includes/GlobalFunctions.php

   1 <?php
   2 /**
   3  * Global functions used everywhere
   4  * @file
   5  */
   6
   7 if ( !defined( 'MEDIAWIKI' ) ) {
   8         die( "This file is part of MediaWiki, it is not a valid entry point" );
   9 }
  10
  11 // Hide compatibility functions from Doxygen
  12 /// @cond
  13
  14 /**
  15  * Compatibility functions
  16  *
  17  * We support PHP 5.2.3 and up.
  18  * Re-implementations of newer functions or functions in non-standard
  19  * PHP extensions may be included here.
  20  */
  21
  22 if( !function_exists( 'iconv' ) ) {
  23         /** @codeCoverageIgnore */
  24         function iconv( $from, $to, $string ) {
  25                 return Fallback::iconv( $from, $to, $string );
  26         }
  27 }
  28
  29 if ( !function_exists( 'mb_substr' ) ) {
  30         /** @codeCoverageIgnore */
  31         function mb_substr( $str, $start, $count='end' ) {
  32                 return Fallback::mb_substr( $str, $start, $count );
  33         }
  34
  35         /** @codeCoverageIgnore */
  36         function mb_substr_split_unicode( $str, $splitPos ) {
  37                 return Fallback::mb_substr_split_unicode( $str, $splitPos );
  38         }
  39 }
  40
  41 if ( !function_exists( 'mb_strlen' ) ) {
  42         /** @codeCoverageIgnore */
  43         function mb_strlen( $str, $enc = '' ) {
  44                 return Fallback::mb_strlen( $str, $enc );
  45         }
  46 }
  47
  48 if( !function_exists( 'mb_strpos' ) ) {
  49         /** @codeCoverageIgnore */
  50         function mb_strpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  51                 return Fallback::mb_strpos( $haystack, $needle, $offset, $encoding );
  52         }
  53
  54 }
  55
  56 if( !function_exists( 'mb_strrpos' ) ) {
  57         /** @codeCoverageIgnore */
  58         function mb_strrpos( $haystack, $needle, $offset = 0, $encoding = '' ) {
  59                 return Fallback::mb_strrpos( $haystack, $needle, $offset, $encoding );
  60         }
  61 }
  62
  63
  64 // Support for Wietse Venema's taint feature
  65 if ( !function_exists( 'istainted' ) ) {
  66         /** @codeCoverageIgnore */
  67         function istainted( $var ) {
  68                 return 0;
  69         }
  70         /** @codeCoverageIgnore */
  71         function taint( $var, $level = 0 ) {}
  72         /** @codeCoverageIgnore */
  73         function untaint( $var, $level = 0 ) {}
  74         define( 'TC_HTML', 1 );
  75         define( 'TC_SHELL', 1 );
  76         define( 'TC_MYSQL', 1 );
  77         define( 'TC_PCRE', 1 );
  78         define( 'TC_SELF', 1 );
  79 }
  80 /// @endcond
  81
  82 /**
  83  * Like array_diff( $a, $b ) except that it works with two-dimensional arrays.
  84  * @param $a array
  85  * @param $b array
  86  * @return array
  87  */
  88 function wfArrayDiff2( $a, $b ) {
  89         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
  90 }
  91
  92 /**
  93  * @param $a
  94  * @param $b
  95  * @return int
  96  */
  97 function wfArrayDiff2_cmp( $a, $b ) {
  98         if ( !is_array( $a ) ) {
  99                 return strcmp( $a, $b );
 100         } elseif ( count( $a ) !== count( $b ) ) {
 101                 return count( $a ) < count( $b ) ? -1 : 1;
 102         } else {
 103                 reset( $a );
 104                 reset( $b );
 105                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 106                         $cmp = strcmp( $valueA, $valueB );
 107                         if ( $cmp !== 0 ) {
 108                                 return $cmp;
 109                         }
 110                 }
 111                 return 0;
 112         }
 113 }
 114
 115 /**
 116  * Array lookup
 117  * Returns an array where the values in the first array are replaced by the
 118  * values in the second array with the corresponding keys
 119  *
 120  * @param $a Array
 121  * @param $b Array
 122  * @return array
 123  */
 124 function wfArrayLookup( $a, $b ) {
 125         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 126 }
 127
 128 /**
 129  * Appends to second array if $value differs from that in $default
 130  *
 131  * @param $key String|Int
 132  * @param $value Mixed
 133  * @param $default Mixed
 134  * @param $changed Array to alter
 135  */
 136 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 137         if ( is_null( $changed ) ) {
 138                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 139         }
 140         if ( $default[$key] !== $value ) {
 141                 $changed[$key] = $value;
 142         }
 143 }
 144
 145 /**
 146  * Backwards array plus for people who haven't bothered to read the PHP manual
 147  * XXX: will not darn your socks for you.
 148  *
 149  * @param $array1 Array
 150  * @param [$array2, [...]] Arrays
 151  * @return Array
 152  */
 153 function wfArrayMerge( $array1/* ... */ ) {
 154         $args = func_get_args();
 155         $args = array_reverse( $args, true );
 156         $out = array();
 157         foreach ( $args as $arg ) {
 158                 $out += $arg;
 159         }
 160         return $out;
 161 }
 162
 163 /**
 164  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 165  * e.g.
 166  *      wfMergeErrorArrays(
 167  *              array( array( 'x' ) ),
 168  *              array( array( 'x', '2' ) ),
 169  *              array( array( 'x' ) ),
 170  *              array( array( 'y' ) )
 171  *      );
 172  * returns:
 173  *              array(
 174  *              array( 'x', '2' ),
 175  *              array( 'x' ),
 176  *              array( 'y' )
 177  *      )
 178  * @param varargs
 179  * @return Array
 180  */
 181 function wfMergeErrorArrays( /*...*/ ) {
 182         $args = func_get_args();
 183         $out = array();
 184         foreach ( $args as $errors ) {
 185                 foreach ( $errors as $params ) {
 186                         # @todo FIXME: Sometimes get nested arrays for $params,
 187                         # which leads to E_NOTICEs
 188                         $spec = implode( "\t", $params );
 189                         $out[$spec] = $params;
 190                 }
 191         }
 192         return array_values( $out );
 193 }
 194
 195 /**
 196  * Insert array into another array after the specified *KEY*
 197  *
 198  * @param $array Array: The array.
 199  * @param $insert Array: The array to insert.
 200  * @param $after Mixed: The key to insert after
 201  * @return Array
 202  */
 203 function wfArrayInsertAfter( $array, $insert, $after ) {
 204         // Find the offset of the element to insert after.
 205         $keys = array_keys( $array );
 206         $offsetByKey = array_flip( $keys );
 207
 208         $offset = $offsetByKey[$after];
 209
 210         // Insert at the specified offset
 211         $before = array_slice( $array, 0, $offset + 1, true );
 212         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 213
 214         $output = $before + $insert + $after;
 215
 216         return $output;
 217 }
 218
 219 /**
 220  * Recursively converts the parameter (an object) to an array with the same data
 221  *
 222  * @param $objOrArray Object|Array
 223  * @param $recursive Bool
 224  * @return Array
 225  */
 226 function wfObjectToArray( $objOrArray, $recursive = true ) {
 227         $array = array();
 228         if( is_object( $objOrArray ) ) {
 229                 $objOrArray = get_object_vars( $objOrArray );
 230         }
 231         foreach ( $objOrArray as $key => $value ) {
 232                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 233                         $value = wfObjectToArray( $value );
 234                 }
 235
 236                 $array[$key] = $value;
 237         }
 238
 239         return $array;
 240 }
 241
 242 /**
 243  * Wrapper around array_map() which also taints variables
 244  *
 245  * @param  $function Callback
 246  * @param  $input Array
 247  * @return Array
 248  */
 249 function wfArrayMap( $function, $input ) {
 250         $ret = array_map( $function, $input );
 251         foreach ( $ret as $key => $value ) {
 252                 $taint = istainted( $input[$key] );
 253                 if ( $taint ) {
 254                         taint( $ret[$key], $taint );
 255                 }
 256         }
 257         return $ret;
 258 }
 259
 260 /**
 261  * Get a random decimal value between 0 and 1, in a way
 262  * not likely to give duplicate values for any realistic
 263  * number of articles.
 264  *
 265  * @return string
 266  */
 267 function wfRandom() {
 268         # The maximum random value is "only" 2^31-1, so get two random
 269         # values to reduce the chance of dupes
 270         $max = mt_getrandmax() + 1;
 271         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 272                 / $max / $max, 12, '.', '' );
 273         return $rand;
 274 }
 275
 276 /**
 277  * We want some things to be included as literal characters in our title URLs
 278  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 279  * all of the following should be safe:
 280  *
 281  * ;:@&=$-_.+!*'(),
 282  *
 283  * But + is not safe because it's used to indicate a space; &= are only safe in
 284  * paths and not in queries (and we don't distinguish here); ' seems kind of
 285  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 286  * is reserved, we don't care.  So the list we unescape is:
 287  *
 288  * ;:@$!*(),/
 289  *
 290  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 291  * so no fancy : for IIS7.
 292  *
 293  * %2F in the page titles seems to fatally break for some reason.
 294  *
 295  * @param $s String:
 296  * @return string
 297 */
 298 function wfUrlencode( $s ) {
 299         static $needle;
 300         if ( is_null( $s ) ) {
 301                 $needle = null;
 302                 return '';
 303         }
 304
 305         if ( is_null( $needle ) ) {
 306                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 307                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 308                         $needle[] = '%3A';
 309                 }
 310         }
 311
 312         $s = urlencode( $s );
 313         $s = str_ireplace(
 314                 $needle,
 315                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 316                 $s
 317         );
 318
 319         return $s;
 320 }
 321
 322 /**
 323  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 324  * "days=7&limit=100". Options in the first array override options in the second.
 325  * Options set to "" will not be output.
 326  *
 327  * @param $array1 Array ( String|Array )
 328  * @param $array2 Array ( String|Array )
 329  * @param $prefix String
 330  * @return String
 331  */
 332 function wfArrayToCGI( $array1, $array2 = null, $prefix = '' ) {
 333         if ( !is_null( $array2 ) ) {
 334                 $array1 = $array1 + $array2;
 335         }
 336
 337         $cgi = '';
 338         foreach ( $array1 as $key => $value ) {
 339                 if ( $value !== '' ) {
 340                         if ( $cgi != '' ) {
 341                                 $cgi .= '&';
 342                         }
 343                         if ( $prefix !== '' ) {
 344                                 $key = $prefix . "[$key]";
 345                         }
 346                         if ( is_array( $value ) ) {
 347                                 $firstTime = true;
 348                                 foreach ( $value as $k => $v ) {
 349                                         $cgi .= $firstTime ? '' : '&';
 350                                         if ( is_array( $v ) ) {
 351                                                 $cgi .= wfArrayToCGI( $v, null, $key . "[$k]" );
 352                                         } else {
 353                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 354                                         }
 355                                         $firstTime = false;
 356                                 }
 357                         } else {
 358                                 if ( is_object( $value ) ) {
 359                                         $value = $value->__toString();
 360                                 }
 361                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 362                         }
 363                 }
 364         }
 365         return $cgi;
 366 }
 367
 368 /**
 369  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
 370  * its argument and returns the same string in array form.  This allows compa-
 371  * tibility with legacy functions that accept raw query strings instead of nice
 372  * arrays.  Of course, keys and values are urldecode()d.  Don't try passing in-
 373  * valid query strings, or it will explode.
 374  *
 375  * @param $query String: query string
 376  * @return array Array version of input
 377  */
 378 function wfCgiToArray( $query ) {
 379         if ( isset( $query[0] ) && $query[0] == '?' ) {
 380                 $query = substr( $query, 1 );
 381         }
 382         $bits = explode( '&', $query );
 383         $ret = array();
 384         foreach ( $bits as $bit ) {
 385                 if ( $bit === '' ) {
 386                         continue;
 387                 }
 388                 list( $key, $value ) = explode( '=', $bit );
 389                 $key = urldecode( $key );
 390                 $value = urldecode( $value );
 391                 if ( strpos( $key, '[' ) !== false ) {
 392                         $keys = array_reverse( explode( '[', $key ) );
 393                         $key = array_pop( $keys );
 394                         $temp = $value;
 395                         foreach ( $keys as $k ) {
 396                                 $k = substr( $k, 0, -1 );
 397                                 $temp = array( $k => $temp );
 398                         }
 399                         if ( isset( $ret[$key] ) ) {
 400                                 $ret[$key] = array_merge( $ret[$key], $temp );
 401                         } else {
 402                                 $ret[$key] = $temp;
 403                         }
 404                 } else {
 405                         $ret[$key] = $value;
 406                 }
 407         }
 408         return $ret;
 409 }
 410
 411 /**
 412  * Append a query string to an existing URL, which may or may not already
 413  * have query string parameters already. If so, they will be combined.
 414  *
 415  * @param $url String
 416  * @param $query Mixed: string or associative array
 417  * @return string
 418  */
 419 function wfAppendQuery( $url, $query ) {
 420         if ( is_array( $query ) ) {
 421                 $query = wfArrayToCGI( $query );
 422         }
 423         if( $query != '' ) {
 424                 if( false === strpos( $url, '?' ) ) {
 425                         $url .= '?';
 426                 } else {
 427                         $url .= '&';
 428                 }
 429                 $url .= $query;
 430         }
 431         return $url;
 432 }
 433
 434 /**
 435  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 436  * is correct.
 437  *
 438  * The meaning of the PROTO_* constants is as follows:
 439  * PROTO_HTTP: Output a URL starting with http://
 440  * PROTO_HTTPS: Output a URL starting with https://
 441  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 442  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 443  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 444  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 445  *
 446  * @todo this won't work with current-path-relative URLs
 447  * like "subdir/foo.html", etc.
 448  *
 449  * @param $url String: either fully-qualified or a local path + query
 450  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the
 451  *                             protocol to use if $url or $wgServer is
 452  *                             protocol-relative
 453  * @return string Fully-qualified URL, current-path-relative URL or false if
 454  *                no valid URL can be constructed
 455  */
 456 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 457         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 458         $serverUrl = $wgServer;
 459         if ( $defaultProto === PROTO_CANONICAL ) {
 460                 $serverUrl = $wgCanonicalServer;
 461         }
 462         // Make $wgInternalServer fall back to $wgServer if not set
 463         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 464                 $serverUrl = $wgInternalServer;
 465         }
 466         if ( $defaultProto === PROTO_CURRENT ) {
 467                 $defaultProto = WebRequest::detectProtocol() . '://';
 468         }
 469
 470         // Analyze $serverUrl to obtain its protocol
 471         $bits = wfParseUrl( $serverUrl );
 472         $serverHasProto = $bits && $bits['scheme'] != '';
 473
 474         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 475                 if ( $serverHasProto ) {
 476                         $defaultProto = $bits['scheme'] . '://';
 477                 } else {
 478                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 479                         // Fall back to HTTP in this ridiculous case
 480                         $defaultProto = PROTO_HTTP;
 481                 }
 482         }
 483
 484         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 485
 486         if ( substr( $url, 0, 2 ) == '//' ) {
 487                 $url = $defaultProtoWithoutSlashes . $url;
 488         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 489                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 490                 $url = ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 491         }
 492
 493         $bits = wfParseUrl( $url );
 494         if ( $bits && isset( $bits['path'] ) ) {
 495                 $bits['path'] = wfRemoveDotSegments( $bits['path'] );
 496                 return wfAssembleUrl( $bits );
 497         } elseif ( $bits ) {
 498                 # No path to expand
 499                 return $url;
 500         } elseif ( substr( $url, 0, 1 ) != '/' ) {
 501                 # URL is a relative path
 502                 return wfRemoveDotSegments( $url );
 503         }
 504
 505         # Expanded URL is not valid.
 506         return false;
 507 }
 508
 509 /**
 510  * This function will reassemble a URL parsed with wfParseURL.  This is useful
 511  * if you need to edit part of a URL and put it back together.
 512  *
 513  * This is the basic structure used (brackets contain keys for $urlParts):
 514  * [scheme][delimiter][user]:[pass]@[host]:[port][path]?[query]#[fragment]
 515  *
 516  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 517  *
 518  * @param $urlParts Array URL parts, as output from wfParseUrl
 519  * @return string URL assembled from its component parts
 520  */
 521 function wfAssembleUrl( $urlParts ) {
 522         $result = '';
 523
 524         if ( isset( $urlParts['delimiter'] ) ) {
 525                 if ( isset( $urlParts['scheme'] ) ) {
 526                         $result .= $urlParts['scheme'];
 527                 }
 528
 529                 $result .= $urlParts['delimiter'];
 530         }
 531
 532         if ( isset( $urlParts['host'] ) ) {
 533                 if ( isset( $urlParts['user'] ) ) {
 534                         $result .= $urlParts['user'];
 535                         if ( isset( $urlParts['pass'] ) ) {
 536                                 $result .= ':' . $urlParts['pass'];
 537                         }
 538                         $result .= '@';
 539                 }
 540
 541                 $result .= $urlParts['host'];
 542
 543                 if ( isset( $urlParts['port'] ) ) {
 544                         $result .= ':' . $urlParts['port'];
 545                 }
 546         }
 547
 548         if ( isset( $urlParts['path'] ) ) {
 549                 $result .= $urlParts['path'];
 550         }
 551
 552         if ( isset( $urlParts['query'] ) ) {
 553                 $result .= '?' . $urlParts['query'];
 554         }
 555
 556         if ( isset( $urlParts['fragment'] ) ) {
 557                 $result .= '#' . $urlParts['fragment'];
 558         }
 559
 560         return $result;
 561 }
 562
 563 /**
 564  * Remove all dot-segments in the provided URL path.  For example,
 565  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 566  * RFC3986 section 5.2.4.
 567  *
 568  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 569  *
 570  * @param $urlPath String URL path, potentially containing dot-segments
 571  * @return string URL path with all dot-segments removed
 572  */
 573 function wfRemoveDotSegments( $urlPath ) {
 574         $output = '';
 575
 576         while ( $urlPath ) {
 577                 $matches = null;
 578                 if ( preg_match('%^\.\.?/%', $urlPath, $matches) ) {
 579                         # Step A, remove leading "../" or "./"
 580                         $urlPath = substr( $urlPath, strlen( $matches[0] ) );
 581                 } elseif ( preg_match( '%^/\.(/|$)%', $urlPath, $matches ) ) {
 582                         # Step B, replace leading "/.$" or "/./" with "/"
 583                         $start = strlen( $matches[0] );
 584                         $urlPath = '/' . substr( $urlPath, $start );
 585                 } elseif ( preg_match( '%^/\.\.(/|$)%', $urlPath, $matches ) ) {
 586                         # Step C, replace leading "/..$" or "/../" with "/" and
 587                         # remove last path component in output
 588                         $start = strlen( $matches[0] );
 589                         $urlPath = '/' . substr( $urlPath, $start );
 590                         $output = preg_replace('%(^|/)[^/]*$%', '', $output);
 591                 } elseif ( preg_match( '%^\.\.?$%', $urlPath, $matches ) ) {
 592                         # Step D, remove "^..$" or "^.$"
 593                         $urlPath = '';
 594                 } else {
 595                         # Step E, move leading path segment to output
 596                         preg_match( '%^/?[^/]*%', $urlPath, $matches );
 597                         $urlPath = substr( $urlPath, strlen( $matches[0] ) );
 598                         $output .= $matches[0];
 599                 }
 600         }
 601
 602         return $output;
 603 }
 604
 605 /**
 606  * Returns a regular expression of url protocols
 607  *
 608  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 609  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 610  * @return String
 611  */
 612 function wfUrlProtocols( $includeProtocolRelative = true ) {
 613         global $wgUrlProtocols;
 614
 615         // Cache return values separately based on $includeProtocolRelative
 616         static $withProtRel = null, $withoutProtRel = null;
 617         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 618         if ( !is_null( $cachedValue ) ) {
 619                 return $cachedValue;
 620         }
 621
 622         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 623         // with LocalSettings files from 1.5
 624         if ( is_array( $wgUrlProtocols ) ) {
 625                 $protocols = array();
 626                 foreach ( $wgUrlProtocols as $protocol ) {
 627                         // Filter out '//' if !$includeProtocolRelative
 628                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 629                                 $protocols[] = preg_quote( $protocol, '/' );
 630                         }
 631                 }
 632
 633                 $retval = implode( '|', $protocols );
 634         } else {
 635                 // Ignore $includeProtocolRelative in this case
 636                 // This case exists for pre-1.6 compatibility, and we can safely assume
 637                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 638                 // URLs weren't supported until 1.18
 639                 $retval = $wgUrlProtocols;
 640         }
 641
 642         // Cache return value
 643         if ( $includeProtocolRelative ) {
 644                 $withProtRel = $retval;
 645         } else {
 646                 $withoutProtRel = $retval;
 647         }
 648         return $retval;
 649 }
 650
 651 /**
 652  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 653  * you need a regex that matches all URL protocols but does not match protocol-
 654  * relative URLs
 655  * @return String
 656  */
 657 function wfUrlProtocolsWithoutProtRel() {
 658         return wfUrlProtocols( false );
 659 }
 660
 661 /**
 662  * parse_url() work-alike, but non-broken.  Differences:
 663  *
 664  * 1) Does not raise warnings on bad URLs (just returns false)
 665  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 666  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 667  *
 668  * @param $url String: a URL to parse
 669  * @return Array: bits of the URL in an associative array, per PHP docs
 670  */
 671 function wfParseUrl( $url ) {
 672         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 673
 674         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 675         // way to handle them is to just prepend 'http:' and strip the protocol out later
 676         $wasRelative = substr( $url, 0, 2 ) == '//';
 677         if ( $wasRelative ) {
 678                 $url = "http:$url";
 679         }
 680         wfSuppressWarnings();
 681         $bits = parse_url( $url );
 682         wfRestoreWarnings();
 683         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 684         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 685         if ( !$bits || !isset( $bits['scheme'] ) ) {
 686                 return false;
 687         }
 688
 689         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 690         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 691                 $bits['delimiter'] = '://';
 692         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 693                 $bits['delimiter'] = ':';
 694                 // parse_url detects for news: and mailto: the host part of an url as path
 695                 // We have to correct this wrong detection
 696                 if ( isset( $bits['path'] ) ) {
 697                         $bits['host'] = $bits['path'];
 698                         $bits['path'] = '';
 699                 }
 700         } else {
 701                 return false;
 702         }
 703
 704         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 705         if ( !isset( $bits['host'] ) ) {
 706                 $bits['host'] = '';
 707
 708                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 709                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 710                         $bits['path'] = '/' . $bits['path'];
 711                 }
 712         }
 713
 714         // If the URL was protocol-relative, fix scheme and delimiter
 715         if ( $wasRelative ) {
 716                 $bits['scheme'] = '';
 717                 $bits['delimiter'] = '//';
 718         }
 719         return $bits;
 720 }
 721
 722 /**
 723  * Make URL indexes, appropriate for the el_index field of externallinks.
 724  *
 725  * @param $url String
 726  * @return array
 727  */
 728 function wfMakeUrlIndexes( $url ) {
 729         $bits = wfParseUrl( $url );
 730
 731         // Reverse the labels in the hostname, convert to lower case
 732         // For emails reverse domainpart only
 733         if ( $bits['scheme'] == 'mailto' ) {
 734                 $mailparts = explode( '@', $bits['host'], 2 );
 735                 if ( count( $mailparts ) === 2 ) {
 736                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 737                 } else {
 738                         // No domain specified, don't mangle it
 739                         $domainpart = '';
 740                 }
 741                 $reversedHost = $domainpart . '@' . $mailparts[0];
 742         } else {
 743                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 744         }
 745         // Add an extra dot to the end
 746         // Why? Is it in wrong place in mailto links?
 747         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 748                 $reversedHost .= '.';
 749         }
 750         // Reconstruct the pseudo-URL
 751         $prot = $bits['scheme'];
 752         $index = $prot . $bits['delimiter'] . $reversedHost;
 753         // Leave out user and password. Add the port, path, query and fragment
 754         if ( isset( $bits['port'] ) ) {
 755                 $index .= ':' . $bits['port'];
 756         }
 757         if ( isset( $bits['path'] ) ) {
 758                 $index .= $bits['path'];
 759         } else {
 760                 $index .= '/';
 761         }
 762         if ( isset( $bits['query'] ) ) {
 763                 $index .= '?' . $bits['query'];
 764         }
 765         if ( isset( $bits['fragment'] ) ) {
 766                 $index .= '#' . $bits['fragment'];
 767         }
 768
 769         if ( $prot == '' ) {
 770                 return array( "http:$index", "https:$index" );
 771         } else {
 772                 return array( $index );
 773         }
 774 }
 775
 776 /**
 777  * Check whether a given URL has a domain that occurs in a given set of domains
 778  * @param $url string URL
 779  * @param $domains array Array of domains (strings)
 780  * @return bool True if the host part of $url ends in one of the strings in $domains
 781  */
 782 function wfMatchesDomainList( $url, $domains ) {
 783         $bits = wfParseUrl( $url );
 784         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 785                 foreach ( (array)$domains as $domain ) {
 786                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 787                         // We should use something that interprets dots instead
 788                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 789                                 return true;
 790                         }
 791                 }
 792         }
 793         return false;
 794 }
 795
 796 /**
 797  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 798  * In normal operation this is a NOP.
 799  *
 800  * Controlling globals:
 801  * $wgDebugLogFile - points to the log file
 802  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 803  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 804  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 805  *
 806  * @param $text String
 807  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 808  */
 809 function wfDebug( $text, $logonly = false ) {
 810         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 811         global $wgDebugLogPrefix, $wgShowDebug;
 812
 813         static $cache = array(); // Cache of unoutputted messages
 814         $text = wfDebugTimer() . $text;
 815
 816         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 817                 return;
 818         }
 819
 820         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 821                 $cache[] = $text;
 822
 823                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 824                         // add the message and any cached messages to the output
 825                         array_map( array( $wgOut, 'debug' ), $cache );
 826                         $cache = array();
 827                 }
 828         }
 829         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 830                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 831                         # Strip unprintables; they can switch terminal modes when binary data
 832                         # gets dumped, which is pretty annoying.
 833                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 834                         $text = $wgDebugLogPrefix . $text;
 835                         wfErrorLog( $text, $wgDebugLogFile );
 836                 }
 837         }
 838
 839         MWDebug::debugMsg( $text );
 840 }
 841
 842 /**
 843  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 844  */
 845 function wfIsDebugRawPage() {
 846         static $cache;
 847         if ( $cache !== null ) {
 848                 return $cache;
 849         }
 850         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 851         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 852                 || (
 853                         isset( $_SERVER['SCRIPT_NAME'] )
 854                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 855                 ) )
 856         {
 857                 $cache = true;
 858         } else {
 859                 $cache = false;
 860         }
 861         return $cache;
 862 }
 863
 864 /**
 865  * Get microsecond timestamps for debug logs
 866  *
 867  * @return string
 868  */
 869 function wfDebugTimer() {
 870         global $wgDebugTimestamps;
 871         if ( !$wgDebugTimestamps ) {
 872                 return '';
 873         }
 874         static $start = null;
 875
 876         if ( $start === null ) {
 877                 $start = microtime( true );
 878                 $prefix = "\n$start";
 879         } else {
 880                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 881         }
 882         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / (1024*1024) ) );
 883         return "$prefix $mem  " ;
 884 }
 885
 886 /**
 887  * Send a line giving PHP memory usage.
 888  *
 889  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 890  */
 891 function wfDebugMem( $exact = false ) {
 892         $mem = memory_get_usage();
 893         if( !$exact ) {
 894                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 895         } else {
 896                 $mem .= ' bytes';
 897         }
 898         wfDebug( "Memory usage: $mem\n" );
 899 }
 900
 901 /**
 902  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 903  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 904  *
 905  * @param $logGroup String
 906  * @param $text String
 907  * @param $public Bool: whether to log the event in the public log if no private
 908  *                     log file is specified, (default true)
 909  */
 910 function wfDebugLog( $logGroup, $text, $public = true ) {
 911         global $wgDebugLogGroups, $wgShowHostnames;
 912         $text = trim( $text ) . "\n";
 913         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 914                 $time = wfTimestamp( TS_DB );
 915                 $wiki = wfWikiID();
 916                 if ( $wgShowHostnames ) {
 917                         $host = wfHostname();
 918                 } else {
 919                         $host = '';
 920                 }
 921                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 922                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 923                 }
 924         } elseif ( $public === true ) {
 925                 wfDebug( $text, true );
 926         }
 927 }
 928
 929 /**
 930  * Log for database errors
 931  *
 932  * @param $text String: database error message.
 933  */
 934 function wfLogDBError( $text ) {
 935         global $wgDBerrorLog, $wgDBname;
 936         if ( $wgDBerrorLog ) {
 937                 $host = trim(`hostname`);
 938                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 939                 wfErrorLog( $text, $wgDBerrorLog );
 940         }
 941 }
 942
 943 /**
 944  * Log to a file without getting "file size exceeded" signals.
 945  *
 946  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 947  * send lines to the specified port, prefixed by the specified prefix and a space.
 948  *
 949  * @param $text String
 950  * @param $file String filename
 951  */
 952 function wfErrorLog( $text, $file ) {
 953         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 954                 # Needs the sockets extension
 955                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 956                         // IPv6 bracketed host
 957                         $host = $m[2];
 958                         $port = intval( $m[3] );
 959                         $prefix = isset( $m[4] ) ? $m[4] : false;
 960                         $domain = AF_INET6;
 961                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 962                         $host = $m[2];
 963                         if ( !IP::isIPv4( $host ) ) {
 964                                 $host = gethostbyname( $host );
 965                         }
 966                         $port = intval( $m[3] );
 967                         $prefix = isset( $m[4] ) ? $m[4] : false;
 968                         $domain = AF_INET;
 969                 } else {
 970                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 971                 }
 972
 973                 // Clean it up for the multiplexer
 974                 if ( strval( $prefix ) !== '' ) {
 975                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 976
 977                         // Limit to 64KB
 978                         if ( strlen( $text ) > 65506 ) {
 979                                 $text = substr( $text, 0, 65506 );
 980                         }
 981
 982                         if ( substr( $text, -1 ) != "\n" ) {
 983                                 $text .= "\n";
 984                         }
 985                 } elseif ( strlen( $text ) > 65507 ) {
 986                         $text = substr( $text, 0, 65507 );
 987                 }
 988
 989                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 990                 if ( !$sock ) {
 991                         return;
 992                 }
 993
 994                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 995                 socket_close( $sock );
 996         } else {
 997                 wfSuppressWarnings();
 998                 $exists = file_exists( $file );
 999                 $size = $exists ? filesize( $file ) : false;
1000                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
1001                         file_put_contents( $file, $text, FILE_APPEND );
1002                 }
1003                 wfRestoreWarnings();
1004         }
1005 }
1006
1007 /**
1008  * @todo document
1009  */
1010 function wfLogProfilingData() {
1011         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
1012         global $wgProfileLimit, $wgUser;
1013
1014         $profiler = Profiler::instance();
1015
1016         # Profiling must actually be enabled...
1017         if ( $profiler->isStub() ) {
1018                 return;
1019         }
1020
1021         // Get total page request time and only show pages that longer than
1022         // $wgProfileLimit time (default is 0)
1023         $now = wfTime();
1024         $elapsed = $now - $wgRequestTime;
1025         if ( $elapsed <= $wgProfileLimit ) {
1026                 return;
1027         }
1028
1029         $profiler->logData();
1030
1031         // Check whether this should be logged in the debug file.
1032         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
1033                 return;
1034         }
1035
1036         $forward = '';
1037         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
1038                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
1039         }
1040         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
1041                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
1042         }
1043         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
1044                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
1045         }
1046         if ( $forward ) {
1047                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
1048         }
1049         // Don't load $wgUser at this late stage just for statistics purposes
1050         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
1051         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
1052                 $forward .= ' anon';
1053         }
1054         $log = sprintf( "%s\t%04.3f\t%s\n",
1055                 gmdate( 'YmdHis' ), $elapsed,
1056                 urldecode( $wgRequest->getRequestURL() . $forward ) );
1057
1058         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
1059 }
1060
1061 /**
1062  * Check if the wiki read-only lock file is present. This can be used to lock
1063  * off editing functions, but doesn't guarantee that the database will not be
1064  * modified.
1065  *
1066  * @return bool
1067  */
1068 function wfReadOnly() {
1069         global $wgReadOnlyFile, $wgReadOnly;
1070
1071         if ( !is_null( $wgReadOnly ) ) {
1072                 return (bool)$wgReadOnly;
1073         }
1074         if ( $wgReadOnlyFile == '' ) {
1075                 return false;
1076         }
1077         // Set $wgReadOnly for faster access next time
1078         if ( is_file( $wgReadOnlyFile ) ) {
1079                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1080         } else {
1081                 $wgReadOnly = false;
1082         }
1083         return (bool)$wgReadOnly;
1084 }
1085
1086 /**
1087  * @return bool
1088  */
1089 function wfReadOnlyReason() {
1090         global $wgReadOnly;
1091         wfReadOnly();
1092         return $wgReadOnly;
1093 }
1094
1095 /**
1096  * Return a Language object from $langcode
1097  *
1098  * @param $langcode Mixed: either:
1099  *                  - a Language object
1100  *                  - code of the language to get the message for, if it is
1101  *                    a valid code create a language for that language, if
1102  *                    it is a string but not a valid code then make a basic
1103  *                    language object
1104  *                  - a boolean: if it's false then use the global object for
1105  *                    the current user's language (as a fallback for the old parameter
1106  *                    functionality), or if it is true then use global object
1107  *                    for the wiki's content language.
1108  * @return Language object
1109  */
1110 function wfGetLangObj( $langcode = false ) {
1111         # Identify which language to get or create a language object for.
1112         # Using is_object here due to Stub objects.
1113         if( is_object( $langcode ) ) {
1114                 # Great, we already have the object (hopefully)!
1115                 return $langcode;
1116         }
1117
1118         global $wgContLang, $wgLanguageCode;
1119         if( $langcode === true || $langcode === $wgLanguageCode ) {
1120                 # $langcode is the language code of the wikis content language object.
1121                 # or it is a boolean and value is true
1122                 return $wgContLang;
1123         }
1124
1125         global $wgLang;
1126         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1127                 # $langcode is the language code of user language object.
1128                 # or it was a boolean and value is false
1129                 return $wgLang;
1130         }
1131
1132         $validCodes = array_keys( Language::getLanguageNames() );
1133         if( in_array( $langcode, $validCodes ) ) {
1134                 # $langcode corresponds to a valid language.
1135                 return Language::factory( $langcode );
1136         }
1137
1138         # $langcode is a string, but not a valid language code; use content language.
1139         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1140         return $wgContLang;
1141 }
1142
1143 /**
1144  * Old function when $wgBetterDirectionality existed
1145  * Removed in core, kept in extensions for backwards compat.
1146  *
1147  * @deprecated since 1.18
1148  * @return Language
1149  */
1150 function wfUILang() {
1151         global $wgLang;
1152         return $wgLang;
1153 }
1154
1155 /**
1156  * This is the new function for getting translated interface messages.
1157  * See the Message class for documentation how to use them.
1158  * The intention is that this function replaces all old wfMsg* functions.
1159  * @param $key \string Message key.
1160  * Varargs: normal message parameters.
1161  * @return Message
1162  * @since 1.17
1163  */
1164 function wfMessage( $key /*...*/) {
1165         $params = func_get_args();
1166         array_shift( $params );
1167         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1168                 $params = $params[0];
1169         }
1170         return new Message( $key, $params );
1171 }
1172
1173 /**
1174  * This function accepts multiple message keys and returns a message instance
1175  * for the first message which is non-empty. If all messages are empty then an
1176  * instance of the first message key is returned.
1177  * @param varargs: message keys
1178  * @return Message
1179  * @since 1.18
1180  */
1181 function wfMessageFallback( /*...*/ ) {
1182         $args = func_get_args();
1183         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1184 }
1185
1186 /**
1187  * Get a message from anywhere, for the current user language.
1188  *
1189  * Use wfMsgForContent() instead if the message should NOT
1190  * change depending on the user preferences.
1191  *
1192  * @param $key String: lookup key for the message, usually
1193  *    defined in languages/Language.php
1194  *
1195  * Parameters to the message, which can be used to insert variable text into
1196  * it, can be passed to this function in the following formats:
1197  * - One per argument, starting at the second parameter
1198  * - As an array in the second parameter
1199  * These are not shown in the function definition.
1200  *
1201  * @return String
1202  */
1203 function wfMsg( $key ) {
1204         $args = func_get_args();
1205         array_shift( $args );
1206         return wfMsgReal( $key, $args );
1207 }
1208
1209 /**
1210  * Same as above except doesn't transform the message
1211  *
1212  * @param $key String
1213  * @return String
1214  */
1215 function wfMsgNoTrans( $key ) {
1216         $args = func_get_args();
1217         array_shift( $args );
1218         return wfMsgReal( $key, $args, true, false, false );
1219 }
1220
1221 /**
1222  * Get a message from anywhere, for the current global language
1223  * set with $wgLanguageCode.
1224  *
1225  * Use this if the message should NOT change dependent on the
1226  * language set in the user's preferences. This is the case for
1227  * most text written into logs, as well as link targets (such as
1228  * the name of the copyright policy page). Link titles, on the
1229  * other hand, should be shown in the UI language.
1230  *
1231  * Note that MediaWiki allows users to change the user interface
1232  * language in their preferences, but a single installation
1233  * typically only contains content in one language.
1234  *
1235  * Be wary of this distinction: If you use wfMsg() where you should
1236  * use wfMsgForContent(), a user of the software may have to
1237  * customize potentially hundreds of messages in
1238  * order to, e.g., fix a link in every possible language.
1239  *
1240  * @param $key String: lookup key for the message, usually
1241  *     defined in languages/Language.php
1242  * @return String
1243  */
1244 function wfMsgForContent( $key ) {
1245         global $wgForceUIMsgAsContentMsg;
1246         $args = func_get_args();
1247         array_shift( $args );
1248         $forcontent = true;
1249         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1250                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1251         {
1252                 $forcontent = false;
1253         }
1254         return wfMsgReal( $key, $args, true, $forcontent );
1255 }
1256
1257 /**
1258  * Same as above except doesn't transform the message
1259  *
1260  * @param $key String
1261  * @return String
1262  */
1263 function wfMsgForContentNoTrans( $key ) {
1264         global $wgForceUIMsgAsContentMsg;
1265         $args = func_get_args();
1266         array_shift( $args );
1267         $forcontent = true;
1268         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1269                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1270         {
1271                 $forcontent = false;
1272         }
1273         return wfMsgReal( $key, $args, true, $forcontent, false );
1274 }
1275
1276 /**
1277  * Really get a message
1278  *
1279  * @param $key String: key to get.
1280  * @param $args
1281  * @param $useDB Boolean
1282  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1283  * @param $transform Boolean: Whether or not to transform the message.
1284  * @return String: the requested message.
1285  */
1286 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1287         wfProfileIn( __METHOD__ );
1288         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1289         $message = wfMsgReplaceArgs( $message, $args );
1290         wfProfileOut( __METHOD__ );
1291         return $message;
1292 }
1293
1294 /**
1295  * Fetch a message string value, but don't replace any keys yet.
1296  *
1297  * @param $key String
1298  * @param $useDB Bool
1299  * @param $langCode String: Code of the language to get the message for, or
1300  *                  behaves as a content language switch if it is a boolean.
1301  * @param $transform Boolean: whether to parse magic words, etc.
1302  * @return string
1303  */
1304 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1305         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1306
1307         $cache = MessageCache::singleton();
1308         $message = $cache->get( $key, $useDB, $langCode );
1309         if( $message === false ) {
1310                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1311         } elseif ( $transform ) {
1312                 $message = $cache->transform( $message );
1313         }
1314         return $message;
1315 }
1316
1317 /**
1318  * Replace message parameter keys on the given formatted output.
1319  *
1320  * @param $message String
1321  * @param $args Array
1322  * @return string
1323  * @private
1324  */
1325 function wfMsgReplaceArgs( $message, $args ) {
1326         # Fix windows line-endings
1327         # Some messages are split with explode("\n", $msg)
1328         $message = str_replace( "\r", '', $message );
1329
1330         // Replace arguments
1331         if ( count( $args ) ) {
1332                 if ( is_array( $args[0] ) ) {
1333                         $args = array_values( $args[0] );
1334                 }
1335                 $replacementKeys = array();
1336                 foreach( $args as $n => $param ) {
1337                         $replacementKeys['$' . ( $n + 1 )] = $param;
1338                 }
1339                 $message = strtr( $message, $replacementKeys );
1340         }
1341
1342         return $message;
1343 }
1344
1345 /**
1346  * Return an HTML-escaped version of a message.
1347  * Parameter replacements, if any, are done *after* the HTML-escaping,
1348  * so parameters may contain HTML (eg links or form controls). Be sure
1349  * to pre-escape them if you really do want plaintext, or just wrap
1350  * the whole thing in htmlspecialchars().
1351  *
1352  * @param $key String
1353  * @param string ... parameters
1354  * @return string
1355  */
1356 function wfMsgHtml( $key ) {
1357         $args = func_get_args();
1358         array_shift( $args );
1359         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1360 }
1361
1362 /**
1363  * Return an HTML version of message
1364  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1365  * so parameters may contain HTML (eg links or form controls). Be sure
1366  * to pre-escape them if you really do want plaintext, or just wrap
1367  * the whole thing in htmlspecialchars().
1368  *
1369  * @param $key String
1370  * @param string ... parameters
1371  * @return string
1372  */
1373 function wfMsgWikiHtml( $key ) {
1374         $args = func_get_args();
1375         array_shift( $args );
1376         return wfMsgReplaceArgs(
1377                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1378                 /* can't be set to false */ true, /* interface */ true )->getText(),
1379                 $args );
1380 }
1381
1382 /**
1383  * Returns message in the requested format
1384  * @param $key String: key of the message
1385  * @param $options Array: processing rules. Can take the following options:
1386  *   <i>parse</i>: parses wikitext to HTML
1387  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1388  *       p's added by parser or tidy
1389  *   <i>escape</i>: filters message through htmlspecialchars
1390  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1391  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1392  *   <i>parsemag</i>: transform the message using magic phrases
1393  *   <i>content</i>: fetch message for content language instead of interface
1394  * Also can accept a single associative argument, of the form 'language' => 'xx':
1395  *   <i>language</i>: Language object or language code to fetch message for
1396  *       (overriden by <i>content</i>).
1397  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1398  *
1399  * @return String
1400  */
1401 function wfMsgExt( $key, $options ) {
1402         $args = func_get_args();
1403         array_shift( $args );
1404         array_shift( $args );
1405         $options = (array)$options;
1406
1407         foreach( $options as $arrayKey => $option ) {
1408                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1409                         # An unknown index, neither numeric nor "language"
1410                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1411                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1412                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1413                 'replaceafter', 'parsemag', 'content' ) ) ) {
1414                         # A numeric index with unknown value
1415                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1416                 }
1417         }
1418
1419         if( in_array( 'content', $options, true ) ) {
1420                 $forContent = true;
1421                 $langCode = true;
1422                 $langCodeObj = null;
1423         } elseif( array_key_exists( 'language', $options ) ) {
1424                 $forContent = false;
1425                 $langCode = wfGetLangObj( $options['language'] );
1426                 $langCodeObj = $langCode;
1427         } else {
1428                 $forContent = false;
1429                 $langCode = false;
1430                 $langCodeObj = null;
1431         }
1432
1433         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1434
1435         if( !in_array( 'replaceafter', $options, true ) ) {
1436                 $string = wfMsgReplaceArgs( $string, $args );
1437         }
1438
1439         $messageCache = MessageCache::singleton();
1440         if( in_array( 'parse', $options, true ) ) {
1441                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1442         } elseif ( in_array( 'parseinline', $options, true ) ) {
1443                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1444                 $m = array();
1445                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1446                         $string = $m[1];
1447                 }
1448         } elseif ( in_array( 'parsemag', $options, true ) ) {
1449                 $string = $messageCache->transform( $string,
1450                                 !$forContent, $langCodeObj );
1451         }
1452
1453         if ( in_array( 'escape', $options, true ) ) {
1454                 $string = htmlspecialchars ( $string );
1455         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1456                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1457         }
1458
1459         if( in_array( 'replaceafter', $options, true ) ) {
1460                 $string = wfMsgReplaceArgs( $string, $args );
1461         }
1462
1463         return $string;
1464 }
1465
1466 /**
1467  * Since wfMsg() and co suck, they don't return false if the message key they
1468  * looked up didn't exist but a XHTML string, this function checks for the
1469  * nonexistance of messages by checking the MessageCache::get() result directly.
1470  *
1471  * @param $key      String: the message key looked up
1472  * @return Boolean True if the message *doesn't* exist.
1473  */
1474 function wfEmptyMsg( $key ) {
1475         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1476 }
1477
1478 /**
1479  * Throw a debugging exception. This function previously once exited the process,
1480  * but now throws an exception instead, with similar results.
1481  *
1482  * @param $msg String: message shown when dying.
1483  */
1484 function wfDebugDieBacktrace( $msg = '' ) {
1485         throw new MWException( $msg );
1486 }
1487
1488 /**
1489  * Fetch server name for use in error reporting etc.
1490  * Use real server name if available, so we know which machine
1491  * in a server farm generated the current page.
1492  *
1493  * @return string
1494  */
1495 function wfHostname() {
1496         static $host;
1497         if ( is_null( $host ) ) {
1498                 if ( function_exists( 'posix_uname' ) ) {
1499                         // This function not present on Windows
1500                         $uname = posix_uname();
1501                 } else {
1502                         $uname = false;
1503                 }
1504                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1505                         $host = $uname['nodename'];
1506                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1507                         # Windows computer name
1508                         $host = getenv( 'COMPUTERNAME' );
1509                 } else {
1510                         # This may be a virtual server.
1511                         $host = $_SERVER['SERVER_NAME'];
1512                 }
1513         }
1514         return $host;
1515 }
1516
1517 /**
1518  * Returns a HTML comment with the elapsed time since request.
1519  * This method has no side effects.
1520  *
1521  * @return string
1522  */
1523 function wfReportTime() {
1524         global $wgRequestTime, $wgShowHostnames;
1525
1526         $now = wfTime();
1527         $elapsed = $now - $wgRequestTime;
1528
1529         return $wgShowHostnames
1530                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1531                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1532 }
1533
1534 /**
1535  * Safety wrapper for debug_backtrace().
1536  *
1537  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1538  * murky circumstances, which may be triggered in part by stub objects
1539  * or other fancy talkin'.
1540  *
1541  * Will return an empty array if Zend Optimizer is detected or if
1542  * debug_backtrace is disabled, otherwise the output from
1543  * debug_backtrace() (trimmed).
1544  *
1545  * @param $limit int This parameter can be used to limit the number of stack frames returned
1546  *
1547  * @return array of backtrace information
1548  */
1549 function wfDebugBacktrace( $limit = 0 ) {
1550         static $disabled = null;
1551
1552         if( extension_loaded( 'Zend Optimizer' ) ) {
1553                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1554                 return array();
1555         }
1556
1557         if ( is_null( $disabled ) ) {
1558                 $disabled = false;
1559                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1560                 $functions = array_map( 'trim', $functions );
1561                 $functions = array_map( 'strtolower', $functions );
1562                 if ( in_array( 'debug_backtrace', $functions ) ) {
1563                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1564                         $disabled = true;
1565                 }
1566         }
1567         if ( $disabled ) {
1568                 return array();
1569         }
1570
1571         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1572                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit ), 1 );
1573         } else {
1574                 return array_slice( debug_backtrace(), 1 );
1575         }
1576 }
1577
1578 /**
1579  * Get a debug backtrace as a string
1580  *
1581  * @return string
1582  */
1583 function wfBacktrace() {
1584         global $wgCommandLineMode;
1585
1586         if ( $wgCommandLineMode ) {
1587                 $msg = '';
1588         } else {
1589                 $msg = "<ul>\n";
1590         }
1591         $backtrace = wfDebugBacktrace();
1592         foreach( $backtrace as $call ) {
1593                 if( isset( $call['file'] ) ) {
1594                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1595                         $file = $f[count( $f ) - 1];
1596                 } else {
1597                         $file = '-';
1598                 }
1599                 if( isset( $call['line'] ) ) {
1600                         $line = $call['line'];
1601                 } else {
1602                         $line = '-';
1603                 }
1604                 if ( $wgCommandLineMode ) {
1605                         $msg .= "$file line $line calls ";
1606                 } else {
1607                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1608                 }
1609                 if( !empty( $call['class'] ) ) {
1610                         $msg .= $call['class'] . $call['type'];
1611                 }
1612                 $msg .= $call['function'] . '()';
1613
1614                 if ( $wgCommandLineMode ) {
1615                         $msg .= "\n";
1616                 } else {
1617                         $msg .= "</li>\n";
1618                 }
1619         }
1620         if ( $wgCommandLineMode ) {
1621                 $msg .= "\n";
1622         } else {
1623                 $msg .= "</ul>\n";
1624         }
1625
1626         return $msg;
1627 }
1628
1629 /**
1630  * Get the name of the function which called this function
1631  *
1632  * @param $level Int
1633  * @return Bool|string
1634  */
1635 function wfGetCaller( $level = 2 ) {
1636         $backtrace = wfDebugBacktrace( $level );
1637         if ( isset( $backtrace[$level] ) ) {
1638                 return wfFormatStackFrame( $backtrace[$level] );
1639         } else {
1640                 $caller = 'unknown';
1641         }
1642         return $caller;
1643 }
1644
1645 /**
1646  * Return a string consisting of callers in the stack. Useful sometimes
1647  * for profiling specific points.
1648  *
1649  * @param $limit The maximum depth of the stack frame to return, or false for
1650  *               the entire stack.
1651  * @return String
1652  */
1653 function wfGetAllCallers( $limit = 3 ) {
1654         $trace = array_reverse( wfDebugBacktrace() );
1655         if ( !$limit || $limit > count( $trace ) - 1 ) {
1656                 $limit = count( $trace ) - 1;
1657         }
1658         $trace = array_slice( $trace, -$limit - 1, $limit );
1659         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1660 }
1661
1662 /**
1663  * Return a string representation of frame
1664  *
1665  * @param $frame Array
1666  * @return Bool
1667  */
1668 function wfFormatStackFrame( $frame ) {
1669         return isset( $frame['class'] ) ?
1670                 $frame['class'] . '::' . $frame['function'] :
1671                 $frame['function'];
1672 }
1673
1674
1675 /* Some generic result counters, pulled out of SearchEngine */
1676
1677
1678 /**
1679  * @todo document
1680  *
1681  * @param $offset Int
1682  * @param $limit Int
1683  * @return String
1684  */
1685 function wfShowingResults( $offset, $limit ) {
1686         global $wgLang;
1687         return wfMsgExt(
1688                 'showingresults',
1689                 array( 'parseinline' ),
1690                 $wgLang->formatNum( $limit ),
1691                 $wgLang->formatNum( $offset + 1 )
1692         );
1693 }
1694
1695 /**
1696  * Generate (prev x| next x) (20|50|100...) type links for paging
1697  *
1698  * @param $offset String
1699  * @param $limit Integer
1700  * @param $link String
1701  * @param $query String: optional URL query parameter string
1702  * @param $atend Bool: optional param for specified if this is the last page
1703  * @return String
1704  * @deprecated in 1.19; use Language::viewPrevNext() instead
1705  */
1706 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1707         global $wgLang;
1708
1709         $query = wfCgiToArray( $query );
1710
1711         if( is_object( $link ) ) {
1712                 $title = $link;
1713         } else {
1714                 $title = Title::newFromText( $link );
1715                 if( is_null( $title ) ) {
1716                         return false;
1717                 }
1718         }
1719
1720         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1721 }
1722
1723 /**
1724  * Make a list item, used by various special pages
1725  *
1726  * @param $page String Page link
1727  * @param $details String Text between brackets
1728  * @param $oppositedm Boolean   Add the direction mark opposite to your
1729  *                                                              language, to display text properly
1730  * @return String
1731  * @deprecated since 1.19; use Language::specialList() instead
1732  */
1733 function wfSpecialList( $page, $details, $oppositedm = true ) {
1734         global $wgLang;
1735         return $wgLang->specialList( $page, $details, $oppositedm );
1736 }
1737
1738 /**
1739  * @todo document
1740  * @todo FIXME: We may want to blacklist some broken browsers
1741  *
1742  * @param $force Bool
1743  * @return bool Whereas client accept gzip compression
1744  */
1745 function wfClientAcceptsGzip( $force = false ) {
1746         static $result = null;
1747         if ( $result === null || $force ) {
1748                 $result = false;
1749                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1750                         # @todo FIXME: We may want to blacklist some broken browsers
1751                         $m = array();
1752                         if( preg_match(
1753                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1754                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1755                                 $m )
1756                         )
1757                         {
1758                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1759                                         $result = false;
1760                                         return $result;
1761                                 }
1762                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1763                                 $result = true;
1764                         }
1765                 }
1766         }
1767         return $result;
1768 }
1769
1770 /**
1771  * Obtain the offset and limit values from the request string;
1772  * used in special pages
1773  *
1774  * @param $deflimit Int default limit if none supplied
1775  * @param $optionname String Name of a user preference to check against
1776  * @return array
1777  *
1778  */
1779 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1780         global $wgRequest;
1781         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1782 }
1783
1784 /**
1785  * Escapes the given text so that it may be output using addWikiText()
1786  * without any linking, formatting, etc. making its way through. This
1787  * is achieved by substituting certain characters with HTML entities.
1788  * As required by the callers, <nowiki> is not used.
1789  *
1790  * @param $text String: text to be escaped
1791  * @return String
1792  */
1793 function wfEscapeWikiText( $text ) {
1794         $text = strtr( "\n$text", array(
1795                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1796                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1797                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1798                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1799                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1800                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1801         ) );
1802         return substr( $text, 1 );
1803 }
1804
1805 /**
1806  * Get the current unix timetstamp with microseconds.  Useful for profiling
1807  * @return Float
1808  */
1809 function wfTime() {
1810         return microtime( true );
1811 }
1812
1813 /**
1814  * Sets dest to source and returns the original value of dest
1815  * If source is NULL, it just returns the value, it doesn't set the variable
1816  * If force is true, it will set the value even if source is NULL
1817  *
1818  * @param $dest Mixed
1819  * @param $source Mixed
1820  * @param $force Bool
1821  * @return Mixed
1822  */
1823 function wfSetVar( &$dest, $source, $force = false ) {
1824         $temp = $dest;
1825         if ( !is_null( $source ) || $force ) {
1826                 $dest = $source;
1827         }
1828         return $temp;
1829 }
1830
1831 /**
1832  * As for wfSetVar except setting a bit
1833  *
1834  * @param $dest Int
1835  * @param $bit Int
1836  * @param $state Bool
1837  *
1838  * @return bool
1839  */
1840 function wfSetBit( &$dest, $bit, $state = true ) {
1841         $temp = (bool)( $dest & $bit );
1842         if ( !is_null( $state ) ) {
1843                 if ( $state ) {
1844                         $dest |= $bit;
1845                 } else {
1846                         $dest &= ~$bit;
1847                 }
1848         }
1849         return $temp;
1850 }
1851
1852 /**
1853  * A wrapper around the PHP function var_export().
1854  * Either print it or add it to the regular output ($wgOut).
1855  *
1856  * @param $var A PHP variable to dump.
1857  */
1858 function wfVarDump( $var ) {
1859         global $wgOut;
1860         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1861         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1862                 print $s;
1863         } else {
1864                 $wgOut->addHTML( $s );
1865         }
1866 }
1867
1868 /**
1869  * Provide a simple HTTP error.
1870  *
1871  * @param $code Int|String
1872  * @param $label String
1873  * @param $desc String
1874  */
1875 function wfHttpError( $code, $label, $desc ) {
1876         global $wgOut;
1877         $wgOut->disable();
1878         header( "HTTP/1.0 $code $label" );
1879         header( "Status: $code $label" );
1880         $wgOut->sendCacheControl();
1881
1882         header( 'Content-type: text/html; charset=utf-8' );
1883         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1884                 '<html><head><title>' .
1885                 htmlspecialchars( $label ) .
1886                 '</title></head><body><h1>' .
1887                 htmlspecialchars( $label ) .
1888                 '</h1><p>' .
1889                 nl2br( htmlspecialchars( $desc ) ) .
1890                 "</p></body></html>\n";
1891 }
1892
1893 /**
1894  * Clear away any user-level output buffers, discarding contents.
1895  *
1896  * Suitable for 'starting afresh', for instance when streaming
1897  * relatively large amounts of data without buffering, or wanting to
1898  * output image files without ob_gzhandler's compression.
1899  *
1900  * The optional $resetGzipEncoding parameter controls suppression of
1901  * the Content-Encoding header sent by ob_gzhandler; by default it
1902  * is left. See comments for wfClearOutputBuffers() for why it would
1903  * be used.
1904  *
1905  * Note that some PHP configuration options may add output buffer
1906  * layers which cannot be removed; these are left in place.
1907  *
1908  * @param $resetGzipEncoding Bool
1909  */
1910 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1911         if( $resetGzipEncoding ) {
1912                 // Suppress Content-Encoding and Content-Length
1913                 // headers from 1.10+s wfOutputHandler
1914                 global $wgDisableOutputCompression;
1915                 $wgDisableOutputCompression = true;
1916         }
1917         while( $status = ob_get_status() ) {
1918                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1919                         // Probably from zlib.output_compression or other
1920                         // PHP-internal setting which can't be removed.
1921                         //
1922                         // Give up, and hope the result doesn't break
1923                         // output behavior.
1924                         break;
1925                 }
1926                 if( !ob_end_clean() ) {
1927                         // Could not remove output buffer handler; abort now
1928                         // to avoid getting in some kind of infinite loop.
1929                         break;
1930                 }
1931                 if( $resetGzipEncoding ) {
1932                         if( $status['name'] == 'ob_gzhandler' ) {
1933                                 // Reset the 'Content-Encoding' field set by this handler
1934                                 // so we can start fresh.
1935                                 if ( function_exists( 'header_remove' ) ) {
1936                                         // Available since PHP 5.3.0
1937                                         header_remove( 'Content-Encoding' );
1938                                 } else {
1939                                         // We need to provide a valid content-coding. See bug 28069
1940                                         header( 'Content-Encoding: identity' );
1941                                 }
1942                                 break;
1943                         }
1944                 }
1945         }
1946 }
1947
1948 /**
1949  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1950  *
1951  * Clear away output buffers, but keep the Content-Encoding header
1952  * produced by ob_gzhandler, if any.
1953  *
1954  * This should be used for HTTP 304 responses, where you need to
1955  * preserve the Content-Encoding header of the real result, but
1956  * also need to suppress the output of ob_gzhandler to keep to spec
1957  * and avoid breaking Firefox in rare cases where the headers and
1958  * body are broken over two packets.
1959  */
1960 function wfClearOutputBuffers() {
1961         wfResetOutputBuffers( false );
1962 }
1963
1964 /**
1965  * Converts an Accept-* header into an array mapping string values to quality
1966  * factors
1967  *
1968  * @param $accept String
1969  * @param $def String default
1970  * @return Array
1971  */
1972 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1973         # No arg means accept anything (per HTTP spec)
1974         if( !$accept ) {
1975                 return array( $def => 1.0 );
1976         }
1977
1978         $prefs = array();
1979
1980         $parts = explode( ',', $accept );
1981
1982         foreach( $parts as $part ) {
1983                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1984                 $values = explode( ';', trim( $part ) );
1985                 $match = array();
1986                 if ( count( $values ) == 1 ) {
1987                         $prefs[$values[0]] = 1.0;
1988                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1989                         $prefs[$values[0]] = floatval( $match[1] );
1990                 }
1991         }
1992
1993         return $prefs;
1994 }
1995
1996 /**
1997  * Checks if a given MIME type matches any of the keys in the given
1998  * array. Basic wildcards are accepted in the array keys.
1999  *
2000  * Returns the matching MIME type (or wildcard) if a match, otherwise
2001  * NULL if no match.
2002  *
2003  * @param $type String
2004  * @param $avail Array
2005  * @return string
2006  * @private
2007  */
2008 function mimeTypeMatch( $type, $avail ) {
2009         if( array_key_exists( $type, $avail ) ) {
2010                 return $type;
2011         } else {
2012                 $parts = explode( '/', $type );
2013                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2014                         return $parts[0] . '/*';
2015                 } elseif( array_key_exists( '*/*', $avail ) ) {
2016                         return '*/*';
2017                 } else {
2018                         return null;
2019                 }
2020         }
2021 }
2022
2023 /**
2024  * Returns the 'best' match between a client's requested internet media types
2025  * and the server's list of available types. Each list should be an associative
2026  * array of type to preference (preference is a float between 0.0 and 1.0).
2027  * Wildcards in the types are acceptable.
2028  *
2029  * @param $cprefs Array: client's acceptable type list
2030  * @param $sprefs Array: server's offered types
2031  * @return string
2032  *
2033  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2034  * XXX: generalize to negotiate other stuff
2035  */
2036 function wfNegotiateType( $cprefs, $sprefs ) {
2037         $combine = array();
2038
2039         foreach( array_keys( $sprefs ) as $type ) {
2040                 $parts = explode( '/', $type );
2041                 if( $parts[1] != '*' ) {
2042                         $ckey = mimeTypeMatch( $type, $cprefs );
2043                         if( $ckey ) {
2044                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2045                         }
2046                 }
2047         }
2048
2049         foreach( array_keys( $cprefs ) as $type ) {
2050                 $parts = explode( '/', $type );
2051                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2052                         $skey = mimeTypeMatch( $type, $sprefs );
2053                         if( $skey ) {
2054                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2055                         }
2056                 }
2057         }
2058
2059         $bestq = 0;
2060         $besttype = null;
2061
2062         foreach( array_keys( $combine ) as $type ) {
2063                 if( $combine[$type] > $bestq ) {
2064                         $besttype = $type;
2065                         $bestq = $combine[$type];
2066                 }
2067         }
2068
2069         return $besttype;
2070 }
2071
2072 /**
2073  * Reference-counted warning suppression
2074  *
2075  * @param $end Bool
2076  */
2077 function wfSuppressWarnings( $end = false ) {
2078         static $suppressCount = 0;
2079         static $originalLevel = false;
2080
2081         if ( $end ) {
2082                 if ( $suppressCount ) {
2083                         --$suppressCount;
2084                         if ( !$suppressCount ) {
2085                                 error_reporting( $originalLevel );
2086                         }
2087                 }
2088         } else {
2089                 if ( !$suppressCount ) {
2090                         // E_DEPRECATED is undefined in PHP 5.2
2091                         if( !defined( 'E_DEPRECATED' ) ) {
2092                                 define( 'E_DEPRECATED', 8192 );
2093                         }
2094                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2095                 }
2096                 ++$suppressCount;
2097         }
2098 }
2099
2100 /**
2101  * Restore error level to previous value
2102  */
2103 function wfRestoreWarnings() {
2104         wfSuppressWarnings( true );
2105 }
2106
2107 # Autodetect, convert and provide timestamps of various types
2108
2109 /**
2110  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2111  */
2112 define( 'TS_UNIX', 0 );
2113
2114 /**
2115  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2116  */
2117 define( 'TS_MW', 1 );
2118
2119 /**
2120  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2121  */
2122 define( 'TS_DB', 2 );
2123
2124 /**
2125  * RFC 2822 format, for E-mail and HTTP headers
2126  */
2127 define( 'TS_RFC2822', 3 );
2128
2129 /**
2130  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2131  *
2132  * This is used by Special:Export
2133  */
2134 define( 'TS_ISO_8601', 4 );
2135
2136 /**
2137  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2138  *
2139  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2140  *       DateTime tag and page 36 for the DateTimeOriginal and
2141  *       DateTimeDigitized tags.
2142  */
2143 define( 'TS_EXIF', 5 );
2144
2145 /**
2146  * Oracle format time.
2147  */
2148 define( 'TS_ORACLE', 6 );
2149
2150 /**
2151  * Postgres format time.
2152  */
2153 define( 'TS_POSTGRES', 7 );
2154
2155 /**
2156  * DB2 format time
2157  */
2158 define( 'TS_DB2', 8 );
2159
2160 /**
2161  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2162  */
2163 define( 'TS_ISO_8601_BASIC', 9 );
2164
2165 /**
2166  * Get a timestamp string in one of various formats
2167  *
2168  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2169  *                    function will autodetect which format is supplied and act
2170  *                    accordingly.
2171  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2172  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2173  */
2174 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2175         $uts = 0;
2176         $da = array();
2177         $strtime = '';
2178
2179         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2180                 $uts = time();
2181                 $strtime = "@$uts";
2182         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2183                 # TS_DB
2184         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2185                 # TS_EXIF
2186         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2187                 # TS_MW
2188         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2189                 # TS_UNIX
2190                 $uts = $ts;
2191                 $strtime = "@$ts"; // http://php.net/manual/en/datetime.formats.compound.php
2192         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2193                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2194                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2195                                 str_replace( '+00:00', 'UTC', $ts ) );
2196         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2197                 # TS_ISO_8601
2198         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2199                 #TS_ISO_8601_BASIC
2200         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2201                 # TS_POSTGRES
2202         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2203                 # TS_POSTGRES
2204         } elseif (preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/', $ts, $da ) ) {
2205                 # TS_DB2
2206         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2207                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2208                                                         '[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d/S', $ts ) ) { # hh:mm:ss
2209                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2210                 # The regex is a superset of rfc2822 for readability
2211                 $strtime = strtok( $ts, ';' );
2212         } elseif ( preg_match( '/^[A-Z][a-z]{5,8}, \d\d-[A-Z][a-z]{2}-\d{2} \d\d:\d\d:\d\d/', $ts ) ) {
2213                 # TS_RFC850
2214                 $strtime = $ts;
2215         } elseif ( preg_match( '/^[A-Z][a-z]{2} [A-Z][a-z]{2} +\d{1,2} \d\d:\d\d:\d\d \d{4}/', $ts ) ) {
2216                 # asctime
2217                 $strtime = $ts;
2218         } else {
2219                 # Bogus value...
2220                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2221
2222                 return false;
2223         }
2224
2225         static $formats = array(
2226                 TS_UNIX => 'U',
2227                 TS_MW => 'YmdHis',
2228                 TS_DB => 'Y-m-d H:i:s',
2229                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2230                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2231                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2232                 TS_RFC2822 => 'D, d M Y H:i:s',
2233                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2234                 TS_POSTGRES => 'Y-m-d H:i:s',
2235                 TS_DB2 => 'Y-m-d H:i:s',
2236         );
2237
2238         if ( !isset( $formats[$outputtype] ) ) {
2239                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2240         }
2241
2242         if ( function_exists( "date_create" ) ) {
2243                 if ( count( $da ) ) {
2244                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2245                                 (int)$da[1], (int)$da[2], (int)$da[3],
2246                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2247
2248                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2249                 } elseif ( $strtime ) {
2250                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2251                 } else {
2252                         return false;
2253                 }
2254
2255                 if ( !$d ) {
2256                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2257                         return false;
2258                 }
2259
2260                 $output = $d->format( $formats[$outputtype] );
2261         } else {
2262                 if ( count( $da ) ) {
2263                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2264                         // We may want to handle that explicitly at some point
2265                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2266                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2267                 } elseif ( $strtime ) {
2268                         $uts = strtotime( $strtime );
2269                 }
2270
2271                 if ( $uts === false ) {
2272                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2273                         return false;
2274                 }
2275
2276                 if ( TS_UNIX == $outputtype ) {
2277                         return $uts;
2278                 }
2279                 $output = gmdate( $formats[$outputtype], $uts );
2280         }
2281
2282         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2283                 $output .= ' GMT';
2284         }
2285
2286         return $output;
2287 }
2288
2289 /**
2290  * Return a formatted timestamp, or null if input is null.
2291  * For dealing with nullable timestamp columns in the database.
2292  *
2293  * @param $outputtype Integer
2294  * @param $ts String
2295  * @return String
2296  */
2297 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2298         if( is_null( $ts ) ) {
2299                 return null;
2300         } else {
2301                 return wfTimestamp( $outputtype, $ts );
2302         }
2303 }
2304
2305 /**
2306  * Convenience function; returns MediaWiki timestamp for the present time.
2307  *
2308  * @return string
2309  */
2310 function wfTimestampNow() {
2311         # return NOW
2312         return wfTimestamp( TS_MW, time() );
2313 }
2314
2315 /**
2316  * Check if the operating system is Windows
2317  *
2318  * @return Bool: true if it's Windows, False otherwise.
2319  */
2320 function wfIsWindows() {
2321         static $isWindows = null;
2322         if ( $isWindows === null ) {
2323                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2324         }
2325         return $isWindows;
2326 }
2327
2328 /**
2329  * Check if we are running under HipHop
2330  *
2331  * @return Bool
2332  */
2333 function wfIsHipHop() {
2334         return function_exists( 'hphp_thread_set_warmup_enabled' );
2335 }
2336
2337 /**
2338  * Swap two variables
2339  *
2340  * @param $x Mixed
2341  * @param $y Mixed
2342  */
2343 function swap( &$x, &$y ) {
2344         $z = $x;
2345         $x = $y;
2346         $y = $z;
2347 }
2348
2349 /**
2350  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2351  * TEMP environment variables are then checked in sequence, and if none are set
2352  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2353  * or C:\Windows\Temp for Windows and hope for the best.
2354  * It is common to call it with tempnam().
2355  *
2356  * NOTE: When possible, use instead the tmpfile() function to create
2357  * temporary files to avoid race conditions on file creation, etc.
2358  *
2359  * @return String
2360  */
2361 function wfTempDir() {
2362         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2363                 $tmp = getenv( $var );
2364                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2365                         return $tmp;
2366                 }
2367         }
2368         if( function_exists( 'sys_get_temp_dir' ) ) {
2369                 return sys_get_temp_dir();
2370         }
2371         # Usual defaults
2372         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2373 }
2374
2375 /**
2376  * Make directory, and make all parent directories if they don't exist
2377  *
2378  * @param $dir String: full path to directory to create
2379  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2380  * @param $caller String: optional caller param for debugging.
2381  * @return bool
2382  */
2383 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2384         global $wgDirectoryMode;
2385
2386         if ( !is_null( $caller ) ) {
2387                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2388         }
2389
2390         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2391                 return true;
2392         }
2393
2394         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2395
2396         if ( is_null( $mode ) ) {
2397                 $mode = $wgDirectoryMode;
2398         }
2399
2400         // Turn off the normal warning, we're doing our own below
2401         wfSuppressWarnings();
2402         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2403         wfRestoreWarnings();
2404
2405         if( !$ok ) {
2406                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2407                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2408         }
2409         return $ok;
2410 }
2411
2412 /**
2413  * Increment a statistics counter
2414  *
2415  * @param $key String
2416  * @param $count Int
2417  */
2418 function wfIncrStats( $key, $count = 1 ) {
2419         global $wgStatsMethod;
2420
2421         $count = intval( $count );
2422
2423         if( $wgStatsMethod == 'udp' ) {
2424                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2425                 static $socket;
2426
2427                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2428
2429                 if ( !$socket ) {
2430                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2431                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2432                         socket_sendto(
2433                                 $socket,
2434                                 $statline,
2435                                 strlen( $statline ),
2436                                 0,
2437                                 $wgUDPProfilerHost,
2438                                 $wgUDPProfilerPort
2439                         );
2440                 }
2441                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2442                 wfSuppressWarnings();
2443                 socket_sendto(
2444                         $socket,
2445                         $statline,
2446                         strlen( $statline ),
2447                         0,
2448                         $wgUDPProfilerHost,
2449                         $wgUDPProfilerPort
2450                 );
2451                 wfRestoreWarnings();
2452         } elseif( $wgStatsMethod == 'cache' ) {
2453                 global $wgMemc;
2454                 $key = wfMemcKey( 'stats', $key );
2455                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2456                         $wgMemc->add( $key, $count );
2457                 }
2458         } else {
2459                 // Disabled
2460         }
2461 }
2462
2463 /**
2464  * @param $nr Mixed: the number to format
2465  * @param $acc Integer: the number of digits after the decimal point, default 2
2466  * @param $round Boolean: whether or not to round the value, default true
2467  * @return float
2468  */
2469 function wfPercent( $nr, $acc = 2, $round = true ) {
2470         $ret = sprintf( "%.${acc}f", $nr );
2471         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2472 }
2473
2474 /**
2475  * Find out whether or not a mixed variable exists in a string
2476  *
2477  * @param $needle String
2478  * @param $str String
2479  * @param $insensitive Boolean
2480  * @return Boolean
2481  */
2482 function in_string( $needle, $str, $insensitive = false ) {
2483         $func = 'strpos';
2484         if( $insensitive ) $func = 'stripos';
2485
2486         return $func( $str, $needle ) !== false;
2487 }
2488
2489 /**
2490  * Safety wrapper around ini_get() for boolean settings.
2491  * The values returned from ini_get() are pre-normalized for settings
2492  * set via php.ini or php_flag/php_admin_flag... but *not*
2493  * for those set via php_value/php_admin_value.
2494  *
2495  * It's fairly common for people to use php_value instead of php_flag,
2496  * which can leave you with an 'off' setting giving a false positive
2497  * for code that just takes the ini_get() return value as a boolean.
2498  *
2499  * To make things extra interesting, setting via php_value accepts
2500  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2501  * Unrecognized values go false... again opposite PHP's own coercion
2502  * from string to bool.
2503  *
2504  * Luckily, 'properly' set settings will always come back as '0' or '1',
2505  * so we only have to worry about them and the 'improper' settings.
2506  *
2507  * I frickin' hate PHP... :P
2508  *
2509  * @param $setting String
2510  * @return Bool
2511  */
2512 function wfIniGetBool( $setting ) {
2513         $val = ini_get( $setting );
2514         // 'on' and 'true' can't have whitespace around them, but '1' can.
2515         return strtolower( $val ) == 'on'
2516                 || strtolower( $val ) == 'true'
2517                 || strtolower( $val ) == 'yes'
2518                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2519 }
2520
2521 /**
2522  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2523  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2524  *
2525  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2526  *                          should be omitted
2527  * @param $fileName String Name of the library, if not $extension.suffix
2528  * @return Bool - Whether or not the extension is loaded
2529  */
2530 function wfDl( $extension, $fileName = null ) {
2531         if( extension_loaded( $extension ) ) {
2532                 return true;
2533         }
2534
2535         $canDl = false;
2536         $sapi = php_sapi_name();
2537         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2538                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2539         {
2540                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2541                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2542         }
2543
2544         if( $canDl ) {
2545                 $fileName = $fileName ? $fileName : $extension;
2546                 if( wfIsWindows() ) {
2547                         $fileName = 'php_' . $fileName;
2548                 }
2549                 wfSuppressWarnings();
2550                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2551                 wfRestoreWarnings();
2552         }
2553         return extension_loaded( $extension );
2554 }
2555
2556 /**
2557  * Windows-compatible version of escapeshellarg()
2558  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2559  * function puts single quotes in regardless of OS.
2560  *
2561  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2562  * earlier distro releases of PHP)
2563  *
2564  * @param varargs
2565  * @return String
2566  */
2567 function wfEscapeShellArg( ) {
2568         wfInitShellLocale();
2569
2570         $args = func_get_args();
2571         $first = true;
2572         $retVal = '';
2573         foreach ( $args as $arg ) {
2574                 if ( !$first ) {
2575                         $retVal .= ' ';
2576                 } else {
2577                         $first = false;
2578                 }
2579
2580                 if ( wfIsWindows() ) {
2581                         // Escaping for an MSVC-style command line parser and CMD.EXE
2582                         // Refs:
2583                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2584                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2585                         //  * Bug #13518
2586                         //  * CR r63214
2587                         // Double the backslashes before any double quotes. Escape the double quotes.
2588                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2589                         $arg = '';
2590                         $iteration = 0;
2591                         foreach ( $tokens as $token ) {
2592                                 if ( $iteration % 2 == 1 ) {
2593                                         // Delimiter, a double quote preceded by zero or more slashes
2594                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2595                                 } elseif ( $iteration % 4 == 2 ) {
2596                                         // ^ in $token will be outside quotes, need to be escaped
2597                                         $arg .= str_replace( '^', '^^', $token );
2598                                 } else { // $iteration % 4 == 0
2599                                         // ^ in $token will appear inside double quotes, so leave as is
2600                                         $arg .= $token;
2601                                 }
2602                                 $iteration++;
2603                         }
2604                         // Double the backslashes before the end of the string, because
2605                         // we will soon add a quote
2606                         $m = array();
2607                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2608                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2609                         }
2610
2611                         // Add surrounding quotes
2612                         $retVal .= '"' . $arg . '"';
2613                 } else {
2614                         $retVal .= escapeshellarg( $arg );
2615                 }
2616         }
2617         return $retVal;
2618 }
2619
2620 /**
2621  * Execute a shell command, with time and memory limits mirrored from the PHP
2622  * configuration if supported.
2623  * @param $cmd String Command line, properly escaped for shell.
2624  * @param &$retval optional, will receive the program's exit code.
2625  *                 (non-zero is usually failure)
2626  * @param $environ Array optional environment variables which should be
2627  *                 added to the executed command environment.
2628  * @return collected stdout as a string (trailing newlines stripped)
2629  */
2630 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2631         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2632
2633         static $disabled;
2634         if ( is_null( $disabled ) ) {
2635                 $disabled = false;
2636                 if( wfIniGetBool( 'safe_mode' ) ) {
2637                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2638                         $disabled = 'safemode';
2639                 } else {
2640                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2641                         $functions = array_map( 'trim', $functions );
2642                         $functions = array_map( 'strtolower', $functions );
2643                         if ( in_array( 'passthru', $functions ) ) {
2644                                 wfDebug( "passthru is in disabled_functions\n" );
2645                                 $disabled = 'passthru';
2646                         }
2647                 }
2648         }
2649         if ( $disabled ) {
2650                 $retval = 1;
2651                 return $disabled == 'safemode' ?
2652                         'Unable to run external programs in safe mode.' :
2653                         'Unable to run external programs, passthru() is disabled.';
2654         }
2655
2656         wfInitShellLocale();
2657
2658         $envcmd = '';
2659         foreach( $environ as $k => $v ) {
2660                 if ( wfIsWindows() ) {
2661                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2662                          * appear in the environment variable, so we must use carat escaping as documented in
2663                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2664                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2665                          * are listed there but doesn't appear to need it.
2666                          */
2667                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2668                 } else {
2669                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2670                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2671                          */
2672                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2673                 }
2674         }
2675         $cmd = $envcmd . $cmd;
2676
2677         if ( wfIsWindows() ) {
2678                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2679                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2680                 {
2681                         # Hack to work around PHP's flawed invocation of cmd.exe
2682                         # http://news.php.net/php.internals/21796
2683                         # Windows 9x doesn't accept any kind of quotes
2684                         $cmd = '"' . $cmd . '"';
2685                 }
2686         } elseif ( php_uname( 's' ) == 'Linux' ) {
2687                 $time = intval( $wgMaxShellTime );
2688                 $mem = intval( $wgMaxShellMemory );
2689                 $filesize = intval( $wgMaxShellFileSize );
2690
2691                 if ( $time > 0 && $mem > 0 ) {
2692                         $script = "$IP/bin/ulimit4.sh";
2693                         if ( is_executable( $script ) ) {
2694                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2695                         }
2696                 }
2697         }
2698         wfDebug( "wfShellExec: $cmd\n" );
2699
2700         $retval = 1; // error by default?
2701         ob_start();
2702         passthru( $cmd, $retval );
2703         $output = ob_get_contents();
2704         ob_end_clean();
2705
2706         if ( $retval == 127 ) {
2707                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2708         }
2709         return $output;
2710 }
2711
2712 /**
2713  * Workaround for http://bugs.php.net/bug.php?id=45132
2714  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2715  */
2716 function wfInitShellLocale() {
2717         static $done = false;
2718         if ( $done ) {
2719                 return;
2720         }
2721         $done = true;
2722         global $wgShellLocale;
2723         if ( !wfIniGetBool( 'safe_mode' ) ) {
2724                 putenv( "LC_CTYPE=$wgShellLocale" );
2725                 setlocale( LC_CTYPE, $wgShellLocale );
2726         }
2727 }
2728
2729 /**
2730  * Generate a shell-escaped command line string to run a maintenance script.
2731  * Note that $parameters should be a flat array and an option with an argument
2732  * should consist of two consecutive items in the array (do not use "--option value").
2733  * @param $script string MediaWiki maintenance script path
2734  * @param $parameters Array Arguments and options to the script
2735  * @param $options Array Associative array of options:
2736  *              'php': The path to the php executable
2737  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2738  * @return Array
2739  */
2740 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2741         global $wgPhpCli;
2742         // Give site config file a chance to run the script in a wrapper.
2743         // The caller may likely want to call wfBasename() on $script.
2744         wfRunHooks( 'wfShellMaintenanceCmd', array( &$script, &$parameters, &$options ) );
2745         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2746         if ( isset( $options['wrapper'] ) ) {
2747                 $cmd[] = $options['wrapper'];
2748         }
2749         $cmd[] = $script;
2750         // Escape each parameter for shell
2751         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2752 }
2753
2754 /**
2755  * wfMerge attempts to merge differences between three texts.
2756  * Returns true for a clean merge and false for failure or a conflict.
2757  *
2758  * @param $old String
2759  * @param $mine String
2760  * @param $yours String
2761  * @param $result String
2762  * @return Bool
2763  */
2764 function wfMerge( $old, $mine, $yours, &$result ) {
2765         global $wgDiff3;
2766
2767         # This check may also protect against code injection in
2768         # case of broken installations.
2769         wfSuppressWarnings();
2770         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2771         wfRestoreWarnings();
2772
2773         if( !$haveDiff3 ) {
2774                 wfDebug( "diff3 not found\n" );
2775                 return false;
2776         }
2777
2778         # Make temporary files
2779         $td = wfTempDir();
2780         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2781         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2782         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2783
2784         fwrite( $oldtextFile, $old );
2785         fclose( $oldtextFile );
2786         fwrite( $mytextFile, $mine );
2787         fclose( $mytextFile );
2788         fwrite( $yourtextFile, $yours );
2789         fclose( $yourtextFile );
2790
2791         # Check for a conflict
2792         $cmd = $wgDiff3 . ' -a --overlap-only ' .
2793                 wfEscapeShellArg( $mytextName ) . ' ' .
2794                 wfEscapeShellArg( $oldtextName ) . ' ' .
2795                 wfEscapeShellArg( $yourtextName );
2796         $handle = popen( $cmd, 'r' );
2797
2798         if( fgets( $handle, 1024 ) ) {
2799                 $conflict = true;
2800         } else {
2801                 $conflict = false;
2802         }
2803         pclose( $handle );
2804
2805         # Merge differences
2806         $cmd = $wgDiff3 . ' -a -e --merge ' .
2807                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2808         $handle = popen( $cmd, 'r' );
2809         $result = '';
2810         do {
2811                 $data = fread( $handle, 8192 );
2812                 if ( strlen( $data ) == 0 ) {
2813                         break;
2814                 }
2815                 $result .= $data;
2816         } while ( true );
2817         pclose( $handle );
2818         unlink( $mytextName );
2819         unlink( $oldtextName );
2820         unlink( $yourtextName );
2821
2822         if ( $result === '' && $old !== '' && !$conflict ) {
2823                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2824                 $conflict = true;
2825         }
2826         return !$conflict;
2827 }
2828
2829 /**
2830  * Returns unified plain-text diff of two texts.
2831  * Useful for machine processing of diffs.
2832  *
2833  * @param $before String: the text before the changes.
2834  * @param $after String: the text after the changes.
2835  * @param $params String: command-line options for the diff command.
2836  * @return String: unified diff of $before and $after
2837  */
2838 function wfDiff( $before, $after, $params = '-u' ) {
2839         if ( $before == $after ) {
2840                 return '';
2841         }
2842
2843         global $wgDiff;
2844         wfSuppressWarnings();
2845         $haveDiff = $wgDiff && file_exists( $wgDiff );
2846         wfRestoreWarnings();
2847
2848         # This check may also protect against code injection in
2849         # case of broken installations.
2850         if( !$haveDiff ) {
2851                 wfDebug( "diff executable not found\n" );
2852                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2853                 $format = new UnifiedDiffFormatter();
2854                 return $format->format( $diffs );
2855         }
2856
2857         # Make temporary files
2858         $td = wfTempDir();
2859         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2860         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2861
2862         fwrite( $oldtextFile, $before );
2863         fclose( $oldtextFile );
2864         fwrite( $newtextFile, $after );
2865         fclose( $newtextFile );
2866
2867         // Get the diff of the two files
2868         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2869
2870         $h = popen( $cmd, 'r' );
2871
2872         $diff = '';
2873
2874         do {
2875                 $data = fread( $h, 8192 );
2876                 if ( strlen( $data ) == 0 ) {
2877                         break;
2878                 }
2879                 $diff .= $data;
2880         } while ( true );
2881
2882         // Clean up
2883         pclose( $h );
2884         unlink( $oldtextName );
2885         unlink( $newtextName );
2886
2887         // Kill the --- and +++ lines. They're not useful.
2888         $diff_lines = explode( "\n", $diff );
2889         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
2890                 unset( $diff_lines[0] );
2891         }
2892         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
2893                 unset( $diff_lines[1] );
2894         }
2895
2896         $diff = implode( "\n", $diff_lines );
2897
2898         return $diff;
2899 }
2900
2901 /**
2902  * This function works like "use VERSION" in Perl, the program will die with a
2903  * backtrace if the current version of PHP is less than the version provided
2904  *
2905  * This is useful for extensions which due to their nature are not kept in sync
2906  * with releases, and might depend on other versions of PHP than the main code
2907  *
2908  * Note: PHP might die due to parsing errors in some cases before it ever
2909  *       manages to call this function, such is life
2910  *
2911  * @see perldoc -f use
2912  *
2913  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2914  *                 a float
2915  */
2916 function wfUsePHP( $req_ver ) {
2917         $php_ver = PHP_VERSION;
2918
2919         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2920                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2921         }
2922 }
2923
2924 /**
2925  * This function works like "use VERSION" in Perl except it checks the version
2926  * of MediaWiki, the program will die with a backtrace if the current version
2927  * of MediaWiki is less than the version provided.
2928  *
2929  * This is useful for extensions which due to their nature are not kept in sync
2930  * with releases
2931  *
2932  * @see perldoc -f use
2933  *
2934  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2935  *                 a float
2936  */
2937 function wfUseMW( $req_ver ) {
2938         global $wgVersion;
2939
2940         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2941                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2942         }
2943 }
2944
2945 /**
2946  * Return the final portion of a pathname.
2947  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2948  * http://bugs.php.net/bug.php?id=33898
2949  *
2950  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2951  * We'll consider it so always, as we don't want \s in our Unix paths either.
2952  *
2953  * @param $path String
2954  * @param $suffix String: to remove if present
2955  * @return String
2956  */
2957 function wfBaseName( $path, $suffix = '' ) {
2958         $encSuffix = ( $suffix == '' )
2959                 ? ''
2960                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2961         $matches = array();
2962         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2963                 return $matches[1];
2964         } else {
2965                 return '';
2966         }
2967 }
2968
2969 /**
2970  * Generate a relative path name to the given file.
2971  * May explode on non-matching case-insensitive paths,
2972  * funky symlinks, etc.
2973  *
2974  * @param $path String: absolute destination path including target filename
2975  * @param $from String: Absolute source path, directory only
2976  * @return String
2977  */
2978 function wfRelativePath( $path, $from ) {
2979         // Normalize mixed input on Windows...
2980         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2981         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2982
2983         // Trim trailing slashes -- fix for drive root
2984         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2985         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2986
2987         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2988         $against = explode( DIRECTORY_SEPARATOR, $from );
2989
2990         if( $pieces[0] !== $against[0] ) {
2991                 // Non-matching Windows drive letters?
2992                 // Return a full path.
2993                 return $path;
2994         }
2995
2996         // Trim off common prefix
2997         while( count( $pieces ) && count( $against )
2998                 && $pieces[0] == $against[0] ) {
2999                 array_shift( $pieces );
3000                 array_shift( $against );
3001         }
3002
3003         // relative dots to bump us to the parent
3004         while( count( $against ) ) {
3005                 array_unshift( $pieces, '..' );
3006                 array_shift( $against );
3007         }
3008
3009         array_push( $pieces, wfBaseName( $path ) );
3010
3011         return implode( DIRECTORY_SEPARATOR, $pieces );
3012 }
3013
3014 /**
3015  * Do any deferred updates and clear the list
3016  *
3017  * @deprecated since 1.19
3018  * @see DeferredUpdates::doUpdate()
3019  * @param $commit string
3020  */
3021 function wfDoUpdates( $commit = '' ) {
3022         DeferredUpdates::doUpdates( $commit );
3023 }
3024
3025 /**
3026  * Convert an arbitrarily-long digit string from one numeric base
3027  * to another, optionally zero-padding to a minimum column width.
3028  *
3029  * Supports base 2 through 36; digit values 10-36 are represented
3030  * as lowercase letters a-z. Input is case-insensitive.
3031  *
3032  * @param $input String: of digits
3033  * @param $sourceBase Integer: 2-36
3034  * @param $destBase Integer: 2-36
3035  * @param $pad Integer: 1 or greater
3036  * @param $lowercase Boolean
3037  * @return String or false on invalid input
3038  */
3039 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
3040         $input = strval( $input );
3041         if( $sourceBase < 2 ||
3042                 $sourceBase > 36 ||
3043                 $destBase < 2 ||
3044                 $destBase > 36 ||
3045                 $pad < 1 ||
3046                 $sourceBase != intval( $sourceBase ) ||
3047                 $destBase != intval( $destBase ) ||
3048                 $pad != intval( $pad ) ||
3049                 !is_string( $input ) ||
3050                 $input == '' ) {
3051                 return false;
3052         }
3053         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
3054         $inDigits = array();
3055         $outChars = '';
3056
3057         // Decode and validate input string
3058         $input = strtolower( $input );
3059         for( $i = 0; $i < strlen( $input ); $i++ ) {
3060                 $n = strpos( $digitChars, $input[$i] );
3061                 if( $n === false || $n > $sourceBase ) {
3062                         return false;
3063                 }
3064                 $inDigits[] = $n;
3065         }
3066
3067         // Iterate over the input, modulo-ing out an output digit
3068         // at a time until input is gone.
3069         while( count( $inDigits ) ) {
3070                 $work = 0;
3071                 $workDigits = array();
3072
3073                 // Long division...
3074                 foreach( $inDigits as $digit ) {
3075                         $work *= $sourceBase;
3076                         $work += $digit;
3077
3078                         if( $work < $destBase ) {
3079                                 // Gonna need to pull another digit.
3080                                 if( count( $workDigits ) ) {
3081                                         // Avoid zero-padding; this lets us find
3082                                         // the end of the input very easily when
3083                                         // length drops to zero.
3084                                         $workDigits[] = 0;
3085                                 }
3086                         } else {
3087                                 // Finally! Actual division!
3088                                 $workDigits[] = intval( $work / $destBase );
3089
3090                                 // Isn't it annoying that most programming languages
3091                                 // don't have a single divide-and-remainder operator,
3092                                 // even though the CPU implements it that way?
3093                                 $work = $work % $destBase;
3094                         }
3095                 }
3096
3097                 // All that division leaves us with a remainder,
3098                 // which is conveniently our next output digit.
3099                 $outChars .= $digitChars[$work];
3100
3101                 // And we continue!
3102                 $inDigits = $workDigits;
3103         }
3104
3105         while( strlen( $outChars ) < $pad ) {
3106                 $outChars .= '0';
3107         }
3108
3109         return strrev( $outChars );
3110 }
3111
3112 /**
3113  * Create an object with a given name and an array of construct parameters
3114  *
3115  * @param $name String
3116  * @param $p Array: parameters
3117  * @return object
3118  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3119  */
3120 function wfCreateObject( $name, $p ) {
3121         wfDeprecated( __FUNCTION__ );
3122         return MWFunction::newObj( $name, $p );
3123 }
3124
3125 /**
3126  * @return bool
3127  */
3128 function wfHttpOnlySafe() {
3129         global $wgHttpOnlyBlacklist;
3130
3131         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3132                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3133                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3134                                 return false;
3135                         }
3136                 }
3137         }
3138
3139         return true;
3140 }
3141
3142 /**
3143  * Initialise php session
3144  *
3145  * @param $sessionId Bool
3146  */
3147 function wfSetupSession( $sessionId = false ) {
3148         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3149                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3150         if( $wgSessionsInMemcached ) {
3151                 if ( !defined( 'MW_COMPILED' ) ) {
3152                         global $IP;
3153                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
3154                 }
3155                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3156                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3157
3158                 // It's necessary to register a shutdown function to call session_write_close(),
3159                 // because by the time the request shutdown function for the session module is
3160                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3161                 // this way are called before object destruction.
3162                 register_shutdown_function( 'memsess_write_close' );
3163         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3164                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3165                 # hasn't already been set to the desired value (that causes errors)
3166                 ini_set( 'session.save_handler', $wgSessionHandler );
3167         }
3168         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3169         wfDebugLog( 'cookie',
3170                 'session_set_cookie_params: "' . implode( '", "',
3171                         array(
3172                                 0,
3173                                 $wgCookiePath,
3174                                 $wgCookieDomain,
3175                                 $wgCookieSecure,
3176                                 $httpOnlySafe ) ) . '"' );
3177         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3178         session_cache_limiter( 'private, must-revalidate' );
3179         if ( $sessionId ) {
3180                 session_id( $sessionId );
3181         }
3182         wfSuppressWarnings();
3183         session_start();
3184         wfRestoreWarnings();
3185 }
3186
3187 /**
3188  * Get an object from the precompiled serialized directory
3189  *
3190  * @param $name String
3191  * @return Mixed: the variable on success, false on failure
3192  */
3193 function wfGetPrecompiledData( $name ) {
3194         global $IP;
3195
3196         $file = "$IP/serialized/$name";
3197         if ( file_exists( $file ) ) {
3198                 $blob = file_get_contents( $file );
3199                 if ( $blob ) {
3200                         return unserialize( $blob );
3201                 }
3202         }
3203         return false;
3204 }
3205
3206 /**
3207  * Get a cache key
3208  *
3209  * @param varargs
3210  * @return String
3211  */
3212 function wfMemcKey( /*... */ ) {
3213         global $wgCachePrefix;
3214         $prefix = $wgCachePrefix === false ? wfWikiID() : $wgCachePrefix;
3215         $args = func_get_args();
3216         $key = $prefix . ':' . implode( ':', $args );
3217         $key = str_replace( ' ', '_', $key );
3218         return $key;
3219 }
3220
3221 /**
3222  * Get a cache key for a foreign DB
3223  *
3224  * @param $db String
3225  * @param $prefix String
3226  * @param varargs String
3227  * @return String
3228  */
3229 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3230         $args = array_slice( func_get_args(), 2 );
3231         if ( $prefix ) {
3232                 $key = "$db-$prefix:" . implode( ':', $args );
3233         } else {
3234                 $key = $db . ':' . implode( ':', $args );
3235         }
3236         return $key;
3237 }
3238
3239 /**
3240  * Get an ASCII string identifying this wiki
3241  * This is used as a prefix in memcached keys
3242  *
3243  * @return String
3244  */
3245 function wfWikiID() {
3246         global $wgDBprefix, $wgDBname;
3247         if ( $wgDBprefix ) {
3248                 return "$wgDBname-$wgDBprefix";
3249         } else {
3250                 return $wgDBname;
3251         }
3252 }
3253
3254 /**
3255  * Split a wiki ID into DB name and table prefix
3256  *
3257  * @param $wiki String
3258  *
3259  * @return array
3260  */
3261 function wfSplitWikiID( $wiki ) {
3262         $bits = explode( '-', $wiki, 2 );
3263         if ( count( $bits ) < 2 ) {
3264                 $bits[] = '';
3265         }
3266         return $bits;
3267 }
3268
3269 /**
3270  * Get a Database object.
3271  *
3272  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3273  *            master (for write queries), DB_SLAVE for potentially lagged read
3274  *            queries, or an integer >= 0 for a particular server.
3275  *
3276  * @param $groups Mixed: query groups. An array of group names that this query
3277  *                belongs to. May contain a single string if the query is only
3278  *                in one group.
3279  *
3280  * @param $wiki String: the wiki ID, or false for the current wiki
3281  *
3282  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3283  * will always return the same object, unless the underlying connection or load
3284  * balancer is manually destroyed.
3285  *
3286  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3287  * updater to ensure that a proper database is being updated.
3288  *
3289  * @return DatabaseBase
3290  */
3291 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3292         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3293 }
3294
3295 /**
3296  * Get a load balancer object.
3297  *
3298  * @param $wiki String: wiki ID, or false for the current wiki
3299  * @return LoadBalancer
3300  */
3301 function wfGetLB( $wiki = false ) {
3302         return wfGetLBFactory()->getMainLB( $wiki );
3303 }
3304
3305 /**
3306  * Get the load balancer factory object
3307  *
3308  * @return LBFactory
3309  */
3310 function &wfGetLBFactory() {
3311         return LBFactory::singleton();
3312 }
3313
3314 /**
3315  * Find a file.
3316  * Shortcut for RepoGroup::singleton()->findFile()
3317  *
3318  * @param $title String or Title object
3319  * @param $options Associative array of options:
3320  *     time:           requested time for an archived image, or false for the
3321  *                     current version. An image object will be returned which was
3322  *                     created at the specified time.
3323  *
3324  *     ignoreRedirect: If true, do not follow file redirects
3325  *
3326  *     private:        If true, return restricted (deleted) files if the current
3327  *                     user is allowed to view them. Otherwise, such files will not
3328  *                     be found.
3329  *
3330  *     bypassCache:    If true, do not use the process-local cache of File objects
3331  *
3332  * @return File, or false if the file does not exist
3333  */
3334 function wfFindFile( $title, $options = array() ) {
3335         return RepoGroup::singleton()->findFile( $title, $options );
3336 }
3337
3338 /**
3339  * Get an object referring to a locally registered file.
3340  * Returns a valid placeholder object if the file does not exist.
3341  *
3342  * @param $title Title or String
3343  * @return File|null A File, or null if passed an invalid Title
3344  */
3345 function wfLocalFile( $title ) {
3346         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3347 }
3348
3349 /**
3350  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3351  * @deprecated since 1.19
3352  */
3353 function wfStreamFile( $fname, $headers = array() ) {
3354         StreamFile::stream( $fname, $headers );
3355 }
3356
3357 /**
3358  * Should low-performance queries be disabled?
3359  *
3360  * @return Boolean
3361  * @codeCoverageIgnore
3362  */
3363 function wfQueriesMustScale() {
3364         global $wgMiserMode;
3365         return $wgMiserMode
3366                 || ( SiteStats::pages() > 100000
3367                 && SiteStats::edits() > 1000000
3368                 && SiteStats::users() > 10000 );
3369 }
3370
3371 /**
3372  * Get the path to a specified script file, respecting file
3373  * extensions; this is a wrapper around $wgScriptExtension etc.
3374  *
3375  * @param $script String: script filename, sans extension
3376  * @return String
3377  */
3378 function wfScript( $script = 'index' ) {
3379         global $wgScriptPath, $wgScriptExtension;
3380         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3381 }
3382
3383 /**
3384  * Get the script URL.
3385  *
3386  * @return script URL
3387  */
3388 function wfGetScriptUrl() {
3389         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3390                 #
3391                 # as it was called, minus the query string.
3392                 #
3393                 # Some sites use Apache rewrite rules to handle subdomains,
3394                 # and have PHP set up in a weird way that causes PHP_SELF
3395                 # to contain the rewritten URL instead of the one that the
3396                 # outside world sees.
3397                 #
3398                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3399                 # provides containing the "before" URL.
3400                 return $_SERVER['SCRIPT_NAME'];
3401         } else {
3402                 return $_SERVER['URL'];
3403         }
3404 }
3405
3406 /**
3407  * Convenience function converts boolean values into "true"
3408  * or "false" (string) values
3409  *
3410  * @param $value Boolean
3411  * @return String
3412  */
3413 function wfBoolToStr( $value ) {
3414         return $value ? 'true' : 'false';
3415 }
3416
3417 /**
3418  * Load an extension messages file
3419  *
3420  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3421  * @codeCoverageIgnore
3422  */
3423 function wfLoadExtensionMessages() {
3424         wfDeprecated( __FUNCTION__ );
3425 }
3426
3427 /**
3428  * Get a platform-independent path to the null file, e.g. /dev/null
3429  *
3430  * @return string
3431  */
3432 function wfGetNull() {
3433         return wfIsWindows()
3434                 ? 'NUL'
3435                 : '/dev/null';
3436 }
3437
3438 /**
3439  * Throws a warning that $function is deprecated
3440  *
3441  * @param $function String
3442  * @param $version String
3443  * @return null
3444  */
3445 function wfDeprecated( $function, $version = false ) {
3446         static $functionsWarned = array();
3447         if ( !isset( $functionsWarned[$function] ) ) {
3448                 $functionsWarned[$function] = true;
3449                 if ( $version ) {
3450                         global $wgDeprecationReleaseLimit;
3451                         if ( $wgDeprecationReleaseLimit ) {
3452                                 # Strip -* off the end of $version so that branches can use the
3453                                 # format #.##-branchname to avoid issues if the branch is merged into
3454                                 # a version of MediaWiki later than what it was branched from
3455                                 $comparableVersion = preg_replace( '/-.*$/', '', $version );
3456                                 # If the comparableVersion is larger than our release limit then
3457                                 # skip the warning message for the deprecation
3458                                 if ( version_compare( $wgDeprecationReleaseLimit, $comparableVersion, '<' ) ) {
3459                                         return;
3460                                 }
3461                         }
3462                         wfWarn( "Use of $function was deprecated in $version.", 2 );
3463                 } else {
3464                         wfWarn( "Use of $function is deprecated.", 2 );
3465                 }
3466         }
3467 }
3468
3469 /**
3470  * Send a warning either to the debug log or in a PHP error depending on
3471  * $wgDevelopmentWarnings
3472  *
3473  * @param $msg String: message to send
3474  * @param $callerOffset Integer: number of items to go back in the backtrace to
3475  *        find the correct caller (1 = function calling wfWarn, ...)
3476  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3477  *        is true
3478  */
3479 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3480         global $wgDevelopmentWarnings;
3481
3482         $callers = wfDebugBacktrace();
3483         if ( isset( $callers[$callerOffset + 1] ) ) {
3484                 $callerfunc = $callers[$callerOffset + 1];
3485                 $callerfile = $callers[$callerOffset];
3486                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3487                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3488                 } else {
3489                         $file = '(internal function)';
3490                 }
3491                 $func = '';
3492                 if ( isset( $callerfunc['class'] ) ) {
3493                         $func .= $callerfunc['class'] . '::';
3494                 }
3495                 if ( isset( $callerfunc['function'] ) ) {
3496                         $func .= $callerfunc['function'];
3497                 }
3498                 $msg .= " [Called from $func in $file]";
3499         }
3500
3501         if ( $wgDevelopmentWarnings ) {
3502                 trigger_error( $msg, $level );
3503         } else {
3504                 wfDebug( "$msg\n" );
3505         }
3506 }
3507
3508 /**
3509  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3510  * and waiting for it to go down, this waits for the slaves to catch up to the
3511  * master position. Use this when updating very large numbers of rows, as
3512  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3513  * a no-op if there are no slaves.
3514  *
3515  * @param $maxLag Integer (deprecated)
3516  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3517  */
3518 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3519         $lb = wfGetLB( $wiki );
3520         // bug 27975 - Don't try to wait for slaves if there are none
3521         // Prevents permission error when getting master position
3522         if ( $lb->getServerCount() > 1 ) {
3523                 $dbw = $lb->getConnection( DB_MASTER );
3524                 $pos = $dbw->getMasterPos();
3525                 $lb->waitForAll( $pos );
3526         }
3527 }
3528
3529 /**
3530  * Used to be used for outputting text in the installer/updater
3531  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3532  */
3533 function wfOut( $s ) {
3534         wfDeprecated( __METHOD__ );
3535         global $wgCommandLineMode;
3536         if ( $wgCommandLineMode ) {
3537                 echo $s;
3538         } else {
3539                 echo htmlspecialchars( $s );
3540         }
3541         flush();
3542 }
3543
3544 /**
3545  * Count down from $n to zero on the terminal, with a one-second pause
3546  * between showing each number. For use in command-line scripts.
3547  * @codeCoverageIgnore
3548  * @param $n int
3549  */
3550 function wfCountDown( $n ) {
3551         for ( $i = $n; $i >= 0; $i-- ) {
3552                 if ( $i != $n ) {
3553                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3554                 }
3555                 echo $i;
3556                 flush();
3557                 if ( $i ) {
3558                         sleep( 1 );
3559                 }
3560         }
3561         echo "\n";
3562 }
3563
3564 /**
3565  * Generate a random 32-character hexadecimal token.
3566  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3567  *              characters before hashing.
3568  * @return string
3569  * @codeCoverageIgnore
3570  */
3571 function wfGenerateToken( $salt = '' ) {
3572         $salt = serialize( $salt );
3573         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3574 }
3575
3576 /**
3577  * Replace all invalid characters with -
3578  *
3579  * @param $name Mixed: filename to process
3580  * @return String
3581  */
3582 function wfStripIllegalFilenameChars( $name ) {
3583         global $wgIllegalFileChars;
3584         $name = wfBaseName( $name );
3585         $name = preg_replace(
3586                 "/[^" . Title::legalChars() . "]" .
3587                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3588                         "/",
3589                 '-',
3590                 $name
3591         );
3592         return $name;
3593 }
3594
3595 /**
3596  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3597  *
3598  * @return Integer value memory was set to.
3599  */
3600 function wfMemoryLimit() {
3601         global $wgMemoryLimit;
3602         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3603         if( $memlimit != -1 ) {
3604                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3605                 if( $conflimit == -1 ) {
3606                         wfDebug( "Removing PHP's memory limit\n" );
3607                         wfSuppressWarnings();
3608                         ini_set( 'memory_limit', $conflimit );
3609                         wfRestoreWarnings();
3610                         return $conflimit;
3611                 } elseif ( $conflimit > $memlimit ) {
3612                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3613                         wfSuppressWarnings();
3614                         ini_set( 'memory_limit', $conflimit );
3615                         wfRestoreWarnings();
3616                         return $conflimit;
3617                 }
3618         }
3619         return $memlimit;
3620 }
3621
3622 /**
3623  * Converts shorthand byte notation to integer form
3624  *
3625  * @param $string String
3626  * @return Integer
3627  */
3628 function wfShorthandToInteger( $string = '' ) {
3629         $string = trim( $string );
3630         if( $string === '' ) {
3631                 return -1;
3632         }
3633         $last = $string[strlen( $string ) - 1];
3634         $val = intval( $string );
3635         switch( $last ) {
3636                 case 'g':
3637                 case 'G':
3638                         $val *= 1024;
3639                         // break intentionally missing
3640                 case 'm':
3641                 case 'M':
3642                         $val *= 1024;
3643                         // break intentionally missing
3644                 case 'k':
3645                 case 'K':
3646                         $val *= 1024;
3647         }
3648
3649         return $val;
3650 }
3651
3652 /**
3653  * Get the normalised IETF language tag
3654  * See unit test for examples.
3655  *
3656  * @param $code String: The language code.
3657  * @return String: The language code which complying with BCP 47 standards.
3658  */
3659 function wfBCP47( $code ) {
3660         $codeSegment = explode( '-', $code );
3661         $codeBCP = array();
3662         foreach ( $codeSegment as $segNo => $seg ) {
3663                 if ( count( $codeSegment ) > 0 ) {
3664                         // when previous segment is x, it is a private segment and should be lc
3665                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3666                                 $codeBCP[$segNo] = strtolower( $seg );
3667                         // ISO 3166 country code
3668                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3669                                 $codeBCP[$segNo] = strtoupper( $seg );
3670                         // ISO 15924 script code
3671                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3672                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3673                         // Use lowercase for other cases
3674                         } else {
3675                                 $codeBCP[$segNo] = strtolower( $seg );
3676                         }
3677                 } else {
3678                 // Use lowercase for single segment
3679                         $codeBCP[$segNo] = strtolower( $seg );
3680                 }
3681         }
3682         $langCode = implode( '-', $codeBCP );
3683         return $langCode;
3684 }
3685
3686 /**
3687  * Get a cache object.
3688  *
3689  * @param $inputType integer Cache type, one the the CACHE_* constants.
3690  * @return BagOStuff
3691  */
3692 function wfGetCache( $inputType ) {
3693         return ObjectCache::getInstance( $inputType );
3694 }
3695
3696 /**
3697  * Get the main cache object
3698  *
3699  * @return BagOStuff
3700  */
3701 function wfGetMainCache() {
3702         global $wgMainCacheType;
3703         return ObjectCache::getInstance( $wgMainCacheType );
3704 }
3705
3706 /**
3707  * Get the cache object used by the message cache
3708  *
3709  * @return BagOStuff
3710  */
3711 function wfGetMessageCacheStorage() {
3712         global $wgMessageCacheType;
3713         return ObjectCache::getInstance( $wgMessageCacheType );
3714 }
3715
3716 /**
3717  * Get the cache object used by the parser cache
3718  *
3719  * @return BagOStuff
3720  */
3721 function wfGetParserCacheStorage() {
3722         global $wgParserCacheType;
3723         return ObjectCache::getInstance( $wgParserCacheType );
3724 }
3725
3726 /**
3727  * Call hook functions defined in $wgHooks
3728  *
3729  * @param $event String: event name
3730  * @param $args Array: parameters passed to hook functions
3731  * @return Boolean
3732  */
3733 function wfRunHooks( $event, $args = array() ) {
3734         return Hooks::run( $event, $args );
3735 }
3736
3737 /**
3738  * Wrapper around php's unpack.
3739  *
3740  * @param $format String: The format string (See php's docs)
3741  * @param $data: A binary string of binary data
3742  * @param $length integer or false: The minimun length of $data. This is to
3743  *      prevent reading beyond the end of $data. false to disable the check.
3744  *
3745  * Also be careful when using this function to read unsigned 32 bit integer
3746  * because php might make it negative.
3747  *
3748  * @throws MWException if $data not long enough, or if unpack fails
3749  * @return Associative array of the extracted data
3750  */
3751 function wfUnpack( $format, $data, $length=false ) {
3752         if ( $length !== false ) {
3753                 $realLen = strlen( $data );
3754                 if ( $realLen < $length ) {
3755                         throw new MWException( "Tried to use wfUnpack on a "
3756                                 . "string of length $realLen, but needed one "
3757                                 . "of at least length $length."
3758                         );
3759                 }
3760         }
3761
3762         wfSuppressWarnings();
3763         $result = unpack( $format, $data );
3764         wfRestoreWarnings();
3765
3766         if ( $result === false ) {
3767                 // If it cannot extract the packed data.
3768                 throw new MWException( "unpack could not unpack binary data" );
3769         }
3770         return $result;
3771 }