How to run a ZENworks Application Once and only Once: Other Options

After my first article, regarding running an application "Once and only Once per day", I received numerous questions about other ways to do this.  Two of the common questions were -

1. Once and Only Once per day on Specific Days of Week.
        This option allows administrators to run certain actions once a week on a machine, such as a Virus Scan every Monday or every Tuesday, etc....

Simply create the application as specified in the previous "Once and Only Once Per Day".  Then add a single additional system requirement based upon the environment variable %NDAY_OF_WEEK.  %NDAY_OF_WEEK returns a numeric string value equal to the day of the week with Sunday returning a value of "1" and Saturday returning a value of "7".  Therefore if you only want the application to run on Monday, then set a system requirement for the environment variable %NDAY_OF_WEEK to be equal to "2".  The tricky part is that the NDS variable %NDAY_OF_WEEK can't be directly tested in the environment variable section of the application object, even though it can be used in other parts of the application such as setting registry values or writing to a text file.  To get around this, set a variable such as TODAYIS in the login script by issuing a "DOS SET TODAYIS="%NDAY_OF_WEEK".  Then in your application object, test the variable "TODAYIS".

2. Once and only Once per machine - 

Often force run applications may try to run each time a new user logs onto a PC.  Depending on the application, this can become quite a nuisance.  Through a little tweak of the application object, this can be easily prevented.      

Each time an application is run, it will make a registry marker under HKLM .  This key is HKLM\Software\Netware\NAL\1.0\Distribute\[TREENAME]\[GUID].  The GUID is a unique number that will identify each application.  This number can be seen under the properties of the application in NWADMIN32 or ConsoleOne.  You can also identify the registry marker on machines that have run the application since the marker key will contain a value name called "DN" which is equivalent of the fully qualified name of the application object.

Simply Create a SYSTEM REQUIREMENT for the application that is equal to the HKLM registry key that is unique to the application object.  Set the requirement for the NON-EXISTENCE of the key.  This way the application will never try to run again on that machine.