Name

t_look − look at the current event on a transport endpoint

Syntax

#include <xti.h>
int t_look(fd)
int fd;

Arguments

fd
Identifies the transport endpoint where the current event is returned.

Description

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 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 function to be executed. 

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

Return Value

Upon successful completion, 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
Disconnect received

T_UDERR
Datagram error indication

T_ORDREL
Orderly release indication

T_GODATAFlow control restrictions on normal data flow have been lifted. Normal data can be sent again. 

T_GOEXDATA
Flow control restrictions on expedited data flow have been lifted. Expedited data can be sent again.

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

Diagnostics

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

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

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

See Also

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