Help (command)
Encyclopedia
In computing
,
in various command line shells
such as
/4NT
, Windows PowerShell
, Bash, Singularity shell
, Python
and GNU Octave
. It provides online information
about available commands and the shell environment. It is analogous to the Unix
Arguments:
5.x and later.
If no arguments are provided, the command lists the contents of
to display the online help.
Windows NT
-based versions use MS-DOS 5 style help. Versions before Windows Vista
also have a Windows help file (
, help is a short form (implemented as a PowerShell function) for access to the
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.
help [-dms] [pattern]
Computing
Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...
,
help
is a commandCommand (computing)
In computing, a command is a directive to a computer program acting as an interpreter of some kind, in order to perform a specific task. Most commonly a command is a directive to some kind of command line interface, such as a shell....
in various command line shells
Shell (computing)
A shell is a piece of software that provides an interface for users of an operating system which provides access to the services of a kernel. However, the term is also applied very loosely to applications and may include any software that is "built around" a particular component, such as web...
such as
COMMAND.COMCOMMAND.COMCOMMAND.COM is the filename of the default operating system shell for DOS operating systems and the default command line interpreter on Windows 95, Windows 98 and Windows Me...
, cmd.exeCmd.exeCommand Prompt is the Microsoft-supplied command-line interpreter on OS/2, Windows CE and on Windows NT-based operating systems...
, 4DOS4DOS
4DOS is a command line interpreter by JP Software, designed to replace the default command interpreter COMMAND.COM in DOS and Windows 95/98/Me. The 4DOS family of programs are meant to replace the default command processor. 4OS2 and 4NT replace CMD.EXE in OS/2 and Windows NT respectively...
/4NT
4NT
Take Command Console , formerly known as 4DOS for Windows NT and 4NT, is a command line interpreter by JP Software, designed as a substitute for the default command interpreter in Microsoft Windows...
, Windows PowerShell
Windows PowerShell
Windows PowerShell is Microsoft's task automation framework, consisting of a command-line shell and associated scripting language built on top of, and integrated with the .NET Framework...
, Bash, Singularity shell
Singularity (operating system)
Singularity is an experimental operating system being built by Microsoft Research since 2003. It is intended as a highly-dependable OS in which the kernel, device drivers, and applications are all written in managed code.- Workings :...
, Python
Python (programming language)
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...
and GNU Octave
GNU Octave
GNU Octave is a high-level language, primarily intended for numerical computations. It provides a convenient command-line interface for solving linear and nonlinear problems numerically, and for performing other numerical experiments using a language that is mostly compatible with MATLAB...
. It provides online information
Online help
Online help is topic-oriented, procedural or reference information delivered through computer software. It is a form of user assistance. Most online help is designed to give assistance in the use of a software application or operating system, but can also be used to present information on a broad...
about available commands and the shell environment. It is analogous to the Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
manManual page (Unix)Man pages are the extensive documentation that comes preinstalled with almost all substantial Unix and Unix-like operating systems. The Unix command used to display them is man. Each page is a self-contained document.- Usage :...
command. Help means to save someone when they are in danger.Syntax
help [command]Arguments:
command
This command-line argument specifies the name of the command about which information is to be displayed.
DOS
The help command is available in MS-DOSMS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
5.x and later.
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 QBasicQBasicQBasic is an IDE and interpreter for a variant of the BASIC programming language which is based on QuickBASIC. Code entered into the IDE is compiled to an intermediate form, and this intermediate form is immediately interpreted on demand within the IDE. It can run under nearly all versions of DOS...
to view a quickhelpHELP.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 9xWindows 9xWindows 9x is a generic term referring to a series of Microsoft Windows computer operating systems produced since 1995, which were based on the original and later modified Windows 95 kernel...
CD-ROM versions as well. - PC-DOSPC-DOSIBM PC DOS is a DOS system for the IBM Personal Computer and compatibles, manufactured and sold by IBM from the 1980s to the 2000s....
7.xx help usesview.exe
to open OS/2 style INF fileINF fileAn INF file or Setup Information file, is a plain text file used by Microsoft Windows for installation of software and drivers. INF files are most commonly used for installing device drivers for hardware components. Windows includes IExpress.exe for the creation of INF-based installations...
s (cmdref.inf
,dosrexx.inf
anddoserror.inf
), opening these to the appropriate pages.
4DOS/4NT
The 4DOS/4NT help command uses a text user interfaceText user interface
TUI short for: Text User Interface or Textual User Interface , is a retronym that was coined sometime after the invention of graphical user interfaces, to distinguish them from text-based user interfaces...
to display the online help.
cmd.exe
Used without parameters, help lists and briefly describes every system command.Windows NT
Windows NT
Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix. It was intended to complement...
-based versions use MS-DOS 5 style help. Versions before Windows Vista
Windows Vista
Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
also have a Windows help file (
NTCMDS.HLP
or NTCMDS.INF
) in a similar style to MS-DOS 6.Windows PowerShell
In Windows PowerShellWindows PowerShell
Windows PowerShell is Microsoft's task automation framework, consisting of a command-line shell and associated scripting language built on top of, and integrated with the .NET Framework...
, 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
In 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] [pattern]