NAME

t_look - look at the current event on a transport endpoint

SYNOPSIS

#include <xti.h>

int t_look(int fd);

DESCRIPTION

Parameters	Before call	After call
fd	x	/

This 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. Details on events which cause functions to fail [TLOOK] may be found in Events and TLOOK Error Indication.

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

VALID STATES

ALL - apart from T_UNINIT

ERRORS

On failure, t_errno is set to one of the following:

[TBADF]

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

[TPROTO]

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

[TSYSERR]

A system error has occurred during execution of this function.

RETURN VALUE

Upon success, t_look() returns a value that indicates which of the 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.

T_EXDATA

Expedited data received.

T_DISCONNECT

Disconnection received.

T_UDERR

Datagram error indication.

T_ORDREL

Orderly release indication.

T_GODATA

Flow control restrictions on normal data flow that led to a [TFLOW] error have been lifted. Normal data may be sent again.

T_GOEXDATA

Flow control restrictions on expedited data flow that led to a [TFLOW] error have been lifted. Expedited data may be sent again.

On failure, -1 is returned and t_errno is set to indicate the error.

SEE ALSO

t_open(), t_snd(), t_sndudata().

APPLICATION USAGE

Additional functionality is provided through the Event Management (EM) interface.

CHANGE HISTORY

Issue 4

The SYNOPSIS section is placed in the form of a standard C function prototype.