gistfile1.txt

# \e[XX;Ym
# 3X for foreground, 4X for background
# 0:black,1:red,2:green,3:yellow,4:blue,5:magenta,6:cyan,7:white
# ;0/;1 for regular/bold
# \[...\] needed to tell bash to ignore in calculating length
prompt_c_grey='\[\e[30;1m\]'
prompt_c_green='\[\e[32;1m\]'
prompt_c_yellow='\[\e[33;1m\]'
prompt_c_blue='\[\e[34;1m\]'
prompt_c_magenta='\[\e[35;1m\]'
prompt_c_cyan='\[\e[36;1m\]'
prompt_c_reset='\[\e[0m\]'

function prompt_string {
    # previous command return code
    local rc=${1:-$?}
    printf '%s' $prompt_c_green
    # add username to prompt if it doesn't match ME
    if [ "$USER" != "$ME" ] ; then
        printf '\u@'
    fi
    # add hostname
    printf "\h"
    # separator
    printf '%s:' $prompt_c_grey
    # add path
    printf '%s\w' $prompt_c_blue
    # add git info
    if true ; then
        printf ' %s[' $prompt_c_grey
        git status 2>/dev/null | \
          while read -r line; do
            local c=$((c+1))
            if ((c == 1)); then
                if [[ "$line" =~ ^'# Not currently on any branch.' ]] ; then
                    local branch='(none)'
                else
                    local branch=$(echo $line | awk '{ print $4 }')
                fi
                printf '%s%s' $prompt_c_yellow $branch
            elif [[ "$line" =~ ^'# Unmerged paths:' ]] ; then
                printf '%s!' $prompt_c_cyan
            elif [[ "$line" =~ ^'# Changes to be committed:' ]] ; then
                printf '%s~' $prompt_c_cyan
            elif [[ "$line" =~ ^'# Changed but not updated:' ]] ; then
                printf '%s*' $prompt_c_cyan
            fi
        done
        printf '%s]' $prompt_c_grey
    fi
    # add return code and close
    printf ' %s%s\$%s ' $prompt_c_grey $rc $prompt_c_reset
}


PROMPT_COMMAND=prompt_command
prompt_command() { PS1=$(prompt_string $?); }