Demo session used for "Introduction to Erlang" talks and courses.

demo.md

Start an instance of the Erlang run-time system

$ erl

Show information about processes

> i().

Spawn a new process which sleeps for 10 seconds

> spawn(timer, sleep, [10000]).

Verify that the process is listed among the other processes

> i().

Get the PID of the current process

> self().

Send a message to the current process

> self() ! ping.

Flush the mailbox of the current process

> flush().

Start a "named" instance of the Erlang run-time system (i.e. an Erlang node)

$ erl -sname italy

Start another one (in a separate terminal window)

$ erl -sname sweden

Retrieve the current node name

italy@pigeon> node().

Retrieve the current node name

sweden@pigeon> node().

Register the current process under the name foo

sweden@pigeon> register(foo, self()).

Send a message to the registered process

sweden@pigeon> foo ! local.

Send a message to a remote process (pigeon is the name of my machine)

italy@pigeon> {foo, 'sweden@pigeon'} ! {remote, self()}.

Flush the mailbox

sweden@pigeon> flush().

Assign the PID of the current process to the variable S

italy@pigeon> S = self().

Define an anonymous function which displays wow on the node where it gets executed and send a message to a process (which could be remote). The message contain the name of the node where the function is run.

italy@pigeon> F = fun() -> erlang:display(wow), S ! node() end.

Spawn a remote process which will execute the anonymous function

italy@pigeon> spawn('sweden@pigeon', F).

Verify that the message sent above has been received by the remote process

italy@pigeon> flush().