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 define( 'PROTO_HTTP', 'http://' );
 432 define( 'PROTO_HTTPS', 'https://' );
 433 define( 'PROTO_RELATIVE', '//' );
 434 define( 'PROTO_CURRENT', null );
 435
 436 /**
 437  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 438  * is correct.
 439  *
 440  * The meaning of the PROT_* constants is as follows:
 441  * PROT_HTTP: Output a URL starting with http://
 442  * PROT_HTTPS: Output a URL starting with https://
 443  * PROT_RELATIVE: Output a URL starting with // (protocol-relative URL)
 444  * PROT_CURRENT: Output a URL starting with either http:// or https:// , depending on which protocol was used for the current incoming request
 445  *
 446  * @todo this won't work with current-path-relative URLs
 447  * like "subdir/foo.html", etc.
 448  *
 449  * @param $url String: either fully-qualified or a local path + query
 450  * @param $defaultProto Mixed: one of the PROTO_* constants. Determines the protocol to use if $url or $wgServer is protocol-relative
 451  * @return string Fully-qualified URL
 452  */
 453 function wfExpandUrl( $url, $defaultProto = PROTO_CURRENT ) {
 454         global $wgServer;
 455         if ( $defaultProto === PROTO_CURRENT ) {
 456                 $defaultProto = WebRequest::detectProtocol() . '://';
 457         }
 458
 459         // Analyze $wgServer to obtain its protocol
 460         $bits = wfParseUrl( $wgServer );
 461         $serverHasProto = $bits && $bits['scheme'] != '';
 462         $defaultProtoWithoutSlashes = substr( $defaultProto, 0, -2 );
 463
 464         if( substr( $url, 0, 2 ) == '//' ) {
 465                 return $defaultProtoWithoutSlashes . $url;
 466         } elseif( substr( $url, 0, 1 ) == '/' ) {
 467                 // If $wgServer is protocol-relative, prepend $defaultProtoWithoutSlashes, otherwise leave it alone
 468                 return ( $serverHasProto ? '' : $defaultProtoWithoutSlashes ) . $wgServer . $url;
 469         } else {
 470                 return $url;
 471         }
 472 }
 473
 474 /**
 475  * Returns a regular expression of url protocols
 476  *
 477  * @return String
 478  */
 479 function wfUrlProtocols() {
 480         global $wgUrlProtocols;
 481
 482         static $retval = null;
 483         if ( !is_null( $retval ) ) {
 484                 return $retval;
 485         }
 486
 487         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 488         // with LocalSettings files from 1.5
 489         if ( is_array( $wgUrlProtocols ) ) {
 490                 $protocols = array();
 491                 foreach ( $wgUrlProtocols as $protocol ) {
 492                         $protocols[] = preg_quote( $protocol, '/' );
 493                 }
 494
 495                 $retval = implode( '|', $protocols );
 496         } else {
 497                 $retval = $wgUrlProtocols;
 498         }
 499         return $retval;
 500 }
 501
 502 /**
 503  * parse_url() work-alike, but non-broken.  Differences:
 504  *
 505  * 1) Does not raise warnings on bad URLs (just returns false)
 506  * 2) Handles protocols that don't use :// (e.g., mailto: and news: , as well as protocol-relative URLs) correctly
 507  * 3) Adds a "delimiter" element to the array, either '://', ':' or '//' (see (2))
 508  *
 509  * @param $url String: a URL to parse
 510  * @return Array: bits of the URL in an associative array, per PHP docs
 511  */
 512 function wfParseUrl( $url ) {
 513         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 514
 515         // Protocol-relative URLs are handled really badly by parse_url(). It's so bad that the easiest
 516         // way to handle them is to just prepend 'http:' and strip the protocol out later
 517         $wasRelative = substr( $url, 0, 2 ) == '//';
 518         if ( $wasRelative ) {
 519                 $url = "http:$url";
 520         }
 521         wfSuppressWarnings();
 522         $bits = parse_url( $url );
 523         wfRestoreWarnings();
 524         if ( !$bits ) {
 525                 return false;
 526         }
 527
 528         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 529         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 530                 $bits['delimiter'] = '://';
 531         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 532                 $bits['delimiter'] = ':';
 533                 // parse_url detects for news: and mailto: the host part of an url as path
 534                 // We have to correct this wrong detection
 535                 if ( isset( $bits['path'] ) ) {
 536                         $bits['host'] = $bits['path'];
 537                         $bits['path'] = '';
 538                 }
 539         } else {
 540                 return false;
 541         }
 542
 543         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 544         if ( !isset( $bits['host'] ) ) {
 545                 $bits['host'] = '';
 546
 547                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 548                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 549                         $bits['path'] = '/' . $bits['path'];
 550                 }
 551         }
 552
 553         // If the URL was protocol-relative, fix scheme and delimiter
 554         if ( $wasRelative ) {
 555                 $bits['scheme'] = '';
 556                 $bits['delimiter'] = '//';
 557         }
 558         return $bits;
 559 }
 560
 561 /**
 562  * Make a URL index, appropriate for the el_index field of externallinks.
 563  *
 564  * @param $url String
 565  * @return String
 566  */
 567 function wfMakeUrlIndex( $url ) {
 568         $bits = wfParseUrl( $url );
 569
 570         // Reverse the labels in the hostname, convert to lower case
 571         // For emails reverse domainpart only
 572         if ( $bits['scheme'] == 'mailto' ) {
 573                 $mailparts = explode( '@', $bits['host'], 2 );
 574                 if ( count( $mailparts ) === 2 ) {
 575                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 576                 } else {
 577                         // No domain specified, don't mangle it
 578                         $domainpart = '';
 579                 }
 580                 $reversedHost = $domainpart . '@' . $mailparts[0];
 581         } else {
 582                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 583         }
 584         // Add an extra dot to the end
 585         // Why? Is it in wrong place in mailto links?
 586         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 587                 $reversedHost .= '.';
 588         }
 589         // Reconstruct the pseudo-URL
 590         $prot = $bits['scheme'];
 591         $index = $prot . $bits['delimiter'] . $reversedHost;
 592         // Leave out user and password. Add the port, path, query and fragment
 593         if ( isset( $bits['port'] ) ) {
 594                 $index .= ':' . $bits['port'];
 595         }
 596         if ( isset( $bits['path'] ) ) {
 597                 $index .= $bits['path'];
 598         } else {
 599                 $index .= '/';
 600         }
 601         if ( isset( $bits['query'] ) ) {
 602                 $index .= '?' . $bits['query'];
 603         }
 604         if ( isset( $bits['fragment'] ) ) {
 605                 $index .= '#' . $bits['fragment'];
 606         }
 607         return $index;
 608 }
 609
 610 /**
 611  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 612  * In normal operation this is a NOP.
 613  *
 614  * Controlling globals:
 615  * $wgDebugLogFile - points to the log file
 616  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 617  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 618  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 619  *
 620  * @param $text String
 621  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 622  */
 623 function wfDebug( $text, $logonly = false ) {
 624         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 625         global $wgDebugLogPrefix, $wgShowDebug;
 626
 627         static $cache = array(); // Cache of unoutputted messages
 628         $text = wfDebugTimer() . $text;
 629
 630         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 631                 return;
 632         }
 633
 634         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 635                 $cache[] = $text;
 636
 637                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 638                         // add the message and any cached messages to the output
 639                         array_map( array( $wgOut, 'debug' ), $cache );
 640                         $cache = array();
 641                 }
 642         }
 643         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 644                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 645                         # Strip unprintables; they can switch terminal modes when binary data
 646                         # gets dumped, which is pretty annoying.
 647                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 648                         $text = $wgDebugLogPrefix . $text;
 649                         wfErrorLog( $text, $wgDebugLogFile );
 650                 }
 651         }
 652 }
 653
 654 /**
 655  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 656  */
 657 function wfIsDebugRawPage() {
 658         static $cache;
 659         if ( $cache !== null ) {
 660                 return $cache;
 661         }
 662         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 663         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 664                 || (
 665                         isset( $_SERVER['SCRIPT_NAME'] )
 666                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 667                 ) )
 668         {
 669                 $cache = true;
 670         } else {
 671                 $cache = false;
 672         }
 673         return $cache;
 674 }
 675
 676 /**
 677  * Get microsecond timestamps for debug logs
 678  *
 679  * @return string
 680  */
 681 function wfDebugTimer() {
 682         global $wgDebugTimestamps;
 683         if ( !$wgDebugTimestamps ) {
 684                 return '';
 685         }
 686         static $start = null;
 687
 688         if ( $start === null ) {
 689                 $start = microtime( true );
 690                 $prefix = "\n$start";
 691         } else {
 692                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 693         }
 694
 695         return $prefix . '  ';
 696 }
 697
 698 /**
 699  * Send a line giving PHP memory usage.
 700  *
 701  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 702  */
 703 function wfDebugMem( $exact = false ) {
 704         $mem = memory_get_usage();
 705         if( !$exact ) {
 706                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 707         } else {
 708                 $mem .= ' bytes';
 709         }
 710         wfDebug( "Memory usage: $mem\n" );
 711 }
 712
 713 /**
 714  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 715  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 716  *
 717  * @param $logGroup String
 718  * @param $text String
 719  * @param $public Bool: whether to log the event in the public log if no private
 720  *                     log file is specified, (default true)
 721  */
 722 function wfDebugLog( $logGroup, $text, $public = true ) {
 723         global $wgDebugLogGroups, $wgShowHostnames;
 724         $text = trim( $text ) . "\n";
 725         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 726                 $time = wfTimestamp( TS_DB );
 727                 $wiki = wfWikiID();
 728                 if ( $wgShowHostnames ) {
 729                         $host = wfHostname();
 730                 } else {
 731                         $host = '';
 732                 }
 733                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 734                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 735                 }
 736         } elseif ( $public === true ) {
 737                 wfDebug( $text, true );
 738         }
 739 }
 740
 741 /**
 742  * Log for database errors
 743  *
 744  * @param $text String: database error message.
 745  */
 746 function wfLogDBError( $text ) {
 747         global $wgDBerrorLog, $wgDBname;
 748         if ( $wgDBerrorLog ) {
 749                 $host = trim(`hostname`);
 750                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 751                 wfErrorLog( $text, $wgDBerrorLog );
 752         }
 753 }
 754
 755 /**
 756  * Log to a file without getting "file size exceeded" signals.
 757  *
 758  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 759  * send lines to the specified port, prefixed by the specified prefix and a space.
 760  *
 761  * @param $text String
 762  * @param $file String filename
 763  */
 764 function wfErrorLog( $text, $file ) {
 765         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 766                 # Needs the sockets extension
 767                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 768                         // IPv6 bracketed host
 769                         $host = $m[2];
 770                         $port = intval( $m[3] );
 771                         $prefix = isset( $m[4] ) ? $m[4] : false;
 772                         $domain = AF_INET6;
 773                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 774                         $host = $m[2];
 775                         if ( !IP::isIPv4( $host ) ) {
 776                                 $host = gethostbyname( $host );
 777                         }
 778                         $port = intval( $m[3] );
 779                         $prefix = isset( $m[4] ) ? $m[4] : false;
 780                         $domain = AF_INET;
 781                 } else {
 782                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 783                 }
 784
 785                 // Clean it up for the multiplexer
 786                 if ( strval( $prefix ) !== '' ) {
 787                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 788
 789                         // Limit to 64KB
 790                         if ( strlen( $text ) > 65534 ) {
 791                                 $text = substr( $text, 0, 65534 );
 792                         }
 793
 794                         if ( substr( $text, -1 ) != "\n" ) {
 795                                 $text .= "\n";
 796                         }
 797                 } elseif ( strlen( $text ) > 65535 ) {
 798                         $text = substr( $text, 0, 65535 );
 799                 }
 800
 801                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 802                 if ( !$sock ) {
 803                         return;
 804                 }
 805                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 806                 socket_close( $sock );
 807         } else {
 808                 wfSuppressWarnings();
 809                 $exists = file_exists( $file );
 810                 $size = $exists ? filesize( $file ) : false;
 811                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 812                         file_put_contents( $file, $text, FILE_APPEND );
 813                 }
 814                 wfRestoreWarnings();
 815         }
 816 }
 817
 818 /**
 819  * @todo document
 820  */
 821 function wfLogProfilingData() {
 822         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 823         global $wgProfileLimit, $wgUser;
 824
 825         $profiler = Profiler::instance();
 826
 827         # Profiling must actually be enabled...
 828         if ( $profiler->isStub() ) {
 829                 return;
 830         }
 831
 832         // Get total page request time and only show pages that longer than
 833         // $wgProfileLimit time (default is 0)
 834         $now = wfTime();
 835         $elapsed = $now - $wgRequestTime;
 836         if ( $elapsed <= $wgProfileLimit ) {
 837                 return;
 838         }
 839
 840         $profiler->logData();
 841
 842         // Check whether this should be logged in the debug file.
 843         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
 844                 return;
 845         }
 846
 847         $forward = '';
 848         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
 849                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 850         }
 851         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
 852                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 853         }
 854         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
 855                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 856         }
 857         if ( $forward ) {
 858                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 859         }
 860         // Don't load $wgUser at this late stage just for statistics purposes
 861         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
 862         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
 863                 $forward .= ' anon';
 864         }
 865         $log = sprintf( "%s\t%04.3f\t%s\n",
 866                 gmdate( 'YmdHis' ), $elapsed,
 867                 urldecode( $wgRequest->getRequestURL() . $forward ) );
 868
 869         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
 870 }
 871
 872 /**
 873  * Check if the wiki read-only lock file is present. This can be used to lock
 874  * off editing functions, but doesn't guarantee that the database will not be
 875  * modified.
 876  *
 877  * @return bool
 878  */
 879 function wfReadOnly() {
 880         global $wgReadOnlyFile, $wgReadOnly;
 881
 882         if ( !is_null( $wgReadOnly ) ) {
 883                 return (bool)$wgReadOnly;
 884         }
 885         if ( $wgReadOnlyFile == '' ) {
 886                 return false;
 887         }
 888         // Set $wgReadOnly for faster access next time
 889         if ( is_file( $wgReadOnlyFile ) ) {
 890                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
 891         } else {
 892                 $wgReadOnly = false;
 893         }
 894         return (bool)$wgReadOnly;
 895 }
 896
 897 function wfReadOnlyReason() {
 898         global $wgReadOnly;
 899         wfReadOnly();
 900         return $wgReadOnly;
 901 }
 902
 903 /**
 904  * Return a Language object from $langcode
 905  *
 906  * @param $langcode Mixed: either:
 907  *                  - a Language object
 908  *                  - code of the language to get the message for, if it is
 909  *                    a valid code create a language for that language, if
 910  *                    it is a string but not a valid code then make a basic
 911  *                    language object
 912  *                  - a boolean: if it's false then use the current users
 913  *                    language (as a fallback for the old parameter
 914  *                    functionality), or if it is true then use the wikis
 915  * @return Language object
 916  */
 917 function wfGetLangObj( $langcode = false ) {
 918         # Identify which language to get or create a language object for.
 919         # Using is_object here due to Stub objects.
 920         if( is_object( $langcode ) ) {
 921                 # Great, we already have the object (hopefully)!
 922                 return $langcode;
 923         }
 924
 925         global $wgContLang, $wgLanguageCode;
 926         if( $langcode === true || $langcode === $wgLanguageCode ) {
 927                 # $langcode is the language code of the wikis content language object.
 928                 # or it is a boolean and value is true
 929                 return $wgContLang;
 930         }
 931
 932         global $wgLang;
 933         if( $langcode === false || $langcode === $wgLang->getCode() ) {
 934                 # $langcode is the language code of user language object.
 935                 # or it was a boolean and value is false
 936                 return $wgLang;
 937         }
 938
 939         $validCodes = array_keys( Language::getLanguageNames() );
 940         if( in_array( $langcode, $validCodes ) ) {
 941                 # $langcode corresponds to a valid language.
 942                 return Language::factory( $langcode );
 943         }
 944
 945         # $langcode is a string, but not a valid language code; use content language.
 946         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
 947         return $wgContLang;
 948 }
 949
 950 /**
 951  * Old function when $wgBetterDirectionality existed
 952  * Removed in core, kept in extensions for backwards compat.
 953  *
 954  * @deprecated since 1.18
 955  * @return Language
 956  */
 957 function wfUILang() {
 958         global $wgLang;
 959         return $wgLang;
 960 }
 961
 962 /**
 963  * This is the new function for getting translated interface messages.
 964  * See the Message class for documentation how to use them.
 965  * The intention is that this function replaces all old wfMsg* functions.
 966  * @param $key \string Message key.
 967  * Varargs: normal message parameters.
 968  * @return Message
 969  * @since 1.17
 970  */
 971 function wfMessage( $key /*...*/) {
 972         $params = func_get_args();
 973         array_shift( $params );
 974         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 975                 $params = $params[0];
 976         }
 977         return new Message( $key, $params );
 978 }
 979
 980 /**
 981  * This function accepts multiple message keys and returns a message instance
 982  * for the first message which is non-empty. If all messages are empty then an
 983  * instance of the first message key is returned.
 984  * @param varargs: message keys
 985  * @return Message
 986  * @since 1.18
 987  */
 988 function wfMessageFallback( /*...*/ ) {
 989         $args = func_get_args();
 990         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
 991 }
 992
 993 /**
 994  * Get a message from anywhere, for the current user language.
 995  *
 996  * Use wfMsgForContent() instead if the message should NOT
 997  * change depending on the user preferences.
 998  *
 999  * @param $key String: lookup key for the message, usually
1000  *    defined in languages/Language.php
1001  *
1002  * Parameters to the message, which can be used to insert variable text into
1003  * it, can be passed to this function in the following formats:
1004  * - One per argument, starting at the second parameter
1005  * - As an array in the second parameter
1006  * These are not shown in the function definition.
1007  *
1008  * @return String
1009  */
1010 function wfMsg( $key ) {
1011         $args = func_get_args();
1012         array_shift( $args );
1013         return wfMsgReal( $key, $args );
1014 }
1015
1016 /**
1017  * Same as above except doesn't transform the message
1018  *
1019  * @param $key String
1020  * @return String
1021  */
1022 function wfMsgNoTrans( $key ) {
1023         $args = func_get_args();
1024         array_shift( $args );
1025         return wfMsgReal( $key, $args, true, false, false );
1026 }
1027
1028 /**
1029  * Get a message from anywhere, for the current global language
1030  * set with $wgLanguageCode.
1031  *
1032  * Use this if the message should NOT change dependent on the
1033  * language set in the user's preferences. This is the case for
1034  * most text written into logs, as well as link targets (such as
1035  * the name of the copyright policy page). Link titles, on the
1036  * other hand, should be shown in the UI language.
1037  *
1038  * Note that MediaWiki allows users to change the user interface
1039  * language in their preferences, but a single installation
1040  * typically only contains content in one language.
1041  *
1042  * Be wary of this distinction: If you use wfMsg() where you should
1043  * use wfMsgForContent(), a user of the software may have to
1044  * customize potentially hundreds of messages in
1045  * order to, e.g., fix a link in every possible language.
1046  *
1047  * @param $key String: lookup key for the message, usually
1048  *     defined in languages/Language.php
1049  * @return String
1050  */
1051 function wfMsgForContent( $key ) {
1052         global $wgForceUIMsgAsContentMsg;
1053         $args = func_get_args();
1054         array_shift( $args );
1055         $forcontent = true;
1056         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1057                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1058         {
1059                 $forcontent = false;
1060         }
1061         return wfMsgReal( $key, $args, true, $forcontent );
1062 }
1063
1064 /**
1065  * Same as above except doesn't transform the message
1066  *
1067  * @param $key String
1068  * @return String
1069  */
1070 function wfMsgForContentNoTrans( $key ) {
1071         global $wgForceUIMsgAsContentMsg;
1072         $args = func_get_args();
1073         array_shift( $args );
1074         $forcontent = true;
1075         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1076                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1077         {
1078                 $forcontent = false;
1079         }
1080         return wfMsgReal( $key, $args, true, $forcontent, false );
1081 }
1082
1083 /**
1084  * Really get a message
1085  *
1086  * @param $key String: key to get.
1087  * @param $args
1088  * @param $useDB Boolean
1089  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1090  * @param $transform Boolean: Whether or not to transform the message.
1091  * @return String: the requested message.
1092  */
1093 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1094         wfProfileIn( __METHOD__ );
1095         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1096         $message = wfMsgReplaceArgs( $message, $args );
1097         wfProfileOut( __METHOD__ );
1098         return $message;
1099 }
1100
1101 /**
1102  * Fetch a message string value, but don't replace any keys yet.
1103  *
1104  * @param $key String
1105  * @param $useDB Bool
1106  * @param $langCode String: Code of the language to get the message for, or
1107  *                  behaves as a content language switch if it is a boolean.
1108  * @param $transform Boolean: whether to parse magic words, etc.
1109  * @return string
1110  */
1111 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1112         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1113
1114         $cache = MessageCache::singleton();
1115         $message = $cache->get( $key, $useDB, $langCode );
1116         if( $message === false ) {
1117                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1118         } elseif ( $transform ) {
1119                 $message = $cache->transform( $message );
1120         }
1121         return $message;
1122 }
1123
1124 /**
1125  * Replace message parameter keys on the given formatted output.
1126  *
1127  * @param $message String
1128  * @param $args Array
1129  * @return string
1130  * @private
1131  */
1132 function wfMsgReplaceArgs( $message, $args ) {
1133         # Fix windows line-endings
1134         # Some messages are split with explode("\n", $msg)
1135         $message = str_replace( "\r", '', $message );
1136
1137         // Replace arguments
1138         if ( count( $args ) ) {
1139                 if ( is_array( $args[0] ) ) {
1140                         $args = array_values( $args[0] );
1141                 }
1142                 $replacementKeys = array();
1143                 foreach( $args as $n => $param ) {
1144                         $replacementKeys['$' . ( $n + 1 )] = $param;
1145                 }
1146                 $message = strtr( $message, $replacementKeys );
1147         }
1148
1149         return $message;
1150 }
1151
1152 /**
1153  * Return an HTML-escaped version of a message.
1154  * Parameter replacements, if any, are done *after* the HTML-escaping,
1155  * so parameters may contain HTML (eg links or form controls). Be sure
1156  * to pre-escape them if you really do want plaintext, or just wrap
1157  * the whole thing in htmlspecialchars().
1158  *
1159  * @param $key String
1160  * @param string ... parameters
1161  * @return string
1162  */
1163 function wfMsgHtml( $key ) {
1164         $args = func_get_args();
1165         array_shift( $args );
1166         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1167 }
1168
1169 /**
1170  * Return an HTML version of message
1171  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1172  * so parameters may contain HTML (eg links or form controls). Be sure
1173  * to pre-escape them if you really do want plaintext, or just wrap
1174  * the whole thing in htmlspecialchars().
1175  *
1176  * @param $key String
1177  * @param string ... parameters
1178  * @return string
1179  */
1180 function wfMsgWikiHtml( $key ) {
1181         $args = func_get_args();
1182         array_shift( $args );
1183         return wfMsgReplaceArgs(
1184                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null, /* can't be set to false */ true )->getText(),
1185                 $args );
1186 }
1187
1188 /**
1189  * Returns message in the requested format
1190  * @param $key String: key of the message
1191  * @param $options Array: processing rules. Can take the following options:
1192  *   <i>parse</i>: parses wikitext to HTML
1193  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1194  *       p's added by parser or tidy
1195  *   <i>escape</i>: filters message through htmlspecialchars
1196  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1197  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1198  *   <i>parsemag</i>: transform the message using magic phrases
1199  *   <i>content</i>: fetch message for content language instead of interface
1200  * Also can accept a single associative argument, of the form 'language' => 'xx':
1201  *   <i>language</i>: Language object or language code to fetch message for
1202  *       (overriden by <i>content</i>).
1203  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1204  *
1205  * @return String
1206  */
1207 function wfMsgExt( $key, $options ) {
1208         $args = func_get_args();
1209         array_shift( $args );
1210         array_shift( $args );
1211         $options = (array)$options;
1212
1213         foreach( $options as $arrayKey => $option ) {
1214                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1215                         # An unknown index, neither numeric nor "language"
1216                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1217                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1218                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1219                 'replaceafter', 'parsemag', 'content' ) ) ) {
1220                         # A numeric index with unknown value
1221                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1222                 }
1223         }
1224
1225         if( in_array( 'content', $options, true ) ) {
1226                 $forContent = true;
1227                 $langCode = true;
1228                 $langCodeObj = null;
1229         } elseif( array_key_exists( 'language', $options ) ) {
1230                 $forContent = false;
1231                 $langCode = wfGetLangObj( $options['language'] );
1232                 $langCodeObj = $langCode;
1233         } else {
1234                 $forContent = false;
1235                 $langCode = false;
1236                 $langCodeObj = null;
1237         }
1238
1239         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1240
1241         if( !in_array( 'replaceafter', $options, true ) ) {
1242                 $string = wfMsgReplaceArgs( $string, $args );
1243         }
1244
1245         $messageCache = MessageCache::singleton();
1246         if( in_array( 'parse', $options, true ) ) {
1247                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1248         } elseif ( in_array( 'parseinline', $options, true ) ) {
1249                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1250                 $m = array();
1251                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1252                         $string = $m[1];
1253                 }
1254         } elseif ( in_array( 'parsemag', $options, true ) ) {
1255                 $string = $messageCache->transform( $string,
1256                                 !$forContent, $langCodeObj );
1257         }
1258
1259         if ( in_array( 'escape', $options, true ) ) {
1260                 $string = htmlspecialchars ( $string );
1261         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1262                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1263         }
1264
1265         if( in_array( 'replaceafter', $options, true ) ) {
1266                 $string = wfMsgReplaceArgs( $string, $args );
1267         }
1268
1269         return $string;
1270 }
1271
1272 /**
1273  * Since wfMsg() and co suck, they don't return false if the message key they
1274  * looked up didn't exist but a XHTML string, this function checks for the
1275  * nonexistance of messages by checking the MessageCache::get() result directly.
1276  *
1277  * @param $key      String: the message key looked up
1278  * @return Boolean True if the message *doesn't* exist.
1279  */
1280 function wfEmptyMsg( $key ) {
1281         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1282 }
1283
1284 /**
1285  * Throw a debugging exception. This function previously once exited the process,
1286  * but now throws an exception instead, with similar results.
1287  *
1288  * @param $msg String: message shown when dieing.
1289  */
1290 function wfDebugDieBacktrace( $msg = '' ) {
1291         throw new MWException( $msg );
1292 }
1293
1294 /**
1295  * Fetch server name for use in error reporting etc.
1296  * Use real server name if available, so we know which machine
1297  * in a server farm generated the current page.
1298  *
1299  * @return string
1300  */
1301 function wfHostname() {
1302         static $host;
1303         if ( is_null( $host ) ) {
1304                 if ( function_exists( 'posix_uname' ) ) {
1305                         // This function not present on Windows
1306                         $uname = posix_uname();
1307                 } else {
1308                         $uname = false;
1309                 }
1310                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1311                         $host = $uname['nodename'];
1312                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1313                         # Windows computer name
1314                         $host = getenv( 'COMPUTERNAME' );
1315                 } else {
1316                         # This may be a virtual server.
1317                         $host = $_SERVER['SERVER_NAME'];
1318                 }
1319         }
1320         return $host;
1321 }
1322
1323 /**
1324  * Returns a HTML comment with the elapsed time since request.
1325  * This method has no side effects.
1326  *
1327  * @return string
1328  */
1329 function wfReportTime() {
1330         global $wgRequestTime, $wgShowHostnames;
1331
1332         $now = wfTime();
1333         $elapsed = $now - $wgRequestTime;
1334
1335         return $wgShowHostnames
1336                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1337                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1338 }
1339
1340 /**
1341  * Safety wrapper for debug_backtrace().
1342  *
1343  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1344  * murky circumstances, which may be triggered in part by stub objects
1345  * or other fancy talkin'.
1346  *
1347  * Will return an empty array if Zend Optimizer is detected or if
1348  * debug_backtrace is disabled, otherwise the output from
1349  * debug_backtrace() (trimmed).
1350  *
1351  * @return array of backtrace information
1352  */
1353 function wfDebugBacktrace( $limit = 0 ) {
1354         static $disabled = null;
1355
1356         if( extension_loaded( 'Zend Optimizer' ) ) {
1357                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1358                 return array();
1359         }
1360
1361         if ( is_null( $disabled ) ) {
1362                 $disabled = false;
1363                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1364                 $functions = array_map( 'trim', $functions );
1365                 $functions = array_map( 'strtolower', $functions );
1366                 if ( in_array( 'debug_backtrace', $functions ) ) {
1367                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1368                         $disabled = true;
1369                 }
1370         }
1371         if ( $disabled ) {
1372                 return array();
1373         }
1374
1375         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1376                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, 1 ), 1 );
1377         } else {
1378                 return array_slice( debug_backtrace(), 1 );
1379         }
1380 }
1381
1382 /**
1383  * Get a debug backtrace as a string
1384  *
1385  * @return string
1386  */
1387 function wfBacktrace() {
1388         global $wgCommandLineMode;
1389
1390         if ( $wgCommandLineMode ) {
1391                 $msg = '';
1392         } else {
1393                 $msg = "<ul>\n";
1394         }
1395         $backtrace = wfDebugBacktrace();
1396         foreach( $backtrace as $call ) {
1397                 if( isset( $call['file'] ) ) {
1398                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1399                         $file = $f[count( $f ) - 1];
1400                 } else {
1401                         $file = '-';
1402                 }
1403                 if( isset( $call['line'] ) ) {
1404                         $line = $call['line'];
1405                 } else {
1406                         $line = '-';
1407                 }
1408                 if ( $wgCommandLineMode ) {
1409                         $msg .= "$file line $line calls ";
1410                 } else {
1411                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1412                 }
1413                 if( !empty( $call['class'] ) ) {
1414                         $msg .= $call['class'] . $call['type'];
1415                 }
1416                 $msg .= $call['function'] . '()';
1417
1418                 if ( $wgCommandLineMode ) {
1419                         $msg .= "\n";
1420                 } else {
1421                         $msg .= "</li>\n";
1422                 }
1423         }
1424         if ( $wgCommandLineMode ) {
1425                 $msg .= "\n";
1426         } else {
1427                 $msg .= "</ul>\n";
1428         }
1429
1430         return $msg;
1431 }
1432
1433 /**
1434  * Get the name of the function which called this function
1435  *
1436  * @param $level Int
1437  * @return Bool|string
1438  */
1439 function wfGetCaller( $level = 2 ) {
1440         $backtrace = wfDebugBacktrace( $level );
1441         if ( isset( $backtrace[$level] ) ) {
1442                 return wfFormatStackFrame( $backtrace[$level] );
1443         } else {
1444                 $caller = 'unknown';
1445         }
1446         return $caller;
1447 }
1448
1449 /**
1450  * Return a string consisting of callers in the stack. Useful sometimes
1451  * for profiling specific points.
1452  *
1453  * @param $limit The maximum depth of the stack frame to return, or false for
1454  *               the entire stack.
1455  * @return String
1456  */
1457 function wfGetAllCallers( $limit = 3 ) {
1458         $trace = array_reverse( wfDebugBacktrace() );
1459         if ( !$limit || $limit > count( $trace ) - 1 ) {
1460                 $limit = count( $trace ) - 1;
1461         }
1462         $trace = array_slice( $trace, -$limit - 1, $limit );
1463         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1464 }
1465
1466 /**
1467  * Return a string representation of frame
1468  *
1469  * @param $frame Array
1470  * @return Bool
1471  */
1472 function wfFormatStackFrame( $frame ) {
1473         return isset( $frame['class'] ) ?
1474                 $frame['class'] . '::' . $frame['function'] :
1475                 $frame['function'];
1476 }
1477
1478
1479 /* Some generic result counters, pulled out of SearchEngine */
1480
1481
1482 /**
1483  * @todo document
1484  *
1485  * @param $offset Int
1486  * @param $limit Int
1487  * @return String
1488  */
1489 function wfShowingResults( $offset, $limit ) {
1490         global $wgLang;
1491         return wfMsgExt(
1492                 'showingresults',
1493                 array( 'parseinline' ),
1494                 $wgLang->formatNum( $limit ),
1495                 $wgLang->formatNum( $offset + 1 )
1496         );
1497 }
1498
1499 /**
1500  * Generate (prev x| next x) (20|50|100...) type links for paging
1501  *
1502  * @param $offset String
1503  * @param $limit Integer
1504  * @param $link String
1505  * @param $query String: optional URL query parameter string
1506  * @param $atend Bool: optional param for specified if this is the last page
1507  * @return String
1508  */
1509 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1510         global $wgLang;
1511         $fmtLimit = $wgLang->formatNum( $limit );
1512         // @todo FIXME: Why on earth this needs one message for the text and another one for tooltip?
1513         # Get prev/next link display text
1514         $prev = wfMsgExt( 'prevn', array( 'parsemag', 'escape' ), $fmtLimit );
1515         $next = wfMsgExt( 'nextn', array( 'parsemag', 'escape' ), $fmtLimit );
1516         # Get prev/next link title text
1517         $pTitle = wfMsgExt( 'prevn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1518         $nTitle = wfMsgExt( 'nextn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1519         # Fetch the title object
1520         if( is_object( $link ) ) {
1521                 $title =& $link;
1522         } else {
1523                 $title = Title::newFromText( $link );
1524                 if( is_null( $title ) ) {
1525                         return false;
1526                 }
1527         }
1528         # Make 'previous' link
1529         if( 0 != $offset ) {
1530                 $po = $offset - $limit;
1531                 $po = max( $po, 0 );
1532                 $q = "limit={$limit}&offset={$po}";
1533                 if( $query != '' ) {
1534                         $q .= '&' . $query;
1535                 }
1536                 $plink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$pTitle}\" class=\"mw-prevlink\">{$prev}</a>";
1537         } else {
1538                 $plink = $prev;
1539         }
1540         # Make 'next' link
1541         $no = $offset + $limit;
1542         $q = "limit={$limit}&offset={$no}";
1543         if( $query != '' ) {
1544                 $q .= '&' . $query;
1545         }
1546         if( $atend ) {
1547                 $nlink = $next;
1548         } else {
1549                 $nlink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$nTitle}\" class=\"mw-nextlink\">{$next}</a>";
1550         }
1551         # Make links to set number of items per page
1552         $nums = $wgLang->pipeList( array(
1553                 wfNumLink( $offset, 20, $title, $query ),
1554                 wfNumLink( $offset, 50, $title, $query ),
1555                 wfNumLink( $offset, 100, $title, $query ),
1556                 wfNumLink( $offset, 250, $title, $query ),
1557                 wfNumLink( $offset, 500, $title, $query )
1558         ) );
1559         return wfMsgHtml( 'viewprevnext', $plink, $nlink, $nums );
1560 }
1561
1562 /**
1563  * Generate links for (20|50|100...) items-per-page links
1564  *
1565  * @param $offset String
1566  * @param $limit Integer
1567  * @param $title Title
1568  * @param $query String: optional URL query parameter string
1569  */
1570 function wfNumLink( $offset, $limit, $title, $query = '' ) {
1571         global $wgLang;
1572         if( $query == '' ) {
1573                 $q = '';
1574         } else {
1575                 $q = $query.'&';
1576         }
1577         $q .= "limit={$limit}&offset={$offset}";
1578         $fmtLimit = $wgLang->formatNum( $limit );
1579         $lTitle = wfMsgExt( 'shown-title', array( 'parsemag', 'escape' ), $limit );
1580         $s = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$lTitle}\" class=\"mw-numlink\">{$fmtLimit}</a>";
1581         return $s;
1582 }
1583
1584 /**
1585  * @todo document
1586  * @todo FIXME: We may want to blacklist some broken browsers
1587  *
1588  * @param $force Bool
1589  * @return bool Whereas client accept gzip compression
1590  */
1591 function wfClientAcceptsGzip( $force = false ) {
1592         static $result = null;
1593         if ( $result === null || $force ) {
1594                 $result = false;
1595                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1596                         # @todo FIXME: We may want to blacklist some broken browsers
1597                         $m = array();
1598                         if( preg_match(
1599                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1600                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1601                                 $m )
1602                         )
1603                         {
1604                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1605                                         $result = false;
1606                                         return $result;
1607                                 }
1608                                 wfDebug( " accepts gzip\n" );
1609                                 $result = true;
1610                         }
1611                 }
1612         }
1613         return $result;
1614 }
1615
1616 /**
1617  * Obtain the offset and limit values from the request string;
1618  * used in special pages
1619  *
1620  * @param $deflimit Int default limit if none supplied
1621  * @param $optionname String Name of a user preference to check against
1622  * @return array
1623  *
1624  */
1625 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1626         global $wgRequest;
1627         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1628 }
1629
1630 /**
1631  * Escapes the given text so that it may be output using addWikiText()
1632  * without any linking, formatting, etc. making its way through. This
1633  * is achieved by substituting certain characters with HTML entities.
1634  * As required by the callers, <nowiki> is not used.
1635  *
1636  * @param $text String: text to be escaped
1637  * @return String
1638  */
1639 function wfEscapeWikiText( $text ) {
1640         $text = strtr( "\n$text", array(
1641                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1642                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1643                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1644                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1645                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1646                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1647         ) );
1648         return substr( $text, 1 );
1649 }
1650
1651 /**
1652  * Get the current unix timetstamp with microseconds.  Useful for profiling
1653  * @return Float
1654  */
1655 function wfTime() {
1656         return microtime( true );
1657 }
1658
1659 /**
1660  * Sets dest to source and returns the original value of dest
1661  * If source is NULL, it just returns the value, it doesn't set the variable
1662  * If force is true, it will set the value even if source is NULL
1663  *
1664  * @param $dest Mixed
1665  * @param $source Mixed
1666  * @param $force Bool
1667  * @return Mixed
1668  */
1669 function wfSetVar( &$dest, $source, $force = false ) {
1670         $temp = $dest;
1671         if ( !is_null( $source ) || $force ) {
1672                 $dest = $source;
1673         }
1674         return $temp;
1675 }
1676
1677 /**
1678  * As for wfSetVar except setting a bit
1679  *
1680  * @param $dest Int
1681  * @param $bit Int
1682  * @param $state Bool
1683  */
1684 function wfSetBit( &$dest, $bit, $state = true ) {
1685         $temp = (bool)( $dest & $bit );
1686         if ( !is_null( $state ) ) {
1687                 if ( $state ) {
1688                         $dest |= $bit;
1689                 } else {
1690                         $dest &= ~$bit;
1691                 }
1692         }
1693         return $temp;
1694 }
1695
1696 /**
1697  * Windows-compatible version of escapeshellarg()
1698  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
1699  * function puts single quotes in regardless of OS.
1700  *
1701  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
1702  * earlier distro releases of PHP)
1703  *
1704  * @param varargs
1705  * @return String
1706  */
1707 function wfEscapeShellArg( ) {
1708         wfInitShellLocale();
1709
1710         $args = func_get_args();
1711         $first = true;
1712         $retVal = '';
1713         foreach ( $args as $arg ) {
1714                 if ( !$first ) {
1715                         $retVal .= ' ';
1716                 } else {
1717                         $first = false;
1718                 }
1719
1720                 if ( wfIsWindows() ) {
1721                         // Escaping for an MSVC-style command line parser and CMD.EXE
1722                         // Refs:
1723                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
1724                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
1725                         //  * Bug #13518
1726                         //  * CR r63214
1727                         // Double the backslashes before any double quotes. Escape the double quotes.
1728                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
1729                         $arg = '';
1730                         $iteration = 0;
1731                         foreach ( $tokens as $token ) {
1732                                 if ( $iteration % 2 == 1 ) {
1733                                         // Delimiter, a double quote preceded by zero or more slashes
1734                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
1735                                 } elseif ( $iteration % 4 == 2 ) {
1736                                         // ^ in $token will be outside quotes, need to be escaped
1737                                         $arg .= str_replace( '^', '^^', $token );
1738                                 } else { // $iteration % 4 == 0
1739                                         // ^ in $token will appear inside double quotes, so leave as is
1740                                         $arg .= $token;
1741                                 }
1742                                 $iteration++;
1743                         }
1744                         // Double the backslashes before the end of the string, because
1745                         // we will soon add a quote
1746                         $m = array();
1747                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1748                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1749                         }
1750
1751                         // Add surrounding quotes
1752                         $retVal .= '"' . $arg . '"';
1753                 } else {
1754                         $retVal .= escapeshellarg( $arg );
1755                 }
1756         }
1757         return $retVal;
1758 }
1759
1760 /**
1761  * wfMerge attempts to merge differences between three texts.
1762  * Returns true for a clean merge and false for failure or a conflict.
1763  *
1764  * @param $old String
1765  * @param $mine String
1766  * @param $yours String
1767  * @param $result String
1768  * @return Bool
1769  */
1770 function wfMerge( $old, $mine, $yours, &$result ) {
1771         global $wgDiff3;
1772
1773         # This check may also protect against code injection in
1774         # case of broken installations.
1775         wfSuppressWarnings();
1776         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
1777         wfRestoreWarnings();
1778
1779         if( !$haveDiff3 ) {
1780                 wfDebug( "diff3 not found\n" );
1781                 return false;
1782         }
1783
1784         # Make temporary files
1785         $td = wfTempDir();
1786         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1787         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1788         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1789
1790         fwrite( $oldtextFile, $old );
1791         fclose( $oldtextFile );
1792         fwrite( $mytextFile, $mine );
1793         fclose( $mytextFile );
1794         fwrite( $yourtextFile, $yours );
1795         fclose( $yourtextFile );
1796
1797         # Check for a conflict
1798         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1799                 wfEscapeShellArg( $mytextName ) . ' ' .
1800                 wfEscapeShellArg( $oldtextName ) . ' ' .
1801                 wfEscapeShellArg( $yourtextName );
1802         $handle = popen( $cmd, 'r' );
1803
1804         if( fgets( $handle, 1024 ) ) {
1805                 $conflict = true;
1806         } else {
1807                 $conflict = false;
1808         }
1809         pclose( $handle );
1810
1811         # Merge differences
1812         $cmd = $wgDiff3 . ' -a -e --merge ' .
1813                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1814         $handle = popen( $cmd, 'r' );
1815         $result = '';
1816         do {
1817                 $data = fread( $handle, 8192 );
1818                 if ( strlen( $data ) == 0 ) {
1819                         break;
1820                 }
1821                 $result .= $data;
1822         } while ( true );
1823         pclose( $handle );
1824         unlink( $mytextName );
1825         unlink( $oldtextName );
1826         unlink( $yourtextName );
1827
1828         if ( $result === '' && $old !== '' && !$conflict ) {
1829                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1830                 $conflict = true;
1831         }
1832         return !$conflict;
1833 }
1834
1835 /**
1836  * Returns unified plain-text diff of two texts.
1837  * Useful for machine processing of diffs.
1838  *
1839  * @param $before String: the text before the changes.
1840  * @param $after String: the text after the changes.
1841  * @param $params String: command-line options for the diff command.
1842  * @return String: unified diff of $before and $after
1843  */
1844 function wfDiff( $before, $after, $params = '-u' ) {
1845         if ( $before == $after ) {
1846                 return '';
1847         }
1848
1849         global $wgDiff;
1850         wfSuppressWarnings();
1851         $haveDiff = $wgDiff && file_exists( $wgDiff );
1852         wfRestoreWarnings();
1853
1854         # This check may also protect against code injection in
1855         # case of broken installations.
1856         if( !$haveDiff ) {
1857                 wfDebug( "diff executable not found\n" );
1858                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
1859                 $format = new UnifiedDiffFormatter();
1860                 return $format->format( $diffs );
1861         }
1862
1863         # Make temporary files
1864         $td = wfTempDir();
1865         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1866         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
1867
1868         fwrite( $oldtextFile, $before );
1869         fclose( $oldtextFile );
1870         fwrite( $newtextFile, $after );
1871         fclose( $newtextFile );
1872
1873         // Get the diff of the two files
1874         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
1875
1876         $h = popen( $cmd, 'r' );
1877
1878         $diff = '';
1879
1880         do {
1881                 $data = fread( $h, 8192 );
1882                 if ( strlen( $data ) == 0 ) {
1883                         break;
1884                 }
1885                 $diff .= $data;
1886         } while ( true );
1887
1888         // Clean up
1889         pclose( $h );
1890         unlink( $oldtextName );
1891         unlink( $newtextName );
1892
1893         // Kill the --- and +++ lines. They're not useful.
1894         $diff_lines = explode( "\n", $diff );
1895         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
1896                 unset( $diff_lines[0] );
1897         }
1898         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
1899                 unset( $diff_lines[1] );
1900         }
1901
1902         $diff = implode( "\n", $diff_lines );
1903
1904         return $diff;
1905 }
1906
1907 /**
1908  * A wrapper around the PHP function var_export().
1909  * Either print it or add it to the regular output ($wgOut).
1910  *
1911  * @param $var A PHP variable to dump.
1912  */
1913 function wfVarDump( $var ) {
1914         global $wgOut;
1915         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1916         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1917                 print $s;
1918         } else {
1919                 $wgOut->addHTML( $s );
1920         }
1921 }
1922
1923 /**
1924  * Provide a simple HTTP error.
1925  *
1926  * @param $code Int|String
1927  * @param $label String
1928  * @param $desc String
1929  */
1930 function wfHttpError( $code, $label, $desc ) {
1931         global $wgOut;
1932         $wgOut->disable();
1933         header( "HTTP/1.0 $code $label" );
1934         header( "Status: $code $label" );
1935         $wgOut->sendCacheControl();
1936
1937         header( 'Content-type: text/html; charset=utf-8' );
1938         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1939                 '<html><head><title>' .
1940                 htmlspecialchars( $label ) .
1941                 '</title></head><body><h1>' .
1942                 htmlspecialchars( $label ) .
1943                 '</h1><p>' .
1944                 nl2br( htmlspecialchars( $desc ) ) .
1945                 "</p></body></html>\n";
1946 }
1947
1948 /**
1949  * Clear away any user-level output buffers, discarding contents.
1950  *
1951  * Suitable for 'starting afresh', for instance when streaming
1952  * relatively large amounts of data without buffering, or wanting to
1953  * output image files without ob_gzhandler's compression.
1954  *
1955  * The optional $resetGzipEncoding parameter controls suppression of
1956  * the Content-Encoding header sent by ob_gzhandler; by default it
1957  * is left. See comments for wfClearOutputBuffers() for why it would
1958  * be used.
1959  *
1960  * Note that some PHP configuration options may add output buffer
1961  * layers which cannot be removed; these are left in place.
1962  *
1963  * @param $resetGzipEncoding Bool
1964  */
1965 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1966         if( $resetGzipEncoding ) {
1967                 // Suppress Content-Encoding and Content-Length
1968                 // headers from 1.10+s wfOutputHandler
1969                 global $wgDisableOutputCompression;
1970                 $wgDisableOutputCompression = true;
1971         }
1972         while( $status = ob_get_status() ) {
1973                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1974                         // Probably from zlib.output_compression or other
1975                         // PHP-internal setting which can't be removed.
1976                         //
1977                         // Give up, and hope the result doesn't break
1978                         // output behavior.
1979                         break;
1980                 }
1981                 if( !ob_end_clean() ) {
1982                         // Could not remove output buffer handler; abort now
1983                         // to avoid getting in some kind of infinite loop.
1984                         break;
1985                 }
1986                 if( $resetGzipEncoding ) {
1987                         if( $status['name'] == 'ob_gzhandler' ) {
1988                                 // Reset the 'Content-Encoding' field set by this handler
1989                                 // so we can start fresh.
1990                                 if ( function_exists( 'header_remove' ) ) {
1991                                         // Available since PHP 5.3.0
1992                                         header_remove( 'Content-Encoding' );
1993                                 } else {
1994                                         // We need to provide a valid content-coding. See bug 28069
1995                                         header( 'Content-Encoding: identity' );
1996                                 }
1997                                 break;
1998                         }
1999                 }
2000         }
2001 }
2002
2003 /**
2004  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2005  *
2006  * Clear away output buffers, but keep the Content-Encoding header
2007  * produced by ob_gzhandler, if any.
2008  *
2009  * This should be used for HTTP 304 responses, where you need to
2010  * preserve the Content-Encoding header of the real result, but
2011  * also need to suppress the output of ob_gzhandler to keep to spec
2012  * and avoid breaking Firefox in rare cases where the headers and
2013  * body are broken over two packets.
2014  */
2015 function wfClearOutputBuffers() {
2016         wfResetOutputBuffers( false );
2017 }
2018
2019 /**
2020  * Converts an Accept-* header into an array mapping string values to quality
2021  * factors
2022  *
2023  * @param $accept String
2024  * @param $def String default
2025  * @return Array
2026  */
2027 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2028         # No arg means accept anything (per HTTP spec)
2029         if( !$accept ) {
2030                 return array( $def => 1.0 );
2031         }
2032
2033         $prefs = array();
2034
2035         $parts = explode( ',', $accept );
2036
2037         foreach( $parts as $part ) {
2038                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2039                 $values = explode( ';', trim( $part ) );
2040                 $match = array();
2041                 if ( count( $values ) == 1 ) {
2042                         $prefs[$values[0]] = 1.0;
2043                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2044                         $prefs[$values[0]] = floatval( $match[1] );
2045                 }
2046         }
2047
2048         return $prefs;
2049 }
2050
2051 /**
2052  * Checks if a given MIME type matches any of the keys in the given
2053  * array. Basic wildcards are accepted in the array keys.
2054  *
2055  * Returns the matching MIME type (or wildcard) if a match, otherwise
2056  * NULL if no match.
2057  *
2058  * @param $type String
2059  * @param $avail Array
2060  * @return string
2061  * @private
2062  */
2063 function mimeTypeMatch( $type, $avail ) {
2064         if( array_key_exists( $type, $avail ) ) {
2065                 return $type;
2066         } else {
2067                 $parts = explode( '/', $type );
2068                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2069                         return $parts[0] . '/*';
2070                 } elseif( array_key_exists( '*/*', $avail ) ) {
2071                         return '*/*';
2072                 } else {
2073                         return null;
2074                 }
2075         }
2076 }
2077
2078 /**
2079  * Returns the 'best' match between a client's requested internet media types
2080  * and the server's list of available types. Each list should be an associative
2081  * array of type to preference (preference is a float between 0.0 and 1.0).
2082  * Wildcards in the types are acceptable.
2083  *
2084  * @param $cprefs Array: client's acceptable type list
2085  * @param $sprefs Array: server's offered types
2086  * @return string
2087  *
2088  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2089  * XXX: generalize to negotiate other stuff
2090  */
2091 function wfNegotiateType( $cprefs, $sprefs ) {
2092         $combine = array();
2093
2094         foreach( array_keys($sprefs) as $type ) {
2095                 $parts = explode( '/', $type );
2096                 if( $parts[1] != '*' ) {
2097                         $ckey = mimeTypeMatch( $type, $cprefs );
2098                         if( $ckey ) {
2099                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2100                         }
2101                 }
2102         }
2103
2104         foreach( array_keys( $cprefs ) as $type ) {
2105                 $parts = explode( '/', $type );
2106                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2107                         $skey = mimeTypeMatch( $type, $sprefs );
2108                         if( $skey ) {
2109                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2110                         }
2111                 }
2112         }
2113
2114         $bestq = 0;
2115         $besttype = null;
2116
2117         foreach( array_keys( $combine ) as $type ) {
2118                 if( $combine[$type] > $bestq ) {
2119                         $besttype = $type;
2120                         $bestq = $combine[$type];
2121                 }
2122         }
2123
2124         return $besttype;
2125 }
2126
2127 /**
2128  * Reference-counted warning suppression
2129  *
2130  * @param $end Bool
2131  */
2132 function wfSuppressWarnings( $end = false ) {
2133         static $suppressCount = 0;
2134         static $originalLevel = false;
2135
2136         if ( $end ) {
2137                 if ( $suppressCount ) {
2138                         --$suppressCount;
2139                         if ( !$suppressCount ) {
2140                                 error_reporting( $originalLevel );
2141                         }
2142                 }
2143         } else {
2144                 if ( !$suppressCount ) {
2145                         // E_DEPRECATED is undefined in PHP 5.2
2146                         if( !defined( 'E_DEPRECATED' ) ){
2147                                 define( 'E_DEPRECATED', 8192 );
2148                         }
2149                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2150                 }
2151                 ++$suppressCount;
2152         }
2153 }
2154
2155 /**
2156  * Restore error level to previous value
2157  */
2158 function wfRestoreWarnings() {
2159         wfSuppressWarnings( true );
2160 }
2161
2162 # Autodetect, convert and provide timestamps of various types
2163
2164 /**
2165  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2166  */
2167 define( 'TS_UNIX', 0 );
2168
2169 /**
2170  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2171  */
2172 define( 'TS_MW', 1 );
2173
2174 /**
2175  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2176  */
2177 define( 'TS_DB', 2 );
2178
2179 /**
2180  * RFC 2822 format, for E-mail and HTTP headers
2181  */
2182 define( 'TS_RFC2822', 3 );
2183
2184 /**
2185  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2186  *
2187  * This is used by Special:Export
2188  */
2189 define( 'TS_ISO_8601', 4 );
2190
2191 /**
2192  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2193  *
2194  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2195  *       DateTime tag and page 36 for the DateTimeOriginal and
2196  *       DateTimeDigitized tags.
2197  */
2198 define( 'TS_EXIF', 5 );
2199
2200 /**
2201  * Oracle format time.
2202  */
2203 define( 'TS_ORACLE', 6 );
2204
2205 /**
2206  * Postgres format time.
2207  */
2208 define( 'TS_POSTGRES', 7 );
2209
2210 /**
2211  * DB2 format time
2212  */
2213 define( 'TS_DB2', 8 );
2214
2215 /**
2216  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2217  */
2218 define( 'TS_ISO_8601_BASIC', 9 );
2219
2220 /**
2221  * Get a timestamp string in one of various formats
2222  *
2223  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2224  *                    function will autodetect which format is supplied and act
2225  *                    accordingly.
2226  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2227  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2228  */
2229 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2230         $uts = 0;
2231         $da = array();
2232         $strtime = '';
2233
2234         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2235                 $uts = time();
2236                 $strtime = "@$uts";
2237         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2238                 # TS_DB
2239         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2240                 # TS_EXIF
2241         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2242                 # TS_MW
2243         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2244                 # TS_UNIX
2245                 $uts = $ts;
2246                 $strtime = "@$ts"; // Undocumented?
2247         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2248                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2249                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2250                                 str_replace( '+00:00', 'UTC', $ts ) );
2251         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2252                 # TS_ISO_8601
2253         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2254                 #TS_ISO_8601_BASIC
2255         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2256                 # TS_POSTGRES
2257         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2258                 # TS_POSTGRES
2259         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/',$ts,$da)) {
2260                 # TS_DB2
2261         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2262                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2263                                                         '[ \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
2264                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2265                 # The regex is a superset of rfc2822 for readability
2266                 $strtime = strtok( $ts, ';' );
2267         } 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 ) ) {
2268                 # TS_RFC850
2269                 $strtime = $ts;
2270         } 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 ) ) {
2271                 # asctime
2272                 $strtime = $ts;
2273         } else {
2274                 # Bogus value...
2275                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2276
2277                 return false;
2278         }
2279
2280         static $formats = array(
2281                 TS_UNIX => 'U',
2282                 TS_MW => 'YmdHis',
2283                 TS_DB => 'Y-m-d H:i:s',
2284                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2285                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2286                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2287                 TS_RFC2822 => 'D, d M Y H:i:s',
2288                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2289                 TS_POSTGRES => 'Y-m-d H:i:s',
2290                 TS_DB2 => 'Y-m-d H:i:s',
2291         );
2292
2293         if ( !isset( $formats[$outputtype] ) ) {
2294                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2295         }
2296
2297         if ( function_exists( "date_create" ) ) {
2298                 if ( count( $da ) ) {
2299                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2300                                 (int)$da[1], (int)$da[2], (int)$da[3],
2301                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2302
2303                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2304                 } elseif ( $strtime ) {
2305                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2306                 } else {
2307                         return false;
2308                 }
2309
2310                 if ( !$d ) {
2311                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2312                         return false;
2313                 }
2314
2315                 $output = $d->format( $formats[$outputtype] );
2316         } else {
2317                 if ( count( $da ) ) {
2318                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2319                         // We may want to handle that explicitly at some point
2320                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2321                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2322                 } elseif ( $strtime ) {
2323                         $uts = strtotime( $strtime );
2324                 }
2325
2326                 if ( $uts === false ) {
2327                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2328                         return false;
2329                 }
2330
2331                 if ( TS_UNIX == $outputtype ) {
2332                         return $uts;
2333                 }
2334                 $output = gmdate( $formats[$outputtype], $uts );
2335         }
2336
2337         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2338                 $output .= ' GMT';
2339         }
2340
2341         return $output;
2342 }
2343
2344 /**
2345  * Return a formatted timestamp, or null if input is null.
2346  * For dealing with nullable timestamp columns in the database.
2347  *
2348  * @param $outputtype Integer
2349  * @param $ts String
2350  * @return String
2351  */
2352 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2353         if( is_null( $ts ) ) {
2354                 return null;
2355         } else {
2356                 return wfTimestamp( $outputtype, $ts );
2357         }
2358 }
2359
2360 /**
2361  * Convenience function; returns MediaWiki timestamp for the present time.
2362  *
2363  * @return string
2364  */
2365 function wfTimestampNow() {
2366         # return NOW
2367         return wfTimestamp( TS_MW, time() );
2368 }
2369
2370 /**
2371  * Check if the operating system is Windows
2372  *
2373  * @return Bool: true if it's Windows, False otherwise.
2374  */
2375 function wfIsWindows() {
2376         static $isWindows = null;
2377         if ( $isWindows === null ) {
2378                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2379         }
2380         return $isWindows;
2381 }
2382
2383 /**
2384  * Check if we are running under HipHop
2385  *
2386  * @return Bool
2387  */
2388 function wfIsHipHop() {
2389         return function_exists( 'hphp_thread_set_warmup_enabled' );
2390 }
2391
2392 /**
2393  * Swap two variables
2394  *
2395  * @param $x Mixed
2396  * @param $y Mixed
2397  */
2398 function swap( &$x, &$y ) {
2399         $z = $x;
2400         $x = $y;
2401         $y = $z;
2402 }
2403
2404 /**
2405  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2406  * TEMP environment variables are then checked in sequence, and if none are set
2407  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2408  * or C:\Windows\Temp for Windows and hope for the best.
2409  * It is common to call it with tempnam().
2410  *
2411  * NOTE: When possible, use instead the tmpfile() function to create
2412  * temporary files to avoid race conditions on file creation, etc.
2413  *
2414  * @return String
2415  */
2416 function wfTempDir() {
2417         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2418                 $tmp = getenv( $var );
2419                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2420                         return $tmp;
2421                 }
2422         }
2423         if( function_exists( 'sys_get_temp_dir' ) ) {
2424                 return sys_get_temp_dir();
2425         }
2426         # Usual defaults
2427         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2428 }
2429
2430 /**
2431  * Make directory, and make all parent directories if they don't exist
2432  *
2433  * @param $dir String: full path to directory to create
2434  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2435  * @param $caller String: optional caller param for debugging.
2436  * @return bool
2437  */
2438 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2439         global $wgDirectoryMode;
2440
2441         if ( !is_null( $caller ) ) {
2442                 wfDebug( "$caller: called wfMkdirParents($dir)" );
2443         }
2444
2445         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2446                 return true;
2447         }
2448
2449         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2450
2451         if ( is_null( $mode ) ) {
2452                 $mode = $wgDirectoryMode;
2453         }
2454
2455         // Turn off the normal warning, we're doing our own below
2456         wfSuppressWarnings();
2457         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2458         wfRestoreWarnings();
2459
2460         if( !$ok ) {
2461                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2462                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2463         }
2464         return $ok;
2465 }
2466
2467 /**
2468  * Increment a statistics counter
2469  *
2470  * @param $key String
2471  * @param $count Int
2472  */
2473 function wfIncrStats( $key, $count = 1 ) {
2474         global $wgStatsMethod;
2475
2476         $count = intval( $count );
2477
2478         if( $wgStatsMethod == 'udp' ) {
2479                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2480                 static $socket;
2481
2482                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2483
2484                 if ( !$socket ) {
2485                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2486                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2487                         socket_sendto(
2488                                 $socket,
2489                                 $statline,
2490                                 strlen( $statline ),
2491                                 0,
2492                                 $wgUDPProfilerHost,
2493                                 $wgUDPProfilerPort
2494                         );
2495                 }
2496                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2497                 wfSuppressWarnings();
2498                 socket_sendto(
2499                         $socket,
2500                         $statline,
2501                         strlen( $statline ),
2502                         0,
2503                         $wgUDPProfilerHost,
2504                         $wgUDPProfilerPort
2505                 );
2506                 wfRestoreWarnings();
2507         } elseif( $wgStatsMethod == 'cache' ) {
2508                 global $wgMemc;
2509                 $key = wfMemcKey( 'stats', $key );
2510                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2511                         $wgMemc->add( $key, $count );
2512                 }
2513         } else {
2514                 // Disabled
2515         }
2516 }
2517
2518 /**
2519  * @param $nr Mixed: the number to format
2520  * @param $acc Integer: the number of digits after the decimal point, default 2
2521  * @param $round Boolean: whether or not to round the value, default true
2522  * @return float
2523  */
2524 function wfPercent( $nr, $acc = 2, $round = true ) {
2525         $ret = sprintf( "%.${acc}f", $nr );
2526         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2527 }
2528
2529 /**
2530  * Find out whether or not a mixed variable exists in a string
2531  *
2532  * @param $needle String
2533  * @param $str String
2534  * @param $insensitive Boolean
2535  * @return Boolean
2536  */
2537 function in_string( $needle, $str, $insensitive = false ) {
2538         $func = 'strpos';
2539         if( $insensitive ) $func = 'stripos';
2540
2541         return $func( $str, $needle ) !== false;
2542 }
2543
2544 /**
2545  * Make a list item, used by various special pages
2546  *
2547  * @param $page String Page link
2548  * @param $details String Text between brackets
2549  * @param $oppositedm Boolean   Add the direction mark opposite to your
2550  *                                                              language, to display text properly
2551  * @return String
2552  */
2553 function wfSpecialList( $page, $details, $oppositedm = true ) {
2554         global $wgLang;
2555         $dirmark = ( $oppositedm ? $wgLang->getDirMark( true ) : '' ) .
2556                 $wgLang->getDirMark();
2557         $details = $details ? $dirmark . " ($details)" : '';
2558         return $page . $details;
2559 }
2560
2561 /**
2562  * Safety wrapper around ini_get() for boolean settings.
2563  * The values returned from ini_get() are pre-normalized for settings
2564  * set via php.ini or php_flag/php_admin_flag... but *not*
2565  * for those set via php_value/php_admin_value.
2566  *
2567  * It's fairly common for people to use php_value instead of php_flag,
2568  * which can leave you with an 'off' setting giving a false positive
2569  * for code that just takes the ini_get() return value as a boolean.
2570  *
2571  * To make things extra interesting, setting via php_value accepts
2572  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2573  * Unrecognized values go false... again opposite PHP's own coercion
2574  * from string to bool.
2575  *
2576  * Luckily, 'properly' set settings will always come back as '0' or '1',
2577  * so we only have to worry about them and the 'improper' settings.
2578  *
2579  * I frickin' hate PHP... :P
2580  *
2581  * @param $setting String
2582  * @return Bool
2583  */
2584 function wfIniGetBool( $setting ) {
2585         $val = ini_get( $setting );
2586         // 'on' and 'true' can't have whitespace around them, but '1' can.
2587         return strtolower( $val ) == 'on'
2588                 || strtolower( $val ) == 'true'
2589                 || strtolower( $val ) == 'yes'
2590                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2591 }
2592
2593 /**
2594  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2595  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2596  *
2597  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2598  *                          should be omitted
2599  * @param $fileName String Name of the library, if not $extension.suffix
2600  * @return Bool - Whether or not the extension is loaded
2601  */
2602 function wfDl( $extension, $fileName = null ) {
2603         if( extension_loaded( $extension ) ) {
2604                 return true;
2605         }
2606
2607         $canDl = false;
2608         $sapi = php_sapi_name();
2609         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2610                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2611         {
2612                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2613                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2614         }
2615
2616         if( $canDl ) {
2617                 $fileName = $fileName ? $fileName : $extension;
2618                 if( wfIsWindows() ) {
2619                         $fileName = 'php_' . $fileName;
2620                 }
2621                 wfSuppressWarnings();
2622                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2623                 wfRestoreWarnings();
2624         }
2625         return extension_loaded( $extension );
2626 }
2627
2628 /**
2629  * Execute a shell command, with time and memory limits mirrored from the PHP
2630  * configuration if supported.
2631  * @param $cmd String Command line, properly escaped for shell.
2632  * @param &$retval optional, will receive the program's exit code.
2633  *                 (non-zero is usually failure)
2634  * @param $environ Array optional environment variables which should be
2635  *                 added to the executed command environment.
2636  * @return collected stdout as a string (trailing newlines stripped)
2637  */
2638 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2639         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2640
2641         static $disabled;
2642         if ( is_null( $disabled ) ) {
2643                 $disabled = false;
2644                 if( wfIniGetBool( 'safe_mode' ) ) {
2645                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2646                         $disabled = 'safemode';
2647                 } else {
2648                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2649                         $functions = array_map( 'trim', $functions );
2650                         $functions = array_map( 'strtolower', $functions );
2651                         if ( in_array( 'passthru', $functions ) ) {
2652                                 wfDebug( "passthru is in disabled_functions\n" );
2653                                 $disabled = 'passthru';
2654                         }
2655                 }
2656         }
2657         if ( $disabled ) {
2658                 $retval = 1;
2659                 return $disabled == 'safemode' ?
2660                         'Unable to run external programs in safe mode.' :
2661                         'Unable to run external programs, passthru() is disabled.';
2662         }
2663
2664         wfInitShellLocale();
2665
2666         $envcmd = '';
2667         foreach( $environ as $k => $v ) {
2668                 if ( wfIsWindows() ) {
2669                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2670                          * appear in the environment variable, so we must use carat escaping as documented in
2671                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2672                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2673                          * are listed there but doesn't appear to need it.
2674                          */
2675                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2676                 } else {
2677                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2678                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2679                          */
2680                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2681                 }
2682         }
2683         $cmd = $envcmd . $cmd;
2684
2685         if ( wfIsWindows() ) {
2686                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2687                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2688                 {
2689                         # Hack to work around PHP's flawed invocation of cmd.exe
2690                         # http://news.php.net/php.internals/21796
2691                         # Windows 9x doesn't accept any kind of quotes
2692                         $cmd = '"' . $cmd . '"';
2693                 }
2694         } elseif ( php_uname( 's' ) == 'Linux' ) {
2695                 $time = intval( $wgMaxShellTime );
2696                 $mem = intval( $wgMaxShellMemory );
2697                 $filesize = intval( $wgMaxShellFileSize );
2698
2699                 if ( $time > 0 && $mem > 0 ) {
2700                         $script = "$IP/bin/ulimit4.sh";
2701                         if ( is_executable( $script ) ) {
2702                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2703                         }
2704                 }
2705         }
2706         wfDebug( "wfShellExec: $cmd\n" );
2707
2708         $retval = 1; // error by default?
2709         ob_start();
2710         passthru( $cmd, $retval );
2711         $output = ob_get_contents();
2712         ob_end_clean();
2713
2714         if ( $retval == 127 ) {
2715                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2716         }
2717         return $output;
2718 }
2719
2720 /**
2721  * Workaround for http://bugs.php.net/bug.php?id=45132
2722  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2723  */
2724 function wfInitShellLocale() {
2725         static $done = false;
2726         if ( $done ) {
2727                 return;
2728         }
2729         $done = true;
2730         global $wgShellLocale;
2731         if ( !wfIniGetBool( 'safe_mode' ) ) {
2732                 putenv( "LC_CTYPE=$wgShellLocale" );
2733                 setlocale( LC_CTYPE, $wgShellLocale );
2734         }
2735 }
2736
2737 /**
2738  * This function works like "use VERSION" in Perl, the program will die with a
2739  * backtrace if the current version of PHP is less than the version provided
2740  *
2741  * This is useful for extensions which due to their nature are not kept in sync
2742  * with releases, and might depend on other versions of PHP than the main code
2743  *
2744  * Note: PHP might die due to parsing errors in some cases before it ever
2745  *       manages to call this function, such is life
2746  *
2747  * @see perldoc -f use
2748  *
2749  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2750  *                 a float
2751  */
2752 function wfUsePHP( $req_ver ) {
2753         $php_ver = PHP_VERSION;
2754
2755         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2756                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2757         }
2758 }
2759
2760 /**
2761  * This function works like "use VERSION" in Perl except it checks the version
2762  * of MediaWiki, the program will die with a backtrace if the current version
2763  * of MediaWiki is less than the version provided.
2764  *
2765  * This is useful for extensions which due to their nature are not kept in sync
2766  * with releases
2767  *
2768  * @see perldoc -f use
2769  *
2770  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2771  *                 a float
2772  */
2773 function wfUseMW( $req_ver ) {
2774         global $wgVersion;
2775
2776         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2777                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2778         }
2779 }
2780
2781 /**
2782  * Return the final portion of a pathname.
2783  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2784  * http://bugs.php.net/bug.php?id=33898
2785  *
2786  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2787  * We'll consider it so always, as we don't want \s in our Unix paths either.
2788  *
2789  * @param $path String
2790  * @param $suffix String: to remove if present
2791  * @return String
2792  */
2793 function wfBaseName( $path, $suffix = '' ) {
2794         $encSuffix = ( $suffix == '' )
2795                 ? ''
2796                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2797         $matches = array();
2798         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2799                 return $matches[1];
2800         } else {
2801                 return '';
2802         }
2803 }
2804
2805 /**
2806  * Generate a relative path name to the given file.
2807  * May explode on non-matching case-insensitive paths,
2808  * funky symlinks, etc.
2809  *
2810  * @param $path String: absolute destination path including target filename
2811  * @param $from String: Absolute source path, directory only
2812  * @return String
2813  */
2814 function wfRelativePath( $path, $from ) {
2815         // Normalize mixed input on Windows...
2816         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2817         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2818
2819         // Trim trailing slashes -- fix for drive root
2820         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2821         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2822
2823         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2824         $against = explode( DIRECTORY_SEPARATOR, $from );
2825
2826         if( $pieces[0] !== $against[0] ) {
2827                 // Non-matching Windows drive letters?
2828                 // Return a full path.
2829                 return $path;
2830         }
2831
2832         // Trim off common prefix
2833         while( count( $pieces ) && count( $against )
2834                 && $pieces[0] == $against[0] ) {
2835                 array_shift( $pieces );
2836                 array_shift( $against );
2837         }
2838
2839         // relative dots to bump us to the parent
2840         while( count( $against ) ) {
2841                 array_unshift( $pieces, '..' );
2842                 array_shift( $against );
2843         }
2844
2845         array_push( $pieces, wfBaseName( $path ) );
2846
2847         return implode( DIRECTORY_SEPARATOR, $pieces );
2848 }
2849
2850 /**
2851  * Do any deferred updates and clear the list
2852  *
2853  * @param $commit String: set to 'commit' to commit after every update to
2854  *                prevent lock contention
2855  */
2856 function wfDoUpdates( $commit = '' ) {
2857         global $wgDeferredUpdateList;
2858
2859         wfProfileIn( __METHOD__ );
2860
2861         // No need to get master connections in case of empty updates array
2862         if ( !count( $wgDeferredUpdateList ) ) {
2863                 wfProfileOut( __METHOD__ );
2864                 return;
2865         }
2866
2867         $doCommit = $commit == 'commit';
2868         if ( $doCommit ) {
2869                 $dbw = wfGetDB( DB_MASTER );
2870         }
2871
2872         foreach ( $wgDeferredUpdateList as $update ) {
2873                 $update->doUpdate();
2874
2875                 if ( $doCommit && $dbw->trxLevel() ) {
2876                         $dbw->commit();
2877                 }
2878         }
2879
2880         $wgDeferredUpdateList = array();
2881         wfProfileOut( __METHOD__ );
2882 }
2883
2884 /**
2885  * Convert an arbitrarily-long digit string from one numeric base
2886  * to another, optionally zero-padding to a minimum column width.
2887  *
2888  * Supports base 2 through 36; digit values 10-36 are represented
2889  * as lowercase letters a-z. Input is case-insensitive.
2890  *
2891  * @param $input String: of digits
2892  * @param $sourceBase Integer: 2-36
2893  * @param $destBase Integer: 2-36
2894  * @param $pad Integer: 1 or greater
2895  * @param $lowercase Boolean
2896  * @return String or false on invalid input
2897  */
2898 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2899         $input = strval( $input );
2900         if( $sourceBase < 2 ||
2901                 $sourceBase > 36 ||
2902                 $destBase < 2 ||
2903                 $destBase > 36 ||
2904                 $pad < 1 ||
2905                 $sourceBase != intval( $sourceBase ) ||
2906                 $destBase != intval( $destBase ) ||
2907                 $pad != intval( $pad ) ||
2908                 !is_string( $input ) ||
2909                 $input == '' ) {
2910                 return false;
2911         }
2912         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2913         $inDigits = array();
2914         $outChars = '';
2915
2916         // Decode and validate input string
2917         $input = strtolower( $input );
2918         for( $i = 0; $i < strlen( $input ); $i++ ) {
2919                 $n = strpos( $digitChars, $input[$i] );
2920                 if( $n === false || $n > $sourceBase ) {
2921                         return false;
2922                 }
2923                 $inDigits[] = $n;
2924         }
2925
2926         // Iterate over the input, modulo-ing out an output digit
2927         // at a time until input is gone.
2928         while( count( $inDigits ) ) {
2929                 $work = 0;
2930                 $workDigits = array();
2931
2932                 // Long division...
2933                 foreach( $inDigits as $digit ) {
2934                         $work *= $sourceBase;
2935                         $work += $digit;
2936
2937                         if( $work < $destBase ) {
2938                                 // Gonna need to pull another digit.
2939                                 if( count( $workDigits ) ) {
2940                                         // Avoid zero-padding; this lets us find
2941                                         // the end of the input very easily when
2942                                         // length drops to zero.
2943                                         $workDigits[] = 0;
2944                                 }
2945                         } else {
2946                                 // Finally! Actual division!
2947                                 $workDigits[] = intval( $work / $destBase );
2948
2949                                 // Isn't it annoying that most programming languages
2950                                 // don't have a single divide-and-remainder operator,
2951                                 // even though the CPU implements it that way?
2952                                 $work = $work % $destBase;
2953                         }
2954                 }
2955
2956                 // All that division leaves us with a remainder,
2957                 // which is conveniently our next output digit.
2958                 $outChars .= $digitChars[$work];
2959
2960                 // And we continue!
2961                 $inDigits = $workDigits;
2962         }
2963
2964         while( strlen( $outChars ) < $pad ) {
2965                 $outChars .= '0';
2966         }
2967
2968         return strrev( $outChars );
2969 }
2970
2971 /**
2972  * Create an object with a given name and an array of construct parameters
2973  *
2974  * @param $name String
2975  * @param $p Array: parameters
2976  * @deprecated since 1.18, warnings in 1.18, removal in 1.20
2977  */
2978 function wfCreateObject( $name, $p ) {
2979         wfDeprecated( __FUNCTION__ );
2980         return MWFunction::newObj( $name, $p );
2981 }
2982
2983 function wfHttpOnlySafe() {
2984         global $wgHttpOnlyBlacklist;
2985
2986         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
2987                 foreach( $wgHttpOnlyBlacklist as $regex ) {
2988                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
2989                                 return false;
2990                         }
2991                 }
2992         }
2993
2994         return true;
2995 }
2996
2997 /**
2998  * Initialise php session
2999  *
3000  * @param $sessionId Bool
3001  */
3002 function wfSetupSession( $sessionId = false ) {
3003         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
3004                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
3005         if( $wgSessionsInMemcached ) {
3006                 if ( !defined( 'MW_COMPILED' ) ) {
3007                         global $IP;
3008                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
3009                 }
3010                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3011                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3012
3013                 // It's necessary to register a shutdown function to call session_write_close(),
3014                 // because by the time the request shutdown function for the session module is
3015                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3016                 // this way are called before object destruction.
3017                 register_shutdown_function( 'memsess_write_close' );
3018         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3019                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3020                 # hasn't already been set to the desired value (that causes errors)
3021                 ini_set( 'session.save_handler', $wgSessionHandler );
3022         }
3023         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3024         wfDebugLog( 'cookie',
3025                 'session_set_cookie_params: "' . implode( '", "',
3026                         array(
3027                                 0,
3028                                 $wgCookiePath,
3029                                 $wgCookieDomain,
3030                                 $wgCookieSecure,
3031                                 $httpOnlySafe ) ) . '"' );
3032         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3033         session_cache_limiter( 'private, must-revalidate' );
3034         if ( $sessionId ) {
3035                 session_id( $sessionId );
3036         }
3037         wfSuppressWarnings();
3038         session_start();
3039         wfRestoreWarnings();
3040 }
3041
3042 /**
3043  * Get an object from the precompiled serialized directory
3044  *
3045  * @param $name String
3046  * @return Mixed: the variable on success, false on failure
3047  */
3048 function wfGetPrecompiledData( $name ) {
3049         global $IP;
3050
3051         $file = "$IP/serialized/$name";
3052         if ( file_exists( $file ) ) {
3053                 $blob = file_get_contents( $file );
3054                 if ( $blob ) {
3055                         return unserialize( $blob );
3056                 }
3057         }
3058         return false;
3059 }
3060
3061 /**
3062  * Get a cache key
3063  *
3064  * @param varargs
3065  * @return String
3066  */
3067 function wfMemcKey( /*... */ ) {
3068         $args = func_get_args();
3069         $key = wfWikiID() . ':' . implode( ':', $args );
3070         $key = str_replace( ' ', '_', $key );
3071         return $key;
3072 }
3073
3074 /**
3075  * Get a cache key for a foreign DB
3076  *
3077  * @param $db String
3078  * @param $prefix String
3079  * @param varargs String
3080  * @return String
3081  */
3082 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3083         $args = array_slice( func_get_args(), 2 );
3084         if ( $prefix ) {
3085                 $key = "$db-$prefix:" . implode( ':', $args );
3086         } else {
3087                 $key = $db . ':' . implode( ':', $args );
3088         }
3089         return $key;
3090 }
3091
3092 /**
3093  * Get an ASCII string identifying this wiki
3094  * This is used as a prefix in memcached keys
3095  *
3096  * @return String
3097  */
3098 function wfWikiID() {
3099         global $wgDBprefix, $wgDBname;
3100         if ( $wgDBprefix ) {
3101                 return "$wgDBname-$wgDBprefix";
3102         } else {
3103                 return $wgDBname;
3104         }
3105 }
3106
3107 /**
3108  * Split a wiki ID into DB name and table prefix
3109  *
3110  * @param $wiki String
3111  * @param $bits String
3112  */
3113 function wfSplitWikiID( $wiki ) {
3114         $bits = explode( '-', $wiki, 2 );
3115         if ( count( $bits ) < 2 ) {
3116                 $bits[] = '';
3117         }
3118         return $bits;
3119 }
3120
3121 /**
3122  * Get a Database object.
3123  *
3124  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3125  *            master (for write queries), DB_SLAVE for potentially lagged read
3126  *            queries, or an integer >= 0 for a particular server.
3127  *
3128  * @param $groups Mixed: query groups. An array of group names that this query
3129  *                belongs to. May contain a single string if the query is only
3130  *                in one group.
3131  *
3132  * @param $wiki String: the wiki ID, or false for the current wiki
3133  *
3134  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3135  * will always return the same object, unless the underlying connection or load
3136  * balancer is manually destroyed.
3137  *
3138  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3139  * updater to ensure that a proper database is being updated.
3140  *
3141  * @return DatabaseBase
3142  */
3143 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3144         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3145 }
3146
3147 /**
3148  * Get a load balancer object.
3149  *
3150  * @param $wiki String: wiki ID, or false for the current wiki
3151  * @return LoadBalancer
3152  */
3153 function wfGetLB( $wiki = false ) {
3154         return wfGetLBFactory()->getMainLB( $wiki );
3155 }
3156
3157 /**
3158  * Get the load balancer factory object
3159  *
3160  * @return LBFactory
3161  */
3162 function &wfGetLBFactory() {
3163         return LBFactory::singleton();
3164 }
3165
3166 /**
3167  * Find a file.
3168  * Shortcut for RepoGroup::singleton()->findFile()
3169  *
3170  * @param $title String or Title object
3171  * @param $options Associative array of options:
3172  *     time:           requested time for an archived image, or false for the
3173  *                     current version. An image object will be returned which was
3174  *                     created at the specified time.
3175  *
3176  *     ignoreRedirect: If true, do not follow file redirects
3177  *
3178  *     private:        If true, return restricted (deleted) files if the current
3179  *                     user is allowed to view them. Otherwise, such files will not
3180  *                     be found.
3181  *
3182  *     bypassCache:    If true, do not use the process-local cache of File objects
3183  *
3184  * @return File, or false if the file does not exist
3185  */
3186 function wfFindFile( $title, $options = array() ) {
3187         return RepoGroup::singleton()->findFile( $title, $options );
3188 }
3189
3190 /**
3191  * Get an object referring to a locally registered file.
3192  * Returns a valid placeholder object if the file does not exist.
3193  *
3194  * @param $title Title or String
3195  * @return File, or null if passed an invalid Title
3196  */
3197 function wfLocalFile( $title ) {
3198         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3199 }
3200
3201 /**
3202  * Should low-performance queries be disabled?
3203  *
3204  * @return Boolean
3205  * @codeCoverageIgnore
3206  */
3207 function wfQueriesMustScale() {
3208         global $wgMiserMode;
3209         return $wgMiserMode
3210                 || ( SiteStats::pages() > 100000
3211                 && SiteStats::edits() > 1000000
3212                 && SiteStats::users() > 10000 );
3213 }
3214
3215 /**
3216  * Get the path to a specified script file, respecting file
3217  * extensions; this is a wrapper around $wgScriptExtension etc.
3218  *
3219  * @param $script String: script filename, sans extension
3220  * @return String
3221  */
3222 function wfScript( $script = 'index' ) {
3223         global $wgScriptPath, $wgScriptExtension;
3224         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3225 }
3226
3227 /**
3228  * Get the script URL.
3229  *
3230  * @return script URL
3231  */
3232 function wfGetScriptUrl() {
3233         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3234                 #
3235                 # as it was called, minus the query string.
3236                 #
3237                 # Some sites use Apache rewrite rules to handle subdomains,
3238                 # and have PHP set up in a weird way that causes PHP_SELF
3239                 # to contain the rewritten URL instead of the one that the
3240                 # outside world sees.
3241                 #
3242                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3243                 # provides containing the "before" URL.
3244                 return $_SERVER['SCRIPT_NAME'];
3245         } else {
3246                 return $_SERVER['URL'];
3247         }
3248 }
3249
3250 /**
3251  * Convenience function converts boolean values into "true"
3252  * or "false" (string) values
3253  *
3254  * @param $value Boolean
3255  * @return String
3256  */
3257 function wfBoolToStr( $value ) {
3258         return $value ? 'true' : 'false';
3259 }
3260
3261 /**
3262  * Load an extension messages file
3263  *
3264  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3265  * @codeCoverageIgnore
3266  */
3267 function wfLoadExtensionMessages() {
3268         wfDeprecated( __FUNCTION__ );
3269 }
3270
3271 /**
3272  * Get a platform-independent path to the null file, e.g. /dev/null
3273  *
3274  * @return string
3275  */
3276 function wfGetNull() {
3277         return wfIsWindows()
3278                 ? 'NUL'
3279                 : '/dev/null';
3280 }
3281
3282 /**
3283  * Throws a warning that $function is deprecated
3284  *
3285  * @param $function String
3286  * @return null
3287  */
3288 function wfDeprecated( $function ) {
3289         static $functionsWarned = array();
3290         if ( !isset( $functionsWarned[$function] ) ) {
3291                 $functionsWarned[$function] = true;
3292                 wfWarn( "Use of $function is deprecated.", 2 );
3293         }
3294 }
3295
3296 /**
3297  * Send a warning either to the debug log or in a PHP error depending on
3298  * $wgDevelopmentWarnings
3299  *
3300  * @param $msg String: message to send
3301  * @param $callerOffset Integer: number of items to go back in the backtrace to
3302  *        find the correct caller (1 = function calling wfWarn, ...)
3303  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3304  *        is true
3305  */
3306 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3307         global $wgDevelopmentWarnings;
3308
3309         $callers = wfDebugBacktrace();
3310         if ( isset( $callers[$callerOffset + 1] ) ) {
3311                 $callerfunc = $callers[$callerOffset + 1];
3312                 $callerfile = $callers[$callerOffset];
3313                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3314                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3315                 } else {
3316                         $file = '(internal function)';
3317                 }
3318                 $func = '';
3319                 if ( isset( $callerfunc['class'] ) ) {
3320                         $func .= $callerfunc['class'] . '::';
3321                 }
3322                 if ( isset( $callerfunc['function'] ) ) {
3323                         $func .= $callerfunc['function'];
3324                 }
3325                 $msg .= " [Called from $func in $file]";
3326         }
3327
3328         if ( $wgDevelopmentWarnings ) {
3329                 trigger_error( $msg, $level );
3330         } else {
3331                 wfDebug( "$msg\n" );
3332         }
3333 }
3334
3335 /**
3336  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3337  * and waiting for it to go down, this waits for the slaves to catch up to the
3338  * master position. Use this when updating very large numbers of rows, as
3339  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3340  * a no-op if there are no slaves.
3341  *
3342  * @param $maxLag Integer (deprecated)
3343  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3344  * @return null
3345  */
3346 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3347         $lb = wfGetLB( $wiki );
3348         // bug 27975 - Don't try to wait for slaves if there are none
3349         // Prevents permission error when getting master position
3350         if ( $lb->getServerCount() > 1 ) {
3351                 $dbw = $lb->getConnection( DB_MASTER );
3352                 $pos = $dbw->getMasterPos();
3353                 $lb->waitForAll( $pos );
3354         }
3355 }
3356
3357 /**
3358  * Used to be used for outputting text in the installer/updater
3359  * @deprecated since 1.18, warnings in 1.18, remove in 1.20
3360  */
3361 function wfOut( $s ) {
3362         wfDeprecated( __METHOD__ );
3363         global $wgCommandLineMode;
3364         if ( $wgCommandLineMode ) {
3365                 echo $s;
3366         } else {
3367                 echo htmlspecialchars( $s );
3368         }
3369         flush();
3370 }
3371
3372 /**
3373  * Count down from $n to zero on the terminal, with a one-second pause
3374  * between showing each number. For use in command-line scripts.
3375  * @codeCoverageIgnore
3376  */
3377 function wfCountDown( $n ) {
3378         for ( $i = $n; $i >= 0; $i-- ) {
3379                 if ( $i != $n ) {
3380                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3381                 }
3382                 echo $i;
3383                 flush();
3384                 if ( $i ) {
3385                         sleep( 1 );
3386                 }
3387         }
3388         echo "\n";
3389 }
3390
3391 /**
3392  * Generate a random 32-character hexadecimal token.
3393  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3394  *              characters before hashing.
3395  * @return string
3396  * @codeCoverageIgnore
3397  */
3398 function wfGenerateToken( $salt = '' ) {
3399         $salt = serialize( $salt );
3400         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3401 }
3402
3403 /**
3404  * Replace all invalid characters with -
3405  *
3406  * @param $name Mixed: filename to process
3407  * @return String
3408  */
3409 function wfStripIllegalFilenameChars( $name ) {
3410         global $wgIllegalFileChars;
3411         $name = wfBaseName( $name );
3412         $name = preg_replace(
3413                 "/[^" . Title::legalChars() . "]" .
3414                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3415                         "/",
3416                 '-',
3417                 $name
3418         );
3419         return $name;
3420 }
3421
3422 /**
3423  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3424  *
3425  * @return Integer value memory was set to.
3426  */
3427 function wfMemoryLimit() {
3428         global $wgMemoryLimit;
3429         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3430         if( $memlimit != -1 ) {
3431                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3432                 if( $conflimit == -1 ) {
3433                         wfDebug( "Removing PHP's memory limit\n" );
3434                         wfSuppressWarnings();
3435                         ini_set( 'memory_limit', $conflimit );
3436                         wfRestoreWarnings();
3437                         return $conflimit;
3438                 } elseif ( $conflimit > $memlimit ) {
3439                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3440                         wfSuppressWarnings();
3441                         ini_set( 'memory_limit', $conflimit );
3442                         wfRestoreWarnings();
3443                         return $conflimit;
3444                 }
3445         }
3446         return $memlimit;
3447 }
3448
3449 /**
3450  * Converts shorthand byte notation to integer form
3451  *
3452  * @param $string String
3453  * @return Integer
3454  */
3455 function wfShorthandToInteger( $string = '' ) {
3456         $string = trim( $string );
3457         if( $string === '' ) {
3458                 return -1;
3459         }
3460         $last = $string[strlen( $string ) - 1];
3461         $val = intval( $string );
3462         switch( $last ) {
3463                 case 'g':
3464                 case 'G':
3465                         $val *= 1024;
3466                         // break intentionally missing
3467                 case 'm':
3468                 case 'M':
3469                         $val *= 1024;
3470                         // break intentionally missing
3471                 case 'k':
3472                 case 'K':
3473                         $val *= 1024;
3474         }
3475
3476         return $val;
3477 }
3478
3479 /**
3480  * Get the normalised IETF language tag
3481  * See unit test for examples.
3482  *
3483  * @param $code String: The language code.
3484  * @return $langCode String: The language code which complying with BCP 47 standards.
3485  */
3486 function wfBCP47( $code ) {
3487         $codeSegment = explode( '-', $code );
3488         $codeBCP = array();
3489         foreach ( $codeSegment as $segNo => $seg ) {
3490                 if ( count( $codeSegment ) > 0 ) {
3491                         // when previous segment is x, it is a private segment and should be lc
3492                         if( $segNo > 0 && strtolower( $codeSegment[($segNo - 1)] ) == 'x') {
3493                                 $codeBCP[$segNo] = strtolower( $seg );
3494                         // ISO 3166 country code
3495                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3496                                 $codeBCP[$segNo] = strtoupper( $seg );
3497                         // ISO 15924 script code
3498                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3499                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3500                         // Use lowercase for other cases
3501                         } else {
3502                                 $codeBCP[$segNo] = strtolower( $seg );
3503                         }
3504                 } else {
3505                 // Use lowercase for single segment
3506                         $codeBCP[$segNo] = strtolower( $seg );
3507                 }
3508         }
3509         $langCode = implode( '-', $codeBCP );
3510         return $langCode;
3511 }
3512
3513 /**
3514  * Get a cache object.
3515  *
3516  * @param $inputType integer Cache type, one the the CACHE_* constants.
3517  * @return BagOStuff
3518  */
3519 function wfGetCache( $inputType ) {
3520         return ObjectCache::getInstance( $inputType );
3521 }
3522
3523 /**
3524  * Get the main cache object
3525  *
3526  * @return BagOStuff
3527  */
3528 function wfGetMainCache() {
3529         global $wgMainCacheType;
3530         return ObjectCache::getInstance( $wgMainCacheType );
3531 }
3532
3533 /**
3534  * Get the cache object used by the message cache
3535  *
3536  * @return BagOStuff
3537  */
3538 function wfGetMessageCacheStorage() {
3539         global $wgMessageCacheType;
3540         return ObjectCache::getInstance( $wgMessageCacheType );
3541 }
3542
3543 /**
3544  * Get the cache object used by the parser cache
3545  *
3546  * @return BagOStuff
3547  */
3548 function wfGetParserCacheStorage() {
3549         global $wgParserCacheType;
3550         return ObjectCache::getInstance( $wgParserCacheType );
3551 }
3552
3553 /**
3554  * Call hook functions defined in $wgHooks
3555  *
3556  * @param $event String: event name
3557  * @param $args Array: parameters passed to hook functions
3558  * @return Boolean
3559  */
3560 function wfRunHooks( $event, $args = array() ) {
3561         return Hooks::run( $event, $args );
3562 }