t_sndudata(3)                       CLIX                       t_sndudata(3)



  NAME

    t_sndudata - Sends a data unit

  LIBRARY

    The Transport Layer Interface (TLI) Library (libnsl_s.a)

  SYNOPSIS

    #include <tiuser.h>

    int t_sndudata(
      int fd ,
      struct t_unitdata *unitdata );

  PARAMETERS

    fd         Identifies the local transport endpoint through which data will
               be sent.

    unitdata   Points to a t_unitdata structure.

  DESCRIPTION

    The t_sndudata() function is used in connectionless mode to send a data
    unit to another transport user.  The fd parameter 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;

    The netbuf structure is described in intro(3).  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 member of opt to 0.  In this case, the
    provider may use default options.

    If the len member of udata is 0, 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 (with t_open() or fcntl()), t_sndudata() will execute in asynchronous
    mode and will fail under such conditions.




  2/94 - Intergraph Corporation                                              1

  t_sndudata(3)                       CLIX                       t_sndudata(3)



    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.)

  RETURN VALUES

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

  ERRORS

    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 from accepting data at this time.

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

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

  RELATED INFORMATION

    Functions: intro(3), t_rcvudata(3),t_rcvuderr(3)

    AT&T UNIX System V Network Programmer's Guide




















  2                                              Intergraph Corporation - 2/94