computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...

, help is a

command Command may refer to: Computing * Command (computing), a statement in a computer language * COMMAND.COM, the default operating system shell and command-line interpreter for DOS * Command key, a modifier key on Apple Macintosh computer keyboards * ...

in various

command line 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 pro ...

shells such as

COMMAND.COM 





COMMAND.COM is the default command-line interpreter for MS-DOS, Windows 95, Windows 98 and Windows Me. In the case of DOS, it is the default user interface as well. It has an additional role as the usual first program run after boot (init proc ...

cmd.exe 





Command Prompt, also known as cmd.exe or cmd, is the default command-line interpreter for the OS/2, eComStation, ArcaOS, Microsoft Windows (Windows NT family and  Windows CE family), and ReactOS operating systems. On Windows CE .NET 4.2, Windo ...

Bash Bash or BASH may refer to: Arts and entertainment * ''Bash!'' (Rockapella album), 1992 * ''Bash!'' (Dave Bailey album), 1961 * '' Bash: Latter-Day Plays'', a dramatic triptych * ''BASH!'' (role-playing game), a 2005 superhero game * "Bash" ('' ...

, qshell, 4DOS/ 4NT,

Windows PowerShell PowerShell is a task automation and configuration management program from Microsoft, consisting of a command-line shell and the associated scripting language. Initially a Windows component only, known as Windows PowerShell, it was made open-so ...

, Singularity shell,

Python Python may refer to: Snakes * Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia ** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia * Python (mythology), a mythical serpent Computing * Python (pro ...

MATLAB MATLAB (an abbreviation of "MATrix LABoratory") is a proprietary multi-paradigm programming language and numeric computing environment developed by MathWorks. MATLAB allows matrix manipulations, plotting of functions and data, implementa ...

and

GNU Octave GNU Octave is a high-level programming language primarily intended for scientific computing and numerical computation. Octave helps in solving linear and nonlinear problems numerically, and for performing other numerical experiments using a langu ...

. It provides online information about available commands and the shell environment.

Implementations

The command is available in

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

s such as

Multics 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 ...

Heath Company Heathkit is the brand name of kits and other electronic products produced and marketed by the Heath Company. The products over the decades have included electronic test equipment, high fidelity home audio equipment, television receivers, amateu ...

HDOS HDOS is an early microcomputer operating system, originally written for the Heathkit H8 computer system and later also available for the Heathkit H89 and Zenith Z-89 computers. The author was Heath Company employee Gordon Letwin, who later was ...

DOS DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems. DOS may also refer to: Computing * Data over signalling (DoS), multiplexing data onto a signalling channel * Denial-of-service attack (DoS), an attack on a communicat ...

, IBM

OS/2 OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 r ...

eComStation eComStation or eCS is an operating system based on OS/2 Warp for the 32-bit x86 architecture. It was originally developed by Serenity Systems and Mensys BV under license from IBM. It includes additional applications, and support for new hard ...

, ArcaOS, IBM i,

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

, ReactOS, THEOS/OASIS, Zilog

Z80-RIO The Z80 Operating System with Relocatable Modules and I/O Management (Z80-RIO) is a general-purpose operating system developed by Zilog in the late 1970s for various computer systems including the ''Z80 Micro Computer System'' (MCZ-1) series and t ...

Microware Microware Systems Corporation was an American software company based in Clive, Iowa, that produced the OS-9 real-time operating system. Microware Systems Corporation existed as a separate entity from 1977 until September 2001, when it was bought ...

OS-9 OS-9 is a family of real-time, process-based, multitasking, multi-user operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. It was purchased by Radisys Corp in 2001, an ...

Stratus Stratus may refer to: Weather *Stratus cloud, a cloud type **Nimbostratus cloud, a cloud type **Stratocumulus cloud, a cloud type **Altostratus cloud, a cloud type **Altostratus undulatus cloud, a cloud type **Cirrostratus cloud, a cloud type Mus ...

OpenVOS, HP MPE/iX,

Motorola Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorol ...

VERSAdos VERSAdos is an operating system dating back to the early 1980s for use on the Motorola 68000 development system called the ''EXORmacs'' which featured the VERSAbus and an array of option cards. They were typically connected to CDC Phoenix disk driv ...

KolibriOS KolibriOS, or Kolibri, is a small, open-source x86 operating system written completely in assembly. It was forked from MenuetOS in 2004 and has run under independent development since. In a 2009 review piece on alternative operating systems, ...

and also in the DEC

RT-11 RT-11 (Real-time 11) is a discontinued small, low-end, single-user real-time operating system for the full line of Digital Equipment Corporation PDP-11 16-bit computers. RT-11 was first implemented in 1970. It was widely used for real-time computin ...

RSX-11 RSX-11 is a discontinued family of multi-user real-time operating systems for PDP-11 computers created by Digital Equipment Corporation. In widespread use through the late 1970s and early 1980s, RSX-11 was influential in the development of later ...

TOPS-10 TOPS-10 System (''Timesharing / Total Operating System-10'') is a discontinued operating system from Digital Equipment Corporation (DEC) for the PDP-10 (or DECsystem-10) mainframe computer family. Launched in 1967, TOPS-10 evolved from the earlie ...

and

TOPS-20 The TOPS-20 operating system by Digital Equipment Corporation (DEC) is a proprietary OS used on some of DEC's 36-bit mainframe computers. The Hardware Reference Manual was described as for "DECsystem-10/DECSYSTEM-20 Processor" (meaning the DEC PDP- ...

operating systems. Furthermore it is available in the open source

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few ope ...

emulator In computing, an emulator is hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run software or use pe ...

DOSBox DOSBox is a free and open-source emulator which runs software for MS-DOS compatible disk operating systems—primarily video games. It was first released in 2002, when DOS technology was becoming obsolete. Its adoption for running DOS games i ...

and in the EFI shell. On

Unix 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, an ...

, the command is part of the

Source Code Control System Source Code Control System (SCCS) is a version control system designed to track changes in source code and other text files during the development of a piece of software. This allows the user to retrieve any of the previous versions of the origin ...

and prints help information for the SCCS commands.

Multics

The

help command prints descriptions of system commands/active functions and

subroutine In computer programming, a function or subroutine is a sequence of program instructions that performs a specific task, packaged as a unit. This unit can then be used in programs wherever that particular task should be performed. Functions may ...

s. It also prints various information about the system status, system changes, and other general information. This information is selected from segments maintained online, which are in a special format, called information segments. More than 800 information segments are available.

DEC OS/8

The DEC

OS/8 OS/8 is the primary operating system used on the Digital Equipment Corporation's PDP-8 minicomputer. PDP-8 operating systems which precede OS/8 include: * R-L Monitor, also referred to as MS/8. * P?S/8, requiring only 4K of memory. * PDP-8 4K ...

CCL help command prints information on specified OS/8 programs."Concise Command Language" (CCL).

DOS

MS-DOS

The help command is available in

5.x and later versions of the software. The help command with a 'command' parameter would give help on a specific command. If no arguments are provided, the command lists the contents of DOSHELP.HLP. In MS-DOS 6.x this command exists as FASTHELP. The MS-DOS 6.xx help command uses

QBasic QBasic is an integrated development environment (IDE) and interpreter for a variety of dialects of BASIC which are based on QuickBASIC. Code entered into the IDE is compiled to an intermediate representation (IR), and this IR is immediately e ...

to view a quickhelp HELP.HLP file, which contains more extensive information on the commands, with some hyperlinking etc. The MS-DOS 6.22 help system is included on

Windows 9x Windows 9x is a generic term referring to a series of Microsoft Windows computer operating systems produced from 1995 to 2000, which were based on the Windows 95 kernel and its underlying foundation of MS-DOS, both of which were updated in su ...

CD-ROM versions as well.

PC DOS

PC DOS PC or pc may refer to: Arts and entertainment * Player character or playable character, a fictional character controlled by a human player, usually in role-playing games or computer games * '' Port Charles'', an American daytime TV soap opera * ...

5 and 6 help is the same form as MS-DOS 5 help command. PC DOS 7.xx help uses view.exe to open OS/2 style

INF file Inf or INF may refer to: Politics * Intermediate-Range Nuclear Forces Treaty, a 1987 arms control treaty between the United States and the Soviet Union * International Naturist Federation, the global umbrella organisation representing official ...

s (cmdref.inf, dosrexx.inf and doserror.inf), opening these to the appropriate pages.

PC-MOS

The Software Link's

PC-MOS PC-MOS/386 is a multi-user, multitasking computer operating system produced by The Software Link (TSL), announced at COMDEX in November 1986 for February 1987 release. PC-MOS/386, a successor to PC-MOS, can run many MS-DOS programs on the host ...

includes an implementation of help. Like the rest of the operating system, it is licensed under the

GPL v3 The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general u ...

DR-DOS

In DR-DOS, help is a

batch file Batch may refer to: Food and drink * Batch (alcohol), an alcoholic fruit beverage * Batch loaf, a type of bread popular in Ireland * A dialect term for a bread roll used in North Warwickshire, Nuneaton and Coventry, as well as on the Wirra ...

that launches DR-DOS' internal help program, dosbook.

ROM-DOS

Datalight Datalight was a privately held software company specializing in power failsafe and high performance software for preserving data integrity in embedded systems. The company was founded in 1983 by Roy Sherrill, and is headquartered in Bothell, Was ...

ROM-DOS Datalight was a privately held software company specializing in power failsafe and high performance software for preserving data integrity in embedded systems. The company was founded in 1983 by Roy Sherrill, and is headquartered in Bothell, Washi ...

includes an implementation of the command. ROM-DOS was introduced in 1989 as an MS-DOS compatible operating system designed for embedded systems.

FreeDOS

The

FreeDOS FreeDOS (formerly Free-DOS and PD-DOS) is a free software operating system for IBM PC compatible computers. It intends to provide a complete MS-DOS-compatible environment for running Legacy system, legacy software and supporting embedded system ...

version was developed by Joe Cosentino.

4DOS/4NT

The 4DOS/4NT help command uses a

text user interface In computing, text-based user interfaces (TUI) (alternately terminal user interfaces, to reflect a dependence upon the properties of computer terminals and not just text), is a retronym describing a type of user interface (UI) common as an ear ...

to display the online help.

cmd.exe

Used without parameters, help lists and briefly describes every system command.

Windows NT Windows NT is a proprietary graphical operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems sc ...

-based versions use MS-DOS 5 style help. Versions before

Windows Vista Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...

also have a Windows help file (NTCMDS.HLP or NTCMDS.INF) in a similar style to MS-DOS 6.

PowerShell

PowerShell PowerShell is a task automation and configuration management program from Microsoft, consisting of a command-line shell (computing), shell and the associated scripting language. Initially a Windows component only, known as Windows PowerShell, it ...

, help is a short form (implemented as a PowerShell function) for access to the Get-Help Cmdlet. Windows PowerShell includes an extensive, console-based help system, reminiscent of man pages in Unix. The help topics include help for cmdlets, providers, and concepts in PowerShell.

GNU Bash

, the builtin command help' lists all Bash builtin commands if used without arguments. Otherwise, it prints a brief summary of a command. Its syntax is: help dms attern

OpenVMS

HELP is a DCL utility that contains information on the use of commands and descriptions of some OpenVMS concepts such as time formats and lexical functions, as well as lists of commands for a particular purpose (HELP Hints).

Syntax

The command-

syntax In linguistics, syntax () is the study of how words and morphemes combine to form larger units such as phrases and sentences. Central concerns of syntax include word order, grammatical relations, hierarchical sentence structure ( constituency) ...

is: help ommand Arguments: *command This

command-line argument 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 pro ...

specifies the name of the command about which information is to be displayed.

Examples

DOSBox

Z:\>help If you want a list of all supported commands type help /all . A short list of the most often used commands: Directory View. Display/changes the current directory. Clear screen. Copy files. ...

Python

>>> help Type help() for interactive help, or help(object) for help about object. >>> help() Welcome to Python 2.5! This is the online help utility. If this is your first time using Python, you should definitely check out the tutorial on the Internet at https://www.python.org/doc/tut/. Enter the name of any module, keyword, or topic to get help on writing Python programs and using Python modules. To quit this help utility and return to the interpreter, just type "quit". ...

GNU Octave

octave-3.0.0.exe:1> help Help is available for the topics listed below. Additional help for built-in functions and operators is available in the on-line version of the manual. Use the command `doc ' to search the manual index. ...

References

External links

help , Microsoft Docs
{{Unix commands Multics commands External DOS commands MSX-DOS commands OS/2 commands ReactOS commands Windows commands IBM i Qshell commands Microcomputer software Windows administration Technical communication Online help