pcap_open_live(3pcap) — Linux manual page
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)
COLOPHON
This page is part of the libpcap (packet capture library)
project. Information about the project can be found at
⟨http://www.tcpdump.org/⟩. If you have a bug report for this
manual page, see ⟨http://www.tcpdump.org/#patches⟩. This page
was obtained from the project's upstream Git repository
⟨https://github.com/the-tcpdump-group/libpcap.git⟩ on 2024-06-14.
(At that time, the date of the most recent commit that was found
in the repository was 2024-06-04.) If you discover any rendering
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