3.3 Help

The editor provides a number of on-line help facilities, covering a range of areas.

There is one main help command, accessed by Help (Ctrl+H), with many options to give you a wide range of help on editor commands, variables and functions.

There are also further help commands which provide information on Lisp symbols (see 4.8 Documentation).

3.3.1 The help command

Help Editor Command

Options: See below
Key sequence: Ctrl+H option

Provides on-line help. Depending on what information the user has and the type of information required, one of the following options should be selected after invoking the Help command. In most cases a Help command plus option can also be invoked by an extended editor command.

A brief summary of the help options is given directly below, with more detailed information following.

`?`	Display a list of help options.
`q` or `n`	Quit help.
`a` `string`	Display a list of symbols whose names match `string`, in a Symbol Browser tool.
`b`	Display a list of key bindings and associated commands.
`c` `key`	Display the command to which key is bound.
`d` `command`	Describe the editor `command`.
`Ctrl+D` `command`	Bring up the on-line version of this manual for `command`.
`g` `object`	Invoke the appropriate describe `object` command.
`k` key	Describe the command to which `key` is bound.
`Ctrl+K` `key`	Bring up the on-line version of this manual for `key`.
`l`	describe the last 60 keys typed.
`v` `variable`	Describe `variable` and show its current value.
`Ctrl+V` `variable`	Bring up the on-line version of this manual for `variable`.
`w` `command`	Display the key sequence to which `command` is bound.

Apropos Command Editor Command

Arguments: string
Key sequence: None

Displays a list of editor commands, variables, and attributes whose names contain string, in a Help window.

Editor command, variable and attribute names tend to follow patterns which becomes apparent as you look through this manual. For example, commands which perform operations on files tend to contain the string file, that is, Find File, Save File, Print File and so forth.

Use this form of help when you know what you would like to do, but do not know a specific command to do it.

What Command Editor Command

Arguments: key
Key sequence: Ctrl+H C key

Displays the command to which key is bound. For a more detailed description of key use the command Describe Key.

Use this form of help when you know a default binding but want to know the command name.

Note: this command is also available via the menu command Help > Editing > Key to Command.

Describe Command Editor Command

Arguments: command#
Key sequence: Ctrl+H D command

Describes the editor command command. Full documentation of that command is printed in a Help window.

Use this form of help when you know a command name and require full details of that command.

Document Command Editor Command

Arguments: command
Key sequence: Ctrl+H Ctrl+D command

Brings up the on-line version of this manual at the entry for command.

The documentation in the on-line manual differs from the editor on-line help (as produced by Describe Command), but provides similar information. If you are used to the layout and definitions provided in this manual then use this help command instead of Ctrl+H D.

Generic Describe Editor Command

Arguments: object
Key sequence: Ctrl+H G object

Describes object, where object may take the value command, key, attribute or variable.

If object is command, key or variable then the command Describe Command, Describe Key or Describe Editor Variable is invoked respectively.

There is no corresponding describe command if the object is attribute. Attributes are things such as word delimiters, Lisp syntax and parse field separators. If you are not sure of the attributes documented remember that you can press Tab to display a completion list.

Describe Key Editor Command

Arguments: key
Key sequence: Ctrl+H K key

Describes the command to which key is bound. Full documentation of that command is printed in a Help window.

Use this form of help when you know a default binding and require the command name plus full details of that command.

Document Key Editor Command

Arguments: key
Key sequence: Ctrl+H Ctrl+K key

Brings up the on-line version of this manual at the entry for key.

The documentation in the on-line manual differs slightly from the editor on-line help but usually provides you with the same amount of information. If you are used to the layout and definitions provided in this manual then use this help command instead of Describe Key.

What Lossage Editor Command

Arguments: None
Key sequence: Ctrl+H L

Displays the last 60 keys typed.

Describe Editor Variable Editor Command

Arguments: variable
Key sequence: Ctrl+H V variable

Describes variable and prints its current value in a Help window.

Use this form of help when you know a variable name and require a description of that variable and/or its current value.

Document Variable Editor Command

Arguments: variable
Key sequence: Ctrl+H Ctrl+V variable

Brings up the on-line version of this manual at the entry for variable.

Where Is Editor Command

Arguments: command
Key sequence: Ctrl+H W command

Displays the key sequence to which command is bound.

Use this form of help if you know a command name and wish to find the bindings for that command. If no binding exists then a message to this effect is returned.

Note: this command is also available via the menu command Help > Editing > Command to Key.

Describe Bindings Editor Command

Arguments: None
Key sequence: Ctrl+H B

Displays a list of key bindings and associated commands in a Help window. First the minor and major mode bindings for the current buffer are printed, then the global bindings.

3.3.2 Other help commands on UNIX and macOS

Manual Entry Editor Command

Arguments: unix-command
Key sequence: l
Mode: Manual Entry

This command is not implemented on Microsoft Windows.

Displays the UNIX manual page for unix-command. The UNIX utility man is invoked and the manual page is displayed in an Editor window.

The buffer is in Manual Entry mode and you can navigate using keys p, n, s and so on - use Describe Bindings to see all the Manual Entry mode keys.

With no prefix argument, the same buffer is used each time. With a prefix argument, a new buffer is created for each manual page accessed.