Colorful Bash Shell

You can create a colored Bash prompt by modifying the PS1 environment variable in your ~/.bashrc file. The color is set using ANSI escape sequences.

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🛠️ Steps to Color Your Prompt

1. Edit the ~/.bashrc File

Open your Bash configuration file, ~/.bashrc, using a text editor like nano or vim:

Bash

nano ~/.bashrc

2. Add or Modify the PS1 Variable

The $PS1 variable defines your shell prompt. You’ll insert special escape sequences for color and styling.

A Simple Example

Add a line like this to the end of your ~/.bashrc file, or find and replace your existing PS1 definition:

Bash

export PS1='\\[\e[1;32m\\]\u@\h:\\[\e[1;34m\\]\w\\[\e[0m\\]\$ '

Here’s what this example does:

• \\[\e[1;32m\\]: Starts bold (1;) and green (32m) text. The \\[ and \\] are important to tell Bash that the escape sequence doesn’t take up any physical space, which prevents line wrap issues.
• \u@\h:: Prints the username (\u) and hostname (\h) in green.
• \\[\e[1;34m\\]: Switches to bold (1;) and blue (34m) text.
• \w: Prints the current working directory (full path) in blue. Use \W for the basename (last part) of the directory.
• \\[\e[0m\\]: Resets all text attributes (color, bold, etc.) back to the default terminal color. This is crucial so your command input isn’t colored.
• \$ : Prints the prompt symbol ($ for regular users, # for root) followed by a space.

Color and Format Codes

The format for an ANSI color escape sequence is \e[<FORMAT>;<COLOR>m.

Code	Style		Code	Foreground Color
0	Reset/Normal		30	Black
1	Bold/Bright		31	Red
2	Dim		32	Green
4	Underline		33	Yellow
5	Blink (Avoid!)		34	Blue
7	Reverse		35	Magenta
			36	Cyan
			37	White/Light Gray

• Bright Colors: To get brighter versions of the colors (like Bright Red or Light Green), use the Bold code (1;) before the color code, as in 1;31m for Bold Red.

3. Save and Apply Changes

1. Save the file and exit the editor (e.g., in nano, press $\text{Ctrl}+\text{O}$ then $\text{Enter}$, then $\text{Ctrl}+\text{X}$).
2. Apply the changes to your current shell session by running:

Bash

source ~/.bashrc

Your prompt should change immediately! The new prompt will also be active in any new terminal window you open.

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✨ Prompt Elements (Escape Sequences)

These are some common codes you can use in your $PS1 to display information:

Code	Description	Example
\u	Username	john
\h	Hostname (short)	my-server
\W	Basename of CWD	Desktop
\w	Full CWD path	~/Documents/project
\t	Current time (HH:MM:SS)	13:23:15
\@	Current time (AM/PM)	01:23 PM
\d	Current date	Mon Dec 1
\$	Prompt character (# for root, $ otherwise)	$