tt_pattern_callback_add(3) — Subroutines
CDE
NAME
tt_pattern_callback_add − register a message-matching callback function
SYNOPSIS
#include <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_c.h(5). 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:
TT_OK
The operation completed successfully.
TT_ERR_NOMP
The ttsession(1) process is not running and the ToolTalk service cannot restart it.
TT_ERR_POINTER
The pointer passed does not point to an object of the correct type for this operation.