Work with environment variables

## Usage

`circleci env <command> [flags]`

## Available Commands

| Command | Description                                  |
| ------- | -------------------------------------------- |
| `subst` | Substitute environment variables in a string |

## Flags

Global flags: `-c, --config`, `--debug`, `--no-color`, `-q, --quiet` — see `circleci --help`.

## Details

Work with environment variables in CircleCI workflows.

