How Do You Determine The PID of the Parent of a Process

"You should pass self() to the child as one of the arguments to the entry function.

spawn_link(?MODULE, child, [self()])."

@Eridius' answer is the preferred way to do it. Requiring a process to register a name may have unintended side-effects such as increasing the visibility of the process not to mention the hassle of coming up with unique names when you have lots of processes.

"The best way is definitely to pass it as an argument to the function called to start the child process. If you are spawning funs, which generally is a Good Thing to do, be careful of doing:

spawn_link(fun () -> child(self()) end)

which will NOT do as you intended. (Hint: when is self() called)

Generally you should avoid registering a process, i.e. giving it a global name, unless you really want it to be globally known. Spawning a fun means that you don't have to export the spawned function as you should generally avoid exporting functions that aren't meant to be called from other modules."

"You can use the BIF register to give the spawning / parent process a name (an atom) then refer back to the registered name from other processes.

FUNC() ->


%% Do something
%% Then send message to parent
parent ! MESSAGE.


...

register(parent, self()),
spawn(MODULE, FUNC, [ARGS]).

See Getting Started With Erlang §3.3 and The Erlang Reference Manual §10.3."