|
UNIX System Services
z/OS UNIX System Services (z/OS UNIX, or informally USS) is a base element of z/OS. z/OS UNIX is a certified UNIX operating system implementation ( XPG4 UNIX 95) optimized for mainframe architecture. It is the first UNIX 95 to not be derived from the AT&T source code. Through integration with the rest of z/OS, additional Time Sharing Option (TSO) commands are available alongside the usual UNIX services, making it possible to process UNIX files using ISPF. Extensions in JCL make it possible to use these files in batch processing. Overview UNIX System Services allows UNIX applications from other platforms to run on IBM System z mainframes running z/OS. In many cases only a recompile is necessary, although additional effort may be advisable for z/OS integration (such as SMP/E installation support). While z/OS UNIX supports ASCII and Unicode, and there's no technical requirement to modify ASCII and Unicode UNIX applications, many z/OS users often prefer EBCDIC support in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIX
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley ( BSD), Microsoft (Xenix), Sun Microsystems ( SunOS/ Solaris), HP/ HPE ( HP-UX), and IBM ( AIX). The early versions of Unix—which are retrospectively referred to as " Research Unix"—ran on computers such as the PDP-11 and VAX; Unix was commonly used on minicomputers and mainframes from the 1970s onwards. It distinguished itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language (in 1973), which allows U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM System Z
IBM Z is a family name used by IBM for all of its z/Architecture mainframe computers. In July 2017, with another generation of products, the official family was changed to IBM Z from IBM z Systems; the IBM Z family will soon include the newest model, the IBM z17, as well as the z16, z15, z14, and z13 (released under the IBM z Systems/IBM System z names), the IBM zEnterprise models (in common use the zEC12 and z196), the IBM System z10 models (in common use the z10 EC), the IBM System z9 models (in common use the z9EC) and ''IBM eServer zSeries'' models (in common use refers only to the z900 and z990 generations of mainframe). Architecture The ''zSeries,'' ''zEnterprise,'' ''System z'' and ''IBM Z'' families were named for their availability – ''z'' stands for High availability, zero downtime. The systems are built with spare components capable of hot failovers to ensure continuous operations. The IBM Z family maintains full backward compatibility. In effect, current system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shell (computing)
An operating system shell is a computer program that provides relatively broad and direct access to the system on which it runs. The term ''shell'' refers to how it is a relatively thin Abstraction layer, layer around an operating system. A shell is generally a command-line interface (CLI) program although some graphical user interface (GUI) programs are arguably classified as shells too. Overview Operating systems provide various services to their users, including File manager, file management, Process (computing), process management (running and terminating Application program, applications), batch processing, and operating system monitoring and configuration. Most operating system shells are not ''direct'' interfaces to the underlying Kernel (operating system), kernel, even if a shell communicates with the user via peripheral devices attached to the computer directly. Shells are actually special applications that use the kernel API in just the same way as it is used by ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java (programming Language)
Java is a High-level programming language, high-level, General-purpose programming language, general-purpose, Memory safety, memory-safe, object-oriented programming, object-oriented programming language. It is intended to let programmers ''write once, run anywhere'' (Write once, run anywhere, WORA), meaning that compiler, compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to Java bytecode, bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax (programming languages), syntax of Java is similar to C (programming language), C and C++, but has fewer low-level programming language, low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as Reflective programming, reflection and runtime code modification) that are typically not available in traditional compiled languages. Java gained popularity sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VSAM
Virtual Storage Access Method (VSAM) is an IBM direct-access storage device (DASD) file storage access method, first used in the OS/VS1, OS/VS2 Release 1 (SVS) and Release 2 (MVS) operating systems, later used throughout the Multiple Virtual Storage (MVS) architecture and now in z/OS. Originally a record-oriented filesystem, VSAM comprises four data set ''organizations'': key-sequenced (KSDS), relative record (RRDS), entry-sequenced (ESDS) and linear (LDS). The KSDS, RRDS and ESDS organizations contain records, while the LDS organization (added later to VSAM) contains a sequence of pages with no intrinsic record structure, for use as a memory-mapped file. Overview An IBM ''Redbook'' named "VSAM PRIMER" (especially when used with the "Virtual Storage Access Method (VSAM) Options for Advanced Applications" manual) explains the concepts needed to make use of VSAM. IBM uses the term ''data set'' in official documentation as a synonym for ''file'', and ''direct-access storage dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Set (IBM Mainframe)
In the context of IBM mainframe computers in the S/360 line, a data set (IBM preferred) or dataset is a computer file having a record-oriented file, 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 ''computer file, file''. A data set is typically stored on a direct access storage device (DASD) or magnetic tape, however unit record devices, such as punch card readers, card punches, line printers and page printers can provide input/output (I/O) for a data set (file). Data sets are not unstructured streams of bytes, but rather are organized in various logical record and block structures determined by the DSORG (data set organization), RECFM (record format), and other parameters. These parameters are specified at the time of the data set allocation (creation), for example with Job Control Language DD statements. Withi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long Filename
Long filename (LFN) support is Microsoft's backward-compatible extension of the 8.3 filename (short filename) naming scheme used in MS-DOS. Long filenames can be more descriptive, including longer filename extensions such as .jpeg, .tiff, and .html that are common on other operating systems, rather than specialized shortened names such as .jpg, .tif, or .htm. The standard has been common with File Allocation Table (FAT) filesystems since its first implementation in Windows NT 3.5 of 1994. To maintain compatibility with older operating systems, Microsoft formulated a method of generating an 8.3 filename from the long filename (for example, Microsoft.txt to MICROS~1.TXT) and associating it with the file. Compatibility issues Microsoft implemented support for LFNs in the FAT filesystem by using hidden directory entries, of the ''volume label'' type, to store the longer names; this scheme is known as VFAT, and was chosen for compatibility, as volume labels are generally ig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ZFS (z/OS File System)
z/OS File System (zFS) (official name: z/OS® Distributed File Service zSeries® File System) is a POSIX-style hierarchical file system for IBM's z/OS operating system for z System mainframes, a successor to that operating system's HFS. zFS technology was first released in 1995 as the Local File System, a lower layer of the DCE Distributed File System. It was available on MVS/ESA V5R2.2 and all OS/390 OS/390 is an IBM operating system for the System/390 IBM mainframe computers. Overview OS/390 was introduced in late 1995 in an effort to simplify the packaging and ordering for the key, entitled elements needed to complete a fully function ... releases. DFS/LFS was provided as a part of the DCE feature, not part of the base operating system. As a separate feature (outside the DCE feature), zFS was initially released for z/OS as PTFs (patches) for z/OS 1.2, with backports available for z/OS 1.1 and OS/390 2.10. Beginning with z/OS 1.3, zFS is included as a standard fea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hierarchical File System (IBM MVS)
IBM's Hierarchical File System (HFS) is a POSIX-style hierarchical file system for the MVS/ESA/SP through z/OS z/OS is a 64-bit operating system for IBM z/Architecture mainframes, introduced by IBM in October 2000. It derives from and is the successor to OS/390, which in turn was preceded by a string of MVS versions.Starting with the earliest: ... operating systems. IBM introduced HFS on February 9, 1993 in MVS/ESA System Product Version 4 Release 3 OpenEdition with DFSMS/MVS Version 1 Release 2 for 3090 mainframes. On April 6, 1994, IBM introduced MVS/ESA System Product (MVS/ESA SP) Version 5 Release 1, which included MVS OpenEdition (MVS-OE) with HFS as a standard component. IBM continued providing HFS through z/OS 2.4 for z System mainframes. IBM functionally stabilized HFS starting with z/OS 1.7, in 2005. The z/OS File System (zFS) was released as the higher performance successor to HFS in 1995, and IBM recommended migration from HFS to zFS. Following the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ANSI C
ANSI C, ISO C, and Standard C are successive standards for the C programming language published by the American National Standards Institute (ANSI) and ISO/IEC JTC 1/SC 22/WG 14 of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). Historically, the names referred specifically to the original and best-supported version of the standard (known as C89 or C90). Software developers writing in C are encouraged to conform to the standards, as doing so helps portability between compilers. History and outlook The first standard for C was published by ANSI. Although this document was subsequently adopted by ISO/IEC and subsequent revisions published by ISO/IEC have been adopted by ANSI, "ANSI C" is still used to refer to the standard. While some software developers use the term ISO C, others are standards-body neutral and use Standard C. Informal specification: K&R C (''C78'') Informal specification in 1978 (Brian Kernig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
