* Make sure not to crash when the message cache isn't alive

[mediawiki.git] / includes / GlobalFunctions.php

<?php

/**
 * Global functions used everywhere
 * @package MediaWiki
 */

/**
 * Some globals and requires needed
 */

/**
 * Total number of articles
 * @global integer $wgNumberOfArticles
 */
$wgNumberOfArticles = -1; # Unset
/**
 * Total number of views
 * @global integer $wgTotalViews
 */
$wgTotalViews = -1;
/**
 * Total number of edits
 * @global integer $wgTotalEdits
 */
$wgTotalEdits = -1;


require_once( 'DatabaseFunctions.php' );
require_once( 'UpdateClasses.php' );
require_once( 'LogPage.php' );
require_once( 'normal/UtfNormalUtil.php' );

/**
 * Compatibility functions
 * PHP <4.3.x is not actively supported; 4.1.x and 4.2.x might or might not work.
 * <4.1.x will not work, as we use a number of features introduced in 4.1.0
 * such as the new autoglobals.
 */
if( !function_exists('iconv') ) {
        # iconv support is not in the default configuration and so may not be present.
        # Assume will only ever use utf-8 and iso-8859-1.
        # This will *not* work in all circumstances.
        function iconv( $from, $to, $string ) {
                if(strcasecmp( $from, $to ) == 0) return $string;
                if(strcasecmp( $from, 'utf-8' ) == 0) return utf8_decode( $string );
                if(strcasecmp( $to, 'utf-8' ) == 0) return utf8_encode( $string );
                return $string;
        }
}

if( !function_exists('file_get_contents') ) {
        # Exists in PHP 4.3.0+
        function file_get_contents( $filename ) {
                return implode( '', file( $filename ) );
        }
}

if( !function_exists('is_a') ) {
        # Exists in PHP 4.2.0+
        function is_a( $object, $class_name ) {
                return
                        (strcasecmp( get_class( $object ), $class_name ) == 0) ||
                         is_subclass_of( $object, $class_name );
        }
}

# UTF-8 substr function based on a PHP manual comment
if ( !function_exists( 'mb_substr' ) ) {
        function mb_substr( $str, $start ) {
                preg_match_all( '/./us', $str, $ar );

                if( func_num_args() >= 3 ) {
                        $end = func_get_arg( 2 );
                        return join( '', array_slice( $ar[0], $start, $end ) );
                } else {
                        return join( '', array_slice( $ar[0], $start ) );
                }
        }
}

if( !function_exists( 'floatval' ) ) {
        /**
         * First defined in PHP 4.2.0
         * @param mixed $var;
         * @return float
         */
        function floatval( $var ) {
                return (float)$var;
        }
}

/**
 * Where as we got a random seed
 * @var bool $wgTotalViews
 */
$wgRandomSeeded = false;

/**
 * Seed Mersenne Twister
 * Only necessary in PHP < 4.2.0
 *
 * @return bool
 */
function wfSeedRandom() {
        global $wgRandomSeeded;

        if ( ! $wgRandomSeeded && version_compare( phpversion(), '4.2.0' ) < 0 ) {
                $seed = hexdec(substr(md5(microtime()),-8)) & 0x7fffffff;
                mt_srand( $seed );
                $wgRandomSeeded = true;
        }
}

/**
 * Get a random decimal value between 0 and 1, in a way
 * not likely to give duplicate values for any realistic
 * number of articles.
 *
 * @return string
 */
function wfRandom() {
        # The maximum random value is "only" 2^31-1, so get two random
        # values to reduce the chance of dupes
        $max = mt_getrandmax();
        $rand = number_format( (mt_rand() * $max + mt_rand())
                / $max / $max, 12, '.', '' );
        return $rand;
}

/**
 * We want / and : to be included as literal characters in our title URLs.
 * %2F in the page titles seems to fatally break for some reason.
 *
 * @param string $s
 * @return string
*/
function wfUrlencode ( $s ) {
        $s = urlencode( $s );
        $s = preg_replace( '/%3[Aa]/', ':', $s );
        $s = preg_replace( '/%2[Ff]/', '/', $s );

        return $s;
}

/**
 * Sends a line to the debug log if enabled or, optionally, to a comment in output.
 * In normal operation this is a NOP.
 *
 * Controlling globals:
 * $wgDebugLogFile - points to the log file
 * $wgProfileOnly - if set, normal debug messages will not be recorded.
 * $wgDebugRawPage - if false, 'action=raw' hits will not result in debug output.
 * $wgDebugComments - if on, some debug items may appear in comments in the HTML output.
 *
 * @param string $text
 * @param bool $logonly Set true to avoid appearing in HTML when $wgDebugComments is set
 */
function wfDebug( $text, $logonly = false ) {
        global $wgOut, $wgDebugLogFile, $wgDebugComments, $wgProfileOnly, $wgDebugRawPage;

        # Check for raw action using $_GET not $wgRequest, since the latter might not be initialised yet
        if ( isset( $_GET['action'] ) && $_GET['action'] == 'raw' && !$wgDebugRawPage ) {
                return;
        }

        if ( isset( $wgOut ) && $wgDebugComments && !$logonly ) {
                $wgOut->debug( $text );
        }
        if ( '' != $wgDebugLogFile && !$wgProfileOnly ) {
                # Strip unprintables; they can switch terminal modes when binary data
                # gets dumped, which is pretty annoying.
                $text = preg_replace( '![\x00-\x08\x0b\x0c\x0e-\x1f]!', ' ', $text );
                @error_log( $text, 3, $wgDebugLogFile );
        }
}

/**
 * Send a line to a supplementary debug log file, if configured, or main debug log if not.
 * $wgDebugLogGroups[$logGroup] should be set to a filename to send to a separate log.
 *
 * @param string $logGroup
 * @param string $text
 * @param bool $public Whether to log the event in the public log if no private
 *                     log file is specified, (default true)
 */
function wfDebugLog( $logGroup, $text, $public = true ) {
        global $wgDebugLogGroups, $wgDBname;
        if( $text{strlen( $text ) - 1} != "\n" ) $text .= "\n";
        if( isset( $wgDebugLogGroups[$logGroup] ) ) {
                @error_log( "$wgDBname: $text", 3, $wgDebugLogGroups[$logGroup] );
        } else if ( $public === true ) {
                wfDebug( $text, true );
        }
}

/**
 * Log for database errors
 * @param string $text Database error message.
 */
function wfLogDBError( $text ) {
        global $wgDBerrorLog;
        if ( $wgDBerrorLog ) {
                $host = trim(`hostname`);
                $text = date('D M j G:i:s T Y') . "\t$host\t".$text;
                error_log( $text, 3, $wgDBerrorLog );
        }
}

/**
 * @todo document
 */
function logProfilingData() {
        global $wgRequestTime, $wgDebugLogFile, $wgDebugRawPage, $wgRequest;
        global $wgProfiling, $wgProfileStack, $wgProfileLimit, $wgUser;
        $now = wfTime();

        list( $usec, $sec ) = explode( ' ', $wgRequestTime );
        $start = (float)$sec + (float)$usec;
        $elapsed = $now - $start;
        if ( $wgProfiling ) {
                $prof = wfGetProfilingOutput( $start, $elapsed );
                $forward = '';
                if( !empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) )
                        $forward = ' forwarded for ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
                if( !empty( $_SERVER['HTTP_CLIENT_IP'] ) )
                        $forward .= ' client IP ' . $_SERVER['HTTP_CLIENT_IP'];
                if( !empty( $_SERVER['HTTP_FROM'] ) )
                        $forward .= ' from ' . $_SERVER['HTTP_FROM'];
                if( $forward )
                        $forward = "\t(proxied via {$_SERVER['REMOTE_ADDR']}{$forward})";
                if( $wgUser->isAnon() )
                        $forward .= ' anon';
                $log = sprintf( "%s\t%04.3f\t%s\n",
                  gmdate( 'YmdHis' ), $elapsed,
                  urldecode( $_SERVER['REQUEST_URI'] . $forward ) );
                if ( '' != $wgDebugLogFile && ( $wgRequest->getVal('action') != 'raw' || $wgDebugRawPage ) ) {
                        error_log( $log . $prof, 3, $wgDebugLogFile );
                }
        }
}

/**
 * Check if the wiki read-only lock file is present. This can be used to lock
 * off editing functions, but doesn't guarantee that the database will not be
 * modified.
 * @return bool
 */
function wfReadOnly() {
        global $wgReadOnlyFile, $wgReadOnly;

        if ( $wgReadOnly ) {
                return true;
        }
        if ( '' == $wgReadOnlyFile ) {
                return false;
        }

        // Set $wgReadOnly and unset $wgReadOnlyFile, for faster access next time
        if ( is_file( $wgReadOnlyFile ) ) {
                $wgReadOnly = file_get_contents( $wgReadOnlyFile );
        } else {
                $wgReadOnly = false;
        }
        $wgReadOnlyFile = '';
        return $wgReadOnly;
}


/**
 * Get a message from anywhere, for the current user language.
 *
 * Use wfMsgForContent() instead if the message should NOT 
 * change depending on the user preferences.
 *
 * Note that the message may contain HTML, and is therefore
 * not safe for insertion anywhere. Some functions such as
 * addWikiText will do the escaping for you. Use wfMsgHtml()
 * if you need an escaped message.
 *
 * @param string lookup key for the message, usually 
 *    defined in languages/Language.php
 */
function wfMsg( $key ) {
        $args = func_get_args();
        array_shift( $args );
        return wfMsgReal( $key, $args, true );
}

/**
 * Same as above except doesn't transform the message
 */
function wfMsgNoTrans( $key ) {
        $args = func_get_args();
        array_shift( $args );
        return wfMsgReal( $key, $args, true, false );
}

/**
 * Get a message from anywhere, for the current global language
 * set with $wgLanguageCode.
 * 
 * Use this if the message should NOT change  dependent on the 
 * language set in the user's preferences. This is the case for 
 * most text written into logs, as well as link targets (such as 
 * the name of the copyright policy page). Link titles, on the 
 * other hand, should be shown in the UI language.
 *
 * Note that MediaWiki allows users to change the user interface 
 * language in their preferences, but a single installation 
 * typically only contains content in one language.
 * 
 * Be wary of this distinction: If you use wfMsg() where you should 
 * use wfMsgForContent(), a user of the software may have to 
 * customize over 70 messages in order to, e.g., fix a link in every
 * possible language.
 *
 * @param string lookup key for the message, usually 
 *    defined in languages/Language.php
 */
function wfMsgForContent( $key ) {
        global $wgForceUIMsgAsContentMsg;
        $args = func_get_args();
        array_shift( $args );
        $forcontent = true;
        if( is_array( $wgForceUIMsgAsContentMsg ) &&
                in_array( $key, $wgForceUIMsgAsContentMsg ) )
                $forcontent = false;
        return wfMsgReal( $key, $args, true, $forcontent );
}

/**
 * Same as above except doesn't transform the message
 */
function wfMsgForContentNoTrans( $key ) {
        global $wgForceUIMsgAsContentMsg;
        $args = func_get_args();
        array_shift( $args );
        $forcontent = true;
        if( is_array( $wgForceUIMsgAsContentMsg ) &&
                in_array( $key, $wgForceUIMsgAsContentMsg ) )
                $forcontent = false;
        return wfMsgReal( $key, $args, true, $forcontent, false );
}

/**
 * Get a message from the language file, for the UI elements
 */
function wfMsgNoDB( $key ) {
        $args = func_get_args();
        array_shift( $args );
        return wfMsgReal( $key, $args, false );
}

/**
 * Get a message from the language file, for the content
 */
function wfMsgNoDBForContent( $key ) {
        global $wgForceUIMsgAsContentMsg;
        $args = func_get_args();
        array_shift( $args );
        $forcontent = true;
        if( is_array( $wgForceUIMsgAsContentMsg ) &&
                in_array( $key, $wgForceUIMsgAsContentMsg ) )
                $forcontent = false;
        return wfMsgReal( $key, $args, false, $forcontent );
}


/**
 * Really get a message
 */
function wfMsgReal( $key, $args, $useDB, $forContent=false, $transform = true ) {
        $fname = 'wfMsgReal';
        wfProfileIn( $fname );

        $message = wfMsgGetKey( $key, $useDB, $forContent, $transform );
        $message = wfMsgReplaceArgs( $message, $args );
        wfProfileOut( $fname );
        return $message;
}

/**
 * Fetch a message string value, but don't replace any keys yet.
 * @param string $key
 * @param bool $useDB
 * @param bool $forContent
 * @return string
 * @access private
 */
function wfMsgGetKey( $key, $useDB, $forContent = false, $transform = true ) {
        global $wgParser, $wgMsgParserOptions;
        global $wgContLang, $wgLanguageCode;
        global $wgMessageCache, $wgLang;

        if ( is_object( $wgMessageCache ) )
                $transstat = $wgMessageCache->getTransform();
        
        if( is_object( $wgMessageCache ) ) {
                if ( ! $transform )
                        $wgMessageCache->disableTransform();
                $message = $wgMessageCache->get( $key, $useDB, $forContent );
        } else {
                if( $forContent ) {
                        $lang = &$wgContLang;
                } else {
                        $lang = &$wgLang;
                }

                wfSuppressWarnings();

                if( is_object( $lang ) ) {
                        $message = $lang->getMessage( $key );
                } else {
                        $message = false;
                }
                wfRestoreWarnings();
                if($message === false)
                        $message = Language::getMessage($key);
                if ( $transform && strstr( $message, '{{' ) !== false ) {
                        $message = $wgParser->transformMsg($message, $wgMsgParserOptions);
                }
        }

        if ( is_object( $wgMessageCache ) && ! $transform )
                $wgMessageCache->setTransform( $transstat );
        
        return $message;
}

/**
 * Replace message parameter keys on the given formatted output.
 *
 * @param string $message
 * @param array $args
 * @return string
 * @access private
 */
function wfMsgReplaceArgs( $message, $args ) {
        # Fix windows line-endings
        # Some messages are split with explode("\n", $msg)
        $message = str_replace( "\r", '', $message );

        // Replace arguments
        if ( count( $args ) )
                if ( is_array( $args[0] ) )
                        foreach ( $args[0] as $key => $val )
                                $message = str_replace( '$' . $key, $val, $message );
        else {
                foreach( $args as $n => $param )
                        $replacementKeys['$' . ($n + 1)] = $param;
                $message = strtr( $message, $replacementKeys );
        }
        
        return $message;
}

/**
 * Return an HTML-escaped version of a message.
 * Parameter replacements, if any, are done *after* the HTML-escaping,
 * so parameters may contain HTML (eg links or form controls). Be sure
 * to pre-escape them if you really do want plaintext, or just wrap
 * the whole thing in htmlspecialchars().
 *
 * @param string $key
 * @param string ... parameters
 * @return string
 */
function wfMsgHtml( $key ) {
        $args = func_get_args();
        array_shift( $args );
        return wfMsgReplaceArgs( htmlspecialchars( wfMsgGetKey( $key, true ) ), $args );
}

/**
 * Return an HTML version of message
 * Parameter replacements, if any, are done *after* parsing the wiki-text message,
 * so parameters may contain HTML (eg links or form controls). Be sure
 * to pre-escape them if you really do want plaintext, or just wrap
 * the whole thing in htmlspecialchars().
 *
 * @param string $key
 * @param string ... parameters
 * @return string
 */
function wfMsgWikiHtml( $key ) {
        global $wgOut;
        $args = func_get_args();
        array_shift( $args );
        return wfMsgReplaceArgs( $wgOut->parse( wfMsgGetKey( $key, true ), /* can't be set to false */ true ), $args );
}

/**
 * Just like exit() but makes a note of it.
 * Commits open transactions except if the error parameter is set
 */
function wfAbruptExit( $error = false ){
        global $wgLoadBalancer;
        static $called = false;
        if ( $called ){
                exit();
        }
        $called = true;

        if( function_exists( 'debug_backtrace' ) ){ // PHP >= 4.3
                $bt = debug_backtrace();
                for($i = 0; $i < count($bt) ; $i++){
                        $file = isset($bt[$i]['file']) ? $bt[$i]['file'] : "unknown";
                        $line = isset($bt[$i]['line']) ? $bt[$i]['line'] : "unknown";
                        wfDebug("WARNING: Abrupt exit in $file at line $line\n");
                }
        } else {
                wfDebug('WARNING: Abrupt exit\n');
        }
        if ( !$error ) {
                $wgLoadBalancer->closeAll();
        }
        exit();
}

/**
 * @todo document
 */
function wfErrorExit() {
        wfAbruptExit( true );
}

/**
 * Die with a backtrace
 * This is meant as a debugging aid to track down where bad data comes from.
 * Shouldn't be used in production code except maybe in "shouldn't happen" areas.
 *
 * @param string $msg Message shown when dieing.
 */
function wfDebugDieBacktrace( $msg = '' ) {
        global $wgCommandLineMode;

        $backtrace = wfBacktrace();
        if ( $backtrace !== false ) {
                if ( $wgCommandLineMode ) {
                        $msg .= "\nBacktrace:\n$backtrace";
                } else {
                        $msg .= "\n<p>Backtrace:</p>\n$backtrace";
                }
        }
        echo $msg;
        echo wfReportTime()."\n";
        die( -1 );
}

        /**
         * Returns a HTML comment with the elapsed time since request.
         * This method has no side effects.
         * @return string
         */
        function wfReportTime() {
                global $wgRequestTime;

                $now = wfTime();
                list( $usec, $sec ) = explode( ' ', $wgRequestTime );
                $start = (float)$sec + (float)$usec;
                $elapsed = $now - $start;

                # Use real server name if available, so we know which machine
                # in a server farm generated the current page.
                if ( function_exists( 'posix_uname' ) ) {
                        $uname = @posix_uname();
                } else {
                        $uname = false;
                }
                if( is_array( $uname ) && isset( $uname['nodename'] ) ) {
                        $hostname = $uname['nodename'];
                } else {
                        # This may be a virtual server.
                        $hostname = $_SERVER['SERVER_NAME'];
                }
                $com = sprintf( "<!-- Served by %s in %01.2f secs. -->",
                  $hostname, $elapsed );
                return $com;
        }

function wfBacktrace() {
        global $wgCommandLineMode;
        if ( !function_exists( 'debug_backtrace' ) ) {
                return false;
        }

        if ( $wgCommandLineMode ) {
                $msg = '';
        } else {
                $msg = "<ul>\n";
        }
        $backtrace = debug_backtrace();
        foreach( $backtrace as $call ) {
                if( isset( $call['file'] ) ) {
                        $f = explode( DIRECTORY_SEPARATOR, $call['file'] );
                        $file = $f[count($f)-1];
                } else {
                        $file = '-';
                }
                if( isset( $call['line'] ) ) {
                        $line = $call['line'];
                } else {
                        $line = '-';
                }
                if ( $wgCommandLineMode ) {
                        $msg .= "$file line $line calls ";
                } else {
                        $msg .= '<li>' . $file . ' line ' . $line . ' calls ';
                }
                if( !empty( $call['class'] ) ) $msg .= $call['class'] . '::';
                $msg .= $call['function'] . '()';

                if ( $wgCommandLineMode ) {
                        $msg .= "\n";
                } else {
                        $msg .= "</li>\n";
                }
        }
        if ( $wgCommandLineMode ) {
                $msg .= "\n";
        } else {
                $msg .= "</ul>\n";
        }

        return $msg;
}


/* Some generic result counters, pulled out of SearchEngine */


/**
 * @todo document
 */
function wfShowingResults( $offset, $limit ) {
        global $wgLang;
        return wfMsg( 'showingresults', $wgLang->formatNum( $limit ), $wgLang->formatNum( $offset+1 ) );
}

/**
 * @todo document
 */
function wfShowingResultsNum( $offset, $limit, $num ) {
        global $wgLang;
        return wfMsg( 'showingresultsnum', $wgLang->formatNum( $limit ), $wgLang->formatNum( $offset+1 ), $wgLang->formatNum( $num ) );
}

/**
 * @todo document
 */
function wfViewPrevNext( $offset, $limit, $link, $query = '', $atend = false ) {
        global $wgUser, $wgLang;
        $fmtLimit = $wgLang->formatNum( $limit );
        $prev = wfMsg( 'prevn', $fmtLimit );
        $next = wfMsg( 'nextn', $fmtLimit );

        if( is_object( $link ) ) {
                $title =& $link;
        } else {
                $title = Title::newFromText( $link );
                if( is_null( $title ) ) {
                        return false;
                }
        }

        $sk = $wgUser->getSkin();
        if ( 0 != $offset ) {
                $po = $offset - $limit;
                if ( $po < 0 ) { $po = 0; }
                $q = "limit={$limit}&offset={$po}";
                if ( '' != $query ) { $q .= '&'.$query; }
                $plink = '<a href="' . $title->escapeLocalUrl( $q ) . "\">{$prev}</a>";
        } else { $plink = $prev; }

        $no = $offset + $limit;
        $q = 'limit='.$limit.'&offset='.$no;
        if ( '' != $query ) { $q .= '&'.$query; }

        if ( $atend ) {
                $nlink = $next;
        } else {
                $nlink = '<a href="' . $title->escapeLocalUrl( $q ) . "\">{$next}</a>";
        }
        $nums = wfNumLink( $offset, 20, $title, $query ) . ' | ' .
          wfNumLink( $offset, 50, $title, $query ) . ' | ' .
          wfNumLink( $offset, 100, $title, $query ) . ' | ' .
          wfNumLink( $offset, 250, $title, $query ) . ' | ' .
          wfNumLink( $offset, 500, $title, $query );

        return wfMsg( 'viewprevnext', $plink, $nlink, $nums );
}

/**
 * @todo document
 */
function wfNumLink( $offset, $limit, &$title, $query = '' ) {
        global $wgUser, $wgLang;
        if ( '' == $query ) { $q = ''; }
        else { $q = $query.'&'; }
        $q .= 'limit='.$limit.'&offset='.$offset;

        $fmtLimit = $wgLang->formatNum( $limit );
        $s = '<a href="' . $title->escapeLocalUrl( $q ) . "\">{$fmtLimit}</a>";
        return $s;
}

/**
 * @todo document
 * @todo FIXME: we may want to blacklist some broken browsers
 *
 * @return bool Whereas client accept gzip compression
 */
function wfClientAcceptsGzip() {
        global $wgUseGzip;
        if( $wgUseGzip ) {
                # FIXME: we may want to blacklist some broken browsers
                if( preg_match(
                        '/\bgzip(?:;(q)=([0-9]+(?:\.[0-9]+)))?\b/',
                        $_SERVER['HTTP_ACCEPT_ENCODING'],
                        $m ) ) {
                        if( isset( $m[2] ) && ( $m[1] == 'q' ) && ( $m[2] == 0 ) ) return false;
                        wfDebug( " accepts gzip\n" );
                        return true;
                }
        }
        return false;
}

/**
 * Yay, more global functions!
 */
function wfCheckLimits( $deflimit = 50, $optionname = 'rclimit' ) {
        global $wgRequest;
        return $wgRequest->getLimitOffset( $deflimit, $optionname );
}

/**
 * Escapes the given text so that it may be output using addWikiText()
 * without any linking, formatting, etc. making its way through. This
 * is achieved by substituting certain characters with HTML entities.
 * As required by the callers, <nowiki> is not used. It currently does
 * not filter out characters which have special meaning only at the
 * start of a line, such as "*".
 *
 * @param string $text Text to be escaped
 */
function wfEscapeWikiText( $text ) {
        $text = str_replace(
                array( '[',             '|',      '\'',    'ISBN '        , '://'         , "\n=", '{{' ),
                array( '&#91;', '&#124;', '&#39;', 'ISBN&#32;', '&#58;//' , "\n&#61;", '&#123;&#123;' ),
                htmlspecialchars($text) );
        return $text;
}

/**
 * @todo document
 */
function wfQuotedPrintable( $string, $charset = '' ) {
        # Probably incomplete; see RFC 2045
        if( empty( $charset ) ) {
                global $wgInputEncoding;
                $charset = $wgInputEncoding;
        }
        $charset = strtoupper( $charset );
        $charset = str_replace( 'ISO-8859', 'ISO8859', $charset ); // ?

        $illegal = '\x00-\x08\x0b\x0c\x0e-\x1f\x7f-\xff=';
        $replace = $illegal . '\t ?_';
        if( !preg_match( "/[$illegal]/", $string ) ) return $string;
        $out = "=?$charset?Q?";
        $out .= preg_replace( "/([$replace])/e", 'sprintf("=%02X",ord("$1"))', $string );
        $out .= '?=';
        return $out;
}

/**
 * Returns an escaped string suitable for inclusion in a string literal
 * for JavaScript source code.
 * Illegal control characters are assumed not to be present.
 *
 * @param string $string
 * @return string
 */
function wfEscapeJsString( $string ) {
        // See ECMA 262 section 7.8.4 for string literal format
        $pairs = array(
                "\\" => "\\\\",
                "\"" => "\\\"",
                '\'' => '\\\'',
                "\n" => "\\n",
                "\r" => "\\r",

                # To avoid closing the element or CDATA section
                "<" => "\\x3c",
                ">" => "\\x3e",
        );
        return strtr( $string, $pairs );
}

/**
 * @todo document
 * @return float
 */
function wfTime() {
        $st = explode( ' ', microtime() );
        return (float)$st[0] + (float)$st[1];
}

/**
 * Changes the first character to an HTML entity
 */
function wfHtmlEscapeFirst( $text ) {
        $ord = ord($text);
        $newText = substr($text, 1);
        return "&#$ord;$newText";
}

/**
 * Sets dest to source and returns the original value of dest
 * If source is NULL, it just returns the value, it doesn't set the variable
 */
function wfSetVar( &$dest, $source ) {
        $temp = $dest;
        if ( !is_null( $source ) ) {
                $dest = $source;
        }
        return $temp;
}

/**
 * As for wfSetVar except setting a bit
 */
function wfSetBit( &$dest, $bit, $state = true ) {
        $temp = (bool)($dest & $bit );
        if ( !is_null( $state ) ) {
                if ( $state ) {
                        $dest |= $bit;
                } else {
                        $dest &= ~$bit;
                }
        }
        return $temp;
}

/**
 * This function takes two arrays as input, and returns a CGI-style string, e.g.
 * "days=7&limit=100". Options in the first array override options in the second.
 * Options set to "" will not be output.
 */
function wfArrayToCGI( $array1, $array2 = NULL )
{
        if ( !is_null( $array2 ) ) {
                $array1 = $array1 + $array2;
        }

        $cgi = '';
        foreach ( $array1 as $key => $value ) {
                if ( '' !== $value ) {
                        if ( '' != $cgi ) {
                                $cgi .= '&';
                        }
                        $cgi .= urlencode( $key ) . '=' . urlencode( $value );
                }
        }
        return $cgi;
}

/**
 * This is obsolete, use SquidUpdate::purge()
 * @deprecated
 */
function wfPurgeSquidServers ($urlArr) {
        SquidUpdate::purge( $urlArr );
}

/**
 * Windows-compatible version of escapeshellarg()
 * Windows doesn't recognise single-quotes in the shell, but the escapeshellarg()
 * function puts single quotes in regardless of OS
 */
function wfEscapeShellArg( ) {
        $args = func_get_args();
        $first = true;
        $retVal = '';
        foreach ( $args as $arg ) {
                if ( !$first ) {
                        $retVal .= ' ';
                } else {
                        $first = false;
                }

                if ( wfIsWindows() ) {
                        $retVal .= '"' . str_replace( '"','\"', $arg ) . '"';
                } else {
                        $retVal .= escapeshellarg( $arg );
                }
        }
        return $retVal;
}

/**
 * wfMerge attempts to merge differences between three texts.
 * Returns true for a clean merge and false for failure or a conflict.
 */
function wfMerge( $old, $mine, $yours, &$result ){
        global $wgDiff3;

        # This check may also protect against code injection in
        # case of broken installations.
        if(! file_exists( $wgDiff3 ) ){
                wfDebug( "diff3 not found\n" );
                return false;
        }

        # Make temporary files
        $td = wfTempDir();
        $oldtextFile = fopen( $oldtextName = tempnam( $td, 'merge-old-' ), 'w' );
        $mytextFile = fopen( $mytextName = tempnam( $td, 'merge-mine-' ), 'w' );
        $yourtextFile = fopen( $yourtextName = tempnam( $td, 'merge-your-' ), 'w' );

        fwrite( $oldtextFile, $old ); fclose( $oldtextFile );
        fwrite( $mytextFile, $mine ); fclose( $mytextFile );
        fwrite( $yourtextFile, $yours ); fclose( $yourtextFile );

        # Check for a conflict
        $cmd = $wgDiff3 . ' -a --overlap-only ' .
          wfEscapeShellArg( $mytextName ) . ' ' .
          wfEscapeShellArg( $oldtextName ) . ' ' .
          wfEscapeShellArg( $yourtextName );
        $handle = popen( $cmd, 'r' );

        if( fgets( $handle, 1024 ) ){
                $conflict = true;
        } else {
                $conflict = false;
        }
        pclose( $handle );

        # Merge differences
        $cmd = $wgDiff3 . ' -a -e --merge ' .
          wfEscapeShellArg( $mytextName, $oldtextName, $yourtextName );
        $handle = popen( $cmd, 'r' );
        $result = '';
        do {
                $data = fread( $handle, 8192 );
                if ( strlen( $data ) == 0 ) {
                        break;
                }
                $result .= $data;
        } while ( true );
        pclose( $handle );
        unlink( $mytextName ); unlink( $oldtextName ); unlink( $yourtextName );

        if ( $result === '' && $old !== '' && $conflict == false ) {
                wfDebug( "Unexpected null result from diff3. Command: $cmd\n" );
                $conflict = true;
        }
        return ! $conflict;
}

/**
 * @todo document
 */
function wfVarDump( $var ) {
        global $wgOut;
        $s = str_replace("\n","<br />\n", var_export( $var, true ) . "\n");
        if ( headers_sent() || !@is_object( $wgOut ) ) {
                print $s;
        } else {
                $wgOut->addHTML( $s );
        }
}

/**
 * Provide a simple HTTP error.
 */
function wfHttpError( $code, $label, $desc ) {
        global $wgOut;
        $wgOut->disable();
        header( "HTTP/1.0 $code $label" );
        header( "Status: $code $label" );
        $wgOut->sendCacheControl();

        header( 'Content-type: text/html' );
        print "<html><head><title>" .
                htmlspecialchars( $label ) .
                "</title></head><body><h1>" .
                htmlspecialchars( $label ) .
                "</h1><p>" .
                htmlspecialchars( $desc ) .
                "</p></body></html>\n";
}

/**
 * Converts an Accept-* header into an array mapping string values to quality
 * factors
 */
function wfAcceptToPrefs( $accept, $def = '*/*' ) {
        # No arg means accept anything (per HTTP spec)
        if( !$accept ) {
                return array( $def => 1 );
        }

        $prefs = array();

        $parts = explode( ',', $accept );

        foreach( $parts as $part ) {
                # FIXME: doesn't deal with params like 'text/html; level=1'
                @list( $value, $qpart ) = explode( ';', $part );
                if( !isset( $qpart ) ) {
                        $prefs[$value] = 1;
                } elseif( preg_match( '/q\s*=\s*(\d*\.\d+)/', $qpart, $match ) ) {
                        $prefs[$value] = $match[1];
                }
        }

        return $prefs;
}

/**
 * Checks if a given MIME type matches any of the keys in the given
 * array. Basic wildcards are accepted in the array keys.
 *
 * Returns the matching MIME type (or wildcard) if a match, otherwise
 * NULL if no match.
 *
 * @param string $type
 * @param array $avail
 * @return string
 * @access private
 */
function mimeTypeMatch( $type, $avail ) {
        if( array_key_exists($type, $avail) ) {
                return $type;
        } else {
                $parts = explode( '/', $type );
                if( array_key_exists( $parts[0] . '/*', $avail ) ) {
                        return $parts[0] . '/*';
                } elseif( array_key_exists( '*/*', $avail ) ) {
                        return '*/*';
                } else {
                        return NULL;
                }
        }
}

/**
 * Returns the 'best' match between a client's requested internet media types
 * and the server's list of available types. Each list should be an associative
 * array of type to preference (preference is a float between 0.0 and 1.0).
 * Wildcards in the types are acceptable.
 *
 * @param array $cprefs Client's acceptable type list
 * @param array $sprefs Server's offered types
 * @return string
 *
 * @todo FIXME: doesn't handle params like 'text/plain; charset=UTF-8'
 * XXX: generalize to negotiate other stuff
 */
function wfNegotiateType( $cprefs, $sprefs ) {
        $combine = array();

        foreach( array_keys($sprefs) as $type ) {
                $parts = explode( '/', $type );
                if( $parts[1] != '*' ) {
                        $ckey = mimeTypeMatch( $type, $cprefs );
                        if( $ckey ) {
                                $combine[$type] = $sprefs[$type] * $cprefs[$ckey];
                        }
                }
        }

        foreach( array_keys( $cprefs ) as $type ) {
                $parts = explode( '/', $type );
                if( $parts[1] != '*' && !array_key_exists( $type, $sprefs ) ) {
                        $skey = mimeTypeMatch( $type, $sprefs );
                        if( $skey ) {
                                $combine[$type] = $sprefs[$skey] * $cprefs[$type];
                        }
                }
        }

        $bestq = 0;
        $besttype = NULL;

        foreach( array_keys( $combine ) as $type ) {
                if( $combine[$type] > $bestq ) {
                        $besttype = $type;
                        $bestq = $combine[$type];
                }
        }

        return $besttype;
}

/**
 * Array lookup
 * Returns an array where the values in the first array are replaced by the
 * values in the second array with the corresponding keys
 *
 * @return array
 */
function wfArrayLookup( $a, $b ) {
        return array_flip( array_intersect( array_flip( $a ), array_keys( $b ) ) );
}

/**
 * Convenience function; returns MediaWiki timestamp for the present time.
 * @return string
 */
function wfTimestampNow() {
        # return NOW
        return wfTimestamp( TS_MW, time() );
}

/**
 * Reference-counted warning suppression
 */
function wfSuppressWarnings( $end = false ) {
        static $suppressCount = 0;
        static $originalLevel = false;

        if ( $end ) {
                if ( $suppressCount ) {
                        --$suppressCount;
                        if ( !$suppressCount ) {
                                error_reporting( $originalLevel );
                        }
                }
        } else {
                if ( !$suppressCount ) {
                        $originalLevel = error_reporting( E_ALL & ~( E_WARNING | E_NOTICE ) );
                }
                ++$suppressCount;
        }
}

/**
 * Restore error level to previous value
 */
function wfRestoreWarnings() {
        wfSuppressWarnings( true );
}

# Autodetect, convert and provide timestamps of various types

/**
 * Unix time - the number of seconds since 1970-01-01 00:00:00 UTC
 */
define('TS_UNIX', 0);

/**
 * MediaWiki concatenated string timestamp (YYYYMMDDHHMMSS)
 */
define('TS_MW', 1);

/**
 * MySQL DATETIME (YYYY-MM-DD HH:MM:SS)
 */
define('TS_DB', 2);

/**
 * RFC 2822 format, for E-mail and HTTP headers
 */
define('TS_RFC2822', 3);

/**
 * ISO 8601 format with no timezone: 1986-02-09T20:00:00Z
 *
 * This is used by Special:Export 
 */
define('TS_ISO_8601', 4);

/**
 * An Exif timestamp (YYYY:MM:DD HH:MM:SS)
 *
 * @link http://exif.org/Exif2-2.PDF The Exif 2.2 spec, see page 28 for the
 *       DateTime tag and page 36 for the DateTimeOriginal and
 *       DateTimeDigitized tags.
 */
define('TS_EXIF', 5);

/**
 * Oracle format time.
 */
define('TS_ORACLE', 6);

/**
 * @param mixed $outputtype A timestamp in one of the supported formats, the
 *                          function will autodetect which format is supplied
                            and act accordingly.
 * @return string Time in the format specified in $outputtype
 */
function wfTimestamp($outputtype=TS_UNIX,$ts=0) {
        $uts = 0;
        if ($ts==0) {
                $uts=time();
        } elseif (preg_match("/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/",$ts,$da)) {
                # TS_DB
                $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
                            (int)$da[2],(int)$da[3],(int)$da[1]);
        } elseif (preg_match("/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/",$ts,$da)) {
                # TS_EXIF
                $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
                        (int)$da[2],(int)$da[3],(int)$da[1]);
        } elseif (preg_match("/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/",$ts,$da)) {
                # TS_MW
                $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
                            (int)$da[2],(int)$da[3],(int)$da[1]);
        } elseif (preg_match("/^(\d{1,13})$/",$ts,$datearray)) {
                # TS_UNIX
                $uts=$ts;
        } elseif (preg_match('/^(\d{1,2})-(...)-(\d\d(\d\d)?) (\d\d)\.(\d\d)\.(\d\d)/', $ts, $da)) {
                # TS_ORACLE
                $uts = strtotime(preg_replace('/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
                                str_replace("+00:00", "UTC", $ts)));
        } elseif (preg_match('/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})Z$/', $ts, $da)) {
                # TS_ISO_8601
                $uts=gmmktime((int)$da[4],(int)$da[5],(int)$da[6],
                        (int)$da[2],(int)$da[3],(int)$da[1]);
        } else {
                # Bogus value; fall back to the epoch...
                wfDebug("wfTimestamp() fed bogus time value: $outputtype; $ts\n");
                $uts = 0;
        }


        switch($outputtype) {
                case TS_UNIX:
                        return $uts;
                case TS_MW:
                        return gmdate( 'YmdHis', $uts );
                case TS_DB:
                        return gmdate( 'Y-m-d H:i:s', $uts );
                case TS_ISO_8601:
                        return gmdate( 'Y-m-d\TH:i:s\Z', $uts );
                // This shouldn't ever be used, but is included for completeness
                case TS_EXIF:
                        return gmdate(  'Y:m:d H:i:s', $uts );
                case TS_RFC2822:
                        return gmdate( 'D, d M Y H:i:s', $uts ) . ' GMT';
                case TS_ORACLE:
                        return gmdate( 'd-M-y h.i.s A', $uts) . ' +00:00';
                default:
                        wfDebugDieBacktrace( 'wfTimestamp() called with illegal output type.');
        }
}

/**
 * Return a formatted timestamp, or null if input is null.
 * For dealing with nullable timestamp columns in the database.
 * @param int $outputtype
 * @param string $ts
 * @return string
 */
function wfTimestampOrNull( $outputtype = TS_UNIX, $ts = null ) {
        if( is_null( $ts ) ) {
                return null;
        } else {
                return wfTimestamp( $outputtype, $ts );
        }
}

/**
 * Check where as the operating system is Windows
 *
 * @return bool True if it's windows, False otherwise.
 */
function wfIsWindows() {
        if (substr(php_uname(), 0, 7) == 'Windows') {
                return true;
        } else {
                return false;
        }
}

/**
 * Swap two variables
 */
function swap( &$x, &$y ) {
        $z = $x;
        $x = $y;
        $y = $z;
}

function wfGetSiteNotice() {
        global $wgSiteNotice, $wgTitle, $wgOut;
        $fname = 'wfGetSiteNotice';
        wfProfileIn( $fname );

        $notice = wfMsg( 'sitenotice' );
        if( $notice == '&lt;sitenotice&gt;' || $notice == '-' ) {
                $notice = '';
        }
        if( $notice == '' ) {
                # We may also need to override a message with eg downtime info
                # FIXME: make this work!
                $notice = $wgSiteNotice;
        }
        if($notice != '-' && $notice != '') {
                $specialparser = new Parser();
                $parserOutput = $specialparser->parse( $notice, $wgTitle, $wgOut->mParserOptions, false );
                $notice = $parserOutput->getText();
        }
        wfProfileOut( $fname );
        return $notice;
}

/**
 * Format an XML element with given attributes and, optionally, text content.
 * Element and attribute names are assumed to be ready for literal inclusion.
 * Strings are assumed to not contain XML-illegal characters; special
 * characters (<, >, &) are escaped but illegals are not touched.
 *
 * @param string $element
 * @param array $attribs Name=>value pairs. Values will be escaped.
 * @param string $contents NULL to make an open tag only; '' for a contentless closed tag (default)
 * @return string
 */
function wfElement( $element, $attribs = null, $contents = '') {
        $out = '<' . $element;
        if( !is_null( $attribs ) ) {
                foreach( $attribs as $name => $val ) {
                        $out .= ' ' . $name . '="' . htmlspecialchars( $val ) . '"';
                }
        }
        if( is_null( $contents ) ) {
                $out .= '>';
        } else {
                if( $contents == '' ) {
                        $out .= ' />';
                } else {
                        $out .= '>';
                        $out .= htmlspecialchars( $contents );
                        $out .= "</$element>";
                }
        }
        return $out;
}

/**
 * Format an XML element as with wfElement(), but run text through the
 * UtfNormal::cleanUp() validator first to ensure that no invalid UTF-8
 * is passed.
 *
 * @param string $element
 * @param array $attribs Name=>value pairs. Values will be escaped.
 * @param string $contents NULL to make an open tag only; '' for a contentless closed tag (default)
 * @return string
 */
function wfElementClean( $element, $attribs = array(), $contents = '') {
        if( $attribs ) {
                $attribs = array_map( array( 'UtfNormal', 'cleanUp' ), $attribs );
        }
        if( $contents ) {
                $contents = UtfNormal::cleanUp( $contents );
        }
        return wfElement( $element, $attribs, $contents );
}

// Shortcuts
function wfOpenElement( $element ) { return "<$element>"; }
function wfCloseElement( $element ) { return "</$element>"; }

/**
 * Create a namespace selector
 *
 * @param mixed $selected The namespace which should be selected, default ''
 * @param string $allnamespaces Value of a special item denoting all namespaces. Null to not include (default)
 * @return Html string containing the namespace selector
 */
function &HTMLnamespaceselector($selected = '', $allnamespaces = null) {
        global $wgContLang;
        if( $selected !== '' ) {
                if( is_null( $selected ) ) {
                        // No namespace selected; let exact match work without hitting Main
                        $selected = '';
                } else {
                        // Let input be numeric strings without breaking the empty match.
                        $selected = intval( $selected );
                }
        }
        $s = "<select name='namespace' class='namespaceselector'>\n\t";
        $arr = $wgContLang->getFormattedNamespaces();
        if( !is_null($allnamespaces) ) {
                $arr = array($allnamespaces => wfMsgHtml('namespacesall')) + $arr;
        }
        foreach ($arr as $index => $name) {
                if ($index < NS_MAIN) continue;

                $name = $index !== 0 ? $name : wfMsgHtml('blanknamespace');

                if ($index === $selected) {
                        $s .= wfElement("option",
                                        array("value" => $index, "selected" => "selected"),
                                        $name);
                } else {
                        $s .= wfElement("option", array("value" => $index), $name);
                }
        }
        $s .= "\n</select>\n";
        return $s;
}

/** Global singleton instance of MimeMagic. This is initialized on demand,
* please always use the wfGetMimeMagic() function to get the instance.
*
* @private
*/
$wgMimeMagic= NULL;

/** Factory functions for the global MimeMagic object.
* This function always returns the same singleton instance of MimeMagic.
* That objects will be instantiated on the first call to this function.
* If needed, the MimeMagic.php file is automatically included by this function.
* @return MimeMagic the global MimeMagic objects.
*/
function &wfGetMimeMagic() {
        global $wgMimeMagic;

        if (!is_null($wgMimeMagic)) {
                return $wgMimeMagic;
        }

        if (!class_exists("MimeMagic")) {
                #include on demand
                require_once("MimeMagic.php");
        }

        $wgMimeMagic= new MimeMagic();

        return $wgMimeMagic;
}


/**
 * Tries to get the system directory for temporary files.
 * The TMPDIR, TMP, and TEMP environment variables are checked in sequence,
 * and if none are set /tmp is returned as the generic Unix default.
 *
 * NOTE: When possible, use the tempfile() function to create temporary
 * files to avoid race conditions on file creation, etc.
 *
 * @return string
 */
function wfTempDir() {
        foreach( array( 'TMPDIR', 'TMP', 'TEMP' ) as $var ) {
                $tmp = getenv( $var );
                if( $tmp && file_exists( $tmp ) && is_dir( $tmp ) && is_writable( $tmp ) ) {
                        return $tmp;
                }
        }
        # Hope this is Unix of some kind!
        return '/tmp';
}

/**
 * Make directory, and make all parent directories if they don't exist
 */
function wfMkdirParents( $fullDir, $mode ) {
        $parts = explode( '/', $fullDir );
        $path = '';
        
        foreach ( $parts as $dir ) {
                $path .= $dir . '/';
                if ( !is_dir( $path ) ) {
                        if ( !mkdir( $path, $mode ) ) {
                                return false;
                        }
                }
        }
        return true;
}

/**
 * Increment a statistics counter
 */
function wfIncrStats( $key ) {
        global $wgDBname, $wgMemc;
        $key = "$wgDBname:stats:$key";
        if ( is_null( $wgMemc->incr( $key ) ) ) {
                $wgMemc->add( $key, 1 );
        }
}

/**
 * @param mixed $nr The number to format
 * @param int $acc The number of digits after the decimal point, default 2
 * @param bool $round Whether or not to round the value, default true
 * @return float
 */
function wfPercent( $nr, $acc = 2, $round = true ) {
        $ret = sprintf( "%.${acc}f", $nr );
        return $round ? round( $ret, $acc ) . '%' : "$ret%";
}

/**
 * Encrypt a username/password.
 *
 * @param string $userid ID of the user
 * @param string $password Password of the user
 * @return string Hashed password
 */
function wfEncryptPassword( $userid, $password ) {
        global $wgPasswordSalt;
        $p = md5( $password);

        if($wgPasswordSalt)
                return md5( "{$userid}-{$p}" );
        else
                return $p;
}

/**
 * Appends to second array if $value differs from that in $default
 */
function wfAppendToArrayIfNotDefault( $key, $value, $default, &$changed ) {
        if ( is_null( $changed ) ) {
                wfDebugDieBacktrace('GlobalFunctions::wfAppendToArrayIfNotDefault got null');
        }
        if ( $default[$key] !== $value ) {
                $changed[$key] = $value;
        }
}

/**
 * Since wfMsg() and co suck, they don't return false if the message key they
 * looked up didn't exist but a XHTML string, this function checks for the
 * nonexistance of messages by looking at wfMsg() output
 *
 * @param $msg      The message key looked up
 * @param $wfMsgOut The output of wfMsg*()
 * @return bool
 */
function wfEmptyMsg( $msg, $wfMsgOut ) {
        return $wfMsgOut === "&lt;$msg&gt;";
}

/**
 * Find out whether or not a mixed variable exists in a string
 *
 * @param mixed  needle
 * @param string haystack
 * @return bool
 */
function in_string( $needle, $str ) {
        return strpos( $str, $needle ) !== false;
}

/**
 * Returns a regular expression of url protocols
 *
 * @return string
 */
function wfUrlProtocols() {
        global $wgUrlProtocols;

        $x = array();
        foreach ($wgUrlProtocols as $protocol)
                $x[] = preg_quote( $protocol, '/' );
        
        return implode( '|', $x );
}

/**
 * Check if a string is well-formed XML.
 * Must include the surrounding tag.
 *
 * @param string $text
 * @return bool
 *
 * @todo Error position reporting return
 */
function wfIsWellFormedXml( $text ) {
        $parser = xml_parser_create( "UTF-8" );
        
        # case folding violates XML standard, turn it off
        xml_parser_set_option( $parser, XML_OPTION_CASE_FOLDING, false );
        
        if( !xml_parse( $parser, $text, true ) ) {
                $err = xml_error_string( xml_get_error_code( $parser ) );
                $position = xml_get_current_byte_index( $parser );
                //$fragment = $this->extractFragment( $html, $position );
                //$this->mXmlError = "$err at byte $position:\n$fragment";
                xml_parser_free( $parser );
                return false;
        }
        xml_parser_free( $parser );
        return true;
}

/**
 * Check if a string is a well-formed XML fragment.
 * Wraps fragment in an <html> bit and doctype, so it can be a fragment
 * and can use HTML named entities.
 *
 * @param string $text
 * @return bool
 */
function wfIsWellFormedXmlFragment( $text ) {
        $html = 
                '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" ' .
                '"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">' .
                '<html>' .
                $text .
                '</html>';
        return wfIsWellFormedXml( $html );
}

/**
 * shell_exec() with time and memory limits mirrored from the PHP configuration,
 * if supported.
 */
function wfShellExec( $cmd )
{
        global $IP;
        
        if ( php_uname( 's' ) == 'Linux' ) {
                $time = ini_get( 'max_execution_time' );
                $mem = ini_get( 'memory_limit' );
                if( preg_match( '/^([0-9]+)[Mm]$/', trim( $mem ), $m ) ) {
                        $mem = intval( $m[1] * (1024*1024) );
                }
                if ( $time > 0 && $mem > 0 ) {
                        $script = "$IP/bin/ulimit.sh";
                        if ( is_executable( $script ) ) {
                                $memKB = intval( $mem / 1024 );
                                $cmd = escapeshellarg( $script ) . " $time $memKB $cmd";
                        }
                }
        }
        return shell_exec( $cmd );
}

?>