[erlang-questions] erlang restart application

t x <>
Sat Mar 8 11:52:41 CET 2014


@Loic:

  Thanks! This was extremely clear and helpful.

=================================

As a follow up question, is there documentation for erlang.mk
anywhere? I know of the README at https://github.com/extend/erlang.mk
, but it's a bit short on details.

I'm also aware of https://github.com/erlware/relx/wiki/configuration
but I don't really understand it.


What I really want to understand is what happens behind the scenes, a
detailed description of:

  * when I run _rel/bin/websocket_example start
  * how does this use src/websocket.app.src

  * what processes are created? (clearly websocket_app.erl is called)
  * what options are they called with

  * and questions I'm not even asking


I feel that when I run:

make; _rel/bin/websocket_example console

  there's _alot_ of stuff (compared to say, what Programming Erlang,
up to chapter 18, covers) going on behind the scenes.

I'd really like to understand what is happening behind the scenes for
debugging purposes.


What tutorial should I be going through?

Thanks!





On Fri, Mar 7, 2014 at 11:21 PM, Loïc Hoguin <> wrote:
> It's not explained in the getting started on purpose, as this is an advanced
> topic.
>
> Basically this is an OTP application, where hello_erlang_app is an
> application behaviour and the hello_erlang_sup is the main supervisor of
> that application.
>
> To answer your question, you can just use:
>
> application:stop(hello_erlang).
> application:start(hello_erlang).
>
> With hello_erlang the name of the application.
>
> On the other hand you have a release, which means c(hello_erlang_app)
> doesn't operate on your src/ directory anymore (you don't need to use l/1
> after using c/1 by the way as it already does it), so the quickest way is
> most likely to just Ctrl+C twice, type make and restart the VM again.
> Another way is to use a reloader that understands releases.
>
> But yeah, I wouldn't worry about these things for quite some time as you
> don't need to know them to operate Cowboy.
>
>
> On 03/08/2014 08:13 AM, t x wrote:
>>
>> Hi,
>>
>>
>> [apologies for this stream of stupid questions; I haven't figured out
>> how the various pieces work together yet]
>>
>>
>>    I'm reading
>> http://ninenines.eu/docs/en/cowboy/HEAD/guide/getting_started/
>>
>>
>>    In particular, I'm looking at https://gist.github.com/txrev319/9426556
>>
>>
>>    How does the
>>
>>      {registered, [hello_erlang_sup]},
>>      {mod, {hello_erlang_app, []}},
>>
>>    lines work?
>>
>>
>>    In particular, how can I restart the hello_erlang_app app ?
>>
>>    So after I do "_rel/..../ remote_console", I do:
>>
>>    * c(hello_erlang_app).
>>    * l(hello_erlang_app).
>>
>>    --> now, at this point, how do I _restart_ the existing
>> hello_erlang_app ?
>>
>>
>> Thanks!
>> _______________________________________________
>> erlang-questions mailing list
>> 
>> http://erlang.org/mailman/listinfo/erlang-questions
>>
>
> --
> Loïc Hoguin
> http://ninenines.eu



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