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  * @return String
 322  */
 323 function wfArrayToCGI( $array1, $array2 = null ) {
 324         if ( !is_null( $array2 ) ) {
 325                 $array1 = $array1 + $array2;
 326         }
 327
 328         $cgi = '';
 329         foreach ( $array1 as $key => $value ) {
 330                 if ( $value !== '' ) {
 331                         if ( $cgi != '' ) {
 332                                 $cgi .= '&';
 333                         }
 334                         if ( is_array( $value ) ) {
 335                                 $firstTime = true;
 336                                 foreach ( $value as $v ) {
 337                                         $cgi .= ( $firstTime ? '' : '&') .
 338                                                 urlencode( $key . '[]' ) . '=' .
 339                                                 urlencode( $v );
 340                                         $firstTime = false;
 341                                 }
 342                         } else {
 343                                 if ( is_object( $value ) ) {
 344                                         $value = $value->__toString();
 345                                 }
 346                                 $cgi .= urlencode( $key ) . '=' .
 347                                         urlencode( $value );
 348                         }
 349                 }
 350         }
 351         return $cgi;
 352 }
 353
 354 /**
 355  * This is the logical opposite of wfArrayToCGI(): it accepts a query string as
 356  * its argument and returns the same string in array form.  This allows compa-
 357  * tibility with legacy functions that accept raw query strings instead of nice
 358  * arrays.  Of course, keys and values are urldecode()d.  Don't try passing in-
 359  * valid query strings, or it will explode.
 360  *
 361  * @param $query String: query string
 362  * @return array Array version of input
 363  */
 364 function wfCgiToArray( $query ) {
 365         if( isset( $query[0] ) && $query[0] == '?' ) {
 366                 $query = substr( $query, 1 );
 367         }
 368         $bits = explode( '&', $query );
 369         $ret = array();
 370         foreach( $bits as $bit ) {
 371                 if( $bit === '' ) {
 372                         continue;
 373                 }
 374                 list( $key, $value ) = explode( '=', $bit );
 375                 $key = urldecode( $key );
 376                 $value = urldecode( $value );
 377                 $ret[$key] = $value;
 378         }
 379         return $ret;
 380 }
 381
 382 /**
 383  * Append a query string to an existing URL, which may or may not already
 384  * have query string parameters already. If so, they will be combined.
 385  *
 386  * @param $url String
 387  * @param $query Mixed: string or associative array
 388  * @return string
 389  */
 390 function wfAppendQuery( $url, $query ) {
 391         if ( is_array( $query ) ) {
 392                 $query = wfArrayToCGI( $query );
 393         }
 394         if( $query != '' ) {
 395                 if( false === strpos( $url, '?' ) ) {
 396                         $url .= '?';
 397                 } else {
 398                         $url .= '&';
 399                 }
 400                 $url .= $query;
 401         }
 402         return $url;
 403 }
 404
 405 /**
 406  * Expand a potentially local URL to a fully-qualified URL.  Assumes $wgServer
 407  * is correct.
 408  *
 409  * @todo this won't work with current-path-relative URLs
 410  * like "subdir/foo.html", etc.
 411  *
 412  * @param $url String: either fully-qualified or a local path + query
 413  * @return string Fully-qualified URL
 414  */
 415 function wfExpandUrl( $url ) {
 416         global $wgServer;
 417         if( substr( $url, 0, 2 ) == '//' ) {
 418                 $bits = wfParseUrl( $wgServer );
 419                 $scheme = $bits ? $bits['scheme'] : 'http';
 420                 return $scheme . ':' . $url;
 421         } elseif( substr( $url, 0, 1 ) == '/' ) {
 422                 return $wgServer . $url;
 423         } else {
 424                 return $url;
 425         }
 426 }
 427
 428 /**
 429  * Returns a regular expression of url protocols
 430  *
 431  * @return String
 432  */
 433 function wfUrlProtocols() {
 434         global $wgUrlProtocols;
 435
 436         static $retval = null;
 437         if ( !is_null( $retval ) ) {
 438                 return $retval;
 439         }
 440
 441         // Support old-style $wgUrlProtocols strings, for backwards compatibility
 442         // with LocalSettings files from 1.5
 443         if ( is_array( $wgUrlProtocols ) ) {
 444                 $protocols = array();
 445                 foreach ( $wgUrlProtocols as $protocol ) {
 446                         $protocols[] = preg_quote( $protocol, '/' );
 447                 }
 448
 449                 $retval = implode( '|', $protocols );
 450         } else {
 451                 $retval = $wgUrlProtocols;
 452         }
 453         return $retval;
 454 }
 455
 456 /**
 457  * parse_url() work-alike, but non-broken.  Differences:
 458  *
 459  * 1) Does not raise warnings on bad URLs (just returns false)
 460  * 2) Handles protocols that don't use :// (e.g., mailto: and news:) correctly
 461  * 3) Adds a "delimiter" element to the array, either '://' or ':' (see (2))
 462  *
 463  * @param $url String: a URL to parse
 464  * @return Array: bits of the URL in an associative array, per PHP docs
 465  */
 466 function wfParseUrl( $url ) {
 467         global $wgUrlProtocols; // Allow all protocols defined in DefaultSettings/LocalSettings.php
 468         wfSuppressWarnings();
 469         $bits = parse_url( $url );
 470         wfRestoreWarnings();
 471         if ( !$bits ) {
 472                 return false;
 473         }
 474
 475         // most of the protocols are followed by ://, but mailto: and sometimes news: not, check for it
 476         if ( in_array( $bits['scheme'] . '://', $wgUrlProtocols ) ) {
 477                 $bits['delimiter'] = '://';
 478         } elseif ( in_array( $bits['scheme'] . ':', $wgUrlProtocols ) ) {
 479                 $bits['delimiter'] = ':';
 480                 // parse_url detects for news: and mailto: the host part of an url as path
 481                 // We have to correct this wrong detection
 482                 if ( isset( $bits['path'] ) ) {
 483                         $bits['host'] = $bits['path'];
 484                         $bits['path'] = '';
 485                 }
 486         } else {
 487                 return false;
 488         }
 489
 490         /* Provide an empty host for eg. file:/// urls (see bug 28627) */
 491         if ( !isset( $bits['host'] ) ) {
 492                 $bits['host'] = '';
 493
 494                 /* parse_url loses the third / for file:///c:/ urls (but not on variants) */
 495                 if ( substr( $bits['path'], 0, 1 ) !== '/' ) {
 496                         $bits['path'] = '/' . $bits['path'];
 497                 }
 498         }
 499         return $bits;
 500 }
 501
 502 /**
 503  * Make a URL index, appropriate for the el_index field of externallinks.
 504  *
 505  * @param $url String
 506  * @return String
 507  */
 508 function wfMakeUrlIndex( $url ) {
 509         $bits = wfParseUrl( $url );
 510
 511         // Reverse the labels in the hostname, convert to lower case
 512         // For emails reverse domainpart only
 513         if ( $bits['scheme'] == 'mailto' ) {
 514                 $mailparts = explode( '@', $bits['host'], 2 );
 515                 if ( count( $mailparts ) === 2 ) {
 516                         $domainpart = strtolower( implode( '.', array_reverse( explode( '.', $mailparts[1] ) ) ) );
 517                 } else {
 518                         // No domain specified, don't mangle it
 519                         $domainpart = '';
 520                 }
 521                 $reversedHost = $domainpart . '@' . $mailparts[0];
 522         } else {
 523                 $reversedHost = strtolower( implode( '.', array_reverse( explode( '.', $bits['host'] ) ) ) );
 524         }
 525         // Add an extra dot to the end
 526         // Why? Is it in wrong place in mailto links?
 527         if ( substr( $reversedHost, -1, 1 ) !== '.' ) {
 528                 $reversedHost .= '.';
 529         }
 530         // Reconstruct the pseudo-URL
 531         $prot = $bits['scheme'];
 532         $index = $prot . $bits['delimiter'] . $reversedHost;
 533         // Leave out user and password. Add the port, path, query and fragment
 534         if ( isset( $bits['port'] ) ) {
 535                 $index .= ':' . $bits['port'];
 536         }
 537         if ( isset( $bits['path'] ) ) {
 538                 $index .= $bits['path'];
 539         } else {
 540                 $index .= '/';
 541         }
 542         if ( isset( $bits['query'] ) ) {
 543                 $index .= '?' . $bits['query'];
 544         }
 545         if ( isset( $bits['fragment'] ) ) {
 546                 $index .= '#' . $bits['fragment'];
 547         }
 548         return $index;
 549 }
 550
 551 /**
 552  * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 553  * In normal operation this is a NOP.
 554  *
 555  * Controlling globals:
 556  * $wgDebugLogFile - points to the log file
 557  * $wgProfileOnly - if set, normal debug messages will not be recorded.
 558  * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 559  * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 560  *
 561  * @param $text String
 562  * @param $logonly Bool: set true to avoid appearing in HTML when $wgDebugComments is set
 563  */
 564 function wfDebug( $text, $logonly = false ) {
 565         global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;
 566         global $wgDebugLogPrefix, $wgShowDebug;
 567
 568         static $cache = array(); // Cache of unoutputted messages
 569         $text = wfDebugTimer() . $text;
 570
 571         if ( !$wgDebugRawPage && wfIsDebugRawPage() ) {
 572                 return;
 573         }
 574
 575         if ( ( $wgDebugComments || $wgShowDebug ) && !$logonly ) {
 576                 $cache[] = $text;
 577
 578                 if ( isset( $wgOut ) && is_object( $wgOut ) ) {
 579                         // add the message and any cached messages to the output
 580                         array_map( array( $wgOut, 'debug' ), $cache );
 581                         $cache = array();
 582                 }
 583         }
 584         if ( wfRunHooks( 'Debug', array( $text, null /* no log group */ ) ) ) {
 585                 if ( $wgDebugLogFile != '' && !$wgProfileOnly ) {
 586                         # Strip unprintables; they can switch terminal modes when binary data
 587                         # gets dumped, which is pretty annoying.
 588                         $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
 589                         $text = $wgDebugLogPrefix . $text;
 590                         wfErrorLog( $text, $wgDebugLogFile );
 591                 }
 592         }
 593 }
 594
 595 /**
 596  * Returns true if debug logging should be suppressed if $wgDebugRawPage = false
 597  */
 598 function wfIsDebugRawPage() {
 599         static $cache;
 600         if ( $cache !== null ) {
 601                 return $cache;
 602         }
 603         # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
 604         if ( ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' )
 605                 || (
 606                         isset( $_SERVER['SCRIPT_NAME'] )
 607                         && substr( $_SERVER['SCRIPT_NAME'], -8 ) == 'load.php'
 608                 ) )
 609         {
 610                 $cache = true;
 611         } else {
 612                 $cache = false;
 613         }
 614         return $cache;
 615 }
 616
 617 /**
 618  * Get microsecond timestamps for debug logs
 619  *
 620  * @return string
 621  */
 622 function wfDebugTimer() {
 623         global $wgDebugTimestamps;
 624         if ( !$wgDebugTimestamps ) {
 625                 return '';
 626         }
 627         static $start = null;
 628
 629         if ( $start === null ) {
 630                 $start = microtime( true );
 631                 $prefix = "\n$start";
 632         } else {
 633                 $prefix = sprintf( "%6.4f", microtime( true ) - $start );
 634         }
 635
 636         return $prefix . '  ';
 637 }
 638
 639 /**
 640  * Send a line giving PHP memory usage.
 641  *
 642  * @param $exact Bool: print exact values instead of kilobytes (default: false)
 643  */
 644 function wfDebugMem( $exact = false ) {
 645         $mem = memory_get_usage();
 646         if( !$exact ) {
 647                 $mem = floor( $mem / 1024 ) . ' kilobytes';
 648         } else {
 649                 $mem .= ' bytes';
 650         }
 651         wfDebug( "Memory usage: $mem\n" );
 652 }
 653
 654 /**
 655  * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 656  * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 657  *
 658  * @param $logGroup String
 659  * @param $text String
 660  * @param $public Bool: whether to log the event in the public log if no private
 661  *                     log file is specified, (default true)
 662  */
 663 function wfDebugLog( $logGroup, $text, $public = true ) {
 664         global $wgDebugLogGroups, $wgShowHostnames;
 665         $text = trim( $text ) . "\n";
 666         if( isset( $wgDebugLogGroups[$logGroup] ) ) {
 667                 $time = wfTimestamp( TS_DB );
 668                 $wiki = wfWikiID();
 669                 if ( $wgShowHostnames ) {
 670                         $host = wfHostname();
 671                 } else {
 672                         $host = '';
 673                 }
 674                 if ( wfRunHooks( 'Debug', array( $text, $logGroup ) ) ) {
 675                         wfErrorLog( "$time $host $wiki: $text", $wgDebugLogGroups[$logGroup] );
 676                 }
 677         } elseif ( $public === true ) {
 678                 wfDebug( $text, true );
 679         }
 680 }
 681
 682 /**
 683  * Log for database errors
 684  *
 685  * @param $text String: database error message.
 686  */
 687 function wfLogDBError( $text ) {
 688         global $wgDBerrorLog, $wgDBname;
 689         if ( $wgDBerrorLog ) {
 690                 $host = trim(`hostname`);
 691                 $text = date( 'D M j G:i:s T Y' ) . "\t$host\t$wgDBname\t$text";
 692                 wfErrorLog( $text, $wgDBerrorLog );
 693         }
 694 }
 695
 696 /**
 697  * Log to a file without getting "file size exceeded" signals.
 698  *
 699  * Can also log to TCP or UDP with the syntax udp://host:port/prefix. This will
 700  * send lines to the specified port, prefixed by the specified prefix and a space.
 701  *
 702  * @param $text String
 703  * @param $file String filename
 704  */
 705 function wfErrorLog( $text, $file ) {
 706         if ( substr( $file, 0, 4 ) == 'udp:' ) {
 707                 # Needs the sockets extension
 708                 if ( preg_match( '!^(tcp|udp):(?://)?\[([0-9a-fA-F:]+)\]:(\d+)(?:/(.*))?$!', $file, $m ) ) {
 709                         // IPv6 bracketed host
 710                         $host = $m[2];
 711                         $port = intval( $m[3] );
 712                         $prefix = isset( $m[4] ) ? $m[4] : false;
 713                         $domain = AF_INET6;
 714                 } elseif ( preg_match( '!^(tcp|udp):(?://)?([a-zA-Z0-9.-]+):(\d+)(?:/(.*))?$!', $file, $m ) ) {
 715                         $host = $m[2];
 716                         if ( !IP::isIPv4( $host ) ) {
 717                                 $host = gethostbyname( $host );
 718                         }
 719                         $port = intval( $m[3] );
 720                         $prefix = isset( $m[4] ) ? $m[4] : false;
 721                         $domain = AF_INET;
 722                 } else {
 723                         throw new MWException( __METHOD__ . ': Invalid UDP specification' );
 724                 }
 725
 726                 // Clean it up for the multiplexer
 727                 if ( strval( $prefix ) !== '' ) {
 728                         $text = preg_replace( '/^/m', $prefix . ' ', $text );
 729
 730                         // Limit to 64KB
 731                         if ( strlen( $text ) > 65534 ) {
 732                                 $text = substr( $text, 0, 65534 );
 733                         }
 734
 735                         if ( substr( $text, -1 ) != "\n" ) {
 736                                 $text .= "\n";
 737                         }
 738                 } elseif ( strlen( $text ) > 65535 ) {
 739                         $text = substr( $text, 0, 65535 );
 740                 }
 741
 742                 $sock = socket_create( $domain, SOCK_DGRAM, SOL_UDP );
 743                 if ( !$sock ) {
 744                         return;
 745                 }
 746                 socket_sendto( $sock, $text, strlen( $text ), 0, $host, $port );
 747                 socket_close( $sock );
 748         } else {
 749                 wfSuppressWarnings();
 750                 $exists = file_exists( $file );
 751                 $size = $exists ? filesize( $file ) : false;
 752                 if ( !$exists || ( $size !== false && $size + strlen( $text ) < 0x7fffffff ) ) {
 753                         file_put_contents( $file, $text, FILE_APPEND );
 754                 }
 755                 wfRestoreWarnings();
 756         }
 757 }
 758
 759 /**
 760  * @todo document
 761  */
 762 function wfLogProfilingData() {
 763         global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
 764         global $wgProfileLimit, $wgUser;
 765
 766         $profiler = Profiler::instance();
 767
 768         # Profiling must actually be enabled...
 769         if ( $profiler->isStub() ) {
 770                 return;
 771         }
 772
 773         // Get total page request time and only show pages that longer than
 774         // $wgProfileLimit time (default is 0)
 775         $now = wfTime();
 776         $elapsed = $now - $wgRequestTime;
 777         if ( $elapsed <= $wgProfileLimit ) {
 778                 return;
 779         }
 780
 781         $profiler->logData();
 782
 783         // Check whether this should be logged in the debug file.
 784         if ( $wgDebugLogFile == '' || ( !$wgDebugRawPage && wfIsDebugRawPage() ) ) {
 785                 return;
 786         }
 787
 788         $forward = '';
 789         if ( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
 790                 $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
 791         }
 792         if ( !empty( $_SERVER['HTTP_CLIENT_IP'] ) ) {
 793                 $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
 794         }
 795         if ( !empty( $_SERVER['HTTP_FROM'] ) ) {
 796                 $forward .= ' from ' . $_SERVER['HTTP_FROM'];
 797         }
 798         if ( $forward ) {
 799                 $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
 800         }
 801         // Don't load $wgUser at this late stage just for statistics purposes
 802         // @todo FIXME: We can detect some anons even if it is not loaded. See User::getId()
 803         if ( $wgUser->isItemLoaded( 'id' ) && $wgUser->isAnon() ) {
 804                 $forward .= ' anon';
 805         }
 806         $log = sprintf( "%s\t%04.3f\t%s\n",
 807                 gmdate( 'YmdHis' ), $elapsed,
 808                 urldecode( $wgRequest->getRequestURL() . $forward ) );
 809
 810         wfErrorLog( $log . $profiler->getOutput(), $wgDebugLogFile );
 811 }
 812
 813 /**
 814  * Check if the wiki read-only lock file is present. This can be used to lock
 815  * off editing functions, but doesn't guarantee that the database will not be
 816  * modified.
 817  *
 818  * @return bool
 819  */
 820 function wfReadOnly() {
 821         global $wgReadOnlyFile, $wgReadOnly;
 822
 823         if ( !is_null( $wgReadOnly ) ) {
 824                 return (bool)$wgReadOnly;
 825         }
 826         if ( $wgReadOnlyFile == '' ) {
 827                 return false;
 828         }
 829         // Set $wgReadOnly for faster access next time
 830         if ( is_file( $wgReadOnlyFile ) ) {
 831                 $wgReadOnly = file_get_contents( $wgReadOnlyFile );
 832         } else {
 833                 $wgReadOnly = false;
 834         }
 835         return (bool)$wgReadOnly;
 836 }
 837
 838 function wfReadOnlyReason() {
 839         global $wgReadOnly;
 840         wfReadOnly();
 841         return $wgReadOnly;
 842 }
 843
 844 /**
 845  * Return a Language object from $langcode
 846  *
 847  * @param $langcode Mixed: either:
 848  *                  - a Language object
 849  *                  - code of the language to get the message for, if it is
 850  *                    a valid code create a language for that language, if
 851  *                    it is a string but not a valid code then make a basic
 852  *                    language object
 853  *                  - a boolean: if it's false then use the current users
 854  *                    language (as a fallback for the old parameter
 855  *                    functionality), or if it is true then use the wikis
 856  * @return Language object
 857  */
 858 function wfGetLangObj( $langcode = false ) {
 859         # Identify which language to get or create a language object for.
 860         # Using is_object here due to Stub objects.
 861         if( is_object( $langcode ) ) {
 862                 # Great, we already have the object (hopefully)!
 863                 return $langcode;
 864         }
 865
 866         global $wgContLang, $wgLanguageCode;
 867         if( $langcode === true || $langcode === $wgLanguageCode ) {
 868                 # $langcode is the language code of the wikis content language object.
 869                 # or it is a boolean and value is true
 870                 return $wgContLang;
 871         }
 872
 873         global $wgLang;
 874         if( $langcode === false || $langcode === $wgLang->getCode() ) {
 875                 # $langcode is the language code of user language object.
 876                 # or it was a boolean and value is false
 877                 return $wgLang;
 878         }
 879
 880         $validCodes = array_keys( Language::getLanguageNames() );
 881         if( in_array( $langcode, $validCodes ) ) {
 882                 # $langcode corresponds to a valid language.
 883                 return Language::factory( $langcode );
 884         }
 885
 886         # $langcode is a string, but not a valid language code; use content language.
 887         wfDebug( "Invalid language code passed to wfGetLangObj, falling back to content language.\n" );
 888         return $wgContLang;
 889 }
 890
 891 /**
 892  * Use this instead of $wgContLang, when working with user interface.
 893  * User interface is currently hard coded according to wiki content language
 894  * in many ways, especially regarding to text direction. There is lots stuff
 895  * to fix, hence this function to keep the old behaviour unless the global
 896  * $wgBetterDirectionality is enabled (or removed when everything works).
 897  *
 898  * @return Language
 899  */
 900 function wfUILang() {
 901         global $wgBetterDirectionality;
 902         return wfGetLangObj( !$wgBetterDirectionality );
 903 }
 904
 905 /**
 906  * This is the new function for getting translated interface messages.
 907  * See the Message class for documentation how to use them.
 908  * The intention is that this function replaces all old wfMsg* functions.
 909  * @param $key \string Message key.
 910  * Varargs: normal message parameters.
 911  * @return Message
 912  * @since 1.17
 913  */
 914 function wfMessage( $key /*...*/) {
 915         $params = func_get_args();
 916         array_shift( $params );
 917         if ( isset( $params[0] ) && is_array( $params[0] ) ) {
 918                 $params = $params[0];
 919         }
 920         return new Message( $key, $params );
 921 }
 922
 923 /**
 924  * This function accepts multiple message keys and returns a message instance
 925  * for the first message which is non-empty. If all messages are empty then an
 926  * instance of the first message key is returned.
 927  * @param varargs: message keys
 928  * @return Message
 929  * @since 1.18
 930  */
 931 function wfMessageFallback( /*...*/ ) {
 932         $args = func_get_args();
 933         return MWFunction::callArray( 'Message::newFallbackSequence', $args );
 934 }
 935
 936 /**
 937  * Get a message from anywhere, for the current user language.
 938  *
 939  * Use wfMsgForContent() instead if the message should NOT
 940  * change depending on the user preferences.
 941  *
 942  * @param $key String: lookup key for the message, usually
 943  *    defined in languages/Language.php
 944  *
 945  * Parameters to the message, which can be used to insert variable text into
 946  * it, can be passed to this function in the following formats:
 947  * - One per argument, starting at the second parameter
 948  * - As an array in the second parameter
 949  * These are not shown in the function definition.
 950  *
 951  * @return String
 952  */
 953 function wfMsg( $key ) {
 954         $args = func_get_args();
 955         array_shift( $args );
 956         return wfMsgReal( $key, $args );
 957 }
 958
 959 /**
 960  * Same as above except doesn't transform the message
 961  *
 962  * @param $key String
 963  * @return String
 964  */
 965 function wfMsgNoTrans( $key ) {
 966         $args = func_get_args();
 967         array_shift( $args );
 968         return wfMsgReal( $key, $args, true, false, false );
 969 }
 970
 971 /**
 972  * Get a message from anywhere, for the current global language
 973  * set with $wgLanguageCode.
 974  *
 975  * Use this if the message should NOT change dependent on the
 976  * language set in the user's preferences. This is the case for
 977  * most text written into logs, as well as link targets (such as
 978  * the name of the copyright policy page). Link titles, on the
 979  * other hand, should be shown in the UI language.
 980  *
 981  * Note that MediaWiki allows users to change the user interface
 982  * language in their preferences, but a single installation
 983  * typically only contains content in one language.
 984  *
 985  * Be wary of this distinction: If you use wfMsg() where you should
 986  * use wfMsgForContent(), a user of the software may have to
 987  * customize potentially hundreds of messages in
 988  * order to, e.g., fix a link in every possible language.
 989  *
 990  * @param $key String: lookup key for the message, usually
 991  *     defined in languages/Language.php
 992  * @return String
 993  */
 994 function wfMsgForContent( $key ) {
 995         global $wgForceUIMsgAsContentMsg;
 996         $args = func_get_args();
 997         array_shift( $args );
 998         $forcontent = true;
 999         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1000                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1001         {
1002                 $forcontent = false;
1003         }
1004         return wfMsgReal( $key, $args, true, $forcontent );
1005 }
1006
1007 /**
1008  * Same as above except doesn't transform the message
1009  *
1010  * @param $key String
1011  * @return String
1012  */
1013 function wfMsgForContentNoTrans( $key ) {
1014         global $wgForceUIMsgAsContentMsg;
1015         $args = func_get_args();
1016         array_shift( $args );
1017         $forcontent = true;
1018         if( is_array( $wgForceUIMsgAsContentMsg ) &&
1019                 in_array( $key, $wgForceUIMsgAsContentMsg ) )
1020         {
1021                 $forcontent = false;
1022         }
1023         return wfMsgReal( $key, $args, true, $forcontent, false );
1024 }
1025
1026 /**
1027  * Really get a message
1028  *
1029  * @param $key String: key to get.
1030  * @param $args
1031  * @param $useDB Boolean
1032  * @param $forContent Mixed: Language code, or false for user lang, true for content lang.
1033  * @param $transform Boolean: Whether or not to transform the message.
1034  * @return String: the requested message.
1035  */
1036 function wfMsgReal( $key, $args, $useDB = true, $forContent = false, $transform = true ) {
1037         wfProfileIn( __METHOD__ );
1038         $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
1039         $message = wfMsgReplaceArgs( $message, $args );
1040         wfProfileOut( __METHOD__ );
1041         return $message;
1042 }
1043
1044 /**
1045  * Fetch a message string value, but don't replace any keys yet.
1046  *
1047  * @param $key String
1048  * @param $useDB Bool
1049  * @param $langCode String: Code of the language to get the message for, or
1050  *                  behaves as a content language switch if it is a boolean.
1051  * @param $transform Boolean: whether to parse magic words, etc.
1052  * @return string
1053  */
1054 function wfMsgGetKey( $key, $useDB = true, $langCode = false, $transform = true ) {
1055         wfRunHooks( 'NormalizeMessageKey', array( &$key, &$useDB, &$langCode, &$transform ) );
1056
1057         $cache = MessageCache::singleton();
1058         $message = $cache->get( $key, $useDB, $langCode );
1059         if( $message === false ) {
1060                 $message = '&lt;' . htmlspecialchars( $key ) . '&gt;';
1061         } elseif ( $transform ) {
1062                 $message = $cache->transform( $message );
1063         }
1064         return $message;
1065 }
1066
1067 /**
1068  * Replace message parameter keys on the given formatted output.
1069  *
1070  * @param $message String
1071  * @param $args Array
1072  * @return string
1073  * @private
1074  */
1075 function wfMsgReplaceArgs( $message, $args ) {
1076         # Fix windows line-endings
1077         # Some messages are split with explode("\n", $msg)
1078         $message = str_replace( "\r", '', $message );
1079
1080         // Replace arguments
1081         if ( count( $args ) ) {
1082                 if ( is_array( $args[0] ) ) {
1083                         $args = array_values( $args[0] );
1084                 }
1085                 $replacementKeys = array();
1086                 foreach( $args as $n => $param ) {
1087                         $replacementKeys['$' . ( $n + 1 )] = $param;
1088                 }
1089                 $message = strtr( $message, $replacementKeys );
1090         }
1091
1092         return $message;
1093 }
1094
1095 /**
1096  * Return an HTML-escaped version of a message.
1097  * Parameter replacements, if any, are done *after* the HTML-escaping,
1098  * so parameters may contain HTML (eg links or form controls). Be sure
1099  * to pre-escape them if you really do want plaintext, or just wrap
1100  * the whole thing in htmlspecialchars().
1101  *
1102  * @param $key String
1103  * @param string ... parameters
1104  * @return string
1105  */
1106 function wfMsgHtml( $key ) {
1107         $args = func_get_args();
1108         array_shift( $args );
1109         return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key ) ), $args );
1110 }
1111
1112 /**
1113  * Return an HTML version of message
1114  * Parameter replacements, if any, are done *after* parsing the wiki-text message,
1115  * so parameters may contain HTML (eg links or form controls). Be sure
1116  * to pre-escape them if you really do want plaintext, or just wrap
1117  * the whole thing in htmlspecialchars().
1118  *
1119  * @param $key String
1120  * @param string ... parameters
1121  * @return string
1122  */
1123 function wfMsgWikiHtml( $key ) {
1124         $args = func_get_args();
1125         array_shift( $args );
1126         return wfMsgReplaceArgs(
1127                 MessageCache::singleton()->parse( wfMsgGetKey( $key ), null, /* can't be set to false */ true )->getText(),
1128                 $args );
1129 }
1130
1131 /**
1132  * Returns message in the requested format
1133  * @param $key String: key of the message
1134  * @param $options Array: processing rules. Can take the following options:
1135  *   <i>parse</i>: parses wikitext to HTML
1136  *   <i>parseinline</i>: parses wikitext to HTML and removes the surrounding
1137  *       p's added by parser or tidy
1138  *   <i>escape</i>: filters message through htmlspecialchars
1139  *   <i>escapenoentities</i>: same, but allows entity references like &#160; through
1140  *   <i>replaceafter</i>: parameters are substituted after parsing or escaping
1141  *   <i>parsemag</i>: transform the message using magic phrases
1142  *   <i>content</i>: fetch message for content language instead of interface
1143  * Also can accept a single associative argument, of the form 'language' => 'xx':
1144  *   <i>language</i>: Language object or language code to fetch message for
1145  *       (overriden by <i>content</i>).
1146  * Behavior for conflicting options (e.g., parse+parseinline) is undefined.
1147  *
1148  * @return String
1149  */
1150 function wfMsgExt( $key, $options ) {
1151         $args = func_get_args();
1152         array_shift( $args );
1153         array_shift( $args );
1154         $options = (array)$options;
1155
1156         foreach( $options as $arrayKey => $option ) {
1157                 if( !preg_match( '/^[0-9]+|language$/', $arrayKey ) ) {
1158                         # An unknown index, neither numeric nor "language"
1159                         wfWarn( "wfMsgExt called with incorrect parameter key $arrayKey", 1, E_USER_WARNING );
1160                 } elseif( preg_match( '/^[0-9]+$/', $arrayKey ) && !in_array( $option,
1161                 array( 'parse', 'parseinline', 'escape', 'escapenoentities',
1162                 'replaceafter', 'parsemag', 'content' ) ) ) {
1163                         # A numeric index with unknown value
1164                         wfWarn( "wfMsgExt called with incorrect parameter $option", 1, E_USER_WARNING );
1165                 }
1166         }
1167
1168         if( in_array( 'content', $options, true ) ) {
1169                 $forContent = true;
1170                 $langCode = true;
1171                 $langCodeObj = null;
1172         } elseif( array_key_exists( 'language', $options ) ) {
1173                 $forContent = false;
1174                 $langCode = wfGetLangObj( $options['language'] );
1175                 $langCodeObj = $langCode;
1176         } else {
1177                 $forContent = false;
1178                 $langCode = false;
1179                 $langCodeObj = null;
1180         }
1181
1182         $string = wfMsgGetKey( $key, /*DB*/true, $langCode, /*Transform*/false );
1183
1184         if( !in_array( 'replaceafter', $options, true ) ) {
1185                 $string = wfMsgReplaceArgs( $string, $args );
1186         }
1187
1188         $messageCache = MessageCache::singleton();
1189         if( in_array( 'parse', $options, true ) ) {
1190                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1191         } elseif ( in_array( 'parseinline', $options, true ) ) {
1192                 $string = $messageCache->parse( $string, null, true, !$forContent, $langCodeObj )->getText();
1193                 $m = array();
1194                 if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
1195                         $string = $m[1];
1196                 }
1197         } elseif ( in_array( 'parsemag', $options, true ) ) {
1198                 $string = $messageCache->transform( $string,
1199                                 !$forContent, $langCodeObj );
1200         }
1201
1202         if ( in_array( 'escape', $options, true ) ) {
1203                 $string = htmlspecialchars ( $string );
1204         } elseif ( in_array( 'escapenoentities', $options, true ) ) {
1205                 $string = Sanitizer::escapeHtmlAllowEntities( $string );
1206         }
1207
1208         if( in_array( 'replaceafter', $options, true ) ) {
1209                 $string = wfMsgReplaceArgs( $string, $args );
1210         }
1211
1212         return $string;
1213 }
1214
1215 /**
1216  * Since wfMsg() and co suck, they don't return false if the message key they
1217  * looked up didn't exist but a XHTML string, this function checks for the
1218  * nonexistance of messages by checking the MessageCache::get() result directly.
1219  *
1220  * @param $key      String: the message key looked up
1221  * @return Boolean True if the message *doesn't* exist.
1222  */
1223 function wfEmptyMsg( $key ) {
1224         return MessageCache::singleton()->get( $key, /*useDB*/true, /*content*/false ) === false;
1225 }
1226
1227 /**
1228  * Print an error message and die, returning nonzero to the shell if any.  Plain die()
1229  * fails to return nonzero to the shell if you pass a string.  Entry points may customise
1230  * this function to return a prettier error message, but implementations must not assume
1231  * access to any of the usual MediaWiki infrastructure (AutoLoader, localisation, database,
1232  * etc).  This should not be called directly once $wgFullyInitialised is set; instead,
1233  * throw an exception and let Exception.php handle whether or not it's possible to show
1234  * a prettier error.
1235  *
1236  * @param $msg String
1237  */
1238 if( !function_exists( 'wfDie' ) ){
1239         function wfDie( $msg = '' ) {
1240                 echo $msg;
1241                 die( 1 );
1242         }
1243 }
1244
1245 /**
1246  * Throw a debugging exception. This function previously once exited the process,
1247  * but now throws an exception instead, with similar results.
1248  *
1249  * @param $msg String: message shown when dieing.
1250  */
1251 function wfDebugDieBacktrace( $msg = '' ) {
1252         throw new MWException( $msg );
1253 }
1254
1255 /**
1256  * Fetch server name for use in error reporting etc.
1257  * Use real server name if available, so we know which machine
1258  * in a server farm generated the current page.
1259  *
1260  * @return string
1261  */
1262 function wfHostname() {
1263         static $host;
1264         if ( is_null( $host ) ) {
1265                 if ( function_exists( 'posix_uname' ) ) {
1266                         // This function not present on Windows
1267                         $uname = posix_uname();
1268                 } else {
1269                         $uname = false;
1270                 }
1271                 if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
1272                         $host = $uname['nodename'];
1273                 } elseif ( getenv( 'COMPUTERNAME' ) ) {
1274                         # Windows computer name
1275                         $host = getenv( 'COMPUTERNAME' );
1276                 } else {
1277                         # This may be a virtual server.
1278                         $host = $_SERVER['SERVER_NAME'];
1279                 }
1280         }
1281         return $host;
1282 }
1283
1284 /**
1285  * Returns a HTML comment with the elapsed time since request.
1286  * This method has no side effects.
1287  *
1288  * @return string
1289  */
1290 function wfReportTime() {
1291         global $wgRequestTime, $wgShowHostnames;
1292
1293         $now = wfTime();
1294         $elapsed = $now - $wgRequestTime;
1295
1296         return $wgShowHostnames
1297                 ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
1298                 : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
1299 }
1300
1301 /**
1302  * Safety wrapper for debug_backtrace().
1303  *
1304  * With Zend Optimizer 3.2.0 loaded, this causes segfaults under somewhat
1305  * murky circumstances, which may be triggered in part by stub objects
1306  * or other fancy talkin'.
1307  *
1308  * Will return an empty array if Zend Optimizer is detected or if
1309  * debug_backtrace is disabled, otherwise the output from
1310  * debug_backtrace() (trimmed).
1311  *
1312  * @return array of backtrace information
1313  */
1314 function wfDebugBacktrace( $limit = 0 ) {
1315         static $disabled = null;
1316
1317         if( extension_loaded( 'Zend Optimizer' ) ) {
1318                 wfDebug( "Zend Optimizer detected; skipping debug_backtrace for safety.\n" );
1319                 return array();
1320         }
1321
1322         if ( is_null( $disabled ) ) {
1323                 $disabled = false;
1324                 $functions = explode( ',', ini_get( 'disable_functions' ) );
1325                 $functions = array_map( 'trim', $functions );
1326                 $functions = array_map( 'strtolower', $functions );
1327                 if ( in_array( 'debug_backtrace', $functions ) ) {
1328                         wfDebug( "debug_backtrace is in disabled_functions\n" );
1329                         $disabled = true;
1330                 }
1331         }
1332         if ( $disabled ) {
1333                 return array();
1334         }
1335
1336         if ( $limit && version_compare( PHP_VERSION, '5.4.0', '>=' ) ) {
1337                 return array_slice( debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, 1 ), 1 );
1338         } else {
1339                 return array_slice( debug_backtrace(), 1 );
1340         }
1341 }
1342
1343 /**
1344  * Get a debug backtrace as a string
1345  *
1346  * @return string
1347  */
1348 function wfBacktrace() {
1349         global $wgCommandLineMode;
1350
1351         if ( $wgCommandLineMode ) {
1352                 $msg = '';
1353         } else {
1354                 $msg = "<ul>\n";
1355         }
1356         $backtrace = wfDebugBacktrace();
1357         foreach( $backtrace as $call ) {
1358                 if( isset( $call['file'] ) ) {
1359                         $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
1360                         $file = $f[count( $f ) - 1];
1361                 } else {
1362                         $file = '-';
1363                 }
1364                 if( isset( $call['line'] ) ) {
1365                         $line = $call['line'];
1366                 } else {
1367                         $line = '-';
1368                 }
1369                 if ( $wgCommandLineMode ) {
1370                         $msg .= "$file line $line calls ";
1371                 } else {
1372                         $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
1373                 }
1374                 if( !empty( $call['class'] ) ) {
1375                         $msg .= $call['class'] . $call['type'];
1376                 }
1377                 $msg .= $call['function'] . '()';
1378
1379                 if ( $wgCommandLineMode ) {
1380                         $msg .= "\n";
1381                 } else {
1382                         $msg .= "</li>\n";
1383                 }
1384         }
1385         if ( $wgCommandLineMode ) {
1386                 $msg .= "\n";
1387         } else {
1388                 $msg .= "</ul>\n";
1389         }
1390
1391         return $msg;
1392 }
1393
1394 /**
1395  * Get the name of the function which called this function
1396  *
1397  * @param $level Int
1398  * @return Bool|string
1399  */
1400 function wfGetCaller( $level = 2 ) {
1401         $backtrace = wfDebugBacktrace( $level );
1402         if ( isset( $backtrace[$level] ) ) {
1403                 return wfFormatStackFrame( $backtrace[$level] );
1404         } else {
1405                 $caller = 'unknown';
1406         }
1407         return $caller;
1408 }
1409
1410 /**
1411  * Return a string consisting of callers in the stack. Useful sometimes
1412  * for profiling specific points.
1413  *
1414  * @param $limit The maximum depth of the stack frame to return, or false for
1415  *               the entire stack.
1416  * @return String
1417  */
1418 function wfGetAllCallers( $limit = 3 ) {
1419         $trace = array_reverse( wfDebugBacktrace() );
1420         if ( !$limit || $limit > count( $trace ) - 1 ) {
1421                 $limit = count( $trace ) - 1;
1422         }
1423         $trace = array_slice( $trace, -$limit - 1, $limit );
1424         return implode( '/', array_map( 'wfFormatStackFrame', $trace ) );
1425 }
1426
1427 /**
1428  * Return a string representation of frame
1429  *
1430  * @param $frame Array
1431  * @return Bool
1432  */
1433 function wfFormatStackFrame( $frame ) {
1434         return isset( $frame['class'] ) ?
1435                 $frame['class'] . '::' . $frame['function'] :
1436                 $frame['function'];
1437 }
1438
1439
1440 /* Some generic result counters, pulled out of SearchEngine */
1441
1442
1443 /**
1444  * @todo document
1445  *
1446  * @param $offset Int
1447  * @param $limit Int
1448  * @return String
1449  */
1450 function wfShowingResults( $offset, $limit ) {
1451         global $wgLang;
1452         return wfMsgExt(
1453                 'showingresults',
1454                 array( 'parseinline' ),
1455                 $wgLang->formatNum( $limit ),
1456                 $wgLang->formatNum( $offset + 1 )
1457         );
1458 }
1459
1460 /**
1461  * @todo document
1462  *
1463  * @param $offset Int
1464  * @param $limit Int
1465  * @param $num Int
1466  * @return String
1467  */
1468 function wfShowingResultsNum( $offset, $limit, $num ) {
1469         global $wgLang;
1470         return wfMsgExt(
1471                 'showingresultsnum',
1472                 array( 'parseinline' ),
1473                 $wgLang->formatNum( $limit ),
1474                 $wgLang->formatNum( $offset + 1 ),
1475                 $wgLang->formatNum( $num )
1476         );
1477 }
1478
1479 /**
1480  * Generate (prev x| next x) (20|50|100...) type links for paging
1481  *
1482  * @param $offset String
1483  * @param $limit Integer
1484  * @param $link String
1485  * @param $query String: optional URL query parameter string
1486  * @param $atend Bool: optional param for specified if this is the last page
1487  * @return String
1488  */
1489 function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
1490         global $wgLang;
1491         $fmtLimit = $wgLang->formatNum( $limit );
1492         // @todo FIXME: Why on earth this needs one message for the text and another one for tooltip?
1493         # Get prev/next link display text
1494         $prev = wfMsgExt( 'prevn', array( 'parsemag', 'escape' ), $fmtLimit );
1495         $next = wfMsgExt( 'nextn', array( 'parsemag', 'escape' ), $fmtLimit );
1496         # Get prev/next link title text
1497         $pTitle = wfMsgExt( 'prevn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1498         $nTitle = wfMsgExt( 'nextn-title', array( 'parsemag', 'escape' ), $fmtLimit );
1499         # Fetch the title object
1500         if( is_object( $link ) ) {
1501                 $title =& $link;
1502         } else {
1503                 $title = Title::newFromText( $link );
1504                 if( is_null( $title ) ) {
1505                         return false;
1506                 }
1507         }
1508         # Make 'previous' link
1509         if( 0 != $offset ) {
1510                 $po = $offset - $limit;
1511                 $po = max( $po, 0 );
1512                 $q = "limit={$limit}&offset={$po}";
1513                 if( $query != '' ) {
1514                         $q .= '&' . $query;
1515                 }
1516                 $plink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$pTitle}\" class=\"mw-prevlink\">{$prev}</a>";
1517         } else {
1518                 $plink = $prev;
1519         }
1520         # Make 'next' link
1521         $no = $offset + $limit;
1522         $q = "limit={$limit}&offset={$no}";
1523         if( $query != '' ) {
1524                 $q .= '&' . $query;
1525         }
1526         if( $atend ) {
1527                 $nlink = $next;
1528         } else {
1529                 $nlink = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$nTitle}\" class=\"mw-nextlink\">{$next}</a>";
1530         }
1531         # Make links to set number of items per page
1532         $nums = $wgLang->pipeList( array(
1533                 wfNumLink( $offset, 20, $title, $query ),
1534                 wfNumLink( $offset, 50, $title, $query ),
1535                 wfNumLink( $offset, 100, $title, $query ),
1536                 wfNumLink( $offset, 250, $title, $query ),
1537                 wfNumLink( $offset, 500, $title, $query )
1538         ) );
1539         return wfMsgHtml( 'viewprevnext', $plink, $nlink, $nums );
1540 }
1541
1542 /**
1543  * Generate links for (20|50|100...) items-per-page links
1544  *
1545  * @param $offset String
1546  * @param $limit Integer
1547  * @param $title Title
1548  * @param $query String: optional URL query parameter string
1549  */
1550 function wfNumLink( $offset, $limit, $title, $query = '' ) {
1551         global $wgLang;
1552         if( $query == '' ) {
1553                 $q = '';
1554         } else {
1555                 $q = $query.'&';
1556         }
1557         $q .= "limit={$limit}&offset={$offset}";
1558         $fmtLimit = $wgLang->formatNum( $limit );
1559         $lTitle = wfMsgExt( 'shown-title', array( 'parsemag', 'escape' ), $limit );
1560         $s = '<a href="' . $title->escapeLocalURL( $q ) . "\" title=\"{$lTitle}\" class=\"mw-numlink\">{$fmtLimit}</a>";
1561         return $s;
1562 }
1563
1564 /**
1565  * @todo document
1566  * @todo FIXME: We may want to blacklist some broken browsers
1567  *
1568  * @param $force Bool
1569  * @return bool Whereas client accept gzip compression
1570  */
1571 function wfClientAcceptsGzip( $force = false ) {
1572         static $result = null;
1573         if ( $result === null || $force ) {
1574                 $result = false;
1575                 if( isset( $_SERVER['HTTP_ACCEPT_ENCODING'] ) ) {
1576                         # @todo FIXME: We may want to blacklist some broken browsers
1577                         $m = array();
1578                         if( preg_match(
1579                                 '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
1580                                 $_SERVER['HTTP_ACCEPT_ENCODING'],
1581                                 $m )
1582                         )
1583                         {
1584                                 if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) {
1585                                         $result = false;
1586                                         return $result;
1587                                 }
1588                                 wfDebug( " accepts gzip\n" );
1589                                 $result = true;
1590                         }
1591                 }
1592         }
1593         return $result;
1594 }
1595
1596 /**
1597  * Obtain the offset and limit values from the request string;
1598  * used in special pages
1599  *
1600  * @param $deflimit Int default limit if none supplied
1601  * @param $optionname String Name of a user preference to check against
1602  * @return array
1603  *
1604  */
1605 function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
1606         global $wgRequest;
1607         return $wgRequest->getLimitOffset( $deflimit, $optionname );
1608 }
1609
1610 /**
1611  * Escapes the given text so that it may be output using addWikiText()
1612  * without any linking, formatting, etc. making its way through. This
1613  * is achieved by substituting certain characters with HTML entities.
1614  * As required by the callers, <nowiki> is not used.
1615  *
1616  * @param $text String: text to be escaped
1617  * @return String
1618  */
1619 function wfEscapeWikiText( $text ) {
1620         $text = strtr( "\n$text", array(
1621                 '"' => '&#34;', '&' => '&#38;', "'" => '&#39;', '<' => '&#60;',
1622                 '=' => '&#61;', '>' => '&#62;', '[' => '&#91;', ']' => '&#93;',
1623                 '{' => '&#123;', '|' => '&#124;', '}' => '&#125;',
1624                 "\n#" => "\n&#35;", "\n*" => "\n&#42;",
1625                 "\n:" => "\n&#58;", "\n;" => "\n&#59;",
1626                 '://' => '&#58;//', 'ISBN ' => 'ISBN&#32;', 'RFC ' => 'RFC&#32;',
1627         ) );
1628         return substr( $text, 1 );
1629 }
1630
1631 /**
1632  * Get the current unix timetstamp with microseconds.  Useful for profiling
1633  * @return Float
1634  */
1635 function wfTime() {
1636         return microtime( true );
1637 }
1638
1639 /**
1640  * Sets dest to source and returns the original value of dest
1641  * If source is NULL, it just returns the value, it doesn't set the variable
1642  * If force is true, it will set the value even if source is NULL
1643  *
1644  * @param $dest Mixed
1645  * @param $source Mixed
1646  * @param $force Bool
1647  * @return Mixed
1648  */
1649 function wfSetVar( &$dest, $source, $force = false ) {
1650         $temp = $dest;
1651         if ( !is_null( $source ) || $force ) {
1652                 $dest = $source;
1653         }
1654         return $temp;
1655 }
1656
1657 /**
1658  * As for wfSetVar except setting a bit
1659  *
1660  * @param $dest Int
1661  * @param $bit Int
1662  * @param $state Bool
1663  */
1664 function wfSetBit( &$dest, $bit, $state = true ) {
1665         $temp = (bool)( $dest & $bit );
1666         if ( !is_null( $state ) ) {
1667                 if ( $state ) {
1668                         $dest |= $bit;
1669                 } else {
1670                         $dest &= ~$bit;
1671                 }
1672         }
1673         return $temp;
1674 }
1675
1676 /**
1677  * Windows-compatible version of escapeshellarg()
1678  * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
1679  * function puts single quotes in regardless of OS.
1680  *
1681  * Also fixes the locale problems on Linux in PHP 5.2.6+ (bug backported to
1682  * earlier distro releases of PHP)
1683  *
1684  * @param varargs
1685  * @return String
1686  */
1687 function wfEscapeShellArg( ) {
1688         wfInitShellLocale();
1689
1690         $args = func_get_args();
1691         $first = true;
1692         $retVal = '';
1693         foreach ( $args as $arg ) {
1694                 if ( !$first ) {
1695                         $retVal .= ' ';
1696                 } else {
1697                         $first = false;
1698                 }
1699
1700                 if ( wfIsWindows() ) {
1701                         // Escaping for an MSVC-style command line parser and CMD.EXE
1702                         // Refs:
1703                         //  * http://web.archive.org/web/20020708081031/http://mailman.lyra.org/pipermail/scite-interest/2002-March/000436.html
1704                         //  * http://technet.microsoft.com/en-us/library/cc723564.aspx
1705                         //  * Bug #13518
1706                         //  * CR r63214
1707                         // Double the backslashes before any double quotes. Escape the double quotes.
1708                         $tokens = preg_split( '/(\\\\*")/', $arg, -1, PREG_SPLIT_DELIM_CAPTURE );
1709                         $arg = '';
1710                         $iteration = 0;
1711                         foreach ( $tokens as $token ) {
1712                                 if ( $iteration % 2 == 1 ) {
1713                                         // Delimiter, a double quote preceded by zero or more slashes
1714                                         $arg .= str_replace( '\\', '\\\\', substr( $token, 0, -1 ) ) . '\\"';
1715                                 } elseif ( $iteration % 4 == 2 ) {
1716                                         // ^ in $token will be outside quotes, need to be escaped
1717                                         $arg .= str_replace( '^', '^^', $token );
1718                                 } else { // $iteration % 4 == 0
1719                                         // ^ in $token will appear inside double quotes, so leave as is
1720                                         $arg .= $token;
1721                                 }
1722                                 $iteration++;
1723                         }
1724                         // Double the backslashes before the end of the string, because
1725                         // we will soon add a quote
1726                         $m = array();
1727                         if ( preg_match( '/^(.*?)(\\\\+)$/', $arg, $m ) ) {
1728                                 $arg = $m[1] . str_replace( '\\', '\\\\', $m[2] );
1729                         }
1730
1731                         // Add surrounding quotes
1732                         $retVal .= '"' . $arg . '"';
1733                 } else {
1734                         $retVal .= escapeshellarg( $arg );
1735                 }
1736         }
1737         return $retVal;
1738 }
1739
1740 /**
1741  * wfMerge attempts to merge differences between three texts.
1742  * Returns true for a clean merge and false for failure or a conflict.
1743  *
1744  * @param $old String
1745  * @param $mine String
1746  * @param $yours String
1747  * @param $result String
1748  * @return Bool
1749  */
1750 function wfMerge( $old, $mine, $yours, &$result ) {
1751         global $wgDiff3;
1752
1753         # This check may also protect against code injection in
1754         # case of broken installations.
1755         wfSuppressWarnings();
1756         $haveDiff3 = $wgDiff3 && file_exists( $wgDiff3 );
1757         wfRestoreWarnings();
1758
1759         if( !$haveDiff3 ) {
1760                 wfDebug( "diff3 not found\n" );
1761                 return false;
1762         }
1763
1764         # Make temporary files
1765         $td = wfTempDir();
1766         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1767         $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
1768         $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );
1769
1770         fwrite( $oldtextFile, $old );
1771         fclose( $oldtextFile );
1772         fwrite( $mytextFile, $mine );
1773         fclose( $mytextFile );
1774         fwrite( $yourtextFile, $yours );
1775         fclose( $yourtextFile );
1776
1777         # Check for a conflict
1778         $cmd = $wgDiff3 . ' -a --overlap-only ' .
1779                 wfEscapeShellArg( $mytextName ) . ' ' .
1780                 wfEscapeShellArg( $oldtextName ) . ' ' .
1781                 wfEscapeShellArg( $yourtextName );
1782         $handle = popen( $cmd, 'r' );
1783
1784         if( fgets( $handle, 1024 ) ) {
1785                 $conflict = true;
1786         } else {
1787                 $conflict = false;
1788         }
1789         pclose( $handle );
1790
1791         # Merge differences
1792         $cmd = $wgDiff3 . ' -a -e --merge ' .
1793                 wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
1794         $handle = popen( $cmd, 'r' );
1795         $result = '';
1796         do {
1797                 $data = fread( $handle, 8192 );
1798                 if ( strlen( $data ) == 0 ) {
1799                         break;
1800                 }
1801                 $result .= $data;
1802         } while ( true );
1803         pclose( $handle );
1804         unlink( $mytextName );
1805         unlink( $oldtextName );
1806         unlink( $yourtextName );
1807
1808         if ( $result === '' && $old !== '' && !$conflict ) {
1809                 wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
1810                 $conflict = true;
1811         }
1812         return !$conflict;
1813 }
1814
1815 /**
1816  * Returns unified plain-text diff of two texts.
1817  * Useful for machine processing of diffs.
1818  *
1819  * @param $before String: the text before the changes.
1820  * @param $after String: the text after the changes.
1821  * @param $params String: command-line options for the diff command.
1822  * @return String: unified diff of $before and $after
1823  */
1824 function wfDiff( $before, $after, $params = '-u' ) {
1825         if ( $before == $after ) {
1826                 return '';
1827         }
1828
1829         global $wgDiff;
1830         wfSuppressWarnings();
1831         $haveDiff = $wgDiff && file_exists( $wgDiff );
1832         wfRestoreWarnings();
1833
1834         # This check may also protect against code injection in
1835         # case of broken installations.
1836         if( !$haveDiff ) {
1837                 wfDebug( "diff executable not found\n" );
1838                 $diffs = new Diff( explode( "\n", $before ), explode( "\n", $after ) );
1839                 $format = new UnifiedDiffFormatter();
1840                 return $format->format( $diffs );
1841         }
1842
1843         # Make temporary files
1844         $td = wfTempDir();
1845         $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
1846         $newtextFile = fopen( $newtextName = tempnam( $td, 'merge-your-' ), 'w' );
1847
1848         fwrite( $oldtextFile, $before );
1849         fclose( $oldtextFile );
1850         fwrite( $newtextFile, $after );
1851         fclose( $newtextFile );
1852
1853         // Get the diff of the two files
1854         $cmd = "$wgDiff " . $params . ' ' . wfEscapeShellArg( $oldtextName, $newtextName );
1855
1856         $h = popen( $cmd, 'r' );
1857
1858         $diff = '';
1859
1860         do {
1861                 $data = fread( $h, 8192 );
1862                 if ( strlen( $data ) == 0 ) {
1863                         break;
1864                 }
1865                 $diff .= $data;
1866         } while ( true );
1867
1868         // Clean up
1869         pclose( $h );
1870         unlink( $oldtextName );
1871         unlink( $newtextName );
1872
1873         // Kill the --- and +++ lines. They're not useful.
1874         $diff_lines = explode( "\n", $diff );
1875         if ( strpos( $diff_lines[0], '---' ) === 0 ) {
1876                 unset( $diff_lines[0] );
1877         }
1878         if ( strpos( $diff_lines[1], '+++' ) === 0 ) {
1879                 unset( $diff_lines[1] );
1880         }
1881
1882         $diff = implode( "\n", $diff_lines );
1883
1884         return $diff;
1885 }
1886
1887 /**
1888  * A wrapper around the PHP function var_export().
1889  * Either print it or add it to the regular output ($wgOut).
1890  *
1891  * @param $var A PHP variable to dump.
1892  */
1893 function wfVarDump( $var ) {
1894         global $wgOut;
1895         $s = str_replace( "\n", "<br />\n", var_export( $var, true ) . "\n" );
1896         if ( headers_sent() || !isset( $wgOut ) || !is_object( $wgOut ) ) {
1897                 print $s;
1898         } else {
1899                 $wgOut->addHTML( $s );
1900         }
1901 }
1902
1903 /**
1904  * Provide a simple HTTP error.
1905  *
1906  * @param $code Int|String
1907  * @param $label String
1908  * @param $desc String
1909  */
1910 function wfHttpError( $code, $label, $desc ) {
1911         global $wgOut;
1912         $wgOut->disable();
1913         header( "HTTP/1.0 $code $label" );
1914         header( "Status: $code $label" );
1915         $wgOut->sendCacheControl();
1916
1917         header( 'Content-type: text/html; charset=utf-8' );
1918         print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">".
1919                 '<html><head><title>' .
1920                 htmlspecialchars( $label ) .
1921                 '</title></head><body><h1>' .
1922                 htmlspecialchars( $label ) .
1923                 '</h1><p>' .
1924                 nl2br( htmlspecialchars( $desc ) ) .
1925                 "</p></body></html>\n";
1926 }
1927
1928 /**
1929  * Clear away any user-level output buffers, discarding contents.
1930  *
1931  * Suitable for 'starting afresh', for instance when streaming
1932  * relatively large amounts of data without buffering, or wanting to
1933  * output image files without ob_gzhandler's compression.
1934  *
1935  * The optional $resetGzipEncoding parameter controls suppression of
1936  * the Content-Encoding header sent by ob_gzhandler; by default it
1937  * is left. See comments for wfClearOutputBuffers() for why it would
1938  * be used.
1939  *
1940  * Note that some PHP configuration options may add output buffer
1941  * layers which cannot be removed; these are left in place.
1942  *
1943  * @param $resetGzipEncoding Bool
1944  */
1945 function wfResetOutputBuffers( $resetGzipEncoding = true ) {
1946         if( $resetGzipEncoding ) {
1947                 // Suppress Content-Encoding and Content-Length
1948                 // headers from 1.10+s wfOutputHandler
1949                 global $wgDisableOutputCompression;
1950                 $wgDisableOutputCompression = true;
1951         }
1952         while( $status = ob_get_status() ) {
1953                 if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
1954                         // Probably from zlib.output_compression or other
1955                         // PHP-internal setting which can't be removed.
1956                         //
1957                         // Give up, and hope the result doesn't break
1958                         // output behavior.
1959                         break;
1960                 }
1961                 if( !ob_end_clean() ) {
1962                         // Could not remove output buffer handler; abort now
1963                         // to avoid getting in some kind of infinite loop.
1964                         break;
1965                 }
1966                 if( $resetGzipEncoding ) {
1967                         if( $status['name'] == 'ob_gzhandler' ) {
1968                                 // Reset the 'Content-Encoding' field set by this handler
1969                                 // so we can start fresh.
1970                                 if ( function_exists( 'header_remove' ) ) {
1971                                         // Available since PHP 5.3.0
1972                                         header_remove( 'Content-Encoding' );
1973                                 } else {
1974                                         // We need to provide a valid content-coding. See bug 28069
1975                                         header( 'Content-Encoding: identity' );
1976                                 }
1977                                 break;
1978                         }
1979                 }
1980         }
1981 }
1982
1983 /**
1984  * More legible than passing a 'false' parameter to wfResetOutputBuffers():
1985  *
1986  * Clear away output buffers, but keep the Content-Encoding header
1987  * produced by ob_gzhandler, if any.
1988  *
1989  * This should be used for HTTP 304 responses, where you need to
1990  * preserve the Content-Encoding header of the real result, but
1991  * also need to suppress the output of ob_gzhandler to keep to spec
1992  * and avoid breaking Firefox in rare cases where the headers and
1993  * body are broken over two packets.
1994  */
1995 function wfClearOutputBuffers() {
1996         wfResetOutputBuffers( false );
1997 }
1998
1999 /**
2000  * Converts an Accept-* header into an array mapping string values to quality
2001  * factors
2002  *
2003  * @param $accept String
2004  * @param $def String default
2005  * @return Array
2006  */
2007 function wfAcceptToPrefs( $accept, $def = '*/*' ) {
2008         # No arg means accept anything (per HTTP spec)
2009         if( !$accept ) {
2010                 return array( $def => 1.0 );
2011         }
2012
2013         $prefs = array();
2014
2015         $parts = explode( ',', $accept );
2016
2017         foreach( $parts as $part ) {
2018                 # @todo FIXME: Doesn't deal with params like 'text/html; level=1'
2019                 $values = explode( ';', trim( $part ) );
2020                 $match = array();
2021                 if ( count( $values ) == 1 ) {
2022                         $prefs[$values[0]] = 1.0;
2023                 } elseif ( preg_match( '/q\s*=\s*(\d*\.\d+)/', $values[1], $match ) ) {
2024                         $prefs[$values[0]] = floatval( $match[1] );
2025                 }
2026         }
2027
2028         return $prefs;
2029 }
2030
2031 /**
2032  * Checks if a given MIME type matches any of the keys in the given
2033  * array. Basic wildcards are accepted in the array keys.
2034  *
2035  * Returns the matching MIME type (or wildcard) if a match, otherwise
2036  * NULL if no match.
2037  *
2038  * @param $type String
2039  * @param $avail Array
2040  * @return string
2041  * @private
2042  */
2043 function mimeTypeMatch( $type, $avail ) {
2044         if( array_key_exists( $type, $avail ) ) {
2045                 return $type;
2046         } else {
2047                 $parts = explode( '/', $type );
2048                 if( array_key_exists( $parts[0] . '/*', $avail ) ) {
2049                         return $parts[0] . '/*';
2050                 } elseif( array_key_exists( '*/*', $avail ) ) {
2051                         return '*/*';
2052                 } else {
2053                         return null;
2054                 }
2055         }
2056 }
2057
2058 /**
2059  * Returns the 'best' match between a client's requested internet media types
2060  * and the server's list of available types. Each list should be an associative
2061  * array of type to preference (preference is a float between 0.0 and 1.0).
2062  * Wildcards in the types are acceptable.
2063  *
2064  * @param $cprefs Array: client's acceptable type list
2065  * @param $sprefs Array: server's offered types
2066  * @return string
2067  *
2068  * @todo FIXME: Doesn't handle params like 'text/plain; charset=UTF-8'
2069  * XXX: generalize to negotiate other stuff
2070  */
2071 function wfNegotiateType( $cprefs, $sprefs ) {
2072         $combine = array();
2073
2074         foreach( array_keys($sprefs) as $type ) {
2075                 $parts = explode( '/', $type );
2076                 if( $parts[1] != '*' ) {
2077                         $ckey = mimeTypeMatch( $type, $cprefs );
2078                         if( $ckey ) {
2079                                 $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
2080                         }
2081                 }
2082         }
2083
2084         foreach( array_keys( $cprefs ) as $type ) {
2085                 $parts = explode( '/', $type );
2086                 if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
2087                         $skey = mimeTypeMatch( $type, $sprefs );
2088                         if( $skey ) {
2089                                 $combine[$type] = $sprefs[$skey] * $cprefs[$type];
2090                         }
2091                 }
2092         }
2093
2094         $bestq = 0;
2095         $besttype = null;
2096
2097         foreach( array_keys( $combine ) as $type ) {
2098                 if( $combine[$type] > $bestq ) {
2099                         $besttype = $type;
2100                         $bestq = $combine[$type];
2101                 }
2102         }
2103
2104         return $besttype;
2105 }
2106
2107 /**
2108  * Reference-counted warning suppression
2109  *
2110  * @param $end Bool
2111  */
2112 function wfSuppressWarnings( $end = false ) {
2113         static $suppressCount = 0;
2114         static $originalLevel = false;
2115
2116         if ( $end ) {
2117                 if ( $suppressCount ) {
2118                         --$suppressCount;
2119                         if ( !$suppressCount ) {
2120                                 error_reporting( $originalLevel );
2121                         }
2122                 }
2123         } else {
2124                 if ( !$suppressCount ) {
2125                         // E_DEPRECATED is undefined in PHP 5.2
2126                         if( !defined( 'E_DEPRECATED' ) ){
2127                                 define( 'E_DEPRECATED', 8192 );
2128                         }
2129                         $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE | E_USER_WARNING | E_USER_NOTICE | E_DEPRECATED ) );
2130                 }
2131                 ++$suppressCount;
2132         }
2133 }
2134
2135 /**
2136  * Restore error level to previous value
2137  */
2138 function wfRestoreWarnings() {
2139         wfSuppressWarnings( true );
2140 }
2141
2142 # Autodetect, convert and provide timestamps of various types
2143
2144 /**
2145  * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
2146  */
2147 define( 'TS_UNIX', 0 );
2148
2149 /**
2150  * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
2151  */
2152 define( 'TS_MW', 1 );
2153
2154 /**
2155  * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
2156  */
2157 define( 'TS_DB', 2 );
2158
2159 /**
2160  * RFC 2822 format, for E-mail and HTTP headers
2161  */
2162 define( 'TS_RFC2822', 3 );
2163
2164 /**
2165  * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
2166  *
2167  * This is used by Special:Export
2168  */
2169 define( 'TS_ISO_8601', 4 );
2170
2171 /**
2172  * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
2173  *
2174  * @see http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
2175  *       DateTime tag and page 36 for the DateTimeOriginal and
2176  *       DateTimeDigitized tags.
2177  */
2178 define( 'TS_EXIF', 5 );
2179
2180 /**
2181  * Oracle format time.
2182  */
2183 define( 'TS_ORACLE', 6 );
2184
2185 /**
2186  * Postgres format time.
2187  */
2188 define( 'TS_POSTGRES', 7 );
2189
2190 /**
2191  * DB2 format time
2192  */
2193 define( 'TS_DB2', 8 );
2194
2195 /**
2196  * ISO 8601 basic format with no timezone: 19860209T200000Z.  This is used by ResourceLoader
2197  */
2198 define( 'TS_ISO_8601_BASIC', 9 );
2199
2200 /**
2201  * Get a timestamp string in one of various formats
2202  *
2203  * @param $outputtype Mixed: A timestamp in one of the supported formats, the
2204  *                    function will autodetect which format is supplied and act
2205  *                    accordingly.
2206  * @param $ts Mixed: the timestamp to convert or 0 for the current timestamp
2207  * @return Mixed: String / false The same date in the format specified in $outputtype or false
2208  */
2209 function wfTimestamp( $outputtype = TS_UNIX, $ts = 0 ) {
2210         $uts = 0;
2211         $da = array();
2212         $strtime = '';
2213
2214         if ( !$ts ) { // We want to catch 0, '', null... but not date strings starting with a letter.
2215                 $uts = time();
2216                 $strtime = "@$uts";
2217         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2218                 # TS_DB
2219         } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
2220                 # TS_EXIF
2221         } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
2222                 # TS_MW
2223         } elseif ( preg_match( '/^-?\d{1,13}$/D', $ts ) ) {
2224                 # TS_UNIX
2225                 $uts = $ts;
2226                 $strtime = "@$ts"; // Undocumented?
2227         } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
2228                 # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
2229                 $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
2230                                 str_replace( '+00:00', 'UTC', $ts ) );
2231         } elseif ( preg_match( '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2232                 # TS_ISO_8601
2233         } elseif ( preg_match( '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z$/', $ts, $da ) ) {
2234                 #TS_ISO_8601_BASIC
2235         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/', $ts, $da ) ) {
2236                 # TS_POSTGRES
2237         } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/', $ts, $da ) ) {
2238                 # TS_POSTGRES
2239         } elseif (preg_match('/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.\d\d\d$/',$ts,$da)) {
2240                 # TS_DB2
2241         } elseif ( preg_match( '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' . # Day of week
2242                                                         '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .  # dd Mon yyyy
2243                                                         '[ \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
2244                 # TS_RFC2822, accepting a trailing comment. See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
2245                 # The regex is a superset of rfc2822 for readability
2246                 $strtime = strtok( $ts, ';' );
2247         } 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 ) ) {
2248                 # TS_RFC850
2249                 $strtime = $ts;
2250         } 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 ) ) {
2251                 # asctime
2252                 $strtime = $ts;
2253         } else {
2254                 # Bogus value...
2255                 wfDebug("wfTimestamp() fed bogus time value: TYPE=$outputtype; VALUE=$ts\n");
2256
2257                 return false;
2258         }
2259
2260         static $formats = array(
2261                 TS_UNIX => 'U',
2262                 TS_MW => 'YmdHis',
2263                 TS_DB => 'Y-m-d H:i:s',
2264                 TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
2265                 TS_ISO_8601_BASIC => 'Ymd\THis\Z',
2266                 TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
2267                 TS_RFC2822 => 'D, d M Y H:i:s',
2268                 TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
2269                 TS_POSTGRES => 'Y-m-d H:i:s',
2270                 TS_DB2 => 'Y-m-d H:i:s',
2271         );
2272
2273         if ( !isset( $formats[$outputtype] ) ) {
2274                 throw new MWException( 'wfTimestamp() called with illegal output type.' );
2275         }
2276
2277         if ( function_exists( "date_create" ) ) {
2278                 if ( count( $da ) ) {
2279                         $ds = sprintf("%04d-%02d-%02dT%02d:%02d:%02d.00+00:00",
2280                                 (int)$da[1], (int)$da[2], (int)$da[3],
2281                                 (int)$da[4], (int)$da[5], (int)$da[6]);
2282
2283                         $d = date_create( $ds, new DateTimeZone( 'GMT' ) );
2284                 } elseif ( $strtime ) {
2285                         $d = date_create( $strtime, new DateTimeZone( 'GMT' ) );
2286                 } else {
2287                         return false;
2288                 }
2289
2290                 if ( !$d ) {
2291                         wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
2292                         return false;
2293                 }
2294
2295                 $output = $d->format( $formats[$outputtype] );
2296         } else {
2297                 if ( count( $da ) ) {
2298                         // Warning! gmmktime() acts oddly if the month or day is set to 0
2299                         // We may want to handle that explicitly at some point
2300                         $uts = gmmktime( (int)$da[4], (int)$da[5], (int)$da[6],
2301                                 (int)$da[2], (int)$da[3], (int)$da[1] );
2302                 } elseif ( $strtime ) {
2303                         $uts = strtotime( $strtime );
2304                 }
2305
2306                 if ( $uts === false ) {
2307                         wfDebug("wfTimestamp() can't parse the timestamp (non 32-bit time? Update php): $outputtype; $ts\n");
2308                         return false;
2309                 }
2310
2311                 if ( TS_UNIX == $outputtype ) {
2312                         return $uts;
2313                 }
2314                 $output = gmdate( $formats[$outputtype], $uts );
2315         }
2316
2317         if ( ( $outputtype == TS_RFC2822 ) || ( $outputtype == TS_POSTGRES ) ) {
2318                 $output .= ' GMT';
2319         }
2320
2321         return $output;
2322 }
2323
2324 /**
2325  * Return a formatted timestamp, or null if input is null.
2326  * For dealing with nullable timestamp columns in the database.
2327  *
2328  * @param $outputtype Integer
2329  * @param $ts String
2330  * @return String
2331  */
2332 function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
2333         if( is_null( $ts ) ) {
2334                 return null;
2335         } else {
2336                 return wfTimestamp( $outputtype, $ts );
2337         }
2338 }
2339
2340 /**
2341  * Convenience function; returns MediaWiki timestamp for the present time.
2342  *
2343  * @return string
2344  */
2345 function wfTimestampNow() {
2346         # return NOW
2347         return wfTimestamp( TS_MW, time() );
2348 }
2349
2350 /**
2351  * Check if the operating system is Windows
2352  *
2353  * @return Bool: true if it's Windows, False otherwise.
2354  */
2355 function wfIsWindows() {
2356         static $isWindows = null;
2357         if ( $isWindows === null ) {
2358                 $isWindows = substr( php_uname(), 0, 7 ) == 'Windows';
2359         }
2360         return $isWindows;
2361 }
2362
2363 /**
2364  * Check if we are running under HipHop
2365  *
2366  * @return Bool
2367  */
2368 function wfIsHipHop() {
2369         return function_exists( 'hphp_thread_set_warmup_enabled' );
2370 }
2371
2372 /**
2373  * Swap two variables
2374  *
2375  * @param $x Mixed
2376  * @param $y Mixed
2377  */
2378 function swap( &$x, &$y ) {
2379         $z = $x;
2380         $x = $y;
2381         $y = $z;
2382 }
2383
2384 /**
2385  * Tries to get the system directory for temporary files. The TMPDIR, TMP, and
2386  * TEMP environment variables are then checked in sequence, and if none are set
2387  * try sys_get_temp_dir() for PHP >= 5.2.1. All else fails, return /tmp for Unix
2388  * or C:\Windows\Temp for Windows and hope for the best.
2389  * It is common to call it with tempnam().
2390  *
2391  * NOTE: When possible, use instead the tmpfile() function to create
2392  * temporary files to avoid race conditions on file creation, etc.
2393  *
2394  * @return String
2395  */
2396 function wfTempDir() {
2397         foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
2398                 $tmp = getenv( $var );
2399                 if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
2400                         return $tmp;
2401                 }
2402         }
2403         if( function_exists( 'sys_get_temp_dir' ) ) {
2404                 return sys_get_temp_dir();
2405         }
2406         # Usual defaults
2407         return wfIsWindows() ? 'C:\Windows\Temp' : '/tmp';
2408 }
2409
2410 /**
2411  * Make directory, and make all parent directories if they don't exist
2412  *
2413  * @param $dir String: full path to directory to create
2414  * @param $mode Integer: chmod value to use, default is $wgDirectoryMode
2415  * @param $caller String: optional caller param for debugging.
2416  * @return bool
2417  */
2418 function wfMkdirParents( $dir, $mode = null, $caller = null ) {
2419         global $wgDirectoryMode;
2420
2421         if ( !is_null( $caller ) ) {
2422                 wfDebug( "$caller: called wfMkdirParents($dir)" );
2423         }
2424
2425         if( strval( $dir ) === '' || file_exists( $dir ) ) {
2426                 return true;
2427         }
2428
2429         $dir = str_replace( array( '\\', '/' ), DIRECTORY_SEPARATOR, $dir );
2430
2431         if ( is_null( $mode ) ) {
2432                 $mode = $wgDirectoryMode;
2433         }
2434
2435         // Turn off the normal warning, we're doing our own below
2436         wfSuppressWarnings();
2437         $ok = mkdir( $dir, $mode, true ); // PHP5 <3
2438         wfRestoreWarnings();
2439
2440         if( !$ok ) {
2441                 // PHP doesn't report the path in its warning message, so add our own to aid in diagnosis.
2442                 trigger_error( __FUNCTION__ . ": failed to mkdir \"$dir\" mode $mode", E_USER_WARNING );
2443         }
2444         return $ok;
2445 }
2446
2447 /**
2448  * Increment a statistics counter
2449  *
2450  * @param $key String
2451  * @param $count Int
2452  */
2453 function wfIncrStats( $key, $count = 1 ) {
2454         global $wgStatsMethod;
2455
2456         $count = intval( $count );
2457
2458         if( $wgStatsMethod == 'udp' ) {
2459                 global $wgUDPProfilerHost, $wgUDPProfilerPort, $wgDBname, $wgAggregateStatsID;
2460                 static $socket;
2461
2462                 $id = $wgAggregateStatsID !== false ? $wgAggregateStatsID : $wgDBname;
2463
2464                 if ( !$socket ) {
2465                         $socket = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
2466                         $statline = "stats/{$id} - {$count} 1 1 1 1 -total\n";
2467                         socket_sendto(
2468                                 $socket,
2469                                 $statline,
2470                                 strlen( $statline ),
2471                                 0,
2472                                 $wgUDPProfilerHost,
2473                                 $wgUDPProfilerPort
2474                         );
2475                 }
2476                 $statline = "stats/{$id} - {$count} 1 1 1 1 {$key}\n";
2477                 wfSuppressWarnings();
2478                 socket_sendto(
2479                         $socket,
2480                         $statline,
2481                         strlen( $statline ),
2482                         0,
2483                         $wgUDPProfilerHost,
2484                         $wgUDPProfilerPort
2485                 );
2486                 wfRestoreWarnings();
2487         } elseif( $wgStatsMethod == 'cache' ) {
2488                 global $wgMemc;
2489                 $key = wfMemcKey( 'stats', $key );
2490                 if ( is_null( $wgMemc->incr( $key, $count ) ) ) {
2491                         $wgMemc->add( $key, $count );
2492                 }
2493         } else {
2494                 // Disabled
2495         }
2496 }
2497
2498 /**
2499  * @param $nr Mixed: the number to format
2500  * @param $acc Integer: the number of digits after the decimal point, default 2
2501  * @param $round Boolean: whether or not to round the value, default true
2502  * @return float
2503  */
2504 function wfPercent( $nr, $acc = 2, $round = true ) {
2505         $ret = sprintf( "%.${acc}f", $nr );
2506         return $round ? round( $ret, $acc ) . '%' : "$ret%";
2507 }
2508
2509 /**
2510  * Find out whether or not a mixed variable exists in a string
2511  *
2512  * @param $needle String
2513  * @param $str String
2514  * @param $insensitive Boolean
2515  * @return Boolean
2516  */
2517 function in_string( $needle, $str, $insensitive = false ) {
2518         $func = 'strpos';
2519         if( $insensitive ) $func = 'stripos';
2520
2521         return $func( $str, $needle ) !== false;
2522 }
2523
2524 function wfSpecialList( $page, $details ) {
2525         global $wgContLang;
2526         $details = $details ? ' ' . $wgContLang->getDirMark() . "($details)" : '';
2527         return $page . $details;
2528 }
2529
2530 /**
2531  * Safety wrapper around ini_get() for boolean settings.
2532  * The values returned from ini_get() are pre-normalized for settings
2533  * set via php.ini or php_flag/php_admin_flag... but *not*
2534  * for those set via php_value/php_admin_value.
2535  *
2536  * It's fairly common for people to use php_value instead of php_flag,
2537  * which can leave you with an 'off' setting giving a false positive
2538  * for code that just takes the ini_get() return value as a boolean.
2539  *
2540  * To make things extra interesting, setting via php_value accepts
2541  * "true" and "yes" as true, but php.ini and php_flag consider them false. :)
2542  * Unrecognized values go false... again opposite PHP's own coercion
2543  * from string to bool.
2544  *
2545  * Luckily, 'properly' set settings will always come back as '0' or '1',
2546  * so we only have to worry about them and the 'improper' settings.
2547  *
2548  * I frickin' hate PHP... :P
2549  *
2550  * @param $setting String
2551  * @return Bool
2552  */
2553 function wfIniGetBool( $setting ) {
2554         $val = ini_get( $setting );
2555         // 'on' and 'true' can't have whitespace around them, but '1' can.
2556         return strtolower( $val ) == 'on'
2557                 || strtolower( $val ) == 'true'
2558                 || strtolower( $val ) == 'yes'
2559                 || preg_match( "/^\s*[+-]?0*[1-9]/", $val ); // approx C atoi() function
2560 }
2561
2562 /**
2563  * Wrapper function for PHP's dl(). This doesn't work in most situations from
2564  * PHP 5.3 onward, and is usually disabled in shared environments anyway.
2565  *
2566  * @param $extension String A PHP extension. The file suffix (.so or .dll)
2567  *                          should be omitted
2568  * @param $fileName String Name of the library, if not $extension.suffix
2569  * @return Bool - Whether or not the extension is loaded
2570  */
2571 function wfDl( $extension, $fileName = null ) {
2572         if( extension_loaded( $extension ) ) {
2573                 return true;
2574         }
2575
2576         $canDl = false;
2577         $sapi = php_sapi_name();
2578         if( version_compare( PHP_VERSION, '5.3.0', '<' ) ||
2579                 $sapi == 'cli' || $sapi == 'cgi' || $sapi == 'embed' )
2580         {
2581                 $canDl = ( function_exists( 'dl' ) && is_callable( 'dl' )
2582                 && wfIniGetBool( 'enable_dl' ) && !wfIniGetBool( 'safe_mode' ) );
2583         }
2584
2585         if( $canDl ) {
2586                 $fileName = $fileName ? $fileName : $extension;
2587                 if( wfIsWindows() ) {
2588                         $fileName = 'php_' . $fileName;
2589                 }
2590                 wfSuppressWarnings();
2591                 dl( $fileName . '.' . PHP_SHLIB_SUFFIX );
2592                 wfRestoreWarnings();
2593         }
2594         return extension_loaded( $extension );
2595 }
2596
2597 /**
2598  * Execute a shell command, with time and memory limits mirrored from the PHP
2599  * configuration if supported.
2600  * @param $cmd String Command line, properly escaped for shell.
2601  * @param &$retval optional, will receive the program's exit code.
2602  *                 (non-zero is usually failure)
2603  * @param $environ Array optional environment variables which should be
2604  *                 added to the executed command environment.
2605  * @return collected stdout as a string (trailing newlines stripped)
2606  */
2607 function wfShellExec( $cmd, &$retval = null, $environ = array() ) {
2608         global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
2609
2610         static $disabled;
2611         if ( is_null( $disabled ) ) {
2612                 $disabled = false;
2613                 if( wfIniGetBool( 'safe_mode' ) ) {
2614                         wfDebug( "wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n" );
2615                         $disabled = 'safemode';
2616                 } else {
2617                         $functions = explode( ',', ini_get( 'disable_functions' ) );
2618                         $functions = array_map( 'trim', $functions );
2619                         $functions = array_map( 'strtolower', $functions );
2620                         if ( in_array( 'passthru', $functions ) ) {
2621                                 wfDebug( "passthru is in disabled_functions\n" );
2622                                 $disabled = 'passthru';
2623                         }
2624                 }
2625         }
2626         if ( $disabled ) {
2627                 $retval = 1;
2628                 return $disabled == 'safemode' ?
2629                         'Unable to run external programs in safe mode.' :
2630                         'Unable to run external programs, passthru() is disabled.';
2631         }
2632
2633         wfInitShellLocale();
2634
2635         $envcmd = '';
2636         foreach( $environ as $k => $v ) {
2637                 if ( wfIsWindows() ) {
2638                         /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
2639                          * appear in the environment variable, so we must use carat escaping as documented in
2640                          * http://technet.microsoft.com/en-us/library/cc723564.aspx
2641                          * Note however that the quote isn't listed there, but is needed, and the parentheses
2642                          * are listed there but doesn't appear to need it.
2643                          */
2644                         $envcmd .= "set $k=" . preg_replace( '/([&|()<>^"])/', '^\\1', $v ) . '&& ';
2645                 } else {
2646                         /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
2647                          * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
2648                          */
2649                         $envcmd .= "$k=" . escapeshellarg( $v ) . ' ';
2650                 }
2651         }
2652         $cmd = $envcmd . $cmd;
2653
2654         if ( wfIsWindows() ) {
2655                 if ( version_compare( PHP_VERSION, '5.3.0', '<' ) && /* Fixed in 5.3.0 :) */
2656                         ( version_compare( PHP_VERSION, '5.2.1', '>=' ) || php_uname( 's' ) == 'Windows NT' ) )
2657                 {
2658                         # Hack to work around PHP's flawed invocation of cmd.exe
2659                         # http://news.php.net/php.internals/21796
2660                         # Windows 9x doesn't accept any kind of quotes
2661                         $cmd = '"' . $cmd . '"';
2662                 }
2663         } elseif ( php_uname( 's' ) == 'Linux' ) {
2664                 $time = intval( $wgMaxShellTime );
2665                 $mem = intval( $wgMaxShellMemory );
2666                 $filesize = intval( $wgMaxShellFileSize );
2667
2668                 if ( $time > 0 && $mem > 0 ) {
2669                         $script = "$IP/bin/ulimit4.sh";
2670                         if ( is_executable( $script ) ) {
2671                                 $cmd = '/bin/bash ' . escapeshellarg( $script ) . " $time $mem $filesize " . escapeshellarg( $cmd );
2672                         }
2673                 }
2674         }
2675         wfDebug( "wfShellExec: $cmd\n" );
2676
2677         $retval = 1; // error by default?
2678         ob_start();
2679         passthru( $cmd, $retval );
2680         $output = ob_get_contents();
2681         ob_end_clean();
2682
2683         if ( $retval == 127 ) {
2684                 wfDebugLog( 'exec', "Possibly missing executable file: $cmd\n" );
2685         }
2686         return $output;
2687 }
2688
2689 /**
2690  * Workaround for http://bugs.php.net/bug.php?id=45132
2691  * escapeshellarg() destroys non-ASCII characters if LANG is not a UTF-8 locale
2692  */
2693 function wfInitShellLocale() {
2694         static $done = false;
2695         if ( $done ) {
2696                 return;
2697         }
2698         $done = true;
2699         global $wgShellLocale;
2700         if ( !wfIniGetBool( 'safe_mode' ) ) {
2701                 putenv( "LC_CTYPE=$wgShellLocale" );
2702                 setlocale( LC_CTYPE, $wgShellLocale );
2703         }
2704 }
2705
2706 /**
2707  * This function works like "use VERSION" in Perl, the program will die with a
2708  * backtrace if the current version of PHP is less than the version provided
2709  *
2710  * This is useful for extensions which due to their nature are not kept in sync
2711  * with releases, and might depend on other versions of PHP than the main code
2712  *
2713  * Note: PHP might die due to parsing errors in some cases before it ever
2714  *       manages to call this function, such is life
2715  *
2716  * @see perldoc -f use
2717  *
2718  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2719  *                 a float
2720  */
2721 function wfUsePHP( $req_ver ) {
2722         $php_ver = PHP_VERSION;
2723
2724         if ( version_compare( $php_ver, (string)$req_ver, '<' ) ) {
2725                 throw new MWException( "PHP $req_ver required--this is only $php_ver" );
2726         }
2727 }
2728
2729 /**
2730  * This function works like "use VERSION" in Perl except it checks the version
2731  * of MediaWiki, the program will die with a backtrace if the current version
2732  * of MediaWiki is less than the version provided.
2733  *
2734  * This is useful for extensions which due to their nature are not kept in sync
2735  * with releases
2736  *
2737  * @see perldoc -f use
2738  *
2739  * @param $req_ver Mixed: the version to check, can be a string, an integer, or
2740  *                 a float
2741  */
2742 function wfUseMW( $req_ver ) {
2743         global $wgVersion;
2744
2745         if ( version_compare( $wgVersion, (string)$req_ver, '<' ) ) {
2746                 throw new MWException( "MediaWiki $req_ver required--this is only $wgVersion" );
2747         }
2748 }
2749
2750 /**
2751  * Return the final portion of a pathname.
2752  * Reimplemented because PHP5's basename() is buggy with multibyte text.
2753  * http://bugs.php.net/bug.php?id=33898
2754  *
2755  * PHP's basename() only considers '\' a pathchar on Windows and Netware.
2756  * We'll consider it so always, as we don't want \s in our Unix paths either.
2757  *
2758  * @param $path String
2759  * @param $suffix String: to remove if present
2760  * @return String
2761  */
2762 function wfBaseName( $path, $suffix = '' ) {
2763         $encSuffix = ( $suffix == '' )
2764                 ? ''
2765                 : ( '(?:' . preg_quote( $suffix, '#' ) . ')?' );
2766         $matches = array();
2767         if( preg_match( "#([^/\\\\]*?){$encSuffix}[/\\\\]*$#", $path, $matches ) ) {
2768                 return $matches[1];
2769         } else {
2770                 return '';
2771         }
2772 }
2773
2774 /**
2775  * Generate a relative path name to the given file.
2776  * May explode on non-matching case-insensitive paths,
2777  * funky symlinks, etc.
2778  *
2779  * @param $path String: absolute destination path including target filename
2780  * @param $from String: Absolute source path, directory only
2781  * @return String
2782  */
2783 function wfRelativePath( $path, $from ) {
2784         // Normalize mixed input on Windows...
2785         $path = str_replace( '/', DIRECTORY_SEPARATOR, $path );
2786         $from = str_replace( '/', DIRECTORY_SEPARATOR, $from );
2787
2788         // Trim trailing slashes -- fix for drive root
2789         $path = rtrim( $path, DIRECTORY_SEPARATOR );
2790         $from = rtrim( $from, DIRECTORY_SEPARATOR );
2791
2792         $pieces = explode( DIRECTORY_SEPARATOR, dirname( $path ) );
2793         $against = explode( DIRECTORY_SEPARATOR, $from );
2794
2795         if( $pieces[0] !== $against[0] ) {
2796                 // Non-matching Windows drive letters?
2797                 // Return a full path.
2798                 return $path;
2799         }
2800
2801         // Trim off common prefix
2802         while( count( $pieces ) && count( $against )
2803                 && $pieces[0] == $against[0] ) {
2804                 array_shift( $pieces );
2805                 array_shift( $against );
2806         }
2807
2808         // relative dots to bump us to the parent
2809         while( count( $against ) ) {
2810                 array_unshift( $pieces, '..' );
2811                 array_shift( $against );
2812         }
2813
2814         array_push( $pieces, wfBaseName( $path ) );
2815
2816         return implode( DIRECTORY_SEPARATOR, $pieces );
2817 }
2818
2819 /**
2820  * Do any deferred updates and clear the list
2821  *
2822  * @param $commit String: set to 'commit' to commit after every update to
2823  *                prevent lock contention
2824  */
2825 function wfDoUpdates( $commit = '' ) {
2826         global $wgDeferredUpdateList;
2827
2828         wfProfileIn( __METHOD__ );
2829
2830         // No need to get master connections in case of empty updates array
2831         if ( !count( $wgDeferredUpdateList ) ) {
2832                 wfProfileOut( __METHOD__ );
2833                 return;
2834         }
2835
2836         $doCommit = $commit == 'commit';
2837         if ( $doCommit ) {
2838                 $dbw = wfGetDB( DB_MASTER );
2839         }
2840
2841         foreach ( $wgDeferredUpdateList as $update ) {
2842                 $update->doUpdate();
2843
2844                 if ( $doCommit && $dbw->trxLevel() ) {
2845                         $dbw->commit();
2846                 }
2847         }
2848
2849         $wgDeferredUpdateList = array();
2850         wfProfileOut( __METHOD__ );
2851 }
2852
2853 /**
2854  * Convert an arbitrarily-long digit string from one numeric base
2855  * to another, optionally zero-padding to a minimum column width.
2856  *
2857  * Supports base 2 through 36; digit values 10-36 are represented
2858  * as lowercase letters a-z. Input is case-insensitive.
2859  *
2860  * @param $input String: of digits
2861  * @param $sourceBase Integer: 2-36
2862  * @param $destBase Integer: 2-36
2863  * @param $pad Integer: 1 or greater
2864  * @param $lowercase Boolean
2865  * @return String or false on invalid input
2866  */
2867 function wfBaseConvert( $input, $sourceBase, $destBase, $pad = 1, $lowercase = true ) {
2868         $input = strval( $input );
2869         if( $sourceBase < 2 ||
2870                 $sourceBase > 36 ||
2871                 $destBase < 2 ||
2872                 $destBase > 36 ||
2873                 $pad < 1 ||
2874                 $sourceBase != intval( $sourceBase ) ||
2875                 $destBase != intval( $destBase ) ||
2876                 $pad != intval( $pad ) ||
2877                 !is_string( $input ) ||
2878                 $input == '' ) {
2879                 return false;
2880         }
2881         $digitChars = ( $lowercase ) ? '0123456789abcdefghijklmnopqrstuvwxyz' : '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
2882         $inDigits = array();
2883         $outChars = '';
2884
2885         // Decode and validate input string
2886         $input = strtolower( $input );
2887         for( $i = 0; $i < strlen( $input ); $i++ ) {
2888                 $n = strpos( $digitChars, $input[$i] );
2889                 if( $n === false || $n > $sourceBase ) {
2890                         return false;
2891                 }
2892                 $inDigits[] = $n;
2893         }
2894
2895         // Iterate over the input, modulo-ing out an output digit
2896         // at a time until input is gone.
2897         while( count( $inDigits ) ) {
2898                 $work = 0;
2899                 $workDigits = array();
2900
2901                 // Long division...
2902                 foreach( $inDigits as $digit ) {
2903                         $work *= $sourceBase;
2904                         $work += $digit;
2905
2906                         if( $work < $destBase ) {
2907                                 // Gonna need to pull another digit.
2908                                 if( count( $workDigits ) ) {
2909                                         // Avoid zero-padding; this lets us find
2910                                         // the end of the input very easily when
2911                                         // length drops to zero.
2912                                         $workDigits[] = 0;
2913                                 }
2914                         } else {
2915                                 // Finally! Actual division!
2916                                 $workDigits[] = intval( $work / $destBase );
2917
2918                                 // Isn't it annoying that most programming languages
2919                                 // don't have a single divide-and-remainder operator,
2920                                 // even though the CPU implements it that way?
2921                                 $work = $work % $destBase;
2922                         }
2923                 }
2924
2925                 // All that division leaves us with a remainder,
2926                 // which is conveniently our next output digit.
2927                 $outChars .= $digitChars[$work];
2928
2929                 // And we continue!
2930                 $inDigits = $workDigits;
2931         }
2932
2933         while( strlen( $outChars ) < $pad ) {
2934                 $outChars .= '0';
2935         }
2936
2937         return strrev( $outChars );
2938 }
2939
2940 /**
2941  * Create an object with a given name and an array of construct parameters
2942  *
2943  * @param $name String
2944  * @param $p Array: parameters
2945  * @deprecated since 1.18, warnings in 1.19, removal in 1.20
2946  */
2947 function wfCreateObject( $name, $p ) {
2948         wfDeprecated( __FUNCTION__ );
2949         return MWFunction::newObj( $name, $p );
2950 }
2951
2952 function wfHttpOnlySafe() {
2953         global $wgHttpOnlyBlacklist;
2954
2955         if( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
2956                 foreach( $wgHttpOnlyBlacklist as $regex ) {
2957                         if( preg_match( $regex, $_SERVER['HTTP_USER_AGENT'] ) ) {
2958                                 return false;
2959                         }
2960                 }
2961         }
2962
2963         return true;
2964 }
2965
2966 /**
2967  * Initialise php session
2968  *
2969  * @param $sessionId Bool
2970  */
2971 function wfSetupSession( $sessionId = false ) {
2972         global $wgSessionsInMemcached, $wgCookiePath, $wgCookieDomain,
2973                         $wgCookieSecure, $wgCookieHttpOnly, $wgSessionHandler;
2974         if( $wgSessionsInMemcached ) {
2975                 if ( !defined( 'MW_COMPILED' ) ) {
2976                         global $IP;
2977                         require_once( "$IP/includes/cache/MemcachedSessions.php" );
2978                 }
2979                 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read',
2980                         'memsess_write', 'memsess_destroy', 'memsess_gc' );
2981
2982                 // It's necessary to register a shutdown function to call session_write_close(),
2983                 // because by the time the request shutdown function for the session module is
2984                 // called, $wgMemc has already been destroyed. Shutdown functions registered
2985                 // this way are called before object destruction.
2986                 register_shutdown_function( 'memsess_write_close' );
2987         } elseif( $wgSessionHandler && $wgSessionHandler != ini_get( 'session.save_handler' ) ) {
2988                 # Only set this if $wgSessionHandler isn't null and session.save_handler
2989                 # hasn't already been set to the desired value (that causes errors)
2990                 ini_set( 'session.save_handler', $wgSessionHandler );
2991         }
2992         $httpOnlySafe = wfHttpOnlySafe() && $wgCookieHttpOnly;
2993         wfDebugLog( 'cookie',
2994                 'session_set_cookie_params: "' . implode( '", "',
2995                         array(
2996                                 0,
2997                                 $wgCookiePath,
2998                                 $wgCookieDomain,
2999                                 $wgCookieSecure,
3000                                 $httpOnlySafe ) ) . '"' );
3001         session_set_cookie_params( 0, $wgCookiePath, $wgCookieDomain, $wgCookieSecure, $httpOnlySafe );
3002         session_cache_limiter( 'private, must-revalidate' );
3003         if ( $sessionId ) {
3004                 session_id( $sessionId );
3005         }
3006         wfSuppressWarnings();
3007         session_start();
3008         wfRestoreWarnings();
3009 }
3010
3011 /**
3012  * Get an object from the precompiled serialized directory
3013  *
3014  * @param $name String
3015  * @return Mixed: the variable on success, false on failure
3016  */
3017 function wfGetPrecompiledData( $name ) {
3018         global $IP;
3019
3020         $file = "$IP/serialized/$name";
3021         if ( file_exists( $file ) ) {
3022                 $blob = file_get_contents( $file );
3023                 if ( $blob ) {
3024                         return unserialize( $blob );
3025                 }
3026         }
3027         return false;
3028 }
3029
3030 /**
3031  * Get a cache key
3032  *
3033  * @param varargs
3034  * @return String
3035  */
3036 function wfMemcKey( /*... */ ) {
3037         $args = func_get_args();
3038         $key = wfWikiID() . ':' . implode( ':', $args );
3039         $key = str_replace( ' ', '_', $key );
3040         return $key;
3041 }
3042
3043 /**
3044  * Get a cache key for a foreign DB
3045  *
3046  * @param $db String
3047  * @param $prefix String
3048  * @param varargs String
3049  * @return String
3050  */
3051 function wfForeignMemcKey( $db, $prefix /*, ... */ ) {
3052         $args = array_slice( func_get_args(), 2 );
3053         if ( $prefix ) {
3054                 $key = "$db-$prefix:" . implode( ':', $args );
3055         } else {
3056                 $key = $db . ':' . implode( ':', $args );
3057         }
3058         return $key;
3059 }
3060
3061 /**
3062  * Get an ASCII string identifying this wiki
3063  * This is used as a prefix in memcached keys
3064  *
3065  * @return String
3066  */
3067 function wfWikiID() {
3068         global $wgDBprefix, $wgDBname;
3069         if ( $wgDBprefix ) {
3070                 return "$wgDBname-$wgDBprefix";
3071         } else {
3072                 return $wgDBname;
3073         }
3074 }
3075
3076 /**
3077  * Split a wiki ID into DB name and table prefix
3078  *
3079  * @param $wiki String
3080  * @param $bits String
3081  */
3082 function wfSplitWikiID( $wiki ) {
3083         $bits = explode( '-', $wiki, 2 );
3084         if ( count( $bits ) < 2 ) {
3085                 $bits[] = '';
3086         }
3087         return $bits;
3088 }
3089
3090 /**
3091  * Get a Database object.
3092  *
3093  * @param $db Integer: index of the connection to get. May be DB_MASTER for the
3094  *            master (for write queries), DB_SLAVE for potentially lagged read
3095  *            queries, or an integer >= 0 for a particular server.
3096  *
3097  * @param $groups Mixed: query groups. An array of group names that this query
3098  *                belongs to. May contain a single string if the query is only
3099  *                in one group.
3100  *
3101  * @param $wiki String: the wiki ID, or false for the current wiki
3102  *
3103  * Note: multiple calls to wfGetDB(DB_SLAVE) during the course of one request
3104  * will always return the same object, unless the underlying connection or load
3105  * balancer is manually destroyed.
3106  *
3107  * Note 2: use $this->getDB() in maintenance scripts that may be invoked by
3108  * updater to ensure that a proper database is being updated.
3109  *
3110  * @return DatabaseBase
3111  */
3112 function &wfGetDB( $db, $groups = array(), $wiki = false ) {
3113         return wfGetLB( $wiki )->getConnection( $db, $groups, $wiki );
3114 }
3115
3116 /**
3117  * Get a load balancer object.
3118  *
3119  * @param $wiki String: wiki ID, or false for the current wiki
3120  * @return LoadBalancer
3121  */
3122 function wfGetLB( $wiki = false ) {
3123         return wfGetLBFactory()->getMainLB( $wiki );
3124 }
3125
3126 /**
3127  * Get the load balancer factory object
3128  *
3129  * @return LBFactory
3130  */
3131 function &wfGetLBFactory() {
3132         return LBFactory::singleton();
3133 }
3134
3135 /**
3136  * Find a file.
3137  * Shortcut for RepoGroup::singleton()->findFile()
3138  *
3139  * @param $title String or Title object
3140  * @param $options Associative array of options:
3141  *     time:           requested time for an archived image, or false for the
3142  *                     current version. An image object will be returned which was
3143  *                     created at the specified time.
3144  *
3145  *     ignoreRedirect: If true, do not follow file redirects
3146  *
3147  *     private:        If true, return restricted (deleted) files if the current
3148  *                     user is allowed to view them. Otherwise, such files will not
3149  *                     be found.
3150  *
3151  *     bypassCache:    If true, do not use the process-local cache of File objects
3152  *
3153  * @return File, or false if the file does not exist
3154  */
3155 function wfFindFile( $title, $options = array() ) {
3156         return RepoGroup::singleton()->findFile( $title, $options );
3157 }
3158
3159 /**
3160  * Get an object referring to a locally registered file.
3161  * Returns a valid placeholder object if the file does not exist.
3162  *
3163  * @param $title Title or String
3164  * @return File, or null if passed an invalid Title
3165  */
3166 function wfLocalFile( $title ) {
3167         return RepoGroup::singleton()->getLocalRepo()->newFile( $title );
3168 }
3169
3170 /**
3171  * Should low-performance queries be disabled?
3172  *
3173  * @return Boolean
3174  * @codeCoverageIgnore
3175  */
3176 function wfQueriesMustScale() {
3177         global $wgMiserMode;
3178         return $wgMiserMode
3179                 || ( SiteStats::pages() > 100000
3180                 && SiteStats::edits() > 1000000
3181                 && SiteStats::users() > 10000 );
3182 }
3183
3184 /**
3185  * Get the path to a specified script file, respecting file
3186  * extensions; this is a wrapper around $wgScriptExtension etc.
3187  *
3188  * @param $script String: script filename, sans extension
3189  * @return String
3190  */
3191 function wfScript( $script = 'index' ) {
3192         global $wgScriptPath, $wgScriptExtension;
3193         return "{$wgScriptPath}/{$script}{$wgScriptExtension}";
3194 }
3195
3196 /**
3197  * Get the script URL.
3198  *
3199  * @return script URL
3200  */
3201 function wfGetScriptUrl() {
3202         if( isset( $_SERVER['SCRIPT_NAME'] ) ) {
3203                 #
3204                 # as it was called, minus the query string.
3205                 #
3206                 # Some sites use Apache rewrite rules to handle subdomains,
3207                 # and have PHP set up in a weird way that causes PHP_SELF
3208                 # to contain the rewritten URL instead of the one that the
3209                 # outside world sees.
3210                 #
3211                 # If in this mode, use SCRIPT_URL instead, which mod_rewrite
3212                 # provides containing the "before" URL.
3213                 return $_SERVER['SCRIPT_NAME'];
3214         } else {
3215                 return $_SERVER['URL'];
3216         }
3217 }
3218
3219 /**
3220  * Convenience function converts boolean values into "true"
3221  * or "false" (string) values
3222  *
3223  * @param $value Boolean
3224  * @return String
3225  */
3226 function wfBoolToStr( $value ) {
3227         return $value ? 'true' : 'false';
3228 }
3229
3230 /**
3231  * Load an extension messages file
3232  *
3233  * @deprecated since 1.16, warnings in 1.18, remove in 1.20
3234  * @codeCoverageIgnore
3235  */
3236 function wfLoadExtensionMessages() {
3237         wfDeprecated( __FUNCTION__ );
3238 }
3239
3240 /**
3241  * Get a platform-independent path to the null file, e.g. /dev/null
3242  *
3243  * @return string
3244  */
3245 function wfGetNull() {
3246         return wfIsWindows()
3247                 ? 'NUL'
3248                 : '/dev/null';
3249 }
3250
3251 /**
3252  * Throws a warning that $function is deprecated
3253  *
3254  * @param $function String
3255  * @return null
3256  */
3257 function wfDeprecated( $function ) {
3258         static $functionsWarned = array();
3259         if ( !isset( $functionsWarned[$function] ) ) {
3260                 $functionsWarned[$function] = true;
3261                 wfWarn( "Use of $function is deprecated.", 2 );
3262         }
3263 }
3264
3265 /**
3266  * Send a warning either to the debug log or in a PHP error depending on
3267  * $wgDevelopmentWarnings
3268  *
3269  * @param $msg String: message to send
3270  * @param $callerOffset Integer: number of items to go back in the backtrace to
3271  *        find the correct caller (1 = function calling wfWarn, ...)
3272  * @param $level Integer: PHP error level; only used when $wgDevelopmentWarnings
3273  *        is true
3274  */
3275 function wfWarn( $msg, $callerOffset = 1, $level = E_USER_NOTICE ) {
3276         global $wgDevelopmentWarnings;
3277
3278         $callers = wfDebugBacktrace();
3279         if ( isset( $callers[$callerOffset + 1] ) ) {
3280                 $callerfunc = $callers[$callerOffset + 1];
3281                 $callerfile = $callers[$callerOffset];
3282                 if ( isset( $callerfile['file'] ) && isset( $callerfile['line'] ) ) {
3283                         $file = $callerfile['file'] . ' at line ' . $callerfile['line'];
3284                 } else {
3285                         $file = '(internal function)';
3286                 }
3287                 $func = '';
3288                 if ( isset( $callerfunc['class'] ) ) {
3289                         $func .= $callerfunc['class'] . '::';
3290                 }
3291                 if ( isset( $callerfunc['function'] ) ) {
3292                         $func .= $callerfunc['function'];
3293                 }
3294                 $msg .= " [Called from $func in $file]";
3295         }
3296
3297         if ( $wgDevelopmentWarnings ) {
3298                 trigger_error( $msg, $level );
3299         } else {
3300                 wfDebug( "$msg\n" );
3301         }
3302 }
3303
3304 /**
3305  * Modern version of wfWaitForSlaves(). Instead of looking at replication lag
3306  * and waiting for it to go down, this waits for the slaves to catch up to the
3307  * master position. Use this when updating very large numbers of rows, as
3308  * in maintenance scripts, to avoid causing too much lag.  Of course, this is
3309  * a no-op if there are no slaves.
3310  *
3311  * @param $maxLag Integer (deprecated)
3312  * @param $wiki mixed Wiki identifier accepted by wfGetLB
3313  * @return null
3314  */
3315 function wfWaitForSlaves( $maxLag = false, $wiki = false ) {
3316         $lb = wfGetLB( $wiki );
3317         // bug 27975 - Don't try to wait for slaves if there are none
3318         // Prevents permission error when getting master position
3319         if ( $lb->getServerCount() > 1 ) {
3320                 $dbw = $lb->getConnection( DB_MASTER );
3321                 $pos = $dbw->getMasterPos();
3322                 $lb->waitForAll( $pos );
3323         }
3324 }
3325
3326 /**
3327  * Used to be used for outputting text in the installer/updater
3328  * @deprecated since 1.18, warnings in 1.19, remove in 1.20
3329  */
3330 function wfOut( $s ) {
3331         wfDeprecated( __METHOD__ );
3332         global $wgCommandLineMode;
3333         if ( $wgCommandLineMode && !defined( 'MEDIAWIKI_INSTALL' ) ) {
3334                 echo $s;
3335         } else {
3336                 echo htmlspecialchars( $s );
3337         }
3338         flush();
3339 }
3340
3341 /**
3342  * Count down from $n to zero on the terminal, with a one-second pause
3343  * between showing each number. For use in command-line scripts.
3344  * @codeCoverageIgnore
3345  */
3346 function wfCountDown( $n ) {
3347         for ( $i = $n; $i >= 0; $i-- ) {
3348                 if ( $i != $n ) {
3349                         echo str_repeat( "\x08", strlen( $i + 1 ) );
3350                 }
3351                 echo $i;
3352                 flush();
3353                 if ( $i ) {
3354                         sleep( 1 );
3355                 }
3356         }
3357         echo "\n";
3358 }
3359
3360 /**
3361  * Generate a random 32-character hexadecimal token.
3362  * @param $salt Mixed: some sort of salt, if necessary, to add to random
3363  *              characters before hashing.
3364  * @return string
3365  * @codeCoverageIgnore
3366  */
3367 function wfGenerateToken( $salt = '' ) {
3368         $salt = serialize( $salt );
3369         return md5( mt_rand( 0, 0x7fffffff ) . $salt );
3370 }
3371
3372 /**
3373  * Replace all invalid characters with -
3374  *
3375  * @param $name Mixed: filename to process
3376  * @return String
3377  */
3378 function wfStripIllegalFilenameChars( $name ) {
3379         global $wgIllegalFileChars;
3380         $name = wfBaseName( $name );
3381         $name = preg_replace(
3382                 "/[^" . Title::legalChars() . "]" .
3383                         ( $wgIllegalFileChars ? "|[" . $wgIllegalFileChars . "]" : '' ) .
3384                         "/",
3385                 '-',
3386                 $name
3387         );
3388         return $name;
3389 }
3390
3391 /**
3392  * Set PHP's memory limit to the larger of php.ini or $wgMemoryLimit;
3393  *
3394  * @return Integer value memory was set to.
3395  */
3396 function wfMemoryLimit() {
3397         global $wgMemoryLimit;
3398         $memlimit = wfShorthandToInteger( ini_get( 'memory_limit' ) );
3399         if( $memlimit != -1 ) {
3400                 $conflimit = wfShorthandToInteger( $wgMemoryLimit );
3401                 if( $conflimit == -1 ) {
3402                         wfDebug( "Removing PHP's memory limit\n" );
3403                         wfSuppressWarnings();
3404                         ini_set( 'memory_limit', $conflimit );
3405                         wfRestoreWarnings();
3406                         return $conflimit;
3407                 } elseif ( $conflimit > $memlimit ) {
3408                         wfDebug( "Raising PHP's memory limit to $conflimit bytes\n" );
3409                         wfSuppressWarnings();
3410                         ini_set( 'memory_limit', $conflimit );
3411                         wfRestoreWarnings();
3412                         return $conflimit;
3413                 }
3414         }
3415         return $memlimit;
3416 }
3417
3418 /**
3419  * Converts shorthand byte notation to integer form
3420  *
3421  * @param $string String
3422  * @return Integer
3423  */
3424 function wfShorthandToInteger( $string = '' ) {
3425         $string = trim( $string );
3426         if( $string === '' ) {
3427                 return -1;
3428         }
3429         $last = $string[strlen( $string ) - 1];
3430         $val = intval( $string );
3431         switch( $last ) {
3432                 case 'g':
3433                 case 'G':
3434                         $val *= 1024;
3435                         // break intentionally missing
3436                 case 'm':
3437                 case 'M':
3438                         $val *= 1024;
3439                         // break intentionally missing
3440                 case 'k':
3441                 case 'K':
3442                         $val *= 1024;
3443         }
3444
3445         return $val;
3446 }
3447
3448 /**
3449  * Get the normalised IETF language tag
3450  * See unit test for examples.
3451  *
3452  * @param $code String: The language code.
3453  * @return $langCode String: The language code which complying with BCP 47 standards.
3454  */
3455 function wfBCP47( $code ) {
3456         $codeSegment = explode( '-', $code );
3457         $codeBCP = array();
3458         foreach ( $codeSegment as $segNo => $seg ) {
3459                 if ( count( $codeSegment ) > 0 ) {
3460                         // when previous segment is x, it is a private segment and should be lc
3461                         if( $segNo > 0 && strtolower( $codeSegment[($segNo - 1)] ) == 'x') {
3462                                 $codeBCP[$segNo] = strtolower( $seg );
3463                         // ISO 3166 country code
3464                         } elseif ( ( strlen( $seg ) == 2 ) && ( $segNo > 0 ) ) {
3465                                 $codeBCP[$segNo] = strtoupper( $seg );
3466                         // ISO 15924 script code
3467                         } elseif ( ( strlen( $seg ) == 4 ) && ( $segNo > 0 ) ) {
3468                                 $codeBCP[$segNo] = ucfirst( strtolower( $seg ) );
3469                         // Use lowercase for other cases
3470                         } else {
3471                                 $codeBCP[$segNo] = strtolower( $seg );
3472                         }
3473                 } else {
3474                 // Use lowercase for single segment
3475                         $codeBCP[$segNo] = strtolower( $seg );
3476                 }
3477         }
3478         $langCode = implode( '-', $codeBCP );
3479         return $langCode;
3480 }
3481
3482 /**
3483  * Get a cache object.
3484  *
3485  * @param $inputType integer Cache type, one the the CACHE_* constants.
3486  * @return BagOStuff
3487  */
3488 function wfGetCache( $inputType ) {
3489         return ObjectCache::getInstance( $inputType );
3490 }
3491
3492 /**
3493  * Get the main cache object
3494  *
3495  * @return BagOStuff
3496  */
3497 function wfGetMainCache() {
3498         global $wgMainCacheType;
3499         return ObjectCache::getInstance( $wgMainCacheType );
3500 }
3501
3502 /**
3503  * Get the cache object used by the message cache
3504  *
3505  * @return BagOStuff
3506  */
3507 function wfGetMessageCacheStorage() {
3508         global $wgMessageCacheType;
3509         return ObjectCache::getInstance( $wgMessageCacheType );
3510 }
3511
3512 /**
3513  * Get the cache object used by the parser cache
3514  *
3515  * @return BagOStuff
3516  */
3517 function wfGetParserCacheStorage() {
3518         global $wgParserCacheType;
3519         return ObjectCache::getInstance( $wgParserCacheType );
3520 }
3521
3522 /**
3523  * Call hook functions defined in $wgHooks
3524  *
3525  * @param $event String: event name
3526  * @param $args Array: parameters passed to hook functions
3527  * @return Boolean
3528  */
3529 function wfRunHooks( $event, $args = array() ) {
3530         return Hooks::run( $event, $args );
3531 }