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  * Use this instead of $wgContLang, when working with user interface.
 914  * User interface is currently hard coded according to wiki content language
 915  * in many ways, especially regarding to text direction. There is lots stuff
 916  * to fix, hence this function to keep the old behaviour unless the global
 917  * $wgBetterDirectionality is enabled (or removed when everything works).
 918  *
 919  * @return Language
 920  */
 921 function wfUILang() {
 922         global $wgBetterDirectionality;
 923         return wfGetLangObj( !$wgBetterDirectionality );
 924 }
 925
 926 /**
 927  * This is the new function for getting translated interface messages.
 928  * See the Message class for documentation how to use them.
 929  * The intention is that this function replaces all old wfMsg* functions.
 930  * @param $key \string Message key.
 931  * Varargs: normal message parameters.
 932  * @return Message
 933  * @since 1.17
 934  */
 935 function wfMessage( $key /*...*/) {
 936         $params = func_get_args();
 937         array_shift( $params );
 938         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 939                 $params = $params[0];
 940         }
 941         return new Message( $key, $params );
 942 }
 943
 944 /**
 945  * This function accepts multiple message keys and returns a message instance
 946  * for the first message which is non-empty. If all messages are empty then an
 947  * instance of the first message key is returned.
 948  * @param varargs: message keys
 949  * @return Message
 950  * @since 1.18
 951  */
 952 function wfMessageFallback( /*...*/ ) {
 953         $args = func_get_args();
 954         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
 955 }
 956
 957 /**
 958  * Get a message from anywhere, for the current user language.
 959  *
 960  * Use wfMsgForContent() instead if the message should NOT
 961  * change depending on the user preferences.
 962  *
 963  * @param $key String: lookup key for the message, usually
 964  *    defined in languages/Language.php
 965  *
 966  * Parameters to the message, which can be used to insert variable text into
 967  * it, can be passed to this function in the following formats:
 968  * - One per argument, starting at the second parameter
 969  * - As an array in the second parameter
 970  * These are not shown in the function definition.
 971  *
 972  * @return String
 973  */
 974 function wfMsg( $key ) {
 975         $args = func_get_args();
 976         array_shift( $args );
 977         return wfMsgReal( $key, $args );
 978 }
 979
 980 /**
 981  * Same as above except doesn't transform the message
 982  *
 983  * @param $key String
 984  * @return String
 985  */
 986 function wfMsgNoTrans( $key ) {
 987         $args = func_get_args();
 988         array_shift( $args );
 989         return wfMsgReal( $key, $args, true, false, false );
 990 }
 991
 992 /**
 993  * Get a message from anywhere, for the current global language
 994  * set with $wgLanguageCode.
 995  *
 996  * Use this if the message should NOT change dependent on the
 997  * language set in the user's preferences. This is the case for
 998  * most text written into logs, as well as link targets (such as
 999  * the name of the copyright policy page). Link titles, on the
1000  * other hand, should be shown in the UI language.
1001  *
1002  * Note that MediaWiki allows users to change the user interface
1003  * language in their preferences, but a single installation
1004  * typically only contains content in one language.
1005  *
1006  * Be wary of this distinction: If you use wfMsg() where you should
1007  * use wfMsgForContent(), a user of the software may have to
1008  * customize potentially hundreds of messages in
1009  * order to, e.g., fix a link in every possible language.
1010  *
1011  * @param $key String: lookup key for the message, usually
1012  *     defined in languages/Language.php
1013  * @return String
1014  */
1015 function wfMsgForContent( $key ) {
1016         global $wgForceUIMsgAsContentMsg;
1017         $args = func_get_args();
1018         array_shift( $args );
1019         $forcontent = true;
1020         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1021                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1022         {
1023                 $forcontent = false;
1024         }
1025         return wfMsgReal( $key, $args, true, $forcontent );
1026 }
1027
1028 /**
1029  * Same as above except doesn't transform the message
1030  *
1031  * @param $key String
1032  * @return String
1033  */
1034 function wfMsgForContentNoTrans( $key ) {
1035         global $wgForceUIMsgAsContentMsg;
1036         $args = func_get_args();
1037         array_shift( $args );
1038         $forcontent = true;
1039         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1040                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1041         {
1042                 $forcontent = false;
1043         }
1044         return wfMsgReal( $key, $args, true, $forcontent, false );
1045 }
1046
1047 /**
1048  * Really get a message
1049  *
1050  * @param $key String: key to get.
1051  * @param $args
1052  * @param $useDB Boolean
1053  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1054  * @param $transform Boolean: Whether or not to transform the message.
1055  * @return String: the requested message.
1056  */
1057 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1058         wfProfileIn( __METHOD__ );
1059         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1060         $message = wfMsgReplaceArgs( $message, $args );
1061         wfProfileOut( __METHOD__ );
1062         return $message;
1063 }
1064
1065 /**
1066  * Fetch a message string value, but don't replace any keys yet.
1067  *
1068  * @param $key String
1069  * @param $useDB Bool
1070  * @param $langCode String: Code of the language to get the message for, or
1071  *                  behaves as a content language switch if it is a boolean.
1072  * @param $transform Boolean: whether to parse magic words, etc.
1073  * @return string
1074  */
1075 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1076         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1077
1078         $cache = MessageCache::singleton();
1079         $message = $cache->get( $key, $useDB, $langCode );
1080         if( $message === false ) {
1081                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1082         } elseif ( $transform ) {
1083                 $message = $cache->transform( $message );
1084         }
1085         return $message;
1086 }
1087
1088 /**
1089  * Replace message parameter keys on the given formatted output.
1090  *
1091  * @param $message String
1092  * @param $args Array
1093  * @return string
1094  * @private
1095  */
1096 function wfMsgReplaceArgs( $message, $args ) {
1097         # Fix windows line-endings
1098         # Some messages are split with explode("\n", $msg)
1099         $message = str_replace( "\r", '', $message );
1100
1101         // Replace arguments
1102         if ( count( $args ) ) {
1103                 if ( is_array( $args[0] ) ) {
1104                         $args = array_values( $args[0] );
1105                 }
1106                 $replacementKeys = array();
1107                 foreach( $args as $n => $param ) {
1108                         $replacementKeys['$' . ( $n + 1 )] = $param;
1109                 }
1110                 $message = strtr( $message, $replacementKeys );
1111         }
1112
1113         return $message;
1114 }
1115
1116 /**
1117  * Return an HTML-escaped version of a message.
1118  * Parameter replacements, if any, are done *after* the HTML-escaping,
1119  * so parameters may contain HTML (eg links or form controls). Be sure
1120  * to pre-escape them if you really do want plaintext, or just wrap
1121  * the whole thing in htmlspecialchars().
1122  *
1123  * @param $key String
1124  * @param string ... parameters
1125  * @return string
1126  */
1127 function wfMsgHtml( $key ) {
1128         $args = func_get_args();
1129         array_shift( $args );
1130         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1131 }
1132
1133 /**
1134  * Return an HTML version of message
1135  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1136  * so parameters may contain HTML (eg links or form controls). Be sure
1137  * to pre-escape them if you really do want plaintext, or just wrap
1138  * the whole thing in htmlspecialchars().
1139  *
1140  * @param $key String
1141  * @param string ... parameters
1142  * @return string
1143  */
1144 function wfMsgWikiHtml( $key ) {
1145         $args = func_get_args();
1146         array_shift( $args );
1147         return wfMsgReplaceArgs(
1148                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null, /* can't be set to false */ true )->getText(),
1149                 $args );
1150 }
1151
1152 /**
1153  * Returns message in the requested format
1154  * @param $key String: key of the message
1155  * @param $options Array: processing rules. Can take the following options:
1156  *   <i>parse</i>: parses wikitext to HTML
1157  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1158  *       p's added by parser or tidy
1159  *   <i>escape</i>: filters message through htmlspecialchars
1160  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1161  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1162  *   <i>parsemag</i>: transform the message using magic phrases
1163  *   <i>content</i>: fetch message for content language instead of interface
1164  * Also can accept a single associative argument, of the form 'language' => 'xx':
1165  *   <i>language</i>: Language object or language code to fetch message for
1166  *       (overriden by <i>content</i>).
1167  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1168  *
1169  * @return String
1170  */
1171 function wfMsgExt( $key, $options ) {
1172         $args = func_get_args();
1173         array_shift( $args );
1174         array_shift( $args );
1175         $options = (array)$options;
1176
1177         foreach( $options as $arrayKey => $option ) {
1178                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1179                         # An unknown index, neither numeric nor "language"
1180                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1181                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1182                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1183                 'replaceafter', 'parsemag', 'content' ) ) ) {
1184                         # A numeric index with unknown value
1185                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1186                 }
1187         }
1188
1189         if( in_array( 'content', $options, true ) ) {
1190                 $forContent = true;
1191                 $langCode = true;
1192                 $langCodeObj = null;
1193         } elseif( array_key_exists( 'language', $options ) ) {
1194                 $forContent = false;
1195                 $langCode = wfGetLangObj( $options['language'] );
1196                 $langCodeObj = $langCode;
1197         } else {
1198                 $forContent = false;
1199                 $langCode = false;
1200                 $langCodeObj = null;
1201         }
1202
1203         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1204
1205         if( !in_array( 'replaceafter', $options, true ) ) {
1206                 $string = wfMsgReplaceArgs( $string, $args );
1207         }
1208
1209         $messageCache = MessageCache::singleton();
1210         if( in_array( 'parse', $options, true ) ) {
1211                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1212         } elseif ( in_array( 'parseinline', $options, true ) ) {
1213                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1214                 $m = array();
1215                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1216                         $string = $m[1];
1217                 }
1218         } elseif ( in_array( 'parsemag', $options, true ) ) {
1219                 $string = $messageCache->transform( $string,
1220                                 !$forContent, $langCodeObj );
1221         }
1222
1223         if ( in_array( 'escape', $options, true ) ) {
1224                 $string = htmlspecialchars ( $string );
1225         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1226                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1227         }
1228
1229         if( in_array( 'replaceafter', $options, true ) ) {
1230                 $string = wfMsgReplaceArgs( $string, $args );
1231         }
1232
1233         return $string;
1234 }
1235
1236 /**
1237  * Since wfMsg() and co suck, they don't return false if the message key they
1238  * looked up didn't exist but a XHTML string, this function checks for the
1239  * nonexistance of messages by checking the MessageCache::get() result directly.
1240  *
1241  * @param $key      String: the message key looked up
1242  * @return Boolean True if the message *doesn't* exist.
1243  */
1244 function wfEmptyMsg( $key ) {
1245         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1246 }
1247
1248 /**
1249  * Print an error message and die, returning nonzero to the shell if any.  Plain die()
1250  * fails to return nonzero to the shell if you pass a string.  Entry points may customise
1251  * this function to return a prettier error message, but implementations must not assume
1252  * access to any of the usual MediaWiki infrastructure (AutoLoader, localisation, database,
1253  * etc).  This should not be called directly once $wgFullyInitialised is set; instead,
1254  * throw an exception and let Exception.php handle whether or not it's possible to show
1255  * a prettier error.
1256  *
1257  * @param $msg String
1258  */
1259 if( !function_exists( 'wfDie' ) ){
1260         function wfDie( $msg = '' ) {
1261                 echo $msg;
1262                 die( 1 );
1263         }
1264 }
1265
1266 /**
1267  * Throw a debugging exception. This function previously once exited the process,
1268  * but now throws an exception instead, with similar results.
1269  *
1270  * @param $msg String: message shown when dieing.
1271  */
1272 function wfDebugDieBacktrace( $msg = '' ) {
1273         throw new MWException( $msg );
1274 }
1275
1276 /**
1277  * Fetch server name for use in error reporting etc.
1278  * Use real server name if available, so we know which machine
1279  * in a server farm generated the current page.
1280  *
1281  * @return string
1282  */
1283 function wfHostname() {
1284         static $host;
1285         if ( is_null( $host ) ) {
1286                 if ( function_exists( 'posix_uname' ) ) {
1287                         // This function not present on Windows
1288                         $uname = posix_uname();
1289                 } else {
1290                         $uname = false;
1291                 }
1292                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1293                         $host = $uname['nodename'];
1294                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1295                         # Windows computer name
1296                         $host = getenv( 'COMPUTERNAME' );
1297                 } else {
1298                         # This may be a virtual server.
1299                         $host = $_SERVER['SERVER_NAME'];
1300                 }
1301         }
1302         return $host;
1303 }
1304
1305 /**
1306  * Returns a HTML comment with the elapsed time since request.
1307  * This method has no side effects.
1308  *
1309  * @return string
1310  */
1311 function wfReportTime() {
1312         global $wgRequestTime, $wgShowHostnames;
1313
1314         $now = wfTime();
1315         $elapsed = $now - $wgRequestTime;
1316
1317         return $wgShowHostnames
1318                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1319                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1320 }
1321
1322 /**
1323  * Safety wrapper for debug_backtrace().
1324  *
1325  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1326  * murky circumstances, which may be triggered in part by stub objects
1327  * or other fancy talkin'.
1328  *
1329  * Will return an empty array if Zend Optimizer is detected or if
1330  * debug_backtrace is disabled, otherwise the output from
1331  * debug_backtrace() (trimmed).
1332  *
1333  * @return array of backtrace information
1334  */
1335 function wfDebugBacktrace( $limit = 0 ) {
1336         static $disabled = null;
1337
1338         if( extension_loaded( 'Zend Optimizer' ) ) {
1339                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1340                 return array();
1341         }
1342
1343         if ( is_null( $disabled ) ) {
1344                 $disabled = false;
1345                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1346                 $functions = array_map( 'trim', $functions );
1347                 $functions = array_map( 'strtolower', $functions );
1348                 if ( in_array( 'debug_backtrace', $functions ) ) {
1349                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1350                         $disabled = true;
1351                 }
1352         }
1353         if ( $disabled ) {
1354                 return array();
1355         }
1356
1357         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1358                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, 1 ), 1 );
1359         } else {
1360                 return array_slice( debug_backtrace(), 1 );
1361         }
1362 }
1363
1364 /**
1365  * Get a debug backtrace as a string
1366  *
1367  * @return string
1368  */
1369 function wfBacktrace() {
1370         global $wgCommandLineMode;
1371
1372         if ( $wgCommandLineMode ) {
1373                 $msg = '';
1374         } else {
1375                 $msg = "<ul>\n";
1376         }
1377         $backtrace = wfDebugBacktrace();
1378         foreach( $backtrace as $call ) {
1379                 if( isset( $call['file'] ) ) {
1380                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1381                         $file = $f[count( $f ) - 1];
1382                 } else {
1383                         $file = '-';
1384                 }
1385                 if( isset( $call['line'] ) ) {
1386                         $line = $call['line'];
1387                 } else {
1388                         $line = '-';
1389                 }
1390                 if ( $wgCommandLineMode ) {
1391                         $msg .= "$file line $line calls ";
1392                 } else {
1393                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1394                 }
1395                 if( !empty( $call['class'] ) ) {
1396                         $msg .= $call['class'] . $call['type'];
1397                 }
1398                 $msg .= $call['function'] . '()';
1399
1400                 if ( $wgCommandLineMode ) {
1401                         $msg .= "\n";
1402                 } else {
1403                         $msg .= "</li>\n";
1404                 }
1405         }
1406         if ( $wgCommandLineMode ) {
1407                 $msg .= "\n";
1408         } else {
1409                 $msg .= "</ul>\n";
1410         }
1411
1412         return $msg;
1413 }
1414
1415 /**
1416  * Get the name of the function which called this function
1417  *
1418  * @param $level Int
1419  * @return Bool|string
1420  */
1421 function wfGetCaller( $level = 2 ) {
1422         $backtrace = wfDebugBacktrace( $level );
1423         if ( isset( $backtrace[$level] ) ) {
1424                 return wfFormatStackFrame( $backtrace[$level] );
1425         } else {
1426                 $caller = 'unknown';
1427         }
1428         return $caller;
1429 }
1430
1431 /**
1432  * Return a string consisting of callers in the stack. Useful sometimes
1433  * for profiling specific points.
1434  *
1435  * @param $limit The maximum depth of the stack frame to return, or false for
1436  *               the entire stack.
1437  * @return String
1438  */
1439 function wfGetAllCallers( $limit = 3 ) {
1440         $trace = array_reverse( wfDebugBacktrace() );
1441         if ( !$limit || $limit > count( $trace ) - 1 ) {
1442                 $limit = count( $trace ) - 1;
1443         }
1444         $trace = array_slice( $trace, -$limit - 1, $limit );
1445         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1446 }
1447
1448 /**
1449  * Return a string representation of frame
1450  *
1451  * @param $frame Array
1452  * @return Bool
1453  */
1454 function wfFormatStackFrame( $frame ) {
1455         return isset( $frame['class'] ) ?
1456                 $frame['class'] . '::' . $frame['function'] :
1457                 $frame['function'];
1458 }
1459
1460
1461 /* Some generic result counters, pulled out of SearchEngine */
1462
1463
1464 /**
1465  * @todo document
1466  *
1467  * @param $offset Int
1468  * @param $limit Int
1469  * @return String
1470  */
1471 function wfShowingResults( $offset, $limit ) {
1472         global $wgLang;
1473         return wfMsgExt(
1474                 'showingresults',
1475                 array( 'parseinline' ),
1476                 $wgLang->formatNum( $limit ),
1477                 $wgLang->formatNum( $offset + 1 )
1478         );
1479 }
1480
1481 /**
1482  * @todo document
1483  *
1484  * @param $offset Int
1485  * @param $limit Int
1486  * @param $num Int
1487  * @return String
1488  */
1489 function wfShowingResultsNum( $offset, $limit, $num ) {
1490         global $wgLang;
1491         return wfMsgExt(
1492                 'showingresultsnum',
1493                 array( 'parseinline' ),
1494                 $wgLang->formatNum( $limit ),
1495                 $wgLang->formatNum( $offset + 1 ),
1496                 $wgLang->formatNum( $num )
1497         );
1498 }
1499
1500 /**
1501  * Generate (prev x| next x) (20|50|100...) type links for paging
1502  *
1503  * @param $offset String
1504  * @param $limit Integer
1505  * @param $link String
1506  * @param $query String: optional URL query parameter string
1507  * @param $atend Bool: optional param for specified if this is the last page
1508  * @return String
1509  */
1510 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1511         global $wgLang;
1512         $fmtLimit = $wgLang->formatNum( $limit );
1513         // @todo FIXME: Why on earth this needs one message for the text and another one for tooltip?
1514         # Get prev/next link display text
1515         $prev = wfMsgExt( 'prevn', array( 'parsemag', 'escape' ), $fmtLimit );
1516         $next = wfMsgExt( 'nextn', array( 'parsemag', 'escape' ), $fmtLimit );
1517         # Get prev/next link title text
1518         $pTitle = wfMsgExt( 'prevn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1519         $nTitle = wfMsgExt( 'nextn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1520         # Fetch the title object
1521         if( is_object( $link ) ) {
1522                 $title =& $link;
1523         } else {
1524                 $title = Title::newFromText( $link );
1525                 if( is_null( $title ) ) {
1526                         return false;
1527                 }
1528         }
1529         # Make 'previous' link
1530         if( 0 != $offset ) {
1531                 $po = $offset - $limit;
1532                 $po = max( $po, 0 );
1533                 $q = "limit={$limit}&offset={$po}";
1534                 if( $query != '' ) {
1535                         $q .= '&' . $query;
1536                 }
1537                 $plink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$pTitle}\" class=\"mw-prevlink\">{$prev}</a>";
1538         } else {
1539                 $plink = $prev;
1540         }
1541         # Make 'next' link
1542         $no = $offset + $limit;
1543         $q = "limit={$limit}&offset={$no}";
1544         if( $query != '' ) {
1545                 $q .= '&' . $query;
1546         }
1547         if( $atend ) {
1548                 $nlink = $next;
1549         } else {
1550                 $nlink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$nTitle}\" class=\"mw-nextlink\">{$next}</a>";
1551         }
1552         # Make links to set number of items per page
1553         $nums = $wgLang->pipeList( array(
1554                 wfNumLink( $offset, 20, $title, $query ),
1555                 wfNumLink( $offset, 50, $title, $query ),
1556                 wfNumLink( $offset, 100, $title, $query ),
1557                 wfNumLink( $offset, 250, $title, $query ),
1558                 wfNumLink( $offset, 500, $title, $query )
1559         ) );
1560         return wfMsgHtml( 'viewprevnext', $plink, $nlink, $nums );
1561 }
1562
1563 /**
1564  * Generate links for (20|50|100...) items-per-page links
1565  *
1566  * @param $offset String
1567  * @param $limit Integer
1568  * @param $title Title
1569  * @param $query String: optional URL query parameter string
1570  */
1571 function wfNumLink( $offset, $limit, $title, $query = '' ) {
1572         global $wgLang;
1573         if( $query == '' ) {
1574                 $q = '';
1575         } else {
1576                 $q = $query.'&';
1577         }
1578         $q .= "limit={$limit}&offset={$offset}";
1579         $fmtLimit = $wgLang->formatNum( $limit );
1580         $lTitle = wfMsgExt( 'shown-title', array( 'parsemag', 'escape' ), $limit );
1581         $s = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$lTitle}\" class=\"mw-numlink\">{$fmtLimit}</a>";
1582         return $s;
1583 }
1584
1585 /**
1586  * @todo document
1587  * @todo FIXME: We may want to blacklist some broken browsers
1588  *
1589  * @param $force Bool
1590  * @return bool Whereas client accept gzip compression
1591  */
1592 function wfClientAcceptsGzip( $force = false ) {
1593         static $result = null;
1594         if ( $result === null || $force ) {
1595                 $result = false;
1596                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1597                         # @todo FIXME: We may want to blacklist some broken browsers
1598                         $m = array();
1599                         if( preg_match(
1600                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1601                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1602                                 $m )
1603                         )
1604                         {
1605                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1606                                         $result = false;
1607                                         return $result;
1608                                 }
1609                                 wfDebug( " accepts gzip\n" );
1610                                 $result = true;
1611                         }
1612                 }
1613         }
1614         return $result;
1615 }
1616
1617 /**
1618  * Obtain the offset and limit values from the request string;
1619  * used in special pages
1620  *
1621  * @param $deflimit Int default limit if none supplied
1622  * @param $optionname String Name of a user preference to check against
1623  * @return array
1624  *
1625  */
1626 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1627         global $wgRequest;
1628         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1629 }
1630
1631 /**
1632  * Escapes the given text so that it may be output using addWikiText()
1633  * without any linking, formatting, etc. making its way through. This
1634  * is achieved by substituting certain characters with HTML entities.
1635  * As required by the callers, <nowiki> is not used.
1636  *
1637  * @param $text String: text to be escaped
1638  * @return String
1639  */
1640 function wfEscapeWikiText( $text ) {
1641         $text = strtr( "\n$text", array(
1642                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1643                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1644                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1645                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1646                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1647                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1648         ) );
1649         return substr( $text, 1 );
1650 }
1651
1652 /**
1653  * Get the current unix timetstamp with microseconds.  Useful for profiling
1654  * @return Float
1655  */
1656 function wfTime() {
1657         return microtime( true );
1658 }
1659
1660 /**
1661  * Sets dest to source and returns the original value of dest
1662  * If source is NULL, it just returns the value, it doesn't set the variable
1663  * If force is true, it will set the value even if source is NULL
1664  *
1665  * @param $dest Mixed
1666  * @param $source Mixed
1667  * @param $force Bool
1668  * @return Mixed
1669  */
1670 function wfSetVar( &$dest, $source, $force = false ) {
1671         $temp = $dest;
1672         if ( !is_null( $source ) || $force ) {
1673                 $dest = $source;
1674         }
1675         return $temp;
1676 }
1677
1678 /**
1679  * As for wfSetVar except setting a bit
1680  *
1681  * @param $dest Int
1682  * @param $bit Int
1683  * @param $state Bool
1684  */
1685 function wfSetBit( &$dest, $bit, $state = true ) {
1686         $temp = (bool)( $dest & $bit );
1687         if ( !is_null( $state ) ) {
1688                 if ( $state ) {
1689                         $dest |= $bit;
1690                 } else {
1691                         $dest &= ~$bit;
1692                 }
1693         }
1694         return $temp;
1695 }
1696
1697 /**
1698  * Windows-compatible version of escapeshellarg()
1699  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
1700  * function puts single quotes in regardless of OS.
1701  *
1702  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
1703  * earlier distro releases of PHP)
1704  *
1705  * @param varargs
1706  * @return String
1707  */
1708 function wfEscapeShellArg( ) {
1709         wfInitShellLocale();
1710
1711         $args = func_get_args();
1712         $first = true;
1713         $retVal = '';
1714         foreach ( $args as $arg ) {
1715                 if ( !$first ) {
1716                         $retVal .= ' ';
1717                 } else {
1718                         $first = false;
1719                 }
1720
1721                 if ( wfIsWindows() ) {
1722                         // Escaping for an MSVC-style command line parser and CMD.EXE
1723                         // Refs:
1724                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
1725                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
1726                         //  * Bug #13518
1727                         //  * CR r63214
1728                         // Double the backslashes before any double quotes. Escape the double quotes.
1729                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
1730                         $arg = '';
1731                         $iteration = 0;
1732                         foreach ( $tokens as $token ) {
1733                                 if ( $iteration % 2 == 1 ) {
1734                                         // Delimiter, a double quote preceded by zero or more slashes
1735                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
1736                                 } elseif ( $iteration % 4 == 2 ) {
1737                                         // ^ in $token will be outside quotes, need to be escaped
1738                                         $arg .= str_replace( '^', '^^', $token );
1739                                 } else { // $iteration % 4 == 0
1740                                         // ^ in $token will appear inside double quotes, so leave as is
1741                                         $arg .= $token;
1742                                 }
1743                                 $iteration++;
1744                         }
1745                         // Double the backslashes before the end of the string, because
1746                         // we will soon add a quote
1747                         $m = array();
1748                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1749                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1750                         }
1751
1752                         // Add surrounding quotes
1753                         $retVal .= '"' . $arg . '"';
1754                 } else {
1755                         $retVal .= escapeshellarg( $arg );
1756                 }
1757         }
1758         return $retVal;
1759 }
1760
1761 /**
1762  * wfMerge attempts to merge differences between three texts.
1763  * Returns true for a clean merge and false for failure or a conflict.
1764  *
1765  * @param $old String
1766  * @param $mine String
1767  * @param $yours String
1768  * @param $result String
1769  * @return Bool
1770  */
1771 function wfMerge( $old, $mine, $yours, &$result ) {
1772         global $wgDiff3;
1773
1774         # This check may also protect against code injection in
1775         # case of broken installations.
1776         wfSuppressWarnings();
1777         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
1778         wfRestoreWarnings();
1779
1780         if( !$haveDiff3 ) {
1781                 wfDebug( "diff3 not found\n" );
1782                 return false;
1783         }
1784
1785         # Make temporary files
1786         $td = wfTempDir();
1787         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1788         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1789         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1790
1791         fwrite( $oldtextFile, $old );
1792         fclose( $oldtextFile );
1793         fwrite( $mytextFile, $mine );
1794         fclose( $mytextFile );
1795         fwrite( $yourtextFile, $yours );
1796         fclose( $yourtextFile );
1797
1798         # Check for a conflict
1799         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1800                 wfEscapeShellArg( $mytextName ) . ' ' .
1801                 wfEscapeShellArg( $oldtextName ) . ' ' .
1802                 wfEscapeShellArg( $yourtextName );
1803         $handle = popen( $cmd, 'r' );
1804
1805         if( fgets( $handle, 1024 ) ) {
1806                 $conflict = true;
1807         } else {
1808                 $conflict = false;
1809         }
1810         pclose( $handle );
1811
1812         # Merge differences
1813         $cmd = $wgDiff3 . ' -a -e --merge ' .
1814                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1815         $handle = popen( $cmd, 'r' );
1816         $result = '';
1817         do {
1818                 $data = fread( $handle, 8192 );
1819                 if ( strlen( $data ) == 0 ) {
1820                         break;
1821                 }
1822                 $result .= $data;
1823         } while ( true );
1824         pclose( $handle );
1825         unlink( $mytextName );
1826         unlink( $oldtextName );
1827         unlink( $yourtextName );
1828
1829         if ( $result === '' && $old !== '' && !$conflict ) {
1830                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1831                 $conflict = true;
1832         }
1833         return !$conflict;
1834 }
1835
1836 /**
1837  * Returns unified plain-text diff of two texts.
1838  * Useful for machine processing of diffs.
1839  *
1840  * @param $before String: the text before the changes.
1841  * @param $after String: the text after the changes.
1842  * @param $params String: command-line options for the diff command.
1843  * @return String: unified diff of $before and $after
1844  */
1845 function wfDiff( $before, $after, $params = '-u' ) {
1846         if ( $before == $after ) {
1847                 return '';
1848         }
1849
1850         global $wgDiff;
1851         wfSuppressWarnings();
1852         $haveDiff = $wgDiff && file_exists( $wgDiff );
1853         wfRestoreWarnings();
1854
1855         # This check may also protect against code injection in
1856         # case of broken installations.
1857         if( !$haveDiff ) {
1858                 wfDebug( "diff executable not found\n" );
1859                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
1860                 $format = new UnifiedDiffFormatter();
1861                 return $format->format( $diffs );
1862         }
1863
1864         # Make temporary files
1865         $td = wfTempDir();
1866         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1867         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
1868
1869         fwrite( $oldtextFile, $before );
1870         fclose( $oldtextFile );
1871         fwrite( $newtextFile, $after );
1872         fclose( $newtextFile );
1873
1874         // Get the diff of the two files
1875         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
1876
1877         $h = popen( $cmd, 'r' );
1878
1879         $diff = '';
1880
1881         do {
1882                 $data = fread( $h, 8192 );
1883                 if ( strlen( $data ) == 0 ) {
1884                         break;
1885                 }
1886                 $diff .= $data;
1887         } while ( true );
1888
1889         // Clean up
1890         pclose( $h );
1891         unlink( $oldtextName );
1892         unlink( $newtextName );
1893
1894         // Kill the --- and +++ lines. They're not useful.
1895         $diff_lines = explode( "\n", $diff );
1896         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
1897                 unset( $diff_lines[0] );
1898         }
1899         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
1900                 unset( $diff_lines[1] );
1901         }
1902
1903         $diff = implode( "\n", $diff_lines );
1904
1905         return $diff;
1906 }
1907
1908 /**
1909  * A wrapper around the PHP function var_export().
1910  * Either print it or add it to the regular output ($wgOut).
1911  *
1912  * @param $var A PHP variable to dump.
1913  */
1914 function wfVarDump( $var ) {
1915         global $wgOut;
1916         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1917         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1918                 print $s;
1919         } else {
1920                 $wgOut->addHTML( $s );
1921         }
1922 }
1923
1924 /**
1925  * Provide a simple HTTP error.
1926  *
1927  * @param $code Int|String
1928  * @param $label String
1929  * @param $desc String
1930  */
1931 function wfHttpError( $code, $label, $desc ) {
1932         global $wgOut;
1933         $wgOut->disable();
1934         header( "HTTP/1.0 $code $label" );
1935         header( "Status: $code $label" );
1936         $wgOut->sendCacheControl();
1937
1938         header( 'Content-type: text/html; charset=utf-8' );
1939         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1940                 '<html><head><title>' .
1941                 htmlspecialchars( $label ) .
1942                 '</title></head><body><h1>' .
1943                 htmlspecialchars( $label ) .
1944                 '</h1><p>' .
1945                 nl2br( htmlspecialchars( $desc ) ) .
1946                 "</p></body></html>\n";
1947 }
1948
1949 /**
1950  * Clear away any user-level output buffers, discarding contents.
1951  *
1952  * Suitable for 'starting afresh', for instance when streaming
1953  * relatively large amounts of data without buffering, or wanting to
1954  * output image files without ob_gzhandler's compression.
1955  *
1956  * The optional $resetGzipEncoding parameter controls suppression of
1957  * the Content-Encoding header sent by ob_gzhandler; by default it
1958  * is left. See comments for wfClearOutputBuffers() for why it would
1959  * be used.
1960  *
1961  * Note that some PHP configuration options may add output buffer
1962  * layers which cannot be removed; these are left in place.
1963  *
1964  * @param $resetGzipEncoding Bool
1965  */
1966 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1967         if( $resetGzipEncoding ) {
1968                 // Suppress Content-Encoding and Content-Length
1969                 // headers from 1.10+s wfOutputHandler
1970                 global $wgDisableOutputCompression;
1971                 $wgDisableOutputCompression = true;
1972         }
1973         while( $status = ob_get_status() ) {
1974                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1975                         // Probably from zlib.output_compression or other
1976                         // PHP-internal setting which can't be removed.
1977                         //
1978                         // Give up, and hope the result doesn't break
1979                         // output behavior.
1980                         break;
1981                 }
1982                 if( !ob_end_clean() ) {
1983                         // Could not remove output buffer handler; abort now
1984                         // to avoid getting in some kind of infinite loop.
1985                         break;
1986                 }
1987                 if( $resetGzipEncoding ) {
1988                         if( $status['name'] == 'ob_gzhandler' ) {
1989                                 // Reset the 'Content-Encoding' field set by this handler
1990                                 // so we can start fresh.
1991                                 if ( function_exists( 'header_remove' ) ) {
1992                                         // Available since PHP 5.3.0
1993                                         header_remove( 'Content-Encoding' );
1994                                 } else {
1995                                         // We need to provide a valid content-coding. See bug 28069
1996                                         header( 'Content-Encoding: identity' );
1997                                 }
1998                                 break;
1999                         }
2000                 }
2001         }
2002 }
2003
2004 /**
2005  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
2006  *
2007  * Clear away output buffers, but keep the Content-Encoding header
2008  * produced by ob_gzhandler, if any.
2009  *
2010  * This should be used for HTTP 304 responses, where you need to
2011  * preserve the Content-Encoding header of the real result, but
2012  * also need to suppress the output of ob_gzhandler to keep to spec
2013  * and avoid breaking Firefox in rare cases where the headers and
2014  * body are broken over two packets.
2015  */
2016 function wfClearOutputBuffers() {
2017         wfResetOutputBuffers( false );
2018 }
2019
2020 /**
2021  * Converts an Accept-* header into an array mapping string values to quality
2022  * factors
2023  *
2024  * @param $accept String
2025  * @param $def String default
2026  * @return Array
2027  */
2028 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2029         # No arg means accept anything (per HTTP spec)
2030         if( !$accept ) {
2031                 return array( $def => 1.0 );
2032         }
2033
2034         $prefs = array();
2035
2036         $parts = explode( ',', $accept );
2037
2038         foreach( $parts as $part ) {
2039                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2040                 $values = explode( ';', trim( $part ) );
2041                 $match = array();
2042                 if ( count( $values ) == 1 ) {
2043                         $prefs[$values[0]] = 1.0;
2044                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2045                         $prefs[$values[0]] = floatval( $match[1] );
2046                 }
2047         }
2048
2049         return $prefs;
2050 }
2051
2052 /**
2053  * Checks if a given MIME type matches any of the keys in the given
2054  * array. Basic wildcards are accepted in the array keys.
2055  *
2056  * Returns the matching MIME type (or wildcard) if a match, otherwise
2057  * NULL if no match.
2058  *
2059  * @param $type String
2060  * @param $avail Array
2061  * @return string
2062  * @private
2063  */
2064 function mimeTypeMatch( $type, $avail ) {
2065         if( array_key_exists( $type, $avail ) ) {
2066                 return $type;
2067         } else {
2068                 $parts = explode( '/', $type );
2069                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2070                         return $parts[0] . '/*';
2071                 } elseif( array_key_exists( '*/*', $avail ) ) {
2072                         return '*/*';
2073                 } else {
2074                         return null;
2075                 }
2076         }
2077 }
2078
2079 /**
2080  * Returns the 'best' match between a client's requested internet media types
2081  * and the server's list of available types. Each list should be an associative
2082  * array of type to preference (preference is a float between 0.0 and 1.0).
2083  * Wildcards in the types are acceptable.
2084  *
2085  * @param $cprefs Array: client's acceptable type list
2086  * @param $sprefs Array: server's offered types
2087  * @return string
2088  *
2089  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2090  * XXX: generalize to negotiate other stuff
2091  */
2092 function wfNegotiateType( $cprefs, $sprefs ) {
2093         $combine = array();
2094
2095         foreach( array_keys($sprefs) as $type ) {
2096                 $parts = explode( '/', $type );
2097                 if( $parts[1] != '*' ) {
2098                         $ckey = mimeTypeMatch( $type, $cprefs );
2099                         if( $ckey ) {
2100                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2101                         }
2102                 }
2103         }
2104
2105         foreach( array_keys( $cprefs ) as $type ) {
2106                 $parts = explode( '/', $type );
2107                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2108                         $skey = mimeTypeMatch( $type, $sprefs );
2109                         if( $skey ) {
2110                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2111                         }
2112                 }
2113         }
2114
2115         $bestq = 0;
2116         $besttype = null;
2117
2118         foreach( array_keys( $combine ) as $type ) {
2119                 if( $combine[$type] > $bestq ) {
2120                         $besttype = $type;
2121                         $bestq = $combine[$type];
2122                 }
2123         }
2124
2125         return $besttype;
2126 }
2127
2128 /**
2129  * Reference-counted warning suppression
2130  *
2131  * @param $end Bool
2132  */
2133 function wfSuppressWarnings( $end = false ) {
2134         static $suppressCount = 0;
2135         static $originalLevel = false;
2136
2137         if ( $end ) {
2138                 if ( $suppressCount ) {
2139                         --$suppressCount;
2140                         if ( !$suppressCount ) {
2141                                 error_reporting( $originalLevel );
2142                         }
2143                 }
2144         } else {
2145                 if ( !$suppressCount ) {
2146                         // E_DEPRECATED is undefined in PHP 5.2
2147                         if( !defined( 'E_DEPRECATED' ) ){
2148                                 define( 'E_DEPRECATED', 8192 );
2149                         }
2150                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2151                 }
2152                 ++$suppressCount;
2153         }
2154 }
2155
2156 /**
2157  * Restore error level to previous value
2158  */
2159 function wfRestoreWarnings() {
2160         wfSuppressWarnings( true );
2161 }
2162
2163 # Autodetect, convert and provide timestamps of various types
2164
2165 /**
2166  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2167  */
2168 define( 'TS_UNIX', 0 );
2169
2170 /**
2171  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2172  */
2173 define( 'TS_MW', 1 );
2174
2175 /**
2176  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2177  */
2178 define( 'TS_DB', 2 );
2179
2180 /**
2181  * RFC 2822 format, for E-mail and HTTP headers
2182  */
2183 define( 'TS_RFC2822', 3 );
2184
2185 /**
2186  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2187  *
2188  * This is used by Special:Export
2189  */
2190 define( 'TS_ISO_8601', 4 );
2191
2192 /**
2193  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2194  *
2195  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2196  *       DateTime tag and page 36 for the DateTimeOriginal and
2197  *       DateTimeDigitized tags.
2198  */
2199 define( 'TS_EXIF', 5 );
2200
2201 /**
2202  * Oracle format time.
2203  */
2204 define( 'TS_ORACLE', 6 );
2205
2206 /**
2207  * Postgres format time.
2208  */
2209 define( 'TS_POSTGRES', 7 );
2210
2211 /**
2212  * DB2 format time
2213  */
2214 define( 'TS_DB2', 8 );
2215
2216 /**
2217  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2218  */
2219 define( 'TS_ISO_8601_BASIC', 9 );
2220
2221 /**
2222  * Get a timestamp string in one of various formats
2223  *
2224  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2225  *                    function will autodetect which format is supplied and act
2226  *                    accordingly.
2227  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2228  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2229  */
2230 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2231         $uts = 0;
2232         $da = array();
2233         $strtime = '';
2234
2235         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2236                 $uts = time();
2237                 $strtime = "@$uts";
2238         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2239                 # TS_DB
2240         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2241                 # TS_EXIF
2242         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2243                 # TS_MW
2244         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2245                 # TS_UNIX
2246                 $uts = $ts;
2247                 $strtime = "@$ts"; // Undocumented?
2248         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2249                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2250                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2251                                 str_replace( '+00:00', 'UTC', $ts ) );
2252         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2253                 # TS_ISO_8601
2254         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2255                 #TS_ISO_8601_BASIC
2256         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2257                 # TS_POSTGRES
2258         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2259                 # TS_POSTGRES
2260         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/',$ts,$da)) {
2261                 # TS_DB2
2262         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2263                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2264                                                         '[ \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
2265                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2266                 # The regex is a superset of rfc2822 for readability
2267                 $strtime = strtok( $ts, ';' );
2268         } 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 ) ) {
2269                 # TS_RFC850
2270                 $strtime = $ts;
2271         } 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 ) ) {
2272                 # asctime
2273                 $strtime = $ts;
2274         } else {
2275                 # Bogus value...
2276                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2277
2278                 return false;
2279         }
2280
2281         static $formats = array(
2282                 TS_UNIX => 'U',
2283                 TS_MW => 'YmdHis',
2284                 TS_DB => 'Y-m-d H:i:s',
2285                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2286                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2287                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2288                 TS_RFC2822 => 'D, d M Y H:i:s',
2289                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2290                 TS_POSTGRES => 'Y-m-d H:i:s',
2291                 TS_DB2 => 'Y-m-d H:i:s',
2292         );
2293
2294         if ( !isset( $formats[$outputtype] ) ) {
2295                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2296         }
2297
2298         if ( function_exists( "date_create" ) ) {
2299                 if ( count( $da ) ) {
2300                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2301                                 (int)$da[1], (int)$da[2], (int)$da[3],
2302                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2303
2304                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2305                 } elseif ( $strtime ) {
2306                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2307                 } else {
2308                         return false;
2309                 }
2310
2311                 if ( !$d ) {
2312                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2313                         return false;
2314                 }
2315
2316                 $output = $d->format( $formats[$outputtype] );
2317         } else {
2318                 if ( count( $da ) ) {
2319                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2320                         // We may want to handle that explicitly at some point
2321                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2322                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2323                 } elseif ( $strtime ) {
2324                         $uts = strtotime( $strtime );
2325                 }
2326
2327                 if ( $uts === false ) {
2328                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2329                         return false;
2330                 }
2331
2332                 if ( TS_UNIX == $outputtype ) {
2333                         return $uts;
2334                 }
2335                 $output = gmdate( $formats[$outputtype], $uts );
2336         }
2337
2338         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2339                 $output .= ' GMT';
2340         }
2341
2342         return $output;
2343 }
2344
2345 /**
2346  * Return a formatted timestamp, or null if input is null.
2347  * For dealing with nullable timestamp columns in the database.
2348  *
2349  * @param $outputtype Integer
2350  * @param $ts String
2351  * @return String
2352  */
2353 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2354         if( is_null( $ts ) ) {
2355                 return null;
2356         } else {
2357                 return wfTimestamp( $outputtype, $ts );
2358         }
2359 }
2360
2361 /**
2362  * Convenience function; returns MediaWiki timestamp for the present time.
2363  *
2364  * @return string
2365  */
2366 function wfTimestampNow() {
2367         # return NOW
2368         return wfTimestamp( TS_MW, time() );
2369 }
2370
2371 /**
2372  * Check if the operating system is Windows
2373  *
2374  * @return Bool: true if it's Windows, False otherwise.
2375  */
2376 function wfIsWindows() {
2377         static $isWindows = null;
2378         if ( $isWindows === null ) {
2379                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2380         }
2381         return $isWindows;
2382 }
2383
2384 /**
2385  * Check if we are running under HipHop
2386  *
2387  * @return Bool
2388  */
2389 function wfIsHipHop() {
2390         return function_exists( 'hphp_thread_set_warmup_enabled' );
2391 }
2392
2393 /**
2394  * Swap two variables
2395  *
2396  * @param $x Mixed
2397  * @param $y Mixed
2398  */
2399 function swap( &$x, &$y ) {
2400         $z = $x;
2401         $x = $y;
2402         $y = $z;
2403 }
2404
2405 /**
2406  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2407  * TEMP environment variables are then checked in sequence, and if none are set
2408  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2409  * or C:\Windows\Temp for Windows and hope for the best.
2410  * It is common to call it with tempnam().
2411  *
2412  * NOTE: When possible, use instead the tmpfile() function to create
2413  * temporary files to avoid race conditions on file creation, etc.
2414  *
2415  * @return String
2416  */
2417 function wfTempDir() {
2418         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2419                 $tmp = getenv( $var );
2420                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2421                         return $tmp;
2422                 }
2423         }
2424         if( function_exists( 'sys_get_temp_dir' ) ) {
2425                 return sys_get_temp_dir();
2426         }
2427         # Usual defaults
2428         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2429 }
2430
2431 /**
2432  * Make directory, and make all parent directories if they don't exist
2433  *
2434  * @param $dir String: full path to directory to create
2435  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2436  * @param $caller String: optional caller param for debugging.
2437  * @return bool
2438  */
2439 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2440         global $wgDirectoryMode;
2441
2442         if ( !is_null( $caller ) ) {
2443                 wfDebug( "$caller: called wfMkdirParents($dir)" );
2444         }
2445
2446         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2447                 return true;
2448         }
2449
2450         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2451
2452         if ( is_null( $mode ) ) {
2453                 $mode = $wgDirectoryMode;
2454         }
2455
2456         // Turn off the normal warning, we're doing our own below
2457         wfSuppressWarnings();
2458         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2459         wfRestoreWarnings();
2460
2461         if( !$ok ) {
2462                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2463                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2464         }
2465         return $ok;
2466 }
2467
2468 /**
2469  * Increment a statistics counter
2470  *
2471  * @param $key String
2472  * @param $count Int
2473  */
2474 function wfIncrStats( $key, $count = 1 ) {
2475         global $wgStatsMethod;
2476
2477         $count = intval( $count );
2478
2479         if( $wgStatsMethod == 'udp' ) {
2480                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2481                 static $socket;
2482
2483                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2484
2485                 if ( !$socket ) {
2486                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2487                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2488                         socket_sendto(
2489                                 $socket,
2490                                 $statline,
2491                                 strlen( $statline ),
2492                                 0,
2493                                 $wgUDPProfilerHost,
2494                                 $wgUDPProfilerPort
2495                         );
2496                 }
2497                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2498                 wfSuppressWarnings();
2499                 socket_sendto(
2500                         $socket,
2501                         $statline,
2502                         strlen( $statline ),
2503                         0,
2504                         $wgUDPProfilerHost,
2505                         $wgUDPProfilerPort
2506                 );
2507                 wfRestoreWarnings();
2508         } elseif( $wgStatsMethod == 'cache' ) {
2509                 global $wgMemc;
2510                 $key = wfMemcKey( 'stats', $key );
2511                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2512                         $wgMemc->add( $key, $count );
2513                 }
2514         } else {
2515                 // Disabled
2516         }
2517 }
2518
2519 /**
2520  * @param $nr Mixed: the number to format
2521  * @param $acc Integer: the number of digits after the decimal point, default 2
2522  * @param $round Boolean: whether or not to round the value, default true
2523  * @return float
2524  */
2525 function wfPercent( $nr, $acc = 2, $round = true ) {
2526         $ret = sprintf( "%.${acc}f", $nr );
2527         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2528 }
2529
2530 /**
2531  * Find out whether or not a mixed variable exists in a string
2532  *
2533  * @param $needle String
2534  * @param $str String
2535  * @param $insensitive Boolean
2536  * @return Boolean
2537  */
2538 function in_string( $needle, $str, $insensitive = false ) {
2539         $func = 'strpos';
2540         if( $insensitive ) $func = 'stripos';
2541
2542         return $func( $str, $needle ) !== false;
2543 }
2544
2545 function wfSpecialList( $page, $details ) {
2546         $details = $details ? ' ' . wfUILang()->getDirMark() . "($details)" : '';
2547         return $page . $details;
2548 }
2549
2550 /**
2551  * Safety wrapper around ini_get() for boolean settings.
2552  * The values returned from ini_get() are pre-normalized for settings
2553  * set via php.ini or php_flag/php_admin_flag... but *not*
2554  * for those set via php_value/php_admin_value.
2555  *
2556  * It's fairly common for people to use php_value instead of php_flag,
2557  * which can leave you with an 'off' setting giving a false positive
2558  * for code that just takes the ini_get() return value as a boolean.
2559  *
2560  * To make things extra interesting, setting via php_value accepts
2561  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2562  * Unrecognized values go false... again opposite PHP's own coercion
2563  * from string to bool.
2564  *
2565  * Luckily, 'properly' set settings will always come back as '0' or '1',
2566  * so we only have to worry about them and the 'improper' settings.
2567  *
2568  * I frickin' hate PHP... :P
2569  *
2570  * @param $setting String
2571  * @return Bool
2572  */
2573 function wfIniGetBool( $setting ) {
2574         $val = ini_get( $setting );
2575         // 'on' and 'true' can't have whitespace around them, but '1' can.
2576         return strtolower( $val ) == 'on'
2577                 || strtolower( $val ) == 'true'
2578                 || strtolower( $val ) == 'yes'
2579                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2580 }
2581
2582 /**
2583  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2584  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2585  *
2586  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2587  *                          should be omitted
2588  * @param $fileName String Name of the library, if not $extension.suffix
2589  * @return Bool - Whether or not the extension is loaded
2590  */
2591 function wfDl( $extension, $fileName = null ) {
2592         if( extension_loaded( $extension ) ) {
2593                 return true;
2594         }
2595
2596         $canDl = false;
2597         $sapi = php_sapi_name();
2598         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2599                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2600         {
2601                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2602                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2603         }
2604
2605         if( $canDl ) {
2606                 $fileName = $fileName ? $fileName : $extension;
2607                 if( wfIsWindows() ) {
2608                         $fileName = 'php_' . $fileName;
2609                 }
2610                 wfSuppressWarnings();
2611                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2612                 wfRestoreWarnings();
2613         }
2614         return extension_loaded( $extension );
2615 }
2616
2617 /**
2618  * Execute a shell command, with time and memory limits mirrored from the PHP
2619  * configuration if supported.
2620  * @param $cmd String Command line, properly escaped for shell.
2621  * @param &$retval optional, will receive the program's exit code.
2622  *                 (non-zero is usually failure)
2623  * @param $environ Array optional environment variables which should be
2624  *                 added to the executed command environment.
2625  * @return collected stdout as a string (trailing newlines stripped)
2626  */
2627 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2628         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2629
2630         static $disabled;
2631         if ( is_null( $disabled ) ) {
2632                 $disabled = false;
2633                 if( wfIniGetBool( 'safe_mode' ) ) {
2634                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2635                         $disabled = 'safemode';
2636                 } else {
2637                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2638                         $functions = array_map( 'trim', $functions );
2639                         $functions = array_map( 'strtolower', $functions );
2640                         if ( in_array( 'passthru', $functions ) ) {
2641                                 wfDebug( "passthru is in disabled_functions\n" );
2642                                 $disabled = 'passthru';
2643                         }
2644                 }
2645         }
2646         if ( $disabled ) {
2647                 $retval = 1;
2648                 return $disabled == 'safemode' ?
2649                         'Unable to run external programs in safe mode.' :
2650                         'Unable to run external programs, passthru() is disabled.';
2651         }
2652
2653         wfInitShellLocale();
2654
2655         $envcmd = '';
2656         foreach( $environ as $k => $v ) {
2657                 if ( wfIsWindows() ) {
2658                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2659                          * appear in the environment variable, so we must use carat escaping as documented in
2660                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2661                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2662                          * are listed there but doesn't appear to need it.
2663                          */
2664                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2665                 } else {
2666                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2667                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2668                          */
2669                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2670                 }
2671         }
2672         $cmd = $envcmd . $cmd;
2673
2674         if ( wfIsWindows() ) {
2675                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2676                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2677                 {
2678                         # Hack to work around PHP's flawed invocation of cmd.exe
2679                         # http://news.php.net/php.internals/21796
2680                         # Windows 9x doesn't accept any kind of quotes
2681                         $cmd = '"' . $cmd . '"';
2682                 }
2683         } elseif ( php_uname( 's' ) == 'Linux' ) {
2684                 $time = intval( $wgMaxShellTime );
2685                 $mem = intval( $wgMaxShellMemory );
2686                 $filesize = intval( $wgMaxShellFileSize );
2687
2688                 if ( $time > 0 && $mem > 0 ) {
2689                         $script = "$IP/bin/ulimit4.sh";
2690                         if ( is_executable( $script ) ) {
2691                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2692                         }
2693                 }
2694         }
2695         wfDebug( "wfShellExec: $cmd\n" );
2696
2697         $retval = 1; // error by default?
2698         ob_start();
2699         passthru( $cmd, $retval );
2700         $output = ob_get_contents();
2701         ob_end_clean();
2702
2703         if ( $retval == 127 ) {
2704                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2705         }
2706         return $output;
2707 }
2708
2709 /**
2710  * Workaround for http://bugs.php.net/bug.php?id=45132
2711  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2712  */
2713 function wfInitShellLocale() {
2714         static $done = false;
2715         if ( $done ) {
2716                 return;
2717         }
2718         $done = true;
2719         global $wgShellLocale;
2720         if ( !wfIniGetBool( 'safe_mode' ) ) {
2721                 putenv( "LC_CTYPE=$wgShellLocale" );
2722                 setlocale( LC_CTYPE, $wgShellLocale );
2723         }
2724 }
2725
2726 /**
2727  * This function works like "use VERSION" in Perl, the program will die with a
2728  * backtrace if the current version of PHP is less than the version provided
2729  *
2730  * This is useful for extensions which due to their nature are not kept in sync
2731  * with releases, and might depend on other versions of PHP than the main code
2732  *
2733  * Note: PHP might die due to parsing errors in some cases before it ever
2734  *       manages to call this function, such is life
2735  *
2736  * @see perldoc -f use
2737  *
2738  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2739  *                 a float
2740  */
2741 function wfUsePHP( $req_ver ) {
2742         $php_ver = PHP_VERSION;
2743
2744         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2745                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2746         }
2747 }
2748
2749 /**
2750  * This function works like "use VERSION" in Perl except it checks the version
2751  * of MediaWiki, the program will die with a backtrace if the current version
2752  * of MediaWiki is less than the version provided.
2753  *
2754  * This is useful for extensions which due to their nature are not kept in sync
2755  * with releases
2756  *
2757  * @see perldoc -f use
2758  *
2759  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2760  *                 a float
2761  */
2762 function wfUseMW( $req_ver ) {
2763         global $wgVersion;
2764
2765         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2766                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2767         }
2768 }
2769
2770 /**
2771  * Return the final portion of a pathname.
2772  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2773  * http://bugs.php.net/bug.php?id=33898
2774  *
2775  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2776  * We'll consider it so always, as we don't want \s in our Unix paths either.
2777  *
2778  * @param $path String
2779  * @param $suffix String: to remove if present
2780  * @return String
2781  */
2782 function wfBaseName( $path, $suffix = '' ) {
2783         $encSuffix = ( $suffix == '' )
2784                 ? ''
2785                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2786         $matches = array();
2787         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2788                 return $matches[1];
2789         } else {
2790                 return '';
2791         }
2792 }
2793
2794 /**
2795  * Generate a relative path name to the given file.
2796  * May explode on non-matching case-insensitive paths,
2797  * funky symlinks, etc.
2798  *
2799  * @param $path String: absolute destination path including target filename
2800  * @param $from String: Absolute source path, directory only
2801  * @return String
2802  */
2803 function wfRelativePath( $path, $from ) {
2804         // Normalize mixed input on Windows...
2805         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2806         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2807
2808         // Trim trailing slashes -- fix for drive root
2809         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2810         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2811
2812         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2813         $against = explode( DIRECTORY_SEPARATOR, $from );
2814
2815         if( $pieces[0] !== $against[0] ) {
2816                 // Non-matching Windows drive letters?
2817                 // Return a full path.
2818                 return $path;
2819         }
2820
2821         // Trim off common prefix
2822         while( count( $pieces ) && count( $against )
2823                 && $pieces[0] == $against[0] ) {
2824                 array_shift( $pieces );
2825                 array_shift( $against );
2826         }
2827
2828         // relative dots to bump us to the parent
2829         while( count( $against ) ) {
2830                 array_unshift( $pieces, '..' );
2831                 array_shift( $against );
2832         }
2833
2834         array_push( $pieces, wfBaseName( $path ) );
2835
2836         return implode( DIRECTORY_SEPARATOR, $pieces );
2837 }
2838
2839 /**
2840  * Do any deferred updates and clear the list
2841  *
2842  * @param $commit String: set to 'commit' to commit after every update to
2843  *                prevent lock contention
2844  */
2845 function wfDoUpdates( $commit = '' ) {
2846         global $wgDeferredUpdateList;
2847
2848         wfProfileIn( __METHOD__ );
2849
2850         // No need to get master connections in case of empty updates array
2851         if ( !count( $wgDeferredUpdateList ) ) {
2852                 wfProfileOut( __METHOD__ );
2853                 return;
2854         }
2855
2856         $doCommit = $commit == 'commit';
2857         if ( $doCommit ) {
2858                 $dbw = wfGetDB( DB_MASTER );
2859         }
2860
2861         foreach ( $wgDeferredUpdateList as $update ) {
2862                 $update->doUpdate();
2863
2864                 if ( $doCommit && $dbw->trxLevel() ) {
2865                         $dbw->commit();
2866                 }
2867         }
2868
2869         $wgDeferredUpdateList = array();
2870         wfProfileOut( __METHOD__ );
2871 }
2872
2873 /**
2874  * Convert an arbitrarily-long digit string from one numeric base
2875  * to another, optionally zero-padding to a minimum column width.
2876  *
2877  * Supports base 2 through 36; digit values 10-36 are represented
2878  * as lowercase letters a-z. Input is case-insensitive.
2879  *
2880  * @param $input String: of digits
2881  * @param $sourceBase Integer: 2-36
2882  * @param $destBase Integer: 2-36
2883  * @param $pad Integer: 1 or greater
2884  * @param $lowercase Boolean
2885  * @return String or false on invalid input
2886  */
2887 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2888         $input = strval( $input );
2889         if( $sourceBase < 2 ||
2890                 $sourceBase > 36 ||
2891                 $destBase < 2 ||
2892                 $destBase > 36 ||
2893                 $pad < 1 ||
2894                 $sourceBase != intval( $sourceBase ) ||
2895                 $destBase != intval( $destBase ) ||
2896                 $pad != intval( $pad ) ||
2897                 !is_string( $input ) ||
2898                 $input == '' ) {
2899                 return false;
2900         }
2901         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2902         $inDigits = array();
2903         $outChars = '';
2904
2905         // Decode and validate input string
2906         $input = strtolower( $input );
2907         for( $i = 0; $i < strlen( $input ); $i++ ) {
2908                 $n = strpos( $digitChars, $input[$i] );
2909                 if( $n === false || $n > $sourceBase ) {
2910                         return false;
2911                 }
2912                 $inDigits[] = $n;
2913         }
2914
2915         // Iterate over the input, modulo-ing out an output digit
2916         // at a time until input is gone.
2917         while( count( $inDigits ) ) {
2918                 $work = 0;
2919                 $workDigits = array();
2920
2921                 // Long division...
2922                 foreach( $inDigits as $digit ) {
2923                         $work *= $sourceBase;
2924                         $work += $digit;
2925
2926                         if( $work < $destBase ) {
2927                                 // Gonna need to pull another digit.
2928                                 if( count( $workDigits ) ) {
2929                                         // Avoid zero-padding; this lets us find
2930                                         // the end of the input very easily when
2931                                         // length drops to zero.
2932                                         $workDigits[] = 0;
2933                                 }
2934                         } else {
2935                                 // Finally! Actual division!
2936                                 $workDigits[] = intval( $work / $destBase );
2937
2938                                 // Isn't it annoying that most programming languages
2939                                 // don't have a single divide-and-remainder operator,
2940                                 // even though the CPU implements it that way?
2941                                 $work = $work % $destBase;
2942                         }
2943                 }
2944
2945                 // All that division leaves us with a remainder,
2946                 // which is conveniently our next output digit.
2947                 $outChars .= $digitChars[$work];
2948
2949                 // And we continue!
2950                 $inDigits = $workDigits;
2951         }
2952
2953         while( strlen( $outChars ) < $pad ) {
2954                 $outChars .= '0';
2955         }
2956
2957         return strrev( $outChars );
2958 }
2959
2960 /**
2961  * Create an object with a given name and an array of construct parameters
2962  *
2963  * @param $name String
2964  * @param $p Array: parameters
2965  * @deprecated since 1.18, warnings in 1.19, removal in 1.20
2966  */
2967 function wfCreateObject( $name, $p ) {
2968         wfDeprecated( __FUNCTION__ );
2969         return MWFunction::newObj( $name, $p );
2970 }
2971
2972 function wfHttpOnlySafe() {
2973         global $wgHttpOnlyBlacklist;
2974
2975         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
2976                 foreach( $wgHttpOnlyBlacklist as $regex ) {
2977                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
2978                                 return false;
2979                         }
2980                 }
2981         }
2982
2983         return true;
2984 }
2985
2986 /**
2987  * Initialise php session
2988  *
2989  * @param $sessionId Bool
2990  */
2991 function wfSetupSession( $sessionId = false ) {
2992         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
2993                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
2994         if( $wgSessionsInMemcached ) {
2995                 if ( !defined( 'MW_COMPILED' ) ) {
2996                         global $IP;
2997                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
2998                 }
2999                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
3000                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
3001
3002                 // It's necessary to register a shutdown function to call session_write_close(),
3003                 // because by the time the request shutdown function for the session module is
3004                 // called, $wgMemc has already been destroyed. Shutdown functions registered
3005                 // this way are called before object destruction.
3006                 register_shutdown_function( 'memsess_write_close' );
3007         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
3008                 # Only set this if $wgSessionHandler isn't null and session.save_handler
3009                 # hasn't already been set to the desired value (that causes errors)
3010                 ini_set( 'session.save_handler', $wgSessionHandler );
3011         }
3012         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
3013         wfDebugLog( 'cookie',
3014                 'session_set_cookie_params: "' . implode( '", "',
3015                         array(
3016                                 0,
3017                                 $wgCookiePath,
3018                                 $wgCookieDomain,
3019                                 $wgCookieSecure,
3020                                 $httpOnlySafe ) ) . '"' );
3021         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3022         session_cache_limiter( 'private, must-revalidate' );
3023         if ( $sessionId ) {
3024                 session_id( $sessionId );
3025         }
3026         wfSuppressWarnings();
3027         session_start();
3028         wfRestoreWarnings();
3029 }
3030
3031 /**
3032  * Get an object from the precompiled serialized directory
3033  *
3034  * @param $name String
3035  * @return Mixed: the variable on success, false on failure
3036  */
3037 function wfGetPrecompiledData( $name ) {
3038         global $IP;
3039
3040         $file = "$IP/serialized/$name";
3041         if ( file_exists( $file ) ) {
3042                 $blob = file_get_contents( $file );
3043                 if ( $blob ) {
3044                         return unserialize( $blob );
3045                 }
3046         }
3047         return false;
3048 }
3049
3050 /**
3051  * Get a cache key
3052  *
3053  * @param varargs
3054  * @return String
3055  */
3056 function wfMemcKey( /*... */ ) {
3057         $args = func_get_args();
3058         $key = wfWikiID() . ':' . implode( ':', $args );
3059         $key = str_replace( ' ', '_', $key );
3060         return $key;
3061 }
3062
3063 /**
3064  * Get a cache key for a foreign DB
3065  *
3066  * @param $db String
3067  * @param $prefix String
3068  * @param varargs String
3069  * @return String
3070  */
3071 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3072         $args = array_slice( func_get_args(), 2 );
3073         if ( $prefix ) {
3074                 $key = "$db-$prefix:" . implode( ':', $args );
3075         } else {
3076                 $key = $db . ':' . implode( ':', $args );
3077         }
3078         return $key;
3079 }
3080
3081 /**
3082  * Get an ASCII string identifying this wiki
3083  * This is used as a prefix in memcached keys
3084  *
3085  * @return String
3086  */
3087 function wfWikiID() {
3088         global $wgDBprefix, $wgDBname;
3089         if ( $wgDBprefix ) {
3090                 return "$wgDBname-$wgDBprefix";
3091         } else {
3092                 return $wgDBname;
3093         }
3094 }
3095
3096 /**
3097  * Split a wiki ID into DB name and table prefix
3098  *
3099  * @param $wiki String
3100  * @param $bits String
3101  */
3102 function wfSplitWikiID( $wiki ) {
3103         $bits = explode( '-', $wiki, 2 );
3104         if ( count( $bits ) < 2 ) {
3105                 $bits[] = '';
3106         }
3107         return $bits;
3108 }
3109
3110 /**
3111  * Get a Database object.
3112  *
3113  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3114  *            master (for write queries), DB_SLAVE for potentially lagged read
3115  *            queries, or an integer >= 0 for a particular server.
3116  *
3117  * @param $groups Mixed: query groups. An array of group names that this query
3118  *                belongs to. May contain a single string if the query is only
3119  *                in one group.
3120  *
3121  * @param $wiki String: the wiki ID, or false for the current wiki
3122  *
3123  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3124  * will always return the same object, unless the underlying connection or load
3125  * balancer is manually destroyed.
3126  *
3127  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3128  * updater to ensure that a proper database is being updated.
3129  *
3130  * @return DatabaseBase
3131  */
3132 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3133         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3134 }
3135
3136 /**
3137  * Get a load balancer object.
3138  *
3139  * @param $wiki String: wiki ID, or false for the current wiki
3140  * @return LoadBalancer
3141  */
3142 function wfGetLB( $wiki = false ) {
3143         return wfGetLBFactory()->getMainLB( $wiki );
3144 }
3145
3146 /**
3147  * Get the load balancer factory object
3148  *
3149  * @return LBFactory
3150  */
3151 function &wfGetLBFactory() {
3152         return LBFactory::singleton();
3153 }
3154
3155 /**
3156  * Find a file.
3157  * Shortcut for RepoGroup::singleton()->findFile()
3158  *
3159  * @param $title String or Title object
3160  * @param $options Associative array of options:
3161  *     time:           requested time for an archived image, or false for the
3162  *                     current version. An image object will be returned which was
3163  *                     created at the specified time.
3164  *
3165  *     ignoreRedirect: If true, do not follow file redirects
3166  *
3167  *     private:        If true, return restricted (deleted) files if the current
3168  *                     user is allowed to view them. Otherwise, such files will not
3169  *                     be found.
3170  *
3171  *     bypassCache:    If true, do not use the process-local cache of File objects
3172  *
3173  * @return File, or false if the file does not exist
3174  */
3175 function wfFindFile( $title, $options = array() ) {
3176         return RepoGroup::singleton()->findFile( $title, $options );
3177 }
3178
3179 /**
3180  * Get an object referring to a locally registered file.
3181  * Returns a valid placeholder object if the file does not exist.
3182  *
3183  * @param $title Title or String
3184  * @return File, or null if passed an invalid Title
3185  */
3186 function wfLocalFile( $title ) {
3187         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3188 }
3189
3190 /**
3191  * Should low-performance queries be disabled?
3192  *
3193  * @return Boolean
3194  * @codeCoverageIgnore
3195  */
3196 function wfQueriesMustScale() {
3197         global $wgMiserMode;
3198         return $wgMiserMode
3199                 || ( SiteStats::pages() > 100000
3200                 && SiteStats::edits() > 1000000
3201                 && SiteStats::users() > 10000 );
3202 }
3203
3204 /**
3205  * Get the path to a specified script file, respecting file
3206  * extensions; this is a wrapper around $wgScriptExtension etc.
3207  *
3208  * @param $script String: script filename, sans extension
3209  * @return String
3210  */
3211 function wfScript( $script = 'index' ) {
3212         global $wgScriptPath, $wgScriptExtension;
3213         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3214 }
3215
3216 /**
3217  * Get the script URL.
3218  *
3219  * @return script URL
3220  */
3221 function wfGetScriptUrl() {
3222         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3223                 #
3224                 # as it was called, minus the query string.
3225                 #
3226                 # Some sites use Apache rewrite rules to handle subdomains,
3227                 # and have PHP set up in a weird way that causes PHP_SELF
3228                 # to contain the rewritten URL instead of the one that the
3229                 # outside world sees.
3230                 #
3231                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3232                 # provides containing the "before" URL.
3233                 return $_SERVER['SCRIPT_NAME'];
3234         } else {
3235                 return $_SERVER['URL'];
3236         }
3237 }
3238
3239 /**
3240  * Convenience function converts boolean values into "true"
3241  * or "false" (string) values
3242  *
3243  * @param $value Boolean
3244  * @return String
3245  */
3246 function wfBoolToStr( $value ) {
3247         return $value ? 'true' : 'false';
3248 }
3249
3250 /**
3251  * Load an extension messages file
3252  *
3253  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3254  * @codeCoverageIgnore
3255  */
3256 function wfLoadExtensionMessages() {
3257         wfDeprecated( __FUNCTION__ );
3258 }
3259
3260 /**
3261  * Get a platform-independent path to the null file, e.g. /dev/null
3262  *
3263  * @return string
3264  */
3265 function wfGetNull() {
3266         return wfIsWindows()
3267                 ? 'NUL'
3268                 : '/dev/null';
3269 }
3270
3271 /**
3272  * Throws a warning that $function is deprecated
3273  *
3274  * @param $function String
3275  * @return null
3276  */
3277 function wfDeprecated( $function ) {
3278         static $functionsWarned = array();
3279         if ( !isset( $functionsWarned[$function] ) ) {
3280                 $functionsWarned[$function] = true;
3281                 wfWarn( "Use of $function is deprecated.", 2 );
3282         }
3283 }
3284
3285 /**
3286  * Send a warning either to the debug log or in a PHP error depending on
3287  * $wgDevelopmentWarnings
3288  *
3289  * @param $msg String: message to send
3290  * @param $callerOffset Integer: number of items to go back in the backtrace to
3291  *        find the correct caller (1 = function calling wfWarn, ...)
3292  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3293  *        is true
3294  */
3295 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3296         global $wgDevelopmentWarnings;
3297
3298         $callers = wfDebugBacktrace();
3299         if ( isset( $callers[$callerOffset + 1] ) ) {
3300                 $callerfunc = $callers[$callerOffset + 1];
3301                 $callerfile = $callers[$callerOffset];
3302                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3303                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3304                 } else {
3305                         $file = '(internal function)';
3306                 }
3307                 $func = '';
3308                 if ( isset( $callerfunc['class'] ) ) {
3309                         $func .= $callerfunc['class'] . '::';
3310                 }
3311                 if ( isset( $callerfunc['function'] ) ) {
3312                         $func .= $callerfunc['function'];
3313                 }
3314                 $msg .= " [Called from $func in $file]";
3315         }
3316
3317         if ( $wgDevelopmentWarnings ) {
3318                 trigger_error( $msg, $level );
3319         } else {
3320                 wfDebug( "$msg\n" );
3321         }
3322 }
3323
3324 /**
3325  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3326  * and waiting for it to go down, this waits for the slaves to catch up to the
3327  * master position. Use this when updating very large numbers of rows, as
3328  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3329  * a no-op if there are no slaves.
3330  *
3331  * @param $maxLag Integer (deprecated)
3332  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3333  * @return null
3334  */
3335 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3336         $lb = wfGetLB( $wiki );
3337         // bug 27975 - Don't try to wait for slaves if there are none
3338         // Prevents permission error when getting master position
3339         if ( $lb->getServerCount() > 1 ) {
3340                 $dbw = $lb->getConnection( DB_MASTER );
3341                 $pos = $dbw->getMasterPos();
3342                 $lb->waitForAll( $pos );
3343         }
3344 }
3345
3346 /**
3347  * Used to be used for outputting text in the installer/updater
3348  * @deprecated since 1.18, warnings in 1.19, remove in 1.20
3349  */
3350 function wfOut( $s ) {
3351         wfDeprecated( __METHOD__ );
3352         global $wgCommandLineMode;
3353         if ( $wgCommandLineMode ) {
3354                 echo $s;
3355         } else {
3356                 echo htmlspecialchars( $s );
3357         }
3358         flush();
3359 }
3360
3361 /**
3362  * Count down from $n to zero on the terminal, with a one-second pause
3363  * between showing each number. For use in command-line scripts.
3364  * @codeCoverageIgnore
3365  */
3366 function wfCountDown( $n ) {
3367         for ( $i = $n; $i >= 0; $i-- ) {
3368                 if ( $i != $n ) {
3369                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3370                 }
3371                 echo $i;
3372                 flush();
3373                 if ( $i ) {
3374                         sleep( 1 );
3375                 }
3376         }
3377         echo "\n";
3378 }
3379
3380 /**
3381  * Generate a random 32-character hexadecimal token.
3382  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3383  *              characters before hashing.
3384  * @return string
3385  * @codeCoverageIgnore
3386  */
3387 function wfGenerateToken( $salt = '' ) {
3388         $salt = serialize( $salt );
3389         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3390 }
3391
3392 /**
3393  * Replace all invalid characters with -
3394  *
3395  * @param $name Mixed: filename to process
3396  * @return String
3397  */
3398 function wfStripIllegalFilenameChars( $name ) {
3399         global $wgIllegalFileChars;
3400         $name = wfBaseName( $name );
3401         $name = preg_replace(
3402                 "/[^" . Title::legalChars() . "]" .
3403                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3404                         "/",
3405                 '-',
3406                 $name
3407         );
3408         return $name;
3409 }
3410
3411 /**
3412  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3413  *
3414  * @return Integer value memory was set to.
3415  */
3416 function wfMemoryLimit() {
3417         global $wgMemoryLimit;
3418         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3419         if( $memlimit != -1 ) {
3420                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3421                 if( $conflimit == -1 ) {
3422                         wfDebug( "Removing PHP's memory limit\n" );
3423                         wfSuppressWarnings();
3424                         ini_set( 'memory_limit', $conflimit );
3425                         wfRestoreWarnings();
3426                         return $conflimit;
3427                 } elseif ( $conflimit > $memlimit ) {
3428                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3429                         wfSuppressWarnings();
3430                         ini_set( 'memory_limit', $conflimit );
3431                         wfRestoreWarnings();
3432                         return $conflimit;
3433                 }
3434         }
3435         return $memlimit;
3436 }
3437
3438 /**
3439  * Converts shorthand byte notation to integer form
3440  *
3441  * @param $string String
3442  * @return Integer
3443  */
3444 function wfShorthandToInteger( $string = '' ) {
3445         $string = trim( $string );
3446         if( $string === '' ) {
3447                 return -1;
3448         }
3449         $last = $string[strlen( $string ) - 1];
3450         $val = intval( $string );
3451         switch( $last ) {
3452                 case 'g':
3453                 case 'G':
3454                         $val *= 1024;
3455                         // break intentionally missing
3456                 case 'm':
3457                 case 'M':
3458                         $val *= 1024;
3459                         // break intentionally missing
3460                 case 'k':
3461                 case 'K':
3462                         $val *= 1024;
3463         }
3464
3465         return $val;
3466 }
3467
3468 /**
3469  * Get the normalised IETF language tag
3470  * See unit test for examples.
3471  *
3472  * @param $code String: The language code.
3473  * @return $langCode String: The language code which complying with BCP 47 standards.
3474  */
3475 function wfBCP47( $code ) {
3476         $codeSegment = explode( '-', $code );
3477         $codeBCP = array();
3478         foreach ( $codeSegment as $segNo => $seg ) {
3479                 if ( count( $codeSegment ) > 0 ) {
3480                         // when previous segment is x, it is a private segment and should be lc
3481                         if( $segNo > 0 && strtolower( $codeSegment[($segNo - 1)] ) == 'x') {
3482                                 $codeBCP[$segNo] = strtolower( $seg );
3483                         // ISO 3166 country code
3484                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3485                                 $codeBCP[$segNo] = strtoupper( $seg );
3486                         // ISO 15924 script code
3487                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3488                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3489                         // Use lowercase for other cases
3490                         } else {
3491                                 $codeBCP[$segNo] = strtolower( $seg );
3492                         }
3493                 } else {
3494                 // Use lowercase for single segment
3495                         $codeBCP[$segNo] = strtolower( $seg );
3496                 }
3497         }
3498         $langCode = implode( '-', $codeBCP );
3499         return $langCode;
3500 }
3501
3502 /**
3503  * Get a cache object.
3504  *
3505  * @param $inputType integer Cache type, one the the CACHE_* constants.
3506  * @return BagOStuff
3507  */
3508 function wfGetCache( $inputType ) {
3509         return ObjectCache::getInstance( $inputType );
3510 }
3511
3512 /**
3513  * Get the main cache object
3514  *
3515  * @return BagOStuff
3516  */
3517 function wfGetMainCache() {
3518         global $wgMainCacheType;
3519         return ObjectCache::getInstance( $wgMainCacheType );
3520 }
3521
3522 /**
3523  * Get the cache object used by the message cache
3524  *
3525  * @return BagOStuff
3526  */
3527 function wfGetMessageCacheStorage() {
3528         global $wgMessageCacheType;
3529         return ObjectCache::getInstance( $wgMessageCacheType );
3530 }
3531
3532 /**
3533  * Get the cache object used by the parser cache
3534  *
3535  * @return BagOStuff
3536  */
3537 function wfGetParserCacheStorage() {
3538         global $wgParserCacheType;
3539         return ObjectCache::getInstance( $wgParserCacheType );
3540 }
3541
3542 /**
3543  * Call hook functions defined in $wgHooks
3544  *
3545  * @param $event String: event name
3546  * @param $args Array: parameters passed to hook functions
3547  * @return Boolean
3548  */
3549 function wfRunHooks( $event, $args = array() ) {
3550         return Hooks::run( $event, $args );
3551 }
3552
3553 /**
3554  * Unserialize a string to a PHP value without throwing E_NOTICE. Simply a
3555  * wrapper around unserialize()
3556  *
3557  * @param $data string The serialized string
3558  * @return mixed
3559  */
3560 function wfUnserialize( $data ) {
3561         wfSuppressWarnings();
3562         $result = unserialize( $data );
3563         wfRestoreWarnings();
3564         return $result;
3565 }