dotenv-cli

What is dotenv-cli?

The dotenv-cli package is a command-line interface tool that allows you to load environment variables from a .env file into your shell environment. This is particularly useful for managing environment variables in development and testing environments.

What are dotenv-cli's main functionalities?

Load environment variables from a .env file

This feature allows you to load environment variables from a specified .env file and run a command with those variables. In this example, the environment variables from the .env file are loaded and then the Node.js application (app.js) is executed with those variables.

dotenv -e .env -- node app.js

Specify multiple .env files

This feature allows you to load environment variables from multiple .env files. The variables from the files are merged, with the latter files overriding the former ones if there are conflicts. In this example, variables from both .env and .env.local are loaded before running the Node.js application.

dotenv -e .env -e .env.local -- node app.js

Use different .env files for different environments

This feature allows you to specify different .env files for different environments, such as production, development, or testing. In this example, the environment variables from the .env.production file are loaded before running the Node.js application.

dotenv -e .env.production -- node app.js

Other packages similar to dotenv-cli

cross-env

The cross-env package allows you to set environment variables across different platforms in a consistent manner. Unlike dotenv-cli, which loads variables from a .env file, cross-env allows you to set them directly in the command line. This can be useful for setting variables in a cross-platform way, but it does not provide the same file-based management of environment variables.

env-cmd

The env-cmd package allows you to set environment variables from a file or inline. It is similar to dotenv-cli in that it can load variables from a file, but it also provides more flexibility in terms of specifying variables directly in the command line. Env-cmd also supports JSON and JavaScript configuration files, offering more versatility compared to dotenv-cli.

dotenv

The dotenv package is a zero-dependency module that loads environment variables from a .env file into process.env. While it is similar to dotenv-cli in terms of loading variables from a .env file, it is designed to be used programmatically within your Node.js application rather than as a command-line tool.

README

dotenv-cli

Installing

NPM

$ npm install -g dotenv-cli

Yarn

$ yarn global add dotenv-cli

pnpm

pnpm add -g dotenv-cli

Usage

$ dotenv <command with arguments>

This will load the variables from the .env file in the current working directory and then run the command (using the new set of environment variables).

Custom .env files

Another .env file could be specified using the -e flag:

$ dotenv -e .env2 <command with arguments>

Multiple .env files can be specified, and will be processed in order:

$ dotenv -e .env3 -e .env4 <command with arguments>

Cascading env variables

Some applications load from .env, .env.development, .env.local, and .env.development.local (see #37 for more information). dotenv-cli supports this using the -c flag for just .env and .env.local and -c development for the ones above. The -c flag can be used together with the -e flag. The following example will cascade env files located one folder up in the directory tree (../.env followed by ../.env.local):

dotenv -e ../.env -c 

Setting variable from command line

It is possible to set variable directly from command line using the -v flag:

$ dotenv -v VARIABLE=somevalue <command with arguments>

Multiple variables can be specified:

$ dotenv -v VARIABLE1=somevalue1 -v VARIABLE2=somevalue2 <command with arguments>

Variables set up from command line have higher priority than from env files.

Purpose of this is that standard approach VARIABLE=somevalue <command with arguments> doesn't work on Windows. The -v flag works on all the platforms.

Check env variable

If you want to check the value of an environment variable, use the -p flag

$ dotenv -p NODE_ENV

Flags to the underlying command

If you want to pass flags to the inner command use -- after all the flags to dotenv-cli.

E.g. the following command without dotenv-cli:

mvn exec:java -Dexec.args="-g -f"

will become the following command with dotenv-cli:

$ dotenv -- mvn exec:java -Dexec.args="-g -f"

or in case the env file is at .my-env

$ dotenv -e .my-env -- mvn exec:java -Dexec.args="-g -f"

Variable expansion

We support expanding env variables inside .env files (See dotenv-expand npm package for more information)

For example:

IP=127.0.0.1
PORT=1234
APP_URL=http://${IP}:${PORT}

Using the above example .env file, process.env.APP_URL would be http://127.0.0.1:1234.

Variable expansion in the command

If your .env file looks like:

SAY_HI=hello!

you might expect dotenv echo "$SAY_HI" to display hello!. In fact, this is not what happens: your shell will first interpret your command before passing it to dotenv-cli, so if SAY_HI envvar is set to "", the command will be expanded into dotenv echo: that's why dotenv-cli cannot make the expansion you expect.

Possible solutions

1. Bash and escape

One possible way to get the desired result is:

$ dotenv -- bash -c 'echo "$SAY_HI"'

In bash, everything between ' is not interpreted but passed as is. Since $SAY_HI is inside '' brackets, it's passed as a string literal.

Therefore, dotenv-cli will start a child process bash -c 'echo "$SAY_HI"' with the env variable SAY_HI set correctly which means bash will run echo "$SAY_HI" in the right environment which will print correctly hello

1. Subscript encapsulation

Another solution is simply to encapsulate your script in another subscript.

Example here with npm scripts in a package.json

{
  "scripts": {
    "_print-stuff": "echo $STUFF",
    "print-stuff": "dotenv -- npm run _print-stuff",
  }
}

Debugging

You can add the --debug flag to output the .env files that would be processed and exit.

License

MIT