Command Shell

A shell is a program that translates text commands (like ls, vim, reboot etc) into instructions for your computer. The default shell on NixOS is bash, but it can be easily changed.

Note: Zsh is used here as an example. You can use other shells, e.g. fish or nushell.

Enable

When adding a new shell, always enable the shell system-wide, even if it's already enabled in your Home Manager configuration, otherwise it won't source the necessary files.

For example, for Zsh:

/etc/nixos/configuration.nix

programs.zsh.enable = true;

Changing the default shell

For all users

To set a command shell as the default for all users, use the defaultUserShell option.

For example, to set Zsh as the default user shell for all users:

/etc/nixos/configuration.nix

users.defaultUserShell = pkgs.zsh;

For a specific user

To set a command shell as the default for a particular user, use the <name>.shell <name>.shell option.

For example, to set user "myuser"'s shell to fish:

/etc/nixos/configuration.nix

users.users.myuser.shell = pkgs.fish;

You can also choose whether or not a user should use the default shell:

/etc/nixos/configuration.nix

users.users.myuser.useDefaultShell = true;

Changing /bin/sh

Warning: Please note that NixOS assumes all over the place that the shell is bash, so override the default setting only if you know what you're doing.

/bin/sh is a symlink to your default POSIX-compliant shell. It's used when writing shell scripts, so that the script works on all machines independently of which shell the user is using. /bin/sh doesn't have to be the same as your interactive shell (i.e. the one you use in your terminal). For example, some people set their interactive shells to zsh/fish but set /bin/sh to dash, because it's fast and scripts don't need any of those fancy zsh/fish features.

To change your default POSIX shell on NixOS, use

# Dash is just an example, you can use whatever you want
environment.binsh = "${pkgs.dash}/bin/dash";

See also

• Fish
• Nushell
• Zsh