t_sndudata(3N)    UNIX System V(Networking Support Utilities)    t_sndudata(3N)


NAME
      tsndudata - send a data unit

SYNOPSIS
      #include <tiuser.h>

      int tsndudata (int fd, struct tunitdata *unitdata);

DESCRIPTION
      This function is used in connectionless mode to send a data unit to
      another transport user.  fd identifies the local transport endpoint
      through which data will be sent, and unitdata points to a tunitdata
      structure containing the following members:

            struct netbuf addr;
            struct netbuf opt;
            struct netbuf udata;

      netbuf is described in intro(3N).  In unitdata, addr specifies the
      protocol address of the destination user, opt identifies protocol-
      specific options that the user wants associated with this request, and
      udata specifies the user data to be sent.  The user may choose not to
      specify what protocol options are associated with the transfer by setting
      the len field of opt to zero.  In this case, the provider may use default
      options.

      If the len field of udata is zero, and the sending of zero bytes is not
      supported by the underlying transport provider, tsndudata will return -1
      with terrno set to TBADDATA.

      By default, tsndudata operates in synchronous mode and may wait if flow
      control restrictions prevent the data from being accepted by the local
      transport provider at the time the call is made.  However, if ONDELAY or
      ONONBLOCK is set (via topen or fcntl), tsndudata will execute in
      asynchronous mode and will fail under such conditions.

      If tsndudata is issued from an invalid state, or if the amount of data
      specified in udata exceeds the TSDU size as returned in the tsdu field of
      the info argument of topen or tgetinfo, the provider will generate an
      EPROTO protocol error.  (See TSYSERR below.)  If the state is invalid,
      this error may not occur until a subsequent reference is made to the
      transport endpoint.

      On failure, terrno may be set to one of the following:

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

      TFLOW             ONDELAY or ONONBLOCK was set, but the flow control
                        mechanism prevented the transport provider from
                        accepting data at this time.



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t_sndudata(3N)    UNIX System V(Networking Support Utilities)    t_sndudata(3N)


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

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

      TBADDATA          nbytes is zero and sending zero bytes is not supported
                        by the transport provider.

SEE ALSO
      intro(3N), trcvudata(3N), trcvuderr(3N)
      Programmer's Guide:  Networking Interfaces

DIAGNOSTICS
      tsndudata returns 0 on successful completion and -1 on failure terrno
      is set to indicate the error.






































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