Editing Object (IBM i) (section)

==Overview==

IBM i objects share similarities with objects in [[object-oriented programming]], but there are differences as well. There are similarities in that when [[Volatile memory|storage]] is allocated for something, that something is of a specific type, and only a specific set of programs are allowed to act upon that object. There are differences in that IBM i objects cannot be inherited, and the set of object types is fixed, and only IBM has the ability to create new ones.

The number of object '''types''' is huge and a small subset of them are available to users. The human readable form of the object type is always a three to six character mnemonic preceded by an asterisk. What follows is a short list of the more commonly used objects and their mnemonics:
* *LIB: Library (where everything below, except directories and stream files, is stored; libraries cannot exist within other libraries).
* *PGM: Program (for compiled languages: CL, RPG-IV, C, C++, COBOL, etc. and there are no interface restrictions between the languages).
* *MODULE: Module (linkable into a program from a compiled language above and here too there are no restrictions on linkability between languages).
* *SRVPGM: Service program (dynamic set of one or more modules, akin to a DLL file in [[Microsoft Windows]]).
* *BNDDIR: Binding directory (holds a list of modules and service programs and is used when creating programs).
* *CMD: Command (an object used for calling programs that allows users to prompt for their parameters; can be created with the Command Definition language). See [[Control Language]] for more information.
* *MENU: Menu (accessed with the GO command).
* *FILE: File (IBM i files can be used for data, input/output devices, and source code, depending on sub type).
* *DTAARA: Data area (small bits of storage used to store tiny items of data for fast access).
* *DIR: Directory (part of the Integrated File System that is equivalent to [[Unix]] and [[Microsoft Windows]] hierarchical file systems).
* *STMF: Stream file (traditional file that would be familiar to most [[Unix]] and [[Microsoft Windows]] users and only stored in directories).
* *JRN & *JRNRCV: Journal and journal receiver (used to journal changes to files, data areas, and stream files).
* *USRPRF: User profile (allows users to sign-on to the system).
* *JOBD: Job description (used when submitting/starting jobs).
* *SBSD: Subsystem description (used when starting subsystems; this is the place where user jobs run).
* *JOBQ: Job queue (used to queue up batch jobs to run in a subsystem).
* *LIND: Line description (communications line: Ethernet, token ring, etc.).
* *CTLD: Controller description (communications controller for lines, workstations, etc.).
* *DEVD: Device description (communications device for lines, workstations, printers tape drives, etc.)
* *DTAQ: Data queue (used to queue up data entries for fast retrieval by other jobs).
* *MSGQ: Message queue (used to send message to users, can also be used like a data queue).
* *OUTQ: Output queue (used to queue up output to a printer).
* *USRSPC: User space - a generic data-containing object of arbitrary size (up to 16T).