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:

        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.

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