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TERM_ATTACH(3)		    libdill Library Functions		  TERM_ATTACH(3)

NAME
     term_attach - creates TERM protocol on top of underlying socket

SYNOPSIS
	    #include <libdill.h>

	    int term_attach(
		int s,
		const void* buf,
		size_t len,
		int64_t deadline);

DESCRIPTION
     TERM  is a protocol that implements clean terminal handshake between peers.
     When creating the protocol instance user specifies the terminal message  to
     use.   When  closing  the protocol, terminal messages are exchanged between
     peers in both directions.	After the protocol shuts down the peers agree on
     their position in the message stream.

     This function instantiates TERM protocol on top of the underlying protocol.

     s: Handle of the underlying socket.  It must be a message protocol.

     buf: The terminal message.

     len: Size of the terminal message, in bytes.

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

     The socket can be cleanly shut down using term_detach function.

     This  function is not available if libdill is compiled with --disable-sock-
     ets option.

RETURN VALUE
     In case of success the function returns newly created  socket  handle.   In
     case of error it returns -1 and sets errno to one of the values below.

ERRORS
     * EBADF: Invalid handle.

     * ECANCELED: Current coroutine was canceled.

     * EMFILE: The maximum number of file descriptors in the process are already
       open.

     * ENFILE:	The maximum number of file descriptors in the system are already
       open.

     * ENOMEM: Not enough memory.

     * ENOTSUP: The handle does not support this operation.

     * EPROTO: Underlying socket is not a message socket.

     * ETIMEDOUT: Deadline was reached.

EXAMPLE
	    s = term_attach(s, "STOP", 4);
	    ...
	    /* Send terminal message to the peer. */
	    term_done(s, -1);
	    /* Process remaining inbound messages. */
	    while(1) {
		char buf[256];
		ssize_t sz = mrecv(s, buf, sizeof(buf), -1);
		/* Check whether terminal message was received from the peer. */
		if(sz < 0 && errno == EPIPE) break;
		frobnicate(buff, sz);
	    }
	    s = term_detach(s);

SEE ALSO
     hclose(3) mrecv(3) mrecvl(3) msend(3) msendl(3)  now(3)  term_attach_mem(3)
     term_detach(3) term_done(3)

libdill 							  TERM_ATTACH(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=term_attach&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>

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