Realpath() alternative for nonexisting paths

[NumbersTada]

Description

I need to check if the path is valid so it is not pointing to a higher directory than the uploads directory when using my PHP script for uploading files. But I need it to work with non existing paths too. I need something like os.path.normpath() from Python.

[cmb69]

I need something like os.path.normpath() from Python.

It seems to me that this can be written in userland (not particularly difficult), but it would ignore any (sym)links, so it might not be the best idea.

Consider to pursue the RFC process.