USEREXIT
The USEREXIT option specifies a user-defined exit that will be given control to manage an event.
Syntax
Parameters
- Yes
- Specifies that event logging to the user exit receiver begins automatically at server startup.
- No
- Specifies that event logging to the user exit receiver does not begin automatically at server startup. When this parameter has been specified, you must begin event logging manually by issuing the BEGIN EVENTLOGGING command.

module_name
Specifies the module name of the user exit. 
This is the name of a shared library
containing the exit. The module name can be either a fully qualified
path name or just the module name itself. If it is just the module
name, it is loaded from the current directory.
DLL_name
Specifies the DLL name that contains the user-exit function.
function
Specifies the name of the user-exit function in the DLL.
Examples

userexit yes dllname.dll dllmodulename

userexit yes fevent.exit 