[EXT] Convert an integer to a MAC address in unlang / expr

[Brian Julin]

James Wood <james.wood at purplewifi.com>

> Thanks Brian and Alan for your advice.
>
> If I just perform the mask transform on the last octet this works but of
> course it returns the result as an int, so I can't find any built in
> function to get that back to hex.

> This is what I've ended up with; please let me know if you feel there is a
> better/cleaner way without needing the IF statement

Take only the first digit into %{6}.  Then mask with 0xC.  Then divide by 16.

0/16 is 0, 64/16 is 4, 128/16 is 8 and 192/16 is 12.

So then just one if statement makes 12 into "C" and you can just put
that back in with a hard coded 0 after it... no need to convert 0 to "0"
or 4 to "4" or 8 to "8", they should stringify on their own.