comment_later

#COMPARE VARIABLE WITH A LIST IN AN IF
[[ ! $COLOR =~ BLUE|RED|GREEN ]] && {
        echo "Incorrect options provided"
        exit 1
}

#GETOPS
#!/bin/bash

while getopts "brgc:" OPTION; do
    case $OPTION in
    b)
        COLOR=BLUE
        ;;
    r)
        COLOR=RED
        ;;
    g)
        COLOR=GREEN
        ;;
    c)
        COLOR=$OPTARG
        [[ ! $COLOR =~ BLUE|RED|GREEN ]] && {
            echo "Incorrect options provided"
            exit 1
        }
        ;;
    *)
        echo "Incorrect options provided"
        exit 1
        ;;
    esac
done

echo "Color is $COLOR"
exit 0;


#################################3
compare versions
function version_gt() { test "$(echo "$@" | tr " " "\n" | sort -V | head -n 1)" != "$1"; }
function version_le() { test "$(echo "$@" | tr " " "\n" | sort -V | head -n 1)" == "$1"; }
function version_lt() { test "$(echo "$@" | tr " " "\n" | sort -rV | head -n 1)" != "$1"; }
function version_ge() { test "$(echo "$@" | tr " " "\n" | sort -rV | head -n 1)" == "$1"; }