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         if ( $defaultProto === PROTO_CANONICAL ) {
 502                 $serverUrl = $wgCanonicalServer;
 503         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 504                 // Make $wgInternalServer fall back to $wgServer if not set
 505                 $serverUrl = $wgInternalServer;
 506         } else {
 507                 $serverUrl = $wgServer;
 508                 if ( $defaultProto === PROTO_CURRENT ) {
 509                         $defaultProto = $wgRequest->getProtocol() . '://';
 510                 }
 511         }
 512
 513         // Analyze $serverUrl to obtain its protocol
 514         $bits = wfParseUrl( $serverUrl );
 515         $serverHasProto = $bits && $bits['scheme'] != '';
 516
 517         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 518                 if ( $serverHasProto ) {
 519                         $defaultProto = $bits['scheme'] . '://';
 520                 } else {
 521                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 522                         // This really isn't supposed to happen. Fall back to HTTP in this
 523                         // ridiculous case.
 524                         $defaultProto = PROTO_HTTP;
 525                 }
 526         }
 527
 528         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 529
 530         if ( substr( $url, 0, 2 ) == '//' ) {
 531                 $url = $defaultProtoWithoutSlashes . $url;
 532         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 533                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 534                 // otherwise leave it alone.
 535                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 536         }
 537
 538         $bits = wfParseUrl( $url );
 539         if ( $bits && isset( $bits['path'] ) ) {
 540                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 541                 return wfAssembleUrl( $bits );
 542         } elseif ( $bits ) {
 543                 # No path to expand
 544                 return $url;
 545         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 546                 # URL is a relative path
 547                 return wfRemoveDotSegments( $url );
 548         }
 549
 550         # Expanded URL is not valid.
 551         return false;
 552 }
 553
 554 /**
 555  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 556  * if you need to edit part of a URL and put it back together.
 557  *
 558  * This is the basic structure used (brackets contain keys for $urlParts):
 559  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 560  *
 561  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 562  *
 563  * @since 1.19
 564  * @param array $urlParts URL parts, as output from wfParseUrl
 565  * @return string URL assembled from its component parts
 566  */
 567 function wfAssembleUrl( $urlParts ) {
 568         $result = '';
 569
 570         if ( isset( $urlParts['delimiter'] ) ) {
 571                 if ( isset( $urlParts['scheme'] ) ) {
 572                         $result .= $urlParts['scheme'];
 573                 }
 574
 575                 $result .= $urlParts['delimiter'];
 576         }
 577
 578         if ( isset( $urlParts['host'] ) ) {
 579                 if ( isset( $urlParts['user'] ) ) {
 580                         $result .= $urlParts['user'];
 581                         if ( isset( $urlParts['pass'] ) ) {
 582                                 $result .= ':' . $urlParts['pass'];
 583                         }
 584                         $result .= '@';
 585                 }
 586
 587                 $result .= $urlParts['host'];
 588
 589                 if ( isset( $urlParts['port'] ) ) {
 590                         $result .= ':' . $urlParts['port'];
 591                 }
 592         }
 593
 594         if ( isset( $urlParts['path'] ) ) {
 595                 $result .= $urlParts['path'];
 596         }
 597
 598         if ( isset( $urlParts['query'] ) ) {
 599                 $result .= '?' . $urlParts['query'];
 600         }
 601
 602         if ( isset( $urlParts['fragment'] ) ) {
 603                 $result .= '#' . $urlParts['fragment'];
 604         }
 605
 606         return $result;
 607 }
 608
 609 /**
 610  * Remove all dot-segments in the provided URL path.  For example,
 611  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 612  * RFC3986 section 5.2.4.
 613  *
 614  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 615  *
 616  * @param string $urlPath URL path, potentially containing dot-segments
 617  * @return string URL path with all dot-segments removed
 618  */
 619 function wfRemoveDotSegments( $urlPath ) {
 620         $output = '';
 621         $inputOffset = 0;
 622         $inputLength = strlen( $urlPath );
 623
 624         while ( $inputOffset < $inputLength ) {
 625                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 626                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 627                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 628                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 629                 $trimOutput = false;
 630
 631                 if ( $prefixLengthTwo == './' ) {
 632                         # Step A, remove leading "./"
 633                         $inputOffset += 2;
 634                 } elseif ( $prefixLengthThree == '../' ) {
 635                         # Step A, remove leading "../"
 636                         $inputOffset += 3;
 637                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 638                         # Step B, replace leading "/.$" with "/"
 639                         $inputOffset += 1;
 640                         $urlPath[$inputOffset] = '/';
 641                 } elseif ( $prefixLengthThree == '/./' ) {
 642                         # Step B, replace leading "/./" with "/"
 643                         $inputOffset += 2;
 644                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 645                         # Step C, replace leading "/..$" with "/" and
 646                         # remove last path component in output
 647                         $inputOffset += 2;
 648                         $urlPath[$inputOffset] = '/';
 649                         $trimOutput = true;
 650                 } elseif ( $prefixLengthFour == '/../' ) {
 651                         # Step C, replace leading "/../" with "/" and
 652                         # remove last path component in output
 653                         $inputOffset += 3;
 654                         $trimOutput = true;
 655                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 656                         # Step D, remove "^.$"
 657                         $inputOffset += 1;
 658                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 659                         # Step D, remove "^..$"
 660                         $inputOffset += 2;
 661                 } else {
 662                         # Step E, move leading path segment to output
 663                         if ( $prefixLengthOne == '/' ) {
 664                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 665                         } else {
 666                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 667                         }
 668                         if ( $slashPos === false ) {
 669                                 $output .= substr( $urlPath, $inputOffset );
 670                                 $inputOffset = $inputLength;
 671                         } else {
 672                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 673                                 $inputOffset += $slashPos - $inputOffset;
 674                         }
 675                 }
 676
 677                 if ( $trimOutput ) {
 678                         $slashPos = strrpos( $output, '/' );
 679                         if ( $slashPos === false ) {
 680                                 $output = '';
 681                         } else {
 682                                 $output = substr( $output, 0, $slashPos );
 683                         }
 684                 }
 685         }
 686
 687         return $output;
 688 }
 689
 690 /**
 691  * Returns a regular expression of url protocols
 692  *
 693  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 694  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 695  * @return string
 696  */
 697 function wfUrlProtocols( $includeProtocolRelative = true ) {
 698         global $wgUrlProtocols;
 699
 700         // Cache return values separately based on $includeProtocolRelative
 701         static $withProtRel = null, $withoutProtRel = null;
 702         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 703         if ( !is_null( $cachedValue ) ) {
 704                 return $cachedValue;
 705         }
 706
 707         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 708         // with LocalSettings files from 1.5
 709         if ( is_array( $wgUrlProtocols ) ) {
 710                 $protocols = array();
 711                 foreach ( $wgUrlProtocols as $protocol ) {
 712                         // Filter out '//' if !$includeProtocolRelative
 713                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 714                                 $protocols[] = preg_quote( $protocol, '/' );
 715                         }
 716                 }
 717
 718                 $retval = implode( '|', $protocols );
 719         } else {
 720                 // Ignore $includeProtocolRelative in this case
 721                 // This case exists for pre-1.6 compatibility, and we can safely assume
 722                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 723                 // URLs weren't supported until 1.18
 724                 $retval = $wgUrlProtocols;
 725         }
 726
 727         // Cache return value
 728         if ( $includeProtocolRelative ) {
 729                 $withProtRel = $retval;
 730         } else {
 731                 $withoutProtRel = $retval;
 732         }
 733         return $retval;
 734 }
 735
 736 /**
 737  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 738  * you need a regex that matches all URL protocols but does not match protocol-
 739  * relative URLs
 740  * @return string
 741  */
 742 function wfUrlProtocolsWithoutProtRel() {
 743         return wfUrlProtocols( false );
 744 }
 745
 746 /**
 747  * parse_url() work-alike, but non-broken.  Differences:
 748  *
 749  * 1) Does not raise warnings on bad URLs (just returns false).
 750  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 751  *    protocol-relative URLs) correctly.
 752  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 753  *
 754  * @param string $url A URL to parse
 755  * @return string[] Bits of the URL in an associative array, per PHP docs
 756  */
 757 function wfParseUrl( $url ) {
 758         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 759
 760         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 761         // bad that the easiest way to handle them is to just prepend 'http:' and
 762         // strip the protocol out later.
 763         $wasRelative = substr( $url, 0, 2 ) == '//';
 764         if ( $wasRelative ) {
 765                 $url = "http:$url";
 766         }
 767         wfSuppressWarnings();
 768         $bits = parse_url( $url );
 769         wfRestoreWarnings();
 770         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 771         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 772         if ( !$bits || !isset( $bits['scheme'] ) ) {
 773                 return false;
 774         }
 775
 776         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 777         $bits['scheme'] = strtolower( $bits['scheme'] );
 778
 779         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 780         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 781                 $bits['delimiter'] = '://';
 782         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 783                 $bits['delimiter'] = ':';
 784                 // parse_url detects for news: and mailto: the host part of an url as path
 785                 // We have to correct this wrong detection
 786                 if ( isset( $bits['path'] ) ) {
 787                         $bits['host'] = $bits['path'];
 788                         $bits['path'] = '';
 789                 }
 790         } else {
 791                 return false;
 792         }
 793
 794         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 795         if ( !isset( $bits['host'] ) ) {
 796                 $bits['host'] = '';
 797
 798                 // bug 45069
 799                 if ( isset( $bits['path'] ) ) {
 800                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 801                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 802                                 $bits['path'] = '/' . $bits['path'];
 803                         }
 804                 } else {
 805                         $bits['path'] = '';
 806                 }
 807         }
 808
 809         // If the URL was protocol-relative, fix scheme and delimiter
 810         if ( $wasRelative ) {
 811                 $bits['scheme'] = '';
 812                 $bits['delimiter'] = '//';
 813         }
 814         return $bits;
 815 }
 816
 817 /**
 818  * Take a URL, make sure it's expanded to fully qualified, and replace any
 819  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 820  * for more compact display and legibility for local audiences.
 821  *
 822  * @todo handle punycode domains too
 823  *
 824  * @param string $url
 825  * @return string
 826  */
 827 function wfExpandIRI( $url ) {
 828         return preg_replace_callback(
 829                 '/((?:%[89A-F][0-9A-F])+)/i',
 830                 'wfExpandIRI_callback',
 831                 wfExpandUrl( $url )
 832         );
 833 }
 834
 835 /**
 836  * Private callback for wfExpandIRI
 837  * @param array $matches
 838  * @return string
 839  */
 840 function wfExpandIRI_callback( $matches ) {
 841         return urldecode( $matches[1] );
 842 }
 843
 844 /**
 845  * Make URL indexes, appropriate for the el_index field of externallinks.
 846  *
 847  * @param string $url
 848  * @return array
 849  */
 850 function wfMakeUrlIndexes( $url ) {
 851         $bits = wfParseUrl( $url );
 852
 853         // Reverse the labels in the hostname, convert to lower case
 854         // For emails reverse domainpart only
 855         if ( $bits['scheme'] == 'mailto' ) {
 856                 $mailparts = explode( '@', $bits['host'], 2 );
 857                 if ( count( $mailparts ) === 2 ) {
 858                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 859                 } else {
 860                         // No domain specified, don't mangle it
 861                         $domainpart = '';
 862                 }
 863                 $reversedHost = $domainpart . '@' . $mailparts[0];
 864         } else {
 865                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 866         }
 867         // Add an extra dot to the end
 868         // Why? Is it in wrong place in mailto links?
 869         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 870                 $reversedHost .= '.';
 871         }
 872         // Reconstruct the pseudo-URL
 873         $prot = $bits['scheme'];
 874         $index = $prot . $bits['delimiter'] . $reversedHost;
 875         // Leave out user and password. Add the port, path, query and fragment
 876         if ( isset( $bits['port'] ) ) {
 877                 $index .= ':' . $bits['port'];
 878         }
 879         if ( isset( $bits['path'] ) ) {
 880                 $index .= $bits['path'];
 881         } else {
 882                 $index .= '/';
 883         }
 884         if ( isset( $bits['query'] ) ) {
 885                 $index .= '?' . $bits['query'];
 886         }
 887         if ( isset( $bits['fragment'] ) ) {
 888                 $index .= '#' . $bits['fragment'];
 889         }
 890
 891         if ( $prot == '' ) {
 892                 return array( "http:$index", "https:$index" );
 893         } else {
 894                 return array( $index );
 895         }
 896 }
 897
 898 /**
 899  * Check whether a given URL has a domain that occurs in a given set of domains
 900  * @param string $url URL
 901  * @param array $domains Array of domains (strings)
 902  * @return bool True if the host part of $url ends in one of the strings in $domains
 903  */
 904 function wfMatchesDomainList( $url, $domains ) {
 905         $bits = wfParseUrl( $url );
 906         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 907                 $host = '.' . $bits['host'];
 908                 foreach ( (array)$domains as $domain ) {
 909                         $domain = '.' . $domain;
 910                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 911                                 return true;
 912                         }
 913                 }
 914         }
 915         return false;
 916 }
 917
 918 /**
 919  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 920  * In normal operation this is a NOP.
 921  *
 922  * Controlling globals:
 923  * $wgDebugLogFile - points to the log file
 924  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 925  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 926  *
 927  * @param string $text
 928  * @param string|bool $dest Destination of the message:
 929  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 930  *     - 'log': only to the log and not in HTML
 931  *   For backward compatibility, it can also take a boolean:
 932  *     - true: same as 'all'
 933  *     - false: same as 'log'
 934  */
 935 function wfDebug( $text, $dest = 'all' ) {
 936         global $wgDebugLogFile, $wgDebugRawPage, $wgDebugLogPrefix;
 937
 938         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 939                 return;
 940         }
 941
 942         // Turn $dest into a string if it's a boolean (for b/c)
 943         if ( $dest === true ) {
 944                 $dest = 'all';
 945         } elseif ( $dest === false ) {
 946                 $dest = 'log';
 947         }
 948
 949         $timer = wfDebugTimer();
 950         if ( $timer !== '' ) {
 951                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 952         }
 953
 954         if ( $dest === 'all' ) {
 955                 MWDebug::debugMsg( $text );
 956         }
 957
 958         if ( $wgDebugLogFile != '' ) {
 959                 # Strip unprintables; they can switch terminal modes when binary data
 960                 # gets dumped, which is pretty annoying.
 961                 $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 962                 $text = $wgDebugLogPrefix . $text;
 963                 wfErrorLog( $text, $wgDebugLogFile );
 964         }
 965 }
 966
 967 /**
 968  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 969  * @return bool
 970  */
 971 function wfIsDebugRawPage() {
 972         static $cache;
 973         if ( $cache !== null ) {
 974                 return $cache;
 975         }
 976         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 977         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 978                 || (
 979                         isset( $_SERVER['SCRIPT_NAME'] )
 980                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 981                 )
 982         ) {
 983                 $cache = true;
 984         } else {
 985                 $cache = false;
 986         }
 987         return $cache;
 988 }
 989
 990 /**
 991  * Get microsecond timestamps for debug logs
 992  *
 993  * @return string
 994  */
 995 function wfDebugTimer() {
 996         global $wgDebugTimestamps, $wgRequestTime;
 997
 998         if ( !$wgDebugTimestamps ) {
 999                 return '';
1000         }
1001
1002         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1003         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1004         return "$prefix $mem  ";
1005 }
1006
1007 /**
1008  * Send a line giving PHP memory usage.
1009  *
1010  * @param bool $exact Print exact values instead of kilobytes (default: false)
1011  */
1012 function wfDebugMem( $exact = false ) {
1013         $mem = memory_get_usage();
1014         if ( !$exact ) {
1015                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1016         } else {
1017                 $mem .= ' bytes';
1018         }
1019         wfDebug( "Memory usage: $mem\n" );
1020 }
1021
1022 /**
1023  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1024  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to a string
1025  * filename or an associative array mapping 'destination' to the desired filename. The
1026  * associative array may also contain a 'sample' key with an integer value, specifying
1027  * a sampling factor.
1028  *
1029  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1030  *
1031  * @param string $logGroup
1032  * @param string $text
1033  * @param string|bool $dest Destination of the message:
1034  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1035  *     - 'log': only to the log and not in HTML
1036  *     - 'private': only to the specifc log if set in $wgDebugLogGroups and
1037  *       discarded otherwise
1038  *   For backward compatibility, it can also take a boolean:
1039  *     - true: same as 'all'
1040  *     - false: same as 'private'
1041  */
1042 function wfDebugLog( $logGroup, $text, $dest = 'all' ) {
1043         global $wgDebugLogGroups;
1044
1045         $text = trim( $text ) . "\n";
1046
1047         // Turn $dest into a string if it's a boolean (for b/c)
1048         if ( $dest === true ) {
1049                 $dest = 'all';
1050         } elseif ( $dest === false ) {
1051                 $dest = 'private';
1052         }
1053
1054         if ( !isset( $wgDebugLogGroups[$logGroup] ) ) {
1055                 if ( $dest !== 'private' ) {
1056                         wfDebug( "[$logGroup] $text", $dest );
1057                 }
1058                 return;
1059         }
1060
1061         if ( $dest === 'all' ) {
1062                 MWDebug::debugMsg( "[$logGroup] $text" );
1063         }
1064
1065         $logConfig = $wgDebugLogGroups[$logGroup];
1066         if ( $logConfig === false ) {
1067                 return;
1068         }
1069         if ( is_array( $logConfig ) ) {
1070                 if ( isset( $logConfig['sample'] ) && mt_rand( 1, $logConfig['sample'] ) !== 1 ) {
1071                         return;
1072                 }
1073                 $destination = $logConfig['destination'];
1074         } else {
1075                 $destination = strval( $logConfig );
1076         }
1077
1078         $time = wfTimestamp( TS_DB );
1079         $wiki = wfWikiID();
1080         $host = wfHostname();
1081         wfErrorLog( "$time $host $wiki: $text", $destination );
1082 }
1083
1084 /**
1085  * Log for database errors
1086  *
1087  * @param string $text Database error message.
1088  */
1089 function wfLogDBError( $text ) {
1090         global $wgDBerrorLog, $wgDBerrorLogTZ;
1091         static $logDBErrorTimeZoneObject = null;
1092
1093         if ( $wgDBerrorLog ) {
1094                 $host = wfHostname();
1095                 $wiki = wfWikiID();
1096
1097                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1098                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1099                 }
1100
1101                 // Workaround for https://bugs.php.net/bug.php?id=52063
1102                 // Can be removed when min PHP > 5.3.2
1103                 if ( $logDBErrorTimeZoneObject === null ) {
1104                         $d = date_create( "now" );
1105                 } else {
1106                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1107                 }
1108
1109                 $date = $d->format( 'D M j G:i:s T Y' );
1110
1111                 $text = "$date\t$host\t$wiki\t" . trim( $text ) . "\n";
1112                 wfErrorLog( $text, $wgDBerrorLog );
1113         }
1114 }
1115
1116 /**
1117  * Throws a warning that $function is deprecated
1118  *
1119  * @param string $function
1120  * @param string|bool $version Version of MediaWiki that the function
1121  *    was deprecated in (Added in 1.19).
1122  * @param string|bool $component Added in 1.19.
1123  * @param int $callerOffset How far up the call stack is the original
1124  *    caller. 2 = function that called the function that called
1125  *    wfDeprecated (Added in 1.20)
1126  *
1127  * @return null
1128  */
1129 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1130         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1131 }
1132
1133 /**
1134  * Send a warning either to the debug log or in a PHP error depending on
1135  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1136  *
1137  * @param string $msg message to send
1138  * @param int $callerOffset Number of items to go back in the backtrace to
1139  *        find the correct caller (1 = function calling wfWarn, ...)
1140  * @param int $level PHP error level; defaults to E_USER_NOTICE;
1141  *        only used when $wgDevelopmentWarnings is true
1142  */
1143 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1144         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1145 }
1146
1147 /**
1148  * Send a warning as a PHP error and the debug log. This is intended for logging
1149  * warnings in production. For logging development warnings, use WfWarn instead.
1150  *
1151  * @param string $msg Message to send
1152  * @param int $callerOffset Number of items to go back in the backtrace to
1153  *        find the correct caller (1 = function calling wfLogWarning, ...)
1154  * @param int $level PHP error level; defaults to E_USER_WARNING
1155  */
1156 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1157         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1158 }
1159
1160 /**
1161  * Log to a file without getting "file size exceeded" signals.
1162  *
1163  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1164  * send lines to the specified port, prefixed by the specified prefix and a space.
1165  *
1166  * @param string $text
1167  * @param string $file Filename
1168  * @throws MWException
1169  */
1170 function wfErrorLog( $text, $file ) {
1171         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1172                 # Needs the sockets extension
1173                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1174                         // IPv6 bracketed host
1175                         $host = $m[2];
1176                         $port = intval( $m[3] );
1177                         $prefix = isset( $m[4] ) ? $m[4] : false;
1178                         $domain = AF_INET6;
1179                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1180                         $host = $m[2];
1181                         if ( !IP::isIPv4( $host ) ) {
1182                                 $host = gethostbyname( $host );
1183                         }
1184                         $port = intval( $m[3] );
1185                         $prefix = isset( $m[4] ) ? $m[4] : false;
1186                         $domain = AF_INET;
1187                 } else {
1188                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1189                 }
1190
1191                 // Clean it up for the multiplexer
1192                 if ( strval( $prefix ) !== '' ) {
1193                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1194
1195                         // Limit to 64KB
1196                         if ( strlen( $text ) > 65506 ) {
1197                                 $text = substr( $text, 0, 65506 );
1198                         }
1199
1200                         if ( substr( $text, -1 ) != "\n" ) {
1201                                 $text .= "\n";
1202                         }
1203                 } elseif ( strlen( $text ) > 65507 ) {
1204                         $text = substr( $text, 0, 65507 );
1205                 }
1206
1207                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1208                 if ( !$sock ) {
1209                         return;
1210                 }
1211
1212                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1213                 socket_close( $sock );
1214         } else {
1215                 wfSuppressWarnings();
1216                 $exists = file_exists( $file );
1217                 $size = $exists ? filesize( $file ) : false;
1218                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1219                         file_put_contents( $file, $text, FILE_APPEND );
1220                 }
1221                 wfRestoreWarnings();
1222         }
1223 }
1224
1225 /**
1226  * @todo document
1227  */
1228 function wfLogProfilingData() {
1229         global $wgRequestTime, $wgDebugLogFile, $wgDebugLogGroups, $wgDebugRawPage;
1230         global $wgProfileLimit, $wgUser, $wgRequest;
1231
1232         StatCounter::singleton()->flush();
1233
1234         $profiler = Profiler::instance();
1235
1236         # Profiling must actually be enabled...
1237         if ( $profiler->isStub() ) {
1238                 return;
1239         }
1240
1241         // Get total page request time and only show pages that longer than
1242         // $wgProfileLimit time (default is 0)
1243         $elapsed = microtime( true ) - $wgRequestTime;
1244         if ( $elapsed <= $wgProfileLimit ) {
1245                 return;
1246         }
1247
1248         $profiler->logData();
1249
1250         // Check whether this should be logged in the debug file.
1251         if ( isset( $wgDebugLogGroups['profileoutput'] )
1252                 && $wgDebugLogGroups['profileoutput'] === false
1253         ) {
1254                 // Explicitely disabled
1255                 return;
1256         }
1257         if ( !isset( $wgDebugLogGroups['profileoutput'] ) && $wgDebugLogFile == '' ) {
1258                 // Logging not enabled; no point going further
1259                 return;
1260         }
1261         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
1262                 return;
1263         }
1264
1265         $forward = '';
1266         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1267                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1268         }
1269         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1270                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1271         }
1272         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1273                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1274         }
1275         if ( $forward ) {
1276                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1277         }
1278         // Don't load $wgUser at this late stage just for statistics purposes
1279         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1280         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1281                 $forward .= ' anon';
1282         }
1283
1284         // Command line script uses a FauxRequest object which does not have
1285         // any knowledge about an URL and throw an exception instead.
1286         try {
1287                 $requestUrl = $wgRequest->getRequestURL();
1288         } catch ( MWException $e ) {
1289                 $requestUrl = 'n/a';
1290         }
1291
1292         $log = sprintf( "%s\t%04.3f\t%s\n",
1293                 gmdate( 'YmdHis' ), $elapsed,
1294                 urldecode( $requestUrl . $forward ) );
1295
1296         wfDebugLog( 'profileoutput', $log . $profiler->getOutput() );
1297 }
1298
1299 /**
1300  * Increment a statistics counter
1301  *
1302  * @param string $key
1303  * @param int $count
1304  * @return void
1305  */
1306 function wfIncrStats( $key, $count = 1 ) {
1307         StatCounter::singleton()->incr( $key, $count );
1308 }
1309
1310 /**
1311  * Check whether the wiki is in read-only mode.
1312  *
1313  * @return bool
1314  */
1315 function wfReadOnly() {
1316         return wfReadOnlyReason() !== false;
1317 }
1318
1319 /**
1320  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1321  *
1322  * @return string|bool String when in read-only mode; false otherwise
1323  */
1324 function wfReadOnlyReason() {
1325         global $wgReadOnly, $wgReadOnlyFile;
1326
1327         if ( $wgReadOnly === null ) {
1328                 // Set $wgReadOnly for faster access next time
1329                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1330                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1331                 } else {
1332                         $wgReadOnly = false;
1333                 }
1334         }
1335
1336         return $wgReadOnly;
1337 }
1338
1339 /**
1340  * Return a Language object from $langcode
1341  *
1342  * @param Language|string|bool $langcode Either:
1343  *                  - a Language object
1344  *                  - code of the language to get the message for, if it is
1345  *                    a valid code create a language for that language, if
1346  *                    it is a string but not a valid code then make a basic
1347  *                    language object
1348  *                  - a boolean: if it's false then use the global object for
1349  *                    the current user's language (as a fallback for the old parameter
1350  *                    functionality), or if it is true then use global object
1351  *                    for the wiki's content language.
1352  * @return Language
1353  */
1354 function wfGetLangObj( $langcode = false ) {
1355         # Identify which language to get or create a language object for.
1356         # Using is_object here due to Stub objects.
1357         if ( is_object( $langcode ) ) {
1358                 # Great, we already have the object (hopefully)!
1359                 return $langcode;
1360         }
1361
1362         global $wgContLang, $wgLanguageCode;
1363         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1364                 # $langcode is the language code of the wikis content language object.
1365                 # or it is a boolean and value is true
1366                 return $wgContLang;
1367         }
1368
1369         global $wgLang;
1370         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1371                 # $langcode is the language code of user language object.
1372                 # or it was a boolean and value is false
1373                 return $wgLang;
1374         }
1375
1376         $validCodes = array_keys( Language::fetchLanguageNames() );
1377         if ( in_array( $langcode, $validCodes ) ) {
1378                 # $langcode corresponds to a valid language.
1379                 return Language::factory( $langcode );
1380         }
1381
1382         # $langcode is a string, but not a valid language code; use content language.
1383         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1384         return $wgContLang;
1385 }
1386
1387 /**
1388  * This is the function for getting translated interface messages.
1389  *
1390  * @see Message class for documentation how to use them.
1391  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1392  *
1393  * This function replaces all old wfMsg* functions.
1394  *
1395  * @param string $key Message key
1396  * @param mixed [$params,...] Normal message parameters
1397  * @return Message
1398  *
1399  * @since 1.17
1400  *
1401  * @see Message::__construct
1402  */
1403 function wfMessage( $key /*...*/ ) {
1404         $params = func_get_args();
1405         array_shift( $params );
1406         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1407                 $params = $params[0];
1408         }
1409         return new Message( $key, $params );
1410 }
1411
1412 /**
1413  * This function accepts multiple message keys and returns a message instance
1414  * for the first message which is non-empty. If all messages are empty then an
1415  * instance of the first message key is returned.
1416  *
1417  * @param string|string[] [$keys,...] Message keys
1418  * @return Message
1419  *
1420  * @since 1.18
1421  *
1422  * @see Message::newFallbackSequence
1423  */
1424 function wfMessageFallback( /*...*/ ) {
1425         $args = func_get_args();
1426         return call_user_func_array( 'Message::newFallbackSequence', $args );
1427 }
1428
1429 /**
1430  * Get a message from anywhere, for the current user language.
1431  *
1432  * Use wfMsgForContent() instead if the message should NOT
1433  * change depending on the user preferences.
1434  *
1435  * @deprecated since 1.18
1436  *
1437  * @param string $key lookup key for the message, usually
1438  *    defined in languages/Language.php
1439  *
1440  * Parameters to the message, which can be used to insert variable text into
1441  * it, can be passed to this function in the following formats:
1442  * - One per argument, starting at the second parameter
1443  * - As an array in the second parameter
1444  * These are not shown in the function definition.
1445  *
1446  * @return string
1447  */
1448 function wfMsg( $key ) {
1449         wfDeprecated( __METHOD__, '1.21' );
1450
1451         $args = func_get_args();
1452         array_shift( $args );
1453         return wfMsgReal( $key, $args );
1454 }
1455
1456 /**
1457  * Same as above except doesn't transform the message
1458  *
1459  * @deprecated since 1.18
1460  *
1461  * @param string $key
1462  * @return string
1463  */
1464 function wfMsgNoTrans( $key ) {
1465         wfDeprecated( __METHOD__, '1.21' );
1466
1467         $args = func_get_args();
1468         array_shift( $args );
1469         return wfMsgReal( $key, $args, true, false, false );
1470 }
1471
1472 /**
1473  * Get a message from anywhere, for the current global language
1474  * set with $wgLanguageCode.
1475  *
1476  * Use this if the message should NOT change dependent on the
1477  * language set in the user's preferences. This is the case for
1478  * most text written into logs, as well as link targets (such as
1479  * the name of the copyright policy page). Link titles, on the
1480  * other hand, should be shown in the UI language.
1481  *
1482  * Note that MediaWiki allows users to change the user interface
1483  * language in their preferences, but a single installation
1484  * typically only contains content in one language.
1485  *
1486  * Be wary of this distinction: If you use wfMsg() where you should
1487  * use wfMsgForContent(), a user of the software may have to
1488  * customize potentially hundreds of messages in
1489  * order to, e.g., fix a link in every possible language.
1490  *
1491  * @deprecated since 1.18
1492  *
1493  * @param string $key Lookup key for the message, usually
1494  *     defined in languages/Language.php
1495  * @return string
1496  */
1497 function wfMsgForContent( $key ) {
1498         wfDeprecated( __METHOD__, '1.21' );
1499
1500         global $wgForceUIMsgAsContentMsg;
1501         $args = func_get_args();
1502         array_shift( $args );
1503         $forcontent = true;
1504         if ( is_array( $wgForceUIMsgAsContentMsg )
1505                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1506         ) {
1507                 $forcontent = false;
1508         }
1509         return wfMsgReal( $key, $args, true, $forcontent );
1510 }
1511
1512 /**
1513  * Same as above except doesn't transform the message
1514  *
1515  * @deprecated since 1.18
1516  *
1517  * @param string $key
1518  * @return string
1519  */
1520 function wfMsgForContentNoTrans( $key ) {
1521         wfDeprecated( __METHOD__, '1.21' );
1522
1523         global $wgForceUIMsgAsContentMsg;
1524         $args = func_get_args();
1525         array_shift( $args );
1526         $forcontent = true;
1527         if ( is_array( $wgForceUIMsgAsContentMsg )
1528                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1529         ) {
1530                 $forcontent = false;
1531         }
1532         return wfMsgReal( $key, $args, true, $forcontent, false );
1533 }
1534
1535 /**
1536  * Really get a message
1537  *
1538  * @deprecated since 1.18
1539  *
1540  * @param string $key Key to get.
1541  * @param array $args
1542  * @param bool $useDB
1543  * @param string|bool $forContent Language code, or false for user lang, true for content lang.
1544  * @param bool $transform Whether or not to transform the message.
1545  * @return string The requested message.
1546  */
1547 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1548         wfDeprecated( __METHOD__, '1.21' );
1549
1550         wfProfileIn( __METHOD__ );
1551         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1552         $message = wfMsgReplaceArgs( $message, $args );
1553         wfProfileOut( __METHOD__ );
1554         return $message;
1555 }
1556
1557 /**
1558  * Fetch a message string value, but don't replace any keys yet.
1559  *
1560  * @deprecated since 1.18
1561  *
1562  * @param string $key
1563  * @param bool $useDB
1564  * @param string|bool $langCode Code of the language to get the message for, or
1565  *   behaves as a content language switch if it is a boolean.
1566  * @param bool $transform Whether to parse magic words, etc.
1567  * @return string
1568  */
1569 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1570         wfDeprecated( __METHOD__, '1.21' );
1571
1572         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1573
1574         $cache = MessageCache::singleton();
1575         $message = $cache->get( $key, $useDB, $langCode );
1576         if ( $message === false ) {
1577                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1578         } elseif ( $transform ) {
1579                 $message = $cache->transform( $message );
1580         }
1581         return $message;
1582 }
1583
1584 /**
1585  * Replace message parameter keys on the given formatted output.
1586  *
1587  * @param string $message
1588  * @param array $args
1589  * @return string
1590  * @private
1591  */
1592 function wfMsgReplaceArgs( $message, $args ) {
1593         # Fix windows line-endings
1594         # Some messages are split with explode("\n", $msg)
1595         $message = str_replace( "\r", '', $message );
1596
1597         // Replace arguments
1598         if ( count( $args ) ) {
1599                 if ( is_array( $args[0] ) ) {
1600                         $args = array_values( $args[0] );
1601                 }
1602                 $replacementKeys = array();
1603                 foreach ( $args as $n => $param ) {
1604                         $replacementKeys['$' . ( $n + 1 )] = $param;
1605                 }
1606                 $message = strtr( $message, $replacementKeys );
1607         }
1608
1609         return $message;
1610 }
1611
1612 /**
1613  * Return an HTML-escaped version of a message.
1614  * Parameter replacements, if any, are done *after* the HTML-escaping,
1615  * so parameters may contain HTML (eg links or form controls). Be sure
1616  * to pre-escape them if you really do want plaintext, or just wrap
1617  * the whole thing in htmlspecialchars().
1618  *
1619  * @deprecated since 1.18
1620  *
1621  * @param string $key
1622  * @param string [$args,...] Parameters
1623  * @return string
1624  */
1625 function wfMsgHtml( $key ) {
1626         wfDeprecated( __METHOD__, '1.21' );
1627
1628         $args = func_get_args();
1629         array_shift( $args );
1630         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1631 }
1632
1633 /**
1634  * Return an HTML version of message
1635  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1636  * so parameters may contain HTML (eg links or form controls). Be sure
1637  * to pre-escape them if you really do want plaintext, or just wrap
1638  * the whole thing in htmlspecialchars().
1639  *
1640  * @deprecated since 1.18
1641  *
1642  * @param string $key
1643  * @param string [$args,...] Parameters
1644  * @return string
1645  */
1646 function wfMsgWikiHtml( $key ) {
1647         wfDeprecated( __METHOD__, '1.21' );
1648
1649         $args = func_get_args();
1650         array_shift( $args );
1651         return wfMsgReplaceArgs(
1652                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1653                 /* can't be set to false */ true, /* interface */ true )->getText(),
1654                 $args );
1655 }
1656
1657 /**
1658  * Returns message in the requested format
1659  *
1660  * @deprecated since 1.18
1661  *
1662  * @param string $key Key of the message
1663  * @param array $options Processing rules.
1664  *   Can take the following options:
1665  *     parse: parses wikitext to HTML
1666  *     parseinline: parses wikitext to HTML and removes the surrounding
1667  *       p's added by parser or tidy
1668  *     escape: filters message through htmlspecialchars
1669  *     escapenoentities: same, but allows entity references like &#160; through
1670  *     replaceafter: parameters are substituted after parsing or escaping
1671  *     parsemag: transform the message using magic phrases
1672  *     content: fetch message for content language instead of interface
1673  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1674  *     language: Language object or language code to fetch message for
1675  *       (overridden by content).
1676  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1677  *
1678  * @return string
1679  */
1680 function wfMsgExt( $key, $options ) {
1681         wfDeprecated( __METHOD__, '1.21' );
1682
1683         $args = func_get_args();
1684         array_shift( $args );
1685         array_shift( $args );
1686         $options = (array)$options;
1687
1688         foreach ( $options as $arrayKey => $option ) {
1689                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1690                         # An unknown index, neither numeric nor "language"
1691                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1692                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1693                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1694                 'replaceafter', 'parsemag', 'content' ) ) ) {
1695                         # A numeric index with unknown value
1696                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1697                 }
1698         }
1699
1700         if ( in_array( 'content', $options, true ) ) {
1701                 $forContent = true;
1702                 $langCode = true;
1703                 $langCodeObj = null;
1704         } elseif ( array_key_exists( 'language', $options ) ) {
1705                 $forContent = false;
1706                 $langCode = wfGetLangObj( $options['language'] );
1707                 $langCodeObj = $langCode;
1708         } else {
1709                 $forContent = false;
1710                 $langCode = false;
1711                 $langCodeObj = null;
1712         }
1713
1714         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1715
1716         if ( !in_array( 'replaceafter', $options, true ) ) {
1717                 $string = wfMsgReplaceArgs( $string, $args );
1718         }
1719
1720         $messageCache = MessageCache::singleton();
1721         $parseInline = in_array( 'parseinline', $options, true );
1722         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1723                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1724                 if ( $string instanceof ParserOutput ) {
1725                         $string = $string->getText();
1726                 }
1727
1728                 if ( $parseInline ) {
1729                         $m = array();
1730                         if ( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1731                                 $string = $m[1];
1732                         }
1733                 }
1734         } elseif ( in_array( 'parsemag', $options, true ) ) {
1735                 $string = $messageCache->transform( $string,
1736                                 !$forContent, $langCodeObj );
1737         }
1738
1739         if ( in_array( 'escape', $options, true ) ) {
1740                 $string = htmlspecialchars ( $string );
1741         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1742                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1743         }
1744
1745         if ( in_array( 'replaceafter', $options, true ) ) {
1746                 $string = wfMsgReplaceArgs( $string, $args );
1747         }
1748
1749         return $string;
1750 }
1751
1752 /**
1753  * Since wfMsg() and co suck, they don't return false if the message key they
1754  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1755  * nonexistence of messages by checking the MessageCache::get() result directly.
1756  *
1757  * @deprecated since 1.18. Use Message::isDisabled().
1758  *
1759  * @param string $key The message key looked up
1760  * @return bool True if the message *doesn't* exist.
1761  */
1762 function wfEmptyMsg( $key ) {
1763         wfDeprecated( __METHOD__, '1.21' );
1764
1765         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1766 }
1767
1768 /**
1769  * Throw a debugging exception. This function previously once exited the process,
1770  * but now throws an exception instead, with similar results.
1771  *
1772  * @deprecated since 1.22; just throw an MWException yourself
1773  * @param string $msg Message shown when dying.
1774  * @throws MWException
1775  */
1776 function wfDebugDieBacktrace( $msg = '' ) {
1777         wfDeprecated( __FUNCTION__, '1.22' );
1778         throw new MWException( $msg );
1779 }
1780
1781 /**
1782  * Fetch server name for use in error reporting etc.
1783  * Use real server name if available, so we know which machine
1784  * in a server farm generated the current page.
1785  *
1786  * @return string
1787  */
1788 function wfHostname() {
1789         static $host;
1790         if ( is_null( $host ) ) {
1791
1792                 # Hostname overriding
1793                 global $wgOverrideHostname;
1794                 if ( $wgOverrideHostname !== false ) {
1795                         # Set static and skip any detection
1796                         $host = $wgOverrideHostname;
1797                         return $host;
1798                 }
1799
1800                 if ( function_exists( 'posix_uname' ) ) {
1801                         // This function not present on Windows
1802                         $uname = posix_uname();
1803                 } else {
1804                         $uname = false;
1805                 }
1806                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1807                         $host = $uname['nodename'];
1808                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1809                         # Windows computer name
1810                         $host = getenv( 'COMPUTERNAME' );
1811                 } else {
1812                         # This may be a virtual server.
1813                         $host = $_SERVER['SERVER_NAME'];
1814                 }
1815         }
1816         return $host;
1817 }
1818
1819 /**
1820  * Returns a script tag that stores the amount of time it took MediaWiki to
1821  * handle the request in milliseconds as 'wgBackendResponseTime'.
1822  *
1823  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1824  * hostname of the server handling the request.
1825  *
1826  * @return string
1827  */
1828 function wfReportTime() {
1829         global $wgRequestTime, $wgShowHostnames;
1830
1831         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1832         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1833         if ( $wgShowHostnames ) {
1834                 $reportVars[ 'wgHostname' ] = wfHostname();
1835         }
1836         return Skin::makeVariablesScript( $reportVars );
1837 }
1838
1839 /**
1840  * Safety wrapper for debug_backtrace().
1841  *
1842  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1843  * murky circumstances, which may be triggered in part by stub objects
1844  * or other fancy talking'.
1845  *
1846  * Will return an empty array if Zend Optimizer is detected or if
1847  * debug_backtrace is disabled, otherwise the output from
1848  * debug_backtrace() (trimmed).
1849  *
1850  * @param int $limit This parameter can be used to limit the number of stack frames returned
1851  *
1852  * @return array Array of backtrace information
1853  */
1854 function wfDebugBacktrace( $limit = 0 ) {
1855         static $disabled = null;
1856
1857         if ( extension_loaded( 'Zend Optimizer' ) ) {
1858                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1859                 return array();
1860         }
1861
1862         if ( is_null( $disabled ) ) {
1863                 $disabled = false;
1864                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1865                 $functions = array_map( 'trim', $functions );
1866                 $functions = array_map( 'strtolower', $functions );
1867                 if ( in_array( 'debug_backtrace', $functions ) ) {
1868                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1869                         $disabled = true;
1870                 }
1871         }
1872         if ( $disabled ) {
1873                 return array();
1874         }
1875
1876         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1877                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1878         } else {
1879                 return array_slice( debug_backtrace(), 1 );
1880         }
1881 }
1882
1883 /**
1884  * Get a debug backtrace as a string
1885  *
1886  * @return string
1887  */
1888 function wfBacktrace() {
1889         global $wgCommandLineMode;
1890
1891         if ( $wgCommandLineMode ) {
1892                 $msg = '';
1893         } else {
1894                 $msg = "<ul>\n";
1895         }
1896         $backtrace = wfDebugBacktrace();
1897         foreach ( $backtrace as $call ) {
1898                 if ( isset( $call['file'] ) ) {
1899                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1900                         $file = $f[count( $f ) - 1];
1901                 } else {
1902                         $file = '-';
1903                 }
1904                 if ( isset( $call['line'] ) ) {
1905                         $line = $call['line'];
1906                 } else {
1907                         $line = '-';
1908                 }
1909                 if ( $wgCommandLineMode ) {
1910                         $msg .= "$file line $line calls ";
1911                 } else {
1912                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1913                 }
1914                 if ( !empty( $call['class'] ) ) {
1915                         $msg .= $call['class'] . $call['type'];
1916                 }
1917                 $msg .= $call['function'] . '()';
1918
1919                 if ( $wgCommandLineMode ) {
1920                         $msg .= "\n";
1921                 } else {
1922                         $msg .= "</li>\n";
1923                 }
1924         }
1925         if ( $wgCommandLineMode ) {
1926                 $msg .= "\n";
1927         } else {
1928                 $msg .= "</ul>\n";
1929         }
1930
1931         return $msg;
1932 }
1933
1934 /**
1935  * Get the name of the function which called this function
1936  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1937  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1938  * wfGetCaller( 3 ) is the parent of that.
1939  *
1940  * @param int $level
1941  * @return string
1942  */
1943 function wfGetCaller( $level = 2 ) {
1944         $backtrace = wfDebugBacktrace( $level + 1 );
1945         if ( isset( $backtrace[$level] ) ) {
1946                 return wfFormatStackFrame( $backtrace[$level] );
1947         } else {
1948                 return 'unknown';
1949         }
1950 }
1951
1952 /**
1953  * Return a string consisting of callers in the stack. Useful sometimes
1954  * for profiling specific points.
1955  *
1956  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1957  * @return string
1958  */
1959 function wfGetAllCallers( $limit = 3 ) {
1960         $trace = array_reverse( wfDebugBacktrace() );
1961         if ( !$limit || $limit > count( $trace ) - 1 ) {
1962                 $limit = count( $trace ) - 1;
1963         }
1964         $trace = array_slice( $trace, -$limit - 1, $limit );
1965         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1966 }
1967
1968 /**
1969  * Return a string representation of frame
1970  *
1971  * @param array $frame
1972  * @return string
1973  */
1974 function wfFormatStackFrame( $frame ) {
1975         return isset( $frame['class'] ) ?
1976                 $frame['class'] . '::' . $frame['function'] :
1977                 $frame['function'];
1978 }
1979
1980 /* Some generic result counters, pulled out of SearchEngine */
1981
1982 /**
1983  * @todo document
1984  *
1985  * @param int $offset
1986  * @param int $limit
1987  * @return string
1988  */
1989 function wfShowingResults( $offset, $limit ) {
1990         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1991 }
1992
1993 /**
1994  * Generate (prev x| next x) (20|50|100...) type links for paging
1995  *
1996  * @param string $offset
1997  * @param int $limit
1998  * @param string $link
1999  * @param string $query Optional URL query parameter string
2000  * @param bool $atend Optional param for specified if this is the last page
2001  * @return string
2002  * @deprecated since 1.19; use Language::viewPrevNext() instead
2003  */
2004 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
2005         wfDeprecated( __METHOD__, '1.19' );
2006
2007         global $wgLang;
2008
2009         $query = wfCgiToArray( $query );
2010
2011         if ( is_object( $link ) ) {
2012                 $title = $link;
2013         } else {
2014                 $title = Title::newFromText( $link );
2015                 if ( is_null( $title ) ) {
2016                         return false;
2017                 }
2018         }
2019
2020         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
2021 }
2022
2023 /**
2024  * @todo document
2025  * @todo FIXME: We may want to blacklist some broken browsers
2026  *
2027  * @param bool $force
2028  * @return bool Whereas client accept gzip compression
2029  */
2030 function wfClientAcceptsGzip( $force = false ) {
2031         static $result = null;
2032         if ( $result === null || $force ) {
2033                 $result = false;
2034                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2035                         # @todo FIXME: We may want to blacklist some broken browsers
2036                         $m = array();
2037                         if ( preg_match(
2038                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2039                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
2040                                         $m
2041                                 )
2042                         ) {
2043                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2044                                         $result = false;
2045                                         return $result;
2046                                 }
2047                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2048                                 $result = true;
2049                         }
2050                 }
2051         }
2052         return $result;
2053 }
2054
2055 /**
2056  * Obtain the offset and limit values from the request string;
2057  * used in special pages
2058  *
2059  * @param int $deflimit Default limit if none supplied
2060  * @param string $optionname Name of a user preference to check against
2061  * @return array
2062  */
2063 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2064         global $wgRequest;
2065         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2066 }
2067
2068 /**
2069  * Escapes the given text so that it may be output using addWikiText()
2070  * without any linking, formatting, etc. making its way through. This
2071  * is achieved by substituting certain characters with HTML entities.
2072  * As required by the callers, "<nowiki>" is not used.
2073  *
2074  * @param string $text Text to be escaped
2075  * @return string
2076  */
2077 function wfEscapeWikiText( $text ) {
2078         static $repl = null, $repl2 = null;
2079         if ( $repl === null ) {
2080                 $repl = array(
2081                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2082                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2083                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2084                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2085                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2086                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2087                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2088                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2089                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2090                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2091                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2092                         '__' => '_&#95;', '://' => '&#58;//',
2093                 );
2094
2095                 // We have to catch everything "\s" matches in PCRE
2096                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2097                         $repl["$magic "] = "$magic&#32;";
2098                         $repl["$magic\t"] = "$magic&#9;";
2099                         $repl["$magic\r"] = "$magic&#13;";
2100                         $repl["$magic\n"] = "$magic&#10;";
2101                         $repl["$magic\f"] = "$magic&#12;";
2102                 }
2103
2104                 // And handle protocols that don't use "://"
2105                 global $wgUrlProtocols;
2106                 $repl2 = array();
2107                 foreach ( $wgUrlProtocols as $prot ) {
2108                         if ( substr( $prot, -1 ) === ':' ) {
2109                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2110                         }
2111                 }
2112                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2113         }
2114         $text = substr( strtr( "\n$text", $repl ), 1 );
2115         $text = preg_replace( $repl2, '$1&#58;', $text );
2116         return $text;
2117 }
2118
2119 /**
2120  * Get the current unix timestamp with microseconds.  Useful for profiling
2121  * @deprecated since 1.22; call microtime() directly
2122  * @return float
2123  */
2124 function wfTime() {
2125         wfDeprecated( __FUNCTION__, '1.22' );
2126         return microtime( true );
2127 }
2128
2129 /**
2130  * Sets dest to source and returns the original value of dest
2131  * If source is NULL, it just returns the value, it doesn't set the variable
2132  * If force is true, it will set the value even if source is NULL
2133  *
2134  * @param mixed $dest
2135  * @param mixed $source
2136  * @param bool $force
2137  * @return mixed
2138  */
2139 function wfSetVar( &$dest, $source, $force = false ) {
2140         $temp = $dest;
2141         if ( !is_null( $source ) || $force ) {
2142                 $dest = $source;
2143         }
2144         return $temp;
2145 }
2146
2147 /**
2148  * As for wfSetVar except setting a bit
2149  *
2150  * @param int $dest
2151  * @param int $bit
2152  * @param bool $state
2153  *
2154  * @return bool
2155  */
2156 function wfSetBit( &$dest, $bit, $state = true ) {
2157         $temp = (bool)( $dest & $bit );
2158         if ( !is_null( $state ) ) {
2159                 if ( $state ) {
2160                         $dest |= $bit;
2161                 } else {
2162                         $dest &= ~$bit;
2163                 }
2164         }
2165         return $temp;
2166 }
2167
2168 /**
2169  * A wrapper around the PHP function var_export().
2170  * Either print it or add it to the regular output ($wgOut).
2171  *
2172  * @param mixed $var A PHP variable to dump.
2173  */
2174 function wfVarDump( $var ) {
2175         global $wgOut;
2176         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2177         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2178                 print $s;
2179         } else {
2180                 $wgOut->addHTML( $s );
2181         }
2182 }
2183
2184 /**
2185  * Provide a simple HTTP error.
2186  *
2187  * @param int|string $code
2188  * @param string $label
2189  * @param string $desc
2190  */
2191 function wfHttpError( $code, $label, $desc ) {
2192         global $wgOut;
2193         $wgOut->disable();
2194         header( "HTTP/1.0 $code $label" );
2195         header( "Status: $code $label" );
2196         $wgOut->sendCacheControl();
2197
2198         header( 'Content-type: text/html; charset=utf-8' );
2199         print "<!doctype html>" .
2200                 '<html><head><title>' .
2201                 htmlspecialchars( $label ) .
2202                 '</title></head><body><h1>' .
2203                 htmlspecialchars( $label ) .
2204                 '</h1><p>' .
2205                 nl2br( htmlspecialchars( $desc ) ) .
2206                 "</p></body></html>\n";
2207 }
2208
2209 /**
2210  * Clear away any user-level output buffers, discarding contents.
2211  *
2212  * Suitable for 'starting afresh', for instance when streaming
2213  * relatively large amounts of data without buffering, or wanting to
2214  * output image files without ob_gzhandler's compression.
2215  *
2216  * The optional $resetGzipEncoding parameter controls suppression of
2217  * the Content-Encoding header sent by ob_gzhandler; by default it
2218  * is left. See comments for wfClearOutputBuffers() for why it would
2219  * be used.
2220  *
2221  * Note that some PHP configuration options may add output buffer
2222  * layers which cannot be removed; these are left in place.
2223  *
2224  * @param bool $resetGzipEncoding
2225  */
2226 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2227         if ( $resetGzipEncoding ) {
2228                 // Suppress Content-Encoding and Content-Length
2229                 // headers from 1.10+s wfOutputHandler
2230                 global $wgDisableOutputCompression;
2231                 $wgDisableOutputCompression = true;
2232         }
2233         while ( $status = ob_get_status() ) {
2234                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2235                         // Probably from zlib.output_compression or other
2236                         // PHP-internal setting which can't be removed.
2237                         //
2238                         // Give up, and hope the result doesn't break
2239                         // output behavior.
2240                         break;
2241                 }
2242                 if ( !ob_end_clean() ) {
2243                         // Could not remove output buffer handler; abort now
2244                         // to avoid getting in some kind of infinite loop.
2245                         break;
2246                 }
2247                 if ( $resetGzipEncoding ) {
2248                         if ( $status['name'] == 'ob_gzhandler' ) {
2249                                 // Reset the 'Content-Encoding' field set by this handler
2250                                 // so we can start fresh.
2251                                 header_remove( 'Content-Encoding' );
2252                                 break;
2253                         }
2254                 }
2255         }
2256 }
2257
2258 /**
2259  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2260  *
2261  * Clear away output buffers, but keep the Content-Encoding header
2262  * produced by ob_gzhandler, if any.
2263  *
2264  * This should be used for HTTP 304 responses, where you need to
2265  * preserve the Content-Encoding header of the real result, but
2266  * also need to suppress the output of ob_gzhandler to keep to spec
2267  * and avoid breaking Firefox in rare cases where the headers and
2268  * body are broken over two packets.
2269  */
2270 function wfClearOutputBuffers() {
2271         wfResetOutputBuffers( false );
2272 }
2273
2274 /**
2275  * Converts an Accept-* header into an array mapping string values to quality
2276  * factors
2277  *
2278  * @param string $accept
2279  * @param string $def default
2280  * @return float[] Associative array of string => float pairs
2281  */
2282 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2283         # No arg means accept anything (per HTTP spec)
2284         if ( !$accept ) {
2285                 return array( $def => 1.0 );
2286         }
2287
2288         $prefs = array();
2289
2290         $parts = explode( ',', $accept );
2291
2292         foreach ( $parts as $part ) {
2293                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2294                 $values = explode( ';', trim( $part ) );
2295                 $match = array();
2296                 if ( count( $values ) == 1 ) {
2297                         $prefs[$values[0]] = 1.0;
2298                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2299                         $prefs[$values[0]] = floatval( $match[1] );
2300                 }
2301         }
2302
2303         return $prefs;
2304 }
2305
2306 /**
2307  * Checks if a given MIME type matches any of the keys in the given
2308  * array. Basic wildcards are accepted in the array keys.
2309  *
2310  * Returns the matching MIME type (or wildcard) if a match, otherwise
2311  * NULL if no match.
2312  *
2313  * @param string $type
2314  * @param array $avail
2315  * @return string
2316  * @private
2317  */
2318 function mimeTypeMatch( $type, $avail ) {
2319         if ( array_key_exists( $type, $avail ) ) {
2320                 return $type;
2321         } else {
2322                 $parts = explode( '/', $type );
2323                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2324                         return $parts[0] . '/*';
2325                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2326                         return '*/*';
2327                 } else {
2328                         return null;
2329                 }
2330         }
2331 }
2332
2333 /**
2334  * Returns the 'best' match between a client's requested internet media types
2335  * and the server's list of available types. Each list should be an associative
2336  * array of type to preference (preference is a float between 0.0 and 1.0).
2337  * Wildcards in the types are acceptable.
2338  *
2339  * @param array $cprefs Client's acceptable type list
2340  * @param array $sprefs Server's offered types
2341  * @return string
2342  *
2343  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2344  * XXX: generalize to negotiate other stuff
2345  */
2346 function wfNegotiateType( $cprefs, $sprefs ) {
2347         $combine = array();
2348
2349         foreach ( array_keys( $sprefs ) as $type ) {
2350                 $parts = explode( '/', $type );
2351                 if ( $parts[1] != '*' ) {
2352                         $ckey = mimeTypeMatch( $type, $cprefs );
2353                         if ( $ckey ) {
2354                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2355                         }
2356                 }
2357         }
2358
2359         foreach ( array_keys( $cprefs ) as $type ) {
2360                 $parts = explode( '/', $type );
2361                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2362                         $skey = mimeTypeMatch( $type, $sprefs );
2363                         if ( $skey ) {
2364                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2365                         }
2366                 }
2367         }
2368
2369         $bestq = 0;
2370         $besttype = null;
2371
2372         foreach ( array_keys( $combine ) as $type ) {
2373                 if ( $combine[$type] > $bestq ) {
2374                         $besttype = $type;
2375                         $bestq = $combine[$type];
2376                 }
2377         }
2378
2379         return $besttype;
2380 }
2381
2382 /**
2383  * Reference-counted warning suppression
2384  *
2385  * @param bool $end
2386  */
2387 function wfSuppressWarnings( $end = false ) {
2388         static $suppressCount = 0;
2389         static $originalLevel = false;
2390
2391         if ( $end ) {
2392                 if ( $suppressCount ) {
2393                         --$suppressCount;
2394                         if ( !$suppressCount ) {
2395                                 error_reporting( $originalLevel );
2396                         }
2397                 }
2398         } else {
2399                 if ( !$suppressCount ) {
2400                         $originalLevel = error_reporting( E_ALL & ~(
2401                                 E_WARNING |
2402                                 E_NOTICE |
2403                                 E_USER_WARNING |
2404                                 E_USER_NOTICE |
2405                                 E_DEPRECATED |
2406                                 E_USER_DEPRECATED |
2407                                 E_STRICT
2408                         ) );
2409                 }
2410                 ++$suppressCount;
2411         }
2412 }
2413
2414 /**
2415  * Restore error level to previous value
2416  */
2417 function wfRestoreWarnings() {
2418         wfSuppressWarnings( true );
2419 }
2420
2421 # Autodetect, convert and provide timestamps of various types
2422
2423 /**
2424  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2425  */
2426 define( 'TS_UNIX', 0 );
2427
2428 /**
2429  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2430  */
2431 define( 'TS_MW', 1 );
2432
2433 /**
2434  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2435  */
2436 define( 'TS_DB', 2 );
2437
2438 /**
2439  * RFC 2822 format, for E-mail and HTTP headers
2440  */
2441 define( 'TS_RFC2822', 3 );
2442
2443 /**
2444  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2445  *
2446  * This is used by Special:Export
2447  */
2448 define( 'TS_ISO_8601', 4 );
2449
2450 /**
2451  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2452  *
2453  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2454  *       DateTime tag and page 36 for the DateTimeOriginal and
2455  *       DateTimeDigitized tags.
2456  */
2457 define( 'TS_EXIF', 5 );
2458
2459 /**
2460  * Oracle format time.
2461  */
2462 define( 'TS_ORACLE', 6 );
2463
2464 /**
2465  * Postgres format time.
2466  */
2467 define( 'TS_POSTGRES', 7 );
2468
2469 /**
2470  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2471  */
2472 define( 'TS_ISO_8601_BASIC', 9 );
2473
2474 /**
2475  * Get a timestamp string in one of various formats
2476  *
2477  * @param mixed $outputtype A timestamp in one of the supported formats, the
2478  *   function will autodetect which format is supplied and act accordingly.
2479  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2480  * @return string|bool String / false The same date in the format specified in $outputtype or false
2481  */
2482 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2483         try {
2484                 $timestamp = new MWTimestamp( $ts );
2485                 return $timestamp->getTimestamp( $outputtype );
2486         } catch ( TimestampException $e ) {
2487                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2488                 return false;
2489         }
2490 }
2491
2492 /**
2493  * Return a formatted timestamp, or null if input is null.
2494  * For dealing with nullable timestamp columns in the database.
2495  *
2496  * @param int $outputtype
2497  * @param string $ts
2498  * @return string
2499  */
2500 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2501         if ( is_null( $ts ) ) {
2502                 return null;
2503         } else {
2504                 return wfTimestamp( $outputtype, $ts );
2505         }
2506 }
2507
2508 /**
2509  * Convenience function; returns MediaWiki timestamp for the present time.
2510  *
2511  * @return string
2512  */
2513 function wfTimestampNow() {
2514         # return NOW
2515         return wfTimestamp( TS_MW, time() );
2516 }
2517
2518 /**
2519  * Check if the operating system is Windows
2520  *
2521  * @return bool True if it's Windows, false otherwise.
2522  */
2523 function wfIsWindows() {
2524         static $isWindows = null;
2525         if ( $isWindows === null ) {
2526                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2527         }
2528         return $isWindows;
2529 }
2530
2531 /**
2532  * Check if we are running under HHVM
2533  *
2534  * @return bool
2535  */
2536 function wfIsHHVM() {
2537         return defined( 'HHVM_VERSION' );
2538 }
2539
2540 /**
2541  * Swap two variables
2542  *
2543  * @param mixed $x
2544  * @param mixed $y
2545  */
2546 function swap( &$x, &$y ) {
2547         $z = $x;
2548         $x = $y;
2549         $y = $z;
2550 }
2551
2552 /**
2553  * Tries to get the system directory for temporary files. First
2554  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2555  * environment variables are then checked in sequence, and if none are
2556  * set try sys_get_temp_dir().
2557  *
2558  * NOTE: When possible, use instead the tmpfile() function to create
2559  * temporary files to avoid race conditions on file creation, etc.
2560  *
2561  * @return string
2562  */
2563 function wfTempDir() {
2564         global $wgTmpDirectory;
2565
2566         if ( $wgTmpDirectory !== false ) {
2567                 return $wgTmpDirectory;
2568         }
2569
2570         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2571
2572         foreach ( $tmpDir as $tmp ) {
2573                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2574                         return $tmp;
2575                 }
2576         }
2577         return sys_get_temp_dir();
2578 }
2579
2580 /**
2581  * Make directory, and make all parent directories if they don't exist
2582  *
2583  * @param string $dir Full path to directory to create
2584  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2585  * @param string $caller Optional caller param for debugging.
2586  * @throws MWException
2587  * @return bool
2588  */
2589 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2590         global $wgDirectoryMode;
2591
2592         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2593                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2594         }
2595
2596         if ( !is_null( $caller ) ) {
2597                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2598         }
2599
2600         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2601                 return true;
2602         }
2603
2604         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2605
2606         if ( is_null( $mode ) ) {
2607                 $mode = $wgDirectoryMode;
2608         }
2609
2610         // Turn off the normal warning, we're doing our own below
2611         wfSuppressWarnings();
2612         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2613         wfRestoreWarnings();
2614
2615         if ( !$ok ) {
2616                 //directory may have been created on another request since we last checked
2617                 if ( is_dir( $dir ) ) {
2618                         return true;
2619                 }
2620
2621                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2622                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2623         }
2624         return $ok;
2625 }
2626
2627 /**
2628  * Remove a directory and all its content.
2629  * Does not hide error.
2630  * @param string $dir
2631  */
2632 function wfRecursiveRemoveDir( $dir ) {
2633         wfDebug( __FUNCTION__ . "( $dir )\n" );
2634         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2635         if ( is_dir( $dir ) ) {
2636                 $objects = scandir( $dir );
2637                 foreach ( $objects as $object ) {
2638                         if ( $object != "." && $object != ".." ) {
2639                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2640                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2641                                 } else {
2642                                         unlink( $dir . '/' . $object );
2643                                 }
2644                         }
2645                 }
2646                 reset( $objects );
2647                 rmdir( $dir );
2648         }
2649 }
2650
2651 /**
2652  * @param int $nr The number to format
2653  * @param int $acc The number of digits after the decimal point, default 2
2654  * @param bool $round Whether or not to round the value, default true
2655  * @return string
2656  */
2657 function wfPercent( $nr, $acc = 2, $round = true ) {
2658         $ret = sprintf( "%.${acc}f", $nr );
2659         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2660 }
2661
2662 /**
2663  * Safety wrapper around ini_get() for boolean settings.
2664  * The values returned from ini_get() are pre-normalized for settings
2665  * set via php.ini or php_flag/php_admin_flag... but *not*
2666  * for those set via php_value/php_admin_value.
2667  *
2668  * It's fairly common for people to use php_value instead of php_flag,
2669  * which can leave you with an 'off' setting giving a false positive
2670  * for code that just takes the ini_get() return value as a boolean.
2671  *
2672  * To make things extra interesting, setting via php_value accepts
2673  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2674  * Unrecognized values go false... again opposite PHP's own coercion
2675  * from string to bool.
2676  *
2677  * Luckily, 'properly' set settings will always come back as '0' or '1',
2678  * so we only have to worry about them and the 'improper' settings.
2679  *
2680  * I frickin' hate PHP... :P
2681  *
2682  * @param string $setting
2683  * @return bool
2684  */
2685 function wfIniGetBool( $setting ) {
2686         $val = strtolower( ini_get( $setting ) );
2687         // 'on' and 'true' can't have whitespace around them, but '1' can.
2688         return $val == 'on'
2689                 || $val == 'true'
2690                 || $val == 'yes'
2691                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2692 }
2693
2694 /**
2695  * Windows-compatible version of escapeshellarg()
2696  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2697  * function puts single quotes in regardless of OS.
2698  *
2699  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2700  * earlier distro releases of PHP)
2701  *
2702  * @param string [$args,...]
2703  * @return string
2704  */
2705 function wfEscapeShellArg( /*...*/ ) {
2706         wfInitShellLocale();
2707
2708         $args = func_get_args();
2709         $first = true;
2710         $retVal = '';
2711         foreach ( $args as $arg ) {
2712                 if ( !$first ) {
2713                         $retVal .= ' ';
2714                 } else {
2715                         $first = false;
2716                 }
2717
2718                 if ( wfIsWindows() ) {
2719                         // Escaping for an MSVC-style command line parser and CMD.EXE
2720                         // @codingStandardsIgnoreStart For long URLs
2721                         // Refs:
2722                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2723                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2724                         //  * Bug #13518
2725                         //  * CR r63214
2726                         // Double the backslashes before any double quotes. Escape the double quotes.
2727                         // @codingStandardsIgnoreEnd
2728                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2729                         $arg = '';
2730                         $iteration = 0;
2731                         foreach ( $tokens as $token ) {
2732                                 if ( $iteration % 2 == 1 ) {
2733                                         // Delimiter, a double quote preceded by zero or more slashes
2734                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2735                                 } elseif ( $iteration % 4 == 2 ) {
2736                                         // ^ in $token will be outside quotes, need to be escaped
2737                                         $arg .= str_replace( '^', '^^', $token );
2738                                 } else { // $iteration % 4 == 0
2739                                         // ^ in $token will appear inside double quotes, so leave as is
2740                                         $arg .= $token;
2741                                 }
2742                                 $iteration++;
2743                         }
2744                         // Double the backslashes before the end of the string, because
2745                         // we will soon add a quote
2746                         $m = array();
2747                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2748                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2749                         }
2750
2751                         // Add surrounding quotes
2752                         $retVal .= '"' . $arg . '"';
2753                 } else {
2754                         $retVal .= escapeshellarg( $arg );
2755                 }
2756         }
2757         return $retVal;
2758 }
2759
2760 /**
2761  * Check if wfShellExec() is effectively disabled via php.ini config
2762  *
2763  * @return bool|string False or one of (safemode,disabled)
2764  * @since 1.22
2765  */
2766 function wfShellExecDisabled() {
2767         static $disabled = null;
2768         if ( is_null( $disabled ) ) {
2769                 $disabled = false;
2770                 if ( wfIniGetBool( 'safe_mode' ) ) {
2771                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2772                         $disabled = 'safemode';
2773                 } else {
2774                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2775                         $functions = array_map( 'trim', $functions );
2776                         $functions = array_map( 'strtolower', $functions );
2777                         if ( in_array( 'proc_open', $functions ) ) {
2778                                 wfDebug( "proc_open is in disabled_functions\n" );
2779                                 $disabled = 'disabled';
2780                         }
2781                 }
2782         }
2783         return $disabled;
2784 }
2785
2786 /**
2787  * Execute a shell command, with time and memory limits mirrored from the PHP
2788  * configuration if supported.
2789  *
2790  * @param string $cmd Command line, properly escaped for shell.
2791  * @param null|mixed &$retval Optional, will receive the program's exit code.
2792  *   (non-zero is usually failure). If there is an error from
2793  *   read, select, or proc_open(), this will be set to -1.
2794  * @param array $environ Optional environment variables which should be
2795  *   added to the executed command environment.
2796  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2797  *   this overwrites the global wgMaxShell* limits.
2798  * @param array $options Array of options:
2799  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2800  *     including errors from limit.sh
2801  *
2802  * @return string Collected stdout as a string
2803  */
2804 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2805         $limits = array(), $options = array()
2806 ) {
2807         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2808                 $wgMaxShellWallClockTime, $wgShellCgroup;
2809
2810         $disabled = wfShellExecDisabled();
2811         if ( $disabled ) {
2812                 $retval = 1;
2813                 return $disabled == 'safemode' ?
2814                         'Unable to run external programs in safe mode.' :
2815                         'Unable to run external programs, proc_open() is disabled.';
2816         }
2817
2818         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2819
2820         wfInitShellLocale();
2821
2822         $envcmd = '';
2823         foreach ( $environ as $k => $v ) {
2824                 if ( wfIsWindows() ) {
2825                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2826                          * appear in the environment variable, so we must use carat escaping as documented in
2827                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2828                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2829                          * are listed there but doesn't appear to need it.
2830                          */
2831                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2832                 } else {
2833                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2834                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2835                          */
2836                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2837                 }
2838         }
2839         $cmd = $envcmd . $cmd;
2840
2841         $useLogPipe = false;
2842         if ( php_uname( 's' ) == 'Linux' ) {
2843                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2844                 if ( isset( $limits['walltime'] ) ) {
2845                         $wallTime = intval( $limits['walltime'] );
2846                 } elseif ( isset( $limits['time'] ) ) {
2847                         $wallTime = $time;
2848                 } else {
2849                         $wallTime = intval( $wgMaxShellWallClockTime );
2850                 }
2851                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2852                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2853
2854                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2855                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2856                                 escapeshellarg( $cmd ) . ' ' .
2857                                 escapeshellarg(
2858                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2859                                         "MW_CPU_LIMIT=$time; " .
2860                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2861                                         "MW_MEM_LIMIT=$mem; " .
2862                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2863                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2864                                         "MW_USE_LOG_PIPE=yes"
2865                                 );
2866                         $useLogPipe = true;
2867                 } elseif ( $includeStderr ) {
2868                         $cmd .= ' 2>&1';
2869                 }
2870         } elseif ( $includeStderr ) {
2871                 $cmd .= ' 2>&1';
2872         }
2873         wfDebug( "wfShellExec: $cmd\n" );
2874
2875         $desc = array(
2876                 0 => array( 'file', 'php://stdin', 'r' ),
2877                 1 => array( 'pipe', 'w' ),
2878                 2 => array( 'file', 'php://stderr', 'w' ) );
2879         if ( $useLogPipe ) {
2880                 $desc[3] = array( 'pipe', 'w' );
2881         }
2882         $pipes = null;
2883         $proc = proc_open( $cmd, $desc, $pipes );
2884         if ( !$proc ) {
2885                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2886                 $retval = -1;
2887                 return '';
2888         }
2889         $outBuffer = $logBuffer = '';
2890         $emptyArray = array();
2891         $status = false;
2892         $logMsg = false;
2893
2894         // According to the documentation, it is possible for stream_select()
2895         // to fail due to EINTR. I haven't managed to induce this in testing
2896         // despite sending various signals. If it did happen, the error
2897         // message would take the form:
2898         //
2899         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2900         //
2901         // where [4] is the value of the macro EINTR and "Interrupted system
2902         // call" is string which according to the Linux manual is "possibly"
2903         // localised according to LC_MESSAGES.
2904         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2905         $eintrMessage = "stream_select(): unable to select [$eintr]";
2906
2907         // Build a table mapping resource IDs to pipe FDs to work around a
2908         // PHP 5.3 issue in which stream_select() does not preserve array keys
2909         // <https://bugs.php.net/bug.php?id=53427>.
2910         $fds = array();
2911         foreach ( $pipes as $fd => $pipe ) {
2912                 $fds[(int)$pipe] = $fd;
2913         }
2914
2915         while ( true ) {
2916                 $status = proc_get_status( $proc );
2917                 if ( !$status['running'] ) {
2918                         break;
2919                 }
2920                 $status = false;
2921
2922                 $readyPipes = $pipes;
2923
2924                 // Clear last error
2925                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2926                 @trigger_error( '' );
2927                 if ( @stream_select( $readyPipes, $emptyArray, $emptyArray, null ) === false ) {
2928                         // @codingStandardsIgnoreEnd
2929                         $error = error_get_last();
2930                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2931                                 continue;
2932                         } else {
2933                                 trigger_error( $error['message'], E_USER_WARNING );
2934                                 $logMsg = $error['message'];
2935                                 break;
2936                         }
2937                 }
2938                 foreach ( $readyPipes as $pipe ) {
2939                         $block = fread( $pipe, 65536 );
2940                         $fd = $fds[(int)$pipe];
2941                         if ( $block === '' ) {
2942                                 // End of file
2943                                 fclose( $pipes[$fd] );
2944                                 unset( $pipes[$fd] );
2945                                 if ( !$pipes ) {
2946                                         break 2;
2947                                 }
2948                         } elseif ( $block === false ) {
2949                                 // Read error
2950                                 $logMsg = "Error reading from pipe";
2951                                 break 2;
2952                         } elseif ( $fd == 1 ) {
2953                                 // From stdout
2954                                 $outBuffer .= $block;
2955                         } elseif ( $fd == 3 ) {
2956                                 // From log FD
2957                                 $logBuffer .= $block;
2958                                 if ( strpos( $block, "\n" ) !== false ) {
2959                                         $lines = explode( "\n", $logBuffer );
2960                                         $logBuffer = array_pop( $lines );
2961                                         foreach ( $lines as $line ) {
2962                                                 wfDebugLog( 'exec', $line );
2963                                         }
2964                                 }
2965                         }
2966                 }
2967         }
2968
2969         foreach ( $pipes as $pipe ) {
2970                 fclose( $pipe );
2971         }
2972
2973         // Use the status previously collected if possible, since proc_get_status()
2974         // just calls waitpid() which will not return anything useful the second time.
2975         if ( $status === false ) {
2976                 $status = proc_get_status( $proc );
2977         }
2978
2979         if ( $logMsg !== false ) {
2980                 // Read/select error
2981                 $retval = -1;
2982                 proc_close( $proc );
2983         } elseif ( $status['signaled'] ) {
2984                 $logMsg = "Exited with signal {$status['termsig']}";
2985                 $retval = 128 + $status['termsig'];
2986                 proc_close( $proc );
2987         } else {
2988                 if ( $status['running'] ) {
2989                         $retval = proc_close( $proc );
2990                 } else {
2991                         $retval = $status['exitcode'];
2992                         proc_close( $proc );
2993                 }
2994                 if ( $retval == 127 ) {
2995                         $logMsg = "Possibly missing executable file";
2996                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2997                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2998                 }
2999         }
3000
3001         if ( $logMsg !== false ) {
3002                 wfDebugLog( 'exec', "$logMsg: $cmd" );
3003         }
3004
3005         return $outBuffer;
3006 }
3007
3008 /**
3009  * Execute a shell command, returning both stdout and stderr. Convenience
3010  * function, as all the arguments to wfShellExec can become unwieldy.
3011  *
3012  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
3013  * @param string $cmd Command line, properly escaped for shell.
3014  * @param null|mixed &$retval Optional, will receive the program's exit code.
3015  *   (non-zero is usually failure)
3016  * @param array $environ optional environment variables which should be
3017  *   added to the executed command environment.
3018  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
3019  *   this overwrites the global wgShellMax* limits.
3020  * @return string Collected stdout and stderr as a string
3021  */
3022 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
3023         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
3024 }
3025
3026 /**
3027  * Workaround for http://bugs.php.net/bug.php?id=45132
3028  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
3029  */
3030 function wfInitShellLocale() {
3031         static $done = false;
3032         if ( $done ) {
3033                 return;
3034         }
3035         $done = true;
3036         global $wgShellLocale;
3037         if ( !wfIniGetBool( 'safe_mode' ) ) {
3038                 putenv( "LC_CTYPE=$wgShellLocale" );
3039                 setlocale( LC_CTYPE, $wgShellLocale );
3040         }
3041 }
3042
3043 /**
3044  * Alias to wfShellWikiCmd()
3045  *
3046  * @see wfShellWikiCmd()
3047  */
3048 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
3049         return wfShellWikiCmd( $script, $parameters, $options );
3050 }
3051
3052 /**
3053  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3054  * Note that $parameters should be a flat array and an option with an argument
3055  * should consist of two consecutive items in the array (do not use "--option value").
3056  *
3057  * @param string $script MediaWiki cli script path
3058  * @param array $parameters Arguments and options to the script
3059  * @param array $options Associative array of options:
3060  *              'php': The path to the php executable
3061  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3062  * @return string
3063  */
3064 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3065         global $wgPhpCli;
3066         // Give site config file a chance to run the script in a wrapper.
3067         // The caller may likely want to call wfBasename() on $script.
3068         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3069         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3070         if ( isset( $options['wrapper'] ) ) {
3071                 $cmd[] = $options['wrapper'];
3072         }
3073         $cmd[] = $script;
3074         // Escape each parameter for shell
3075         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
3076 }
3077
3078 /**
3079  * wfMerge attempts to merge differences between three texts.
3080  * Returns true for a clean merge and false for failure or a conflict.
3081  *
3082  * @param string $old
3083  * @param string $mine
3084  * @param string $yours
3085  * @param string $result
3086  * @return bool
3087  */
3088 function wfMerge( $old, $mine, $yours, &$result ) {
3089         global $wgDiff3;
3090
3091         # This check may also protect against code injection in
3092         # case of broken installations.
3093         wfSuppressWarnings();
3094         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3095         wfRestoreWarnings();
3096
3097         if ( !$haveDiff3 ) {
3098                 wfDebug( "diff3 not found\n" );
3099                 return false;
3100         }
3101
3102         # Make temporary files
3103         $td = wfTempDir();
3104         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3105         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3106         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3107
3108         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3109         #       a newline character. To avoid this, we normalize the trailing whitespace before
3110         #       creating the diff.
3111
3112         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3113         fclose( $oldtextFile );
3114         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3115         fclose( $mytextFile );
3116         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3117         fclose( $yourtextFile );
3118
3119         # Check for a conflict
3120         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3121                 wfEscapeShellArg( $mytextName ) . ' ' .
3122                 wfEscapeShellArg( $oldtextName ) . ' ' .
3123                 wfEscapeShellArg( $yourtextName );
3124         $handle = popen( $cmd, 'r' );
3125
3126         if ( fgets( $handle, 1024 ) ) {
3127                 $conflict = true;
3128         } else {
3129                 $conflict = false;
3130         }
3131         pclose( $handle );
3132
3133         # Merge differences
3134         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3135                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3136         $handle = popen( $cmd, 'r' );
3137         $result = '';
3138         do {
3139                 $data = fread( $handle, 8192 );
3140                 if ( strlen( $data ) == 0 ) {
3141                         break;
3142                 }
3143                 $result .= $data;
3144         } while ( true );
3145         pclose( $handle );
3146         unlink( $mytextName );
3147         unlink( $oldtextName );
3148         unlink( $yourtextName );
3149
3150         if ( $result === '' && $old !== '' && !$conflict ) {
3151                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3152                 $conflict = true;
3153         }
3154         return !$conflict;
3155 }
3156
3157 /**
3158  * Returns unified plain-text diff of two texts.
3159  * Useful for machine processing of diffs.
3160  *
3161  * @param string $before The text before the changes.
3162  * @param string $after The text after the changes.
3163  * @param string $params Command-line options for the diff command.
3164  * @return string Unified diff of $before and $after
3165  */
3166 function wfDiff( $before, $after, $params = '-u' ) {
3167         if ( $before == $after ) {
3168                 return '';
3169         }
3170
3171         global $wgDiff;
3172         wfSuppressWarnings();
3173         $haveDiff = $wgDiff && file_exists( $wgDiff );
3174         wfRestoreWarnings();
3175
3176         # This check may also protect against code injection in
3177         # case of broken installations.
3178         if ( !$haveDiff ) {
3179                 wfDebug( "diff executable not found\n" );
3180                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3181                 $format = new UnifiedDiffFormatter();
3182                 return $format->format( $diffs );
3183         }
3184
3185         # Make temporary files
3186         $td = wfTempDir();
3187         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3188         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3189
3190         fwrite( $oldtextFile, $before );
3191         fclose( $oldtextFile );
3192         fwrite( $newtextFile, $after );
3193         fclose( $newtextFile );
3194
3195         // Get the diff of the two files
3196         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3197
3198         $h = popen( $cmd, 'r' );
3199
3200         $diff = '';
3201
3202         do {
3203                 $data = fread( $h, 8192 );
3204                 if ( strlen( $data ) == 0 ) {
3205                         break;
3206                 }
3207                 $diff .= $data;
3208         } while ( true );
3209
3210         // Clean up
3211         pclose( $h );
3212         unlink( $oldtextName );
3213         unlink( $newtextName );
3214
3215         // Kill the --- and +++ lines. They're not useful.
3216         $diff_lines = explode( "\n", $diff );
3217         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3218                 unset( $diff_lines[0] );
3219         }
3220         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3221                 unset( $diff_lines[1] );
3222         }
3223
3224         $diff = implode( "\n", $diff_lines );
3225
3226         return $diff;
3227 }
3228
3229 /**
3230  * This function works like "use VERSION" in Perl, the program will die with a
3231  * backtrace if the current version of PHP is less than the version provided
3232  *
3233  * This is useful for extensions which due to their nature are not kept in sync
3234  * with releases, and might depend on other versions of PHP than the main code
3235  *
3236  * Note: PHP might die due to parsing errors in some cases before it ever
3237  *       manages to call this function, such is life
3238  *
3239  * @see perldoc -f use
3240  *
3241  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3242  * @throws MWException
3243  */
3244 function wfUsePHP( $req_ver ) {
3245         $php_ver = PHP_VERSION;
3246
3247         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3248                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3249         }
3250 }
3251
3252 /**
3253  * This function works like "use VERSION" in Perl except it checks the version
3254  * of MediaWiki, the program will die with a backtrace if the current version
3255  * of MediaWiki is less than the version provided.
3256  *
3257  * This is useful for extensions which due to their nature are not kept in sync
3258  * with releases
3259  *
3260  * Note: Due to the behavior of PHP's version_compare() which is used in this
3261  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3262  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3263  * targeted version number. For example if you wanted to allow any variation
3264  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3265  * not result in the same comparison due to the internal logic of
3266  * version_compare().
3267  *
3268  * @see perldoc -f use
3269  *
3270  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3271  * @throws MWException
3272  */
3273 function wfUseMW( $req_ver ) {
3274         global $wgVersion;
3275
3276         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3277                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3278         }
3279 }
3280
3281 /**
3282  * Return the final portion of a pathname.
3283  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3284  * http://bugs.php.net/bug.php?id=33898
3285  *
3286  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3287  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3288  *
3289  * @param string $path
3290  * @param string $suffix String to remove if present
3291  * @return string
3292  */
3293 function wfBaseName( $path, $suffix = '' ) {
3294         if ( $suffix == '' ) {
3295                 $encSuffix = '';
3296         } else {
3297                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3298         }
3299
3300         $matches = array();
3301         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3302                 return $matches[1];
3303         } else {
3304                 return '';
3305         }
3306 }
3307
3308 /**
3309  * Generate a relative path name to the given file.
3310  * May explode on non-matching case-insensitive paths,
3311  * funky symlinks, etc.
3312  *
3313  * @param string $path Absolute destination path including target filename
3314  * @param string $from Absolute source path, directory only
3315  * @return string
3316  */
3317 function wfRelativePath( $path, $from ) {
3318         // Normalize mixed input on Windows...
3319         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3320         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3321
3322         // Trim trailing slashes -- fix for drive root
3323         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3324         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3325
3326         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3327         $against = explode( DIRECTORY_SEPARATOR, $from );
3328
3329         if ( $pieces[0] !== $against[0] ) {
3330                 // Non-matching Windows drive letters?
3331                 // Return a full path.
3332                 return $path;
3333         }
3334
3335         // Trim off common prefix
3336         while ( count( $pieces ) && count( $against )
3337                 && $pieces[0] == $against[0] ) {
3338                 array_shift( $pieces );
3339                 array_shift( $against );
3340         }
3341
3342         // relative dots to bump us to the parent
3343         while ( count( $against ) ) {
3344                 array_unshift( $pieces, '..' );
3345                 array_shift( $against );
3346         }
3347
3348         array_push( $pieces, wfBaseName( $path ) );
3349
3350         return implode( DIRECTORY_SEPARATOR, $pieces );
3351 }
3352
3353 /**
3354  * Convert an arbitrarily-long digit string from one numeric base
3355  * to another, optionally zero-padding to a minimum column width.
3356  *
3357  * Supports base 2 through 36; digit values 10-36 are represented
3358  * as lowercase letters a-z. Input is case-insensitive.
3359  *
3360  * @param string $input Input number
3361  * @param int $sourceBase Base of the input number
3362  * @param int $destBase Desired base of the output
3363  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3364  * @param bool $lowercase Whether to output in lowercase or uppercase
3365  * @param string $engine Either "gmp", "bcmath", or "php"
3366  * @return string|bool The output number as a string, or false on error
3367  */
3368 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3369         $lowercase = true, $engine = 'auto'
3370 ) {
3371         $input = (string)$input;
3372         if (
3373                 $sourceBase < 2 ||
3374                 $sourceBase > 36 ||
3375                 $destBase < 2 ||
3376                 $destBase > 36 ||
3377                 $sourceBase != (int)$sourceBase ||
3378                 $destBase != (int)$destBase ||
3379                 $pad != (int)$pad ||
3380                 !preg_match(
3381                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3382                         $input
3383                 )
3384         ) {
3385                 return false;
3386         }
3387
3388         static $baseChars = array(
3389                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3390                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3391                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3392                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3393                 34 => 'y', 35 => 'z',
3394
3395                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3396                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3397                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3398                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3399                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3400                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3401         );
3402
3403         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3404                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3405         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3406                 $decimal = '0';
3407                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3408                         $decimal = bcmul( $decimal, $sourceBase );
3409                         $decimal = bcadd( $decimal, $baseChars[$char] );
3410                 }
3411
3412                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3413                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3414                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3415                 }
3416                 // @codingStandardsIgnoreEnd
3417
3418                 $result = strrev( $result );
3419         } else {
3420                 $inDigits = array();
3421                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3422                         $inDigits[] = $baseChars[$char];
3423                 }
3424
3425                 // Iterate over the input, modulo-ing out an output digit
3426                 // at a time until input is gone.
3427                 $result = '';
3428                 while ( $inDigits ) {
3429                         $work = 0;
3430                         $workDigits = array();
3431
3432                         // Long division...
3433                         foreach ( $inDigits as $digit ) {
3434                                 $work *= $sourceBase;
3435                                 $work += $digit;
3436
3437                                 if ( $workDigits || $work >= $destBase ) {
3438                                         $workDigits[] = (int)( $work / $destBase );
3439                                 }
3440                                 $work %= $destBase;
3441                         }
3442
3443                         // All that division leaves us with a remainder,
3444                         // which is conveniently our next output digit.
3445                         $result .= $baseChars[$work];
3446
3447                         // And we continue!
3448                         $inDigits = $workDigits;
3449                 }
3450
3451                 $result = strrev( $result );
3452         }
3453
3454         if ( !$lowercase ) {
3455                 $result = strtoupper( $result );
3456         }
3457
3458         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3459 }
3460
3461 /**
3462  * Check if there is sufficient entropy in php's built-in session generation
3463  *
3464  * @return bool true = there is sufficient entropy
3465  */
3466 function wfCheckEntropy() {
3467         return (
3468                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3469                         || ini_get( 'session.entropy_file' )
3470                 )
3471                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3472 }
3473
3474 /**
3475  * Override session_id before session startup if php's built-in
3476  * session generation code is not secure.
3477  */
3478 function wfFixSessionID() {
3479         // If the cookie or session id is already set we already have a session and should abort
3480         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3481                 return;
3482         }
3483
3484         // PHP's built-in session entropy is enabled if:
3485         // - entropy_file is set or you're on Windows with php 5.3.3+
3486         // - AND entropy_length is > 0
3487         // We treat it as disabled if it doesn't have an entropy length of at least 32
3488         $entropyEnabled = wfCheckEntropy();
3489
3490         // If built-in entropy is not enabled or not sufficient override PHP's
3491         // built in session id generation code
3492         if ( !$entropyEnabled ) {
3493                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3494                         "overriding session id generation using our cryptrand source.\n" );
3495                 session_id( MWCryptRand::generateHex( 32 ) );
3496         }
3497 }
3498
3499 /**
3500  * Reset the session_id
3501  *
3502  * @since 1.22
3503  */
3504 function wfResetSessionID() {
3505         global $wgCookieSecure;
3506         $oldSessionId = session_id();
3507         $cookieParams = session_get_cookie_params();
3508         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3509                 session_regenerate_id( false );
3510         } else {
3511                 $tmp = $_SESSION;
3512                 session_destroy();
3513                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3514                 $_SESSION = $tmp;
3515         }
3516         $newSessionId = session_id();
3517         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3518 }
3519
3520 /**
3521  * Initialise php session
3522  *
3523  * @param bool $sessionId
3524  */
3525 function wfSetupSession( $sessionId = false ) {
3526         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3527                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3528         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3529                 ObjectCacheSessionHandler::install();
3530         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3531                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3532                 # hasn't already been set to the desired value (that causes errors)
3533                 ini_set( 'session.save_handler', $wgSessionHandler );
3534         }
3535         session_set_cookie_params(
3536                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3537         session_cache_limiter( 'private, must-revalidate' );
3538         if ( $sessionId ) {
3539                 session_id( $sessionId );
3540         } else {
3541                 wfFixSessionID();
3542         }
3543         wfSuppressWarnings();
3544         session_start();
3545         wfRestoreWarnings();
3546 }
3547
3548 /**
3549  * Get an object from the precompiled serialized directory
3550  *
3551  * @param string $name
3552  * @return mixed The variable on success, false on failure
3553  */
3554 function wfGetPrecompiledData( $name ) {
3555         global $IP;
3556
3557         $file = "$IP/serialized/$name";
3558         if ( file_exists( $file ) ) {
3559                 $blob = file_get_contents( $file );
3560                 if ( $blob ) {
3561                         return unserialize( $blob );
3562                 }
3563         }
3564         return false;
3565 }
3566
3567 /**
3568  * Get a cache key
3569  *
3570  * @param string [$args,...]
3571  * @return string
3572  */
3573 function wfMemcKey( /*...*/ ) {
3574         global $wgCachePrefix;
3575         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3576         $args = func_get_args();
3577         $key = $prefix . ':' . implode( ':', $args );
3578         $key = str_replace( ' ', '_', $key );
3579         return $key;
3580 }
3581
3582 /**
3583  * Get a cache key for a foreign DB
3584  *
3585  * @param string $db
3586  * @param string $prefix
3587  * @param string [$args,...]
3588  * @return string
3589  */
3590 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3591         $args = array_slice( func_get_args(), 2 );
3592         if ( $prefix ) {
3593                 $key = "$db-$prefix:" . implode( ':', $args );
3594         } else {
3595                 $key = $db . ':' . implode( ':', $args );
3596         }
3597         return str_replace( ' ', '_', $key );
3598 }
3599
3600 /**
3601  * Get an ASCII string identifying this wiki
3602  * This is used as a prefix in memcached keys
3603  *
3604  * @return string
3605  */
3606 function wfWikiID() {
3607         global $wgDBprefix, $wgDBname;
3608         if ( $wgDBprefix ) {
3609                 return "$wgDBname-$wgDBprefix";
3610         } else {
3611                 return $wgDBname;
3612         }
3613 }
3614
3615 /**
3616  * Split a wiki ID into DB name and table prefix
3617  *
3618  * @param string $wiki
3619  *
3620  * @return array
3621  */
3622 function wfSplitWikiID( $wiki ) {
3623         $bits = explode( '-', $wiki, 2 );
3624         if ( count( $bits ) < 2 ) {
3625                 $bits[] = '';
3626         }
3627         return $bits;
3628 }
3629
3630 /**
3631  * Get a Database object.
3632  *
3633  * @param int $db Index of the connection to get. May be DB_MASTER for the
3634  *            master (for write queries), DB_SLAVE for potentially lagged read
3635  *            queries, or an integer >= 0 for a particular server.
3636  *
3637  * @param string|string[] $groups Query groups. An array of group names that this query
3638  *                belongs to. May contain a single string if the query is only
3639  *                in one group.
3640  *
3641  * @param string|bool $wiki The wiki ID, or false for the current wiki
3642  *
3643  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3644  * will always return the same object, unless the underlying connection or load
3645  * balancer is manually destroyed.
3646  *
3647  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3648  * updater to ensure that a proper database is being updated.
3649  *
3650  * @return DatabaseBase
3651  */
3652 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3653         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3654 }
3655
3656 /**
3657  * Get a load balancer object.
3658  *
3659  * @param string|bool $wiki wiki ID, or false for the current wiki
3660  * @return LoadBalancer
3661  */
3662 function wfGetLB( $wiki = false ) {
3663         return wfGetLBFactory()->getMainLB( $wiki );
3664 }
3665
3666 /**
3667  * Get the load balancer factory object
3668  *
3669  * @return LBFactory
3670  */
3671 function &wfGetLBFactory() {
3672         return LBFactory::singleton();
3673 }
3674
3675 /**
3676  * Find a file.
3677  * Shortcut for RepoGroup::singleton()->findFile()
3678  *
3679  * @param string $title or Title object
3680  * @param array $options Associative array of options:
3681  *     time:           requested time for an archived image, or false for the
3682  *                     current version. An image object will be returned which was
3683  *                     created at the specified time.
3684  *
3685  *     ignoreRedirect: If true, do not follow file redirects
3686  *
3687  *     private:        If true, return restricted (deleted) files if the current
3688  *                     user is allowed to view them. Otherwise, such files will not
3689  *                     be found.
3690  *
3691  *     bypassCache:    If true, do not use the process-local cache of File objects
3692  *
3693  * @return File|bool File, or false if the file does not exist
3694  */
3695 function wfFindFile( $title, $options = array() ) {
3696         return RepoGroup::singleton()->findFile( $title, $options );
3697 }
3698
3699 /**
3700  * Get an object referring to a locally registered file.
3701  * Returns a valid placeholder object if the file does not exist.
3702  *
3703  * @param Title|string $title
3704  * @return LocalFile|null A File, or null if passed an invalid Title
3705  */
3706 function wfLocalFile( $title ) {
3707         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3708 }
3709
3710 /**
3711  * Should low-performance queries be disabled?
3712  *
3713  * @return bool
3714  * @codeCoverageIgnore
3715  */
3716 function wfQueriesMustScale() {
3717         global $wgMiserMode;
3718         return $wgMiserMode
3719                 || ( SiteStats::pages() > 100000
3720                 && SiteStats::edits() > 1000000
3721                 && SiteStats::users() > 10000 );
3722 }
3723
3724 /**
3725  * Get the path to a specified script file, respecting file
3726  * extensions; this is a wrapper around $wgScriptExtension etc.
3727  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3728  *
3729  * @param string $script Script filename, sans extension
3730  * @return string
3731  */
3732 function wfScript( $script = 'index' ) {
3733         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3734         if ( $script === 'index' ) {
3735                 return $wgScript;
3736         } elseif ( $script === 'load' ) {
3737                 return $wgLoadScript;
3738         } else {
3739                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3740         }
3741 }
3742
3743 /**
3744  * Get the script URL.
3745  *
3746  * @return string script URL
3747  */
3748 function wfGetScriptUrl() {
3749         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3750                 #
3751                 # as it was called, minus the query string.
3752                 #
3753                 # Some sites use Apache rewrite rules to handle subdomains,
3754                 # and have PHP set up in a weird way that causes PHP_SELF
3755                 # to contain the rewritten URL instead of the one that the
3756                 # outside world sees.
3757                 #
3758                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3759                 # provides containing the "before" URL.
3760                 return $_SERVER['SCRIPT_NAME'];
3761         } else {
3762                 return $_SERVER['URL'];
3763         }
3764 }
3765
3766 /**
3767  * Convenience function converts boolean values into "true"
3768  * or "false" (string) values
3769  *
3770  * @param bool $value
3771  * @return string
3772  */
3773 function wfBoolToStr( $value ) {
3774         return $value ? 'true' : 'false';
3775 }
3776
3777 /**
3778  * Get a platform-independent path to the null file, e.g. /dev/null
3779  *
3780  * @return string
3781  */
3782 function wfGetNull() {
3783         return wfIsWindows() ? 'NUL' : '/dev/null';
3784 }
3785
3786 /**
3787  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3788  * and waiting for it to go down, this waits for the slaves to catch up to the
3789  * master position. Use this when updating very large numbers of rows, as
3790  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3791  * a no-op if there are no slaves.
3792  *
3793  * @param int|bool $maxLag (deprecated)
3794  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3795  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3796  */
3797 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3798         if ( $cluster !== false ) {
3799                 $lb = wfGetLBFactory()->getExternalLB( $cluster );
3800         } else {
3801                 $lb = wfGetLB( $wiki );
3802         }
3803
3804         // bug 27975 - Don't try to wait for slaves if there are none
3805         // Prevents permission error when getting master position
3806         if ( $lb->getServerCount() > 1 ) {
3807                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3808                 $pos = $dbw->getMasterPos();
3809                 // The DBMS may not support getMasterPos() or the whole
3810                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3811                 if ( $pos !== false ) {
3812                         $lb->waitForAll( $pos );
3813                 }
3814         }
3815 }
3816
3817 /**
3818  * Count down from $seconds to zero on the terminal, with a one-second pause
3819  * between showing each number. For use in command-line scripts.
3820  *
3821  * @codeCoverageIgnore
3822  * @param int $seconds
3823  */
3824 function wfCountDown( $seconds ) {
3825         for ( $i = $seconds; $i >= 0; $i-- ) {
3826                 if ( $i != $seconds ) {
3827                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3828                 }
3829                 echo $i;
3830                 flush();
3831                 if ( $i ) {
3832                         sleep( 1 );
3833                 }
3834         }
3835         echo "\n";
3836 }
3837
3838 /**
3839  * Replace all invalid characters with -
3840  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3841  * By default, $wgIllegalFileChars = ':'
3842  *
3843  * @param string $name Filename to process
3844  * @return string
3845  */
3846 function wfStripIllegalFilenameChars( $name ) {
3847         global $wgIllegalFileChars;
3848         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3849         $name = wfBaseName( $name );
3850         $name = preg_replace(
3851                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3852                 '-',
3853                 $name
3854         );
3855         return $name;
3856 }
3857
3858 /**
3859  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3860  *
3861  * @return int Value the memory limit was set to.
3862  */
3863 function wfMemoryLimit() {
3864         global $wgMemoryLimit;
3865         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3866         if ( $memlimit != -1 ) {
3867                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3868                 if ( $conflimit == -1 ) {
3869                         wfDebug( "Removing PHP's memory limit\n" );
3870                         wfSuppressWarnings();
3871                         ini_set( 'memory_limit', $conflimit );
3872                         wfRestoreWarnings();
3873                         return $conflimit;
3874                 } elseif ( $conflimit > $memlimit ) {
3875                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3876                         wfSuppressWarnings();
3877                         ini_set( 'memory_limit', $conflimit );
3878                         wfRestoreWarnings();
3879                         return $conflimit;
3880                 }
3881         }
3882         return $memlimit;
3883 }
3884
3885 /**
3886  * Converts shorthand byte notation to integer form
3887  *
3888  * @param string $string
3889  * @return int
3890  */
3891 function wfShorthandToInteger( $string = '' ) {
3892         $string = trim( $string );
3893         if ( $string === '' ) {
3894                 return -1;
3895         }
3896         $last = $string[strlen( $string ) - 1];
3897         $val = intval( $string );
3898         switch ( $last ) {
3899                 case 'g':
3900                 case 'G':
3901                         $val *= 1024;
3902                         // break intentionally missing
3903                 case 'm':
3904                 case 'M':
3905                         $val *= 1024;
3906                         // break intentionally missing
3907                 case 'k':
3908                 case 'K':
3909                         $val *= 1024;
3910         }
3911
3912         return $val;
3913 }
3914
3915 /**
3916  * Get the normalised IETF language tag
3917  * See unit test for examples.
3918  *
3919  * @param string $code The language code.
3920  * @return string The language code which complying with BCP 47 standards.
3921  */
3922 function wfBCP47( $code ) {
3923         $codeSegment = explode( '-', $code );
3924         $codeBCP = array();
3925         foreach ( $codeSegment as $segNo => $seg ) {
3926                 // when previous segment is x, it is a private segment and should be lc
3927                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3928                         $codeBCP[$segNo] = strtolower( $seg );
3929                 // ISO 3166 country code
3930                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3931                         $codeBCP[$segNo] = strtoupper( $seg );
3932                 // ISO 15924 script code
3933                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3934                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3935                 // Use lowercase for other cases
3936                 } else {
3937                         $codeBCP[$segNo] = strtolower( $seg );
3938                 }
3939         }
3940         $langCode = implode( '-', $codeBCP );
3941         return $langCode;
3942 }
3943
3944 /**
3945  * Get a cache object.
3946  *
3947  * @param int $inputType Cache type, one the the CACHE_* constants.
3948  * @return BagOStuff
3949  */
3950 function wfGetCache( $inputType ) {
3951         return ObjectCache::getInstance( $inputType );
3952 }
3953
3954 /**
3955  * Get the main cache object
3956  *
3957  * @return BagOStuff
3958  */
3959 function wfGetMainCache() {
3960         global $wgMainCacheType;
3961         return ObjectCache::getInstance( $wgMainCacheType );
3962 }
3963
3964 /**
3965  * Get the cache object used by the message cache
3966  *
3967  * @return BagOStuff
3968  */
3969 function wfGetMessageCacheStorage() {
3970         global $wgMessageCacheType;
3971         return ObjectCache::getInstance( $wgMessageCacheType );
3972 }
3973
3974 /**
3975  * Get the cache object used by the parser cache
3976  *
3977  * @return BagOStuff
3978  */
3979 function wfGetParserCacheStorage() {
3980         global $wgParserCacheType;
3981         return ObjectCache::getInstance( $wgParserCacheType );
3982 }
3983
3984 /**
3985  * Get the cache object used by the language converter
3986  *
3987  * @return BagOStuff
3988  */
3989 function wfGetLangConverterCacheStorage() {
3990         global $wgLanguageConverterCacheType;
3991         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3992 }
3993
3994 /**
3995  * Call hook functions defined in $wgHooks
3996  *
3997  * @param string $event Event name
3998  * @param array $args Parameters passed to hook functions
3999  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
4000  *
4001  * @return bool True if no handler aborted the hook
4002  */
4003 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
4004         return Hooks::run( $event, $args, $deprecatedVersion );
4005 }
4006
4007 /**
4008  * Wrapper around php's unpack.
4009  *
4010  * @param string $format The format string (See php's docs)
4011  * @param string $data A binary string of binary data
4012  * @param int|bool $length The minimum length of $data or false. This is to
4013  *      prevent reading beyond the end of $data. false to disable the check.
4014  *
4015  * Also be careful when using this function to read unsigned 32 bit integer
4016  * because php might make it negative.
4017  *
4018  * @throws MWException if $data not long enough, or if unpack fails
4019  * @return array Associative array of the extracted data
4020  */
4021 function wfUnpack( $format, $data, $length = false ) {
4022         if ( $length !== false ) {
4023                 $realLen = strlen( $data );
4024                 if ( $realLen < $length ) {
4025                         throw new MWException( "Tried to use wfUnpack on a "
4026                                 . "string of length $realLen, but needed one "
4027                                 . "of at least length $length."
4028                         );
4029                 }
4030         }
4031
4032         wfSuppressWarnings();
4033         $result = unpack( $format, $data );
4034         wfRestoreWarnings();
4035
4036         if ( $result === false ) {
4037                 // If it cannot extract the packed data.
4038                 throw new MWException( "unpack could not unpack binary data" );
4039         }
4040         return $result;
4041 }
4042
4043 /**
4044  * Determine if an image exists on the 'bad image list'.
4045  *
4046  * The format of MediaWiki:Bad_image_list is as follows:
4047  *    * Only list items (lines starting with "*") are considered
4048  *    * The first link on a line must be a link to a bad image
4049  *    * Any subsequent links on the same line are considered to be exceptions,
4050  *      i.e. articles where the image may occur inline.
4051  *
4052  * @param string $name The image name to check
4053  * @param Title|bool $contextTitle The page on which the image occurs, if known
4054  * @param string $blacklist Wikitext of a file blacklist
4055  * @return bool
4056  */
4057 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4058         static $badImageCache = null; // based on bad_image_list msg
4059         wfProfileIn( __METHOD__ );
4060
4061         # Handle redirects
4062         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4063         if ( $redirectTitle ) {
4064                 $name = $redirectTitle->getDBkey();
4065         }
4066
4067         # Run the extension hook
4068         $bad = false;
4069         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
4070                 wfProfileOut( __METHOD__ );
4071                 return $bad;
4072         }
4073
4074         $cacheable = ( $blacklist === null );
4075         if ( $cacheable && $badImageCache !== null ) {
4076                 $badImages = $badImageCache;
4077         } else { // cache miss
4078                 if ( $blacklist === null ) {
4079                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4080                 }
4081                 # Build the list now
4082                 $badImages = array();
4083                 $lines = explode( "\n", $blacklist );
4084                 foreach ( $lines as $line ) {
4085                         # List items only
4086                         if ( substr( $line, 0, 1 ) !== '*' ) {
4087                                 continue;
4088                         }
4089
4090                         # Find all links
4091                         $m = array();
4092                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4093                                 continue;
4094                         }
4095
4096                         $exceptions = array();
4097                         $imageDBkey = false;
4098                         foreach ( $m[1] as $i => $titleText ) {
4099                                 $title = Title::newFromText( $titleText );
4100                                 if ( !is_null( $title ) ) {
4101                                         if ( $i == 0 ) {
4102                                                 $imageDBkey = $title->getDBkey();
4103                                         } else {
4104                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4105                                         }
4106                                 }
4107                         }
4108
4109                         if ( $imageDBkey !== false ) {
4110                                 $badImages[$imageDBkey] = $exceptions;
4111                         }
4112                 }
4113                 if ( $cacheable ) {
4114                         $badImageCache = $badImages;
4115                 }
4116         }
4117
4118         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4119         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4120         wfProfileOut( __METHOD__ );
4121         return $bad;
4122 }
4123
4124 /**
4125  * Determine whether the client at a given source IP is likely to be able to
4126  * access the wiki via HTTPS.
4127  *
4128  * @param string $ip The IPv4/6 address in the normal human-readable form
4129  * @return bool
4130  */
4131 function wfCanIPUseHTTPS( $ip ) {
4132         $canDo = true;
4133         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4134         return !!$canDo;
4135 }
4136
4137 /**
4138  * Work out the IP address based on various globals
4139  * For trusted proxies, use the XFF client IP (first of the chain)
4140  *
4141  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4142  * @return string
4143  */
4144 function wfGetIP() {
4145         wfDeprecated( __METHOD__, '1.19' );
4146         global $wgRequest;
4147         return $wgRequest->getIP();
4148 }
4149
4150 /**
4151  * Checks if an IP is a trusted proxy provider.
4152  * Useful to tell if X-Forwarded-For data is possibly bogus.
4153  * Squid cache servers for the site are whitelisted.
4154  *
4155  * @param string $ip
4156  * @return bool
4157  */
4158 function wfIsTrustedProxy( $ip ) {
4159         $trusted = wfIsConfiguredProxy( $ip );
4160         wfRunHooks( 'IsTrustedProxy', array( &$ip, &$trusted ) );
4161         return $trusted;
4162 }
4163
4164 /**
4165  * Checks if an IP matches a proxy we've configured.
4166  *
4167  * @param string $ip
4168  * @return bool
4169  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4170  */
4171 function wfIsConfiguredProxy( $ip ) {
4172         global $wgSquidServers, $wgSquidServersNoPurge;
4173
4174         // quick check of known proxy servers
4175         $trusted = in_array( $ip, $wgSquidServers )
4176                 || in_array( $ip, $wgSquidServersNoPurge );
4177
4178         if ( !$trusted ) {
4179                 // slightly slower check to see if the ip is listed directly or in a CIDR
4180                 // block in $wgSquidServersNoPurge
4181                 foreach ( $wgSquidServersNoPurge as $block ) {
4182                         if ( strpos( $block, '/' ) !== false && IP::isInRange( $ip, $block ) ) {
4183                                 $trusted = true;
4184                                 break;
4185                         }
4186                 }
4187         }
4188         return $trusted;
4189 }