Plan 9 from User Space's /usr/local/plan9/plumb/fileaddr 

addrelem='((#?[0-9]+)|(/[A-Za-z0-9_\^]+/?)|[.$])'
addr=:($addrelem([,;+\-]$addrelem)*)

Space Glenda

Copyright © 2005 Lucent Technologies, Russ Cox, MIT.
See license for details.