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( 'iconv' ) ) {
  39         /**
  40          * @codeCoverageIgnore
  41          * @return string
  42          */
  43         function iconv( $from, $to, $string ) {
  44                 return Fallback::iconv( $from, $to, $string );
  45         }
  46 }
  47
  48 if ( !function_exists( 'mb_substr' ) ) {
  49         /**
  50          * @codeCoverageIgnore
  51          * @return string
  52          */
  53         function mb_substr( $str, $start, $count = 'end' ) {
  54                 return Fallback::mb_substr( $str, $start, $count );
  55         }
  56
  57         /**
  58          * @codeCoverageIgnore
  59          * @return int
  60          */
  61         function mb_substr_split_unicode( $str, $splitPos ) {
  62                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  63         }
  64 }
  65
  66 if ( !function_exists( 'mb_strlen' ) ) {
  67         /**
  68          * @codeCoverageIgnore
  69          * @return int
  70          */
  71         function mb_strlen( $str, $enc = '' ) {
  72                 return Fallback::mb_strlen( $str, $enc );
  73         }
  74 }
  75
  76 if ( !function_exists( 'mb_strpos' ) ) {
  77         /**
  78          * @codeCoverageIgnore
  79          * @return int
  80          */
  81         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  82                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  83         }
  84 }
  85
  86 if ( !function_exists( 'mb_strrpos' ) ) {
  87         /**
  88          * @codeCoverageIgnore
  89          * @return int
  90          */
  91         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  92                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  93         }
  94 }
  95
  96 // gzdecode function only exists in PHP >= 5.4.0
  97 // http://php.net/gzdecode
  98 if ( !function_exists( 'gzdecode' ) ) {
  99         /**
 100          * @codeCoverageIgnore
 101          * @return string
 102          */
 103         function gzdecode( $data ) {
 104                 return gzinflate( substr( $data, 10, -8 ) );
 105         }
 106 }
 107 /// @endcond
 108
 109 /**
 110  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
 111  * @param array $a
 112  * @param array $b
 113  * @return array
 114  */
 115 function wfArrayDiff2( $a, $b ) {
 116         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 117 }
 118
 119 /**
 120  * @param array|string $a
 121  * @param array|string $b
 122  * @return int
 123  */
 124 function wfArrayDiff2_cmp( $a, $b ) {
 125         if ( is_string( $a ) && is_string( $b ) ) {
 126                 return strcmp( $a, $b );
 127         } elseif ( count( $a ) !== count( $b ) ) {
 128                 return count( $a ) < count( $b ) ? -1 : 1;
 129         } else {
 130                 reset( $a );
 131                 reset( $b );
 132                 while ( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 133                         $cmp = strcmp( $valueA, $valueB );
 134                         if ( $cmp !== 0 ) {
 135                                 return $cmp;
 136                         }
 137                 }
 138                 return 0;
 139         }
 140 }
 141
 142 /**
 143  * Array lookup
 144  * Returns an array where the values in array $b are replaced by the
 145  * values in array $a with the corresponding keys
 146  *
 147  * @deprecated since 1.22; use array_intersect_key()
 148  * @param array $a
 149  * @param array $b
 150  * @return array
 151  */
 152 function wfArrayLookup( $a, $b ) {
 153         wfDeprecated( __FUNCTION__, '1.22' );
 154         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 155 }
 156
 157 /**
 158  * Appends to second array if $value differs from that in $default
 159  *
 160  * @param string|int $key
 161  * @param mixed $value
 162  * @param mixed $default
 163  * @param array $changed Array to alter
 164  * @throws MWException
 165  */
 166 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 167         if ( is_null( $changed ) ) {
 168                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 169         }
 170         if ( $default[$key] !== $value ) {
 171                 $changed[$key] = $value;
 172         }
 173 }
 174
 175 /**
 176  * Backwards array plus for people who haven't bothered to read the PHP manual
 177  * XXX: will not darn your socks for you.
 178  *
 179  * @deprecated since 1.22; use array_replace()
 180  *
 181  * @param array $array1 Initial array to merge.
 182  * @param array [$array2,...] Variable list of arrays to merge.
 183  * @return array
 184  */
 185 function wfArrayMerge( $array1 /*...*/ ) {
 186         wfDeprecated( __FUNCTION__, '1.22' );
 187         $args = func_get_args();
 188         $args = array_reverse( $args, true );
 189         $out = array();
 190         foreach ( $args as $arg ) {
 191                 $out += $arg;
 192         }
 193         return $out;
 194 }
 195
 196 /**
 197  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 198  * e.g.
 199  *      wfMergeErrorArrays(
 200  *              array( array( 'x' ) ),
 201  *              array( array( 'x', '2' ) ),
 202  *              array( array( 'x' ) ),
 203  *              array( array( 'y' ) )
 204  *      );
 205  * returns:
 206  *              array(
 207  *              array( 'x', '2' ),
 208  *              array( 'x' ),
 209  *              array( 'y' )
 210  *      )
 211  *
 212  * @param array [$array1,...]
 213  * @return array
 214  */
 215 function wfMergeErrorArrays( /*...*/ ) {
 216         $args = func_get_args();
 217         $out = array();
 218         foreach ( $args as $errors ) {
 219                 foreach ( $errors as $params ) {
 220                         # @todo FIXME: Sometimes get nested arrays for $params,
 221                         # which leads to E_NOTICEs
 222                         $spec = implode( "\t", $params );
 223                         $out[$spec] = $params;
 224                 }
 225         }
 226         return array_values( $out );
 227 }
 228
 229 /**
 230  * Insert array into another array after the specified *KEY*
 231  *
 232  * @param array $array The array.
 233  * @param array $insert The array to insert.
 234  * @param mixed $after The key to insert after
 235  * @return array
 236  */
 237 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 238         // Find the offset of the element to insert after.
 239         $keys = array_keys( $array );
 240         $offsetByKey = array_flip( $keys );
 241
 242         $offset = $offsetByKey[$after];
 243
 244         // Insert at the specified offset
 245         $before = array_slice( $array, 0, $offset + 1, true );
 246         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 247
 248         $output = $before + $insert + $after;
 249
 250         return $output;
 251 }
 252
 253 /**
 254  * Recursively converts the parameter (an object) to an array with the same data
 255  *
 256  * @param object|array $objOrArray
 257  * @param bool $recursive
 258  * @return array
 259  */
 260 function wfObjectToArray( $objOrArray, $recursive = true ) {
 261         $array = array();
 262         if ( is_object( $objOrArray ) ) {
 263                 $objOrArray = get_object_vars( $objOrArray );
 264         }
 265         foreach ( $objOrArray as $key => $value ) {
 266                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 267                         $value = wfObjectToArray( $value );
 268                 }
 269
 270                 $array[$key] = $value;
 271         }
 272
 273         return $array;
 274 }
 275
 276 /**
 277  * Get a random decimal value between 0 and 1, in a way
 278  * not likely to give duplicate values for any realistic
 279  * number of articles.
 280  *
 281  * @return string
 282  */
 283 function wfRandom() {
 284         # The maximum random value is "only" 2^31-1, so get two random
 285         # values to reduce the chance of dupes
 286         $max = mt_getrandmax() + 1;
 287         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 288
 289         return $rand;
 290 }
 291
 292 /**
 293  * Get a random string containing a number of pseudo-random hex
 294  * characters.
 295  * @note This is not secure, if you are trying to generate some sort
 296  *       of token please use MWCryptRand instead.
 297  *
 298  * @param int $length The length of the string to generate
 299  * @return string
 300  * @since 1.20
 301  */
 302 function wfRandomString( $length = 32 ) {
 303         $str = '';
 304         for ( $n = 0; $n < $length; $n += 7 ) {
 305                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 306         }
 307         return substr( $str, 0, $length );
 308 }
 309
 310 /**
 311  * We want some things to be included as literal characters in our title URLs
 312  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 313  * all of the following should be safe:
 314  *
 315  * ;:@&=$-_.+!*'(),
 316  *
 317  * But + is not safe because it's used to indicate a space; &= are only safe in
 318  * paths and not in queries (and we don't distinguish here); ' seems kind of
 319  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 320  * is reserved, we don't care.  So the list we unescape is:
 321  *
 322  * ;:@$!*(),/
 323  *
 324  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 325  * so no fancy : for IIS7.
 326  *
 327  * %2F in the page titles seems to fatally break for some reason.
 328  *
 329  * @param string $s
 330  * @return string
 331  */
 332 function wfUrlencode( $s ) {
 333         static $needle;
 334
 335         if ( is_null( $s ) ) {
 336                 $needle = null;
 337                 return '';
 338         }
 339
 340         if ( is_null( $needle ) ) {
 341                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 342                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 343                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 344                 ) {
 345                         $needle[] = '%3A';
 346                 }
 347         }
 348
 349         $s = urlencode( $s );
 350         $s = str_ireplace(
 351                 $needle,
 352                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 353                 $s
 354         );
 355
 356         return $s;
 357 }
 358
 359 /**
 360  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 361  * "days=7&limit=100". Options in the first array override options in the second.
 362  * Options set to null or false will not be output.
 363  *
 364  * @param array $array1 ( String|Array )
 365  * @param array $array2 ( String|Array )
 366  * @param string $prefix
 367  * @return string
 368  */
 369 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 370         if ( !is_null( $array2 ) ) {
 371                 $array1 = $array1 + $array2;
 372         }
 373
 374         $cgi = '';
 375         foreach ( $array1 as $key => $value ) {
 376                 if ( !is_null( $value ) && $value !== false ) {
 377                         if ( $cgi != '' ) {
 378                                 $cgi .= '&';
 379                         }
 380                         if ( $prefix !== '' ) {
 381                                 $key = $prefix . "[$key]";
 382                         }
 383                         if ( is_array( $value ) ) {
 384                                 $firstTime = true;
 385                                 foreach ( $value as $k => $v ) {
 386                                         $cgi .= $firstTime ? '' : '&';
 387                                         if ( is_array( $v ) ) {
 388                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 389                                         } else {
 390                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 391                                         }
 392                                         $firstTime = false;
 393                                 }
 394                         } else {
 395                                 if ( is_object( $value ) ) {
 396                                         $value = $value->__toString();
 397                                 }
 398                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 399                         }
 400                 }
 401         }
 402         return $cgi;
 403 }
 404
 405 /**
 406  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 407  * its argument and returns the same string in array form.  This allows compatibility
 408  * with legacy functions that accept raw query strings instead of nice
 409  * arrays.  Of course, keys and values are urldecode()d.
 410  *
 411  * @param string $query Query string
 412  * @return string[] Array version of input
 413  */
 414 function wfCgiToArray( $query ) {
 415         if ( isset( $query[0] ) && $query[0] == '?' ) {
 416                 $query = substr( $query, 1 );
 417         }
 418         $bits = explode( '&', $query );
 419         $ret = array();
 420         foreach ( $bits as $bit ) {
 421                 if ( $bit === '' ) {
 422                         continue;
 423                 }
 424                 if ( strpos( $bit, '=' ) === false ) {
 425                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 426                         $key = $bit;
 427                         $value = '';
 428                 } else {
 429                         list( $key, $value ) = explode( '=', $bit );
 430                 }
 431                 $key = urldecode( $key );
 432                 $value = urldecode( $value );
 433                 if ( strpos( $key, '[' ) !== false ) {
 434                         $keys = array_reverse( explode( '[', $key ) );
 435                         $key = array_pop( $keys );
 436                         $temp = $value;
 437                         foreach ( $keys as $k ) {
 438                                 $k = substr( $k, 0, -1 );
 439                                 $temp = array( $k => $temp );
 440                         }
 441                         if ( isset( $ret[$key] ) ) {
 442                                 $ret[$key] = array_merge( $ret[$key], $temp );
 443                         } else {
 444                                 $ret[$key] = $temp;
 445                         }
 446                 } else {
 447                         $ret[$key] = $value;
 448                 }
 449         }
 450         return $ret;
 451 }
 452
 453 /**
 454  * Append a query string to an existing URL, which may or may not already
 455  * have query string parameters already. If so, they will be combined.
 456  *
 457  * @param string $url
 458  * @param string|string[] $query String or associative array
 459  * @return string
 460  */
 461 function wfAppendQuery( $url, $query ) {
 462         if ( is_array( $query ) ) {
 463                 $query = wfArrayToCgi( $query );
 464         }
 465         if ( $query != '' ) {
 466                 if ( false === strpos( $url, '?' ) ) {
 467                         $url .= '?';
 468                 } else {
 469                         $url .= '&';
 470                 }
 471                 $url .= $query;
 472         }
 473         return $url;
 474 }
 475
 476 /**
 477  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 478  * is correct.
 479  *
 480  * The meaning of the PROTO_* constants is as follows:
 481  * PROTO_HTTP: Output a URL starting with http://
 482  * PROTO_HTTPS: Output a URL starting with https://
 483  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 484  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 485  *    on which protocol was used for the current incoming request
 486  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 487  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 488  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 489  *
 490  * @todo this won't work with current-path-relative URLs
 491  * like "subdir/foo.html", etc.
 492  *
 493  * @param string $url Either fully-qualified or a local path + query
 494  * @param string $defaultProto One of the PROTO_* constants. Determines the
 495  *    protocol to use if $url or $wgServer is protocol-relative
 496  * @return string Fully-qualified URL, current-path-relative URL or false if
 497  *    no valid URL can be constructed
 498  */
 499 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 500         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest,
 501                 $wgHttpsPort;
 502         if ( $defaultProto === PROTO_CANONICAL ) {
 503                 $serverUrl = $wgCanonicalServer;
 504         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 505                 // Make $wgInternalServer fall back to $wgServer if not set
 506                 $serverUrl = $wgInternalServer;
 507         } else {
 508                 $serverUrl = $wgServer;
 509                 if ( $defaultProto === PROTO_CURRENT ) {
 510                         $defaultProto = $wgRequest->getProtocol() . '://';
 511                 }
 512         }
 513
 514         // Analyze $serverUrl to obtain its protocol
 515         $bits = wfParseUrl( $serverUrl );
 516         $serverHasProto = $bits && $bits['scheme'] != '';
 517
 518         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 519                 if ( $serverHasProto ) {
 520                         $defaultProto = $bits['scheme'] . '://';
 521                 } else {
 522                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 523                         // This really isn't supposed to happen. Fall back to HTTP in this
 524                         // ridiculous case.
 525                         $defaultProto = PROTO_HTTP;
 526                 }
 527         }
 528
 529         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 530
 531         if ( substr( $url, 0, 2 ) == '//' ) {
 532                 $url = $defaultProtoWithoutSlashes . $url;
 533         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 534                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 535                 // otherwise leave it alone.
 536                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 537         }
 538
 539         $bits = wfParseUrl( $url );
 540
 541         // ensure proper port for HTTPS arrives in URL
 542         // https://bugzilla.wikimedia.org/show_bug.cgi?id=65184
 543         if ( $defaultProto === PROTO_HTTPS && $wgHttpsPort != 443 ) {
 544                 $bits['port'] = $wgHttpsPort;
 545         }
 546
 547         if ( $bits && isset( $bits['path'] ) ) {
 548                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 549                 return wfAssembleUrl( $bits );
 550         } elseif ( $bits ) {
 551                 # No path to expand
 552                 return $url;
 553         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 554                 # URL is a relative path
 555                 return wfRemoveDotSegments( $url );
 556         }
 557
 558         # Expanded URL is not valid.
 559         return false;
 560 }
 561
 562 /**
 563  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 564  * if you need to edit part of a URL and put it back together.
 565  *
 566  * This is the basic structure used (brackets contain keys for $urlParts):
 567  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 568  *
 569  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 570  *
 571  * @since 1.19
 572  * @param array $urlParts URL parts, as output from wfParseUrl
 573  * @return string URL assembled from its component parts
 574  */
 575 function wfAssembleUrl( $urlParts ) {
 576         $result = '';
 577
 578         if ( isset( $urlParts['delimiter'] ) ) {
 579                 if ( isset( $urlParts['scheme'] ) ) {
 580                         $result .= $urlParts['scheme'];
 581                 }
 582
 583                 $result .= $urlParts['delimiter'];
 584         }
 585
 586         if ( isset( $urlParts['host'] ) ) {
 587                 if ( isset( $urlParts['user'] ) ) {
 588                         $result .= $urlParts['user'];
 589                         if ( isset( $urlParts['pass'] ) ) {
 590                                 $result .= ':' . $urlParts['pass'];
 591                         }
 592                         $result .= '@';
 593                 }
 594
 595                 $result .= $urlParts['host'];
 596
 597                 if ( isset( $urlParts['port'] ) ) {
 598                         $result .= ':' . $urlParts['port'];
 599                 }
 600         }
 601
 602         if ( isset( $urlParts['path'] ) ) {
 603                 $result .= $urlParts['path'];
 604         }
 605
 606         if ( isset( $urlParts['query'] ) ) {
 607                 $result .= '?' . $urlParts['query'];
 608         }
 609
 610         if ( isset( $urlParts['fragment'] ) ) {
 611                 $result .= '#' . $urlParts['fragment'];
 612         }
 613
 614         return $result;
 615 }
 616
 617 /**
 618  * Remove all dot-segments in the provided URL path.  For example,
 619  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 620  * RFC3986 section 5.2.4.
 621  *
 622  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 623  *
 624  * @param string $urlPath URL path, potentially containing dot-segments
 625  * @return string URL path with all dot-segments removed
 626  */
 627 function wfRemoveDotSegments( $urlPath ) {
 628         $output = '';
 629         $inputOffset = 0;
 630         $inputLength = strlen( $urlPath );
 631
 632         while ( $inputOffset < $inputLength ) {
 633                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 634                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 635                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 636                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 637                 $trimOutput = false;
 638
 639                 if ( $prefixLengthTwo == './' ) {
 640                         # Step A, remove leading "./"
 641                         $inputOffset += 2;
 642                 } elseif ( $prefixLengthThree == '../' ) {
 643                         # Step A, remove leading "../"
 644                         $inputOffset += 3;
 645                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 646                         # Step B, replace leading "/.$" with "/"
 647                         $inputOffset += 1;
 648                         $urlPath[$inputOffset] = '/';
 649                 } elseif ( $prefixLengthThree == '/./' ) {
 650                         # Step B, replace leading "/./" with "/"
 651                         $inputOffset += 2;
 652                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 653                         # Step C, replace leading "/..$" with "/" and
 654                         # remove last path component in output
 655                         $inputOffset += 2;
 656                         $urlPath[$inputOffset] = '/';
 657                         $trimOutput = true;
 658                 } elseif ( $prefixLengthFour == '/../' ) {
 659                         # Step C, replace leading "/../" with "/" and
 660                         # remove last path component in output
 661                         $inputOffset += 3;
 662                         $trimOutput = true;
 663                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 664                         # Step D, remove "^.$"
 665                         $inputOffset += 1;
 666                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 667                         # Step D, remove "^..$"
 668                         $inputOffset += 2;
 669                 } else {
 670                         # Step E, move leading path segment to output
 671                         if ( $prefixLengthOne == '/' ) {
 672                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 673                         } else {
 674                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 675                         }
 676                         if ( $slashPos === false ) {
 677                                 $output .= substr( $urlPath, $inputOffset );
 678                                 $inputOffset = $inputLength;
 679                         } else {
 680                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 681                                 $inputOffset += $slashPos - $inputOffset;
 682                         }
 683                 }
 684
 685                 if ( $trimOutput ) {
 686                         $slashPos = strrpos( $output, '/' );
 687                         if ( $slashPos === false ) {
 688                                 $output = '';
 689                         } else {
 690                                 $output = substr( $output, 0, $slashPos );
 691                         }
 692                 }
 693         }
 694
 695         return $output;
 696 }
 697
 698 /**
 699  * Returns a regular expression of url protocols
 700  *
 701  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 702  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 703  * @return string
 704  */
 705 function wfUrlProtocols( $includeProtocolRelative = true ) {
 706         global $wgUrlProtocols;
 707
 708         // Cache return values separately based on $includeProtocolRelative
 709         static $withProtRel = null, $withoutProtRel = null;
 710         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 711         if ( !is_null( $cachedValue ) ) {
 712                 return $cachedValue;
 713         }
 714
 715         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 716         // with LocalSettings files from 1.5
 717         if ( is_array( $wgUrlProtocols ) ) {
 718                 $protocols = array();
 719                 foreach ( $wgUrlProtocols as $protocol ) {
 720                         // Filter out '//' if !$includeProtocolRelative
 721                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 722                                 $protocols[] = preg_quote( $protocol, '/' );
 723                         }
 724                 }
 725
 726                 $retval = implode( '|', $protocols );
 727         } else {
 728                 // Ignore $includeProtocolRelative in this case
 729                 // This case exists for pre-1.6 compatibility, and we can safely assume
 730                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 731                 // URLs weren't supported until 1.18
 732                 $retval = $wgUrlProtocols;
 733         }
 734
 735         // Cache return value
 736         if ( $includeProtocolRelative ) {
 737                 $withProtRel = $retval;
 738         } else {
 739                 $withoutProtRel = $retval;
 740         }
 741         return $retval;
 742 }
 743
 744 /**
 745  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 746  * you need a regex that matches all URL protocols but does not match protocol-
 747  * relative URLs
 748  * @return string
 749  */
 750 function wfUrlProtocolsWithoutProtRel() {
 751         return wfUrlProtocols( false );
 752 }
 753
 754 /**
 755  * parse_url() work-alike, but non-broken.  Differences:
 756  *
 757  * 1) Does not raise warnings on bad URLs (just returns false).
 758  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 759  *    protocol-relative URLs) correctly.
 760  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 761  *
 762  * @param string $url A URL to parse
 763  * @return string[] Bits of the URL in an associative array, per PHP docs
 764  */
 765 function wfParseUrl( $url ) {
 766         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 767
 768         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 769         // bad that the easiest way to handle them is to just prepend 'http:' and
 770         // strip the protocol out later.
 771         $wasRelative = substr( $url, 0, 2 ) == '//';
 772         if ( $wasRelative ) {
 773                 $url = "http:$url";
 774         }
 775         wfSuppressWarnings();
 776         $bits = parse_url( $url );
 777         wfRestoreWarnings();
 778         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 779         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 780         if ( !$bits || !isset( $bits['scheme'] ) ) {
 781                 return false;
 782         }
 783
 784         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 785         $bits['scheme'] = strtolower( $bits['scheme'] );
 786
 787         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 788         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 789                 $bits['delimiter'] = '://';
 790         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 791                 $bits['delimiter'] = ':';
 792                 // parse_url detects for news: and mailto: the host part of an url as path
 793                 // We have to correct this wrong detection
 794                 if ( isset( $bits['path'] ) ) {
 795                         $bits['host'] = $bits['path'];
 796                         $bits['path'] = '';
 797                 }
 798         } else {
 799                 return false;
 800         }
 801
 802         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 803         if ( !isset( $bits['host'] ) ) {
 804                 $bits['host'] = '';
 805
 806                 // bug 45069
 807                 if ( isset( $bits['path'] ) ) {
 808                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 809                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 810                                 $bits['path'] = '/' . $bits['path'];
 811                         }
 812                 } else {
 813                         $bits['path'] = '';
 814                 }
 815         }
 816
 817         // If the URL was protocol-relative, fix scheme and delimiter
 818         if ( $wasRelative ) {
 819                 $bits['scheme'] = '';
 820                 $bits['delimiter'] = '//';
 821         }
 822         return $bits;
 823 }
 824
 825 /**
 826  * Take a URL, make sure it's expanded to fully qualified, and replace any
 827  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 828  * for more compact display and legibility for local audiences.
 829  *
 830  * @todo handle punycode domains too
 831  *
 832  * @param string $url
 833  * @return string
 834  */
 835 function wfExpandIRI( $url ) {
 836         return preg_replace_callback(
 837                 '/((?:%[89A-F][0-9A-F])+)/i',
 838                 'wfExpandIRI_callback',
 839                 wfExpandUrl( $url )
 840         );
 841 }
 842
 843 /**
 844  * Private callback for wfExpandIRI
 845  * @param array $matches
 846  * @return string
 847  */
 848 function wfExpandIRI_callback( $matches ) {
 849         return urldecode( $matches[1] );
 850 }
 851
 852 /**
 853  * Make URL indexes, appropriate for the el_index field of externallinks.
 854  *
 855  * @param string $url
 856  * @return array
 857  */
 858 function wfMakeUrlIndexes( $url ) {
 859         $bits = wfParseUrl( $url );
 860
 861         // Reverse the labels in the hostname, convert to lower case
 862         // For emails reverse domainpart only
 863         if ( $bits['scheme'] == 'mailto' ) {
 864                 $mailparts = explode( '@', $bits['host'], 2 );
 865                 if ( count( $mailparts ) === 2 ) {
 866                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 867                 } else {
 868                         // No domain specified, don't mangle it
 869                         $domainpart = '';
 870                 }
 871                 $reversedHost = $domainpart . '@' . $mailparts[0];
 872         } else {
 873                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 874         }
 875         // Add an extra dot to the end
 876         // Why? Is it in wrong place in mailto links?
 877         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 878                 $reversedHost .= '.';
 879         }
 880         // Reconstruct the pseudo-URL
 881         $prot = $bits['scheme'];
 882         $index = $prot . $bits['delimiter'] . $reversedHost;
 883         // Leave out user and password. Add the port, path, query and fragment
 884         if ( isset( $bits['port'] ) ) {
 885                 $index .= ':' . $bits['port'];
 886         }
 887         if ( isset( $bits['path'] ) ) {
 888                 $index .= $bits['path'];
 889         } else {
 890                 $index .= '/';
 891         }
 892         if ( isset( $bits['query'] ) ) {
 893                 $index .= '?' . $bits['query'];
 894         }
 895         if ( isset( $bits['fragment'] ) ) {
 896                 $index .= '#' . $bits['fragment'];
 897         }
 898
 899         if ( $prot == '' ) {
 900                 return array( "http:$index", "https:$index" );
 901         } else {
 902                 return array( $index );
 903         }
 904 }
 905
 906 /**
 907  * Check whether a given URL has a domain that occurs in a given set of domains
 908  * @param string $url URL
 909  * @param array $domains Array of domains (strings)
 910  * @return bool True if the host part of $url ends in one of the strings in $domains
 911  */
 912 function wfMatchesDomainList( $url, $domains ) {
 913         $bits = wfParseUrl( $url );
 914         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 915                 $host = '.' . $bits['host'];
 916                 foreach ( (array)$domains as $domain ) {
 917                         $domain = '.' . $domain;
 918                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 919                                 return true;
 920                         }
 921                 }
 922         }
 923         return false;
 924 }
 925
 926 /**
 927  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 928  * In normal operation this is a NOP.
 929  *
 930  * Controlling globals:
 931  * $wgDebugLogFile - points to the log file
 932  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 933  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 934  *
 935  * @param string $text
 936  * @param string|bool $dest Destination of the message:
 937  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 938  *     - 'log': only to the log and not in HTML
 939  *   For backward compatibility, it can also take a boolean:
 940  *     - true: same as 'all'
 941  *     - false: same as 'log'
 942  */
 943 function wfDebug( $text, $dest = 'all' ) {
 944         global $wgDebugLogFile, $wgDebugRawPage, $wgDebugLogPrefix;
 945
 946         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 947                 return;
 948         }
 949
 950         // Turn $dest into a string if it's a boolean (for b/c)
 951         if ( $dest === true ) {
 952                 $dest = 'all';
 953         } elseif ( $dest === false ) {
 954                 $dest = 'log';
 955         }
 956
 957         $timer = wfDebugTimer();
 958         if ( $timer !== '' ) {
 959                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 960         }
 961
 962         if ( $dest === 'all' ) {
 963                 MWDebug::debugMsg( $text );
 964         }
 965
 966         if ( $wgDebugLogFile != '' ) {
 967                 # Strip unprintables; they can switch terminal modes when binary data
 968                 # gets dumped, which is pretty annoying.
 969                 $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 970                 $text = $wgDebugLogPrefix . $text;
 971                 wfErrorLog( $text, $wgDebugLogFile );
 972         }
 973 }
 974
 975 /**
 976  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 977  * @return bool
 978  */
 979 function wfIsDebugRawPage() {
 980         static $cache;
 981         if ( $cache !== null ) {
 982                 return $cache;
 983         }
 984         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 985         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 986                 || (
 987                         isset( $_SERVER['SCRIPT_NAME'] )
 988                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 989                 )
 990         ) {
 991                 $cache = true;
 992         } else {
 993                 $cache = false;
 994         }
 995         return $cache;
 996 }
 997
 998 /**
 999  * Get microsecond timestamps for debug logs
1000  *
1001  * @return string
1002  */
1003 function wfDebugTimer() {
1004         global $wgDebugTimestamps, $wgRequestTime;
1005
1006         if ( !$wgDebugTimestamps ) {
1007                 return '';
1008         }
1009
1010         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1011         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1012         return "$prefix $mem  ";
1013 }
1014
1015 /**
1016  * Send a line giving PHP memory usage.
1017  *
1018  * @param bool $exact Print exact byte values instead of kibibytes (default: false)
1019  */
1020 function wfDebugMem( $exact = false ) {
1021         $mem = memory_get_usage();
1022         if ( !$exact ) {
1023                 $mem = floor( $mem / 1024 ) . ' KiB';
1024         } else {
1025                 $mem .= ' B';
1026         }
1027         wfDebug( "Memory usage: $mem\n" );
1028 }
1029
1030 /**
1031  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1032  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to a string
1033  * filename or an associative array mapping 'destination' to the desired filename. The
1034  * associative array may also contain a 'sample' key with an integer value, specifying
1035  * a sampling factor.
1036  *
1037  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1038  *
1039  * @param string $logGroup
1040  * @param string $text
1041  * @param string|bool $dest Destination of the message:
1042  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1043  *     - 'log': only to the log and not in HTML
1044  *     - 'private': only to the specifc log if set in $wgDebugLogGroups and
1045  *       discarded otherwise
1046  *   For backward compatibility, it can also take a boolean:
1047  *     - true: same as 'all'
1048  *     - false: same as 'private'
1049  */
1050 function wfDebugLog( $logGroup, $text, $dest = 'all' ) {
1051         global $wgDebugLogGroups;
1052
1053         $text = trim( $text ) . "\n";
1054
1055         // Turn $dest into a string if it's a boolean (for b/c)
1056         if ( $dest === true ) {
1057                 $dest = 'all';
1058         } elseif ( $dest === false ) {
1059                 $dest = 'private';
1060         }
1061
1062         if ( !isset( $wgDebugLogGroups[$logGroup] ) ) {
1063                 if ( $dest !== 'private' ) {
1064                         wfDebug( "[$logGroup] $text", $dest );
1065                 }
1066                 return;
1067         }
1068
1069         if ( $dest === 'all' ) {
1070                 MWDebug::debugMsg( "[$logGroup] $text" );
1071         }
1072
1073         $logConfig = $wgDebugLogGroups[$logGroup];
1074         if ( $logConfig === false ) {
1075                 return;
1076         }
1077         if ( is_array( $logConfig ) ) {
1078                 if ( isset( $logConfig['sample'] ) && mt_rand( 1, $logConfig['sample'] ) !== 1 ) {
1079                         return;
1080                 }
1081                 $destination = $logConfig['destination'];
1082         } else {
1083                 $destination = strval( $logConfig );
1084         }
1085
1086         $time = wfTimestamp( TS_DB );
1087         $wiki = wfWikiID();
1088         $host = wfHostname();
1089         wfErrorLog( "$time $host $wiki: $text", $destination );
1090 }
1091
1092 /**
1093  * Log for database errors
1094  *
1095  * @param string $text Database error message.
1096  */
1097 function wfLogDBError( $text ) {
1098         global $wgDBerrorLog, $wgDBerrorLogTZ;
1099         static $logDBErrorTimeZoneObject = null;
1100
1101         if ( $wgDBerrorLog ) {
1102                 $host = wfHostname();
1103                 $wiki = wfWikiID();
1104
1105                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1106                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1107                 }
1108
1109                 // Workaround for https://bugs.php.net/bug.php?id=52063
1110                 // Can be removed when min PHP > 5.3.2
1111                 if ( $logDBErrorTimeZoneObject === null ) {
1112                         $d = date_create( "now" );
1113                 } else {
1114                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1115                 }
1116
1117                 $date = $d->format( 'D M j G:i:s T Y' );
1118
1119                 $text = "$date\t$host\t$wiki\t" . trim( $text ) . "\n";
1120                 wfErrorLog( $text, $wgDBerrorLog );
1121         }
1122 }
1123
1124 /**
1125  * Throws a warning that $function is deprecated
1126  *
1127  * @param string $function
1128  * @param string|bool $version Version of MediaWiki that the function
1129  *    was deprecated in (Added in 1.19).
1130  * @param string|bool $component Added in 1.19.
1131  * @param int $callerOffset How far up the call stack is the original
1132  *    caller. 2 = function that called the function that called
1133  *    wfDeprecated (Added in 1.20)
1134  *
1135  * @return null
1136  */
1137 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1138         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1139 }
1140
1141 /**
1142  * Send a warning either to the debug log or in a PHP error depending on
1143  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1144  *
1145  * @param string $msg message to send
1146  * @param int $callerOffset Number of items to go back in the backtrace to
1147  *        find the correct caller (1 = function calling wfWarn, ...)
1148  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1149  *        only used when $wgDevelopmentWarnings is true
1150  */
1151 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1152         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1153 }
1154
1155 /**
1156  * Send a warning as a PHP error and the debug log. This is intended for logging
1157  * warnings in production. For logging development warnings, use WfWarn instead.
1158  *
1159  * @param string $msg Message to send
1160  * @param int $callerOffset Number of items to go back in the backtrace to
1161  *        find the correct caller (1 = function calling wfLogWarning, ...)
1162  * @param int $level PHP error level; defaults to E_USER_WARNING
1163  */
1164 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1165         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1166 }
1167
1168 /**
1169  * Log to a file without getting "file size exceeded" signals.
1170  *
1171  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1172  * send lines to the specified port, prefixed by the specified prefix and a space.
1173  *
1174  * @param string $text
1175  * @param string $file Filename
1176  * @throws MWException
1177  */
1178 function wfErrorLog( $text, $file ) {
1179         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1180                 # Needs the sockets extension
1181                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1182                         // IPv6 bracketed host
1183                         $host = $m[2];
1184                         $port = intval( $m[3] );
1185                         $prefix = isset( $m[4] ) ? $m[4] : false;
1186                         $domain = AF_INET6;
1187                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1188                         $host = $m[2];
1189                         if ( !IP::isIPv4( $host ) ) {
1190                                 $host = gethostbyname( $host );
1191                         }
1192                         $port = intval( $m[3] );
1193                         $prefix = isset( $m[4] ) ? $m[4] : false;
1194                         $domain = AF_INET;
1195                 } else {
1196                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1197                 }
1198
1199                 // Clean it up for the multiplexer
1200                 if ( strval( $prefix ) !== '' ) {
1201                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1202
1203                         // Limit to 64KB
1204                         if ( strlen( $text ) > 65506 ) {
1205                                 $text = substr( $text, 0, 65506 );
1206                         }
1207
1208                         if ( substr( $text, -1 ) != "\n" ) {
1209                                 $text .= "\n";
1210                         }
1211                 } elseif ( strlen( $text ) > 65507 ) {
1212                         $text = substr( $text, 0, 65507 );
1213                 }
1214
1215                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1216                 if ( !$sock ) {
1217                         return;
1218                 }
1219
1220                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1221                 socket_close( $sock );
1222         } else {
1223                 wfSuppressWarnings();
1224                 $exists = file_exists( $file );
1225                 $size = $exists ? filesize( $file ) : false;
1226                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1227                         file_put_contents( $file, $text, FILE_APPEND );
1228                 }
1229                 wfRestoreWarnings();
1230         }
1231 }
1232
1233 /**
1234  * @todo document
1235  */
1236 function wfLogProfilingData() {
1237         global $wgRequestTime, $wgDebugLogFile, $wgDebugLogGroups, $wgDebugRawPage;
1238         global $wgProfileLimit, $wgUser, $wgRequest;
1239
1240         StatCounter::singleton()->flush();
1241
1242         $profiler = Profiler::instance();
1243
1244         # Profiling must actually be enabled...
1245         if ( $profiler->isStub() ) {
1246                 return;
1247         }
1248
1249         // Get total page request time and only show pages that longer than
1250         // $wgProfileLimit time (default is 0)
1251         $elapsed = microtime( true ) - $wgRequestTime;
1252         if ( $elapsed <= $wgProfileLimit ) {
1253                 return;
1254         }
1255
1256         $profiler->logData();
1257
1258         // Check whether this should be logged in the debug file.
1259         if ( isset( $wgDebugLogGroups['profileoutput'] )
1260                 && $wgDebugLogGroups['profileoutput'] === false
1261         ) {
1262                 // Explicitely disabled
1263                 return;
1264         }
1265         if ( !isset( $wgDebugLogGroups['profileoutput'] ) && $wgDebugLogFile == '' ) {
1266                 // Logging not enabled; no point going further
1267                 return;
1268         }
1269         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1270                 return;
1271         }
1272
1273         $forward = '';
1274         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1275                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1276         }
1277         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1278                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1279         }
1280         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1281                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1282         }
1283         if ( $forward ) {
1284                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1285         }
1286         // Don't load $wgUser at this late stage just for statistics purposes
1287         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1288         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1289                 $forward .= ' anon';
1290         }
1291
1292         // Command line script uses a FauxRequest object which does not have
1293         // any knowledge about an URL and throw an exception instead.
1294         try {
1295                 $requestUrl = $wgRequest->getRequestURL();
1296         } catch ( MWException $e ) {
1297                 $requestUrl = 'n/a';
1298         }
1299
1300         $log = sprintf( "%s\t%04.3f\t%s\n",
1301                 gmdate( 'YmdHis' ), $elapsed,
1302                 urldecode( $requestUrl . $forward ) );
1303
1304         wfDebugLog( 'profileoutput', $log . $profiler->getOutput() );
1305 }
1306
1307 /**
1308  * Increment a statistics counter
1309  *
1310  * @param string $key
1311  * @param int $count
1312  * @return void
1313  */
1314 function wfIncrStats( $key, $count = 1 ) {
1315         StatCounter::singleton()->incr( $key, $count );
1316 }
1317
1318 /**
1319  * Check whether the wiki is in read-only mode.
1320  *
1321  * @return bool
1322  */
1323 function wfReadOnly() {
1324         return wfReadOnlyReason() !== false;
1325 }
1326
1327 /**
1328  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1329  *
1330  * @return string|bool String when in read-only mode; false otherwise
1331  */
1332 function wfReadOnlyReason() {
1333         global $wgReadOnly, $wgReadOnlyFile;
1334
1335         if ( $wgReadOnly === null ) {
1336                 // Set $wgReadOnly for faster access next time
1337                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1338                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1339                 } else {
1340                         $wgReadOnly = false;
1341                 }
1342         }
1343
1344         return $wgReadOnly;
1345 }
1346
1347 /**
1348  * Return a Language object from $langcode
1349  *
1350  * @param Language|string|bool $langcode Either:
1351  *                  - a Language object
1352  *                  - code of the language to get the message for, if it is
1353  *                    a valid code create a language for that language, if
1354  *                    it is a string but not a valid code then make a basic
1355  *                    language object
1356  *                  - a boolean: if it's false then use the global object for
1357  *                    the current user's language (as a fallback for the old parameter
1358  *                    functionality), or if it is true then use global object
1359  *                    for the wiki's content language.
1360  * @return Language
1361  */
1362 function wfGetLangObj( $langcode = false ) {
1363         # Identify which language to get or create a language object for.
1364         # Using is_object here due to Stub objects.
1365         if ( is_object( $langcode ) ) {
1366                 # Great, we already have the object (hopefully)!
1367                 return $langcode;
1368         }
1369
1370         global $wgContLang, $wgLanguageCode;
1371         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1372                 # $langcode is the language code of the wikis content language object.
1373                 # or it is a boolean and value is true
1374                 return $wgContLang;
1375         }
1376
1377         global $wgLang;
1378         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1379                 # $langcode is the language code of user language object.
1380                 # or it was a boolean and value is false
1381                 return $wgLang;
1382         }
1383
1384         $validCodes = array_keys( Language::fetchLanguageNames() );
1385         if ( in_array( $langcode, $validCodes ) ) {
1386                 # $langcode corresponds to a valid language.
1387                 return Language::factory( $langcode );
1388         }
1389
1390         # $langcode is a string, but not a valid language code; use content language.
1391         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1392         return $wgContLang;
1393 }
1394
1395 /**
1396  * This is the function for getting translated interface messages.
1397  *
1398  * @see Message class for documentation how to use them.
1399  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1400  *
1401  * This function replaces all old wfMsg* functions.
1402  *
1403  * @param string $key Message key
1404  * @param mixed [$params,...] Normal message parameters
1405  * @return Message
1406  *
1407  * @since 1.17
1408  *
1409  * @see Message::__construct
1410  */
1411 function wfMessage( $key /*...*/ ) {
1412         $params = func_get_args();
1413         array_shift( $params );
1414         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1415                 $params = $params[0];
1416         }
1417         return new Message( $key, $params );
1418 }
1419
1420 /**
1421  * This function accepts multiple message keys and returns a message instance
1422  * for the first message which is non-empty. If all messages are empty then an
1423  * instance of the first message key is returned.
1424  *
1425  * @param string|string[] [$keys,...] Message keys
1426  * @return Message
1427  *
1428  * @since 1.18
1429  *
1430  * @see Message::newFallbackSequence
1431  */
1432 function wfMessageFallback( /*...*/ ) {
1433         $args = func_get_args();
1434         return call_user_func_array( 'Message::newFallbackSequence', $args );
1435 }
1436
1437 /**
1438  * Get a message from anywhere, for the current user language.
1439  *
1440  * Use wfMsgForContent() instead if the message should NOT
1441  * change depending on the user preferences.
1442  *
1443  * @deprecated since 1.18
1444  *
1445  * @param string $key lookup key for the message, usually
1446  *    defined in languages/Language.php
1447  *
1448  * Parameters to the message, which can be used to insert variable text into
1449  * it, can be passed to this function in the following formats:
1450  * - One per argument, starting at the second parameter
1451  * - As an array in the second parameter
1452  * These are not shown in the function definition.
1453  *
1454  * @return string
1455  */
1456 function wfMsg( $key ) {
1457         wfDeprecated( __METHOD__, '1.21' );
1458
1459         $args = func_get_args();
1460         array_shift( $args );
1461         return wfMsgReal( $key, $args );
1462 }
1463
1464 /**
1465  * Same as above except doesn't transform the message
1466  *
1467  * @deprecated since 1.18
1468  *
1469  * @param string $key
1470  * @return string
1471  */
1472 function wfMsgNoTrans( $key ) {
1473         wfDeprecated( __METHOD__, '1.21' );
1474
1475         $args = func_get_args();
1476         array_shift( $args );
1477         return wfMsgReal( $key, $args, true, false, false );
1478 }
1479
1480 /**
1481  * Get a message from anywhere, for the current global language
1482  * set with $wgLanguageCode.
1483  *
1484  * Use this if the message should NOT change dependent on the
1485  * language set in the user's preferences. This is the case for
1486  * most text written into logs, as well as link targets (such as
1487  * the name of the copyright policy page). Link titles, on the
1488  * other hand, should be shown in the UI language.
1489  *
1490  * Note that MediaWiki allows users to change the user interface
1491  * language in their preferences, but a single installation
1492  * typically only contains content in one language.
1493  *
1494  * Be wary of this distinction: If you use wfMsg() where you should
1495  * use wfMsgForContent(), a user of the software may have to
1496  * customize potentially hundreds of messages in
1497  * order to, e.g., fix a link in every possible language.
1498  *
1499  * @deprecated since 1.18
1500  *
1501  * @param string $key Lookup key for the message, usually
1502  *     defined in languages/Language.php
1503  * @return string
1504  */
1505 function wfMsgForContent( $key ) {
1506         wfDeprecated( __METHOD__, '1.21' );
1507
1508         global $wgForceUIMsgAsContentMsg;
1509         $args = func_get_args();
1510         array_shift( $args );
1511         $forcontent = true;
1512         if ( is_array( $wgForceUIMsgAsContentMsg )
1513                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1514         ) {
1515                 $forcontent = false;
1516         }
1517         return wfMsgReal( $key, $args, true, $forcontent );
1518 }
1519
1520 /**
1521  * Same as above except doesn't transform the message
1522  *
1523  * @deprecated since 1.18
1524  *
1525  * @param string $key
1526  * @return string
1527  */
1528 function wfMsgForContentNoTrans( $key ) {
1529         wfDeprecated( __METHOD__, '1.21' );
1530
1531         global $wgForceUIMsgAsContentMsg;
1532         $args = func_get_args();
1533         array_shift( $args );
1534         $forcontent = true;
1535         if ( is_array( $wgForceUIMsgAsContentMsg )
1536                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1537         ) {
1538                 $forcontent = false;
1539         }
1540         return wfMsgReal( $key, $args, true, $forcontent, false );
1541 }
1542
1543 /**
1544  * Really get a message
1545  *
1546  * @deprecated since 1.18
1547  *
1548  * @param string $key Key to get.
1549  * @param array $args
1550  * @param bool $useDB
1551  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1552  * @param bool $transform Whether or not to transform the message.
1553  * @return string The requested message.
1554  */
1555 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1556         wfDeprecated( __METHOD__, '1.21' );
1557
1558         wfProfileIn( __METHOD__ );
1559         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1560         $message = wfMsgReplaceArgs( $message, $args );
1561         wfProfileOut( __METHOD__ );
1562         return $message;
1563 }
1564
1565 /**
1566  * Fetch a message string value, but don't replace any keys yet.
1567  *
1568  * @deprecated since 1.18
1569  *
1570  * @param string $key
1571  * @param bool $useDB
1572  * @param string|bool $langCode Code of the language to get the message for, or
1573  *   behaves as a content language switch if it is a boolean.
1574  * @param bool $transform Whether to parse magic words, etc.
1575  * @return string
1576  */
1577 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1578         wfDeprecated( __METHOD__, '1.21' );
1579
1580         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1581
1582         $cache = MessageCache::singleton();
1583         $message = $cache->get( $key, $useDB, $langCode );
1584         if ( $message === false ) {
1585                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1586         } elseif ( $transform ) {
1587                 $message = $cache->transform( $message );
1588         }
1589         return $message;
1590 }
1591
1592 /**
1593  * Replace message parameter keys on the given formatted output.
1594  *
1595  * @param string $message
1596  * @param array $args
1597  * @return string
1598  * @private
1599  */
1600 function wfMsgReplaceArgs( $message, $args ) {
1601         # Fix windows line-endings
1602         # Some messages are split with explode("\n", $msg)
1603         $message = str_replace( "\r", '', $message );
1604
1605         // Replace arguments
1606         if ( count( $args ) ) {
1607                 if ( is_array( $args[0] ) ) {
1608                         $args = array_values( $args[0] );
1609                 }
1610                 $replacementKeys = array();
1611                 foreach ( $args as $n => $param ) {
1612                         $replacementKeys['$' . ( $n + 1 )] = $param;
1613                 }
1614                 $message = strtr( $message, $replacementKeys );
1615         }
1616
1617         return $message;
1618 }
1619
1620 /**
1621  * Return an HTML-escaped version of a message.
1622  * Parameter replacements, if any, are done *after* the HTML-escaping,
1623  * so parameters may contain HTML (eg links or form controls). Be sure
1624  * to pre-escape them if you really do want plaintext, or just wrap
1625  * the whole thing in htmlspecialchars().
1626  *
1627  * @deprecated since 1.18
1628  *
1629  * @param string $key
1630  * @param string [$args,...] Parameters
1631  * @return string
1632  */
1633 function wfMsgHtml( $key ) {
1634         wfDeprecated( __METHOD__, '1.21' );
1635
1636         $args = func_get_args();
1637         array_shift( $args );
1638         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1639 }
1640
1641 /**
1642  * Return an HTML version of message
1643  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1644  * so parameters may contain HTML (eg links or form controls). Be sure
1645  * to pre-escape them if you really do want plaintext, or just wrap
1646  * the whole thing in htmlspecialchars().
1647  *
1648  * @deprecated since 1.18
1649  *
1650  * @param string $key
1651  * @param string [$args,...] Parameters
1652  * @return string
1653  */
1654 function wfMsgWikiHtml( $key ) {
1655         wfDeprecated( __METHOD__, '1.21' );
1656
1657         $args = func_get_args();
1658         array_shift( $args );
1659         return wfMsgReplaceArgs(
1660                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1661                 /* can't be set to false */ true, /* interface */ true )->getText(),
1662                 $args );
1663 }
1664
1665 /**
1666  * Returns message in the requested format
1667  *
1668  * @deprecated since 1.18
1669  *
1670  * @param string $key Key of the message
1671  * @param array $options Processing rules.
1672  *   Can take the following options:
1673  *     parse: parses wikitext to HTML
1674  *     parseinline: parses wikitext to HTML and removes the surrounding
1675  *       p's added by parser or tidy
1676  *     escape: filters message through htmlspecialchars
1677  *     escapenoentities: same, but allows entity references like &#160; through
1678  *     replaceafter: parameters are substituted after parsing or escaping
1679  *     parsemag: transform the message using magic phrases
1680  *     content: fetch message for content language instead of interface
1681  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1682  *     language: Language object or language code to fetch message for
1683  *       (overridden by content).
1684  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1685  *
1686  * @return string
1687  */
1688 function wfMsgExt( $key, $options ) {
1689         wfDeprecated( __METHOD__, '1.21' );
1690
1691         $args = func_get_args();
1692         array_shift( $args );
1693         array_shift( $args );
1694         $options = (array)$options;
1695
1696         foreach ( $options as $arrayKey => $option ) {
1697                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1698                         # An unknown index, neither numeric nor "language"
1699                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1700                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1701                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1702                 'replaceafter', 'parsemag', 'content' ) ) ) {
1703                         # A numeric index with unknown value
1704                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1705                 }
1706         }
1707
1708         if ( in_array( 'content', $options, true ) ) {
1709                 $forContent = true;
1710                 $langCode = true;
1711                 $langCodeObj = null;
1712         } elseif ( array_key_exists( 'language', $options ) ) {
1713                 $forContent = false;
1714                 $langCode = wfGetLangObj( $options['language'] );
1715                 $langCodeObj = $langCode;
1716         } else {
1717                 $forContent = false;
1718                 $langCode = false;
1719                 $langCodeObj = null;
1720         }
1721
1722         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1723
1724         if ( !in_array( 'replaceafter', $options, true ) ) {
1725                 $string = wfMsgReplaceArgs( $string, $args );
1726         }
1727
1728         $messageCache = MessageCache::singleton();
1729         $parseInline = in_array( 'parseinline', $options, true );
1730         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1731                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1732                 if ( $string instanceof ParserOutput ) {
1733                         $string = $string->getText();
1734                 }
1735
1736                 if ( $parseInline ) {
1737                         $string = Parser::stripOuterParagraph( $string );
1738                 }
1739         } elseif ( in_array( 'parsemag', $options, true ) ) {
1740                 $string = $messageCache->transform( $string,
1741                                 !$forContent, $langCodeObj );
1742         }
1743
1744         if ( in_array( 'escape', $options, true ) ) {
1745                 $string = htmlspecialchars ( $string );
1746         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1747                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1748         }
1749
1750         if ( in_array( 'replaceafter', $options, true ) ) {
1751                 $string = wfMsgReplaceArgs( $string, $args );
1752         }
1753
1754         return $string;
1755 }
1756
1757 /**
1758  * Since wfMsg() and co suck, they don't return false if the message key they
1759  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1760  * nonexistence of messages by checking the MessageCache::get() result directly.
1761  *
1762  * @deprecated since 1.18. Use Message::isDisabled().
1763  *
1764  * @param string $key The message key looked up
1765  * @return bool True if the message *doesn't* exist.
1766  */
1767 function wfEmptyMsg( $key ) {
1768         wfDeprecated( __METHOD__, '1.21' );
1769
1770         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1771 }
1772
1773 /**
1774  * Throw a debugging exception. This function previously once exited the process,
1775  * but now throws an exception instead, with similar results.
1776  *
1777  * @deprecated since 1.22; just throw an MWException yourself
1778  * @param string $msg Message shown when dying.
1779  * @throws MWException
1780  */
1781 function wfDebugDieBacktrace( $msg = '' ) {
1782         wfDeprecated( __FUNCTION__, '1.22' );
1783         throw new MWException( $msg );
1784 }
1785
1786 /**
1787  * Fetch server name for use in error reporting etc.
1788  * Use real server name if available, so we know which machine
1789  * in a server farm generated the current page.
1790  *
1791  * @return string
1792  */
1793 function wfHostname() {
1794         static $host;
1795         if ( is_null( $host ) ) {
1796
1797                 # Hostname overriding
1798                 global $wgOverrideHostname;
1799                 if ( $wgOverrideHostname !== false ) {
1800                         # Set static and skip any detection
1801                         $host = $wgOverrideHostname;
1802                         return $host;
1803                 }
1804
1805                 if ( function_exists( 'posix_uname' ) ) {
1806                         // This function not present on Windows
1807                         $uname = posix_uname();
1808                 } else {
1809                         $uname = false;
1810                 }
1811                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1812                         $host = $uname['nodename'];
1813                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1814                         # Windows computer name
1815                         $host = getenv( 'COMPUTERNAME' );
1816                 } else {
1817                         # This may be a virtual server.
1818                         $host = $_SERVER['SERVER_NAME'];
1819                 }
1820         }
1821         return $host;
1822 }
1823
1824 /**
1825  * Returns a script tag that stores the amount of time it took MediaWiki to
1826  * handle the request in milliseconds as 'wgBackendResponseTime'.
1827  *
1828  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1829  * hostname of the server handling the request.
1830  *
1831  * @return string
1832  */
1833 function wfReportTime() {
1834         global $wgRequestTime, $wgShowHostnames;
1835
1836         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1837         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1838         if ( $wgShowHostnames ) {
1839                 $reportVars[ 'wgHostname' ] = wfHostname();
1840         }
1841         return Skin::makeVariablesScript( $reportVars );
1842 }
1843
1844 /**
1845  * Safety wrapper for debug_backtrace().
1846  *
1847  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1848  * murky circumstances, which may be triggered in part by stub objects
1849  * or other fancy talking'.
1850  *
1851  * Will return an empty array if Zend Optimizer is detected or if
1852  * debug_backtrace is disabled, otherwise the output from
1853  * debug_backtrace() (trimmed).
1854  *
1855  * @param int $limit This parameter can be used to limit the number of stack frames returned
1856  *
1857  * @return array Array of backtrace information
1858  */
1859 function wfDebugBacktrace( $limit = 0 ) {
1860         static $disabled = null;
1861
1862         if ( extension_loaded( 'Zend Optimizer' ) ) {
1863                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1864                 return array();
1865         }
1866
1867         if ( is_null( $disabled ) ) {
1868                 $disabled = false;
1869                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1870                 $functions = array_map( 'trim', $functions );
1871                 $functions = array_map( 'strtolower', $functions );
1872                 if ( in_array( 'debug_backtrace', $functions ) ) {
1873                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1874                         $disabled = true;
1875                 }
1876         }
1877         if ( $disabled ) {
1878                 return array();
1879         }
1880
1881         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1882                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1883         } else {
1884                 return array_slice( debug_backtrace(), 1 );
1885         }
1886 }
1887
1888 /**
1889  * Get a debug backtrace as a string
1890  *
1891  * @return string
1892  */
1893 function wfBacktrace() {
1894         global $wgCommandLineMode;
1895
1896         if ( $wgCommandLineMode ) {
1897                 $msg = '';
1898         } else {
1899                 $msg = "<ul>\n";
1900         }
1901         $backtrace = wfDebugBacktrace();
1902         foreach ( $backtrace as $call ) {
1903                 if ( isset( $call['file'] ) ) {
1904                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1905                         $file = $f[count( $f ) - 1];
1906                 } else {
1907                         $file = '-';
1908                 }
1909                 if ( isset( $call['line'] ) ) {
1910                         $line = $call['line'];
1911                 } else {
1912                         $line = '-';
1913                 }
1914                 if ( $wgCommandLineMode ) {
1915                         $msg .= "$file line $line calls ";
1916                 } else {
1917                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1918                 }
1919                 if ( !empty( $call['class'] ) ) {
1920                         $msg .= $call['class'] . $call['type'];
1921                 }
1922                 $msg .= $call['function'] . '()';
1923
1924                 if ( $wgCommandLineMode ) {
1925                         $msg .= "\n";
1926                 } else {
1927                         $msg .= "</li>\n";
1928                 }
1929         }
1930         if ( $wgCommandLineMode ) {
1931                 $msg .= "\n";
1932         } else {
1933                 $msg .= "</ul>\n";
1934         }
1935
1936         return $msg;
1937 }
1938
1939 /**
1940  * Get the name of the function which called this function
1941  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1942  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1943  * wfGetCaller( 3 ) is the parent of that.
1944  *
1945  * @param int $level
1946  * @return string
1947  */
1948 function wfGetCaller( $level = 2 ) {
1949         $backtrace = wfDebugBacktrace( $level + 1 );
1950         if ( isset( $backtrace[$level] ) ) {
1951                 return wfFormatStackFrame( $backtrace[$level] );
1952         } else {
1953                 return 'unknown';
1954         }
1955 }
1956
1957 /**
1958  * Return a string consisting of callers in the stack. Useful sometimes
1959  * for profiling specific points.
1960  *
1961  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1962  * @return string
1963  */
1964 function wfGetAllCallers( $limit = 3 ) {
1965         $trace = array_reverse( wfDebugBacktrace() );
1966         if ( !$limit || $limit > count( $trace ) - 1 ) {
1967                 $limit = count( $trace ) - 1;
1968         }
1969         $trace = array_slice( $trace, -$limit - 1, $limit );
1970         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1971 }
1972
1973 /**
1974  * Return a string representation of frame
1975  *
1976  * @param array $frame
1977  * @return string
1978  */
1979 function wfFormatStackFrame( $frame ) {
1980         return isset( $frame['class'] ) ?
1981                 $frame['class'] . '::' . $frame['function'] :
1982                 $frame['function'];
1983 }
1984
1985 /* Some generic result counters, pulled out of SearchEngine */
1986
1987 /**
1988  * @todo document
1989  *
1990  * @param int $offset
1991  * @param int $limit
1992  * @return string
1993  */
1994 function wfShowingResults( $offset, $limit ) {
1995         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1996 }
1997
1998 /**
1999  * Generate (prev x| next x) (20|50|100...) type links for paging
2000  *
2001  * @param string $offset
2002  * @param int $limit
2003  * @param string $link
2004  * @param string $query Optional URL query parameter string
2005  * @param bool $atend Optional param for specified if this is the last page
2006  * @return string
2007  * @deprecated since 1.19; use Language::viewPrevNext() instead
2008  */
2009 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
2010         wfDeprecated( __METHOD__, '1.19' );
2011
2012         global $wgLang;
2013
2014         $query = wfCgiToArray( $query );
2015
2016         if ( is_object( $link ) ) {
2017                 $title = $link;
2018         } else {
2019                 $title = Title::newFromText( $link );
2020                 if ( is_null( $title ) ) {
2021                         return false;
2022                 }
2023         }
2024
2025         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
2026 }
2027
2028 /**
2029  * @todo document
2030  * @todo FIXME: We may want to blacklist some broken browsers
2031  *
2032  * @param bool $force
2033  * @return bool Whereas client accept gzip compression
2034  */
2035 function wfClientAcceptsGzip( $force = false ) {
2036         static $result = null;
2037         if ( $result === null || $force ) {
2038                 $result = false;
2039                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2040                         # @todo FIXME: We may want to blacklist some broken browsers
2041                         $m = array();
2042                         if ( preg_match(
2043                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2044                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
2045                                         $m
2046                                 )
2047                         ) {
2048                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2049                                         $result = false;
2050                                         return $result;
2051                                 }
2052                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2053                                 $result = true;
2054                         }
2055                 }
2056         }
2057         return $result;
2058 }
2059
2060 /**
2061  * Obtain the offset and limit values from the request string;
2062  * used in special pages
2063  *
2064  * @param int $deflimit Default limit if none supplied
2065  * @param string $optionname Name of a user preference to check against
2066  * @return array
2067  */
2068 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2069         global $wgRequest;
2070         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2071 }
2072
2073 /**
2074  * Escapes the given text so that it may be output using addWikiText()
2075  * without any linking, formatting, etc. making its way through. This
2076  * is achieved by substituting certain characters with HTML entities.
2077  * As required by the callers, "<nowiki>" is not used.
2078  *
2079  * @param string $text Text to be escaped
2080  * @return string
2081  */
2082 function wfEscapeWikiText( $text ) {
2083         static $repl = null, $repl2 = null;
2084         if ( $repl === null ) {
2085                 $repl = array(
2086                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2087                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2088                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2089                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2090                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2091                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2092                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2093                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2094                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2095                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2096                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2097                         '__' => '_&#95;', '://' => '&#58;//',
2098                 );
2099
2100                 // We have to catch everything "\s" matches in PCRE
2101                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2102                         $repl["$magic "] = "$magic&#32;";
2103                         $repl["$magic\t"] = "$magic&#9;";
2104                         $repl["$magic\r"] = "$magic&#13;";
2105                         $repl["$magic\n"] = "$magic&#10;";
2106                         $repl["$magic\f"] = "$magic&#12;";
2107                 }
2108
2109                 // And handle protocols that don't use "://"
2110                 global $wgUrlProtocols;
2111                 $repl2 = array();
2112                 foreach ( $wgUrlProtocols as $prot ) {
2113                         if ( substr( $prot, -1 ) === ':' ) {
2114                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2115                         }
2116                 }
2117                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2118         }
2119         $text = substr( strtr( "\n$text", $repl ), 1 );
2120         $text = preg_replace( $repl2, '$1&#58;', $text );
2121         return $text;
2122 }
2123
2124 /**
2125  * Get the current unix timestamp with microseconds.  Useful for profiling
2126  * @deprecated since 1.22; call microtime() directly
2127  * @return float
2128  */
2129 function wfTime() {
2130         wfDeprecated( __FUNCTION__, '1.22' );
2131         return microtime( true );
2132 }
2133
2134 /**
2135  * Sets dest to source and returns the original value of dest
2136  * If source is NULL, it just returns the value, it doesn't set the variable
2137  * If force is true, it will set the value even if source is NULL
2138  *
2139  * @param mixed $dest
2140  * @param mixed $source
2141  * @param bool $force
2142  * @return mixed
2143  */
2144 function wfSetVar( &$dest, $source, $force = false ) {
2145         $temp = $dest;
2146         if ( !is_null( $source ) || $force ) {
2147                 $dest = $source;
2148         }
2149         return $temp;
2150 }
2151
2152 /**
2153  * As for wfSetVar except setting a bit
2154  *
2155  * @param int $dest
2156  * @param int $bit
2157  * @param bool $state
2158  *
2159  * @return bool
2160  */
2161 function wfSetBit( &$dest, $bit, $state = true ) {
2162         $temp = (bool)( $dest & $bit );
2163         if ( !is_null( $state ) ) {
2164                 if ( $state ) {
2165                         $dest |= $bit;
2166                 } else {
2167                         $dest &= ~$bit;
2168                 }
2169         }
2170         return $temp;
2171 }
2172
2173 /**
2174  * A wrapper around the PHP function var_export().
2175  * Either print it or add it to the regular output ($wgOut).
2176  *
2177  * @param mixed $var A PHP variable to dump.
2178  */
2179 function wfVarDump( $var ) {
2180         global $wgOut;
2181         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2182         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2183                 print $s;
2184         } else {
2185                 $wgOut->addHTML( $s );
2186         }
2187 }
2188
2189 /**
2190  * Provide a simple HTTP error.
2191  *
2192  * @param int|string $code
2193  * @param string $label
2194  * @param string $desc
2195  */
2196 function wfHttpError( $code, $label, $desc ) {
2197         global $wgOut;
2198         $wgOut->disable();
2199         header( "HTTP/1.0 $code $label" );
2200         header( "Status: $code $label" );
2201         $wgOut->sendCacheControl();
2202
2203         header( 'Content-type: text/html; charset=utf-8' );
2204         print "<!doctype html>" .
2205                 '<html><head><title>' .
2206                 htmlspecialchars( $label ) .
2207                 '</title></head><body><h1>' .
2208                 htmlspecialchars( $label ) .
2209                 '</h1><p>' .
2210                 nl2br( htmlspecialchars( $desc ) ) .
2211                 "</p></body></html>\n";
2212 }
2213
2214 /**
2215  * Clear away any user-level output buffers, discarding contents.
2216  *
2217  * Suitable for 'starting afresh', for instance when streaming
2218  * relatively large amounts of data without buffering, or wanting to
2219  * output image files without ob_gzhandler's compression.
2220  *
2221  * The optional $resetGzipEncoding parameter controls suppression of
2222  * the Content-Encoding header sent by ob_gzhandler; by default it
2223  * is left. See comments for wfClearOutputBuffers() for why it would
2224  * be used.
2225  *
2226  * Note that some PHP configuration options may add output buffer
2227  * layers which cannot be removed; these are left in place.
2228  *
2229  * @param bool $resetGzipEncoding
2230  */
2231 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2232         if ( $resetGzipEncoding ) {
2233                 // Suppress Content-Encoding and Content-Length
2234                 // headers from 1.10+s wfOutputHandler
2235                 global $wgDisableOutputCompression;
2236                 $wgDisableOutputCompression = true;
2237         }
2238         while ( $status = ob_get_status() ) {
2239                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2240                         // Probably from zlib.output_compression or other
2241                         // PHP-internal setting which can't be removed.
2242                         //
2243                         // Give up, and hope the result doesn't break
2244                         // output behavior.
2245                         break;
2246                 }
2247                 if ( !ob_end_clean() ) {
2248                         // Could not remove output buffer handler; abort now
2249                         // to avoid getting in some kind of infinite loop.
2250                         break;
2251                 }
2252                 if ( $resetGzipEncoding ) {
2253                         if ( $status['name'] == 'ob_gzhandler' ) {
2254                                 // Reset the 'Content-Encoding' field set by this handler
2255                                 // so we can start fresh.
2256                                 header_remove( 'Content-Encoding' );
2257                                 break;
2258                         }
2259                 }
2260         }
2261 }
2262
2263 /**
2264  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2265  *
2266  * Clear away output buffers, but keep the Content-Encoding header
2267  * produced by ob_gzhandler, if any.
2268  *
2269  * This should be used for HTTP 304 responses, where you need to
2270  * preserve the Content-Encoding header of the real result, but
2271  * also need to suppress the output of ob_gzhandler to keep to spec
2272  * and avoid breaking Firefox in rare cases where the headers and
2273  * body are broken over two packets.
2274  */
2275 function wfClearOutputBuffers() {
2276         wfResetOutputBuffers( false );
2277 }
2278
2279 /**
2280  * Converts an Accept-* header into an array mapping string values to quality
2281  * factors
2282  *
2283  * @param string $accept
2284  * @param string $def default
2285  * @return float[] Associative array of string => float pairs
2286  */
2287 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2288         # No arg means accept anything (per HTTP spec)
2289         if ( !$accept ) {
2290                 return array( $def => 1.0 );
2291         }
2292
2293         $prefs = array();
2294
2295         $parts = explode( ',', $accept );
2296
2297         foreach ( $parts as $part ) {
2298                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2299                 $values = explode( ';', trim( $part ) );
2300                 $match = array();
2301                 if ( count( $values ) == 1 ) {
2302                         $prefs[$values[0]] = 1.0;
2303                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2304                         $prefs[$values[0]] = floatval( $match[1] );
2305                 }
2306         }
2307
2308         return $prefs;
2309 }
2310
2311 /**
2312  * Checks if a given MIME type matches any of the keys in the given
2313  * array. Basic wildcards are accepted in the array keys.
2314  *
2315  * Returns the matching MIME type (or wildcard) if a match, otherwise
2316  * NULL if no match.
2317  *
2318  * @param string $type
2319  * @param array $avail
2320  * @return string
2321  * @private
2322  */
2323 function mimeTypeMatch( $type, $avail ) {
2324         if ( array_key_exists( $type, $avail ) ) {
2325                 return $type;
2326         } else {
2327                 $parts = explode( '/', $type );
2328                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2329                         return $parts[0] . '/*';
2330                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2331                         return '*/*';
2332                 } else {
2333                         return null;
2334                 }
2335         }
2336 }
2337
2338 /**
2339  * Returns the 'best' match between a client's requested internet media types
2340  * and the server's list of available types. Each list should be an associative
2341  * array of type to preference (preference is a float between 0.0 and 1.0).
2342  * Wildcards in the types are acceptable.
2343  *
2344  * @param array $cprefs Client's acceptable type list
2345  * @param array $sprefs Server's offered types
2346  * @return string
2347  *
2348  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2349  * XXX: generalize to negotiate other stuff
2350  */
2351 function wfNegotiateType( $cprefs, $sprefs ) {
2352         $combine = array();
2353
2354         foreach ( array_keys( $sprefs ) as $type ) {
2355                 $parts = explode( '/', $type );
2356                 if ( $parts[1] != '*' ) {
2357                         $ckey = mimeTypeMatch( $type, $cprefs );
2358                         if ( $ckey ) {
2359                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2360                         }
2361                 }
2362         }
2363
2364         foreach ( array_keys( $cprefs ) as $type ) {
2365                 $parts = explode( '/', $type );
2366                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2367                         $skey = mimeTypeMatch( $type, $sprefs );
2368                         if ( $skey ) {
2369                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2370                         }
2371                 }
2372         }
2373
2374         $bestq = 0;
2375         $besttype = null;
2376
2377         foreach ( array_keys( $combine ) as $type ) {
2378                 if ( $combine[$type] > $bestq ) {
2379                         $besttype = $type;
2380                         $bestq = $combine[$type];
2381                 }
2382         }
2383
2384         return $besttype;
2385 }
2386
2387 /**
2388  * Reference-counted warning suppression
2389  *
2390  * @param bool $end
2391  */
2392 function wfSuppressWarnings( $end = false ) {
2393         static $suppressCount = 0;
2394         static $originalLevel = false;
2395
2396         if ( $end ) {
2397                 if ( $suppressCount ) {
2398                         --$suppressCount;
2399                         if ( !$suppressCount ) {
2400                                 error_reporting( $originalLevel );
2401                         }
2402                 }
2403         } else {
2404                 if ( !$suppressCount ) {
2405                         $originalLevel = error_reporting( E_ALL & ~(
2406                                 E_WARNING |
2407                                 E_NOTICE |
2408                                 E_USER_WARNING |
2409                                 E_USER_NOTICE |
2410                                 E_DEPRECATED |
2411                                 E_USER_DEPRECATED |
2412                                 E_STRICT
2413                         ) );
2414                 }
2415                 ++$suppressCount;
2416         }
2417 }
2418
2419 /**
2420  * Restore error level to previous value
2421  */
2422 function wfRestoreWarnings() {
2423         wfSuppressWarnings( true );
2424 }
2425
2426 # Autodetect, convert and provide timestamps of various types
2427
2428 /**
2429  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2430  */
2431 define( 'TS_UNIX', 0 );
2432
2433 /**
2434  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2435  */
2436 define( 'TS_MW', 1 );
2437
2438 /**
2439  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2440  */
2441 define( 'TS_DB', 2 );
2442
2443 /**
2444  * RFC 2822 format, for E-mail and HTTP headers
2445  */
2446 define( 'TS_RFC2822', 3 );
2447
2448 /**
2449  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2450  *
2451  * This is used by Special:Export
2452  */
2453 define( 'TS_ISO_8601', 4 );
2454
2455 /**
2456  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2457  *
2458  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2459  *       DateTime tag and page 36 for the DateTimeOriginal and
2460  *       DateTimeDigitized tags.
2461  */
2462 define( 'TS_EXIF', 5 );
2463
2464 /**
2465  * Oracle format time.
2466  */
2467 define( 'TS_ORACLE', 6 );
2468
2469 /**
2470  * Postgres format time.
2471  */
2472 define( 'TS_POSTGRES', 7 );
2473
2474 /**
2475  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2476  */
2477 define( 'TS_ISO_8601_BASIC', 9 );
2478
2479 /**
2480  * Get a timestamp string in one of various formats
2481  *
2482  * @param mixed $outputtype A timestamp in one of the supported formats, the
2483  *   function will autodetect which format is supplied and act accordingly.
2484  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2485  * @return string|bool String / false The same date in the format specified in $outputtype or false
2486  */
2487 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2488         try {
2489                 $timestamp = new MWTimestamp( $ts );
2490                 return $timestamp->getTimestamp( $outputtype );
2491         } catch ( TimestampException $e ) {
2492                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2493                 return false;
2494         }
2495 }
2496
2497 /**
2498  * Return a formatted timestamp, or null if input is null.
2499  * For dealing with nullable timestamp columns in the database.
2500  *
2501  * @param int $outputtype
2502  * @param string $ts
2503  * @return string
2504  */
2505 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2506         if ( is_null( $ts ) ) {
2507                 return null;
2508         } else {
2509                 return wfTimestamp( $outputtype, $ts );
2510         }
2511 }
2512
2513 /**
2514  * Convenience function; returns MediaWiki timestamp for the present time.
2515  *
2516  * @return string
2517  */
2518 function wfTimestampNow() {
2519         # return NOW
2520         return wfTimestamp( TS_MW, time() );
2521 }
2522
2523 /**
2524  * Check if the operating system is Windows
2525  *
2526  * @return bool True if it's Windows, false otherwise.
2527  */
2528 function wfIsWindows() {
2529         static $isWindows = null;
2530         if ( $isWindows === null ) {
2531                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2532         }
2533         return $isWindows;
2534 }
2535
2536 /**
2537  * Check if we are running under HHVM
2538  *
2539  * @return bool
2540  */
2541 function wfIsHHVM() {
2542         return defined( 'HHVM_VERSION' );
2543 }
2544
2545 /**
2546  * Swap two variables
2547  *
2548  * @param mixed $x
2549  * @param mixed $y
2550  */
2551 function swap( &$x, &$y ) {
2552         $z = $x;
2553         $x = $y;
2554         $y = $z;
2555 }
2556
2557 /**
2558  * Tries to get the system directory for temporary files. First
2559  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2560  * environment variables are then checked in sequence, and if none are
2561  * set try sys_get_temp_dir().
2562  *
2563  * NOTE: When possible, use instead the tmpfile() function to create
2564  * temporary files to avoid race conditions on file creation, etc.
2565  *
2566  * @return string
2567  */
2568 function wfTempDir() {
2569         global $wgTmpDirectory;
2570
2571         if ( $wgTmpDirectory !== false ) {
2572                 return $wgTmpDirectory;
2573         }
2574
2575         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2576
2577         foreach ( $tmpDir as $tmp ) {
2578                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2579                         return $tmp;
2580                 }
2581         }
2582         return sys_get_temp_dir();
2583 }
2584
2585 /**
2586  * Make directory, and make all parent directories if they don't exist
2587  *
2588  * @param string $dir Full path to directory to create
2589  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2590  * @param string $caller Optional caller param for debugging.
2591  * @throws MWException
2592  * @return bool
2593  */
2594 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2595         global $wgDirectoryMode;
2596
2597         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2598                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2599         }
2600
2601         if ( !is_null( $caller ) ) {
2602                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2603         }
2604
2605         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2606                 return true;
2607         }
2608
2609         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2610
2611         if ( is_null( $mode ) ) {
2612                 $mode = $wgDirectoryMode;
2613         }
2614
2615         // Turn off the normal warning, we're doing our own below
2616         wfSuppressWarnings();
2617         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2618         wfRestoreWarnings();
2619
2620         if ( !$ok ) {
2621                 //directory may have been created on another request since we last checked
2622                 if ( is_dir( $dir ) ) {
2623                         return true;
2624                 }
2625
2626                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2627                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2628         }
2629         return $ok;
2630 }
2631
2632 /**
2633  * Remove a directory and all its content.
2634  * Does not hide error.
2635  * @param string $dir
2636  */
2637 function wfRecursiveRemoveDir( $dir ) {
2638         wfDebug( __FUNCTION__ . "( $dir )\n" );
2639         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2640         if ( is_dir( $dir ) ) {
2641                 $objects = scandir( $dir );
2642                 foreach ( $objects as $object ) {
2643                         if ( $object != "." && $object != ".." ) {
2644                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2645                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2646                                 } else {
2647                                         unlink( $dir . '/' . $object );
2648                                 }
2649                         }
2650                 }
2651                 reset( $objects );
2652                 rmdir( $dir );
2653         }
2654 }
2655
2656 /**
2657  * @param int $nr The number to format
2658  * @param int $acc The number of digits after the decimal point, default 2
2659  * @param bool $round Whether or not to round the value, default true
2660  * @return string
2661  */
2662 function wfPercent( $nr, $acc = 2, $round = true ) {
2663         $ret = sprintf( "%.${acc}f", $nr );
2664         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2665 }
2666
2667 /**
2668  * Safety wrapper around ini_get() for boolean settings.
2669  * The values returned from ini_get() are pre-normalized for settings
2670  * set via php.ini or php_flag/php_admin_flag... but *not*
2671  * for those set via php_value/php_admin_value.
2672  *
2673  * It's fairly common for people to use php_value instead of php_flag,
2674  * which can leave you with an 'off' setting giving a false positive
2675  * for code that just takes the ini_get() return value as a boolean.
2676  *
2677  * To make things extra interesting, setting via php_value accepts
2678  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2679  * Unrecognized values go false... again opposite PHP's own coercion
2680  * from string to bool.
2681  *
2682  * Luckily, 'properly' set settings will always come back as '0' or '1',
2683  * so we only have to worry about them and the 'improper' settings.
2684  *
2685  * I frickin' hate PHP... :P
2686  *
2687  * @param string $setting
2688  * @return bool
2689  */
2690 function wfIniGetBool( $setting ) {
2691         $val = strtolower( ini_get( $setting ) );
2692         // 'on' and 'true' can't have whitespace around them, but '1' can.
2693         return $val == 'on'
2694                 || $val == 'true'
2695                 || $val == 'yes'
2696                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2697 }
2698
2699 /**
2700  * Windows-compatible version of escapeshellarg()
2701  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2702  * function puts single quotes in regardless of OS.
2703  *
2704  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2705  * earlier distro releases of PHP)
2706  *
2707  * @param string [$args,...]
2708  * @return string
2709  */
2710 function wfEscapeShellArg( /*...*/ ) {
2711         wfInitShellLocale();
2712
2713         $args = func_get_args();
2714         $first = true;
2715         $retVal = '';
2716         foreach ( $args as $arg ) {
2717                 if ( !$first ) {
2718                         $retVal .= ' ';
2719                 } else {
2720                         $first = false;
2721                 }
2722
2723                 if ( wfIsWindows() ) {
2724                         // Escaping for an MSVC-style command line parser and CMD.EXE
2725                         // @codingStandardsIgnoreStart For long URLs
2726                         // Refs:
2727                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2728                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2729                         //  * Bug #13518
2730                         //  * CR r63214
2731                         // Double the backslashes before any double quotes. Escape the double quotes.
2732                         // @codingStandardsIgnoreEnd
2733                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2734                         $arg = '';
2735                         $iteration = 0;
2736                         foreach ( $tokens as $token ) {
2737                                 if ( $iteration % 2 == 1 ) {
2738                                         // Delimiter, a double quote preceded by zero or more slashes
2739                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2740                                 } elseif ( $iteration % 4 == 2 ) {
2741                                         // ^ in $token will be outside quotes, need to be escaped
2742                                         $arg .= str_replace( '^', '^^', $token );
2743                                 } else { // $iteration % 4 == 0
2744                                         // ^ in $token will appear inside double quotes, so leave as is
2745                                         $arg .= $token;
2746                                 }
2747                                 $iteration++;
2748                         }
2749                         // Double the backslashes before the end of the string, because
2750                         // we will soon add a quote
2751                         $m = array();
2752                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2753                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2754                         }
2755
2756                         // Add surrounding quotes
2757                         $retVal .= '"' . $arg . '"';
2758                 } else {
2759                         $retVal .= escapeshellarg( $arg );
2760                 }
2761         }
2762         return $retVal;
2763 }
2764
2765 /**
2766  * Check if wfShellExec() is effectively disabled via php.ini config
2767  *
2768  * @return bool|string False or one of (safemode,disabled)
2769  * @since 1.22
2770  */
2771 function wfShellExecDisabled() {
2772         static $disabled = null;
2773         if ( is_null( $disabled ) ) {
2774                 $disabled = false;
2775                 if ( wfIniGetBool( 'safe_mode' ) ) {
2776                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2777                         $disabled = 'safemode';
2778                 } else {
2779                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2780                         $functions = array_map( 'trim', $functions );
2781                         $functions = array_map( 'strtolower', $functions );
2782                         if ( in_array( 'proc_open', $functions ) ) {
2783                                 wfDebug( "proc_open is in disabled_functions\n" );
2784                                 $disabled = 'disabled';
2785                         }
2786                 }
2787         }
2788         return $disabled;
2789 }
2790
2791 /**
2792  * Execute a shell command, with time and memory limits mirrored from the PHP
2793  * configuration if supported.
2794  *
2795  * @param string $cmd Command line, properly escaped for shell.
2796  * @param null|mixed &$retval Optional, will receive the program's exit code.
2797  *   (non-zero is usually failure). If there is an error from
2798  *   read, select, or proc_open(), this will be set to -1.
2799  * @param array $environ Optional environment variables which should be
2800  *   added to the executed command environment.
2801  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2802  *   this overwrites the global wgMaxShell* limits.
2803  * @param array $options Array of options:
2804  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2805  *     including errors from limit.sh
2806  *
2807  * @return string Collected stdout as a string
2808  */
2809 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2810         $limits = array(), $options = array()
2811 ) {
2812         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2813                 $wgMaxShellWallClockTime, $wgShellCgroup;
2814
2815         $disabled = wfShellExecDisabled();
2816         if ( $disabled ) {
2817                 $retval = 1;
2818                 return $disabled == 'safemode' ?
2819                         'Unable to run external programs in safe mode.' :
2820                         'Unable to run external programs, proc_open() is disabled.';
2821         }
2822
2823         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2824
2825         wfInitShellLocale();
2826
2827         $envcmd = '';
2828         foreach ( $environ as $k => $v ) {
2829                 if ( wfIsWindows() ) {
2830                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2831                          * appear in the environment variable, so we must use carat escaping as documented in
2832                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2833                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2834                          * are listed there but doesn't appear to need it.
2835                          */
2836                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2837                 } else {
2838                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2839                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2840                          */
2841                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2842                 }
2843         }
2844         $cmd = $envcmd . $cmd;
2845
2846         $useLogPipe = false;
2847         if ( php_uname( 's' ) == 'Linux' ) {
2848                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2849                 if ( isset( $limits['walltime'] ) ) {
2850                         $wallTime = intval( $limits['walltime'] );
2851                 } elseif ( isset( $limits['time'] ) ) {
2852                         $wallTime = $time;
2853                 } else {
2854                         $wallTime = intval( $wgMaxShellWallClockTime );
2855                 }
2856                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2857                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2858
2859                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2860                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2861                                 escapeshellarg( $cmd ) . ' ' .
2862                                 escapeshellarg(
2863                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2864                                         "MW_CPU_LIMIT=$time; " .
2865                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2866                                         "MW_MEM_LIMIT=$mem; " .
2867                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2868                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2869                                         "MW_USE_LOG_PIPE=yes"
2870                                 );
2871                         $useLogPipe = true;
2872                 } elseif ( $includeStderr ) {
2873                         $cmd .= ' 2>&1';
2874                 }
2875         } elseif ( $includeStderr ) {
2876                 $cmd .= ' 2>&1';
2877         }
2878         wfDebug( "wfShellExec: $cmd\n" );
2879
2880         $desc = array(
2881                 0 => array( 'file', 'php://stdin', 'r' ),
2882                 1 => array( 'pipe', 'w' ),
2883                 2 => array( 'file', 'php://stderr', 'w' ) );
2884         if ( $useLogPipe ) {
2885                 $desc[3] = array( 'pipe', 'w' );
2886         }
2887         $pipes = null;
2888         $proc = proc_open( $cmd, $desc, $pipes );
2889         if ( !$proc ) {
2890                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2891                 $retval = -1;
2892                 return '';
2893         }
2894         $outBuffer = $logBuffer = '';
2895         $emptyArray = array();
2896         $status = false;
2897         $logMsg = false;
2898
2899         // According to the documentation, it is possible for stream_select()
2900         // to fail due to EINTR. I haven't managed to induce this in testing
2901         // despite sending various signals. If it did happen, the error
2902         // message would take the form:
2903         //
2904         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2905         //
2906         // where [4] is the value of the macro EINTR and "Interrupted system
2907         // call" is string which according to the Linux manual is "possibly"
2908         // localised according to LC_MESSAGES.
2909         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2910         $eintrMessage = "stream_select(): unable to select [$eintr]";
2911
2912         // Build a table mapping resource IDs to pipe FDs to work around a
2913         // PHP 5.3 issue in which stream_select() does not preserve array keys
2914         // <https://bugs.php.net/bug.php?id=53427>.
2915         $fds = array();
2916         foreach ( $pipes as $fd => $pipe ) {
2917                 $fds[(int)$pipe] = $fd;
2918         }
2919
2920         while ( true ) {
2921                 $status = proc_get_status( $proc );
2922                 if ( !$status['running'] ) {
2923                         break;
2924                 }
2925                 $status = false;
2926
2927                 $readyPipes = $pipes;
2928
2929                 // Clear last error
2930                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2931                 @trigger_error( '' );
2932                 if ( @stream_select( $readyPipes, $emptyArray, $emptyArray, null ) === false ) {
2933                         // @codingStandardsIgnoreEnd
2934                         $error = error_get_last();
2935                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2936                                 continue;
2937                         } else {
2938                                 trigger_error( $error['message'], E_USER_WARNING );
2939                                 $logMsg = $error['message'];
2940                                 break;
2941                         }
2942                 }
2943                 foreach ( $readyPipes as $pipe ) {
2944                         $block = fread( $pipe, 65536 );
2945                         $fd = $fds[(int)$pipe];
2946                         if ( $block === '' ) {
2947                                 // End of file
2948                                 fclose( $pipes[$fd] );
2949                                 unset( $pipes[$fd] );
2950                                 if ( !$pipes ) {
2951                                         break 2;
2952                                 }
2953                         } elseif ( $block === false ) {
2954                                 // Read error
2955                                 $logMsg = "Error reading from pipe";
2956                                 break 2;
2957                         } elseif ( $fd == 1 ) {
2958                                 // From stdout
2959                                 $outBuffer .= $block;
2960                         } elseif ( $fd == 3 ) {
2961                                 // From log FD
2962                                 $logBuffer .= $block;
2963                                 if ( strpos( $block, "\n" ) !== false ) {
2964                                         $lines = explode( "\n", $logBuffer );
2965                                         $logBuffer = array_pop( $lines );
2966                                         foreach ( $lines as $line ) {
2967                                                 wfDebugLog( 'exec', $line );
2968                                         }
2969                                 }
2970                         }
2971                 }
2972         }
2973
2974         foreach ( $pipes as $pipe ) {
2975                 fclose( $pipe );
2976         }
2977
2978         // Use the status previously collected if possible, since proc_get_status()
2979         // just calls waitpid() which will not return anything useful the second time.
2980         if ( $status === false ) {
2981                 $status = proc_get_status( $proc );
2982         }
2983
2984         if ( $logMsg !== false ) {
2985                 // Read/select error
2986                 $retval = -1;
2987                 proc_close( $proc );
2988         } elseif ( $status['signaled'] ) {
2989                 $logMsg = "Exited with signal {$status['termsig']}";
2990                 $retval = 128 + $status['termsig'];
2991                 proc_close( $proc );
2992         } else {
2993                 if ( $status['running'] ) {
2994                         $retval = proc_close( $proc );
2995                 } else {
2996                         $retval = $status['exitcode'];
2997                         proc_close( $proc );
2998                 }
2999                 if ( $retval == 127 ) {
3000                         $logMsg = "Possibly missing executable file";
3001                 } elseif ( $retval >= 129 && $retval <= 192 ) {
3002                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
3003                 }
3004         }
3005
3006         if ( $logMsg !== false ) {
3007                 wfDebugLog( 'exec', "$logMsg: $cmd" );
3008         }
3009
3010         return $outBuffer;
3011 }
3012
3013 /**
3014  * Execute a shell command, returning both stdout and stderr. Convenience
3015  * function, as all the arguments to wfShellExec can become unwieldy.
3016  *
3017  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
3018  * @param string $cmd Command line, properly escaped for shell.
3019  * @param null|mixed &$retval Optional, will receive the program's exit code.
3020  *   (non-zero is usually failure)
3021  * @param array $environ optional environment variables which should be
3022  *   added to the executed command environment.
3023  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
3024  *   this overwrites the global wgShellMax* limits.
3025  * @return string Collected stdout and stderr as a string
3026  */
3027 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
3028         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
3029 }
3030
3031 /**
3032  * Workaround for http://bugs.php.net/bug.php?id=45132
3033  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
3034  */
3035 function wfInitShellLocale() {
3036         static $done = false;
3037         if ( $done ) {
3038                 return;
3039         }
3040         $done = true;
3041         global $wgShellLocale;
3042         if ( !wfIniGetBool( 'safe_mode' ) ) {
3043                 putenv( "LC_CTYPE=$wgShellLocale" );
3044                 setlocale( LC_CTYPE, $wgShellLocale );
3045         }
3046 }
3047
3048 /**
3049  * Alias to wfShellWikiCmd()
3050  *
3051  * @see wfShellWikiCmd()
3052  */
3053 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
3054         return wfShellWikiCmd( $script, $parameters, $options );
3055 }
3056
3057 /**
3058  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3059  * Note that $parameters should be a flat array and an option with an argument
3060  * should consist of two consecutive items in the array (do not use "--option value").
3061  *
3062  * @param string $script MediaWiki cli script path
3063  * @param array $parameters Arguments and options to the script
3064  * @param array $options Associative array of options:
3065  *              'php': The path to the php executable
3066  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3067  * @return string
3068  */
3069 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3070         global $wgPhpCli;
3071         // Give site config file a chance to run the script in a wrapper.
3072         // The caller may likely want to call wfBasename() on $script.
3073         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3074         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3075         if ( isset( $options['wrapper'] ) ) {
3076                 $cmd[] = $options['wrapper'];
3077         }
3078         $cmd[] = $script;
3079         // Escape each parameter for shell
3080         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
3081 }
3082
3083 /**
3084  * wfMerge attempts to merge differences between three texts.
3085  * Returns true for a clean merge and false for failure or a conflict.
3086  *
3087  * @param string $old
3088  * @param string $mine
3089  * @param string $yours
3090  * @param string $result
3091  * @return bool
3092  */
3093 function wfMerge( $old, $mine, $yours, &$result ) {
3094         global $wgDiff3;
3095
3096         # This check may also protect against code injection in
3097         # case of broken installations.
3098         wfSuppressWarnings();
3099         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3100         wfRestoreWarnings();
3101
3102         if ( !$haveDiff3 ) {
3103                 wfDebug( "diff3 not found\n" );
3104                 return false;
3105         }
3106
3107         # Make temporary files
3108         $td = wfTempDir();
3109         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3110         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3111         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3112
3113         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3114         #       a newline character. To avoid this, we normalize the trailing whitespace before
3115         #       creating the diff.
3116
3117         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3118         fclose( $oldtextFile );
3119         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3120         fclose( $mytextFile );
3121         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3122         fclose( $yourtextFile );
3123
3124         # Check for a conflict
3125         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3126                 wfEscapeShellArg( $mytextName ) . ' ' .
3127                 wfEscapeShellArg( $oldtextName ) . ' ' .
3128                 wfEscapeShellArg( $yourtextName );
3129         $handle = popen( $cmd, 'r' );
3130
3131         if ( fgets( $handle, 1024 ) ) {
3132                 $conflict = true;
3133         } else {
3134                 $conflict = false;
3135         }
3136         pclose( $handle );
3137
3138         # Merge differences
3139         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3140                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3141         $handle = popen( $cmd, 'r' );
3142         $result = '';
3143         do {
3144                 $data = fread( $handle, 8192 );
3145                 if ( strlen( $data ) == 0 ) {
3146                         break;
3147                 }
3148                 $result .= $data;
3149         } while ( true );
3150         pclose( $handle );
3151         unlink( $mytextName );
3152         unlink( $oldtextName );
3153         unlink( $yourtextName );
3154
3155         if ( $result === '' && $old !== '' && !$conflict ) {
3156                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3157                 $conflict = true;
3158         }
3159         return !$conflict;
3160 }
3161
3162 /**
3163  * Returns unified plain-text diff of two texts.
3164  * Useful for machine processing of diffs.
3165  *
3166  * @param string $before The text before the changes.
3167  * @param string $after The text after the changes.
3168  * @param string $params Command-line options for the diff command.
3169  * @return string Unified diff of $before and $after
3170  */
3171 function wfDiff( $before, $after, $params = '-u' ) {
3172         if ( $before == $after ) {
3173                 return '';
3174         }
3175
3176         global $wgDiff;
3177         wfSuppressWarnings();
3178         $haveDiff = $wgDiff && file_exists( $wgDiff );
3179         wfRestoreWarnings();
3180
3181         # This check may also protect against code injection in
3182         # case of broken installations.
3183         if ( !$haveDiff ) {
3184                 wfDebug( "diff executable not found\n" );
3185                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3186                 $format = new UnifiedDiffFormatter();
3187                 return $format->format( $diffs );
3188         }
3189
3190         # Make temporary files
3191         $td = wfTempDir();
3192         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3193         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3194
3195         fwrite( $oldtextFile, $before );
3196         fclose( $oldtextFile );
3197         fwrite( $newtextFile, $after );
3198         fclose( $newtextFile );
3199
3200         // Get the diff of the two files
3201         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3202
3203         $h = popen( $cmd, 'r' );
3204
3205         $diff = '';
3206
3207         do {
3208                 $data = fread( $h, 8192 );
3209                 if ( strlen( $data ) == 0 ) {
3210                         break;
3211                 }
3212                 $diff .= $data;
3213         } while ( true );
3214
3215         // Clean up
3216         pclose( $h );
3217         unlink( $oldtextName );
3218         unlink( $newtextName );
3219
3220         // Kill the --- and +++ lines. They're not useful.
3221         $diff_lines = explode( "\n", $diff );
3222         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3223                 unset( $diff_lines[0] );
3224         }
3225         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3226                 unset( $diff_lines[1] );
3227         }
3228
3229         $diff = implode( "\n", $diff_lines );
3230
3231         return $diff;
3232 }
3233
3234 /**
3235  * This function works like "use VERSION" in Perl, the program will die with a
3236  * backtrace if the current version of PHP is less than the version provided
3237  *
3238  * This is useful for extensions which due to their nature are not kept in sync
3239  * with releases, and might depend on other versions of PHP than the main code
3240  *
3241  * Note: PHP might die due to parsing errors in some cases before it ever
3242  *       manages to call this function, such is life
3243  *
3244  * @see perldoc -f use
3245  *
3246  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3247  * @throws MWException
3248  */
3249 function wfUsePHP( $req_ver ) {
3250         $php_ver = PHP_VERSION;
3251
3252         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3253                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3254         }
3255 }
3256
3257 /**
3258  * This function works like "use VERSION" in Perl except it checks the version
3259  * of MediaWiki, the program will die with a backtrace if the current version
3260  * of MediaWiki is less than the version provided.
3261  *
3262  * This is useful for extensions which due to their nature are not kept in sync
3263  * with releases
3264  *
3265  * Note: Due to the behavior of PHP's version_compare() which is used in this
3266  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3267  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3268  * targeted version number. For example if you wanted to allow any variation
3269  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3270  * not result in the same comparison due to the internal logic of
3271  * version_compare().
3272  *
3273  * @see perldoc -f use
3274  *
3275  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3276  * @throws MWException
3277  */
3278 function wfUseMW( $req_ver ) {
3279         global $wgVersion;
3280
3281         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3282                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3283         }
3284 }
3285
3286 /**
3287  * Return the final portion of a pathname.
3288  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3289  * http://bugs.php.net/bug.php?id=33898
3290  *
3291  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3292  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3293  *
3294  * @param string $path
3295  * @param string $suffix String to remove if present
3296  * @return string
3297  */
3298 function wfBaseName( $path, $suffix = '' ) {
3299         if ( $suffix == '' ) {
3300                 $encSuffix = '';
3301         } else {
3302                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3303         }
3304
3305         $matches = array();
3306         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3307                 return $matches[1];
3308         } else {
3309                 return '';
3310         }
3311 }
3312
3313 /**
3314  * Generate a relative path name to the given file.
3315  * May explode on non-matching case-insensitive paths,
3316  * funky symlinks, etc.
3317  *
3318  * @param string $path Absolute destination path including target filename
3319  * @param string $from Absolute source path, directory only
3320  * @return string
3321  */
3322 function wfRelativePath( $path, $from ) {
3323         // Normalize mixed input on Windows...
3324         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3325         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3326
3327         // Trim trailing slashes -- fix for drive root
3328         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3329         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3330
3331         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3332         $against = explode( DIRECTORY_SEPARATOR, $from );
3333
3334         if ( $pieces[0] !== $against[0] ) {
3335                 // Non-matching Windows drive letters?
3336                 // Return a full path.
3337                 return $path;
3338         }
3339
3340         // Trim off common prefix
3341         while ( count( $pieces ) && count( $against )
3342                 && $pieces[0] == $against[0] ) {
3343                 array_shift( $pieces );
3344                 array_shift( $against );
3345         }
3346
3347         // relative dots to bump us to the parent
3348         while ( count( $against ) ) {
3349                 array_unshift( $pieces, '..' );
3350                 array_shift( $against );
3351         }
3352
3353         array_push( $pieces, wfBaseName( $path ) );
3354
3355         return implode( DIRECTORY_SEPARATOR, $pieces );
3356 }
3357
3358 /**
3359  * Convert an arbitrarily-long digit string from one numeric base
3360  * to another, optionally zero-padding to a minimum column width.
3361  *
3362  * Supports base 2 through 36; digit values 10-36 are represented
3363  * as lowercase letters a-z. Input is case-insensitive.
3364  *
3365  * @param string $input Input number
3366  * @param int $sourceBase Base of the input number
3367  * @param int $destBase Desired base of the output
3368  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3369  * @param bool $lowercase Whether to output in lowercase or uppercase
3370  * @param string $engine Either "gmp", "bcmath", or "php"
3371  * @return string|bool The output number as a string, or false on error
3372  */
3373 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3374         $lowercase = true, $engine = 'auto'
3375 ) {
3376         $input = (string)$input;
3377         if (
3378                 $sourceBase < 2 ||
3379                 $sourceBase > 36 ||
3380                 $destBase < 2 ||
3381                 $destBase > 36 ||
3382                 $sourceBase != (int)$sourceBase ||
3383                 $destBase != (int)$destBase ||
3384                 $pad != (int)$pad ||
3385                 !preg_match(
3386                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3387                         $input
3388                 )
3389         ) {
3390                 return false;
3391         }
3392
3393         static $baseChars = array(
3394                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3395                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3396                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3397                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3398                 34 => 'y', 35 => 'z',
3399
3400                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3401                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3402                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3403                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3404                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3405                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3406         );
3407
3408         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3409                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3410         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3411                 $decimal = '0';
3412                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3413                         $decimal = bcmul( $decimal, $sourceBase );
3414                         $decimal = bcadd( $decimal, $baseChars[$char] );
3415                 }
3416
3417                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3418                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3419                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3420                 }
3421                 // @codingStandardsIgnoreEnd
3422
3423                 $result = strrev( $result );
3424         } else {
3425                 $inDigits = array();
3426                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3427                         $inDigits[] = $baseChars[$char];
3428                 }
3429
3430                 // Iterate over the input, modulo-ing out an output digit
3431                 // at a time until input is gone.
3432                 $result = '';
3433                 while ( $inDigits ) {
3434                         $work = 0;
3435                         $workDigits = array();
3436
3437                         // Long division...
3438                         foreach ( $inDigits as $digit ) {
3439                                 $work *= $sourceBase;
3440                                 $work += $digit;
3441
3442                                 if ( $workDigits || $work >= $destBase ) {
3443                                         $workDigits[] = (int)( $work / $destBase );
3444                                 }
3445                                 $work %= $destBase;
3446                         }
3447
3448                         // All that division leaves us with a remainder,
3449                         // which is conveniently our next output digit.
3450                         $result .= $baseChars[$work];
3451
3452                         // And we continue!
3453                         $inDigits = $workDigits;
3454                 }
3455
3456                 $result = strrev( $result );
3457         }
3458
3459         if ( !$lowercase ) {
3460                 $result = strtoupper( $result );
3461         }
3462
3463         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3464 }
3465
3466 /**
3467  * Check if there is sufficient entropy in php's built-in session generation
3468  *
3469  * @return bool true = there is sufficient entropy
3470  */
3471 function wfCheckEntropy() {
3472         return (
3473                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3474                         || ini_get( 'session.entropy_file' )
3475                 )
3476                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3477 }
3478
3479 /**
3480  * Override session_id before session startup if php's built-in
3481  * session generation code is not secure.
3482  */
3483 function wfFixSessionID() {
3484         // If the cookie or session id is already set we already have a session and should abort
3485         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3486                 return;
3487         }
3488
3489         // PHP's built-in session entropy is enabled if:
3490         // - entropy_file is set or you're on Windows with php 5.3.3+
3491         // - AND entropy_length is > 0
3492         // We treat it as disabled if it doesn't have an entropy length of at least 32
3493         $entropyEnabled = wfCheckEntropy();
3494
3495         // If built-in entropy is not enabled or not sufficient override PHP's
3496         // built in session id generation code
3497         if ( !$entropyEnabled ) {
3498                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3499                         "overriding session id generation using our cryptrand source.\n" );
3500                 session_id( MWCryptRand::generateHex( 32 ) );
3501         }
3502 }
3503
3504 /**
3505  * Reset the session_id
3506  *
3507  * @since 1.22
3508  */
3509 function wfResetSessionID() {
3510         global $wgCookieSecure;
3511         $oldSessionId = session_id();
3512         $cookieParams = session_get_cookie_params();
3513         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3514                 session_regenerate_id( false );
3515         } else {
3516                 $tmp = $_SESSION;
3517                 session_destroy();
3518                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3519                 $_SESSION = $tmp;
3520         }
3521         $newSessionId = session_id();
3522         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3523 }
3524
3525 /**
3526  * Initialise php session
3527  *
3528  * @param bool $sessionId
3529  */
3530 function wfSetupSession( $sessionId = false ) {
3531         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3532                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3533         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3534                 ObjectCacheSessionHandler::install();
3535         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3536                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3537                 # hasn't already been set to the desired value (that causes errors)
3538                 ini_set( 'session.save_handler', $wgSessionHandler );
3539         }
3540         session_set_cookie_params(
3541                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3542         session_cache_limiter( 'private, must-revalidate' );
3543         if ( $sessionId ) {
3544                 session_id( $sessionId );
3545         } else {
3546                 wfFixSessionID();
3547         }
3548         wfSuppressWarnings();
3549         session_start();
3550         wfRestoreWarnings();
3551 }
3552
3553 /**
3554  * Get an object from the precompiled serialized directory
3555  *
3556  * @param string $name
3557  * @return mixed The variable on success, false on failure
3558  */
3559 function wfGetPrecompiledData( $name ) {
3560         global $IP;
3561
3562         $file = "$IP/serialized/$name";
3563         if ( file_exists( $file ) ) {
3564                 $blob = file_get_contents( $file );
3565                 if ( $blob ) {
3566                         return unserialize( $blob );
3567                 }
3568         }
3569         return false;
3570 }
3571
3572 /**
3573  * Get a cache key
3574  *
3575  * @param string [$args,...]
3576  * @return string
3577  */
3578 function wfMemcKey( /*...*/ ) {
3579         global $wgCachePrefix;
3580         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3581         $args = func_get_args();
3582         $key = $prefix . ':' . implode( ':', $args );
3583         $key = str_replace( ' ', '_', $key );
3584         return $key;
3585 }
3586
3587 /**
3588  * Get a cache key for a foreign DB
3589  *
3590  * @param string $db
3591  * @param string $prefix
3592  * @param string [$args,...]
3593  * @return string
3594  */
3595 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3596         $args = array_slice( func_get_args(), 2 );
3597         if ( $prefix ) {
3598                 $key = "$db-$prefix:" . implode( ':', $args );
3599         } else {
3600                 $key = $db . ':' . implode( ':', $args );
3601         }
3602         return str_replace( ' ', '_', $key );
3603 }
3604
3605 /**
3606  * Get an ASCII string identifying this wiki
3607  * This is used as a prefix in memcached keys
3608  *
3609  * @return string
3610  */
3611 function wfWikiID() {
3612         global $wgDBprefix, $wgDBname;
3613         if ( $wgDBprefix ) {
3614                 return "$wgDBname-$wgDBprefix";
3615         } else {
3616                 return $wgDBname;
3617         }
3618 }
3619
3620 /**
3621  * Split a wiki ID into DB name and table prefix
3622  *
3623  * @param string $wiki
3624  *
3625  * @return array
3626  */
3627 function wfSplitWikiID( $wiki ) {
3628         $bits = explode( '-', $wiki, 2 );
3629         if ( count( $bits ) < 2 ) {
3630                 $bits[] = '';
3631         }
3632         return $bits;
3633 }
3634
3635 /**
3636  * Get a Database object.
3637  *
3638  * @param int $db Index of the connection to get. May be DB_MASTER for the
3639  *            master (for write queries), DB_SLAVE for potentially lagged read
3640  *            queries, or an integer >= 0 for a particular server.
3641  *
3642  * @param string|string[] $groups Query groups. An array of group names that this query
3643  *                belongs to. May contain a single string if the query is only
3644  *                in one group.
3645  *
3646  * @param string|bool $wiki The wiki ID, or false for the current wiki
3647  *
3648  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3649  * will always return the same object, unless the underlying connection or load
3650  * balancer is manually destroyed.
3651  *
3652  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3653  * updater to ensure that a proper database is being updated.
3654  *
3655  * @return DatabaseBase
3656  */
3657 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3658         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3659 }
3660
3661 /**
3662  * Get a load balancer object.
3663  *
3664  * @param string|bool $wiki wiki ID, or false for the current wiki
3665  * @return LoadBalancer
3666  */
3667 function wfGetLB( $wiki = false ) {
3668         return wfGetLBFactory()->getMainLB( $wiki );
3669 }
3670
3671 /**
3672  * Get the load balancer factory object
3673  *
3674  * @return LBFactory
3675  */
3676 function &wfGetLBFactory() {
3677         return LBFactory::singleton();
3678 }
3679
3680 /**
3681  * Find a file.
3682  * Shortcut for RepoGroup::singleton()->findFile()
3683  *
3684  * @param string $title or Title object
3685  * @param array $options Associative array of options:
3686  *     time:           requested time for an archived image, or false for the
3687  *                     current version. An image object will be returned which was
3688  *                     created at the specified time.
3689  *
3690  *     ignoreRedirect: If true, do not follow file redirects
3691  *
3692  *     private:        If true, return restricted (deleted) files if the current
3693  *                     user is allowed to view them. Otherwise, such files will not
3694  *                     be found.
3695  *
3696  *     bypassCache:    If true, do not use the process-local cache of File objects
3697  *
3698  * @return File|bool File, or false if the file does not exist
3699  */
3700 function wfFindFile( $title, $options = array() ) {
3701         return RepoGroup::singleton()->findFile( $title, $options );
3702 }
3703
3704 /**
3705  * Get an object referring to a locally registered file.
3706  * Returns a valid placeholder object if the file does not exist.
3707  *
3708  * @param Title|string $title
3709  * @return LocalFile|null A File, or null if passed an invalid Title
3710  */
3711 function wfLocalFile( $title ) {
3712         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3713 }
3714
3715 /**
3716  * Should low-performance queries be disabled?
3717  *
3718  * @return bool
3719  * @codeCoverageIgnore
3720  */
3721 function wfQueriesMustScale() {
3722         global $wgMiserMode;
3723         return $wgMiserMode
3724                 || ( SiteStats::pages() > 100000
3725                 && SiteStats::edits() > 1000000
3726                 && SiteStats::users() > 10000 );
3727 }
3728
3729 /**
3730  * Get the path to a specified script file, respecting file
3731  * extensions; this is a wrapper around $wgScriptExtension etc.
3732  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3733  *
3734  * @param string $script Script filename, sans extension
3735  * @return string
3736  */
3737 function wfScript( $script = 'index' ) {
3738         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3739         if ( $script === 'index' ) {
3740                 return $wgScript;
3741         } elseif ( $script === 'load' ) {
3742                 return $wgLoadScript;
3743         } else {
3744                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3745         }
3746 }
3747
3748 /**
3749  * Get the script URL.
3750  *
3751  * @return string script URL
3752  */
3753 function wfGetScriptUrl() {
3754         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3755                 #
3756                 # as it was called, minus the query string.
3757                 #
3758                 # Some sites use Apache rewrite rules to handle subdomains,
3759                 # and have PHP set up in a weird way that causes PHP_SELF
3760                 # to contain the rewritten URL instead of the one that the
3761                 # outside world sees.
3762                 #
3763                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3764                 # provides containing the "before" URL.
3765                 return $_SERVER['SCRIPT_NAME'];
3766         } else {
3767                 return $_SERVER['URL'];
3768         }
3769 }
3770
3771 /**
3772  * Convenience function converts boolean values into "true"
3773  * or "false" (string) values
3774  *
3775  * @param bool $value
3776  * @return string
3777  */
3778 function wfBoolToStr( $value ) {
3779         return $value ? 'true' : 'false';
3780 }
3781
3782 /**
3783  * Get a platform-independent path to the null file, e.g. /dev/null
3784  *
3785  * @return string
3786  */
3787 function wfGetNull() {
3788         return wfIsWindows() ? 'NUL' : '/dev/null';
3789 }
3790
3791 /**
3792  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3793  * and waiting for it to go down, this waits for the slaves to catch up to the
3794  * master position. Use this when updating very large numbers of rows, as
3795  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3796  * a no-op if there are no slaves.
3797  *
3798  * @param int|bool $maxLag (deprecated)
3799  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3800  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3801  */
3802 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3803         if ( $cluster !== false ) {
3804                 $lb = wfGetLBFactory()->getExternalLB( $cluster );
3805         } else {
3806                 $lb = wfGetLB( $wiki );
3807         }
3808
3809         // bug 27975 - Don't try to wait for slaves if there are none
3810         // Prevents permission error when getting master position
3811         if ( $lb->getServerCount() > 1 ) {
3812                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3813                 $pos = $dbw->getMasterPos();
3814                 // The DBMS may not support getMasterPos() or the whole
3815                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3816                 if ( $pos !== false ) {
3817                         $lb->waitForAll( $pos );
3818                 }
3819         }
3820 }
3821
3822 /**
3823  * Count down from $seconds to zero on the terminal, with a one-second pause
3824  * between showing each number. For use in command-line scripts.
3825  *
3826  * @codeCoverageIgnore
3827  * @param int $seconds
3828  */
3829 function wfCountDown( $seconds ) {
3830         for ( $i = $seconds; $i >= 0; $i-- ) {
3831                 if ( $i != $seconds ) {
3832                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3833                 }
3834                 echo $i;
3835                 flush();
3836                 if ( $i ) {
3837                         sleep( 1 );
3838                 }
3839         }
3840         echo "\n";
3841 }
3842
3843 /**
3844  * Replace all invalid characters with -
3845  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3846  * By default, $wgIllegalFileChars = ':'
3847  *
3848  * @param string $name Filename to process
3849  * @return string
3850  */
3851 function wfStripIllegalFilenameChars( $name ) {
3852         global $wgIllegalFileChars;
3853         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3854         $name = wfBaseName( $name );
3855         $name = preg_replace(
3856                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3857                 '-',
3858                 $name
3859         );
3860         return $name;
3861 }
3862
3863 /**
3864  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3865  *
3866  * @return int Value the memory limit was set to.
3867  */
3868 function wfMemoryLimit() {
3869         global $wgMemoryLimit;
3870         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3871         if ( $memlimit != -1 ) {
3872                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3873                 if ( $conflimit == -1 ) {
3874                         wfDebug( "Removing PHP's memory limit\n" );
3875                         wfSuppressWarnings();
3876                         ini_set( 'memory_limit', $conflimit );
3877                         wfRestoreWarnings();
3878                         return $conflimit;
3879                 } elseif ( $conflimit > $memlimit ) {
3880                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3881                         wfSuppressWarnings();
3882                         ini_set( 'memory_limit', $conflimit );
3883                         wfRestoreWarnings();
3884                         return $conflimit;
3885                 }
3886         }
3887         return $memlimit;
3888 }
3889
3890 /**
3891  * Converts shorthand byte notation to integer form
3892  *
3893  * @param string $string
3894  * @return int
3895  */
3896 function wfShorthandToInteger( $string = '' ) {
3897         $string = trim( $string );
3898         if ( $string === '' ) {
3899                 return -1;
3900         }
3901         $last = $string[strlen( $string ) - 1];
3902         $val = intval( $string );
3903         switch ( $last ) {
3904                 case 'g':
3905                 case 'G':
3906                         $val *= 1024;
3907                         // break intentionally missing
3908                 case 'm':
3909                 case 'M':
3910                         $val *= 1024;
3911                         // break intentionally missing
3912                 case 'k':
3913                 case 'K':
3914                         $val *= 1024;
3915         }
3916
3917         return $val;
3918 }
3919
3920 /**
3921  * Get the normalised IETF language tag
3922  * See unit test for examples.
3923  *
3924  * @param string $code The language code.
3925  * @return string The language code which complying with BCP 47 standards.
3926  */
3927 function wfBCP47( $code ) {
3928         $codeSegment = explode( '-', $code );
3929         $codeBCP = array();
3930         foreach ( $codeSegment as $segNo => $seg ) {
3931                 // when previous segment is x, it is a private segment and should be lc
3932                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3933                         $codeBCP[$segNo] = strtolower( $seg );
3934                 // ISO 3166 country code
3935                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3936                         $codeBCP[$segNo] = strtoupper( $seg );
3937                 // ISO 15924 script code
3938                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3939                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3940                 // Use lowercase for other cases
3941                 } else {
3942                         $codeBCP[$segNo] = strtolower( $seg );
3943                 }
3944         }
3945         $langCode = implode( '-', $codeBCP );
3946         return $langCode;
3947 }
3948
3949 /**
3950  * Get a cache object.
3951  *
3952  * @param int $inputType Cache type, one the the CACHE_* constants.
3953  * @return BagOStuff
3954  */
3955 function wfGetCache( $inputType ) {
3956         return ObjectCache::getInstance( $inputType );
3957 }
3958
3959 /**
3960  * Get the main cache object
3961  *
3962  * @return BagOStuff
3963  */
3964 function wfGetMainCache() {
3965         global $wgMainCacheType;
3966         return ObjectCache::getInstance( $wgMainCacheType );
3967 }
3968
3969 /**
3970  * Get the cache object used by the message cache
3971  *
3972  * @return BagOStuff
3973  */
3974 function wfGetMessageCacheStorage() {
3975         global $wgMessageCacheType;
3976         return ObjectCache::getInstance( $wgMessageCacheType );
3977 }
3978
3979 /**
3980  * Get the cache object used by the parser cache
3981  *
3982  * @return BagOStuff
3983  */
3984 function wfGetParserCacheStorage() {
3985         global $wgParserCacheType;
3986         return ObjectCache::getInstance( $wgParserCacheType );
3987 }
3988
3989 /**
3990  * Get the cache object used by the language converter
3991  *
3992  * @return BagOStuff
3993  */
3994 function wfGetLangConverterCacheStorage() {
3995         global $wgLanguageConverterCacheType;
3996         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3997 }
3998
3999 /**
4000  * Call hook functions defined in $wgHooks
4001  *
4002  * @param string $event Event name
4003  * @param array $args Parameters passed to hook functions
4004  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
4005  *
4006  * @return bool True if no handler aborted the hook
4007  */
4008 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
4009         return Hooks::run( $event, $args, $deprecatedVersion );
4010 }
4011
4012 /**
4013  * Wrapper around php's unpack.
4014  *
4015  * @param string $format The format string (See php's docs)
4016  * @param string $data A binary string of binary data
4017  * @param int|bool $length The minimum length of $data or false. This is to
4018  *      prevent reading beyond the end of $data. false to disable the check.
4019  *
4020  * Also be careful when using this function to read unsigned 32 bit integer
4021  * because php might make it negative.
4022  *
4023  * @throws MWException if $data not long enough, or if unpack fails
4024  * @return array Associative array of the extracted data
4025  */
4026 function wfUnpack( $format, $data, $length = false ) {
4027         if ( $length !== false ) {
4028                 $realLen = strlen( $data );
4029                 if ( $realLen < $length ) {
4030                         throw new MWException( "Tried to use wfUnpack on a "
4031                                 . "string of length $realLen, but needed one "
4032                                 . "of at least length $length."
4033                         );
4034                 }
4035         }
4036
4037         wfSuppressWarnings();
4038         $result = unpack( $format, $data );
4039         wfRestoreWarnings();
4040
4041         if ( $result === false ) {
4042                 // If it cannot extract the packed data.
4043                 throw new MWException( "unpack could not unpack binary data" );
4044         }
4045         return $result;
4046 }
4047
4048 /**
4049  * Determine if an image exists on the 'bad image list'.
4050  *
4051  * The format of MediaWiki:Bad_image_list is as follows:
4052  *    * Only list items (lines starting with "*") are considered
4053  *    * The first link on a line must be a link to a bad image
4054  *    * Any subsequent links on the same line are considered to be exceptions,
4055  *      i.e. articles where the image may occur inline.
4056  *
4057  * @param string $name The image name to check
4058  * @param Title|bool $contextTitle The page on which the image occurs, if known
4059  * @param string $blacklist Wikitext of a file blacklist
4060  * @return bool
4061  */
4062 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4063         static $badImageCache = null; // based on bad_image_list msg
4064         wfProfileIn( __METHOD__ );
4065
4066         # Handle redirects
4067         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4068         if ( $redirectTitle ) {
4069                 $name = $redirectTitle->getDBkey();
4070         }
4071
4072         # Run the extension hook
4073         $bad = false;
4074         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
4075                 wfProfileOut( __METHOD__ );
4076                 return $bad;
4077         }
4078
4079         $cacheable = ( $blacklist === null );
4080         if ( $cacheable && $badImageCache !== null ) {
4081                 $badImages = $badImageCache;
4082         } else { // cache miss
4083                 if ( $blacklist === null ) {
4084                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4085                 }
4086                 # Build the list now
4087                 $badImages = array();
4088                 $lines = explode( "\n", $blacklist );
4089                 foreach ( $lines as $line ) {
4090                         # List items only
4091                         if ( substr( $line, 0, 1 ) !== '*' ) {
4092                                 continue;
4093                         }
4094
4095                         # Find all links
4096                         $m = array();
4097                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4098                                 continue;
4099                         }
4100
4101                         $exceptions = array();
4102                         $imageDBkey = false;
4103                         foreach ( $m[1] as $i => $titleText ) {
4104                                 $title = Title::newFromText( $titleText );
4105                                 if ( !is_null( $title ) ) {
4106                                         if ( $i == 0 ) {
4107                                                 $imageDBkey = $title->getDBkey();
4108                                         } else {
4109                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4110                                         }
4111                                 }
4112                         }
4113
4114                         if ( $imageDBkey !== false ) {
4115                                 $badImages[$imageDBkey] = $exceptions;
4116                         }
4117                 }
4118                 if ( $cacheable ) {
4119                         $badImageCache = $badImages;
4120                 }
4121         }
4122
4123         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4124         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4125         wfProfileOut( __METHOD__ );
4126         return $bad;
4127 }
4128
4129 /**
4130  * Determine whether the client at a given source IP is likely to be able to
4131  * access the wiki via HTTPS.
4132  *
4133  * @param string $ip The IPv4/6 address in the normal human-readable form
4134  * @return bool
4135  */
4136 function wfCanIPUseHTTPS( $ip ) {
4137         $canDo = true;
4138         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4139         return !!$canDo;
4140 }
4141
4142 /**
4143  * Work out the IP address based on various globals
4144  * For trusted proxies, use the XFF client IP (first of the chain)
4145  *
4146  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4147  * @return string
4148  */
4149 function wfGetIP() {
4150         wfDeprecated( __METHOD__, '1.19' );
4151         global $wgRequest;
4152         return $wgRequest->getIP();
4153 }
4154
4155 /**
4156  * Checks if an IP is a trusted proxy provider.
4157  * Useful to tell if X-Forwarded-For data is possibly bogus.
4158  * Squid cache servers for the site are whitelisted.
4159  * @deprecated Since 1.24, use IP::isTrustedProxy()
4160  *
4161  * @param string $ip
4162  * @return bool
4163  */
4164 function wfIsTrustedProxy( $ip ) {
4165         return IP::isTrustedProxy( $ip );
4166 }
4167
4168 /**
4169  * Checks if an IP matches a proxy we've configured.
4170  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4171  *
4172  * @param string $ip
4173  * @return bool
4174  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4175  */
4176 function wfIsConfiguredProxy( $ip ) {
4177         return IP::isTrustedProxy( $ip );
4178 }