View Source mix escript.build (Mix v1.15.0-dev)
Builds an escript for the project.
An escript is an executable that can be invoked from the command line. An escript can run on any machine that has Erlang/OTP installed and by default does not require Elixir to be installed, as Elixir is embedded as part of the escript.
This task guarantees the project and its dependencies are
compiled and packages them inside an escript. Before invoking
mix escript.build, it is only necessary to define a
key with a
:main_module option in your
escript: [main_module: MyApp.CLI]
Escripts should be used as a mechanism to share scripts between
developers and not as a deployment mechanism. For running live
systems, consider using
mix run or building releases. See
Application module for more information on systems
All of the configuration defined in
be included as part of the escript.
config/runtime.exs is also
included for Elixir escripts. Once the configuration is loaded,
this task starts the current application. If this is not desired,
:app configuration to nil.
This task also removes documentation and debugging chunks from
.beam files to reduce the size of the escript.
If this is not desired, check the
Note: escripts do not support projects and dependencies that need to store or read artifacts from the priv directory.
Command line options
Expects the same command line options as
The following option must be specified in your
:main_module- the module to be invoked once the escript starts. The module must contain a function named
main/1that will receive the command line arguments. By default the arguments are given as a list of binaries, but if project is configured with
language: :erlangit will be a list of charlists.
The remaining options can be specified to further customize the escript:
:name- the name of the generated escript. Defaults to app name.
:path- the path to write the escript to. Defaults to app name.
:app- the app that starts with the escript. Defaults to app name. Set it to
nilif no application should be started.
truestrips BEAM code in the escript to remove chunks unnecessary at runtime, such as debug information and documentation. Can be set to
[keep: ["Docs", "Dbgi"]]to strip while keeping some chunks that would otherwise be stripped, like docs, and debug info, for instance. Defaults to
trueembeds Elixir and its children apps (
mix, and the like) mentioned in the
:applicationslist inside the
truefor Elixir projects,
falsefor Erlang projects. Note: if you set this to
falsefor an Elixir project, you will have to add paths to Elixir's
ERL_LIBSenvironment variable when running the resulting escript, in order for the code loader to be able to find
:elixirapplication and its children applications (if they are used).
:shebang- shebang interpreter directive used to execute the escript. Defaults to
"#! /usr/bin/env escript\n".
:comment- comment line to follow shebang directive in the escript. Defaults to
:emu_args- emulator arguments to embed in the escript file. Defaults to
There is one project-level option that affects how the escript is generated:
language: :elixir | :erlang- set it to
:erlangfor Erlang projects managed by Mix. Doing so will ensure Elixir is not embedded by default. Your app will still be started as part of escript loading, with the config used during build.
defmodule MyApp.MixProject do use Mix.Project def project do [ app: :my_app, version: "0.0.1", escript: escript() ] end def escript do [main_module: MyApp.CLI] end end
defmodule MyApp.CLI do def main(_args) do IO.puts("Hello from MyApp!") end end