The default command-line interpreter or shell in most distros is Bash, but you can install another shell from your system repositories and turn it into your default shell.

Install a shell

First step is, obviously, to install a shell. There are several shells (check my list) but for this tutorial I am going to use Fish.

# Debian/Ubuntu
sudo apt install fish

# Arch
sudo pacman -S fish

You can run Fish inside your current shell by typing fish.

Change default user shell

We can use chsh to change user login shell. First, you need to know the full path of your new shell (run which fish). Then, run chsh with the parameter -s and the shell path.

chsh -s /usr/bin/fish

Type your user password and log out. When you log in again, your default shell will be Fish.

You can also edit /etc/passwd and change the last part of your user’s line.

# User 'ricardo'
ricardo:x:1000:1000::/home/ricardo:/bin/bash