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.

       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

       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)

                                         18 October 2014                  PCAP_SETNONBLOCK(3PCAP)