echo_with_color

#!/bin/bash

echo_with_color(){
    # start and eof
    START='\033['
    EOF='\033[0m'

    # background
    BG_BLACK='40;'
    BG_RED='41;'
    BG_GREEN='42;'
    BG_YELOW='43;'
    BG_BLUE='44;'
    BG_PURPLE='45;'
    BG_DARK_GREEN='46;'
    BG_WHITE='47;'

    # font bold
    BOLD='1;'

    # font color
    BLACK='30m'
    RED='31m'
    GREEN='32m'
    YELOW='33m'
    BLUE='34m'
    PURPLE='35m'
    DARK_GREEN='36m'
    WHITE='37m'

    helpFunction(){
        echo ""
        echo "Usage: echo_with_color [-c font_color] [-g bg_color] [-b] <string>"
        echo ""
        echo -e "  -c \tFont color, support black(k), red(r), green(g), yellow(y),"
        echo -e "     \tblue(b), purple(p), dark_green(d) and white(w)"
        echo -e "  -g \tBackground color, support black(k), red(r), green(g), yellow(y),"
        echo -e "     \tblue(b), purple(p), dark_green(d) and white(w)"
        echo -e "  -b \tUse bold font"
        echo -e "  -h \tHelp"
        echo -e "  <string> \tThe string you want to display in terminal"
        exit 1
    }

    main(){
        # arguments
        key_color="c"
        key_bg="g"
        key_bold="b"
        key_help="h"

        if [ $# -eq 0 ] ; then
            helpFunction
        fi

        while getopts ":${key_color}:${key_bg}:${key_bold}${key_help}" arg
        do
           case "$arg" in
              ${key_color} )  font_color="$OPTARG" ;;
              ${key_bg}    )  bg_color="$OPTARG";;
              ${key_bold}  )  is_bold=true;;
              ${key_help}|?)  helpFunction ;; # Print helpFunction in case parameter is non-existent
           esac
        done

        # remove args above from arg list
        shift $(($OPTIND - 1))

        # string
        string=$1

        # start formulate string
        final_string="${START}"
        if [ "$is_bold" ]; then
           final_string="${final_string}${BOLD}"
        fi

        # background color
        if [ "$bg_color" ]; then
            case $bg_color in
                "k"|"black"     )  color=${BG_BLACK};;
                "r"|"red"       )  color=${BG_RED};;
                "g"|"green"     )  color=${BG_GREEN};;
                "y"|"yellow"    )  color=${BG_YELOW};;
                "b"|"blue"      )  color=${BG_BLUE};;
                "p"|"purple"    )  color=${BG_PURPLE};;
                "d"|"dark_green")  color=${BG_DARK_GREEN};;
                "w"|"white"     )  color=${BG_WHITE};;
                *) echo "Only support black(k), red(r), green(g), yellow(y), blue(b), purple(p), dark_green(d) and white(w) for background color." && exit 1;;
            esac
            final_string="${final_string}${color}"
        fi

        # font color
        if [ -z "$font_color" ]; then
           font_color="white"
        fi
        case $font_color in
            "k"|"black"     )  color=${BLACK};;
            "r"|"red"       )  color=${RED};;
            "g"|"green"     )  color=${GREEN};;
            "y"|"yellow"    )  color=${YELOW};;
            "b"|"blue"      )  color=${BLUE};;
            "p"|"purple"    )  color=${PURPLE};;
            "d"|"dark_green")  color=${DARK_GREEN};;
            "w"|"white"     )  color=${WHITE};;
            *) echo "Only support black(k), red(r), green(g), yellow(y), blue(b), purple(p), dark_green(d) and white(w) for font color." && exit 1;;
        esac
        final_string="${final_string}${color}"

        # end of string
        final_string="${final_string}${string}${EOF}"

        echo -e "${final_string}"
    }

    # Entry
    main $@
}

echo_with_color $@