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help is a command in various command line shells such as
cmd.exe, Bash, 4DOS/4NT, Windows PowerShell, Singularity shell, Python and GNU Octave. It provides online information about available commands and the shell environment. The command is also available in the DEC RT-11 operating system. On Unix, the command is part of the Source Code Control System and prints help information for the SCCS commands.
commandThis command-line argument specifies the name of the command about which information is to be displayed.
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.HLPfile, 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.exeto open OS/2 style INF files (
doserror.inf), opening these to the appropriate pages.
The 4DOS/4NT help command uses a text user interface to display the online help.
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.INF) in a similar style to MS-DOS 6.
In Windows PowerShell, 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.
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]
Z:\>help If 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. ...
>>> 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". ...
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. ...