If you're looking for information on the libpcap file format, you might find what you need here: http://wiki.wireshark.org/Development/LibpcapFileFormat.
But if you're looking for "a utility which should take the pcap as input and produce output on the screen in user freindly [sic] way.", well then look no further: http://www.wireshark.org/download.html. Well, OK there are plenty of other packet sniffers out there, so feel free to keeping looking. Here's a start: http://en.wikipedia.org/wiki/Packet_analyzer#Notable_packet_analyzers.
Or maybe what you're really looking for is a way to add your own proprietary protocol dissector to Wireshark? These should help you:
From: [email protected] on behalf of prashanth joshi
Sent: Mon 2/22/2010 9:49 PM
To: [email protected]
Subject: [Wireshark-dev] Need help regarding interpreting a pcap file.
what is the format fo the data stored in the pcaps?
I have got a requirement where in I need to read a pcap and then the contents of the packets need to be displayed on the screen. The packets have proprietary information. How do I go about this? Any suggestions would be heartily welcome. The requirement is that of a utility which should take the pcap as input and produce out put on the screen in user freindly way.
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