8.2 Init File Examples

For customizing Emacs, you need to put Lisp expressions in your init.el file. The following are some useful Lisp expressions. If you find any of them useful, just type them in your init.el file:

• The following expression will make TAB in C mode insert a real tab character if the cursor or point is in the middle of the line. Now hitting the TAB key will indent a line only if the cursor is at the left margin or in the line’s indentation:

  (setq c-tab-always-indent nil)
  

  The value of the variable c-tab-always-indent is usually ‘t’ for ‘true’. When this variable is true, then hitting the TAB key always indents the current line.

• This expression will turn on the auto-fill-mode when you are in text mode:

  (setq text-mode-hook 'turn-on-auto-fill)
  

  This mode will automatically break lines when you type a space so that the lines don’t become too long. The length of the lines is controlled by the variable fill-column. You can set this variable to a value you wish. Look at the documentation for this variable to see its default value. To change the value to 75 for example, use:

  (setq-default fill-column 75)
  

  This will change the value of this variable globally.

• The following expression will enable the use of eval-expression without confirmation:

  (put 'eval-expression 'disabled nil)
  

  Now when you use eval-expression, it will print the value of the expression you specify in the echo area without confirming with you.

• This expression will remove the binding of C-x C-c, because its easy to hit this key by mistake and you will exit Emacs unintentionally. You can use the Exit Emacs option from the File menu to exit Emacs.

  (global-set-key "\C-x\C-c" nil)
  

  Now if you type C-x C-c, you won’t exit Emacs.

• The following expression will make the BACKSPACE and the DEL key work in the same manner:

  (global-set-key 'backspace [delete])
  

• This expression will make searches case sensitive:

  (setq-default case-fold-search nil)
  

  If we use "setq" instead of "setq-default" then searches will be case-sensitive only in the current buffer’s local value. In this case the buffer would be the init.el file. Since this would not be too helpful and we want to have case-sensitive searches in all buffers, we have to use "setq-default".

• This expression will enable the font-lock mode when you are using texinfo mode:

  (add-hook 'texinfo-mode-hook 'turn-on-font-lock)
  

  See Minor Modes, for information on font-lock mode.

• Rebinds the key C-x l to run the function make-symbolic-link:

  (global-set-key "\C-xl" 'make-symbolic-link)
  

  We use the single quote before "make-symbolic-link" because its a function name. You can also use the following expression which does the same thing:

  (define-key global-map "C-xl" 'make-symbolic-link)
  

• The following expression will bind C-x l to run the function make-symbolic-link in C mode only:

  (define-key c-mode-map "C-xl" 'make-symbolic-link)
  

  Instead of binding C-xl to run make-symbolic-link, you can bind the F1 key to run this function:

  (define-key c-mode-map 'f1 'make-symbolic-link)
  

  Here, you have to use lower case for naming function keys like F1.

• You can bind the function undo i.e. C-x u to any key, for example to F2:

  (global-set-key 'f2 'undo)
  

• The following statement will display the current time in the modeline of the buffer:

  (display-time)
  

• This displays the current line number on which the cursor is present in the modeline:

  (setq line-number-mode t)
  

• If you don’t want the text to be highlighted when you use commands for marking regions so as to use the kill and yank commands later, you can use the following expression in your init.el file:

  (setq zmacs-regions nil)
  

  Now if you use a command like C-x C-p (mark-page), the text will not be highlighted.

• To control the number of buffers listed when you select the Buffers menu, you need to set the variable buffers-menu-max-size to whatever value you wish. For example, if you want 20 buffers to be listed when you select Buffers use:

  (setq buffers-menu-max-size 20)
  

• If you want the window title area to display the full directory/name of the current buffer’s file, and not just the name, use:

  (setq frame-title-format "%S: %f")
  

• To get rid of the menu, use :

  (set-menubar nil)
  

• If you want an extensive menu-bar use the following expression in your init.el file.

  (load "big-menubar")
  

  If you want to write your own menus, you can look at some of the examples in /usr/local/share/sxemacs/xemacs-packages/lisp/edit-utils/big-menubar.el file.

For more information on initializing your init.el file, See Init File in SXEmacs User’s Manual. You should also look at /usr/local/share/sxemacs-VERSION/etc/sample.init.el, which is a sample init.el file. It contains some of the commonly desired customizations in Emacs.