Skip to content

Latest commit

 

History

History
95 lines (72 loc) · 3.3 KB

file-erlang-startup.rst

File metadata and controls

95 lines (72 loc) · 3.3 KB
Raw

The ~/.erlang startup file

Home page:https://github.com/pierre-rouleau/about-erlang
Navigation:Prev, Top
Created:Monday, June 7 2021.
Author: Pierre Rouleau <prouleau001@gmail.com>
Modified:2021-06-07 15:57:00, updated by Pierre Rouleau.
Copyright: © 2021, Pierre Rouleau

Table of Contents

1   The ~/.erlang file

As described in the erl configuration man page, when Erlang/OTP is started it searches for the file .erlang in the user's home directory and evaluates its content as Erlang expressions if it finds one.

You can start several configuration settings inside that file or put logic to detect the current project and apply a configuration that is required for the current project.

You can also compile and load the content of other files. A file often used by Erlang users is a user-default file that is generic and applies to all projects.

Here's an example for the content of a .erlang file:

%%% File      : .erlang
%%% Purpose   : Erlang Shell Configuration.
%%% Created   : Monday, June  7 2021.
%%% Author    : Pierre Rouleau <prouleau001@gmail.com>
%%% Time-stamp: <2021-06-07 14:24:09, updated by Pierre Rouleau>
%%% Copyright © 2021, Pierre Rouleau
%%% License   : MIT
%%% ------------------------------------------------------------------------------------------------
%%% Header Description: Erlang Shell Configuration.
%%%
%%%
%%% References:
%%% - http://erlang.org/doc/man/erl.html#configuration
%%%
%%% ================================================================================================
io:format("Executing user profile in ~~/.erlang\n", []).
UD = filename:absname_join(os:getenv("HOME"), "dev/erlang/base/user_default.erl").
shell_default:c(UD).
io:format("Completed ~~/.erlang\n", []).
%%% ------------------------------------------------------------------------------------------------

2   A User Default File

As described by this Pluralsight article, you can create extra commands to use inside the Erlang shell. Like cmd to execute a shell utility command, shown below:

-module(user_default).
-export([cmd/1]).


cmd(Cmd) ->
   io:format("~s~n", [os:cmd(Cmd)]).

3   Centralizing all Erlang Configuration Files in a DVCS repo

Ideally your .erlang file should be stored in a VCS. You could create a Erlang setup specific project under the control of a DVCS like GIT, Mercurial or any other and store the file in that directory. Then you create a symlink inside your home directory to that file.