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, -1 is returned and errbuf is filled in with an
       appropriate error message; otherwise, 0 is returned.   In  ``non-block-
       ing''  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(3), pcap_loop(3), pcap_next_ex(3), pcap_geterr(3)



                                18 October 2014            PCAP_SETNONBLOCK(3)