pcap_fileno - get the file descriptor for a live capture
#include <pcap/pcap.h>
int pcap_fileno(pcap_t *p);
If p refers to a network device that was opened for a live capture using
a combination of pcap_create() and pcap_activate(), or using
pcap_open_live(), pcap_fileno() returns the file descriptor from
which captured packets are read.
If p refers to a ``savefile'' that was opened using
functions such as pcap_open_offline() or pcap_fopen_offline(),
a ``dead'' pcap_t opened using pcap_open_dead(), or a
pcap_t that was created with pcap_create() but that has not
yet been activated with pcap_activate(), it returns -1.
pcap(3), pcap_create(3), pcap_activate(3), pcap_open_live(3),
pcap_open_offline(3), pcap_fopen_offline(3), pcap_open_dead(3)