Tim Rowe wrote:
> I need to get at the character code used to represent a character.  I
> realise that "f"[0] will return the code for "f" (102), but I read in
> a FAQ that this behaviour may change, and I can't find any other way
> of doing it.  Would somebody point me to what I am missing, please?

Easy:

irb(main):002:0> ?f
=> 102