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Wireshark-dev: [Wireshark-dev] Possible New Option for Tshark?

From: Craig Votava <craig.votava@xxxxxxxxxxxxxxxxxx>
Date: Thu, 21 Oct 2010 15:29:36 -0500
Folks-

I wrote a Perl script that feeds pcap data to an instance of tshark running in a child process, then takes the decoded output to present to the user.

The problem is that I don't know when tshark is done sending output back to me. This becomes a problem when running on Windows machines, as you cannot do a non-blocking read on a file descriptor (more details on this at http://www.perlmonks.org/?node_id=864690).

At first, I looked for a blank line. That works pretty good, except when there's an error in the decoding, and the dissector throws in blank lines around it's error output.

My next thought was to "frame" all of my requests between some small, easily identified message (an ARP for example - my output never has ARPs to decode).

Then it occurred to me, that the right way is to have a tshark command line option, along the lines of --separator '---END OF DECODE', that would get tshark to print that out after each message was dissected.

What are your thoughts on this?

Thanks

-Craig

Craig Votava
Alcatel-Lucent