Banner程序

  

  
function random( $max )  
{  
        $x = rand();  
        $y = getrandmax();  

        $r = $x / $y * ($max -1 );  

        $r = round( $r++ );  
        return $r;  
}  

  
$i = 0;  
$d   = dir( ".");  
while($entry=$d->read())  
        if (substr($entry,0,6) ==  "banner")  
                $array[$i++] = $entry;  
$d->close();  


  
$r = random( $i );  

  
Header(  "Pragma: no-cache" );  
Header(  "Expires: Monday 01-Jan-80 12:00:00 GMT" );  
Header(  "Content-type:  image/gif");  
passthru(  "cat $array[$r]" );  

?>