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Dynamic Loading
Dynamic loading is a mechanism by which a computer program can, at run time, load a library (or other binary) into memory, retrieve the addresses of functions and variables contained in the library, execute those functions or access those variables, and unload the library from memory. It is one of the three mechanisms by which a computer program can use some other software within the program; the others are static linking and dynamic linking. Unlike static linking and dynamic linking, dynamic loading allows a computer program to start up in the absence of these libraries, to discover available libraries, and to potentially gain additional functionality. History Dynamic loading was a common technique for IBM's operating systems for System/360 such as OS/360, particularly for I/O subroutines, and for COBOL and PL/I runtime libraries, and continues to be used in IBM's operating systems for z/Architecture, such as z/OS. As far as the application programmer is concerned, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Load
An active load or dynamic load is a component or a circuit that functions as a current-stable nonlinear resistor. Circuit design In circuit design, an active load is a circuit component made up of ''active devices'', such as transistors, intended to present a high small-signal impedance yet not requiring a large DC voltage drop, as would occur if a large resistor were used instead. Such large AC load impedances may be desirable, for example, to increase the AC gain of some types of amplifier. Most commonly the active load is the output part of a current mirror and is represented in an idealized manner as a current source. Usually, it is only a ''constant-current resistor'' that is a part of the whole current source including a ''constant voltage source'' as well (the power supply ''VCC'' on the figures below). Common base example In Figure 1 the load is a resistor, and the current through the resistor is determined by Ohm's law as: :I_C = \frac {R_C}. As a consequence of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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: * OS/VS2 Release 2 through Release 3.8 * MVS/System Extensions (MVS/SE) * MVS/System Product (MVS/SP) Version 1 * MVS/System Product Version 2 (MVS/Extended Architecture, MVS/XA) * MVS/System Product Version 3 (MVS/Enterprise Systems Architecture, MVS/ESA) * MVS/ESA SP Version 4 * MVS/ESA SP Version 5 Like OS/390, z/OS combines a number of formerly separate, related products, some of which are still optional. z/OS has the attributes of modern operating systems but also retains much of the older functionality that originated in the 1960s and is still in regular use—z/OS is designed for backward compatibility. Major characteristics z/OS supportsSome, e.g., TSO/E, are bundled with z/OS, others, e.g., CICS, are separately priced. stable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, packaged as a Linux distribution (distro), which includes the kernel and supporting system software and library (computing), libraries—most of which are provided by third parties—to create a complete operating system, designed as a clone of Unix and released under the copyleft GPL license. List of Linux distributions, Thousands of Linux distributions exist, many based directly or indirectly on other distributions; popular Linux distributions include Debian, Fedora Linux, Linux Mint, Arch Linux, and Ubuntu, while commercial distributions include Red Hat Enterprise Linux, SUSE Linux Enterprise, and ChromeOS. Linux distributions are frequently used in server platforms. Many Linux distributions use the word "Linux" in their name, but the Free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacOS
macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. Within the market of Desktop computer, desktop and laptop computers, it is the Usage share of operating systems#Desktop and laptop computers, second most widely used desktop OS, after Microsoft Windows and ahead of all Linux distributions, including ChromeOS and SteamOS. , the most recent release of macOS is MacOS Sequoia, macOS 15 Sequoia, the 21st major version of macOS. Mac OS X succeeded classic Mac OS, the primary Mac operating systems, Macintosh operating system from 1984 to 2001. Its underlying architecture came from NeXT's NeXTSTEP, as a result of NeXT#1997–2006: Acquisition by Apple, Apple's acquisition of NeXT, which also brought Steve Jobs back to Apple. The first desktop version, Mac OS X 10.0, was released on March 24, 2001. Mac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix-like
A Unix-like (sometimes referred to as UN*X, *nix or *NIX) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-like Application software, application is one that behaves like the corresponding List of POSIX commands, Unix command or Unix shell, shell. Although there are general Unix philosophy, philosophies for Unix design, there is no technical standard defining the term, and opinions can differ about the degree to which a particular operating system or application is Unix-like. Some well-known examples of Unix-like operating systems include Linux, FreeBSD and OpenBSD. These systems are often used on servers as well as on personal computers and other devices. Many popular applications, such as the Apache HTTP Server, Apache web server and the Bash (Unix shell), Bash shell, are also designed to be used on Unix-like systems. Definition The Open ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Programs
A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangible components. A ''computer program'' in its human-readable form is called source code. Source code needs another computer program to Execution (computing), execute because computers can only execute their native machine instructions. Therefore, source code may be Translator (computing), translated to machine instructions using a compiler written for the language. (Assembly language programs are translated using an Assembler (computing), assembler.) The resulting file is called an executable. Alternatively, source code may execute within an interpreter (computing), interpreter written for the language. If the executable is requested for execution, then the operating system Loader (computing), loads it into Random-access memory, memory and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apache Web Server
The Apache HTTP Server ( ) is a free and open-source cross-platform web server, released under the terms of Apache License 2.0. It is developed and maintained by a community of developers under the auspices of the Apache Software Foundation. The vast majority of Apache HTTP Server instances run on a Linux distribution, but current versions also run on Microsoft Windows, OpenVMS, and a wide variety of Unix-like systems. Past versions also ran on NetWare, OS/2 and other operating systems, including ports to mainframes. Originally based on the NCSA HTTPd server, development of Apache began in early 1995 after work on the NCSA code stalled. Apache played a key role in the initial growth of the World Wide Web, quickly overtaking NCSA HTTPd as the dominant HTTP server. In 2009, it became the first web server software to serve more than 100 million websites. , Netcraft estimated that Apache served 17.83% of the million busiest websites, with the other top four being Cloudflar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plug-in (computing)
In computing, a plug-in (also spelled plugin) or add-in (also addin, add-on, or addon) is a software component that extends the functionality of an existing software system without requiring the system to be software build, re-built. A plug-in software feature, feature is one way that a system can be customizable. Applications support plug-ins for a variety of reasons including: * Enable third-party developers to extend an application * Support easily adding new features * Reduce the size of an application by not loading unused features * Separate source code from an application because of incompatible software licenses Examples Examples of plug-in use for various categories of applications: * Digital audio workstations and audio editing software use audio plug-ins to generate, process or analyze sound. Ardour (software), Ardour, Audacity (audio editor), Audacity, Cubase, FL Studio, Logic Pro, Logic Pro X and Pro Tools are examples of such systems. * Email clients use plug-i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shared Libraries
In computing, a library is a collection of resources that can be leveraged during software development to implement a computer program. Commonly, a library consists of executable code such as compiled functions and classes, or a library can be a collection of source code. A resource library may contain data such as images and Text string, text. A library can be used by multiple, independent consumers (programs and other libraries). This differs from resources defined in a program which can usually only be used by that program. When a consumer uses a library resource, it gains the value of the library without having to implement it itself. Libraries encourage software reuse in a Modular programming, modular fashion. Libraries can use other libraries resulting in a hierarchy of libraries in a program. When writing code that uses a library, a programmer only needs to know how to use it not its internal details. For example, a program could use a library that Abstraction (comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
24/7
In commerce and industry, 24/7 or 24-7 service (usually pronounced "twenty-four seven") is service that is available at any time and usually, every day. An alternate orthography for the numerical part includes 24×7 (usually pronounced "twenty-four by seven"). The numerals stand for "24 hours a day, 7 days a week". Less commonly used, 24/7/52 (adding "52 weeks") and 24/7/365 service (adding "365 days") make it clear that service is available every day of the year. Synonyms include around-the-clock service (with/without hyphens) and all day every day, especially in British English, and nonstop service, but the latter can also refer to other things, such as public transport services which go between two stations without stopping. The ''Oxford English Dictionary'' (OED) defines the term as "twenty-four hours a day, seven days a week; constantly". It lists its first reference to 24/7 to be from a 1983 story in the US magazine ''Sports Illustrated'' in which Louisiana State Universi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Application Program
Application software is any computer program that is intended for end-user use not operating, administering or programming the computer. An application (app, application program, software application) is any program that can be categorized as application software. Common types of applications include word processor, media player and accounting software. The term ''application software'' refers to all applications collectively and can be used to differentiate from system and utility software. Applications may be bundled with the computer and its system software or published separately. Applications may be proprietary or open-source. The short term ''app'' (coined in 1981 or earlier) became popular with the 2008 introduction of the iOS App Store, to refer to applications for mobile devices such as smartphones and tablets. Later, with introduction of the Mac App Store (in 2010) and Windows Store (in 2011), the term was extended in popular use to include desktop applicati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel (operating System)
A kernel is a computer program at the core of a computer's operating system that always has complete control over everything in the system. The kernel is also responsible for preventing and mitigating conflicts between different processes. It is the portion of the operating system code that is always resident in memory and facilitates interactions between hardware and software components. A full kernel controls all hardware resources (e.g. I/O, memory, cryptography) via device drivers, arbitrates conflicts between processes concerning such resources, and optimizes the use of common resources, such as CPU, cache, file systems, and network sockets. On most systems, the kernel is one of the first programs loaded on startup (after the bootloader). It handles the rest of startup as well as memory, peripherals, and input/output (I/O) requests from software, translating them into data-processing instructions for the central processing unit. The critical code of the kernel is usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
