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<?php
//·½·¨Ò»:
function extend_1($file_name)
{
$retval="";
$pt=strrpos($file_name, ".");
if ($pt) $retval=substr($file_name, $pt+1, strlen($file_name) - $pt);
return ($retval);
}
//·½·¨¶þ
function extend_2($file_name)
{
$extend = pathinfo($file_name);
$extend = strtolower($extend["extension"]);
return $extend;
}
//·½·¨Èý
function extend_3($file_name)
{
$extend =explode("." , $file_name);
$va=count($extend)-1;
return $extend[$va];
}
//·½·¨ËÄ
function getFileExt($file_name)
{
        while($dot = strpos($file_name, "."))
        {
                $file_name = substr($file_name, $dot+1);
        }
        return $file_name;
}
?>