void silc_log_set_callback(SilcLogType type, SilcLogCb cb,
                               void *context);

    Set `cb' as the default callback function for the logging channel
    `type'.  When SilcLog receives a message for this channel, it will
    trigger the callback function.  If the callback function returns TRUE
    SilcLog will assume the input as handled and won't run its default
    handler.

    You can disable/remove a callback by setting it to NULL or calling the
    function silc_log_reset_callbacks.  If set, the callback function
    must be in the form described by SilcLogCb.

    silc_log_reset_callbacks