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UDP_RECV(3)		   libdill Library Functions		   UDP_RECV(3)

NAME
       udp_recv	- receives an UDP packet

SYNOPSIS
	      #include <libdill.h>

	      ssize_t udp_recv(
		  int s,
		  struct ipaddr* addr,
		  void*	buf,
		  size_t len,
		  int64_t deadline);

DESCRIPTION
       UDP  is	an  unreliable message-based protocol defined in RFC 768.  The
       size of the message is limited.	The protocol has no initial or	termi-
       nal handshake.  A single	socket can be used to different	destinations.

       This function receives a	single UDP packet.

       s: Handle of the	UDP socket.

       addr:  Out  parameter.  IP address of the sender	of the packet.	Can be
       NULL.

       buf: Buffer to receive the data to.

       len: Size of the	buffer,	in bytes.

       deadline: A point in time when the operation should time	out,  in  mil-
       liseconds.   Use	the now	function to get	your current point in time.  0
       means immediate timeout,	i.e., perform the operation if possible	or re-
       turn  without  blocking	if  not.  -1 means no deadline,	i.e., the call
       will block forever if the operation cannot be performed.

       This function is	not available  if  libdill  is	compiled  with	--dis-
       able-sockets option.

RETURN VALUE
       In  case	 of success the	function returns size of the received message,
       in bytes.  In case of error it returns -1 and sets errno	to one of  the
       values below.

ERRORS
       o EBADF:	Invalid	handle.

       o EBUSY:	The handle is currently	being used by a	different coroutine.

       o ECANCELED: Current coroutine was canceled.

       o EINVAL: Invalid argument.

       o EMSGSIZE: The data won't fit into the supplied	buffer.

       o ENOTSUP: The handle does not support this operation.

       o ETIMEDOUT: Deadline was reached.

EXAMPLE
	      struct ipaddr local;
	      ipaddr_local(&local, NULL, 5555, 0);
	      struct ipaddr remote;
	      ipaddr_remote(&remote, "server.example.org", 5555, 0, -1);
	      int s = udp_open(&local, &remote);
	      udp_send(s1, NULL, "ABC",	3);
	      char buf[2000];
	      ssize_t sz = udp_recv(s, NULL, buf, sizeof(buf), -1);
	      hclose(s);

SEE ALSO
       mrecv(3)	   mrecvl(3)	msend(3)    msendl(3)	 now(3)	   udp_open(3)
       udp_open_mem(3) udp_recvl(3) udp_send(3)	udp_sendl(3)

libdill								   UDP_RECV(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLE | SEE ALSO

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