Emacs for development and more

Lots of students "have to" use Emacs in different course, e.g. some programming courses. This is a little introduction for students who have not used Emacs before.

Java-mode

Java-mode helps you indent the code correctly, gives you color syntax and some other functionality. If Emacs does not load java-mode when you open a java source-file, you have to add ".java" in a variable called auto-mode-alist. Try the follwing code:

      (setq auto-mode-alist (append
                             (list
                              '("\\.cc$" . c-mode)
                              '("\\.c$" . c-mode)
                              '("\\.C$" . c-mode)
                              '("\\.pl$" . perl-mode)
                              '("\\.el$" . lisp-mode)
                              '("\\.html$" . html-helper-mode)
                              '("\\.java$" . java-mode)
                             )
                            auto-mode-alist))
    

Here you see several examples to get different modes depending on the filename. This assumes that you have the different modes installed on your computer, and that's usually no problem if you have a standard Emacs-installation.

To activate this feature immediately set the cursor after the last parenthesis and press C-x C-e (read about keystrokes [1]). To make the changes permanent place the code above your startup-file (.emacs).

Syntax highlighting

font-lock-mode

There are several packages which can give you nice colors in Emacs. The most widely used is font-lock which gives you nice colors in most of the modes. font-lock is a part of the standard Emacs-distribution.

The easiest way to load font-lock-mode is to add the following line to your start-up file[2]:

      (global-font-lock-mode)
    

JDEE

JDEE is a package which does more than just coloring and indenting your code. It also makes it easier to run different java-programs, e.g. java and javac. It gives you a Speed bar which gives you a nice overview of the code and lots of other features. JDEE has a web site , with user manual (which also is a part of the JDEE-installation).

You can find a nice picture, installation procedure and download link here . Note that the startup file on this page is made for Emacs 19.34. To set up JDEE for newer version of Emacsen (note the plural form ;)) you usually just need to add following lines in your start-up file:

(Provided that JDEE is installed in /emacs/lisp/jde-2.1.4 in your home directory)[3].

      (add-to-list 'load-path (expand-file-name "~/emacs/lisp/jde-2.1.4"))
      (autoload 'jde-mode "jde" "Java Development Enviroment" t)
    

Now you can load JDE with the commando M-x jde and the press enter. To make Emacs start JDE automatically you have to adjust the variable auto-mode-alist (see the section above about font-lock). Just replace java-mode (in the code) with jde-mode.

Commands to make Emacs a even better friend

C-h is almost the most important keystroke in Emacs. You use it to access the help-function.

Useful links

• Gnu Emacs' homepage
• GNU Emacs FAQ For Windows 95/98/ME/NT/XP and 2000
• Gnus - read news and mail with Emacs