10. Help

Af provides extensive help features accessible through the command C-h (help-command). C-h is a prefix key that is used only for documentation-printing commands. The characters that you can type after C-h are called help options. One help option is C-h; that is how you ask for help about using C-h. To cancel, type C-g.

C-h C-h displays a list of the possible help options. Typing C-h again displays a longer list of the options, each with a brief description.

10.1 Documentation for a Key		Asking what a key does in af.
10.2 Help by Command, Mode or Variable Name		Asking about a things via their names.
10.3 Help for Lists of Things		Asking for lists of things.
10.4 Apropos		Asking what pertains to a given topic.
10.5 Other Help Commands		Other help commands.

10.1 Documentation for a Key

The most basic C-h options are C-h c (describe-key-briefly) and C-h k (describe-key). C-h c key prints in the echo area the name of the command that key is bound to. For example, C-h c C-n prints `next-line'. Since command names are chosen to describe what the commands do, this is a good way to get a very brief description of what key does.

C-h k key is similar but gives more information: it displays the documentation string of the command as well as its name. This is too big for the echo area, so typeout is used for the display.

10.2 Help by Command, Mode or Variable Name

C-h f (describe-function) reads the name of an af command, keyboard macro or afl function using the minibuffer, then displays that function's documentation string to typeout. For example,

C-h f delete-message RET

displays the documentation of delete-message. This is the only way to get the documentation of a command that is not bound to any key (one which you would normally run using M-x).

C-h v (describe-variable) is like C-h f but describes configuration variables instead of commands and functions (see section 21.4 Variables).

C-h m (describe-mode) is also like C-h f but describes major and minor modes rather than commands and functions (see section 3.3 Major Modes).

10.3 Help for Lists of Things

C-h b (list-bindings) displays the current key bindings active in af to typeout. The global bindings are shown first, and then those for each of the major modes. This be quite a long list, but might be useful as a wall chart.

C-h d (list-commands) lists all of af's commands, with their bindings, to typeout. Bindings which only take effect in mail mode are listed in square brackets (eg `[M-s]'). Bindings for typeout mode only are listed in braces (eg `{C-f}'). Bindings that are minibuffer-specific are listed in parentheses (eg `(SPC)').

C-h C-f lists all of the afl functions to typeout. Only those functions which are not also commands are listed. This is quite a short list at present (see section 22. Afl).

C-h C-k list-kbd-macros lists all of the named keyboard macros, with their values, to typeout (see section 21.5 Keyboard Macros).

C-h C-v lists all of the af configuration variables, with their values, to typeout (see section 21.4 Variables).

C-h C-a (list-aliases) lists all the mail aliases you have defined to typeout, along with their values (see section 8.7 Defining and Using Mail Aliases).

10.4 Apropos

A more sophisticated sort of question to ask is, "What is relevant for working with messages?" To ask this question, type C-h a message RET, which displays a list of all command, function, keyboard macro and variable names that contain `message', including open-message, print-message, and so on. The bindings for each command is listed with that command, in the same format as list-bindings (see section 10.3 Help for Lists of Things). Similarly the values of keyboard macros and variables are listed. The a in C-h a stands for `Apropos'; C-h a runs the command command-apropos.

Because C-h a looks only for things whose names contain the string which you specify, you must use ingenuity in choosing the string. If you are looking for commands for reading messages and C-h a read-message RET doesn't reveal any, don't give up. Try just read, or just message. Be persistent. Also note that you can use a regular expression as the argument, for more flexibility (see section 15.4 Syntax of Regular Expressions).

Here is a set of arguments to give to C-h a that covers many classes of af commands, since there are strong conventions for naming the standard af commands. By giving you a feel for the naming conventions, this set should also serve to aid you in developing a technique for picking apropos strings.

char, line, word, region, list, buffer, window, file, mode, beginning, end, forward, backward, next, previous, up, down, search, goto, kill, delete, mark, insert, yank, case, set, what, view, describe, default, print, page, message, send.

10.5 Other Help Commands

C-h i (info) runs the Info program, which is used for browsing through structured documentation files. The entire af manual is available within Info. Type h after entering Info to run a tutorial on using Info.

If something surprising happens, and you are not sure what commands you typed, use C-h l (view-lossage). C-h l prints the last 100 command characters you typed in. If you see commands that you don't know, you can use C-h c to find out what they do.

Af has numerous major modes, each of which redefines keys and alters the behaviour of some commands. C-h j (describe-major-mode) prints documentation on the current major mode to typeout.

The other C-h options display assorted useful information. C-h n (view-af-news) displays information on recent changes to af. C-h C-w (display-no-warranty) displays details on the complete absence of warranty for af. C-h C-c (describe-copying) displays the conditions you must obey in distributing copies of af.