Bash prompt customization

The Unix shell bash allows to customize the prompt in different ways. The file /etc/bash.bashrc changes the bash configuration for every user on the Unix system. The variable PS1 changes the shell prompt with escaped characters.

Bash Prompt Escape Sequences

From the man pages:

\a     an ASCII bell character (07)
\d     the date  in  "Weekday  Month  Date" format (e.g., "Tue May 26")
\e     an ASCII escape character (033)
\h     the hostname up to the first `.'
\H     the hostname
\j     the  number of jobs currently managed by the shell
\l     the basename of the shell's terminal device name
\n     newline
\r     carriage return
\s     the  name  of  the shell, the basename of $0 (the portion following the final slash)
\t     the current time in 24-hour HH:MM:SS format
\T     the current time in 12-hour HH:MM:SS format
\@     the current time in 12-hour am/pm format
\u     the username of the current user
\v     the version of bash (e.g., 2.00)
\V     the release of bash,  version  +  patchlevel (e.g., 2.00.0)
\w     the current working directory
\W     the  basename  of the current working direc­tory
\!     the history number of this command
\#     the command number of this command
\$     if the effective UID is 0, a #, otherwise a $
\nnn   the  character  corresponding  to  the octal number nnn
\\     a backslash
\[     begin a sequence of non-printing characters, which could be used to embed a terminal con­trol sequence into the prompt
\]     end a sequence of non-printing characters

Colors

#####################################################
# Color Table:
# Black       0;30     Dark Gray     1;30
# Blue        0;34     Light Blue    1;34
# Green       0;32     Light Green   1;32
# Cyan        0;36     Light Cyan    1;36
# Red         0;31     Light Red     1;31
# Purple      0;35     Light Purple  1;35
# Brown       0;33     Yellow        1;33
# Light Gray  0;37     White         1;37
#
#
# Bold        1;COLOR
# Underscore  4;COLOR
# Blink       5;COLOR
# Inverse     7;COLOR
# Concealed   8;COLOR
#
# Reset       \[\033[m\]
#
#
# USAGE: \[\033[COLORm\]
#

Examples:

PS1="\[\033[1;31m\]\u\[\033[0;1;33m\]@\[\033[1;32m\]\h\[\033[1;33m\]:\[\033[0;36m\]\w\[\033[1;33m\]->\[\033[0m\] "

PS1='\[\033[0;35m\]\u@\h \[\033[0;36m\]\w\[\033[0;32m\] #\[\033[m\] '

Examples with git Branch:

This requires to add .git-completion to the user profile. In the file /etc/bash.bashrc the following statement must be added:

source ~/.git-completion

Afterwards it is possible to use the git branch information in the shell prompt:

# with newLine
PS1=' \[\033[0;35m\]\u@\h \[\033[0;36m\]\w\[\033[0;32m\]`__git_ps1 " (%s)"` \n #\[\033[00m\]\[\033[0;37m\] '

# without newLine
PS1='\[\033[0;35m\]\u@\h \[\033[0;36m\]\w\[\033[0;32m\]`__git_ps1 " (%s)"` #\[\033[00m\]\[\033[0;37m\] '

External links

• tldp.org: Bash Prompt HOWTO
• Digital Formula: Pimp my prompt
• Github: git completion bash extension