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)

                                                  5 April 2008                           PCAP_SETNONBLOCK(3PCAP)