Suppose I'm running bash on a Unix-ish system - not necessarily Linux and not necessarily very new; and it may not have every bit of software I'd like.
Now, I have a relative path for which I want to get the absolute path. What's the most robust and portable way of doing this?
The answers here seem to mostly assume the GNU core utilities are installed, which I would rather not do.
Bonus points if your answer works on any Bourne Shell variant.