Mercurial and Git repository bash prompt

.bash_prompt

# Default prompt
DEFAULT_PROMPT="\u@\h:\w$ "

# Separator
SEPARATOR=·

# Use the compiled front-end to Mercurial
HG=/usr/bin/chg

# Disable all Mercurial extensions
HGRCPATH=

# Plain, parseable output
HGPLAIN=1

function make_prompt {
        local HG_ROOT=$(${HG} root 2>/dev/null)
        local GIT_ROOT=$(git rev-parse --show-toplevel 2>/dev/null)

        if [ -n "${HG_ROOT}" ]; then
                # Mercurial project
                local VCS=hg
                local PROJECT_BRANCH=$(${HG} identify -b)
                local PROJECT_PATH="${PWD#$HG_ROOT}"
                local PROJECT_NAME=${HG_ROOT##*/}
                export PS1="${VCS}${SEPARATOR}${PROJECT_BRANCH}@${PROJECT_NAME}:${PROJECT_PATH:=/}$ "
        elif [ -n "${GIT_ROOT}" ]; then
                # Git project
                local VCS=git
                local PROJECT_BRANCH=$(git branch | grep '^*' | awk '{print $2}')
                local PROJECT_PATH="${PWD#$GIT_ROOT}"
                local PROJECT_NAME=${GIT_ROOT##*/}
                export PS1="${VCS}${SEPARATOR}${PROJECT_BRANCH}@${PROJECT_NAME}:${PROJECT_PATH:=/}$ "
        else
                export PS1=${DEFAULT_PROMPT}
        fi
}

export PROMPT_COMMAND=make_prompt