Nihongo ha koko (In Japanese)

Emacs Lisp Tips or small functions

• I want to know about emacs, how can I start?
• I do not know how to use *.el files. Give me a hint?
• I want to jump .C file to .hh file or vise versa.
• I want to count the words and characters in my region.
• Can I do where(csh)/type(sh) command for emacs lisp program? I want to get the elisp path.
• I want to replace the Japanese-Zenkaku numbers to ASCII all.
• Japanese XEmacs can not get rid of Japanese menu. LANG=C makes the menu invisible.

I want to know about emacs, how can I start?

There are many way to do that.

• Ask it emacs.
  • M-x help-with-tutorial
  • M-x info (and read Emacs/XEmacs section)
• Ask it web.
  Select one of your favorite search engine, type ``introduction of emacs''.
• Ask it your friends.
  If you know someone who knows emacs, ask to them is good way. (And do not forget to thank him/her for helping you. Also, to the Emacs developers... I thank them.)
• Read some books.
  You can easy to find some books about emacs.

I do not know how to use *.el files. Give me a hint?

• Using Emacs startup file. (.emacs)
  
  

  When you start up the emacs (without -q option), emacs usually read .emacs file. (some xemacs uses .xemacs/init.el). Then you can just copy and paste functions in it. But this is a little bit cumbersome.

• The function autoload load elisp (Emacs Lisp) file dynamically. Dynamically means it will not be loaded unless you really use. But you should give some information to the emacs:

  • What function/command do you want to use later.
  • Which file contains that function/command.
  For example, (autoload 'e-function "elisp-file" "" t nil) tells to the emacs that when the e-function called, emacs should read the file elisp-file.

  But how the emacs find the elisp-file? For example, you put your elisp file somewhere, how can the emacs find that? It can not be to search whole your filesystem. The emacs find files using the load-path variable. This is a kind of PATH variable in shell. So you add your path to the load-path, set autoload, then the emacs find a mapping of command/function and elisp file. Adding your path to load-path is done by next in your .emacs file:

  ;;
  ;; load path
  ;;
  (setq load-path (append (list
                           "/your/emacs/lisp/files/under/this/directory"
                           )
  			 load-path))
       

I want to jump .C file to .hh file or vise versa.

Next small program may help you. changeh2c.el

Setting up:

• Add next line to your .emacs file.

  ;;
  ;; changeh2c : change .hh and .C file with one command
  ;;
  (autoload 'changeh2c "changeh2c" "change .hh and .C file with one command" t nil)
       

• Put short cut key to this for your convenience, for examle ``f8''.
  • If you do not mind the global binding, add next line.

      (global-set-key 'f8 'changeh2c)	  
    	  

  • Or you want to use this key binding only in some mode, put next line to your mode hook. Next is an example of c++-mode. However, you should know a little bit about emacs lisp in this case. Please check you have no other hook for your mode.

      (defun my-cpp-mode-common-hook ()
        (progn
          (local-set-key 'f8 'changeh2c)
        ))
      (add-hook 'c-mode-common-hook 'my-cpp-mode-common-hook)
    	  

• Specified file jump.

  • Sometimes, you may want to jump especially file from a file. For this purpose this elisp accept a local variable changeh2c-other-file.

    Ex. in some html mode (here example is yahtml, jump from index.html to index-j.html.

     <!-- Local Variables: *** -->
     <!-- mode:yahtml *** -->
     <!-- changeh2c-other-file:"index-j.html" *** -->
     <!-- End: *** -->
    	  

  • a reason of this.

    changeh2c is confused by the situation with one suffix may include a part of other suffix. For example, assume there are 'a-j-j.html a-j.html, a.html' files and suffixes '-j.html, .html'. Your buffer has a-j.html. Then which suffix should be matched? And which file should be selected to the destination to jump. You can make a rule for this and also you can remember each buffer's find-file history to avoid to jump yourself. But, I think this implementation is not to worth.

    However, I have files index.html and index-j.html. More precisely, I should name these as index-e.html (English) and index-j.html (Japanese). But, some web server's settings do not accept the index-e.html as the default file. Then, some specified file jump is needed.

I want to count the words and characters in my region.

Next small program may help you. wc.el

Setting up:

• Add next line to your .emacs file.

  ;;
  ;; wc.el (word counter)
  ;;
  (autoload 'count-chars-region "wc" nil t)
       

• Select a region and type M-x count-chars-region.

Can I do where(csh)/type(sh) command for emacs lisp program? I want to get the elisp path.

Next small program may help you. where.el

Setting up:

• Add next line to your .emacs file.

  ;;
  ;; where
  ;; 
  (autoload 'where-is-in "where" "where *.el" t)
       

• Select a region and type M-x where-is-in. Then input which filename do you want. ex. where.el

I want to replace the Japanese-Zenkaku numbers to ASCII all.

Next small program may help you. replace-zen-to-ascii-region.el

Setting up:

• Add next line to your .emacs file.

  ;;
  ;; replace zenkaku -> ascii region
  ;;
  (autoload 'replace-zen-to-ascii-region "replace-zen-to-ascii-region" nil t)
       

• Select a region and type M-x replace-zen-to-ascii-region.

Japanese XEmacs can not get rid of Japanese menu. LANG=C makes the menu invisible.

Around app-defaults directory, ja/Emacs or something similar file exists. Usually, this Xresource file is read according to LANG or LC_ALL. However, some (Japanese) distribution seems hard coded this environment variable somewhere. In such case, you can put LANG as de or fr, if you are OK. Or, change the Xdefaults according to this app-defaults file.