bug#60592: 30.0.50; emacsclient: exit with a different code when the request times out

[Sean Whitton]

Hello,

When calling 'emacsclient --timeout N --eval' from scripts, it would be
nice if you could determine for sure when a failure was just due to a
timeout, rather than, say, a Lisp exception.

inotifywait(1) exits with code 2 to indicate a timeout.
emacsclient could do the same.

We might then consider adding a separate exit code for a Lisp error.
Then a failure of emacsclient to connect, a request that timed out, and
an error from Lisp would be readily distinguishable.

At present the best one could do is parse emacsclient's output, but
that doesn't seem robust.

-- 
Sean Whitton