How do I connect to an Erlang node which uses a short name?

Question

When I run erl -sname foo, the node name created uses the hostname, rather than "localhost", so it is generated as, for example, foo@roger-pc.

I then register(shell, self()), and I can send messages to it from another node (erl -sname bar) as follows:

{shell, 'foo@roger-pc'} ! {hello, world}.

But it doesn't work if I use {shell, foo} ! {knock, knock}. The message is never received.

How do I connect to an Erlang node on the same PC which is using a short name? Or: how do I derive the "@roger-pc" part of the destination node name? Or: should I just use erl -name foo@localhost to register a long name?

Some background: I'm writing a an escript which spawns an erl process, and I'd like to be able to send messages from that OS process back to the original script.

Answer 1

you can specify 'localhost' explicitly for sname.

first shell

erl -sname ax@localhost
register(rcvr, self()).

second shell

erl -sname bx@localhost
net_kernel:connect_node(ax@localhost).
{rcvr, ax@localhost} ! hello.

and first shell again

(ax@localhost)7> flush().
Shell got hello
ok