikis content language object.
1374                 # or it is a boolean and value is true
1375                 return $wgContLang;
1376         }
1377
1378         global $wgLang;
1379         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1380                 # $langcode is the language code of user language object.
1381                 # or it was a boolean and value is false
1382                 return $wgLang;
1383         }
1384
1385         $validCodes = array_keys( Language::fetchLanguageNames() );
1386         if ( in_array( $langcode, $validCodes ) ) {
1387                 # $langcode corresponds to a valid language.
1388                 return Language::factory( $langcode );
1389         }
1390
1391         # $langcode is a string, but not a valid language code; use content language.
1392         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1393         return $wgContLang;
1394 }
1395
1396 /**
1397  * This is the function for getting translated interface messages.
1398  *
1399  * @see Message class for documentation how to use them.
1400  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1401  *
1402  * This function replaces all old wfMsg* functions.
1403  *
1404  * @param string $key Message key
1405  * @param mixed $params,... Normal message parameters
1406  * @return Message
1407  *
1408  * @since 1.17
1409  *
1410  * @see Message::__construct
1411  */
1412 function wfMessage( $key /*...*/ ) {
1413         $params = func_get_args();
1414         array_shift( $params );
1415         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1416                 $params = $params[0];
1417         }
1418         return new Message( $key, $params );
1419 }
1420
1421 /**
1422  * This function accepts multiple message keys and returns a message instance
1423  * for the first message which is non-empty. If all messages are empty then an
1424  * instance of the first message key is returned.
1425  *
1426  * @param string|string[] $keys,... Message keys
1427  * @return Message
1428  *
1429  * @since 1.18
1430  *
1431  * @see Message::newFallbackSequence
1432  */
1433 function wfMessageFallback( /*...*/ ) {
1434         $args = func_get_args();
1435         return call_user_func_array( 'Message::newFallbackSequence', $args );
1436 }
1437
1438 /**
1439  * Get a message from anywhere, for the current user language.
1440  *
1441  * Use wfMsgForContent() instead if the message should NOT
1442  * change depending on the user preferences.
1443  *
1444  * @deprecated since 1.18
1445  *
1446  * @param string $key Lookup key for the message, usually
1447  *    defined in languages/Language.php
1448  *
1449  * Parameters to the message, which can be used to insert variable text into
1450  * it, can be passed to this function in the following formats:
1451  * - One per argument, starting at the second parameter
1452  * - As an array in the second parameter
1453  * These are not shown in the function definition.
1454  *
1455  * @return string
1456  */
1457 function wfMsg( $key ) {
1458         wfDeprecated( __METHOD__, '1.21' );
1459
1460         $args = func_get_args();
1461         array_shift( $args );
1462         return wfMsgReal( $key, $args );
1463 }
1464
1465 /**
1466  * Same as above except doesn't transform the message
1467  *
1468  * @deprecated since 1.18
1469  *
1470  * @param string $key
1471  * @return string
1472  */
1473 function wfMsgNoTrans( $key ) {
1474         wfDeprecated( __METHOD__, '1.21' );
1475
1476         $args = func_get_args();
1477         array_shift( $args );
1478         return wfMsgReal( $key, $args, true, false, false );
1479 }
1480
1481 /**
1482  * Get a message from anywhere, for the current global language
1483  * set with $wgLanguageCode.
1484  *
1485  * Use this if the message should NOT change dependent on the
1486  * language set in the user's preferences. This is the case for
1487  * most text written into logs, as well as link targets (such as
1488  * the name of the copyright policy page). Link titles, on the
1489  * other hand, should be shown in the UI language.
1490  *
1491  * Note that MediaWiki allows users to change the user interface
1492  * language in their preferences, but a single installation
1493  * typically only contains content in one language.
1494  *
1495  * Be wary of this distinction: If you use wfMsg() where you should
1496  * use wfMsgForContent(), a user of the software may have to
1497  * customize potentially hundreds of messages in
1498  * order to, e.g., fix a link in every possible language.
1499  *
1500  * @deprecated since 1.18
1501  *
1502  * @param string $key Lookup key for the message, usually
1503  *     defined in languages/Language.php
1504  * @return string
1505  */
1506 function wfMsgForContent( $key ) {
1507         wfDeprecated( __METHOD__, '1.21' );
1508
1509         global $wgForceUIMsgAsContentMsg;
1510         $args = func_get_args();
1511         array_shift( $args );
1512         $forcontent = true;
1513         if ( is_array( $wgForceUIMsgAsContentMsg )
1514                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1515         ) {
1516                 $forcontent = false;
1517         }
1518         return wfMsgReal( $key, $args, true, $forcontent );
1519 }
1520
1521 /**
1522  * Same as above except doesn't transform the message
1523  *
1524  * @deprecated since 1.18
1525  *
1526  * @param string $key
1527  * @return string
1528  */
1529 function wfMsgForContentNoTrans( $key ) {
1530         wfDeprecated( __METHOD__, '1.21' );
1531
1532         global $wgForceUIMsgAsContentMsg;
1533         $args = func_get_args();
1534         array_shift( $args );
1535         $forcontent = true;
1536         if ( is_array( $wgForceUIMsgAsContentMsg )
1537                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1538         ) {
1539                 $forcontent = false;
1540         }
1541         return wfMsgReal( $key, $args, true, $forcontent, false );
1542 }
1543
1544 /**
1545  * Really get a message
1546  *
1547  * @deprecated since 1.18
1548  *
1549  * @param string $key Key to get.
1550  * @param array $args
1551  * @param bool $useDB
1552  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1553  * @param bool $transform Whether or not to transform the message.
1554  * @return string The requested message.
1555  */
1556 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1557         wfDeprecated( __METHOD__, '1.21' );
1558
1559         wfProfileIn( __METHOD__ );
1560         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1561         $message = wfMsgReplaceArgs( $message, $args );
1562         wfProfileOut( __METHOD__ );
1563         return $message;
1564 }
1565
1566 /**
1567  * Fetch a message string value, but don't replace any keys yet.
1568  *
1569  * @deprecated since 1.18
1570  *
1571  * @param string $key
1572  * @param bool $useDB
1573  * @param string|bool $langCode Code of the language to get the message for, or
1574  *   behaves as a content language switch if it is a boolean.
1575  * @param bool $transform Whether to parse magic words, etc.
1576  * @return string
1577  */
1578 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1579         wfDeprecated( __METHOD__, '1.21' );
1580
1581         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1582
1583         $cache = MessageCache::singleton();
1584         $message = $cache->get( $key, $useDB, $langCode );
1585         if ( $message === false ) {
1586                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1587         } elseif ( $transform ) {
1588                 $message = $cache->transform( $message );
1589         }
1590         return $message;
1591 }
1592
1593 /**
1594  * Replace message parameter keys on the given formatted output.
1595  *
1596  * @param string $message
1597  * @param array $args
1598  * @return string
1599  * @private
1600  */
1601 function wfMsgReplaceArgs( $message, $args ) {
1602         # Fix windows line-endings
1603         # Some messages are split with explode("\n", $msg)
1604         $message = str_replace( "\r", '', $message );
1605
1606         // Replace arguments
1607         if ( count( $args ) ) {
1608                 if ( is_array( $args[0] ) ) {
1609                         $args = array_values( $args[0] );
1610                 }
1611                 $replacementKeys = array();
1612                 foreach ( $args as $n => $param ) {
1613                         $replacementKeys['$' . ( $n + 1 )] = $param;
1614                 }
1615                 $message = strtr( $message, $replacementKeys );
1616         }
1617
1618         return $message;
1619 }
1620
1621 /**
1622  * Return an HTML-escaped version of a message.
1623  * Parameter replacements, if any, are done *after* the HTML-escaping,
1624  * so parameters may contain HTML (eg links or form controls). Be sure
1625  * to pre-escape them if you really do want plaintext, or just wrap
1626  * the whole thing in htmlspecialchars().
1627  *
1628  * @deprecated since 1.18
1629  *
1630  * @param string $key
1631  * @param string $args,... Parameters
1632  * @return string
1633  */
1634 function wfMsgHtml( $key ) {
1635         wfDeprecated( __METHOD__, '1.21' );
1636
1637         $args = func_get_args();
1638         array_shift( $args );
1639         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1640 }
1641
1642 /**
1643  * Return an HTML version of message
1644  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1645  * so parameters may contain HTML (eg links or form controls). Be sure
1646  * to pre-escape them if you really do want plaintext, or just wrap
1647  * the whole thing in htmlspecialchars().
1648  *
1649  * @deprecated since 1.18
1650  *
1651  * @param string $key
1652  * @param string $args,... Parameters
1653  * @return string
1654  */
1655 function wfMsgWikiHtml( $key ) {
1656         wfDeprecated( __METHOD__, '1.21' );
1657
1658         $args = func_get_args();
1659         array_shift( $args );
1660         return wfMsgReplaceArgs(
1661                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1662                 /* can't be set to false */ true, /* interface */ true )->getText(),
1663                 $args );
1664 }
1665
1666 /**
1667  * Returns message in the requested format
1668  *
1669  * @deprecated since 1.18
1670  *
1671  * @param string $key Key of the message
1672  * @param array $options Processing rules.
1673  *   Can take the following options:
1674  *     parse: parses wikitext to HTML
1675  *     parseinline: parses wikitext to HTML and removes the surrounding
1676  *       p's added by parser or tidy
1677  *     escape: filters message through htmlspecialchars
1678  *     escapenoentities: same, but allows entity references like &#160; through
1679  *     replaceafter: parameters are substituted after parsing or escaping
1680  *     parsemag: transform the message using magic phrases
1681  *     content: fetch message for content language instead of interface
1682  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1683  *     language: Language object or language code to fetch message for
1684  *       (overridden by content).
1685  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1686  *
1687  * @return string
1688  */
1689 function wfMsgExt( $key, $options ) {
1690         wfDeprecated( __METHOD__, '1.21' );
1691
1692         $args = func_get_args();
1693         array_shift( $args );
1694         array_shift( $args );
1695         $options = (array)$options;
1696
1697         foreach ( $options as $arrayKey => $option ) {
1698                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1699                         # An unknown index, neither numeric nor "language"
1700                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1701                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1702                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1703                 'replaceafter', 'parsemag', 'content' ) ) ) {
1704                         # A numeric index with unknown value
1705                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1706                 }
1707         }
1708
1709         if ( in_array( 'content', $options, true ) ) {
1710                 $forContent = true;
1711                 $langCode = true;
1712                 $langCodeObj = null;
1713         } elseif ( array_key_exists( 'language', $options ) ) {
1714                 $forContent = false;
1715                 $langCode = wfGetLangObj( $options['language'] );
1716                 $langCodeObj = $langCode;
1717         } else {
1718                 $forContent = false;
1719                 $langCode = false;
1720                 $langCodeObj = null;
1721         }
1722
1723         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1724
1725         if ( !in_array( 'replaceafter', $options, true ) ) {
1726                 $string = wfMsgReplaceArgs( $string, $args );
1727         }
1728
1729         $messageCache = MessageCache::singleton();
1730         $parseInline = in_array( 'parseinline', $options, true );
1731         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1732                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1733                 if ( $string instanceof ParserOutput ) {
1734                         $string = $string->getText();
1735                 }
1736
1737                 if ( $parseInline ) {
1738                         $string = Parser::stripOuterParagraph( $string );
1739                 }
1740         } elseif ( in_array( 'parsemag', $options, true ) ) {
1741                 $string = $messageCache->transform( $string,
1742                                 !$forContent, $langCodeObj );
1743         }
1744
1745         if ( in_array( 'escape', $options, true ) ) {
1746                 $string = htmlspecialchars ( $string );
1747         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1748                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1749         }
1750
1751         if ( in_array( 'replaceafter', $options, true ) ) {
1752                 $string = wfMsgReplaceArgs( $string, $args );
1753         }
1754
1755         return $string;
1756 }
1757
1758 /**
1759  * Since wfMsg() and co suck, they don't return false if the message key they
1760  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1761  * nonexistence of messages by checking the MessageCache::get() result directly.
1762  *
1763  * @deprecated since 1.18. Use Message::isDisabled().
1764  *
1765  * @param string $key The message key looked up
1766  * @return bool True if the message *doesn't* exist.
1767  */
1768 function wfEmptyMsg( $key ) {
1769         wfDeprecated( __METHOD__, '1.21' );
1770
1771         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1772 }
1773
1774 /**
1775  * Fetch server name for use in error reporting etc.
1776  * Use real server name if available, so we know which machine
1777  * in a server farm generated the current page.
1778  *
1779  * @return string
1780  */
1781 function wfHostname() {
1782         static $host;
1783         if ( is_null( $host ) ) {
1784
1785                 # Hostname overriding
1786                 global $wgOverrideHostname;
1787                 if ( $wgOverrideHostname !== false ) {
1788                         # Set static and skip any detection
1789                         $host = $wgOverrideHostname;
1790                         return $host;
1791                 }
1792
1793                 if ( function_exists( 'posix_uname' ) ) {
1794                         // This function not present on Windows
1795                         $uname = posix_uname();
1796                 } else {
1797                         $uname = false;
1798                 }
1799                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1800                         $host = $uname['nodename'];
1801                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1802                         # Windows computer name
1803                         $host = getenv( 'COMPUTERNAME' );
1804                 } else {
1805                         # This may be a virtual server.
1806                         $host = $_SERVER['SERVER_NAME'];
1807                 }
1808         }
1809         return $host;
1810 }
1811
1812 /**
1813  * Returns a script tag that stores the amount of time it took MediaWiki to
1814  * handle the request in milliseconds as 'wgBackendResponseTime'.
1815  *
1816  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1817  * hostname of the server handling the request.
1818  *
1819  * @return string
1820  */
1821 function wfReportTime() {
1822         global $wgRequestTime, $wgShowHostnames;
1823
1824         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1825         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1826         if ( $wgShowHostnames ) {
1827                 $reportVars['wgHostname'] = wfHostname();
1828         }
1829         return Skin::makeVariablesScript( $reportVars );
1830 }
1831
1832 /**
1833  * Safety wrapper for debug_backtrace().
1834  *
1835  * Will return an empty array if debug_backtrace is disabled, otherwise
1836  * the output from debug_backtrace() (trimmed).
1837  *
1838  * @param int $limit This parameter can be used to limit the number of stack frames returned
1839  *
1840  * @return array Array of backtrace information
1841  */
1842 function wfDebugBacktrace( $limit = 0 ) {
1843         static $disabled = null;
1844
1845         if ( is_null( $disabled ) ) {
1846                 $disabled = !function_exists( 'debug_backtrace' );
1847                 if ( $disabled ) {
1848                         wfDebug( "debug_backtrace() is disabled\n" );
1849                 }
1850         }
1851         if ( $disabled ) {
1852                 return array();
1853         }
1854
1855         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1856                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1857         } else {
1858                 return array_slice( debug_backtrace(), 1 );
1859         }
1860 }
1861
1862 /**
1863  * Get a debug backtrace as a string
1864  *
1865  * @return string
1866  */
1867 function wfBacktrace() {
1868         global $wgCommandLineMode;
1869
1870         if ( $wgCommandLineMode ) {
1871                 $msg = '';
1872         } else {
1873                 $msg = "<ul>\n";
1874         }
1875         $backtrace = wfDebugBacktrace();
1876         foreach ( $backtrace as $call ) {
1877                 if ( isset( $call['file'] ) ) {
1878                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1879                         $file = $f[count( $f ) - 1];
1880                 } else {
1881                         $file = '-';
1882                 }
1883                 if ( isset( $call['line'] ) ) {
1884                         $line = $call['line'];
1885                 } else {
1886                         $line = '-';
1887                 }
1888                 if ( $wgCommandLineMode ) {
1889                         $msg .= "$file line $line calls ";
1890                 } else {
1891                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1892                 }
1893                 if ( !empty( $call['class'] ) ) {
1894                         $msg .= $call['class'] . $call['type'];
1895                 }
1896                 $msg .= $call['function'] . '()';
1897
1898                 if ( $wgCommandLineMode ) {
1899                         $msg .= "\n";
1900                 } else {
1901                         $msg .= "</li>\n";
1902                 }
1903         }
1904         if ( $wgCommandLineMode ) {
1905                 $msg .= "\n";
1906         } else {
1907                 $msg .= "</ul>\n";
1908         }
1909
1910         return $msg;
1911 }
1912
1913 /**
1914  * Get the name of the function which called this function
1915  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1916  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1917  * wfGetCaller( 3 ) is the parent of that.
1918  *
1919  * @param int $level
1920  * @return string
1921  */
1922 function wfGetCaller( $level = 2 ) {
1923         $backtrace = wfDebugBacktrace( $level + 1 );
1924         if ( isset( $backtrace[$level] ) ) {
1925                 return wfFormatStackFrame( $backtrace[$level] );
1926         } else {
1927                 return 'unknown';
1928         }
1929 }
1930
1931 /**
1932  * Return a string consisting of callers in the stack. Useful sometimes
1933  * for profiling specific points.
1934  *
1935  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1936  * @return string
1937  */
1938 function wfGetAllCallers( $limit = 3 ) {
1939         $trace = array_reverse( wfDebugBacktrace() );
1940         if ( !$limit || $limit > count( $trace ) - 1 ) {
1941                 $limit = count( $trace ) - 1;
1942         }
1943         $trace = array_slice( $trace, -$limit - 1, $limit );
1944         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1945 }
1946
1947 /**
1948  * Return a string representation of frame
1949  *
1950  * @param array $frame
1951  * @return string
1952  */
1953 function wfFormatStackFrame( $frame ) {
1954         return isset( $frame['class'] ) ?
1955                 $frame['class'] . '::' . $frame['function'] :
1956                 $frame['function'];
1957 }
1958
1959 /* Some generic result counters, pulled out of SearchEngine */
1960
1961 /**
1962  * @todo document
1963  *
1964  * @param int $offset
1965  * @param int $limit
1966  * @return string
1967  */
1968 function wfShowingResults( $offset, $limit ) {
1969         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1970 }
1971
1972 /**
1973  * @todo document
1974  * @todo FIXME: We may want to blacklist some broken browsers
1975  *
1976  * @param bool $force
1977  * @return bool Whereas client accept gzip compression
1978  */
1979 function wfClientAcceptsGzip( $force = false ) {
1980         static $result = null;
1981         if ( $result === null || $force ) {
1982                 $result = false;
1983                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1984                         # @todo FIXME: We may want to blacklist some broken browsers
1985                         $m = array();
1986                         if ( preg_match(
1987                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1988                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
1989                                         $m
1990                                 )
1991                         ) {
1992                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1993                                         $result = false;
1994                                         return $result;
1995                                 }
1996                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1997                                 $result = true;
1998                         }
1999                 }
2000         }
2001         return $result;
2002 }
2003
2004 /**
2005  * Obtain the offset and limit values from the request string;
2006  * used in special pages
2007  *
2008  * @param int $deflimit Default limit if none supplied
2009  * @param string $optionname Name of a user preference to check against
2010  * @return array
2011  * @deprecated since 1.24, just call WebRequest::getLimitOffset() directly
2012  */
2013 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2014         global $wgRequest;
2015         wfDeprecated( __METHOD__, '1.24' );
2016         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2017 }
2018
2019 /**
2020  * Escapes the given text so that it may be output using addWikiText()
2021  * without any linking, formatting, etc. making its way through. This
2022  * is achieved by substituting certain characters with HTML entities.
2023  * As required by the callers, "<nowiki>" is not used.
2024  *
2025  * @param string $text Text to be escaped
2026  * @return string
2027  */
2028 function wfEscapeWikiText( $text ) {
2029         static $repl = null, $repl2 = null;
2030         if ( $repl === null ) {
2031                 $repl = array(
2032                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2033                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2034                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2035                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2036                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2037                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2038                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2039                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2040                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2041                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2042                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2043                         '__' => '_&#95;', '://' => '&#58;//',
2044                 );
2045
2046                 // We have to catch everything "\s" matches in PCRE
2047                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2048                         $repl["$magic "] = "$magic&#32;";
2049                         $repl["$magic\t"] = "$magic&#9;";
2050                         $repl["$magic\r"] = "$magic&#13;";
2051                         $repl["$magic\n"] = "$magic&#10;";
2052                         $repl["$magic\f"] = "$magic&#12;";
2053                 }
2054
2055                 // And handle protocols that don't use "://"
2056                 global $wgUrlProtocols;
2057                 $repl2 = array();
2058                 foreach ( $wgUrlProtocols as $prot ) {
2059                         if ( substr( $prot, -1 ) === ':' ) {
2060                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2061                         }
2062                 }
2063                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2064         }
2065         $text = substr( strtr( "\n$text", $repl ), 1 );
2066         $text = preg_replace( $repl2, '$1&#58;', $text );
2067         return $text;
2068 }
2069
2070 /**
2071  * Sets dest to source and returns the original value of dest
2072  * If source is NULL, it just returns the value, it doesn't set the variable
2073  * If force is true, it will set the value even if source is NULL
2074  *
2075  * @param mixed $dest
2076  * @param mixed $source
2077  * @param bool $force
2078  * @return mixed
2079  */
2080 function wfSetVar( &$dest, $source, $force = false ) {
2081         $temp = $dest;
2082         if ( !is_null( $source ) || $force ) {
2083                 $dest = $source;
2084         }
2085         return $temp;
2086 }
2087
2088 /**
2089  * As for wfSetVar except setting a bit
2090  *
2091  * @param int $dest
2092  * @param int $bit
2093  * @param bool $state
2094  *
2095  * @return bool
2096  */
2097 function wfSetBit( &$dest, $bit, $state = true ) {
2098         $temp = (bool)( $dest & $bit );
2099         if ( !is_null( $state ) ) {
2100                 if ( $state ) {
2101                         $dest |= $bit;
2102                 } else {
2103                         $dest &= ~$bit;
2104                 }
2105         }
2106         return $temp;
2107 }
2108
2109 /**
2110  * A wrapper around the PHP function var_export().
2111  * Either print it or add it to the regular output ($wgOut).
2112  *
2113  * @param mixed $var A PHP variable to dump.
2114  */
2115 function wfVarDump( $var ) {
2116         global $wgOut;
2117         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2118         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2119                 print $s;
2120         } else {
2121                 $wgOut->addHTML( $s );
2122         }
2123 }
2124
2125 /**
2126  * Provide a simple HTTP error.
2127  *
2128  * @param int|string $code
2129  * @param string $label
2130  * @param string $desc
2131  */
2132 function wfHttpError( $code, $label, $desc ) {
2133         global $wgOut;
2134         $wgOut->disable();
2135         header( "HTTP/1.0 $code $label" );
2136         header( "Status: $code $label" );
2137         $wgOut->sendCacheControl();
2138
2139         header( 'Content-type: text/html; charset=utf-8' );
2140         print "<!doctype html>" .
2141                 '<html><head><title>' .
2142                 htmlspecialchars( $label ) .
2143                 '</title></head><body><h1>' .
2144                 htmlspecialchars( $label ) .
2145                 '</h1><p>' .
2146                 nl2br( htmlspecialchars( $desc ) ) .
2147                 "</p></body></html>\n";
2148 }
2149
2150 /**
2151  * Clear away any user-level output buffers, discarding contents.
2152  *
2153  * Suitable for 'starting afresh', for instance when streaming
2154  * relatively large amounts of data without buffering, or wanting to
2155  * output image files without ob_gzhandler's compression.
2156  *
2157  * The optional $resetGzipEncoding parameter controls suppression of
2158  * the Content-Encoding header sent by ob_gzhandler; by default it
2159  * is left. See comments for wfClearOutputBuffers() for why it would
2160  * be used.
2161  *
2162  * Note that some PHP configuration options may add output buffer
2163  * layers which cannot be removed; these are left in place.
2164  *
2165  * @param bool $resetGzipEncoding
2166  */
2167 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2168         if ( $resetGzipEncoding ) {
2169                 // Suppress Content-Encoding and Content-Length
2170                 // headers from 1.10+s wfOutputHandler
2171                 global $wgDisableOutputCompression;
2172                 $wgDisableOutputCompression = true;
2173         }
2174         while ( $status = ob_get_status() ) {
2175                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2176                         // Probably from zlib.output_compression or other
2177                         // PHP-internal setting which can't be removed.
2178                         //
2179                         // Give up, and hope the result doesn't break
2180                         // output behavior.
2181                         break;
2182                 }
2183                 if ( !ob_end_clean() ) {
2184                         // Could not remove output buffer handler; abort now
2185                         // to avoid getting in some kind of infinite loop.
2186                         break;
2187                 }
2188                 if ( $resetGzipEncoding ) {
2189                         if ( $status['name'] == 'ob_gzhandler' ) {
2190                                 // Reset the 'Content-Encoding' field set by this handler
2191                                 // so we can start fresh.
2192                                 header_remove( 'Content-Encoding' );
2193                                 break;
2194                         }
2195                 }
2196         }
2197 }
2198
2199 /**
2200  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2201  *
2202  * Clear away output buffers, but keep the Content-Encoding header
2203  * produced by ob_gzhandler, if any.
2204  *
2205  * This should be used for HTTP 304 responses, where you need to
2206  * preserve the Content-Encoding header of the real result, but
2207  * also need to suppress the output of ob_gzhandler to keep to spec
2208  * and avoid breaking Firefox in rare cases where the headers and
2209  * body are broken over two packets.
2210  */
2211 function wfClearOutputBuffers() {
2212         wfResetOutputBuffers( false );
2213 }
2214
2215 /**
2216  * Converts an Accept-* header into an array mapping string values to quality
2217  * factors
2218  *
2219  * @param string $accept
2220  * @param string $def Default
2221  * @return float[] Associative array of string => float pairs
2222  */
2223 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2224         # No arg means accept anything (per HTTP spec)
2225         if ( !$accept ) {
2226                 return array( $def => 1.0 );
2227         }
2228
2229         $prefs = array();
2230
2231         $parts = explode( ',', $accept );
2232
2233         foreach ( $parts as $part ) {
2234                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2235                 $values = explode( ';', trim( $part ) );
2236                 $match = array();
2237                 if ( count( $values ) == 1 ) {
2238                         $prefs[$values[0]] = 1.0;
2239                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2240                         $prefs[$values[0]] = floatval( $match[1] );
2241                 }
2242         }
2243
2244         return $prefs;
2245 }
2246
2247 /**
2248  * Checks if a given MIME type matches any of the keys in the given
2249  * array. Basic wildcards are accepted in the array keys.
2250  *
2251  * Returns the matching MIME type (or wildcard) if a match, otherwise
2252  * NULL if no match.
2253  *
2254  * @param string $type
2255  * @param array $avail
2256  * @return string
2257  * @private
2258  */
2259 function mimeTypeMatch( $type, $avail ) {
2260         if ( array_key_exists( $type, $avail ) ) {
2261                 return $type;
2262         } else {
2263                 $parts = explode( '/', $type );
2264                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2265                         return $parts[0] . '/*';
2266                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2267                         return '*/*';
2268                 } else {
2269                         return null;
2270                 }
2271         }
2272 }
2273
2274 /**
2275  * Returns the 'best' match between a client's requested internet media types
2276  * and the server's list of available types. Each list should be an associative
2277  * array of type to preference (preference is a float between 0.0 and 1.0).
2278  * Wildcards in the types are acceptable.
2279  *
2280  * @param array $cprefs Client's acceptable type list
2281  * @param array $sprefs Server's offered types
2282  * @return string
2283  *
2284  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2285  * XXX: generalize to negotiate other stuff
2286  */
2287 function wfNegotiateType( $cprefs, $sprefs ) {
2288         $combine = array();
2289
2290         foreach ( array_keys( $sprefs ) as $type ) {
2291                 $parts = explode( '/', $type );
2292                 if ( $parts[1] != '*' ) {
2293                         $ckey = mimeTypeMatch( $type, $cprefs );
2294                         if ( $ckey ) {
2295                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2296                         }
2297                 }
2298         }
2299
2300         foreach ( array_keys( $cprefs ) as $type ) {
2301                 $parts = explode( '/', $type );
2302                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2303                         $skey = mimeTypeMatch( $type, $sprefs );
2304                         if ( $skey ) {
2305                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2306                         }
2307                 }
2308         }
2309
2310         $bestq = 0;
2311         $besttype = null;
2312
2313         foreach ( array_keys( $combine ) as $type ) {
2314                 if ( $combine[$type] > $bestq ) {
2315                         $besttype = $type;
2316                         $bestq = $combine[$type];
2317                 }
2318         }
2319
2320         return $besttype;
2321 }
2322
2323 /**
2324  * Reference-counted warning suppression
2325  *
2326  * @param bool $end
2327  */
2328 function wfSuppressWarnings( $end = false ) {
2329         static $suppressCount = 0;
2330         static $originalLevel = false;
2331
2332         if ( $end ) {
2333                 if ( $suppressCount ) {
2334                         --$suppressCount;
2335                         if ( !$suppressCount ) {
2336                                 error_reporting( $originalLevel );
2337                         }
2338                 }
2339         } else {
2340                 if ( !$suppressCount ) {
2341                         $originalLevel = error_reporting( E_ALL & ~(
2342                                 E_WARNING |
2343                                 E_NOTICE |
2344                                 E_USER_WARNING |
2345                                 E_USER_NOTICE |
2346                                 E_DEPRECATED |
2347                                 E_USER_DEPRECATED |
2348                                 E_STRICT
2349                         ) );
2350                 }
2351                 ++$suppressCount;
2352         }
2353 }
2354
2355 /**
2356  * Restore error level to previous value
2357  */
2358 function wfRestoreWarnings() {
2359         wfSuppressWarnings( true );
2360 }
2361
2362 # Autodetect, convert and provide timestamps of various types
2363
2364 /**
2365  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2366  */
2367 define( 'TS_UNIX', 0 );
2368
2369 /**
2370  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2371  */
2372 define( 'TS_MW', 1 );
2373
2374 /**
2375  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2376  */
2377 define( 'TS_DB', 2 );
2378
2379 /**
2380  * RFC 2822 format, for E-mail and HTTP headers
2381  */
2382 define( 'TS_RFC2822', 3 );
2383
2384 /**
2385  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2386  *
2387  * This is used by Special:Export
2388  */
2389 define( 'TS_ISO_8601', 4 );
2390
2391 /**
2392  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2393  *
2394  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2395  *       DateTime tag and page 36 for the DateTimeOriginal and
2396  *       DateTimeDigitized tags.
2397  */
2398 define( 'TS_EXIF', 5 );
2399
2400 /**
2401  * Oracle format time.
2402  */
2403 define( 'TS_ORACLE', 6 );
2404
2405 /**
2406  * Postgres format time.
2407  */
2408 define( 'TS_POSTGRES', 7 );
2409
2410 /**
2411  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2412  */
2413 define( 'TS_ISO_8601_BASIC', 9 );
2414
2415 /**
2416  * Get a timestamp string in one of various formats
2417  *
2418  * @param mixed $outputtype A timestamp in one of the supported formats, the
2419  *   function will autodetect which format is supplied and act accordingly.
2420  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2421  * @return string|bool String / false The same date in the format specified in $outputtype or false
2422  */
2423 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2424         try {
2425                 $timestamp = new MWTimestamp( $ts );
2426                 return $timestamp->getTimestamp( $outputtype );
2427         } catch ( TimestampException $e ) {
2428                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2429                 return false;
2430         }
2431 }
2432
2433 /**
2434  * Return a formatted timestamp, or null if input is null.
2435  * For dealing with nullable timestamp columns in the database.
2436  *
2437  * @param int $outputtype
2438  * @param string $ts
2439  * @return string
2440  */
2441 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2442         if ( is_null( $ts ) ) {
2443                 return null;
2444         } else {
2445                 return wfTimestamp( $outputtype, $ts );
2446         }
2447 }
2448
2449 /**
2450  * Convenience function; returns MediaWiki timestamp for the present time.
2451  *
2452  * @return string
2453  */
2454 function wfTimestampNow() {
2455         # return NOW
2456         return wfTimestamp( TS_MW, time() );
2457 }
2458
2459 /**
2460  * Check if the operating system is Windows
2461  *
2462  * @return bool True if it's Windows, false otherwise.
2463  */
2464 function wfIsWindows() {
2465         static $isWindows = null;
2466         if ( $isWindows === null ) {
2467                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2468         }
2469         return $isWindows;
2470 }
2471
2472 /**
2473  * Check if we are running under HHVM
2474  *
2475  * @return bool
2476  */
2477 function wfIsHHVM() {
2478         return defined( 'HHVM_VERSION' );
2479 }
2480
2481 /**
2482  * Swap two variables
2483  *
2484  * @deprecated since 1.24
2485  * @param mixed $x
2486  * @param mixed $y
2487  */
2488 function swap( &$x, &$y ) {
2489         wfDeprecated( __FUNCTION__, '1.24' );
2490         $z = $x;
2491         $x = $y;
2492         $y = $z;
2493 }
2494
2495 /**
2496  * Tries to get the system directory for temporary files. First
2497  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2498  * environment variables are then checked in sequence, and if none are
2499  * set try sys_get_temp_dir().
2500  *
2501  * NOTE: When possible, use instead the tmpfile() function to create
2502  * temporary files to avoid race conditions on file creation, etc.
2503  *
2504  * @return string
2505  */
2506 function wfTempDir() {
2507         global $wgTmpDirectory;
2508
2509         if ( $wgTmpDirectory !== false ) {
2510                 return $wgTmpDirectory;
2511         }
2512
2513         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2514
2515         foreach ( $tmpDir as $tmp ) {
2516                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2517                         return $tmp;
2518                 }
2519         }
2520         return sys_get_temp_dir();
2521 }
2522
2523 /**
2524  * Make directory, and make all parent directories if they don't exist
2525  *
2526  * @param string $dir Full path to directory to create
2527  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2528  * @param string $caller Optional caller param for debugging.
2529  * @throws MWException
2530  * @return bool
2531  */
2532 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2533         global $wgDirectoryMode;
2534
2535         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2536                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2537         }
2538
2539         if ( !is_null( $caller ) ) {
2540                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2541         }
2542
2543         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2544                 return true;
2545         }
2546
2547         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2548
2549         if ( is_null( $mode ) ) {
2550                 $mode = $wgDirectoryMode;
2551         }
2552
2553         // Turn off the normal warning, we're doing our own below
2554         wfSuppressWarnings();
2555         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2556         wfRestoreWarnings();
2557
2558         if ( !$ok ) {
2559                 //directory may have been created on another request since we last checked
2560                 if ( is_dir( $dir ) ) {
2561                         return true;
2562                 }
2563
2564                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2565                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2566         }
2567         return $ok;
2568 }
2569
2570 /**
2571  * Remove a directory and all its content.
2572  * Does not hide error.
2573  * @param string $dir
2574  */
2575 function wfRecursiveRemoveDir( $dir ) {
2576         wfDebug( __FUNCTION__ . "( $dir )\n" );
2577         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2578         if ( is_dir( $dir ) ) {
2579                 $objects = scandir( $dir );
2580                 foreach ( $objects as $object ) {
2581                         if ( $object != "." && $object != ".." ) {
2582                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2583                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2584                                 } else {
2585                                         unlink( $dir . '/' . $object );
2586                                 }
2587                         }
2588                 }
2589                 reset( $objects );
2590                 rmdir( $dir );
2591         }
2592 }
2593
2594 /**
2595  * @param int $nr The number to format
2596  * @param int $acc The number of digits after the decimal point, default 2
2597  * @param bool $round Whether or not to round the value, default true
2598  * @return string
2599  */
2600 function wfPercent( $nr, $acc = 2, $round = true ) {
2601         $ret = sprintf( "%.${acc}f", $nr );
2602         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2603 }
2604
2605 /**
2606  * Safety wrapper around ini_get() for boolean settings.
2607  * The values returned from ini_get() are pre-normalized for settings
2608  * set via php.ini or php_flag/php_admin_flag... but *not*
2609  * for those set via php_value/php_admin_value.
2610  *
2611  * It's fairly common for people to use php_value instead of php_flag,
2612  * which can leave you with an 'off' setting giving a false positive
2613  * for code that just takes the ini_get() return value as a boolean.
2614  *
2615  * To make things extra interesting, setting via php_value accepts
2616  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2617  * Unrecognized values go false... again opposite PHP's own coercion
2618  * from string to bool.
2619  *
2620  * Luckily, 'properly' set settings will always come back as '0' or '1',
2621  * so we only have to worry about them and the 'improper' settings.
2622  *
2623  * I frickin' hate PHP... :P
2624  *
2625  * @param string $setting
2626  * @return bool
2627  */
2628 function wfIniGetBool( $setting ) {
2629         $val = strtolower( ini_get( $setting ) );
2630         // 'on' and 'true' can't have whitespace around them, but '1' can.
2631         return $val == 'on'
2632                 || $val == 'true'
2633                 || $val == 'yes'
2634                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2635 }
2636
2637 /**
2638  * Windows-compatible version of escapeshellarg()
2639  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2640  * function puts single quotes in regardless of OS.
2641  *
2642  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2643  * earlier distro releases of PHP)
2644  *
2645  * @param string $args,...
2646  * @return string
2647  */
2648 function wfEscapeShellArg( /*...*/ ) {
2649         wfInitShellLocale();
2650
2651         $args = func_get_args();
2652         $first = true;
2653         $retVal = '';
2654         foreach ( $args as $arg ) {
2655                 if ( !$first ) {
2656                         $retVal .= ' ';
2657                 } else {
2658                         $first = false;
2659                 }
2660
2661                 if ( wfIsWindows() ) {
2662                         // Escaping for an MSVC-style command line parser and CMD.EXE
2663                         // @codingStandardsIgnoreStart For long URLs
2664                         // Refs:
2665                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2666                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2667                         //  * Bug #13518
2668                         //  * CR r63214
2669                         // Double the backslashes before any double quotes. Escape the double quotes.
2670                         // @codingStandardsIgnoreEnd
2671                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2672                         $arg = '';
2673                         $iteration = 0;
2674                         foreach ( $tokens as $token ) {
2675                                 if ( $iteration % 2 == 1 ) {
2676                                         // Delimiter, a double quote preceded by zero or more slashes
2677                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2678                                 } elseif ( $iteration % 4 == 2 ) {
2679                                         // ^ in $token will be outside quotes, need to be escaped
2680                                         $arg .= str_replace( '^', '^^', $token );
2681                                 } else { // $iteration % 4 == 0
2682                                         // ^ in $token will appear inside double quotes, so leave as is
2683                                         $arg .= $token;
2684                                 }
2685                                 $iteration++;
2686                         }
2687                         // Double the backslashes before the end of the string, because
2688                         // we will soon add a quote
2689                         $m = array();
2690                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2691                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2692                         }
2693
2694                         // Add surrounding quotes
2695                         $retVal .= '"' . $arg . '"';
2696                 } else {
2697                         $retVal .= escapeshellarg( $arg );
2698                 }
2699         }
2700         return $retVal;
2701 }
2702
2703 /**
2704  * Check if wfShellExec() is effectively disabled via php.ini config
2705  *
2706  * @return bool|string False or one of (safemode,disabled)
2707  * @since 1.22
2708  */
2709 function wfShellExecDisabled() {
2710         static $disabled = null;
2711         if ( is_null( $disabled ) ) {
2712                 if ( wfIniGetBool( 'safe_mode' ) ) {
2713                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2714                         $disabled = 'safemode';
2715                 } elseif ( !function_exists( 'proc_open' ) ) {
2716                         wfDebug( "proc_open() is disabled\n" );
2717                         $disabled = 'disabled';
2718                 } else {
2719                         $disabled = false;
2720                 }
2721         }
2722         return $disabled;
2723 }
2724
2725 /**
2726  * Execute a shell command, with time and memory limits mirrored from the PHP
2727  * configuration if supported.
2728  *
2729  * @param string|string[] $cmd If string, a properly shell-escaped command line,
2730  *   or an array of unescaped arguments, in which case each value will be escaped
2731  *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
2732  * @param null|mixed &$retval Optional, will receive the program's exit code.
2733  *   (non-zero is usually failure). If there is an error from
2734  *   read, select, or proc_open(), this will be set to -1.
2735  * @param array $environ Optional environment variables which should be
2736  *   added to the executed command environment.
2737  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2738  *   this overwrites the global wgMaxShell* limits.
2739  * @param array $options Array of options:
2740  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2741  *     including errors from limit.sh
2742  *
2743  * @return string Collected stdout as a string
2744  */
2745 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2746         $limits = array(), $options = array()
2747 ) {
2748         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2749                 $wgMaxShellWallClockTime, $wgShellCgroup;
2750
2751         $disabled = wfShellExecDisabled();
2752         if ( $disabled ) {
2753                 $retval = 1;
2754                 return $disabled == 'safemode' ?
2755                         'Unable to run external programs in safe mode.' :
2756                         'Unable to run external programs, proc_open() is disabled.';
2757         }
2758
2759         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2760
2761         wfInitShellLocale();
2762
2763         $envcmd = '';
2764         foreach ( $environ as $k => $v ) {
2765                 if ( wfIsWindows() ) {
2766                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2767                          * appear in the environment variable, so we must use carat escaping as documented in
2768                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2769                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2770                          * are listed there but doesn't appear to need it.
2771                          */
2772                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2773                 } else {
2774                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2775                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2776                          */
2777                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2778                 }
2779         }
2780         if ( is_array( $cmd ) ) {
2781                 // Command line may be given as an array, escape each value and glue them together with a space
2782                 $cmdVals = array();
2783                 foreach ( $cmd as $val ) {
2784                         $cmdVals[] = wfEscapeShellArg( $val );
2785                 }
2786                 $cmd = implode( ' ', $cmdVals );
2787         }
2788
2789         $cmd = $envcmd . $cmd;
2790
2791         $useLogPipe = false;
2792         if ( is_executable( '/bin/bash' ) ) {
2793                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2794                 if ( isset( $limits['walltime'] ) ) {
2795                         $wallTime = intval( $limits['walltime'] );
2796                 } elseif ( isset( $limits['time'] ) ) {
2797                         $wallTime = $time;
2798                 } else {
2799                         $wallTime = intval( $wgMaxShellWallClockTime );
2800                 }
2801                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2802                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2803
2804                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2805                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2806                                 escapeshellarg( $cmd ) . ' ' .
2807                                 escapeshellarg(
2808                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2809                                         "MW_CPU_LIMIT=$time; " .
2810                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2811                                         "MW_MEM_LIMIT=$mem; " .
2812                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2813                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2814                                         "MW_USE_LOG_PIPE=yes"
2815                                 );
2816                         $useLogPipe = true;
2817                 } elseif ( $includeStderr ) {
2818                         $cmd .= ' 2>&1';
2819                 }
2820         } elseif ( $includeStderr ) {
2821                 $cmd .= ' 2>&1';
2822         }
2823         wfDebug( "wfShellExec: $cmd\n" );
2824
2825         $desc = array(
2826                 0 => array( 'file', 'php://stdin', 'r' ),
2827                 1 => array( 'pipe', 'w' ),
2828                 2 => array( 'file', 'php://stderr', 'w' ) );
2829         if ( $useLogPipe ) {
2830                 $desc[3] = array( 'pipe', 'w' );
2831         }
2832         $pipes = null;
2833         $proc = proc_open( $cmd, $desc, $pipes );
2834         if ( !$proc ) {
2835                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2836                 $retval = -1;
2837                 return '';
2838         }
2839         $outBuffer = $logBuffer = '';
2840         $emptyArray = array();
2841         $status = false;
2842         $logMsg = false;
2843
2844         // According to the documentation, it is possible for stream_select()
2845         // to fail due to EINTR. I haven't managed to induce this in testing
2846         // despite sending various signals. If it did happen, the error
2847         // message would take the form:
2848         //
2849         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2850         //
2851         // where [4] is the value of the macro EINTR and "Interrupted system
2852         // call" is string which according to the Linux manual is "possibly"
2853         // localised according to LC_MESSAGES.
2854         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2855         $eintrMessage = "stream_select(): unable to select [$eintr]";
2856
2857         // Build a table mapping resource IDs to pipe FDs to work around a
2858         // PHP 5.3 issue in which stream_select() does not preserve array keys
2859         // <https://bugs.php.net/bug.php?id=53427>.
2860         $fds = array();
2861         foreach ( $pipes as $fd => $pipe ) {
2862                 $fds[(int)$pipe] = $fd;
2863         }
2864
2865         $running = true;
2866         $timeout = null;
2867         $numReadyPipes = 0;
2868
2869         while ( $running === true || $numReadyPipes !== 0 ) {
2870                 if ( $running ) {
2871                         $status = proc_get_status( $proc );
2872                         // If the process has terminated, switch to nonblocking selects
2873                         // for getting any data still waiting to be read.
2874                         if ( !$status['running'] ) {
2875                                 $running = false;
2876                                 $timeout = 0;
2877                         }
2878                 }
2879
2880                 $readyPipes = $pipes;
2881
2882                 // Clear last error
2883                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2884                 @trigger_error( '' );
2885                 $numReadyPipes = @stream_select( $readyPipes, $emptyArray, $emptyArray, $timeout );
2886                 if ( $numReadyPipes === false ) {
2887                         // @codingStandardsIgnoreEnd
2888                         $error = error_get_last();
2889                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2890                                 continue;
2891                         } else {
2892                                 trigger_error( $error['message'], E_USER_WARNING );
2893                                 $logMsg = $error['message'];
2894                                 break;
2895                         }
2896                 }
2897                 foreach ( $readyPipes as $pipe ) {
2898                         $block = fread( $pipe, 65536 );
2899                         $fd = $fds[(int)$pipe];
2900                         if ( $block === '' ) {
2901                                 // End of file
2902                                 fclose( $pipes[$fd] );
2903                                 unset( $pipes[$fd] );
2904                                 if ( !$pipes ) {
2905                                         break 2;
2906                                 }
2907                         } elseif ( $block === false ) {
2908                                 // Read error
2909                                 $logMsg = "Error reading from pipe";
2910                                 break 2;
2911                         } elseif ( $fd == 1 ) {
2912                                 // From stdout
2913                                 $outBuffer .= $block;
2914                         } elseif ( $fd == 3 ) {
2915                                 // From log FD
2916                                 $logBuffer .= $block;
2917                                 if ( strpos( $block, "\n" ) !== false ) {
2918                                         $lines = explode( "\n", $logBuffer );
2919                                         $logBuffer = array_pop( $lines );
2920                                         foreach ( $lines as $line ) {
2921                                                 wfDebugLog( 'exec', $line );
2922                                         }
2923                                 }
2924                         }
2925                 }
2926         }
2927
2928         foreach ( $pipes as $pipe ) {
2929                 fclose( $pipe );
2930         }
2931
2932         // Use the status previously collected if possible, since proc_get_status()
2933         // just calls waitpid() which will not return anything useful the second time.
2934         if ( $running ) {
2935                 $status = proc_get_status( $proc );
2936         }
2937
2938         if ( $logMsg !== false ) {
2939                 // Read/select error
2940                 $retval = -1;
2941                 proc_close( $proc );
2942         } elseif ( $status['signaled'] ) {
2943                 $logMsg = "Exited with signal {$status['termsig']}";
2944                 $retval = 128 + $status['termsig'];
2945                 proc_close( $proc );
2946         } else {
2947                 if ( $status['running'] ) {
2948                         $retval = proc_close( $proc );
2949                 } else {
2950                         $retval = $status['exitcode'];
2951                         proc_close( $proc );
2952                 }
2953                 if ( $retval == 127 ) {
2954                         $logMsg = "Possibly missing executable file";
2955                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2956                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2957                 }
2958         }
2959
2960         if ( $logMsg !== false ) {
2961                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2962         }
2963
2964         return $outBuffer;
2965 }
2966
2967 /**
2968  * Execute a shell command, returning both stdout and stderr. Convenience
2969  * function, as all the arguments to wfShellExec can become unwieldy.
2970  *
2971  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2972  * @param string $cmd Command line, properly escaped for shell.
2973  * @param null|mixed &$retval Optional, will receive the program's exit code.
2974  *   (non-zero is usually failure)
2975  * @param array $environ Optional environment variables which should be
2976  *   added to the executed command environment.
2977  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2978  *   this overwrites the global wgMaxShell* limits.
2979  * @return string Collected stdout and stderr as a string
2980  */
2981 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
2982         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
2983 }
2984
2985 /**
2986  * Workaround for http://bugs.php.net/bug.php?id=45132
2987  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2988  */
2989 function wfInitShellLocale() {
2990         static $done = false;
2991         if ( $done ) {
2992                 return;
2993         }
2994         $done = true;
2995         global $wgShellLocale;
2996         if ( !wfIniGetBool( 'safe_mode' ) ) {
2997                 putenv( "LC_CTYPE=$wgShellLocale" );
2998                 setlocale( LC_CTYPE, $wgShellLocale );
2999         }
3000 }
3001
3002 /**
3003  * Alias to wfShellWikiCmd()
3004  *
3005  * @see wfShellWikiCmd()
3006  */
3007 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
3008         return wfShellWikiCmd( $script, $parameters, $options );
3009 }
3010
3011 /**
3012  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3013  * Note that $parameters should be a flat array and an option with an argument
3014  * should consist of two consecutive items in the array (do not use "--option value").
3015  *
3016  * @param string $script MediaWiki cli script path
3017  * @param array $parameters Arguments and options to the script
3018  * @param array $options Associative array of options:
3019  *              'php': The path to the php executable
3020  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3021  * @return string
3022  */
3023 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3024         global $wgPhpCli;
3025         // Give site config file a chance to run the script in a wrapper.
3026         // The caller may likely want to call wfBasename() on $script.
3027         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3028         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3029         if ( isset( $options['wrapper'] ) ) {
3030                 $cmd[] = $options['wrapper'];
3031         }
3032         $cmd[] = $script;
3033         // Escape each parameter for shell
3034         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
3035 }
3036
3037 /**
3038  * wfMerge attempts to merge differences between three texts.
3039  * Returns true for a clean merge and false for failure or a conflict.
3040  *
3041  * @param string $old
3042  * @param string $mine
3043  * @param string $yours
3044  * @param string $result
3045  * @return bool
3046  */
3047 function wfMerge( $old, $mine, $yours, &$result ) {
3048         global $wgDiff3;
3049
3050         # This check may also protect against code injection in
3051         # case of broken installations.
3052         wfSuppressWarnings();
3053         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3054         wfRestoreWarnings();
3055
3056         if ( !$haveDiff3 ) {
3057                 wfDebug( "diff3 not found\n" );
3058                 return false;
3059         }
3060
3061         # Make temporary files
3062         $td = wfTempDir();
3063         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3064         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3065         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3066
3067         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3068         #       a newline character. To avoid this, we normalize the trailing whitespace before
3069         #       creating the diff.
3070
3071         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3072         fclose( $oldtextFile );
3073         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3074         fclose( $mytextFile );
3075         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3076         fclose( $yourtextFile );
3077
3078         # Check for a conflict
3079         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3080                 wfEscapeShellArg( $mytextName ) . ' ' .
3081                 wfEscapeShellArg( $oldtextName ) . ' ' .
3082                 wfEscapeShellArg( $yourtextName );
3083         $handle = popen( $cmd, 'r' );
3084
3085         if ( fgets( $handle, 1024 ) ) {
3086                 $conflict = true;
3087         } else {
3088                 $conflict = false;
3089         }
3090         pclose( $handle );
3091
3092         # Merge differences
3093         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3094                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3095         $handle = popen( $cmd, 'r' );
3096         $result = '';
3097         do {
3098                 $data = fread( $handle, 8192 );
3099                 if ( strlen( $data ) == 0 ) {
3100                         break;
3101                 }
3102                 $result .= $data;
3103         } while ( true );
3104         pclose( $handle );
3105         unlink( $mytextName );
3106         unlink( $oldtextName );
3107         unlink( $yourtextName );
3108
3109         if ( $result === '' && $old !== '' && !$conflict ) {
3110                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3111                 $conflict = true;
3112         }
3113         return !$conflict;
3114 }
3115
3116 /**
3117  * Returns unified plain-text diff of two texts.
3118  * Useful for machine processing of diffs.
3119  *
3120  * @param string $before The text before the changes.
3121  * @param string $after The text after the changes.
3122  * @param string $params Command-line options for the diff command.
3123  * @return string Unified diff of $before and $after
3124  */
3125 function wfDiff( $before, $after, $params = '-u' ) {
3126         if ( $before == $after ) {
3127                 return '';
3128         }
3129
3130         global $wgDiff;
3131         wfSuppressWarnings();
3132         $haveDiff = $wgDiff && file_exists( $wgDiff );
3133         wfRestoreWarnings();
3134
3135         # This check may also protect against code injection in
3136         # case of broken installations.
3137         if ( !$haveDiff ) {
3138                 wfDebug( "diff executable not found\n" );
3139                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3140                 $format = new UnifiedDiffFormatter();
3141                 return $format->format( $diffs );
3142         }
3143
3144         # Make temporary files
3145         $td = wfTempDir();
3146         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3147         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3148
3149         fwrite( $oldtextFile, $before );
3150         fclose( $oldtextFile );
3151         fwrite( $newtextFile, $after );
3152         fclose( $newtextFile );
3153
3154         // Get the diff of the two files
3155         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3156
3157         $h = popen( $cmd, 'r' );
3158
3159         $diff = '';
3160
3161         do {
3162                 $data = fread( $h, 8192 );
3163                 if ( strlen( $data ) == 0 ) {
3164                         break;
3165                 }
3166                 $diff .= $data;
3167         } while ( true );
3168
3169         // Clean up
3170         pclose( $h );
3171         unlink( $oldtextName );
3172         unlink( $newtextName );
3173
3174         // Kill the --- and +++ lines. They're not useful.
3175         $diff_lines = explode( "\n", $diff );
3176         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3177                 unset( $diff_lines[0] );
3178         }
3179         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3180                 unset( $diff_lines[1] );
3181         }
3182
3183         $diff = implode( "\n", $diff_lines );
3184
3185         return $diff;
3186 }
3187
3188 /**
3189  * This function works like "use VERSION" in Perl, the program will die with a
3190  * backtrace if the current version of PHP is less than the version provided
3191  *
3192  * This is useful for extensions which due to their nature are not kept in sync
3193  * with releases, and might depend on other versions of PHP than the main code
3194  *
3195  * Note: PHP might die due to parsing errors in some cases before it ever
3196  *       manages to call this function, such is life
3197  *
3198  * @see perldoc -f use
3199  *
3200  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3201  * @throws MWException
3202  */
3203 function wfUsePHP( $req_ver ) {
3204         $php_ver = PHP_VERSION;
3205
3206         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3207                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3208         }
3209 }
3210
3211 /**
3212  * This function works like "use VERSION" in Perl except it checks the version
3213  * of MediaWiki, the program will die with a backtrace if the current version
3214  * of MediaWiki is less than the version provided.
3215  *
3216  * This is useful for extensions which due to their nature are not kept in sync
3217  * with releases
3218  *
3219  * Note: Due to the behavior of PHP's version_compare() which is used in this
3220  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3221  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3222  * targeted version number. For example if you wanted to allow any variation
3223  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3224  * not result in the same comparison due to the internal logic of
3225  * version_compare().
3226  *
3227  * @see perldoc -f use
3228  *
3229  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3230  * @throws MWException
3231  */
3232 function wfUseMW( $req_ver ) {
3233         global $wgVersion;
3234
3235         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3236                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3237         }
3238 }
3239
3240 /**
3241  * Return the final portion of a pathname.
3242  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3243  * http://bugs.php.net/bug.php?id=33898
3244  *
3245  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3246  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3247  *
3248  * @param string $path
3249  * @param string $suffix String to remove if present
3250  * @return string
3251  */
3252 function wfBaseName( $path, $suffix = '' ) {
3253         if ( $suffix == '' ) {
3254                 $encSuffix = '';
3255         } else {
3256                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3257         }
3258
3259         $matches = array();
3260         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3261                 return $matches[1];
3262         } else {
3263                 return '';
3264         }
3265 }
3266
3267 /**
3268  * Generate a relative path name to the given file.
3269  * May explode on non-matching case-insensitive paths,
3270  * funky symlinks, etc.
3271  *
3272  * @param string $path Absolute destination path including target filename
3273  * @param string $from Absolute source path, directory only
3274  * @return string
3275  */
3276 function wfRelativePath( $path, $from ) {
3277         // Normalize mixed input on Windows...
3278         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3279         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3280
3281         // Trim trailing slashes -- fix for drive root
3282         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3283         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3284
3285         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3286         $against = explode( DIRECTORY_SEPARATOR, $from );
3287
3288         if ( $pieces[0] !== $against[0] ) {
3289                 // Non-matching Windows drive letters?
3290                 // Return a full path.
3291                 return $path;
3292         }
3293
3294         // Trim off common prefix
3295         while ( count( $pieces ) && count( $against )
3296                 && $pieces[0] == $against[0] ) {
3297                 array_shift( $pieces );
3298                 array_shift( $against );
3299         }
3300
3301         // relative dots to bump us to the parent
3302         while ( count( $against ) ) {
3303                 array_unshift( $pieces, '..' );
3304                 array_shift( $against );
3305         }
3306
3307         array_push( $pieces, wfBaseName( $path ) );
3308
3309         return implode( DIRECTORY_SEPARATOR, $pieces );
3310 }
3311
3312 /**
3313  * Convert an arbitrarily-long digit string from one numeric base
3314  * to another, optionally zero-padding to a minimum column width.
3315  *
3316  * Supports base 2 through 36; digit values 10-36 are represented
3317  * as lowercase letters a-z. Input is case-insensitive.
3318  *
3319  * @param string $input Input number
3320  * @param int $sourceBase Base of the input number
3321  * @param int $destBase Desired base of the output
3322  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3323  * @param bool $lowercase Whether to output in lowercase or uppercase
3324  * @param string $engine Either "gmp", "bcmath", or "php"
3325  * @return string|bool The output number as a string, or false on error
3326  */
3327 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3328         $lowercase = true, $engine = 'auto'
3329 ) {
3330         $input = (string)$input;
3331         if (
3332                 $sourceBase < 2 ||
3333                 $sourceBase > 36 ||
3334                 $destBase < 2 ||
3335                 $destBase > 36 ||
3336                 $sourceBase != (int)$sourceBase ||
3337                 $destBase != (int)$destBase ||
3338                 $pad != (int)$pad ||
3339                 !preg_match(
3340                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3341                         $input
3342                 )
3343         ) {
3344                 return false;
3345         }
3346
3347         static $baseChars = array(
3348                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3349                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3350                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3351                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3352                 34 => 'y', 35 => 'z',
3353
3354                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3355                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3356                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3357                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3358                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3359                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3360         );
3361
3362         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3363                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3364         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3365                 $decimal = '0';
3366                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3367                         $decimal = bcmul( $decimal, $sourceBase );
3368                         $decimal = bcadd( $decimal, $baseChars[$char] );
3369                 }
3370
3371                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3372                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3373                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3374                 }
3375                 // @codingStandardsIgnoreEnd
3376
3377                 $result = strrev( $result );
3378         } else {
3379                 $inDigits = array();
3380                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3381                         $inDigits[] = $baseChars[$char];
3382                 }
3383
3384                 // Iterate over the input, modulo-ing out an output digit
3385                 // at a time until input is gone.
3386                 $result = '';
3387                 while ( $inDigits ) {
3388                         $work = 0;
3389                         $workDigits = array();
3390
3391                         // Long division...
3392                         foreach ( $inDigits as $digit ) {
3393                                 $work *= $sourceBase;
3394                                 $work += $digit;
3395
3396                                 if ( $workDigits || $work >= $destBase ) {
3397                                         $workDigits[] = (int)( $work / $destBase );
3398                                 }
3399                                 $work %= $destBase;
3400                         }
3401
3402                         // All that division leaves us with a remainder,
3403                         // which is conveniently our next output digit.
3404                         $result .= $baseChars[$work];
3405
3406                         // And we continue!
3407                         $inDigits = $workDigits;
3408                 }
3409
3410                 $result = strrev( $result );
3411         }
3412
3413         if ( !$lowercase ) {
3414                 $result = strtoupper( $result );
3415         }
3416
3417         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3418 }
3419
3420 /**
3421  * Check if there is sufficient entropy in php's built-in session generation
3422  *
3423  * @return bool True = there is sufficient entropy
3424  */
3425 function wfCheckEntropy() {
3426         return (
3427                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3428                         || ini_get( 'session.entropy_file' )
3429                 )
3430                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3431 }
3432
3433 /**
3434  * Override session_id before session startup if php's built-in
3435  * session generation code is not secure.
3436  */
3437 function wfFixSessionID() {
3438         // If the cookie or session id is already set we already have a session and should abort
3439         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3440                 return;
3441         }
3442
3443         // PHP's built-in session entropy is enabled if:
3444         // - entropy_file is set or you're on Windows with php 5.3.3+
3445         // - AND entropy_length is > 0
3446         // We treat it as disabled if it doesn't have an entropy length of at least 32
3447         $entropyEnabled = wfCheckEntropy();
3448
3449         // If built-in entropy is not enabled or not sufficient override PHP's
3450         // built in session id generation code
3451         if ( !$entropyEnabled ) {
3452                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3453                         "overriding session id generation using our cryptrand source.\n" );
3454                 session_id( MWCryptRand::generateHex( 32 ) );
3455         }
3456 }
3457
3458 /**
3459  * Reset the session_id
3460  *
3461  * @since 1.22
3462  */
3463 function wfResetSessionID() {
3464         global $wgCookieSecure;
3465         $oldSessionId = session_id();
3466         $cookieParams = session_get_cookie_params();
3467         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3468                 session_regenerate_id( false );
3469         } else {
3470                 $tmp = $_SESSION;
3471                 session_destroy();
3472                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3473                 $_SESSION = $tmp;
3474         }
3475         $newSessionId = session_id();
3476         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3477 }
3478
3479 /**
3480  * Initialise php session
3481  *
3482  * @param bool $sessionId
3483  */
3484 function wfSetupSession( $sessionId = false ) {
3485         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3486                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3487         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3488                 ObjectCacheSessionHandler::install();
3489         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3490                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3491                 # hasn't already been set to the desired value (that causes errors)
3492                 ini_set( 'session.save_handler', $wgSessionHandler );
3493         }
3494         session_set_cookie_params(
3495                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3496         session_cache_limiter( 'private, must-revalidate' );
3497         if ( $sessionId ) {
3498                 session_id( $sessionId );
3499         } else {
3500                 wfFixSessionID();
3501         }
3502         wfSuppressWarnings();
3503         session_start();
3504         wfRestoreWarnings();
3505 }
3506
3507 /**
3508  * Get an object from the precompiled serialized directory
3509  *
3510  * @param string $name
3511  * @return mixed The variable on success, false on failure
3512  */
3513 function wfGetPrecompiledData( $name ) {
3514         global $IP;
3515
3516         $file = "$IP/serialized/$name";
3517         if ( file_exists( $file ) ) {
3518                 $blob = file_get_contents( $file );
3519                 if ( $blob ) {
3520                         return unserialize( $blob );
3521                 }
3522         }
3523         return false;
3524 }
3525
3526 /**
3527  * Get a cache key
3528  *
3529  * @param string $args,...
3530  * @return string
3531  */
3532 function wfMemcKey( /*...*/ ) {
3533         global $wgCachePrefix;
3534         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3535         $args = func_get_args();
3536         $key = $prefix . ':' . implode( ':', $args );
3537         $key = str_replace( ' ', '_', $key );
3538         return $key;
3539 }
3540
3541 /**
3542  * Get a cache key for a foreign DB
3543  *
3544  * @param string $db
3545  * @param string $prefix
3546  * @param string $args,...
3547  * @return string
3548  */
3549 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3550         $args = array_slice( func_get_args(), 2 );
3551         if ( $prefix ) {
3552                 $key = "$db-$prefix:" . implode( ':', $args );
3553         } else {
3554                 $key = $db . ':' . implode( ':', $args );
3555         }
3556         return str_replace( ' ', '_', $key );
3557 }
3558
3559 /**
3560  * Get an ASCII string identifying this wiki
3561  * This is used as a prefix in memcached keys
3562  *
3563  * @return string
3564  */
3565 function wfWikiID() {
3566         global $wgDBprefix, $wgDBname;
3567         if ( $wgDBprefix ) {
3568                 return "$wgDBname-$wgDBprefix";
3569         } else {
3570                 return $wgDBname;
3571         }
3572 }
3573
3574 /**
3575  * Split a wiki ID into DB name and table prefix
3576  *
3577  * @param string $wiki
3578  *
3579  * @return array
3580  */
3581 function wfSplitWikiID( $wiki ) {
3582         $bits = explode( '-', $wiki, 2 );
3583         if ( count( $bits ) < 2 ) {
3584                 $bits[] = '';
3585         }
3586         return $bits;
3587 }
3588
3589 /**
3590  * Get a Database object.
3591  *
3592  * @param int $db Index of the connection to get. May be DB_MASTER for the
3593  *            master (for write queries), DB_SLAVE for potentially lagged read
3594  *            queries, or an integer >= 0 for a particular server.
3595  *
3596  * @param string|string[] $groups Query groups. An array of group names that this query
3597  *                belongs to. May contain a single string if the query is only
3598  *                in one group.
3599  *
3600  * @param string|bool $wiki The wiki ID, or false for the current wiki
3601  *
3602  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3603  * will always return the same object, unless the underlying connection or load
3604  * balancer is manually destroyed.
3605  *
3606  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3607  * updater to ensure that a proper database is being updated.
3608  *
3609  * @return DatabaseBase
3610  */
3611 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3612         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3613 }
3614
3615 /**
3616  * Get a load balancer object.
3617  *
3618  * @param string|bool $wiki Wiki ID, or false for the current wiki
3619  * @return LoadBalancer
3620  */
3621 function wfGetLB( $wiki = false ) {
3622         return wfGetLBFactory()->getMainLB( $wiki );
3623 }
3624
3625 /**
3626  * Get the load balancer factory object
3627  *
3628  * @return LBFactory
3629  */
3630 function &wfGetLBFactory() {
3631         return LBFactory::singleton();
3632 }
3633
3634 /**
3635  * Find a file.
3636  * Shortcut for RepoGroup::singleton()->findFile()
3637  *
3638  * @param string $title String or Title object
3639  * @param array $options Associative array of options:
3640  *     time:           requested time for an archived image, or false for the
3641  *                     current version. An image object will be returned which was
3642  *                     created at the specified time.
3643  *
3644  *     ignoreRedirect: If true, do not follow file redirects
3645  *
3646  *     private:        If true, return restricted (deleted) files if the current
3647  *                     user is allowed to view them. Otherwise, such files will not
3648  *                     be found.
3649  *
3650  *     bypassCache:    If true, do not use the process-local cache of File objects
3651  *
3652  * @return File|bool File, or false if the file does not exist
3653  */
3654 function wfFindFile( $title, $options = array() ) {
3655         return RepoGroup::singleton()->findFile( $title, $options );
3656 }
3657
3658 /**
3659  * Get an object referring to a locally registered file.
3660  * Returns a valid placeholder object if the file does not exist.
3661  *
3662  * @param Title|string $title
3663  * @return LocalFile|null A File, or null if passed an invalid Title
3664  */
3665 function wfLocalFile( $title ) {
3666         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3667 }
3668
3669 /**
3670  * Should low-performance queries be disabled?
3671  *
3672  * @return bool
3673  * @codeCoverageIgnore
3674  */
3675 function wfQueriesMustScale() {
3676         global $wgMiserMode;
3677         return $wgMiserMode
3678                 || ( SiteStats::pages() > 100000
3679                 && SiteStats::edits() > 1000000
3680                 && SiteStats::users() > 10000 );
3681 }
3682
3683 /**
3684  * Get the path to a specified script file, respecting file
3685  * extensions; this is a wrapper around $wgScriptExtension etc.
3686  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3687  *
3688  * @param string $script Script filename, sans extension
3689  * @return string
3690  */
3691 function wfScript( $script = 'index' ) {
3692         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3693         if ( $script === 'index' ) {
3694                 return $wgScript;
3695         } elseif ( $script === 'load' ) {
3696                 return $wgLoadScript;
3697         } else {
3698                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3699         }
3700 }
3701
3702 /**
3703  * Get the script URL.
3704  *
3705  * @return string Script URL
3706  */
3707 function wfGetScriptUrl() {
3708         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3709                 #
3710                 # as it was called, minus the query string.
3711                 #
3712                 # Some sites use Apache rewrite rules to handle subdomains,
3713                 # and have PHP set up in a weird way that causes PHP_SELF
3714                 # to contain the rewritten URL instead of the one that the
3715                 # outside world sees.
3716                 #
3717                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3718                 # provides containing the "before" URL.
3719                 return $_SERVER['SCRIPT_NAME'];
3720         } else {
3721                 return $_SERVER['URL'];
3722         }
3723 }
3724
3725 /**
3726  * Convenience function converts boolean values into "true"
3727  * or "false" (string) values
3728  *
3729  * @param bool $value
3730  * @return string
3731  */
3732 function wfBoolToStr( $value ) {
3733         return $value ? 'true' : 'false';
3734 }
3735
3736 /**
3737  * Get a platform-independent path to the null file, e.g. /dev/null
3738  *
3739  * @return string
3740  */
3741 function wfGetNull() {
3742         return wfIsWindows() ? 'NUL' : '/dev/null';
3743 }
3744
3745 /**
3746  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3747  * and waiting for it to go down, this waits for the slaves to catch up to the
3748  * master position. Use this when updating very large numbers of rows, as
3749  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3750  * a no-op if there are no slaves.
3751  *
3752  * @param float|null $ifWritesSince Only wait if writes were done since this UNIX timestamp
3753  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3754  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3755  * @return bool Success (able to connect and no timeouts reached)
3756  */
3757 function wfWaitForSlaves( $ifWritesSince = false, $wiki = false, $cluster = false ) {
3758         // B/C: first argument used to be "max seconds of lag"; ignore such values
3759         $ifWritesSince = ( $ifWritesSince > 1e9 ) ? $ifWritesSince : false;
3760
3761         if ( $cluster !== false ) {
3762                 $lb = wfGetLBFactory()->getExternalLB( $cluster );
3763         } else {
3764                 $lb = wfGetLB( $wiki );
3765         }
3766
3767         // bug 27975 - Don't try to wait for slaves if there are none
3768         // Prevents permission error when getting master position
3769         if ( $lb->getServerCount() > 1 ) {
3770                 if ( $ifWritesSince && !$lb->hasMasterConnection() ) {
3771                         return true; // assume no writes done
3772                 }
3773                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3774                 if ( $ifWritesSince && $dbw->lastDoneWrites() < $ifWritesSince ) {
3775                         return true; // no writes since the last wait
3776                 }
3777                 $pos = $dbw->getMasterPos();
3778                 // The DBMS may not support getMasterPos() or the whole
3779                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3780                 if ( $pos !== false ) {
3781                         return $lb->waitForAll( $pos, PHP_SAPI === 'cli' ? 86400 : null );
3782                 }
3783         }
3784
3785         return true;
3786 }
3787
3788 /**
3789  * Count down from $seconds to zero on the terminal, with a one-second pause
3790  * between showing each number. For use in command-line scripts.
3791  *
3792  * @codeCoverageIgnore
3793  * @param int $seconds
3794  */
3795 function wfCountDown( $seconds ) {
3796         for ( $i = $seconds; $i >= 0; $i-- ) {
3797                 if ( $i != $seconds ) {
3798                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3799                 }
3800                 echo $i;
3801                 flush();
3802                 if ( $i ) {
3803                         sleep( 1 );
3804                 }
3805         }
3806         echo "\n";
3807 }
3808
3809 /**
3810  * Replace all invalid characters with -
3811  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3812  * By default, $wgIllegalFileChars = ':'
3813  *
3814  * @param string $name Filename to process
3815  * @return string
3816  */
3817 function wfStripIllegalFilenameChars( $name ) {
3818         global $wgIllegalFileChars;
3819         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3820         $name = wfBaseName( $name );
3821         $name = preg_replace(
3822                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3823                 '-',
3824                 $name
3825         );
3826         return $name;
3827 }
3828
3829 /**
3830  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3831  *
3832  * @return int Value the memory limit was set to.
3833  */
3834 function wfMemoryLimit() {
3835         global $wgMemoryLimit;
3836         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3837         if ( $memlimit != -1 ) {
3838                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3839                 if ( $conflimit == -1 ) {
3840                         wfDebug( "Removing PHP's memory limit\n" );
3841                         wfSuppressWarnings();
3842                         ini_set( 'memory_limit', $conflimit );
3843                         wfRestoreWarnings();
3844                         return $conflimit;
3845                 } elseif ( $conflimit > $memlimit ) {
3846                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3847                         wfSuppressWarnings();
3848                         ini_set( 'memory_limit', $conflimit );
3849                         wfRestoreWarnings();
3850                         return $conflimit;
3851                 }
3852         }
3853         return $memlimit;
3854 }
3855
3856 /**
3857  * Converts shorthand byte notation to integer form
3858  *
3859  * @param string $string
3860  * @return int
3861  */
3862 function wfShorthandToInteger( $string = '' ) {
3863         $string = trim( $string );
3864         if ( $string === '' ) {
3865                 return -1;
3866         }
3867         $last = $string[strlen( $string ) - 1];
3868         $val = intval( $string );
3869         switch ( $last ) {
3870                 case 'g':
3871                 case 'G':
3872                         $val *= 1024;
3873                         // break intentionally missing
3874                 case 'm':
3875                 case 'M':
3876                         $val *= 1024;
3877                         // break intentionally missing
3878                 case 'k':
3879                 case 'K':
3880                         $val *= 1024;
3881         }
3882
3883         return $val;
3884 }
3885
3886 /**
3887  * Get the normalised IETF language tag
3888  * See unit test for examples.
3889  *
3890  * @param string $code The language code.
3891  * @return string The language code which complying with BCP 47 standards.
3892  */
3893 function wfBCP47( $code ) {
3894         $codeSegment = explode( '-', $code );
3895         $codeBCP = array();
3896         foreach ( $codeSegment as $segNo => $seg ) {
3897                 // when previous segment is x, it is a private segment and should be lc
3898                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3899                         $codeBCP[$segNo] = strtolower( $seg );
3900                 // ISO 3166 country code
3901                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3902                         $codeBCP[$segNo] = strtoupper( $seg );
3903                 // ISO 15924 script code
3904                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3905                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3906                 // Use lowercase for other cases
3907                 } else {
3908                         $codeBCP[$segNo] = strtolower( $seg );
3909                 }
3910         }
3911         $langCode = implode( '-', $codeBCP );
3912         return $langCode;
3913 }
3914
3915 /**
3916  * Get a cache object.
3917  *
3918  * @param int $inputType Cache type, one the the CACHE_* constants.
3919  * @return BagOStuff
3920  */
3921 function wfGetCache( $inputType ) {
3922         return ObjectCache::getInstance( $inputType );
3923 }
3924
3925 /**
3926  * Get the main cache object
3927  *
3928  * @return BagOStuff
3929  */
3930 function wfGetMainCache() {
3931         global $wgMainCacheType;
3932         return ObjectCache::getInstance( $wgMainCacheType );
3933 }
3934
3935 /**
3936  * Get the cache object used by the message cache
3937  *
3938  * @return BagOStuff
3939  */
3940 function wfGetMessageCacheStorage() {
3941         global $wgMessageCacheType;
3942         return ObjectCache::getInstance( $wgMessageCacheType );
3943 }
3944
3945 /**
3946  * Get the cache object used by the parser cache
3947  *
3948  * @return BagOStuff
3949  */
3950 function wfGetParserCacheStorage() {
3951         global $wgParserCacheType;
3952         return ObjectCache::getInstance( $wgParserCacheType );
3953 }
3954
3955 /**
3956  * Get the cache object used by the language converter
3957  *
3958  * @return BagOStuff
3959  */
3960 function wfGetLangConverterCacheStorage() {
3961         global $wgLanguageConverterCacheType;
3962         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3963 }
3964
3965 /**
3966  * Call hook functions defined in $wgHooks
3967  *
3968  * @param string $event Event name
3969  * @param array $args Parameters passed to hook functions
3970  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3971  *
3972  * @return bool True if no handler aborted the hook
3973  */
3974 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3975         return Hooks::run( $event, $args, $deprecatedVersion );
3976 }
3977
3978 /**
3979  * Wrapper around php's unpack.
3980  *
3981  * @param string $format The format string (See php's docs)
3982  * @param string $data A binary string of binary data
3983  * @param int|bool $length The minimum length of $data or false. This is to
3984  *      prevent reading beyond the end of $data. false to disable the check.
3985  *
3986  * Also be careful when using this function to read unsigned 32 bit integer
3987  * because php might make it negative.
3988  *
3989  * @throws MWException If $data not long enough, or if unpack fails
3990  * @return array Associative array of the extracted data
3991  */
3992 function wfUnpack( $format, $data, $length = false ) {
3993         if ( $length !== false ) {
3994                 $realLen = strlen( $data );
3995                 if ( $realLen < $length ) {
3996                         throw new MWException( "Tried to use wfUnpack on a "
3997                                 . "string of length $realLen, but needed one "
3998                                 . "of at least length $length."
3999                         );
4000                 }
4001         }
4002
4003         wfSuppressWarnings();
4004         $result = unpack( $format, $data );
4005         wfRestoreWarnings();
4006
4007         if ( $result === false ) {
4008                 // If it cannot extract the packed data.
4009                 throw new MWException( "unpack could not unpack binary data" );
4010         }
4011         return $result;
4012 }
4013
4014 /**
4015  * Determine if an image exists on the 'bad image list'.
4016  *
4017  * The format of MediaWiki:Bad_image_list is as follows:
4018  *    * Only list items (lines starting with "*") are considered
4019  *    * The first link on a line must be a link to a bad image
4020  *    * Any subsequent links on the same line are considered to be exceptions,
4021  *      i.e. articles where the image may occur inline.
4022  *
4023  * @param string $name The image name to check
4024  * @param Title|bool $contextTitle The page on which the image occurs, if known
4025  * @param string $blacklist Wikitext of a file blacklist
4026  * @return bool
4027  */
4028 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4029         static $badImageCache = null; // based on bad_image_list msg
4030         wfProfileIn( __METHOD__ );
4031
4032         # Handle redirects
4033         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4034         if ( $redirectTitle ) {
4035                 $name = $redirectTitle->getDBkey();
4036         }
4037
4038         # Run the extension hook
4039         $bad = false;
4040         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
4041                 wfProfileOut( __METHOD__ );
4042                 return $bad;
4043         }
4044
4045         $cacheable = ( $blacklist === null );
4046         if ( $cacheable && $badImageCache !== null ) {
4047                 $badImages = $badImageCache;
4048         } else { // cache miss
4049                 if ( $blacklist === null ) {
4050                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4051                 }
4052                 # Build the list now
4053                 $badImages = array();
4054                 $lines = explode( "\n", $blacklist );
4055                 foreach ( $lines as $line ) {
4056                         # List items only
4057                         if ( substr( $line, 0, 1 ) !== '*' ) {
4058                                 continue;
4059                         }
4060
4061                         # Find all links
4062                         $m = array();
4063                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4064                                 continue;
4065                         }
4066
4067                         $exceptions = array();
4068                         $imageDBkey = false;
4069                         foreach ( $m[1] as $i => $titleText ) {
4070                                 $title = Title::newFromText( $titleText );
4071                                 if ( !is_null( $title ) ) {
4072                                         if ( $i == 0 ) {
4073                                                 $imageDBkey = $title->getDBkey();
4074                                         } else {
4075                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4076                                         }
4077                                 }
4078                         }
4079
4080                         if ( $imageDBkey !== false ) {
4081                                 $badImages[$imageDBkey] = $exceptions;
4082                         }
4083                 }
4084                 if ( $cacheable ) {
4085                         $badImageCache = $badImages;
4086                 }
4087         }
4088
4089         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4090         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4091         wfProfileOut( __METHOD__ );
4092         return $bad;
4093 }
4094
4095 /**
4096  * Determine whether the client at a given source IP is likely to be able to
4097  * access the wiki via HTTPS.
4098  *
4099  * @param string $ip The IPv4/6 address in the normal human-readable form
4100  * @return bool
4101  */
4102 function wfCanIPUseHTTPS( $ip ) {
4103         $canDo = true;
4104         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4105         return !!$canDo;
4106 }
4107
4108 /**
4109  * Work out the IP address based on various globals
4110  * For trusted proxies, use the XFF client IP (first of the chain)
4111  *
4112  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4113  * @return string
4114  */
4115 function wfGetIP() {
4116         wfDeprecated( __METHOD__, '1.19' );
4117         global $wgRequest;
4118         return $wgRequest->getIP();
4119 }
4120
4121 /**
4122  * Checks if an IP is a trusted proxy provider.
4123  * Useful to tell if X-Forwarded-For data is possibly bogus.
4124  * Squid cache servers for the site are whitelisted.
4125  * @deprecated Since 1.24, use IP::isTrustedProxy()
4126  *
4127  * @param string $ip
4128  * @return bool
4129  */
4130 function wfIsTrustedProxy( $ip ) {
4131         return IP::isTrustedProxy( $ip );
4132 }
4133
4134 /**
4135  * Checks if an IP matches a proxy we've configured.
4136  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4137  *
4138  * @param string $ip
4139  * @return bool
4140  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4141  */
4142 function wfIsConfiguredProxy( $ip ) {
4143         return IP::isConfiguredProxy( $ip );
4144 }