[Download postscript version]

 

Getting more information

This brief chapter on emacs tricks is far from being complete. Emacs provides many more capabilities. To inform and help the user, emacs provides two different help systems, info and ``normal'' help. The normal help system is called by typing C-h and the info system with M-x info or C-h i.

The help system provides powerful functions for quickly finding the desired information. Table 8 explains some of the capabilities.

 

Key Action Explanation

C-h a command apropos Shows all the commands that contain a string entered in form of a regular expression. Typing just Return shows a list of the ~1000 commands. If you would like to know about the different search functions, try C-h a search and you will find out about interesting commands, such as M-x tags-search.

C-h b describe bindings All active key bindings are shown within the corresponding mode. This feature is invaluable for example in Bib TeX mode, with its dozens of special bindings. Further, commands you knew they existed but did not dare to ask for, are listed.

C-h c describe key briefly Describes the function that is bound to a certain key shortcut.

C-h f describe function Gives a description of the function.

C-h C-f info about function Jumps to the info page describing the function specified. This facility also gives you background information about the command. Further, similar functions are also described on the same info page, which is also very useful.

C-h m describe mode Gives a thorough description about the current mode used.

C-h w Where is the function This help function shows you how a given function can be called. It will display the shortcut key or where to find the function in the menu.

The info pages provide detailed help on a program. Emacs is just one of the chapters of the info system, which is invoked by typing M-x info. Table 9 shows some of the valid commands in info mode.

 

Key Action Explanation

? help about info Displays the valid info commands briefly.

d jump to root node Takes you back to the first info node.

m visit topic Pick menu item specified by name or abbreviation.

u up one level Go back to next higher page (usually to the page where we typed ``m'').

l last page Go back to the last page visited.

s search regexp Search the regexp on the current page.

1, 2, ... visit nth entry Opens the nth menu entry of the current page.

Especially for GNU programs, the provided information is excellent. It contains examples, background information, cross references to follow, etc. Info is also a separate program, you can call it from the shell, for example info gcc will open directly the gcc section.