Most of the time, I tend to prefer glob to opendir followed by readdir, but that's mostly stylistic.

For glob, you would do something vaguely like:

my @list = glob('*');
[download]

I believe glob ignores hidden files (on *ix, files with names starting with "."), while readdir doesn't. With readdir, you'll always get at least two files, as . (the directory itself) and .. (its parent) will (almost) always show up (offhand, I don't know if .. will show up for the root directory on *ix), so you'll have to handle these if you're going to recurse through a directory tree, a la find.