Message modification modules are used to change the content of messages being processed. They can be implemented using either the output module or the parser module interface. From the rsyslog core’s point of view, they actually are output or parser modules, it is their implementation that makes them special.
Currently, there do not exist any such modules, but could be written with the methods the engine provides. They could be used, for example, to:
Message modification modules are usually written for one specific task and thus usually are not generic enough to be reused. However, existing module’s code is probably an excellent starting base for writing a new module. Currently, the following modules existin inside the source tree