pcap_setnonblock(3) - NetBSD Manual Pages

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PCAP_SETNONBLOCK(3)                                        PCAP_SETNONBLOCK(3)




NAME

       pcap_setnonblock, pcap_getnonblock - set or get the state of non-block-
       ing 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 non-
       block 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(3) will, if no packets  are  currently  available  to  be
       read,  return 0 immediately rather than blocking waiting for packets to
       arrive.  pcap_loop(3) and pcap_next(3) will not  work  in  ``non-block-
       ing'' mode.

       When   first   activated   with   pcap_activate(3)   or   opened   with
       pcap_open_live(3) , 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 appro-
       priate error message.

       errbuf is assumed to be able to hold at least PCAP_ERRBUF_SIZE chars.


SEE ALSO

       pcap(3), pcap_next_ex(3), pcap_geterr(3)



                                 25 July 2018              PCAP_SETNONBLOCK(3)