Setup

To get the most out of nu, it is important to setup your path and env for easy access. There are other ways to view these values and variables, however setting up your nu configuration will make it much easier as these have cross-platform support.

Configure your path and other environment variables

In your env.nu, you can set up your environment.

To configure environment variables, you use the $env variable:

$env.TITLE = 'Nu Test'
$env.VALUE = 123

To add paths to the PATH environment variable, you can append them:

$env.PATH ++= ['~/.local/bin']

Because you can append a list of paths, you can append multiple at once. You can also use subcommands to construct the paths in line.

$env.PATH ++= [ '~/.local/bin', ($env.CARGO_HOME | path join "bin") ]

Because PATH order makes a difference, you may want to prepend your paths instead, so that they take precedence over other executables with the same name:

use std/util "path add"
path add '~/.local/bin'

For more information, see the documentation about environment variables and PATH configuration.

How to list your environment variables

$env
# => ─────────────────────────────────┬────────────────────────────────────────────
# =>  ALLUSERSPROFILE                 │ C:\ProgramData
# =>  CARGO_PKG_AUTHORS               │ The Nu Project Contributors
# =>  CARGO_PKG_DESCRIPTION           │ A new type of shell
# =>  CARGO_PKG_HOMEPAGE              │ https://www.nushell.sh
# =>  CARGO_PKG_LICENSE               │ MIT
# =>  CARGO_PKG_LICENSE_FILE          │
# =>  CARGO_PKG_NAME                  │ nu
# =>  CARGO_PKG_REPOSITORY            │ https://github.com/nushell/nushell
# =>  CARGO_PKG_VERSION               │ 0.59.0
# =>  CARGO_PKG_VERSION_MAJOR         │ 0

Let's practise that and set $EDITOR in our env.nu file using vim (or an editor of your choice)

vim $nu.env-path

Note: if you've never used vim before and you want to leave typing :q! will close without saving.

Go to the end of the file and add

$env.EDITOR = 'vim'

or emacs, vscode or whatever editor you like. Don't forget that the program needs to be accessible on the PATH and to reload your configuration with exec nu on linux/mac or restart your nushell on windows.

You should now be able to run config nu or config env and edit those files easily.

How to get a single environment variable's value

$env.APPDATA

Use hooks to export state via environment variables

Additional tools like starship run with every prompt showing up in nushell. starship in particular replaces the default prompt with its own. To be most compatible, the starship binary will run every prompt render and is absolute stateless. Nushell, however, is very stateful in a single instance.

Hooks allow registration of custom callback functions. In this case, the pre_prompt hook is very useful. With it, we can export state information as an environment variable, for example, what overlays are currently activated.

# set NU_OVERLAYS with overlay list, useful for starship prompt
$env.config.hooks.pre_prompt = ($env.config.hooks.pre_prompt | append {||
  let overlays = overlay list | range 1..
  if not ($overlays | is-empty) {
    $env.NU_OVERLAYS = $overlays | str join ", "
  } else {
    $env.NU_OVERLAYS = null
  }
})

Now in starship, we can use this environment variable to display what modules are active.

[env_var.NU_OVERLAYS]
symbol = '📌 '
format = 'with [$symbol($env_value )]($style)'
style = 'red'