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)