VAX/VMS allows two different sorts of Processes to be created; Subprocesses
and Detached Processes. Subprocesses inherit the context of the creating
Process. Thus the same set of VAX/VMS Logical Names and Symbols is available
to them. However, each Subprocess reduces the deductable quotas of the
parent, restricting the number of subprocesses that may be created. Subprocesses
may either execute a DCL Command or an Executable Image, where a DCL Command
might be to execute a DCL Command procedure.
Detached Processes do not inherit any context from the parent and thus only
have access to the System and Group Logical Names. A Detached Process can only
execute an Executable Image and not a DCL Procedure. Special VAX/VMS privileges
are necessary in order to create a Detached Process.
UIPACK does not check that these privileges have been granted before attempting
to create a Detached Process. The Application Programmer must ensure that
the correct privileges are granted to either the account from which the
Server program is to be run or to the Server Program itself.