ACS can be used to define a prefix which precedes the name for all file/JV names which are not recorded in the alias catalog.
This allows a user to create a separate “subcatalog” under his or her user ID and to create, process, and delete files/JVs in it independent of the other files which belong to the same user ID but are not part of the subcatalog.
A subcatalog of this type is identified by a partially qualified file name (the last character must be a period). This partially qualified name is inserted as a prefix for the file names entered with all commands and macros, provided these file names do not contain a user ID and have not been recorded in alias catalog entries.
One of the typical applications of the prefix function is when several users share the same BS2000 user ID. By using an appropriate prefix rule (e.g. prefix=name/project), each user can work in a separate subcatalog and make use of commands and programs for file processing without having to manually insert the prefix before each file name. The same procedures with “fixed” file names can also be used without changes on any subcatalog.
The rules for prefix insertion are defined as follows:
If the file/JV name has been entered as an alias in the alias catalog of the task, no prefix is inserted. In other words, such files/JVs can still be accessed without a user ID (e.g. START-PROGRAM FROM-FILE=EDT), but no prefix will be inserted.
No prefix is inserted if the file/JV name contains a user ID which differs from that of the current task.
If the file/JV name contains the user's own user ID, the prefix will be inserted only if it consists of just a catalog ID and if the file name itself does not contain a catalog ID.
A single catalog ID can be defined as a prefix (in the form “:catid:”). It is then inserted before all file/JV names associated with the user's own user ID in the current task. This is effectively equivalent to a temporary, task-local change to the default catalog ID. Only catalog IDs on the system-local (pubsets of the home system) may be specified; RFA is not supported by ACS.
If the file name and the prefix contain a catalog ID, the prefix is not inserted.
File names with the user ID TSOS are never supplemented with a prefix.
If the file/JV name contains a catalog ID (but not a user ID), the prefix is inserted immediately after the catalog ID.
If the file/JV name becomes too long (i.e. > 54 characters) as a result of inserting the prefix, the file name is considered invalid and rejected.
An option can be used to control whether a prefix is to be inserted even if a file/JV name already begins with the same string that is defined as the prefix.
Restrictions when inserting a prefix
When a prefix for file names is defined for a task, the prefix is only inserted before file names which are specified without a user ID and not recorded in the alias catalog.
START-EXECUTABLE-PROGRAM FROM-FILE=EDT is converted to: START-EXECUTABLE-PROGRAM FROM-FILE=<prefix.>EDT
Any file/JV name that is to be supplied with a prefix must not be contained as an alias in the alias catalog of the task.
The inserted prefix is a component of the name under which the file/JV is cataloged in the TSOSCAT file catalog. It must therefore be defined with ACS or explicitly specified as a component of the file/JV name whenever the file is subsequently accessed.
The specified file/JV name must comply with naming conventions even if another prefix is added later.
If DAMP files are created under the user's own user ID and prefix insertion is used, all internal files of DAMP are also addressed with the preceding prefix.