BASH Shell Change The Color of Shell Prompt on Linux or UNIX

How do I change the color of my shell prompt under Linux or Unix operating systems?

You can change the color of your shell prompt to impress your friend or to make your own life quite easy while working at the command prompt. BASH shell is the default under Linux and Apple OS X. Your current prompt setting is stored in a shell variable called PS1. There are other variables too, like PS2, PS3 and PS4.

Bash displays the primary prompt PS1 when it is ready to read a command, and the secondary prompt PS2 when it needs more input to complete a command. Bash allows these prompt strings to be customized by inserting a number of backslash-escaped special characters.

Task: Display current BASH prompt (PS1)

Use the echo command to display current BASH prompt:
$ echo $PS1
Sample outputs:

[\[email protected] \W]\$

Here is another output from my Debian based system:
$ echo $PS1
Sample outputs:

[e]0;[email protected]: wa]${debian_chroot:+($debian_chroot)}[email protected]:w$

By default the command prompt is set to [[email protected] W]$. The backslash-escaped special characters are decoded as follows:

  • u: Display the current username .
  • h: Display the hostname
  • W: Print the base of current working directory.
  • $: Display # (indicates root user) if the effective UID is 0, otherwise display a $.

Task: Modify current BASH prompt

Before you modify settings save your old prompt using the following command:
oldps1="$PS1"
So if you messed up, you can switch back easily using the following syntax:
PS1="$oldps1"
Use the export command to setup a new shell prompt:
$ export PS1="[\[email protected]\H \W \@]\$ "
Sample outputs:

Fig.01: New prompt in action

Where,

  • H: Display FQDN hostname.
  • @: Display current time in 12-hour am/pm format

Task: Add colors to the prompt

To add colors to the shell prompt use the following export command syntax:
'e[x;ym $PS1 e[m'
Where,

  • e[ : Start color scheme.
  • x;y : Color pair to use (x;y)
  • $PS1 : Your shell prompt variable.
  • e[m : Stop color scheme.

To set a red color prompt, type the following command:
$ export PS1="e[0;31m[[email protected] W]$ e[m "
Sample outputs:

Fig.02: Adding the colors to the prompt

A list of color codes

Color Code
Black 0;30
Blue 0;34
Green 0;32
Cyan 0;36
Red 0;31
Purple 0;35
Brown 0;33
Blue 0;34
Green 0;32
Cyan 0;36
Red 0;31
Purple 0;35
Brown 0;33

Note: You need to replace digit 0 with 1 to get light color version.

Task: How do I make the prompt setting permanent?

Your new shell prompt setting set by $PS1 is temporary i.e. when you logout setting will be lost. To have it set every time you login to your workstation add above export command to your $HOME/.bash_profile file or $HOME/.bashrc file.
$ cd
$ vi .bash_profile

OR
$ vi $HOME/.bashrc
Append the following line:
export PS1="e[0;31m[[email protected] W]$ e[m"
Save and close the file in vim/vi.

Bash Change The Color of Shell Prompt Example

Add the following command in ~/.bashrc:

# let us setup prompt
export PS1="[e[32m][[e[m][e[31m]u[e[m][e[33m]@[e[m][e[32m]h[e[m]:[e[36m]w[e[m][e[32m]][e[m][e[32;47m]$[e[m] "

You will get prompt as follows:

Here is another example that include exit status of command as well:

# 
#u - user name
#h - short hostname
#W - current working dir
#? - exit status of the command
export PS1="{[e[32m]u[e[m]@[e[36m]h[e[m]:W_$?}$ "

Say hello to tput command

You can also use tput command to set terminal and modify the prompt settings. For example, to display RED color prompt using a tput:
export PS1="[$(tput setaf 1)][email protected]:w $ [$(tput sgr0)]"

A list of handy tput command line options

  • tput bold – Bold effect
  • tput rev – Display inverse colors
  • tput sgr0 – Reset everything
  • tput setaf {CODE}– Set foreground color, see color {CODE} table below for more information.
  • tput setab {CODE}– Set background color, see color {CODE} table below for more information.

Various color codes for the tput command

Color {code} Color
0 Black
1 Red
2 Green
3 Yellow
4 Blue
5 Magenta
6 Cyan
7 White
Recommend readings
This entry is 5 of 5 in the Coloring Outputs in the CLI Apps Tutorial series. Keep reading the rest of the series:

  1. How to enable colorized output for ls command in MacOS X Terminal
  2. How To Turn On/Off Colors For ls Command In Bash On a Linux/Unix
  3. Turn off color in Linux terminal/bash session
  4. Turn On or Off Color Syntax Highlighting In vi or vim Editor
  5. BASH Shell: Change The Color of My Shell Prompt Under Linux or UNIX

Posted by: SXI ADMIN

The author is the creator of SXI LLC and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.