[Rd] "Human-style" sort() of alphanum strings?

[Henrik Bengtsson]

I know it is fairly easy to implement (though not always well
defined), but is there an existing sort function out there that takes
alphanum strings and sort them in a "human" fashion?  For example,
instead of:

z1.doc z10.doc z100.doc z101.doc z11.doc z2.doc

it should out put:

z1.doc z2.doc z10.doc z11.doc z100.doc z101.doc

(from http://www.davekoelle.com/alphanum.html).

/Henrik