Set color bash prompt according to active virtualenv, git branch and return status of last command.

bash_prompt.sh

#!/bin/bash
#
# DESCRIPTION:
#
#   Set the bash prompt according to:
#    * the active virtualenv
#    * the branch/status of the current git repository
#    * the return value of the previous command
#    * the fact you just came from Windows and are used to having newlines in
#      your prompts.
#
# USAGE:
#
#   1. Save this file as ~/.bash_prompt
#   2. Add the following line to the end of your ~/.bashrc or ~/.bash_profile:
#        . ~/.bash_prompt
#
# LINEAGE:
#
#   Based on work by woods
#
#   https://gist.github.com/31967

# The various escape codes that we can use to color our prompt.
        RED="\[\033[0;31m\]"
     YELLOW="\[\033[1;33m\]"
      GREEN="\[\033[0;32m\]"
       BLUE="\[\033[1;34m\]"
  LIGHT_RED="\[\033[1;31m\]"
LIGHT_GREEN="\[\033[1;32m\]"
      WHITE="\[\033[1;37m\]"
 LIGHT_GRAY="\[\033[0;37m\]"
 COLOR_NONE="\[\e[0m\]"

# Detect whether the current directory is a git repository.
function is_git_repository {
  git branch > /dev/null 2>&1
}

# Determine the branch/state information for this git repository.
function set_git_branch {
  # Capture the output of the "git status" command.
  git_status="$(git status 2> /dev/null)"

  # Set color based on clean/staged/dirty.
  if [[ ${git_status} =~ "working directory clean" ]]; then
    state="${GREEN}"
  elif [[ ${git_status} =~ "Changes to be committed" ]]; then
    state="${YELLOW}"
  else
    state="${LIGHT_RED}"
  fi

  # Set arrow icon based on status against remote.
  remote_pattern="# Your branch is (.*) of"
  if [[ ${git_status} =~ ${remote_pattern} ]]; then
    if [[ ${BASH_REMATCH[1]} == "ahead" ]]; then
      remote="↑"
    else
      remote="↓"
    fi
  else
    remote=""
  fi
  diverge_pattern="# Your branch and (.*) have diverged"
  if [[ ${git_status} =~ ${diverge_pattern} ]]; then
    remote="↕"
  fi

  # Get the name of the branch.
  branch_pattern="^# On branch ([^${IFS}]*)"
  if [[ ${git_status} =~ ${branch_pattern} ]]; then
    branch=${BASH_REMATCH[1]}
  fi

  # Set the final branch string.
  BRANCH="${state}(${branch})${remote}${COLOR_NONE} "
}

# Return the prompt symbol to use, colorized based on the return value of the
# previous command.
function set_prompt_symbol () {
  if test $1 -eq 0 ; then
      PROMPT_SYMBOL="\$"
  else
      PROMPT_SYMBOL="${LIGHT_RED}\$${COLOR_NONE}"
  fi
}

# Determine active Python virtualenv details.
function set_virtualenv () {
  if test -z "$VIRTUAL_ENV" ; then
      PYTHON_VIRTUALENV=""
  else
      PYTHON_VIRTUALENV="${BLUE}[`basename \"$VIRTUAL_ENV\"`]${COLOR_NONE} "
  fi
}

# Set the full bash prompt.
function set_bash_prompt () {
  # Set the PROMPT_SYMBOL variable. We do this first so we don't lose the
  # return value of the last command.
  set_prompt_symbol $?

  # Set the PYTHON_VIRTUALENV variable.
  set_virtualenv

  # Set the BRANCH variable.
  if is_git_repository ; then
    set_git_branch
  else
    BRANCH=''
  fi

  # Set the bash prompt variable.
  PS1="
${PYTHON_VIRTUALENV}${GREEN}\u@\h ${YELLOW}\w${COLOR_NONE} ${BRANCH}
${PROMPT_SYMBOL} "
}

# Tell bash to execute this function just before displaying its prompt.
PROMPT_COMMAND=set_bash_prompt

Thanks, this is great.

+1 Steak Sauce

Thanks a lot. I changed the PS1 line to keep the prompt and the cursor in the same line:

  PS1="${PYTHON_VIRTUALENV}${GREEN}\u@\h ${YELLOW}\w${COLOR_NONE} ${BRANCH}${PROMPT_SYMBOL} "

TODO: make a color scheme for a terminal with light background too.

This broke for me when I recently updated to git 1.8.5.5 (via macports). To fix it, I amended lines 71-74 to look like this:

      branch_pattern="^(# )?On branch ([^${IFS}]*)"
      if [[ ${git_status} =~ ${branch_pattern} ]]; then
        branch=${BASH_REMATCH[2]}
      fi

Thanks for posting this script. It's great!

Line 55 is not working properly if the branch is behind the tracked branch. I have corrected the regex:

remote_pattern="# Your branch is (ahead|behind)+ "

Thanks a lot.

Just a quick note on fetching branch name in git (v1.9.1) - line number 71-74.
It will not work for version newer than 1.7 (based on my try outs).

Here is my command which version independent.
branch="$(git rev-parse --abbrev-ref HEAD)" # replace all 4 lines with this.

Thank you for your very helpful code.
When I apply it to my terminal in Ubuntu 14.04. It doesn't work for Git. It doesn't show git branch name and remote status.
Thanks to this error, I learned a lot. I changed some code and debug with bash script (which is the first time I work with bash script ^_^). I had a lot of fun.

Thank you very much.

Using ubuntu 15.04 and the git branch name is not shown. @canhnht, do you mind sharing your fix?

You can find a version here with the above mentioned fixes that works for me on Ubuntu 15.10 with git 2.5.0.

Updated version with pyenv support: https://gist.github.com/romanlevin/5e9422045bb6a5eb6558cbe371cd8635

The big issue with this is that it's incompatible with conda or any other prompt changers.

Hi @hultberg, Sorry for the delay 😉
Here is my bash_aliases.sh file.

For all languages of git

branch=`git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/\1/'`

Excellent work, adding docker-machine to the prompt

  # Add docker-machine to terminal prompt
  # check if `docker-machine` command exists
  if command -v docker-machine > /dev/null; then
    # fetch the first running machine name
    local machine=$(docker-machine ls | grep "Running" | head -n 1 | awk '{ print $1 }')
    if [ "$machine" == "" ]; then
      DOCKER_MACHINE=''
    else
      DOCKER_MACHINE="$YELLOW\$(__docker_machine_ps1) "
    fi
  fi

  # Set the bash prompt variable.
PS1="
${DOCKER_MACHINE}${PYTHON_VIRTUALENV}${BRANCH}${GREEN}\u@\h${BLUE}\w${COLOR_NONE}
${PROMPT_SYMBOL} "
}

Regards!