Yet another bash/zsh prompt script

Here we have yet another script for Git-aware customization of the command prompt in Bash and zsh. Unlike all the other scripts, I wrote this one, so it's better.

Features:

• lets you know if you have mail in $MAIL
• shows chroot, virtualenv, and Conda environment prompt prefixes
• automatically truncates the current directory path if it gets too long
• shows the status of the current Git repository (see below)
• thoroughly documented and easily customizable
• supports both Bash and zsh
• can optionally output just the Git status, in case you want to combine it with your own prompt string

Requirements

• Python 3, version 3.5 or higher
• Git, version 1.7.10 or higher
• bash or zsh

Installation & Setup

1. Save ps1.py to your computer somewhere (I put my copy at ~/share/ps1.py)

2. If using Bash, add the following line to the end of your ~/.bashrc:

   PROMPT_COMMAND="$PROMPT_COMMAND"'; PS1="$(/usr/bin/python3 ~/share/ps1.py "${PS1_GIT:-}")"'

   If using zsh, add the following to the end of your ~/.zshrc:

   precmd_ps1_py() { PS1="$(/usr/bin/python3 ~/share/ps1.py --zsh "${PS1_GIT:-}")" }
   precmd_functions+=( precmd_ps1_py )

   If you want to use just the Git status portion of the script's output and combine it with your own prompt string, replace the PS1 assignment with your desired prompt, with $(/usr/bin/python3 ~/share/ps1.py --git-only "${PS1_GIT:-}") inserted where you want the Git status string.

   Replace /usr/bin/python3 with the path to your Python 3 interpreter, and replace ~/share/ps1.py with the location you saved ps1.py at as appropriate.

3. Open a new shell

4. Enjoy!

5. If the Git integration causes you trouble (either because something breaks or just because it's taking too long to run), it can be temporarily disabled by running PS1_GIT=off on the command line.

Usage

python3 ps1.py [<options>] [<git flag>]

ps1.py outputs a single line containing a stylized prompt string for the current directory. By default, the stylization is in a format usable in Bash's PS1 variable, though the --ansi and --zsh option can be supplied to change the format.

ps1.py takes a single optional argument. If this argument is "off", then the Git integration is disabled. If it is any other value or not specified, the Git integration is enabled.

Options

Git Status Symbols

When inside a Git repository, a number of symbols showing the current HEAD and its status are added near the end of the prompt. Except for the @ separator and the HEAD itself, individual symbols are omitted when not relevant. From left to right, the symbols are:

• @ — separator
• + (bold light yellow) — Indicates there are stashed changes
• the name of the HEAD (light green) — the name of the current branch (if any), or the name of the currently checked-out tag (if any), or the short form of the current commit hash; turns light blue when the repository is in detached HEAD state
• +n (green) — how many commits HEAD is ahead of upstream
• -n (red) — how many commits HEAD is behind upstream
• * — Indicates whether there are any staged or unstaged changes in the working tree:
  • Green: There are staged changes
  • Red: There are unstaged changes
  • Bold light yellow: There are both staged and unstaged changes
• + (bold red) — Indicates there are untracked files in the working tree
• [STATE] (magenta) — Shows what activity Git is currently in the middle of, if any:
  • [BSECT] — bisecting
  • [CHYPK] — cherry-picking
  • [MERGE] — merging
  • [REBAS] — rebasing
  • [REVRT] — reverting
• ! (bold red) — Indicates there are paths with merge conflicts