5. Erl_Interface
5 Erl_Interface
This section outlines an example of how to solve the example problem in Problem Example by using a port and Erl_Interface. It is necessary to read the port example in Ports before reading this section.
5.1 Erlang Program
The following example shows an Erlang program communicating with a C program over a plain port with home made encoding:
-module(complex1).
-export([start/1, stop/0, init/1]).
-export([foo/1, bar/1]).
start(ExtPrg) ->
spawn(?MODULE, init, [ExtPrg]).
stop() ->
complex ! stop.
foo(X) ->
call_port({foo, X}).
bar(Y) ->
call_port({bar, Y}).
call_port(Msg) ->
complex ! {call, self(), Msg},
receive
{complex, Result} ->
Result
end.
init(ExtPrg) ->
register(complex, self()),
