.bash_prompt

#!/usr/bin/env bash

if [[ $COLORTERM = gnome-* && $TERM = xterm ]] && infocmp gnome-256color >/dev/null 2>&1; then
    export TERM='gnome-256color';
elif infocmp xterm-256color >/dev/null 2>&1; then
    export TERM='xterm-256color';
fi;

prompt_git() {
  local s='';
  local branchName='';

  # Check if the current directory is in a Git repository.
  if [ $(git rev-parse --is-inside-work-tree &>/dev/null; echo "${?}") == '0' ]; then

    # check if the current directory is in .git before running git checks
    if [ "$(git rev-parse --is-inside-git-dir 2> /dev/null)" == 'false' ]; then

      # Ensure the index is up to date.
      git update-index --really-refresh -q &>/dev/null;

      # Check for uncommitted changes in the index.
      if ! $(git diff --quiet --ignore-submodules --cached); then
        s+='+';
      fi;

      # Check for unstaged changes.
      if ! $(git diff-files --quiet --ignore-submodules --); then
        s+='!';
      fi;

      # Check for untracked files.
      if [ -n "$(git ls-files --others --exclude-standard)" ]; then
        s+='?';
      fi;

      # Check for stashed files.
      if $(git rev-parse --verify refs/stash &>/dev/null); then
        s+='$';
      fi;

    fi;

    # Get the short symbolic ref.
    # If HEAD isn’t a symbolic ref, get the short SHA for the latest commit
    # Otherwise, just give up.
    branchName="$(git symbolic-ref --quiet --short HEAD 2> /dev/null || \
      git rev-parse --short HEAD 2> /dev/null || \
      echo '(unknown)')";

    [ -n "${s}" ] && s=" [${s}]";

    echo -e "${1}${branchName}${2}${s}";
  else
    return;
  fi;
}

# Fix colors to be used here
reset="\e[0m";
black="\e[1;30m";
blue="\e[1;34m";
cyan="\e[1;36m";
green="\e[1;32m";
orange="\e[1;33m";
purple="\e[1;35m";
red="\e[1;31m";
violet="\e[1;35m";
white="\e[1;37m";
yellow="\e[1;33m";

# Highlight the user name when logged in as root.
if [[ "${USER}" == "root" ]]; then
  userStyle="${red}";
else
  userStyle="${green}";
fi;

# Set the terminal title and prompt.
PS1="\[\033]0;\W\007\]";        # working directory base name
PS1+="\[${bold}\]";             # newline

if [ -n "$VIRTUAL_ENV" ]; then  # virtualenv name
    PS1+="(${purple}`basename ${VIRTUAL_ENV}`${reset}) "
fi;
# Show only the last 3 dirnames
PROMPT_DIRTRIM=3
PS1+="\[${userStyle}\]\u";      # username
PS1+="\[${white}\]@";           # @
PS1+="\[${yellow}\]\h";         # host
PS1+="\[${white}\]:";           # :
PS1+="\[${cyan}\]\w";           # working directory full path
PS1+="\$(prompt_git \"\[${white}\] (\[${violet}\]\" \"\[${white}\])\")"; # Git repository details
PS1+="\[${white}\] λ \[${reset}\]"; # `λ` (and reset color)
export PS1;

PS2="\[${yellow}\]→ \[${reset}\]";
export PS2;