Parsing back directories to DOCUMENT_ROOT?

Does anyone have a nice snippet of code to parse back up a directory tree (like doing a 'cd ..; pwd' but without changing directory)? I have a function that generates a sort of backtrace up a directory tree: Home -> Software -> PHP -> My PHP Example It would generate this automagically. I have code that works, but the URLs it generates are hideous: /software/php/../../ for home, as an example. I'm using explode, which presents other problems, like multiple '/'s causing it to act weird. I figured *someone* must have done something like this. Thanks. Ciao! -- It has just been discovered that research causes cancer in rats. The Doctor What: A Holtje Production http://docwhat.gerf.org/ docwhat@gerf.org KF6VNC