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Who (Unix)
The standard Unix command who displays a list of users who are currently logged into the computer. The who command is related to the command , which provides the same information but also displays additional data and statistics. History A command that displays the names of users logged in was first implemented within Multics. Later, it appeared in Version 1 Unix and became part of the X/Open Portability Guide since issue 2 of 1987. It was inherited into the first version of POSIX.1 and the Single Unix Specification. The version of who bundled in GNU coreutils was written by Joseph Arceneaux, David MacKenzie, and Michael Stone. Specification The Single UNIX Specification (SUS) specifies that who should list information about accessible users. The XSI extension also specifies that the data of the username, terminal, login time, process ID, and time since last activity occurred on the terminal, furthermore, an alternate system database used for user information can be spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AT&T Bell Laboratories
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by multinational company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several laboratories in the United States and around the world. Researchers working at Bell Laboratories are credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B, C, C++, S, SNOBOL, AWK, AMPL, and others. Nine Nobel Prizes have been awarded for work completed at Bell Laboratories. Bell Labs had its origin in the complex corporate organization of the Bell System telephone conglomerate. In the late 19th century, the laboratory began as the Western Electric Engineering Department, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Unix Programs
Standard may refer to: Symbols * Colours, standards and guidons, kinds of military signs * Standard (emblem), a type of a large symbol or emblem used for identification Norms, conventions or requirements * Standard (metrology), an object that bears a defined relationship to a unit of measure used for calibration of measuring devices * Standard (timber unit), an obsolete measure of timber used in trade * Breed standard (also called bench standard), in animal fancy and animal husbandry * BioCompute Standard, a standard for next generation sequencing * ''De facto'' standard, product or system with market dominance * Gold standard, a monetary system based on gold; also used metaphorically for the best of several options, against which the others are measured * Internet Standard, a specification ratified as an open standard by the Internet Engineering Task Force * Learning standards, standards applied to education content * Standard displacement, a naval term describing the weig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix User Management And Support-related Utilities
Unix (; trademarked as UNIX) is a family of multitasking, multiuser 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). In the early 1990s, AT&T sold its rights in Unix to Novell, which then sold the UNIX trademark to The Open Group, an industry consortium founded in 1996. The Open Group allows the use of the mark for certified operating systems that comply with the Single UNIX Specification (SUS). Unix systems are characterized by a modular design that is sometimes called the "Unix philosophy". According to this philosophy, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multics Commands
Multics ("Multiplexed Information and Computing Service") is an influential early time-sharing operating system based on the concept of a single-level memory.Dennis M. Ritchie, "The Evolution of the Unix Time-sharing System", Communications of the ACM, Vol. 17, 1984, pp. 365-375. Nathan Gregory writes that Multics "has influenced all modern operating systems since, from microcomputers to mainframes." Initial planning and development for Multics started in 1964, in Cambridge, Massachusetts. Originally it was a cooperative project led by MIT (Project MAC with Fernando Corbató) along with General Electric and Bell Labs. It was developed on the GE 645 computer, which was specially designed for it; the first one was delivered to MIT in January 1967. GE offered their earlier 635 systems with an early timesharing system known as "Mark I" and intended to offer the 645 with Multics as a larger successor. Bell withdrew from the project in 1969 as it became clear it would not deliver a wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manual Page
A man page (short for manual page) is a form of software documentation usually found on a Unix or Unix-like operating system. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts. A user may invoke a man page by issuing the man command. By default, man typically uses a terminal pager program such as more or less to display its output. Man pages are often referred to as an ''on-line'' or ''online'' form of software documentation, * even though the man command does not require internet access, dating back to the times when printed ''out-of-band'' manuals were the norm. History In the first two years of the history of Unix, no documentation existed. The Unix Programmer's Manual' was first published on November 3, 1971. The first actual man pages were written by Dennis Ritchie and Ken Thompson at the insistence of their manager Doug McIlroy in 1971. Aside from the man pages, the ''Programmer's ... [...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] |
Init (Unix)
In Unix-based computer operating systems, init (short for ''initialization'') is the first process started during booting of the computer system. Init is a daemon process that continues running until the system is shut down. It is the direct or indirect ancestor of all other processes and automatically adopts all orphaned processes. Init is started by the kernel during the booting process; a kernel panic will occur if the kernel is unable to start it. Init is typically assigned process identifier 1. In Unix systems such as System III and System V, the design of init has diverged from the functionality provided by the init in Research Unix and its BSD derivatives. Up until recently, most Linux distributions employed a traditional init that was somewhat compatible with System V, while some distributions such as Slackware use BSD-style startup scripts, and others such as Gentoo have their own customized versions. Since then, several additional init implementations have b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command Line Interface
A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and providing information to them as to what actions they are to perform. In some cases the invocation is conditional based on conditions established by the user or previous executables. Such access was first provided by computer terminals starting in the mid-1960s. This provided an interactive environment not available with punched cards or other input methods. Today, many users rely upon graphical user interfaces and menu-driven interactions. However, some programming and maintenance tasks may not have a graphical user interface and use a command line. Alternatives to the command-line interface include text-based user interface menus (for example, IBM AIX SMIT), keyboard shortcuts, and various desktop metaphors centered on the pointer (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zombie Process
On Unix and Unix-like computer operating systems, a zombie process or defunct process is a process that has completed execution (via the exit system call) but still has an entry in the process table: it is a process in the " Terminated state". This occurs for the child processes, where the entry is still needed to allow the parent process to read its child's exit status: once the exit status is read via the wait system call, the zombie's entry is removed from the process table and it is said to be "reaped". A child process always first becomes a zombie before being removed from the resource table. In most cases, under normal system operation zombies are immediately waited on by their parent and then reaped by the system – processes that stay zombies for a long time are generally an error and cause a resource leak, but the only resource they occupy is the process table entry – process ID. The term ''zombie process'' derives from the common definition of zombie — an undea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tty (Unix)
In computing, tty is a command in Unix and Unix-like operating systems to print the file name of the terminal connected to standard input. tty stands for TeleTYpewriter. Usage The tty command is commonly used to check if the output medium is a terminal. The command prints the file name of the terminal connected to standard input. If no file is detected (in case, it's being run as part of a script or the command is being piped) "not a tty" is printed to stdout and the command exits with an exit status of 1. The command also can be run in silent mode (tty -s) where no output is produced, and the command exits with an appropriate exit status. See also * Pseudoterminal * Teleprinter A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations. Initia ... References External links * * * * * * {{ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X/Open System Interfaces Extension
X/Open group (also known as the Open Group for Unix Systems and incorporated in 1987 as X/Open Company, Ltd.) was a consortium founded by several European UNIX systems manufacturers in 1984 to identify and promote open standards in the field of information technology. More specifically, the original aim was to define a single specification for operating systems derived from UNIX, to increase the interoperability of applications and reduce the cost of porting software. Its original members were Bull, ICL, Siemens, Olivetti, and Nixdorf—a group sometimes referred to as BISON. Philips and Ericsson joined in 1985, at which point the name X/Open was adopted. The group published its specifications as X/Open Portability Guide, starting with Issue 1 in 1985, and later as ''X/Open CAE Specification''. In 1987, X/Open was incorporated as X/Open Company, Ltd. By March 1988, X/Open grew to 13 members: AT&T, Digital, Hewlett-Packard, Sun Microsystems, Unisys, NCR, Olivetti, Bull, Ericsson, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
