pcap_set_immediate_mode(3pcap) — Linux manual page
PCAP_SET_IMMEDIATE_MODE(3PCAP) PCAP_SET_IMMEDIATE_MODE(3PCAP)
NAME
pcap_set_immediate_mode - set immediate mode for a not-yet-
activated capture handle
SYNOPSIS
#include <pcap/pcap.h>
int pcap_set_immediate_mode(pcap_t *p, int immediate_mode);
DESCRIPTION
pcap_set_immediate_mode() sets whether immediate mode should be
set on a capture handle when the handle is activated. In
immediate mode, packets are always delivered as soon as they
arrive, with no buffering. If immediate_mode is non-zero,
immediate mode will be set, otherwise it will not be set.
RETURN VALUE
pcap_set_immediate_mode() returns 0 on success or
PCAP_ERROR_ACTIVATED if called on a capture handle that has been
activated.
BACKWARD COMPATIBILITY
This function became available in libpcap release 1.5.0. In
previous releases, if immediate delivery of packets is required:
on FreeBSD, NetBSD, OpenBSD, DragonFly BSD, macOS, and
Solaris 11, immediate mode must be turned on with a
BIOCIMMEDIATE ioctl(2), as documented in bpf(4), on the
descriptor returned by pcap_fileno(3PCAP), after
pcap_activate(3PCAP) is called;
on Solaris 10 and earlier versions of Solaris, immediate
mode must be turned on by using a read timeout of 0 when
opening the device (this will not provide immediate
delivery of packets on other platforms, so don't assume
it's sufficient);
on Windows, immediate mode must be turned on by calling
pcap_setmintocopy() with a size of 0.
On Linux, with previous releases of libpcap, capture devices are
always in immediate mode; however, in 1.5.0 and later, they are,
by default, not in immediate mode, so if
pcap_set_immediate_mode() is available, it should be used.
On other platforms, capture devices are always in immediate mode.
SEE ALSO
pcap(3PCAP), 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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