#!/bin/bash

function highlight() {
    if [ "$1" == "--help" ] || [ "$1" == "-h" ]; then
        printf "usage: ./highlight [-i] '<regex>'[red|white|green|cyan]\n"
        printf "  -[h?]  : this message\n"
        printf "  -i     : case insensitive matching\n"
        printf "  <regex>: standard regex, some character such as | must be escaped\n"
        printf "  [rwgc] : the color to highlight with, white is default\n"
        printf "\n"
        return;
    fi
    if [ "$1" == "-i" ]; then
        case_ins="i"
        shift
    else
        case_ins=""
    fi

    regex=$1
    color_code=37

    case "$2" in
    r|red)
        color_code=31
    ;;
    w|white)
        color_code=37
    ;;
    g|green)
        color_code=32
    ;;
    c|cyan)
        color_code=36
    ;;
    esac

    sed -e "s/\($regex\)/\[1;$color_code;40m\1\/g$case_ins"
}