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Ipcrm
ipcrm is a Unix and Linux command which will mark System V interprocess communication API kernel entities for removal. Actual removal is deferred until the last connected process has detached. System V IPC kernel entities are: *Shared memory (interprocess communication) segments *Message queues *Semaphore arrays Implementations On Linux, the command is provided by the util-linux package. The command has also been ported to the IBM i operating system. See also *List of Unix commands *ipcs ipcs is a Unix and Linux command to list System V InterProcess Communication System's API kernel entities to ''stdout''. System V IPC kernel entities are: *Shared memory segments *Message queues *Semaphore arrays Implementations On Linux, the c ... – provide information on ipc facilities References External linksipcrm- ipcrm man page {{Unix commands Unix SUS2008 utilities IBM i Qshell commands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-source Software
Open-source software (OSS) is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. Open-source software is a prominent example of open collaboration, meaning any capable user is able to participate online in development, making the number of possible contributors indefinite. The ability to examine the code facilitates public trust in the software. Open-source software development can bring in diverse perspectives beyond those of a single company. A 2008 report by the Standish Group stated that adoption of open-source software models has resulted in savings of about $60 billion per year for consumers. Open source code can be used for studying and allows capable end users to adapt software to their personal needs in a similar way user scripts an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shared Memory (interprocess Communication)
In computer science, shared memory is memory that may be simultaneously accessed by multiple programs with an intent to provide communication among them or avoid redundant copies. Shared memory is an efficient means of passing data between programs. Depending on context, programs may run on a single processor or on multiple separate processors. Using memory for communication inside a single program, e.g. among its multiple threads, is also referred to as shared memory. In hardware In computer hardware, ''shared memory'' refers to a (typically large) block of random access memory (RAM) that can be accessed by several different central processing units (CPUs) in a multiprocessor computer system. Shared memory systems may use: * uniform memory access (UMA): all the processors share the physical memory uniformly; * non-uniform memory access (NUMA): memory access time depends on the memory location relative to a processor; * cache-only memory architecture (COMA): the local memor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ipcs
ipcs is a Unix and Linux command to list System V InterProcess Communication System's API kernel entities to ''stdout''. System V IPC kernel entities are: *Shared memory segments *Message queues *Semaphore arrays Implementations On Linux, the command is provided by the util-linux package. The command has also been ported to the IBM i operating system. See also *List of Unix commands *ipcrm ipcrm is a Unix and Linux command which will mark System V interprocess communication API kernel entities for removal. Actual removal is deferred until the last connected process has detached. System V IPC kernel entities are: *Shared memory (int ... References External links * {{Unix commands Unix SUS2008 utilities IBM i Qshell commands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Unix Commands
This is a list of Unix commands as specified by IEEE Std 1003.1-2008, which is part of the Single UNIX Specification (SUS). These commands can be found on Unix operating systems and most Unix-like operating systems. List See also * List of GNU Core Utilities commands * List of GNOME applications * List of GNU packages * List of KDE applications * List of Unix daemons * List of web browsers for Unix and Unix-like operating systems * Unix philosophy The Unix philosophy, originated by Ken Thompson, is a set of cultural norms and philosophical approaches to minimalist, modular software development. It is based on the experience of leading developers of the Unix operating system. Early Unix de ... * Footnotes External links IEEE Std 1003.1,2004 specificationsIEEE Std 1003.1,2008 specifications– configurable list of equivalent programs for *nix systems. – explains the names of many Unix commands. {{Unix commands Unix programs System administration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Util-linux
is a standard package distributed by the Linux Kernel Organization for use as part of the Linux operating system. A fork, (with meaning "next generation"), was created when development stalled, but has been renamed back to , and is the official version of the package. Contents Included It includes the following utilities: Removed Utilities formerly included, but removed : * arch * chkdupexe * clock * cytune * ddate (removed from default build before being removed altogether) * elvtune * fastboot * fasthalt * halt * initctl * ramsize (formerly a symlink to rdev) * rdev * reboot * rootflags (formerly a symlink to rdev) * shutdown * simpleinit * tailf * vidmode (formerly a symlink to rdev) See also * BusyBox * cat (Unix) * CUPS * GNU Core Utilities * Toybox * uname References External links The util-linux code repository.pub/linux/utils/util-linuxon Kernel.org kernel.org is the main distribution point of source code for the Linux kernel, which is the base of the Linux ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which includes the kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name "GNU/Linux" to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian, Fedora Linux, and Ubuntu, the latter of which itself consists of many different distributions and modifications, including Lubuntu and Xubuntu. Commercial distributions include Red Hat Enterprise Linux and SUSE Linux Enterprise. Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma. Distributions intended for ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semaphore (programming)
In computer science, a semaphore is a variable or abstract data type used to control access to a common resource by multiple threads and avoid critical section problems in a concurrent system such as a multitasking operating system. Semaphores are a type of synchronization primitive. A trivial semaphore is a plain variable that is changed (for example, incremented or decremented, or toggled) depending on programmer-defined conditions. A useful way to think of a semaphore as used in a real-world system is as a record of how many units of a particular resource are available, coupled with operations to adjust that record ''safely'' (i.e., to avoid race conditions) as units are acquired or become free, and, if necessary, wait until a unit of the resource becomes available. Semaphores are a useful tool in the prevention of race conditions; however, their use is not a guarantee that a program is free from these problems. Semaphores which allow an arbitrary resource count are calle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Message Queue
In computer science, message queues and mailboxes are software-engineering components typically used for inter-process communication (IPC), or for inter- thread communication within the same process. They use a queue for messaging – the passing of control or of content. Group communication systems provide similar kinds of functionality. The message queue paradigm is a sibling of the publisher/subscriber pattern, and is typically one part of a larger message-oriented middleware system. Most messaging systems support both the publisher/subscriber and message queue models in their API, e.g. Java Message Service (JMS). Remit and ownership Message queues implement an asynchronous communication pattern between two or more processes/threads whereby the sending and receiving party do not need to interact with the message queue at the same time. Messages placed onto the queue are stored until the recipient retrieves them. Message queues have implicit or explicit limits on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel (computer Science)
The kernel is a computer program at the core of a computer's operating system and generally has complete control over everything in the system. 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 utilization of common resources e.g. CPU & cache usage, 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 usually loaded into a separate area of memory, which is protected from access by applicati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commercial Software
Commercial software, or seldom payware, is a computer software that is produced for sale or that serves commercial purposes. Commercial software can be proprietary software or free and open-source software. Background and challenge While software creation by programming is a time and labor-intensive process, comparable to the creation of physical goods, the reproduction, duplication and sharing of software as digital goods is in comparison disproportionately easy. No special machines or expensive additional resources are required, unlike almost all physical goods and products. Once a software is created it can be copied in infinite numbers, for almost zero cost, by anyone. This made commercialization of software for the mass market in the beginning of the computing era impossible. Unlike hardware, it was not seen as trade-able and commercialize-able good. Software was plainly shared for free (hacker culture) or distributed bundled with sold hardware, as part of the service t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System V
Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, and 4. System V Release 4 (SVR4) was commercially the most successful version, being the result of an effort, marketed as ''Unix System Unification'', which solicited the collaboration of the major Unix vendors. It was the source of several common commercial Unix features. System V is sometimes abbreviated to SysV. , the AT&T-derived Unix market is divided between four System V variants: IBM's AIX, Hewlett Packard Enterprise's HP-UX and Oracle's Solaris, plus the free-software illumos forked from OpenSolaris. Overview Introduction System V was the successor to 1982's UNIX System III. While AT&T developed and sold hardware that ran System V, most customers ran a version from a reseller, based on AT&T's reference implementation. A s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command (computing)
In computing, a command is a directive to a computer program to perform a specific task. It may be issued via a command-line interface, such as a shell, or as input to a network service as part of a network protocol, or as an event in a graphical user interface triggered by the user selecting an option in a menu. Specifically, the term ''command'' is used in imperative computer languages. The name arises because statements in these languages are usually written in a manner similar to the imperative mood used in many natural languages. If one views a statement in an imperative language as being like a sentence in a natural language, then a command is generally like a verb in such a language. Many programs allow specially formatted arguments, known as flags or options, which modify the default behaviour of the program, while further arguments may provide objects, such as files, to act on. As an analogy to a natural language, the flags are adverbs, while the other arguments are o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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