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( $needle ) ) {
 298                 $needle = array( '%3B', '%40', '%24', '%21', '%2A', '%28', '%29', '%2C', '%2F' );
 299                 if ( !isset( $_SERVER['SERVER_SOFTWARE'] ) || ( strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/7' ) === false ) ) {
 300                         $needle[] = '%3A';
 301                 }
 302         }
 303
 304         $s = urlencode( $s );
 305         $s = str_ireplace(
 306                 $needle,
 307                 array( ';', '@', '$', '!', '*', '(', ')', ',', '/', ':' ),
 308                 $s
 309         );
 310
 311         return $s;
 312 }
 313
 314 /**
 315  * This function takes two arrays as input, and returns a CGI-style string, e.g.
 316  * "days=7&limit=100". Options in the first array override options in the second.
 317  * Options set to "" will not be output.
 318  *
 319  * @param $array1 Array ( String|Array )
 320  * @param $array2 Array ( String|Array )
 321  * @param $prefix String
 322  * @return String
 323  */
 324 function wfArrayToCGI( $array1, $array2 = null, $prefix = '' ) {
 325         if ( !is_null( $array2 ) ) {
 326                 $array1 = $array1 + $array2;
 327         }
 328
 329         $cgi = '';
 330         foreach ( $array1 as $key => $value ) {
 331                 if ( $value !== '' ) {
 332                         if ( $cgi != '' ) {
 333                                 $cgi .= '&';
 334                         }
 335                         if ( $prefix !== '' ) {
 336                                 $key = $prefix . "[$key]";
 337                         }
 338                         if ( is_array( $value ) ) {
 339                                 $firstTime = true;
 340                                 foreach ( $value as $k => $v ) {
 341                                         $cgi .= $firstTime ? '' : '&';
 342                                         if ( is_array( $v ) ) {
 343                                                 $cgi .= wfArrayToCGI( $v, null, $key . "[$k]" );
 344                                         } else {
 345                                                 $cgi .= urlencode( $key . "[$k]" ) . '=' . urlencode( $v );
 346                                         }
 347                                         $firstTime = false;
 348                                 }
 349                         } else {
 350                                 if ( is_object( $value ) ) {
 351                                         $value = $value->__toString();
 352                                 }
 353                                 $cgi .= urlencode( $key ) . '=' . urlencode( $value );
 354                         }
 355                 }
 356         }
 357         return $cgi;
 358 }
 359
 360 /**
 361  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
 362  * its argument and returns the same string in array form.  This allows compa-
 363  * tibility with legacy functions that accept raw query strings instead of nice
 364  * arrays.  Of course, keys and values are urldecode()d.  Don't try passing in-
 365  * valid query strings, or it will explode.
 366  *
 367  * @param $query String: query string
 368  * @return array Array version of input
 369  */
 370 function wfCgiToArray( $query ) {
 371         if ( isset( $query[0] ) && $query[0] == '?' ) {
 372                 $query = substr( $query, 1 );
 373         }
 374         $bits = explode( '&', $query );
 375         $ret = array();
 376         foreach ( $bits as $bit ) {
 377                 if ( $bit === '' ) {
 378                         continue;
 379                 }
 380                 list( $key, $value ) = explode( '=', $bit );
 381                 $key = urldecode( $key );
 382                 $value = urldecode( $value );
 383                 if ( strpos( $key, '[' ) !== false ) {
 384                         $keys = array_reverse( explode( '[', $key ) );
 385                         $key = array_pop( $keys );
 386                         $temp = $value;
 387                         foreach ( $keys as $k ) {
 388                                 $k = substr( $k, 0, -1 );
 389                                 $temp = array( $k => $temp );
 390                         }
 391                         if ( isset( $ret[$key] ) ) {
 392                                 $ret[$key] = array_merge( $ret[$key], $temp );
 393                         } else {
 394                                 $ret[$key] = $temp;
 395                         }
 396                 } else {
 397                         $ret[$key] = $value;
 398                 }
 399         }
 400         return $ret;
 401 }
 402
 403 /**
 404  * Append a query string to an existing URL, which may or may not already
 405  * have query string parameters already. If so, they will be combined.
 406  *
 407  * @param $url String
 408  * @param $query Mixed: string or associative array
 409  * @return string
 410  */
 411 function wfAppendQuery( $url, $query ) {
 412         if ( is_array( $query ) ) {
 413                 $query = wfArrayToCGI( $query );
 414         }
 415         if( $query != '' ) {
 416                 if( false === strpos( $url, '?' ) ) {
 417                         $url .= '?';
 418                 } else {
 419                         $url .= '&';
 420                 }
 421                 $url .= $query;
 422         }
 423         return $url;
 424 }
 425
 426 /**
 427  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 428  * is correct.
 429  *
 430  * @todo this won't work with current-path-relative URLs
 431  * like "subdir/foo.html", etc.
 432  *
 433  * @param $url String: either fully-qualified or a local path + query
 434  * @return string Fully-qualified URL
 435  */
 436 function wfExpandUrl( $url ) {
 437         global $wgServer;
 438         if( substr( $url, 0, 2 ) == '//' ) {
 439                 $bits = wfParseUrl( $wgServer );
 440                 $scheme = $bits ? $bits['scheme'] : 'http';
 441                 return $scheme . ':' . $url;
 442         } elseif( substr( $url, 0, 1 ) == '/' ) {
 443                 return $wgServer . $url;
 444         } else {
 445                 return $url;
 446         }
 447 }
 448
 449 /**
 450  * Returns a regular expression of url protocols
 451  *
 452  * @return String
 453  */
 454 function wfUrlProtocols() {
 455         global $wgUrlProtocols;
 456
 457         static $retval = null;
 458         if ( !is_null( $retval ) ) {
 459                 return $retval;
 460         }
 461
 462         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 463         // with LocalSettings files from 1.5
 464         if ( is_array( $wgUrlProtocols ) ) {
 465                 $protocols = array();
 466                 foreach ( $wgUrlProtocols as $protocol ) {
 467                         $protocols[] = preg_quote( $protocol, '/' );
 468                 }
 469
 470                 $retval = implode( '|', $protocols );
 471         } else {
 472                 $retval = $wgUrlProtocols;
 473         }
 474         return $retval;
 475 }
 476
 477 /**
 478  * parse_url() work-alike, but non-broken.  Differences:
 479  *
 480  * 1) Does not raise warnings on bad URLs (just returns false)
 481  * 2) Handles protocols that don't use :// (e.g., mailto: and news:) correctly
 482  * 3) Adds a "delimiter" element to the array, either '://' or ':' (see (2))
 483  *
 484  * @param $url String: a URL to parse
 485  * @return Array: bits of the URL in an associative array, per PHP docs
 486  */
 487 function wfParseUrl( $url ) {
 488         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 489         wfSuppressWarnings();
 490         $bits = parse_url( $url );
 491         wfRestoreWarnings();
 492         if ( !$bits ) {
 493                 return false;
 494         }
 495
 496         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 497         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 498                 $bits['delimiter'] = '://';
 499         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 500                 $bits['delimiter'] = ':';
 501                 // parse_url detects for news: and mailto: the host part of an url as path
 502                 // We have to correct this wrong detection
 503                 if ( isset( $bits['path'] ) ) {
 504                         $bits['host'] = $bits['path'];
 505                         $bits['path'] = '';
 506                 }
 507         } else {
 508                 return false;
 509         }
 510
 511         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 512         if ( !isset( $bits['host'] ) ) {
 513                 $bits['host'] = '';
 514
 515                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 516                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 517                         $bits['path'] = '/' . $bits['path'];
 518                 }
 519         }
 520         return $bits;
 521 }
 522
 523 /**
 524  * Make a URL index, appropriate for the el_index field of externallinks.
 525  *
 526  * @param $url String
 527  * @return String
 528  */
 529 function wfMakeUrlIndex( $url ) {
 530         $bits = wfParseUrl( $url );
 531
 532         // Reverse the labels in the hostname, convert to lower case
 533         // For emails reverse domainpart only
 534         if ( $bits['scheme'] == 'mailto' ) {
 535                 $mailparts = explode( '@', $bits['host'], 2 );
 536                 if ( count( $mailparts ) === 2 ) {
 537                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 538                 } else {
 539                         // No domain specified, don't mangle it
 540                         $domainpart = '';
 541                 }
 542                 $reversedHost = $domainpart . '@' . $mailparts[0];
 543         } else {
 544                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 545         }
 546         // Add an extra dot to the end
 547         // Why? Is it in wrong place in mailto links?
 548         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 549                 $reversedHost .= '.';
 550         }
 551         // Reconstruct the pseudo-URL
 552         $prot = $bits['scheme'];
 553         $index = $prot . $bits['delimiter'] . $reversedHost;
 554         // Leave out user and password. Add the port, path, query and fragment
 555         if ( isset( $bits['port'] ) ) {
 556                 $index .= ':' . $bits['port'];
 557         }
 558         if ( isset( $bits['path'] ) ) {
 559                 $index .= $bits['path'];
 560         } else {
 561                 $index .= '/';
 562         }
 563         if ( isset( $bits['query'] ) ) {
 564                 $index .= '?' . $bits['query'];
 565         }
 566         if ( isset( $bits['fragment'] ) ) {
 567                 $index .= '#' . $bits['fragment'];
 568         }
 569         return $index;
 570 }
 571
 572 /**
 573  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 574  * In normal operation this is a NOP.
 575  *
 576  * Controlling globals:
 577  * $wgDebugLogFile - points to the log file
 578  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 579  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 580  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 581  *
 582  * @param $text String
 583  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 584  */
 585 function wfDebug( $text, $logonly = false ) {
 586         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 587         global $wgDebugLogPrefix, $wgShowDebug;
 588
 589         static $cache = array(); // Cache of unoutputted messages
 590         $text = wfDebugTimer() . $text;
 591
 592         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 593                 return;
 594         }
 595
 596         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 597                 $cache[] = $text;
 598
 599                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 600                         // add the message and any cached messages to the output
 601                         array_map( array( $wgOut, 'debug' ), $cache );
 602                         $cache = array();
 603                 }
 604         }
 605         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 606                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 607                         # Strip unprintables; they can switch terminal modes when binary data
 608                         # gets dumped, which is pretty annoying.
 609                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 610                         $text = $wgDebugLogPrefix . $text;
 611                         wfErrorLog( $text, $wgDebugLogFile );
 612                 }
 613         }
 614 }
 615
 616 /**
 617  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 618  */
 619 function wfIsDebugRawPage() {
 620         static $cache;
 621         if ( $cache !== null ) {
 622                 return $cache;
 623         }
 624         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 625         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 626                 || (
 627                         isset( $_SERVER['SCRIPT_NAME'] )
 628                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 629                 ) )
 630         {
 631                 $cache = true;
 632         } else {
 633                 $cache = false;
 634         }
 635         return $cache;
 636 }
 637
 638 /**
 639  * Get microsecond timestamps for debug logs
 640  *
 641  * @return string
 642  */
 643 function wfDebugTimer() {
 644         global $wgDebugTimestamps;
 645         if ( !$wgDebugTimestamps ) {
 646                 return '';
 647         }
 648         static $start = null;
 649
 650         if ( $start === null ) {
 651                 $start = microtime( true );
 652                 $prefix = "\n$start";
 653         } else {
 654                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 655         }
 656
 657         return $prefix . '  ';
 658 }
 659
 660 /**
 661  * Send a line giving PHP memory usage.
 662  *
 663  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 664  */
 665 function wfDebugMem( $exact = false ) {
 666         $mem = memory_get_usage();
 667         if( !$exact ) {
 668                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 669         } else {
 670                 $mem .= ' bytes';
 671         }
 672         wfDebug( "Memory usage: $mem\n" );
 673 }
 674
 675 /**
 676  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 677  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 678  *
 679  * @param $logGroup String
 680  * @param $text String
 681  * @param $public Bool: whether to log the event in the public log if no private
 682  *                     log file is specified, (default true)
 683  */
 684 function wfDebugLog( $logGroup, $text, $public = true ) {
 685         global $wgDebugLogGroups, $wgShowHostnames;
 686         $text = trim( $text ) . "\n";
 687         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 688                 $time = wfTimestamp( TS_DB );
 689                 $wiki = wfWikiID();
 690                 if ( $wgShowHostnames ) {
 691                         $host = wfHostname();
 692                 } else {
 693                         $host = '';
 694                 }
 695                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 696                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 697                 }
 698         } elseif ( $public === true ) {
 699                 wfDebug( $text, true );
 700         }
 701 }
 702
 703 /**
 704  * Log for database errors
 705  *
 706  * @param $text String: database error message.
 707  */
 708 function wfLogDBError( $text ) {
 709         global $wgDBerrorLog, $wgDBname;
 710         if ( $wgDBerrorLog ) {
 711                 $host = trim(`hostname`);
 712                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 713                 wfErrorLog( $text, $wgDBerrorLog );
 714         }
 715 }
 716
 717 /**
 718  * Log to a file without getting "file size exceeded" signals.
 719  *
 720  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 721  * send lines to the specified port, prefixed by the specified prefix and a space.
 722  *
 723  * @param $text String
 724  * @param $file String filename
 725  */
 726 function wfErrorLog( $text, $file ) {
 727         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 728                 # Needs the sockets extension
 729                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 730                         // IPv6 bracketed host
 731                         $host = $m[2];
 732                         $port = intval( $m[3] );
 733                         $prefix = isset( $m[4] ) ? $m[4] : false;
 734                         $domain = AF_INET6;
 735                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 736                         $host = $m[2];
 737                         if ( !IP::isIPv4( $host ) ) {
 738                                 $host = gethostbyname( $host );
 739                         }
 740                         $port = intval( $m[3] );
 741                         $prefix = isset( $m[4] ) ? $m[4] : false;
 742                         $domain = AF_INET;
 743                 } else {
 744                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 745                 }
 746
 747                 // Clean it up for the multiplexer
 748                 if ( strval( $prefix ) !== '' ) {
 749                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 750
 751                         // Limit to 64KB
 752                         if ( strlen( $text ) > 65534 ) {
 753                                 $text = substr( $text, 0, 65534 );
 754                         }
 755
 756                         if ( substr( $text, -1 ) != "\n" ) {
 757                                 $text .= "\n";
 758                         }
 759                 } elseif ( strlen( $text ) > 65535 ) {
 760                         $text = substr( $text, 0, 65535 );
 761                 }
 762
 763                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 764                 if ( !$sock ) {
 765                         return;
 766                 }
 767                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 768                 socket_close( $sock );
 769         } else {
 770                 wfSuppressWarnings();
 771                 $exists = file_exists( $file );
 772                 $size = $exists ? filesize( $file ) : false;
 773                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 774                         file_put_contents( $file, $text, FILE_APPEND );
 775                 }
 776                 wfRestoreWarnings();
 777         }
 778 }
 779
 780 /**
 781  * @todo document
 782  */
 783 function wfLogProfilingData() {
 784         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 785         global $wgProfileLimit, $wgUser;
 786
 787         $profiler = Profiler::instance();
 788
 789         # Profiling must actually be enabled...
 790         if ( $profiler->isStub() ) {
 791                 return;
 792         }
 793
 794         // Get total page request time and only show pages that longer than
 795         // $wgProfileLimit time (default is 0)
 796         $now = wfTime();
 797         $elapsed = $now - $wgRequestTime;
 798         if ( $elapsed <= $wgProfileLimit ) {
 799                 return;
 800         }
 801
 802         $profiler->logData();
 803
 804         // Check whether this should be logged in the debug file.
 805         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
 806                 return;
 807         }
 808
 809         $forward = '';
 810         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
 811                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 812         }
 813         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
 814                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 815         }
 816         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
 817                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 818         }
 819         if ( $forward ) {
 820                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 821         }
 822         // Don't load $wgUser at this late stage just for statistics purposes
 823         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
 824         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
 825                 $forward .= ' anon';
 826         }
 827         $log = sprintf( "%s\t%04.3f\t%s\n",
 828                 gmdate( 'YmdHis' ), $elapsed,
 829                 urldecode( $wgRequest->getRequestURL() . $forward ) );
 830
 831         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
 832 }
 833
 834 /**
 835  * Check if the wiki read-only lock file is present. This can be used to lock
 836  * off editing functions, but doesn't guarantee that the database will not be
 837  * modified.
 838  *
 839  * @return bool
 840  */
 841 function wfReadOnly() {
 842         global $wgReadOnlyFile, $wgReadOnly;
 843
 844         if ( !is_null( $wgReadOnly ) ) {
 845                 return (bool)$wgReadOnly;
 846         }
 847         if ( $wgReadOnlyFile == '' ) {
 848                 return false;
 849         }
 850         // Set $wgReadOnly for faster access next time
 851         if ( is_file( $wgReadOnlyFile ) ) {
 852                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
 853         } else {
 854                 $wgReadOnly = false;
 855         }
 856         return (bool)$wgReadOnly;
 857 }
 858
 859 function wfReadOnlyReason() {
 860         global $wgReadOnly;
 861         wfReadOnly();
 862         return $wgReadOnly;
 863 }
 864
 865 /**
 866  * Return a Language object from $langcode
 867  *
 868  * @param $langcode Mixed: either:
 869  *                  - a Language object
 870  *                  - code of the language to get the message for, if it is
 871  *                    a valid code create a language for that language, if
 872  *                    it is a string but not a valid code then make a basic
 873  *                    language object
 874  *                  - a boolean: if it's false then use the current users
 875  *                    language (as a fallback for the old parameter
 876  *                    functionality), or if it is true then use the wikis
 877  * @return Language object
 878  */
 879 function wfGetLangObj( $langcode = false ) {
 880         # Identify which language to get or create a language object for.
 881         # Using is_object here due to Stub objects.
 882         if( is_object( $langcode ) ) {
 883                 # Great, we already have the object (hopefully)!
 884                 return $langcode;
 885         }
 886
 887         global $wgContLang, $wgLanguageCode;
 888         if( $langcode === true || $langcode === $wgLanguageCode ) {
 889                 # $langcode is the language code of the wikis content language object.
 890                 # or it is a boolean and value is true
 891                 return $wgContLang;
 892         }
 893
 894         global $wgLang;
 895         if( $langcode === false || $langcode === $wgLang->getCode() ) {
 896                 # $langcode is the language code of user language object.
 897                 # or it was a boolean and value is false
 898                 return $wgLang;
 899         }
 900
 901         $validCodes = array_keys( Language::getLanguageNames() );
 902         if( in_array( $langcode, $validCodes ) ) {
 903                 # $langcode corresponds to a valid language.
 904                 return Language::factory( $langcode );
 905         }
 906
 907         # $langcode is a string, but not a valid language code; use content language.
 908         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
 909         return $wgContLang;
 910 }
 911
 912 /**
 913  * Old function when $wgBetterDirectionality existed
 914  * Removed in core, kept in extensions for backwards compat.
 915  *
 916  * @deprecated since 1.19
 917  * @return Language
 918  */
 919 function wfUILang() {
 920         global $wgLang;
 921         return $wgLang;
 922 }
 923
 924 /**
 925  * This is the new function for getting translated interface messages.
 926  * See the Message class for documentation how to use them.
 927  * The intention is that this function replaces all old wfMsg* functions.
 928  * @param $key \string Message key.
 929  * Varargs: normal message parameters.
 930  * @return Message
 931  * @since 1.17
 932  */
 933 function wfMessage( $key /*...*/) {
 934         $params = func_get_args();
 935         array_shift( $params );
 936         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 937                 $params = $params[0];
 938         }
 939         return new Message( $key, $params );
 940 }
 941
 942 /**
 943  * This function accepts multiple message keys and returns a message instance
 944  * for the first message which is non-empty. If all messages are empty then an
 945  * instance of the first message key is returned.
 946  * @param varargs: message keys
 947  * @return Message
 948  * @since 1.18
 949  */
 950 function wfMessageFallback( /*...*/ ) {
 951         $args = func_get_args();
 952         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
 953 }
 954
 955 /**
 956  * Get a message from anywhere, for the current user language.
 957  *
 958  * Use wfMsgForContent() instead if the message should NOT
 959  * change depending on the user preferences.
 960  *
 961  * @param $key String: lookup key for the message, usually
 962  *    defined in languages/Language.php
 963  *
 964  * Parameters to the message, which can be used to insert variable text into
 965  * it, can be passed to this function in the following formats:
 966  * - One per argument, starting at the second parameter
 967  * - As an array in the second parameter
 968  * These are not shown in the function definition.
 969  *
 970  * @return String
 971  */
 972 function wfMsg( $key ) {
 973         $args = func_get_args();
 974         array_shift( $args );
 975         return wfMsgReal( $key, $args );
 976 }
 977
 978 /**
 979  * Same as above except doesn't transform the message
 980  *
 981  * @param $key String
 982  * @return String
 983  */
 984 function wfMsgNoTrans( $key ) {
 985         $args = func_get_args();
 986         array_shift( $args );
 987         return wfMsgReal( $key, $args, true, false, false );
 988 }
 989
 990 /**
 991  * Get a message from anywhere, for the current global language
 992  * set with $wgLanguageCode.
 993  *
 994  * Use this if the message should NOT change dependent on the
 995  * language set in the user's preferences. This is the case for
 996  * most text written into logs, as well as link targets (such as
 997  * the name of the copyright policy page). Link titles, on the
 998  * other hand, should be shown in the UI language.
 999  *
1000  * Note that MediaWiki allows users to change the user interface
1001  * language in their preferences, but a single installation
1002  * typically only contains content in one language.
1003  *
1004  * Be wary of this distinction: If you use wfMsg() where you should
1005  * use wfMsgForContent(), a user of the software may have to
1006  * customize potentially hundreds of messages in
1007  * order to, e.g., fix a link in every possible language.
1008  *
1009  * @param $key String: lookup key for the message, usually
1010  *     defined in languages/Language.php
1011  * @return String
1012  */
1013 function wfMsgForContent( $key ) {
1014         global $wgForceUIMsgAsContentMsg;
1015         $args = func_get_args();
1016         array_shift( $args );
1017         $forcontent = true;
1018         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1019                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1020         {
1021                 $forcontent = false;
1022         }
1023         return wfMsgReal( $key, $args, true, $forcontent );
1024 }
1025
1026 /**
1027  * Same as above except doesn't transform the message
1028  *
1029  * @param $key String
1030  * @return String
1031  */
1032 function wfMsgForContentNoTrans( $key ) {
1033         global $wgForceUIMsgAsContentMsg;
1034         $args = func_get_args();
1035         array_shift( $args );
1036         $forcontent = true;
1037         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1038                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1039         {
1040                 $forcontent = false;
1041         }
1042         return wfMsgReal( $key, $args, true, $forcontent, false );
1043 }
1044
1045 /**
1046  * Really get a message
1047  *
1048  * @param $key String: key to get.
1049  * @param $args
1050  * @param $useDB Boolean
1051  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1052  * @param $transform Boolean: Whether or not to transform the message.
1053  * @return String: the requested message.
1054  */
1055 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1056         wfProfileIn( __METHOD__ );
1057         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1058         $message = wfMsgReplaceArgs( $message, $args );
1059         wfProfileOut( __METHOD__ );
1060         return $message;
1061 }
1062
1063 /**
1064  * Fetch a message string value, but don't replace any keys yet.
1065  *
1066  * @param $key String
1067  * @param $useDB Bool
1068  * @param $langCode String: Code of the language to get the message for, or
1069  *                  behaves as a content language switch if it is a boolean.
1070  * @param $transform Boolean: whether to parse magic words, etc.
1071  * @return string
1072  */
1073 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1074         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1075
1076         $cache = MessageCache::singleton();
1077         $message = $cache->get( $key, $useDB, $langCode );
1078         if( $message === false ) {
1079                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1080         } elseif ( $transform ) {
1081                 $message = $cache->transform( $message );
1082         }
1083         return $message;
1084 }
1085
1086 /**
1087  * Replace message parameter keys on the given formatted output.
1088  *
1089  * @param $message String
1090  * @param $args Array
1091  * @return string
1092  * @private
1093  */
1094 function wfMsgReplaceArgs( $message, $args ) {
1095         # Fix windows line-endings
1096         # Some messages are split with explode("\n", $msg)
1097         $message = str_replace( "\r", '', $message );
1098
1099         // Replace arguments
1100         if ( count( $args ) ) {
1101                 if ( is_array( $args[0] ) ) {
1102                         $args = array_values( $args[0] );
1103                 }
1104                 $replacementKeys = array();
1105                 foreach( $args as $n => $param ) {
1106                         $replacementKeys['$' . ( $n + 1 )] = $param;
1107                 }
1108                 $message = strtr( $message, $replacementKeys );
1109         }
1110
1111         return $message;
1112 }
1113
1114 /**
1115  * Return an HTML-escaped version of a message.
1116  * Parameter replacements, if any, are done *after* the HTML-escaping,
1117  * so parameters may contain HTML (eg links or form controls). Be sure
1118  * to pre-escape them if you really do want plaintext, or just wrap
1119  * the whole thing in htmlspecialchars().
1120  *
1121  * @param $key String
1122  * @param string ... parameters
1123  * @return string
1124  */
1125 function wfMsgHtml( $key ) {
1126         $args = func_get_args();
1127         array_shift( $args );
1128         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1129 }
1130
1131 /**
1132  * Return an HTML version of message
1133  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1134  * so parameters may contain HTML (eg links or form controls). Be sure
1135  * to pre-escape them if you really do want plaintext, or just wrap
1136  * the whole thing in htmlspecialchars().
1137  *
1138  * @param $key String
1139  * @param string ... parameters
1140  * @return string
1141  */
1142 function wfMsgWikiHtml( $key ) {
1143         $args = func_get_args();
1144         array_shift( $args );
1145         return wfMsgReplaceArgs(
1146                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null, /* can't be set to false */ true )->getText(),
1147                 $args );
1148 }
1149
1150 /**
1151  * Returns message in the requested format
1152  * @param $key String: key of the message
1153  * @param $options Array: processing rules. Can take the following options:
1154  *   <i>parse</i>: parses wikitext to HTML
1155  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1156  *       p's added by parser or tidy
1157  *   <i>escape</i>: filters message through htmlspecialchars
1158  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1159  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1160  *   <i>parsemag</i>: transform the message using magic phrases
1161  *   <i>content</i>: fetch message for content language instead of interface
1162  * Also can accept a single associative argument, of the form 'language' => 'xx':
1163  *   <i>language</i>: Language object or language code to fetch message for
1164  *       (overriden by <i>content</i>).
1165  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1166  *
1167  * @return String
1168  */
1169 function wfMsgExt( $key, $options ) {
1170         $args = func_get_args();
1171         array_shift( $args );
1172         array_shift( $args );
1173         $options = (array)$options;
1174
1175         foreach( $options as $arrayKey => $option ) {
1176                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1177                         # An unknown index, neither numeric nor "language"
1178                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1179                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1180                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1181                 'replaceafter', 'parsemag', 'content' ) ) ) {
1182                         # A numeric index with unknown value
1183                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1184                 }
1185         }
1186
1187         if( in_array( 'content', $options, true ) ) {
1188                 $forContent = true;
1189                 $langCode = true;
1190                 $langCodeObj = null;
1191         } elseif( array_key_exists( 'language', $options ) ) {
1192                 $forContent = false;
1193                 $langCode = wfGetLangObj( $options['language'] );
1194                 $langCodeObj = $langCode;
1195         } else {
1196                 $forContent = false;
1197                 $langCode = false;
1198                 $langCodeObj = null;
1199         }
1200
1201         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1202
1203         if( !in_array( 'replaceafter', $options, true ) ) {
1204                 $string = wfMsgReplaceArgs( $string, $args );
1205         }
1206
1207         $messageCache = MessageCache::singleton();
1208         if( in_array( 'parse', $options, true ) ) {
1209                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1210         } elseif ( in_array( 'parseinline', $options, true ) ) {
1211                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1212                 $m = array();
1213                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1214                         $string = $m[1];
1215                 }
1216         } elseif ( in_array( 'parsemag', $options, true ) ) {
1217                 $string = $messageCache->transform( $string,
1218                                 !$forContent, $langCodeObj );
1219         }
1220
1221         if ( in_array( 'escape', $options, true ) ) {
1222                 $string = htmlspecialchars ( $string );
1223         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1224                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1225         }
1226
1227         if( in_array( 'replaceafter', $options, true ) ) {
1228                 $string = wfMsgReplaceArgs( $string, $args );
1229         }
1230
1231         return $string;
1232 }
1233
1234 /**
1235  * Since wfMsg() and co suck, they don't return false if the message key they
1236  * looked up didn't exist but a XHTML string, this function checks for the
1237  * nonexistance of messages by checking the MessageCache::get() result directly.
1238  *
1239  * @param $key      String: the message key looked up
1240  * @return Boolean True if the message *doesn't* exist.
1241  */
1242 function wfEmptyMsg( $key ) {
1243         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1244 }
1245
1246 /**
1247  * Throw a debugging exception. This function previously once exited the process,
1248  * but now throws an exception instead, with similar results.
1249  *
1250  * @param $msg String: message shown when dieing.
1251  */
1252 function wfDebugDieBacktrace( $msg = '' ) {
1253         throw new MWException( $msg );
1254 }
1255
1256 /**
1257  * Fetch server name for use in error reporting etc.
1258  * Use real server name if available, so we know which machine
1259  * in a server farm generated the current page.
1260  *
1261  * @return string
1262  */
1263 function wfHostname() {
1264         static $host;
1265         if ( is_null( $host ) ) {
1266                 if ( function_exists( 'posix_uname' ) ) {
1267                         // This function not present on Windows
1268                         $uname = posix_uname();
1269                 } else {
1270                         $uname = false;
1271                 }
1272                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1273                         $host = $uname['nodename'];
1274                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1275                         # Windows computer name
1276                         $host = getenv( 'COMPUTERNAME' );
1277                 } else {
1278                         # This may be a virtual server.
1279                         $host = $_SERVER['SERVER_NAME'];
1280                 }
1281         }
1282         return $host;
1283 }
1284
1285 /**
1286  * Returns a HTML comment with the elapsed time since request.
1287  * This method has no side effects.
1288  *
1289  * @return string
1290  */
1291 function wfReportTime() {
1292         global $wgRequestTime, $wgShowHostnames;
1293
1294         $now = wfTime();
1295         $elapsed = $now - $wgRequestTime;
1296
1297         return $wgShowHostnames
1298                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1299                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1300 }
1301
1302 /**
1303  * Safety wrapper for debug_backtrace().
1304  *
1305  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1306  * murky circumstances, which may be triggered in part by stub objects
1307  * or other fancy talkin'.
1308  *
1309  * Will return an empty array if Zend Optimizer is detected or if
1310  * debug_backtrace is disabled, otherwise the output from
1311  * debug_backtrace() (trimmed).
1312  *
1313  * @return array of backtrace information
1314  */
1315 function wfDebugBacktrace( $limit = 0 ) {
1316         static $disabled = null;
1317
1318         if( extension_loaded( 'Zend Optimizer' ) ) {
1319                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1320                 return array();
1321         }
1322
1323         if ( is_null( $disabled ) ) {
1324                 $disabled = false;
1325                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1326                 $functions = array_map( 'trim', $functions );
1327                 $functions = array_map( 'strtolower', $functions );
1328                 if ( in_array( 'debug_backtrace', $functions ) ) {
1329                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1330                         $disabled = true;
1331                 }
1332         }
1333         if ( $disabled ) {
1334                 return array();
1335         }
1336
1337         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1338                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, 1 ), 1 );
1339         } else {
1340                 return array_slice( debug_backtrace(), 1 );
1341         }
1342 }
1343
1344 /**
1345  * Get a debug backtrace as a string
1346  *
1347  * @return string
1348  */
1349 function wfBacktrace() {
1350         global $wgCommandLineMode;
1351
1352         if ( $wgCommandLineMode ) {
1353                 $msg = '';
1354         } else {
1355                 $msg = "<ul>\n";
1356         }
1357         $backtrace = wfDebugBacktrace();
1358         foreach( $backtrace as $call ) {
1359                 if( isset( $call['file'] ) ) {
1360                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1361                         $file = $f[count( $f ) - 1];
1362                 } else {
1363                         $file = '-';
1364                 }
1365                 if( isset( $call['line'] ) ) {
1366                         $line = $call['line'];
1367                 } else {
1368                         $line = '-';
1369                 }
1370                 if ( $wgCommandLineMode ) {
1371                         $msg .= "$file line $line calls ";
1372                 } else {
1373                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1374                 }
1375                 if( !empty( $call['class'] ) ) {
1376                         $msg .= $call['class'] . $call['type'];
1377                 }
1378                 $msg .= $call['function'] . '()';
1379
1380                 if ( $wgCommandLineMode ) {
1381                         $msg .= "\n";
1382                 } else {
1383                         $msg .= "</li>\n";
1384                 }
1385         }
1386         if ( $wgCommandLineMode ) {
1387                 $msg .= "\n";
1388         } else {
1389                 $msg .= "</ul>\n";
1390         }
1391
1392         return $msg;
1393 }
1394
1395 /**
1396  * Get the name of the function which called this function
1397  *
1398  * @param $level Int
1399  * @return Bool|string
1400  */
1401 function wfGetCaller( $level = 2 ) {
1402         $backtrace = wfDebugBacktrace( $level );
1403         if ( isset( $backtrace[$level] ) ) {
1404                 return wfFormatStackFrame( $backtrace[$level] );
1405         } else {
1406                 $caller = 'unknown';
1407         }
1408         return $caller;
1409 }
1410
1411 /**
1412  * Return a string consisting of callers in the stack. Useful sometimes
1413  * for profiling specific points.
1414  *
1415  * @param $limit The maximum depth of the stack frame to return, or false for
1416  *               the entire stack.
1417  * @return String
1418  */
1419 function wfGetAllCallers( $limit = 3 ) {
1420         $trace = array_reverse( wfDebugBacktrace() );
1421         if ( !$limit || $limit > count( $trace ) - 1 ) {
1422                 $limit = count( $trace ) - 1;
1423         }
1424         $trace = array_slice( $trace, -$limit - 1, $limit );
1425         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1426 }
1427
1428 /**
1429  * Return a string representation of frame
1430  *
1431  * @param $frame Array
1432  * @return Bool
1433  */
1434 function wfFormatStackFrame( $frame ) {
1435         return isset( $frame['class'] ) ?
1436                 $frame['class'] . '::' . $frame['function'] :
1437                 $frame['function'];
1438 }
1439
1440
1441 /* Some generic result counters, pulled out of SearchEngine */
1442
1443
1444 /**
1445  * @todo document
1446  *
1447  * @param $offset Int
1448  * @param $limit Int
1449  * @return String
1450  */
1451 function wfShowingResults( $offset, $limit ) {
1452         global $wgLang;
1453         return wfMsgExt(
1454                 'showingresults',
1455                 array( 'parseinline' ),
1456                 $wgLang->formatNum( $limit ),
1457                 $wgLang->formatNum( $offset + 1 )
1458         );
1459 }
1460
1461 /**
1462  * Generate (prev x| next x) (20|50|100...) type links for paging
1463  *
1464  * @param $offset String
1465  * @param $limit Integer
1466  * @param $link String
1467  * @param $query String: optional URL query parameter string
1468  * @param $atend Bool: optional param for specified if this is the last page
1469  * @return String
1470  */
1471 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1472         global $wgLang;
1473         $fmtLimit = $wgLang->formatNum( $limit );
1474         // @todo FIXME: Why on earth this needs one message for the text and another one for tooltip?
1475         # Get prev/next link display text
1476         $prev = wfMsgExt( 'prevn', array( 'parsemag', 'escape' ), $fmtLimit );
1477         $next = wfMsgExt( 'nextn', array( 'parsemag', 'escape' ), $fmtLimit );
1478         # Get prev/next link title text
1479         $pTitle = wfMsgExt( 'prevn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1480         $nTitle = wfMsgExt( 'nextn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1481         # Fetch the title object
1482         if( is_object( $link ) ) {
1483                 $title =& $link;
1484         } else {
1485                 $title = Title::newFromText( $link );
1486                 if( is_null( $title ) ) {
1487                         return false;
1488                 }
1489         }
1490         # Make 'previous' link
1491         if( 0 != $offset ) {
1492                 $po = $offset - $limit;
1493                 $po = max( $po, 0 );
1494                 $q = "limit={$limit}&offset={$po}";
1495                 if( $query != '' ) {
1496                         $q .= '&' . $query;
1497                 }
1498                 $plink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$pTitle}\" class=\"mw-prevlink\">{$prev}</a>";
1499         } else {
1500                 $plink = $prev;
1501         }
1502         # Make 'next' link
1503         $no = $offset + $limit;
1504         $q = "limit={$limit}&offset={$no}";
1505         if( $query != '' ) {
1506                 $q .= '&' . $query;
1507         }
1508         if( $atend ) {
1509                 $nlink = $next;
1510         } else {
1511                 $nlink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$nTitle}\" class=\"mw-nextlink\">{$next}</a>";
1512         }
1513         # Make links to set number of items per page
1514         $nums = $wgLang->pipeList( array(
1515                 wfNumLink( $offset, 20, $title, $query ),
1516                 wfNumLink( $offset, 50, $title, $query ),
1517                 wfNumLink( $offset, 100, $title, $query ),
1518                 wfNumLink( $offset, 250, $title, $query ),
1519                 wfNumLink( $offset, 500, $title, $query )
1520         ) );
1521         return wfMsgHtml( 'viewprevnext', $plink, $nlink, $nums );
1522 }
1523
1524 /**
1525  * Generate links for (20|50|100...) items-per-page links
1526  *
1527  * @param $offset String
1528  * @param $limit Integer
1529  * @param $title Title
1530  * @param $query String: optional URL query parameter string
1531  */
1532 function wfNumLink( $offset, $limit, $title, $query = '' ) {
1533         global $wgLang;
1534         if( $query == '' ) {
1535                 $q = '';
1536         } else {
1537                 $q = $query.'&';
1538         }
1539         $q .= "limit={$limit}&offset={$offset}";
1540         $fmtLimit = $wgLang->formatNum( $limit );
1541         $lTitle = wfMsgExt( 'shown-title', array( 'parsemag', 'escape' ), $limit );
1542         $s = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$lTitle}\" class=\"mw-numlink\">{$fmtLimit}</a>";
1543         return $s;
1544 }
1545
1546 /**
1547  * @todo document
1548  * @todo FIXME: We may want to blacklist some broken browsers
1549  *
1550  * @param $force Bool
1551  * @return bool Whereas client accept gzip compression
1552  */
1553 function wfClientAcceptsGzip( $force = false ) {
1554         static $result = null;
1555         if ( $result === null || $force ) {
1556                 $result = false;
1557                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1558                         # @todo FIXME: We may want to blacklist some broken browsers
1559                         $m = array();
1560                         if( preg_match(
1561                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1562                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1563                                 $m )
1564                         )
1565                         {
1566                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1567                                         $result = false;
1568                                         return $result;
1569                                 }
1570                                 wfDebug( " accepts gzip\n" );
1571                                 $result = true;
1572                         }
1573                 }
1574         }
1575         return $result;
1576 }
1577
1578 /**
1579  * Obtain the offset and limit values from the request string;
1580  * used in special pages
1581  *
1582  * @param $deflimit Int default limit if none supplied
1583  * @param $optionname String Name of a user preference to check against
1584  * @return array
1585  *
1586  */
1587 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1588         global $wgRequest;
1589         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1590 }
1591
1592 /**
1593  * Escapes the given text so that it may be output using addWikiText()
1594  * without any linking, formatting, etc. making its way through. This
1595  * is achieved by substituting certain characters with HTML entities.
1596  * As required by the callers, <nowiki> is not used.
1597  *
1598  * @param $text String: text to be escaped
1599  * @return String
1600  */
1601 function wfEscapeWikiText( $text ) {
1602         $text = strtr( "\n$text", array(
1603                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1604                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1605                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1606                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1607                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1608                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1609         ) );
1610         return substr( $text, 1 );
1611 }
1612
1613 /**
1614  * Get the current unix timetstamp with microseconds.  Useful for profiling
1615  * @return Float
1616  */
1617 function wfTime() {
1618         return microtime( true );
1619 }
1620
1621 /**
1622  * Sets dest to source and returns the original value of dest
1623  * If source is NULL, it just returns the value, it doesn't set the variable
1624  * If force is true, it will set the value even if source is NULL
1625  *
1626  * @param $dest Mixed
1627  * @param $source Mixed
1628  * @param $force Bool
1629  * @return Mixed
1630  */
1631 function wfSetVar( &$dest, $source, $force = false ) {
1632         $temp = $dest;
1633         if ( !is_null( $source ) || $force ) {
1634                 $dest = $source;
1635         }
1636         return $temp;
1637 }
1638
1639 /**
1640  * As for wfSetVar except setting a bit
1641  *
1642  * @param $dest Int
1643  * @param $bit Int
1644  * @param $state Bool
1645  */
1646 function wfSetBit( &$dest, $bit, $state = true ) {
1647         $temp = (bool)( $dest & $bit );
1648         if ( !is_null( $state ) ) {
1649                 if ( $state ) {
1650                         $dest |= $bit;
1651                 } else {
1652                         $dest &= ~$bit;
1653                 }
1654         }
1655         return $temp;
1656 }
1657
1658 /**
1659  * Windows-compatible version of escapeshellarg()
1660  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
1661  * function puts single quotes in regardless of OS.
1662  *
1663  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
1664  * earlier distro releases of PHP)
1665  *
1666  * @param varargs
1667  * @return String
1668  */
1669 function wfEscapeShellArg( ) {
1670         wfInitShellLocale();
1671
1672         $args = func_get_args();
1673         $first = true;
1674         $retVal = '';
1675         foreach ( $args as $arg ) {
1676                 if ( !$first ) {
1677                         $retVal .= ' ';
1678                 } else {
1679                         $first = false;
1680                 }
1681
1682                 if ( wfIsWindows() ) {
1683                         // Escaping for an MSVC-style command line parser and CMD.EXE
1684                         // Refs:
1685                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
1686                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
1687                         //  * Bug #13518
1688                         //  * CR r63214
1689                         // Double the backslashes before any double quotes. Escape the double quotes.
1690                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
1691                         $arg = '';
1692                         $iteration = 0;
1693                         foreach ( $tokens as $token ) {
1694                                 if ( $iteration % 2 == 1 ) {
1695                                         // Delimiter, a double quote preceded by zero or more slashes
1696                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
1697                                 } elseif ( $iteration % 4 == 2 ) {
1698                                         // ^ in $token will be outside quotes, need to be escaped
1699                                         $arg .= str_replace( '^', '^^', $token );
1700                                 } else { // $iteration % 4 == 0
1701                                         // ^ in $token will appear inside double quotes, so leave as is
1702                                         $arg .= $token;
1703                                 }
1704                                 $iteration++;
1705                         }
1706                         // Double the backslashes before the end of the string, because
1707                         // we will soon add a quote
1708                         $m = array();
1709                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1710                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1711                         }
1712
1713                         // Add surrounding quotes
1714                         $retVal .= '"' . $arg . '"';
1715                 } else {
1716                         $retVal .= escapeshellarg( $arg );
1717                 }
1718         }
1719         return $retVal;
1720 }
1721
1722 /**
1723  * wfMerge attempts to merge differences between three texts.
1724  * Returns true for a clean merge and false for failure or a conflict.
1725  *
1726  * @param $old String
1727  * @param $mine String
1728  * @param $yours String
1729  * @param $result String
1730  * @return Bool
1731  */
1732 function wfMerge( $old, $mine, $yours, &$result ) {
1733         global $wgDiff3;
1734
1735         # This check may also protect against code injection in
1736         # case of broken installations.
1737         wfSuppressWarnings();
1738         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
1739         wfRestoreWarnings();
1740
1741         if( !$haveDiff3 ) {
1742                 wfDebug( "diff3 not found\n" );
1743                 return false;
1744         }
1745
1746         # Make temporary files
1747         $td = wfTempDir();
1748         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1749         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1750         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1751
1752         fwrite( $oldtextFile, $old );
1753         fclose( $oldtextFile );
1754         fwrite( $mytextFile, $mine );
1755         fclose( $mytextFile );
1756         fwrite( $yourtextFile, $yours );
1757         fclose( $yourtextFile );
1758
1759         # Check for a conflict
1760         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1761                 wfEscapeShellArg( $mytextName ) . ' ' .
1762                 wfEscapeShellArg( $oldtextName ) . ' ' .
1763                 wfEscapeShellArg( $yourtextName );
1764         $handle = popen( $cmd, 'r' );
1765
1766         if( fgets( $handle, 1024 ) ) {
1767                 $conflict = true;
1768         } else {
1769                 $conflict = false;
1770         }
1771         pclose( $handle );
1772
1773         # Merge differences
1774         $cmd = $wgDiff3 . ' -a -e --merge ' .
1775                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1776         $handle = popen( $cmd, 'r' );
1777         $result = '';
1778         do {
1779                 $data = fread( $handle, 8192 );
1780                 if ( strlen( $data ) == 0 ) {
1781                         break;
1782                 }
1783                 $result .= $data;
1784         } while ( true );
1785         pclose( $handle );
1786         unlink( $mytextName );
1787         unlink( $oldtextName );
1788         unlink( $yourtextName );
1789
1790         if ( $result === '' && $old !== '' && !$conflict ) {
1791                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1792                 $conflict = true;
1793         }
1794         return !$conflict;
1795 }
1796
1797 /**
1798  * Returns unified plain-text diff of two texts.
1799  * Useful for machine processing of diffs.
1800  *
1801  * @param $before String: the text before the changes.
1802  * @param $after String: the text after the changes.
1803  * @param $params String: command-line options for the diff command.
1804  * @return String: unified diff of $before and $after
1805  */
1806 function wfDiff( $before, $after, $params = '-u' ) {
1807         if ( $before == $after ) {
1808                 return '';
1809         }
1810
1811         global $wgDiff;
1812         wfSuppressWarnings();
1813         $haveDiff = $wgDiff && file_exists( $wgDiff );
1814         wfRestoreWarnings();
1815
1816         # This check may also protect against code injection in
1817         # case of broken installations.
1818         if( !$haveDiff ) {
1819                 wfDebug( "diff executable not found\n" );
1820                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
1821                 $format = new UnifiedDiffFormatter();
1822                 return $format->format( $diffs );
1823         }
1824
1825         # Make temporary files
1826         $td = wfTempDir();
1827         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1828         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
1829
1830         fwrite( $oldtextFile, $before );
1831         fclose( $oldtextFile );
1832         fwrite( $newtextFile, $after );
1833         fclose( $newtextFile );
1834
1835         // Get the diff of the two files
1836         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
1837
1838         $h = popen( $cmd, 'r' );
1839
1840         $diff = '';
1841
1842         do {
1843                 $data = fread( $h, 8192 );
1844                 if ( strlen( $data ) == 0 ) {
1845                         break;
1846                 }
1847                 $diff .= $data;
1848         } while ( true );
1849
1850         // Clean up
1851         pclose( $h );
1852         unlink( $oldtextName );
1853         unlink( $newtextName );
1854
1855         // Kill the --- and +++ lines. They're not useful.
1856         $diff_lines = explode( "\n", $diff );
1857         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
1858                 unset( $diff_lines[0] );
1859         }
1860         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
1861                 unset( $diff_lines[1] );
1862         }
1863
1864         $diff = implode( "\n", $diff_lines );
1865
1866         return $diff;
1867 }
1868
1869 /**
1870  * A wrapper around the PHP function var_export().
1871  * Either print it or add it to the regular output ($wgOut).
1872  *
1873  * @param $var A PHP variable to dump.
1874  */
1875 function wfVarDump( $var ) {
1876         global $wgOut;
1877         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1878         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1879                 print $s;
1880         } else {
1881                 $wgOut->addHTML( $s );
1882         }
1883 }
1884
1885 /**
1886  * Provide a simple HTTP error.
1887  *
1888  * @param $code Int|String
1889  * @param $label String
1890  * @param $desc String
1891  */
1892 function wfHttpError( $code, $label, $desc ) {
1893         global $wgOut;
1894         $wgOut->disable();
1895         header( "HTTP/1.0 $code $label" );
1896         header( "Status: $code $label" );
1897         $wgOut->sendCacheControl();
1898
1899         header( 'Content-type: text/html; charset=utf-8' );
1900         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1901                 '<html><head><title>' .
1902                 htmlspecialchars( $label ) .
1903                 '</title></head><body><h1>' .
1904                 htmlspecialchars( $label ) .
1905                 '</h1><p>' .
1906                 nl2br( htmlspecialchars( $desc ) ) .
1907                 "</p></body></html>\n";
1908 }
1909
1910 /**
1911  * Clear away any user-level output buffers, discarding contents.
1912  *
1913  * Suitable for 'starting afresh', for instance when streaming
1914  * relatively large amounts of data without buffering, or wanting to
1915  * output image files without ob_gzhandler's compression.
1916  *
1917  * The optional $resetGzipEncoding parameter controls suppression of
1918  * the Content-Encoding header sent by ob_gzhandler; by default it
1919  * is left. See comments for wfClearOutputBuffers() for why it would
1920  * be used.
1921  *
1922  * Note that some PHP configuration options may add output buffer
1923  * layers which cannot be removed; these are left in place.
1924  *
1925  * @param $resetGzipEncoding Bool
1926  */
1927 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1928         if( $resetGzipEncoding ) {
1929                 // Suppress Content-Encoding and Content-Length
1930                 // headers from 1.10+s wfOutputHandler
1931                 global $wgDisableOutputCompression;
1932                 $wgDisableOutputCompression = true;
1933         }
1934         while( $status = ob_get_status() ) {
1935                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1936                         // Probably from zlib.output_compression or other
1937                         // PHP-internal setting which can't be removed.
1938                         //
1939                         // Give up, and hope the result doesn't break
1940                         // output behavior.
1941                         break;
1942                 }
1943                 if( !ob_end_clean() ) {
1944                         // Could not remove output buffer handler; abort now
1945                         // to avoid getting in some kind of infinite loop.
1946                         break;
1947                 }
1948                 if( $resetGzipEncoding ) {
1949                         if( $status['name'] == 'ob_gzhandler' ) {
1950                                 // Reset the 'Content-Encoding' field set by this handler
1951                                 // so we can start fresh.
1952                                 if ( function_exists( 'header_remove' ) ) {
1953                                         // Available since PHP 5.3.0
1954                                         header_remove( 'Content-Encoding' );
1955                                 } else {
1956                                         // We need to provide a valid content-coding. See bug 28069
1957                                         header( 'Content-Encoding: identity' );
1958                                 }
1959                                 break;
1960                         }
1961                 }
1962         }
1963 }
1964
1965 /**
1966  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1967  *
1968  * Clear away output buffers, but keep the Content-Encoding header
1969  * produced by ob_gzhandler, if any.
1970  *
1971  * This should be used for HTTP 304 responses, where you need to
1972  * preserve the Content-Encoding header of the real result, but
1973  * also need to suppress the output of ob_gzhandler to keep to spec
1974  * and avoid breaking Firefox in rare cases where the headers and
1975  * body are broken over two packets.
1976  */
1977 function wfClearOutputBuffers() {
1978         wfResetOutputBuffers( false );
1979 }
1980
1981 /**
1982  * Converts an Accept-* header into an array mapping string values to quality
1983  * factors
1984  *
1985  * @param $accept String
1986  * @param $def String default
1987  * @return Array
1988  */
1989 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
1990         # No arg means accept anything (per HTTP spec)
1991         if( !$accept ) {
1992                 return array( $def => 1.0 );
1993         }
1994
1995         $prefs = array();
1996
1997         $parts = explode( ',', $accept );
1998
1999         foreach( $parts as $part ) {
2000                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2001                 $values = explode( ';', trim( $part ) );
2002                 $match = array();
2003                 if ( count( $values ) == 1 ) {
2004                         $prefs[$values[0]] = 1.0;
2005                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2006                         $prefs[$values[0]] = floatval( $match[1] );
2007                 }
2008         }
2009
2010         return $prefs;
2011 }
2012
2013 /**
2014  * Checks if a given MIME type matches any of the keys in the given
2015  * array. Basic wildcards are accepted in the array keys.
2016  *
2017  * Returns the matching MIME type (or wildcard) if a match, otherwise
2018  * NULL if no match.
2019  *
2020  * @param $type String
2021  * @param $avail Array
2022  * @return string
2023  * @private
2024  */
2025 function mimeTypeMatch( $type, $avail ) {
2026         if( array_key_exists( $type, $avail ) ) {
2027                 return $type;
2028         } else {
2029                 $parts = explode( '/', $type );
2030                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2031                         return $parts[0] . '/*';
2032                 } elseif( array_key_exists( '*/*', $avail ) ) {
2033                         return '*/*';
2034                 } else {
2035                         return null;
2036                 }
2037         }
2038 }
2039
2040 /**
2041  * Returns the 'best' match between a client's requested internet media types
2042  * and the server's list of available types. Each list should be an associative
2043  * array of type to preference (preference is a float between 0.0 and 1.0).
2044  * Wildcards in the types are acceptable.
2045  *
2046  * @param $cprefs Array: client's acceptable type list
2047  * @param $sprefs Array: server's offered types
2048  * @return string
2049  *
2050  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2051  * XXX: generalize to negotiate other stuff
2052  */
2053 function wfNegotiateType( $cprefs, $sprefs ) {
2054         $combine = array();
2055
2056         foreach( array_keys($sprefs) as $type ) {
2057                 $parts = explode( '/', $type );
2058                 if( $parts[1] != '*' ) {
2059                         $ckey = mimeTypeMatch( $type, $cprefs );
2060                         if( $ckey ) {
2061                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2062                         }
2063                 }
2064         }
2065
2066         foreach( array_keys( $cprefs ) as $type ) {
2067                 $parts = explode( '/', $type );
2068                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2069                         $skey = mimeTypeMatch( $type, $sprefs );
2070                         if( $skey ) {
2071                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2072                         }
2073                 }
2074         }
2075
2076         $bestq = 0;
2077         $besttype = null;
2078
2079         foreach( array_keys( $combine ) as $type ) {
2080                 if( $combine[$type] > $bestq ) {
2081                         $besttype = $type;
2082                         $bestq = $combine[$type];
2083                 }
2084         }
2085
2086         return $besttype;
2087 }
2088
2089 /**
2090  * Reference-counted warning suppression
2091  *
2092  * @param $end Bool
2093  */
2094 function wfSuppressWarnings( $end = false ) {
2095         static $suppressCount = 0;
2096         static $originalLevel = false;
2097
2098         if ( $end ) {
2099                 if ( $suppressCount ) {
2100                         --$suppressCount;
2101                         if ( !$suppressCount ) {
2102                                 error_reporting( $originalLevel );
2103                         }
2104                 }
2105         } else {
2106                 if ( !$suppressCount ) {
2107                         // E_DEPRECATED is undefined in PHP 5.2
2108                         if( !defined( 'E_DEPRECATED' ) ){
2109                                 define( 'E_DEPRECATED', 8192 );
2110                         }
2111                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2112                 }
2113                 ++$suppressCount;
2114         }
2115 }
2116
2117 /**
2118  * Restore error level to previous value
2119  */
2120 function wfRestoreWarnings() {
2121         wfSuppressWarnings( true );
2122 }
2123
2124 # Autodetect, convert and provide timestamps of various types
2125
2126 /**
2127  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2128  */
2129 define( 'TS_UNIX', 0 );
2130
2131 /**
2132  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2133  */
2134 define( 'TS_MW', 1 );
2135
2136 /**
2137  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2138  */
2139 define( 'TS_DB', 2 );
2140
2141 /**
2142  * RFC 2822 format, for E-mail and HTTP headers
2143  */
2144 define( 'TS_RFC2822', 3 );
2145
2146 /**
2147  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2148  *
2149  * This is used by Special:Export
2150  */
2151 define( 'TS_ISO_8601', 4 );
2152
2153 /**
2154  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2155  *
2156  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2157  *       DateTime tag and page 36 for the DateTimeOriginal and
2158  *       DateTimeDigitized tags.
2159  */
2160 define( 'TS_EXIF', 5 );
2161
2162 /**
2163  * Oracle format time.
2164  */
2165 define( 'TS_ORACLE', 6 );
2166
2167 /**
2168  * Postgres format time.
2169  */
2170 define( 'TS_POSTGRES', 7 );
2171
2172 /**
2173  * DB2 format time
2174  */
2175 define( 'TS_DB2', 8 );
2176
2177 /**
2178  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2179  */
2180 define( 'TS_ISO_8601_BASIC', 9 );
2181
2182 /**
2183  * Get a timestamp string in one of various formats
2184  *
2185  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2186  *                    function will autodetect which format is supplied and act
2187  *                    accordingly.
2188  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2189  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2190  */
2191 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2192         $uts = 0;
2193         $da = array();
2194         $strtime = '';
2195
2196         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2197                 $uts = time();
2198                 $strtime = "@$uts";
2199         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2200                 # TS_DB
2201         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2202                 # TS_EXIF
2203         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2204                 # TS_MW
2205         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2206                 # TS_UNIX
2207                 $uts = $ts;
2208                 $strtime = "@$ts"; // Undocumented?
2209         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2210                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2211                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2212                                 str_replace( '+00:00', 'UTC', $ts ) );
2213         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2214                 # TS_ISO_8601
2215         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2216                 #TS_ISO_8601_BASIC
2217         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2218                 # TS_POSTGRES
2219         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2220                 # TS_POSTGRES
2221         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/',$ts,$da)) {
2222                 # TS_DB2
2223         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2224                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2225                                                         '[ \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
2226                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2227                 # The regex is a superset of rfc2822 for readability
2228                 $strtime = strtok( $ts, ';' );
2229         } 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 ) ) {
2230                 # TS_RFC850
2231                 $strtime = $ts;
2232         } 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 ) ) {
2233                 # asctime
2234                 $strtime = $ts;
2235         } else {
2236                 # Bogus value...
2237                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2238
2239                 return false;
2240         }
2241
2242         static $formats = array(
2243                 TS_UNIX => 'U',
2244                 TS_MW => 'YmdHis',
2245                 TS_DB => 'Y-m-d H:i:s',
2246                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2247                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2248                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2249                 TS_RFC2822 => 'D, d M Y H:i:s',
2250                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2251                 TS_POSTGRES => 'Y-m-d H:i:s',
2252                 TS_DB2 => 'Y-m-d H:i:s',
2253         );
2254
2255         if ( !isset( $formats[$outputtype] ) ) {
2256                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2257         }
2258
2259         if ( function_exists( "date_create" ) ) {
2260                 if ( count( $da ) ) {
2261                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2262                                 (int)$da[1], (int)$da[2], (int)$da[3],
2263                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2264
2265                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2266                 } elseif ( $strtime ) {
2267                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2268                 } else {
2269                         return false;
2270                 }
2271
2272                 if ( !$d ) {
2273                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2274                         return false;
2275                 }
2276
2277                 $output = $d->format( $formats[$outputtype] );
2278         } else {
2279                 if ( count( $da ) ) {
2280                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2281                         // We may want to handle that explicitly at some point
2282                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2283                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2284                 } elseif ( $strtime ) {
2285                         $uts = strtotime( $strtime );
2286                 }
2287
2288                 if ( $uts === false ) {
2289                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2290                         return false;
2291                 }
2292
2293                 if ( TS_UNIX == $outputtype ) {
2294                         return $uts;
2295                 }
2296                 $output = gmdate( $formats[$outputtype], $uts );
2297         }
2298
2299         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2300                 $output .= ' GMT';
2301         }
2302
2303         return $output;
2304 }
2305
2306 /**
2307  * Return a formatted timestamp, or null if input is null.
2308  * For dealing with nullable timestamp columns in the database.
2309  *
2310  * @param $outputtype Integer
2311  * @param $ts String
2312  * @return String
2313  */
2314 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2315         if( is_null( $ts ) ) {
2316                 return null;
2317         } else {
2318                 return wfTimestamp( $outputtype, $ts );
2319         }
2320 }
2321
2322 /**
2323  * Convenience function; returns MediaWiki timestamp for the present time.
2324  *
2325  * @return string
2326  */
2327 function wfTimestampNow() {
2328         # return NOW
2329         return wfTimestamp( TS_MW, time() );
2330 }
2331
2332 /**
2333  * Check if the operating system is Windows
2334  *
2335  * @return Bool: true if it's Windows, False otherwise.
2336  */
2337 function wfIsWindows() {
2338         static $isWindows = null;
2339         if ( $isWindows === null ) {
2340                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2341         }
2342         return $isWindows;
2343 }
2344
2345 /**
2346  * Check if we are running under HipHop
2347  *
2348  * @return Bool
2349  */
2350 function wfIsHipHop() {
2351         return function_exists( 'hphp_thread_set_warmup_enabled' );
2352 }
2353
2354 /**
2355  * Swap two variables
2356  *
2357  * @param $x Mixed
2358  * @param $y Mixed
2359  */
2360 function swap( &$x, &$y ) {
2361         $z = $x;
2362         $x = $y;
2363         $y = $z;
2364 }
2365
2366 /**
2367  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2368  * TEMP environment variables are then checked in sequence, and if none are set
2369  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2370  * or C:\Windows\Temp for Windows and hope for the best.
2371  * It is common to call it with tempnam().
2372  *
2373  * NOTE: When possible, use instead the tmpfile() function to create
2374  * temporary files to avoid race conditions on file creation, etc.
2375  *
2376  * @return String
2377  */
2378 function wfTempDir() {
2379         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2380                 $tmp = getenv( $var );
2381                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2382                         return $tmp;
2383                 }
2384         }
2385         if( function_exists( 'sys_get_temp_dir' ) ) {
2386                 return sys_get_temp_dir();
2387         }
2388         # Usual defaults
2389         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2390 }
2391
2392 /**
2393  * Make directory, and make all parent directories if they don't exist
2394  *
2395  * @param $dir String: full path to directory to create
2396  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2397  * @param $caller String: optional caller param for debugging.
2398  * @return bool
2399  */
2400 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2401         global $wgDirectoryMode;
2402
2403         if ( !is_null( $caller ) ) {
2404                 wfDebug( "$caller: called wfMkdirParents($dir)" );
2405         }
2406
2407         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2408                 return true;
2409         }
2410
2411         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2412
2413         if ( is_null( $mode ) ) {
2414                 $mode = $wgDirectoryMode;
2415         }
2416
2417         // Turn off the normal warning, we're doing our own below
2418         wfSuppressWarnings();
2419         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2420         wfRestoreWarnings();
2421
2422         if( !$ok ) {
2423                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2424                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2425         }
2426         return $ok;
2427 }
2428
2429 /**
2430  * Increment a statistics counter
2431  *
2432  * @param $key String
2433  * @param $count Int
2434  */
2435 function wfIncrStats( $key, $count = 1 ) {
2436         global $wgStatsMethod;
2437
2438         $count = intval( $count );
2439
2440         if( $wgStatsMethod == 'udp' ) {
2441                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2442                 static $socket;
2443
2444                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2445
2446                 if ( !$socket ) {
2447                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2448                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2449                         socket_sendto(
2450                                 $socket,
2451                                 $statline,
2452                                 strlen( $statline ),
2453                                 0,
2454                                 $wgUDPProfilerHost,
2455                                 $wgUDPProfilerPort
2456                         );
2457                 }
2458                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2459                 wfSuppressWarnings();
2460                 socket_sendto(
2461                         $socket,
2462                         $statline,
2463                         strlen( $statline ),
2464                         0,
2465                         $wgUDPProfilerHost,
2466                         $wgUDPProfilerPort
2467                 );
2468                 wfRestoreWarnings();
2469         } elseif( $wgStatsMethod == 'cache' ) {
2470                 global $wgMemc;
2471                 $key = wfMemcKey( 'stats', $key );
2472                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2473                         $wgMemc->add( $key, $count );
2474                 }
2475         } else {
2476                 // Disabled
2477         }
2478 }
2479
2480 /**
2481  * @param $nr Mixed: the number to format
2482  * @param $acc Integer: the number of digits after the decimal point, default 2
2483  * @param $round Boolean: whether or not to round the value, default true
2484  * @return float
2485  */
2486 function wfPercent( $nr, $acc = 2, $round = true ) {
2487         $ret = sprintf( "%.${acc}f", $nr );
2488         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2489 }
2490
2491 /**
2492  * Find out whether or not a mixed variable exists in a string
2493  *
2494  * @param $needle String
2495  * @param $str String
2496  * @param $insensitive Boolean
2497  * @return Boolean
2498  */
2499 function in_string( $needle, $str, $insensitive = false ) {
2500         $func = 'strpos';
2501         if( $insensitive ) $func = 'stripos';
2502
2503         return $func( $str, $needle ) !== false;
2504 }
2505
2506 /**
2507  * Make a list item, used by various special pages
2508  *
2509  * @param $page String Page link
2510  * @param $details String Text between brackets
2511  * @param $oppositedm Boolean   Add the direction mark opposite to your
2512  *                                                              language, to display text properly
2513  * @return String
2514  */
2515 function wfSpecialList( $page, $details, $oppositedm = true ) {
2516         global $wgLang;
2517         $dirmark = ( $oppositedm ? $wgLang->getDirMark( true ) : '' ) .
2518                 $wgLang->getDirMark();
2519         $details = $details ? $dirmark . "($details)" : '';
2520         return $page . $details;
2521 }
2522
2523 /**
2524  * Safety wrapper around ini_get() for boolean settings.
2525  * The values returned from ini_get() are pre-normalized for settings
2526  * set via php.ini or php_flag/php_admin_flag... but *not*
2527  * for those set via php_value/php_admin_value.
2528  *
2529  * It's fairly common for people to use php_value instead of php_flag,
2530  * which can leave you with an 'off' setting giving a false positive
2531  * for code that just takes the ini_get() return value as a boolean.
2532  *
2533  * To make things extra interesting, setting via php_value accepts
2534  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2535  * Unrecognized values go false... again opposite PHP's own coercion
2536  * from string to bool.
2537  *
2538  * Luckily, 'properly' set settings will always come back as '0' or '1',
2539  * so we only have to worry about them and the 'improper' settings.
2540  *
2541  * I frickin' hate PHP... :P
2542  *
2543  * @param $setting String
2544  * @return Bool
2545  */
2546 function wfIniGetBool( $setting ) {
2547         $val = ini_get( $setting );
2548         // 'on' and 'true' can't have whitespace around them, but '1' can.
2549         return strtolower( $val ) == 'on'
2550                 || strtolower( $val ) == 'true'
2551                 || strtolower( $val ) == 'yes'
2552                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2553 }
2554
2555 /**
2556  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2557  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2558  *
2559  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2560  *                          should be omitted
2561  * @param $fileName String Name of the library, if not $extension.suffix
2562  * @return Bool - Whether or not the extension is loaded
2563  */
2564 function wfDl( $extension, $fileName = null ) {
2565         if( extension_loaded( $extension ) ) {
2566                 return true;
2567         }
2568
2569         $canDl = false;
2570         $sapi = php_sapi_name();
2571         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2572                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2573         {
2574                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2575                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2576         }
2577
2578         if( $canDl ) {
2579                 $fileName = $fileName ? $fileName : $extension;
2580                 if( wfIsWindows() ) {
2581                         $fileName = 'php_' . $fileName;
2582                 }
2583                 wfSuppressWarnings();
2584                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2585                 wfRestoreWarnings();
2586         }
2587         return extension_loaded( $extension );
2588 }
2589
2590 /**
2591  * Execute a shell command, with time and memory limits mirrored from the PHP
2592  * configuration if supported.
2593  * @param $cmd String Command line, properly escaped for shell.
2594  * @param &$retval optional, will receive the program's exit code.
2595  *                 (non-zero is usually failure)
2596  * @param $environ Array optional environment variables which should be
2597  *                 added to the executed command environment.
2598  * @return collected stdout as a string (trailing newlines stripped)
2599  */
2600 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2601         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2602
2603         static $disabled;
2604         if ( is_null( $disabled ) ) {
2605                 $disabled = false;
2606                 if( wfIniGetBool( 'safe_mode' ) ) {
2607                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2608                         $disabled = 'safemode';
2609                 } else {
2610                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2611                         $functions = array_map( 'trim', $functions );
2612                         $functions = array_map( 'strtolower', $functions );
2613                         if ( in_array( 'passthru', $functions ) ) {
2614                                 wfDebug( "passthru is in disabled_functions\n" );
2615                                 $disabled = 'passthru';
2616                         }
2617                 }
2618         }
2619         if ( $disabled ) {
2620                 $retval = 1;
2621                 return $disabled == 'safemode' ?
2622                         'Unable to run external programs in safe mode.' :
2623                         'Unable to run external programs, passthru() is disabled.';
2624         }
2625
2626         wfInitShellLocale();
2627
2628         $envcmd = '';
2629         foreach( $environ as $k => $v ) {
2630                 if ( wfIsWindows() ) {
2631                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2632                          * appear in the environment variable, so we must use carat escaping as documented in
2633                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2634                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2635                          * are listed there but doesn't appear to need it.
2636                          */
2637                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2638                 } else {
2639                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2640                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2641                          */
2642                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2643                 }
2644         }
2645         $cmd = $envcmd . $cmd;
2646
2647         if ( wfIsWindows() ) {
2648                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2649                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2650                 {
2651                         # Hack to work around PHP's flawed invocation of cmd.exe
2652                         # http://news.php.net/php.internals/21796
2653                         # Windows 9x doesn't accept any kind of quotes
2654                         $cmd = '"' . $cmd . '"';
2655                 }
2656         } elseif ( php_uname( 's' ) == 'Linux' ) {
2657                 $time = intval( $wgMaxShellTime );
2658                 $mem = intval( $wgMaxShellMemory );
2659                 $filesize = intval( $wgMaxShellFileSize );
2660
2661                 if ( $time > 0 && $mem > 0 ) {
2662                         $script = "$IP/bin/ulimit4.sh";
2663                         if ( is_executable( $script ) ) {
2664                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2665                         }
2666                 }
2667         }
2668         wfDebug( "wfShellExec: $cmd\n" );
2669
2670         $retval = 1; // error by default?
2671         ob_start();
2672         passthru( $cmd, $retval );
2673         $output = ob_get_contents();
2674         ob_end_clean();
2675
2676         if ( $retval == 127 ) {
2677                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2678         }
2679         return $output;
2680 }
2681
2682 /**
2683  * Workaround for http://bugs.php.net/bug.php?id=45132
2684  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2685  */
2686 function wfInitShellLocale() {
2687         static $done = false;
2688         if ( $done ) {
2689                 return;
2690         }
2691         $done = true;
2692         global $wgShellLocale;
2693         if ( !wfIniGetBool( 'safe_mode' ) ) {
2694                 putenv( "LC_CTYPE=$wgShellLocale" );
2695                 setlocale( LC_CTYPE, $wgShellLocale );
2696         }
2697 }
2698
2699 /**
2700  * This function works like "use VERSION" in Perl, the program will die with a
2701  * backtrace if the current version of PHP is less than the version provided
2702  *
2703  * This is useful for extensions which due to their nature are not kept in sync
2704  * with releases, and might depend on other versions of PHP than the main code
2705  *
2706  * Note: PHP might die due to parsing errors in some cases before it ever
2707  *       manages to call this function, such is life
2708  *
2709  * @see perldoc -f use
2710  *
2711  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2712  *                 a float
2713  */
2714 function wfUsePHP( $req_ver ) {
2715         $php_ver = PHP_VERSION;
2716
2717         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2718                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2719         }
2720 }
2721
2722 /**
2723  * This function works like "use VERSION" in Perl except it checks the version
2724  * of MediaWiki, the program will die with a backtrace if the current version
2725  * of MediaWiki is less than the version provided.
2726  *
2727  * This is useful for extensions which due to their nature are not kept in sync
2728  * with releases
2729  *
2730  * @see perldoc -f use
2731  *
2732  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2733  *                 a float
2734  */
2735 function wfUseMW( $req_ver ) {
2736         global $wgVersion;
2737
2738         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2739                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2740         }
2741 }
2742
2743 /**
2744  * Return the final portion of a pathname.
2745  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2746  * http://bugs.php.net/bug.php?id=33898
2747  *
2748  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2749  * We'll consider it so always, as we don't want \s in our Unix paths either.
2750  *
2751  * @param $path String
2752  * @param $suffix String: to remove if present
2753  * @return String
2754  */
2755 function wfBaseName( $path, $suffix = '' ) {
2756         $encSuffix = ( $suffix == '' )
2757                 ? ''
2758                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2759         $matches = array();
2760         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2761                 return $matches[1];
2762         } else {
2763                 return '';
2764         }
2765 }
2766
2767 /**
2768  * Generate a relative path name to the given file.
2769  * May explode on non-matching case-insensitive paths,
2770  * funky symlinks, etc.
2771  *
2772  * @param $path String: absolute destination path including target filename
2773  * @param $from String: Absolute source path, directory only
2774  * @return String
2775  */
2776 function wfRelativePath( $path, $from ) {
2777         // Normalize mixed input on Windows...
2778         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2779         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2780
2781         // Trim trailing slashes -- fix for drive root
2782         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2783         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2784
2785         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2786         $against = explode( DIRECTORY_SEPARATOR, $from );
2787
2788         if( $pieces[0] !== $against[0] ) {
2789                 // Non-matching Windows drive letters?
2790                 // Return a full path.
2791                 return $path;
2792         }
2793
2794         // Trim off common prefix
2795         while( count( $pieces ) && count( $against )
2796                 && $pieces[0] == $against[0] ) {
2797                 array_shift( $pieces );
2798                 array_shift( $against );
2799         }
2800
2801         // relative dots to bump us to the parent
2802         while( count( $against ) ) {
2803                 array_unshift( $pieces, '..' );
2804                 array_shift( $against );
2805         }
2806
2807         array_push( $pieces, wfBaseName( $path ) );
2808
2809         return implode( DIRECTORY_SEPARATOR, $pieces );
2810 }
2811
2812 /**
2813  * Do any deferred updates and clear the list
2814  *
2815  * @param $commit String: set to 'commit' to commit after every update to
2816  *                prevent lock contention
2817  */
2818 function wfDoUpdates( $commit = '' ) {
2819         global $wgDeferredUpdateList;
2820
2821         wfProfileIn( __METHOD__ );
2822
2823         // No need to get master connections in case of empty updates array
2824         if ( !count( $wgDeferredUpdateList ) ) {
2825                 wfProfileOut( __METHOD__ );
2826                 return;
2827         }
2828
2829         $doCommit = $commit == 'commit';
2830         if ( $doCommit ) {
2831                 $dbw = wfGetDB( DB_MASTER );
2832         }
2833
2834         foreach ( $wgDeferredUpdateList as $update ) {
2835                 $update->doUpdate();
2836
2837                 if ( $doCommit && $dbw->trxLevel() ) {
2838                         $dbw->commit();
2839                 }
2840         }
2841
2842         $wgDeferredUpdateList = array();
2843         wfProfileOut( __METHOD__ );
2844 }
2845
2846 /**
2847  * Convert an arbitrarily-long digit string from one numeric base
2848  * to another, optionally zero-padding to a minimum column width.
2849  *
2850  * Supports base 2 through 36; digit values 10-36 are represented
2851  * as lowercase letters a-z. Input is case-insensitive.
2852  *
2853  * @param $input String: of digits
2854  * @param $sourceBase Integer: 2-36
2855  * @param $destBase Integer: 2-36
2856  * @param $pad Integer: 1 or greater
2857  * @param $lowercase Boolean
2858  * @return String or false on invalid input
2859  */
2860 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2861         $input = strval( $input );
2862         if( $sourceBase < 2 ||
2863                 $sourceBase > 36 ||
2864                 $destBase < 2 ||
2865                 $destBase > 36 ||
2866                 $pad < 1 ||
2867                 $sourceBase != intval( $sourceBase ) ||
2868                 $destBase != intval( $destBase ) ||
2869                 $pad != intval( $pad ) ||
2870                 !is_string( $input ) ||
2871                 $input == '' ) {
2872                 return false;
2873         }
2874         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2875         $inDigits = array();
2876         $outChars = '';
2877
2878         // Decode and validate input string
2879         $input = strtolower( $input );
2880         for( $i = 0; $i < strlen( $input ); $i++ ) {
2881                 $n = strpos( $digitChars, $input[$i] );
2882                 if( $n === false || $n > $sourceBase ) {
2883                         return false;
2884                 }
2885                 $inDigits[] = $n;
2886         }
2887
2888         // Iterate over the input, modulo-ing out an output digit
2889         // at a time until input is gone.
2890         while( count( $inDigits ) ) {
2891                 $work = 0;
2892                 $workDigits = array();
2893
2894                 // Long division...
2895                 foreach( $inDigits as $digit ) {
2896                         $work *= $sourceBase;
2897                         $work += $digit;
2898
2899                         if( $work < $destBase ) {
2900                                 // Gonna need to pull another digit.
2901                                 if( count( $workDigits ) ) {
2902                                         // Avoid zero-padding; this lets us find
2903                                         // the end of the input very easily when
2904                                         // length drops to zero.
2905                                         $workDigits[] = 0;
2906                                 }
2907                         } else {
2908                                 // Finally! Actual division!
2909                                 $workDigits[] = intval( $work / $destBase );
2910
2911                                 // Isn't it annoying that most programming languages
2912                                 // don't have a single divide-and-remainder operator,
2913                                 // even though the CPU implements it that way?
2914                                 $work = $work % $destBase;
2915                         }
2916                 }
2917
2918                 // All that division leaves us with a remainder,
2919                 // which is conveniently our next output digit.
2920                 $outChars .= $digitChars[$work];
2921
2922                 // And we continue!
2923                 $inDigits = $workDigits;
2924         }
2925
2926         while( strlen( $outChars ) < $pad ) {
2927                 $outChars .= '0';
2928         }
2929
2930         return strrev( $outChars );
2931 }
2932
2933 /**
2934  * Create an object with a given name and an array of construct parameters
2935  *
2936  * @param $name String
2937  * @param $p Array: parameters
2938  * @deprecated since 1.18, warnings in 1.19, removal in 1.20
2939  */
2940 function wfCreateObject( $name, $p ) {
2941         wfDeprecated( __FUNCTION__ );
2942         return MWFunction::newObj( $name, $p );
2943 }
2944
2945 function wfHttpOnlySafe() {
2946         global $wgHttpOnlyBlacklist;
2947
2948         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
2949                 foreach( $wgHttpOnlyBlacklist as $regex ) {
2950                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
2951                                 return false;
2952                         }
2953                 }
2954         }
2955
2956         return true;
2957 }
2958
2959 /**
2960  * Initialise php session
2961  *
2962  * @param $sessionId Bool
2963  */
2964 function wfSetupSession( $sessionId = false ) {
2965         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
2966                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
2967         if( $wgSessionsInMemcached ) {
2968                 if ( !defined( 'MW_COMPILED' ) ) {
2969                         global $IP;
2970                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
2971                 }
2972                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
2973                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
2974
2975                 // It's necessary to register a shutdown function to call session_write_close(),
2976                 // because by the time the request shutdown function for the session module is
2977                 // called, $wgMemc has already been destroyed. Shutdown functions registered
2978                 // this way are called before object destruction.
2979                 register_shutdown_function( 'memsess_write_close' );
2980         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
2981                 # Only set this if $wgSessionHandler isn't null and session.save_handler
2982                 # hasn't already been set to the desired value (that causes errors)
2983                 ini_set( 'session.save_handler', $wgSessionHandler );
2984         }
2985         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
2986         wfDebugLog( 'cookie',
2987                 'session_set_cookie_params: "' . implode( '", "',
2988                         array(
2989                                 0,
2990                                 $wgCookiePath,
2991                                 $wgCookieDomain,
2992                                 $wgCookieSecure,
2993                                 $httpOnlySafe ) ) . '"' );
2994         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
2995         session_cache_limiter( 'private, must-revalidate' );
2996         if ( $sessionId ) {
2997                 session_id( $sessionId );
2998         }
2999         wfSuppressWarnings();
3000         session_start();
3001         wfRestoreWarnings();
3002 }
3003
3004 /**
3005  * Get an object from the precompiled serialized directory
3006  *
3007  * @param $name String
3008  * @return Mixed: the variable on success, false on failure
3009  */
3010 function wfGetPrecompiledData( $name ) {
3011         global $IP;
3012
3013         $file = "$IP/serialized/$name";
3014         if ( file_exists( $file ) ) {
3015                 $blob = file_get_contents( $file );
3016                 if ( $blob ) {
3017                         return unserialize( $blob );
3018                 }
3019         }
3020         return false;
3021 }
3022
3023 /**
3024  * Get a cache key
3025  *
3026  * @param varargs
3027  * @return String
3028  */
3029 function wfMemcKey( /*... */ ) {
3030         $args = func_get_args();
3031         $key = wfWikiID() . ':' . implode( ':', $args );
3032         $key = str_replace( ' ', '_', $key );
3033         return $key;
3034 }
3035
3036 /**
3037  * Get a cache key for a foreign DB
3038  *
3039  * @param $db String
3040  * @param $prefix String
3041  * @param varargs String
3042  * @return String
3043  */
3044 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3045         $args = array_slice( func_get_args(), 2 );
3046         if ( $prefix ) {
3047                 $key = "$db-$prefix:" . implode( ':', $args );
3048         } else {
3049                 $key = $db . ':' . implode( ':', $args );
3050         }
3051         return $key;
3052 }
3053
3054 /**
3055  * Get an ASCII string identifying this wiki
3056  * This is used as a prefix in memcached keys
3057  *
3058  * @return String
3059  */
3060 function wfWikiID() {
3061         global $wgDBprefix, $wgDBname;
3062         if ( $wgDBprefix ) {
3063                 return "$wgDBname-$wgDBprefix";
3064         } else {
3065                 return $wgDBname;
3066         }
3067 }
3068
3069 /**
3070  * Split a wiki ID into DB name and table prefix
3071  *
3072  * @param $wiki String
3073  * @param $bits String
3074  */
3075 function wfSplitWikiID( $wiki ) {
3076         $bits = explode( '-', $wiki, 2 );
3077         if ( count( $bits ) < 2 ) {
3078                 $bits[] = '';
3079         }
3080         return $bits;
3081 }
3082
3083 /**
3084  * Get a Database object.
3085  *
3086  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3087  *            master (for write queries), DB_SLAVE for potentially lagged read
3088  *            queries, or an integer >= 0 for a particular server.
3089  *
3090  * @param $groups Mixed: query groups. An array of group names that this query
3091  *                belongs to. May contain a single string if the query is only
3092  *                in one group.
3093  *
3094  * @param $wiki String: the wiki ID, or false for the current wiki
3095  *
3096  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3097  * will always return the same object, unless the underlying connection or load
3098  * balancer is manually destroyed.
3099  *
3100  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3101  * updater to ensure that a proper database is being updated.
3102  *
3103  * @return DatabaseBase
3104  */
3105 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3106         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3107 }
3108
3109 /**
3110  * Get a load balancer object.
3111  *
3112  * @param $wiki String: wiki ID, or false for the current wiki
3113  * @return LoadBalancer
3114  */
3115 function wfGetLB( $wiki = false ) {
3116         return wfGetLBFactory()->getMainLB( $wiki );
3117 }
3118
3119 /**
3120  * Get the load balancer factory object
3121  *
3122  * @return LBFactory
3123  */
3124 function &wfGetLBFactory() {
3125         return LBFactory::singleton();
3126 }
3127
3128 /**
3129  * Find a file.
3130  * Shortcut for RepoGroup::singleton()->findFile()
3131  *
3132  * @param $title String or Title object
3133  * @param $options Associative array of options:
3134  *     time:           requested time for an archived image, or false for the
3135  *                     current version. An image object will be returned which was
3136  *                     created at the specified time.
3137  *
3138  *     ignoreRedirect: If true, do not follow file redirects
3139  *
3140  *     private:        If true, return restricted (deleted) files if the current
3141  *                     user is allowed to view them. Otherwise, such files will not
3142  *                     be found.
3143  *
3144  *     bypassCache:    If true, do not use the process-local cache of File objects
3145  *
3146  * @return File, or false if the file does not exist
3147  */
3148 function wfFindFile( $title, $options = array() ) {
3149         return RepoGroup::singleton()->findFile( $title, $options );
3150 }
3151
3152 /**
3153  * Get an object referring to a locally registered file.
3154  * Returns a valid placeholder object if the file does not exist.
3155  *
3156  * @param $title Title or String
3157  * @return File, or null if passed an invalid Title
3158  */
3159 function wfLocalFile( $title ) {
3160         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3161 }
3162
3163 /**
3164  * Should low-performance queries be disabled?
3165  *
3166  * @return Boolean
3167  * @codeCoverageIgnore
3168  */
3169 function wfQueriesMustScale() {
3170         global $wgMiserMode;
3171         return $wgMiserMode
3172                 || ( SiteStats::pages() > 100000
3173                 && SiteStats::edits() > 1000000
3174                 && SiteStats::users() > 10000 );
3175 }
3176
3177 /**
3178  * Get the path to a specified script file, respecting file
3179  * extensions; this is a wrapper around $wgScriptExtension etc.
3180  *
3181  * @param $script String: script filename, sans extension
3182  * @return String
3183  */
3184 function wfScript( $script = 'index' ) {
3185         global $wgScriptPath, $wgScriptExtension;
3186         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3187 }
3188
3189 /**
3190  * Get the script URL.
3191  *
3192  * @return script URL
3193  */
3194 function wfGetScriptUrl() {
3195         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3196                 #
3197                 # as it was called, minus the query string.
3198                 #
3199                 # Some sites use Apache rewrite rules to handle subdomains,
3200                 # and have PHP set up in a weird way that causes PHP_SELF
3201                 # to contain the rewritten URL instead of the one that the
3202                 # outside world sees.
3203                 #
3204                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3205                 # provides containing the "before" URL.
3206                 return $_SERVER['SCRIPT_NAME'];
3207         } else {
3208                 return $_SERVER['URL'];
3209         }
3210 }
3211
3212 /**
3213  * Convenience function converts boolean values into "true"
3214  * or "false" (string) values
3215  *
3216  * @param $value Boolean
3217  * @return String
3218  */
3219 function wfBoolToStr( $value ) {
3220         return $value ? 'true' : 'false';
3221 }
3222
3223 /**
3224  * Load an extension messages file
3225  *
3226  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3227  * @codeCoverageIgnore
3228  */
3229 function wfLoadExtensionMessages() {
3230         wfDeprecated( __FUNCTION__ );
3231 }
3232
3233 /**
3234  * Get a platform-independent path to the null file, e.g. /dev/null
3235  *
3236  * @return string
3237  */
3238 function wfGetNull() {
3239         return wfIsWindows()
3240                 ? 'NUL'
3241                 : '/dev/null';
3242 }
3243
3244 /**
3245  * Throws a warning that $function is deprecated
3246  *
3247  * @param $function String
3248  * @return null
3249  */
3250 function wfDeprecated( $function ) {
3251         static $functionsWarned = array();
3252         if ( !isset( $functionsWarned[$function] ) ) {
3253                 $functionsWarned[$function] = true;
3254                 wfWarn( "Use of $function is deprecated.", 2 );
3255         }
3256 }
3257
3258 /**
3259  * Send a warning either to the debug log or in a PHP error depending on
3260  * $wgDevelopmentWarnings
3261  *
3262  * @param $msg String: message to send
3263  * @param $callerOffset Integer: number of items to go back in the backtrace to
3264  *        find the correct caller (1 = function calling wfWarn, ...)
3265  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3266  *        is true
3267  */
3268 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3269         global $wgDevelopmentWarnings;
3270
3271         $callers = wfDebugBacktrace();
3272         if ( isset( $callers[$callerOffset + 1] ) ) {
3273                 $callerfunc = $callers[$callerOffset + 1];
3274                 $callerfile = $callers[$callerOffset];
3275                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3276                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3277                 } else {
3278                         $file = '(internal function)';
3279                 }
3280                 $func = '';
3281                 if ( isset( $callerfunc['class'] ) ) {
3282                         $func .= $callerfunc['class'] . '::';
3283                 }
3284                 if ( isset( $callerfunc['function'] ) ) {
3285                         $func .= $callerfunc['function'];
3286                 }
3287                 $msg .= " [Called from $func in $file]";
3288         }
3289
3290         if ( $wgDevelopmentWarnings ) {
3291                 trigger_error( $msg, $level );
3292         } else {
3293                 wfDebug( "$msg\n" );
3294         }
3295 }
3296
3297 /**
3298  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3299  * and waiting for it to go down, this waits for the slaves to catch up to the
3300  * master position. Use this when updating very large numbers of rows, as
3301  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3302  * a no-op if there are no slaves.
3303  *
3304  * @param $maxLag Integer (deprecated)
3305  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3306  * @return null
3307  */
3308 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3309         $lb = wfGetLB( $wiki );
3310         // bug 27975 - Don't try to wait for slaves if there are none
3311         // Prevents permission error when getting master position
3312         if ( $lb->getServerCount() > 1 ) {
3313                 $dbw = $lb->getConnection( DB_MASTER );
3314                 $pos = $dbw->getMasterPos();
3315                 $lb->waitForAll( $pos );
3316         }
3317 }
3318
3319 /**
3320  * Used to be used for outputting text in the installer/updater
3321  * @deprecated since 1.18, warnings in 1.19, remove in 1.20
3322  */
3323 function wfOut( $s ) {
3324         wfDeprecated( __METHOD__ );
3325         global $wgCommandLineMode;
3326         if ( $wgCommandLineMode ) {
3327                 echo $s;
3328         } else {
3329                 echo htmlspecialchars( $s );
3330         }
3331         flush();
3332 }
3333
3334 /**
3335  * Count down from $n to zero on the terminal, with a one-second pause
3336  * between showing each number. For use in command-line scripts.
3337  * @codeCoverageIgnore
3338  */
3339 function wfCountDown( $n ) {
3340         for ( $i = $n; $i >= 0; $i-- ) {
3341                 if ( $i != $n ) {
3342                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3343                 }
3344                 echo $i;
3345                 flush();
3346                 if ( $i ) {
3347                         sleep( 1 );
3348                 }
3349         }
3350         echo "\n";
3351 }
3352
3353 /**
3354  * Generate a random 32-character hexadecimal token.
3355  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3356  *              characters before hashing.
3357  * @return string
3358  * @codeCoverageIgnore
3359  */
3360 function wfGenerateToken( $salt = '' ) {
3361         $salt = serialize( $salt );
3362         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3363 }
3364
3365 /**
3366  * Replace all invalid characters with -
3367  *
3368  * @param $name Mixed: filename to process
3369  * @return String
3370  */
3371 function wfStripIllegalFilenameChars( $name ) {
3372         global $wgIllegalFileChars;
3373         $name = wfBaseName( $name );
3374         $name = preg_replace(
3375                 "/[^" . Title::legalChars() . "]" .
3376                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3377                         "/",
3378                 '-',
3379                 $name
3380         );
3381         return $name;
3382 }
3383
3384 /**
3385  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3386  *
3387  * @return Integer value memory was set to.
3388  */
3389 function wfMemoryLimit() {
3390         global $wgMemoryLimit;
3391         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3392         if( $memlimit != -1 ) {
3393                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3394                 if( $conflimit == -1 ) {
3395                         wfDebug( "Removing PHP's memory limit\n" );
3396                         wfSuppressWarnings();
3397                         ini_set( 'memory_limit', $conflimit );
3398                         wfRestoreWarnings();
3399                         return $conflimit;
3400                 } elseif ( $conflimit > $memlimit ) {
3401                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3402                         wfSuppressWarnings();
3403                         ini_set( 'memory_limit', $conflimit );
3404                         wfRestoreWarnings();
3405                         return $conflimit;
3406                 }
3407         }
3408         return $memlimit;
3409 }
3410
3411 /**
3412  * Converts shorthand byte notation to integer form
3413  *
3414  * @param $string String
3415  * @return Integer
3416  */
3417 function wfShorthandToInteger( $string = '' ) {
3418         $string = trim( $string );
3419         if( $string === '' ) {
3420                 return -1;
3421         }
3422         $last = $string[strlen( $string ) - 1];
3423         $val = intval( $string );
3424         switch( $last ) {
3425                 case 'g':
3426                 case 'G':
3427                         $val *= 1024;
3428                         // break intentionally missing
3429                 case 'm':
3430                 case 'M':
3431                         $val *= 1024;
3432                         // break intentionally missing
3433                 case 'k':
3434                 case 'K':
3435                         $val *= 1024;
3436         }
3437
3438         return $val;
3439 }
3440
3441 /**
3442  * Get the normalised IETF language tag
3443  * See unit test for examples.
3444  *
3445  * @param $code String: The language code.
3446  * @return $langCode String: The language code which complying with BCP 47 standards.
3447  */
3448 function wfBCP47( $code ) {
3449         $codeSegment = explode( '-', $code );
3450         $codeBCP = array();
3451         foreach ( $codeSegment as $segNo => $seg ) {
3452                 if ( count( $codeSegment ) > 0 ) {
3453                         // when previous segment is x, it is a private segment and should be lc
3454                         if( $segNo > 0 && strtolower( $codeSegment[($segNo - 1)] ) == 'x') {
3455                                 $codeBCP[$segNo] = strtolower( $seg );
3456                         // ISO 3166 country code
3457                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3458                                 $codeBCP[$segNo] = strtoupper( $seg );
3459                         // ISO 15924 script code
3460                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3461                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3462                         // Use lowercase for other cases
3463                         } else {
3464                                 $codeBCP[$segNo] = strtolower( $seg );
3465                         }
3466                 } else {
3467                 // Use lowercase for single segment
3468                         $codeBCP[$segNo] = strtolower( $seg );
3469                 }
3470         }
3471         $langCode = implode( '-', $codeBCP );
3472         return $langCode;
3473 }
3474
3475 /**
3476  * Get a cache object.
3477  *
3478  * @param $inputType integer Cache type, one the the CACHE_* constants.
3479  * @return BagOStuff
3480  */
3481 function wfGetCache( $inputType ) {
3482         return ObjectCache::getInstance( $inputType );
3483 }
3484
3485 /**
3486  * Get the main cache object
3487  *
3488  * @return BagOStuff
3489  */
3490 function wfGetMainCache() {
3491         global $wgMainCacheType;
3492         return ObjectCache::getInstance( $wgMainCacheType );
3493 }
3494
3495 /**
3496  * Get the cache object used by the message cache
3497  *
3498  * @return BagOStuff
3499  */
3500 function wfGetMessageCacheStorage() {
3501         global $wgMessageCacheType;
3502         return ObjectCache::getInstance( $wgMessageCacheType );
3503 }
3504
3505 /**
3506  * Get the cache object used by the parser cache
3507  *
3508  * @return BagOStuff
3509  */
3510 function wfGetParserCacheStorage() {
3511         global $wgParserCacheType;
3512         return ObjectCache::getInstance( $wgParserCacheType );
3513 }
3514
3515 /**
3516  * Call hook functions defined in $wgHooks
3517  *
3518  * @param $event String: event name
3519  * @param $args Array: parameters passed to hook functions
3520  * @return Boolean
3521  */
3522 function wfRunHooks( $event, $args = array() ) {
3523         return Hooks::run( $event, $args );
3524 }