T_SNDUDATA(3N)       INTERACTIVE UNIX System       T_SNDUDATA(3N)



          NAME
               t_sndudata - send a data unit

          SYNOPSIS
               #include <tiuser.h>

               int t_sndudata(fd, unitdata)
               int fd;
               struct t_unitdata *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 t_unitdata structure containing the
               following members:

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

               Netbuf is described in intro(3).  In unitdata, addr speci-
               fies the protocol address of the destination user, opt iden-
               tifies protocol-specific options that the user wants associ-
               ated 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, no data unit will be
               passed to the transport provider; t_sndudata will not send
               zero-length data units.

               By default, t_sndudata 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 O_NDELAY is set (via t_open
               or fcntl), t_sndudata will execute in asynchronous mode and
               will fail under such conditions.

               If t_sndudata is issued from an invalid state, or if the
               amount of data specified in udata exceeds the TSDU size as
               returned by t_open or t_getinfo, the provider will generate
               an EPROTO protocol error.  (See TSYSERR below.)

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

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

               [TFLOW]           O_NDELAY was set, but the flow control
                                 mechanism prevented the transport provider


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          T_SNDUDATA(3N)       INTERACTIVE UNIX System       T_SNDUDATA(3N)



                                 from accepting data at this time.

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

               [TSYSERR]         A system error has occurred during execu-
                                 tion of this function.

          SEE ALSO
               intro(3), t_rcvudata(3N), t_rcvuderr(3N).
               Programmer's Guide.

          DIAGNOSTICS
               The t_sndudata function returns 0 on successful completion
               and -1 on failure, and t_errno is set to indicate the error.








































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