help (command)

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In computing, help is a command in various non-UNIX command line shells such as COMMAND.COM, cmd.exe, Bash, 4DOS/4NT, Windows PowerShell, Singularity shell, Python and GNU Octave. It provides online information about available commands and the shell environment.

On UNIX, help is part of the Source Code Control System. and prints help information for the SCCS commands.

Syntax[edit]

help [command]

Arguments:

  • command This command-line argument specifies the name of the command about which information is to be displayed.

Implementations[edit]

DOS[edit]

The help command is available in MS-DOS 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. In DR-DOS, HELP is a batch file that launches DR-DOS' internal help program, DOSBOOK.

  • The MS-DOS 6.xx help command uses QBasic 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 CD-ROM versions as well.
  • PC DOS 7.xx help uses view.exe to open OS/2 style INF files (cmdref.inf, dosrexx.inf and doserror.inf), opening these to the appropriate pages.

4DOS/4NT[edit]

The 4DOS/4NT help command uses a text user interface to display the online help.

cmd.exe[edit]

Used without parameters, help lists and briefly describes every system command. Windows NT-based versions use MS-DOS 5 style help. Versions before Windows Vista also have a Windows help file (NTCMDS.HLP or NTCMDS.INF) in a similar style to MS-DOS 6.

Windows PowerShell[edit]

In Windows PowerShell, 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[edit]

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]

Examples[edit]

DOS[edit]

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

Python[edit]

>>> 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[edit]

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 <topic>' to search the manual index.
...

See also[edit]

References[edit]