RE: (2) One for the regexp fans (nnnn:nnnn:nnnn)

[ybiC]

Another common format for MAC address display is nnnn:nnnn:nnnn (common amongst Cisco gear, anyway).   In either case, it's the same 12 hex digits, only the delimiter and break-points change.

Is simple code that handles both formats possible?
    cheers,
    ybiC

[nuance]

You could probably do something like:

if $str =~ m!\.!
    {$str =~ s/(\.?[0-9a-eA-E]*)/(substr("0$1", -2))/ge;}
else
    {$str =~ s/(:?[0-9a-eA-E]*)/(substr("0$1", -4))/ge;}

Nuance