Access to environment variables: process.env

The process global module has the env attribute to return information on the environment variable. The process.env attribute contains an object and it represents the list of environment variables. Each attribute is an environment variable. The process module is a global module, which means that you don’t have to import the process module manually, but it is automatically available in your code.

For retrieving the environment variables object:

console.log(process.env)

If you want to access a specific environment variable via the name (for example to the PATH environment variable):

console.log(process.env.PATH)

If you have to access dynamically to an environment variable, you can use the square brackets:

const envVarName = 'PATH'
if (envVarName in process.env) {
  console.log(process.env[envVarName])
} else {
  console.log('no %s defined', envVarName)
}

If you want to walk through all the environment variables you can iterate on the object attributes via Object.keys() method:

Object.keys(process.env).forEach(function (key, index) {
  console.log(key, index, process.env[key])
})