ultrix man page for t_snd

t_snd(3xti)															       t_snd(3xti)

Name
       t_snd - send data or expedited data over a connection

Syntax
       #include <xti.h>

       int t_snd(fd, buf, nbytes, flags)
       int fd;
       char *buf;
       unsigned nbytes;
       int flags;

Arguments
       fd	 Identifies the local transport endpoint over which data should be sent.

       buf	 Points to the user data.

       nbytes	 Specifies the number of bytes of user data to be sent.

       flags	 Specifies any optional flags described below:

		 T_EXPEDITED   If  set	in  flags,  the  data  is  sent  as  expedited data and is subject to the interpretations of the transport
			       provider.

		 T_MORE        If set in flags, this indicates to the transport provider that the transport service data unit (TSDU) or  expedited
			       transport  service  data unit (ETSDU) is being sent through multiple calls. Each with the T_MORE flag set indicates
			       that another follows with more data for the current TSDU.  The end of TSDU or ETSDU is identified by  a	call  with
			       the  T_MORE  flag  not set. Use of T_MORE enables a user to break up large logical data units without losing bound-
			       aries of those units at the other end of the connection. The flag implies nothing about how the	data  is  packaged
			       for  transfer  below  the transport interface.  If the transport provider does not support the concept of a TSDU as
			       indicated in the info argument on return from or the T_MORE flag is not meaningful and should be ignored.

Description
       This function is used to send either normal or expedited data.

       By default, operates in synchronous mode and may wait if flow control restrictions prevent the data from being accepted by the local trans-
       port  provider  at the time the call is made. However, if O_NONBLOCK is set by means of or executes in asynchronous mode, and fails immedi-
       ately, if there are flow control restrictions. The process can arrange to be informed when the flow control  restrictions  are  cleared	by
       means of

       On  successful completion, returns the number of bytes accepted by the transport provider. Normally, this equals the number of bytes speci-
       fied in nbytes. However, if O_NONBLOCK is set, it is possible that only part of the data is accepted by the  transport  provider.  In  this
       case,  returns a value that is less than the value of nbytes. If nbytes is zero and sending of zero octets is not supported by the underly-
       ing transport service, the returns -1 with t_errno set to [TBADDATA].

       The size of each TSDU or ETSDU must not exceed the limits of the transport provider as returned in the TSDU or ETSDU  fields  of  the  info
       argument of or Failure to comply results in protocol error (see [TSYSERR] under the DIAGNOSTICS section).

       The error [TLOOK] may be returned to inform the process that an event, such as a disconnect, has occurred.

       It  is  important  to  remember that the transport provider treats all users of a transport endpoint as a single user. Therefore if several
       processes issue concurrent calls, then the different data may be intermixed.

       --------------------------------------
       Parameters   Before Call   After Call
       --------------------------------------
       fd	    x		  /
       buf	    x(x)	  /

       nbytes	    x		  /
       flags	    x		  /
       --------------------------------------

Return Values
       Upon successful completion, t_errno returns the number of bytes accepted by the transport provider. On failure, a value of -1 is  returned,
       and t_errno is set to indicate the error.

       In  asynchronous mode, if the number of bytes accepted by the transport provider is less than the number of bytes requested, this may indi-
       cate that the transport provider is blocked due to flow control.

Diagnostics
       On failure, t_errno is set to one of the following:

       [TBADF]		   The specified file descriptor does not refer to a transport endpoint.

       [TOUTSTATE]	   The function was issued in the wrong sequence on the transport endpoint referenced by fd.

       [TBADFLAG]	   An invalid flag was specified.

       [TFLOW]		   O_NONBLOCK was set, but the flow control mechanism prevented the transport provider from accepting  any  data  at  this
			   time.

       [TBADDATA]	   Illegal amount of data: zero octets is not supported.

       [TLOOK]		   An asynchronous event has occurred on the transport endpoint.

       [TNOTSUPPORT]	   This function is not supported by the underlying transport provider.

       [TSYSERR]	   A  system  error has occurred during execution of this function. A protocol error may not cause t_errno to fail until a
			   subsequent access of the transport endpoint.

See Also
																       t_snd(3xti)