[[sfx]]
== Self-extracting releases

Erlang.mk allows you to package xref:relx[Relx releases] as
self-extracting archives. These archives contain all the
files in the release and come in the form of a script that
will extract and run the release automatically.

This allows you to package the release as a single file
that can then be executed.

This feature is currently experimental. Feedback is much
appreciated.

=== Generating the self-extracting archive

To generate a self-extracting release, all you need to do
is pass the `SFX=1` variable to Make when you build the
release:

[source,bash]
$ make SFX=1

This will create a self-extracting archive in
`$RELX_OUTPUT_DIR/<name>.run`. For example if the release
is named `hello_world` and `$RELX_OUTPUT_DIR` is the default,
the file will be located at `_rel/hello_world.run`.

=== Running the release

Simply execute the script to get started:

[source,bash]
----
$ ./_rel/hello_world.run
Exec: /tmp/tmp.3eeEq7E1ta/erts-8.1/bin/erlexec ...
Root: /tmp/tmp.3eeEq7E1ta
/tmp/tmp.3eeEq7E1ta
Erlang/OTP 19 [erts-8.1] [source] [64-bit] [smp:4:4] ...

Eshell V8.1  (abort with ^G)
(hello_world@localhost)1>
----

As you can see the archive is extracted to a temporary
directory before the release can be started.

The self-extracting script currently only supports starting
the release in `console` mode.