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, PCAP_ERROR 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(3PCAP)
       will,  if  no packets are currently available to be read, return 0 immediately rather than
       blocking waiting for packets to arrive.  pcap_loop(3PCAP) and  pcap_next(3PCAP)  will  not
       work in ``non-blocking'' mode.

       When  first  activated  with pcap_activate(3PCAP) or opened with pcap_open_live(3PCAP) , 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, PCAP_ERROR  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_next_ex(3PCAP), pcap_geterr(3PCAP)

                                           25 July 2018                   PCAP_SETNONBLOCK(3PCAP)