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Monday, 7 April 2014

A Powerline style prompt for your shell


A Powerline like prompt for Bash, ZSH and Fish:
MacVim+Solarized+Powerline+CtrlP
  • Shows some important details about the git/svn/hg/fossil branch:
    • Displays the current branch which changes background color when the branch is dirty
    • A '+' appears when untracked files are present
    • When the local branch differs from the remote, the difference in number of commits is shown along with '⇡' or '⇣' indicating whether a git push or pull is pending
  • Changes color if the last command exited with a failure code
  • If you're too deep into a directory tree, shortens the displayed path with an ellipsis
  • Shows the current Python virtualenv environment
  • It's easy to customize and extend. See below for details.

Setup

This script uses ANSI color codes to display colors in a terminal. These are notoriously non-portable, so may not work for you out of the box, but try setting your $TERM to xterm-256color, because that works for me.
  • Patch the font you use for your terminal: see https://github.com/Lokaltog/powerline-fonts
    • If you struggle too much to get working fonts in your terminal, you can use "compatible" mode.
    • If you're using old patched fonts, you have to use the older symbols. Basically reverse this commit in your copy
  • Clone this repository somewhere:
    git clone https://github.com/milkbikis/powerline-shell
    
  • Copy config.py.dist to config.py and edit it to configure the segments you want. Then run
    ./install.py
    
    • This will generate powerline-shell.py
  • (optional) Create a symlink to this python script in your home:
    ln -s <path/to/powerline-shell.py> ~/powerline-shell.py
    
    • If you don't want the symlink, just modify the path in the commands below
  • For python2.6 you have to install argparse
    pip install argparse
    

All Shells:

There are a few optional arguments which can be seen by running powerline-shell.py --help.
  --cwd-only            Only show the current directory
  --cwd-max-depth CWD_MAX_DEPTH
                        Maximum number of directories to show in path
  --colorize-hostname   Colorize the hostname based on a hash of itself.
  --mode {patched,compatible,flat}
                        The characters used to make separators between
                        segments

Bash:

Add the following to your .bashrc:
    function _update_ps1() {
       export PS1="$(~/powerline-shell.py $? 2> /dev/null)"
    }

    export PROMPT_COMMAND="_update_ps1; $PROMPT_COMMAND"

ZSH:

Add the following to your .zshrc:
    function powerline_precmd() {
      export PS1="$(~/powerline-shell.py $? --shell zsh 2> /dev/null)"
    }

    function install_powerline_precmd() {
      for s in "${precmd_functions[@]}"; do
        if [ "$s" = "powerline_precmd" ]; then
          return
        fi
      done
      precmd_functions+=(powerline_precmd)
    }

    install_powerline_precmd

Fish:

Redefine fish_prompt in ~/.config/fish/config.fish:
    function fish_prompt
        ~/powerline-shell.py $status --shell bare ^/dev/null
    end

Customization

Adding, Removing and Re-arranging segments

The config.py file defines which segments are drawn and in which order. Simply comment out and rearrange segment names to get your desired arrangement. Every time you change config.py, run install.py, which will generate a new powerline-shell.py customized to your configuration. You should see the new prompt immediately.

Contributing new types of segments

The segments directory contains python scripts which are injected as is into a single file powerline-shell.py.template. Each segment script defines a function that inserts one or more segments into the prompt. If you want to add a new segment, simply create a new file in the segments directory and add its name to the config.py file at the appropriate location.
Make sure that your script does not introduce new globals which might conflict with other scripts. Your script should fail silently and run quickly in any scenario.
Make sure you introduce new default colors in themes/default.py for every new segment you create. Test your segment with this theme first.

Themes

The themes directory stores themes for your prompt, which are basically color values used by segments. The default.py defines a default theme which can be used standalone, and every other theme falls back to it if they miss colors for any segments. Create new themes by copying any other existing theme and changing the values. To use a theme, set the THEME variable in config.py to the name of your theme.
A script for testing color combinations is provided at themes/colortest.py. Note that the colors you see may vary depending on your terminal. When designing a theme, please test your theme on multiple terminals, especially with default settings.

from  https://github.com/milkbikis/powerline-shell