[RFA] New substitute-path commands

[Eli Zaretskii]

> Date: Fri, 14 Jul 2006 09:05:59 -0400
> From: Daniel Jacobowitz <drow@false.org>
> Cc: Joel Brobecker <brobecker@adacore.com>, gdb@sources.redhat.com
> 
> > If this _adds_ a rule, then "set SOMETHING" is not a good UI, IMO.
> > How about just "substitute-path", similar to "dir", which also _adds_
> > a directory?
> 
> This was my suggestion, so I'll defend it :-)  I think of it as set "the
> substitution path for FROM" to "TO".  The parallel is set env VAR
> VALUE, which sets the environment variable VAR to VALUE.

In that case, we should at least have "show substitute-path FROM", not
just "show substitute-path".