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Screenshot of a sample Bash session, taken on Gentoo Linux.

Screenshot of the MS-DOS command line interface.

Screenshot of Apple Computer's CommandShell in A/UX 3.0.1.

Screenshot of Windows PowerShell RC 1, running under Windows Vista

A command line interface or CLI is a tool for interacting with computers, often using a text terminal or remote shell client software, such as PuTTY. CLIs originated when teletype machines were connected to computers in the 1950s. Offering immediate interaction and feedback, they are an advancement over mechanical punch card technology. Image File history File links Broom_icon. ... Image File history File links Please see the file description page for further information. ... A command line interpreter is a computer program which reads lines of text that the user types and interprets them in the context of a given operating system or programming language. ... Download high resolution version (709x691, 20 KB)Screenshot of a sample session of bash on Linux. ... Download high resolution version (709x691, 20 KB)Screenshot of a sample session of bash on Linux. ... bash is a Unix shell written for the GNU Project. ... The Gentoo Linux operating system (pronounced ) is a Linux distribution named after the Gentoo penguin. ... Image File history File links MS-DOS_6. ... Image File history File links MS-DOS_6. ... Microsofts disk operating system, MS-DOS, was Microsofts implementation of DOS, which was the first popular operating system for the IBM PC, and until recently, was widely used on the PC compatible platform. ... Image File history File links Aux. ... Image File history File links Aux. ... Apple Inc. ... A/UX (from Apple Unix) is Apple Computers implementation of the Unix operating system for some of their Macintosh computers. ... Image File history File links Download high resolution version (677x740, 97 KB) Summary Self-made screenshot of PowerShell running on Vista. ... Image File history File links Download high resolution version (677x740, 97 KB) Summary Self-made screenshot of PowerShell running on Vista. ... Windows PowerShell, previously Microsoft Shell or MSH (codenamed Monad) is an extensible command line interface (CLI) shell and scripting language product developed by Microsoft. ... Windows Vista is the latest release of Microsoft Windows, a line of graphical operating systems used on personal computers, including home and business desktops, notebook computers, Tablet PCs, and media centers. ... Human–computer interaction (HCI) or, alternatively, computer–human interaction (symbolized as Χ χ Chi, the 22nd letter of the Greek alphabet) is the study of interaction between people (users) and computers. ... A typical text terminal produces input and displays output and errors A text terminal or often just terminal (sometimes text console) is a serial computer interface for text entry and display. ... PuTTY is a free SSH, Telnet, rlogin, and raw TCP client. ... Teletype machines in World War II A teleprinter (teletypewriter, teletype or TTY for TeleTYpe/TeleTYpewriter) is a now largely obsolete electro-mechanical typewriter which can be used to communicate typed messages from point to point through a simple electrical communications channel, often just a pair of wires. ... // Recovering from World War II and its aftermath, the economic miracle emerged in West Germany and Italy. ... Punched cards (or Hollerith cards, or IBM cards), are pieces of stiff paper that contain digital information represented by the presence or absence of holes in predefined positions. ...

With cathode ray tubes making way for graphics development, CLIs continues to coevolve with graphical user interfaces (GUIs) like Microsoft Windows, Mac OS, and the X Window System. Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT Electron guns Electron beams Focusing coils Deflection coils Anode connection Mask for separating beams for red, green, and blue part of displayed image Phosphor layer with red, green, and blue zones Close-up of the phosphor... Bumblebees and the flowers they pollinate co-evolve so that the flower is dependent on the bee and the bee is dependent on the flower for survival In Biology, Co-evolution is the mutual evolutionary influence between two species that become dependent on each other. ... A graphical user interface (or GUI, often pronounced gooey), is a particular case of user interface for interacting with a computer which employs graphical images and widgets in addition to text to represent the information and actions available to the user. ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... This article or section does not cite its references or sources. ... KDE 3. ...

Usage

CLIs are often used by programmers and system administrators (especially in Unix-based operating systems), in engineering and scientific environments, and by a smaller subset of technically advanced home users. CLIs are also popular among people with visual disability^{[citation needed]}. Filiation of Unix and Unix-like systems Unix (officially trademarked as UNIX®) is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. ...

A program that implements such interface is often called a command line interpreter or shell. Examples include the various Unix shells (sh, ksh, csh, tcsh, bash, etc.), the historical CP/M, and DOS's command.com ("Command Prompt"), the latter two based heavily on DEC's RSX and RSTS CLIs. A command line interpreter is a computer program which reads lines of text that the user types and interprets them in the context of a given operating system or programming language. ... In computing, a shell is a piece of software that provides an interface for users (command line interpreter). ... Screenshot of a sample Bash session, taken on Gentoo Linux. ... CP/M was an operating system originally created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc. ... ‹ The template below has been proposed for deletion. ... COMMAND.COM is the name for the default operating system shell (or command line interpreter) for DOS and 16/32bits versions of Windows (95/98/98 SE/Me). ... The DEC logo Digital Equipment Corporation was a pioneering American company in the computer industry. ... RSX-11: A family of real-time operating systems mainly for PDP-11 computers created by Digital Equipment Corporation (DEC), common in the late 1970s and early 1980s, designed for and much used in process control, but also popular for program development. ... RSTS/E (an acronym for Resource Sharing Time Sharing Extended) was a multi-user time-shared operating system developed by Digital Equipment Corporation (DEC) for the PDP-11 series of 16-bit minicomputers, and used primarily during the 1970s and 1980s, although some installations were still being upgraded well into...

In November 2006, Microsoft released version 1.0 of Windows PowerShell (formerly codenamed Monad), which combined features of traditional Unix shells with their object-oriented penis .NET Framework. MinGW and Cygwin are open source packages for Windows that offers a Unix like CLI. Microsoft provides a Unix CLI for Windows through their Services for UNIX add-on. Microsoft is one of few companies engaging itself in the console wars Where they are up against sony, nintendo, and of course sharps new console which may cause a threat. ... Windows PowerShell, previously Microsoft Shell or MSH (codenamed Monad) is an extensible command line interface (CLI) shell and scripting language product developed by Microsoft. ... This article or section does not adequately cite its references or sources. ... MinGW or Mingw32 (Minimalist GNU for Windows) is a software port of the GNU toolchain to the Win32 platform. ... Cygwin is a collection of free software tools originally developed by Cygnus Solutions to allow various versions of Microsoft Windows to act somewhat like a Unix system. ... Microsoft Windows Services for UNIX (SFU) is a package which provides a Unix compliant environment on Microsoft Windows computers. ...

The latest versions of the Macintosh operating system are based on a variation of UNIX called Darwin. On these computers, users can access a UNIX-like command prompt called terminal found in the /Applications/Utilities folder. The Macintosh 128K, the first Macintosh computer, introduced in 1984, upgraded to a 512K Fat Mac The Macintosh, or Mac, is a line of personal computers designed, developed, manufactured, and marketed by Apple. ...

Anatomy of a CLI

A CLI can generally be considered as consisting of syntax and semantics. The syntax is the grammar that all commands must follow. In the case of Operating Systems (OS), MS-DOS and UNIX each define their own set of rules that all commands must follow. In the case of embedded systems, each vendor, such as Nortel, Juniper Networks or Cisco Systems, each define their own proprietary set of rules that all commands within their CLI conform to. These rules also dictate how a user navigates through the system of commands. For other uses, see Syntax (disambiguation). ... Semantics (Greek semantikos, giving signs, significant, symptomatic, from sema, sign) refers to the aspects of meaning that are expressed in a language, code, or other form of representation. ... In computing, an operating system (OS) is the system software responsible for the direct control and management of hardware and basic system operations. ... Microsofts disk operating system, MS-DOS, was Microsofts implementation of DOS, which was the first popular operating system for the IBM PC, and until recently, was widely used on the PC compatible platform. ... Filiation of Unix and Unix-like systems Unix (officially trademarked as UNIX®) is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. ... What is an Embedded System? Electronic devices that incorporate a computer(usually a microprocessor) within their implementation. ... Northern Telecommunications Networks, commonly known as Nortel, is a telecommunications equipment manufacturer headquartered in Canada. ... Juniper Networks NASDAQ: JNPR is a telecommunications equipment company. ... A Cisco ASM/2-32EM router deployed at CERN in 1987. ...

The semantics define what sort of operations are possible, and on what sort of data these operations can be performed.

It may be possible for two different CLIs to agree on either syntax or semantics, but it is only when they agree on both that they can be considered sufficiently similar to allow users to use both systems without needing to relearn anything as well as enable re-use of scripts.

In its simplest form, a CLI displays a prompt, the user types a command on the keyboard and executes the command (usually with the Enter key), and the computer executes the command, providing textual output. Command Prompt on Windows XP. A command prompt (or just prompt) is a character or string of characters used in a command line interface to indicate that the computer is ready to accept typed input. ...

Unlike a button or menu item in a GUI, a command line is typically self-documenting, stating exactly what the user wants done. In addition, command lines usually include many defaults that can be changed to customize the results. Command-line commands can be saved by assigning a character string or alias to represent the full command, or several commands can be grouped to perform a more complex sequence — for instance, compile the program, install it, and run it — creating a single command, called a command procedure. These advantages mean that a user has to figure out a command or series of commands only once, because they can be saved to use again. Typically, default is the result when no action is taken. ... In various branches of mathematics and computer science, strings are sequences of various simple objects (symbols, tokens, characters, etc. ... In Unix shells (like csh, bash, etc. ...

The commands given to a CLI are often of the form

 [doSomething] [how] [toFiles] 

or

 [doSomething] [how] [sourceFile] [destinationFile] 

or

 [doSomething] [how] < [inputFile] > [outputFile] 

doSomething is, in effect, a verb, how an adverb (for example, should the command be executed "verbosely" or "quietly") and toFiles an object or objects (typically one or more files) on which the command should act. The '>' in the second example is a redirection token, telling the command line interpreter to send the output of the command not to the screen but to the file named on the right of the '>'. Another redirection token is the pipe ('|'), which tells the CLI to use the output of one command as the input to the next command; this "operator-stream" mechanism can be very powerful. This article or section is in need of attention from an expert on the subject. ... An adverb is not a part of speech. ... It has been suggested that this article or section be merged with Tokenizing. ... Vertical bar, verti-bar, vertical line, divider line, or pipe is the name of the character (|). Broken bar (¦) is a separate character. ...

Another aspect of a CLI is navigation. In some CLIs, the commands issued are decoupled from their conceptual place within the command hierarchy. This usually involves being able to specify relative or absolute paths to command and data. Examples of this sort of system include MS-DOS and UNIX, which both provide forms of a change directory command to take users through a set of directories that hold command and data. Other CLIs limit the set of commands that a user can perform to the place within the command hierarchy. The place within the hierarchy and the options available are often referred to as a mode. In these systems the user might traverse through a series of sub-hierarchies, each with their own set of commands. For example, if the CLI had two modes called interfaces and system, the user would enter the word 'interface' at the command prompt and then enter an interface mode. At this point system commands are not accessible and would not be accessible until the user explicitly exits the interface model. Within the interface mode, the user would have access to a series of commands, and perhaps additional command modes.

Command prompt

A command prompt (or just prompt) is a sequence of (one or more) characters used in a command line interface to indicate availability to accept commands. Command prompts usually end with one of the characters $, #, :, > and often include other information, such as the path of the current working directory. For computer operating systems that support a hierarchial file system, the working directory is the directory path that a user or program has designated to be the directory for files referenced by name only, or by a relative path (as contrasted with using both a files name and a...

It is common for prompts to be modifiable by the user. Depending on the environment, they may include colors, special characters, and other elements like the current time, in order, for instance, to make the prompt more informative or visually pleasing, or to easily distinguish sessions on various machines.

In MS-DOS and in the Windows command line interpreter the prompt is modifiable by issuing a prompt command or by changing the value of the %PROMPT% environment variable. The default C:> style is obtained, for instance, with "prompt $P$G". Microsofts disk operating system, MS-DOS, was Microsofts implementation of DOS, which was the first popular operating system for the IBM PC, and until recently, was widely used on the PC compatible platform. ... A command line interpreter is a computer program which reads lines of text that the user types and interprets them in the context of a given operating system or programming language. ... Environment variables are a set of dynamic values that can affect the way running processes will behave on a computer. ...

On Unix systems, the $PS1 variable can be used, although other variables also may have an impact on what appears on the screen (depending on what shell is being used). In the bash shell, a prompt of the form Filiation of Unix and Unix-like systems Unix (officially trademarked as UNIX®) is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. ... Screenshot of a sample Bash session, taken on Gentoo Linux. ... bash is a Unix shell written for the GNU Project. ...

[time] user@host: work_dir $

could be set by issuing the command

export PS1='[t] u@H: $(pwd) $'

CLI vs GUI

The neutrality of this section is disputed. Please see the discussion on the talk page.

Screenshot of the MATLAB 6.5 command line interface and GUI.

1. CLI environments tend to consume less resources than GUIs.
2. CLI applications typically use standard I/O (stdio), allowing them to easily work together in scripts.
3. Some applications provide both a CLI and a GUI.
4. CLIs can be unsuitable for some applications such as raster painting programs
5. GUIs are better suited for devices without keyboards such as PDAs, electronic voting machines, ATMs, arcade machines, electronic gambling machines, or kiosks.

Image File history File links Unbalanced_scales. ... Image File history File links Download high resolution version (1280x994, 39 KB) Summary This is a screenshot showing MATLAB 6. ... Image File history File links Download high resolution version (1280x994, 39 KB) Summary This is a screenshot showing MATLAB 6. ... MATLAB is a numerical computing environment and programming language. ... Palm IIIxe PDA Personal digital assistants (PDAs or palmtops) are handheld devices that were originally designed as personal organizers, but became much more versatile over the years. ... Electronic Voting Machines (EVM) are used in Indian General Elections to implement electronic voting. ... An NCR Personas 85-Series interior, multi-function ATM in the USA Smaller indoor ATMs dispense money inside convenience stores and other busy areas, such as this off-premise Wincor Nixdorf mono-function ATM in Sweden. ... This arcade cabinet, containing Centipede, is an upright. ... a pagoda-like kiosk in Lausanne. ...

References

See also

• In the Beginning...was the Command Line
• Scripting language
• Shell (computing)

In the Beginning. ... Scripting languages (commonly called scripting programming languages or script languages) are computer programming languages that are typically interpreted and can be typed directly from a keyboard. ... In computing, a shell is a piece of software that provides an interface for users (command line interpreter). ...

External links

• Linux Command Line — a list of unix shell commands.
• Command Line Warriors — an open site about Command Line Computing.
• The Interaction-Design.org Encyclopedia entry on Interaction Styles, comparing Command Line Interfaces with other Interaction Styles
• Command lines versus GUIs
• The Windows XP Command Line, Batch Files, and Scripting
• "GetPot. Object oriented command line parsing." Library available for C++, Python, Java, and Ruby.
• "Object-Oriented Command Line Interfaces" — Article describing the use of the TE-Common CLI library for Java (also available for .NET).
• PHP Command Line Interface — All about PHP CLI SAPI (using PHP in command line).
• - Setting up the console for Windows - A basic guide to setting up and using the command line for Windows.
• The Command Line -- The Best Newbie Interface? -- essay/memoir alleging/demonstrating that the CLI is actually more intuitive than the GUI, at least for adult newbies.