Function to increment increment a provide MAC address (or use autogenerated MAC)

increment-mac.sh

increment-mac() {
    local DESC="\e[1m${FUNCNAME}: Prints incrementing MAC address numbers\e[0m\n"
    [[ $1 = '--desc' ]] && { printf "${DESC}";return; }
    increment-mac_usage() {
        printf "\n${DESC}\n"
        
        printf "\e[2GUsage: ${FUNCNAME%%_*} [OPTIONS]\n\n"
        
        printf "\e[2GOptions:\n"
        printf "\e[4G -c, --count \e[20GNumber of MAC address to print\n"
        printf "\e[4G -m, --mac \e[20GStarting MAC address to use (default: autogenerated MAC)\n"
        
        printf "\n\e[2GEx:\n"
        printf "\e[4G \"${FUNCNAME%%_*} -c 5\" will output:\n"
        printf "\e[4G 52:54:ec:59:9a:e9\n"
        printf "\e[4G 52:54:ec:59:9a:ea\n"
        printf "\e[4G 52:54:ec:59:9a:eb\n"
        printf "\e[4G 52:54:ec:59:9a:ec\n"
        printf "\e[4G 52:54:ec:59:9a:ed\n\n"
        printf "\e[2GEx:\n"
        printf "\e[4G \"${FUNCNAME%%_*} -c 5 -m 8c:ae:4c:fd:9e:47\" will output:\n"
        printf "\e[4G 8c:ae:4c:fd:9e:47\n"
        printf "\e[4G 8c:ae:4c:fd:9e:48\n"
        printf "\e[4G 8c:ae:4c:fd:9e:49\n"
        printf "\e[4G 8c:ae:4c:fd:9e:4a\n"
        printf "\e[4G 8c:ae:4c:fd:9e:4b\n\n"

        printf "\n\e[2GNotes:\n"       
        
        printf "\e[4G - If -c,--count option is not used, or the argument provided\n"
        printf "\e[7G is not a whole number, the default count of 100 will be used\n\n"

        printf "\e[4G - If -m,--mac option is not used, or the argument provided\n"
        printf "\e[7G is not a valid MAC, a randomly generated MAC address will be used\n\n"
        }
    local MACREGEX='^([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})$'
    ARGS=`getopt -o c:m:h -l count:,mac:,help -n ${FUNCNAME} -- "$@"`
    eval set -- "$ARGS"
    while true ; do
        case "$1" in
            -c|--count) local COUNT="${2}";shift 2;;
            -m|--mac) local MAC="${2}";shift 2;;
            -h|--help) ${FUNCNAME}_usage;return 0;;
            --) shift;break;;
        esac
    done	
	[[ -n ${COUNT} && $((10#${COUNT})) =~ ^[0-9]+$ ]] || { [[ -n ${COUNT} ]] && printf "\e[1;31m${COUNT} is invalid.\e[0m\nUsing default of 100\n\n";local COUNT=100; }
	[[ -z ${COUNT} ]] && local COUNT=100
    [[ -n ${MAC} && ${MAC} =~ ${MACREGEX} ]] || { [[ -n ${MAC} ]] && printf "\e[1;31m${MAC} is not a valid MAC Address.\e[0m\nUsing autogenerated MAC\n\n";local MAC=; }
	if [[ -z ${MAC} ]];then 
		local START=$(printf "%d\n" 0x"$(printf '5254%02x%02x%02x%02x\n' $((RANDOM%256)) $((RANDOM%256)) $((RANDOM%256)) $((RANDOM%256)))")
	else
		local START=$(printf "%d\n" "0x${MAC//:/}")
	fi
	printf "%x\n" $(seq ${START} 1 $(((${START}-1)+${COUNT})))|sed 's/..\B/&:/g'
}