1PCAP_SETNONBLOCK(3PCAP)                                PCAP_SETNONBLOCK(3PCAP)
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NAME

6       pcap_setnonblock, pcap_getnonblock - set or get the state of non-block‐
7       ing mode on a capture device
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SYNOPSIS

10       #include <pcap/pcap.h>
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12       char errbuf[PCAP_ERRBUF_SIZE];
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14       int pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf);
15       int pcap_getnonblock(pcap_t *p, char *errbuf);
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DESCRIPTION

18       pcap_setnonblock() puts a capture handle into ``non-blocking'' mode, or
19       takes  it  out  of ``non-blocking'' mode, depending on whether the non‐
20       block argument is non-zero or zero.  It has no effect on ``savefiles''.
21       If  there  is  an error, -1 is returned and errbuf is filled in with an
22       appropriate error message; otherwise, 0 is returned.   In  ``non-block‐
23       ing''  mode,  an  attempt  to  read  from  the  capture descriptor with
24       pcap_dispatch() will, if no packets are currently available to be read,
25       return  0  immediately  rather  than  blocking  waiting  for packets to
26       arrive.  pcap_loop() and pcap_next() will not work in  ``non-blocking''
27       mode.
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29       When    first   activated   with   pcap_activate()   or   opened   with
30       pcap_open_live() , a capture handle is not in ``non-blocking mode'';  a
31       call  to  pcap_setnonblock() is required in order to put it into ``non-
32       blocking'' mode.
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RETURN VALUE

35       pcap_getnonblock() returns the current ``non-blocking''  state  of  the
36       capture  descriptor; it always returns 0 on ``savefiles''.  If there is
37       an error, -1 is returned and errbuf is filled in  with  an  appropriate
38       error message.
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40       errbuf is assumed to be able to hold at least PCAP_ERRBUF_SIZE chars.
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SEE ALSO

43       pcap(3PCAP), pcap_loop(3PCAP), pcap_next_ex(3PCAP), pcap_geterr(3PCAP)
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47                                18 October 2014        PCAP_SETNONBLOCK(3PCAP)
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