PCAP_SETNONBLOCK(3PCAP)                              PCAP_SETNONBLOCK(3PCAP)

NAME         top

       pcap_setnonblock,  pcap_getnonblock  -  set  or get the state of non-
       blocking mode on a capture device

SYNOPSIS         top

       #include <pcap/pcap.h>

       char errbuf[PCAP_ERRBUF_SIZE];

       int pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf);
       int pcap_getnonblock(pcap_t *p, char *errbuf);

DESCRIPTION         top

       pcap_setnonblock() puts a capture handle into ``non-blocking'' mode,
       or takes it out of ``non-blocking'' mode, depending on whether the
       nonblock argument is non-zero or zero.  It has no effect on
       ``savefiles''.  If there is an error, -1 is returned and errbuf is
       filled in with an appropriate error message; otherwise, 0 is
       returned.  In ``non-blocking'' mode, an attempt to read from the
       capture descriptor with pcap_dispatch() will, if no packets are
       currently available to be read, return 0 immediately rather than
       blocking waiting for packets to arrive.  pcap_loop() and pcap_next()
       will not work in ``non-blocking'' mode.

       When first activated with pcap_activate() or opened with
       pcap_open_live() , a capture handle is not in ``non-blocking mode'';
       a call to pcap_setnonblock() is required in order to put it into
       ``non-blocking'' mode.

RETURN VALUE         top

       pcap_getnonblock() returns the current ``non-blocking'' state of the
       capture descriptor; it always returns 0 on ``savefiles''.  If there
       is an error, -1 is returned and errbuf is filled in with an
       appropriate error message.

       errbuf is assumed to be able to hold at least PCAP_ERRBUF_SIZE chars.

SEE ALSO         top

       pcap(3PCAP), pcap_loop(3PCAP), pcap_next_ex(3PCAP),

COLOPHON         top

       This page is part of the libpcap (packet capture library) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual
       page, see ⟨⟩.  This page was obtained
       from the project's upstream Git repository
       ⟨⟩ on 2018-04-30.
       (At that time, the date of the most recent commit that was found in
       the repository was 2018-04-30.)  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

                               18 October 2014       PCAP_SETNONBLOCK(3PCAP)