bash git prompt

.git_prompt

# git prompt
DULL=0
FG_BLACK=30
FG_RED=31
FG_GREEN=32
FG_YELLOW=33
FG_BLUE=34
FG_CYAN=36
FG_WHITE=37
BG_NULL=00
ESC="\033"
NORMAL="$ESC[m"
RESET="$ESC[${DULL};${FG_WHITE};${BG_NULL}m"
RED="$ESC[${DULL};${FG_RED}m"
GREEN="$ESC[${DULL};${FG_GREEN}m"
YELLOW="$ESC[${DULL};${FG_YELLOW}m"
BLUE="$ESC[${DULL};${FG_BLUE}m"
CYAN="$ESC[${DULL};${FG_CYAN}m"
WHITE="$ESC[${DULL};${FG_WHITE}m"

git_prompt() {
    local leader="$(prompt_leader)"
    local g="$(__gitdir)"
    if [ -n "$g" ]; then
        local MINUTES_SINCE_LAST_COMMIT=`minutes_since_last_commit`
        if [ "$MINUTES_SINCE_LAST_COMMIT" -gt 30 ]; then
            local COLOR=${RED}
        elif [ "$MINUTES_SINCE_LAST_COMMIT" -gt 10 ]; then
            local COLOR=${YELLOW}
        else
            local COLOR=${GREEN}
        fi
        local SINCE_LAST_COMMIT="${COLOR}$(minutes_since_last_commit)m${NORMAL}"
        # The __git_ps1 function inserts the current git branch where %s is
        local GIT_PROMPT=`__git_ps1 "(${CYAN}%s${NORMAL}|${SINCE_LAST_COMMIT}) ${leader}"`
        echo ${GIT_PROMPT}
    else
        echo `printf -- "${leader}"`
    fi
}

function minutes_since_last_commit {
    now=`date +%s`
    last_commit=`git log --pretty=format:'%at' -1`
    seconds_since_last_commit=$((now-last_commit))
    minutes_since_last_commit=$((seconds_since_last_commit/60))
    echo $minutes_since_last_commit
}

function prompt_leader {
    local CODE=$?
    if [[ $CODE -eq 0 ]] ; then
        local COLOR=${GREEN}
    else
        local COLOR=${RED}
    fi

    echo "${COLOR}→${NORMAL}"
}

PS1="\h:\W \$(git_prompt) "