Looks at the current event on a transport end point.
Transport Layer Interface Library (libtli.a)
#include <tiuser.h>int t_look(fd)
int fd;
The t_look subroutine returns the current event on the transport end point specified by the fd parameter. This subroutine enables a transport provider to notify a transport user of an asynchronous event when the user is issuing 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 subroutine executed.
This subroutine also enables a transport user to poll a transport end point periodically for asynchronous events.
| Item | Description |
|---|---|
| fd | Specifies the transport end point. |
On successful completion, the t_look subroutine returns a value that indicates which of the allowable events has occurred, or returns a value of 0 if no event exists. One of the following events is returned:
| Event | Description |
|---|---|
| T_CONNECT | Indicates connect confirmation received. |
| T_DATA | Indicates normal data received. |
| T_DISCONNECT | Indicates disconnect received. |
| T_ERROR | Indicates fatal error. |
| T_EXDATA | Indicates expedited data received. |
| T_LISTEN | Indicates connection indication received. |
| T_ORDREL | Indicates orderly release. |
| T_UDERR | Indicates datagram error. |
If the t_look subroutine is unsuccessful, a value of -1 is returned, and the t_errno variable is set to indicate the error.
If unsuccessful, the t_errno variable is set to one of the following:
| Value | Description |
|---|---|
| TBADF | The specified file descriptor does not refer to a transport end point. |
| TSYSERR | A system error has occurred during execution of this function. |