tt_pattern_callback_add(3)

NAME
tt_pattern_callback_add - register a message-matching callback function

SYNOPSIS
#include <Tt/tt_c.h>

Tt_status tt_pattern_callback_add(Tt_pattern m,
	Tt_message_callback f);

DESCRIPTION
The tt_pattern_callback_add() function registers a callback function that will be automatically invoked by tt_message_receive(3) whenever a message matches the pattern.

The callback is defined in <Tt/tt_c.h>. If the callback returns TT_CALLBACK_CONTINUE, other callbacks will be run; if no callback returns TT_CALLBACK_PROCESSED, tt_message_receive(3) returns the message. If the callback returns TT_CALLBACK_PROCESSED, no further callbacks will be invoked for this event; tt_message_receive(3) does not return the message.

The m argument is the opaque handle for the pattern involved in this operation.

The f argument is the message callback to be run.

RETURN VALUE
Upon successful completion, the tt_pattern_callback_add() function returns the status of the operation as one of the following Tt_status values:

    The operation completed successfully.
    The ttsession(1) process is not running and the ToolTalk service cannot restart it.
    The pointer passed does not point to an object of the correct type for this operation.

SEE ALSO
Tttt_c(5), tt_pattern_register(3), tt_message_receive(3).