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).

Alternatively, if you do not need to pass arguments to the command, you can use the shorthand:

$ dotenv <command>

Custom .env files

Another .env file could be specified using the -e flag (this will replace loading .env file):

$ dotenv -e .env2 -- <command with arguments>

Multiple .env files can be specified, and will be processed in order, but only sets variables if they haven't already been set. So the first one wins (existing env variables win over the first file and the first file wins over the second file):

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

Cascading env variables

Some applications load env variables from multiple .env files depending on the environment:

• .env
• .env.local
• .env.development
• .env.development.local

dotenv-cli supports this using the -c flag:

• -c loads .env and .env.local
• -c test loads .env, .env.local, .env.test, and .env.test.local

See #37 for more information.

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.

Disabling variable expansion

If your .env variables include values that should not be expanded (e.g. PASSWORD="pas$word"), you can pass flag --no-expand to dotenv-cli to disable variable expansion.

For example:

dotenv --no-expand <command>

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"
  }
}

This example is used in a project setting (has a package.json). Should always install locally npm install -D dotenv-cli

Debugging

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

Override

Override any environment variables that have already been set on your machine with values from your .env file.

dotenv -e .env.test -o -- jest

License

MIT