direnv
1 min read
Shell extension that automatically loads/unloads environment variables when entering/leaving a directory. Uses .envrc files. Hooks into bash, zsh, fish, tcsh, and elvish.
Workflow
sh
echo 'export API_KEY=abc123' > .envrc
direnv allow # must explicitly allow new/changed .envrc
cd .. # env vars are unloaded automatically
cd project/ # env vars are loaded again
Shell setup
sh
# fish
echo 'direnv hook fish | source' >> ~/.config/fish/config.fish
# bash
echo 'eval "$(direnv hook bash)"' >> ~/.bashrc
# zsh
echo 'eval "$(direnv hook zsh)"' >> ~/.zshrc
Key commands
| Command | Effect |
|---|---|
direnv allow | Trust the current .envrc |
direnv deny | Block the current .envrc |
direnv reload | Re-evaluate .envrc without leaving directory |
direnv edit | Open .envrc in $EDITOR and auto-allow on save |
direnv status | Show current state |
direnv exec /path cmd | Run command in the env of a given directory |
NixOS / Home Manager
nix
programs.direnv = {
enable = true;
nix-direnv.enable = true; # faster nix integration with caching
};