BEGIN {
  "nix build -f '<nixpkgs>' nmap --no-link --json | jq -r '.[0].outputs.out'"|getline nmap
  db = nmap"/share/nmap/nmap-mac-prefixes"
  while((getline line < db) > 0)
    {
      n = split(line, rec, " ");
      prefix = rec[1]
      vendors[prefix] = rec[2]
      for (i=3; i<n; i++)
        vendors[prefix] = vendors[prefix]" "rec[i]
    }
  FS=" |%"
}

/ff:fe/ {
  eui64 = $4
  eui48 = eui64
  gsub(/ff:fe|fe80::/, "", eui48)
  gsub(":", "", eui48)
  mac = xor(strtonum("0x"eui48), lshift(1, 41))
  prefix = substr(sprintf("%X", mac), 0, 6)
  mac = sprintf("%012x", mac)
  prettymac = ""
  for (i=0; i<=6; i++)
  { prettymac = prettymac substr(mac,2*i+1,2)
    if (i < 5) prettymac = prettymac":"
  }
  printf("%25s\t%s\t%s\n", eui64, prettymac, vendors[prefix])
}