Re: One for the regexp fans

[davorg]

Do MAC addresses always have six sections? If so, you could do something like this:

my $fmt = '%02x' x 6;
$mac = sprintf $fmt, map hex, split /\./, $mac;

It's still two lines, but the first is just there so I don't have to type '%02x' six times :)

Oh, and it's not really a regex solution - sorry!

--
<http://www.dave.org.uk>

European Perl Conference - Sept 22/24 2000, ICA, London
<http://www.yapc.org/Europe/>

[Odud]

Nice idea - I'd got a bit hung up on the solution being an RE. I think that they are always "dotted-sex!" format (the string comes from calling netstat -i and I have to cope with the different formats produced by HP-UX, AIX, and OSF1). Perhaps we can have a pint together at yapc::Europe?

[Anonymous Monk]

Not much to offer except curiosity and frustration on my own efforts. On your HP-UX interface queries, does it render "raw" (no colon or dash delimiter) 12 characters, with leading zeroes, or does it provide you with the delimiter. I'm using "lanscan -a" on the HP-UX interfaces, getting my 12 char MAC address, trying to insert colons every two characters, then stripping the lead zeroes. That's my fallback position after I baked my brain on making the DEC OSF1 "netstat -i | grep '<Link>' |egrep -v "s10|lo0|ppp0"|awk '{print $1}' | sort -u`" system call for-loop kludge work, which at least renders multi-line output of valid, live interfaces. If I can get either to work, I'll die a happy man...as I thrust my head through the display :-) ...---... SOS !!! -raddude

[Odud]

In the end I decided that I didn't need the :s - and so I just take whatever format the OS (HP-UX, AIX, or OSF/1) reports and use that. The justification being that if you need to get involved with MAC addresses then you can probably cope with the different formats!

[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

[merlyn]

davorg says:

It's still two lines, but the first is just there so I don't have to type '%02x' six times :)

Well then, don't!

$mac = sprintf "%02x" x 6, map hex, split /\./, $mac;

There. One line. :)

-- Randal L. Schwartz, Perl hacker