This workaround does seem dodgey to me. I did a bit of looking around and this is what I found.

First stop the Net::FTP docs. Nothing helpful there except a few commands I don't recognise.

Next stop the RFC Net::FTP says it was based on at IETF. Then test the information I found.

The command $ftp->list(filename) returns (on my linux system) the same symbolic link `ls` type information for a file AND the dereferenced directory in the case of a directory.

So if the returned starts with a 'd', the link points to a directory and otherwise not (I think).

Note: $ftp->list(filename) returns a glob, so you'll have to read from it like a filehandle.

Hope that points you in a better direction....