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 values instead of kilobytes (default: false)
1019  */
1020 function wfDebugMem( $exact = false ) {
1021         $mem = memory_get_usage();
1022         if ( !$exact ) {
1023                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1024         } else {
1025                 $mem .= ' bytes';
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                         $m = array();
1738                         if ( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1739                                 $string = $m[1];
1740                         }
1741                 }
1742         } elseif ( in_array( 'parsemag', $options, true ) ) {
1743                 $string = $messageCache->transform( $string,
1744                                 !$forContent, $langCodeObj );
1745         }
1746
1747         if ( in_array( 'escape', $options, true ) ) {
1748                 $string = htmlspecialchars ( $string );
1749         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1750                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1751         }
1752
1753         if ( in_array( 'replaceafter', $options, true ) ) {
1754                 $string = wfMsgReplaceArgs( $string, $args );
1755         }
1756
1757         return $string;
1758 }
1759
1760 /**
1761  * Since wfMsg() and co suck, they don't return false if the message key they
1762  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1763  * nonexistence of messages by checking the MessageCache::get() result directly.
1764  *
1765  * @deprecated since 1.18. Use Message::isDisabled().
1766  *
1767  * @param string $key The message key looked up
1768  * @return bool True if the message *doesn't* exist.
1769  */
1770 function wfEmptyMsg( $key ) {
1771         wfDeprecated( __METHOD__, '1.21' );
1772
1773         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1774 }
1775
1776 /**
1777  * Throw a debugging exception. This function previously once exited the process,
1778  * but now throws an exception instead, with similar results.
1779  *
1780  * @deprecated since 1.22; just throw an MWException yourself
1781  * @param string $msg Message shown when dying.
1782  * @throws MWException
1783  */
1784 function wfDebugDieBacktrace( $msg = '' ) {
1785         wfDeprecated( __FUNCTION__, '1.22' );
1786         throw new MWException( $msg );
1787 }
1788
1789 /**
1790  * Fetch server name for use in error reporting etc.
1791  * Use real server name if available, so we know which machine
1792  * in a server farm generated the current page.
1793  *
1794  * @return string
1795  */
1796 function wfHostname() {
1797         static $host;
1798         if ( is_null( $host ) ) {
1799
1800                 # Hostname overriding
1801                 global $wgOverrideHostname;
1802                 if ( $wgOverrideHostname !== false ) {
1803                         # Set static and skip any detection
1804                         $host = $wgOverrideHostname;
1805                         return $host;
1806                 }
1807
1808                 if ( function_exists( 'posix_uname' ) ) {
1809                         // This function not present on Windows
1810                         $uname = posix_uname();
1811                 } else {
1812                         $uname = false;
1813                 }
1814                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1815                         $host = $uname['nodename'];
1816                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1817                         # Windows computer name
1818                         $host = getenv( 'COMPUTERNAME' );
1819                 } else {
1820                         # This may be a virtual server.
1821                         $host = $_SERVER['SERVER_NAME'];
1822                 }
1823         }
1824         return $host;
1825 }
1826
1827 /**
1828  * Returns a script tag that stores the amount of time it took MediaWiki to
1829  * handle the request in milliseconds as 'wgBackendResponseTime'.
1830  *
1831  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1832  * hostname of the server handling the request.
1833  *
1834  * @return string
1835  */
1836 function wfReportTime() {
1837         global $wgRequestTime, $wgShowHostnames;
1838
1839         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1840         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1841         if ( $wgShowHostnames ) {
1842                 $reportVars[ 'wgHostname' ] = wfHostname();
1843         }
1844         return Skin::makeVariablesScript( $reportVars );
1845 }
1846
1847 /**
1848  * Safety wrapper for debug_backtrace().
1849  *
1850  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1851  * murky circumstances, which may be triggered in part by stub objects
1852  * or other fancy talking'.
1853  *
1854  * Will return an empty array if Zend Optimizer is detected or if
1855  * debug_backtrace is disabled, otherwise the output from
1856  * debug_backtrace() (trimmed).
1857  *
1858  * @param int $limit This parameter can be used to limit the number of stack frames returned
1859  *
1860  * @return array Array of backtrace information
1861  */
1862 function wfDebugBacktrace( $limit = 0 ) {
1863         static $disabled = null;
1864
1865         if ( extension_loaded( 'Zend Optimizer' ) ) {
1866                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1867                 return array();
1868         }
1869
1870         if ( is_null( $disabled ) ) {
1871                 $disabled = false;
1872                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1873                 $functions = array_map( 'trim', $functions );
1874                 $functions = array_map( 'strtolower', $functions );
1875                 if ( in_array( 'debug_backtrace', $functions ) ) {
1876                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1877                         $disabled = true;
1878                 }
1879         }
1880         if ( $disabled ) {
1881                 return array();
1882         }
1883
1884         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1885                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1886         } else {
1887                 return array_slice( debug_backtrace(), 1 );
1888         }
1889 }
1890
1891 /**
1892  * Get a debug backtrace as a string
1893  *
1894  * @return string
1895  */
1896 function wfBacktrace() {
1897         global $wgCommandLineMode;
1898
1899         if ( $wgCommandLineMode ) {
1900                 $msg = '';
1901         } else {
1902                 $msg = "<ul>\n";
1903         }
1904         $backtrace = wfDebugBacktrace();
1905         foreach ( $backtrace as $call ) {
1906                 if ( isset( $call['file'] ) ) {
1907                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1908                         $file = $f[count( $f ) - 1];
1909                 } else {
1910                         $file = '-';
1911                 }
1912                 if ( isset( $call['line'] ) ) {
1913                         $line = $call['line'];
1914                 } else {
1915                         $line = '-';
1916                 }
1917                 if ( $wgCommandLineMode ) {
1918                         $msg .= "$file line $line calls ";
1919                 } else {
1920                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1921                 }
1922                 if ( !empty( $call['class'] ) ) {
1923                         $msg .= $call['class'] . $call['type'];
1924                 }
1925                 $msg .= $call['function'] . '()';
1926
1927                 if ( $wgCommandLineMode ) {
1928                         $msg .= "\n";
1929                 } else {
1930                         $msg .= "</li>\n";
1931                 }
1932         }
1933         if ( $wgCommandLineMode ) {
1934                 $msg .= "\n";
1935         } else {
1936                 $msg .= "</ul>\n";
1937         }
1938
1939         return $msg;
1940 }
1941
1942 /**
1943  * Get the name of the function which called this function
1944  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1945  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1946  * wfGetCaller( 3 ) is the parent of that.
1947  *
1948  * @param int $level
1949  * @return string
1950  */
1951 function wfGetCaller( $level = 2 ) {
1952         $backtrace = wfDebugBacktrace( $level + 1 );
1953         if ( isset( $backtrace[$level] ) ) {
1954                 return wfFormatStackFrame( $backtrace[$level] );
1955         } else {
1956                 return 'unknown';
1957         }
1958 }
1959
1960 /**
1961  * Return a string consisting of callers in the stack. Useful sometimes
1962  * for profiling specific points.
1963  *
1964  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1965  * @return string
1966  */
1967 function wfGetAllCallers( $limit = 3 ) {
1968         $trace = array_reverse( wfDebugBacktrace() );
1969         if ( !$limit || $limit > count( $trace ) - 1 ) {
1970                 $limit = count( $trace ) - 1;
1971         }
1972         $trace = array_slice( $trace, -$limit - 1, $limit );
1973         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1974 }
1975
1976 /**
1977  * Return a string representation of frame
1978  *
1979  * @param array $frame
1980  * @return string
1981  */
1982 function wfFormatStackFrame( $frame ) {
1983         return isset( $frame['class'] ) ?
1984                 $frame['class'] . '::' . $frame['function'] :
1985                 $frame['function'];
1986 }
1987
1988 /* Some generic result counters, pulled out of SearchEngine */
1989
1990 /**
1991  * @todo document
1992  *
1993  * @param int $offset
1994  * @param int $limit
1995  * @return string
1996  */
1997 function wfShowingResults( $offset, $limit ) {
1998         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1999 }
2000
2001 /**
2002  * Generate (prev x| next x) (20|50|100...) type links for paging
2003  *
2004  * @param string $offset
2005  * @param int $limit
2006  * @param string $link
2007  * @param string $query Optional URL query parameter string
2008  * @param bool $atend Optional param for specified if this is the last page
2009  * @return string
2010  * @deprecated since 1.19; use Language::viewPrevNext() instead
2011  */
2012 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
2013         wfDeprecated( __METHOD__, '1.19' );
2014
2015         global $wgLang;
2016
2017         $query = wfCgiToArray( $query );
2018
2019         if ( is_object( $link ) ) {
2020                 $title = $link;
2021         } else {
2022                 $title = Title::newFromText( $link );
2023                 if ( is_null( $title ) ) {
2024                         return false;
2025                 }
2026         }
2027
2028         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
2029 }
2030
2031 /**
2032  * @todo document
2033  * @todo FIXME: We may want to blacklist some broken browsers
2034  *
2035  * @param bool $force
2036  * @return bool Whereas client accept gzip compression
2037  */
2038 function wfClientAcceptsGzip( $force = false ) {
2039         static $result = null;
2040         if ( $result === null || $force ) {
2041                 $result = false;
2042                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2043                         # @todo FIXME: We may want to blacklist some broken browsers
2044                         $m = array();
2045                         if ( preg_match(
2046                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2047                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
2048                                         $m
2049                                 )
2050                         ) {
2051                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2052                                         $result = false;
2053                                         return $result;
2054                                 }
2055                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2056                                 $result = true;
2057                         }
2058                 }
2059         }
2060         return $result;
2061 }
2062
2063 /**
2064  * Obtain the offset and limit values from the request string;
2065  * used in special pages
2066  *
2067  * @param int $deflimit Default limit if none supplied
2068  * @param string $optionname Name of a user preference to check against
2069  * @return array
2070  */
2071 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2072         global $wgRequest;
2073         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2074 }
2075
2076 /**
2077  * Escapes the given text so that it may be output using addWikiText()
2078  * without any linking, formatting, etc. making its way through. This
2079  * is achieved by substituting certain characters with HTML entities.
2080  * As required by the callers, "<nowiki>" is not used.
2081  *
2082  * @param string $text Text to be escaped
2083  * @return string
2084  */
2085 function wfEscapeWikiText( $text ) {
2086         static $repl = null, $repl2 = null;
2087         if ( $repl === null ) {
2088                 $repl = array(
2089                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2090                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2091                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2092                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2093                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2094                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2095                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2096                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2097                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2098                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2099                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2100                         '__' => '_&#95;', '://' => '&#58;//',
2101                 );
2102
2103                 // We have to catch everything "\s" matches in PCRE
2104                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2105                         $repl["$magic "] = "$magic&#32;";
2106                         $repl["$magic\t"] = "$magic&#9;";
2107                         $repl["$magic\r"] = "$magic&#13;";
2108                         $repl["$magic\n"] = "$magic&#10;";
2109                         $repl["$magic\f"] = "$magic&#12;";
2110                 }
2111
2112                 // And handle protocols that don't use "://"
2113                 global $wgUrlProtocols;
2114                 $repl2 = array();
2115                 foreach ( $wgUrlProtocols as $prot ) {
2116                         if ( substr( $prot, -1 ) === ':' ) {
2117                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2118                         }
2119                 }
2120                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2121         }
2122         $text = substr( strtr( "\n$text", $repl ), 1 );
2123         $text = preg_replace( $repl2, '$1&#58;', $text );
2124         return $text;
2125 }
2126
2127 /**
2128  * Get the current unix timestamp with microseconds.  Useful for profiling
2129  * @deprecated since 1.22; call microtime() directly
2130  * @return float
2131  */
2132 function wfTime() {
2133         wfDeprecated( __FUNCTION__, '1.22' );
2134         return microtime( true );
2135 }
2136
2137 /**
2138  * Sets dest to source and returns the original value of dest
2139  * If source is NULL, it just returns the value, it doesn't set the variable
2140  * If force is true, it will set the value even if source is NULL
2141  *
2142  * @param mixed $dest
2143  * @param mixed $source
2144  * @param bool $force
2145  * @return mixed
2146  */
2147 function wfSetVar( &$dest, $source, $force = false ) {
2148         $temp = $dest;
2149         if ( !is_null( $source ) || $force ) {
2150                 $dest = $source;
2151         }
2152         return $temp;
2153 }
2154
2155 /**
2156  * As for wfSetVar except setting a bit
2157  *
2158  * @param int $dest
2159  * @param int $bit
2160  * @param bool $state
2161  *
2162  * @return bool
2163  */
2164 function wfSetBit( &$dest, $bit, $state = true ) {
2165         $temp = (bool)( $dest & $bit );
2166         if ( !is_null( $state ) ) {
2167                 if ( $state ) {
2168                         $dest |= $bit;
2169                 } else {
2170                         $dest &= ~$bit;
2171                 }
2172         }
2173         return $temp;
2174 }
2175
2176 /**
2177  * A wrapper around the PHP function var_export().
2178  * Either print it or add it to the regular output ($wgOut).
2179  *
2180  * @param mixed $var A PHP variable to dump.
2181  */
2182 function wfVarDump( $var ) {
2183         global $wgOut;
2184         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2185         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2186                 print $s;
2187         } else {
2188                 $wgOut->addHTML( $s );
2189         }
2190 }
2191
2192 /**
2193  * Provide a simple HTTP error.
2194  *
2195  * @param int|string $code
2196  * @param string $label
2197  * @param string $desc
2198  */
2199 function wfHttpError( $code, $label, $desc ) {
2200         global $wgOut;
2201         $wgOut->disable();
2202         header( "HTTP/1.0 $code $label" );
2203         header( "Status: $code $label" );
2204         $wgOut->sendCacheControl();
2205
2206         header( 'Content-type: text/html; charset=utf-8' );
2207         print "<!doctype html>" .
2208                 '<html><head><title>' .
2209                 htmlspecialchars( $label ) .
2210                 '</title></head><body><h1>' .
2211                 htmlspecialchars( $label ) .
2212                 '</h1><p>' .
2213                 nl2br( htmlspecialchars( $desc ) ) .
2214                 "</p></body></html>\n";
2215 }
2216
2217 /**
2218  * Clear away any user-level output buffers, discarding contents.
2219  *
2220  * Suitable for 'starting afresh', for instance when streaming
2221  * relatively large amounts of data without buffering, or wanting to
2222  * output image files without ob_gzhandler's compression.
2223  *
2224  * The optional $resetGzipEncoding parameter controls suppression of
2225  * the Content-Encoding header sent by ob_gzhandler; by default it
2226  * is left. See comments for wfClearOutputBuffers() for why it would
2227  * be used.
2228  *
2229  * Note that some PHP configuration options may add output buffer
2230  * layers which cannot be removed; these are left in place.
2231  *
2232  * @param bool $resetGzipEncoding
2233  */
2234 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2235         if ( $resetGzipEncoding ) {
2236                 // Suppress Content-Encoding and Content-Length
2237                 // headers from 1.10+s wfOutputHandler
2238                 global $wgDisableOutputCompression;
2239                 $wgDisableOutputCompression = true;
2240         }
2241         while ( $status = ob_get_status() ) {
2242                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2243                         // Probably from zlib.output_compression or other
2244                         // PHP-internal setting which can't be removed.
2245                         //
2246                         // Give up, and hope the result doesn't break
2247                         // output behavior.
2248                         break;
2249                 }
2250                 if ( !ob_end_clean() ) {
2251                         // Could not remove output buffer handler; abort now
2252                         // to avoid getting in some kind of infinite loop.
2253                         break;
2254                 }
2255                 if ( $resetGzipEncoding ) {
2256                         if ( $status['name'] == 'ob_gzhandler' ) {
2257                                 // Reset the 'Content-Encoding' field set by this handler
2258                                 // so we can start fresh.
2259                                 header_remove( 'Content-Encoding' );
2260                                 break;
2261                         }
2262                 }
2263         }
2264 }
2265
2266 /**
2267  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2268  *
2269  * Clear away output buffers, but keep the Content-Encoding header
2270  * produced by ob_gzhandler, if any.
2271  *
2272  * This should be used for HTTP 304 responses, where you need to
2273  * preserve the Content-Encoding header of the real result, but
2274  * also need to suppress the output of ob_gzhandler to keep to spec
2275  * and avoid breaking Firefox in rare cases where the headers and
2276  * body are broken over two packets.
2277  */
2278 function wfClearOutputBuffers() {
2279         wfResetOutputBuffers( false );
2280 }
2281
2282 /**
2283  * Converts an Accept-* header into an array mapping string values to quality
2284  * factors
2285  *
2286  * @param string $accept
2287  * @param string $def default
2288  * @return float[] Associative array of string => float pairs
2289  */
2290 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2291         # No arg means accept anything (per HTTP spec)
2292         if ( !$accept ) {
2293                 return array( $def => 1.0 );
2294         }
2295
2296         $prefs = array();
2297
2298         $parts = explode( ',', $accept );
2299
2300         foreach ( $parts as $part ) {
2301                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2302                 $values = explode( ';', trim( $part ) );
2303                 $match = array();
2304                 if ( count( $values ) == 1 ) {
2305                         $prefs[$values[0]] = 1.0;
2306                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2307                         $prefs[$values[0]] = floatval( $match[1] );
2308                 }
2309         }
2310
2311         return $prefs;
2312 }
2313
2314 /**
2315  * Checks if a given MIME type matches any of the keys in the given
2316  * array. Basic wildcards are accepted in the array keys.
2317  *
2318  * Returns the matching MIME type (or wildcard) if a match, otherwise
2319  * NULL if no match.
2320  *
2321  * @param string $type
2322  * @param array $avail
2323  * @return string
2324  * @private
2325  */
2326 function mimeTypeMatch( $type, $avail ) {
2327         if ( array_key_exists( $type, $avail ) ) {
2328                 return $type;
2329         } else {
2330                 $parts = explode( '/', $type );
2331                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2332                         return $parts[0] . '/*';
2333                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2334                         return '*/*';
2335                 } else {
2336                         return null;
2337                 }
2338         }
2339 }
2340
2341 /**
2342  * Returns the 'best' match between a client's requested internet media types
2343  * and the server's list of available types. Each list should be an associative
2344  * array of type to preference (preference is a float between 0.0 and 1.0).
2345  * Wildcards in the types are acceptable.
2346  *
2347  * @param array $cprefs Client's acceptable type list
2348  * @param array $sprefs Server's offered types
2349  * @return string
2350  *
2351  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2352  * XXX: generalize to negotiate other stuff
2353  */
2354 function wfNegotiateType( $cprefs, $sprefs ) {
2355         $combine = array();
2356
2357         foreach ( array_keys( $sprefs ) as $type ) {
2358                 $parts = explode( '/', $type );
2359                 if ( $parts[1] != '*' ) {
2360                         $ckey = mimeTypeMatch( $type, $cprefs );
2361                         if ( $ckey ) {
2362                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2363                         }
2364                 }
2365         }
2366
2367         foreach ( array_keys( $cprefs ) as $type ) {
2368                 $parts = explode( '/', $type );
2369                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2370                         $skey = mimeTypeMatch( $type, $sprefs );
2371                         if ( $skey ) {
2372                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2373                         }
2374                 }
2375         }
2376
2377         $bestq = 0;
2378         $besttype = null;
2379
2380         foreach ( array_keys( $combine ) as $type ) {
2381                 if ( $combine[$type] > $bestq ) {
2382                         $besttype = $type;
2383                         $bestq = $combine[$type];
2384                 }
2385         }
2386
2387         return $besttype;
2388 }
2389
2390 /**
2391  * Reference-counted warning suppression
2392  *
2393  * @param bool $end
2394  */
2395 function wfSuppressWarnings( $end = false ) {
2396         static $suppressCount = 0;
2397         static $originalLevel = false;
2398
2399         if ( $end ) {
2400                 if ( $suppressCount ) {
2401                         --$suppressCount;
2402                         if ( !$suppressCount ) {
2403                                 error_reporting( $originalLevel );
2404                         }
2405                 }
2406         } else {
2407                 if ( !$suppressCount ) {
2408                         $originalLevel = error_reporting( E_ALL & ~(
2409                                 E_WARNING |
2410                                 E_NOTICE |
2411                                 E_USER_WARNING |
2412                                 E_USER_NOTICE |
2413                                 E_DEPRECATED |
2414                                 E_USER_DEPRECATED |
2415                                 E_STRICT
2416                         ) );
2417                 }
2418                 ++$suppressCount;
2419         }
2420 }
2421
2422 /**
2423  * Restore error level to previous value
2424  */
2425 function wfRestoreWarnings() {
2426         wfSuppressWarnings( true );
2427 }
2428
2429 # Autodetect, convert and provide timestamps of various types
2430
2431 /**
2432  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2433  */
2434 define( 'TS_UNIX', 0 );
2435
2436 /**
2437  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2438  */
2439 define( 'TS_MW', 1 );
2440
2441 /**
2442  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2443  */
2444 define( 'TS_DB', 2 );
2445
2446 /**
2447  * RFC 2822 format, for E-mail and HTTP headers
2448  */
2449 define( 'TS_RFC2822', 3 );
2450
2451 /**
2452  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2453  *
2454  * This is used by Special:Export
2455  */
2456 define( 'TS_ISO_8601', 4 );
2457
2458 /**
2459  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2460  *
2461  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2462  *       DateTime tag and page 36 for the DateTimeOriginal and
2463  *       DateTimeDigitized tags.
2464  */
2465 define( 'TS_EXIF', 5 );
2466
2467 /**
2468  * Oracle format time.
2469  */
2470 define( 'TS_ORACLE', 6 );
2471
2472 /**
2473  * Postgres format time.
2474  */
2475 define( 'TS_POSTGRES', 7 );
2476
2477 /**
2478  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2479  */
2480 define( 'TS_ISO_8601_BASIC', 9 );
2481
2482 /**
2483  * Get a timestamp string in one of various formats
2484  *
2485  * @param mixed $outputtype A timestamp in one of the supported formats, the
2486  *   function will autodetect which format is supplied and act accordingly.
2487  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2488  * @return string|bool String / false The same date in the format specified in $outputtype or false
2489  */
2490 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2491         try {
2492                 $timestamp = new MWTimestamp( $ts );
2493                 return $timestamp->getTimestamp( $outputtype );
2494         } catch ( TimestampException $e ) {
2495                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2496                 return false;
2497         }
2498 }
2499
2500 /**
2501  * Return a formatted timestamp, or null if input is null.
2502  * For dealing with nullable timestamp columns in the database.
2503  *
2504  * @param int $outputtype
2505  * @param string $ts
2506  * @return string
2507  */
2508 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2509         if ( is_null( $ts ) ) {
2510                 return null;
2511         } else {
2512                 return wfTimestamp( $outputtype, $ts );
2513         }
2514 }
2515
2516 /**
2517  * Convenience function; returns MediaWiki timestamp for the present time.
2518  *
2519  * @return string
2520  */
2521 function wfTimestampNow() {
2522         # return NOW
2523         return wfTimestamp( TS_MW, time() );
2524 }
2525
2526 /**
2527  * Check if the operating system is Windows
2528  *
2529  * @return bool True if it's Windows, false otherwise.
2530  */
2531 function wfIsWindows() {
2532         static $isWindows = null;
2533         if ( $isWindows === null ) {
2534                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2535         }
2536         return $isWindows;
2537 }
2538
2539 /**
2540  * Check if we are running under HHVM
2541  *
2542  * @return bool
2543  */
2544 function wfIsHHVM() {
2545         return defined( 'HHVM_VERSION' );
2546 }
2547
2548 /**
2549  * Swap two variables
2550  *
2551  * @param mixed $x
2552  * @param mixed $y
2553  */
2554 function swap( &$x, &$y ) {
2555         $z = $x;
2556         $x = $y;
2557         $y = $z;
2558 }
2559
2560 /**
2561  * Tries to get the system directory for temporary files. First
2562  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2563  * environment variables are then checked in sequence, and if none are
2564  * set try sys_get_temp_dir().
2565  *
2566  * NOTE: When possible, use instead the tmpfile() function to create
2567  * temporary files to avoid race conditions on file creation, etc.
2568  *
2569  * @return string
2570  */
2571 function wfTempDir() {
2572         global $wgTmpDirectory;
2573
2574         if ( $wgTmpDirectory !== false ) {
2575                 return $wgTmpDirectory;
2576         }
2577
2578         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2579
2580         foreach ( $tmpDir as $tmp ) {
2581                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2582                         return $tmp;
2583                 }
2584         }
2585         return sys_get_temp_dir();
2586 }
2587
2588 /**
2589  * Make directory, and make all parent directories if they don't exist
2590  *
2591  * @param string $dir Full path to directory to create
2592  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2593  * @param string $caller Optional caller param for debugging.
2594  * @throws MWException
2595  * @return bool
2596  */
2597 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2598         global $wgDirectoryMode;
2599
2600         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2601                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2602         }
2603
2604         if ( !is_null( $caller ) ) {
2605                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2606         }
2607
2608         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2609                 return true;
2610         }
2611
2612         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2613
2614         if ( is_null( $mode ) ) {
2615                 $mode = $wgDirectoryMode;
2616         }
2617
2618         // Turn off the normal warning, we're doing our own below
2619         wfSuppressWarnings();
2620         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2621         wfRestoreWarnings();
2622
2623         if ( !$ok ) {
2624                 //directory may have been created on another request since we last checked
2625                 if ( is_dir( $dir ) ) {
2626                         return true;
2627                 }
2628
2629                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2630                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2631         }
2632         return $ok;
2633 }
2634
2635 /**
2636  * Remove a directory and all its content.
2637  * Does not hide error.
2638  * @param string $dir
2639  */
2640 function wfRecursiveRemoveDir( $dir ) {
2641         wfDebug( __FUNCTION__ . "( $dir )\n" );
2642         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2643         if ( is_dir( $dir ) ) {
2644                 $objects = scandir( $dir );
2645                 foreach ( $objects as $object ) {
2646                         if ( $object != "." && $object != ".." ) {
2647                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2648                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2649                                 } else {
2650                                         unlink( $dir . '/' . $object );
2651                                 }
2652                         }
2653                 }
2654                 reset( $objects );
2655                 rmdir( $dir );
2656         }
2657 }
2658
2659 /**
2660  * @param int $nr The number to format
2661  * @param int $acc The number of digits after the decimal point, default 2
2662  * @param bool $round Whether or not to round the value, default true
2663  * @return string
2664  */
2665 function wfPercent( $nr, $acc = 2, $round = true ) {
2666         $ret = sprintf( "%.${acc}f", $nr );
2667         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2668 }
2669
2670 /**
2671  * Safety wrapper around ini_get() for boolean settings.
2672  * The values returned from ini_get() are pre-normalized for settings
2673  * set via php.ini or php_flag/php_admin_flag... but *not*
2674  * for those set via php_value/php_admin_value.
2675  *
2676  * It's fairly common for people to use php_value instead of php_flag,
2677  * which can leave you with an 'off' setting giving a false positive
2678  * for code that just takes the ini_get() return value as a boolean.
2679  *
2680  * To make things extra interesting, setting via php_value accepts
2681  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2682  * Unrecognized values go false... again opposite PHP's own coercion
2683  * from string to bool.
2684  *
2685  * Luckily, 'properly' set settings will always come back as '0' or '1',
2686  * so we only have to worry about them and the 'improper' settings.
2687  *
2688  * I frickin' hate PHP... :P
2689  *
2690  * @param string $setting
2691  * @return bool
2692  */
2693 function wfIniGetBool( $setting ) {
2694         $val = strtolower( ini_get( $setting ) );
2695         // 'on' and 'true' can't have whitespace around them, but '1' can.
2696         return $val == 'on'
2697                 || $val == 'true'
2698                 || $val == 'yes'
2699                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2700 }
2701
2702 /**
2703  * Windows-compatible version of escapeshellarg()
2704  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2705  * function puts single quotes in regardless of OS.
2706  *
2707  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2708  * earlier distro releases of PHP)
2709  *
2710  * @param string [$args,...]
2711  * @return string
2712  */
2713 function wfEscapeShellArg( /*...*/ ) {
2714         wfInitShellLocale();
2715
2716         $args = func_get_args();
2717         $first = true;
2718         $retVal = '';
2719         foreach ( $args as $arg ) {
2720                 if ( !$first ) {
2721                         $retVal .= ' ';
2722                 } else {
2723                         $first = false;
2724                 }
2725
2726                 if ( wfIsWindows() ) {
2727                         // Escaping for an MSVC-style command line parser and CMD.EXE
2728                         // @codingStandardsIgnoreStart For long URLs
2729                         // Refs:
2730                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2731                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2732                         //  * Bug #13518
2733                         //  * CR r63214
2734                         // Double the backslashes before any double quotes. Escape the double quotes.
2735                         // @codingStandardsIgnoreEnd
2736                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2737                         $arg = '';
2738                         $iteration = 0;
2739                         foreach ( $tokens as $token ) {
2740                                 if ( $iteration % 2 == 1 ) {
2741                                         // Delimiter, a double quote preceded by zero or more slashes
2742                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2743                                 } elseif ( $iteration % 4 == 2 ) {
2744                                         // ^ in $token will be outside quotes, need to be escaped
2745                                         $arg .= str_replace( '^', '^^', $token );
2746                                 } else { // $iteration % 4 == 0
2747                                         // ^ in $token will appear inside double quotes, so leave as is
2748                                         $arg .= $token;
2749                                 }
2750                                 $iteration++;
2751                         }
2752                         // Double the backslashes before the end of the string, because
2753                         // we will soon add a quote
2754                         $m = array();
2755                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2756                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2757                         }
2758
2759                         // Add surrounding quotes
2760                         $retVal .= '"' . $arg . '"';
2761                 } else {
2762                         $retVal .= escapeshellarg( $arg );
2763                 }
2764         }
2765         return $retVal;
2766 }
2767
2768 /**
2769  * Check if wfShellExec() is effectively disabled via php.ini config
2770  *
2771  * @return bool|string False or one of (safemode,disabled)
2772  * @since 1.22
2773  */
2774 function wfShellExecDisabled() {
2775         static $disabled = null;
2776         if ( is_null( $disabled ) ) {
2777                 $disabled = false;
2778                 if ( wfIniGetBool( 'safe_mode' ) ) {
2779                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2780                         $disabled = 'safemode';
2781                 } else {
2782                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2783                         $functions = array_map( 'trim', $functions );
2784                         $functions = array_map( 'strtolower', $functions );
2785                         if ( in_array( 'proc_open', $functions ) ) {
2786                                 wfDebug( "proc_open is in disabled_functions\n" );
2787                                 $disabled = 'disabled';
2788                         }
2789                 }
2790         }
2791         return $disabled;
2792 }
2793
2794 /**
2795  * Execute a shell command, with time and memory limits mirrored from the PHP
2796  * configuration if supported.
2797  *
2798  * @param string $cmd Command line, properly escaped for shell.
2799  * @param null|mixed &$retval Optional, will receive the program's exit code.
2800  *   (non-zero is usually failure). If there is an error from
2801  *   read, select, or proc_open(), this will be set to -1.
2802  * @param array $environ Optional environment variables which should be
2803  *   added to the executed command environment.
2804  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2805  *   this overwrites the global wgMaxShell* limits.
2806  * @param array $options Array of options:
2807  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2808  *     including errors from limit.sh
2809  *
2810  * @return string Collected stdout as a string
2811  */
2812 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2813         $limits = array(), $options = array()
2814 ) {
2815         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2816                 $wgMaxShellWallClockTime, $wgShellCgroup;
2817
2818         $disabled = wfShellExecDisabled();
2819         if ( $disabled ) {
2820                 $retval = 1;
2821                 return $disabled == 'safemode' ?
2822                         'Unable to run external programs in safe mode.' :
2823                         'Unable to run external programs, proc_open() is disabled.';
2824         }
2825
2826         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2827
2828         wfInitShellLocale();
2829
2830         $envcmd = '';
2831         foreach ( $environ as $k => $v ) {
2832                 if ( wfIsWindows() ) {
2833                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2834                          * appear in the environment variable, so we must use carat escaping as documented in
2835                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2836                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2837                          * are listed there but doesn't appear to need it.
2838                          */
2839                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2840                 } else {
2841                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2842                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2843                          */
2844                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2845                 }
2846         }
2847         $cmd = $envcmd . $cmd;
2848
2849         $useLogPipe = false;
2850         if ( php_uname( 's' ) == 'Linux' ) {
2851                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2852                 if ( isset( $limits['walltime'] ) ) {
2853                         $wallTime = intval( $limits['walltime'] );
2854                 } elseif ( isset( $limits['time'] ) ) {
2855                         $wallTime = $time;
2856                 } else {
2857                         $wallTime = intval( $wgMaxShellWallClockTime );
2858                 }
2859                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2860                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2861
2862                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2863                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2864                                 escapeshellarg( $cmd ) . ' ' .
2865                                 escapeshellarg(
2866                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2867                                         "MW_CPU_LIMIT=$time; " .
2868                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2869                                         "MW_MEM_LIMIT=$mem; " .
2870                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2871                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2872                                         "MW_USE_LOG_PIPE=yes"
2873                                 );
2874                         $useLogPipe = true;
2875                 } elseif ( $includeStderr ) {
2876                         $cmd .= ' 2>&1';
2877                 }
2878         } elseif ( $includeStderr ) {
2879                 $cmd .= ' 2>&1';
2880         }
2881         wfDebug( "wfShellExec: $cmd\n" );
2882
2883         $desc = array(
2884                 0 => array( 'file', 'php://stdin', 'r' ),
2885                 1 => array( 'pipe', 'w' ),
2886                 2 => array( 'file', 'php://stderr', 'w' ) );
2887         if ( $useLogPipe ) {
2888                 $desc[3] = array( 'pipe', 'w' );
2889         }
2890         $pipes = null;
2891         $proc = proc_open( $cmd, $desc, $pipes );
2892         if ( !$proc ) {
2893                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2894                 $retval = -1;
2895                 return '';
2896         }
2897         $outBuffer = $logBuffer = '';
2898         $emptyArray = array();
2899         $status = false;
2900         $logMsg = false;
2901
2902         // According to the documentation, it is possible for stream_select()
2903         // to fail due to EINTR. I haven't managed to induce this in testing
2904         // despite sending various signals. If it did happen, the error
2905         // message would take the form:
2906         //
2907         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2908         //
2909         // where [4] is the value of the macro EINTR and "Interrupted system
2910         // call" is string which according to the Linux manual is "possibly"
2911         // localised according to LC_MESSAGES.
2912         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2913         $eintrMessage = "stream_select(): unable to select [$eintr]";
2914
2915         // Build a table mapping resource IDs to pipe FDs to work around a
2916         // PHP 5.3 issue in which stream_select() does not preserve array keys
2917         // <https://bugs.php.net/bug.php?id=53427>.
2918         $fds = array();
2919         foreach ( $pipes as $fd => $pipe ) {
2920                 $fds[(int)$pipe] = $fd;
2921         }
2922
2923         while ( true ) {
2924                 $status = proc_get_status( $proc );
2925                 if ( !$status['running'] ) {
2926                         break;
2927                 }
2928                 $status = false;
2929
2930                 $readyPipes = $pipes;
2931
2932                 // Clear last error
2933                 @trigger_error( '' );
2934                 if ( @stream_select( $readyPipes, $emptyArray, $emptyArray, null ) === false ) {
2935                         $error = error_get_last();
2936                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2937                                 continue;
2938                         } else {
2939                                 trigger_error( $error['message'], E_USER_WARNING );
2940                                 $logMsg = $error['message'];
2941                                 break;
2942                         }
2943                 }
2944                 foreach ( $readyPipes as $pipe ) {
2945                         $block = fread( $pipe, 65536 );
2946                         $fd = $fds[(int)$pipe];
2947                         if ( $block === '' ) {
2948                                 // End of file
2949                                 fclose( $pipes[$fd] );
2950                                 unset( $pipes[$fd] );
2951                                 if ( !$pipes ) {
2952                                         break 2;
2953                                 }
2954                         } elseif ( $block === false ) {
2955                                 // Read error
2956                                 $logMsg = "Error reading from pipe";
2957                                 break 2;
2958                         } elseif ( $fd == 1 ) {
2959                                 // From stdout
2960                                 $outBuffer .= $block;
2961                         } elseif ( $fd == 3 ) {
2962                                 // From log FD
2963                                 $logBuffer .= $block;
2964                                 if ( strpos( $block, "\n" ) !== false ) {
2965                                         $lines = explode( "\n", $logBuffer );
2966                                         $logBuffer = array_pop( $lines );
2967                                         foreach ( $lines as $line ) {
2968                                                 wfDebugLog( 'exec', $line );
2969                                         }
2970                                 }
2971                         }
2972                 }
2973         }
2974
2975         foreach ( $pipes as $pipe ) {
2976                 fclose( $pipe );
2977         }
2978
2979         // Use the status previously collected if possible, since proc_get_status()
2980         // just calls waitpid() which will not return anything useful the second time.
2981         if ( $status === false ) {
2982                 $status = proc_get_status( $proc );
2983         }
2984
2985         if ( $logMsg !== false ) {
2986                 // Read/select error
2987                 $retval = -1;
2988                 proc_close( $proc );
2989         } elseif ( $status['signaled'] ) {
2990                 $logMsg = "Exited with signal {$status['termsig']}";
2991                 $retval = 128 + $status['termsig'];
2992                 proc_close( $proc );
2993         } else {
2994                 if ( $status['running'] ) {
2995                         $retval = proc_close( $proc );
2996                 } else {
2997                         $retval = $status['exitcode'];
2998                         proc_close( $proc );
2999                 }
3000                 if ( $retval == 127 ) {
3001                         $logMsg = "Possibly missing executable file";
3002                 } elseif ( $retval >= 129 && $retval <= 192 ) {
3003                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
3004                 }
3005         }
3006
3007         if ( $logMsg !== false ) {
3008                 wfDebugLog( 'exec', "$logMsg: $cmd" );
3009         }
3010
3011         return $outBuffer;
3012 }
3013
3014 /**
3015  * Execute a shell command, returning both stdout and stderr. Convenience
3016  * function, as all the arguments to wfShellExec can become unwieldy.
3017  *
3018  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
3019  * @param string $cmd Command line, properly escaped for shell.
3020  * @param null|mixed &$retval Optional, will receive the program's exit code.
3021  *   (non-zero is usually failure)
3022  * @param array $environ optional environment variables which should be
3023  *   added to the executed command environment.
3024  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
3025  *   this overwrites the global wgShellMax* limits.
3026  * @return string Collected stdout and stderr as a string
3027  */
3028 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
3029         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
3030 }
3031
3032 /**
3033  * Workaround for http://bugs.php.net/bug.php?id=45132
3034  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
3035  */
3036 function wfInitShellLocale() {
3037         static $done = false;
3038         if ( $done ) {
3039                 return;
3040         }
3041         $done = true;
3042         global $wgShellLocale;
3043         if ( !wfIniGetBool( 'safe_mode' ) ) {
3044                 putenv( "LC_CTYPE=$wgShellLocale" );
3045                 setlocale( LC_CTYPE, $wgShellLocale );
3046         }
3047 }
3048
3049 /**
3050  * Alias to wfShellWikiCmd()
3051  *
3052  * @see wfShellWikiCmd()
3053  */
3054 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
3055         return wfShellWikiCmd( $script, $parameters, $options );
3056 }
3057
3058 /**
3059  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3060  * Note that $parameters should be a flat array and an option with an argument
3061  * should consist of two consecutive items in the array (do not use "--option value").
3062  *
3063  * @param string $script MediaWiki cli script path
3064  * @param array $parameters Arguments and options to the script
3065  * @param array $options Associative array of options:
3066  *              'php': The path to the php executable
3067  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3068  * @return string
3069  */
3070 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3071         global $wgPhpCli;
3072         // Give site config file a chance to run the script in a wrapper.
3073         // The caller may likely want to call wfBasename() on $script.
3074         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3075         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3076         if ( isset( $options['wrapper'] ) ) {
3077                 $cmd[] = $options['wrapper'];
3078         }
3079         $cmd[] = $script;
3080         // Escape each parameter for shell
3081         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
3082 }
3083
3084 /**
3085  * wfMerge attempts to merge differences between three texts.
3086  * Returns true for a clean merge and false for failure or a conflict.
3087  *
3088  * @param string $old
3089  * @param string $mine
3090  * @param string $yours
3091  * @param string $result
3092  * @return bool
3093  */
3094 function wfMerge( $old, $mine, $yours, &$result ) {
3095         global $wgDiff3;
3096
3097         # This check may also protect against code injection in
3098         # case of broken installations.
3099         wfSuppressWarnings();
3100         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3101         wfRestoreWarnings();
3102
3103         if ( !$haveDiff3 ) {
3104                 wfDebug( "diff3 not found\n" );
3105                 return false;
3106         }
3107
3108         # Make temporary files
3109         $td = wfTempDir();
3110         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3111         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3112         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3113
3114         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3115         #       a newline character. To avoid this, we normalize the trailing whitespace before
3116         #       creating the diff.
3117
3118         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3119         fclose( $oldtextFile );
3120         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3121         fclose( $mytextFile );
3122         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3123         fclose( $yourtextFile );
3124
3125         # Check for a conflict
3126         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3127                 wfEscapeShellArg( $mytextName ) . ' ' .
3128                 wfEscapeShellArg( $oldtextName ) . ' ' .
3129                 wfEscapeShellArg( $yourtextName );
3130         $handle = popen( $cmd, 'r' );
3131
3132         if ( fgets( $handle, 1024 ) ) {
3133                 $conflict = true;
3134         } else {
3135                 $conflict = false;
3136         }
3137         pclose( $handle );
3138
3139         # Merge differences
3140         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3141                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3142         $handle = popen( $cmd, 'r' );
3143         $result = '';
3144         do {
3145                 $data = fread( $handle, 8192 );
3146                 if ( strlen( $data ) == 0 ) {
3147                         break;
3148                 }
3149                 $result .= $data;
3150         } while ( true );
3151         pclose( $handle );
3152         unlink( $mytextName );
3153         unlink( $oldtextName );
3154         unlink( $yourtextName );
3155
3156         if ( $result === '' && $old !== '' && !$conflict ) {
3157                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3158                 $conflict = true;
3159         }
3160         return !$conflict;
3161 }
3162
3163 /**
3164  * Returns unified plain-text diff of two texts.
3165  * Useful for machine processing of diffs.
3166  *
3167  * @param string $before The text before the changes.
3168  * @param string $after The text after the changes.
3169  * @param string $params Command-line options for the diff command.
3170  * @return string Unified diff of $before and $after
3171  */
3172 function wfDiff( $before, $after, $params = '-u' ) {
3173         if ( $before == $after ) {
3174                 return '';
3175         }
3176
3177         global $wgDiff;
3178         wfSuppressWarnings();
3179         $haveDiff = $wgDiff && file_exists( $wgDiff );
3180         wfRestoreWarnings();
3181
3182         # This check may also protect against code injection in
3183         # case of broken installations.
3184         if ( !$haveDiff ) {
3185                 wfDebug( "diff executable not found\n" );
3186                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3187                 $format = new UnifiedDiffFormatter();
3188                 return $format->format( $diffs );
3189         }
3190
3191         # Make temporary files
3192         $td = wfTempDir();
3193         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3194         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3195
3196         fwrite( $oldtextFile, $before );
3197         fclose( $oldtextFile );
3198         fwrite( $newtextFile, $after );
3199         fclose( $newtextFile );
3200
3201         // Get the diff of the two files
3202         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3203
3204         $h = popen( $cmd, 'r' );
3205
3206         $diff = '';
3207
3208         do {
3209                 $data = fread( $h, 8192 );
3210                 if ( strlen( $data ) == 0 ) {
3211                         break;
3212                 }
3213                 $diff .= $data;
3214         } while ( true );
3215
3216         // Clean up
3217         pclose( $h );
3218         unlink( $oldtextName );
3219         unlink( $newtextName );
3220
3221         // Kill the --- and +++ lines. They're not useful.
3222         $diff_lines = explode( "\n", $diff );
3223         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3224                 unset( $diff_lines[0] );
3225         }
3226         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3227                 unset( $diff_lines[1] );
3228         }
3229
3230         $diff = implode( "\n", $diff_lines );
3231
3232         return $diff;
3233 }
3234
3235 /**
3236  * This function works like "use VERSION" in Perl, the program will die with a
3237  * backtrace if the current version of PHP is less than the version provided
3238  *
3239  * This is useful for extensions which due to their nature are not kept in sync
3240  * with releases, and might depend on other versions of PHP than the main code
3241  *
3242  * Note: PHP might die due to parsing errors in some cases before it ever
3243  *       manages to call this function, such is life
3244  *
3245  * @see perldoc -f use
3246  *
3247  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3248  * @throws MWException
3249  */
3250 function wfUsePHP( $req_ver ) {
3251         $php_ver = PHP_VERSION;
3252
3253         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3254                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3255         }
3256 }
3257
3258 /**
3259  * This function works like "use VERSION" in Perl except it checks the version
3260  * of MediaWiki, the program will die with a backtrace if the current version
3261  * of MediaWiki is less than the version provided.
3262  *
3263  * This is useful for extensions which due to their nature are not kept in sync
3264  * with releases
3265  *
3266  * Note: Due to the behavior of PHP's version_compare() which is used in this
3267  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3268  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3269  * targeted version number. For example if you wanted to allow any variation
3270  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3271  * not result in the same comparison due to the internal logic of
3272  * version_compare().
3273  *
3274  * @see perldoc -f use
3275  *
3276  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3277  * @throws MWException
3278  */
3279 function wfUseMW( $req_ver ) {
3280         global $wgVersion;
3281
3282         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3283                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3284         }
3285 }
3286
3287 /**
3288  * Return the final portion of a pathname.
3289  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3290  * http://bugs.php.net/bug.php?id=33898
3291  *
3292  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3293  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3294  *
3295  * @param string $path
3296  * @param string $suffix String to remove if present
3297  * @return string
3298  */
3299 function wfBaseName( $path, $suffix = '' ) {
3300         if ( $suffix == '' ) {
3301                 $encSuffix = '';
3302         } else {
3303                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3304         }
3305
3306         $matches = array();
3307         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3308                 return $matches[1];
3309         } else {
3310                 return '';
3311         }
3312 }
3313
3314 /**
3315  * Generate a relative path name to the given file.
3316  * May explode on non-matching case-insensitive paths,
3317  * funky symlinks, etc.
3318  *
3319  * @param string $path Absolute destination path including target filename
3320  * @param string $from Absolute source path, directory only
3321  * @return string
3322  */
3323 function wfRelativePath( $path, $from ) {
3324         // Normalize mixed input on Windows...
3325         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3326         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3327
3328         // Trim trailing slashes -- fix for drive root
3329         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3330         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3331
3332         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3333         $against = explode( DIRECTORY_SEPARATOR, $from );
3334
3335         if ( $pieces[0] !== $against[0] ) {
3336                 // Non-matching Windows drive letters?
3337                 // Return a full path.
3338                 return $path;
3339         }
3340
3341         // Trim off common prefix
3342         while ( count( $pieces ) && count( $against )
3343                 && $pieces[0] == $against[0] ) {
3344                 array_shift( $pieces );
3345                 array_shift( $against );
3346         }
3347
3348         // relative dots to bump us to the parent
3349         while ( count( $against ) ) {
3350                 array_unshift( $pieces, '..' );
3351                 array_shift( $against );
3352         }
3353
3354         array_push( $pieces, wfBaseName( $path ) );
3355
3356         return implode( DIRECTORY_SEPARATOR, $pieces );
3357 }
3358
3359 /**
3360  * Convert an arbitrarily-long digit string from one numeric base
3361  * to another, optionally zero-padding to a minimum column width.
3362  *
3363  * Supports base 2 through 36; digit values 10-36 are represented
3364  * as lowercase letters a-z. Input is case-insensitive.
3365  *
3366  * @param string $input Input number
3367  * @param int $sourceBase Base of the input number
3368  * @param int $destBase Desired base of the output
3369  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3370  * @param bool $lowercase Whether to output in lowercase or uppercase
3371  * @param string $engine Either "gmp", "bcmath", or "php"
3372  * @return string|bool The output number as a string, or false on error
3373  */
3374 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3375         $lowercase = true, $engine = 'auto'
3376 ) {
3377         $input = (string)$input;
3378         if (
3379                 $sourceBase < 2 ||
3380                 $sourceBase > 36 ||
3381                 $destBase < 2 ||
3382                 $destBase > 36 ||
3383                 $sourceBase != (int)$sourceBase ||
3384                 $destBase != (int)$destBase ||
3385                 $pad != (int)$pad ||
3386                 !preg_match(
3387                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3388                         $input
3389                 )
3390         ) {
3391                 return false;
3392         }
3393
3394         static $baseChars = array(
3395                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3396                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3397                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3398                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3399                 34 => 'y', 35 => 'z',
3400
3401                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3402                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3403                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3404                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3405                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3406                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3407         );
3408
3409         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3410                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3411         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3412                 $decimal = '0';
3413                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3414                         $decimal = bcmul( $decimal, $sourceBase );
3415                         $decimal = bcadd( $decimal, $baseChars[$char] );
3416                 }
3417
3418                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3419                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3420                 }
3421
3422                 $result = strrev( $result );
3423         } else {
3424                 $inDigits = array();
3425                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3426                         $inDigits[] = $baseChars[$char];
3427                 }
3428
3429                 // Iterate over the input, modulo-ing out an output digit
3430                 // at a time until input is gone.
3431                 $result = '';
3432                 while ( $inDigits ) {
3433                         $work = 0;
3434                         $workDigits = array();
3435
3436                         // Long division...
3437                         foreach ( $inDigits as $digit ) {
3438                                 $work *= $sourceBase;
3439                                 $work += $digit;
3440
3441                                 if ( $workDigits || $work >= $destBase ) {
3442                                         $workDigits[] = (int)( $work / $destBase );
3443                                 }
3444                                 $work %= $destBase;
3445                         }
3446
3447                         // All that division leaves us with a remainder,
3448                         // which is conveniently our next output digit.
3449                         $result .= $baseChars[$work];
3450
3451                         // And we continue!
3452                         $inDigits = $workDigits;
3453                 }
3454
3455                 $result = strrev( $result );
3456         }
3457
3458         if ( !$lowercase ) {
3459                 $result = strtoupper( $result );
3460         }
3461
3462         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3463 }
3464
3465 /**
3466  * Check if there is sufficient entropy in php's built-in session generation
3467  *
3468  * @return bool true = there is sufficient entropy
3469  */
3470 function wfCheckEntropy() {
3471         return (
3472                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3473                         || ini_get( 'session.entropy_file' )
3474                 )
3475                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3476 }
3477
3478 /**
3479  * Override session_id before session startup if php's built-in
3480  * session generation code is not secure.
3481  */
3482 function wfFixSessionID() {
3483         // If the cookie or session id is already set we already have a session and should abort
3484         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3485                 return;
3486         }
3487
3488         // PHP's built-in session entropy is enabled if:
3489         // - entropy_file is set or you're on Windows with php 5.3.3+
3490         // - AND entropy_length is > 0
3491         // We treat it as disabled if it doesn't have an entropy length of at least 32
3492         $entropyEnabled = wfCheckEntropy();
3493
3494         // If built-in entropy is not enabled or not sufficient override PHP's
3495         // built in session id generation code
3496         if ( !$entropyEnabled ) {
3497                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3498                         "overriding session id generation using our cryptrand source.\n" );
3499                 session_id( MWCryptRand::generateHex( 32 ) );
3500         }
3501 }
3502
3503 /**
3504  * Reset the session_id
3505  *
3506  * @since 1.22
3507  */
3508 function wfResetSessionID() {
3509         global $wgCookieSecure;
3510         $oldSessionId = session_id();
3511         $cookieParams = session_get_cookie_params();
3512         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3513                 session_regenerate_id( false );
3514         } else {
3515                 $tmp = $_SESSION;
3516                 session_destroy();
3517                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3518                 $_SESSION = $tmp;
3519         }
3520         $newSessionId = session_id();
3521         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3522 }
3523
3524 /**
3525  * Initialise php session
3526  *
3527  * @param bool $sessionId
3528  */
3529 function wfSetupSession( $sessionId = false ) {
3530         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3531                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3532         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3533                 ObjectCacheSessionHandler::install();
3534         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3535                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3536                 # hasn't already been set to the desired value (that causes errors)
3537                 ini_set( 'session.save_handler', $wgSessionHandler );
3538         }
3539         session_set_cookie_params(
3540                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3541         session_cache_limiter( 'private, must-revalidate' );
3542         if ( $sessionId ) {
3543                 session_id( $sessionId );
3544         } else {
3545                 wfFixSessionID();
3546         }
3547         wfSuppressWarnings();
3548         session_start();
3549         wfRestoreWarnings();
3550 }
3551
3552 /**
3553  * Get an object from the precompiled serialized directory
3554  *
3555  * @param string $name
3556  * @return mixed The variable on success, false on failure
3557  */
3558 function wfGetPrecompiledData( $name ) {
3559         global $IP;
3560
3561         $file = "$IP/serialized/$name";
3562         if ( file_exists( $file ) ) {
3563                 $blob = file_get_contents( $file );
3564                 if ( $blob ) {
3565                         return unserialize( $blob );
3566                 }
3567         }
3568         return false;
3569 }
3570
3571 /**
3572  * Get a cache key
3573  *
3574  * @param string [$args,...]
3575  * @return string
3576  */
3577 function wfMemcKey( /*...*/ ) {
3578         global $wgCachePrefix;
3579         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3580         $args = func_get_args();
3581         $key = $prefix . ':' . implode( ':', $args );
3582         $key = str_replace( ' ', '_', $key );
3583         return $key;
3584 }
3585
3586 /**
3587  * Get a cache key for a foreign DB
3588  *
3589  * @param string $db
3590  * @param string $prefix
3591  * @param string [$args,...]
3592  * @return string
3593  */
3594 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3595         $args = array_slice( func_get_args(), 2 );
3596         if ( $prefix ) {
3597                 $key = "$db-$prefix:" . implode( ':', $args );
3598         } else {
3599                 $key = $db . ':' . implode( ':', $args );
3600         }
3601         return str_replace( ' ', '_', $key );
3602 }
3603
3604 /**
3605  * Get an ASCII string identifying this wiki
3606  * This is used as a prefix in memcached keys
3607  *
3608  * @return string
3609  */
3610 function wfWikiID() {
3611         global $wgDBprefix, $wgDBname;
3612         if ( $wgDBprefix ) {
3613                 return "$wgDBname-$wgDBprefix";
3614         } else {
3615                 return $wgDBname;
3616         }
3617 }
3618
3619 /**
3620  * Split a wiki ID into DB name and table prefix
3621  *
3622  * @param string $wiki
3623  *
3624  * @return array
3625  */
3626 function wfSplitWikiID( $wiki ) {
3627         $bits = explode( '-', $wiki, 2 );
3628         if ( count( $bits ) < 2 ) {
3629                 $bits[] = '';
3630         }
3631         return $bits;
3632 }
3633
3634 /**
3635  * Get a Database object.
3636  *
3637  * @param int $db Index of the connection to get. May be DB_MASTER for the
3638  *            master (for write queries), DB_SLAVE for potentially lagged read
3639  *            queries, or an integer >= 0 for a particular server.
3640  *
3641  * @param string|string[] $groups Query groups. An array of group names that this query
3642  *                belongs to. May contain a single string if the query is only
3643  *                in one group.
3644  *
3645  * @param string|bool $wiki The wiki ID, or false for the current wiki
3646  *
3647  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3648  * will always return the same object, unless the underlying connection or load
3649  * balancer is manually destroyed.
3650  *
3651  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3652  * updater to ensure that a proper database is being updated.
3653  *
3654  * @return DatabaseBase
3655  */
3656 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3657         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3658 }
3659
3660 /**
3661  * Get a load balancer object.
3662  *
3663  * @param string|bool $wiki wiki ID, or false for the current wiki
3664  * @return LoadBalancer
3665  */
3666 function wfGetLB( $wiki = false ) {
3667         return wfGetLBFactory()->getMainLB( $wiki );
3668 }
3669
3670 /**
3671  * Get the load balancer factory object
3672  *
3673  * @return LBFactory
3674  */
3675 function &wfGetLBFactory() {
3676         return LBFactory::singleton();
3677 }
3678
3679 /**
3680  * Find a file.
3681  * Shortcut for RepoGroup::singleton()->findFile()
3682  *
3683  * @param string $title or Title object
3684  * @param array $options Associative array of options:
3685  *     time:           requested time for an archived image, or false for the
3686  *                     current version. An image object will be returned which was
3687  *                     created at the specified time.
3688  *
3689  *     ignoreRedirect: If true, do not follow file redirects
3690  *
3691  *     private:        If true, return restricted (deleted) files if the current
3692  *                     user is allowed to view them. Otherwise, such files will not
3693  *                     be found.
3694  *
3695  *     bypassCache:    If true, do not use the process-local cache of File objects
3696  *
3697  * @return File|bool File, or false if the file does not exist
3698  */
3699 function wfFindFile( $title, $options = array() ) {
3700         return RepoGroup::singleton()->findFile( $title, $options );
3701 }
3702
3703 /**
3704  * Get an object referring to a locally registered file.
3705  * Returns a valid placeholder object if the file does not exist.
3706  *
3707  * @param Title|string $title
3708  * @return LocalFile|null A File, or null if passed an invalid Title
3709  */
3710 function wfLocalFile( $title ) {
3711         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3712 }
3713
3714 /**
3715  * Should low-performance queries be disabled?
3716  *
3717  * @return bool
3718  * @codeCoverageIgnore
3719  */
3720 function wfQueriesMustScale() {
3721         global $wgMiserMode;
3722         return $wgMiserMode
3723                 || ( SiteStats::pages() > 100000
3724                 && SiteStats::edits() > 1000000
3725                 && SiteStats::users() > 10000 );
3726 }
3727
3728 /**
3729  * Get the path to a specified script file, respecting file
3730  * extensions; this is a wrapper around $wgScriptExtension etc.
3731  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3732  *
3733  * @param string $script Script filename, sans extension
3734  * @return string
3735  */
3736 function wfScript( $script = 'index' ) {
3737         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3738         if ( $script === 'index' ) {
3739                 return $wgScript;
3740         } elseif ( $script === 'load' ) {
3741                 return $wgLoadScript;
3742         } else {
3743                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3744         }
3745 }
3746
3747 /**
3748  * Get the script URL.
3749  *
3750  * @return string script URL
3751  */
3752 function wfGetScriptUrl() {
3753         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3754                 #
3755                 # as it was called, minus the query string.
3756                 #
3757                 # Some sites use Apache rewrite rules to handle subdomains,
3758                 # and have PHP set up in a weird way that causes PHP_SELF
3759                 # to contain the rewritten URL instead of the one that the
3760                 # outside world sees.
3761                 #
3762                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3763                 # provides containing the "before" URL.
3764                 return $_SERVER['SCRIPT_NAME'];
3765         } else {
3766                 return $_SERVER['URL'];
3767         }
3768 }
3769
3770 /**
3771  * Convenience function converts boolean values into "true"
3772  * or "false" (string) values
3773  *
3774  * @param bool $value
3775  * @return string
3776  */
3777 function wfBoolToStr( $value ) {
3778         return $value ? 'true' : 'false';
3779 }
3780
3781 /**
3782  * Get a platform-independent path to the null file, e.g. /dev/null
3783  *
3784  * @return string
3785  */
3786 function wfGetNull() {
3787         return wfIsWindows() ? 'NUL' : '/dev/null';
3788 }
3789
3790 /**
3791  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3792  * and waiting for it to go down, this waits for the slaves to catch up to the
3793  * master position. Use this when updating very large numbers of rows, as
3794  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3795  * a no-op if there are no slaves.
3796  *
3797  * @param int|bool $maxLag (deprecated)
3798  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3799  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3800  */
3801 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3802         if ( $cluster !== false ) {
3803                 $lb = wfGetLBFactory()->getExternalLB( $cluster );
3804         } else {
3805                 $lb = wfGetLB( $wiki );
3806         }
3807
3808         // bug 27975 - Don't try to wait for slaves if there are none
3809         // Prevents permission error when getting master position
3810         if ( $lb->getServerCount() > 1 ) {
3811                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3812                 $pos = $dbw->getMasterPos();
3813                 // The DBMS may not support getMasterPos() or the whole
3814                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3815                 if ( $pos !== false ) {
3816                         $lb->waitForAll( $pos );
3817                 }
3818         }
3819 }
3820
3821 /**
3822  * Count down from $seconds to zero on the terminal, with a one-second pause
3823  * between showing each number. For use in command-line scripts.
3824  *
3825  * @codeCoverageIgnore
3826  * @param int $seconds
3827  */
3828 function wfCountDown( $seconds ) {
3829         for ( $i = $seconds; $i >= 0; $i-- ) {
3830                 if ( $i != $seconds ) {
3831                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3832                 }
3833                 echo $i;
3834                 flush();
3835                 if ( $i ) {
3836                         sleep( 1 );
3837                 }
3838         }
3839         echo "\n";
3840 }
3841
3842 /**
3843  * Replace all invalid characters with -
3844  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3845  * By default, $wgIllegalFileChars = ':'
3846  *
3847  * @param string $name Filename to process
3848  * @return string
3849  */
3850 function wfStripIllegalFilenameChars( $name ) {
3851         global $wgIllegalFileChars;
3852         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3853         $name = wfBaseName( $name );
3854         $name = preg_replace(
3855                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3856                 '-',
3857                 $name
3858         );
3859         return $name;
3860 }
3861
3862 /**
3863  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3864  *
3865  * @return int Value the memory limit was set to.
3866  */
3867 function wfMemoryLimit() {
3868         global $wgMemoryLimit;
3869         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3870         if ( $memlimit != -1 ) {
3871                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3872                 if ( $conflimit == -1 ) {
3873                         wfDebug( "Removing PHP's memory limit\n" );
3874                         wfSuppressWarnings();
3875                         ini_set( 'memory_limit', $conflimit );
3876                         wfRestoreWarnings();
3877                         return $conflimit;
3878                 } elseif ( $conflimit > $memlimit ) {
3879                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3880                         wfSuppressWarnings();
3881                         ini_set( 'memory_limit', $conflimit );
3882                         wfRestoreWarnings();
3883                         return $conflimit;
3884                 }
3885         }
3886         return $memlimit;
3887 }
3888
3889 /**
3890  * Converts shorthand byte notation to integer form
3891  *
3892  * @param string $string
3893  * @return int
3894  */
3895 function wfShorthandToInteger( $string = '' ) {
3896         $string = trim( $string );
3897         if ( $string === '' ) {
3898                 return -1;
3899         }
3900         $last = $string[strlen( $string ) - 1];
3901         $val = intval( $string );
3902         switch ( $last ) {
3903                 case 'g':
3904                 case 'G':
3905                         $val *= 1024;
3906                         // break intentionally missing
3907                 case 'm':
3908                 case 'M':
3909                         $val *= 1024;
3910                         // break intentionally missing
3911                 case 'k':
3912                 case 'K':
3913                         $val *= 1024;
3914         }
3915
3916         return $val;
3917 }
3918
3919 /**
3920  * Get the normalised IETF language tag
3921  * See unit test for examples.
3922  *
3923  * @param string $code The language code.
3924  * @return string The language code which complying with BCP 47 standards.
3925  */
3926 function wfBCP47( $code ) {
3927         $codeSegment = explode( '-', $code );
3928         $codeBCP = array();
3929         foreach ( $codeSegment as $segNo => $seg ) {
3930                 // when previous segment is x, it is a private segment and should be lc
3931                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3932                         $codeBCP[$segNo] = strtolower( $seg );
3933                 // ISO 3166 country code
3934                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3935                         $codeBCP[$segNo] = strtoupper( $seg );
3936                 // ISO 15924 script code
3937                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3938                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3939                 // Use lowercase for other cases
3940                 } else {
3941                         $codeBCP[$segNo] = strtolower( $seg );
3942                 }
3943         }
3944         $langCode = implode( '-', $codeBCP );
3945         return $langCode;
3946 }
3947
3948 /**
3949  * Get a cache object.
3950  *
3951  * @param int $inputType Cache type, one the the CACHE_* constants.
3952  * @return BagOStuff
3953  */
3954 function wfGetCache( $inputType ) {
3955         return ObjectCache::getInstance( $inputType );
3956 }
3957
3958 /**
3959  * Get the main cache object
3960  *
3961  * @return BagOStuff
3962  */
3963 function wfGetMainCache() {
3964         global $wgMainCacheType;
3965         return ObjectCache::getInstance( $wgMainCacheType );
3966 }
3967
3968 /**
3969  * Get the cache object used by the message cache
3970  *
3971  * @return BagOStuff
3972  */
3973 function wfGetMessageCacheStorage() {
3974         global $wgMessageCacheType;
3975         return ObjectCache::getInstance( $wgMessageCacheType );
3976 }
3977
3978 /**
3979  * Get the cache object used by the parser cache
3980  *
3981  * @return BagOStuff
3982  */
3983 function wfGetParserCacheStorage() {
3984         global $wgParserCacheType;
3985         return ObjectCache::getInstance( $wgParserCacheType );
3986 }
3987
3988 /**
3989  * Get the cache object used by the language converter
3990  *
3991  * @return BagOStuff
3992  */
3993 function wfGetLangConverterCacheStorage() {
3994         global $wgLanguageConverterCacheType;
3995         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3996 }
3997
3998 /**
3999  * Call hook functions defined in $wgHooks
4000  *
4001  * @param string $event Event name
4002  * @param array $args Parameters passed to hook functions
4003  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
4004  *
4005  * @return bool True if no handler aborted the hook
4006  */
4007 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
4008         return Hooks::run( $event, $args, $deprecatedVersion );
4009 }
4010
4011 /**
4012  * Wrapper around php's unpack.
4013  *
4014  * @param string $format The format string (See php's docs)
4015  * @param string $data A binary string of binary data
4016  * @param int|bool $length The minimum length of $data or false. This is to
4017  *      prevent reading beyond the end of $data. false to disable the check.
4018  *
4019  * Also be careful when using this function to read unsigned 32 bit integer
4020  * because php might make it negative.
4021  *
4022  * @throws MWException if $data not long enough, or if unpack fails
4023  * @return array Associative array of the extracted data
4024  */
4025 function wfUnpack( $format, $data, $length = false ) {
4026         if ( $length !== false ) {
4027                 $realLen = strlen( $data );
4028                 if ( $realLen < $length ) {
4029                         throw new MWException( "Tried to use wfUnpack on a "
4030                                 . "string of length $realLen, but needed one "
4031                                 . "of at least length $length."
4032                         );
4033                 }
4034         }
4035
4036         wfSuppressWarnings();
4037         $result = unpack( $format, $data );
4038         wfRestoreWarnings();
4039
4040         if ( $result === false ) {
4041                 // If it cannot extract the packed data.
4042                 throw new MWException( "unpack could not unpack binary data" );
4043         }
4044         return $result;
4045 }
4046
4047 /**
4048  * Determine if an image exists on the 'bad image list'.
4049  *
4050  * The format of MediaWiki:Bad_image_list is as follows:
4051  *    * Only list items (lines starting with "*") are considered
4052  *    * The first link on a line must be a link to a bad image
4053  *    * Any subsequent links on the same line are considered to be exceptions,
4054  *      i.e. articles where the image may occur inline.
4055  *
4056  * @param string $name The image name to check
4057  * @param Title|bool $contextTitle The page on which the image occurs, if known
4058  * @param string $blacklist Wikitext of a file blacklist
4059  * @return bool
4060  */
4061 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4062         static $badImageCache = null; // based on bad_image_list msg
4063         wfProfileIn( __METHOD__ );
4064
4065         # Handle redirects
4066         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4067         if ( $redirectTitle ) {
4068                 $name = $redirectTitle->getDBkey();
4069         }
4070
4071         # Run the extension hook
4072         $bad = false;
4073         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
4074                 wfProfileOut( __METHOD__ );
4075                 return $bad;
4076         }
4077
4078         $cacheable = ( $blacklist === null );
4079         if ( $cacheable && $badImageCache !== null ) {
4080                 $badImages = $badImageCache;
4081         } else { // cache miss
4082                 if ( $blacklist === null ) {
4083                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4084                 }
4085                 # Build the list now
4086                 $badImages = array();
4087                 $lines = explode( "\n", $blacklist );
4088                 foreach ( $lines as $line ) {
4089                         # List items only
4090                         if ( substr( $line, 0, 1 ) !== '*' ) {
4091                                 continue;
4092                         }
4093
4094                         # Find all links
4095                         $m = array();
4096                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4097                                 continue;
4098                         }
4099
4100                         $exceptions = array();
4101                         $imageDBkey = false;
4102                         foreach ( $m[1] as $i => $titleText ) {
4103                                 $title = Title::newFromText( $titleText );
4104                                 if ( !is_null( $title ) ) {
4105                                         if ( $i == 0 ) {
4106                                                 $imageDBkey = $title->getDBkey();
4107                                         } else {
4108                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4109                                         }
4110                                 }
4111                         }
4112
4113                         if ( $imageDBkey !== false ) {
4114                                 $badImages[$imageDBkey] = $exceptions;
4115                         }
4116                 }
4117                 if ( $cacheable ) {
4118                         $badImageCache = $badImages;
4119                 }
4120         }
4121
4122         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4123         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4124         wfProfileOut( __METHOD__ );
4125         return $bad;
4126 }
4127
4128 /**
4129  * Determine whether the client at a given source IP is likely to be able to
4130  * access the wiki via HTTPS.
4131  *
4132  * @param string $ip The IPv4/6 address in the normal human-readable form
4133  * @return bool
4134  */
4135 function wfCanIPUseHTTPS( $ip ) {
4136         $canDo = true;
4137         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4138         return !!$canDo;
4139 }
4140
4141 /**
4142  * Work out the IP address based on various globals
4143  * For trusted proxies, use the XFF client IP (first of the chain)
4144  *
4145  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4146  * @return string
4147  */
4148 function wfGetIP() {
4149         wfDeprecated( __METHOD__, '1.19' );
4150         global $wgRequest;
4151         return $wgRequest->getIP();
4152 }
4153
4154 /**
4155  * Checks if an IP is a trusted proxy provider.
4156  * Useful to tell if X-Forwarded-For data is possibly bogus.
4157  * Squid cache servers for the site are whitelisted.
4158  *
4159  * @param string $ip
4160  * @return bool
4161  */
4162 function wfIsTrustedProxy( $ip ) {
4163         $trusted = wfIsConfiguredProxy( $ip );
4164         wfRunHooks( 'IsTrustedProxy', array( &$ip, &$trusted ) );
4165         return $trusted;
4166 }
4167
4168 /**
4169  * Checks if an IP matches a proxy we've configured.
4170  *
4171  * @param string $ip
4172  * @return bool
4173  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4174  */
4175 function wfIsConfiguredProxy( $ip ) {
4176         global $wgSquidServers, $wgSquidServersNoPurge;
4177
4178         // quick check of known proxy servers
4179         $trusted = in_array( $ip, $wgSquidServers )
4180                 || in_array( $ip, $wgSquidServersNoPurge );
4181
4182         if ( !$trusted ) {
4183                 // slightly slower check to see if the ip is listed directly or in a CIDR
4184                 // block in $wgSquidServersNoPurge
4185                 foreach ( $wgSquidServersNoPurge as $block ) {
4186                         if ( strpos( $block, '/' ) !== false && IP::isInRange( $ip, $block ) ) {
4187                                 $trusted = true;
4188                                 break;
4189                         }
4190                 }
4191         }
4192         return $trusted;
4193 }