Please note that the content of this book primarily consists of articles
available from Wikipedia or other free sources online. In the field of
computer network administration, pcap (packet capture) consists of an
application programming interface (API) for capturing network traffic.
Unix-like systems implement pcap in the libpcap library; Windows uses a
port of libpcap known as WinPcap. Monitoring software may use libpcap
and/or WinPcap to capture packets travelling over a network and, in
newer versions, to transmit packets on a network at the link layer, as
well as to get a list of network interfaces for possible use with
libpcap or WinPcap. Libpcap and WinPcap also support saving captured
packets to a file, and reading files containing saved packets;
applications can be written, using libpcap or WinPcap, to be able to
capture network traffic and analyze it, or to read a saved capture and
analyze it, using the same analysis code. A capture file saved in the
format that libpcap and WinPcap use can be read by applications that
understand that format.
