pcap_file() returns the standard I/O stream of the ``savefile,'' if a ``savefile''
was opened with
pcap_open_offline(3),
or
NULL, if a network device was opened with
pcap_create(3)
and
pcap_activate(3),
or with
pcap_open_live(3).
Note that the Packet Capture library is usually built with large file
support, so the standard I/O stream of the ``savefile'' might refer to
a file larger than 2 gigabytes; applications that use
pcap_file() should, if possible, use calls that support large files on the return
value of
pcap_file() or the value returned by
fileno(3)
when passed the return value of
pcap_file().
