v7 t_rcv man page on unix.com

t_rcv(3NSL)					       Networking Services Library Functions					       t_rcv(3NSL)

NAME
       t_rcv - receive data or expedited data sent over a connection

SYNOPSIS
       #include <xti.h>

       int t_rcv(int fd, void *buf, unsigned int nbytes, int *flags);

DESCRIPTION
       This  routine is part of the XTI interfaces which evolved from the TLI interfaces. XTI represents the future evolution of these interfaces.
       However, TLI interfaces are supported for compatibility. When using a TLI routine that has the same name as an XTI routine,  the   tiuser.h
       header file must be used.  Refer to the	TLI COMPATIBILITY section for a description of differences between the two interfaces.

       This  function  receives  either  normal or expedited data. The argument fd identifies the local transport endpoint through which data will
       arrive, buf points to a receive buffer where user data will be placed, and nbytes specifies the size of the receive  buffer.  The  argument
       flags may be set on return from t_rcv() and specifies optional flags as described below.

       By default, t_rcv() operates in synchronous mode and will wait for data to arrive if none is currently available. However, if O_NONBLOCK is
       set by means of t_open(3NSL) or fcntl(2), t_rcv() will execute in asynchronous mode and will fail if no data  is  available.   See  TNODATA
       below.

       On  return  from  the call, if  T_MORE is set in flags, this indicates that there is more data, and the current transport service data unit
       (TSDU) or expedited transport service data unit (ETSDU) must be received in multiple t_rcv() calls. In  the  asynchronous  mode,  or  under
       unusual	conditions (for example, the arrival of a signal or  T_EXDATA event),  the  T_MORE flag may be set on return from the t_rcv() call
       even when the number of bytes received is less than the size of the receive buffer specified. Each t_rcv() with the  T_MORE flag set  indi-
       cates  that another t_rcv() must follow to get more data for the current TSDU. The end of the TSDU is identified by the return of a t_rcv()
       call with the  T_MORE flag not set. If the transport provider does not support the concept of a TSDU as indicated in the info  argument	on
       return  from  t_open(3NSL) or t_getinfo(3NSL), the  T_MORE flag is not meaningful and should be ignored.  If nbytes is greater than zero on
       the call to t_rcv(), t_rcv() will return  0 only if the end of a TSDU is being returned to the user.

       On return, the data is expedited if  T_EXPEDITED is set in flags.  If  T_MORE is also set, it indicates that the number of expedited  bytes
       exceeded  nbytes,  a signal has interrupted the	call, or that an entire ETSDU was not available (only for transport protocols that support
       fragmentation of ETSDUs).  The rest of the ETSDU will be returned by subsequent calls to   t_rcv() which will return with  T_EXPEDITED  set
       in  flags.  The	end  of the ETSDU is identified by the return of a  t_rcv() call with  T_EXPEDITED set and  T_MORE cleared.  If the entire
       ETSDU is not available it is possible for normal data fragments to be returned between the initial and final fragments of an ETSDU.

       If a signal arrives, t_rcv() returns, giving the user any data currently available.  If no data is available,  t_rcv()  returns	 -1,  sets
       t_errno	to  TSYSERR  and   errno to EINTR.  If some data is available,	t_rcv() returns the number of bytes received and  T_MORE is set in
       flags.

       In synchronous mode, the only way for the user to be notified of the arrival of normal or expedited data is to issue this function or check
       for  the  T_DATA or  T_EXDATA events using the t_look(3NSL) function.  Additionally, the process can arrange to be notified by means of the
       EM interface.

RETURN VALUES
       On successful completion, t_rcv() returns the number of bytes received. Otherwise, it returns  1 on failure and t_errno is set to  indicate
       the error.

VALID STATES
       T_DATAXFER, T_OUTREL.

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

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

       TLOOK	       An asynchronous event has occurred on this transport endpoint and requires immediate attention.

       TNODATA	       O_NONBLOCK was set, but no data is currently available from the transport provider.

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

       TOUTSTATE       The communications endpoint referenced by fd is not in one of the states in which a call to this function is valid.

       TPROTO	       This  error indicates that a communication problem has been detected between XTI and the transport provider for which there
		       is no other suitable XTI error (t_errno).

       TSYSERR	       A system error has occurred during execution of this function.

TLI COMPATIBILITY
       The XTI and TLI interface definitions have common names but use different header files. This, and other semantic  differences  between  the
       two interfaces are described in the subsections below.

   Interface Header
       The XTI interfaces use the header file, xti.h. TLI interfaces should not use this header.  They should use the header:

		 #include <tiuser.h>

   Error Description Values
       The t_errno value that can be set by the XTI interface and cannot be set by the TLI interface is:

		 TPROTO

ATTRIBUTES
       See attributes(5)  for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT Level		     |Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       fcntl(2), t_getinfo(3NSL), t_look(3NSL), t_open(3NSL), t_snd(3NSL), attributes(5)

SunOS 5.10							    28 Jan 2002 						       t_rcv(3NSL)
v7 man page for t_rcv
