When documenting something I have to look up the full path of some file and have it ready for cut-and-paste. I found out the easy way to canonicalize a filename: koos@greenblatt:~$ readlink -f ../../etc/radvd.conf /etc/radvd.conf
koos@greenblatt:~$ readlink -f ../../etc/radvd.conf /etc/radvd.conf