Would generally recommend powerline of bashline or oh-my-zsh or something but this makes a fancy bash prompt from scratch

git_svn_bash_prompt.sh

#!/bin/bash

# Started off being just the git/svn stuff from authors below but then got
# hacked on by me to add other silly things.
#
# Needs:
# - A 256-colour terminal
# - A terminal that supports colour emoji (else you'll need to substitute boring monochrome unicode glyphs and maybe colour them with terminal escapes)
# - Powerline font ("fonts-powerline" on Debian/Ubuntu) for the separator chevrons
# - Add this to your ~/.bashrc like:
#
#   . /path/to/git_svn_bash_prompt.sh
#
# Andy Smith <andy@strugglers.net>

# DESCRIPTION:
#
#   Set the bash prompt according to:
#    * the branch/status of the current git repository
#    * the branch of the current subversion repository
#    * the return value of the previous command
# 
# USAGE:
#
#   1. Save this file as ~/.git_svn_bash_prompt
#   2. Add the following line to the end of your ~/.profile or ~/.bash_profile:
#        . ~/.git_svn_bash_prompt
#
# AUTHOR:
# 
#   Scott Woods <scott@westarete.com>
#   West Arete Computing
#
#   Based on work by halbtuerke and lakiolen.
#
#   http://gist.github.com/31967

# Emoji for bad exit status.
sym_exit_fail="🔥"

sym_branch=""
sym_section=""
sym_sep=""
sym_computer="💻"

# The various escape codes that we can use to color our prompt.
                    RED="\[\033[0;31m\]"
                 YELLOW="\[\033[0;33m\]"
                  GREEN="\[\033[0;32m\]"
                   BLUE="\[\033[0;34m\]"
             LIGHT_BLUE="\[\033[0;36m\]"
              LIGHT_RED="\[\033[1;31m\]"
            LIGHT_GREEN="\[\033[1;32m\]"
                  WHITE="\[\033[1;37m\]"
             LIGHT_GRAY="\[\033[0;37m\]"
             COLOR_NONE="\[\e[0m\]"
   COLOR_BLACK_ON_GREEN="\[\e[0;38;5;16;48;5;72m\]"
  COLOR_GREEN_ON_YELLOW="\[\e[0;38;5;72;48;5;194m\]"
  COLOR_BLACK_ON_YELLOW="\[\e[0;38;5;16;48;5;194m\]"
   COLOR_YELLOW_ON_GRAY="\[\e[0;38;5;194;48;5;247m\]"
COLOR_YELLOW_ON_DEFAULT="\[\e[0;38;5;194;49m\]"
    COLOR_BLACK_ON_GRAY="\[\e[0;38;5;16;48;5;247m\]"
    COLOR_BLACK_ON_GRAY="\[\e[0;38;5;16;48;5;247m\]"
   COLOR_BLACK_ON_LBLUE="\[\e[0;38;5;16;48;5;75m\]"
  COLOR_GRAY_ON_DEFAULT="\[\e[0;38;5;247;49m\]"
 COLOR_LBLUE_ON_DEFAULT="\[\e[0;38;5;75;49m\]"

# Detect whether we're running under tmux.
function is_in_tmux {
    test -n "$TMUX" && hash tmux 2>/dev/null
}

# Detect whether we're running under GNU Screen.
function is_in_screen {
    test -n "$STY" && hash screen 2>/dev/null
}

# Set PROMPT_MUX based on tmux window index and name.
function set_mux_prompt {
    local winidx=$(tmux display-message -p '#I')
    local winname=$(tmux display-message -p '#W')

    PROMPT_MUX="${COLOR_BLACK_ON_LBLUE}${sym_section}${sym_computer} ${winidx} ${sym_sep} ${winname} ${COLOR_LBLUE_ON_DEFAULT}${sym_section}"
}

# Set PROMPT_MUX based on GNU Screen window index and title.
function set_mux_prompt_screen {
    local winidx="$WINDOW"
    # This is absolutely awful. Screen imposes a delay unless you set it to
    # zero, and then you have to set it back again.
    local wintitle=$(screen -X msgwait 0; screen -QX title; screen -X msgwait 3)

    PROMPT_MUX="${COLOR_BLACK_ON_LBLUE}${sym_section}${sym_computer} ${winidx} ${sym_sep} ${wintitle} ${COLOR_LBLUE_ON_DEFAULT}${sym_section}"
}

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

# Detect whether the current directory is a subversion repository.
function is_svn_repository {
    test -d .svn
}

# 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="${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} "
}

# Determine the branch information for this subversion repository. No support
# for svn status, since that needs to hit the remote repository.
function set_svn_branch {
    svn_info="$(svn info | egrep '^URL: ' 2> /dev/null)"

    # Get the name of the branch.
    branch_pattern="^URL: .*/(branches|tags)/([^/]+)"
    trunk_pattern="^URL: .*/trunk(/.*)?$"

    if [[ ${svn_info} =~ $branch_pattern ]]; then
        branch=${BASH_REMATCH[2]}
    elif [[ ${svn_info} =~ $trunk_pattern ]]; then
        branch='trunk'
    fi

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

# Return the prompt symbol to use, colorized based on the return value of the
# previous command.
function set_prompt_symbol () {
    if (( $1 == 0 )); then
        PROMPT_SYMBOL="\$"
    else
        PROMPT_SYMBOL="${sym_exit_fail}${RED}[${COLOR_NONE}$1${RED}]${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 PROMPT_MUX variable. First the default state when not inside tmux
    # or screen.
    PROMPT_MUX="${COLOR_BLACK_ON_LBLUE}${sym_section}${sym_computer}${COLOR_LBLUE_ON_DEFAULT}${sym_section}"

    # Then check if we're inside tmux and then GNU Screen. This is fairly nice
    # for tmux since it's just checking some environment variables. Could be
    # improved for screen.
    if is_in_tmux ; then
        set_mux_prompt
    elif is_in_screen; then
        # Check that screen supports -Q. Really old versions don't!
        if [ -z "$_have_screen_q" ]; then
            if screen -Q info >/dev/null 2>&1; then
                _have_screen_q=1
            else
                # Just so this is not called again.
                _have_screen_q=0
            fi
        fi

        if (( "$_have_screen_q" == 1)); then
            set_mux_prompt_screen
        fi
    fi

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

    # Save history
    history -a

    # Update xterm title
    echo -ne "\033]0;${USER}@${HOSTNAME}: ${PWD}\007"

    # Maybe should look up the user's real home directory rather than just
    # assuming it's in /home/?
    MUNGED_PATH=${PWD/#\/home\/$USER/\~}

    # Truncate path to 40 characters if it's longer.
    if [[ ${#MUNGED_PATH} -gt 39 ]]; then
        MUNGED_PATH="…${MUNGED_PATH:(-39)}"
    else
        MUNGED_PATH="${MUNGED_PATH/#\//}"
    fi

    PROMPT_USER="${COLOR_BLACK_ON_GREEN}${sym_sep}\u${COLOR_GREEN_ON_YELLOW}${sym_section}"
    PROMPT_HOST="${COLOR_BLACK_ON_YELLOW}@\h ${COLOR_YELLOW_ON_DEFAULT}${sym_section}"
    MUNGED_PATH="${MUNGED_PATH//\// ${COLOR_BLACK_ON_GRAY}${sym_sep}${COLOR_BLACK_ON_GRAY} }"
    PROMPT_PATH="${COLOR_BLACK_ON_GRAY}${sym_section}${COLOR_BLACK_ON_GRAY} ${MUNGED_PATH} ${COLOR_GRAY_ON_DEFAULT}${sym_section}"

    PS1="${PROMPT_USER}${PROMPT_HOST}${PROMPT_MUX}${PROMPT_PATH}${COLOR_NONE} ${BRANCH}\n${PROMPT_SYMBOL} "
}

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