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In computing, help is a command in various 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. 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.
Contents
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-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.
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.view.exe to open OS/2 style INF files (cmdref.inf, dosrexx.inf and doserror.inf), opening these to the appropriate pages.4DOS/4NT
The 4DOS/4NT help command uses a text user interface to display the online help.
cmd.exe
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
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
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]