# Module Cmdliner.Cmd.Env

    module Env: sig .. end

Environment variable and their information.

## Environment variables

    type var = string

The type for environment names.

## Environment variable information

    type info = Cmdliner.Term.env_info

    val info : ?deprecated:string ->
           ?docs:string -> ?doc:string -> var -> info

`info ~docs ~doc var` describes an environment variable `var` such that:

- `doc` is the man page information of the environment variable, defaults to `"undocumented"`.
- `docs` is the title of the man page section in which the environment variable will be listed, it defaults to `Cmdliner.Manpage.s_environment`.
- `deprecated`, if specified the environment is deprecated and the string is a message output on standard error when the environment variable gets used to lookup the default value of an argument.

In `doc` the documentation markup language can be used with following variables:

- `$(env)`, the value of `var`.
- The variables mentioned in `val-info`.