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                         $string = Parser::stripOuterParagraph( $string );
1730                 }
1731         } elseif ( in_array( 'parsemag', $options, true ) ) {
1732                 $string = $messageCache->transform( $string,
1733                                 !$forContent, $langCodeObj );
1734         }
1735
1736         if ( in_array( 'escape', $options, true ) ) {
1737                 $string = htmlspecialchars ( $string );
1738         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1739                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1740         }
1741
1742         if ( in_array( 'replaceafter', $options, true ) ) {
1743                 $string = wfMsgReplaceArgs( $string, $args );
1744         }
1745
1746         return $string;
1747 }
1748
1749 /**
1750  * Since wfMsg() and co suck, they don't return false if the message key they
1751  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1752  * nonexistence of messages by checking the MessageCache::get() result directly.
1753  *
1754  * @deprecated since 1.18. Use Message::isDisabled().
1755  *
1756  * @param string $key The message key looked up
1757  * @return bool True if the message *doesn't* exist.
1758  */
1759 function wfEmptyMsg( $key ) {
1760         wfDeprecated( __METHOD__, '1.21' );
1761
1762         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1763 }
1764
1765 /**
1766  * Throw a debugging exception. This function previously once exited the process,
1767  * but now throws an exception instead, with similar results.
1768  *
1769  * @deprecated since 1.22; just throw an MWException yourself
1770  * @param string $msg Message shown when dying.
1771  * @throws MWException
1772  */
1773 function wfDebugDieBacktrace( $msg = '' ) {
1774         wfDeprecated( __FUNCTION__, '1.22' );
1775         throw new MWException( $msg );
1776 }
1777
1778 /**
1779  * Fetch server name for use in error reporting etc.
1780  * Use real server name if available, so we know which machine
1781  * in a server farm generated the current page.
1782  *
1783  * @return string
1784  */
1785 function wfHostname() {
1786         static $host;
1787         if ( is_null( $host ) ) {
1788
1789                 # Hostname overriding
1790                 global $wgOverrideHostname;
1791                 if ( $wgOverrideHostname !== false ) {
1792                         # Set static and skip any detection
1793                         $host = $wgOverrideHostname;
1794                         return $host;
1795                 }
1796
1797                 if ( function_exists( 'posix_uname' ) ) {
1798                         // This function not present on Windows
1799                         $uname = posix_uname();
1800                 } else {
1801                         $uname = false;
1802                 }
1803                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1804                         $host = $uname['nodename'];
1805                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1806                         # Windows computer name
1807                         $host = getenv( 'COMPUTERNAME' );
1808                 } else {
1809                         # This may be a virtual server.
1810                         $host = $_SERVER['SERVER_NAME'];
1811                 }
1812         }
1813         return $host;
1814 }
1815
1816 /**
1817  * Returns a script tag that stores the amount of time it took MediaWiki to
1818  * handle the request in milliseconds as 'wgBackendResponseTime'.
1819  *
1820  * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
1821  * hostname of the server handling the request.
1822  *
1823  * @return string
1824  */
1825 function wfReportTime() {
1826         global $wgRequestTime, $wgShowHostnames;
1827
1828         $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
1829         $reportVars = array( 'wgBackendResponseTime' => $responseTime );
1830         if ( $wgShowHostnames ) {
1831                 $reportVars[ 'wgHostname' ] = wfHostname();
1832         }
1833         return Skin::makeVariablesScript( $reportVars );
1834 }
1835
1836 /**
1837  * Safety wrapper for debug_backtrace().
1838  *
1839  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1840  * murky circumstances, which may be triggered in part by stub objects
1841  * or other fancy talking'.
1842  *
1843  * Will return an empty array if Zend Optimizer is detected or if
1844  * debug_backtrace is disabled, otherwise the output from
1845  * debug_backtrace() (trimmed).
1846  *
1847  * @param int $limit This parameter can be used to limit the number of stack frames returned
1848  *
1849  * @return array Array of backtrace information
1850  */
1851 function wfDebugBacktrace( $limit = 0 ) {
1852         static $disabled = null;
1853
1854         if ( extension_loaded( 'Zend Optimizer' ) ) {
1855                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1856                 return array();
1857         }
1858
1859         if ( is_null( $disabled ) ) {
1860                 $disabled = false;
1861                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1862                 $functions = array_map( 'trim', $functions );
1863                 $functions = array_map( 'strtolower', $functions );
1864                 if ( in_array( 'debug_backtrace', $functions ) ) {
1865                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1866                         $disabled = true;
1867                 }
1868         }
1869         if ( $disabled ) {
1870                 return array();
1871         }
1872
1873         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1874                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1875         } else {
1876                 return array_slice( debug_backtrace(), 1 );
1877         }
1878 }
1879
1880 /**
1881  * Get a debug backtrace as a string
1882  *
1883  * @return string
1884  */
1885 function wfBacktrace() {
1886         global $wgCommandLineMode;
1887
1888         if ( $wgCommandLineMode ) {
1889                 $msg = '';
1890         } else {
1891                 $msg = "<ul>\n";
1892         }
1893         $backtrace = wfDebugBacktrace();
1894         foreach ( $backtrace as $call ) {
1895                 if ( isset( $call['file'] ) ) {
1896                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1897                         $file = $f[count( $f ) - 1];
1898                 } else {
1899                         $file = '-';
1900                 }
1901                 if ( isset( $call['line'] ) ) {
1902                         $line = $call['line'];
1903                 } else {
1904                         $line = '-';
1905                 }
1906                 if ( $wgCommandLineMode ) {
1907                         $msg .= "$file line $line calls ";
1908                 } else {
1909                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1910                 }
1911                 if ( !empty( $call['class'] ) ) {
1912                         $msg .= $call['class'] . $call['type'];
1913                 }
1914                 $msg .= $call['function'] . '()';
1915
1916                 if ( $wgCommandLineMode ) {
1917                         $msg .= "\n";
1918                 } else {
1919                         $msg .= "</li>\n";
1920                 }
1921         }
1922         if ( $wgCommandLineMode ) {
1923                 $msg .= "\n";
1924         } else {
1925                 $msg .= "</ul>\n";
1926         }
1927
1928         return $msg;
1929 }
1930
1931 /**
1932  * Get the name of the function which called this function
1933  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1934  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1935  * wfGetCaller( 3 ) is the parent of that.
1936  *
1937  * @param int $level
1938  * @return string
1939  */
1940 function wfGetCaller( $level = 2 ) {
1941         $backtrace = wfDebugBacktrace( $level + 1 );
1942         if ( isset( $backtrace[$level] ) ) {
1943                 return wfFormatStackFrame( $backtrace[$level] );
1944         } else {
1945                 return 'unknown';
1946         }
1947 }
1948
1949 /**
1950  * Return a string consisting of callers in the stack. Useful sometimes
1951  * for profiling specific points.
1952  *
1953  * @param int $limit The maximum depth of the stack frame to return, or false for the entire stack.
1954  * @return string
1955  */
1956 function wfGetAllCallers( $limit = 3 ) {
1957         $trace = array_reverse( wfDebugBacktrace() );
1958         if ( !$limit || $limit > count( $trace ) - 1 ) {
1959                 $limit = count( $trace ) - 1;
1960         }
1961         $trace = array_slice( $trace, -$limit - 1, $limit );
1962         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1963 }
1964
1965 /**
1966  * Return a string representation of frame
1967  *
1968  * @param array $frame
1969  * @return string
1970  */
1971 function wfFormatStackFrame( $frame ) {
1972         return isset( $frame['class'] ) ?
1973                 $frame['class'] . '::' . $frame['function'] :
1974                 $frame['function'];
1975 }
1976
1977 /* Some generic result counters, pulled out of SearchEngine */
1978
1979 /**
1980  * @todo document
1981  *
1982  * @param int $offset
1983  * @param int $limit
1984  * @return string
1985  */
1986 function wfShowingResults( $offset, $limit ) {
1987         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1988 }
1989
1990 /**
1991  * Generate (prev x| next x) (20|50|100...) type links for paging
1992  *
1993  * @param string $offset
1994  * @param int $limit
1995  * @param string $link
1996  * @param string $query Optional URL query parameter string
1997  * @param bool $atend Optional param for specified if this is the last page
1998  * @return string
1999  * @deprecated since 1.19; use Language::viewPrevNext() instead
2000  */
2001 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
2002         wfDeprecated( __METHOD__, '1.19' );
2003
2004         global $wgLang;
2005
2006         $query = wfCgiToArray( $query );
2007
2008         if ( is_object( $link ) ) {
2009                 $title = $link;
2010         } else {
2011                 $title = Title::newFromText( $link );
2012                 if ( is_null( $title ) ) {
2013                         return false;
2014                 }
2015         }
2016
2017         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
2018 }
2019
2020 /**
2021  * @todo document
2022  * @todo FIXME: We may want to blacklist some broken browsers
2023  *
2024  * @param bool $force
2025  * @return bool Whereas client accept gzip compression
2026  */
2027 function wfClientAcceptsGzip( $force = false ) {
2028         static $result = null;
2029         if ( $result === null || $force ) {
2030                 $result = false;
2031                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2032                         # @todo FIXME: We may want to blacklist some broken browsers
2033                         $m = array();
2034                         if ( preg_match(
2035                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2036                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
2037                                         $m
2038                                 )
2039                         ) {
2040                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2041                                         $result = false;
2042                                         return $result;
2043                                 }
2044                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2045                                 $result = true;
2046                         }
2047                 }
2048         }
2049         return $result;
2050 }
2051
2052 /**
2053  * Obtain the offset and limit values from the request string;
2054  * used in special pages
2055  *
2056  * @param int $deflimit Default limit if none supplied
2057  * @param string $optionname Name of a user preference to check against
2058  * @return array
2059  */
2060 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2061         global $wgRequest;
2062         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2063 }
2064
2065 /**
2066  * Escapes the given text so that it may be output using addWikiText()
2067  * without any linking, formatting, etc. making its way through. This
2068  * is achieved by substituting certain characters with HTML entities.
2069  * As required by the callers, "<nowiki>" is not used.
2070  *
2071  * @param string $text Text to be escaped
2072  * @return string
2073  */
2074 function wfEscapeWikiText( $text ) {
2075         static $repl = null, $repl2 = null;
2076         if ( $repl === null ) {
2077                 $repl = array(
2078                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2079                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2080                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2081                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2082                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2083                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2084                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2085                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2086                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2087                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2088                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2089                         '__' => '_&#95;', '://' => '&#58;//',
2090                 );
2091
2092                 // We have to catch everything "\s" matches in PCRE
2093                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2094                         $repl["$magic "] = "$magic&#32;";
2095                         $repl["$magic\t"] = "$magic&#9;";
2096                         $repl["$magic\r"] = "$magic&#13;";
2097                         $repl["$magic\n"] = "$magic&#10;";
2098                         $repl["$magic\f"] = "$magic&#12;";
2099                 }
2100
2101                 // And handle protocols that don't use "://"
2102                 global $wgUrlProtocols;
2103                 $repl2 = array();
2104                 foreach ( $wgUrlProtocols as $prot ) {
2105                         if ( substr( $prot, -1 ) === ':' ) {
2106                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2107                         }
2108                 }
2109                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2110         }
2111         $text = substr( strtr( "\n$text", $repl ), 1 );
2112         $text = preg_replace( $repl2, '$1&#58;', $text );
2113         return $text;
2114 }
2115
2116 /**
2117  * Get the current unix timestamp with microseconds.  Useful for profiling
2118  * @deprecated since 1.22; call microtime() directly
2119  * @return float
2120  */
2121 function wfTime() {
2122         wfDeprecated( __FUNCTION__, '1.22' );
2123         return microtime( true );
2124 }
2125
2126 /**
2127  * Sets dest to source and returns the original value of dest
2128  * If source is NULL, it just returns the value, it doesn't set the variable
2129  * If force is true, it will set the value even if source is NULL
2130  *
2131  * @param mixed $dest
2132  * @param mixed $source
2133  * @param bool $force
2134  * @return mixed
2135  */
2136 function wfSetVar( &$dest, $source, $force = false ) {
2137         $temp = $dest;
2138         if ( !is_null( $source ) || $force ) {
2139                 $dest = $source;
2140         }
2141         return $temp;
2142 }
2143
2144 /**
2145  * As for wfSetVar except setting a bit
2146  *
2147  * @param int $dest
2148  * @param int $bit
2149  * @param bool $state
2150  *
2151  * @return bool
2152  */
2153 function wfSetBit( &$dest, $bit, $state = true ) {
2154         $temp = (bool)( $dest & $bit );
2155         if ( !is_null( $state ) ) {
2156                 if ( $state ) {
2157                         $dest |= $bit;
2158                 } else {
2159                         $dest &= ~$bit;
2160                 }
2161         }
2162         return $temp;
2163 }
2164
2165 /**
2166  * A wrapper around the PHP function var_export().
2167  * Either print it or add it to the regular output ($wgOut).
2168  *
2169  * @param mixed $var A PHP variable to dump.
2170  */
2171 function wfVarDump( $var ) {
2172         global $wgOut;
2173         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2174         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2175                 print $s;
2176         } else {
2177                 $wgOut->addHTML( $s );
2178         }
2179 }
2180
2181 /**
2182  * Provide a simple HTTP error.
2183  *
2184  * @param int|string $code
2185  * @param string $label
2186  * @param string $desc
2187  */
2188 function wfHttpError( $code, $label, $desc ) {
2189         global $wgOut;
2190         $wgOut->disable();
2191         header( "HTTP/1.0 $code $label" );
2192         header( "Status: $code $label" );
2193         $wgOut->sendCacheControl();
2194
2195         header( 'Content-type: text/html; charset=utf-8' );
2196         print "<!doctype html>" .
2197                 '<html><head><title>' .
2198                 htmlspecialchars( $label ) .
2199                 '</title></head><body><h1>' .
2200                 htmlspecialchars( $label ) .
2201                 '</h1><p>' .
2202                 nl2br( htmlspecialchars( $desc ) ) .
2203                 "</p></body></html>\n";
2204 }
2205
2206 /**
2207  * Clear away any user-level output buffers, discarding contents.
2208  *
2209  * Suitable for 'starting afresh', for instance when streaming
2210  * relatively large amounts of data without buffering, or wanting to
2211  * output image files without ob_gzhandler's compression.
2212  *
2213  * The optional $resetGzipEncoding parameter controls suppression of
2214  * the Content-Encoding header sent by ob_gzhandler; by default it
2215  * is left. See comments for wfClearOutputBuffers() for why it would
2216  * be used.
2217  *
2218  * Note that some PHP configuration options may add output buffer
2219  * layers which cannot be removed; these are left in place.
2220  *
2221  * @param bool $resetGzipEncoding
2222  */
2223 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2224         if ( $resetGzipEncoding ) {
2225                 // Suppress Content-Encoding and Content-Length
2226                 // headers from 1.10+s wfOutputHandler
2227                 global $wgDisableOutputCompression;
2228                 $wgDisableOutputCompression = true;
2229         }
2230         while ( $status = ob_get_status() ) {
2231                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2232                         // Probably from zlib.output_compression or other
2233                         // PHP-internal setting which can't be removed.
2234                         //
2235                         // Give up, and hope the result doesn't break
2236                         // output behavior.
2237                         break;
2238                 }
2239                 if ( !ob_end_clean() ) {
2240                         // Could not remove output buffer handler; abort now
2241                         // to avoid getting in some kind of infinite loop.
2242                         break;
2243                 }
2244                 if ( $resetGzipEncoding ) {
2245                         if ( $status['name'] == 'ob_gzhandler' ) {
2246                                 // Reset the 'Content-Encoding' field set by this handler
2247                                 // so we can start fresh.
2248                                 header_remove( 'Content-Encoding' );
2249                                 break;
2250                         }
2251                 }
2252         }
2253 }
2254
2255 /**
2256  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2257  *
2258  * Clear away output buffers, but keep the Content-Encoding header
2259  * produced by ob_gzhandler, if any.
2260  *
2261  * This should be used for HTTP 304 responses, where you need to
2262  * preserve the Content-Encoding header of the real result, but
2263  * also need to suppress the output of ob_gzhandler to keep to spec
2264  * and avoid breaking Firefox in rare cases where the headers and
2265  * body are broken over two packets.
2266  */
2267 function wfClearOutputBuffers() {
2268         wfResetOutputBuffers( false );
2269 }
2270
2271 /**
2272  * Converts an Accept-* header into an array mapping string values to quality
2273  * factors
2274  *
2275  * @param string $accept
2276  * @param string $def default
2277  * @return float[] Associative array of string => float pairs
2278  */
2279 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2280         # No arg means accept anything (per HTTP spec)
2281         if ( !$accept ) {
2282                 return array( $def => 1.0 );
2283         }
2284
2285         $prefs = array();
2286
2287         $parts = explode( ',', $accept );
2288
2289         foreach ( $parts as $part ) {
2290                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2291                 $values = explode( ';', trim( $part ) );
2292                 $match = array();
2293                 if ( count( $values ) == 1 ) {
2294                         $prefs[$values[0]] = 1.0;
2295                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2296                         $prefs[$values[0]] = floatval( $match[1] );
2297                 }
2298         }
2299
2300         return $prefs;
2301 }
2302
2303 /**
2304  * Checks if a given MIME type matches any of the keys in the given
2305  * array. Basic wildcards are accepted in the array keys.
2306  *
2307  * Returns the matching MIME type (or wildcard) if a match, otherwise
2308  * NULL if no match.
2309  *
2310  * @param string $type
2311  * @param array $avail
2312  * @return string
2313  * @private
2314  */
2315 function mimeTypeMatch( $type, $avail ) {
2316         if ( array_key_exists( $type, $avail ) ) {
2317                 return $type;
2318         } else {
2319                 $parts = explode( '/', $type );
2320                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2321                         return $parts[0] . '/*';
2322                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2323                         return '*/*';
2324                 } else {
2325                         return null;
2326                 }
2327         }
2328 }
2329
2330 /**
2331  * Returns the 'best' match between a client's requested internet media types
2332  * and the server's list of available types. Each list should be an associative
2333  * array of type to preference (preference is a float between 0.0 and 1.0).
2334  * Wildcards in the types are acceptable.
2335  *
2336  * @param array $cprefs Client's acceptable type list
2337  * @param array $sprefs Server's offered types
2338  * @return string
2339  *
2340  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2341  * XXX: generalize to negotiate other stuff
2342  */
2343 function wfNegotiateType( $cprefs, $sprefs ) {
2344         $combine = array();
2345
2346         foreach ( array_keys( $sprefs ) as $type ) {
2347                 $parts = explode( '/', $type );
2348                 if ( $parts[1] != '*' ) {
2349                         $ckey = mimeTypeMatch( $type, $cprefs );
2350                         if ( $ckey ) {
2351                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2352                         }
2353                 }
2354         }
2355
2356         foreach ( array_keys( $cprefs ) as $type ) {
2357                 $parts = explode( '/', $type );
2358                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2359                         $skey = mimeTypeMatch( $type, $sprefs );
2360                         if ( $skey ) {
2361                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2362                         }
2363                 }
2364         }
2365
2366         $bestq = 0;
2367         $besttype = null;
2368
2369         foreach ( array_keys( $combine ) as $type ) {
2370                 if ( $combine[$type] > $bestq ) {
2371                         $besttype = $type;
2372                         $bestq = $combine[$type];
2373                 }
2374         }
2375
2376         return $besttype;
2377 }
2378
2379 /**
2380  * Reference-counted warning suppression
2381  *
2382  * @param bool $end
2383  */
2384 function wfSuppressWarnings( $end = false ) {
2385         static $suppressCount = 0;
2386         static $originalLevel = false;
2387
2388         if ( $end ) {
2389                 if ( $suppressCount ) {
2390                         --$suppressCount;
2391                         if ( !$suppressCount ) {
2392                                 error_reporting( $originalLevel );
2393                         }
2394                 }
2395         } else {
2396                 if ( !$suppressCount ) {
2397                         $originalLevel = error_reporting( E_ALL & ~(
2398                                 E_WARNING |
2399                                 E_NOTICE |
2400                                 E_USER_WARNING |
2401                                 E_USER_NOTICE |
2402                                 E_DEPRECATED |
2403                                 E_USER_DEPRECATED |
2404                                 E_STRICT
2405                         ) );
2406                 }
2407                 ++$suppressCount;
2408         }
2409 }
2410
2411 /**
2412  * Restore error level to previous value
2413  */
2414 function wfRestoreWarnings() {
2415         wfSuppressWarnings( true );
2416 }
2417
2418 # Autodetect, convert and provide timestamps of various types
2419
2420 /**
2421  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2422  */
2423 define( 'TS_UNIX', 0 );
2424
2425 /**
2426  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2427  */
2428 define( 'TS_MW', 1 );
2429
2430 /**
2431  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2432  */
2433 define( 'TS_DB', 2 );
2434
2435 /**
2436  * RFC 2822 format, for E-mail and HTTP headers
2437  */
2438 define( 'TS_RFC2822', 3 );
2439
2440 /**
2441  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2442  *
2443  * This is used by Special:Export
2444  */
2445 define( 'TS_ISO_8601', 4 );
2446
2447 /**
2448  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2449  *
2450  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2451  *       DateTime tag and page 36 for the DateTimeOriginal and
2452  *       DateTimeDigitized tags.
2453  */
2454 define( 'TS_EXIF', 5 );
2455
2456 /**
2457  * Oracle format time.
2458  */
2459 define( 'TS_ORACLE', 6 );
2460
2461 /**
2462  * Postgres format time.
2463  */
2464 define( 'TS_POSTGRES', 7 );
2465
2466 /**
2467  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2468  */
2469 define( 'TS_ISO_8601_BASIC', 9 );
2470
2471 /**
2472  * Get a timestamp string in one of various formats
2473  *
2474  * @param mixed $outputtype A timestamp in one of the supported formats, the
2475  *   function will autodetect which format is supplied and act accordingly.
2476  * @param mixed $ts Optional timestamp to convert, default 0 for the current time
2477  * @return string|bool String / false The same date in the format specified in $outputtype or false
2478  */
2479 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2480         try {
2481                 $timestamp = new MWTimestamp( $ts );
2482                 return $timestamp->getTimestamp( $outputtype );
2483         } catch ( TimestampException $e ) {
2484                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2485                 return false;
2486         }
2487 }
2488
2489 /**
2490  * Return a formatted timestamp, or null if input is null.
2491  * For dealing with nullable timestamp columns in the database.
2492  *
2493  * @param int $outputtype
2494  * @param string $ts
2495  * @return string
2496  */
2497 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2498         if ( is_null( $ts ) ) {
2499                 return null;
2500         } else {
2501                 return wfTimestamp( $outputtype, $ts );
2502         }
2503 }
2504
2505 /**
2506  * Convenience function; returns MediaWiki timestamp for the present time.
2507  *
2508  * @return string
2509  */
2510 function wfTimestampNow() {
2511         # return NOW
2512         return wfTimestamp( TS_MW, time() );
2513 }
2514
2515 /**
2516  * Check if the operating system is Windows
2517  *
2518  * @return bool True if it's Windows, false otherwise.
2519  */
2520 function wfIsWindows() {
2521         static $isWindows = null;
2522         if ( $isWindows === null ) {
2523                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2524         }
2525         return $isWindows;
2526 }
2527
2528 /**
2529  * Check if we are running under HHVM
2530  *
2531  * @return bool
2532  */
2533 function wfIsHHVM() {
2534         return defined( 'HHVM_VERSION' );
2535 }
2536
2537 /**
2538  * Swap two variables
2539  *
2540  * @param mixed $x
2541  * @param mixed $y
2542  */
2543 function swap( &$x, &$y ) {
2544         $z = $x;
2545         $x = $y;
2546         $y = $z;
2547 }
2548
2549 /**
2550  * Tries to get the system directory for temporary files. First
2551  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2552  * environment variables are then checked in sequence, and if none are
2553  * set try sys_get_temp_dir().
2554  *
2555  * NOTE: When possible, use instead the tmpfile() function to create
2556  * temporary files to avoid race conditions on file creation, etc.
2557  *
2558  * @return string
2559  */
2560 function wfTempDir() {
2561         global $wgTmpDirectory;
2562
2563         if ( $wgTmpDirectory !== false ) {
2564                 return $wgTmpDirectory;
2565         }
2566
2567         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2568
2569         foreach ( $tmpDir as $tmp ) {
2570                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2571                         return $tmp;
2572                 }
2573         }
2574         return sys_get_temp_dir();
2575 }
2576
2577 /**
2578  * Make directory, and make all parent directories if they don't exist
2579  *
2580  * @param string $dir Full path to directory to create
2581  * @param int $mode Chmod value to use, default is $wgDirectoryMode
2582  * @param string $caller Optional caller param for debugging.
2583  * @throws MWException
2584  * @return bool
2585  */
2586 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2587         global $wgDirectoryMode;
2588
2589         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2590                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2591         }
2592
2593         if ( !is_null( $caller ) ) {
2594                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2595         }
2596
2597         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2598                 return true;
2599         }
2600
2601         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2602
2603         if ( is_null( $mode ) ) {
2604                 $mode = $wgDirectoryMode;
2605         }
2606
2607         // Turn off the normal warning, we're doing our own below
2608         wfSuppressWarnings();
2609         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2610         wfRestoreWarnings();
2611
2612         if ( !$ok ) {
2613                 //directory may have been created on another request since we last checked
2614                 if ( is_dir( $dir ) ) {
2615                         return true;
2616                 }
2617
2618                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2619                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2620         }
2621         return $ok;
2622 }
2623
2624 /**
2625  * Remove a directory and all its content.
2626  * Does not hide error.
2627  * @param string $dir
2628  */
2629 function wfRecursiveRemoveDir( $dir ) {
2630         wfDebug( __FUNCTION__ . "( $dir )\n" );
2631         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2632         if ( is_dir( $dir ) ) {
2633                 $objects = scandir( $dir );
2634                 foreach ( $objects as $object ) {
2635                         if ( $object != "." && $object != ".." ) {
2636                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2637                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2638                                 } else {
2639                                         unlink( $dir . '/' . $object );
2640                                 }
2641                         }
2642                 }
2643                 reset( $objects );
2644                 rmdir( $dir );
2645         }
2646 }
2647
2648 /**
2649  * @param int $nr The number to format
2650  * @param int $acc The number of digits after the decimal point, default 2
2651  * @param bool $round Whether or not to round the value, default true
2652  * @return string
2653  */
2654 function wfPercent( $nr, $acc = 2, $round = true ) {
2655         $ret = sprintf( "%.${acc}f", $nr );
2656         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2657 }
2658
2659 /**
2660  * Safety wrapper around ini_get() for boolean settings.
2661  * The values returned from ini_get() are pre-normalized for settings
2662  * set via php.ini or php_flag/php_admin_flag... but *not*
2663  * for those set via php_value/php_admin_value.
2664  *
2665  * It's fairly common for people to use php_value instead of php_flag,
2666  * which can leave you with an 'off' setting giving a false positive
2667  * for code that just takes the ini_get() return value as a boolean.
2668  *
2669  * To make things extra interesting, setting via php_value accepts
2670  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2671  * Unrecognized values go false... again opposite PHP's own coercion
2672  * from string to bool.
2673  *
2674  * Luckily, 'properly' set settings will always come back as '0' or '1',
2675  * so we only have to worry about them and the 'improper' settings.
2676  *
2677  * I frickin' hate PHP... :P
2678  *
2679  * @param string $setting
2680  * @return bool
2681  */
2682 function wfIniGetBool( $setting ) {
2683         $val = strtolower( ini_get( $setting ) );
2684         // 'on' and 'true' can't have whitespace around them, but '1' can.
2685         return $val == 'on'
2686                 || $val == 'true'
2687                 || $val == 'yes'
2688                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2689 }
2690
2691 /**
2692  * Windows-compatible version of escapeshellarg()
2693  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2694  * function puts single quotes in regardless of OS.
2695  *
2696  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2697  * earlier distro releases of PHP)
2698  *
2699  * @param string [$args,...]
2700  * @return string
2701  */
2702 function wfEscapeShellArg( /*...*/ ) {
2703         wfInitShellLocale();
2704
2705         $args = func_get_args();
2706         $first = true;
2707         $retVal = '';
2708         foreach ( $args as $arg ) {
2709                 if ( !$first ) {
2710                         $retVal .= ' ';
2711                 } else {
2712                         $first = false;
2713                 }
2714
2715                 if ( wfIsWindows() ) {
2716                         // Escaping for an MSVC-style command line parser and CMD.EXE
2717                         // @codingStandardsIgnoreStart For long URLs
2718                         // Refs:
2719                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2720                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2721                         //  * Bug #13518
2722                         //  * CR r63214
2723                         // Double the backslashes before any double quotes. Escape the double quotes.
2724                         // @codingStandardsIgnoreEnd
2725                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2726                         $arg = '';
2727                         $iteration = 0;
2728                         foreach ( $tokens as $token ) {
2729                                 if ( $iteration % 2 == 1 ) {
2730                                         // Delimiter, a double quote preceded by zero or more slashes
2731                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2732                                 } elseif ( $iteration % 4 == 2 ) {
2733                                         // ^ in $token will be outside quotes, need to be escaped
2734                                         $arg .= str_replace( '^', '^^', $token );
2735                                 } else { // $iteration % 4 == 0
2736                                         // ^ in $token will appear inside double quotes, so leave as is
2737                                         $arg .= $token;
2738                                 }
2739                                 $iteration++;
2740                         }
2741                         // Double the backslashes before the end of the string, because
2742                         // we will soon add a quote
2743                         $m = array();
2744                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2745                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2746                         }
2747
2748                         // Add surrounding quotes
2749                         $retVal .= '"' . $arg . '"';
2750                 } else {
2751                         $retVal .= escapeshellarg( $arg );
2752                 }
2753         }
2754         return $retVal;
2755 }
2756
2757 /**
2758  * Check if wfShellExec() is effectively disabled via php.ini config
2759  *
2760  * @return bool|string False or one of (safemode,disabled)
2761  * @since 1.22
2762  */
2763 function wfShellExecDisabled() {
2764         static $disabled = null;
2765         if ( is_null( $disabled ) ) {
2766                 $disabled = false;
2767                 if ( wfIniGetBool( 'safe_mode' ) ) {
2768                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2769                         $disabled = 'safemode';
2770                 } else {
2771                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2772                         $functions = array_map( 'trim', $functions );
2773                         $functions = array_map( 'strtolower', $functions );
2774                         if ( in_array( 'proc_open', $functions ) ) {
2775                                 wfDebug( "proc_open is in disabled_functions\n" );
2776                                 $disabled = 'disabled';
2777                         }
2778                 }
2779         }
2780         return $disabled;
2781 }
2782
2783 /**
2784  * Execute a shell command, with time and memory limits mirrored from the PHP
2785  * configuration if supported.
2786  *
2787  * @param string $cmd Command line, properly escaped for shell.
2788  * @param null|mixed &$retval Optional, will receive the program's exit code.
2789  *   (non-zero is usually failure). If there is an error from
2790  *   read, select, or proc_open(), this will be set to -1.
2791  * @param array $environ Optional environment variables which should be
2792  *   added to the executed command environment.
2793  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
2794  *   this overwrites the global wgMaxShell* limits.
2795  * @param array $options Array of options:
2796  *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
2797  *     including errors from limit.sh
2798  *
2799  * @return string Collected stdout as a string
2800  */
2801 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2802         $limits = array(), $options = array()
2803 ) {
2804         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2805                 $wgMaxShellWallClockTime, $wgShellCgroup;
2806
2807         $disabled = wfShellExecDisabled();
2808         if ( $disabled ) {
2809                 $retval = 1;
2810                 return $disabled == 'safemode' ?
2811                         'Unable to run external programs in safe mode.' :
2812                         'Unable to run external programs, proc_open() is disabled.';
2813         }
2814
2815         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2816
2817         wfInitShellLocale();
2818
2819         $envcmd = '';
2820         foreach ( $environ as $k => $v ) {
2821                 if ( wfIsWindows() ) {
2822                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2823                          * appear in the environment variable, so we must use carat escaping as documented in
2824                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2825                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2826                          * are listed there but doesn't appear to need it.
2827                          */
2828                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2829                 } else {
2830                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2831                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2832                          */
2833                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2834                 }
2835         }
2836         $cmd = $envcmd . $cmd;
2837
2838         $useLogPipe = false;
2839         if ( php_uname( 's' ) == 'Linux' ) {
2840                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2841                 if ( isset( $limits['walltime'] ) ) {
2842                         $wallTime = intval( $limits['walltime'] );
2843                 } elseif ( isset( $limits['time'] ) ) {
2844                         $wallTime = $time;
2845                 } else {
2846                         $wallTime = intval( $wgMaxShellWallClockTime );
2847                 }
2848                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2849                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2850
2851                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2852                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2853                                 escapeshellarg( $cmd ) . ' ' .
2854                                 escapeshellarg(
2855                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2856                                         "MW_CPU_LIMIT=$time; " .
2857                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2858                                         "MW_MEM_LIMIT=$mem; " .
2859                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2860                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2861                                         "MW_USE_LOG_PIPE=yes"
2862                                 );
2863                         $useLogPipe = true;
2864                 } elseif ( $includeStderr ) {
2865                         $cmd .= ' 2>&1';
2866                 }
2867         } elseif ( $includeStderr ) {
2868                 $cmd .= ' 2>&1';
2869         }
2870         wfDebug( "wfShellExec: $cmd\n" );
2871
2872         $desc = array(
2873                 0 => array( 'file', 'php://stdin', 'r' ),
2874                 1 => array( 'pipe', 'w' ),
2875                 2 => array( 'file', 'php://stderr', 'w' ) );
2876         if ( $useLogPipe ) {
2877                 $desc[3] = array( 'pipe', 'w' );
2878         }
2879         $pipes = null;
2880         $proc = proc_open( $cmd, $desc, $pipes );
2881         if ( !$proc ) {
2882                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2883                 $retval = -1;
2884                 return '';
2885         }
2886         $outBuffer = $logBuffer = '';
2887         $emptyArray = array();
2888         $status = false;
2889         $logMsg = false;
2890
2891         // According to the documentation, it is possible for stream_select()
2892         // to fail due to EINTR. I haven't managed to induce this in testing
2893         // despite sending various signals. If it did happen, the error
2894         // message would take the form:
2895         //
2896         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2897         //
2898         // where [4] is the value of the macro EINTR and "Interrupted system
2899         // call" is string which according to the Linux manual is "possibly"
2900         // localised according to LC_MESSAGES.
2901         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2902         $eintrMessage = "stream_select(): unable to select [$eintr]";
2903
2904         // Build a table mapping resource IDs to pipe FDs to work around a
2905         // PHP 5.3 issue in which stream_select() does not preserve array keys
2906         // <https://bugs.php.net/bug.php?id=53427>.
2907         $fds = array();
2908         foreach ( $pipes as $fd => $pipe ) {
2909                 $fds[(int)$pipe] = $fd;
2910         }
2911
2912         while ( true ) {
2913                 $status = proc_get_status( $proc );
2914                 if ( !$status['running'] ) {
2915                         break;
2916                 }
2917                 $status = false;
2918
2919                 $readyPipes = $pipes;
2920
2921                 // Clear last error
2922                 // @codingStandardsIgnoreStart Generic.PHP.NoSilencedErrors.Discouraged
2923                 @trigger_error( '' );
2924                 if ( @stream_select( $readyPipes, $emptyArray, $emptyArray, null ) === false ) {
2925                         // @codingStandardsIgnoreEnd
2926                         $error = error_get_last();
2927                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2928                                 continue;
2929                         } else {
2930                                 trigger_error( $error['message'], E_USER_WARNING );
2931                                 $logMsg = $error['message'];
2932                                 break;
2933                         }
2934                 }
2935                 foreach ( $readyPipes as $pipe ) {
2936                         $block = fread( $pipe, 65536 );
2937                         $fd = $fds[(int)$pipe];
2938                         if ( $block === '' ) {
2939                                 // End of file
2940                                 fclose( $pipes[$fd] );
2941                                 unset( $pipes[$fd] );
2942                                 if ( !$pipes ) {
2943                                         break 2;
2944                                 }
2945                         } elseif ( $block === false ) {
2946                                 // Read error
2947                                 $logMsg = "Error reading from pipe";
2948                                 break 2;
2949                         } elseif ( $fd == 1 ) {
2950                                 // From stdout
2951                                 $outBuffer .= $block;
2952                         } elseif ( $fd == 3 ) {
2953                                 // From log FD
2954                                 $logBuffer .= $block;
2955                                 if ( strpos( $block, "\n" ) !== false ) {
2956                                         $lines = explode( "\n", $logBuffer );
2957                                         $logBuffer = array_pop( $lines );
2958                                         foreach ( $lines as $line ) {
2959                                                 wfDebugLog( 'exec', $line );
2960                                         }
2961                                 }
2962                         }
2963                 }
2964         }
2965
2966         foreach ( $pipes as $pipe ) {
2967                 fclose( $pipe );
2968         }
2969
2970         // Use the status previously collected if possible, since proc_get_status()
2971         // just calls waitpid() which will not return anything useful the second time.
2972         if ( $status === false ) {
2973                 $status = proc_get_status( $proc );
2974         }
2975
2976         if ( $logMsg !== false ) {
2977                 // Read/select error
2978                 $retval = -1;
2979                 proc_close( $proc );
2980         } elseif ( $status['signaled'] ) {
2981                 $logMsg = "Exited with signal {$status['termsig']}";
2982                 $retval = 128 + $status['termsig'];
2983                 proc_close( $proc );
2984         } else {
2985                 if ( $status['running'] ) {
2986                         $retval = proc_close( $proc );
2987                 } else {
2988                         $retval = $status['exitcode'];
2989                         proc_close( $proc );
2990                 }
2991                 if ( $retval == 127 ) {
2992                         $logMsg = "Possibly missing executable file";
2993                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2994                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2995                 }
2996         }
2997
2998         if ( $logMsg !== false ) {
2999                 wfDebugLog( 'exec', "$logMsg: $cmd" );
3000         }
3001
3002         return $outBuffer;
3003 }
3004
3005 /**
3006  * Execute a shell command, returning both stdout and stderr. Convenience
3007  * function, as all the arguments to wfShellExec can become unwieldy.
3008  *
3009  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
3010  * @param string $cmd Command line, properly escaped for shell.
3011  * @param null|mixed &$retval Optional, will receive the program's exit code.
3012  *   (non-zero is usually failure)
3013  * @param array $environ optional environment variables which should be
3014  *   added to the executed command environment.
3015  * @param array $limits Optional array with limits(filesize, memory, time, walltime)
3016  *   this overwrites the global wgShellMax* limits.
3017  * @return string Collected stdout and stderr as a string
3018  */
3019 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
3020         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
3021 }
3022
3023 /**
3024  * Workaround for http://bugs.php.net/bug.php?id=45132
3025  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
3026  */
3027 function wfInitShellLocale() {
3028         static $done = false;
3029         if ( $done ) {
3030                 return;
3031         }
3032         $done = true;
3033         global $wgShellLocale;
3034         if ( !wfIniGetBool( 'safe_mode' ) ) {
3035                 putenv( "LC_CTYPE=$wgShellLocale" );
3036                 setlocale( LC_CTYPE, $wgShellLocale );
3037         }
3038 }
3039
3040 /**
3041  * Alias to wfShellWikiCmd()
3042  *
3043  * @see wfShellWikiCmd()
3044  */
3045 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
3046         return wfShellWikiCmd( $script, $parameters, $options );
3047 }
3048
3049 /**
3050  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3051  * Note that $parameters should be a flat array and an option with an argument
3052  * should consist of two consecutive items in the array (do not use "--option value").
3053  *
3054  * @param string $script MediaWiki cli script path
3055  * @param array $parameters Arguments and options to the script
3056  * @param array $options Associative array of options:
3057  *              'php': The path to the php executable
3058  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3059  * @return string
3060  */
3061 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3062         global $wgPhpCli;
3063         // Give site config file a chance to run the script in a wrapper.
3064         // The caller may likely want to call wfBasename() on $script.
3065         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3066         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3067         if ( isset( $options['wrapper'] ) ) {
3068                 $cmd[] = $options['wrapper'];
3069         }
3070         $cmd[] = $script;
3071         // Escape each parameter for shell
3072         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
3073 }
3074
3075 /**
3076  * wfMerge attempts to merge differences between three texts.
3077  * Returns true for a clean merge and false for failure or a conflict.
3078  *
3079  * @param string $old
3080  * @param string $mine
3081  * @param string $yours
3082  * @param string $result
3083  * @return bool
3084  */
3085 function wfMerge( $old, $mine, $yours, &$result ) {
3086         global $wgDiff3;
3087
3088         # This check may also protect against code injection in
3089         # case of broken installations.
3090         wfSuppressWarnings();
3091         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3092         wfRestoreWarnings();
3093
3094         if ( !$haveDiff3 ) {
3095                 wfDebug( "diff3 not found\n" );
3096                 return false;
3097         }
3098
3099         # Make temporary files
3100         $td = wfTempDir();
3101         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3102         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3103         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3104
3105         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3106         #       a newline character. To avoid this, we normalize the trailing whitespace before
3107         #       creating the diff.
3108
3109         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3110         fclose( $oldtextFile );
3111         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3112         fclose( $mytextFile );
3113         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3114         fclose( $yourtextFile );
3115
3116         # Check for a conflict
3117         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3118                 wfEscapeShellArg( $mytextName ) . ' ' .
3119                 wfEscapeShellArg( $oldtextName ) . ' ' .
3120                 wfEscapeShellArg( $yourtextName );
3121         $handle = popen( $cmd, 'r' );
3122
3123         if ( fgets( $handle, 1024 ) ) {
3124                 $conflict = true;
3125         } else {
3126                 $conflict = false;
3127         }
3128         pclose( $handle );
3129
3130         # Merge differences
3131         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3132                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3133         $handle = popen( $cmd, 'r' );
3134         $result = '';
3135         do {
3136                 $data = fread( $handle, 8192 );
3137                 if ( strlen( $data ) == 0 ) {
3138                         break;
3139                 }
3140                 $result .= $data;
3141         } while ( true );
3142         pclose( $handle );
3143         unlink( $mytextName );
3144         unlink( $oldtextName );
3145         unlink( $yourtextName );
3146
3147         if ( $result === '' && $old !== '' && !$conflict ) {
3148                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3149                 $conflict = true;
3150         }
3151         return !$conflict;
3152 }
3153
3154 /**
3155  * Returns unified plain-text diff of two texts.
3156  * Useful for machine processing of diffs.
3157  *
3158  * @param string $before The text before the changes.
3159  * @param string $after The text after the changes.
3160  * @param string $params Command-line options for the diff command.
3161  * @return string Unified diff of $before and $after
3162  */
3163 function wfDiff( $before, $after, $params = '-u' ) {
3164         if ( $before == $after ) {
3165                 return '';
3166         }
3167
3168         global $wgDiff;
3169         wfSuppressWarnings();
3170         $haveDiff = $wgDiff && file_exists( $wgDiff );
3171         wfRestoreWarnings();
3172
3173         # This check may also protect against code injection in
3174         # case of broken installations.
3175         if ( !$haveDiff ) {
3176                 wfDebug( "diff executable not found\n" );
3177                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3178                 $format = new UnifiedDiffFormatter();
3179                 return $format->format( $diffs );
3180         }
3181
3182         # Make temporary files
3183         $td = wfTempDir();
3184         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3185         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3186
3187         fwrite( $oldtextFile, $before );
3188         fclose( $oldtextFile );
3189         fwrite( $newtextFile, $after );
3190         fclose( $newtextFile );
3191
3192         // Get the diff of the two files
3193         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3194
3195         $h = popen( $cmd, 'r' );
3196
3197         $diff = '';
3198
3199         do {
3200                 $data = fread( $h, 8192 );
3201                 if ( strlen( $data ) == 0 ) {
3202                         break;
3203                 }
3204                 $diff .= $data;
3205         } while ( true );
3206
3207         // Clean up
3208         pclose( $h );
3209         unlink( $oldtextName );
3210         unlink( $newtextName );
3211
3212         // Kill the --- and +++ lines. They're not useful.
3213         $diff_lines = explode( "\n", $diff );
3214         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3215                 unset( $diff_lines[0] );
3216         }
3217         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3218                 unset( $diff_lines[1] );
3219         }
3220
3221         $diff = implode( "\n", $diff_lines );
3222
3223         return $diff;
3224 }
3225
3226 /**
3227  * This function works like "use VERSION" in Perl, the program will die with a
3228  * backtrace if the current version of PHP is less than the version provided
3229  *
3230  * This is useful for extensions which due to their nature are not kept in sync
3231  * with releases, and might depend on other versions of PHP than the main code
3232  *
3233  * Note: PHP might die due to parsing errors in some cases before it ever
3234  *       manages to call this function, such is life
3235  *
3236  * @see perldoc -f use
3237  *
3238  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3239  * @throws MWException
3240  */
3241 function wfUsePHP( $req_ver ) {
3242         $php_ver = PHP_VERSION;
3243
3244         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3245                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3246         }
3247 }
3248
3249 /**
3250  * This function works like "use VERSION" in Perl except it checks the version
3251  * of MediaWiki, the program will die with a backtrace if the current version
3252  * of MediaWiki is less than the version provided.
3253  *
3254  * This is useful for extensions which due to their nature are not kept in sync
3255  * with releases
3256  *
3257  * Note: Due to the behavior of PHP's version_compare() which is used in this
3258  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3259  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3260  * targeted version number. For example if you wanted to allow any variation
3261  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3262  * not result in the same comparison due to the internal logic of
3263  * version_compare().
3264  *
3265  * @see perldoc -f use
3266  *
3267  * @param string|int|float $req_ver The version to check, can be a string, an integer, or a float
3268  * @throws MWException
3269  */
3270 function wfUseMW( $req_ver ) {
3271         global $wgVersion;
3272
3273         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3274                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3275         }
3276 }
3277
3278 /**
3279  * Return the final portion of a pathname.
3280  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3281  * http://bugs.php.net/bug.php?id=33898
3282  *
3283  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3284  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3285  *
3286  * @param string $path
3287  * @param string $suffix String to remove if present
3288  * @return string
3289  */
3290 function wfBaseName( $path, $suffix = '' ) {
3291         if ( $suffix == '' ) {
3292                 $encSuffix = '';
3293         } else {
3294                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3295         }
3296
3297         $matches = array();
3298         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3299                 return $matches[1];
3300         } else {
3301                 return '';
3302         }
3303 }
3304
3305 /**
3306  * Generate a relative path name to the given file.
3307  * May explode on non-matching case-insensitive paths,
3308  * funky symlinks, etc.
3309  *
3310  * @param string $path Absolute destination path including target filename
3311  * @param string $from Absolute source path, directory only
3312  * @return string
3313  */
3314 function wfRelativePath( $path, $from ) {
3315         // Normalize mixed input on Windows...
3316         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3317         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3318
3319         // Trim trailing slashes -- fix for drive root
3320         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3321         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3322
3323         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3324         $against = explode( DIRECTORY_SEPARATOR, $from );
3325
3326         if ( $pieces[0] !== $against[0] ) {
3327                 // Non-matching Windows drive letters?
3328                 // Return a full path.
3329                 return $path;
3330         }
3331
3332         // Trim off common prefix
3333         while ( count( $pieces ) && count( $against )
3334                 && $pieces[0] == $against[0] ) {
3335                 array_shift( $pieces );
3336                 array_shift( $against );
3337         }
3338
3339         // relative dots to bump us to the parent
3340         while ( count( $against ) ) {
3341                 array_unshift( $pieces, '..' );
3342                 array_shift( $against );
3343         }
3344
3345         array_push( $pieces, wfBaseName( $path ) );
3346
3347         return implode( DIRECTORY_SEPARATOR, $pieces );
3348 }
3349
3350 /**
3351  * Convert an arbitrarily-long digit string from one numeric base
3352  * to another, optionally zero-padding to a minimum column width.
3353  *
3354  * Supports base 2 through 36; digit values 10-36 are represented
3355  * as lowercase letters a-z. Input is case-insensitive.
3356  *
3357  * @param string $input Input number
3358  * @param int $sourceBase Base of the input number
3359  * @param int $destBase Desired base of the output
3360  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3361  * @param bool $lowercase Whether to output in lowercase or uppercase
3362  * @param string $engine Either "gmp", "bcmath", or "php"
3363  * @return string|bool The output number as a string, or false on error
3364  */
3365 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3366         $lowercase = true, $engine = 'auto'
3367 ) {
3368         $input = (string)$input;
3369         if (
3370                 $sourceBase < 2 ||
3371                 $sourceBase > 36 ||
3372                 $destBase < 2 ||
3373                 $destBase > 36 ||
3374                 $sourceBase != (int)$sourceBase ||
3375                 $destBase != (int)$destBase ||
3376                 $pad != (int)$pad ||
3377                 !preg_match(
3378                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3379                         $input
3380                 )
3381         ) {
3382                 return false;
3383         }
3384
3385         static $baseChars = array(
3386                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3387                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3388                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3389                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3390                 34 => 'y', 35 => 'z',
3391
3392                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3393                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3394                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3395                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3396                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3397                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3398         );
3399
3400         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3401                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3402         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3403                 $decimal = '0';
3404                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3405                         $decimal = bcmul( $decimal, $sourceBase );
3406                         $decimal = bcadd( $decimal, $baseChars[$char] );
3407                 }
3408
3409                 // @codingStandardsIgnoreStart Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
3410                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3411                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3412                 }
3413                 // @codingStandardsIgnoreEnd
3414
3415                 $result = strrev( $result );
3416         } else {
3417                 $inDigits = array();
3418                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3419                         $inDigits[] = $baseChars[$char];
3420                 }
3421
3422                 // Iterate over the input, modulo-ing out an output digit
3423                 // at a time until input is gone.
3424                 $result = '';
3425                 while ( $inDigits ) {
3426                         $work = 0;
3427                         $workDigits = array();
3428
3429                         // Long division...
3430                         foreach ( $inDigits as $digit ) {
3431                                 $work *= $sourceBase;
3432                                 $work += $digit;
3433
3434                                 if ( $workDigits || $work >= $destBase ) {
3435                                         $workDigits[] = (int)( $work / $destBase );
3436                                 }
3437                                 $work %= $destBase;
3438                         }
3439
3440                         // All that division leaves us with a remainder,
3441                         // which is conveniently our next output digit.
3442                         $result .= $baseChars[$work];
3443
3444                         // And we continue!
3445                         $inDigits = $workDigits;
3446                 }
3447
3448                 $result = strrev( $result );
3449         }
3450
3451         if ( !$lowercase ) {
3452                 $result = strtoupper( $result );
3453         }
3454
3455         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3456 }
3457
3458 /**
3459  * Check if there is sufficient entropy in php's built-in session generation
3460  *
3461  * @return bool true = there is sufficient entropy
3462  */
3463 function wfCheckEntropy() {
3464         return (
3465                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3466                         || ini_get( 'session.entropy_file' )
3467                 )
3468                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3469 }
3470
3471 /**
3472  * Override session_id before session startup if php's built-in
3473  * session generation code is not secure.
3474  */
3475 function wfFixSessionID() {
3476         // If the cookie or session id is already set we already have a session and should abort
3477         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3478                 return;
3479         }
3480
3481         // PHP's built-in session entropy is enabled if:
3482         // - entropy_file is set or you're on Windows with php 5.3.3+
3483         // - AND entropy_length is > 0
3484         // We treat it as disabled if it doesn't have an entropy length of at least 32
3485         $entropyEnabled = wfCheckEntropy();
3486
3487         // If built-in entropy is not enabled or not sufficient override PHP's
3488         // built in session id generation code
3489         if ( !$entropyEnabled ) {
3490                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3491                         "overriding session id generation using our cryptrand source.\n" );
3492                 session_id( MWCryptRand::generateHex( 32 ) );
3493         }
3494 }
3495
3496 /**
3497  * Reset the session_id
3498  *
3499  * @since 1.22
3500  */
3501 function wfResetSessionID() {
3502         global $wgCookieSecure;
3503         $oldSessionId = session_id();
3504         $cookieParams = session_get_cookie_params();
3505         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3506                 session_regenerate_id( false );
3507         } else {
3508                 $tmp = $_SESSION;
3509                 session_destroy();
3510                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3511                 $_SESSION = $tmp;
3512         }
3513         $newSessionId = session_id();
3514         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3515 }
3516
3517 /**
3518  * Initialise php session
3519  *
3520  * @param bool $sessionId
3521  */
3522 function wfSetupSession( $sessionId = false ) {
3523         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3524                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3525         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3526                 ObjectCacheSessionHandler::install();
3527         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3528                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3529                 # hasn't already been set to the desired value (that causes errors)
3530                 ini_set( 'session.save_handler', $wgSessionHandler );
3531         }
3532         session_set_cookie_params(
3533                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3534         session_cache_limiter( 'private, must-revalidate' );
3535         if ( $sessionId ) {
3536                 session_id( $sessionId );
3537         } else {
3538                 wfFixSessionID();
3539         }
3540         wfSuppressWarnings();
3541         session_start();
3542         wfRestoreWarnings();
3543 }
3544
3545 /**
3546  * Get an object from the precompiled serialized directory
3547  *
3548  * @param string $name
3549  * @return mixed The variable on success, false on failure
3550  */
3551 function wfGetPrecompiledData( $name ) {
3552         global $IP;
3553
3554         $file = "$IP/serialized/$name";
3555         if ( file_exists( $file ) ) {
3556                 $blob = file_get_contents( $file );
3557                 if ( $blob ) {
3558                         return unserialize( $blob );
3559                 }
3560         }
3561         return false;
3562 }
3563
3564 /**
3565  * Get a cache key
3566  *
3567  * @param string [$args,...]
3568  * @return string
3569  */
3570 function wfMemcKey( /*...*/ ) {
3571         global $wgCachePrefix;
3572         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3573         $args = func_get_args();
3574         $key = $prefix . ':' . implode( ':', $args );
3575         $key = str_replace( ' ', '_', $key );
3576         return $key;
3577 }
3578
3579 /**
3580  * Get a cache key for a foreign DB
3581  *
3582  * @param string $db
3583  * @param string $prefix
3584  * @param string [$args,...]
3585  * @return string
3586  */
3587 function wfForeignMemcKey( $db, $prefix /*...*/ ) {
3588         $args = array_slice( func_get_args(), 2 );
3589         if ( $prefix ) {
3590                 $key = "$db-$prefix:" . implode( ':', $args );
3591         } else {
3592                 $key = $db . ':' . implode( ':', $args );
3593         }
3594         return str_replace( ' ', '_', $key );
3595 }
3596
3597 /**
3598  * Get an ASCII string identifying this wiki
3599  * This is used as a prefix in memcached keys
3600  *
3601  * @return string
3602  */
3603 function wfWikiID() {
3604         global $wgDBprefix, $wgDBname;
3605         if ( $wgDBprefix ) {
3606                 return "$wgDBname-$wgDBprefix";
3607         } else {
3608                 return $wgDBname;
3609         }
3610 }
3611
3612 /**
3613  * Split a wiki ID into DB name and table prefix
3614  *
3615  * @param string $wiki
3616  *
3617  * @return array
3618  */
3619 function wfSplitWikiID( $wiki ) {
3620         $bits = explode( '-', $wiki, 2 );
3621         if ( count( $bits ) < 2 ) {
3622                 $bits[] = '';
3623         }
3624         return $bits;
3625 }
3626
3627 /**
3628  * Get a Database object.
3629  *
3630  * @param int $db Index of the connection to get. May be DB_MASTER for the
3631  *            master (for write queries), DB_SLAVE for potentially lagged read
3632  *            queries, or an integer >= 0 for a particular server.
3633  *
3634  * @param string|string[] $groups Query groups. An array of group names that this query
3635  *                belongs to. May contain a single string if the query is only
3636  *                in one group.
3637  *
3638  * @param string|bool $wiki The wiki ID, or false for the current wiki
3639  *
3640  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3641  * will always return the same object, unless the underlying connection or load
3642  * balancer is manually destroyed.
3643  *
3644  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3645  * updater to ensure that a proper database is being updated.
3646  *
3647  * @return DatabaseBase
3648  */
3649 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3650         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3651 }
3652
3653 /**
3654  * Get a load balancer object.
3655  *
3656  * @param string|bool $wiki wiki ID, or false for the current wiki
3657  * @return LoadBalancer
3658  */
3659 function wfGetLB( $wiki = false ) {
3660         return wfGetLBFactory()->getMainLB( $wiki );
3661 }
3662
3663 /**
3664  * Get the load balancer factory object
3665  *
3666  * @return LBFactory
3667  */
3668 function &wfGetLBFactory() {
3669         return LBFactory::singleton();
3670 }
3671
3672 /**
3673  * Find a file.
3674  * Shortcut for RepoGroup::singleton()->findFile()
3675  *
3676  * @param string $title or Title object
3677  * @param array $options Associative array of options:
3678  *     time:           requested time for an archived image, or false for the
3679  *                     current version. An image object will be returned which was
3680  *                     created at the specified time.
3681  *
3682  *     ignoreRedirect: If true, do not follow file redirects
3683  *
3684  *     private:        If true, return restricted (deleted) files if the current
3685  *                     user is allowed to view them. Otherwise, such files will not
3686  *                     be found.
3687  *
3688  *     bypassCache:    If true, do not use the process-local cache of File objects
3689  *
3690  * @return File|bool File, or false if the file does not exist
3691  */
3692 function wfFindFile( $title, $options = array() ) {
3693         return RepoGroup::singleton()->findFile( $title, $options );
3694 }
3695
3696 /**
3697  * Get an object referring to a locally registered file.
3698  * Returns a valid placeholder object if the file does not exist.
3699  *
3700  * @param Title|string $title
3701  * @return LocalFile|null A File, or null if passed an invalid Title
3702  */
3703 function wfLocalFile( $title ) {
3704         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3705 }
3706
3707 /**
3708  * Should low-performance queries be disabled?
3709  *
3710  * @return bool
3711  * @codeCoverageIgnore
3712  */
3713 function wfQueriesMustScale() {
3714         global $wgMiserMode;
3715         return $wgMiserMode
3716                 || ( SiteStats::pages() > 100000
3717                 && SiteStats::edits() > 1000000
3718                 && SiteStats::users() > 10000 );
3719 }
3720
3721 /**
3722  * Get the path to a specified script file, respecting file
3723  * extensions; this is a wrapper around $wgScriptExtension etc.
3724  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3725  *
3726  * @param string $script Script filename, sans extension
3727  * @return string
3728  */
3729 function wfScript( $script = 'index' ) {
3730         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3731         if ( $script === 'index' ) {
3732                 return $wgScript;
3733         } elseif ( $script === 'load' ) {
3734                 return $wgLoadScript;
3735         } else {
3736                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3737         }
3738 }
3739
3740 /**
3741  * Get the script URL.
3742  *
3743  * @return string script URL
3744  */
3745 function wfGetScriptUrl() {
3746         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3747                 #
3748                 # as it was called, minus the query string.
3749                 #
3750                 # Some sites use Apache rewrite rules to handle subdomains,
3751                 # and have PHP set up in a weird way that causes PHP_SELF
3752                 # to contain the rewritten URL instead of the one that the
3753                 # outside world sees.
3754                 #
3755                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3756                 # provides containing the "before" URL.
3757                 return $_SERVER['SCRIPT_NAME'];
3758         } else {
3759                 return $_SERVER['URL'];
3760         }
3761 }
3762
3763 /**
3764  * Convenience function converts boolean values into "true"
3765  * or "false" (string) values
3766  *
3767  * @param bool $value
3768  * @return string
3769  */
3770 function wfBoolToStr( $value ) {
3771         return $value ? 'true' : 'false';
3772 }
3773
3774 /**
3775  * Get a platform-independent path to the null file, e.g. /dev/null
3776  *
3777  * @return string
3778  */
3779 function wfGetNull() {
3780         return wfIsWindows() ? 'NUL' : '/dev/null';
3781 }
3782
3783 /**
3784  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3785  * and waiting for it to go down, this waits for the slaves to catch up to the
3786  * master position. Use this when updating very large numbers of rows, as
3787  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3788  * a no-op if there are no slaves.
3789  *
3790  * @param int|bool $maxLag (deprecated)
3791  * @param string|bool $wiki Wiki identifier accepted by wfGetLB
3792  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3793  */
3794 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3795         if ( $cluster !== false ) {
3796                 $lb = wfGetLBFactory()->getExternalLB( $cluster );
3797         } else {
3798                 $lb = wfGetLB( $wiki );
3799         }
3800
3801         // bug 27975 - Don't try to wait for slaves if there are none
3802         // Prevents permission error when getting master position
3803         if ( $lb->getServerCount() > 1 ) {
3804                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3805                 $pos = $dbw->getMasterPos();
3806                 // The DBMS may not support getMasterPos() or the whole
3807                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3808                 if ( $pos !== false ) {
3809                         $lb->waitForAll( $pos );
3810                 }
3811         }
3812 }
3813
3814 /**
3815  * Count down from $seconds to zero on the terminal, with a one-second pause
3816  * between showing each number. For use in command-line scripts.
3817  *
3818  * @codeCoverageIgnore
3819  * @param int $seconds
3820  */
3821 function wfCountDown( $seconds ) {
3822         for ( $i = $seconds; $i >= 0; $i-- ) {
3823                 if ( $i != $seconds ) {
3824                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3825                 }
3826                 echo $i;
3827                 flush();
3828                 if ( $i ) {
3829                         sleep( 1 );
3830                 }
3831         }
3832         echo "\n";
3833 }
3834
3835 /**
3836  * Replace all invalid characters with -
3837  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3838  * By default, $wgIllegalFileChars = ':'
3839  *
3840  * @param string $name Filename to process
3841  * @return string
3842  */
3843 function wfStripIllegalFilenameChars( $name ) {
3844         global $wgIllegalFileChars;
3845         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3846         $name = wfBaseName( $name );
3847         $name = preg_replace(
3848                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3849                 '-',
3850                 $name
3851         );
3852         return $name;
3853 }
3854
3855 /**
3856  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3857  *
3858  * @return int Value the memory limit was set to.
3859  */
3860 function wfMemoryLimit() {
3861         global $wgMemoryLimit;
3862         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3863         if ( $memlimit != -1 ) {
3864                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3865                 if ( $conflimit == -1 ) {
3866                         wfDebug( "Removing PHP's memory limit\n" );
3867                         wfSuppressWarnings();
3868                         ini_set( 'memory_limit', $conflimit );
3869                         wfRestoreWarnings();
3870                         return $conflimit;
3871                 } elseif ( $conflimit > $memlimit ) {
3872                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3873                         wfSuppressWarnings();
3874                         ini_set( 'memory_limit', $conflimit );
3875                         wfRestoreWarnings();
3876                         return $conflimit;
3877                 }
3878         }
3879         return $memlimit;
3880 }
3881
3882 /**
3883  * Converts shorthand byte notation to integer form
3884  *
3885  * @param string $string
3886  * @return int
3887  */
3888 function wfShorthandToInteger( $string = '' ) {
3889         $string = trim( $string );
3890         if ( $string === '' ) {
3891                 return -1;
3892         }
3893         $last = $string[strlen( $string ) - 1];
3894         $val = intval( $string );
3895         switch ( $last ) {
3896                 case 'g':
3897                 case 'G':
3898                         $val *= 1024;
3899                         // break intentionally missing
3900                 case 'm':
3901                 case 'M':
3902                         $val *= 1024;
3903                         // break intentionally missing
3904                 case 'k':
3905                 case 'K':
3906                         $val *= 1024;
3907         }
3908
3909         return $val;
3910 }
3911
3912 /**
3913  * Get the normalised IETF language tag
3914  * See unit test for examples.
3915  *
3916  * @param string $code The language code.
3917  * @return string The language code which complying with BCP 47 standards.
3918  */
3919 function wfBCP47( $code ) {
3920         $codeSegment = explode( '-', $code );
3921         $codeBCP = array();
3922         foreach ( $codeSegment as $segNo => $seg ) {
3923                 // when previous segment is x, it is a private segment and should be lc
3924                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3925                         $codeBCP[$segNo] = strtolower( $seg );
3926                 // ISO 3166 country code
3927                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3928                         $codeBCP[$segNo] = strtoupper( $seg );
3929                 // ISO 15924 script code
3930                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3931                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3932                 // Use lowercase for other cases
3933                 } else {
3934                         $codeBCP[$segNo] = strtolower( $seg );
3935                 }
3936         }
3937         $langCode = implode( '-', $codeBCP );
3938         return $langCode;
3939 }
3940
3941 /**
3942  * Get a cache object.
3943  *
3944  * @param int $inputType Cache type, one the the CACHE_* constants.
3945  * @return BagOStuff
3946  */
3947 function wfGetCache( $inputType ) {
3948         return ObjectCache::getInstance( $inputType );
3949 }
3950
3951 /**
3952  * Get the main cache object
3953  *
3954  * @return BagOStuff
3955  */
3956 function wfGetMainCache() {
3957         global $wgMainCacheType;
3958         return ObjectCache::getInstance( $wgMainCacheType );
3959 }
3960
3961 /**
3962  * Get the cache object used by the message cache
3963  *
3964  * @return BagOStuff
3965  */
3966 function wfGetMessageCacheStorage() {
3967         global $wgMessageCacheType;
3968         return ObjectCache::getInstance( $wgMessageCacheType );
3969 }
3970
3971 /**
3972  * Get the cache object used by the parser cache
3973  *
3974  * @return BagOStuff
3975  */
3976 function wfGetParserCacheStorage() {
3977         global $wgParserCacheType;
3978         return ObjectCache::getInstance( $wgParserCacheType );
3979 }
3980
3981 /**
3982  * Get the cache object used by the language converter
3983  *
3984  * @return BagOStuff
3985  */
3986 function wfGetLangConverterCacheStorage() {
3987         global $wgLanguageConverterCacheType;
3988         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3989 }
3990
3991 /**
3992  * Call hook functions defined in $wgHooks
3993  *
3994  * @param string $event Event name
3995  * @param array $args Parameters passed to hook functions
3996  * @param string|null $deprecatedVersion Optionally mark hook as deprecated with version number
3997  *
3998  * @return bool True if no handler aborted the hook
3999  */
4000 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
4001         return Hooks::run( $event, $args, $deprecatedVersion );
4002 }
4003
4004 /**
4005  * Wrapper around php's unpack.
4006  *
4007  * @param string $format The format string (See php's docs)
4008  * @param string $data A binary string of binary data
4009  * @param int|bool $length The minimum length of $data or false. This is to
4010  *      prevent reading beyond the end of $data. false to disable the check.
4011  *
4012  * Also be careful when using this function to read unsigned 32 bit integer
4013  * because php might make it negative.
4014  *
4015  * @throws MWException if $data not long enough, or if unpack fails
4016  * @return array Associative array of the extracted data
4017  */
4018 function wfUnpack( $format, $data, $length = false ) {
4019         if ( $length !== false ) {
4020                 $realLen = strlen( $data );
4021                 if ( $realLen < $length ) {
4022                         throw new MWException( "Tried to use wfUnpack on a "
4023                                 . "string of length $realLen, but needed one "
4024                                 . "of at least length $length."
4025                         );
4026                 }
4027         }
4028
4029         wfSuppressWarnings();
4030         $result = unpack( $format, $data );
4031         wfRestoreWarnings();
4032
4033         if ( $result === false ) {
4034                 // If it cannot extract the packed data.
4035                 throw new MWException( "unpack could not unpack binary data" );
4036         }
4037         return $result;
4038 }
4039
4040 /**
4041  * Determine if an image exists on the 'bad image list'.
4042  *
4043  * The format of MediaWiki:Bad_image_list is as follows:
4044  *    * Only list items (lines starting with "*") are considered
4045  *    * The first link on a line must be a link to a bad image
4046  *    * Any subsequent links on the same line are considered to be exceptions,
4047  *      i.e. articles where the image may occur inline.
4048  *
4049  * @param string $name The image name to check
4050  * @param Title|bool $contextTitle The page on which the image occurs, if known
4051  * @param string $blacklist Wikitext of a file blacklist
4052  * @return bool
4053  */
4054 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4055         static $badImageCache = null; // based on bad_image_list msg
4056         wfProfileIn( __METHOD__ );
4057
4058         # Handle redirects
4059         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4060         if ( $redirectTitle ) {
4061                 $name = $redirectTitle->getDBkey();
4062         }
4063
4064         # Run the extension hook
4065         $bad = false;
4066         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
4067                 wfProfileOut( __METHOD__ );
4068                 return $bad;
4069         }
4070
4071         $cacheable = ( $blacklist === null );
4072         if ( $cacheable && $badImageCache !== null ) {
4073                 $badImages = $badImageCache;
4074         } else { // cache miss
4075                 if ( $blacklist === null ) {
4076                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4077                 }
4078                 # Build the list now
4079                 $badImages = array();
4080                 $lines = explode( "\n", $blacklist );
4081                 foreach ( $lines as $line ) {
4082                         # List items only
4083                         if ( substr( $line, 0, 1 ) !== '*' ) {
4084                                 continue;
4085                         }
4086
4087                         # Find all links
4088                         $m = array();
4089                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4090                                 continue;
4091                         }
4092
4093                         $exceptions = array();
4094                         $imageDBkey = false;
4095                         foreach ( $m[1] as $i => $titleText ) {
4096                                 $title = Title::newFromText( $titleText );
4097                                 if ( !is_null( $title ) ) {
4098                                         if ( $i == 0 ) {
4099                                                 $imageDBkey = $title->getDBkey();
4100                                         } else {
4101                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4102                                         }
4103                                 }
4104                         }
4105
4106                         if ( $imageDBkey !== false ) {
4107                                 $badImages[$imageDBkey] = $exceptions;
4108                         }
4109                 }
4110                 if ( $cacheable ) {
4111                         $badImageCache = $badImages;
4112                 }
4113         }
4114
4115         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4116         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4117         wfProfileOut( __METHOD__ );
4118         return $bad;
4119 }
4120
4121 /**
4122  * Determine whether the client at a given source IP is likely to be able to
4123  * access the wiki via HTTPS.
4124  *
4125  * @param string $ip The IPv4/6 address in the normal human-readable form
4126  * @return bool
4127  */
4128 function wfCanIPUseHTTPS( $ip ) {
4129         $canDo = true;
4130         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4131         return !!$canDo;
4132 }
4133
4134 /**
4135  * Work out the IP address based on various globals
4136  * For trusted proxies, use the XFF client IP (first of the chain)
4137  *
4138  * @deprecated since 1.19; call $wgRequest->getIP() directly.
4139  * @return string
4140  */
4141 function wfGetIP() {
4142         wfDeprecated( __METHOD__, '1.19' );
4143         global $wgRequest;
4144         return $wgRequest->getIP();
4145 }
4146
4147 /**
4148  * Checks if an IP is a trusted proxy provider.
4149  * Useful to tell if X-Forwarded-For data is possibly bogus.
4150  * Squid cache servers for the site are whitelisted.
4151  * @deprecated Since 1.24, use IP::isTrustedProxy()
4152  *
4153  * @param string $ip
4154  * @return bool
4155  */
4156 function wfIsTrustedProxy( $ip ) {
4157         return IP::isTrustedProxy( $ip );
4158 }
4159
4160 /**
4161  * Checks if an IP matches a proxy we've configured.
4162  * @deprecated Since 1.24, use IP::isConfiguredProxy()
4163  *
4164  * @param string $ip
4165  * @return bool
4166  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4167  */
4168 function wfIsConfiguredProxy( $ip ) {
4169         return IP::isTrustedProxy( $ip );
4170 }