hex tools in coreutils

[Ian Malone]

Hi,

I'm wondering if anyone can suggest ways of handling hex/binary data
with coreutils? I've just written a script which uses xxd to patch a
file (here be monsters and all that), and wondering if there are any
tools which can be used to do something similar: neither hexdump nor
xxd are part of coreutils. od is, but can't do the reverse hex to
binary conversion that xxd can do.

Thanks for your time,
-- 
imalone