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 $a array
 112  * @param $b array
 113  * @return array
 114  */
 115 function wfArrayDiff2( $a, $b ) {
 116         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
 117 }
 118
 119 /**
 120  * @param $a array|string
 121  * @param $b array|string
 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 $a Array
 149  * @param $b Array
 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 $key String|Int
 161  * @param $value Mixed
 162  * @param $default Mixed
 163  * @param array $changed 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  * @param $array1 Array
 181  * @param [$array2, [...]] Arrays
 182  * @return Array
 183  */
 184 function wfArrayMerge( $array1/* ... */ ) {
 185         wfDeprecated( __FUNCTION__, '1.22' );
 186         $args = func_get_args();
 187         $args = array_reverse( $args, true );
 188         $out = array();
 189         foreach ( $args as $arg ) {
 190                 $out += $arg;
 191         }
 192         return $out;
 193 }
 194
 195 /**
 196  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 197  * e.g.
 198  *      wfMergeErrorArrays(
 199  *              array( array( 'x' ) ),
 200  *              array( array( 'x', '2' ) ),
 201  *              array( array( 'x' ) ),
 202  *              array( array( 'y' ) )
 203  *      );
 204  * returns:
 205  *              array(
 206  *              array( 'x', '2' ),
 207  *              array( 'x' ),
 208  *              array( 'y' )
 209  *      )
 210  * @param varargs
 211  * @return Array
 212  */
 213 function wfMergeErrorArrays( /*...*/ ) {
 214         $args = func_get_args();
 215         $out = array();
 216         foreach ( $args as $errors ) {
 217                 foreach ( $errors as $params ) {
 218                         # @todo FIXME: Sometimes get nested arrays for $params,
 219                         # which leads to E_NOTICEs
 220                         $spec = implode( "\t", $params );
 221                         $out[$spec] = $params;
 222                 }
 223         }
 224         return array_values( $out );
 225 }
 226
 227 /**
 228  * Insert array into another array after the specified *KEY*
 229  *
 230  * @param array $array The array.
 231  * @param array $insert The array to insert.
 232  * @param $after Mixed: The key to insert after
 233  * @return Array
 234  */
 235 function wfArrayInsertAfter( array $array, array $insert, $after ) {
 236         // Find the offset of the element to insert after.
 237         $keys = array_keys( $array );
 238         $offsetByKey = array_flip( $keys );
 239
 240         $offset = $offsetByKey[$after];
 241
 242         // Insert at the specified offset
 243         $before = array_slice( $array, 0, $offset + 1, true );
 244         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 245
 246         $output = $before + $insert + $after;
 247
 248         return $output;
 249 }
 250
 251 /**
 252  * Recursively converts the parameter (an object) to an array with the same data
 253  *
 254  * @param $objOrArray Object|Array
 255  * @param $recursive Bool
 256  * @return Array
 257  */
 258 function wfObjectToArray( $objOrArray, $recursive = true ) {
 259         $array = array();
 260         if ( is_object( $objOrArray ) ) {
 261                 $objOrArray = get_object_vars( $objOrArray );
 262         }
 263         foreach ( $objOrArray as $key => $value ) {
 264                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 265                         $value = wfObjectToArray( $value );
 266                 }
 267
 268                 $array[$key] = $value;
 269         }
 270
 271         return $array;
 272 }
 273
 274 /**
 275  * Get a random decimal value between 0 and 1, in a way
 276  * not likely to give duplicate values for any realistic
 277  * number of articles.
 278  *
 279  * @return string
 280  */
 281 function wfRandom() {
 282         # The maximum random value is "only" 2^31-1, so get two random
 283         # values to reduce the chance of dupes
 284         $max = mt_getrandmax() + 1;
 285         $rand = number_format( ( mt_rand() * $max + mt_rand() ) / $max / $max, 12, '.', '' );
 286
 287         return $rand;
 288 }
 289
 290 /**
 291  * Get a random string containing a number of pseudo-random hex
 292  * characters.
 293  * @note This is not secure, if you are trying to generate some sort
 294  *       of token please use MWCryptRand instead.
 295  *
 296  * @param int $length The length of the string to generate
 297  * @return String
 298  * @since 1.20
 299  */
 300 function wfRandomString( $length = 32 ) {
 301         $str = '';
 302         for ( $n = 0; $n < $length; $n += 7 ) {
 303                 $str .= sprintf( '%07x', mt_rand() & 0xfffffff );
 304         }
 305         return substr( $str, 0, $length );
 306 }
 307
 308 /**
 309  * We want some things to be included as literal characters in our title URLs
 310  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 311  * all of the following should be safe:
 312  *
 313  * ;:@&=$-_.+!*'(),
 314  *
 315  * But + is not safe because it's used to indicate a space; &= are only safe in
 316  * paths and not in queries (and we don't distinguish here); ' seems kind of
 317  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 318  * is reserved, we don't care.  So the list we unescape is:
 319  *
 320  * ;:@$!*(),/
 321  *
 322  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 323  * so no fancy : for IIS7.
 324  *
 325  * %2F in the page titles seems to fatally break for some reason.
 326  *
 327  * @param $s String:
 328  * @return string
 329  */
 330 function wfUrlencode( $s ) {
 331         static $needle;
 332
 333         if ( is_null( $s ) ) {
 334                 $needle = null;
 335                 return '';
 336         }
 337
 338         if ( is_null( $needle ) ) {
 339                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 340                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) ||
 341                         ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false )
 342                 ) {
 343                         $needle[] = '%3A';
 344                 }
 345         }
 346
 347         $s = urlencode( $s );
 348         $s = str_ireplace(
 349                 $needle,
 350                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 351                 $s
 352         );
 353
 354         return $s;
 355 }
 356
 357 /**
 358  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 359  * "days=7&limit=100". Options in the first array override options in the second.
 360  * Options set to null or false will not be output.
 361  *
 362  * @param array $array1 ( String|Array )
 363  * @param array $array2 ( String|Array )
 364  * @param $prefix String
 365  * @return String
 366  */
 367 function wfArrayToCgi( $array1, $array2 = null, $prefix = '' ) {
 368         if ( !is_null( $array2 ) ) {
 369                 $array1 = $array1 + $array2;
 370         }
 371
 372         $cgi = '';
 373         foreach ( $array1 as $key => $value ) {
 374                 if ( !is_null( $value ) && $value !== false ) {
 375                         if ( $cgi != '' ) {
 376                                 $cgi .= '&';
 377                         }
 378                         if ( $prefix !== '' ) {
 379                                 $key = $prefix . "[$key]";
 380                         }
 381                         if ( is_array( $value ) ) {
 382                                 $firstTime = true;
 383                                 foreach ( $value as $k => $v ) {
 384                                         $cgi .= $firstTime ? '' : '&';
 385                                         if ( is_array( $v ) ) {
 386                                                 $cgi .= wfArrayToCgi( $v, null, $key . "[$k]" );
 387                                         } else {
 388                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 389                                         }
 390                                         $firstTime = false;
 391                                 }
 392                         } else {
 393                                 if ( is_object( $value ) ) {
 394                                         $value = $value->__toString();
 395                                 }
 396                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 397                         }
 398                 }
 399         }
 400         return $cgi;
 401 }
 402
 403 /**
 404  * This is the logical opposite of wfArrayToCgi(): it accepts a query string as
 405  * its argument and returns the same string in array form.  This allows compatibility
 406  * with legacy functions that accept raw query strings instead of nice
 407  * arrays.  Of course, keys and values are urldecode()d.
 408  *
 409  * @param string $query query string
 410  * @return array Array version of input
 411  */
 412 function wfCgiToArray( $query ) {
 413         if ( isset( $query[0] ) && $query[0] == '?' ) {
 414                 $query = substr( $query, 1 );
 415         }
 416         $bits = explode( '&', $query );
 417         $ret = array();
 418         foreach ( $bits as $bit ) {
 419                 if ( $bit === '' ) {
 420                         continue;
 421                 }
 422                 if ( strpos( $bit, '=' ) === false ) {
 423                         // Pieces like &qwerty become 'qwerty' => '' (at least this is what php does)
 424                         $key = $bit;
 425                         $value = '';
 426                 } else {
 427                         list( $key, $value ) = explode( '=', $bit );
 428                 }
 429                 $key = urldecode( $key );
 430                 $value = urldecode( $value );
 431                 if ( strpos( $key, '[' ) !== false ) {
 432                         $keys = array_reverse( explode( '[', $key ) );
 433                         $key = array_pop( $keys );
 434                         $temp = $value;
 435                         foreach ( $keys as $k ) {
 436                                 $k = substr( $k, 0, -1 );
 437                                 $temp = array( $k => $temp );
 438                         }
 439                         if ( isset( $ret[$key] ) ) {
 440                                 $ret[$key] = array_merge( $ret[$key], $temp );
 441                         } else {
 442                                 $ret[$key] = $temp;
 443                         }
 444                 } else {
 445                         $ret[$key] = $value;
 446                 }
 447         }
 448         return $ret;
 449 }
 450
 451 /**
 452  * Append a query string to an existing URL, which may or may not already
 453  * have query string parameters already. If so, they will be combined.
 454  *
 455  * @param $url String
 456  * @param $query Mixed: string or associative array
 457  * @return string
 458  */
 459 function wfAppendQuery( $url, $query ) {
 460         if ( is_array( $query ) ) {
 461                 $query = wfArrayToCgi( $query );
 462         }
 463         if ( $query != '' ) {
 464                 if ( false === strpos( $url, '?' ) ) {
 465                         $url .= '?';
 466                 } else {
 467                         $url .= '&';
 468                 }
 469                 $url .= $query;
 470         }
 471         return $url;
 472 }
 473
 474 /**
 475  * Expand a potentially local URL to a fully-qualified URL. Assumes $wgServer
 476  * is correct.
 477  *
 478  * The meaning of the PROTO_* constants is as follows:
 479  * PROTO_HTTP: Output a URL starting with http://
 480  * PROTO_HTTPS: Output a URL starting with https://
 481  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 482  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending
 483  *    on which protocol was used for the current incoming request
 484  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer.
 485  *    For protocol-relative URLs, use the protocol of $wgCanonicalServer
 486  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 487  *
 488  * @todo this won't work with current-path-relative URLs
 489  * like "subdir/foo.html", etc.
 490  *
 491  * @param string $url either fully-qualified or a local path + query
 492  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 493  *    protocol to use if $url or $wgServer is protocol-relative
 494  * @return string Fully-qualified URL, current-path-relative URL or false if
 495  *    no valid URL can be constructed
 496  */
 497 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 498         global $wgServer, $wgCanonicalServer, $wgInternalServer, $wgRequest;
 499         if ( $defaultProto === PROTO_CANONICAL ) {
 500                 $serverUrl = $wgCanonicalServer;
 501         } elseif ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 502                 // Make $wgInternalServer fall back to $wgServer if not set
 503                 $serverUrl = $wgInternalServer;
 504         } else {
 505                 $serverUrl = $wgServer;
 506                 if ( $defaultProto === PROTO_CURRENT ) {
 507                         $defaultProto = $wgRequest->getProtocol() . '://';
 508                 }
 509         }
 510
 511         // Analyze $serverUrl to obtain its protocol
 512         $bits = wfParseUrl( $serverUrl );
 513         $serverHasProto = $bits && $bits['scheme'] != '';
 514
 515         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 516                 if ( $serverHasProto ) {
 517                         $defaultProto = $bits['scheme'] . '://';
 518                 } else {
 519                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol.
 520                         // This really isn't supposed to happen. Fall back to HTTP in this
 521                         // ridiculous case.
 522                         $defaultProto = PROTO_HTTP;
 523                 }
 524         }
 525
 526         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 527
 528         if ( substr( $url, 0, 2 ) == '//' ) {
 529                 $url = $defaultProtoWithoutSlashes . $url;
 530         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 531                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes,
 532                 // otherwise leave it alone.
 533                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 534         }
 535
 536         $bits = wfParseUrl( $url );
 537         if ( $bits && isset( $bits['path'] ) ) {
 538                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 539                 return wfAssembleUrl( $bits );
 540         } elseif ( $bits ) {
 541                 # No path to expand
 542                 return $url;
 543         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 544                 # URL is a relative path
 545                 return wfRemoveDotSegments( $url );
 546         }
 547
 548         # Expanded URL is not valid.
 549         return false;
 550 }
 551
 552 /**
 553  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 554  * if you need to edit part of a URL and put it back together.
 555  *
 556  * This is the basic structure used (brackets contain keys for $urlParts):
 557  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 558  *
 559  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 560  *
 561  * @since 1.19
 562  * @param array $urlParts URL parts, as output from wfParseUrl
 563  * @return string URL assembled from its component parts
 564  */
 565 function wfAssembleUrl( $urlParts ) {
 566         $result = '';
 567
 568         if ( isset( $urlParts['delimiter'] ) ) {
 569                 if ( isset( $urlParts['scheme'] ) ) {
 570                         $result .= $urlParts['scheme'];
 571                 }
 572
 573                 $result .= $urlParts['delimiter'];
 574         }
 575
 576         if ( isset( $urlParts['host'] ) ) {
 577                 if ( isset( $urlParts['user'] ) ) {
 578                         $result .= $urlParts['user'];
 579                         if ( isset( $urlParts['pass'] ) ) {
 580                                 $result .= ':' . $urlParts['pass'];
 581                         }
 582                         $result .= '@';
 583                 }
 584
 585                 $result .= $urlParts['host'];
 586
 587                 if ( isset( $urlParts['port'] ) ) {
 588                         $result .= ':' . $urlParts['port'];
 589                 }
 590         }
 591
 592         if ( isset( $urlParts['path'] ) ) {
 593                 $result .= $urlParts['path'];
 594         }
 595
 596         if ( isset( $urlParts['query'] ) ) {
 597                 $result .= '?' . $urlParts['query'];
 598         }
 599
 600         if ( isset( $urlParts['fragment'] ) ) {
 601                 $result .= '#' . $urlParts['fragment'];
 602         }
 603
 604         return $result;
 605 }
 606
 607 /**
 608  * Remove all dot-segments in the provided URL path.  For example,
 609  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 610  * RFC3986 section 5.2.4.
 611  *
 612  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 613  *
 614  * @param string $urlPath URL path, potentially containing dot-segments
 615  * @return string URL path with all dot-segments removed
 616  */
 617 function wfRemoveDotSegments( $urlPath ) {
 618         $output = '';
 619         $inputOffset = 0;
 620         $inputLength = strlen( $urlPath );
 621
 622         while ( $inputOffset < $inputLength ) {
 623                 $prefixLengthOne = substr( $urlPath, $inputOffset, 1 );
 624                 $prefixLengthTwo = substr( $urlPath, $inputOffset, 2 );
 625                 $prefixLengthThree = substr( $urlPath, $inputOffset, 3 );
 626                 $prefixLengthFour = substr( $urlPath, $inputOffset, 4 );
 627                 $trimOutput = false;
 628
 629                 if ( $prefixLengthTwo == './' ) {
 630                         # Step A, remove leading "./"
 631                         $inputOffset += 2;
 632                 } elseif ( $prefixLengthThree == '../' ) {
 633                         # Step A, remove leading "../"
 634                         $inputOffset += 3;
 635                 } elseif ( ( $prefixLengthTwo == '/.' ) && ( $inputOffset + 2 == $inputLength ) ) {
 636                         # Step B, replace leading "/.$" with "/"
 637                         $inputOffset += 1;
 638                         $urlPath[$inputOffset] = '/';
 639                 } elseif ( $prefixLengthThree == '/./' ) {
 640                         # Step B, replace leading "/./" with "/"
 641                         $inputOffset += 2;
 642                 } elseif ( $prefixLengthThree == '/..' && ( $inputOffset + 3 == $inputLength ) ) {
 643                         # Step C, replace leading "/..$" with "/" and
 644                         # remove last path component in output
 645                         $inputOffset += 2;
 646                         $urlPath[$inputOffset] = '/';
 647                         $trimOutput = true;
 648                 } elseif ( $prefixLengthFour == '/../' ) {
 649                         # Step C, replace leading "/../" with "/" and
 650                         # remove last path component in output
 651                         $inputOffset += 3;
 652                         $trimOutput = true;
 653                 } elseif ( ( $prefixLengthOne == '.' ) && ( $inputOffset + 1 == $inputLength ) ) {
 654                         # Step D, remove "^.$"
 655                         $inputOffset += 1;
 656                 } elseif ( ( $prefixLengthTwo == '..' ) && ( $inputOffset + 2 == $inputLength ) ) {
 657                         # Step D, remove "^..$"
 658                         $inputOffset += 2;
 659                 } else {
 660                         # Step E, move leading path segment to output
 661                         if ( $prefixLengthOne == '/' ) {
 662                                 $slashPos = strpos( $urlPath, '/', $inputOffset + 1 );
 663                         } else {
 664                                 $slashPos = strpos( $urlPath, '/', $inputOffset );
 665                         }
 666                         if ( $slashPos === false ) {
 667                                 $output .= substr( $urlPath, $inputOffset );
 668                                 $inputOffset = $inputLength;
 669                         } else {
 670                                 $output .= substr( $urlPath, $inputOffset, $slashPos - $inputOffset );
 671                                 $inputOffset += $slashPos - $inputOffset;
 672                         }
 673                 }
 674
 675                 if ( $trimOutput ) {
 676                         $slashPos = strrpos( $output, '/' );
 677                         if ( $slashPos === false ) {
 678                                 $output = '';
 679                         } else {
 680                                 $output = substr( $output, 0, $slashPos );
 681                         }
 682                 }
 683         }
 684
 685         return $output;
 686 }
 687
 688 /**
 689  * Returns a regular expression of url protocols
 690  *
 691  * @param bool $includeProtocolRelative If false, remove '//' from the returned protocol list.
 692  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 693  * @return String
 694  */
 695 function wfUrlProtocols( $includeProtocolRelative = true ) {
 696         global $wgUrlProtocols;
 697
 698         // Cache return values separately based on $includeProtocolRelative
 699         static $withProtRel = null, $withoutProtRel = null;
 700         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 701         if ( !is_null( $cachedValue ) ) {
 702                 return $cachedValue;
 703         }
 704
 705         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 706         // with LocalSettings files from 1.5
 707         if ( is_array( $wgUrlProtocols ) ) {
 708                 $protocols = array();
 709                 foreach ( $wgUrlProtocols as $protocol ) {
 710                         // Filter out '//' if !$includeProtocolRelative
 711                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 712                                 $protocols[] = preg_quote( $protocol, '/' );
 713                         }
 714                 }
 715
 716                 $retval = implode( '|', $protocols );
 717         } else {
 718                 // Ignore $includeProtocolRelative in this case
 719                 // This case exists for pre-1.6 compatibility, and we can safely assume
 720                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 721                 // URLs weren't supported until 1.18
 722                 $retval = $wgUrlProtocols;
 723         }
 724
 725         // Cache return value
 726         if ( $includeProtocolRelative ) {
 727                 $withProtRel = $retval;
 728         } else {
 729                 $withoutProtRel = $retval;
 730         }
 731         return $retval;
 732 }
 733
 734 /**
 735  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 736  * you need a regex that matches all URL protocols but does not match protocol-
 737  * relative URLs
 738  * @return String
 739  */
 740 function wfUrlProtocolsWithoutProtRel() {
 741         return wfUrlProtocols( false );
 742 }
 743
 744 /**
 745  * parse_url() work-alike, but non-broken.  Differences:
 746  *
 747  * 1) Does not raise warnings on bad URLs (just returns false).
 748  * 2) Handles protocols that don't use :// (e.g., mailto: and news:, as well as
 749  *    protocol-relative URLs) correctly.
 750  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2)).
 751  *
 752  * @param string $url a URL to parse
 753  * @return Array: bits of the URL in an associative array, per PHP docs
 754  */
 755 function wfParseUrl( $url ) {
 756         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 757
 758         // Protocol-relative URLs are handled really badly by parse_url(). It's so
 759         // bad that the easiest way to handle them is to just prepend 'http:' and
 760         // strip the protocol out later.
 761         $wasRelative = substr( $url, 0, 2 ) == '//';
 762         if ( $wasRelative ) {
 763                 $url = "http:$url";
 764         }
 765         wfSuppressWarnings();
 766         $bits = parse_url( $url );
 767         wfRestoreWarnings();
 768         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 769         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 770         if ( !$bits || !isset( $bits['scheme'] ) ) {
 771                 return false;
 772         }
 773
 774         // parse_url() incorrectly handles schemes case-sensitively. Convert it to lowercase.
 775         $bits['scheme'] = strtolower( $bits['scheme'] );
 776
 777         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 778         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 779                 $bits['delimiter'] = '://';
 780         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 781                 $bits['delimiter'] = ':';
 782                 // parse_url detects for news: and mailto: the host part of an url as path
 783                 // We have to correct this wrong detection
 784                 if ( isset( $bits['path'] ) ) {
 785                         $bits['host'] = $bits['path'];
 786                         $bits['path'] = '';
 787                 }
 788         } else {
 789                 return false;
 790         }
 791
 792         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 793         if ( !isset( $bits['host'] ) ) {
 794                 $bits['host'] = '';
 795
 796                 // bug 45069
 797                 if ( isset( $bits['path'] ) ) {
 798                         /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 799                         if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 800                                 $bits['path'] = '/' . $bits['path'];
 801                         }
 802                 } else {
 803                         $bits['path'] = '';
 804                 }
 805         }
 806
 807         // If the URL was protocol-relative, fix scheme and delimiter
 808         if ( $wasRelative ) {
 809                 $bits['scheme'] = '';
 810                 $bits['delimiter'] = '//';
 811         }
 812         return $bits;
 813 }
 814
 815 /**
 816  * Take a URL, make sure it's expanded to fully qualified, and replace any
 817  * encoded non-ASCII Unicode characters with their UTF-8 original forms
 818  * for more compact display and legibility for local audiences.
 819  *
 820  * @todo handle punycode domains too
 821  *
 822  * @param $url string
 823  * @return string
 824  */
 825 function wfExpandIRI( $url ) {
 826         return preg_replace_callback(
 827                 '/((?:%[89A-F][0-9A-F])+)/i',
 828                 'wfExpandIRI_callback',
 829                 wfExpandUrl( $url )
 830         );
 831 }
 832
 833 /**
 834  * Private callback for wfExpandIRI
 835  * @param array $matches
 836  * @return string
 837  */
 838 function wfExpandIRI_callback( $matches ) {
 839         return urldecode( $matches[1] );
 840 }
 841
 842 /**
 843  * Make URL indexes, appropriate for the el_index field of externallinks.
 844  *
 845  * @param $url String
 846  * @return array
 847  */
 848 function wfMakeUrlIndexes( $url ) {
 849         $bits = wfParseUrl( $url );
 850
 851         // Reverse the labels in the hostname, convert to lower case
 852         // For emails reverse domainpart only
 853         if ( $bits['scheme'] == 'mailto' ) {
 854                 $mailparts = explode( '@', $bits['host'], 2 );
 855                 if ( count( $mailparts ) === 2 ) {
 856                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 857                 } else {
 858                         // No domain specified, don't mangle it
 859                         $domainpart = '';
 860                 }
 861                 $reversedHost = $domainpart . '@' . $mailparts[0];
 862         } else {
 863                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 864         }
 865         // Add an extra dot to the end
 866         // Why? Is it in wrong place in mailto links?
 867         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 868                 $reversedHost .= '.';
 869         }
 870         // Reconstruct the pseudo-URL
 871         $prot = $bits['scheme'];
 872         $index = $prot . $bits['delimiter'] . $reversedHost;
 873         // Leave out user and password. Add the port, path, query and fragment
 874         if ( isset( $bits['port'] ) ) {
 875                 $index .= ':' . $bits['port'];
 876         }
 877         if ( isset( $bits['path'] ) ) {
 878                 $index .= $bits['path'];
 879         } else {
 880                 $index .= '/';
 881         }
 882         if ( isset( $bits['query'] ) ) {
 883                 $index .= '?' . $bits['query'];
 884         }
 885         if ( isset( $bits['fragment'] ) ) {
 886                 $index .= '#' . $bits['fragment'];
 887         }
 888
 889         if ( $prot == '' ) {
 890                 return array( "http:$index", "https:$index" );
 891         } else {
 892                 return array( $index );
 893         }
 894 }
 895
 896 /**
 897  * Check whether a given URL has a domain that occurs in a given set of domains
 898  * @param string $url URL
 899  * @param array $domains Array of domains (strings)
 900  * @return bool True if the host part of $url ends in one of the strings in $domains
 901  */
 902 function wfMatchesDomainList( $url, $domains ) {
 903         $bits = wfParseUrl( $url );
 904         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 905                 $host = '.' . $bits['host'];
 906                 foreach ( (array)$domains as $domain ) {
 907                         $domain = '.' . $domain;
 908                         if ( substr( $host, -strlen( $domain ) ) === $domain ) {
 909                                 return true;
 910                         }
 911                 }
 912         }
 913         return false;
 914 }
 915
 916 /**
 917  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 918  * In normal operation this is a NOP.
 919  *
 920  * Controlling globals:
 921  * $wgDebugLogFile - points to the log file
 922  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 923  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 924  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 925  *
 926  * @param $text String
 927  * @param string|bool $dest Destination of the message:
 928  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
 929  *     - 'log': only to the log and not in HTML
 930  *   For backward compatibility, it can also take a boolean:
 931  *     - true: same as 'all'
 932  *     - false: same as 'log'
 933  */
 934 function wfDebug( $text, $dest = 'all' ) {
 935         global $wgDebugLogFile, $wgProfileOnly, $wgDebugRawPage, $wgDebugLogPrefix;
 936
 937         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 938                 return;
 939         }
 940
 941         // Turn $dest into a string if it's a boolean (for b/c)
 942         if ( $dest === true ) {
 943                 $dest = 'all';
 944         } elseif ( $dest === false ) {
 945                 $dest = 'log';
 946         }
 947
 948         $timer = wfDebugTimer();
 949         if ( $timer !== '' ) {
 950                 $text = preg_replace( '/[^\n]/', $timer . '\0', $text, 1 );
 951         }
 952
 953         if ( $dest === 'all' ) {
 954                 MWDebug::debugMsg( $text );
 955         }
 956
 957         if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 958                 # Strip unprintables; they can switch terminal modes when binary data
 959                 # gets dumped, which is pretty annoying.
 960                 $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 961                 $text = $wgDebugLogPrefix . $text;
 962                 wfErrorLog( $text, $wgDebugLogFile );
 963         }
 964 }
 965
 966 /**
 967  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 968  * @return bool
 969  */
 970 function wfIsDebugRawPage() {
 971         static $cache;
 972         if ( $cache !== null ) {
 973                 return $cache;
 974         }
 975         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 976         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 977                 || (
 978                         isset( $_SERVER['SCRIPT_NAME'] )
 979                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 980                 )
 981         ) {
 982                 $cache = true;
 983         } else {
 984                 $cache = false;
 985         }
 986         return $cache;
 987 }
 988
 989 /**
 990  * Get microsecond timestamps for debug logs
 991  *
 992  * @return string
 993  */
 994 function wfDebugTimer() {
 995         global $wgDebugTimestamps, $wgRequestTime;
 996
 997         if ( !$wgDebugTimestamps ) {
 998                 return '';
 999         }
1000
1001         $prefix = sprintf( "%6.4f", microtime( true ) - $wgRequestTime );
1002         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / ( 1024 * 1024 ) ) );
1003         return "$prefix $mem  ";
1004 }
1005
1006 /**
1007  * Send a line giving PHP memory usage.
1008  *
1009  * @param bool $exact print exact values instead of kilobytes (default: false)
1010  */
1011 function wfDebugMem( $exact = false ) {
1012         $mem = memory_get_usage();
1013         if ( !$exact ) {
1014                 $mem = floor( $mem / 1024 ) . ' kilobytes';
1015         } else {
1016                 $mem .= ' bytes';
1017         }
1018         wfDebug( "Memory usage: $mem\n" );
1019 }
1020
1021 /**
1022  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
1023  * To configure a supplementary log file, set $wgDebugLogGroups[$logGroup] to a string
1024  * filename or an associative array mapping 'destination' to the desired filename. The
1025  * associative array may also contain a 'sample' key with an integer value, specifying
1026  * a sampling factor.
1027  *
1028  * @since 1.23 support for sampling log messages via $wgDebugLogGroups.
1029  *
1030  * @param string $logGroup
1031  * @param string $text
1032  * @param string|bool $dest Destination of the message:
1033  *     - 'all': both to the log and HTML (debug toolbar or HTML comments)
1034  *     - 'log': only to the log and not in HTML
1035  *     - 'private': only to the specifc log if set in $wgDebugLogGroups and
1036  *       discarded otherwise
1037  *   For backward compatibility, it can also take a boolean:
1038  *     - true: same as 'all'
1039  *     - false: same as 'private'
1040  */
1041 function wfDebugLog( $logGroup, $text, $dest = 'all' ) {
1042         global $wgDebugLogGroups;
1043
1044         $text = trim( $text ) . "\n";
1045
1046         // Turn $dest into a string if it's a boolean (for b/c)
1047         if ( $dest === true ) {
1048                 $dest = 'all';
1049         } elseif ( $dest === false ) {
1050                 $dest = 'private';
1051         }
1052
1053         if ( !isset( $wgDebugLogGroups[$logGroup] ) ) {
1054                 if ( $dest !== 'private' ) {
1055                         wfDebug( "[$logGroup] $text", $dest );
1056                 }
1057                 return;
1058         }
1059
1060         if ( $dest === 'all' ) {
1061                 MWDebug::debugMsg( "[$logGroup] $text" );
1062         }
1063
1064         $logConfig = $wgDebugLogGroups[$logGroup];
1065         if ( $logConfig === false ) {
1066                 return;
1067         }
1068         if ( is_array( $logConfig ) ) {
1069                 if ( isset( $logConfig['sample'] ) && mt_rand( 1, $logConfig['sample'] ) !== 1 ) {
1070                         return;
1071                 }
1072                 $destination = $logConfig['destination'];
1073         } else {
1074                 $destination = strval( $logConfig );
1075         }
1076
1077         $time = wfTimestamp( TS_DB );
1078         $wiki = wfWikiID();
1079         $host = wfHostname();
1080         wfErrorLog( "$time $host $wiki: $text", $destination );
1081 }
1082
1083 /**
1084  * Log for database errors
1085  *
1086  * @param string $text database error message.
1087  */
1088 function wfLogDBError( $text ) {
1089         global $wgDBerrorLog, $wgDBerrorLogTZ;
1090         static $logDBErrorTimeZoneObject = null;
1091
1092         if ( $wgDBerrorLog ) {
1093                 $host = wfHostname();
1094                 $wiki = wfWikiID();
1095
1096                 if ( $wgDBerrorLogTZ && !$logDBErrorTimeZoneObject ) {
1097                         $logDBErrorTimeZoneObject = new DateTimeZone( $wgDBerrorLogTZ );
1098                 }
1099
1100                 // Workaround for https://bugs.php.net/bug.php?id=52063
1101                 // Can be removed when min PHP > 5.3.2
1102                 if ( $logDBErrorTimeZoneObject === null ) {
1103                         $d = date_create( "now" );
1104                 } else {
1105                         $d = date_create( "now", $logDBErrorTimeZoneObject );
1106                 }
1107
1108                 $date = $d->format( 'D M j G:i:s T Y' );
1109
1110                 $text = "$date\t$host\t$wiki\t" . trim( $text ) . "\n";
1111                 wfErrorLog( $text, $wgDBerrorLog );
1112         }
1113 }
1114
1115 /**
1116  * Throws a warning that $function is deprecated
1117  *
1118  * @param $function String
1119  * @param string|bool $version Version of MediaWiki that the function
1120  *    was deprecated in (Added in 1.19).
1121  * @param string|bool $component Added in 1.19.
1122  * @param $callerOffset integer: How far up the call stack is the original
1123  *    caller. 2 = function that called the function that called
1124  *    wfDeprecated (Added in 1.20)
1125  *
1126  * @return null
1127  */
1128 function wfDeprecated( $function, $version = false, $component = false, $callerOffset = 2 ) {
1129         MWDebug::deprecated( $function, $version, $component, $callerOffset + 1 );
1130 }
1131
1132 /**
1133  * Send a warning either to the debug log or in a PHP error depending on
1134  * $wgDevelopmentWarnings. To log warnings in production, use wfLogWarning() instead.
1135  *
1136  * @param string $msg message to send
1137  * @param $callerOffset Integer: number of items to go back in the backtrace to
1138  *        find the correct caller (1 = function calling wfWarn, ...)
1139  * @param $level Integer: PHP error level; defaults to E_USER_NOTICE;
1140  *        only used when $wgDevelopmentWarnings is true
1141  */
1142 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
1143         MWDebug::warning( $msg, $callerOffset + 1, $level, 'auto' );
1144 }
1145
1146 /**
1147  * Send a warning as a PHP error and the debug log. This is intended for logging
1148  * warnings in production. For logging development warnings, use WfWarn instead.
1149  *
1150  * @param $msg String: message to send
1151  * @param $callerOffset Integer: number of items to go back in the backtrace to
1152  *        find the correct caller (1 = function calling wfLogWarning, ...)
1153  * @param $level Integer: PHP error level; defaults to E_USER_WARNING
1154  */
1155 function wfLogWarning( $msg, $callerOffset = 1, $level = E_USER_WARNING ) {
1156         MWDebug::warning( $msg, $callerOffset + 1, $level, 'production' );
1157 }
1158
1159 /**
1160  * Log to a file without getting "file size exceeded" signals.
1161  *
1162  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
1163  * send lines to the specified port, prefixed by the specified prefix and a space.
1164  *
1165  * @param $text String
1166  * @param string $file filename
1167  * @throws MWException
1168  */
1169 function wfErrorLog( $text, $file ) {
1170         if ( substr( $file, 0, 4 ) == 'udp:' ) {
1171                 # Needs the sockets extension
1172                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
1173                         // IPv6 bracketed host
1174                         $host = $m[2];
1175                         $port = intval( $m[3] );
1176                         $prefix = isset( $m[4] ) ? $m[4] : false;
1177                         $domain = AF_INET6;
1178                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
1179                         $host = $m[2];
1180                         if ( !IP::isIPv4( $host ) ) {
1181                                 $host = gethostbyname( $host );
1182                         }
1183                         $port = intval( $m[3] );
1184                         $prefix = isset( $m[4] ) ? $m[4] : false;
1185                         $domain = AF_INET;
1186                 } else {
1187                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
1188                 }
1189
1190                 // Clean it up for the multiplexer
1191                 if ( strval( $prefix ) !== '' ) {
1192                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
1193
1194                         // Limit to 64KB
1195                         if ( strlen( $text ) > 65506 ) {
1196                                 $text = substr( $text, 0, 65506 );
1197                         }
1198
1199                         if ( substr( $text, -1 ) != "\n" ) {
1200                                 $text .= "\n";
1201                         }
1202                 } elseif ( strlen( $text ) > 65507 ) {
1203                         $text = substr( $text, 0, 65507 );
1204                 }
1205
1206                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
1207                 if ( !$sock ) {
1208                         return;
1209                 }
1210
1211                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
1212                 socket_close( $sock );
1213         } else {
1214                 wfSuppressWarnings();
1215                 $exists = file_exists( $file );
1216                 $size = $exists ? filesize( $file ) : false;
1217                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1218                         file_put_contents( $file, $text, FILE_APPEND );
1219                 }
1220                 wfRestoreWarnings();
1221         }
1222 }
1223
1224 /**
1225  * @todo document
1226  */
1227 function wfLogProfilingData() {
1228         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1229         global $wgProfileLimit, $wgUser;
1230
1231         StatCounter::singleton()->flush();
1232
1233         $profiler = Profiler::instance();
1234
1235         # Profiling must actually be enabled...
1236         if ( $profiler->isStub() ) {
1237                 return;
1238         }
1239
1240         // Get total page request time and only show pages that longer than
1241         // $wgProfileLimit time (default is 0)
1242         $elapsed = microtime( true ) - $wgRequestTime;
1243         if ( $elapsed <= $wgProfileLimit ) {
1244                 return;
1245         }
1246
1247         $profiler->logData();
1248
1249         // Check whether this should be logged in the debug file.
1250         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1251                 return;
1252         }
1253
1254         $forward = '';
1255         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1256                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1257         }
1258         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1259                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1260         }
1261         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1262                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1263         }
1264         if ( $forward ) {
1265                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1266         }
1267         // Don't load $wgUser at this late stage just for statistics purposes
1268         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1269         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1270                 $forward .= ' anon';
1271         }
1272
1273         // Command line script uses a FauxRequest object which does not have
1274         // any knowledge about an URL and throw an exception instead.
1275         try {
1276                 $requestUrl = $wgRequest->getRequestURL();
1277         } catch ( MWException $e ) {
1278                 $requestUrl = 'n/a';
1279         }
1280
1281         $log = sprintf( "%s\t%04.3f\t%s\n",
1282                 gmdate( 'YmdHis' ), $elapsed,
1283                 urldecode( $requestUrl . $forward ) );
1284
1285         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1286 }
1287
1288 /**
1289  * Increment a statistics counter
1290  *
1291  * @param $key String
1292  * @param $count Int
1293  * @return void
1294  */
1295 function wfIncrStats( $key, $count = 1 ) {
1296         StatCounter::singleton()->incr( $key, $count );
1297 }
1298
1299 /**
1300  * Check whether the wiki is in read-only mode.
1301  *
1302  * @return bool
1303  */
1304 function wfReadOnly() {
1305         return wfReadOnlyReason() !== false;
1306 }
1307
1308 /**
1309  * Get the value of $wgReadOnly or the contents of $wgReadOnlyFile.
1310  *
1311  * @return string|bool: String when in read-only mode; false otherwise
1312  */
1313 function wfReadOnlyReason() {
1314         global $wgReadOnly, $wgReadOnlyFile;
1315
1316         if ( $wgReadOnly === null ) {
1317                 // Set $wgReadOnly for faster access next time
1318                 if ( is_file( $wgReadOnlyFile ) && filesize( $wgReadOnlyFile ) > 0 ) {
1319                         $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1320                 } else {
1321                         $wgReadOnly = false;
1322                 }
1323         }
1324
1325         return $wgReadOnly;
1326 }
1327
1328 /**
1329  * Return a Language object from $langcode
1330  *
1331  * @param $langcode Mixed: either:
1332  *                  - a Language object
1333  *                  - code of the language to get the message for, if it is
1334  *                    a valid code create a language for that language, if
1335  *                    it is a string but not a valid code then make a basic
1336  *                    language object
1337  *                  - a boolean: if it's false then use the global object for
1338  *                    the current user's language (as a fallback for the old parameter
1339  *                    functionality), or if it is true then use global object
1340  *                    for the wiki's content language.
1341  * @return Language object
1342  */
1343 function wfGetLangObj( $langcode = false ) {
1344         # Identify which language to get or create a language object for.
1345         # Using is_object here due to Stub objects.
1346         if ( is_object( $langcode ) ) {
1347                 # Great, we already have the object (hopefully)!
1348                 return $langcode;
1349         }
1350
1351         global $wgContLang, $wgLanguageCode;
1352         if ( $langcode === true || $langcode === $wgLanguageCode ) {
1353                 # $langcode is the language code of the wikis content language object.
1354                 # or it is a boolean and value is true
1355                 return $wgContLang;
1356         }
1357
1358         global $wgLang;
1359         if ( $langcode === false || $langcode === $wgLang->getCode() ) {
1360                 # $langcode is the language code of user language object.
1361                 # or it was a boolean and value is false
1362                 return $wgLang;
1363         }
1364
1365         $validCodes = array_keys( Language::fetchLanguageNames() );
1366         if ( in_array( $langcode, $validCodes ) ) {
1367                 # $langcode corresponds to a valid language.
1368                 return Language::factory( $langcode );
1369         }
1370
1371         # $langcode is a string, but not a valid language code; use content language.
1372         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1373         return $wgContLang;
1374 }
1375
1376 /**
1377  * This is the function for getting translated interface messages.
1378  *
1379  * @see Message class for documentation how to use them.
1380  * @see https://www.mediawiki.org/wiki/Manual:Messages_API
1381  *
1382  * This function replaces all old wfMsg* functions.
1383  *
1384  * @param $key \string Message key.
1385  * Varargs: normal message parameters.
1386  * @return Message
1387  * @since 1.17
1388  */
1389 function wfMessage( $key /*...*/) {
1390         $params = func_get_args();
1391         array_shift( $params );
1392         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1393                 $params = $params[0];
1394         }
1395         return new Message( $key, $params );
1396 }
1397
1398 /**
1399  * This function accepts multiple message keys and returns a message instance
1400  * for the first message which is non-empty. If all messages are empty then an
1401  * instance of the first message key is returned.
1402  * @param varargs: message keys
1403  * @return Message
1404  * @since 1.18
1405  */
1406 function wfMessageFallback( /*...*/ ) {
1407         $args = func_get_args();
1408         return call_user_func_array( 'Message::newFallbackSequence', $args );
1409 }
1410
1411 /**
1412  * Get a message from anywhere, for the current user language.
1413  *
1414  * Use wfMsgForContent() instead if the message should NOT
1415  * change depending on the user preferences.
1416  *
1417  * @deprecated since 1.18
1418  *
1419  * @param string $key lookup key for the message, usually
1420  *    defined in languages/Language.php
1421  *
1422  * Parameters to the message, which can be used to insert variable text into
1423  * it, can be passed to this function in the following formats:
1424  * - One per argument, starting at the second parameter
1425  * - As an array in the second parameter
1426  * These are not shown in the function definition.
1427  *
1428  * @return String
1429  */
1430 function wfMsg( $key ) {
1431         wfDeprecated( __METHOD__, '1.21' );
1432
1433         $args = func_get_args();
1434         array_shift( $args );
1435         return wfMsgReal( $key, $args );
1436 }
1437
1438 /**
1439  * Same as above except doesn't transform the message
1440  *
1441  * @deprecated since 1.18
1442  *
1443  * @param $key String
1444  * @return String
1445  */
1446 function wfMsgNoTrans( $key ) {
1447         wfDeprecated( __METHOD__, '1.21' );
1448
1449         $args = func_get_args();
1450         array_shift( $args );
1451         return wfMsgReal( $key, $args, true, false, false );
1452 }
1453
1454 /**
1455  * Get a message from anywhere, for the current global language
1456  * set with $wgLanguageCode.
1457  *
1458  * Use this if the message should NOT change dependent on the
1459  * language set in the user's preferences. This is the case for
1460  * most text written into logs, as well as link targets (such as
1461  * the name of the copyright policy page). Link titles, on the
1462  * other hand, should be shown in the UI language.
1463  *
1464  * Note that MediaWiki allows users to change the user interface
1465  * language in their preferences, but a single installation
1466  * typically only contains content in one language.
1467  *
1468  * Be wary of this distinction: If you use wfMsg() where you should
1469  * use wfMsgForContent(), a user of the software may have to
1470  * customize potentially hundreds of messages in
1471  * order to, e.g., fix a link in every possible language.
1472  *
1473  * @deprecated since 1.18
1474  *
1475  * @param string $key lookup key for the message, usually
1476  *     defined in languages/Language.php
1477  * @return String
1478  */
1479 function wfMsgForContent( $key ) {
1480         wfDeprecated( __METHOD__, '1.21' );
1481
1482         global $wgForceUIMsgAsContentMsg;
1483         $args = func_get_args();
1484         array_shift( $args );
1485         $forcontent = true;
1486         if ( is_array( $wgForceUIMsgAsContentMsg )
1487                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1488         ) {
1489                 $forcontent = false;
1490         }
1491         return wfMsgReal( $key, $args, true, $forcontent );
1492 }
1493
1494 /**
1495  * Same as above except doesn't transform the message
1496  *
1497  * @deprecated since 1.18
1498  *
1499  * @param $key String
1500  * @return String
1501  */
1502 function wfMsgForContentNoTrans( $key ) {
1503         wfDeprecated( __METHOD__, '1.21' );
1504
1505         global $wgForceUIMsgAsContentMsg;
1506         $args = func_get_args();
1507         array_shift( $args );
1508         $forcontent = true;
1509         if ( is_array( $wgForceUIMsgAsContentMsg )
1510                 && in_array( $key, $wgForceUIMsgAsContentMsg )
1511         ) {
1512                 $forcontent = false;
1513         }
1514         return wfMsgReal( $key, $args, true, $forcontent, false );
1515 }
1516
1517 /**
1518  * Really get a message
1519  *
1520  * @deprecated since 1.18
1521  *
1522  * @param string $key key to get.
1523  * @param $args
1524  * @param $useDB Boolean
1525  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1526  * @param $transform Boolean: Whether or not to transform the message.
1527  * @return String: the requested message.
1528  */
1529 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1530         wfDeprecated( __METHOD__, '1.21' );
1531
1532         wfProfileIn( __METHOD__ );
1533         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1534         $message = wfMsgReplaceArgs( $message, $args );
1535         wfProfileOut( __METHOD__ );
1536         return $message;
1537 }
1538
1539 /**
1540  * Fetch a message string value, but don't replace any keys yet.
1541  *
1542  * @deprecated since 1.18
1543  *
1544  * @param $key String
1545  * @param $useDB Bool
1546  * @param string $langCode Code of the language to get the message for, or
1547  *                  behaves as a content language switch if it is a boolean.
1548  * @param $transform Boolean: whether to parse magic words, etc.
1549  * @return string
1550  */
1551 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1552         wfDeprecated( __METHOD__, '1.21' );
1553
1554         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1555
1556         $cache = MessageCache::singleton();
1557         $message = $cache->get( $key, $useDB, $langCode );
1558         if ( $message === false ) {
1559                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1560         } elseif ( $transform ) {
1561                 $message = $cache->transform( $message );
1562         }
1563         return $message;
1564 }
1565
1566 /**
1567  * Replace message parameter keys on the given formatted output.
1568  *
1569  * @param $message String
1570  * @param $args Array
1571  * @return string
1572  * @private
1573  */
1574 function wfMsgReplaceArgs( $message, $args ) {
1575         # Fix windows line-endings
1576         # Some messages are split with explode("\n", $msg)
1577         $message = str_replace( "\r", '', $message );
1578
1579         // Replace arguments
1580         if ( count( $args ) ) {
1581                 if ( is_array( $args[0] ) ) {
1582                         $args = array_values( $args[0] );
1583                 }
1584                 $replacementKeys = array();
1585                 foreach ( $args as $n => $param ) {
1586                         $replacementKeys['$' . ( $n + 1 )] = $param;
1587                 }
1588                 $message = strtr( $message, $replacementKeys );
1589         }
1590
1591         return $message;
1592 }
1593
1594 /**
1595  * Return an HTML-escaped version of a message.
1596  * Parameter replacements, if any, are done *after* the HTML-escaping,
1597  * so parameters may contain HTML (eg links or form controls). Be sure
1598  * to pre-escape them if you really do want plaintext, or just wrap
1599  * the whole thing in htmlspecialchars().
1600  *
1601  * @deprecated since 1.18
1602  *
1603  * @param $key String
1604  * @param string ... parameters
1605  * @return string
1606  */
1607 function wfMsgHtml( $key ) {
1608         wfDeprecated( __METHOD__, '1.21' );
1609
1610         $args = func_get_args();
1611         array_shift( $args );
1612         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1613 }
1614
1615 /**
1616  * Return an HTML version of message
1617  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1618  * so parameters may contain HTML (eg links or form controls). Be sure
1619  * to pre-escape them if you really do want plaintext, or just wrap
1620  * the whole thing in htmlspecialchars().
1621  *
1622  * @deprecated since 1.18
1623  *
1624  * @param $key String
1625  * @param string ... parameters
1626  * @return string
1627  */
1628 function wfMsgWikiHtml( $key ) {
1629         wfDeprecated( __METHOD__, '1.21' );
1630
1631         $args = func_get_args();
1632         array_shift( $args );
1633         return wfMsgReplaceArgs(
1634                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1635                 /* can't be set to false */ true, /* interface */ true )->getText(),
1636                 $args );
1637 }
1638
1639 /**
1640  * Returns message in the requested format
1641  *
1642  * @deprecated since 1.18
1643  *
1644  * @param string $key key of the message
1645  * @param array $options processing rules.
1646  *   Can take the following options:
1647  *     parse: parses wikitext to HTML
1648  *     parseinline: parses wikitext to HTML and removes the surrounding
1649  *       p's added by parser or tidy
1650  *     escape: filters message through htmlspecialchars
1651  *     escapenoentities: same, but allows entity references like &#160; through
1652  *     replaceafter: parameters are substituted after parsing or escaping
1653  *     parsemag: transform the message using magic phrases
1654  *     content: fetch message for content language instead of interface
1655  *   Also can accept a single associative argument, of the form 'language' => 'xx':
1656  *     language: Language object or language code to fetch message for
1657  *       (overridden by content).
1658  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1659  *
1660  * @return String
1661  */
1662 function wfMsgExt( $key, $options ) {
1663         wfDeprecated( __METHOD__, '1.21' );
1664
1665         $args = func_get_args();
1666         array_shift( $args );
1667         array_shift( $args );
1668         $options = (array)$options;
1669
1670         foreach ( $options as $arrayKey => $option ) {
1671                 if ( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1672                         # An unknown index, neither numeric nor "language"
1673                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1674                 } elseif ( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1675                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1676                 'replaceafter', 'parsemag', 'content' ) ) ) {
1677                         # A numeric index with unknown value
1678                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1679                 }
1680         }
1681
1682         if ( in_array( 'content', $options, true ) ) {
1683                 $forContent = true;
1684                 $langCode = true;
1685                 $langCodeObj = null;
1686         } elseif ( array_key_exists( 'language', $options ) ) {
1687                 $forContent = false;
1688                 $langCode = wfGetLangObj( $options['language'] );
1689                 $langCodeObj = $langCode;
1690         } else {
1691                 $forContent = false;
1692                 $langCode = false;
1693                 $langCodeObj = null;
1694         }
1695
1696         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1697
1698         if ( !in_array( 'replaceafter', $options, true ) ) {
1699                 $string = wfMsgReplaceArgs( $string, $args );
1700         }
1701
1702         $messageCache = MessageCache::singleton();
1703         $parseInline = in_array( 'parseinline', $options, true );
1704         if ( in_array( 'parse', $options, true ) || $parseInline ) {
1705                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj );
1706                 if ( $string instanceof ParserOutput ) {
1707                         $string = $string->getText();
1708                 }
1709
1710                 if ( $parseInline ) {
1711                         $m = array();
1712                         if ( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1713                                 $string = $m[1];
1714                         }
1715                 }
1716         } elseif ( in_array( 'parsemag', $options, true ) ) {
1717                 $string = $messageCache->transform( $string,
1718                                 !$forContent, $langCodeObj );
1719         }
1720
1721         if ( in_array( 'escape', $options, true ) ) {
1722                 $string = htmlspecialchars ( $string );
1723         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1724                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1725         }
1726
1727         if ( in_array( 'replaceafter', $options, true ) ) {
1728                 $string = wfMsgReplaceArgs( $string, $args );
1729         }
1730
1731         return $string;
1732 }
1733
1734 /**
1735  * Since wfMsg() and co suck, they don't return false if the message key they
1736  * looked up didn't exist but instead the key wrapped in <>'s, this function checks for the
1737  * nonexistence of messages by checking the MessageCache::get() result directly.
1738  *
1739  * @deprecated since 1.18. Use Message::isDisabled().
1740  *
1741  * @param $key      String: the message key looked up
1742  * @return Boolean True if the message *doesn't* exist.
1743  */
1744 function wfEmptyMsg( $key ) {
1745         wfDeprecated( __METHOD__, '1.21' );
1746
1747         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1748 }
1749
1750 /**
1751  * Throw a debugging exception. This function previously once exited the process,
1752  * but now throws an exception instead, with similar results.
1753  *
1754  * @deprecated since 1.22; just throw an MWException yourself
1755  * @param string $msg message shown when dying.
1756  * @throws MWException
1757  */
1758 function wfDebugDieBacktrace( $msg = '' ) {
1759         wfDeprecated( __FUNCTION__, '1.22' );
1760         throw new MWException( $msg );
1761 }
1762
1763 /**
1764  * Fetch server name for use in error reporting etc.
1765  * Use real server name if available, so we know which machine
1766  * in a server farm generated the current page.
1767  *
1768  * @return string
1769  */
1770 function wfHostname() {
1771         static $host;
1772         if ( is_null( $host ) ) {
1773
1774                 # Hostname overriding
1775                 global $wgOverrideHostname;
1776                 if ( $wgOverrideHostname !== false ) {
1777                         # Set static and skip any detection
1778                         $host = $wgOverrideHostname;
1779                         return $host;
1780                 }
1781
1782                 if ( function_exists( 'posix_uname' ) ) {
1783                         // This function not present on Windows
1784                         $uname = posix_uname();
1785                 } else {
1786                         $uname = false;
1787                 }
1788                 if ( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1789                         $host = $uname['nodename'];
1790                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1791                         # Windows computer name
1792                         $host = getenv( 'COMPUTERNAME' );
1793                 } else {
1794                         # This may be a virtual server.
1795                         $host = $_SERVER['SERVER_NAME'];
1796                 }
1797         }
1798         return $host;
1799 }
1800
1801 /**
1802  * Returns a HTML comment with the elapsed time since request.
1803  * This method has no side effects.
1804  *
1805  * @return string
1806  */
1807 function wfReportTime() {
1808         global $wgRequestTime, $wgShowHostnames;
1809
1810         $elapsed = microtime( true ) - $wgRequestTime;
1811
1812         return $wgShowHostnames
1813                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1814                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1815 }
1816
1817 /**
1818  * Safety wrapper for debug_backtrace().
1819  *
1820  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1821  * murky circumstances, which may be triggered in part by stub objects
1822  * or other fancy talking'.
1823  *
1824  * Will return an empty array if Zend Optimizer is detected or if
1825  * debug_backtrace is disabled, otherwise the output from
1826  * debug_backtrace() (trimmed).
1827  *
1828  * @param int $limit This parameter can be used to limit the number of stack frames returned
1829  *
1830  * @return array of backtrace information
1831  */
1832 function wfDebugBacktrace( $limit = 0 ) {
1833         static $disabled = null;
1834
1835         if ( extension_loaded( 'Zend Optimizer' ) ) {
1836                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1837                 return array();
1838         }
1839
1840         if ( is_null( $disabled ) ) {
1841                 $disabled = false;
1842                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1843                 $functions = array_map( 'trim', $functions );
1844                 $functions = array_map( 'strtolower', $functions );
1845                 if ( in_array( 'debug_backtrace', $functions ) ) {
1846                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1847                         $disabled = true;
1848                 }
1849         }
1850         if ( $disabled ) {
1851                 return array();
1852         }
1853
1854         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1855                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit + 1 ), 1 );
1856         } else {
1857                 return array_slice( debug_backtrace(), 1 );
1858         }
1859 }
1860
1861 /**
1862  * Get a debug backtrace as a string
1863  *
1864  * @return string
1865  */
1866 function wfBacktrace() {
1867         global $wgCommandLineMode;
1868
1869         if ( $wgCommandLineMode ) {
1870                 $msg = '';
1871         } else {
1872                 $msg = "<ul>\n";
1873         }
1874         $backtrace = wfDebugBacktrace();
1875         foreach ( $backtrace as $call ) {
1876                 if ( isset( $call['file'] ) ) {
1877                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1878                         $file = $f[count( $f ) - 1];
1879                 } else {
1880                         $file = '-';
1881                 }
1882                 if ( isset( $call['line'] ) ) {
1883                         $line = $call['line'];
1884                 } else {
1885                         $line = '-';
1886                 }
1887                 if ( $wgCommandLineMode ) {
1888                         $msg .= "$file line $line calls ";
1889                 } else {
1890                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1891                 }
1892                 if ( !empty( $call['class'] ) ) {
1893                         $msg .= $call['class'] . $call['type'];
1894                 }
1895                 $msg .= $call['function'] . '()';
1896
1897                 if ( $wgCommandLineMode ) {
1898                         $msg .= "\n";
1899                 } else {
1900                         $msg .= "</li>\n";
1901                 }
1902         }
1903         if ( $wgCommandLineMode ) {
1904                 $msg .= "\n";
1905         } else {
1906                 $msg .= "</ul>\n";
1907         }
1908
1909         return $msg;
1910 }
1911
1912 /**
1913  * Get the name of the function which called this function
1914  * wfGetCaller( 1 ) is the function with the wfGetCaller() call (ie. __FUNCTION__)
1915  * wfGetCaller( 2 ) [default] is the caller of the function running wfGetCaller()
1916  * wfGetCaller( 3 ) is the parent of that.
1917  *
1918  * @param $level Int
1919  * @return string
1920  */
1921 function wfGetCaller( $level = 2 ) {
1922         $backtrace = wfDebugBacktrace( $level + 1 );
1923         if ( isset( $backtrace[$level] ) ) {
1924                 return wfFormatStackFrame( $backtrace[$level] );
1925         } else {
1926                 return 'unknown';
1927         }
1928 }
1929
1930 /**
1931  * Return a string consisting of callers in the stack. Useful sometimes
1932  * for profiling specific points.
1933  *
1934  * @param int $limit The maximum depth of the stack frame to return, or false for
1935  *               the entire stack.
1936  * @return String
1937  */
1938 function wfGetAllCallers( $limit = 3 ) {
1939         $trace = array_reverse( wfDebugBacktrace() );
1940         if ( !$limit || $limit > count( $trace ) - 1 ) {
1941                 $limit = count( $trace ) - 1;
1942         }
1943         $trace = array_slice( $trace, -$limit - 1, $limit );
1944         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1945 }
1946
1947 /**
1948  * Return a string representation of frame
1949  *
1950  * @param $frame Array
1951  * @return string
1952  */
1953 function wfFormatStackFrame( $frame ) {
1954         return isset( $frame['class'] ) ?
1955                 $frame['class'] . '::' . $frame['function'] :
1956                 $frame['function'];
1957 }
1958
1959 /* Some generic result counters, pulled out of SearchEngine */
1960
1961 /**
1962  * @todo document
1963  *
1964  * @param $offset Int
1965  * @param $limit Int
1966  * @return String
1967  */
1968 function wfShowingResults( $offset, $limit ) {
1969         return wfMessage( 'showingresults' )->numParams( $limit, $offset + 1 )->parse();
1970 }
1971
1972 /**
1973  * Generate (prev x| next x) (20|50|100...) type links for paging
1974  *
1975  * @param $offset String
1976  * @param $limit Integer
1977  * @param $link String
1978  * @param string $query optional URL query parameter string
1979  * @param bool $atend optional param for specified if this is the last page
1980  * @return String
1981  * @deprecated in 1.19; use Language::viewPrevNext() instead
1982  */
1983 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1984         wfDeprecated( __METHOD__, '1.19' );
1985
1986         global $wgLang;
1987
1988         $query = wfCgiToArray( $query );
1989
1990         if ( is_object( $link ) ) {
1991                 $title = $link;
1992         } else {
1993                 $title = Title::newFromText( $link );
1994                 if ( is_null( $title ) ) {
1995                         return false;
1996                 }
1997         }
1998
1999         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
2000 }
2001
2002 /**
2003  * @todo document
2004  * @todo FIXME: We may want to blacklist some broken browsers
2005  *
2006  * @param $force Bool
2007  * @return bool Whereas client accept gzip compression
2008  */
2009 function wfClientAcceptsGzip( $force = false ) {
2010         static $result = null;
2011         if ( $result === null || $force ) {
2012                 $result = false;
2013                 if ( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
2014                         # @todo FIXME: We may want to blacklist some broken browsers
2015                         $m = array();
2016                         if ( preg_match(
2017                                         '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
2018                                         $_SERVER['HTTP_ACCEPT_ENCODING'],
2019                                         $m
2020                                 )
2021                         ) {
2022                                 if ( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
2023                                         $result = false;
2024                                         return $result;
2025                                 }
2026                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
2027                                 $result = true;
2028                         }
2029                 }
2030         }
2031         return $result;
2032 }
2033
2034 /**
2035  * Obtain the offset and limit values from the request string;
2036  * used in special pages
2037  *
2038  * @param int $deflimit default limit if none supplied
2039  * @param string $optionname Name of a user preference to check against
2040  * @return array
2041  *
2042  */
2043 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
2044         global $wgRequest;
2045         return $wgRequest->getLimitOffset( $deflimit, $optionname );
2046 }
2047
2048 /**
2049  * Escapes the given text so that it may be output using addWikiText()
2050  * without any linking, formatting, etc. making its way through. This
2051  * is achieved by substituting certain characters with HTML entities.
2052  * As required by the callers, "<nowiki>" is not used.
2053  *
2054  * @param string $text text to be escaped
2055  * @return String
2056  */
2057 function wfEscapeWikiText( $text ) {
2058         static $repl = null, $repl2 = null;
2059         if ( $repl === null ) {
2060                 $repl = array(
2061                         '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
2062                         '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
2063                         '{' => '&#123;', '|' => '&#124;', '}' => '&#125;', ';' => '&#59;',
2064                         "\n#" => "\n&#35;", "\r#" => "\r&#35;",
2065                         "\n*" => "\n&#42;", "\r*" => "\r&#42;",
2066                         "\n:" => "\n&#58;", "\r:" => "\r&#58;",
2067                         "\n " => "\n&#32;", "\r " => "\r&#32;",
2068                         "\n\n" => "\n&#10;", "\r\n" => "&#13;\n",
2069                         "\n\r" => "\n&#13;", "\r\r" => "\r&#13;",
2070                         "\n\t" => "\n&#9;", "\r\t" => "\r&#9;", // "\n\t\n" is treated like "\n\n"
2071                         "\n----" => "\n&#45;---", "\r----" => "\r&#45;---",
2072                         '__' => '_&#95;', '://' => '&#58;//',
2073                 );
2074
2075                 // We have to catch everything "\s" matches in PCRE
2076                 foreach ( array( 'ISBN', 'RFC', 'PMID' ) as $magic ) {
2077                         $repl["$magic "] = "$magic&#32;";
2078                         $repl["$magic\t"] = "$magic&#9;";
2079                         $repl["$magic\r"] = "$magic&#13;";
2080                         $repl["$magic\n"] = "$magic&#10;";
2081                         $repl["$magic\f"] = "$magic&#12;";
2082                 }
2083
2084                 // And handle protocols that don't use "://"
2085                 global $wgUrlProtocols;
2086                 $repl2 = array();
2087                 foreach ( $wgUrlProtocols as $prot ) {
2088                         if ( substr( $prot, -1 ) === ':' ) {
2089                                 $repl2[] = preg_quote( substr( $prot, 0, -1 ), '/' );
2090                         }
2091                 }
2092                 $repl2 = $repl2 ? '/\b(' . join( '|', $repl2 ) . '):/i' : '/^(?!)/';
2093         }
2094         $text = substr( strtr( "\n$text", $repl ), 1 );
2095         $text = preg_replace( $repl2, '$1&#58;', $text );
2096         return $text;
2097 }
2098
2099 /**
2100  * Get the current unix timestamp with microseconds.  Useful for profiling
2101  * @deprecated since 1.22; call microtime() directly
2102  * @return Float
2103  */
2104 function wfTime() {
2105         wfDeprecated( __FUNCTION__, '1.22' );
2106         return microtime( true );
2107 }
2108
2109 /**
2110  * Sets dest to source and returns the original value of dest
2111  * If source is NULL, it just returns the value, it doesn't set the variable
2112  * If force is true, it will set the value even if source is NULL
2113  *
2114  * @param $dest Mixed
2115  * @param $source Mixed
2116  * @param $force Bool
2117  * @return Mixed
2118  */
2119 function wfSetVar( &$dest, $source, $force = false ) {
2120         $temp = $dest;
2121         if ( !is_null( $source ) || $force ) {
2122                 $dest = $source;
2123         }
2124         return $temp;
2125 }
2126
2127 /**
2128  * As for wfSetVar except setting a bit
2129  *
2130  * @param $dest Int
2131  * @param $bit Int
2132  * @param $state Bool
2133  *
2134  * @return bool
2135  */
2136 function wfSetBit( &$dest, $bit, $state = true ) {
2137         $temp = (bool)( $dest & $bit );
2138         if ( !is_null( $state ) ) {
2139                 if ( $state ) {
2140                         $dest |= $bit;
2141                 } else {
2142                         $dest &= ~$bit;
2143                 }
2144         }
2145         return $temp;
2146 }
2147
2148 /**
2149  * A wrapper around the PHP function var_export().
2150  * Either print it or add it to the regular output ($wgOut).
2151  *
2152  * @param $var mixed A PHP variable to dump.
2153  */
2154 function wfVarDump( $var ) {
2155         global $wgOut;
2156         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
2157         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
2158                 print $s;
2159         } else {
2160                 $wgOut->addHTML( $s );
2161         }
2162 }
2163
2164 /**
2165  * Provide a simple HTTP error.
2166  *
2167  * @param $code Int|String
2168  * @param $label String
2169  * @param $desc String
2170  */
2171 function wfHttpError( $code, $label, $desc ) {
2172         global $wgOut;
2173         $wgOut->disable();
2174         header( "HTTP/1.0 $code $label" );
2175         header( "Status: $code $label" );
2176         $wgOut->sendCacheControl();
2177
2178         header( 'Content-type: text/html; charset=utf-8' );
2179         print "<!doctype html>" .
2180                 '<html><head><title>' .
2181                 htmlspecialchars( $label ) .
2182                 '</title></head><body><h1>' .
2183                 htmlspecialchars( $label ) .
2184                 '</h1><p>' .
2185                 nl2br( htmlspecialchars( $desc ) ) .
2186                 "</p></body></html>\n";
2187 }
2188
2189 /**
2190  * Clear away any user-level output buffers, discarding contents.
2191  *
2192  * Suitable for 'starting afresh', for instance when streaming
2193  * relatively large amounts of data without buffering, or wanting to
2194  * output image files without ob_gzhandler's compression.
2195  *
2196  * The optional $resetGzipEncoding parameter controls suppression of
2197  * the Content-Encoding header sent by ob_gzhandler; by default it
2198  * is left. See comments for wfClearOutputBuffers() for why it would
2199  * be used.
2200  *
2201  * Note that some PHP configuration options may add output buffer
2202  * layers which cannot be removed; these are left in place.
2203  *
2204  * @param $resetGzipEncoding Bool
2205  */
2206 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
2207         if ( $resetGzipEncoding ) {
2208                 // Suppress Content-Encoding and Content-Length
2209                 // headers from 1.10+s wfOutputHandler
2210                 global $wgDisableOutputCompression;
2211                 $wgDisableOutputCompression = true;
2212         }
2213         while ( $status = ob_get_status() ) {
2214                 if ( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
2215                         // Probably from zlib.output_compression or other
2216                         // PHP-internal setting which can't be removed.
2217                         //
2218                         // Give up, and hope the result doesn't break
2219                         // output behavior.
2220                         break;
2221                 }
2222                 if ( !ob_end_clean() ) {
2223                         // Could not remove output buffer handler; abort now
2224                         // to avoid getting in some kind of infinite loop.
2225                         break;
2226                 }
2227                 if ( $resetGzipEncoding ) {
2228                         if ( $status['name'] == 'ob_gzhandler' ) {
2229                                 // Reset the 'Content-Encoding' field set by this handler
2230                                 // so we can start fresh.
2231                                 header_remove( 'Content-Encoding' );
2232                                 break;
2233                         }
2234                 }
2235         }
2236 }
2237
2238 /**
2239  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2240  *
2241  * Clear away output buffers, but keep the Content-Encoding header
2242  * produced by ob_gzhandler, if any.
2243  *
2244  * This should be used for HTTP 304 responses, where you need to
2245  * preserve the Content-Encoding header of the real result, but
2246  * also need to suppress the output of ob_gzhandler to keep to spec
2247  * and avoid breaking Firefox in rare cases where the headers and
2248  * body are broken over two packets.
2249  */
2250 function wfClearOutputBuffers() {
2251         wfResetOutputBuffers( false );
2252 }
2253
2254 /**
2255  * Converts an Accept-* header into an array mapping string values to quality
2256  * factors
2257  *
2258  * @param $accept String
2259  * @param string $def default
2260  * @return Array
2261  */
2262 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2263         # No arg means accept anything (per HTTP spec)
2264         if ( !$accept ) {
2265                 return array( $def => 1.0 );
2266         }
2267
2268         $prefs = array();
2269
2270         $parts = explode( ',', $accept );
2271
2272         foreach ( $parts as $part ) {
2273                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2274                 $values = explode( ';', trim( $part ) );
2275                 $match = array();
2276                 if ( count( $values ) == 1 ) {
2277                         $prefs[$values[0]] = 1.0;
2278                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2279                         $prefs[$values[0]] = floatval( $match[1] );
2280                 }
2281         }
2282
2283         return $prefs;
2284 }
2285
2286 /**
2287  * Checks if a given MIME type matches any of the keys in the given
2288  * array. Basic wildcards are accepted in the array keys.
2289  *
2290  * Returns the matching MIME type (or wildcard) if a match, otherwise
2291  * NULL if no match.
2292  *
2293  * @param $type String
2294  * @param $avail Array
2295  * @return string
2296  * @private
2297  */
2298 function mimeTypeMatch( $type, $avail ) {
2299         if ( array_key_exists( $type, $avail ) ) {
2300                 return $type;
2301         } else {
2302                 $parts = explode( '/', $type );
2303                 if ( array_key_exists( $parts[0] . '/*', $avail ) ) {
2304                         return $parts[0] . '/*';
2305                 } elseif ( array_key_exists( '*/*', $avail ) ) {
2306                         return '*/*';
2307                 } else {
2308                         return null;
2309                 }
2310         }
2311 }
2312
2313 /**
2314  * Returns the 'best' match between a client's requested internet media types
2315  * and the server's list of available types. Each list should be an associative
2316  * array of type to preference (preference is a float between 0.0 and 1.0).
2317  * Wildcards in the types are acceptable.
2318  *
2319  * @param array $cprefs client's acceptable type list
2320  * @param array $sprefs server's offered types
2321  * @return string
2322  *
2323  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2324  * XXX: generalize to negotiate other stuff
2325  */
2326 function wfNegotiateType( $cprefs, $sprefs ) {
2327         $combine = array();
2328
2329         foreach ( array_keys( $sprefs ) as $type ) {
2330                 $parts = explode( '/', $type );
2331                 if ( $parts[1] != '*' ) {
2332                         $ckey = mimeTypeMatch( $type, $cprefs );
2333                         if ( $ckey ) {
2334                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2335                         }
2336                 }
2337         }
2338
2339         foreach ( array_keys( $cprefs ) as $type ) {
2340                 $parts = explode( '/', $type );
2341                 if ( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2342                         $skey = mimeTypeMatch( $type, $sprefs );
2343                         if ( $skey ) {
2344                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2345                         }
2346                 }
2347         }
2348
2349         $bestq = 0;
2350         $besttype = null;
2351
2352         foreach ( array_keys( $combine ) as $type ) {
2353                 if ( $combine[$type] > $bestq ) {
2354                         $besttype = $type;
2355                         $bestq = $combine[$type];
2356                 }
2357         }
2358
2359         return $besttype;
2360 }
2361
2362 /**
2363  * Reference-counted warning suppression
2364  *
2365  * @param $end Bool
2366  */
2367 function wfSuppressWarnings( $end = false ) {
2368         static $suppressCount = 0;
2369         static $originalLevel = false;
2370
2371         if ( $end ) {
2372                 if ( $suppressCount ) {
2373                         --$suppressCount;
2374                         if ( !$suppressCount ) {
2375                                 error_reporting( $originalLevel );
2376                         }
2377                 }
2378         } else {
2379                 if ( !$suppressCount ) {
2380                         $originalLevel = error_reporting( E_ALL & ~(
2381                                 E_WARNING |
2382                                 E_NOTICE |
2383                                 E_USER_WARNING |
2384                                 E_USER_NOTICE |
2385                                 E_DEPRECATED |
2386                                 E_USER_DEPRECATED |
2387                                 E_STRICT
2388                         ) );
2389                 }
2390                 ++$suppressCount;
2391         }
2392 }
2393
2394 /**
2395  * Restore error level to previous value
2396  */
2397 function wfRestoreWarnings() {
2398         wfSuppressWarnings( true );
2399 }
2400
2401 # Autodetect, convert and provide timestamps of various types
2402
2403 /**
2404  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2405  */
2406 define( 'TS_UNIX', 0 );
2407
2408 /**
2409  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2410  */
2411 define( 'TS_MW', 1 );
2412
2413 /**
2414  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2415  */
2416 define( 'TS_DB', 2 );
2417
2418 /**
2419  * RFC 2822 format, for E-mail and HTTP headers
2420  */
2421 define( 'TS_RFC2822', 3 );
2422
2423 /**
2424  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2425  *
2426  * This is used by Special:Export
2427  */
2428 define( 'TS_ISO_8601', 4 );
2429
2430 /**
2431  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2432  *
2433  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2434  *       DateTime tag and page 36 for the DateTimeOriginal and
2435  *       DateTimeDigitized tags.
2436  */
2437 define( 'TS_EXIF', 5 );
2438
2439 /**
2440  * Oracle format time.
2441  */
2442 define( 'TS_ORACLE', 6 );
2443
2444 /**
2445  * Postgres format time.
2446  */
2447 define( 'TS_POSTGRES', 7 );
2448
2449 /**
2450  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2451  */
2452 define( 'TS_ISO_8601_BASIC', 9 );
2453
2454 /**
2455  * Get a timestamp string in one of various formats
2456  *
2457  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2458  *                    function will autodetect which format is supplied and act
2459  *                    accordingly.
2460  * @param $ts Mixed: optional timestamp to convert, default 0 for the current time
2461  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2462  */
2463 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2464         try {
2465                 $timestamp = new MWTimestamp( $ts );
2466                 return $timestamp->getTimestamp( $outputtype );
2467         } catch ( TimestampException $e ) {
2468                 wfDebug( "wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n" );
2469                 return false;
2470         }
2471 }
2472
2473 /**
2474  * Return a formatted timestamp, or null if input is null.
2475  * For dealing with nullable timestamp columns in the database.
2476  *
2477  * @param $outputtype Integer
2478  * @param $ts String
2479  * @return String
2480  */
2481 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2482         if ( is_null( $ts ) ) {
2483                 return null;
2484         } else {
2485                 return wfTimestamp( $outputtype, $ts );
2486         }
2487 }
2488
2489 /**
2490  * Convenience function; returns MediaWiki timestamp for the present time.
2491  *
2492  * @return string
2493  */
2494 function wfTimestampNow() {
2495         # return NOW
2496         return wfTimestamp( TS_MW, time() );
2497 }
2498
2499 /**
2500  * Check if the operating system is Windows
2501  *
2502  * @return Bool: true if it's Windows, False otherwise.
2503  */
2504 function wfIsWindows() {
2505         static $isWindows = null;
2506         if ( $isWindows === null ) {
2507                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2508         }
2509         return $isWindows;
2510 }
2511
2512 /**
2513  * Check if we are running under HHVM
2514  *
2515  * @return Bool
2516  */
2517 function wfIsHHVM() {
2518         return defined( 'HHVM_VERSION' );
2519 }
2520
2521 /**
2522  * Swap two variables
2523  *
2524  * @param $x Mixed
2525  * @param $y Mixed
2526  */
2527 function swap( &$x, &$y ) {
2528         $z = $x;
2529         $x = $y;
2530         $y = $z;
2531 }
2532
2533 /**
2534  * Tries to get the system directory for temporary files. First
2535  * $wgTmpDirectory is checked, and then the TMPDIR, TMP, and TEMP
2536  * environment variables are then checked in sequence, and if none are
2537  * set try sys_get_temp_dir().
2538  *
2539  * NOTE: When possible, use instead the tmpfile() function to create
2540  * temporary files to avoid race conditions on file creation, etc.
2541  *
2542  * @return String
2543  */
2544 function wfTempDir() {
2545         global $wgTmpDirectory;
2546
2547         if ( $wgTmpDirectory !== false ) {
2548                 return $wgTmpDirectory;
2549         }
2550
2551         $tmpDir = array_map( "getenv", array( 'TMPDIR', 'TMP', 'TEMP' ) );
2552
2553         foreach ( $tmpDir as $tmp ) {
2554                 if ( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2555                         return $tmp;
2556                 }
2557         }
2558         return sys_get_temp_dir();
2559 }
2560
2561 /**
2562  * Make directory, and make all parent directories if they don't exist
2563  *
2564  * @param string $dir full path to directory to create
2565  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2566  * @param string $caller optional caller param for debugging.
2567  * @throws MWException
2568  * @return bool
2569  */
2570 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2571         global $wgDirectoryMode;
2572
2573         if ( FileBackend::isStoragePath( $dir ) ) { // sanity
2574                 throw new MWException( __FUNCTION__ . " given storage path '$dir'." );
2575         }
2576
2577         if ( !is_null( $caller ) ) {
2578                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2579         }
2580
2581         if ( strval( $dir ) === '' || ( file_exists( $dir ) && is_dir( $dir ) ) ) {
2582                 return true;
2583         }
2584
2585         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2586
2587         if ( is_null( $mode ) ) {
2588                 $mode = $wgDirectoryMode;
2589         }
2590
2591         // Turn off the normal warning, we're doing our own below
2592         wfSuppressWarnings();
2593         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2594         wfRestoreWarnings();
2595
2596         if ( !$ok ) {
2597                 //directory may have been created on another request since we last checked
2598                 if ( is_dir( $dir ) ) {
2599                         return true;
2600                 }
2601
2602                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2603                 wfLogWarning( sprintf( "failed to mkdir \"%s\" mode 0%o", $dir, $mode ) );
2604         }
2605         return $ok;
2606 }
2607
2608 /**
2609  * Remove a directory and all its content.
2610  * Does not hide error.
2611  */
2612 function wfRecursiveRemoveDir( $dir ) {
2613         wfDebug( __FUNCTION__ . "( $dir )\n" );
2614         // taken from http://de3.php.net/manual/en/function.rmdir.php#98622
2615         if ( is_dir( $dir ) ) {
2616                 $objects = scandir( $dir );
2617                 foreach ( $objects as $object ) {
2618                         if ( $object != "." && $object != ".." ) {
2619                                 if ( filetype( $dir . '/' . $object ) == "dir" ) {
2620                                         wfRecursiveRemoveDir( $dir . '/' . $object );
2621                                 } else {
2622                                         unlink( $dir . '/' . $object );
2623                                 }
2624                         }
2625                 }
2626                 reset( $objects );
2627                 rmdir( $dir );
2628         }
2629 }
2630
2631 /**
2632  * @param $nr Mixed: the number to format
2633  * @param $acc Integer: the number of digits after the decimal point, default 2
2634  * @param $round Boolean: whether or not to round the value, default true
2635  * @return float
2636  */
2637 function wfPercent( $nr, $acc = 2, $round = true ) {
2638         $ret = sprintf( "%.${acc}f", $nr );
2639         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2640 }
2641
2642 /**
2643  * Safety wrapper around ini_get() for boolean settings.
2644  * The values returned from ini_get() are pre-normalized for settings
2645  * set via php.ini or php_flag/php_admin_flag... but *not*
2646  * for those set via php_value/php_admin_value.
2647  *
2648  * It's fairly common for people to use php_value instead of php_flag,
2649  * which can leave you with an 'off' setting giving a false positive
2650  * for code that just takes the ini_get() return value as a boolean.
2651  *
2652  * To make things extra interesting, setting via php_value accepts
2653  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2654  * Unrecognized values go false... again opposite PHP's own coercion
2655  * from string to bool.
2656  *
2657  * Luckily, 'properly' set settings will always come back as '0' or '1',
2658  * so we only have to worry about them and the 'improper' settings.
2659  *
2660  * I frickin' hate PHP... :P
2661  *
2662  * @param $setting String
2663  * @return Bool
2664  */
2665 function wfIniGetBool( $setting ) {
2666         $val = strtolower( ini_get( $setting ) );
2667         // 'on' and 'true' can't have whitespace around them, but '1' can.
2668         return $val == 'on'
2669                 || $val == 'true'
2670                 || $val == 'yes'
2671                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2672 }
2673
2674 /**
2675  * Windows-compatible version of escapeshellarg()
2676  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2677  * function puts single quotes in regardless of OS.
2678  *
2679  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2680  * earlier distro releases of PHP)
2681  *
2682  * @param varargs
2683  * @return String
2684  */
2685 function wfEscapeShellArg() {
2686         wfInitShellLocale();
2687
2688         $args = func_get_args();
2689         $first = true;
2690         $retVal = '';
2691         foreach ( $args as $arg ) {
2692                 if ( !$first ) {
2693                         $retVal .= ' ';
2694                 } else {
2695                         $first = false;
2696                 }
2697
2698                 if ( wfIsWindows() ) {
2699                         // Escaping for an MSVC-style command line parser and CMD.EXE
2700                         // @codingStandardsIgnoreStart For long URLs
2701                         // Refs:
2702                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2703                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2704                         //  * Bug #13518
2705                         //  * CR r63214
2706                         // Double the backslashes before any double quotes. Escape the double quotes.
2707                         // @codingStandardsIgnoreEnd
2708                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2709                         $arg = '';
2710                         $iteration = 0;
2711                         foreach ( $tokens as $token ) {
2712                                 if ( $iteration % 2 == 1 ) {
2713                                         // Delimiter, a double quote preceded by zero or more slashes
2714                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2715                                 } elseif ( $iteration % 4 == 2 ) {
2716                                         // ^ in $token will be outside quotes, need to be escaped
2717                                         $arg .= str_replace( '^', '^^', $token );
2718                                 } else { // $iteration % 4 == 0
2719                                         // ^ in $token will appear inside double quotes, so leave as is
2720                                         $arg .= $token;
2721                                 }
2722                                 $iteration++;
2723                         }
2724                         // Double the backslashes before the end of the string, because
2725                         // we will soon add a quote
2726                         $m = array();
2727                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2728                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2729                         }
2730
2731                         // Add surrounding quotes
2732                         $retVal .= '"' . $arg . '"';
2733                 } else {
2734                         $retVal .= escapeshellarg( $arg );
2735                 }
2736         }
2737         return $retVal;
2738 }
2739
2740 /**
2741  * Check if wfShellExec() is effectively disabled via php.ini config
2742  * @return bool|string False or one of (safemode,disabled)
2743  * @since 1.22
2744  */
2745 function wfShellExecDisabled() {
2746         static $disabled = null;
2747         if ( is_null( $disabled ) ) {
2748                 $disabled = false;
2749                 if ( wfIniGetBool( 'safe_mode' ) ) {
2750                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2751                         $disabled = 'safemode';
2752                 } else {
2753                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2754                         $functions = array_map( 'trim', $functions );
2755                         $functions = array_map( 'strtolower', $functions );
2756                         if ( in_array( 'proc_open', $functions ) ) {
2757                                 wfDebug( "proc_open is in disabled_functions\n" );
2758                                 $disabled = 'disabled';
2759                         }
2760                 }
2761         }
2762         return $disabled;
2763 }
2764
2765 /**
2766  * Execute a shell command, with time and memory limits mirrored from the PHP
2767  * configuration if supported.
2768  * @param string $cmd Command line, properly escaped for shell.
2769  * @param &$retval null|Mixed optional, will receive the program's exit code.
2770  *                 (non-zero is usually failure). If there is an error from
2771  *                 read, select, or proc_open(), this will be set to -1.
2772  * @param array $environ optional environment variables which should be
2773  *                 added to the executed command environment.
2774  * @param array $limits optional array with limits(filesize, memory, time, walltime)
2775  *                 this overwrites the global wgMaxShell* limits.
2776  * @param array $options Array of options:
2777  *    - duplicateStderr: Set this to true to duplicate stderr to stdout,
2778  *      including errors from limit.sh
2779  *
2780  * @return string collected stdout as a string
2781  */
2782 function wfShellExec( $cmd, &$retval = null, $environ = array(),
2783         $limits = array(), $options = array()
2784 ) {
2785         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime,
2786                 $wgMaxShellWallClockTime, $wgShellCgroup;
2787
2788         $disabled = wfShellExecDisabled();
2789         if ( $disabled ) {
2790                 $retval = 1;
2791                 return $disabled == 'safemode' ?
2792                         'Unable to run external programs in safe mode.' :
2793                         'Unable to run external programs, proc_open() is disabled.';
2794         }
2795
2796         $includeStderr = isset( $options['duplicateStderr'] ) && $options['duplicateStderr'];
2797
2798         wfInitShellLocale();
2799
2800         $envcmd = '';
2801         foreach ( $environ as $k => $v ) {
2802                 if ( wfIsWindows() ) {
2803                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2804                          * appear in the environment variable, so we must use carat escaping as documented in
2805                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2806                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2807                          * are listed there but doesn't appear to need it.
2808                          */
2809                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2810                 } else {
2811                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2812                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2813                          */
2814                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2815                 }
2816         }
2817         $cmd = $envcmd . $cmd;
2818
2819         $useLogPipe = false;
2820         if ( php_uname( 's' ) == 'Linux' ) {
2821                 $time = intval ( isset( $limits['time'] ) ? $limits['time'] : $wgMaxShellTime );
2822                 if ( isset( $limits['walltime'] ) ) {
2823                         $wallTime = intval( $limits['walltime'] );
2824                 } elseif ( isset( $limits['time'] ) ) {
2825                         $wallTime = $time;
2826                 } else {
2827                         $wallTime = intval( $wgMaxShellWallClockTime );
2828                 }
2829                 $mem = intval ( isset( $limits['memory'] ) ? $limits['memory'] : $wgMaxShellMemory );
2830                 $filesize = intval ( isset( $limits['filesize'] ) ? $limits['filesize'] : $wgMaxShellFileSize );
2831
2832                 if ( $time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0 ) {
2833                         $cmd = '/bin/bash ' . escapeshellarg( "$IP/includes/limit.sh" ) . ' ' .
2834                                 escapeshellarg( $cmd ) . ' ' .
2835                                 escapeshellarg(
2836                                         "MW_INCLUDE_STDERR=" . ( $includeStderr ? '1' : '' ) . ';' .
2837                                         "MW_CPU_LIMIT=$time; " .
2838                                         'MW_CGROUP=' . escapeshellarg( $wgShellCgroup ) . '; ' .
2839                                         "MW_MEM_LIMIT=$mem; " .
2840                                         "MW_FILE_SIZE_LIMIT=$filesize; " .
2841                                         "MW_WALL_CLOCK_LIMIT=$wallTime; " .
2842                                         "MW_USE_LOG_PIPE=yes"
2843                                 );
2844                         $useLogPipe = true;
2845                 } elseif ( $includeStderr ) {
2846                         $cmd .= ' 2>&1';
2847                 }
2848         } elseif ( $includeStderr ) {
2849                 $cmd .= ' 2>&1';
2850         }
2851         wfDebug( "wfShellExec: $cmd\n" );
2852
2853         $desc = array(
2854                 0 => array( 'file', 'php://stdin', 'r' ),
2855                 1 => array( 'pipe', 'w' ),
2856                 2 => array( 'file', 'php://stderr', 'w' ) );
2857         if ( $useLogPipe ) {
2858                 $desc[3] = array( 'pipe', 'w' );
2859         }
2860
2861         # TODO/FIXME: This is a bad hack to workaround an HHVM bug that prevents
2862         # proc_open() from opening stdin/stdout, so use /dev/null *for now*
2863         # See bug 56597 / https://github.com/facebook/hhvm/issues/1247 for more info
2864         if ( wfIsHHVM() ) {
2865                 $desc[0] = array( 'file', '/dev/null', 'r' );
2866                 $desc[2] = array( 'file', '/dev/null', 'w' );
2867         }
2868
2869         $pipes = null;
2870         $proc = proc_open( $cmd, $desc, $pipes );
2871         if ( !$proc ) {
2872                 wfDebugLog( 'exec', "proc_open() failed: $cmd" );
2873                 $retval = -1;
2874                 return '';
2875         }
2876         $outBuffer = $logBuffer = '';
2877         $emptyArray = array();
2878         $status = false;
2879         $logMsg = false;
2880
2881         // According to the documentation, it is possible for stream_select()
2882         // to fail due to EINTR. I haven't managed to induce this in testing
2883         // despite sending various signals. If it did happen, the error
2884         // message would take the form:
2885         //
2886         // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
2887         //
2888         // where [4] is the value of the macro EINTR and "Interrupted system
2889         // call" is string which according to the Linux manual is "possibly"
2890         // localised according to LC_MESSAGES.
2891         $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
2892         $eintrMessage = "stream_select(): unable to select [$eintr]";
2893
2894         // Build a table mapping resource IDs to pipe FDs to work around a
2895         // PHP 5.3 issue in which stream_select() does not preserve array keys
2896         // <https://bugs.php.net/bug.php?id=53427>.
2897         $fds = array();
2898         foreach ( $pipes as $fd => $pipe ) {
2899                 $fds[(int)$pipe] = $fd;
2900         }
2901
2902         while ( true ) {
2903                 $status = proc_get_status( $proc );
2904                 if ( !$status['running'] ) {
2905                         break;
2906                 }
2907                 $status = false;
2908
2909                 $readyPipes = $pipes;
2910
2911                 // Clear last error
2912                 @trigger_error( '' );
2913                 if ( @stream_select( $readyPipes, $emptyArray, $emptyArray, null ) === false ) {
2914                         $error = error_get_last();
2915                         if ( strncmp( $error['message'], $eintrMessage, strlen( $eintrMessage ) ) == 0 ) {
2916                                 continue;
2917                         } else {
2918                                 trigger_error( $error['message'], E_USER_WARNING );
2919                                 $logMsg = $error['message'];
2920                                 break;
2921                         }
2922                 }
2923                 foreach ( $readyPipes as $pipe ) {
2924                         $block = fread( $pipe, 65536 );
2925                         $fd = $fds[(int)$pipe];
2926                         if ( $block === '' ) {
2927                                 // End of file
2928                                 fclose( $pipes[$fd] );
2929                                 unset( $pipes[$fd] );
2930                                 if ( !$pipes ) {
2931                                         break 2;
2932                                 }
2933                         } elseif ( $block === false ) {
2934                                 // Read error
2935                                 $logMsg = "Error reading from pipe";
2936                                 break 2;
2937                         } elseif ( $fd == 1 ) {
2938                                 // From stdout
2939                                 $outBuffer .= $block;
2940                         } elseif ( $fd == 3 ) {
2941                                 // From log FD
2942                                 $logBuffer .= $block;
2943                                 if ( strpos( $block, "\n" ) !== false ) {
2944                                         $lines = explode( "\n", $logBuffer );
2945                                         $logBuffer = array_pop( $lines );
2946                                         foreach ( $lines as $line ) {
2947                                                 wfDebugLog( 'exec', $line );
2948                                         }
2949                                 }
2950                         }
2951                 }
2952         }
2953
2954         foreach ( $pipes as $pipe ) {
2955                 fclose( $pipe );
2956         }
2957
2958         // Use the status previously collected if possible, since proc_get_status()
2959         // just calls waitpid() which will not return anything useful the second time.
2960         if ( $status === false ) {
2961                 $status = proc_get_status( $proc );
2962         }
2963
2964         if ( $logMsg !== false ) {
2965                 // Read/select error
2966                 $retval = -1;
2967                 proc_close( $proc );
2968         } elseif ( $status['signaled'] ) {
2969                 $logMsg = "Exited with signal {$status['termsig']}";
2970                 $retval = 128 + $status['termsig'];
2971                 proc_close( $proc );
2972         } else {
2973                 if ( $status['running'] ) {
2974                         $retval = proc_close( $proc );
2975                 } else {
2976                         $retval = $status['exitcode'];
2977                         proc_close( $proc );
2978                 }
2979                 if ( $retval == 127 ) {
2980                         $logMsg = "Possibly missing executable file";
2981                 } elseif ( $retval >= 129 && $retval <= 192 ) {
2982                         $logMsg = "Probably exited with signal " . ( $retval - 128 );
2983                 }
2984         }
2985
2986         if ( $logMsg !== false ) {
2987                 wfDebugLog( 'exec', "$logMsg: $cmd" );
2988         }
2989
2990         return $outBuffer;
2991 }
2992
2993 /**
2994  * Execute a shell command, returning both stdout and stderr. Convenience
2995  * function, as all the arguments to wfShellExec can become unwieldy.
2996  *
2997  * @note This also includes errors from limit.sh, e.g. if $wgMaxShellFileSize is exceeded.
2998  * @param string $cmd Command line, properly escaped for shell.
2999  * @param &$retval null|Mixed optional, will receive the program's exit code.
3000  *                 (non-zero is usually failure)
3001  * @param array $environ optional environment variables which should be
3002  *                 added to the executed command environment.
3003  * @param array $limits optional array with limits(filesize, memory, time, walltime)
3004  *                 this overwrites the global wgShellMax* limits.
3005  * @return string collected stdout and stderr as a string
3006  */
3007 function wfShellExecWithStderr( $cmd, &$retval = null, $environ = array(), $limits = array() ) {
3008         return wfShellExec( $cmd, $retval, $environ, $limits, array( 'duplicateStderr' => true ) );
3009 }
3010
3011 /**
3012  * Workaround for http://bugs.php.net/bug.php?id=45132
3013  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
3014  */
3015 function wfInitShellLocale() {
3016         static $done = false;
3017         if ( $done ) {
3018                 return;
3019         }
3020         $done = true;
3021         global $wgShellLocale;
3022         if ( !wfIniGetBool( 'safe_mode' ) ) {
3023                 putenv( "LC_CTYPE=$wgShellLocale" );
3024                 setlocale( LC_CTYPE, $wgShellLocale );
3025         }
3026 }
3027
3028 /**
3029  * Alias to wfShellWikiCmd()
3030  * @see wfShellWikiCmd()
3031  */
3032 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
3033         return wfShellWikiCmd( $script, $parameters, $options );
3034 }
3035
3036 /**
3037  * Generate a shell-escaped command line string to run a MediaWiki cli script.
3038  * Note that $parameters should be a flat array and an option with an argument
3039  * should consist of two consecutive items in the array (do not use "--option value").
3040  * @param string $script MediaWiki cli script path
3041  * @param array $parameters Arguments and options to the script
3042  * @param array $options Associative array of options:
3043  *              'php': The path to the php executable
3044  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
3045  * @return Array
3046  */
3047 function wfShellWikiCmd( $script, array $parameters = array(), array $options = array() ) {
3048         global $wgPhpCli;
3049         // Give site config file a chance to run the script in a wrapper.
3050         // The caller may likely want to call wfBasename() on $script.
3051         wfRunHooks( 'wfShellWikiCmd', array( &$script, &$parameters, &$options ) );
3052         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
3053         if ( isset( $options['wrapper'] ) ) {
3054                 $cmd[] = $options['wrapper'];
3055         }
3056         $cmd[] = $script;
3057         // Escape each parameter for shell
3058         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
3059 }
3060
3061 /**
3062  * wfMerge attempts to merge differences between three texts.
3063  * Returns true for a clean merge and false for failure or a conflict.
3064  *
3065  * @param $old String
3066  * @param $mine String
3067  * @param $yours String
3068  * @param $result String
3069  * @return Bool
3070  */
3071 function wfMerge( $old, $mine, $yours, &$result ) {
3072         global $wgDiff3;
3073
3074         # This check may also protect against code injection in
3075         # case of broken installations.
3076         wfSuppressWarnings();
3077         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
3078         wfRestoreWarnings();
3079
3080         if ( !$haveDiff3 ) {
3081                 wfDebug( "diff3 not found\n" );
3082                 return false;
3083         }
3084
3085         # Make temporary files
3086         $td = wfTempDir();
3087         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3088         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
3089         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
3090
3091         # NOTE: diff3 issues a warning to stderr if any of the files does not end with
3092         #       a newline character. To avoid this, we normalize the trailing whitespace before
3093         #       creating the diff.
3094
3095         fwrite( $oldtextFile, rtrim( $old ) . "\n" );
3096         fclose( $oldtextFile );
3097         fwrite( $mytextFile, rtrim( $mine ) . "\n" );
3098         fclose( $mytextFile );
3099         fwrite( $yourtextFile, rtrim( $yours ) . "\n" );
3100         fclose( $yourtextFile );
3101
3102         # Check for a conflict
3103         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a --overlap-only ' .
3104                 wfEscapeShellArg( $mytextName ) . ' ' .
3105                 wfEscapeShellArg( $oldtextName ) . ' ' .
3106                 wfEscapeShellArg( $yourtextName );
3107         $handle = popen( $cmd, 'r' );
3108
3109         if ( fgets( $handle, 1024 ) ) {
3110                 $conflict = true;
3111         } else {
3112                 $conflict = false;
3113         }
3114         pclose( $handle );
3115
3116         # Merge differences
3117         $cmd = wfEscapeShellArg( $wgDiff3 ) . ' -a -e --merge ' .
3118                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
3119         $handle = popen( $cmd, 'r' );
3120         $result = '';
3121         do {
3122                 $data = fread( $handle, 8192 );
3123                 if ( strlen( $data ) == 0 ) {
3124                         break;
3125                 }
3126                 $result .= $data;
3127         } while ( true );
3128         pclose( $handle );
3129         unlink( $mytextName );
3130         unlink( $oldtextName );
3131         unlink( $yourtextName );
3132
3133         if ( $result === '' && $old !== '' && !$conflict ) {
3134                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
3135                 $conflict = true;
3136         }
3137         return !$conflict;
3138 }
3139
3140 /**
3141  * Returns unified plain-text diff of two texts.
3142  * Useful for machine processing of diffs.
3143  *
3144  * @param string $before the text before the changes.
3145  * @param string $after the text after the changes.
3146  * @param string $params command-line options for the diff command.
3147  * @return String: unified diff of $before and $after
3148  */
3149 function wfDiff( $before, $after, $params = '-u' ) {
3150         if ( $before == $after ) {
3151                 return '';
3152         }
3153
3154         global $wgDiff;
3155         wfSuppressWarnings();
3156         $haveDiff = $wgDiff && file_exists( $wgDiff );
3157         wfRestoreWarnings();
3158
3159         # This check may also protect against code injection in
3160         # case of broken installations.
3161         if ( !$haveDiff ) {
3162                 wfDebug( "diff executable not found\n" );
3163                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
3164                 $format = new UnifiedDiffFormatter();
3165                 return $format->format( $diffs );
3166         }
3167
3168         # Make temporary files
3169         $td = wfTempDir();
3170         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
3171         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
3172
3173         fwrite( $oldtextFile, $before );
3174         fclose( $oldtextFile );
3175         fwrite( $newtextFile, $after );
3176         fclose( $newtextFile );
3177
3178         // Get the diff of the two files
3179         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
3180
3181         $h = popen( $cmd, 'r' );
3182
3183         $diff = '';
3184
3185         do {
3186                 $data = fread( $h, 8192 );
3187                 if ( strlen( $data ) == 0 ) {
3188                         break;
3189                 }
3190                 $diff .= $data;
3191         } while ( true );
3192
3193         // Clean up
3194         pclose( $h );
3195         unlink( $oldtextName );
3196         unlink( $newtextName );
3197
3198         // Kill the --- and +++ lines. They're not useful.
3199         $diff_lines = explode( "\n", $diff );
3200         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
3201                 unset( $diff_lines[0] );
3202         }
3203         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
3204                 unset( $diff_lines[1] );
3205         }
3206
3207         $diff = implode( "\n", $diff_lines );
3208
3209         return $diff;
3210 }
3211
3212 /**
3213  * This function works like "use VERSION" in Perl, the program will die with a
3214  * backtrace if the current version of PHP is less than the version provided
3215  *
3216  * This is useful for extensions which due to their nature are not kept in sync
3217  * with releases, and might depend on other versions of PHP than the main code
3218  *
3219  * Note: PHP might die due to parsing errors in some cases before it ever
3220  *       manages to call this function, such is life
3221  *
3222  * @see perldoc -f use
3223  *
3224  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3225  *                 a float
3226  * @throws MWException
3227  */
3228 function wfUsePHP( $req_ver ) {
3229         $php_ver = PHP_VERSION;
3230
3231         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
3232                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
3233         }
3234 }
3235
3236 /**
3237  * This function works like "use VERSION" in Perl except it checks the version
3238  * of MediaWiki, the program will die with a backtrace if the current version
3239  * of MediaWiki is less than the version provided.
3240  *
3241  * This is useful for extensions which due to their nature are not kept in sync
3242  * with releases
3243  *
3244  * Note: Due to the behavior of PHP's version_compare() which is used in this
3245  * function, if you want to allow the 'wmf' development versions add a 'c' (or
3246  * any single letter other than 'a', 'b' or 'p') as a post-fix to your
3247  * targeted version number. For example if you wanted to allow any variation
3248  * of 1.22 use `wfUseMW( '1.22c' )`. Using an 'a' or 'b' instead of 'c' will
3249  * not result in the same comparison due to the internal logic of
3250  * version_compare().
3251  *
3252  * @see perldoc -f use
3253  *
3254  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
3255  *                 a float
3256  * @throws MWException
3257  */
3258 function wfUseMW( $req_ver ) {
3259         global $wgVersion;
3260
3261         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
3262                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
3263         }
3264 }
3265
3266 /**
3267  * Return the final portion of a pathname.
3268  * Reimplemented because PHP5's "basename()" is buggy with multibyte text.
3269  * http://bugs.php.net/bug.php?id=33898
3270  *
3271  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
3272  * We'll consider it so always, as we don't want '\s' in our Unix paths either.
3273  *
3274  * @param $path String
3275  * @param string $suffix to remove if present
3276  * @return String
3277  */
3278 function wfBaseName( $path, $suffix = '' ) {
3279         if ( $suffix == '' ) {
3280                 $encSuffix = '';
3281         } else {
3282                 $encSuffix = '(?:' . preg_quote( $suffix, '#' ) . ')?';
3283         }
3284
3285         $matches = array();
3286         if ( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
3287                 return $matches[1];
3288         } else {
3289                 return '';
3290         }
3291 }
3292
3293 /**
3294  * Generate a relative path name to the given file.
3295  * May explode on non-matching case-insensitive paths,
3296  * funky symlinks, etc.
3297  *
3298  * @param string $path absolute destination path including target filename
3299  * @param string $from Absolute source path, directory only
3300  * @return String
3301  */
3302 function wfRelativePath( $path, $from ) {
3303         // Normalize mixed input on Windows...
3304         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
3305         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
3306
3307         // Trim trailing slashes -- fix for drive root
3308         $path = rtrim( $path, DIRECTORY_SEPARATOR );
3309         $from = rtrim( $from, DIRECTORY_SEPARATOR );
3310
3311         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
3312         $against = explode( DIRECTORY_SEPARATOR, $from );
3313
3314         if ( $pieces[0] !== $against[0] ) {
3315                 // Non-matching Windows drive letters?
3316                 // Return a full path.
3317                 return $path;
3318         }
3319
3320         // Trim off common prefix
3321         while ( count( $pieces ) && count( $against )
3322                 && $pieces[0] == $against[0] ) {
3323                 array_shift( $pieces );
3324                 array_shift( $against );
3325         }
3326
3327         // relative dots to bump us to the parent
3328         while ( count( $against ) ) {
3329                 array_unshift( $pieces, '..' );
3330                 array_shift( $against );
3331         }
3332
3333         array_push( $pieces, wfBaseName( $path ) );
3334
3335         return implode( DIRECTORY_SEPARATOR, $pieces );
3336 }
3337
3338 /**
3339  * Convert an arbitrarily-long digit string from one numeric base
3340  * to another, optionally zero-padding to a minimum column width.
3341  *
3342  * Supports base 2 through 36; digit values 10-36 are represented
3343  * as lowercase letters a-z. Input is case-insensitive.
3344  *
3345  * @param string $input Input number
3346  * @param int $sourceBase Base of the input number
3347  * @param int $destBase Desired base of the output
3348  * @param int $pad Minimum number of digits in the output (pad with zeroes)
3349  * @param bool $lowercase Whether to output in lowercase or uppercase
3350  * @param string $engine Either "gmp", "bcmath", or "php"
3351  * @return string|bool The output number as a string, or false on error
3352  */
3353 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1,
3354         $lowercase = true, $engine = 'auto'
3355 ) {
3356         $input = (string)$input;
3357         if (
3358                 $sourceBase < 2 ||
3359                 $sourceBase > 36 ||
3360                 $destBase < 2 ||
3361                 $destBase > 36 ||
3362                 $sourceBase != (int)$sourceBase ||
3363                 $destBase != (int)$destBase ||
3364                 $pad != (int)$pad ||
3365                 !preg_match(
3366                         "/^[" . substr( '0123456789abcdefghijklmnopqrstuvwxyz', 0, $sourceBase ) . "]+$/i",
3367                         $input
3368                 )
3369         ) {
3370                 return false;
3371         }
3372
3373         static $baseChars = array(
3374                 10 => 'a', 11 => 'b', 12 => 'c', 13 => 'd', 14 => 'e', 15 => 'f',
3375                 16 => 'g', 17 => 'h', 18 => 'i', 19 => 'j', 20 => 'k', 21 => 'l',
3376                 22 => 'm', 23 => 'n', 24 => 'o', 25 => 'p', 26 => 'q', 27 => 'r',
3377                 28 => 's', 29 => 't', 30 => 'u', 31 => 'v', 32 => 'w', 33 => 'x',
3378                 34 => 'y', 35 => 'z',
3379
3380                 '0' => 0, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5,
3381                 '6' => 6, '7' => 7, '8' => 8, '9' => 9, 'a' => 10, 'b' => 11,
3382                 'c' => 12, 'd' => 13, 'e' => 14, 'f' => 15, 'g' => 16, 'h' => 17,
3383                 'i' => 18, 'j' => 19, 'k' => 20, 'l' => 21, 'm' => 22, 'n' => 23,
3384                 'o' => 24, 'p' => 25, 'q' => 26, 'r' => 27, 's' => 28, 't' => 29,
3385                 'u' => 30, 'v' => 31, 'w' => 32, 'x' => 33, 'y' => 34, 'z' => 35
3386         );
3387
3388         if ( extension_loaded( 'gmp' ) && ( $engine == 'auto' || $engine == 'gmp' ) ) {
3389                 $result = gmp_strval( gmp_init( $input, $sourceBase ), $destBase );
3390         } elseif ( extension_loaded( 'bcmath' ) && ( $engine == 'auto' || $engine == 'bcmath' ) ) {
3391                 $decimal = '0';
3392                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3393                         $decimal = bcmul( $decimal, $sourceBase );
3394                         $decimal = bcadd( $decimal, $baseChars[$char] );
3395                 }
3396
3397                 for ( $result = ''; bccomp( $decimal, 0 ); $decimal = bcdiv( $decimal, $destBase, 0 ) ) {
3398                         $result .= $baseChars[bcmod( $decimal, $destBase )];
3399                 }
3400
3401                 $result = strrev( $result );
3402         } else {
3403                 $inDigits = array();
3404                 foreach ( str_split( strtolower( $input ) ) as $char ) {
3405                         $inDigits[] = $baseChars[$char];
3406                 }
3407
3408                 // Iterate over the input, modulo-ing out an output digit
3409                 // at a time until input is gone.
3410                 $result = '';
3411                 while ( $inDigits ) {
3412                         $work = 0;
3413                         $workDigits = array();
3414
3415                         // Long division...
3416                         foreach ( $inDigits as $digit ) {
3417                                 $work *= $sourceBase;
3418                                 $work += $digit;
3419
3420                                 if ( $workDigits || $work >= $destBase ) {
3421                                         $workDigits[] = (int)( $work / $destBase );
3422                                 }
3423                                 $work %= $destBase;
3424                         }
3425
3426                         // All that division leaves us with a remainder,
3427                         // which is conveniently our next output digit.
3428                         $result .= $baseChars[$work];
3429
3430                         // And we continue!
3431                         $inDigits = $workDigits;
3432                 }
3433
3434                 $result = strrev( $result );
3435         }
3436
3437         if ( !$lowercase ) {
3438                 $result = strtoupper( $result );
3439         }
3440
3441         return str_pad( $result, $pad, '0', STR_PAD_LEFT );
3442 }
3443
3444 /**
3445  * Check if there is sufficient entropy in php's built-in session generation
3446  * @return bool true = there is sufficient entropy
3447  */
3448 function wfCheckEntropy() {
3449         return (
3450                         ( wfIsWindows() && version_compare( PHP_VERSION, '5.3.3', '>=' ) )
3451                         || ini_get( 'session.entropy_file' )
3452                 )
3453                 && intval( ini_get( 'session.entropy_length' ) ) >= 32;
3454 }
3455
3456 /**
3457  * Override session_id before session startup if php's built-in
3458  * session generation code is not secure.
3459  */
3460 function wfFixSessionID() {
3461         // If the cookie or session id is already set we already have a session and should abort
3462         if ( isset( $_COOKIE[session_name()] ) || session_id() ) {
3463                 return;
3464         }
3465
3466         // PHP's built-in session entropy is enabled if:
3467         // - entropy_file is set or you're on Windows with php 5.3.3+
3468         // - AND entropy_length is > 0
3469         // We treat it as disabled if it doesn't have an entropy length of at least 32
3470         $entropyEnabled = wfCheckEntropy();
3471
3472         // If built-in entropy is not enabled or not sufficient override PHP's
3473         // built in session id generation code
3474         if ( !$entropyEnabled ) {
3475                 wfDebug( __METHOD__ . ": PHP's built in entropy is disabled or not sufficient, " .
3476                         "overriding session id generation using our cryptrand source.\n" );
3477                 session_id( MWCryptRand::generateHex( 32 ) );
3478         }
3479 }
3480
3481 /**
3482  * Reset the session_id
3483  * @since 1.22
3484  */
3485 function wfResetSessionID() {
3486         global $wgCookieSecure;
3487         $oldSessionId = session_id();
3488         $cookieParams = session_get_cookie_params();
3489         if ( wfCheckEntropy() && $wgCookieSecure == $cookieParams['secure'] ) {
3490                 session_regenerate_id( false );
3491         } else {
3492                 $tmp = $_SESSION;
3493                 session_destroy();
3494                 wfSetupSession( MWCryptRand::generateHex( 32 ) );
3495                 $_SESSION = $tmp;
3496         }
3497         $newSessionId = session_id();
3498         wfRunHooks( 'ResetSessionID', array( $oldSessionId, $newSessionId ) );
3499 }
3500
3501 /**
3502  * Initialise php session
3503  *
3504  * @param $sessionId Bool
3505  */
3506 function wfSetupSession( $sessionId = false ) {
3507         global $wgSessionsInMemcached, $wgSessionsInObjectCache, $wgCookiePath, $wgCookieDomain,
3508                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3509         if ( $wgSessionsInObjectCache || $wgSessionsInMemcached ) {
3510                 ObjectCacheSessionHandler::install();
3511         } elseif ( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3512                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3513                 # hasn't already been set to the desired value (that causes errors)
3514                 ini_set( 'session.save_handler', $wgSessionHandler );
3515         }
3516         wfDebugLog( 'cookie',
3517                 'session_set_cookie_params: "' . implode( '", "',
3518                         array(
3519                                 0,
3520                                 $wgCookiePath,
3521                                 $wgCookieDomain,
3522                                 $wgCookieSecure,
3523                                 $wgCookieHttpOnly ) ) . '"' );
3524         session_set_cookie_params(
3525                 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $wgCookieHttpOnly );
3526         session_cache_limiter( 'private, must-revalidate' );
3527         if ( $sessionId ) {
3528                 session_id( $sessionId );
3529         } else {
3530                 wfFixSessionID();
3531         }
3532         wfSuppressWarnings();
3533         session_start();
3534         wfRestoreWarnings();
3535 }
3536
3537 /**
3538  * Get an object from the precompiled serialized directory
3539  *
3540  * @param $name String
3541  * @return Mixed: the variable on success, false on failure
3542  */
3543 function wfGetPrecompiledData( $name ) {
3544         global $IP;
3545
3546         $file = "$IP/serialized/$name";
3547         if ( file_exists( $file ) ) {
3548                 $blob = file_get_contents( $file );
3549                 if ( $blob ) {
3550                         return unserialize( $blob );
3551                 }
3552         }
3553         return false;
3554 }
3555
3556 /**
3557  * Get a cache key
3558  *
3559  * @param varargs
3560  * @return String
3561  */
3562 function wfMemcKey( /*... */ ) {
3563         global $wgCachePrefix;
3564         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3565         $args = func_get_args();
3566         $key = $prefix . ':' . implode( ':', $args );
3567         $key = str_replace( ' ', '_', $key );
3568         return $key;
3569 }
3570
3571 /**
3572  * Get a cache key for a foreign DB
3573  *
3574  * @param $db String
3575  * @param $prefix String
3576  * @param varargs String
3577  * @return String
3578  */
3579 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3580         $args = array_slice( func_get_args(), 2 );
3581         if ( $prefix ) {
3582                 $key = "$db-$prefix:" . implode( ':', $args );
3583         } else {
3584                 $key = $db . ':' . implode( ':', $args );
3585         }
3586         return str_replace( ' ', '_', $key );
3587 }
3588
3589 /**
3590  * Get an ASCII string identifying this wiki
3591  * This is used as a prefix in memcached keys
3592  *
3593  * @return String
3594  */
3595 function wfWikiID() {
3596         global $wgDBprefix, $wgDBname;
3597         if ( $wgDBprefix ) {
3598                 return "$wgDBname-$wgDBprefix";
3599         } else {
3600                 return $wgDBname;
3601         }
3602 }
3603
3604 /**
3605  * Split a wiki ID into DB name and table prefix
3606  *
3607  * @param $wiki String
3608  *
3609  * @return array
3610  */
3611 function wfSplitWikiID( $wiki ) {
3612         $bits = explode( '-', $wiki, 2 );
3613         if ( count( $bits ) < 2 ) {
3614                 $bits[] = '';
3615         }
3616         return $bits;
3617 }
3618
3619 /**
3620  * Get a Database object.
3621  *
3622  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3623  *            master (for write queries), DB_SLAVE for potentially lagged read
3624  *            queries, or an integer >= 0 for a particular server.
3625  *
3626  * @param $groups Mixed: query groups. An array of group names that this query
3627  *                belongs to. May contain a single string if the query is only
3628  *                in one group.
3629  *
3630  * @param string $wiki the wiki ID, or false for the current wiki
3631  *
3632  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3633  * will always return the same object, unless the underlying connection or load
3634  * balancer is manually destroyed.
3635  *
3636  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3637  * updater to ensure that a proper database is being updated.
3638  *
3639  * @return DatabaseBase
3640  */
3641 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3642         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3643 }
3644
3645 /**
3646  * Get a load balancer object.
3647  *
3648  * @param string $wiki wiki ID, or false for the current wiki
3649  * @return LoadBalancer
3650  */
3651 function wfGetLB( $wiki = false ) {
3652         return wfGetLBFactory()->getMainLB( $wiki );
3653 }
3654
3655 /**
3656  * Get the load balancer factory object
3657  *
3658  * @return LBFactory
3659  */
3660 function &wfGetLBFactory() {
3661         return LBFactory::singleton();
3662 }
3663
3664 /**
3665  * Find a file.
3666  * Shortcut for RepoGroup::singleton()->findFile()
3667  *
3668  * @param string $title or Title object
3669  * @param array $options Associative array of options:
3670  *     time:           requested time for an archived image, or false for the
3671  *                     current version. An image object will be returned which was
3672  *                     created at the specified time.
3673  *
3674  *     ignoreRedirect: If true, do not follow file redirects
3675  *
3676  *     private:        If true, return restricted (deleted) files if the current
3677  *                     user is allowed to view them. Otherwise, such files will not
3678  *                     be found.
3679  *
3680  *     bypassCache:    If true, do not use the process-local cache of File objects
3681  *
3682  * @return File, or false if the file does not exist
3683  */
3684 function wfFindFile( $title, $options = array() ) {
3685         return RepoGroup::singleton()->findFile( $title, $options );
3686 }
3687
3688 /**
3689  * Get an object referring to a locally registered file.
3690  * Returns a valid placeholder object if the file does not exist.
3691  *
3692  * @param $title Title|String
3693  * @return LocalFile|null A File, or null if passed an invalid Title
3694  */
3695 function wfLocalFile( $title ) {
3696         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3697 }
3698
3699 /**
3700  * Should low-performance queries be disabled?
3701  *
3702  * @return Boolean
3703  * @codeCoverageIgnore
3704  */
3705 function wfQueriesMustScale() {
3706         global $wgMiserMode;
3707         return $wgMiserMode
3708                 || ( SiteStats::pages() > 100000
3709                 && SiteStats::edits() > 1000000
3710                 && SiteStats::users() > 10000 );
3711 }
3712
3713 /**
3714  * Get the path to a specified script file, respecting file
3715  * extensions; this is a wrapper around $wgScriptExtension etc.
3716  * except for 'index' and 'load' which use $wgScript/$wgLoadScript
3717  *
3718  * @param string $script script filename, sans extension
3719  * @return String
3720  */
3721 function wfScript( $script = 'index' ) {
3722         global $wgScriptPath, $wgScriptExtension, $wgScript, $wgLoadScript;
3723         if ( $script === 'index' ) {
3724                 return $wgScript;
3725         } elseif ( $script === 'load' ) {
3726                 return $wgLoadScript;
3727         } else {
3728                 return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3729         }
3730 }
3731
3732 /**
3733  * Get the script URL.
3734  *
3735  * @return string script URL
3736  */
3737 function wfGetScriptUrl() {
3738         if ( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3739                 #
3740                 # as it was called, minus the query string.
3741                 #
3742                 # Some sites use Apache rewrite rules to handle subdomains,
3743                 # and have PHP set up in a weird way that causes PHP_SELF
3744                 # to contain the rewritten URL instead of the one that the
3745                 # outside world sees.
3746                 #
3747                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3748                 # provides containing the "before" URL.
3749                 return $_SERVER['SCRIPT_NAME'];
3750         } else {
3751                 return $_SERVER['URL'];
3752         }
3753 }
3754
3755 /**
3756  * Convenience function converts boolean values into "true"
3757  * or "false" (string) values
3758  *
3759  * @param $value Boolean
3760  * @return String
3761  */
3762 function wfBoolToStr( $value ) {
3763         return $value ? 'true' : 'false';
3764 }
3765
3766 /**
3767  * Get a platform-independent path to the null file, e.g. /dev/null
3768  *
3769  * @return string
3770  */
3771 function wfGetNull() {
3772         return wfIsWindows() ? 'NUL' : '/dev/null';
3773 }
3774
3775 /**
3776  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3777  * and waiting for it to go down, this waits for the slaves to catch up to the
3778  * master position. Use this when updating very large numbers of rows, as
3779  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3780  * a no-op if there are no slaves.
3781  *
3782  * @param int|bool $maxLag (deprecated)
3783  * @param mixed $wiki Wiki identifier accepted by wfGetLB
3784  * @param string|bool $cluster Cluster name accepted by LBFactory. Default: false.
3785  */
3786 function wfWaitForSlaves( $maxLag = false, $wiki = false, $cluster = false ) {
3787         if ( $cluster !== false ) {
3788                 $lb = wfGetLBFactory()->getExternalLB( $cluster );
3789         } else {
3790                 $lb = wfGetLB( $wiki );
3791         }
3792
3793         // bug 27975 - Don't try to wait for slaves if there are none
3794         // Prevents permission error when getting master position
3795         if ( $lb->getServerCount() > 1 ) {
3796                 $dbw = $lb->getConnection( DB_MASTER, array(), $wiki );
3797                 $pos = $dbw->getMasterPos();
3798                 // The DBMS may not support getMasterPos() or the whole
3799                 // load balancer might be fake (e.g. $wgAllDBsAreLocalhost).
3800                 if ( $pos !== false ) {
3801                         $lb->waitForAll( $pos );
3802                 }
3803         }
3804 }
3805
3806 /**
3807  * Count down from $n to zero on the terminal, with a one-second pause
3808  * between showing each number. For use in command-line scripts.
3809  * @codeCoverageIgnore
3810  * @param $n int
3811  */
3812 function wfCountDown( $n ) {
3813         for ( $i = $n; $i >= 0; $i-- ) {
3814                 if ( $i != $n ) {
3815                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3816                 }
3817                 echo $i;
3818                 flush();
3819                 if ( $i ) {
3820                         sleep( 1 );
3821                 }
3822         }
3823         echo "\n";
3824 }
3825
3826 /**
3827  * Replace all invalid characters with -
3828  * Additional characters can be defined in $wgIllegalFileChars (see bug 20489)
3829  * By default, $wgIllegalFileChars = ':'
3830  *
3831  * @param $name Mixed: filename to process
3832  * @return String
3833  */
3834 function wfStripIllegalFilenameChars( $name ) {
3835         global $wgIllegalFileChars;
3836         $illegalFileChars = $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '';
3837         $name = wfBaseName( $name );
3838         $name = preg_replace(
3839                 "/[^" . Title::legalChars() . "]" . $illegalFileChars . "/",
3840                 '-',
3841                 $name
3842         );
3843         return $name;
3844 }
3845
3846 /**
3847  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3848  *
3849  * @return Integer value memory was set to.
3850  */
3851 function wfMemoryLimit() {
3852         global $wgMemoryLimit;
3853         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3854         if ( $memlimit != -1 ) {
3855                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3856                 if ( $conflimit == -1 ) {
3857                         wfDebug( "Removing PHP's memory limit\n" );
3858                         wfSuppressWarnings();
3859                         ini_set( 'memory_limit', $conflimit );
3860                         wfRestoreWarnings();
3861                         return $conflimit;
3862                 } elseif ( $conflimit > $memlimit ) {
3863                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3864                         wfSuppressWarnings();
3865                         ini_set( 'memory_limit', $conflimit );
3866                         wfRestoreWarnings();
3867                         return $conflimit;
3868                 }
3869         }
3870         return $memlimit;
3871 }
3872
3873 /**
3874  * Converts shorthand byte notation to integer form
3875  *
3876  * @param $string String
3877  * @return Integer
3878  */
3879 function wfShorthandToInteger( $string = '' ) {
3880         $string = trim( $string );
3881         if ( $string === '' ) {
3882                 return -1;
3883         }
3884         $last = $string[strlen( $string ) - 1];
3885         $val = intval( $string );
3886         switch ( $last ) {
3887                 case 'g':
3888                 case 'G':
3889                         $val *= 1024;
3890                         // break intentionally missing
3891                 case 'm':
3892                 case 'M':
3893                         $val *= 1024;
3894                         // break intentionally missing
3895                 case 'k':
3896                 case 'K':
3897                         $val *= 1024;
3898         }
3899
3900         return $val;
3901 }
3902
3903 /**
3904  * Get the normalised IETF language tag
3905  * See unit test for examples.
3906  *
3907  * @param string $code The language code.
3908  * @return String: The language code which complying with BCP 47 standards.
3909  */
3910 function wfBCP47( $code ) {
3911         $codeSegment = explode( '-', $code );
3912         $codeBCP = array();
3913         foreach ( $codeSegment as $segNo => $seg ) {
3914                 // when previous segment is x, it is a private segment and should be lc
3915                 if ( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3916                         $codeBCP[$segNo] = strtolower( $seg );
3917                 // ISO 3166 country code
3918                 } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3919                         $codeBCP[$segNo] = strtoupper( $seg );
3920                 // ISO 15924 script code
3921                 } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3922                         $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3923                 // Use lowercase for other cases
3924                 } else {
3925                         $codeBCP[$segNo] = strtolower( $seg );
3926                 }
3927         }
3928         $langCode = implode( '-', $codeBCP );
3929         return $langCode;
3930 }
3931
3932 /**
3933  * Get a cache object.
3934  *
3935  * @param $inputType integer Cache type, one the the CACHE_* constants.
3936  * @return BagOStuff
3937  */
3938 function wfGetCache( $inputType ) {
3939         return ObjectCache::getInstance( $inputType );
3940 }
3941
3942 /**
3943  * Get the main cache object
3944  *
3945  * @return BagOStuff
3946  */
3947 function wfGetMainCache() {
3948         global $wgMainCacheType;
3949         return ObjectCache::getInstance( $wgMainCacheType );
3950 }
3951
3952 /**
3953  * Get the cache object used by the message cache
3954  *
3955  * @return BagOStuff
3956  */
3957 function wfGetMessageCacheStorage() {
3958         global $wgMessageCacheType;
3959         return ObjectCache::getInstance( $wgMessageCacheType );
3960 }
3961
3962 /**
3963  * Get the cache object used by the parser cache
3964  *
3965  * @return BagOStuff
3966  */
3967 function wfGetParserCacheStorage() {
3968         global $wgParserCacheType;
3969         return ObjectCache::getInstance( $wgParserCacheType );
3970 }
3971
3972 /**
3973  * Get the cache object used by the language converter
3974  *
3975  * @return BagOStuff
3976  */
3977 function wfGetLangConverterCacheStorage() {
3978         global $wgLanguageConverterCacheType;
3979         return ObjectCache::getInstance( $wgLanguageConverterCacheType );
3980 }
3981
3982 /**
3983  * Call hook functions defined in $wgHooks
3984  *
3985  * @param string $event event name
3986  * @param array $args parameters passed to hook functions
3987  * @param string|null $deprecatedVersion optionally mark hook as deprecated with version number
3988  *
3989  * @return Boolean True if no handler aborted the hook
3990  */
3991 function wfRunHooks( $event, array $args = array(), $deprecatedVersion = null ) {
3992         return Hooks::run( $event, $args, $deprecatedVersion );
3993 }
3994
3995 /**
3996  * Wrapper around php's unpack.
3997  *
3998  * @param string $format The format string (See php's docs)
3999  * @param $data: A binary string of binary data
4000  * @param $length integer or false: The minimum length of $data. This is to
4001  *      prevent reading beyond the end of $data. false to disable the check.
4002  *
4003  * Also be careful when using this function to read unsigned 32 bit integer
4004  * because php might make it negative.
4005  *
4006  * @throws MWException if $data not long enough, or if unpack fails
4007  * @return array Associative array of the extracted data
4008  */
4009 function wfUnpack( $format, $data, $length = false ) {
4010         if ( $length !== false ) {
4011                 $realLen = strlen( $data );
4012                 if ( $realLen < $length ) {
4013                         throw new MWException( "Tried to use wfUnpack on a "
4014                                 . "string of length $realLen, but needed one "
4015                                 . "of at least length $length."
4016                         );
4017                 }
4018         }
4019
4020         wfSuppressWarnings();
4021         $result = unpack( $format, $data );
4022         wfRestoreWarnings();
4023
4024         if ( $result === false ) {
4025                 // If it cannot extract the packed data.
4026                 throw new MWException( "unpack could not unpack binary data" );
4027         }
4028         return $result;
4029 }
4030
4031 /**
4032  * Determine if an image exists on the 'bad image list'.
4033  *
4034  * The format of MediaWiki:Bad_image_list is as follows:
4035  *    * Only list items (lines starting with "*") are considered
4036  *    * The first link on a line must be a link to a bad image
4037  *    * Any subsequent links on the same line are considered to be exceptions,
4038  *      i.e. articles where the image may occur inline.
4039  *
4040  * @param string $name the image name to check
4041  * @param $contextTitle Title|bool the page on which the image occurs, if known
4042  * @param string $blacklist wikitext of a file blacklist
4043  * @return bool
4044  */
4045 function wfIsBadImage( $name, $contextTitle = false, $blacklist = null ) {
4046         static $badImageCache = null; // based on bad_image_list msg
4047         wfProfileIn( __METHOD__ );
4048
4049         # Handle redirects
4050         $redirectTitle = RepoGroup::singleton()->checkRedirect( Title::makeTitle( NS_FILE, $name ) );
4051         if ( $redirectTitle ) {
4052                 $name = $redirectTitle->getDBkey();
4053         }
4054
4055         # Run the extension hook
4056         $bad = false;
4057         if ( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
4058                 wfProfileOut( __METHOD__ );
4059                 return $bad;
4060         }
4061
4062         $cacheable = ( $blacklist === null );
4063         if ( $cacheable && $badImageCache !== null ) {
4064                 $badImages = $badImageCache;
4065         } else { // cache miss
4066                 if ( $blacklist === null ) {
4067                         $blacklist = wfMessage( 'bad_image_list' )->inContentLanguage()->plain(); // site list
4068                 }
4069                 # Build the list now
4070                 $badImages = array();
4071                 $lines = explode( "\n", $blacklist );
4072                 foreach ( $lines as $line ) {
4073                         # List items only
4074                         if ( substr( $line, 0, 1 ) !== '*' ) {
4075                                 continue;
4076                         }
4077
4078                         # Find all links
4079                         $m = array();
4080                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
4081                                 continue;
4082                         }
4083
4084                         $exceptions = array();
4085                         $imageDBkey = false;
4086                         foreach ( $m[1] as $i => $titleText ) {
4087                                 $title = Title::newFromText( $titleText );
4088                                 if ( !is_null( $title ) ) {
4089                                         if ( $i == 0 ) {
4090                                                 $imageDBkey = $title->getDBkey();
4091                                         } else {
4092                                                 $exceptions[$title->getPrefixedDBkey()] = true;
4093                                         }
4094                                 }
4095                         }
4096
4097                         if ( $imageDBkey !== false ) {
4098                                 $badImages[$imageDBkey] = $exceptions;
4099                         }
4100                 }
4101                 if ( $cacheable ) {
4102                         $badImageCache = $badImages;
4103                 }
4104         }
4105
4106         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
4107         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
4108         wfProfileOut( __METHOD__ );
4109         return $bad;
4110 }
4111
4112 /**
4113  * Determine whether the client at a given source IP is likely to be able to
4114  * access the wiki via HTTPS.
4115  *
4116  * @param string $ip The IPv4/6 address in the normal human-readable form
4117  * @return boolean
4118  */
4119 function wfCanIPUseHTTPS( $ip ) {
4120         $canDo = true;
4121         wfRunHooks( 'CanIPUseHTTPS', array( $ip, &$canDo ) );
4122         return !!$canDo;
4123 }
4124
4125 /**
4126  * Work out the IP address based on various globals
4127  * For trusted proxies, use the XFF client IP (first of the chain)
4128  *
4129  * @deprecated in 1.19; call $wgRequest->getIP() directly.
4130  * @return string
4131  */
4132 function wfGetIP() {
4133         wfDeprecated( __METHOD__, '1.19' );
4134         global $wgRequest;
4135         return $wgRequest->getIP();
4136 }
4137
4138 /**
4139  * Checks if an IP is a trusted proxy provider.
4140  * Useful to tell if X-Forwarded-For data is possibly bogus.
4141  * Squid cache servers for the site are whitelisted.
4142  *
4143  * @param $ip String
4144  * @return bool
4145  */
4146 function wfIsTrustedProxy( $ip ) {
4147         $trusted = wfIsConfiguredProxy( $ip );
4148         wfRunHooks( 'IsTrustedProxy', array( &$ip, &$trusted ) );
4149         return $trusted;
4150 }
4151
4152 /**
4153  * Checks if an IP matches a proxy we've configured.
4154  * @param $ip String
4155  * @return bool
4156  * @since 1.23 Supports CIDR ranges in $wgSquidServersNoPurge
4157  */
4158 function wfIsConfiguredProxy( $ip ) {
4159         global $wgSquidServers, $wgSquidServersNoPurge;
4160
4161         // quick check of known proxy servers
4162         $trusted = in_array( $ip, $wgSquidServers )
4163                 || in_array( $ip, $wgSquidServersNoPurge );
4164
4165         if ( !$trusted ) {
4166                 // slightly slower check to see if the ip is listed directly or in a CIDR
4167                 // block in $wgSquidServersNoPurge
4168                 foreach ( $wgSquidServersNoPurge as $block ) {
4169                         if ( strpos( $block, '/' ) !== false && IP::isInRange( $ip, $block ) ) {
4170                                 $trusted = true;
4171                                 break;
4172                         }
4173                 }
4174         }
4175         return $trusted;
4176 }