use File::Find;
...
# there are directory d:\perl\source\test\öa  and file d:\perl\source\test\öa\ü.txt under \test\

$srcdir="d:\\perl\\source\\test";  
$dstdir="d:\\test2";
finddepth(\&check_and_copy, $srcdir); 

# sub check_and_copy  check the time of file/dir and only copy the updated file/dir to $dstdir

##</code><code>##

$srcdir="d:\\perl\\source\\test";  
if(Encode::is_utf8($srcdir) ){    
 	print " src is_utf8\n";
}else{ 
	print " src is_NOT_utf8\n";
}
# I got "src is_NOT_utf8",  I heared Perl use UTF8 internal. but it seems that's not so simple.

##</code><code>##

use utf8;
$srcdir="d:\\perl\\source\\test\\öa";  
# I got "Malformed UTF-8 character (unexpected non-continuation byte 0x61, immediately after start byte 0xf6)"