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W (Unix)
The command w on many Unix-like operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...s provides a quick summary of every user logged into a computer, what each user is currently doing, and what load all the activity is imposing on the computer itself. The command is a one-command combination of several other Unix programs: , , and . Example Sample output (which may vary between systems): $ w 11:12am up 608 day(s), 19:56, 6 users, load average: 0.36, 0.36, 0.37 User tty login@ idle what smithj pts/5 8:52am w jonesm pts/23 20Apr06 28 -bash harry pts/18 9:01am 9 pine peterb pts/19 21Apr06 emacs -nw html/index.html janetmcq pts/8 10:12am 3days -csh singh pts/12 16Apr06 5:29 /usr/bin/perl -w perl/tes ... [...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] |
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] |
Command (computing)
In computing, a command is an instruction received via an external Interface (computing), interface that directs the behavior of a computer program. Commonly, commands are sent to a program via a command-line interface, a scripting language, script, a network protocol, or as an event triggered in a graphical user interface. Many commands support arguments to specify input and to modify default behavior. Terminology and syntax varies but there are notable common approaches. Typically, an option or a flag is a name (without Whitespace character, whitespace) with a prefix such as dash or Slash (punctuation), slash that modifies default behavior. An option might have a required value that follows it. Typically, flag refers to an option that does not have a following value. A parameter is an argument that specifies input to the command and its meaning is based on its position in the command line relative to other parameters; generally ignoring options. A parameter can specify anything ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for efficient use of the system and may also include accounting software for cost allocation of Scheduling (computing), processor time, mass storage, peripherals, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computerfrom cellular phones and video game consoles to web servers and supercomputers. , Android (operating system), Android is the most popular operating system with a 46% market share, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Load (computing)
In UNIX computing, the system load is a measure of the amount of computational work that a computer system performs. The load average represents the average system load over a period of time. It conventionally appears in the form of three numbers which represent the system load during the last one-, five-, and fifteen-minute periods. Unix-style load calculation All Unix and Unix-like systems generate a dimensionless Software metric, metric of three "load average" numbers in the kernel (operating system), kernel. Users can easily query the current result from a Unix shell by running the uptime command: $ uptime 14:34:03 up 10:43, 4 users, load average: 0.06, 0.11, 0.09 The W (Unix), w and top (software), top commands show the same three load average numbers, as do a range of graphical user interface utilities. In operating systems based on the Linux kernel, this information can be easily accessed by reading the procfs, /proc/loadavg file. To explore this kind of infor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 for the CTSS operating system by ''Noel Morris'' in 1965. This inspired ''Tom Van Vleck'' to write a Multics version. Later, it appeared in Version 1 Unix and became part of the X/Open Portability Guide since issue 2 of 1987. It was inherited by the first version of POSIX.1 and the Single Unix Specification. The existence of presupposes the existence of an online group of users in a shared collegial environment with a need to communicate with each other. 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 ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uptime
Uptime is a Measurement, measure of system reliability, expressed as the period of system time, time a machine, typically a computer, has been continuously working and available. Uptime is the opposite of downtime. It is often used as a measure of computer operating system reliability or stability, in that this time represents the time a computer can be left unattended without crash (computing), crashing or needing to be booting, rebooted for administrative or maintenance purposes. Conversely, long uptime may indicate negligence, because some critical updates can require reboots on some platforms. Records In 2005, Novell reported a server with a 6-year uptime. This level of uptime is common when servers are maintained under an industrial context and host critical applications such as banking systems. Netcraft maintains the uptime records for many thousands of web hosting computers. A server running Novell NetWare has been reported to have been shut down after 16 years of uptime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ps (Unix)
In most Unix and Unix-like operating systems, the ps (''process status'') program displays the currently-running processes. The related Unix utility top provides a real-time view of the running processes. Implementations KolibriOS includes an implementation of the command. The command has also been ported to the IBM i operating system. In Windows PowerShell, ps is a predefined command alias for the Get-Process cmdlet, which essentially serves the same purpose. Examples # ps PID TTY TIME CMD 7431 pts/0 00:00:00 su 7434 pts/0 00:00:00 bash 18585 pts/0 00:00:00 ps Users can pipeline ps with other commands, such as less to view the process status output one page at a time: $ ps -A , less Users can also utilize the ps command in conjunction with the grep command (see the pgrep and pkill commands) to find information about a single process, such as its id: $ # Trying to find the PID of `firefox-bin` which is 2701 $ ps -A , grep firefox-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
