Tips and a summary of most common and useful commands for finding help in Emacs.

emacs-finding-help.txt

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                             EMACS SUMMARY

                             Fernando Basso
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Table of Contents
─────────────────

1 Help in Emacs                                                   :help:
.. 1.1 Basic Concepts                                         :concepts:
.. 1.2 List of useful commands                                :commands:
..... 1.2.1 Apropos





1 Help in Emacs                                                   :help:
═══════════════

  Knowing how to obtain help inside Emacs is important!


1.1 Basic Concepts                                            :concepts:
──────────────────

  `META' is `Alt'. `M-a' is `Alt-a'.

  `CTRL' is `Control', and `C-c' is `Ctrl-c'.

  `Shift' is `S'.

  `Delete' is the `Delete' key. Not to be confused with `DEL' which is
  the `Backspace' key.

  `C-f' is a single input event but not a complete key (it waits for
  some other input events to make a complete key).

  `C-x C-f' is two input events and they form a complete key because
  they indeed invoke a function (`find-file' in this case).

  *key sequence* (or key, for short) → one or more input events that is
  meaningful as a unit.  If it invokes a command, we call it a *complete
  key*. If it isn't long enough to invoke a command, we call it a
  *prefix key*.

  `C-x' and `C-x 4' are prefix keys, whereas `C-/' or `C-x C-s' are
  complete keys.

  A prefix key makes emacs wait for further input, a complete key does
  not and it invokes a command.

  By default, the prefix keys in Emacs are `C-c', `C-h', `C-x', `C-x
  <RET>', `C-x @', `C-x a', `C-x n', `C-x r', `C-x v', `C-x 4', `C-x 5',
  `C-x 6', `<ESC>', `M-g', and `M-o'.  (`<F1>' and `<F2>' are aliases
  for `C-h' and `C-x 6'.)

  Try those prefix keys followed by `C-h', for instance, `C-x C-h', `C-x
  a C-h' or `M-g C-h'.

  `C-h' is the “help” prefix key.


1.2 List of useful commands                                   :commands:
───────────────────────────

  Tutorial:

  ┌────
  │ C-h t
  └────

  Show all key bindings:

  ┌────
  │ C-h b
  └────

  General help:

  ┌────
  │ C-h C-h
  │ C-h C-?
  └────

  Describe input key/event and see what function it invokes:

  ┌────
  │ C-h k (describe-key)
  │ C-h k <some input keys>
  │ C-h k C-x C-s
  │ C-h c (describe-key-briefly)
  │ C-h c C-x C-s
  └────

  Describe a function and see which key bindings (if any) invoke it:

  ┌────
  │ C-h f (describe-function)
  │ C-h f <some function>
  │ C-h f next-line
  └────

  Information about the current major mode:

  ┌────
  │ C-h m
  └────

  And that tells you that the prefix key is, say, `C-c'. Now you can do

  ┌────
  │ C-c C-h
  └────

  to see all key bindings for that mode.

  Key bindings and help for a specific mode, like the “Rectangles” mode:

  ┌────
  │ C-x r ?
  │ C-x r C-h
  │ C-h i m Emacs RET m Rectangles RET
  │ M-x info-emacs-manual RET m Rectangles RET
  └────


  Documentation for a variable:

  ┌────
  │ C-h v <variable name>
  │ C-h v inhibit-startup-screen
  │ C-h v initial-buffer-choice
  └────


1.2.1 Apropos
╌╌╌╌╌╌╌╌╌╌╌╌╌

  Find help about something, using a string as the search:

  ┌────
  │ M-x apropos RET <string> RET
  │ M-x apropos RET insert RET
  │ M-x apropos RET truncate RET
  └────