PureLine - A Pure Bash Powerline PS1 Command Prompt

A simple but powerful Powerline style prompt for the Bash shell written in Bash script.

This project was inspired by Bash-Powerline-Shell. It has been redesigned to make configuration easier and to use only the basic terminal colors - allowing colors to be set by the terminal (eg Xresources or profiles).

The result ... is PureLine.

Main Features

Modules for the PS1 prompt include;

Time: with an option for HH:MM or HH:MM:SS
Battery: a battery power indicator
Host: shows the hostname with option for hostname or username@hostname
User: similar to host, but only shown when on an SSH connection
Path: optional arg 0 to show fullpath, 1 for the current dir and any other number to trim the path
Read Only: an indicator for read only directories
Jobs: show the number of running background jobs
Virtual Environment: shows the name of an active python virtual environment
Git: shows a git branch name, and the status of the repository
Git_stash: shows number of a git stash
Git_ahead_behind: status against upstream
Return Code: shows the return code when last command fails
Prompt: a simple prompt, useful after after a Newline
Newline: split the prompt across one or more lines

All the modules are optional and can be enabled or disabled in a config file.

Unicode symbols used

Hard separator between modules
Soft separator betwen modules of the same color: 
Read-only status of current directory: 
Return code from previous bash command: ⚑
Number of background jobs: ⏎ followed by number
Python Virtual Environment:λ
Battery indicator when charging:⚡
Battery indicator when discharging:▮
Git Branch:  & Git Stash: 🐿
Number of modified files in git repo: ✚
Number of staged files in git repo: ✔
Number of conflicted files in git repo: ✘

Setup

Prerequisites

Some of the unicode symbols require a special font to be used in your terminal. Please use one of the powerline fonts available at: https://github.com/Lokaltog/powerline-fonts
- DejaVu Sans Mono for Powerline is a popular choice
- The screenshots above use Hack for Powerline
Almost all current terminals have the unicode support needed by PureLine. If you have used PowerLine fonts before, then you already know if Pureline will be supported in your terminal. But if you do have issues with any of the symbols, try testing a different terminal, eg, uxterm in place of xterm.

Install

Git Clone

$ cd ~
$ git clone https://github.com/chris-marsh/pureline.git
$ cp pureline/example-config.conf ~/.pureline.conf

In your .bashrc or .profile, whichever is used, source the pureline script as follows:

source ~/pureline/pureline ~/.pureline.conf

The powerline fonts need more effort to work on tty screens, so a useful tip is to only source PureLine if you are on a gui;

if [ "$TERM" != "linux" ]; then
    source ~/pureline/pureline ~/.pureline.conf
fi

Customization

The config file contains lines which are sourced by PureLine. Each line loads a module. For example;

declare -a pureline_modules=(
#    Name                   Background  Foreground  Option
#   'time_module                Purple      Black       false'  # Show seconds
#   'battery_module             Blue        Black'
#   'newline_module'
    'user_module                Yellow      Black       false'   # show hostname
    'host_module                Yellow      Black       false'   # show username
#   'virtual_env_module         Blue        Black'
    'path_module                Blue        Black       0'
    'read_only_module           Red         White'
#   'jobs_module                Purple	    White'
#   'git_module                 Green       Black       Red'    # FG Color for dirty status
#   'git_stash_module           Green       Black'
#   'git_ahead_behind_module    Green       Black'
    'return_code_module         Red         White'
#   'prompt_module              Purple	    Black'
)

To remove a module, comment or delete the relevant line. You can rearrange the modules in any order you prefer. The first two parameters are background and foreground colors which can be customized. Some modules may have additional options.

Default Colors

The colors default colors available are:

Black
Green
Yellow
Blue
Purple
Cyan
White

Using these colors, your command prompt will use the color theme of your terminal.

Custom 256 Colors

You can also define your own custom colors in the config file;

colors[Orange]='\[\e[38;5;208m\]'           # 256 Col Orange Foreground
colors[On_Orange]='\[\e[48;5;208m\]'        # 256 Col Orange Background
colors[LightGrey]='\[\e[38;5;250m\]'        # 256 Col Light Grey Foreground
colors[On_LightGrey]='\[\e[48;5;250m\]'     # 256 Col Light Grey Background
colors[DarkGrey]='\[\e[38;5;240m\]'         # 256 Col Dark Grey Foreground
colors[On_DarkGrey]='\[\e[48;5;240m\]'      # 256 Col Dark Grey Background

The colors must be defined in pairs of background and foreground colors.

Developing New Modules

New modules can be easily created by following a template from existing functions. For example:

function time_module {
    local bg_color=$1                  # Set the background color
    local fg_color=$2                  # Set the foregropund color
    local content="\t"                 # Set the content to be displayed
    PS1+=$(section_end $bg_color)
    PS1+=$(section_content $fg_color $bg_color " $content ")
    __last_color=$bg_color
}

The $content variable can be modified to show any output wanted on the prompt

Additional resources

Bash tips: Colors and formatting : Flozz' Misc Bash Tips for Colors and Formatting
FileFormat.info: Unicode Characters in the 'Symbol, Other' Category
PS1 cheat sheet: Prompt variable characters for customizing the output of the PS1 prompt.

hstejas/pureline