@(#) $Header: /tcpdump/master/libpcap/pcap_setnonblock.3pcap,v 1.3 2008-04-06 02:53:22 guy Exp $ Copyright (c) 1994, 1996, 1997 The Regents of the University of California. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that: (1) source code distributions retain the above copyright notice and this paragraph in its entirety, (2) distributions including binary code include the above copyright notice and this paragraph in its entirety in the documentation or other materials provided with the distribution, and (3) all advertising materials mentioning features or use of this software display the following acknowledgement: ``This product includes software developed by the University of California, Lawrence Berkeley Laboratory and its contributors.'' Neither the name of the University nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. PCAP_SETNONBLOCK 3PCAP "5 April 2008"
NAME
pcap_setnonblock, pcap_getnonblock - set or get the state of
non-blocking mode on a capture device
SYNOPSIS
#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
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.
RETURN VALUE
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
pcap(3PCAP), pcap_loop(3PCAP), pcap_next_ex(3PCAP), pcap_geterr(3PCAP)