Shell Integration

Tracking Environment Variables¶

When a Hermit environment is activated, Hermit will install a shell hook to keep your shell’s environment variables synchronized with Hermit’s environment variables as you add and remove packages. This hook executes prior to each command.

Custom Shell Hooks¶

You can define custom functions that are called when Hermit environments are activated or deactivated.

`hermit_on_activate`¶

Called after a Hermit environment is activated. Has access to $HERMIT_ENV and other Hermit variables.

Bash/Zsh example:

hermit_on_activate() {
  export MY_VAR="value"
  PS1="🐚 $PS1"  # Customize prompt when prompt = "none" in bin/hermit.hcl
}

Fish example:

function hermit_on_activate
  set -gx MY_VAR "value"
end

`hermit_on_deactivate`¶

Called when deactivating an environment (via deactivate-hermit or when switching environments).

Bash/Zsh example:

hermit_on_deactivate() {
  unset MY_VAR
  PS1=${PS1#"🐚 "} # Remove the shell when deactivating
}

Fish example:

function hermit_on_deactivate
  set -e MY_VAR
end

Define these functions in your shell’s RC file (~/.bashrc, ~/.zshrc, or ~/.config/fish/config.fish). They are optional.

Tip: Set prompt = "none" in your bin/hermit.hcl to disable Hermit’s default prompt modification and use hermit_on_activate to customize PS1 instead.

Shell Hooks¶

Hermit can also install shell integration hooks to provide * Automatic environment activation / deactivation of Hermit environments as you change directories in your terminal. * Shell completion for the Hermit commands and packages

Zsh¶

This will install Hermit hooks into your ~/.zshrc file. Restart your shell in order for the changes to take effect.

hermit shell-hooks --zsh

To enable the ZSH command completion, you also need to manually initialise the completion system. A simple example on how to do this is to add this to your ~/.zshrc file, before the Hermit hooks:

autoload -U compinit && compinit -i

See the ZSH Documentation for more information

Bash¶

This will install Hermit hooks into your ~/.bashrc file. Restart your shell in order for the changes to take effect.

hermit shell-hooks --bash

Fish¶

This will install Hermit hooks into ~/.config/fish/conf.d/hermit.fish. Restart your shell in order for the changes to take effect.

hermit shell-hooks --fish