One of the most basic principles to understand on the AS/400, iSeries and System i platform is the object file system. To effectively administer and operate the platform it's important to comprehend the underlying file system structure and semantics.

An "object" is a basic building block of the entire file system found on the AS/400 platform. Put very simply, everything that is stored outside of the IFS portion (which is a special part of the system) is referred to as an object. Objects includes libraries, files and even configuration pieces of the operating system like output queues and user profiles.

What distinguishes objects from one another is the object type and the attribute. The type denotes if the object is a library, database file and so on. But at the root of the file system, from a user perspective anyway, are libraries. Within libraries are the individual objects such as files, programs and so forth. A library cannot contain another library and at the root of the file system can be only libraries. Still with me so far?

To review objects and where they are stored you simply use the generic Work with Objects command WRKOBJ. This command allows you to review objects that are stored within a library. WRKOBJ will display the object name, type, library it is stored in, description and the attribute. The attribute is another field that can help you identify what exactly an object is. For example an object can have a type of file and an attribute of physical file.

Object names are limited to ten characters or less and cannot start with a number. IBM supplied objects (ie objects that are a part of the core operating system that you should not mess around with) always start with the letter Q. There are two exceptions however and those are the QGPL and QUSRSYS libraries which are generally used by a system administrator to store non system objects like output queues and some initial CL programs since they are a part of the default library list.

As you need to work with specific object types, like changing something about a library you will need to use specific commands for the object type. For instance in the case of a library you would use the Work with Library command WRKLIB. Some of the more popular object specific commands include Change Physical File or CHGPF, Work With File or WRKF and Create Duplicate Object or CRTDUPOBJ.

One super tip is to learn how to use the Programming Development Manager, more commonly known as PDM to work with objects. Traditionally used by programmers for cranking out lines of RPG, CL and DDS specs, PDM is tailor made for working with libraries and objects contained within libraries.

With PDM you can change objects, copy them, delete and more very quickly and easily. PDM even has nifty position to fields and other shortcuts built right in that make finding and working with an object quick and easy. You also have the capability to filter object lists by name (generic or with the * wildcard) type and object attribute.

John Andersen is an author, seasoned AS/400 administrator and IT manager. To discover how to quickly and easily get up to speed with your AS/400 and iSeries platform checkout Midrange Jump Start dot com.