 | This article needs additional citations for verification .(December 2009) |
On many computing platforms everything is a file, but in contrast in IBM i everything is an object. [1]
| | This article needs additional citations for verification .(December 2009) |
On many computing platforms everything is a file, but in contrast in IBM i everything is an object. [1]
IBM i objects share similarities with objects in object-oriented programming, but there are differences as well. There are similarities in that when 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:
A library (*LIB) on IBM i is an object that is used as a system directory to keep track of other objects. Objects are not stored inside libraries, but rather libraries are used as namespaces for objects. Libraries are a "system" object, and therefore only one instance of any given Library "name" is possible. They're made to appear as if they're stored in the QSYS library.
Generally speaking all libraries created by IBM for use by the operating system begin with the letter 'Q'.
IBM Standard Libraries:
A library list (*LIBL) is an object which specifies a default set of locations to look for an object (similar to the PATH mechanism of other operating systems). This object doesn't exist on its own and is always associated with another object like a job or a job description (*JOBD). Some job descriptions specify the special value *SYSVAL which means that the library list can be found in the system value QUSRLIBL. As of OS/400 V5R1, the user portion of the Library List can contain up to 250 library names. Prior to that it could only have 25 libraries.
A job's library list consists of four sections:
QSYS, QHLPSYS, QUSRSYS, etc. The system portion can hold up to 15 library names. The default contents of the system portion are specified in the QSYSLIBL system value. The contents of the system portion can be changed for the current job to differ from QSYSLIBL by using the CHGSYSLIBL command. CHGCURLIB command. To change it for the user on all future jobs use the CHGUSRPRF command.SBMJOB command's INLLIBL parameter. A job's library list can be changed locally with the EDTLIBL(Edit Library List), CHGLIBL(Change Library List), ADDLIBLE(Add Library List Entry), and RMVLIBLE(Remove Library List Entry) command.In computer science, an abstract data type (ADT) is a mathematical model for data types. An abstract data type is defined by its behavior (semantics) from the point of view of a user, of the data, specifically in terms of possible values, possible operations on data of this type, and the behavior of these operations. This mathematical model contrasts with data structures, which are concrete representations of data, and are the point of view of an implementer, not a user.
In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and subroutines, classes, values or type specifications. In IBM's OS/360 and its successors they are referred to as partitioned data sets.
In computing, Interactive System Productivity Facility (ISPF) is a software product for many historic IBM mainframe operating systems and currently the z/OS and z/VM operating systems that run on IBM mainframes. It includes a screen editor, the user interface of which was emulated by some microcomputer editors sold commercially starting in the late 1980s, including SPF/PC.
Job Control Language (JCL) is a name for scripting languages used on IBM mainframe operating systems to instruct the system on how to run a batch job or start a subsystem.
Adabas, a contraction of “adaptable database system," is a database package that was developed by Software AG to run on IBM mainframes. It was launched in 1971 as a non-relational database. As of 2019, Adabas is marketed for use on a wider range of platforms, including Linux, Unix, and Windows.
The Control Language (CL) is a scripting language originally created by IBM for the System/38 Control Program Facility and later used in OS/400. It bears a resemblance to the IBM Job Control Language and consists of a set of command objects (*CMD) used to invoke traditional programs or get help on what those programs do. CL can also be used to create CL programs where there are additional commands that provide program-like functionality
The cron command-line utility is a job scheduler on Unix-like operating systems. Users who set up and maintain software environments use cron to schedule jobs, also known as cron jobs, to run periodically at fixed times, dates, or intervals. It typically automates system maintenance or administration—though its general-purpose nature makes it useful for things like downloading files from the Internet and downloading email at regular intervals.
In computer systems a loader is the part of an operating system that is responsible for loading programs and libraries. It is one of the essential stages in the process of starting a program, as it places programs into memory and prepares them for execution. Loading a program involves either memory-mapping or copying the contents of the executable file containing the program instructions into memory, and then carrying out other required preparatory tasks to prepare the executable for running. Once loading is complete, the operating system starts the program by passing control to the loaded program code.
Disk Operating System/360, also DOS/360, or simply DOS, is the discontinued first member of a sequence of operating systems for IBM System/360, System/370 and later mainframes. It was announced by IBM on the last day of 1964, and it was first delivered in June 1966. In its time, DOS/360 was the most widely used operating system in the world.
The MCP is the operating system of the Burroughs B5000/B5500/B5700 and the B6500 and successors, including the Unisys Clearpath/MCP systems.
In the context of IBM mainframe computers in the S/360 line, a data set or dataset is a computer file having a record organization. Use of this term began with, e.g., DOS/360, OS/360, and is still used by their successors, including the current z/OS. Documentation for these systems historically preferred this term rather than file.
This article discusses support programs included in or available for OS/360 and successors. IBM categorizes some of these programs as utilities and others as service aids; the boundaries are not always consistent or obvious. Many, but not all, of these programs match the types in utility software.
Extended file attributes are file system features that enable users to associate computer files with metadata not interpreted by the filesystem, whereas regular attributes have a purpose strictly defined by the filesystem. Unlike forks, which can usually be as large as the maximum file size, extended attributes are usually limited in size to a value significantly smaller than the maximum file size. Typical uses include storing the author of a document, the character encoding of a plain-text document, or a checksum, cryptographic hash or digital certificate, and discretionary access control information.
The Parallel Virtual File System (PVFS) is an open-source parallel file system. A parallel file system is a type of distributed file system that distributes file data across multiple servers and provides for concurrent access by multiple tasks of a parallel application. PVFS was designed for use in large scale cluster computing. PVFS focuses on high performance access to large data sets. It consists of a server process and a client library, both of which are written entirely of user-level code. A Linux kernel module and pvfs-client process allow the file system to be mounted and used with standard utilities. The client library provides for high performance access via the message passing interface (MPI). PVFS is being jointly developed between The Parallel Architecture Research Laboratory at Clemson University and the Mathematics and Computer Science Division at Argonne National Laboratory, and the Ohio Supercomputer Center. PVFS development has been funded by NASA Goddard Space Flight Center, The DOE Office of Science Advanced Scientific Computing Research program, NSF PACI and HECURA programs, and other government and private agencies. PVFS is now known as OrangeFS in its newest development branch.
In IBM mainframe operating systems, basic partitioned access method (BPAM) is an access method for libraries, called partitioned datasets (PDSes) in IBM terminology. BPAM is used in OS/360, OS/VS2, MVS, z/OS, and others.
OS/360, officially known as IBM System/360 Operating System, is a discontinued batch processing operating system developed by IBM for their then-new System/360 mainframe computer, announced in 1964; it was influenced by the earlier IBSYS/IBJOB and Input/Output Control System (IOCS) packages for the IBM 7090/7094 and even more so by the PR155 Operating System for the IBM 1410/7010 processors. It was one of the earliest operating systems to require the computer hardware to include at least one direct access storage device.
System Modification Program/Extended (SMP/E), the proprietary version of System Modification Program (SMP), "is a tool designed to manage the installation of software products on [a] z/OS system and to track the modifications" to those products.
OS 2200 is the operating system for the Unisys ClearPath Dorado family of mainframe systems. The operating system kernel of OS 2200 is a lineal descendant of Exec 8 for the UNIVAC 1108. Documentation and other information on current and past Unisys systems can be found on the Unisys public support website.
MTS System Architecture describes the software organization of the Michigan Terminal System, a time-sharing computer operating system in use from 1967 to 1999 on IBM S/360-67, IBM System/370, and compatible computers.
Distributed Data Management Architecture (DDM) is IBM's open, published software architecture for creating, managing and accessing data on a remote computer. DDM was initially designed to support record-oriented files; it was extended to support hierarchical directories, stream-oriented files, queues, and system command processing; it was further extended to be the base of IBM's Distributed Relational Database Architecture (DRDA); and finally, it was extended to support data description and conversion. Defined in the period from 1980 to 1993, DDM specifies necessary components, messages, and protocols, all based on the principles of object-orientation. DDM is not, in itself, a piece of software; the implementation of DDM takes the form of client and server products. As an open architecture, products can implement subsets of DDM architecture and products can extend DDM to meet additional requirements. Taken together, DDM products implement a distributed file system.
IBM mini/midrange computers, workstations, and servers | |||
|---|---|---|---|
| IBM 1130 | |||
| IBM 1400 | |||
| IBM System | |||
| AS/400 |
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| RS/6000 |
| ||
| Other | |||
* Also based on the System/36 | |||
