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PCAP_GET_REQUIRED_SELECT_TILibrary)FunctionPCAP_GET_REQUIRED_SELECT_TIMEOUT(3)

NAME
       pcap_get_required_select_timeout	- get a	file descriptor	on which a se-
       lect() can be done for a	live capture

SYNOPSIS
       #include	<pcap/pcap.h>

       struct timeval *pcap_get_required_select_timeout(pcap_t *p);

DESCRIPTION
       pcap_get_required_select_timeout() returns, on UNIX,  a	pointer	 to  a
       struct  timeval	containing  a  value  that must	be used	as the minimum
       timeout in select(2), poll(2), epoll_wait(2),  and  kevent()  calls  if
       pcap_get_selectable_fd(3) returns PCAP_ERROR.

       The  timeout  that should be used in those calls	must be	no larger than
       the	smallest      of      all      timeouts	     returned	    by
       pcap_get_required_select_timeout()  for devices from which packets will
       be captured.

       The device for which pcap_get_selectable_fd() returned PCAP_ERROR  must
       be  put	in  non-blocking mode with pcap_setnonblock(3),	and an attempt
       must always be made to read packets from	the device when	the  select(),
       poll(), epoll_wait(), or	kevent() call returns.

       Note that a device on which a read can be done without blocking may, on
       some platforms, not have	any packets to read if the packet buffer time-
       out  has	 expired.   A call to pcap_dispatch(3) or pcap_next_ex(3) will
       return 0	in this	case, but will not block.

       pcap_get_required_select_timeout() is not available on Windows.

RETURN VALUE
       A pointer to a struct timeval is	returned if the	timeout	 is  required;
       otherwise NULL is returned.

BACKWARD COMPATIBILITY
       This  function  became available	in libpcap release 1.9.0.  In previous
       releases, select(), poll(), epoll_wait(), and kevent() cannot  be  used
       on any capture source for which pcap_get_selectable_fd returns -1.

SEE ALSO
       pcap(3),	 pcap_get_selectable_fd(3), select(2), poll(2),	epoll_wait(2),
       kqueue(2)

				 25 July 20PCAP_GET_REQUIRED_SELECT_TIMEOUT(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | BACKWARD COMPATIBILITY | SEE ALSO

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