Returns the unique and valid MAC address in format 00:16:3E:xx:xx:xx.

mac

#!/usr/bin/env bash
#
#: usage: mac <string>
#:
#: Returns the unique and valid MAC address in format 00:16:3E:xx:xx:xx.
#: The <string> uses to create an unique part of the address.

function help() {
    sed -En 's/^#:[[:space:]]?//p' $0
}

function hex() {
    local unique=$1 || $(hostname -f 2>/dev/null)
    echo 00163e$(echo $unique | md5)
}

function mac() {
    echo $(hex $1) | sed -e 's/\(..\)\(..\)\(..\)\(..\)\(..\)\(..\).*/\1:\2:\3:\4:\5:\6/'
}

if [[ $# -ne 1 ]]; then
    help && exit;
fi

mac "$@"