Wireshark-dev: Re: [Wireshark-dev] Add restrictions to arguments of dumpcap

From: Gerald Combs <gerald@xxxxxxxxxxxxx>
Date: Wed, 06 May 2009 12:10:36 -0700

Michael Tüxen wrote:
> Dear all,
> 
> I'm implementing the support of simultaniously
> capturing from multiple interfaces in dumpcap.
> The first step, the support of writing in pcapng is done.
> 
> Now I need to be able to specify multiple interfaces
> on the command line and also provide interface
> specific options. I think something like
> 
> dumpcap -n -i lo0 -f udp -s 100 -y whatever -i en0 -s 0 -f sctp - y  
> whatever
> 
> should be possible. So I would like to require that you
> need to specify the -i options before -f, -s, and -y.
> The values specified by -f, -s, and -y only apply to
> the interface specified before using the -i option.
> It is also required to specify -n for using pcapng.
> 
> What do you think? Is this acceptable?

What happens if you specify a -f/-s/-y option only once with multiple
interfaces, e.g.

  dumpcap -i en0 -f udp -i en1

Would "-f udp" apply to both interfaces or just en1?