t_look(3)                                                         t_look(3)




 NAME    [Toc]    [Back]
      t_look() - look at the current event on a transport endpoint

 SYNOPSIS    [Toc]    [Back]
      #include <xti.h>            /* for X/OPEN Transport Interface - XTI */
      /* or */
      #include <tiuser.h>         /* for Transport Layer Interface - TLI  */

      int t_look (fd);
      int fd;

 DESCRIPTION    [Toc]    [Back]
      The t_look() function returns the current event on the transport
      endpoint specified by fd.  This function enables a transport provider
      to notify a transport user of an asynchronous event when the user is
      calling functions in synchronous mode.  Certain events require
      immediate notification of the user and are indicated by a specific
      error, [TLOOK], on the current or next function to be executed.

      This function also enables a transport user to poll a transport
      endpoint periodically for asynchronous events.

    Thread-Safeness    [Toc]    [Back]
      The t_look() function is safe to be called by multithreaded
      applications, and it is thread-safe for both POSIX Threads and DCE
      User Threads.  It has a cancellation point.  It is neither asynccancel
 safe nor async-signal safe.  Finally, it is not fork-safe.

    Valid States    [Toc]    [Back]
      All  - apart from T_UNINIT.

 XTI Internet Protocol-specific Information    [Toc]    [Back]
      As soon as a segment with the TCP urgent pointer set enters the TCP
      receive buffer, the event T_EXDATA is indicated.  T_EXDATA remains set
      until all data up to the byte pointed to by the TCP urgent pointer has
      been received.  If the urgent pointer is updated, and the user has not
      yet received the byte previously pointed to by the urgent pointer, the
      update is transparent to the user.

 RETURN VALUE    [Toc]    [Back]
      Upon success, t_look() returns a value that indicates which of the
      following allowable events has occurred, or returns zero if no event
      exists. One of the following events is returned:

      T_LISTEN           connection indication received.

      T_CONNECT          connect confirmation received.

      T_DATA             normal data received.





 Hewlett-Packard Company            - 1 -   HP-UX 11i Version 2: August 2003






 t_look(3)                                                         t_look(3)




      T_ERROR            (TLI ONLY) fatal error occurred.

      T_EXDATA           expedited data received.

      T_DISCONNECT       disconnect received.

      T_UDERR            datagram error indication.

      T_ORDREL           orderly release indication.

      T_GODATA           (XTI only) flow control restrictions on normal data
                         flow have been lifted. Normal data may be sent
                         again.

      T_GOEXDATA         (XTI only) flow control restrictions on expedited
                         data flow have been lifted. Expedited data may be
                         sent again.

 ERRORS    [Toc]    [Back]
      On failure, t_errno is set to one of the following:

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

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

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

 SEE ALSO    [Toc]    [Back]
      t_open(3), t_snd(3), t_sndudata(3).

 STANDARDS CONFORMANCE    [Toc]    [Back]
      t_look(): SVID2, XPG3, XPG4


 Hewlett-Packard Company            - 2 -   HP-UX 11i Version 2: August 2003