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  */
  85 function wfArrayDiff2( $a, $b ) {
  86         return array_udiff( $a, $b, 'wfArrayDiff2_cmp' );
  87 }
  88
  89 /**
  90  * @param $a
  91  * @param $b
  92  * @return int
  93  */
  94 function wfArrayDiff2_cmp( $a, $b ) {
  95         if ( !is_array( $a ) ) {
  96                 return strcmp( $a, $b );
  97         } elseif ( count( $a ) !== count( $b ) ) {
  98                 return count( $a ) < count( $b ) ? -1 : 1;
  99         } else {
 100                 reset( $a );
 101                 reset( $b );
 102                 while( ( list( , $valueA ) = each( $a ) ) && ( list( , $valueB ) = each( $b ) ) ) {
 103                         $cmp = strcmp( $valueA, $valueB );
 104                         if ( $cmp !== 0 ) {
 105                                 return $cmp;
 106                         }
 107                 }
 108                 return 0;
 109         }
 110 }
 111
 112 /**
 113  * Array lookup
 114  * Returns an array where the values in the first array are replaced by the
 115  * values in the second array with the corresponding keys
 116  *
 117  * @param $a Array
 118  * @param $b Array
 119  * @return array
 120  */
 121 function wfArrayLookup( $a, $b ) {
 122         return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
 123 }
 124
 125 /**
 126  * Appends to second array if $value differs from that in $default
 127  *
 128  * @param $key String|Int
 129  * @param $value Mixed
 130  * @param $default Mixed
 131  * @param $changed Array to alter
 132  */
 133 function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
 134         if ( is_null( $changed ) ) {
 135                 throw new MWException( 'GlobalFunctions::wfAppendToArrayIfNotDefault got null' );
 136         }
 137         if ( $default[$key] !== $value ) {
 138                 $changed[$key] = $value;
 139         }
 140 }
 141
 142 /**
 143  * Backwards array plus for people who haven't bothered to read the PHP manual
 144  * XXX: will not darn your socks for you.
 145  *
 146  * @param $array1 Array
 147  * @param [$array2, [...]] Arrays
 148  * @return Array
 149  */
 150 function wfArrayMerge( $array1/* ... */ ) {
 151         $args = func_get_args();
 152         $args = array_reverse( $args, true );
 153         $out = array();
 154         foreach ( $args as $arg ) {
 155                 $out += $arg;
 156         }
 157         return $out;
 158 }
 159
 160 /**
 161  * Merge arrays in the style of getUserPermissionsErrors, with duplicate removal
 162  * e.g.
 163  *      wfMergeErrorArrays(
 164  *              array( array( 'x' ) ),
 165  *              array( array( 'x', '2' ) ),
 166  *              array( array( 'x' ) ),
 167  *              array( array( 'y' ) )
 168  *      );
 169  * returns:
 170  *              array(
 171  *              array( 'x', '2' ),
 172  *              array( 'x' ),
 173  *              array( 'y' )
 174  *      )
 175  * @param varargs
 176  * @return Array
 177  */
 178 function wfMergeErrorArrays( /*...*/ ) {
 179         $args = func_get_args();
 180         $out = array();
 181         foreach ( $args as $errors ) {
 182                 foreach ( $errors as $params ) {
 183                         # @todo FIXME: Sometimes get nested arrays for $params,
 184                         # which leads to E_NOTICEs
 185                         $spec = implode( "\t", $params );
 186                         $out[$spec] = $params;
 187                 }
 188         }
 189         return array_values( $out );
 190 }
 191
 192 /**
 193  * Insert array into another array after the specified *KEY*
 194  *
 195  * @param $array Array: The array.
 196  * @param $insert Array: The array to insert.
 197  * @param $after Mixed: The key to insert after
 198  * @return Array
 199  */
 200 function wfArrayInsertAfter( $array, $insert, $after ) {
 201         // Find the offset of the element to insert after.
 202         $keys = array_keys( $array );
 203         $offsetByKey = array_flip( $keys );
 204
 205         $offset = $offsetByKey[$after];
 206
 207         // Insert at the specified offset
 208         $before = array_slice( $array, 0, $offset + 1, true );
 209         $after = array_slice( $array, $offset + 1, count( $array ) - $offset, true );
 210
 211         $output = $before + $insert + $after;
 212
 213         return $output;
 214 }
 215
 216 /**
 217  * Recursively converts the parameter (an object) to an array with the same data
 218  *
 219  * @param $objOrArray Object|Array
 220  * @param $recursive Bool
 221  * @return Array
 222  */
 223 function wfObjectToArray( $objOrArray, $recursive = true ) {
 224         $array = array();
 225         if( is_object( $objOrArray ) ) {
 226                 $objOrArray = get_object_vars( $objOrArray );
 227         }
 228         foreach ( $objOrArray as $key => $value ) {
 229                 if ( $recursive && ( is_object( $value ) || is_array( $value ) ) ) {
 230                         $value = wfObjectToArray( $value );
 231                 }
 232
 233                 $array[$key] = $value;
 234         }
 235
 236         return $array;
 237 }
 238
 239 /**
 240  * Wrapper around array_map() which also taints variables
 241  *
 242  * @param  $function Callback
 243  * @param  $input Array
 244  * @return Array
 245  */
 246 function wfArrayMap( $function, $input ) {
 247         $ret = array_map( $function, $input );
 248         foreach ( $ret as $key => $value ) {
 249                 $taint = istainted( $input[$key] );
 250                 if ( $taint ) {
 251                         taint( $ret[$key], $taint );
 252                 }
 253         }
 254         return $ret;
 255 }
 256
 257 /**
 258  * Get a random decimal value between 0 and 1, in a way
 259  * not likely to give duplicate values for any realistic
 260  * number of articles.
 261  *
 262  * @return string
 263  */
 264 function wfRandom() {
 265         # The maximum random value is "only" 2^31-1, so get two random
 266         # values to reduce the chance of dupes
 267         $max = mt_getrandmax() + 1;
 268         $rand = number_format( ( mt_rand() * $max + mt_rand() )
 269                 / $max / $max, 12, '.', '' );
 270         return $rand;
 271 }
 272
 273 /**
 274  * We want some things to be included as literal characters in our title URLs
 275  * for prettiness, which urlencode encodes by default.  According to RFC 1738,
 276  * all of the following should be safe:
 277  *
 278  * ;:@&=$-_.+!*'(),
 279  *
 280  * But + is not safe because it's used to indicate a space; &= are only safe in
 281  * paths and not in queries (and we don't distinguish here); ' seems kind of
 282  * scary; and urlencode() doesn't touch -_. to begin with.  Plus, although /
 283  * is reserved, we don't care.  So the list we unescape is:
 284  *
 285  * ;:@$!*(),/
 286  *
 287  * However, IIS7 redirects fail when the url contains a colon (Bug 22709),
 288  * so no fancy : for IIS7.
 289  *
 290  * %2F in the page titles seems to fatally break for some reason.
 291  *
 292  * @param $s String:
 293  * @return string
 294 */
 295 function wfUrlencode( $s ) {
 296         static $needle;
 297         if ( is_null( $s ) ) {
 298                 $needle = null;
 299                 return '';
 300         }
 301
 302         if ( is_null( $needle ) ) {
 303                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 304                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 305                         $needle[] = '%3A';
 306                 }
 307         }
 308
 309         $s = urlencode( $s );
 310         $s = str_ireplace(
 311                 $needle,
 312                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 313                 $s
 314         );
 315
 316         return $s;
 317 }
 318
 319 /**
 320  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 321  * "days=7&limit=100". Options in the first array override options in the second.
 322  * Options set to "" will not be output.
 323  *
 324  * @param $array1 Array ( String|Array )
 325  * @param $array2 Array ( String|Array )
 326  * @param $prefix String
 327  * @return String
 328  */
 329 function wfArrayToCGI( $array1, $array2 = null, $prefix = '' ) {
 330         if ( !is_null( $array2 ) ) {
 331                 $array1 = $array1 + $array2;
 332         }
 333
 334         $cgi = '';
 335         foreach ( $array1 as $key => $value ) {
 336                 if ( $value !== '' ) {
 337                         if ( $cgi != '' ) {
 338                                 $cgi .= '&';
 339                         }
 340                         if ( $prefix !== '' ) {
 341                                 $key = $prefix . "[$key]";
 342                         }
 343                         if ( is_array( $value ) ) {
 344                                 $firstTime = true;
 345                                 foreach ( $value as $k => $v ) {
 346                                         $cgi .= $firstTime ? '' : '&';
 347                                         if ( is_array( $v ) ) {
 348                                                 $cgi .= wfArrayToCGI( $v, null, $key . "[$k]" );
 349                                         } else {
 350                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 351                                         }
 352                                         $firstTime = false;
 353                                 }
 354                         } else {
 355                                 if ( is_object( $value ) ) {
 356                                         $value = $value->__toString();
 357                                 }
 358                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 359                         }
 360                 }
 361         }
 362         return $cgi;
 363 }
 364
 365 /**
 366  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
 367  * its argument and returns the same string in array form.  This allows compa-
 368  * tibility with legacy functions that accept raw query strings instead of nice
 369  * arrays.  Of course, keys and values are urldecode()d.  Don't try passing in-
 370  * valid query strings, or it will explode.
 371  *
 372  * @param $query String: query string
 373  * @return array Array version of input
 374  */
 375 function wfCgiToArray( $query ) {
 376         if ( isset( $query[0] ) && $query[0] == '?' ) {
 377                 $query = substr( $query, 1 );
 378         }
 379         $bits = explode( '&', $query );
 380         $ret = array();
 381         foreach ( $bits as $bit ) {
 382                 if ( $bit === '' ) {
 383                         continue;
 384                 }
 385                 list( $key, $value ) = explode( '=', $bit );
 386                 $key = urldecode( $key );
 387                 $value = urldecode( $value );
 388                 if ( strpos( $key, '[' ) !== false ) {
 389                         $keys = array_reverse( explode( '[', $key ) );
 390                         $key = array_pop( $keys );
 391                         $temp = $value;
 392                         foreach ( $keys as $k ) {
 393                                 $k = substr( $k, 0, -1 );
 394                                 $temp = array( $k => $temp );
 395                         }
 396                         if ( isset( $ret[$key] ) ) {
 397                                 $ret[$key] = array_merge( $ret[$key], $temp );
 398                         } else {
 399                                 $ret[$key] = $temp;
 400                         }
 401                 } else {
 402                         $ret[$key] = $value;
 403                 }
 404         }
 405         return $ret;
 406 }
 407
 408 /**
 409  * Append a query string to an existing URL, which may or may not already
 410  * have query string parameters already. If so, they will be combined.
 411  *
 412  * @param $url String
 413  * @param $query Mixed: string or associative array
 414  * @return string
 415  */
 416 function wfAppendQuery( $url, $query ) {
 417         if ( is_array( $query ) ) {
 418                 $query = wfArrayToCGI( $query );
 419         }
 420         if( $query != '' ) {
 421                 if( false === strpos( $url, '?' ) ) {
 422                         $url .= '?';
 423                 } else {
 424                         $url .= '&';
 425                 }
 426                 $url .= $query;
 427         }
 428         return $url;
 429 }
 430
 431 /**
 432  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 433  * is correct.
 434  *
 435  * The meaning of the PROTO_* constants is as follows:
 436  * PROTO_HTTP: Output a URL starting with http://
 437  * PROTO_HTTPS: Output a URL starting with https://
 438  * PROTO_RELATIVE: Output a URL starting with // (protocol-relative URL)
 439  * PROTO_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 440  * PROTO_CANONICAL: For URLs without a domain, like /w/index.php , use $wgCanonicalServer. For protocol-relative URLs, use the protocol of $wgCanonicalServer
 441  * PROTO_INTERNAL: Like PROTO_CANONICAL, but uses $wgInternalServer instead of $wgCanonicalServer
 442  *
 443  * @todo this won't work with current-path-relative URLs
 444  * like "subdir/foo.html", etc.
 445  *
 446  * @param $url String: either fully-qualified or a local path + query
 447  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the protocol to use if $url or $wgServer is protocol-relative
 448  * @return string Fully-qualified URL
 449  */
 450 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 451         global $wgServer, $wgCanonicalServer, $wgInternalServer;
 452         $serverUrl = $wgServer;
 453         if ( $defaultProto === PROTO_CANONICAL ) {
 454                 $serverUrl = $wgCanonicalServer;
 455         }
 456         // Make $wgInternalServer fall back to $wgServer if not set
 457         if ( $defaultProto === PROTO_INTERNAL && $wgInternalServer !== false ) {
 458                 $serverUrl = $wgInternalServer;
 459         }
 460         if ( $defaultProto === PROTO_CURRENT ) {
 461                 $defaultProto = WebRequest::detectProtocol() . '://';
 462         }
 463
 464         // Analyze $serverUrl to obtain its protocol
 465         $bits = wfParseUrl( $serverUrl );
 466         $serverHasProto = $bits && $bits['scheme'] != '';
 467
 468         if ( $defaultProto === PROTO_CANONICAL || $defaultProto === PROTO_INTERNAL ) {
 469                 if ( $serverHasProto ) {
 470                         $defaultProto = $bits['scheme'] . '://';
 471                 } else {
 472                         // $wgCanonicalServer or $wgInternalServer doesn't have a protocol. This really isn't supposed to happen
 473                         // Fall back to HTTP in this ridiculous case
 474                         $defaultProto = PROTO_HTTP;
 475                 }
 476         }
 477
 478         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 479
 480         if ( substr( $url, 0, 2 ) == '//' ) {
 481                 return $defaultProtoWithoutSlashes . $url;
 482         } elseif ( substr( $url, 0, 1 ) == '/' ) {
 483                 // If $serverUrl is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 484                 return ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $serverUrl . $url;
 485         } else {
 486                 return $url;
 487         }
 488 }
 489
 490 /**
 491  * Remove all dot-segments in the provided URL path.  For example,
 492  * '/a/./b/../c/' becomes '/a/c/'.  For details on the algorithm, please see
 493  * RFC3986 section 5.2.4.
 494  *
 495  * @todo Need to integrate this into wfExpandUrl (bug 32168)
 496  *
 497  * @param $urlPath String URL path, potentially containing dot-segments
 498  * @return string URL path with all dot-segments removed
 499  */
 500 function wfRemoveDotSegments( $urlPath ) {
 501         $output = '';
 502
 503         while ( $urlPath ) {
 504                 $matches = null;
 505                 if ( preg_match('%^\.\.?/%', $urlPath, $matches) ) {
 506                         # Step A, remove leading "../" or "./"
 507                         $urlPath = substr( $urlPath, strlen( $matches[0] ) );
 508                 } elseif ( preg_match( '%^/\.(/|$)%', $urlPath, $matches ) ) {
 509                         # Step B, replace leading "/.$" or "/./" with "/"
 510                         $start = strlen( $matches[0] );
 511                         $urlPath = '/' . substr( $urlPath, $start );
 512                 } elseif ( preg_match( '%^/\.\.(/|$)%', $urlPath, $matches ) ) {
 513                         # Step C, replace leading "/..$" or "/../" with "/" and
 514                         # remove last path component in output
 515                         $start = strlen( $matches[0] );
 516                         $urlPath = '/' . substr( $urlPath, $start );
 517                         $output = preg_replace('%(^|/)[^/]*$%', '', $output);
 518                 } elseif ( preg_match( '%^\.\.?$%', $urlPath, $matches ) ) {
 519                         # Step D, remove "^..$" or "^.$"
 520                         $urlPath = '';
 521                 } else {
 522                         # Step E, move leading path segment to output
 523                         preg_match( '%^/?[^/]*%', $urlPath, $matches );
 524                         $urlPath = substr( $urlPath, strlen( $matches[0] ) );
 525                         $output .= $matches[0];
 526                 }
 527         }
 528
 529         return $output;
 530 }
 531
 532 /**
 533  * Returns a regular expression of url protocols
 534  *
 535  * @param $includeProtocolRelative bool If false, remove '//' from the returned protocol list.
 536  *        DO NOT USE this directly, use wfUrlProtocolsWithoutProtRel() instead
 537  * @return String
 538  */
 539 function wfUrlProtocols( $includeProtocolRelative = true ) {
 540         global $wgUrlProtocols;
 541
 542         // Cache return values separately based on $includeProtocolRelative
 543         static $withProtRel = null, $withoutProtRel = null;
 544         $cachedValue = $includeProtocolRelative ? $withProtRel : $withoutProtRel;
 545         if ( !is_null( $cachedValue ) ) {
 546                 return $cachedValue;
 547         }
 548
 549         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 550         // with LocalSettings files from 1.5
 551         if ( is_array( $wgUrlProtocols ) ) {
 552                 $protocols = array();
 553                 foreach ( $wgUrlProtocols as $protocol ) {
 554                         // Filter out '//' if !$includeProtocolRelative
 555                         if ( $includeProtocolRelative || $protocol !== '//' ) {
 556                                 $protocols[] = preg_quote( $protocol, '/' );
 557                         }
 558                 }
 559
 560                 $retval = implode( '|', $protocols );
 561         } else {
 562                 // Ignore $includeProtocolRelative in this case
 563                 // This case exists for pre-1.6 compatibility, and we can safely assume
 564                 // that '//' won't appear in a pre-1.6 config because protocol-relative
 565                 // URLs weren't supported until 1.18
 566                 $retval = $wgUrlProtocols;
 567         }
 568
 569         // Cache return value
 570         if ( $includeProtocolRelative ) {
 571                 $withProtRel = $retval;
 572         } else {
 573                 $withoutProtRel = $retval;
 574         }
 575         return $retval;
 576 }
 577
 578 /**
 579  * Like wfUrlProtocols(), but excludes '//' from the protocol list. Use this if
 580  * you need a regex that matches all URL protocols but does not match protocol-
 581  * relative URLs
 582  * @return String
 583  */
 584 function wfUrlProtocolsWithoutProtRel() {
 585         return wfUrlProtocols( false );
 586 }
 587
 588 /**
 589  * parse_url() work-alike, but non-broken.  Differences:
 590  *
 591  * 1) Does not raise warnings on bad URLs (just returns false)
 592  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 593  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 594  *
 595  * @param $url String: a URL to parse
 596  * @return Array: bits of the URL in an associative array, per PHP docs
 597  */
 598 function wfParseUrl( $url ) {
 599         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 600
 601         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 602         // way to handle them is to just prepend 'http:' and strip the protocol out later
 603         $wasRelative = substr( $url, 0, 2 ) == '//';
 604         if ( $wasRelative ) {
 605                 $url = "http:$url";
 606         }
 607         wfSuppressWarnings();
 608         $bits = parse_url( $url );
 609         wfRestoreWarnings();
 610         // parse_url() returns an array without scheme for some invalid URLs, e.g.
 611         // parse_url("%0Ahttp://example.com") == array( 'host' => '%0Ahttp', 'path' => 'example.com' )
 612         if ( !$bits || !isset( $bits['scheme'] ) ) {
 613                 return false;
 614         }
 615
 616         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 617         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 618                 $bits['delimiter'] = '://';
 619         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 620                 $bits['delimiter'] = ':';
 621                 // parse_url detects for news: and mailto: the host part of an url as path
 622                 // We have to correct this wrong detection
 623                 if ( isset( $bits['path'] ) ) {
 624                         $bits['host'] = $bits['path'];
 625                         $bits['path'] = '';
 626                 }
 627         } else {
 628                 return false;
 629         }
 630
 631         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 632         if ( !isset( $bits['host'] ) ) {
 633                 $bits['host'] = '';
 634
 635                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 636                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 637                         $bits['path'] = '/' . $bits['path'];
 638                 }
 639         }
 640
 641         // If the URL was protocol-relative, fix scheme and delimiter
 642         if ( $wasRelative ) {
 643                 $bits['scheme'] = '';
 644                 $bits['delimiter'] = '//';
 645         }
 646         return $bits;
 647 }
 648
 649 /**
 650  * Make URL indexes, appropriate for the el_index field of externallinks.
 651  *
 652  * @param $url String
 653  * @return array
 654  */
 655 function wfMakeUrlIndexes( $url ) {
 656         $bits = wfParseUrl( $url );
 657
 658         // Reverse the labels in the hostname, convert to lower case
 659         // For emails reverse domainpart only
 660         if ( $bits['scheme'] == 'mailto' ) {
 661                 $mailparts = explode( '@', $bits['host'], 2 );
 662                 if ( count( $mailparts ) === 2 ) {
 663                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 664                 } else {
 665                         // No domain specified, don't mangle it
 666                         $domainpart = '';
 667                 }
 668                 $reversedHost = $domainpart . '@' . $mailparts[0];
 669         } else {
 670                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 671         }
 672         // Add an extra dot to the end
 673         // Why? Is it in wrong place in mailto links?
 674         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 675                 $reversedHost .= '.';
 676         }
 677         // Reconstruct the pseudo-URL
 678         $prot = $bits['scheme'];
 679         $index = $prot . $bits['delimiter'] . $reversedHost;
 680         // Leave out user and password. Add the port, path, query and fragment
 681         if ( isset( $bits['port'] ) ) {
 682                 $index .= ':' . $bits['port'];
 683         }
 684         if ( isset( $bits['path'] ) ) {
 685                 $index .= $bits['path'];
 686         } else {
 687                 $index .= '/';
 688         }
 689         if ( isset( $bits['query'] ) ) {
 690                 $index .= '?' . $bits['query'];
 691         }
 692         if ( isset( $bits['fragment'] ) ) {
 693                 $index .= '#' . $bits['fragment'];
 694         }
 695
 696         if ( $prot == '' ) {
 697                 return array( "http:$index", "https:$index" );
 698         } else {
 699                 return array( $index );
 700         }
 701 }
 702
 703 /**
 704  * Check whether a given URL has a domain that occurs in a given set of domains
 705  * @param $url string URL
 706  * @param $domains array Array of domains (strings)
 707  * @return bool True if the host part of $url ends in one of the strings in $domains
 708  */
 709 function wfMatchesDomainList( $url, $domains ) {
 710         $bits = wfParseUrl( $url );
 711         if ( is_array( $bits ) && isset( $bits['host'] ) ) {
 712                 foreach ( (array)$domains as $domain ) {
 713                         // FIXME: This gives false positives. http://nds-nl.wikipedia.org will match nl.wikipedia.org
 714                         // We should use something that interprets dots instead
 715                         if ( substr( $bits['host'], -strlen( $domain ) ) === $domain ) {
 716                                 return true;
 717                         }
 718                 }
 719         }
 720         return false;
 721 }
 722
 723 /**
 724  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 725  * In normal operation this is a NOP.
 726  *
 727  * Controlling globals:
 728  * $wgDebugLogFile - points to the log file
 729  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 730  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 731  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 732  *
 733  * @param $text String
 734  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 735  */
 736 function wfDebug( $text, $logonly = false ) {
 737         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 738         global $wgDebugLogPrefix, $wgShowDebug;
 739
 740         static $cache = array(); // Cache of unoutputted messages
 741         $text = wfDebugTimer() . $text;
 742
 743         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 744                 return;
 745         }
 746
 747         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 748                 $cache[] = $text;
 749
 750                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 751                         // add the message and any cached messages to the output
 752                         array_map( array( $wgOut, 'debug' ), $cache );
 753                         $cache = array();
 754                 }
 755         }
 756         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 757                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 758                         # Strip unprintables; they can switch terminal modes when binary data
 759                         # gets dumped, which is pretty annoying.
 760                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1a\x1c-\x1f]!', ' ', $text );
 761                         $text = $wgDebugLogPrefix . $text;
 762                         wfErrorLog( $text, $wgDebugLogFile );
 763                 }
 764         }
 765 }
 766
 767 /**
 768  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 769  */
 770 function wfIsDebugRawPage() {
 771         static $cache;
 772         if ( $cache !== null ) {
 773                 return $cache;
 774         }
 775         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 776         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 777                 || (
 778                         isset( $_SERVER['SCRIPT_NAME'] )
 779                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 780                 ) )
 781         {
 782                 $cache = true;
 783         } else {
 784                 $cache = false;
 785         }
 786         return $cache;
 787 }
 788
 789 /**
 790  * Get microsecond timestamps for debug logs
 791  *
 792  * @return string
 793  */
 794 function wfDebugTimer() {
 795         global $wgDebugTimestamps;
 796         if ( !$wgDebugTimestamps ) {
 797                 return '';
 798         }
 799         static $start = null;
 800
 801         if ( $start === null ) {
 802                 $start = microtime( true );
 803                 $prefix = "\n$start";
 804         } else {
 805                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 806         }
 807         $mem = sprintf( "%5.1fM", ( memory_get_usage( true ) / (1024*1024) ) );
 808         return "$prefix $mem  " ;
 809 }
 810
 811 /**
 812  * Send a line giving PHP memory usage.
 813  *
 814  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 815  */
 816 function wfDebugMem( $exact = false ) {
 817         $mem = memory_get_usage();
 818         if( !$exact ) {
 819                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 820         } else {
 821                 $mem .= ' bytes';
 822         }
 823         wfDebug( "Memory usage: $mem\n" );
 824 }
 825
 826 /**
 827  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 828  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 829  *
 830  * @param $logGroup String
 831  * @param $text String
 832  * @param $public Bool: whether to log the event in the public log if no private
 833  *                     log file is specified, (default true)
 834  */
 835 function wfDebugLog( $logGroup, $text, $public = true ) {
 836         global $wgDebugLogGroups, $wgShowHostnames;
 837         $text = trim( $text ) . "\n";
 838         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 839                 $time = wfTimestamp( TS_DB );
 840                 $wiki = wfWikiID();
 841                 if ( $wgShowHostnames ) {
 842                         $host = wfHostname();
 843                 } else {
 844                         $host = '';
 845                 }
 846                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 847                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 848                 }
 849         } elseif ( $public === true ) {
 850                 wfDebug( $text, true );
 851         }
 852 }
 853
 854 /**
 855  * Log for database errors
 856  *
 857  * @param $text String: database error message.
 858  */
 859 function wfLogDBError( $text ) {
 860         global $wgDBerrorLog, $wgDBname;
 861         if ( $wgDBerrorLog ) {
 862                 $host = trim(`hostname`);
 863                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 864                 wfErrorLog( $text, $wgDBerrorLog );
 865         }
 866 }
 867
 868 /**
 869  * Log to a file without getting "file size exceeded" signals.
 870  *
 871  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 872  * send lines to the specified port, prefixed by the specified prefix and a space.
 873  *
 874  * @param $text String
 875  * @param $file String filename
 876  */
 877 function wfErrorLog( $text, $file ) {
 878         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 879                 # Needs the sockets extension
 880                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 881                         // IPv6 bracketed host
 882                         $host = $m[2];
 883                         $port = intval( $m[3] );
 884                         $prefix = isset( $m[4] ) ? $m[4] : false;
 885                         $domain = AF_INET6;
 886                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 887                         $host = $m[2];
 888                         if ( !IP::isIPv4( $host ) ) {
 889                                 $host = gethostbyname( $host );
 890                         }
 891                         $port = intval( $m[3] );
 892                         $prefix = isset( $m[4] ) ? $m[4] : false;
 893                         $domain = AF_INET;
 894                 } else {
 895                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 896                 }
 897
 898                 // Clean it up for the multiplexer
 899                 if ( strval( $prefix ) !== '' ) {
 900                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 901
 902                         // Limit to 64KB
 903                         if ( strlen( $text ) > 65506 ) {
 904                                 $text = substr( $text, 0, 65506 );
 905                         }
 906
 907                         if ( substr( $text, -1 ) != "\n" ) {
 908                                 $text .= "\n";
 909                         }
 910                 } elseif ( strlen( $text ) > 65507 ) {
 911                         $text = substr( $text, 0, 65507 );
 912                 }
 913
 914                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 915                 if ( !$sock ) {
 916                         return;
 917                 }
 918
 919                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 920                 socket_close( $sock );
 921         } else {
 922                 wfSuppressWarnings();
 923                 $exists = file_exists( $file );
 924                 $size = $exists ? filesize( $file ) : false;
 925                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 926                         file_put_contents( $file, $text, FILE_APPEND );
 927                 }
 928                 wfRestoreWarnings();
 929         }
 930 }
 931
 932 /**
 933  * @todo document
 934  */
 935 function wfLogProfilingData() {
 936         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 937         global $wgProfileLimit, $wgUser;
 938
 939         $profiler = Profiler::instance();
 940
 941         # Profiling must actually be enabled...
 942         if ( $profiler->isStub() ) {
 943                 return;
 944         }
 945
 946         // Get total page request time and only show pages that longer than
 947         // $wgProfileLimit time (default is 0)
 948         $now = wfTime();
 949         $elapsed = $now - $wgRequestTime;
 950         if ( $elapsed <= $wgProfileLimit ) {
 951                 return;
 952         }
 953
 954         $profiler->logData();
 955
 956         // Check whether this should be logged in the debug file.
 957         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
 958                 return;
 959         }
 960
 961         $forward = '';
 962         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
 963                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 964         }
 965         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
 966                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 967         }
 968         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
 969                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 970         }
 971         if ( $forward ) {
 972                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 973         }
 974         // Don't load $wgUser at this late stage just for statistics purposes
 975         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
 976         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
 977                 $forward .= ' anon';
 978         }
 979         $log = sprintf( "%s\t%04.3f\t%s\n",
 980                 gmdate( 'YmdHis' ), $elapsed,
 981                 urldecode( $wgRequest->getRequestURL() . $forward ) );
 982
 983         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
 984 }
 985
 986 /**
 987  * Check if the wiki read-only lock file is present. This can be used to lock
 988  * off editing functions, but doesn't guarantee that the database will not be
 989  * modified.
 990  *
 991  * @return bool
 992  */
 993 function wfReadOnly() {
 994         global $wgReadOnlyFile, $wgReadOnly;
 995
 996         if ( !is_null( $wgReadOnly ) ) {
 997                 return (bool)$wgReadOnly;
 998         }
 999         if ( $wgReadOnlyFile == '' ) {
1000                 return false;
1001         }
1002         // Set $wgReadOnly for faster access next time
1003         if ( is_file( $wgReadOnlyFile ) ) {
1004                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
1005         } else {
1006                 $wgReadOnly = false;
1007         }
1008         return (bool)$wgReadOnly;
1009 }
1010
1011 /**
1012  * @return bool
1013  */
1014 function wfReadOnlyReason() {
1015         global $wgReadOnly;
1016         wfReadOnly();
1017         return $wgReadOnly;
1018 }
1019
1020 /**
1021  * Return a Language object from $langcode
1022  *
1023  * @param $langcode Mixed: either:
1024  *                  - a Language object
1025  *                  - code of the language to get the message for, if it is
1026  *                    a valid code create a language for that language, if
1027  *                    it is a string but not a valid code then make a basic
1028  *                    language object
1029  *                  - a boolean: if it's false then use the global object for
1030  *                    the current user's language (as a fallback for the old parameter
1031  *                    functionality), or if it is true then use global object
1032  *                    for the wiki's content language.
1033  * @return Language object
1034  */
1035 function wfGetLangObj( $langcode = false ) {
1036         # Identify which language to get or create a language object for.
1037         # Using is_object here due to Stub objects.
1038         if( is_object( $langcode ) ) {
1039                 # Great, we already have the object (hopefully)!
1040                 return $langcode;
1041         }
1042
1043         global $wgContLang, $wgLanguageCode;
1044         if( $langcode === true || $langcode === $wgLanguageCode ) {
1045                 # $langcode is the language code of the wikis content language object.
1046                 # or it is a boolean and value is true
1047                 return $wgContLang;
1048         }
1049
1050         global $wgLang;
1051         if( $langcode === false || $langcode === $wgLang->getCode() ) {
1052                 # $langcode is the language code of user language object.
1053                 # or it was a boolean and value is false
1054                 return $wgLang;
1055         }
1056
1057         $validCodes = array_keys( Language::getLanguageNames() );
1058         if( in_array( $langcode, $validCodes ) ) {
1059                 # $langcode corresponds to a valid language.
1060                 return Language::factory( $langcode );
1061         }
1062
1063         # $langcode is a string, but not a valid language code; use content language.
1064         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
1065         return $wgContLang;
1066 }
1067
1068 /**
1069  * Old function when $wgBetterDirectionality existed
1070  * Removed in core, kept in extensions for backwards compat.
1071  *
1072  * @deprecated since 1.18
1073  * @return Language
1074  */
1075 function wfUILang() {
1076         global $wgLang;
1077         return $wgLang;
1078 }
1079
1080 /**
1081  * This is the new function for getting translated interface messages.
1082  * See the Message class for documentation how to use them.
1083  * The intention is that this function replaces all old wfMsg* functions.
1084  * @param $key \string Message key.
1085  * Varargs: normal message parameters.
1086  * @return Message
1087  * @since 1.17
1088  */
1089 function wfMessage( $key /*...*/) {
1090         $params = func_get_args();
1091         array_shift( $params );
1092         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
1093                 $params = $params[0];
1094         }
1095         return new Message( $key, $params );
1096 }
1097
1098 /**
1099  * This function accepts multiple message keys and returns a message instance
1100  * for the first message which is non-empty. If all messages are empty then an
1101  * instance of the first message key is returned.
1102  * @param varargs: message keys
1103  * @return Message
1104  * @since 1.18
1105  */
1106 function wfMessageFallback( /*...*/ ) {
1107         $args = func_get_args();
1108         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
1109 }
1110
1111 /**
1112  * Get a message from anywhere, for the current user language.
1113  *
1114  * Use wfMsgForContent() instead if the message should NOT
1115  * change depending on the user preferences.
1116  *
1117  * @param $key String: lookup key for the message, usually
1118  *    defined in languages/Language.php
1119  *
1120  * Parameters to the message, which can be used to insert variable text into
1121  * it, can be passed to this function in the following formats:
1122  * - One per argument, starting at the second parameter
1123  * - As an array in the second parameter
1124  * These are not shown in the function definition.
1125  *
1126  * @return String
1127  */
1128 function wfMsg( $key ) {
1129         $args = func_get_args();
1130         array_shift( $args );
1131         return wfMsgReal( $key, $args );
1132 }
1133
1134 /**
1135  * Same as above except doesn't transform the message
1136  *
1137  * @param $key String
1138  * @return String
1139  */
1140 function wfMsgNoTrans( $key ) {
1141         $args = func_get_args();
1142         array_shift( $args );
1143         return wfMsgReal( $key, $args, true, false, false );
1144 }
1145
1146 /**
1147  * Get a message from anywhere, for the current global language
1148  * set with $wgLanguageCode.
1149  *
1150  * Use this if the message should NOT change dependent on the
1151  * language set in the user's preferences. This is the case for
1152  * most text written into logs, as well as link targets (such as
1153  * the name of the copyright policy page). Link titles, on the
1154  * other hand, should be shown in the UI language.
1155  *
1156  * Note that MediaWiki allows users to change the user interface
1157  * language in their preferences, but a single installation
1158  * typically only contains content in one language.
1159  *
1160  * Be wary of this distinction: If you use wfMsg() where you should
1161  * use wfMsgForContent(), a user of the software may have to
1162  * customize potentially hundreds of messages in
1163  * order to, e.g., fix a link in every possible language.
1164  *
1165  * @param $key String: lookup key for the message, usually
1166  *     defined in languages/Language.php
1167  * @return String
1168  */
1169 function wfMsgForContent( $key ) {
1170         global $wgForceUIMsgAsContentMsg;
1171         $args = func_get_args();
1172         array_shift( $args );
1173         $forcontent = true;
1174         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1175                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1176         {
1177                 $forcontent = false;
1178         }
1179         return wfMsgReal( $key, $args, true, $forcontent );
1180 }
1181
1182 /**
1183  * Same as above except doesn't transform the message
1184  *
1185  * @param $key String
1186  * @return String
1187  */
1188 function wfMsgForContentNoTrans( $key ) {
1189         global $wgForceUIMsgAsContentMsg;
1190         $args = func_get_args();
1191         array_shift( $args );
1192         $forcontent = true;
1193         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1194                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1195         {
1196                 $forcontent = false;
1197         }
1198         return wfMsgReal( $key, $args, true, $forcontent, false );
1199 }
1200
1201 /**
1202  * Really get a message
1203  *
1204  * @param $key String: key to get.
1205  * @param $args
1206  * @param $useDB Boolean
1207  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1208  * @param $transform Boolean: Whether or not to transform the message.
1209  * @return String: the requested message.
1210  */
1211 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1212         wfProfileIn( __METHOD__ );
1213         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1214         $message = wfMsgReplaceArgs( $message, $args );
1215         wfProfileOut( __METHOD__ );
1216         return $message;
1217 }
1218
1219 /**
1220  * Fetch a message string value, but don't replace any keys yet.
1221  *
1222  * @param $key String
1223  * @param $useDB Bool
1224  * @param $langCode String: Code of the language to get the message for, or
1225  *                  behaves as a content language switch if it is a boolean.
1226  * @param $transform Boolean: whether to parse magic words, etc.
1227  * @return string
1228  */
1229 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1230         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1231
1232         $cache = MessageCache::singleton();
1233         $message = $cache->get( $key, $useDB, $langCode );
1234         if( $message === false ) {
1235                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1236         } elseif ( $transform ) {
1237                 $message = $cache->transform( $message );
1238         }
1239         return $message;
1240 }
1241
1242 /**
1243  * Replace message parameter keys on the given formatted output.
1244  *
1245  * @param $message String
1246  * @param $args Array
1247  * @return string
1248  * @private
1249  */
1250 function wfMsgReplaceArgs( $message, $args ) {
1251         # Fix windows line-endings
1252         # Some messages are split with explode("\n", $msg)
1253         $message = str_replace( "\r", '', $message );
1254
1255         // Replace arguments
1256         if ( count( $args ) ) {
1257                 if ( is_array( $args[0] ) ) {
1258                         $args = array_values( $args[0] );
1259                 }
1260                 $replacementKeys = array();
1261                 foreach( $args as $n => $param ) {
1262                         $replacementKeys['$' . ( $n + 1 )] = $param;
1263                 }
1264                 $message = strtr( $message, $replacementKeys );
1265         }
1266
1267         return $message;
1268 }
1269
1270 /**
1271  * Return an HTML-escaped version of a message.
1272  * Parameter replacements, if any, are done *after* the HTML-escaping,
1273  * so parameters may contain HTML (eg links or form controls). Be sure
1274  * to pre-escape them if you really do want plaintext, or just wrap
1275  * the whole thing in htmlspecialchars().
1276  *
1277  * @param $key String
1278  * @param string ... parameters
1279  * @return string
1280  */
1281 function wfMsgHtml( $key ) {
1282         $args = func_get_args();
1283         array_shift( $args );
1284         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1285 }
1286
1287 /**
1288  * Return an HTML version of message
1289  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1290  * so parameters may contain HTML (eg links or form controls). Be sure
1291  * to pre-escape them if you really do want plaintext, or just wrap
1292  * the whole thing in htmlspecialchars().
1293  *
1294  * @param $key String
1295  * @param string ... parameters
1296  * @return string
1297  */
1298 function wfMsgWikiHtml( $key ) {
1299         $args = func_get_args();
1300         array_shift( $args );
1301         return wfMsgReplaceArgs(
1302                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null,
1303                 /* can't be set to false */ true, /* interface */ true )->getText(),
1304                 $args );
1305 }
1306
1307 /**
1308  * Returns message in the requested format
1309  * @param $key String: key of the message
1310  * @param $options Array: processing rules. Can take the following options:
1311  *   <i>parse</i>: parses wikitext to HTML
1312  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1313  *       p's added by parser or tidy
1314  *   <i>escape</i>: filters message through htmlspecialchars
1315  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1316  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1317  *   <i>parsemag</i>: transform the message using magic phrases
1318  *   <i>content</i>: fetch message for content language instead of interface
1319  * Also can accept a single associative argument, of the form 'language' => 'xx':
1320  *   <i>language</i>: Language object or language code to fetch message for
1321  *       (overriden by <i>content</i>).
1322  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1323  *
1324  * @return String
1325  */
1326 function wfMsgExt( $key, $options ) {
1327         $args = func_get_args();
1328         array_shift( $args );
1329         array_shift( $args );
1330         $options = (array)$options;
1331
1332         foreach( $options as $arrayKey => $option ) {
1333                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1334                         # An unknown index, neither numeric nor "language"
1335                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1336                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1337                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1338                 'replaceafter', 'parsemag', 'content' ) ) ) {
1339                         # A numeric index with unknown value
1340                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1341                 }
1342         }
1343
1344         if( in_array( 'content', $options, true ) ) {
1345                 $forContent = true;
1346                 $langCode = true;
1347                 $langCodeObj = null;
1348         } elseif( array_key_exists( 'language', $options ) ) {
1349                 $forContent = false;
1350                 $langCode = wfGetLangObj( $options['language'] );
1351                 $langCodeObj = $langCode;
1352         } else {
1353                 $forContent = false;
1354                 $langCode = false;
1355                 $langCodeObj = null;
1356         }
1357
1358         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1359
1360         if( !in_array( 'replaceafter', $options, true ) ) {
1361                 $string = wfMsgReplaceArgs( $string, $args );
1362         }
1363
1364         $messageCache = MessageCache::singleton();
1365         if( in_array( 'parse', $options, true ) ) {
1366                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1367         } elseif ( in_array( 'parseinline', $options, true ) ) {
1368                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1369                 $m = array();
1370                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1371                         $string = $m[1];
1372                 }
1373         } elseif ( in_array( 'parsemag', $options, true ) ) {
1374                 $string = $messageCache->transform( $string,
1375                                 !$forContent, $langCodeObj );
1376         }
1377
1378         if ( in_array( 'escape', $options, true ) ) {
1379                 $string = htmlspecialchars ( $string );
1380         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1381                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1382         }
1383
1384         if( in_array( 'replaceafter', $options, true ) ) {
1385                 $string = wfMsgReplaceArgs( $string, $args );
1386         }
1387
1388         return $string;
1389 }
1390
1391 /**
1392  * Since wfMsg() and co suck, they don't return false if the message key they
1393  * looked up didn't exist but a XHTML string, this function checks for the
1394  * nonexistance of messages by checking the MessageCache::get() result directly.
1395  *
1396  * @param $key      String: the message key looked up
1397  * @return Boolean True if the message *doesn't* exist.
1398  */
1399 function wfEmptyMsg( $key ) {
1400         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1401 }
1402
1403 /**
1404  * Throw a debugging exception. This function previously once exited the process,
1405  * but now throws an exception instead, with similar results.
1406  *
1407  * @param $msg String: message shown when dying.
1408  */
1409 function wfDebugDieBacktrace( $msg = '' ) {
1410         throw new MWException( $msg );
1411 }
1412
1413 /**
1414  * Fetch server name for use in error reporting etc.
1415  * Use real server name if available, so we know which machine
1416  * in a server farm generated the current page.
1417  *
1418  * @return string
1419  */
1420 function wfHostname() {
1421         static $host;
1422         if ( is_null( $host ) ) {
1423                 if ( function_exists( 'posix_uname' ) ) {
1424                         // This function not present on Windows
1425                         $uname = posix_uname();
1426                 } else {
1427                         $uname = false;
1428                 }
1429                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1430                         $host = $uname['nodename'];
1431                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1432                         # Windows computer name
1433                         $host = getenv( 'COMPUTERNAME' );
1434                 } else {
1435                         # This may be a virtual server.
1436                         $host = $_SERVER['SERVER_NAME'];
1437                 }
1438         }
1439         return $host;
1440 }
1441
1442 /**
1443  * Returns a HTML comment with the elapsed time since request.
1444  * This method has no side effects.
1445  *
1446  * @return string
1447  */
1448 function wfReportTime() {
1449         global $wgRequestTime, $wgShowHostnames;
1450
1451         $now = wfTime();
1452         $elapsed = $now - $wgRequestTime;
1453
1454         return $wgShowHostnames
1455                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1456                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1457 }
1458
1459 /**
1460  * Safety wrapper for debug_backtrace().
1461  *
1462  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1463  * murky circumstances, which may be triggered in part by stub objects
1464  * or other fancy talkin'.
1465  *
1466  * Will return an empty array if Zend Optimizer is detected or if
1467  * debug_backtrace is disabled, otherwise the output from
1468  * debug_backtrace() (trimmed).
1469  *
1470  * @param $limit int This parameter can be used to limit the number of stack frames returned
1471  *
1472  * @return array of backtrace information
1473  */
1474 function wfDebugBacktrace( $limit = 0 ) {
1475         static $disabled = null;
1476
1477         if( extension_loaded( 'Zend Optimizer' ) ) {
1478                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1479                 return array();
1480         }
1481
1482         if ( is_null( $disabled ) ) {
1483                 $disabled = false;
1484                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1485                 $functions = array_map( 'trim', $functions );
1486                 $functions = array_map( 'strtolower', $functions );
1487                 if ( in_array( 'debug_backtrace', $functions ) ) {
1488                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1489                         $disabled = true;
1490                 }
1491         }
1492         if ( $disabled ) {
1493                 return array();
1494         }
1495
1496         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1497                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, $limit ), 1 );
1498         } else {
1499                 return array_slice( debug_backtrace(), 1 );
1500         }
1501 }
1502
1503 /**
1504  * Get a debug backtrace as a string
1505  *
1506  * @return string
1507  */
1508 function wfBacktrace() {
1509         global $wgCommandLineMode;
1510
1511         if ( $wgCommandLineMode ) {
1512                 $msg = '';
1513         } else {
1514                 $msg = "<ul>\n";
1515         }
1516         $backtrace = wfDebugBacktrace();
1517         foreach( $backtrace as $call ) {
1518                 if( isset( $call['file'] ) ) {
1519                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1520                         $file = $f[count( $f ) - 1];
1521                 } else {
1522                         $file = '-';
1523                 }
1524                 if( isset( $call['line'] ) ) {
1525                         $line = $call['line'];
1526                 } else {
1527                         $line = '-';
1528                 }
1529                 if ( $wgCommandLineMode ) {
1530                         $msg .= "$file line $line calls ";
1531                 } else {
1532                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1533                 }
1534                 if( !empty( $call['class'] ) ) {
1535                         $msg .= $call['class'] . $call['type'];
1536                 }
1537                 $msg .= $call['function'] . '()';
1538
1539                 if ( $wgCommandLineMode ) {
1540                         $msg .= "\n";
1541                 } else {
1542                         $msg .= "</li>\n";
1543                 }
1544         }
1545         if ( $wgCommandLineMode ) {
1546                 $msg .= "\n";
1547         } else {
1548                 $msg .= "</ul>\n";
1549         }
1550
1551         return $msg;
1552 }
1553
1554 /**
1555  * Get the name of the function which called this function
1556  *
1557  * @param $level Int
1558  * @return Bool|string
1559  */
1560 function wfGetCaller( $level = 2 ) {
1561         $backtrace = wfDebugBacktrace( $level );
1562         if ( isset( $backtrace[$level] ) ) {
1563                 return wfFormatStackFrame( $backtrace[$level] );
1564         } else {
1565                 $caller = 'unknown';
1566         }
1567         return $caller;
1568 }
1569
1570 /**
1571  * Return a string consisting of callers in the stack. Useful sometimes
1572  * for profiling specific points.
1573  *
1574  * @param $limit The maximum depth of the stack frame to return, or false for
1575  *               the entire stack.
1576  * @return String
1577  */
1578 function wfGetAllCallers( $limit = 3 ) {
1579         $trace = array_reverse( wfDebugBacktrace() );
1580         if ( !$limit || $limit > count( $trace ) - 1 ) {
1581                 $limit = count( $trace ) - 1;
1582         }
1583         $trace = array_slice( $trace, -$limit - 1, $limit );
1584         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1585 }
1586
1587 /**
1588  * Return a string representation of frame
1589  *
1590  * @param $frame Array
1591  * @return Bool
1592  */
1593 function wfFormatStackFrame( $frame ) {
1594         return isset( $frame['class'] ) ?
1595                 $frame['class'] . '::' . $frame['function'] :
1596                 $frame['function'];
1597 }
1598
1599
1600 /* Some generic result counters, pulled out of SearchEngine */
1601
1602
1603 /**
1604  * @todo document
1605  *
1606  * @param $offset Int
1607  * @param $limit Int
1608  * @return String
1609  */
1610 function wfShowingResults( $offset, $limit ) {
1611         global $wgLang;
1612         return wfMsgExt(
1613                 'showingresults',
1614                 array( 'parseinline' ),
1615                 $wgLang->formatNum( $limit ),
1616                 $wgLang->formatNum( $offset + 1 )
1617         );
1618 }
1619
1620 /**
1621  * Generate (prev x| next x) (20|50|100...) type links for paging
1622  *
1623  * @param $offset String
1624  * @param $limit Integer
1625  * @param $link String
1626  * @param $query String: optional URL query parameter string
1627  * @param $atend Bool: optional param for specified if this is the last page
1628  * @return String
1629  * @deprecated in 1.19; use Language::viewPrevNext() instead
1630  */
1631 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1632         global $wgLang;
1633
1634         $query = wfCgiToArray( $query );
1635
1636         if( is_object( $link ) ) {
1637                 $title = $link;
1638         } else {
1639                 $title = Title::newFromText( $link );
1640                 if( is_null( $title ) ) {
1641                         return false;
1642                 }
1643         }
1644
1645         return $wgLang->viewPrevNext( $title, $offset, $limit, $query, $atend );
1646 }
1647
1648 /**
1649  * Make a list item, used by various special pages
1650  *
1651  * @param $page String Page link
1652  * @param $details String Text between brackets
1653  * @param $oppositedm Boolean   Add the direction mark opposite to your
1654  *                                                              language, to display text properly
1655  * @return String
1656  * @deprecated since 1.19; use Language::specialList() instead
1657  */
1658 function wfSpecialList( $page, $details, $oppositedm = true ) {
1659         global $wgLang;
1660         return $wgLang->specialList( $page, $details, $oppositedm );
1661 }
1662
1663 /**
1664  * @todo document
1665  * @todo FIXME: We may want to blacklist some broken browsers
1666  *
1667  * @param $force Bool
1668  * @return bool Whereas client accept gzip compression
1669  */
1670 function wfClientAcceptsGzip( $force = false ) {
1671         static $result = null;
1672         if ( $result === null || $force ) {
1673                 $result = false;
1674                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1675                         # @todo FIXME: We may want to blacklist some broken browsers
1676                         $m = array();
1677                         if( preg_match(
1678                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1679                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1680                                 $m )
1681                         )
1682                         {
1683                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1684                                         $result = false;
1685                                         return $result;
1686                                 }
1687                                 wfDebug( "wfClientAcceptsGzip: client accepts gzip.\n" );
1688                                 $result = true;
1689                         }
1690                 }
1691         }
1692         return $result;
1693 }
1694
1695 /**
1696  * Obtain the offset and limit values from the request string;
1697  * used in special pages
1698  *
1699  * @param $deflimit Int default limit if none supplied
1700  * @param $optionname String Name of a user preference to check against
1701  * @return array
1702  *
1703  */
1704 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1705         global $wgRequest;
1706         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1707 }
1708
1709 /**
1710  * Escapes the given text so that it may be output using addWikiText()
1711  * without any linking, formatting, etc. making its way through. This
1712  * is achieved by substituting certain characters with HTML entities.
1713  * As required by the callers, <nowiki> is not used.
1714  *
1715  * @param $text String: text to be escaped
1716  * @return String
1717  */
1718 function wfEscapeWikiText( $text ) {
1719         $text = strtr( "\n$text", array(
1720                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1721                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1722                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1723                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1724                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1725                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1726         ) );
1727         return substr( $text, 1 );
1728 }
1729
1730 /**
1731  * Get the current unix timetstamp with microseconds.  Useful for profiling
1732  * @return Float
1733  */
1734 function wfTime() {
1735         return microtime( true );
1736 }
1737
1738 /**
1739  * Sets dest to source and returns the original value of dest
1740  * If source is NULL, it just returns the value, it doesn't set the variable
1741  * If force is true, it will set the value even if source is NULL
1742  *
1743  * @param $dest Mixed
1744  * @param $source Mixed
1745  * @param $force Bool
1746  * @return Mixed
1747  */
1748 function wfSetVar( &$dest, $source, $force = false ) {
1749         $temp = $dest;
1750         if ( !is_null( $source ) || $force ) {
1751                 $dest = $source;
1752         }
1753         return $temp;
1754 }
1755
1756 /**
1757  * As for wfSetVar except setting a bit
1758  *
1759  * @param $dest Int
1760  * @param $bit Int
1761  * @param $state Bool
1762  */
1763 function wfSetBit( &$dest, $bit, $state = true ) {
1764         $temp = (bool)( $dest & $bit );
1765         if ( !is_null( $state ) ) {
1766                 if ( $state ) {
1767                         $dest |= $bit;
1768                 } else {
1769                         $dest &= ~$bit;
1770                 }
1771         }
1772         return $temp;
1773 }
1774
1775 /**
1776  * A wrapper around the PHP function var_export().
1777  * Either print it or add it to the regular output ($wgOut).
1778  *
1779  * @param $var A PHP variable to dump.
1780  */
1781 function wfVarDump( $var ) {
1782         global $wgOut;
1783         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1784         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1785                 print $s;
1786         } else {
1787                 $wgOut->addHTML( $s );
1788         }
1789 }
1790
1791 /**
1792  * Provide a simple HTTP error.
1793  *
1794  * @param $code Int|String
1795  * @param $label String
1796  * @param $desc String
1797  */
1798 function wfHttpError( $code, $label, $desc ) {
1799         global $wgOut;
1800         $wgOut->disable();
1801         header( "HTTP/1.0 $code $label" );
1802         header( "Status: $code $label" );
1803         $wgOut->sendCacheControl();
1804
1805         header( 'Content-type: text/html; charset=utf-8' );
1806         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1807                 '<html><head><title>' .
1808                 htmlspecialchars( $label ) .
1809                 '</title></head><body><h1>' .
1810                 htmlspecialchars( $label ) .
1811                 '</h1><p>' .
1812                 nl2br( htmlspecialchars( $desc ) ) .
1813                 "</p></body></html>\n";
1814 }
1815
1816 /**
1817  * Clear away any user-level output buffers, discarding contents.
1818  *
1819  * Suitable for 'starting afresh', for instance when streaming
1820  * relatively large amounts of data without buffering, or wanting to
1821  * output image files without ob_gzhandler's compression.
1822  *
1823  * The optional $resetGzipEncoding parameter controls suppression of
1824  * the Content-Encoding header sent by ob_gzhandler; by default it
1825  * is left. See comments for wfClearOutputBuffers() for why it would
1826  * be used.
1827  *
1828  * Note that some PHP configuration options may add output buffer
1829  * layers which cannot be removed; these are left in place.
1830  *
1831  * @param $resetGzipEncoding Bool
1832  */
1833 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1834         if( $resetGzipEncoding ) {
1835                 // Suppress Content-Encoding and Content-Length
1836                 // headers from 1.10+s wfOutputHandler
1837                 global $wgDisableOutputCompression;
1838                 $wgDisableOutputCompression = true;
1839         }
1840         while( $status = ob_get_status() ) {
1841                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1842                         // Probably from zlib.output_compression or other
1843                         // PHP-internal setting which can't be removed.
1844                         //
1845                         // Give up, and hope the result doesn't break
1846                         // output behavior.
1847                         break;
1848                 }
1849                 if( !ob_end_clean() ) {
1850                         // Could not remove output buffer handler; abort now
1851                         // to avoid getting in some kind of infinite loop.
1852                         break;
1853                 }
1854                 if( $resetGzipEncoding ) {
1855                         if( $status['name'] == 'ob_gzhandler' ) {
1856                                 // Reset the 'Content-Encoding' field set by this handler
1857                                 // so we can start fresh.
1858                                 if ( function_exists( 'header_remove' ) ) {
1859                                         // Available since PHP 5.3.0
1860                                         header_remove( 'Content-Encoding' );
1861                                 } else {
1862                                         // We need to provide a valid content-coding. See bug 28069
1863                                         header( 'Content-Encoding: identity' );
1864                                 }
1865                                 break;
1866                         }
1867                 }
1868         }
1869 }
1870
1871 /**
1872  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1873  *
1874  * Clear away output buffers, but keep the Content-Encoding header
1875  * produced by ob_gzhandler, if any.
1876  *
1877  * This should be used for HTTP 304 responses, where you need to
1878  * preserve the Content-Encoding header of the real result, but
1879  * also need to suppress the output of ob_gzhandler to keep to spec
1880  * and avoid breaking Firefox in rare cases where the headers and
1881  * body are broken over two packets.
1882  */
1883 function wfClearOutputBuffers() {
1884         wfResetOutputBuffers( false );
1885 }
1886
1887 /**
1888  * Converts an Accept-* header into an array mapping string values to quality
1889  * factors
1890  *
1891  * @param $accept String
1892  * @param $def String default
1893  * @return Array
1894  */
1895 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1896         # No arg means accept anything (per HTTP spec)
1897         if( !$accept ) {
1898                 return array( $def => 1.0 );
1899         }
1900
1901         $prefs = array();
1902
1903         $parts = explode( ',', $accept );
1904
1905         foreach( $parts as $part ) {
1906                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
1907                 $values = explode( ';', trim( $part ) );
1908                 $match = array();
1909                 if ( count( $values ) == 1 ) {
1910                         $prefs[$values[0]] = 1.0;
1911                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
1912                         $prefs[$values[0]] = floatval( $match[1] );
1913                 }
1914         }
1915
1916         return $prefs;
1917 }
1918
1919 /**
1920  * Checks if a given MIME type matches any of the keys in the given
1921  * array. Basic wildcards are accepted in the array keys.
1922  *
1923  * Returns the matching MIME type (or wildcard) if a match, otherwise
1924  * NULL if no match.
1925  *
1926  * @param $type String
1927  * @param $avail Array
1928  * @return string
1929  * @private
1930  */
1931 function mimeTypeMatch( $type, $avail ) {
1932         if( array_key_exists( $type, $avail ) ) {
1933                 return $type;
1934         } else {
1935                 $parts = explode( '/', $type );
1936                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
1937                         return $parts[0] . '/*';
1938                 } elseif( array_key_exists( '*/*', $avail ) ) {
1939                         return '*/*';
1940                 } else {
1941                         return null;
1942                 }
1943         }
1944 }
1945
1946 /**
1947  * Returns the 'best' match between a client's requested internet media types
1948  * and the server's list of available types. Each list should be an associative
1949  * array of type to preference (preference is a float between 0.0 and 1.0).
1950  * Wildcards in the types are acceptable.
1951  *
1952  * @param $cprefs Array: client's acceptable type list
1953  * @param $sprefs Array: server's offered types
1954  * @return string
1955  *
1956  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
1957  * XXX: generalize to negotiate other stuff
1958  */
1959 function wfNegotiateType( $cprefs, $sprefs ) {
1960         $combine = array();
1961
1962         foreach( array_keys( $sprefs ) as $type ) {
1963                 $parts = explode( '/', $type );
1964                 if( $parts[1] != '*' ) {
1965                         $ckey = mimeTypeMatch( $type, $cprefs );
1966                         if( $ckey ) {
1967                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
1968                         }
1969                 }
1970         }
1971
1972         foreach( array_keys( $cprefs ) as $type ) {
1973                 $parts = explode( '/', $type );
1974                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
1975                         $skey = mimeTypeMatch( $type, $sprefs );
1976                         if( $skey ) {
1977                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
1978                         }
1979                 }
1980         }
1981
1982         $bestq = 0;
1983         $besttype = null;
1984
1985         foreach( array_keys( $combine ) as $type ) {
1986                 if( $combine[$type] > $bestq ) {
1987                         $besttype = $type;
1988                         $bestq = $combine[$type];
1989                 }
1990         }
1991
1992         return $besttype;
1993 }
1994
1995 /**
1996  * Reference-counted warning suppression
1997  *
1998  * @param $end Bool
1999  */
2000 function wfSuppressWarnings( $end = false ) {
2001         static $suppressCount = 0;
2002         static $originalLevel = false;
2003
2004         if ( $end ) {
2005                 if ( $suppressCount ) {
2006                         --$suppressCount;
2007                         if ( !$suppressCount ) {
2008                                 error_reporting( $originalLevel );
2009                         }
2010                 }
2011         } else {
2012                 if ( !$suppressCount ) {
2013                         // E_DEPRECATED is undefined in PHP 5.2
2014                         if( !defined( 'E_DEPRECATED' ) ) {
2015                                 define( 'E_DEPRECATED', 8192 );
2016                         }
2017                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2018                 }
2019                 ++$suppressCount;
2020         }
2021 }
2022
2023 /**
2024  * Restore error level to previous value
2025  */
2026 function wfRestoreWarnings() {
2027         wfSuppressWarnings( true );
2028 }
2029
2030 # Autodetect, convert and provide timestamps of various types
2031
2032 /**
2033  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2034  */
2035 define( 'TS_UNIX', 0 );
2036
2037 /**
2038  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2039  */
2040 define( 'TS_MW', 1 );
2041
2042 /**
2043  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2044  */
2045 define( 'TS_DB', 2 );
2046
2047 /**
2048  * RFC 2822 format, for E-mail and HTTP headers
2049  */
2050 define( 'TS_RFC2822', 3 );
2051
2052 /**
2053  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2054  *
2055  * This is used by Special:Export
2056  */
2057 define( 'TS_ISO_8601', 4 );
2058
2059 /**
2060  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2061  *
2062  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2063  *       DateTime tag and page 36 for the DateTimeOriginal and
2064  *       DateTimeDigitized tags.
2065  */
2066 define( 'TS_EXIF', 5 );
2067
2068 /**
2069  * Oracle format time.
2070  */
2071 define( 'TS_ORACLE', 6 );
2072
2073 /**
2074  * Postgres format time.
2075  */
2076 define( 'TS_POSTGRES', 7 );
2077
2078 /**
2079  * DB2 format time
2080  */
2081 define( 'TS_DB2', 8 );
2082
2083 /**
2084  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2085  */
2086 define( 'TS_ISO_8601_BASIC', 9 );
2087
2088 /**
2089  * Get a timestamp string in one of various formats
2090  *
2091  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2092  *                    function will autodetect which format is supplied and act
2093  *                    accordingly.
2094  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2095  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2096  */
2097 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2098         $uts = 0;
2099         $da = array();
2100         $strtime = '';
2101
2102         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2103                 $uts = time();
2104                 $strtime = "@$uts";
2105         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2106                 # TS_DB
2107         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2108                 # TS_EXIF
2109         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2110                 # TS_MW
2111         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2112                 # TS_UNIX
2113                 $uts = $ts;
2114                 $strtime = "@$ts"; // Undocumented?
2115         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2116                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2117                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2118                                 str_replace( '+00:00', 'UTC', $ts ) );
2119         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2120                 # TS_ISO_8601
2121         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2122                 #TS_ISO_8601_BASIC
2123         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2124                 # TS_POSTGRES
2125         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2126                 # TS_POSTGRES
2127         } elseif (preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/', $ts, $da ) ) {
2128                 # TS_DB2
2129         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2130                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2131                                                         '[ \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
2132                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2133                 # The regex is a superset of rfc2822 for readability
2134                 $strtime = strtok( $ts, ';' );
2135         } 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 ) ) {
2136                 # TS_RFC850
2137                 $strtime = $ts;
2138         } 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 ) ) {
2139                 # asctime
2140                 $strtime = $ts;
2141         } else {
2142                 # Bogus value...
2143                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2144
2145                 return false;
2146         }
2147
2148         static $formats = array(
2149                 TS_UNIX => 'U',
2150                 TS_MW => 'YmdHis',
2151                 TS_DB => 'Y-m-d H:i:s',
2152                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2153                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2154                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2155                 TS_RFC2822 => 'D, d M Y H:i:s',
2156                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2157                 TS_POSTGRES => 'Y-m-d H:i:s',
2158                 TS_DB2 => 'Y-m-d H:i:s',
2159         );
2160
2161         if ( !isset( $formats[$outputtype] ) ) {
2162                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2163         }
2164
2165         if ( function_exists( "date_create" ) ) {
2166                 if ( count( $da ) ) {
2167                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2168                                 (int)$da[1], (int)$da[2], (int)$da[3],
2169                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2170
2171                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2172                 } elseif ( $strtime ) {
2173                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2174                 } else {
2175                         return false;
2176                 }
2177
2178                 if ( !$d ) {
2179                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2180                         return false;
2181                 }
2182
2183                 $output = $d->format( $formats[$outputtype] );
2184         } else {
2185                 if ( count( $da ) ) {
2186                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2187                         // We may want to handle that explicitly at some point
2188                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2189                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2190                 } elseif ( $strtime ) {
2191                         $uts = strtotime( $strtime );
2192                 }
2193
2194                 if ( $uts === false ) {
2195                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2196                         return false;
2197                 }
2198
2199                 if ( TS_UNIX == $outputtype ) {
2200                         return $uts;
2201                 }
2202                 $output = gmdate( $formats[$outputtype], $uts );
2203         }
2204
2205         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2206                 $output .= ' GMT';
2207         }
2208
2209         return $output;
2210 }
2211
2212 /**
2213  * Return a formatted timestamp, or null if input is null.
2214  * For dealing with nullable timestamp columns in the database.
2215  *
2216  * @param $outputtype Integer
2217  * @param $ts String
2218  * @return String
2219  */
2220 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2221         if( is_null( $ts ) ) {
2222                 return null;
2223         } else {
2224                 return wfTimestamp( $outputtype, $ts );
2225         }
2226 }
2227
2228 /**
2229  * Convenience function; returns MediaWiki timestamp for the present time.
2230  *
2231  * @return string
2232  */
2233 function wfTimestampNow() {
2234         # return NOW
2235         return wfTimestamp( TS_MW, time() );
2236 }
2237
2238 /**
2239  * Check if the operating system is Windows
2240  *
2241  * @return Bool: true if it's Windows, False otherwise.
2242  */
2243 function wfIsWindows() {
2244         static $isWindows = null;
2245         if ( $isWindows === null ) {
2246                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2247         }
2248         return $isWindows;
2249 }
2250
2251 /**
2252  * Check if we are running under HipHop
2253  *
2254  * @return Bool
2255  */
2256 function wfIsHipHop() {
2257         return function_exists( 'hphp_thread_set_warmup_enabled' );
2258 }
2259
2260 /**
2261  * Swap two variables
2262  *
2263  * @param $x Mixed
2264  * @param $y Mixed
2265  */
2266 function swap( &$x, &$y ) {
2267         $z = $x;
2268         $x = $y;
2269         $y = $z;
2270 }
2271
2272 /**
2273  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2274  * TEMP environment variables are then checked in sequence, and if none are set
2275  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2276  * or C:\Windows\Temp for Windows and hope for the best.
2277  * It is common to call it with tempnam().
2278  *
2279  * NOTE: When possible, use instead the tmpfile() function to create
2280  * temporary files to avoid race conditions on file creation, etc.
2281  *
2282  * @return String
2283  */
2284 function wfTempDir() {
2285         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2286                 $tmp = getenv( $var );
2287                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2288                         return $tmp;
2289                 }
2290         }
2291         if( function_exists( 'sys_get_temp_dir' ) ) {
2292                 return sys_get_temp_dir();
2293         }
2294         # Usual defaults
2295         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2296 }
2297
2298 /**
2299  * Make directory, and make all parent directories if they don't exist
2300  *
2301  * @param $dir String: full path to directory to create
2302  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2303  * @param $caller String: optional caller param for debugging.
2304  * @return bool
2305  */
2306 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2307         global $wgDirectoryMode;
2308
2309         if ( !is_null( $caller ) ) {
2310                 wfDebug( "$caller: called wfMkdirParents($dir)\n" );
2311         }
2312
2313         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2314                 return true;
2315         }
2316
2317         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2318
2319         if ( is_null( $mode ) ) {
2320                 $mode = $wgDirectoryMode;
2321         }
2322
2323         // Turn off the normal warning, we're doing our own below
2324         wfSuppressWarnings();
2325         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2326         wfRestoreWarnings();
2327
2328         if( !$ok ) {
2329                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2330                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2331         }
2332         return $ok;
2333 }
2334
2335 /**
2336  * Increment a statistics counter
2337  *
2338  * @param $key String
2339  * @param $count Int
2340  */
2341 function wfIncrStats( $key, $count = 1 ) {
2342         global $wgStatsMethod;
2343
2344         $count = intval( $count );
2345
2346         if( $wgStatsMethod == 'udp' ) {
2347                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2348                 static $socket;
2349
2350                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2351
2352                 if ( !$socket ) {
2353                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2354                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2355                         socket_sendto(
2356                                 $socket,
2357                                 $statline,
2358                                 strlen( $statline ),
2359                                 0,
2360                                 $wgUDPProfilerHost,
2361                                 $wgUDPProfilerPort
2362                         );
2363                 }
2364                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2365                 wfSuppressWarnings();
2366                 socket_sendto(
2367                         $socket,
2368                         $statline,
2369                         strlen( $statline ),
2370                         0,
2371                         $wgUDPProfilerHost,
2372                         $wgUDPProfilerPort
2373                 );
2374                 wfRestoreWarnings();
2375         } elseif( $wgStatsMethod == 'cache' ) {
2376                 global $wgMemc;
2377                 $key = wfMemcKey( 'stats', $key );
2378                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2379                         $wgMemc->add( $key, $count );
2380                 }
2381         } else {
2382                 // Disabled
2383         }
2384 }
2385
2386 /**
2387  * @param $nr Mixed: the number to format
2388  * @param $acc Integer: the number of digits after the decimal point, default 2
2389  * @param $round Boolean: whether or not to round the value, default true
2390  * @return float
2391  */
2392 function wfPercent( $nr, $acc = 2, $round = true ) {
2393         $ret = sprintf( "%.${acc}f", $nr );
2394         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2395 }
2396
2397 /**
2398  * Find out whether or not a mixed variable exists in a string
2399  *
2400  * @param $needle String
2401  * @param $str String
2402  * @param $insensitive Boolean
2403  * @return Boolean
2404  */
2405 function in_string( $needle, $str, $insensitive = false ) {
2406         $func = 'strpos';
2407         if( $insensitive ) $func = 'stripos';
2408
2409         return $func( $str, $needle ) !== false;
2410 }
2411
2412 /**
2413  * Safety wrapper around ini_get() for boolean settings.
2414  * The values returned from ini_get() are pre-normalized for settings
2415  * set via php.ini or php_flag/php_admin_flag... but *not*
2416  * for those set via php_value/php_admin_value.
2417  *
2418  * It's fairly common for people to use php_value instead of php_flag,
2419  * which can leave you with an 'off' setting giving a false positive
2420  * for code that just takes the ini_get() return value as a boolean.
2421  *
2422  * To make things extra interesting, setting via php_value accepts
2423  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2424  * Unrecognized values go false... again opposite PHP's own coercion
2425  * from string to bool.
2426  *
2427  * Luckily, 'properly' set settings will always come back as '0' or '1',
2428  * so we only have to worry about them and the 'improper' settings.
2429  *
2430  * I frickin' hate PHP... :P
2431  *
2432  * @param $setting String
2433  * @return Bool
2434  */
2435 function wfIniGetBool( $setting ) {
2436         $val = ini_get( $setting );
2437         // 'on' and 'true' can't have whitespace around them, but '1' can.
2438         return strtolower( $val ) == 'on'
2439                 || strtolower( $val ) == 'true'
2440                 || strtolower( $val ) == 'yes'
2441                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2442 }
2443
2444 /**
2445  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2446  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2447  *
2448  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2449  *                          should be omitted
2450  * @param $fileName String Name of the library, if not $extension.suffix
2451  * @return Bool - Whether or not the extension is loaded
2452  */
2453 function wfDl( $extension, $fileName = null ) {
2454         if( extension_loaded( $extension ) ) {
2455                 return true;
2456         }
2457
2458         $canDl = false;
2459         $sapi = php_sapi_name();
2460         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2461                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2462         {
2463                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2464                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2465         }
2466
2467         if( $canDl ) {
2468                 $fileName = $fileName ? $fileName : $extension;
2469                 if( wfIsWindows() ) {
2470                         $fileName = 'php_' . $fileName;
2471                 }
2472                 wfSuppressWarnings();
2473                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2474                 wfRestoreWarnings();
2475         }
2476         return extension_loaded( $extension );
2477 }
2478
2479 /**
2480  * Windows-compatible version of escapeshellarg()
2481  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
2482  * function puts single quotes in regardless of OS.
2483  *
2484  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
2485  * earlier distro releases of PHP)
2486  *
2487  * @param varargs
2488  * @return String
2489  */
2490 function wfEscapeShellArg( ) {
2491         wfInitShellLocale();
2492
2493         $args = func_get_args();
2494         $first = true;
2495         $retVal = '';
2496         foreach ( $args as $arg ) {
2497                 if ( !$first ) {
2498                         $retVal .= ' ';
2499                 } else {
2500                         $first = false;
2501                 }
2502
2503                 if ( wfIsWindows() ) {
2504                         // Escaping for an MSVC-style command line parser and CMD.EXE
2505                         // Refs:
2506                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
2507                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
2508                         //  * Bug #13518
2509                         //  * CR r63214
2510                         // Double the backslashes before any double quotes. Escape the double quotes.
2511                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
2512                         $arg = '';
2513                         $iteration = 0;
2514                         foreach ( $tokens as $token ) {
2515                                 if ( $iteration % 2 == 1 ) {
2516                                         // Delimiter, a double quote preceded by zero or more slashes
2517                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
2518                                 } elseif ( $iteration % 4 == 2 ) {
2519                                         // ^ in $token will be outside quotes, need to be escaped
2520                                         $arg .= str_replace( '^', '^^', $token );
2521                                 } else { // $iteration % 4 == 0
2522                                         // ^ in $token will appear inside double quotes, so leave as is
2523                                         $arg .= $token;
2524                                 }
2525                                 $iteration++;
2526                         }
2527                         // Double the backslashes before the end of the string, because
2528                         // we will soon add a quote
2529                         $m = array();
2530                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
2531                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
2532                         }
2533
2534                         // Add surrounding quotes
2535                         $retVal .= '"' . $arg . '"';
2536                 } else {
2537                         $retVal .= escapeshellarg( $arg );
2538                 }
2539         }
2540         return $retVal;
2541 }
2542
2543 /**
2544  * Execute a shell command, with time and memory limits mirrored from the PHP
2545  * configuration if supported.
2546  * @param $cmd String Command line, properly escaped for shell.
2547  * @param &$retval optional, will receive the program's exit code.
2548  *                 (non-zero is usually failure)
2549  * @param $environ Array optional environment variables which should be
2550  *                 added to the executed command environment.
2551  * @return collected stdout as a string (trailing newlines stripped)
2552  */
2553 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2554         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2555
2556         static $disabled;
2557         if ( is_null( $disabled ) ) {
2558                 $disabled = false;
2559                 if( wfIniGetBool( 'safe_mode' ) ) {
2560                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2561                         $disabled = 'safemode';
2562                 } else {
2563                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2564                         $functions = array_map( 'trim', $functions );
2565                         $functions = array_map( 'strtolower', $functions );
2566                         if ( in_array( 'passthru', $functions ) ) {
2567                                 wfDebug( "passthru is in disabled_functions\n" );
2568                                 $disabled = 'passthru';
2569                         }
2570                 }
2571         }
2572         if ( $disabled ) {
2573                 $retval = 1;
2574                 return $disabled == 'safemode' ?
2575                         'Unable to run external programs in safe mode.' :
2576                         'Unable to run external programs, passthru() is disabled.';
2577         }
2578
2579         wfInitShellLocale();
2580
2581         $envcmd = '';
2582         foreach( $environ as $k => $v ) {
2583                 if ( wfIsWindows() ) {
2584                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2585                          * appear in the environment variable, so we must use carat escaping as documented in
2586                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2587                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2588                          * are listed there but doesn't appear to need it.
2589                          */
2590                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2591                 } else {
2592                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2593                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2594                          */
2595                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2596                 }
2597         }
2598         $cmd = $envcmd . $cmd;
2599
2600         if ( wfIsWindows() ) {
2601                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2602                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2603                 {
2604                         # Hack to work around PHP's flawed invocation of cmd.exe
2605                         # http://news.php.net/php.internals/21796
2606                         # Windows 9x doesn't accept any kind of quotes
2607                         $cmd = '"' . $cmd . '"';
2608                 }
2609         } elseif ( php_uname( 's' ) == 'Linux' ) {
2610                 $time = intval( $wgMaxShellTime );
2611                 $mem = intval( $wgMaxShellMemory );
2612                 $filesize = intval( $wgMaxShellFileSize );
2613
2614                 if ( $time > 0 && $mem > 0 ) {
2615                         $script = "$IP/bin/ulimit4.sh";
2616                         if ( is_executable( $script ) ) {
2617                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2618                         }
2619                 }
2620         }
2621         wfDebug( "wfShellExec: $cmd\n" );
2622
2623         $retval = 1; // error by default?
2624         ob_start();
2625         passthru( $cmd, $retval );
2626         $output = ob_get_contents();
2627         ob_end_clean();
2628
2629         if ( $retval == 127 ) {
2630                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2631         }
2632         return $output;
2633 }
2634
2635 /**
2636  * Workaround for http://bugs.php.net/bug.php?id=45132
2637  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2638  */
2639 function wfInitShellLocale() {
2640         static $done = false;
2641         if ( $done ) {
2642                 return;
2643         }
2644         $done = true;
2645         global $wgShellLocale;
2646         if ( !wfIniGetBool( 'safe_mode' ) ) {
2647                 putenv( "LC_CTYPE=$wgShellLocale" );
2648                 setlocale( LC_CTYPE, $wgShellLocale );
2649         }
2650 }
2651
2652 /**
2653  * Generate a shell-escaped command line string to run a maintenance script.
2654  * Note that $parameters should be a flat array and an option with an argument
2655  * should consist of two consecutive items in the array (do not use "--option value").
2656  * @param $script string MediaWiki maintenance script path
2657  * @param $parameters Array Arguments and options to the script
2658  * @param $options Array Associative array of options:
2659  *              'php': The path to the php executable
2660  *              'wrapper': Path to a PHP wrapper to handle the maintenance script
2661  * @return Array
2662  */
2663 function wfShellMaintenanceCmd( $script, array $parameters = array(), array $options = array() ) {
2664         global $wgPhpCli;
2665         // Give site config file a chance to run the script in a wrapper.
2666         // The caller may likely want to call wfBasename() on $script.
2667         wfRunHooks( 'wfShellMaintenanceCmd', array( &$script, &$parameters, &$options ) );
2668         $cmd = isset( $options['php'] ) ? array( $options['php'] ) : array( $wgPhpCli );
2669         if ( isset( $options['wrapper'] ) ) {
2670                 $cmd[] = $options['wrapper'];
2671         }
2672         $cmd[] = $script;
2673         // Escape each parameter for shell
2674         return implode( " ", array_map( 'wfEscapeShellArg', array_merge( $cmd, $parameters ) ) );
2675 }
2676
2677 /**
2678  * wfMerge attempts to merge differences between three texts.
2679  * Returns true for a clean merge and false for failure or a conflict.
2680  *
2681  * @param $old String
2682  * @param $mine String
2683  * @param $yours String
2684  * @param $result String
2685  * @return Bool
2686  */
2687 function wfMerge( $old, $mine, $yours, &$result ) {
2688         global $wgDiff3;
2689
2690         # This check may also protect against code injection in
2691         # case of broken installations.
2692         wfSuppressWarnings();
2693         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
2694         wfRestoreWarnings();
2695
2696         if( !$haveDiff3 ) {
2697                 wfDebug( "diff3 not found\n" );
2698                 return false;
2699         }
2700
2701         # Make temporary files
2702         $td = wfTempDir();
2703         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2704         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
2705         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
2706
2707         fwrite( $oldtextFile, $old );
2708         fclose( $oldtextFile );
2709         fwrite( $mytextFile, $mine );
2710         fclose( $mytextFile );
2711         fwrite( $yourtextFile, $yours );
2712         fclose( $yourtextFile );
2713
2714         # Check for a conflict
2715         $cmd = $wgDiff3 . ' -a --overlap-only ' .
2716                 wfEscapeShellArg( $mytextName ) . ' ' .
2717                 wfEscapeShellArg( $oldtextName ) . ' ' .
2718                 wfEscapeShellArg( $yourtextName );
2719         $handle = popen( $cmd, 'r' );
2720
2721         if( fgets( $handle, 1024 ) ) {
2722                 $conflict = true;
2723         } else {
2724                 $conflict = false;
2725         }
2726         pclose( $handle );
2727
2728         # Merge differences
2729         $cmd = $wgDiff3 . ' -a -e --merge ' .
2730                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
2731         $handle = popen( $cmd, 'r' );
2732         $result = '';
2733         do {
2734                 $data = fread( $handle, 8192 );
2735                 if ( strlen( $data ) == 0 ) {
2736                         break;
2737                 }
2738                 $result .= $data;
2739         } while ( true );
2740         pclose( $handle );
2741         unlink( $mytextName );
2742         unlink( $oldtextName );
2743         unlink( $yourtextName );
2744
2745         if ( $result === '' && $old !== '' && !$conflict ) {
2746                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
2747                 $conflict = true;
2748         }
2749         return !$conflict;
2750 }
2751
2752 /**
2753  * Returns unified plain-text diff of two texts.
2754  * Useful for machine processing of diffs.
2755  *
2756  * @param $before String: the text before the changes.
2757  * @param $after String: the text after the changes.
2758  * @param $params String: command-line options for the diff command.
2759  * @return String: unified diff of $before and $after
2760  */
2761 function wfDiff( $before, $after, $params = '-u' ) {
2762         if ( $before == $after ) {
2763                 return '';
2764         }
2765
2766         global $wgDiff;
2767         wfSuppressWarnings();
2768         $haveDiff = $wgDiff && file_exists( $wgDiff );
2769         wfRestoreWarnings();
2770
2771         # This check may also protect against code injection in
2772         # case of broken installations.
2773         if( !$haveDiff ) {
2774                 wfDebug( "diff executable not found\n" );
2775                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
2776                 $format = new UnifiedDiffFormatter();
2777                 return $format->format( $diffs );
2778         }
2779
2780         # Make temporary files
2781         $td = wfTempDir();
2782         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
2783         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
2784
2785         fwrite( $oldtextFile, $before );
2786         fclose( $oldtextFile );
2787         fwrite( $newtextFile, $after );
2788         fclose( $newtextFile );
2789
2790         // Get the diff of the two files
2791         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
2792
2793         $h = popen( $cmd, 'r' );
2794
2795         $diff = '';
2796
2797         do {
2798                 $data = fread( $h, 8192 );
2799                 if ( strlen( $data ) == 0 ) {
2800                         break;
2801                 }
2802                 $diff .= $data;
2803         } while ( true );
2804
2805         // Clean up
2806         pclose( $h );
2807         unlink( $oldtextName );
2808         unlink( $newtextName );
2809
2810         // Kill the --- and +++ lines. They're not useful.
2811         $diff_lines = explode( "\n", $diff );
2812         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
2813                 unset( $diff_lines[0] );
2814         }
2815         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
2816                 unset( $diff_lines[1] );
2817         }
2818
2819         $diff = implode( "\n", $diff_lines );
2820
2821         return $diff;
2822 }
2823
2824 /**
2825  * This function works like "use VERSION" in Perl, the program will die with a
2826  * backtrace if the current version of PHP is less than the version provided
2827  *
2828  * This is useful for extensions which due to their nature are not kept in sync
2829  * with releases, and might depend on other versions of PHP than the main code
2830  *
2831  * Note: PHP might die due to parsing errors in some cases before it ever
2832  *       manages to call this function, such is life
2833  *
2834  * @see perldoc -f use
2835  *
2836  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2837  *                 a float
2838  */
2839 function wfUsePHP( $req_ver ) {
2840         $php_ver = PHP_VERSION;
2841
2842         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2843                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2844         }
2845 }
2846
2847 /**
2848  * This function works like "use VERSION" in Perl except it checks the version
2849  * of MediaWiki, the program will die with a backtrace if the current version
2850  * of MediaWiki is less than the version provided.
2851  *
2852  * This is useful for extensions which due to their nature are not kept in sync
2853  * with releases
2854  *
2855  * @see perldoc -f use
2856  *
2857  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2858  *                 a float
2859  */
2860 function wfUseMW( $req_ver ) {
2861         global $wgVersion;
2862
2863         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2864                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2865         }
2866 }
2867
2868 /**
2869  * Return the final portion of a pathname.
2870  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2871  * http://bugs.php.net/bug.php?id=33898
2872  *
2873  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2874  * We'll consider it so always, as we don't want \s in our Unix paths either.
2875  *
2876  * @param $path String
2877  * @param $suffix String: to remove if present
2878  * @return String
2879  */
2880 function wfBaseName( $path, $suffix = '' ) {
2881         $encSuffix = ( $suffix == '' )
2882                 ? ''
2883                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2884         $matches = array();
2885         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2886                 return $matches[1];
2887         } else {
2888                 return '';
2889         }
2890 }
2891
2892 /**
2893  * Generate a relative path name to the given file.
2894  * May explode on non-matching case-insensitive paths,
2895  * funky symlinks, etc.
2896  *
2897  * @param $path String: absolute destination path including target filename
2898  * @param $from String: Absolute source path, directory only
2899  * @return String
2900  */
2901 function wfRelativePath( $path, $from ) {
2902         // Normalize mixed input on Windows...
2903         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2904         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2905
2906         // Trim trailing slashes -- fix for drive root
2907         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2908         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2909
2910         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2911         $against = explode( DIRECTORY_SEPARATOR, $from );
2912
2913         if( $pieces[0] !== $against[0] ) {
2914                 // Non-matching Windows drive letters?
2915                 // Return a full path.
2916                 return $path;
2917         }
2918
2919         // Trim off common prefix
2920         while( count( $pieces ) && count( $against )
2921                 && $pieces[0] == $against[0] ) {
2922                 array_shift( $pieces );
2923                 array_shift( $against );
2924         }
2925
2926         // relative dots to bump us to the parent
2927         while( count( $against ) ) {
2928                 array_unshift( $pieces, '..' );
2929                 array_shift( $against );
2930         }
2931
2932         array_push( $pieces, wfBaseName( $path ) );
2933
2934         return implode( DIRECTORY_SEPARATOR, $pieces );
2935 }
2936
2937 /**
2938  * Do any deferred updates and clear the list
2939  *
2940  * @deprecated since 1.19
2941  * @see DeferredUpdates::doUpdate()
2942  * @param $commit string
2943  */
2944 function wfDoUpdates( $commit = '' ) {
2945         DeferredUpdates::doUpdates( $commit );
2946 }
2947
2948 /**
2949  * Convert an arbitrarily-long digit string from one numeric base
2950  * to another, optionally zero-padding to a minimum column width.
2951  *
2952  * Supports base 2 through 36; digit values 10-36 are represented
2953  * as lowercase letters a-z. Input is case-insensitive.
2954  *
2955  * @param $input String: of digits
2956  * @param $sourceBase Integer: 2-36
2957  * @param $destBase Integer: 2-36
2958  * @param $pad Integer: 1 or greater
2959  * @param $lowercase Boolean
2960  * @return String or false on invalid input
2961  */
2962 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2963         $input = strval( $input );
2964         if( $sourceBase < 2 ||
2965                 $sourceBase > 36 ||
2966                 $destBase < 2 ||
2967                 $destBase > 36 ||
2968                 $pad < 1 ||
2969                 $sourceBase != intval( $sourceBase ) ||
2970                 $destBase != intval( $destBase ) ||
2971                 $pad != intval( $pad ) ||
2972                 !is_string( $input ) ||
2973                 $input == '' ) {
2974                 return false;
2975         }
2976         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2977         $inDigits = array();
2978         $outChars = '';
2979
2980         // Decode and validate input string
2981         $input = strtolower( $input );
2982         for( $i = 0; $i < strlen( $input ); $i++ ) {
2983                 $n = strpos( $digitChars, $input[$i] );
2984                 if( $n === false || $n > $sourceBase ) {
2985                         return false;
2986                 }
2987                 $inDigits[] = $n;
2988         }
2989
2990         // Iterate over the input, modulo-ing out an output digit
2991         // at a time until input is gone.
2992         while( count( $inDigits ) ) {
2993                 $work = 0;
2994                 $workDigits = array();
2995
2996                 // Long division...
2997                 foreach( $inDigits as $digit ) {
2998                         $work *= $sourceBase;
2999                         $work += $digit;
3000
3001                         if( $work < $destBase ) {
3002                                 // Gonna need to pull another digit.
3003                                 if( count( $workDigits ) ) {
3004                                         // Avoid zero-padding; this lets us find
3005                                         // the end of the input very easily when
3006                                         // length drops to zero.
3007                                         $workDigits[] = 0;
3008                                 }
3009                         } else {
3010                                 // Finally! Actual division!
3011                                 $workDigits[] = intval( $work / $destBase );
3012
3013                                 // Isn't it annoying that most programming languages
3014                                 // don't have a single divide-and-remainder operator,
3015                                 // even though the CPU implements it that way?
3016                                 $work = $work % $destBase;
3017                         }
3018                 }
3019
3020                 // All that division leaves us with a remainder,
3021                 // which is conveniently our next output digit.
3022                 $outChars .= $digitChars[$work];
3023
3024                 // And we continue!
3025                 $inDigits = $workDigits;
3026         }
3027
3028         while( strlen( $outChars ) < $pad ) {
3029                 $outChars .= '0';
3030         }
3031
3032         return strrev( $outChars );
3033 }
3034
3035 /**
3036  * Create an object with a given name and an array of construct parameters
3037  *
3038  * @param $name String
3039  * @param $p Array: parameters
3040  * @return object
3041  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
3042  */
3043 function wfCreateObject( $name, $p ) {
3044         wfDeprecated( __FUNCTION__ );
3045         return MWFunction::newObj( $name, $p );
3046 }
3047
3048 /**
3049  * @return bool
3050  */
3051 function wfHttpOnlySafe() {
3052         global $wgHttpOnlyBlacklist;
3053
3054         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
3055                 foreach( $wgHttpOnlyBlacklist as $regex ) {
3056                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
3057                                 return false;
3058                         }
3059                 }
3060         }
3061
3062         return true;
3063 }
3064
3065 /**
3066  * Initialise php session
3067  *
3068  * @param $sessionId Bool
3069  */
3070 function wfSetupSession( $sessionId = false ) {
3071         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3072                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3073         if( $wgSessionsInMemcached ) {
3074                 if ( !defined( 'MW_COMPILED' ) ) {
3075                         global $IP;
3076                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
3077                 }
3078                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3079                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3080
3081                 // It's necessary to register a shutdown function to call session_write_close(),
3082                 // because by the time the request shutdown function for the session module is
3083                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3084                 // this way are called before object destruction.
3085                 register_shutdown_function( 'memsess_write_close' );
3086         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3087                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3088                 # hasn't already been set to the desired value (that causes errors)
3089                 ini_set( 'session.save_handler', $wgSessionHandler );
3090         }
3091         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3092         wfDebugLog( 'cookie',
3093                 'session_set_cookie_params: "' . implode( '", "',
3094                         array(
3095                                 0,
3096                                 $wgCookiePath,
3097                                 $wgCookieDomain,
3098                                 $wgCookieSecure,
3099                                 $httpOnlySafe ) ) . '"' );
3100         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3101         session_cache_limiter( 'private, must-revalidate' );
3102         if ( $sessionId ) {
3103                 session_id( $sessionId );
3104         }
3105         wfSuppressWarnings();
3106         session_start();
3107         wfRestoreWarnings();
3108 }
3109
3110 /**
3111  * Get an object from the precompiled serialized directory
3112  *
3113  * @param $name String
3114  * @return Mixed: the variable on success, false on failure
3115  */
3116 function wfGetPrecompiledData( $name ) {
3117         global $IP;
3118
3119         $file = "$IP/serialized/$name";
3120         if ( file_exists( $file ) ) {
3121                 $blob = file_get_contents( $file );
3122                 if ( $blob ) {
3123                         return unserialize( $blob );
3124                 }
3125         }
3126         return false;
3127 }
3128
3129 /**
3130  * Get a cache key
3131  *
3132  * @param varargs
3133  * @return String
3134  */
3135 function wfMemcKey( /*... */ ) {
3136         $args = func_get_args();
3137         $key = wfWikiID() . ':' . implode( ':', $args );
3138         $key = str_replace( ' ', '_', $key );
3139         return $key;
3140 }
3141
3142 /**
3143  * Get a cache key for a foreign DB
3144  *
3145  * @param $db String
3146  * @param $prefix String
3147  * @param varargs String
3148  * @return String
3149  */
3150 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3151         $args = array_slice( func_get_args(), 2 );
3152         if ( $prefix ) {
3153                 $key = "$db-$prefix:" . implode( ':', $args );
3154         } else {
3155                 $key = $db . ':' . implode( ':', $args );
3156         }
3157         return $key;
3158 }
3159
3160 /**
3161  * Get an ASCII string identifying this wiki
3162  * This is used as a prefix in memcached keys
3163  *
3164  * @return String
3165  */
3166 function wfWikiID() {
3167         global $wgDBprefix, $wgDBname, $wgWikiID;
3168         if ( $wgWikiID !== false ) {
3169                 return $wgWikiID;
3170         } elseif ( $wgDBprefix ) {
3171                 return "$wgDBname-$wgDBprefix";
3172         } else {
3173                 return $wgDBname;
3174         }
3175 }
3176
3177 /**
3178  * Split a wiki ID into DB name and table prefix
3179  *
3180  * @param $wiki String
3181  *
3182  * @return array
3183  */
3184 function wfSplitWikiID( $wiki ) {
3185         $bits = explode( '-', $wiki, 2 );
3186         if ( count( $bits ) < 2 ) {
3187                 $bits[] = '';
3188         }
3189         return $bits;
3190 }
3191
3192 /**
3193  * Get a Database object.
3194  *
3195  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3196  *            master (for write queries), DB_SLAVE for potentially lagged read
3197  *            queries, or an integer >= 0 for a particular server.
3198  *
3199  * @param $groups Mixed: query groups. An array of group names that this query
3200  *                belongs to. May contain a single string if the query is only
3201  *                in one group.
3202  *
3203  * @param $wiki String: the wiki ID, or false for the current wiki
3204  *
3205  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3206  * will always return the same object, unless the underlying connection or load
3207  * balancer is manually destroyed.
3208  *
3209  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3210  * updater to ensure that a proper database is being updated.
3211  *
3212  * @return DatabaseBase
3213  */
3214 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3215         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3216 }
3217
3218 /**
3219  * Get a load balancer object.
3220  *
3221  * @param $wiki String: wiki ID, or false for the current wiki
3222  * @return LoadBalancer
3223  */
3224 function wfGetLB( $wiki = false ) {
3225         return wfGetLBFactory()->getMainLB( $wiki );
3226 }
3227
3228 /**
3229  * Get the load balancer factory object
3230  *
3231  * @return LBFactory
3232  */
3233 function &wfGetLBFactory() {
3234         return LBFactory::singleton();
3235 }
3236
3237 /**
3238  * Find a file.
3239  * Shortcut for RepoGroup::singleton()->findFile()
3240  *
3241  * @param $title String or Title object
3242  * @param $options Associative array of options:
3243  *     time:           requested time for an archived image, or false for the
3244  *                     current version. An image object will be returned which was
3245  *                     created at the specified time.
3246  *
3247  *     ignoreRedirect: If true, do not follow file redirects
3248  *
3249  *     private:        If true, return restricted (deleted) files if the current
3250  *                     user is allowed to view them. Otherwise, such files will not
3251  *                     be found.
3252  *
3253  *     bypassCache:    If true, do not use the process-local cache of File objects
3254  *
3255  * @return File, or false if the file does not exist
3256  */
3257 function wfFindFile( $title, $options = array() ) {
3258         return RepoGroup::singleton()->findFile( $title, $options );
3259 }
3260
3261 /**
3262  * Get an object referring to a locally registered file.
3263  * Returns a valid placeholder object if the file does not exist.
3264  *
3265  * @param $title Title or String
3266  * @return File|null A File, or null if passed an invalid Title
3267  */
3268 function wfLocalFile( $title ) {
3269         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3270 }
3271
3272 /**
3273  * Stream a file to the browser. Back-compat alias for StreamFile::stream()
3274  * @deprecated since 1.19
3275  */
3276 function wfStreamFile( $fname, $headers = array() ) {
3277         StreamFile::stream( $fname, $headers );
3278 }
3279
3280 /**
3281  * Should low-performance queries be disabled?
3282  *
3283  * @return Boolean
3284  * @codeCoverageIgnore
3285  */
3286 function wfQueriesMustScale() {
3287         global $wgMiserMode;
3288         return $wgMiserMode
3289                 || ( SiteStats::pages() > 100000
3290                 && SiteStats::edits() > 1000000
3291                 && SiteStats::users() > 10000 );
3292 }
3293
3294 /**
3295  * Get the path to a specified script file, respecting file
3296  * extensions; this is a wrapper around $wgScriptExtension etc.
3297  *
3298  * @param $script String: script filename, sans extension
3299  * @return String
3300  */
3301 function wfScript( $script = 'index' ) {
3302         global $wgScriptPath, $wgScriptExtension;
3303         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3304 }
3305
3306 /**
3307  * Get the script URL.
3308  *
3309  * @return script URL
3310  */
3311 function wfGetScriptUrl() {
3312         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3313                 #
3314                 # as it was called, minus the query string.
3315                 #
3316                 # Some sites use Apache rewrite rules to handle subdomains,
3317                 # and have PHP set up in a weird way that causes PHP_SELF
3318                 # to contain the rewritten URL instead of the one that the
3319                 # outside world sees.
3320                 #
3321                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3322                 # provides containing the "before" URL.
3323                 return $_SERVER['SCRIPT_NAME'];
3324         } else {
3325                 return $_SERVER['URL'];
3326         }
3327 }
3328
3329 /**
3330  * Convenience function converts boolean values into "true"
3331  * or "false" (string) values
3332  *
3333  * @param $value Boolean
3334  * @return String
3335  */
3336 function wfBoolToStr( $value ) {
3337         return $value ? 'true' : 'false';
3338 }
3339
3340 /**
3341  * Load an extension messages file
3342  *
3343  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3344  * @codeCoverageIgnore
3345  */
3346 function wfLoadExtensionMessages() {
3347         wfDeprecated( __FUNCTION__ );
3348 }
3349
3350 /**
3351  * Get a platform-independent path to the null file, e.g. /dev/null
3352  *
3353  * @return string
3354  */
3355 function wfGetNull() {
3356         return wfIsWindows()
3357                 ? 'NUL'
3358                 : '/dev/null';
3359 }
3360
3361 /**
3362  * Throws a warning that $function is deprecated
3363  *
3364  * @param $function String
3365  * @param $version String
3366  * @return null
3367  */
3368 function wfDeprecated( $function, $version = false ) {
3369         static $functionsWarned = array();
3370         if ( !isset( $functionsWarned[$function] ) ) {
3371                 $functionsWarned[$function] = true;
3372                 if ( $version ) {
3373                         global $wgDeprecationReleaseLimit;
3374                         if ( $wgDeprecationReleaseLimit ) {
3375                                 # Strip -* off the end of $version so that branches can use the
3376                                 # format #.##-branchname to avoid issues if the branch is merged into
3377                                 # a version of MediaWiki later than what it was branched from
3378                                 $comparableVersion = preg_replace( '/-.*$/', '', $version );
3379                                 # If the comparableVersion is larger than our release limit then
3380                                 # skip the warning message for the deprecation
3381                                 if ( version_compare( $wgDeprecationReleaseLimit, $comparableVersion, '<' ) ) {
3382                                         return;
3383                                 }
3384                         }
3385                         wfWarn( "Use of $function was deprecated in $version.", 2 );
3386                 } else {
3387                         wfWarn( "Use of $function is deprecated.", 2 );
3388                 }
3389         }
3390 }
3391
3392 /**
3393  * Send a warning either to the debug log or in a PHP error depending on
3394  * $wgDevelopmentWarnings
3395  *
3396  * @param $msg String: message to send
3397  * @param $callerOffset Integer: number of items to go back in the backtrace to
3398  *        find the correct caller (1 = function calling wfWarn, ...)
3399  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3400  *        is true
3401  */
3402 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3403         global $wgDevelopmentWarnings;
3404
3405         $callers = wfDebugBacktrace();
3406         if ( isset( $callers[$callerOffset + 1] ) ) {
3407                 $callerfunc = $callers[$callerOffset + 1];
3408                 $callerfile = $callers[$callerOffset];
3409                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3410                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3411                 } else {
3412                         $file = '(internal function)';
3413                 }
3414                 $func = '';
3415                 if ( isset( $callerfunc['class'] ) ) {
3416                         $func .= $callerfunc['class'] . '::';
3417                 }
3418                 if ( isset( $callerfunc['function'] ) ) {
3419                         $func .= $callerfunc['function'];
3420                 }
3421                 $msg .= " [Called from $func in $file]";
3422         }
3423
3424         if ( $wgDevelopmentWarnings ) {
3425                 trigger_error( $msg, $level );
3426         } else {
3427                 wfDebug( "$msg\n" );
3428         }
3429 }
3430
3431 /**
3432  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3433  * and waiting for it to go down, this waits for the slaves to catch up to the
3434  * master position. Use this when updating very large numbers of rows, as
3435  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3436  * a no-op if there are no slaves.
3437  *
3438  * @param $maxLag Integer (deprecated)
3439  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3440  */
3441 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3442         $lb = wfGetLB( $wiki );
3443         // bug 27975 - Don't try to wait for slaves if there are none
3444         // Prevents permission error when getting master position
3445         if ( $lb->getServerCount() > 1 ) {
3446                 $dbw = $lb->getConnection( DB_MASTER );
3447                 $pos = $dbw->getMasterPos();
3448                 $lb->waitForAll( $pos );
3449         }
3450 }
3451
3452 /**
3453  * Used to be used for outputting text in the installer/updater
3454  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3455  */
3456 function wfOut( $s ) {
3457         wfDeprecated( __METHOD__ );
3458         global $wgCommandLineMode;
3459         if ( $wgCommandLineMode ) {
3460                 echo $s;
3461         } else {
3462                 echo htmlspecialchars( $s );
3463         }
3464         flush();
3465 }
3466
3467 /**
3468  * Count down from $n to zero on the terminal, with a one-second pause
3469  * between showing each number. For use in command-line scripts.
3470  * @codeCoverageIgnore
3471  * @param $n int
3472  */
3473 function wfCountDown( $n ) {
3474         for ( $i = $n; $i >= 0; $i-- ) {
3475                 if ( $i != $n ) {
3476                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3477                 }
3478                 echo $i;
3479                 flush();
3480                 if ( $i ) {
3481                         sleep( 1 );
3482                 }
3483         }
3484         echo "\n";
3485 }
3486
3487 /**
3488  * Generate a random 32-character hexadecimal token.
3489  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3490  *              characters before hashing.
3491  * @return string
3492  * @codeCoverageIgnore
3493  */
3494 function wfGenerateToken( $salt = '' ) {
3495         $salt = serialize( $salt );
3496         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3497 }
3498
3499 /**
3500  * Replace all invalid characters with -
3501  *
3502  * @param $name Mixed: filename to process
3503  * @return String
3504  */
3505 function wfStripIllegalFilenameChars( $name ) {
3506         global $wgIllegalFileChars;
3507         $name = wfBaseName( $name );
3508         $name = preg_replace(
3509                 "/[^" . Title::legalChars() . "]" .
3510                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3511                         "/",
3512                 '-',
3513                 $name
3514         );
3515         return $name;
3516 }
3517
3518 /**
3519  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3520  *
3521  * @return Integer value memory was set to.
3522  */
3523 function wfMemoryLimit() {
3524         global $wgMemoryLimit;
3525         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3526         if( $memlimit != -1 ) {
3527                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3528                 if( $conflimit == -1 ) {
3529                         wfDebug( "Removing PHP's memory limit\n" );
3530                         wfSuppressWarnings();
3531                         ini_set( 'memory_limit', $conflimit );
3532                         wfRestoreWarnings();
3533                         return $conflimit;
3534                 } elseif ( $conflimit > $memlimit ) {
3535                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3536                         wfSuppressWarnings();
3537                         ini_set( 'memory_limit', $conflimit );
3538                         wfRestoreWarnings();
3539                         return $conflimit;
3540                 }
3541         }
3542         return $memlimit;
3543 }
3544
3545 /**
3546  * Converts shorthand byte notation to integer form
3547  *
3548  * @param $string String
3549  * @return Integer
3550  */
3551 function wfShorthandToInteger( $string = '' ) {
3552         $string = trim( $string );
3553         if( $string === '' ) {
3554                 return -1;
3555         }
3556         $last = $string[strlen( $string ) - 1];
3557         $val = intval( $string );
3558         switch( $last ) {
3559                 case 'g':
3560                 case 'G':
3561                         $val *= 1024;
3562                         // break intentionally missing
3563                 case 'm':
3564                 case 'M':
3565                         $val *= 1024;
3566                         // break intentionally missing
3567                 case 'k':
3568                 case 'K':
3569                         $val *= 1024;
3570         }
3571
3572         return $val;
3573 }
3574
3575 /**
3576  * Get the normalised IETF language tag
3577  * See unit test for examples.
3578  *
3579  * @param $code String: The language code.
3580  * @return String: The language code which complying with BCP 47 standards.
3581  */
3582 function wfBCP47( $code ) {
3583         $codeSegment = explode( '-', $code );
3584         $codeBCP = array();
3585         foreach ( $codeSegment as $segNo => $seg ) {
3586                 if ( count( $codeSegment ) > 0 ) {
3587                         // when previous segment is x, it is a private segment and should be lc
3588                         if( $segNo > 0 && strtolower( $codeSegment[( $segNo - 1 )] ) == 'x' ) {
3589                                 $codeBCP[$segNo] = strtolower( $seg );
3590                         // ISO 3166 country code
3591                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3592                                 $codeBCP[$segNo] = strtoupper( $seg );
3593                         // ISO 15924 script code
3594                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3595                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3596                         // Use lowercase for other cases
3597                         } else {
3598                                 $codeBCP[$segNo] = strtolower( $seg );
3599                         }
3600                 } else {
3601                 // Use lowercase for single segment
3602                         $codeBCP[$segNo] = strtolower( $seg );
3603                 }
3604         }
3605         $langCode = implode( '-', $codeBCP );
3606         return $langCode;
3607 }
3608
3609 /**
3610  * Get a cache object.
3611  *
3612  * @param $inputType integer Cache type, one the the CACHE_* constants.
3613  * @return BagOStuff
3614  */
3615 function wfGetCache( $inputType ) {
3616         return ObjectCache::getInstance( $inputType );
3617 }
3618
3619 /**
3620  * Get the main cache object
3621  *
3622  * @return BagOStuff
3623  */
3624 function wfGetMainCache() {
3625         global $wgMainCacheType;
3626         return ObjectCache::getInstance( $wgMainCacheType );
3627 }
3628
3629 /**
3630  * Get the cache object used by the message cache
3631  *
3632  * @return BagOStuff
3633  */
3634 function wfGetMessageCacheStorage() {
3635         global $wgMessageCacheType;
3636         return ObjectCache::getInstance( $wgMessageCacheType );
3637 }
3638
3639 /**
3640  * Get the cache object used by the parser cache
3641  *
3642  * @return BagOStuff
3643  */
3644 function wfGetParserCacheStorage() {
3645         global $wgParserCacheType;
3646         return ObjectCache::getInstance( $wgParserCacheType );
3647 }
3648
3649 /**
3650  * Call hook functions defined in $wgHooks
3651  *
3652  * @param $event String: event name
3653  * @param $args Array: parameters passed to hook functions
3654  * @return Boolean
3655  */
3656 function wfRunHooks( $event, $args = array() ) {
3657         return Hooks::run( $event, $args );
3658 }
3659
3660 /**
3661  * Wrapper around php's unpack.
3662  *
3663  * @param $format String: The format string (See php's docs)
3664  * @param $data: A binary string of binary data
3665  * @param $length integer or false: The minimun length of $data. This is to
3666  *      prevent reading beyond the end of $data. false to disable the check.
3667  *
3668  * Also be careful when using this function to read unsigned 32 bit integer
3669  * because php might make it negative.
3670  *
3671  * @throws MWException if $data not long enough, or if unpack fails
3672  * @return Associative array of the extracted data
3673  */
3674 function wfUnpack( $format, $data, $length=false ) {
3675         if ( $length !== false ) {
3676                 $realLen = strlen( $data );
3677                 if ( $realLen < $length ) {
3678                         throw new MWException( "Tried to use wfUnpack on a "
3679                                 . "string of length $realLen, but needed one "
3680                                 . "of at least length $length."
3681                         );
3682                 }
3683         }
3684
3685         wfSuppressWarnings();
3686         $result = unpack( $format, $data );
3687         wfRestoreWarnings();
3688
3689         if ( $result === false ) {
3690                 // If it cannot extract the packed data.
3691                 throw new MWException( "unpack could not unpack binary data" );
3692         }
3693         return $result;
3694 }