PCAP_OPEN_LIVE(3PCAP) PCAP_OPEN_LIVE(3PCAP)
NAME
pcap_open_live - open a device for capturing
SYNOPSIS
#include <pcap/pcap.h> char errbuf[PCAP_ERRBUF_SIZE]; pcap_t *pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, char *errbuf);DESCRIPTION
pcap_open_live() is used to obtain a packet capture handle to look at
packets on the network.
device is a string that specifies the
network device to open; on all supported Linux systems, as well as on
recent versions of macOS and Solaris, a
device argument of "any" or
NULL can be used to capture packets from all network interfaces. The
latter should not be confused with all available capture devices as
seen by
pcap_findalldevs(3PCAP), which may also include D-Bus, USB
etc.
snaplen specifies the snapshot length to be set on the handle. If
the packet data should not be truncated at the end, a value of 262144
should be sufficient for most devices, but D-Bus devices require a
value of 128MB (128*1024*1024).
promisc specifies whether the interface is to be put into promiscuous
mode. If
promisc is non-zero, promiscuous mode will be set,
otherwise it will not be set.
to_ms specifies the packet buffer timeout, as a non-negative value,
in milliseconds. (See
pcap(3PCAP) for an explanation of the packet
buffer timeout.)
errbuf is a buffer large enough to hold at least
PCAP_ERRBUF_SIZE chars.
RETURN VALUE
pcap_open_live() returns a
pcap_t * on success and
NULL on failure.
If
NULL is returned,
errbuf is filled in with an appropriate error
message.
errbuf may also be set to warning text when
pcap_open_live() succeeds; to detect this case the caller should
store a zero-length string in
errbuf before calling
pcap_open_live()
and display the warning to the user if
errbuf is no longer a zero-
length string.
SEE ALSO
pcap_create(3PCAP),
pcap_activate(3PCAP) 4 March 2024 PCAP_OPEN_LIVE(3PCAP)
