The copy commands currently do not provide a way to disambiguate the expected destination of a copy. Ex.
fs -put myfile path/mydir
If "mydir" is an existing directory, then the copy produces path/mydir/file. If "mydir" does not exist at all, the copy produces path/mydir. The file has unexpectedly been renamed to what was expected to be a directory! It's standard unix shell behavior, but it lacks a special trait.
Unix allows a user to disambiguate their intent by allowing path/mydir/ or path/mydir/. to mean "mydir" is always be treated as a directory. If the copy succeeds, it will always be called path/mydir/myfile.