https://github.com/tecosaur/dotenv.jl

Get environment variables from .env files in your Julia projects.
https://github.com/tecosaur/dotenv.jl

dotenv julia julia-language

Last synced: about 1 month ago
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Get environment variables from .env files in your Julia projects.

• Host: GitHub
• URL: https://github.com/tecosaur/dotenv.jl
• Owner: tecosaur
• License: mit
• Created: 2018-07-31T02:22:41.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2024-08-08T15:51:15.000Z (3 months ago)
• Last Synced: 2024-10-12T23:21:47.889Z (about 1 month ago)
• Topics: dotenv, julia, julia-language
• Language: Julia
• Size: 58.6 KB
• Stars: 55
• Watchers: 5
• Forks: 6
• Open Issues: 0
• Metadata Files:
  • Readme: README.org
  • License: LICENSE.md

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README

        
#+title: DotEnv.jl

#+author: tecosaur

#+html: 

#+html: 

DotEnv.jl is a lightweight package that loads environment variables from =.env=

files into [[https://docs.julialang.org/en/latest/manual/environment-variables/][=ENV=]]. Storing configuration in the environment is based on [[http://12factor.net/config][The

Twelve-Factor App]] methodology.

Please don't store secrets in dotenv files, and if you must at least ensure the

dotenv file(s) are listed in =.gitignore=.

* Usage

#+begin_src julia

using DotEnv

DotEnv.load!()

#+end_src

Create a =.env= file in your project. You can add environment-specific variables

using the rule =NAME=VALUE=.  For example:

#+begin_src conf

#.env file

DB_HOST=127.0.0.1

DB_USER=john

DB_PASS=42

#+end_src

When ~DotEnv.load!()~ is called, all variables declared in the =.env= file that

are not already present in =ENV= are loaded into it.

#+begin_src julia

julia> ENV["DB_PASS"]

"42"

#+end_src

To load variables from dotenv files even when they are already present in the

environment dictionary, pass =override = true= to ~DotEnv.load!~.

* Unloading environment changes

~DotEnv.unload!()~ will reverse the changes of ~DotEnv.load!()~.

This works even when the environment is modified incrementally (i.e. loading

files one at a time).

* Read a dotenv file

~config~ reads a dotenv file, parse the content, applies variable expansion, but

does _not_ modify the base environment dictionary.

#+begin_src julia

julia> using DotEnv

julia> cfg = DotEnv.config() # defaults to reading `.env`

DotEnv.EnvOverlay{Base.EnvDict} with 3 entries:

  "DB_PASS" => "42"

  "DB_HOST" => "127.0.0.1"

  "DB_USER" => "john"

#+end_src

* Parsing

~DotEnv.parse~ accepts a ~String~ or an ~IOBuffer~ (Any value that can be converted into ~String~), and it will return

a ~Dict~ with the parsed keys and values.

#+begin_src julia

julia> using DotEnv

julia> DotEnv.parse("FOO=bar\nBAR=baz")

Dict{String, String} with 2 entries:

  "FOO" => "bar"

  "BAR" => "baz"

#+end_src

** Parsing Rules

1. Leading whitespace is ignored

2. Empty lines, and lines starting with =#= are skipped

3. =export= prefixes are ignored (e.g. =export FOO=bar=)

4. Empty assignments are regarded as the empty string(=EMPTY== becomes ~"EMPTY" => ""~)

5. Keys and values are separated by === or =:=, and any amount of whitespace

6. All values are strings, but can be quoted with single (='=) or double quotes (="=)

7. Quotes of the same type may occur within quoted values, but must be escaped with =\=

8. Inline comments are started with a =#= outside of a quoted value

9. Inside double quoted values, =\n= newlines are expanded, allowing for multiline values

10. Extra spaces are removed from both ends of an unquoted value (e.g. =FOO= some

    value = becomes ~"FOO" => "some value"~)

11. Variable expansion occurs within unquoted and double-quoted values. =$NAME=,

    =${NAME}=, and =${NAME:-default}= expansions are all supported.

12. Malformed lines are silently skipped