NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | BACKWARD COMPATIBILITY | SEE ALSO | COLOPHON

PCAP_SET_IMMEDIATE_MODE(3PCAP)                PCAP_SET_IMMEDIATE_MODE(3PCAP)

NAME         top

       pcap_set_immediate_mode  - set immediate mode for a not-yet-activated
       capture handle

SYNOPSIS         top

       #include <pcap/pcap.h>

       int pcap_set_immediate_mode(pcap_t *p, int immediate_mode);

DESCRIPTION         top

       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         top

       pcap_set_immediate_mode() returns 0 on success or
       PCAP_ERROR_ACTIVATED if called on a capture handle that has been
       activated.

BACKWARD COMPATIBILITY         top

       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 Digital UNIX/Tru64 UNIX, immediate mode must be turned on
              by doing a BIOCMBIC ioctl, as documented in packetfilter(7),
              to clear the ENBATCH flag on the descriptor returned by
              pcap_fileno(3PCAP), after pcap_activate(3PCAP) is called;

              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         top

       pcap(3PCAP), pcap_create(3PCAP), pcap_activate(3PCAP)

COLOPHON         top

       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 2019-07-28.
       (At that time, the date of the most recent commit that was found in
       the repository was 2019-07-25.)  If you discover any rendering prob‐
       lems in this HTML version of the page, or you believe there is a bet‐
       ter or more up-to-date source for the page, or you have corrections
       or improvements to the information in this COLOPHON (which is not
       part of the original manual page), send a mail to man-pages@man7.org

                               22 August 2018 PCAP_SET_IMMEDIATE_MODE(3PCAP)