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Running an Init on Target System (3 of 16)

Running Environment Check Routine (DIFROM and DIFQ Variables)

The ENVIRONMENT CHECK ROUTINE is a field in the Package file that may indicate a routine to run as part of the init process. If the developer has included a routine name in the ENVIRONMENT CHECK ROUTINE field, this routine is run next. The routine is written by package developers to provide capabilities not possible from the init routines alone.

The developer's Environment Check routine may be used to explore the current system and halt the init process under certain conditions. For example, if a prior version of the package must be initialized before this one, a warning message might be displayed and the process halted.

The DIFQ variable is used to stop the init process. Within the Environment Check routine, the developer may kill DIFQ if conditions warrant the stopping of the init process.

The DIFROM variable is defined throughout the init process. It contains the version number of the incoming package. The developer can use it for checking in any pre- or post-init routines.


Reviewed/Updated: March 10, 2007