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shellerlangspawn

Erlang: Shell not returning after spawn

-module(core_profile).

-export([start/0]).

start() ->
    register(eProfile, spawn(loop())),
    ok.

loop() ->
    receive
            {Key, Pid} -> Pid ! getKey();
            {name, Pid} -> Pid ! getName();
            {address, Pid} -> Pid ! getAddress()
    end,
    loop().

This is my code

when I try to start the loop from the shell i get stuck.

2> Pid = spawn(fun()-> a end).     
<0.39.0>
3>c(core_profile.erl).
{ok, core_profile}
4>core_profile:start().

shouldn't the command return ok and then give me the next command line, instead of doing nothing?

Solution

  • When you do spawn(loop()) the loop function is called to evaluate a result (which will be passed on to spawn, so you enter the infinite loop.

    Instead of calling the function you must pass the function reference by doing spawn(fun loop/0).