Modifying the Bash prompt string (username@hostname:~$)

When we open a terminal or run a shell, we see a prompt such as user@hostname: /home/$. Different GNU/Linux distributions have different prompts and different colors. The PS1 environment variable defines the primary prompt. The default prompt is defined by a line in the ~/.bashrc file.

• View the line used to set the PS1 variable:

        $ cat ~/.bashrc | grep PS1 
        PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '

• To modify the prompt, enter the following command:

        slynux@localhost: ~$ PS1="PROMPT> " # Prompt string changed 
        PROMPT> Type commands here.

• We can use colored text using the special escape sequences such as \e[1;31 (refer to the Displaying output in a terminal recipe of this chapter).

Certain special characters expand to system parameters. For example, \u expands to username, \h expands to hostname, and \w expands to the current working directory.