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
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.
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 2017-04-25. If
you discover any rendering problems in this HTML version of the page,
or you believe there is a better 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 email@example.com
18 October 2014 PCAP_SETNONBLOCK(3PCAP)