Wireshark-users: Re: [Wireshark-users] cannot capture packets from wifi router (Netgear WNDR3700)
From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Tue, 6 Dec 2011 09:55:43 -0800
On Dec 6, 2011, at 9:13 AM, Philip Anil-QBW348 wrote:

> 
>  > I had upgraded to ubuntu 11.10.
>  > $ dpkg --get-selections | grep libpcap
>  > libpcap0.8                                      install
>  >
>  > From the above, is it using libpcap 0.8 ?
> 
> No, use synaptic to check the version (1.1.1-8)
> 
> -------
> I run synaptic and observe the dependencies for wireshark. It lists libpcap0.8

If you start up Synaptic and look for "libpcap", it shows the Package as "libpcap0.8" and the Installed Version as "1.1.1-2".  The "0.8" in "libpcap0.8" is not a version number, it's just a random collection of ASCII characters tacked onto the package name. The version number is "1.1.1-2", meaning it's libpcap version 1.1.1 (and, presumably, the second, or maybe third, revision by Debian of the 1.1.1 version).

The "do not treat a random sequence of characters at the end of the package name as a version number, even if the sequence at the end matches the regular expression "[0-9.]*"" rule also applies to some other packages - the search for "libpcap" also found "libpcap-ruby1.8", the "Latest Version" of which (at least in Ubuntu 10.10) is 0.6-10.  In that case, the "1.8" apparently refers to Ruby 1.8 itself rather than to the version number of the libpcap bindings for Ruby.

I guess numbers are tacked onto the end of the package name if they think they need to maintain multiple flavors of the same piece of software.  Why they apparently thought that libpcap 0.7 and 0.8, for example, required different packages, but all dot-releases of libpcap after 0.8 didn't require their own packages, I have no idea; perhaps I didn't explicitly say "we're not going to break binary compatibility in libpcap" until 0.8, and they were unnecessarily afraid of source or binary compatibility breaking until then.  If it were up to me, there'd just be "libpcap", but it's not up to me....