.env file loader

Loads and strictly parses .env file contents, sets environment variables.

Uses a fast recursive descent parser written in V.
Shows detailed error messages with location context.

Synopsis

import prantlf.dotenv { load_env }

load_env(true)!

Installation

You can install this package either from VPM or from GitHub:

v install prantlf.dotenv
v install --git https://github.com/prantlf/v-dotenv

API

The following types and functions are exported:

LoadError

The following error will be thrown if a malformed file is loaded:

struct LoadError {
	reason string
	offset int
	line   int
	column int
}

(e &LoadError) msg() string
(e &LoadError) msg_full() string

load_env(overwrite bool) !bool

Loads and parses the contents of the file .env from the current directory, sets environment variables. Returns true if the file was found and processed. Returns false early, if the file wasn't found. If the argument overwrite is true, existing environment variables will be overwritten with values from the .env file, otherwise they will retain their previous values.

import prantlf.dotenv { load_env }

load_env(true)!

load_user_env(overwrite bool) !bool

Loads and parses the contents of the file .env from the user's home directory, sets environment variables. Returns true if the file was found and processed. Returns false early, if the file wasn't found. If the argument overwrite is true, existing environment variables will be overwritten with values from the .env file, otherwise they will retain their previous values.

import prantlf.dotenv { load_user_env }

load_user_env(true)!

load_file(file string, overwrite bool) !bool

Loads and parses the contents of the specified file from the current directory, sets environment variables. Returns true if the file was found and processed. Returns false early, if the file wasn't found. If the argument overwrite is true, existing environment variables will be overwritten with values from the specified file, otherwise they will retain their previous values.

import prantlf.dotenv { load_env }

load_file('.env.local', true)!

Errors

For example, loading a file with the following contents:

answer

will fail with the following message, obtainable with msg:

unexpected end encountered when parsing a property name on line 1, column 7

A longer and colourful message can ve obtained with msg_full:

unexpected end encountered when parsing a property name:
1 | answer
  |       ^

The message is formatted using the error fields, for example:

LoadError {
  reason  string = 'unexpected end encountered when parsing a property name'
  offset  int    = 7
  line    int    = 1
  column  int    = 7
}

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Lint and test your code.

License

Licensed under the MIT license.