how read the current dir with readdir()

[Fking]

if ( $dh = opendir($nav) ) {
while ( false !== ( $file = readdir($dh) ) )

sometimes $nav is empty, when it's empty i need to read the current dir, where the script is executed.

how?

[planetsim]

$nav = (!empty($nav))?$nav:getcwd();

/*
basically this represents

if (!empty($nav)) 
{
  $nav = $nav;
} 
else 
{
  $nav = getcwd(); //get the current working directory
}
*/

if ( $dh = opendir($nav) ) 
{
  while (false !== ($file=readdir($dh)))
}

[Fking]

thank you!
but now i need a way to get the URL path
without the name of the current page at the end