If you plan to include support for files and directories you may also want to have a look at what @interkosmos did with fortran-unix and in particular the binding to dirent.
It is not portable to Windows but you can make it so with that dirent.h header.
Just some food for thoughts for your path functionality. When working with Nuke (in C#) I came across their AbsolutePath (resp. RelativePath) object which I found very convenient. In brief, it overloads the / operator so that you can build paths in a very visual way (e.g. newpath = root / folder / filename) and the operator takes care of choosing / or \ depending on the os and does the proper file concatenation.